<html>
<head>
<title>LLVM Assembly Language Reference Manual</title>
+ <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
+ <meta name="author" content="Chris Lattner">
+ <meta name="description"
+ content="LLVM Assembly Language Reference Manual.">
<link rel="stylesheet" href="llvm.css" type="text/css">
</head>
<li><a href="#abstract">Abstract</a></li>
<li><a href="#introduction">Introduction</a></li>
<li><a href="#identifiers">Identifiers</a></li>
+ <li><a href="#highlevel">High Level Structure</a>
+ <ol>
+ <li><a href="#modulestructure">Module Structure</a></li>
+ <li><a href="#linkage">Linkage Types</a></li>
+ <li><a href="#callingconv">Calling Conventions</a></li>
+ <li><a href="#globalvars">Global Variables</a></li>
+ <li><a href="#functionstructure">Functions</a></li>
+ <li><a href="#aliasstructure">Aliases</a>
+ <li><a href="#paramattrs">Parameter Attributes</a></li>
+ <li><a href="#gc">Garbage Collector Names</a></li>
+ <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
+ <li><a href="#datalayout">Data Layout</a></li>
+ </ol>
+ </li>
<li><a href="#typesystem">Type System</a>
<ol>
- <li><a href="#t_primitive">Primitive Types</a>
+ <li><a href="#t_classifications">Type Classifications</a></li>
+ <li><a href="#t_primitive">Primitive Types</a>
<ol>
- <li><a href="#t_classifications">Type Classifications</a></li>
+ <li><a href="#t_floating">Floating Point Types</a></li>
+ <li><a href="#t_void">Void Type</a></li>
+ <li><a href="#t_label">Label Type</a></li>
</ol>
</li>
<li><a href="#t_derived">Derived Types</a>
<ol>
+ <li><a href="#t_integer">Integer Type</a></li>
<li><a href="#t_array">Array Type</a></li>
<li><a href="#t_function">Function Type</a></li>
<li><a href="#t_pointer">Pointer Type</a></li>
<li><a href="#t_struct">Structure Type</a></li>
-<!-- <li><a href="#t_packed" >Packed Type</a> -->
+ <li><a href="#t_pstruct">Packed Structure Type</a></li>
+ <li><a href="#t_vector">Vector Type</a></li>
+ <li><a href="#t_opaque">Opaque Type</a></li>
</ol>
</li>
</ol>
</li>
- <li><a href="#highlevel">High Level Structure</a>
+ <li><a href="#constants">Constants</a>
<ol>
- <li><a href="#modulestructure">Module Structure</a></li>
- <li><a href="#globalvars">Global Variables</a></li>
- <li><a href="#functionstructure">Function Structure</a></li>
+ <li><a href="#simpleconstants">Simple Constants</a>
+ <li><a href="#aggregateconstants">Aggregate Constants</a>
+ <li><a href="#globalconstants">Global Variable and Function Addresses</a>
+ <li><a href="#undefvalues">Undefined Values</a>
+ <li><a href="#constantexprs">Constant Expressions</a>
+ </ol>
+ </li>
+ <li><a href="#othervalues">Other Values</a>
+ <ol>
+ <li><a href="#inlineasm">Inline Assembler Expressions</a>
</ol>
</li>
<li><a href="#instref">Instruction Reference</a>
<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
+ <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
</ol>
</li>
<li><a href="#binaryops">Binary Operations</a>
<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
- <li><a href="#i_div">'<tt>div</tt>' Instruction</a></li>
- <li><a href="#i_rem">'<tt>rem</tt>' Instruction</a></li>
- <li><a href="#i_setcc">'<tt>set<i>cc</i></tt>' Instructions</a></li>
+ <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
+ <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
+ <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
+ <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
+ <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
+ <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
</ol>
</li>
<li><a href="#bitwiseops">Bitwise Binary Operations</a>
<ol>
+ <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
+ <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
+ <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
- <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
- <li><a href="#i_shr">'<tt>shr</tt>' Instruction</a></li>
</ol>
</li>
- <li><a href="#memoryops">Memory Access Operations</a>
+ <li><a href="#vectorops">Vector Operations</a>
+ <ol>
+ <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
+ <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
+ <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
+ </ol>
+ </li>
+ <li><a href="#aggregateops">Aggregate Operations</a>
+ <ol>
+ <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
+ <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
+ </ol>
+ </li>
+ <li><a href="#memoryops">Memory Access and Addressing Operations</a>
<ol>
<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
- <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
- <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
- <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
+
<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
+
<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
+
<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
</ol>
</li>
+ <li><a href="#convertops">Conversion Operations</a>
+ <ol>
+ <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
+ <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
+ <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
+ <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
+ <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
+ <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
+ <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
+ <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
+ <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
+ <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
+ <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
+ <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
+ </ol>
<li><a href="#otherops">Other Operations</a>
<ol>
+ <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
+ <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
+ <li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
+ <li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
- <li><a href="#i_cast">'<tt>cast .. to</tt>' Instruction</a></li>
<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
- <li><a href="#i_vanext">'<tt>vanext</tt>' Instruction</a></li>
- <li><a href="#i_vaarg">'<tt>vaarg</tt>' Instruction</a></li>
+ <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
+ <li><a href="#i_getresult">'<tt>getresult</tt>' Instruction</a></li>
</ol>
</li>
</ol>
<ol>
<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
<ol>
- <li><a href="#i_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
- <li><a href="#i_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
- <li><a href="#i_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
+ <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
+ <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
+ <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
</ol>
</li>
<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
<ol>
- <li><a href="#i_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
- <li><a href="#i_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
- <li><a href="#i_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
+ <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
+ <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
+ <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
</ol>
</li>
<li><a href="#int_codegen">Code Generator Intrinsics</a>
<ol>
- <li><a href="#i_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
- <li><a href="#i_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
+ <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
+ <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
+ <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
+ <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
+ <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
+ <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
+ <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
</ol>
</li>
- <li><a href="#int_os">Operating System Intrinsics</a>
+ <li><a href="#int_libc">Standard C Library Intrinsics</a>
<ol>
- <li><a href="#i_readport">'<tt>llvm.readport</tt>' Intrinsic</a></li>
- <li><a href="#i_writeport">'<tt>llvm.writeport</tt>' Intrinsic</a></li>
- <li><a href="#i_readio">'<tt>llvm.readio</tt>' Intrinsic</a></li>
- <li><a href="#i_writeio">'<tt>llvm.writeio</tt>' Intrinsic</a></li>
+ <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
+ <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
+ <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
+ <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
+ <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
+ <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
+ <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
+ <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
</ol>
- <li><a href="#int_libc">Standard C Library Intrinsics</a>
+ </li>
+ <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
<ol>
- <li><a href="#i_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a></li>
- <li><a href="#i_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a></li>
- <li><a href="#i_memset">'<tt>llvm.memset</tt>' Intrinsic</a></li>
- <li><a href="#i_isnan">'<tt>llvm.isnan</tt>' Intrinsic</a></li>
- <li><a href="#i_isunordered">'<tt>llvm.isunordered</tt>' Intrinsic</a></li>
+ <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
+ <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
+ <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
+ <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
+ <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
+ <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
</ol>
</li>
<li><a href="#int_debugger">Debugger intrinsics</a></li>
+ <li><a href="#int_eh">Exception Handling intrinsics</a></li>
+ <li><a href="#int_trampoline">Trampoline Intrinsic</a>
+ <ol>
+ <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
+ </ol>
+ </li>
+ <li><a href="#int_atomics">Atomic intrinsics</a>
+ <ol>
+ <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
+ <li><a href="#int_atomic_lcs"><tt>llvm.atomic.lcs</tt></a></li>
+ <li><a href="#int_atomic_las"><tt>llvm.atomic.las</tt></a></li>
+ <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
+ </ol>
+ </li>
+ <li><a href="#int_general">General intrinsics</a>
+ <ol>
+ <li><a href="#int_var_annotation">
+ <tt>llvm.var.annotation</tt>' Intrinsic</a></li>
+ <li><a href="#int_annotation">
+ <tt>llvm.annotation.*</tt>' Intrinsic</a></li>
+ <li><a href="#int_trap">
+ <tt>llvm.trap</tt>' Intrinsic</a></li>
+ </ol>
+ </li>
</ol>
</li>
</ol>
<div class="doc_text">
<p>The LLVM code representation is designed to be used in three
-different forms: as an in-memory compiler IR, as an on-disk bytecode
+different forms: as an in-memory compiler IR, as an on-disk bitcode
representation (suitable for fast loading by a Just-In-Time compiler),
and as a human readable assembly language representation. This allows
LLVM to provide a powerful intermediate representation for efficient
of LLVM are all equivalent. This document describes the human readable
representation and notation.</p>
-<p>The LLVM representation aims to be a light-weight and low-level
+<p>The LLVM representation aims to be light-weight and low-level
while being expressive, typed, and extensible at the same time. It
aims to be a "universal IR" of sorts, by being at a low enough level
that high-level ideas may be cleanly mapped to it (similar to how
accepts and what is considered 'well formed'. For example, the
following instruction is syntactically okay, but not well formed:</p>
+<div class="doc_code">
<pre>
- %x = <a href="#i_add">add</a> int 1, %x
+%x = <a href="#i_add">add</a> i32 1, %x
</pre>
+</div>
<p>...because the definition of <tt>%x</tt> does not dominate all of
its uses. The LLVM infrastructure provides a verification pass that may
be used to verify that an LLVM module is well formed. This pass is
-automatically run by the parser after parsing input assembly, and by
-the optimizer before it outputs bytecode. The violations pointed out
+automatically run by the parser after parsing input assembly and by
+the optimizer before it outputs bitcode. The violations pointed out
by the verifier pass indicate bugs in transformation passes or input to
the parser.</p>
+</div>
-<!-- Describe the typesetting conventions here. --> </div>
+<!-- Describe the typesetting conventions here. -->
<!-- *********************************************************************** -->
<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
<div class="doc_text">
-<p>LLVM uses three different forms of identifiers, for different
-purposes:</p>
+ <p>LLVM identifiers come in two basic types: global and local. Global
+ identifiers (functions, global variables) begin with the @ character. Local
+ identifiers (register names, types) begin with the % character. Additionally,
+ there are three different formats for identifiers, for different purposes:
<ol>
- <li>Numeric constants are represented as you would expect: 12, -3
-123.421, etc. Floating point constants have an optional hexadecimal
-notation.</li>
- <li>Named values are represented as a string of characters with a '%'
-prefix. For example, %foo, %DivisionByZero,
-%a.really.long.identifier. The actual regular expression used is '<tt>%[a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
-Identifiers which require other characters in their names can be
-surrounded with quotes. In this way, anything except a <tt>"</tt>
-character can be used in a name.</li>
- <li>Unnamed values are represented as an unsigned numeric value with
-a '%' prefix. For example, %12, %2, %44.</li>
-</ol>
-<p>LLVM requires that values start with a '%' sign for two reasons:
-Compilers don't need to worry about name clashes with reserved words,
-and the set of reserved words may be expanded in the future without
-penalty. Additionally, unnamed identifiers allow a compiler to quickly
-come up with a temporary variable without having to avoid symbol table
-conflicts.</p>
-<p>Reserved words in LLVM are very similar to reserved words in other
-languages. There are keywords for different opcodes ('<tt><a
- href="#i_add">add</a></tt>', '<tt><a href="#i_cast">cast</a></tt>', '<tt><a
- href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
- href="#t_void">void</a></tt>', '<tt><a href="#t_uint">uint</a></tt>',
-etc...), and others. These reserved words cannot conflict with
-variable names, because none of them start with a '%' character.</p>
-<p>Here is an example of LLVM code to multiply the integer variable '<tt>%X</tt>'
-by 8:</p>
-<p>The easy way:</p>
-<pre> %result = <a href="#i_mul">mul</a> uint %X, 8<br></pre>
-<p>After strength reduction:</p>
-<pre> %result = <a href="#i_shl">shl</a> uint %X, ubyte 3<br></pre>
-<p>And the hard way:</p>
-<pre> <a href="#i_add">add</a> uint %X, %X <i>; yields {uint}:%0</i>
- <a
- href="#i_add">add</a> uint %0, %0 <i>; yields {uint}:%1</i>
- %result = <a
- href="#i_add">add</a> uint %1, %1<br></pre>
-<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
-important lexical features of LLVM:</p>
-<ol>
- <li>Comments are delimited with a '<tt>;</tt>' and go until the end
-of line.</li>
- <li>Unnamed temporaries are created when the result of a computation
-is not assigned to a named value.</li>
- <li>Unnamed temporaries are numbered sequentially</li>
+ <li>Named values are represented as a string of characters with their prefix.
+ For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
+ regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
+ Identifiers which require other characters in their names can be surrounded
+ with quotes. In this way, anything except a <tt>"</tt> character can
+ be used in a named value.</li>
+
+ <li>Unnamed values are represented as an unsigned numeric value with their
+ prefix. For example, %12, @2, %44.</li>
+
+ <li>Constants, which are described in a <a href="#constants">section about
+ constants</a>, below.</li>
</ol>
-<p>...and it also show a convention that we follow in this document.
-When demonstrating instructions, we will follow an instruction with a
-comment that defines the type and name of value produced. Comments are
-shown in italic text.</p>
-<p>The one non-intuitive notation for constants is the optional
-hexidecimal form of floating point constants. For example, the form '<tt>double
-0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
-4.5e+15</tt>' which is also supported by the parser. The only time
-hexadecimal floating point constants are useful (and the only time that
-they are generated by the disassembler) is when an FP constant has to
-be emitted that is not representable as a decimal floating point number
-exactly. For example, NaN's, infinities, and other special cases are
-represented in their IEEE hexadecimal format so that assembly and
-disassembly do not cause any bits to change in the constants.</p>
-</div>
-<!-- *********************************************************************** -->
-<div class="doc_section"> <a name="typesystem">Type System</a> </div>
-<!-- *********************************************************************** -->
-<div class="doc_text">
-<p>The LLVM type system is one of the most important features of the
-intermediate representation. Being typed enables a number of
-optimizations to be performed on the IR directly, without having to do
-extra analyses on the side before the transformation. A strong type
-system makes it easier to read the generated code and enables novel
-analyses and transformations that are not feasible to perform on normal
-three address code representations.</p>
-<!-- The written form for the type system was heavily influenced by the
-syntactic problems with types in the C language<sup><a
-href="#rw_stroustrup">1</a></sup>.<p> --> </div>
-<!-- ======================================================================= -->
-<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
-<div class="doc_text">
-<p>The primitive types are the fundamental building blocks of the LLVM
-system. The current set of primitive types are as follows:</p>
-<table border="0" style="align: center">
- <tbody>
- <tr>
- <td>
- <table border="1" cellspacing="0" cellpadding="4" style="align: center">
- <tbody>
- <tr>
- <td><tt>void</tt></td>
- <td>No value</td>
- </tr>
- <tr>
- <td><tt>ubyte</tt></td>
- <td>Unsigned 8 bit value</td>
- </tr>
- <tr>
- <td><tt>ushort</tt></td>
- <td>Unsigned 16 bit value</td>
- </tr>
- <tr>
- <td><tt>uint</tt></td>
- <td>Unsigned 32 bit value</td>
- </tr>
- <tr>
- <td><tt>ulong</tt></td>
- <td>Unsigned 64 bit value</td>
- </tr>
- <tr>
- <td><tt>float</tt></td>
- <td>32 bit floating point value</td>
- </tr>
- <tr>
- <td><tt>label</tt></td>
- <td>Branch destination</td>
- </tr>
- </tbody>
- </table>
- </td>
- <td valign="top">
- <table border="1" cellspacing="0" cellpadding="4">
- <tbody>
- <tr>
- <td><tt>bool</tt></td>
- <td>True or False value</td>
- </tr>
- <tr>
- <td><tt>sbyte</tt></td>
- <td>Signed 8 bit value</td>
- </tr>
- <tr>
- <td><tt>short</tt></td>
- <td>Signed 16 bit value</td>
- </tr>
- <tr>
- <td><tt>int</tt></td>
- <td>Signed 32 bit value</td>
- </tr>
- <tr>
- <td><tt>long</tt></td>
- <td>Signed 64 bit value</td>
- </tr>
- <tr>
- <td><tt>double</tt></td>
- <td>64 bit floating point value</td>
- </tr>
- </tbody>
- </table>
- </td>
- </tr>
- </tbody>
-</table>
+<p>LLVM requires that values start with a prefix for two reasons: Compilers
+don't need to worry about name clashes with reserved words, and the set of
+reserved words may be expanded in the future without penalty. Additionally,
+unnamed identifiers allow a compiler to quickly come up with a temporary
+variable without having to avoid symbol table conflicts.</p>
-</div>
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="t_classifications">Type
-Classifications</a> </div>
-<div class="doc_text">
-<p>These different primitive types fall into a few useful
-classifications:</p>
+<p>Reserved words in LLVM are very similar to reserved words in other
+languages. There are keywords for different opcodes
+('<tt><a href="#i_add">add</a></tt>',
+ '<tt><a href="#i_bitcast">bitcast</a></tt>',
+ '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
+href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
+and others. These reserved words cannot conflict with variable names, because
+none of them start with a prefix character ('%' or '@').</p>
-<table border="1" cellspacing="0" cellpadding="4">
- <tbody>
- <tr>
- <td><a name="t_signed">signed</a></td>
- <td><tt>sbyte, short, int, long, float, double</tt></td>
- </tr>
- <tr>
- <td><a name="t_unsigned">unsigned</a></td>
- <td><tt>ubyte, ushort, uint, ulong</tt></td>
- </tr>
- <tr>
- <td><a name="t_integer">integer</a></td>
- <td><tt>ubyte, sbyte, ushort, short, uint, int, ulong, long</tt></td>
- </tr>
- <tr>
- <td><a name="t_integral">integral</a></td>
- <td><tt>bool, ubyte, sbyte, ushort, short, uint, int, ulong, long</tt></td>
- </tr>
- <tr>
- <td><a name="t_floating">floating point</a></td>
- <td><tt>float, double</tt></td>
- </tr>
- <tr>
- <td><a name="t_firstclass">first class</a></td>
- <td><tt>bool, ubyte, sbyte, ushort, short,<br>
-uint, int, ulong, long, float, double, <a href="#t_pointer">pointer</a></tt></td>
- </tr>
- </tbody>
-</table>
+<p>Here is an example of LLVM code to multiply the integer variable
+'<tt>%X</tt>' by 8:</p>
-<p>The <a href="#t_firstclass">first class</a> types are perhaps the
-most important. Values of these types are the only ones which can be
-produced by instructions, passed as arguments, or used as operands to
-instructions. This means that all structures and arrays must be
-manipulated either by pointer or by component.</p>
-</div>
-<!-- ======================================================================= -->
-<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
-<div class="doc_text">
-<p>The real power in LLVM comes from the derived types in the system.
-This is what allows a programmer to represent arrays, functions,
-pointers, and other useful types. Note that these derived types may be
-recursive: For example, it is possible to have a two dimensional array.</p>
+<p>The easy way:</p>
+
+<div class="doc_code">
+<pre>
+%result = <a href="#i_mul">mul</a> i32 %X, 8
+</pre>
</div>
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
-<div class="doc_text">
-<h5>Overview:</h5>
-<p>The array type is a very simple derived type that arranges elements
-sequentially in memory. The array type requires a size (number of
-elements) and an underlying data type.</p>
-<h5>Syntax:</h5>
-<pre> [<# elements> x <elementtype>]<br></pre>
-<p>The number of elements is a constant integer value, elementtype may
-be any type with a size.</p>
-<h5>Examples:</h5>
-<p> <tt>[40 x int ]</tt>: Array of 40 integer values.<br>
-<tt>[41 x int ]</tt>: Array of 41 integer values.<br>
-<tt>[40 x uint]</tt>: Array of 40 unsigned integer values.</p>
-<p> </p>
-<p>Here are some examples of multidimensional arrays:</p>
-<table border="0" cellpadding="0" cellspacing="0">
- <tbody>
- <tr>
- <td><tt>[3 x [4 x int]]</tt></td>
- <td>: 3x4 array integer values.</td>
- </tr>
- <tr>
- <td><tt>[12 x [10 x float]]</tt></td>
- <td>: 12x10 array of single precision floating point values.</td>
- </tr>
- <tr>
- <td><tt>[2 x [3 x [4 x uint]]]</tt></td>
- <td>: 2x3x4 array of unsigned integer values.</td>
- </tr>
- </tbody>
-</table>
+<p>After strength reduction:</p>
+<div class="doc_code">
+<pre>
+%result = <a href="#i_shl">shl</a> i32 %X, i8 3
+</pre>
</div>
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
-<div class="doc_text">
-<h5>Overview:</h5>
-<p>The function type can be thought of as a function signature. It
-consists of a return type and a list of formal parameter types.
-Function types are usually used to build virtual function tables
-(which are structures of pointers to functions), for indirect function
-calls, and when defining a function.</p>
-<p>
-The return type of a function type cannot be an aggregate type.
-</p>
-<h5>Syntax:</h5>
-<pre> <returntype> (<parameter list>)<br></pre>
-<p>Where '<tt><parameter list></tt>' is a comma-separated list of
-type specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
-which indicates that the function takes a variable number of arguments.
-Variable argument functions can access their arguments with the <a
- href="#int_varargs">variable argument handling intrinsic</a> functions.</p>
-<h5>Examples:</h5>
-<table border="0" cellpadding="0" cellspacing="0">
- <tbody>
- <tr>
- <td><tt>int (int)</tt></td>
- <td>: function taking an <tt>int</tt>, returning an <tt>int</tt></td>
- </tr>
- <tr>
- <td><tt>float (int, int *) *</tt></td>
- <td>: <a href="#t_pointer">Pointer</a> to a function that takes
-an <tt>int</tt> and a <a href="#t_pointer">pointer</a> to <tt>int</tt>,
-returning <tt>float</tt>.</td>
- </tr>
- <tr>
- <td><tt>int (sbyte *, ...)</tt></td>
- <td>: A vararg function that takes at least one <a
- href="#t_pointer">pointer</a> to <tt>sbyte</tt> (signed char in C),
-which returns an integer. This is the signature for <tt>printf</tt>
-in LLVM.</td>
- </tr>
- </tbody>
-</table>
+<p>And the hard way:</p>
+<div class="doc_code">
+<pre>
+<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
+<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
+%result = <a href="#i_add">add</a> i32 %1, %1
+</pre>
</div>
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
-<div class="doc_text">
-<h5>Overview:</h5>
-<p>The structure type is used to represent a collection of data members
-together in memory. The packing of the field types is defined to match
-the ABI of the underlying processor. The elements of a structure may
-be any type that has a size.</p>
-<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
-and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
-field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
-instruction.</p>
-<h5>Syntax:</h5>
-<pre> { <type list> }<br></pre>
-<h5>Examples:</h5>
-<table border="0" cellpadding="0" cellspacing="0">
- <tbody>
- <tr>
- <td><tt>{ int, int, int }</tt></td>
- <td>: a triple of three <tt>int</tt> values</td>
- </tr>
- <tr>
- <td><tt>{ float, int (int) * }</tt></td>
- <td>: A pair, where the first element is a <tt>float</tt> and the
-second element is a <a href="#t_pointer">pointer</a> to a <a
- href="#t_function">function</a> that takes an <tt>int</tt>, returning
-an <tt>int</tt>.</td>
- </tr>
- </tbody>
-</table>
+<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
+important lexical features of LLVM:</p>
-</div>
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
-<div class="doc_text">
-<h5>Overview:</h5>
-<p>As in many languages, the pointer type represents a pointer or
-reference to another object, which must live in memory.</p>
-<h5>Syntax:</h5>
-<pre> <type> *<br></pre>
-<h5>Examples:</h5>
+<ol>
-<table border="0" cellpadding="0" cellspacing="0">
- <tbody>
- <tr>
- <td><tt>[4x int]*</tt></td>
- <td>: <a href="#t_pointer">pointer</a> to <a href="#t_array">array</a>
-of four <tt>int</tt> values</td>
- </tr>
- <tr>
- <td><tt>int (int *) *</tt></td>
- <td>: A <a href="#t_pointer">pointer</a> to a <a
- href="#t_function">function</a> that takes an <tt>int</tt>, returning
-an <tt>int</tt>.</td>
- </tr>
- </tbody>
-</table>
+ <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
+ line.</li>
-</div>
-<!-- _______________________________________________________________________ --><!--
-<div class="doc_subsubsection">
- <a name="t_packed">Packed Type</a>
-</div>
+ <li>Unnamed temporaries are created when the result of a computation is not
+ assigned to a named value.</li>
-<div class="doc_text">
+ <li>Unnamed temporaries are numbered sequentially</li>
-Mention/decide that packed types work with saturation or not. Maybe have a packed+saturated type in addition to just a packed type.<p>
+</ol>
-Packed types should be 'nonsaturated' because standard data types are not saturated. Maybe have a saturated packed type?<p>
+<p>...and it also shows a convention that we follow in this document. When
+demonstrating instructions, we will follow an instruction with a comment that
+defines the type and name of value produced. Comments are shown in italic
+text.</p>
</div>
---><!-- *********************************************************************** -->
+<!-- *********************************************************************** -->
<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
-<!-- *********************************************************************** --><!-- ======================================================================= -->
-<div class="doc_subsection"> <a name="modulestructure">Module Structure</a> </div>
+<!-- *********************************************************************** -->
+
+<!-- ======================================================================= -->
+<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
+</div>
+
<div class="doc_text">
+
<p>LLVM programs are composed of "Module"s, each of which is a
translation unit of the input programs. Each module consists of
functions, global variables, and symbol table entries. Modules may be
combined together with the LLVM linker, which merges function (and
global variable) definitions, resolves forward declarations, and merges
symbol table entries. Here is an example of the "hello world" module:</p>
+
+<div class="doc_code">
<pre><i>; Declare the string constant as a global constant...</i>
-<a href="#identifiers">
%.LC0</a> = <a href="#linkage_internal">internal</a> <a
- href="#globalvars">constant</a> <a href="#t_array">[13 x sbyte]</a> c"hello world\0A\00" <i>; [13 x sbyte]*</i>
+<a href="#identifiers">
@.LC0</a> = <a href="#linkage_internal">internal</a> <a
+ href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
<i>; External declaration of the puts function</i>
-<a href="#functionstructure">declare</a> int %puts(sbyte*) <i>; int(sbyte*)* </i>
+<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
<i>; Definition of main function</i>
-int %main() { <i>; int()* </i>
- <i>; Convert [13x sbyte]* to sbyte *...</i>
+define i32 @main() { <i>; i32()* </i>
+ <i>; Convert [13x i8 ]* to i8 *...</i>
%cast210 = <a
- href="#i_getelementptr">getelementptr</a> [13 x sbyte]* %.LC0, long 0, long 0 <i>; sbyte*</i>
+ href="#i_getelementptr">getelementptr</a> [13 x i8 ]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
<i>; Call puts function to write out the string to stdout...</i>
<a
- href="#i_call">call</a> int %puts(sbyte* %cast210) <i>; int</i>
+ href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
<a
- href="#i_ret">ret</a> int 0<br>}<br></pre>
+ href="#i_ret">ret</a> i32 0<br>}<br>
+</pre>
+</div>
+
<p>This example is made up of a <a href="#globalvars">global variable</a>
named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
function, and a <a href="#functionstructure">function definition</a>
for "<tt>main</tt>".</p>
-<a name="linkage"> In general, a module is made up of a list of global
-values, where both functions and global variables are global values.
-Global values are represented by a pointer to a memory location (in
-this case, a pointer to an array of char, and a pointer to a function),
-and have one of the following linkage types:</a>
-<p> </p>
+
+<p>In general, a module is made up of a list of global values,
+where both functions and global variables are global values. Global values are
+represented by a pointer to a memory location (in this case, a pointer to an
+array of char, and a pointer to a function), and have one of the following <a
+href="#linkage">linkage types</a>.</p>
+
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="linkage">Linkage Types</a>
+</div>
+
+<div class="doc_text">
+
+<p>
+All Global Variables and Functions have one of the following types of linkage:
+</p>
+
<dl>
- <dt><tt><b><a name="linkage_internal">internal</a></b></tt> </dt>
- <dd>Global values with internal linkage are only directly accessible
-by objects in the current module. In particular, linking code into a
-module with an internal global value may cause the internal to be
-renamed as necessary to avoid collisions. Because the symbol is
-internal to the module, all references can be updated. This
-corresponds to the notion of the '<tt>static</tt>' keyword in C, or the
-idea of "anonymous namespaces" in C++.
- <p> </p>
+
+ <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
+
+ <dd>Global values with internal linkage are only directly accessible by
+ objects in the current module. In particular, linking code into a module with
+ an internal global value may cause the internal to be renamed as necessary to
+ avoid collisions. Because the symbol is internal to the module, all
+ references can be updated. This corresponds to the notion of the
+ '<tt>static</tt>' keyword in C.
</dd>
+
<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
- <dd>"<tt>linkonce</tt>" linkage is similar to <tt>internal</tt>
-linkage, with the twist that linking together two modules defining the
-same <tt>linkonce</tt> globals will cause one of the globals to be
-discarded. This is typically used to implement inline functions.
-Unreferenced <tt>linkonce</tt> globals are allowed to be discarded.
- <p> </p>
+
+ <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
+ the same name when linkage occurs. This is typically used to implement
+ inline functions, templates, or other code which must be generated in each
+ translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
+ allowed to be discarded.
+ </dd>
+
+ <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
+
+ <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
+ linkage, except that unreferenced <tt>common</tt> globals may not be
+ discarded. This is used for globals that may be emitted in multiple
+ translation units, but that are not guaranteed to be emitted into every
+ translation unit that uses them. One example of this is tentative
+ definitions in C, such as "<tt>int X;</tt>" at global scope.
</dd>
+
<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
- <dd>"<tt>weak</tt>" linkage is exactly the same as <tt>linkonce</tt>
-linkage, except that unreferenced <tt>weak</tt> globals may not be
-discarded. This is used to implement constructs in C such as "<tt>int
-X;</tt>" at global scope.
- <p> </p>
+
+ <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
+ that some targets may choose to emit different assembly sequences for them
+ for target-dependent reasons. This is used for globals that are declared
+ "weak" in C source code.
</dd>
+
<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
- <dd>"<tt>appending</tt>" linkage may only be applied to global
-variables of pointer to array type. When two global variables with
-appending linkage are linked together, the two global arrays are
-appended together. This is the LLVM, typesafe, equivalent of having
-the system linker append together "sections" with identical names when
-.o files are linked.
- <p> </p>
+
+ <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
+ pointer to array type. When two global variables with appending linkage are
+ linked together, the two global arrays are appended together. This is the
+ LLVM, typesafe, equivalent of having the system linker append together
+ "sections" with identical names when .o files are linked.
+ </dd>
+
+ <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
+ <dd>The semantics of this linkage follow the ELF model: the symbol is weak
+ until linked, if not linked, the symbol becomes null instead of being an
+ undefined reference.
</dd>
+
<dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
- <dd>If none of the above identifiers are used, the global is
-externally visible, meaning that it participates in linkage and can be
-used to resolve external symbol references.
- <p> </p>
+
+ <dd>If none of the above identifiers are used, the global is externally
+ visible, meaning that it participates in linkage and can be used to resolve
+ external symbol references.
</dd>
</dl>
-<p> </p>
-<p><a name="linkage_external">For example, since the "<tt>.LC0</tt>"
+
+ <p>
+ The next two types of linkage are targeted for Microsoft Windows platform
+ only. They are designed to support importing (exporting) symbols from (to)
+ DLLs.
+ </p>
+
+ <dl>
+ <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
+
+ <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
+ or variable via a global pointer to a pointer that is set up by the DLL
+ exporting the symbol. On Microsoft Windows targets, the pointer name is
+ formed by combining <code>_imp__</code> and the function or variable name.
+ </dd>
+
+ <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
+
+ <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
+ pointer to a pointer in a DLL, so that it can be referenced with the
+ <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
+ name is formed by combining <code>_imp__</code> and the function or variable
+ name.
+ </dd>
+
+</dl>
+
+<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
variable and was linked with this one, one of the two would be renamed,
preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
external (i.e., lacking any linkage declarations), they are accessible
-outside of the current module. It is illegal for a function <i>declaration</i>
-to have any linkage type other than "externally visible".</a></p>
+outside of the current module.</p>
+<p>It is illegal for a function <i>declaration</i>
+to have any linkage type other than "externally visible", <tt>dllimport</tt>,
+or <tt>extern_weak</tt>.</p>
+<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
+linkages.
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="callingconv">Calling Conventions</a>
+</div>
+
+<div class="doc_text">
+
+<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
+and <a href="#i_invoke">invokes</a> can all have an optional calling convention
+specified for the call. The calling convention of any pair of dynamic
+caller/callee must match, or the behavior of the program is undefined. The
+following calling conventions are supported by LLVM, and more may be added in
+the future:</p>
+
+<dl>
+ <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
+
+ <dd>This calling convention (the default if no other calling convention is
+ specified) matches the target C calling conventions. This calling convention
+ supports varargs function calls and tolerates some mismatch in the declared
+ prototype and implemented declaration of the function (as does normal C).
+ </dd>
+
+ <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
+
+ <dd>This calling convention attempts to make calls as fast as possible
+ (e.g. by passing things in registers). This calling convention allows the
+ target to use whatever tricks it wants to produce fast code for the target,
+ without having to conform to an externally specified ABI. Implementations of
+ this convention should allow arbitrary
+ <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
+ supported. This calling convention does not support varargs and requires the
+ prototype of all callees to exactly match the prototype of the function
+ definition.
+ </dd>
+
+ <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
+
+ <dd>This calling convention attempts to make code in the caller as efficient
+ as possible under the assumption that the call is not commonly executed. As
+ such, these calls often preserve all registers so that the call does not break
+ any live ranges in the caller side. This calling convention does not support
+ varargs and requires the prototype of all callees to exactly match the
+ prototype of the function definition.
+ </dd>
+
+ <dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
+
+ <dd>Any calling convention may be specified by number, allowing
+ target-specific calling conventions to be used. Target specific calling
+ conventions start at 64.
+ </dd>
+</dl>
+
+<p>More calling conventions can be added/defined on an as-needed basis, to
+support pascal conventions or any other well-known target-independent
+convention.</p>
+
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="visibility">Visibility Styles</a>
+</div>
+
+<div class="doc_text">
+
+<p>
+All Global Variables and Functions have one of the following visibility styles:
+</p>
+
+<dl>
+ <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
+
+ <dd>On ELF, default visibility means that the declaration is visible to other
+ modules and, in shared libraries, means that the declared entity may be
+ overridden. On Darwin, default visibility means that the declaration is
+ visible to other modules. Default visibility corresponds to "external
+ linkage" in the language.
+ </dd>
+
+ <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
+
+ <dd>Two declarations of an object with hidden visibility refer to the same
+ object if they are in the same shared object. Usually, hidden visibility
+ indicates that the symbol will not be placed into the dynamic symbol table,
+ so no other module (executable or shared library) can reference it
+ directly.
+ </dd>
+
+ <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
+
+ <dd>On ELF, protected visibility indicates that the symbol will be placed in
+ the dynamic symbol table, but that references within the defining module will
+ bind to the local symbol. That is, the symbol cannot be overridden by another
+ module.
+ </dd>
+</dl>
+
</div>
<!-- ======================================================================= -->
<div class="doc_text">
-<p>Global variables define regions of memory allocated at compilation
-time instead of run-time. Global variables may optionally be
-initialized. A variable may be defined as a global "constant", which
-indicates that the contents of the variable will never be modified
-(opening options for optimization).</p>
+<p>Global variables define regions of memory allocated at compilation time
+instead of run-time. Global variables may optionally be initialized, may have
+an explicit section to be placed in, and may have an optional explicit alignment
+specified. A variable may be defined as "thread_local", which means that it
+will not be shared by threads (each thread will have a separated copy of the
+variable). A variable may be defined as a global "constant," which indicates
+that the contents of the variable will <b>never</b> be modified (enabling better
+optimization, allowing the global data to be placed in the read-only section of
+an executable, etc). Note that variables that need runtime initialization
+cannot be marked "constant" as there is a store to the variable.</p>
+
+<p>
+LLVM explicitly allows <em>declarations</em> of global variables to be marked
+constant, even if the final definition of the global is not. This capability
+can be used to enable slightly better optimization of the program, but requires
+the language definition to guarantee that optimizations based on the
+'constantness' are valid for the translation units that do not include the
+definition.
+</p>
<p>As SSA values, global variables define pointer values that are in
-scope (i.e. they dominate) for all basic blocks in the program. Global
+scope (i.e. they dominate) all basic blocks in the program. Global
variables always define a pointer to their "content" type because they
describe a region of memory, and all memory objects in LLVM are
accessed through pointers.</p>
+<p>A global variable may be declared to reside in a target-specifc numbered
+address space. For targets that support them, address spaces may affect how
+optimizations are performed and/or what target instructions are used to access
+the variable. The default address space is zero. The address space qualifier
+must precede any other attributes.</p>
+
+<p>LLVM allows an explicit section to be specified for globals. If the target
+supports it, it will emit globals to the section specified.</p>
+
+<p>An explicit alignment may be specified for a global. If not present, or if
+the alignment is set to zero, the alignment of the global is set by the target
+to whatever it feels convenient. If an explicit alignment is specified, the
+global is forced to have at least that much alignment. All alignments must be
+a power of 2.</p>
+
+<p>For example, the following defines a global in a numbered address space with
+an initializer, section, and alignment:</p>
+
+<div class="doc_code">
+<pre>
+@G = constant float 1.0 addrspace(5), section "foo", align 4
+</pre>
+</div>
+
</div>
<div class="doc_text">
-<p>LLVM function definitions are composed of a (possibly empty) argument list,
-an opening curly brace, a list of basic blocks, and a closing curly brace. LLVM
-function declarations are defined with the "<tt>declare</tt>" keyword, a
-function name, and a function signature.</p>
+<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
+an optional <a href="#linkage">linkage type</a>, an optional
+<a href="#visibility">visibility style</a>, an optional
+<a href="#callingconv">calling convention</a>, a return type, an optional
+<a href="#paramattrs">parameter attribute</a> for the return type, a function
+name, a (possibly empty) argument list (each with optional
+<a href="#paramattrs">parameter attributes</a>), an optional section, an
+optional alignment, an optional <a href="#gc">garbage collector name</a>, an
+opening curly brace, a list of basic blocks, and a closing curly brace.
+
+LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
+optional <a href="#linkage">linkage type</a>, an optional
+<a href="#visibility">visibility style</a>, an optional
+<a href="#callingconv">calling convention</a>, a return type, an optional
+<a href="#paramattrs">parameter attribute</a> for the return type, a function
+name, a possibly empty list of arguments, an optional alignment, and an optional
+<a href="#gc">garbage collector name</a>.</p>
<p>A function definition contains a list of basic blocks, forming the CFG for
the function. Each basic block may optionally start with a label (giving the
with a <a href="#terminators">terminator</a> instruction (such as a branch or
function return).</p>
-<p>The first basic block in program is special in two ways: it is immediately
+<p>The first basic block in a function is special in two ways: it is immediately
executed on entrance to the function, and it is not allowed to have predecessor
basic blocks (i.e. there can not be any branches to the entry block of a
function). Because the block can have no predecessors, it also cannot have any
<a href="#i_phi">PHI nodes</a>.</p>
-<p>LLVM functions are identified by their name and type signature. Hence, two
-functions with the same name but different parameter lists or return values are
-considered different functions, and LLVM will resolves references to each
-appropriately.</p>
+<p>LLVM allows an explicit section to be specified for functions. If the target
+supports it, it will emit functions to the section specified.</p>
+
+<p>An explicit alignment may be specified for a function. If not present, or if
+the alignment is set to zero, the alignment of the function is set by the target
+to whatever it feels convenient. If an explicit alignment is specified, the
+function is forced to have at least that much alignment. All alignments must be
+a power of 2.</p>
</div>
-<!-- *********************************************************************** -->
-<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
-<!-- *********************************************************************** -->
-<div class="doc_text">
-<p>The LLVM instruction set consists of several different
-classifications of instructions: <a href="#terminators">terminator
-instructions</a>, <a href="#binaryops">binary instructions</a>, <a
- href="#memoryops">memory instructions</a>, and <a href="#otherops">other
-instructions</a>.</p>
-</div>
<!-- ======================================================================= -->
-<div class="doc_subsection"> <a name="terminators">Terminator
-Instructions</a> </div>
-<div class="doc_text">
-<p>As mentioned <a href="#functionstructure">previously</a>, every
-basic block in a program ends with a "Terminator" instruction, which
-indicates which block should be executed after the current block is
-finished. These terminator instructions typically yield a '<tt>void</tt>'
-value: they produce control flow, not values (the one exception being
-the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
-<p>There are five different terminator instructions: the '<a
- href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
-instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
-the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, and the '<a
- href="#i_unwind"><tt>unwind</tt></a>' instruction.</p>
+<div class="doc_subsection">
+ <a name="aliasstructure">Aliases</a>
</div>
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
-Instruction</a> </div>
<div class="doc_text">
-<h5>Syntax:</h5>
-<pre> ret <type> <value> <i>; Return a value from a non-void function</i>
- ret void <i>; Return from void function</i>
-</pre>
-<h5>Overview:</h5>
-<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
-value) from a function, back to the caller.</p>
-<p>There are two forms of the '<tt>ret</tt>' instruction: one that
-returns a value and then causes control flow, and one that just causes
-control flow to occur.</p>
-<h5>Arguments:</h5>
-<p>The '<tt>ret</tt>' instruction may return any '<a
- href="#t_firstclass">first class</a>' type. Notice that a function is
-not <a href="#wellformed">well formed</a> if there exists a '<tt>ret</tt>'
-instruction inside of the function that returns a value that does not
-match the return type of the function.</p>
-<h5>Semantics:</h5>
-<p>When the '<tt>ret</tt>' instruction is executed, control flow
-returns back to the calling function's context. If the caller is a "<a
- href="#i_call"><tt>call</tt></a> instruction, execution continues at
-the instruction after the call. If the caller was an "<a
- href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
-at the beginning "normal" of the destination block. If the instruction
-returns a value, that value shall set the call or invoke instruction's
-return value.</p>
-<h5>Example:</h5>
-<pre> ret int 5 <i>; Return an integer value of 5</i>
- ret void <i>; Return from a void function</i>
+ <p>Aliases act as "second name" for the aliasee value (which can be either
+ function, global variable, another alias or bitcast of global value). Aliases
+ may have an optional <a href="#linkage">linkage type</a>, and an
+ optional <a href="#visibility">visibility style</a>.</p>
+
+ <h5>Syntax:</h5>
+
+<div class="doc_code">
+<pre>
+@<Name> = [Linkage] [Visibility] alias <AliaseeTy> @<Aliasee>
</pre>
</div>
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
+
+</div>
+
+
+
+<!-- ======================================================================= -->
+<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
<div class="doc_text">
-<h5>Syntax:</h5>
-<pre> br bool <cond>, label <iftrue>, label <iffalse><br> br label <dest> <i>; Unconditional branch</i>
+ <p>The return type and each parameter of a function type may have a set of
+ <i>parameter attributes</i> associated with them. Parameter attributes are
+ used to communicate additional information about the result or parameters of
+ a function. Parameter attributes are considered to be part of the function,
+ not of the function type, so functions with different parameter attributes
+ can have the same function type.</p>
+
+ <p>Parameter attributes are simple keywords that follow the type specified. If
+ multiple parameter attributes are needed, they are space separated. For
+ example:</p>
+
+<div class="doc_code">
+<pre>
+declare i32 @printf(i8* noalias , ...) nounwind
+declare i32 @atoi(i8*) nounwind readonly
</pre>
-<h5>Overview:</h5>
-<p>The '<tt>br</tt>' instruction is used to cause control flow to
-transfer to a different basic block in the current function. There are
-two forms of this instruction, corresponding to a conditional branch
-and an unconditional branch.</p>
-<h5>Arguments:</h5>
-<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
-single '<tt>bool</tt>' value and two '<tt>label</tt>' values. The
-unconditional form of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>'
-value as a target.</p>
-<h5>Semantics:</h5>
-<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>bool</tt>'
-argument is evaluated. If the value is <tt>true</tt>, control flows
-to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
-control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
-<h5>Example:</h5>
-<pre>Test:<br> %cond = <a href="#i_setcc">seteq</a> int %a, %b<br> br bool %cond, label %IfEqual, label %IfUnequal<br>IfEqual:<br> <a
- href="#i_ret">ret</a> int 1<br>IfUnequal:<br> <a href="#i_ret">ret</a> int 0<br></pre>
</div>
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection">
- <a name="i_switch">'<tt>switch</tt>' Instruction</a>
+
+ <p>Note that any attributes for the function result (<tt>nounwind</tt>,
+ <tt>readonly</tt>) come immediately after the argument list.</p>
+
+ <p>Currently, only the following parameter attributes are defined:</p>
+ <dl>
+ <dt><tt>zeroext</tt></dt>
+ <dd>This indicates that the parameter should be zero extended just before
+ a call to this function.</dd>
+
+ <dt><tt>signext</tt></dt>
+ <dd>This indicates that the parameter should be sign extended just before
+ a call to this function.</dd>
+
+ <dt><tt>inreg</tt></dt>
+ <dd>This indicates that the parameter should be placed in register (if
+ possible) during assembling function call. Support for this attribute is
+ target-specific</dd>
+
+ <dt><tt>byval</tt></dt>
+ <dd>This indicates that the pointer parameter should really be passed by
+ value to the function. The attribute implies that a hidden copy of the
+ pointee is made between the caller and the callee, so the callee is unable
+ to modify the value in the callee. This attribute is only valid on llvm
+ pointer arguments. It is generally used to pass structs and arrays by
+ value, but is also valid on scalars (even though this is silly).</dd>
+
+ <dt><tt>sret</tt></dt>
+ <dd>This indicates that the pointer parameter specifies the address of a
+ structure that is the return value of the function in the source program.
+ Loads and stores to the structure are assumed not to trap.
+ May only be applied to the first parameter.</dd>
+
+ <dt><tt>noalias</tt></dt>
+ <dd>This indicates that the parameter does not alias any global or any other
+ parameter. The caller is responsible for ensuring that this is the case,
+ usually by placing the value in a stack allocation.</dd>
+
+ <dt><tt>noreturn</tt></dt>
+ <dd>This function attribute indicates that the function never returns. This
+ indicates to LLVM that every call to this function should be treated as if
+ an <tt>unreachable</tt> instruction immediately followed the call.</dd>
+
+ <dt><tt>nounwind</tt></dt>
+ <dd>This function attribute indicates that no exceptions unwind out of the
+ function. Usually this is because the function makes no use of exceptions,
+ but it may also be that the function catches any exceptions thrown when
+ executing it.</dd>
+
+ <dt><tt>nest</tt></dt>
+ <dd>This indicates that the parameter can be excised using the
+ <a href="#int_trampoline">trampoline intrinsics</a>.</dd>
+ <dt><tt>readonly</tt></dt>
+ <dd>This function attribute indicates that the function has no side-effects
+ except for producing a return value or throwing an exception. The value
+ returned must only depend on the function arguments and/or global variables.
+ It may use values obtained by dereferencing pointers.</dd>
+ <dt><tt>readnone</tt></dt>
+ <dd>A <tt>readnone</tt> function has the same restrictions as a <tt>readonly</tt>
+ function, but in addition it is not allowed to dereference any pointer arguments
+ or global variables.
+ </dl>
+
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="gc">Garbage Collector Names</a>
</div>
<div class="doc_text">
-<h5>Syntax:</h5>
+<p>Each function may specify a garbage collector name, which is simply a
+string.</p>
+
+<div class="doc_code"><pre
+>define void @f() gc "name" { ...</pre></div>
+
+<p>The compiler declares the supported values of <i>name</i>. Specifying a
+collector which will cause the compiler to alter its output in order to support
+the named garbage collection algorithm.</p>
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="moduleasm">Module-Level Inline Assembly</a>
+</div>
+
+<div class="doc_text">
+<p>
+Modules may contain "module-level inline asm" blocks, which corresponds to the
+GCC "file scope inline asm" blocks. These blocks are internally concatenated by
+LLVM and treated as a single unit, but may be separated in the .ll file if
+desired. The syntax is very simple:
+</p>
+<div class="doc_code">
<pre>
- switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
+module asm "inline asm code goes here"
+module asm "more can go here"
</pre>
+</div>
-<h5>Overview:</h5>
+<p>The strings can contain any character by escaping non-printable characters.
+ The escape sequence used is simply "\xx" where "xx" is the two digit hex code
+ for the number.
+</p>
-<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
-several different places. It is a generalization of the '<tt>br</tt>'
-instruction, allowing a branch to occur to one of many possible
-destinations.</p>
+<p>
+ The inline asm code is simply printed to the machine code .s file when
+ assembly code is generated.
+</p>
+</div>
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="datalayout">Data Layout</a>
+</div>
-<h5>Arguments:</h5>
+<div class="doc_text">
+<p>A module may specify a target specific data layout string that specifies how
+data is to be laid out in memory. The syntax for the data layout is simply:</p>
+<pre> target datalayout = "<i>layout specification</i>"</pre>
+<p>The <i>layout specification</i> consists of a list of specifications
+separated by the minus sign character ('-'). Each specification starts with a
+letter and may include other information after the letter to define some
+aspect of the data layout. The specifications accepted are as follows: </p>
+<dl>
+ <dt><tt>E</tt></dt>
+ <dd>Specifies that the target lays out data in big-endian form. That is, the
+ bits with the most significance have the lowest address location.</dd>
+ <dt><tt>e</tt></dt>
+ <dd>Specifies that hte target lays out data in little-endian form. That is,
+ the bits with the least significance have the lowest address location.</dd>
+ <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
+ <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
+ <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
+ alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
+ too.</dd>
+ <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
+ <dd>This specifies the alignment for an integer type of a given bit
+ <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
+ <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
+ <dd>This specifies the alignment for a vector type of a given bit
+ <i>size</i>.</dd>
+ <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
+ <dd>This specifies the alignment for a floating point type of a given bit
+ <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
+ (double).</dd>
+ <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
+ <dd>This specifies the alignment for an aggregate type of a given bit
+ <i>size</i>.</dd>
+</dl>
+<p>When constructing the data layout for a given target, LLVM starts with a
+default set of specifications which are then (possibly) overriden by the
+specifications in the <tt>datalayout</tt> keyword. The default specifications
+are given in this list:</p>
+<ul>
+ <li><tt>E</tt> - big endian</li>
+ <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
+ <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
+ <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
+ <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
+ <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
+ <li><tt>i64:32:64</tt> - i64 has abi alignment of 32-bits but preferred
+ alignment of 64-bits</li>
+ <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
+ <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
+ <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
+ <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
+ <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
+</ul>
+<p>When llvm is determining the alignment for a given type, it uses the
+following rules:
+<ol>
+ <li>If the type sought is an exact match for one of the specifications, that
+ specification is used.</li>
+ <li>If no match is found, and the type sought is an integer type, then the
+ smallest integer type that is larger than the bitwidth of the sought type is
+ used. If none of the specifications are larger than the bitwidth then the the
+ largest integer type is used. For example, given the default specifications
+ above, the i7 type will use the alignment of i8 (next largest) while both
+ i65 and i256 will use the alignment of i64 (largest specified).</li>
+ <li>If no match is found, and the type sought is a vector type, then the
+ largest vector type that is smaller than the sought vector type will be used
+ as a fall back. This happens because <128 x double> can be implemented in
+ terms of 64 <2 x double>, for example.</li>
+</ol>
+</div>
-<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
-comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
-an array of pairs of comparison value constants and '<tt>label</tt>'s. The
-table is not allowed to contain duplicate constant entries.</p>
+<!-- *********************************************************************** -->
+<div class="doc_section"> <a name="typesystem">Type System</a> </div>
+<!-- *********************************************************************** -->
-<h5>Semantics:</h5>
+<div class="doc_text">
-<p>The <tt>switch</tt> instruction specifies a table of values and
-destinations. When the '<tt>switch</tt>' instruction is executed, this
-table is searched for the given value. If the value is found, the
-corresponding destination is branched to, otherwise the default value
-it transfered to.</p>
+<p>The LLVM type system is one of the most important features of the
+intermediate representation. Being typed enables a number of
+optimizations to be performed on the IR directly, without having to do
+extra analyses on the side before the transformation. A strong type
+system makes it easier to read the generated code and enables novel
+analyses and transformations that are not feasible to perform on normal
+three address code representations.</p>
-<h5>Implementation:</h5>
+</div>
-<p>Depending on properties of the target machine and the particular
-<tt>switch</tt> instruction, this instruction may be code generated in different
-ways, for example as a series of chained conditional branches, or with a lookup
-table.</p>
+<!-- ======================================================================= -->
+<div class="doc_subsection"> <a name="t_classifications">Type
+Classifications</a> </div>
+<div class="doc_text">
+<p>The types fall into a few useful
+classifications:</p>
-<h5>Example:</h5>
+<table border="1" cellspacing="0" cellpadding="4">
+ <tbody>
+ <tr><th>Classification</th><th>Types</th></tr>
+ <tr>
+ <td><a href="#t_integer">integer</a></td>
+ <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
+ </tr>
+ <tr>
+ <td><a href="#t_floating">floating point</a></td>
+ <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
+ </tr>
+ <tr>
+ <td><a name="t_firstclass">first class</a></td>
+ <td><a href="#t_integer">integer</a>,
+ <a href="#t_floating">floating point</a>,
+ <a href="#t_pointer">pointer</a>,
+ <a href="#t_vector">vector</a>,
+ <a href="#t_struct">structure</a>,
+ <a href="#t_array">array</a>,
+ <a href="#t_label">label</a>.
+ </td>
+ </tr>
+ <tr>
+ <td><a href="#t_primitive">primitive</a></td>
+ <td><a href="#t_label">label</a>,
+ <a href="#t_void">void</a>,
+ <a href="#t_floating">floating point</a>.</td>
+ </tr>
+ <tr>
+ <td><a href="#t_derived">derived</a></td>
+ <td><a href="#t_integer">integer</a>,
+ <a href="#t_array">array</a>,
+ <a href="#t_function">function</a>,
+ <a href="#t_pointer">pointer</a>,
+ <a href="#t_struct">structure</a>,
+ <a href="#t_pstruct">packed structure</a>,
+ <a href="#t_vector">vector</a>,
+ <a href="#t_opaque">opaque</a>.
+ </tr>
+ </tbody>
+</table>
-<pre>
- <i>; Emulate a conditional br instruction</i>
- %Val = <a href="#i_cast">cast</a> bool %value to int
- switch int %Val, label %truedest [int 0, label %falsedest ]
+<p>The <a href="#t_firstclass">first class</a> types are perhaps the
+most important. Values of these types are the only ones which can be
+produced by instructions, passed as arguments, or used as operands to
+instructions.</p>
+</div>
- <i>; Emulate an unconditional br instruction</i>
- switch uint 0, label %dest [ ]
+<!-- ======================================================================= -->
+<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
+
+<div class="doc_text">
+<p>The primitive types are the fundamental building blocks of the LLVM
+system.</p>
- <i>; Implement a jump table:</i>
- switch uint %val, label %otherwise [ uint 0, label %onzero
- uint 1, label %onone
- uint 2, label %ontwo ]
-</pre>
</div>
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_invoke">'<tt>invoke</tt>'
-Instruction</a> </div>
+<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
+
+<div class="doc_text">
+ <table>
+ <tbody>
+ <tr><th>Type</th><th>Description</th></tr>
+ <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
+ <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
+ <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
+ <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
+ <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
+ </tbody>
+ </table>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
+
<div class="doc_text">
-<h5>Syntax:</h5>
-<pre> <result> = invoke <ptr to function ty> %<function ptr val>(<function args>)<br> to label <normal label> except label <exception label><br></pre>
<h5>Overview:</h5>
-<p>The '<tt>invoke</tt>' instruction causes control to transfer to a
-specified function, with the possibility of control flow transfer to
-either the '<tt>normal</tt>' <tt>label</tt> label or the '<tt>exception</tt>'<tt>label</tt>.
-If the callee function returns with the "<tt><a href="#i_ret">ret</a></tt>"
-instruction, control flow will return to the "normal" label. If the
-callee (or any indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
-instruction, control is interrupted, and continued at the dynamically
-nearest "except" label.</p>
-<h5>Arguments:</h5>
-<p>This instruction requires several arguments:</p>
-<ol>
- <li>'<tt>ptr to function ty</tt>': shall be the signature of the
-pointer to function value being invoked. In most cases, this is a
-direct function invocation, but indirect <tt>invoke</tt>s are just as
-possible, branching off an arbitrary pointer to function value. </li>
- <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer
-to a function to be invoked. </li>
- <li>'<tt>function args</tt>': argument list whose types match the
-function signature argument types. If the function signature indicates
-the function accepts a variable number of arguments, the extra
-arguments can be specified. </li>
- <li>'<tt>normal label</tt>': the label reached when the called
-function executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
- <li>'<tt>exception label</tt>': the label reached when a callee
-returns with the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
-</ol>
-<h5>Semantics:</h5>
-<p>This instruction is designed to operate as a standard '<tt><a
- href="#i_call">call</a></tt>' instruction in most regards. The
-primary difference is that it establishes an association with a label,
-which is used by the runtime library to unwind the stack.</p>
-<p>This instruction is used in languages with destructors to ensure
-that proper cleanup is performed in the case of either a <tt>longjmp</tt>
-or a thrown exception. Additionally, this is important for
-implementation of '<tt>catch</tt>' clauses in high-level languages that
-support them.</p>
-<h5>Example:</h5>
-<pre> %retval = invoke int %Test(int 15)<br> to label %Continue<br> except label %TestCleanup <i>; {int}:retval set</i>
+<p>The void type does not represent any value and has no size.</p>
+
+<h5>Syntax:</h5>
+
+<pre>
+ void
</pre>
</div>
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
-Instruction</a> </div>
+<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
+
<div class="doc_text">
-<h5>Syntax:</h5>
-<pre> unwind<br></pre>
<h5>Overview:</h5>
-<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing
-control flow at the first callee in the dynamic call stack which used
-an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the
-call. This is primarily used to implement exception handling.</p>
-<h5>Semantics:</h5>
-<p>The '<tt>unwind</tt>' intrinsic causes execution of the current
-function to immediately halt. The dynamic call stack is then searched
-for the first <a href="#i_invoke"><tt>invoke</tt></a> instruction on
-the call stack. Once found, execution continues at the "exceptional"
-destination block specified by the <tt>invoke</tt> instruction. If
-there is no <tt>invoke</tt> instruction in the dynamic call chain,
-undefined behavior results.</p>
+<p>The label type represents code labels.</p>
+
+<h5>Syntax:</h5>
+
+<pre>
+ label
+</pre>
</div>
+
+
+<!-- ======================================================================= -->
+<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
+
+<div class="doc_text">
+
+<p>The real power in LLVM comes from the derived types in the system.
+This is what allows a programmer to represent arrays, functions,
+pointers, and other useful types. Note that these derived types may be
+recursive: For example, it is possible to have a two dimensional array.</p>
+
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
+
+<div class="doc_text">
+
+<h5>Overview:</h5>
+<p>The integer type is a very simple derived type that simply specifies an
+arbitrary bit width for the integer type desired. Any bit width from 1 bit to
+2^23-1 (about 8 million) can be specified.</p>
+
+<h5>Syntax:</h5>
+
+<pre>
+ iN
+</pre>
+
+<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
+value.</p>
+
+<h5>Examples:</h5>
+<table class="layout">
+ <tbody>
+ <tr>
+ <td><tt>i1</tt></td>
+ <td>a single-bit integer.</td>
+ </tr><tr>
+ <td><tt>i32</tt></td>
+ <td>a 32-bit integer.</td>
+ </tr><tr>
+ <td><tt>i1942652</tt></td>
+ <td>a really big integer of over 1 million bits.</td>
+ </tr>
+ </tbody>
+</table>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
+
+<div class="doc_text">
+
+<h5>Overview:</h5>
+
+<p>The array type is a very simple derived type that arranges elements
+sequentially in memory. The array type requires a size (number of
+elements) and an underlying data type.</p>
+
+<h5>Syntax:</h5>
+
+<pre>
+ [<# elements> x <elementtype>]
+</pre>
+
+<p>The number of elements is a constant integer value; elementtype may
+be any type with a size.</p>
+
+<h5>Examples:</h5>
+<table class="layout">
+ <tr class="layout">
+ <td class="left"><tt>[40 x i32]</tt></td>
+ <td class="left">Array of 40 32-bit integer values.</td>
+ </tr>
+ <tr class="layout">
+ <td class="left"><tt>[41 x i32]</tt></td>
+ <td class="left">Array of 41 32-bit integer values.</td>
+ </tr>
+ <tr class="layout">
+ <td class="left"><tt>[4 x i8]</tt></td>
+ <td class="left">Array of 4 8-bit integer values.</td>
+ </tr>
+</table>
+<p>Here are some examples of multidimensional arrays:</p>
+<table class="layout">
+ <tr class="layout">
+ <td class="left"><tt>[3 x [4 x i32]]</tt></td>
+ <td class="left">3x4 array of 32-bit integer values.</td>
+ </tr>
+ <tr class="layout">
+ <td class="left"><tt>[12 x [10 x float]]</tt></td>
+ <td class="left">12x10 array of single precision floating point values.</td>
+ </tr>
+ <tr class="layout">
+ <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
+ <td class="left">2x3x4 array of 16-bit integer values.</td>
+ </tr>
+</table>
+
+<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
+length array. Normally, accesses past the end of an array are undefined in
+LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
+As a special case, however, zero length arrays are recognized to be variable
+length. This allows implementation of 'pascal style arrays' with the LLVM
+type "{ i32, [0 x float]}", for example.</p>
+
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
+<div class="doc_text">
+
+<h5>Overview:</h5>
+
+<p>The function type can be thought of as a function signature. It
+consists of a return type and a list of formal parameter types. The
+return type of a function type is a scalar type, a void type, or a struct type.
+If the return type is a struct type then all struct elements must be of first
+class types, and the struct must have at least one element.</p>
+
+<h5>Syntax:</h5>
+
+<pre>
+ <returntype list> (<parameter list>)
+</pre>
+
+<p>...where '<tt><parameter list></tt>' is a comma-separated list of type
+specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
+which indicates that the function takes a variable number of arguments.
+Variable argument functions can access their arguments with the <a
+ href="#int_varargs">variable argument handling intrinsic</a> functions.
+'<tt><returntype list></tt>' is a comma-separated list of
+<a href="#t_firstclass">first class</a> type specifiers.</p>
+
+<h5>Examples:</h5>
+<table class="layout">
+ <tr class="layout">
+ <td class="left"><tt>i32 (i32)</tt></td>
+ <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
+ </td>
+ </tr><tr class="layout">
+ <td class="left"><tt>float (i16 signext, i32 *) *
+ </tt></td>
+ <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
+ an <tt>i16</tt> that should be sign extended and a
+ <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
+ <tt>float</tt>.
+ </td>
+ </tr><tr class="layout">
+ <td class="left"><tt>i32 (i8*, ...)</tt></td>
+ <td class="left">A vararg function that takes at least one
+ <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
+ which returns an integer. This is the signature for <tt>printf</tt> in
+ LLVM.
+ </td>
+ </tr><tr class="layout">
+ <td class="left"><tt>{i32, i32} (i32)</tt></td>
+ <td class="left">A function taking an <tt>i32></tt>, returning two
+ <tt> i32 </tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
+ </td>
+ </tr>
+</table>
+
+</div>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
+<div class="doc_text">
+<h5>Overview:</h5>
+<p>The structure type is used to represent a collection of data members
+together in memory. The packing of the field types is defined to match
+the ABI of the underlying processor. The elements of a structure may
+be any type that has a size.</p>
+<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
+and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
+field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
+instruction.</p>
+<h5>Syntax:</h5>
+<pre> { <type list> }<br></pre>
+<h5>Examples:</h5>
+<table class="layout">
+ <tr class="layout">
+ <td class="left"><tt>{ i32, i32, i32 }</tt></td>
+ <td class="left">A triple of three <tt>i32</tt> values</td>
+ </tr><tr class="layout">
+ <td class="left"><tt>{ float, i32 (i32) * }</tt></td>
+ <td class="left">A pair, where the first element is a <tt>float</tt> and the
+ second element is a <a href="#t_pointer">pointer</a> to a
+ <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
+ an <tt>i32</tt>.</td>
+ </tr>
+</table>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
+</div>
+<div class="doc_text">
+<h5>Overview:</h5>
+<p>The packed structure type is used to represent a collection of data members
+together in memory. There is no padding between fields. Further, the alignment
+of a packed structure is 1 byte. The elements of a packed structure may
+be any type that has a size.</p>
+<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
+and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
+field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
+instruction.</p>
+<h5>Syntax:</h5>
+<pre> < { <type list> } > <br></pre>
+<h5>Examples:</h5>
+<table class="layout">
+ <tr class="layout">
+ <td class="left"><tt>< { i32, i32, i32 } ></tt></td>
+ <td class="left">A triple of three <tt>i32</tt> values</td>
+ </tr><tr class="layout">
+ <td class="left"><tt>< { float, i32 (i32)* } ></tt></td>
+ <td class="left">A pair, where the first element is a <tt>float</tt> and the
+ second element is a <a href="#t_pointer">pointer</a> to a
+ <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
+ an <tt>i32</tt>.</td>
+ </tr>
+</table>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
+<div class="doc_text">
+<h5>Overview:</h5>
+<p>As in many languages, the pointer type represents a pointer or
+reference to another object, which must live in memory. Pointer types may have
+an optional address space attribute defining the target-specific numbered
+address space where the pointed-to object resides. The default address space is
+zero.</p>
+<h5>Syntax:</h5>
+<pre> <type> *<br></pre>
+<h5>Examples:</h5>
+<table class="layout">
+ <tr class="layout">
+ <td class="left"><tt>[4x i32]*</tt></td>
+ <td class="left">A <a href="#t_pointer">pointer</a> to <a
+ href="#t_array">array</a> of four <tt>i32</tt> values.</td>
+ </tr>
+ <tr class="layout">
+ <td class="left"><tt>i32 (i32 *) *</tt></td>
+ <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
+ href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
+ <tt>i32</tt>.</td>
+ </tr>
+ <tr class="layout">
+ <td class="left"><tt>i32 addrspace(5)*</tt></td>
+ <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
+ that resides in address space #5.</td>
+ </tr>
+</table>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
+<div class="doc_text">
+
+<h5>Overview:</h5>
+
+<p>A vector type is a simple derived type that represents a vector
+of elements. Vector types are used when multiple primitive data
+are operated in parallel using a single instruction (SIMD).
+A vector type requires a size (number of
+elements) and an underlying primitive data type. Vectors must have a power
+of two length (1, 2, 4, 8, 16 ...). Vector types are
+considered <a href="#t_firstclass">first class</a>.</p>
+
+<h5>Syntax:</h5>
+
+<pre>
+ < <# elements> x <elementtype> >
+</pre>
+
+<p>The number of elements is a constant integer value; elementtype may
+be any integer or floating point type.</p>
+
+<h5>Examples:</h5>
+
+<table class="layout">
+ <tr class="layout">
+ <td class="left"><tt><4 x i32></tt></td>
+ <td class="left">Vector of 4 32-bit integer values.</td>
+ </tr>
+ <tr class="layout">
+ <td class="left"><tt><8 x float></tt></td>
+ <td class="left">Vector of 8 32-bit floating-point values.</td>
+ </tr>
+ <tr class="layout">
+ <td class="left"><tt><2 x i64></tt></td>
+ <td class="left">Vector of 2 64-bit integer values.</td>
+ </tr>
+</table>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
+<div class="doc_text">
+
+<h5>Overview:</h5>
+
+<p>Opaque types are used to represent unknown types in the system. This
+corresponds (for example) to the C notion of a forward declared structure type.
+In LLVM, opaque types can eventually be resolved to any type (not just a
+structure type).</p>
+
+<h5>Syntax:</h5>
+
+<pre>
+ opaque
+</pre>
+
+<h5>Examples:</h5>
+
+<table class="layout">
+ <tr class="layout">
+ <td class="left"><tt>opaque</tt></td>
+ <td class="left">An opaque type.</td>
+ </tr>
+</table>
+</div>
+
+
+<!-- *********************************************************************** -->
+<div class="doc_section"> <a name="constants">Constants</a> </div>
+<!-- *********************************************************************** -->
+
+<div class="doc_text">
+
+<p>LLVM has several different basic types of constants. This section describes
+them all and their syntax.</p>
+
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
+
+<div class="doc_text">
+
+<dl>
+ <dt><b>Boolean constants</b></dt>
+
+ <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
+ constants of the <tt><a href="#t_primitive">i1</a></tt> type.
+ </dd>
+
+ <dt><b>Integer constants</b></dt>
+
+ <dd>Standard integers (such as '4') are constants of the <a
+ href="#t_integer">integer</a> type. Negative numbers may be used with
+ integer types.
+ </dd>
+
+ <dt><b>Floating point constants</b></dt>
+
+ <dd>Floating point constants use standard decimal notation (e.g. 123.421),
+ exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
+ notation (see below). The assembler requires the exact decimal value of
+ a floating-point constant. For example, the assembler accepts 1.25 but
+ rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
+ constants must have a <a href="#t_floating">floating point</a> type. </dd>
+
+ <dt><b>Null pointer constants</b></dt>
+
+ <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
+ and must be of <a href="#t_pointer">pointer type</a>.</dd>
+
+</dl>
+
+<p>The one non-intuitive notation for constants is the optional hexadecimal form
+of floating point constants. For example, the form '<tt>double
+0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
+4.5e+15</tt>'. The only time hexadecimal floating point constants are required
+(and the only time that they are generated by the disassembler) is when a
+floating point constant must be emitted but it cannot be represented as a
+decimal floating point number. For example, NaN's, infinities, and other
+special values are represented in their IEEE hexadecimal format so that
+assembly and disassembly do not cause any bits to change in the constants.</p>
+
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
+</div>
+
+<div class="doc_text">
+<p>Aggregate constants arise from aggregation of simple constants
+and smaller aggregate constants.</p>
+
+<dl>
+ <dt><b>Structure constants</b></dt>
+
+ <dd>Structure constants are represented with notation similar to structure
+ type definitions (a comma separated list of elements, surrounded by braces
+ (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
+ where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>". Structure constants
+ must have <a href="#t_struct">structure type</a>, and the number and
+ types of elements must match those specified by the type.
+ </dd>
+
+ <dt><b>Array constants</b></dt>
+
+ <dd>Array constants are represented with notation similar to array type
+ definitions (a comma separated list of elements, surrounded by square brackets
+ (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
+ constants must have <a href="#t_array">array type</a>, and the number and
+ types of elements must match those specified by the type.
+ </dd>
+
+ <dt><b>Vector constants</b></dt>
+
+ <dd>Vector constants are represented with notation similar to vector type
+ definitions (a comma separated list of elements, surrounded by
+ less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
+ i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
+ href="#t_vector">vector type</a>, and the number and types of elements must
+ match those specified by the type.
+ </dd>
+
+ <dt><b>Zero initialization</b></dt>
+
+ <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
+ value to zero of <em>any</em> type, including scalar and aggregate types.
+ This is often used to avoid having to print large zero initializers (e.g. for
+ large arrays) and is always exactly equivalent to using explicit zero
+ initializers.
+ </dd>
+</dl>
+
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="globalconstants">Global Variable and Function Addresses</a>
+</div>
+
+<div class="doc_text">
+
+<p>The addresses of <a href="#globalvars">global variables</a> and <a
+href="#functionstructure">functions</a> are always implicitly valid (link-time)
+constants. These constants are explicitly referenced when the <a
+href="#identifiers">identifier for the global</a> is used and always have <a
+href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
+file:</p>
+
+<div class="doc_code">
+<pre>
+@X = global i32 17
+@Y = global i32 42
+@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
+</pre>
+</div>
+
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
+<div class="doc_text">
+ <p>The string '<tt>undef</tt>' is recognized as a type-less constant that has
+ no specific value. Undefined values may be of any type and be used anywhere
+ a constant is permitted.</p>
+
+ <p>Undefined values indicate to the compiler that the program is well defined
+ no matter what value is used, giving the compiler more freedom to optimize.
+ </p>
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
+</div>
+
+<div class="doc_text">
+
+<p>Constant expressions are used to allow expressions involving other constants
+to be used as constants. Constant expressions may be of any <a
+href="#t_firstclass">first class</a> type and may involve any LLVM operation
+that does not have side effects (e.g. load and call are not supported). The
+following is the syntax for constant expressions:</p>
+
+<dl>
+ <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
+ <dd>Truncate a constant to another type. The bit size of CST must be larger
+ than the bit size of TYPE. Both types must be integers.</dd>
+
+ <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
+ <dd>Zero extend a constant to another type. The bit size of CST must be
+ smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
+
+ <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
+ <dd>Sign extend a constant to another type. The bit size of CST must be
+ smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
+
+ <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
+ <dd>Truncate a floating point constant to another floating point type. The
+ size of CST must be larger than the size of TYPE. Both types must be
+ floating point.</dd>
+
+ <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
+ <dd>Floating point extend a constant to another type. The size of CST must be
+ smaller or equal to the size of TYPE. Both types must be floating point.</dd>
+
+ <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
+ <dd>Convert a floating point constant to the corresponding unsigned integer
+ constant. TYPE must be a scalar or vector integer type. CST must be of scalar
+ or vector floating point type. Both CST and TYPE must be scalars, or vectors
+ of the same number of elements. If the value won't fit in the integer type,
+ the results are undefined.</dd>
+
+ <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
+ <dd>Convert a floating point constant to the corresponding signed integer
+ constant. TYPE must be a scalar or vector integer type. CST must be of scalar
+ or vector floating point type. Both CST and TYPE must be scalars, or vectors
+ of the same number of elements. If the value won't fit in the integer type,
+ the results are undefined.</dd>
+
+ <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
+ <dd>Convert an unsigned integer constant to the corresponding floating point
+ constant. TYPE must be a scalar or vector floating point type. CST must be of
+ scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
+ of the same number of elements. If the value won't fit in the floating point
+ type, the results are undefined.</dd>
+
+ <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
+ <dd>Convert a signed integer constant to the corresponding floating point
+ constant. TYPE must be a scalar or vector floating point type. CST must be of
+ scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
+ of the same number of elements. If the value won't fit in the floating point
+ type, the results are undefined.</dd>
+
+ <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
+ <dd>Convert a pointer typed constant to the corresponding integer constant
+ TYPE must be an integer type. CST must be of pointer type. The CST value is
+ zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
+
+ <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
+ <dd>Convert a integer constant to a pointer constant. TYPE must be a
+ pointer type. CST must be of integer type. The CST value is zero extended,
+ truncated, or unchanged to make it fit in a pointer size. This one is
+ <i>really</i> dangerous!</dd>
+
+ <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
+ <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
+ identical (same number of bits). The conversion is done as if the CST value
+ was stored to memory and read back as TYPE. In other words, no bits change
+ with this operator, just the type. This can be used for conversion of
+ vector types to any other type, as long as they have the same bit width. For
+ pointers it is only valid to cast to another pointer type.
+ </dd>
+
+ <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
+
+ <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
+ constants. As with the <a href="#i_getelementptr">getelementptr</a>
+ instruction, the index list may have zero or more indexes, which are required
+ to make sense for the type of "CSTPTR".</dd>
+
+ <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
+
+ <dd>Perform the <a href="#i_select">select operation</a> on
+ constants.</dd>
+
+ <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
+ <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
+
+ <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
+ <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
+
+ <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
+ <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
+
+ <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
+ <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
+
+ <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
+
+ <dd>Perform the <a href="#i_extractelement">extractelement
+ operation</a> on constants.
+
+ <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
+
+ <dd>Perform the <a href="#i_insertelement">insertelement
+ operation</a> on constants.</dd>
+
+
+ <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
+
+ <dd>Perform the <a href="#i_shufflevector">shufflevector
+ operation</a> on constants.</dd>
+
+ <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
+
+ <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
+ be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
+ binary</a> operations. The constraints on operands are the same as those for
+ the corresponding instruction (e.g. no bitwise operations on floating point
+ values are allowed).</dd>
+</dl>
+</div>
+
+<!-- *********************************************************************** -->
+<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
+<!-- *********************************************************************** -->
+
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+<a name="inlineasm">Inline Assembler Expressions</a>
+</div>
+
+<div class="doc_text">
+
+<p>
+LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
+Module-Level Inline Assembly</a>) through the use of a special value. This
+value represents the inline assembler as a string (containing the instructions
+to emit), a list of operand constraints (stored as a string), and a flag that
+indicates whether or not the inline asm expression has side effects. An example
+inline assembler expression is:
+</p>
+
+<div class="doc_code">
+<pre>
+i32 (i32) asm "bswap $0", "=r,r"
+</pre>
+</div>
+
+<p>
+Inline assembler expressions may <b>only</b> be used as the callee operand of
+a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
+</p>
+
+<div class="doc_code">
+<pre>
+%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
+</pre>
+</div>
+
+<p>
+Inline asms with side effects not visible in the constraint list must be marked
+as having side effects. This is done through the use of the
+'<tt>sideeffect</tt>' keyword, like so:
+</p>
+
+<div class="doc_code">
+<pre>
+call void asm sideeffect "eieio", ""()
+</pre>
+</div>
+
+<p>TODO: The format of the asm and constraints string still need to be
+documented here. Constraints on what can be done (e.g. duplication, moving, etc
+need to be documented).
+</p>
+
+</div>
+
+<!-- *********************************************************************** -->
+<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
+<!-- *********************************************************************** -->
+
+<div class="doc_text">
+
+<p>The LLVM instruction set consists of several different
+classifications of instructions: <a href="#terminators">terminator
+instructions</a>, <a href="#binaryops">binary instructions</a>,
+<a href="#bitwiseops">bitwise binary instructions</a>, <a
+ href="#memoryops">memory instructions</a>, and <a href="#otherops">other
+instructions</a>.</p>
+
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection"> <a name="terminators">Terminator
+Instructions</a> </div>
+
+<div class="doc_text">
+
+<p>As mentioned <a href="#functionstructure">previously</a>, every
+basic block in a program ends with a "Terminator" instruction, which
+indicates which block should be executed after the current block is
+finished. These terminator instructions typically yield a '<tt>void</tt>'
+value: they produce control flow, not values (the one exception being
+the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
+<p>There are six different terminator instructions: the '<a
+ href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
+instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
+the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
+ href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
+ href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
+
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
+Instruction</a> </div>
+<div class="doc_text">
+<h5>Syntax:</h5>
+<pre> ret <type> <value> <i>; Return a value from a non-void function</i>
+ ret void <i>; Return from void function</i>
+ ret <type> <value>, <type> <value> <i>; Return two values from a non-void function </i>
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
+value) from a function back to the caller.</p>
+<p>There are two forms of the '<tt>ret</tt>' instruction: one that
+returns value(s) and then causes control flow, and one that just causes
+control flow to occur.</p>
+
+<h5>Arguments:</h5>
+
+<p>The '<tt>ret</tt>' instruction may return zero, one or multiple values.
+The type of each return value must be a '<a href="#t_firstclass">first
+class</a>' type. Note that a function is not <a href="#wellformed">well
+formed</a> if there exists a '<tt>ret</tt>' instruction inside of the
+function that returns values that do not match the return type of the
+function.</p>
+
+<h5>Semantics:</h5>
+
+<p>When the '<tt>ret</tt>' instruction is executed, control flow
+returns back to the calling function's context. If the caller is a "<a
+ href="#i_call"><tt>call</tt></a>" instruction, execution continues at
+the instruction after the call. If the caller was an "<a
+ href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
+at the beginning of the "normal" destination block. If the instruction
+returns a value, that value shall set the call or invoke instruction's
+return value. If the instruction returns multiple values then these
+values can only be accessed through a '<a href="#i_getresult"><tt>getresult</tt>
+</a>' instruction.</p>
+
+<h5>Example:</h5>
+
+<pre>
+ ret i32 5 <i>; Return an integer value of 5</i>
+ ret void <i>; Return from a void function</i>
+ ret i32 4, i8 2 <i>; Return two values 4 and 2 </i>
+</pre>
+</div>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
+<div class="doc_text">
+<h5>Syntax:</h5>
+<pre> br i1 <cond>, label <iftrue>, label <iffalse><br> br label <dest> <i>; Unconditional branch</i>
+</pre>
+<h5>Overview:</h5>
+<p>The '<tt>br</tt>' instruction is used to cause control flow to
+transfer to a different basic block in the current function. There are
+two forms of this instruction, corresponding to a conditional branch
+and an unconditional branch.</p>
+<h5>Arguments:</h5>
+<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
+single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
+unconditional form of the '<tt>br</tt>' instruction takes a single
+'<tt>label</tt>' value as a target.</p>
+<h5>Semantics:</h5>
+<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
+argument is evaluated. If the value is <tt>true</tt>, control flows
+to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
+control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
+<h5>Example:</h5>
+<pre>Test:<br> %cond = <a href="#i_icmp">icmp</a> eq, i32 %a, %b<br> br i1 %cond, label %IfEqual, label %IfUnequal<br>IfEqual:<br> <a
+ href="#i_ret">ret</a> i32 1<br>IfUnequal:<br> <a href="#i_ret">ret</a> i32 0<br></pre>
+</div>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_switch">'<tt>switch</tt>' Instruction</a>
+</div>
+
+<div class="doc_text">
+<h5>Syntax:</h5>
+
+<pre>
+ switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
+several different places. It is a generalization of the '<tt>br</tt>'
+instruction, allowing a branch to occur to one of many possible
+destinations.</p>
+
+
+<h5>Arguments:</h5>
+
+<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
+comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
+an array of pairs of comparison value constants and '<tt>label</tt>'s. The
+table is not allowed to contain duplicate constant entries.</p>
+
+<h5>Semantics:</h5>
+
+<p>The <tt>switch</tt> instruction specifies a table of values and
+destinations. When the '<tt>switch</tt>' instruction is executed, this
+table is searched for the given value. If the value is found, control flow is
+transfered to the corresponding destination; otherwise, control flow is
+transfered to the default destination.</p>
+
+<h5>Implementation:</h5>
+
+<p>Depending on properties of the target machine and the particular
+<tt>switch</tt> instruction, this instruction may be code generated in different
+ways. For example, it could be generated as a series of chained conditional
+branches or with a lookup table.</p>
+
+<h5>Example:</h5>
+
+<pre>
+ <i>; Emulate a conditional br instruction</i>
+ %Val = <a href="#i_zext">zext</a> i1 %value to i32
+ switch i32 %Val, label %truedest [i32 0, label %falsedest ]
+
+ <i>; Emulate an unconditional br instruction</i>
+ switch i32 0, label %dest [ ]
+
+ <i>; Implement a jump table:</i>
+ switch i32 %val, label %otherwise [ i32 0, label %onzero
+ i32 1, label %onone
+ i32 2, label %ontwo ]
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+
+<pre>
+ <result> = invoke [<a href="#callingconv">cconv</a>] <ptr to function ty> <function ptr val>(<function args>)
+ to label <normal label> unwind label <exception label>
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
+function, with the possibility of control flow transfer to either the
+'<tt>normal</tt>' label or the
+'<tt>exception</tt>' label. If the callee function returns with the
+"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
+"normal" label. If the callee (or any indirect callees) returns with the "<a
+href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
+continued at the dynamically nearest "exception" label. If the callee function
+returns multiple values then individual return values are only accessible through
+a '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
+
+<h5>Arguments:</h5>
+
+<p>This instruction requires several arguments:</p>
+
+<ol>
+ <li>
+ The optional "cconv" marker indicates which <a href="#callingconv">calling
+ convention</a> the call should use. If none is specified, the call defaults
+ to using C calling conventions.
+ </li>
+ <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
+ function value being invoked. In most cases, this is a direct function
+ invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
+ an arbitrary pointer to function value.
+ </li>
+
+ <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
+ function to be invoked. </li>
+
+ <li>'<tt>function args</tt>': argument list whose types match the function
+ signature argument types. If the function signature indicates the function
+ accepts a variable number of arguments, the extra arguments can be
+ specified. </li>
+
+ <li>'<tt>normal label</tt>': the label reached when the called function
+ executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
+
+ <li>'<tt>exception label</tt>': the label reached when a callee returns with
+ the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
+
+</ol>
+
+<h5>Semantics:</h5>
+
+<p>This instruction is designed to operate as a standard '<tt><a
+href="#i_call">call</a></tt>' instruction in most regards. The primary
+difference is that it establishes an association with a label, which is used by
+the runtime library to unwind the stack.</p>
+
+<p>This instruction is used in languages with destructors to ensure that proper
+cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
+exception. Additionally, this is important for implementation of
+'<tt>catch</tt>' clauses in high-level languages that support them.</p>
+
+<h5>Example:</h5>
+<pre>
+ %retval = invoke i32 @Test(i32 15) to label %Continue
+ unwind label %TestCleanup <i>; {i32}:retval set</i>
+ %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
+ unwind label %TestCleanup <i>; {i32}:retval set</i>
+</pre>
+</div>
+
+
+<!-- _______________________________________________________________________ -->
+
+<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
+Instruction</a> </div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre>
+ unwind
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
+at the first callee in the dynamic call stack which used an <a
+href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
+primarily used to implement exception handling.</p>
+
+<h5>Semantics:</h5>
+
+<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
+immediately halt. The dynamic call stack is then searched for the first <a
+href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
+execution continues at the "exceptional" destination block specified by the
+<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
+dynamic call chain, undefined behavior results.</p>
+</div>
+
+<!-- _______________________________________________________________________ -->
+
+<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
+Instruction</a> </div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre>
+ unreachable
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
+instruction is used to inform the optimizer that a particular portion of the
+code is not reachable. This can be used to indicate that the code after a
+no-return function cannot be reached, and other facts.</p>
+
+<h5>Semantics:</h5>
+
+<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
+</div>
+
+
+
+<!-- ======================================================================= -->
+<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
+<div class="doc_text">
+<p>Binary operators are used to do most of the computation in a
+program. They require two operands of the same type, execute an operation on them, and
+produce a single value. The operands might represent
+multiple data, as is the case with the <a href="#t_vector">vector</a> data type.
+The result value has the same type as its operands.</p>
+<p>There are several different binary operators:</p>
+</div>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_add">'<tt>add</tt>' Instruction</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+
+<pre>
+ <result> = add <ty> <var1>, <var2> <i>; yields {ty}:result</i>
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
+
+<h5>Arguments:</h5>
+
+<p>The two arguments to the '<tt>add</tt>' instruction must be <a
+ href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
+ <a href="#t_vector">vector</a> values. Both arguments must have identical
+ types.</p>
+
+<h5>Semantics:</h5>
+
+<p>The value produced is the integer or floating point sum of the two
+operands.</p>
+
+<p>If an integer sum has unsigned overflow, the result returned is the
+mathematical result modulo 2<sup>n</sup>, where n is the bit width of
+the result.</p>
+
+<p>Because LLVM integers use a two's complement representation, this
+instruction is appropriate for both signed and unsigned integers.</p>
+
+<h5>Example:</h5>
+
+<pre>
+ <result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
+</pre>
+</div>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_sub">'<tt>sub</tt>' Instruction</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+
+<pre>
+ <result> = sub <ty> <var1>, <var2> <i>; yields {ty}:result</i>
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>sub</tt>' instruction returns the difference of its two
+operands.</p>
+
+<p>Note that the '<tt>sub</tt>' instruction is used to represent the
+'<tt>neg</tt>' instruction present in most other intermediate
+representations.</p>
+
+<h5>Arguments:</h5>
+
+<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
+ href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
+ or <a href="#t_vector">vector</a> values. Both arguments must have identical
+ types.</p>
+
+<h5>Semantics:</h5>
+
+<p>The value produced is the integer or floating point difference of
+the two operands.</p>
+
+<p>If an integer difference has unsigned overflow, the result returned is the
+mathematical result modulo 2<sup>n</sup>, where n is the bit width of
+the result.</p>
+
+<p>Because LLVM integers use a two's complement representation, this
+instruction is appropriate for both signed and unsigned integers.</p>
+
+<h5>Example:</h5>
+<pre>
+ <result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
+ <result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_mul">'<tt>mul</tt>' Instruction</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre> <result> = mul <ty> <var1>, <var2> <i>; yields {ty}:result</i>
+</pre>
+<h5>Overview:</h5>
+<p>The '<tt>mul</tt>' instruction returns the product of its two
+operands.</p>
+
+<h5>Arguments:</h5>
+
+<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
+href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
+or <a href="#t_vector">vector</a> values. Both arguments must have identical
+types.</p>
+
+<h5>Semantics:</h5>
+
+<p>The value produced is the integer or floating point product of the
+two operands.</p>
+
+<p>If the result of an integer multiplication has unsigned overflow,
+the result returned is the mathematical result modulo
+2<sup>n</sup>, where n is the bit width of the result.</p>
+<p>Because LLVM integers use a two's complement representation, and the
+result is the same width as the operands, this instruction returns the
+correct result for both signed and unsigned integers. If a full product
+(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
+should be sign-extended or zero-extended as appropriate to the
+width of the full product.</p>
+<h5>Example:</h5>
+<pre> <result> = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
+</a></div>
+<div class="doc_text">
+<h5>Syntax:</h5>
+<pre> <result> = udiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
+</pre>
+<h5>Overview:</h5>
+<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
+operands.</p>
+
+<h5>Arguments:</h5>
+
+<p>The two arguments to the '<tt>udiv</tt>' instruction must be
+<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
+values. Both arguments must have identical types.</p>
+
+<h5>Semantics:</h5>
+
+<p>The value produced is the unsigned integer quotient of the two operands.</p>
+<p>Note that unsigned integer division and signed integer division are distinct
+operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
+<p>Division by zero leads to undefined behavior.</p>
+<h5>Example:</h5>
+<pre> <result> = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
+</pre>
+</div>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
+</a> </div>
+<div class="doc_text">
+<h5>Syntax:</h5>
+<pre>
+ <result> = sdiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
+operands.</p>
+
+<h5>Arguments:</h5>
+
+<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
+<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
+values. Both arguments must have identical types.</p>
+
+<h5>Semantics:</h5>
+<p>The value produced is the signed integer quotient of the two operands rounded towards zero.</p>
+<p>Note that signed integer division and unsigned integer division are distinct
+operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
+<p>Division by zero leads to undefined behavior. Overflow also leads to
+undefined behavior; this is a rare case, but can occur, for example,
+by doing a 32-bit division of -2147483648 by -1.</p>
+<h5>Example:</h5>
+<pre> <result> = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
+</pre>
+</div>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
+Instruction</a> </div>
+<div class="doc_text">
+<h5>Syntax:</h5>
+<pre>
+ <result> = fdiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
+</pre>
+<h5>Overview:</h5>
+
+<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
+operands.</p>
+
+<h5>Arguments:</h5>
+
+<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
+<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
+of floating point values. Both arguments must have identical types.</p>
+
+<h5>Semantics:</h5>
+
+<p>The value produced is the floating point quotient of the two operands.</p>
+
+<h5>Example:</h5>
+
+<pre>
+ <result> = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
+</div>
+<div class="doc_text">
+<h5>Syntax:</h5>
+<pre> <result> = urem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
+</pre>
+<h5>Overview:</h5>
+<p>The '<tt>urem</tt>' instruction returns the remainder from the
+unsigned division of its two arguments.</p>
+<h5>Arguments:</h5>
+<p>The two arguments to the '<tt>urem</tt>' instruction must be
+<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
+values. Both arguments must have identical types.</p>
+<h5>Semantics:</h5>
+<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
+This instruction always performs an unsigned division to get the remainder.</p>
+<p>Note that unsigned integer remainder and signed integer remainder are
+distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
+<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
+<h5>Example:</h5>
+<pre> <result> = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
+</pre>
+
+</div>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_srem">'<tt>srem</tt>' Instruction</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+
+<pre>
+ <result> = srem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>srem</tt>' instruction returns the remainder from the
+signed division of its two operands. This instruction can also take
+<a href="#t_vector">vector</a> versions of the values in which case
+the elements must be integers.</p>
+
+<h5>Arguments:</h5>
+
+<p>The two arguments to the '<tt>srem</tt>' instruction must be
+<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
+values. Both arguments must have identical types.</p>
+
+<h5>Semantics:</h5>
+
+<p>This instruction returns the <i>remainder</i> of a division (where the result
+has the same sign as the dividend, <tt>var1</tt>), not the <i>modulo</i>
+operator (where the result has the same sign as the divisor, <tt>var2</tt>) of
+a value. For more information about the difference, see <a
+ href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
+Math Forum</a>. For a table of how this is implemented in various languages,
+please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
+Wikipedia: modulo operation</a>.</p>
+<p>Note that signed integer remainder and unsigned integer remainder are
+distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
+<p>Taking the remainder of a division by zero leads to undefined behavior.
+Overflow also leads to undefined behavior; this is a rare case, but can occur,
+for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
+(The remainder doesn't actually overflow, but this rule lets srem be
+implemented using instructions that return both the result of the division
+and the remainder.)</p>
+<h5>Example:</h5>
+<pre> <result> = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
+</pre>
+
+</div>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre> <result> = frem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
+</pre>
+<h5>Overview:</h5>
+<p>The '<tt>frem</tt>' instruction returns the remainder from the
+division of its two operands.</p>
+<h5>Arguments:</h5>
+<p>The two arguments to the '<tt>frem</tt>' instruction must be
+<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
+of floating point values. Both arguments must have identical types.</p>
+
+<h5>Semantics:</h5>
+
+<p>This instruction returns the <i>remainder</i> of a division.
+The remainder has the same sign as the dividend.</p>
+
+<h5>Example:</h5>
+
+<pre>
+ <result> = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
+</pre>
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
+Operations</a> </div>
+<div class="doc_text">
+<p>Bitwise binary operators are used to do various forms of
+bit-twiddling in a program. They are generally very efficient
+instructions and can commonly be strength reduced from other
+instructions. They require two operands of the same type, execute an operation on them,
+and produce a single value. The resulting value is the same type as its operands.</p>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
+Instruction</a> </div>
+<div class="doc_text">
+<h5>Syntax:</h5>
+<pre> <result> = shl <ty> <var1>, <var2> <i>; yields {ty}:result</i>
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
+the left a specified number of bits.</p>
+
+<h5>Arguments:</h5>
+
+<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
+ href="#t_integer">integer</a> type. '<tt>var2</tt>' is treated as an
+unsigned value. This instruction does not support
+<a href="#t_vector">vector</a> operands.</p>
+
+<h5>Semantics:</h5>
+
+<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup> mod 2<sup>n</sup>,
+where n is the width of the result. If <tt>var2</tt> is (statically or dynamically) negative or
+equal to or larger than the number of bits in <tt>var1</tt>, the result is undefined.</p>
+
+<h5>Example:</h5><pre>
+ <result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
+ <result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
+ <result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
+ <result> = shl i32 1, 32 <i>; undefined</i>
+</pre>
+</div>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
+Instruction</a> </div>
+<div class="doc_text">
+<h5>Syntax:</h5>
+<pre> <result> = lshr <ty> <var1>, <var2> <i>; yields {ty}:result</i>
+</pre>
+
+<h5>Overview:</h5>
+<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
+operand shifted to the right a specified number of bits with zero fill.</p>
+
+<h5>Arguments:</h5>
+<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
+<a href="#t_integer">integer</a> type. '<tt>var2</tt>' is treated as an
+unsigned value. This instruction does not support
+<a href="#t_vector">vector</a> operands.</p>
+
+<h5>Semantics:</h5>
+
+<p>This instruction always performs a logical shift right operation. The most
+significant bits of the result will be filled with zero bits after the
+shift. If <tt>var2</tt> is (statically or dynamically) equal to or larger than
+the number of bits in <tt>var1</tt>, the result is undefined.</p>
+
+<h5>Example:</h5>
+<pre>
+ <result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
+ <result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
+ <result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
+ <result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
+ <result> = lshr i32 1, 32 <i>; undefined</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
+Instruction</a> </div>
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre> <result> = ashr <ty> <var1>, <var2> <i>; yields {ty}:result</i>
+</pre>
+
+<h5>Overview:</h5>
+<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
+operand shifted to the right a specified number of bits with sign extension.</p>
+
+<h5>Arguments:</h5>
+<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
+<a href="#t_integer">integer</a> type. '<tt>var2</tt>' is treated as an
+unsigned value. This instruction does not support
+<a href="#t_vector">vector</a> operands.</p>
+
+<h5>Semantics:</h5>
+<p>This instruction always performs an arithmetic shift right operation,
+The most significant bits of the result will be filled with the sign bit
+of <tt>var1</tt>. If <tt>var2</tt> is (statically or dynamically) equal to or
+larger than the number of bits in <tt>var1</tt>, the result is undefined.
+</p>
+
+<h5>Example:</h5>
+<pre>
+ <result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
+ <result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
+ <result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
+ <result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
+ <result> = ashr i32 1, 32 <i>; undefined</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
+Instruction</a> </div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+
+<pre>
+ <result> = and <ty> <var1>, <var2> <i>; yields {ty}:result</i>
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
+its two operands.</p>
+
+<h5>Arguments:</h5>
+
+<p>The two arguments to the '<tt>and</tt>' instruction must be
+<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
+values. Both arguments must have identical types.</p>
+
+<h5>Semantics:</h5>
+<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
+<p> </p>
+<div style="align: center">
+<table border="1" cellspacing="0" cellpadding="4">
+ <tbody>
+ <tr>
+ <td>In0</td>
+ <td>In1</td>
+ <td>Out</td>
+ </tr>
+ <tr>
+ <td>0</td>
+ <td>0</td>
+ <td>0</td>
+ </tr>
+ <tr>
+ <td>0</td>
+ <td>1</td>
+ <td>0</td>
+ </tr>
+ <tr>
+ <td>1</td>
+ <td>0</td>
+ <td>0</td>
+ </tr>
+ <tr>
+ <td>1</td>
+ <td>1</td>
+ <td>1</td>
+ </tr>
+ </tbody>
+</table>
+</div>
+<h5>Example:</h5>
+<pre>
+ <result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
+ <result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
+ <result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
+</pre>
+</div>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
+<div class="doc_text">
+<h5>Syntax:</h5>
+<pre> <result> = or <ty> <var1>, <var2> <i>; yields {ty}:result</i>
+</pre>
+<h5>Overview:</h5>
+<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
+or of its two operands.</p>
+<h5>Arguments:</h5>
+
+<p>The two arguments to the '<tt>or</tt>' instruction must be
+<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
+values. Both arguments must have identical types.</p>
+<h5>Semantics:</h5>
+<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
+<p> </p>
+<div style="align: center">
+<table border="1" cellspacing="0" cellpadding="4">
+ <tbody>
+ <tr>
+ <td>In0</td>
+ <td>In1</td>
+ <td>Out</td>
+ </tr>
+ <tr>
+ <td>0</td>
+ <td>0</td>
+ <td>0</td>
+ </tr>
+ <tr>
+ <td>0</td>
+ <td>1</td>
+ <td>1</td>
+ </tr>
+ <tr>
+ <td>1</td>
+ <td>0</td>
+ <td>1</td>
+ </tr>
+ <tr>
+ <td>1</td>
+ <td>1</td>
+ <td>1</td>
+ </tr>
+ </tbody>
+</table>
+</div>
+<h5>Example:</h5>
+<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
+ <result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
+ <result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
+</pre>
+</div>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
+Instruction</a> </div>
+<div class="doc_text">
+<h5>Syntax:</h5>
+<pre> <result> = xor <ty> <var1>, <var2> <i>; yields {ty}:result</i>
+</pre>
+<h5>Overview:</h5>
+<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
+or of its two operands. The <tt>xor</tt> is used to implement the
+"one's complement" operation, which is the "~" operator in C.</p>
+<h5>Arguments:</h5>
+<p>The two arguments to the '<tt>xor</tt>' instruction must be
+<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
+values. Both arguments must have identical types.</p>
+
+<h5>Semantics:</h5>
+
+<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
+<p> </p>
+<div style="align: center">
+<table border="1" cellspacing="0" cellpadding="4">
+ <tbody>
+ <tr>
+ <td>In0</td>
+ <td>In1</td>
+ <td>Out</td>
+ </tr>
+ <tr>
+ <td>0</td>
+ <td>0</td>
+ <td>0</td>
+ </tr>
+ <tr>
+ <td>0</td>
+ <td>1</td>
+ <td>1</td>
+ </tr>
+ <tr>
+ <td>1</td>
+ <td>0</td>
+ <td>1</td>
+ </tr>
+ <tr>
+ <td>1</td>
+ <td>1</td>
+ <td>0</td>
+ </tr>
+ </tbody>
+</table>
+</div>
+<p> </p>
+<h5>Example:</h5>
+<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
+ <result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
+ <result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
+ <result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
+</pre>
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="vectorops">Vector Operations</a>
+</div>
+
+<div class="doc_text">
+
+<p>LLVM supports several instructions to represent vector operations in a
+target-independent manner. These instructions cover the element-access and
+vector-specific operations needed to process vectors effectively. While LLVM
+does directly support these vector operations, many sophisticated algorithms
+will want to use target-specific intrinsics to take full advantage of a specific
+target.</p>
+
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+
+<pre>
+ <result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
+</pre>
+
+<h5>Overview:</h5>
+
+<p>
+The '<tt>extractelement</tt>' instruction extracts a single scalar
+element from a vector at a specified index.
+</p>
+
+
+<h5>Arguments:</h5>
+
+<p>
+The first operand of an '<tt>extractelement</tt>' instruction is a
+value of <a href="#t_vector">vector</a> type. The second operand is
+an index indicating the position from which to extract the element.
+The index may be a variable.</p>
+
+<h5>Semantics:</h5>
+
+<p>
+The result is a scalar of the same type as the element type of
+<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
+<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
+results are undefined.
+</p>
+
+<h5>Example:</h5>
+
+<pre>
+ %result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
+</pre>
+</div>
+
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+
+<pre>
+ <result> = insertelement <n x <ty>> <val>, <ty> <elt>, i32 <idx> <i>; yields <n x <ty>></i>
+</pre>
+
+<h5>Overview:</h5>
+
+<p>
+The '<tt>insertelement</tt>' instruction inserts a scalar
+element into a vector at a specified index.
+</p>
+
+
+<h5>Arguments:</h5>
+
+<p>
+The first operand of an '<tt>insertelement</tt>' instruction is a
+value of <a href="#t_vector">vector</a> type. The second operand is a
+scalar value whose type must equal the element type of the first
+operand. The third operand is an index indicating the position at
+which to insert the value. The index may be a variable.</p>
+
+<h5>Semantics:</h5>
+
+<p>
+The result is a vector of the same type as <tt>val</tt>. Its
+element values are those of <tt>val</tt> except at position
+<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
+exceeds the length of <tt>val</tt>, the results are undefined.
+</p>
+
+<h5>Example:</h5>
+
+<pre>
+ %result = insertelement <4 x i32> %vec, i32 1, i32 0 <i>; yields <4 x i32></i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+
+<pre>
+ <result> = shufflevector <n x <ty>> <v1>, <n x <ty>> <v2>, <n x i32> <mask> <i>; yields <n x <ty>></i>
+</pre>
+
+<h5>Overview:</h5>
+
+<p>
+The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
+from two input vectors, returning a vector of the same type.
+</p>
+
+<h5>Arguments:</h5>
+
+<p>
+The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
+with types that match each other and types that match the result of the
+instruction. The third argument is a shuffle mask, which has the same number
+of elements as the other vector type, but whose element type is always 'i32'.
+</p>
+
+<p>
+The shuffle mask operand is required to be a constant vector with either
+constant integer or undef values.
+</p>
+
+<h5>Semantics:</h5>
+
+<p>
+The elements of the two input vectors are numbered from left to right across
+both of the vectors. The shuffle mask operand specifies, for each element of
+the result vector, which element of the two input registers the result element
+gets. The element selector may be undef (meaning "don't care") and the second
+operand may be undef if performing a shuffle from only one vector.
+</p>
+
+<h5>Example:</h5>
+
+<pre>
+ %result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
+ <4 x i32> <i32 0, i32 4, i32 1, i32 5> <i>; yields <4 x i32></i>
+ %result = shufflevector <4 x i32> %v1, <4 x i32> undef,
+ <4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i> - Identity shuffle.
+</pre>
+</div>
+
+
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="aggregateops">Aggregate Operations</a>
+</div>
+
+<div class="doc_text">
+
+<p>LLVM supports several instructions for working with aggregate values.
+</p>
+
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+
+<pre>
+ <result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
+</pre>
+
+<h5>Overview:</h5>
+
+<p>
+The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
+or array element from an aggregate value.
+</p>
+
+
+<h5>Arguments:</h5>
+
+<p>
+The first operand of an '<tt>extractvalue</tt>' instruction is a
+value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
+type. The operands are constant indices to specify which value to extract
+in a similar manner as indices in a
+'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
+</p>
+
+<h5>Semantics:</h5>
+
+<p>
+The result is the value at the position in the aggregate specified by
+the index operands.
+</p>
+
+<h5>Example:</h5>
+
+<pre>
+ %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
+</pre>
+</div>
+
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+
+<pre>
+ <result> = insertvalue <aggregate type> <val>, <ty> <val>, <idx> <i>; yields <n x <ty>></i>
+</pre>
+
+<h5>Overview:</h5>
+
+<p>
+The '<tt>insertvalue</tt>' instruction inserts a value
+into a struct field or array element in an aggregate.
+</p>
+
+
+<h5>Arguments:</h5>
+
+<p>
+The first operand of an '<tt>insertvalue</tt>' instruction is a
+value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
+The second operand is a first-class value to insert.
+The following operands are constant indices
+indicating the position at which to insert the value in a similar manner as
+indices in a
+'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
+The value to insert must have the same type as the value identified
+by the indices.
+
+<h5>Semantics:</h5>
+
+<p>
+The result is an aggregate of the same type as <tt>val</tt>. Its
+value is that of <tt>val</tt> except that the value at the position
+specified by the indices is that of <tt>elt</tt>.
+</p>
+
+<h5>Example:</h5>
+
+<pre>
+ %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
+</pre>
+</div>
+
+
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="memoryops">Memory Access and Addressing Operations</a>
+</div>
+
+<div class="doc_text">
+
+<p>A key design point of an SSA-based representation is how it
+represents memory. In LLVM, no memory locations are in SSA form, which
+makes things very simple. This section describes how to read, write,
+allocate, and free memory in LLVM.</p>
+
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+
+<pre>
+ <result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>malloc</tt>' instruction allocates memory from the system
+heap and returns a pointer to it. The object is always allocated in the generic
+address space (address space zero).</p>
+
+<h5>Arguments:</h5>
+
+<p>The '<tt>malloc</tt>' instruction allocates
+<tt>sizeof(<type>)*NumElements</tt>
+bytes of memory from the operating system and returns a pointer of the
+appropriate type to the program. If "NumElements" is specified, it is the
+number of elements allocated, otherwise "NumElements" is defaulted to be one.
+If a constant alignment is specified, the value result of the allocation is guaranteed to
+be aligned to at least that boundary. If not specified, or if zero, the target can
+choose to align the allocation on any convenient boundary.</p>
+
+<p>'<tt>type</tt>' must be a sized type.</p>
+
+<h5>Semantics:</h5>
+
+<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
+a pointer is returned. The result of a zero byte allocattion is undefined. The
+result is null if there is insufficient memory available.</p>
+
+<h5>Example:</h5>
+
+<pre>
+ %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
+
+ %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
+ %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
+ %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
+ %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
+ %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_free">'<tt>free</tt>' Instruction</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+
+<pre>
+ free <type> <value> <i>; yields {void}</i>
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>free</tt>' instruction returns memory back to the unused
+memory heap to be reallocated in the future.</p>
+
+<h5>Arguments:</h5>
+
+<p>'<tt>value</tt>' shall be a pointer value that points to a value
+that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
+instruction.</p>
+
+<h5>Semantics:</h5>
+
+<p>Access to the memory pointed to by the pointer is no longer defined
+after this instruction executes. If the pointer is null, the operation
+is a noop.</p>
+
+<h5>Example:</h5>
+
+<pre>
+ %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
+ free [4 x i8]* %array
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+
+<pre>
+ <result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
+currently executing function, to be automatically released when this function
+returns to its caller. The object is always allocated in the generic address
+space (address space zero).</p>
+
+<h5>Arguments:</h5>
+
+<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
+bytes of memory on the runtime stack, returning a pointer of the
+appropriate type to the program. If "NumElements" is specified, it is the
+number of elements allocated, otherwise "NumElements" is defaulted to be one.
+If a constant alignment is specified, the value result of the allocation is guaranteed
+to be aligned to at least that boundary. If not specified, or if zero, the target
+can choose to align the allocation on any convenient boundary.</p>
+
+<p>'<tt>type</tt>' may be any sized type.</p>
+
+<h5>Semantics:</h5>
+
+<p>Memory is allocated; a pointer is returned. The operation is undefiend if
+there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
+memory is automatically released when the function returns. The '<tt>alloca</tt>'
+instruction is commonly used to represent automatic variables that must
+have an address available. When the function returns (either with the <tt><a
+ href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt>
+instructions), the memory is reclaimed. Allocating zero bytes
+is legal, but the result is undefined.</p>
+
+<h5>Example:</h5>
+
+<pre>
+ %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
+ %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
+ %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
+ %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
+Instruction</a> </div>
+<div class="doc_text">
+<h5>Syntax:</h5>
+<pre> <result> = load <ty>* <pointer>[, align <alignment>]<br> <result> = volatile load <ty>* <pointer>[, align <alignment>]<br></pre>
+<h5>Overview:</h5>
+<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
+<h5>Arguments:</h5>
+<p>The argument to the '<tt>load</tt>' instruction specifies the memory
+address from which to load. The pointer must point to a <a
+ href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
+marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
+the number or order of execution of this <tt>load</tt> with other
+volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
+instructions. </p>
+<p>
+The optional constant "align" argument specifies the alignment of the operation
+(that is, the alignment of the memory address). A value of 0 or an
+omitted "align" argument means that the operation has the preferential
+alignment for the target. It is the responsibility of the code emitter
+to ensure that the alignment information is correct. Overestimating
+the alignment results in an undefined behavior. Underestimating the
+alignment may produce less efficient code. An alignment of 1 is always
+safe.
+</p>
+<h5>Semantics:</h5>
+<p>The location of memory pointed to is loaded.</p>
+<h5>Examples:</h5>
+<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
+ <a
+ href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
+ %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
+</pre>
+</div>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
+Instruction</a> </div>
+<div class="doc_text">
+<h5>Syntax:</h5>
+<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
+ volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
+</pre>
+<h5>Overview:</h5>
+<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
+<h5>Arguments:</h5>
+<p>There are two arguments to the '<tt>store</tt>' instruction: a value
+to store and an address at which to store it. The type of the '<tt><pointer></tt>'
+operand must be a pointer to the <a href="#t_firstclass">first class</a> type
+of the '<tt><value></tt>'
+operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
+optimizer is not allowed to modify the number or order of execution of
+this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
+ href="#i_store">store</a></tt> instructions.</p>
+<p>
+The optional constant "align" argument specifies the alignment of the operation
+(that is, the alignment of the memory address). A value of 0 or an
+omitted "align" argument means that the operation has the preferential
+alignment for the target. It is the responsibility of the code emitter
+to ensure that the alignment information is correct. Overestimating
+the alignment results in an undefined behavior. Underestimating the
+alignment may produce less efficient code. An alignment of 1 is always
+safe.
+</p>
+<h5>Semantics:</h5>
+<p>The contents of memory are updated to contain '<tt><value></tt>'
+at the location specified by the '<tt><pointer></tt>' operand.</p>
+<h5>Example:</h5>
+<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
+ store i32 3, i32* %ptr <i>; yields {void}</i>
+ %val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
+</div>
+
+<div class="doc_text">
+<h5>Syntax:</h5>
+<pre>
+ <result> = getelementptr <ty>* <ptrval>{, <ty> <idx>}*
+</pre>
+
+<h5>Overview:</h5>
+
+<p>
+The '<tt>getelementptr</tt>' instruction is used to get the address of a
+subelement of an aggregate data structure.</p>
+
+<h5>Arguments:</h5>
+
+<p>This instruction takes a list of integer operands that indicate what
+elements of the aggregate object to index to. The actual types of the arguments
+provided depend on the type of the first pointer argument. The
+'<tt>getelementptr</tt>' instruction is used to index down through the type
+levels of a structure or to a specific index in an array. When indexing into a
+structure, only <tt>i32</tt> integer constants are allowed. When indexing
+into an array or pointer, only integers of 32 or 64 bits are allowed; 32-bit
+values will be sign extended to 64-bits if required.</p>
+
+<p>For example, let's consider a C code fragment and how it gets
+compiled to LLVM:</p>
+
+<div class="doc_code">
+<pre>
+struct RT {
+ char A;
+ int B[10][20];
+ char C;
+};
+struct ST {
+ int X;
+ double Y;
+ struct RT Z;
+};
+
+int *foo(struct ST *s) {
+ return &s[1].Z.B[5][13];
+}
+</pre>
+</div>
+
+<p>The LLVM code generated by the GCC frontend is:</p>
+
+<div class="doc_code">
+<pre>
+%RT = type { i8 , [10 x [20 x i32]], i8 }
+%ST = type { i32, double, %RT }
+
+define i32* %foo(%ST* %s) {
+entry:
+ %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
+ ret i32* %reg
+}
+</pre>
+</div>
+
+<h5>Semantics:</h5>
+
+<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
+on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
+and <a href="#t_array">array</a> types can use a 32-bit or 64-bit
+<a href="#t_integer">integer</a> type but the value will always be sign extended
+to 64-bits. <a href="#t_struct">Structure</a> and <a href="#t_pstruct">packed
+structure</a> types require <tt>i32</tt> <b>constants</b>.</p>
+
+<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
+type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
+}</tt>' type, a structure. The second index indexes into the third element of
+the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
+i8 }</tt>' type, another structure. The third index indexes into the second
+element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
+array. The two dimensions of the array are subscripted into, yielding an
+'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
+to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
+
+<p>Note that it is perfectly legal to index partially through a
+structure, returning a pointer to an inner element. Because of this,
+the LLVM code for the given testcase is equivalent to:</p>
+
+<pre>
+ define i32* %foo(%ST* %s) {
+ %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
+ %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
+ %t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
+ %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
+ %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
+ ret i32* %t5
+ }
+</pre>
+
+<p>Note that it is undefined to access an array out of bounds: array and
+pointer indexes must always be within the defined bounds of the array type.
+The one exception for this rule is zero length arrays. These arrays are
+defined to be accessible as variable length arrays, which requires access
+beyond the zero'th element.</p>
+
+<p>The getelementptr instruction is often confusing. For some more insight
+into how it works, see <a href="GetElementPtr.html">the getelementptr
+FAQ</a>.</p>
+
+<h5>Example:</h5>
+
+<pre>
+ <i>; yields [12 x i8]*:aptr</i>
+ %aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
+</pre>
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
+</div>
+<div class="doc_text">
+<p>The instructions in this category are the conversion instructions (casting)
+which all take a single operand and a type. They perform various bit conversions
+on the operand.</p>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
+</div>
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre>
+ <result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
+</pre>
+
+<h5>Overview:</h5>
+<p>
+The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
+</p>
+
+<h5>Arguments:</h5>
+<p>
+The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
+be an <a href="#t_integer">integer</a> type, and a type that specifies the size
+and type of the result, which must be an <a href="#t_integer">integer</a>
+type. The bit size of <tt>value</tt> must be larger than the bit size of
+<tt>ty2</tt>. Equal sized types are not allowed.</p>
+
+<h5>Semantics:</h5>
+<p>
+The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
+and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
+larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
+It will always truncate bits.</p>
+
+<h5>Example:</h5>
+<pre>
+ %X = trunc i32 257 to i8 <i>; yields i8:1</i>
+ %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
+ %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
+</div>
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre>
+ <result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
+</pre>
+
+<h5>Overview:</h5>
+<p>The '<tt>zext</tt>' instruction zero extends its operand to type
+<tt>ty2</tt>.</p>
+
+
+<h5>Arguments:</h5>
+<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
+<a href="#t_integer">integer</a> type, and a type to cast it to, which must
+also be of <a href="#t_integer">integer</a> type. The bit size of the
+<tt>value</tt> must be smaller than the bit size of the destination type,
+<tt>ty2</tt>.</p>
+
+<h5>Semantics:</h5>
+<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
+bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
+
+<p>When zero extending from i1, the result will always be either 0 or 1.</p>
+
+<h5>Example:</h5>
+<pre>
+ %X = zext i32 257 to i64 <i>; yields i64:257</i>
+ %Y = zext i1 true to i32 <i>; yields i32:1</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
+</div>
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre>
+ <result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
+</pre>
+
+<h5>Overview:</h5>
+<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
+
+<h5>Arguments:</h5>
+<p>
+The '<tt>sext</tt>' instruction takes a value to cast, which must be of
+<a href="#t_integer">integer</a> type, and a type to cast it to, which must
+also be of <a href="#t_integer">integer</a> type. The bit size of the
+<tt>value</tt> must be smaller than the bit size of the destination type,
+<tt>ty2</tt>.</p>
+
+<h5>Semantics:</h5>
+<p>
+The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
+bit (highest order bit) of the <tt>value</tt> until it reaches the bit size of
+the type <tt>ty2</tt>.</p>
+
+<p>When sign extending from i1, the extension always results in -1 or 0.</p>
+
+<h5>Example:</h5>
+<pre>
+ %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
+ %Y = sext i1 true to i32 <i>; yields i32:-1</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+
+<pre>
+ <result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
+</pre>
+
+<h5>Overview:</h5>
+<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
+<tt>ty2</tt>.</p>
+
+
+<h5>Arguments:</h5>
+<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
+ point</a> value to cast and a <a href="#t_floating">floating point</a> type to
+cast it to. The size of <tt>value</tt> must be larger than the size of
+<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
+<i>no-op cast</i>.</p>
+
+<h5>Semantics:</h5>
+<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
+<a href="#t_floating">floating point</a> type to a smaller
+<a href="#t_floating">floating point</a> type. If the value cannot fit within
+the destination type, <tt>ty2</tt>, then the results are undefined.</p>
+
+<h5>Example:</h5>
+<pre>
+ %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
+ %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
+</div>
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre>
+ <result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
+</pre>
+
+<h5>Overview:</h5>
+<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
+floating point value.</p>
+
+<h5>Arguments:</h5>
+<p>The '<tt>fpext</tt>' instruction takes a
+<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
+and a <a href="#t_floating">floating point</a> type to cast it to. The source
+type must be smaller than the destination type.</p>
+
+<h5>Semantics:</h5>
+<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
+<a href="#t_floating">floating point</a> type to a larger
+<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
+used to make a <i>no-op cast</i> because it always changes bits. Use
+<tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
+
+<h5>Example:</h5>
+<pre>
+ %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
+ %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
+</div>
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre>
+ <result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
+</pre>
+
+<h5>Overview:</h5>
+<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
+unsigned integer equivalent of type <tt>ty2</tt>.
+</p>
+
+<h5>Arguments:</h5>
+<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
+scalar or vector <a href="#t_floating">floating point</a> value, and a type
+to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
+type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
+vector integer type with the same number of elements as <tt>ty</tt></p>
+
+<h5>Semantics:</h5>
+<p> The '<tt>fptoui</tt>' instruction converts its
+<a href="#t_floating">floating point</a> operand into the nearest (rounding
+towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
+the results are undefined.</p>
+
+<h5>Example:</h5>
+<pre>
+ %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
+ %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
+ %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
+</div>
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre>
+ <result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
+</pre>
+
+<h5>Overview:</h5>
+<p>The '<tt>fptosi</tt>' instruction converts
+<a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>.
+</p>
+
+<h5>Arguments:</h5>
+<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
+scalar or vector <a href="#t_floating">floating point</a> value, and a type
+to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
+type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
+vector integer type with the same number of elements as <tt>ty</tt></p>
+
+<h5>Semantics:</h5>
+<p>The '<tt>fptosi</tt>' instruction converts its
+<a href="#t_floating">floating point</a> operand into the nearest (rounding
+towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
+the results are undefined.</p>
+
+<h5>Example:</h5>
+<pre>
+ %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
+ %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
+ %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
+</div>
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre>
+ <result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
+</pre>
+
+<h5>Overview:</h5>
+<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
+integer and converts that value to the <tt>ty2</tt> type.</p>
+
+<h5>Arguments:</h5>
+<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
+scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
+to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
+type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
+floating point type with the same number of elements as <tt>ty</tt></p>
+
+<h5>Semantics:</h5>
+<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
+integer quantity and converts it to the corresponding floating point value. If
+the value cannot fit in the floating point value, the results are undefined.</p>
+
+<h5>Example:</h5>
+<pre>
+ %X = uitofp i32 257 to float <i>; yields float:257.0</i>
+ %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
+</div>
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre>
+ <result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
+</pre>
+
+<h5>Overview:</h5>
+<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
+integer and converts that value to the <tt>ty2</tt> type.</p>
+
+<h5>Arguments:</h5>
+<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
+scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
+to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
+type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
+floating point type with the same number of elements as <tt>ty</tt></p>
+
+<h5>Semantics:</h5>
+<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
+integer quantity and converts it to the corresponding floating point value. If
+the value cannot fit in the floating point value, the results are undefined.</p>
+
+<h5>Example:</h5>
+<pre>
+ %X = sitofp i32 257 to float <i>; yields float:257.0</i>
+ %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
+</div>
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre>
+ <result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
+</pre>
+
+<h5>Overview:</h5>
+<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
+the integer type <tt>ty2</tt>.</p>
+
+<h5>Arguments:</h5>
+<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
+must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
+<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
+
+<h5>Semantics:</h5>
+<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
+<tt>ty2</tt> by interpreting the pointer value as an integer and either
+truncating or zero extending that value to the size of the integer type. If
+<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
+<tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
+are the same size, then nothing is done (<i>no-op cast</i>) other than a type
+change.</p>
+
+<h5>Example:</h5>
+<pre>
+ %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
+ %Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
+</div>
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre>
+ <result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
+</pre>
+
+<h5>Overview:</h5>
+<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
+a pointer type, <tt>ty2</tt>.</p>
+
+<h5>Arguments:</h5>
+<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
+value to cast, and a type to cast it to, which must be a
+<a href="#t_pointer">pointer</a> type.
+
+<h5>Semantics:</h5>
+<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
+<tt>ty2</tt> by applying either a zero extension or a truncation depending on
+the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
+size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
+the size of a pointer then a zero extension is done. If they are the same size,
+nothing is done (<i>no-op cast</i>).</p>
+
+<h5>Example:</h5>
+<pre>
+ %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
+ %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
+ %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
+</div>
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+<pre>
+ <result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
+<tt>ty2</tt> without changing any bits.</p>
+
+<h5>Arguments:</h5>
+
+<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
+a first class value, and a type to cast it to, which must also be a <a
+ href="#t_firstclass">first class</a> type. The bit sizes of <tt>value</tt>
+and the destination type, <tt>ty2</tt>, must be identical. If the source
+type is a pointer, the destination type must also be a pointer. This
+instruction supports bitwise conversion of vectors to integers and to vectors
+of other types (as long as they have the same size).</p>
+
+<h5>Semantics:</h5>
+<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
+<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
+this conversion. The conversion is done as if the <tt>value</tt> had been
+stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
+converted to other pointer types with this instruction. To convert pointers to
+other types, use the <a href="#i_inttoptr">inttoptr</a> or
+<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
+
+<h5>Example:</h5>
+<pre>
+ %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
+ %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
+ %Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
+</pre>
+</div>
+
<!-- ======================================================================= -->
-<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
+<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
<div class="doc_text">
-<p>Binary operators are used to do most of the computation in a
-program. They require two operands, execute an operation on them, and
-produce a single value. The result value of a binary operator is not
-necessarily the same type as its operands.</p>
-<p>There are several different binary operators:</p>
+<p>The instructions in this category are the "miscellaneous"
+instructions, which defy better classification.</p>
</div>
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_add">'<tt>add</tt>'
-Instruction</a> </div>
+<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
+</div>
+<div class="doc_text">
+<h5>Syntax:</h5>
+<pre> <result> = icmp <cond> <ty> <var1>, <var2> <i>; yields {i1}:result</i>
+</pre>
+<h5>Overview:</h5>
+<p>The '<tt>icmp</tt>' instruction returns a boolean value based on comparison
+of its two integer or pointer operands.</p>
+<h5>Arguments:</h5>
+<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
+the condition code indicating the kind of comparison to perform. It is not
+a value, just a keyword. The possible condition code are:
+<ol>
+ <li><tt>eq</tt>: equal</li>
+ <li><tt>ne</tt>: not equal </li>
+ <li><tt>ugt</tt>: unsigned greater than</li>
+ <li><tt>uge</tt>: unsigned greater or equal</li>
+ <li><tt>ult</tt>: unsigned less than</li>
+ <li><tt>ule</tt>: unsigned less or equal</li>
+ <li><tt>sgt</tt>: signed greater than</li>
+ <li><tt>sge</tt>: signed greater or equal</li>
+ <li><tt>slt</tt>: signed less than</li>
+ <li><tt>sle</tt>: signed less or equal</li>
+</ol>
+<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
+<a href="#t_pointer">pointer</a> typed. They must also be identical types.</p>
+<h5>Semantics:</h5>
+<p>The '<tt>icmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
+the condition code given as <tt>cond</tt>. The comparison performed always
+yields a <a href="#t_primitive">i1</a> result, as follows:
+<ol>
+ <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
+ <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
+ </li>
+ <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
+ <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
+ <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
+ <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
+ <li><tt>uge</tt>: interprets the operands as unsigned values and yields
+ <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
+ <li><tt>ult</tt>: interprets the operands as unsigned values and yields
+ <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
+ <li><tt>ule</tt>: interprets the operands as unsigned values and yields
+ <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
+ <li><tt>sgt</tt>: interprets the operands as signed values and yields
+ <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
+ <li><tt>sge</tt>: interprets the operands as signed values and yields
+ <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
+ <li><tt>slt</tt>: interprets the operands as signed values and yields
+ <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
+ <li><tt>sle</tt>: interprets the operands as signed values and yields
+ <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
+</ol>
+<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
+values are compared as if they were integers.</p>
+
+<h5>Example:</h5>
+<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
+ <result> = icmp ne float* %X, %X <i>; yields: result=false</i>
+ <result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
+ <result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
+ <result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
+ <result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
+</div>
<div class="doc_text">
<h5>Syntax:</h5>
-<pre> <result> = add <ty> <var1>, <var2> <i>; yields {ty}:result</i>
+<pre> <result> = fcmp <cond> <ty> <var1>, <var2> <i>; yields {i1}:result</i>
</pre>
<h5>Overview:</h5>
-<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
+<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
+of its floating point operands.</p>
<h5>Arguments:</h5>
-<p>The two arguments to the '<tt>add</tt>' instruction must be either <a
- href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
-values. Both arguments must have identical types.</p>
+<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
+the condition code indicating the kind of comparison to perform. It is not
+a value, just a keyword. The possible condition code are:
+<ol>
+ <li><tt>false</tt>: no comparison, always returns false</li>
+ <li><tt>oeq</tt>: ordered and equal</li>
+ <li><tt>ogt</tt>: ordered and greater than </li>
+ <li><tt>oge</tt>: ordered and greater than or equal</li>
+ <li><tt>olt</tt>: ordered and less than </li>
+ <li><tt>ole</tt>: ordered and less than or equal</li>
+ <li><tt>one</tt>: ordered and not equal</li>
+ <li><tt>ord</tt>: ordered (no nans)</li>
+ <li><tt>ueq</tt>: unordered or equal</li>
+ <li><tt>ugt</tt>: unordered or greater than </li>
+ <li><tt>uge</tt>: unordered or greater than or equal</li>
+ <li><tt>ult</tt>: unordered or less than </li>
+ <li><tt>ule</tt>: unordered or less than or equal</li>
+ <li><tt>une</tt>: unordered or not equal</li>
+ <li><tt>uno</tt>: unordered (either nans)</li>
+ <li><tt>true</tt>: no comparison, always returns true</li>
+</ol>
+<p><i>Ordered</i> means that neither operand is a QNAN while
+<i>unordered</i> means that either operand may be a QNAN.</p>
+<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
+<a href="#t_floating">floating point</a> typed. They must have identical
+types.</p>
<h5>Semantics:</h5>
-<p>The value produced is the integer or floating point sum of the two
-operands.</p>
+<p>The '<tt>fcmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
+according to the condition code given as <tt>cond</tt>. The comparison performed
+always yields a <a href="#t_primitive">i1</a> result, as follows:
+<ol>
+ <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
+ <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
+ <tt>var1</tt> is equal to <tt>var2</tt>.</li>
+ <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
+ <tt>var1</tt> is greather than <tt>var2</tt>.</li>
+ <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
+ <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
+ <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
+ <tt>var1</tt> is less than <tt>var2</tt>.</li>
+ <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
+ <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
+ <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
+ <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
+ <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
+ <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
+ <tt>var1</tt> is equal to <tt>var2</tt>.</li>
+ <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
+ <tt>var1</tt> is greater than <tt>var2</tt>.</li>
+ <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
+ <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
+ <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
+ <tt>var1</tt> is less than <tt>var2</tt>.</li>
+ <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
+ <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
+ <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
+ <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
+ <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
+ <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
+</ol>
+
<h5>Example:</h5>
-<pre> <result> = add int 4, %var <i>; yields {int}:result = 4 + %var</i>
+<pre> <result> = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
+ <result> = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
+ <result> = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
+ <result> = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
</pre>
</div>
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_sub">'<tt>sub</tt>'
-Instruction</a> </div>
+<div class="doc_subsubsection">
+ <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
+</div>
<div class="doc_text">
<h5>Syntax:</h5>
-<pre> <result> = sub <ty> <var1>, <var2> <i>; yields {ty}:result</i>
+<pre> <result> = vicmp <cond> <ty> <var1>, <var2> <i>; yields {ty}:result</i>
</pre>
<h5>Overview:</h5>
-<p>The '<tt>sub</tt>' instruction returns the difference of its two
-operands.</p>
-<p>Note that the '<tt>sub</tt>' instruction is used to represent the '<tt>neg</tt>'
-instruction present in most other intermediate representations.</p>
+<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
+element-wise comparison of its two integer vector operands.</p>
<h5>Arguments:</h5>
-<p>The two arguments to the '<tt>sub</tt>' instruction must be either <a
- href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
-values. Both arguments must have identical types.</p>
+<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
+the condition code indicating the kind of comparison to perform. It is not
+a value, just a keyword. The possible condition code are:
+<ol>
+ <li><tt>eq</tt>: equal</li>
+ <li><tt>ne</tt>: not equal </li>
+ <li><tt>ugt</tt>: unsigned greater than</li>
+ <li><tt>uge</tt>: unsigned greater or equal</li>
+ <li><tt>ult</tt>: unsigned less than</li>
+ <li><tt>ule</tt>: unsigned less or equal</li>
+ <li><tt>sgt</tt>: signed greater than</li>
+ <li><tt>sge</tt>: signed greater or equal</li>
+ <li><tt>slt</tt>: signed less than</li>
+ <li><tt>sle</tt>: signed less or equal</li>
+</ol>
+<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
+<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
<h5>Semantics:</h5>
-<p>The value produced is the integer or floating point difference of
-the two operands.</p>
+<p>The '<tt>vicmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
+according to the condition code given as <tt>cond</tt>. The comparison yields a
+<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
+identical type as the values being compared. The most significant bit in each
+element is 1 if the element-wise comparison evaluates to true, and is 0
+otherwise. All other bits of the result are undefined. The condition codes
+are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
+instruction</a>.
+
<h5>Example:</h5>
-<pre> <result> = sub int 4, %var <i>; yields {int}:result = 4 - %var</i>
- <result> = sub int 0, %val <i>; yields {int}:result = -%var</i>
+<pre>
+ <result> = vicmp eq <2 x i32> < i32 4, i32 0>, < i32 5, i32 0> <i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
+ <result> = vicmp ult <2 x i8 > < i8 1, i8 2>, < i8 2, i8 2 > <i>; yields: result=<2 x i8> < i8 -1, i8 0 ></i>
</pre>
</div>
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_mul">'<tt>mul</tt>'
-Instruction</a> </div>
+<div class="doc_subsubsection">
+ <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
+</div>
<div class="doc_text">
<h5>Syntax:</h5>
-<pre> <result> = mul <ty> <var1>, <var2> <i>; yields {ty}:result</i>
-</pre>
+<pre> <result> = vfcmp <cond> <ty> <var1>, <var2></pre>
<h5>Overview:</h5>
-<p>The '<tt>mul</tt>' instruction returns the product of its two
-operands.</p>
+<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
+element-wise comparison of its two floating point vector operands. The output
+elements have the same width as the input elements.</p>
<h5>Arguments:</h5>
-<p>The two arguments to the '<tt>mul</tt>' instruction must be either <a
- href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
-values. Both arguments must have identical types.</p>
+<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
+the condition code indicating the kind of comparison to perform. It is not
+a value, just a keyword. The possible condition code are:
+<ol>
+ <li><tt>false</tt>: no comparison, always returns false</li>
+ <li><tt>oeq</tt>: ordered and equal</li>
+ <li><tt>ogt</tt>: ordered and greater than </li>
+ <li><tt>oge</tt>: ordered and greater than or equal</li>
+ <li><tt>olt</tt>: ordered and less than </li>
+ <li><tt>ole</tt>: ordered and less than or equal</li>
+ <li><tt>one</tt>: ordered and not equal</li>
+ <li><tt>ord</tt>: ordered (no nans)</li>
+ <li><tt>ueq</tt>: unordered or equal</li>
+ <li><tt>ugt</tt>: unordered or greater than </li>
+ <li><tt>uge</tt>: unordered or greater than or equal</li>
+ <li><tt>ult</tt>: unordered or less than </li>
+ <li><tt>ule</tt>: unordered or less than or equal</li>
+ <li><tt>une</tt>: unordered or not equal</li>
+ <li><tt>uno</tt>: unordered (either nans)</li>
+ <li><tt>true</tt>: no comparison, always returns true</li>
+</ol>
+<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
+<a href="#t_floating">floating point</a> typed. They must also be identical
+types.</p>
<h5>Semantics:</h5>
-<p>The value produced is the integer or floating point product of the
-two operands.</p>
-<p>There is no signed vs unsigned multiplication. The appropriate
-action is taken based on the type of the operand.</p>
+<p>The '<tt>vfcmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
+according to the condition code given as <tt>cond</tt>. The comparison yields a
+<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
+an identical number of elements as the values being compared, and each element
+having identical with to the width of the floating point elements. The most
+significant bit in each element is 1 if the element-wise comparison evaluates to
+true, and is 0 otherwise. All other bits of the result are undefined. The
+condition codes are evaluated identically to the
+<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
+
<h5>Example:</h5>
-<pre> <result> = mul int 4, %var <i>; yields {int}:result = 4 * %var</i>
+<pre>
+ <result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 > <i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
+ <result> = vfcmp ult <2 x double> < double 1, double 2 >, < double 2, double 2> <i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
</pre>
</div>
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_div">'<tt>div</tt>'
-Instruction</a> </div>
+<div class="doc_subsubsection">
+ <a name="i_phi">'<tt>phi</tt>' Instruction</a>
+</div>
+
<div class="doc_text">
+
<h5>Syntax:</h5>
-<pre> <result> = div <ty> <var1>, <var2> <i>; yields {ty}:result</i>
-</pre>
+
+<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
<h5>Overview:</h5>
-<p>The '<tt>div</tt>' instruction returns the quotient of its two
-operands.</p>
+<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
+the SSA graph representing the function.</p>
<h5>Arguments:</h5>
-<p>The two arguments to the '<tt>div</tt>' instruction must be either <a
- href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
-values. Both arguments must have identical types.</p>
+
+<p>The type of the incoming values is specified with the first type
+field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
+as arguments, with one pair for each predecessor basic block of the
+current block. Only values of <a href="#t_firstclass">first class</a>
+type may be used as the value arguments to the PHI node. Only labels
+may be used as the label arguments.</p>
+
+<p>There must be no non-phi instructions between the start of a basic
+block and the PHI instructions: i.e. PHI instructions must be first in
+a basic block.</p>
+
<h5>Semantics:</h5>
-<p>The value produced is the integer or floating point quotient of the
-two operands.</p>
+
+<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
+specified by the pair corresponding to the predecessor basic block that executed
+just prior to the current block.</p>
+
<h5>Example:</h5>
-<pre> <result> = div int 4, %var <i>; yields {int}:result = 4 / %var</i>
+<pre>
+Loop: ; Infinite loop that counts from 0 on up...
+ %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
+ %nextindvar = add i32 %indvar, 1
+ br label %Loop
</pre>
</div>
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_rem">'<tt>rem</tt>'
-Instruction</a> </div>
+<div class="doc_subsubsection">
+ <a name="i_select">'<tt>select</tt>' Instruction</a>
+</div>
+
<div class="doc_text">
+
<h5>Syntax:</h5>
-<pre> <result> = rem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
+
+<pre>
+ <result> = select i1 <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
</pre>
+
<h5>Overview:</h5>
-<p>The '<tt>rem</tt>' instruction returns the remainder from the
-division of its two operands.</p>
+
+<p>
+The '<tt>select</tt>' instruction is used to choose one value based on a
+condition, without branching.
+</p>
+
+
<h5>Arguments:</h5>
-<p>The two arguments to the '<tt>rem</tt>' instruction must be either <a
- href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
-values. Both arguments must have identical types.</p>
+
+<p>
+The '<tt>select</tt>' instruction requires an 'i1' value indicating the
+condition, and two values of the same <a href="#t_firstclass">first class</a>
+type. If the val1/val2 are vectors, the entire vectors are selected, not
+individual elements.
+</p>
+
<h5>Semantics:</h5>
-<p>This returns the <i>remainder</i> of a division (where the result
-has the same sign as the divisor), not the <i>modulus</i> (where the
-result has the same sign as the dividend) of a value. For more
-information about the difference, see: <a
- href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
-Math Forum</a>.</p>
+
+<p>
+If the i1 condition evaluates is 1, the instruction returns the first
+value argument; otherwise, it returns the second value argument.
+</p>
+
<h5>Example:</h5>
-<pre> <result> = rem int 4, %var <i>; yields {int}:result = 4 % %var</i>
+
+<pre>
+ %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
</pre>
</div>
+
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_setcc">'<tt>set<i>cc</i></tt>'
-Instructions</a> </div>
+<div class="doc_subsubsection">
+ <a name="i_call">'<tt>call</tt>' Instruction</a>
+</div>
+
<div class="doc_text">
+
<h5>Syntax:</h5>
-<pre> <result> = seteq <ty> <var1>, <var2> <i>; yields {bool}:result</i>
- <result> = setne <ty> <var1>, <var2> <i>; yields {bool}:result</i>
- <result> = setlt <ty> <var1>, <var2> <i>; yields {bool}:result</i>
- <result> = setgt <ty> <var1>, <var2> <i>; yields {bool}:result</i>
- <result> = setle <ty> <var1>, <var2> <i>; yields {bool}:result</i>
- <result> = setge <ty> <var1>, <var2> <i>; yields {bool}:result</i>
+<pre>
+ <result> = [tail] call [<a href="#callingconv">cconv</a>] <ty> [<fnty>*] <fnptrval>(<param list>)
</pre>
+
<h5>Overview:</h5>
-<p>The '<tt>set<i>cc</i></tt>' family of instructions returns a boolean
-value based on a comparison of their two operands.</p>
+
+<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
+
<h5>Arguments:</h5>
-<p>The two arguments to the '<tt>set<i>cc</i></tt>' instructions must
-be of <a href="#t_firstclass">first class</a> type (it is not possible
-to compare '<tt>label</tt>'s, '<tt>array</tt>'s, '<tt>structure</tt>'
-or '<tt>void</tt>' values, etc...). Both arguments must have identical
-types.</p>
+
+<p>This instruction requires several arguments:</p>
+
+<ol>
+ <li>
+ <p>The optional "tail" marker indicates whether the callee function accesses
+ any allocas or varargs in the caller. If the "tail" marker is present, the
+ function call is eligible for tail call optimization. Note that calls may
+ be marked "tail" even if they do not occur before a <a
+ href="#i_ret"><tt>ret</tt></a> instruction.
+ </li>
+ <li>
+ <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
+ convention</a> the call should use. If none is specified, the call defaults
+ to using C calling conventions.
+ </li>
+ <li>
+ <p>'<tt>ty</tt>': the type of the call instruction itself which is also
+ the type of the return value. Functions that return no value are marked
+ <tt><a href="#t_void">void</a></tt>.</p>
+ </li>
+ <li>
+ <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
+ value being invoked. The argument types must match the types implied by
+ this signature. This type can be omitted if the function is not varargs
+ and if the function type does not return a pointer to a function.</p>
+ </li>
+ <li>
+ <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
+ be invoked. In most cases, this is a direct function invocation, but
+ indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
+ to function value.</p>
+ </li>
+ <li>
+ <p>'<tt>function args</tt>': argument list whose types match the
+ function signature argument types. All arguments must be of
+ <a href="#t_firstclass">first class</a> type. If the function signature
+ indicates the function accepts a variable number of arguments, the extra
+ arguments can be specified.</p>
+ </li>
+</ol>
+
<h5>Semantics:</h5>
-<p>The '<tt>seteq</tt>' instruction yields a <tt>true</tt> '<tt>bool</tt>'
-value if both operands are equal.<br>
-The '<tt>setne</tt>' instruction yields a <tt>true</tt> '<tt>bool</tt>'
-value if both operands are unequal.<br>
-The '<tt>setlt</tt>' instruction yields a <tt>true</tt> '<tt>bool</tt>'
-value if the first operand is less than the second operand.<br>
-The '<tt>setgt</tt>' instruction yields a <tt>true</tt> '<tt>bool</tt>'
-value if the first operand is greater than the second operand.<br>
-The '<tt>setle</tt>' instruction yields a <tt>true</tt> '<tt>bool</tt>'
-value if the first operand is less than or equal to the second operand.<br>
-The '<tt>setge</tt>' instruction yields a <tt>true</tt> '<tt>bool</tt>'
-value if the first operand is greater than or equal to the second
-operand.</p>
+
+<p>The '<tt>call</tt>' instruction is used to cause control flow to
+transfer to a specified function, with its incoming arguments bound to
+the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
+instruction in the called function, control flow continues with the
+instruction after the function call, and the return value of the
+function is bound to the result argument. If the callee returns multiple
+values then the return values of the function are only accessible through
+the '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
+
<h5>Example:</h5>
-<pre> <result> = seteq int 4, 5 <i>; yields {bool}:result = false</i>
- <result> = setne float 4, 5 <i>; yields {bool}:result = true</i>
- <result> = setlt uint 4, 5 <i>; yields {bool}:result = true</i>
- <result> = setgt sbyte 4, 5 <i>; yields {bool}:result = false</i>
- <result> = setle sbyte 4, 5 <i>; yields {bool}:result = true</i>
- <result> = setge sbyte 4, 5 <i>; yields {bool}:result = false</i>
+
+<pre>
+ %retval = call i32 @test(i32 %argc)
+ call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
+ %X = tail call i32 @foo() <i>; yields i32</i>
+ %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
+ call void %foo(i8 97 signext)
+
+ %struct.A = type { i32, i8 }
+ %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
+ %gr = getresult %struct.A %r, 0 <i>; yields i32</i>
+ %gr1 = getresult %struct.A %r, 1 <i>; yields i8</i>
</pre>
+
</div>
-<!-- ======================================================================= -->
-<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
-Operations</a> </div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
+</div>
+
<div class="doc_text">
-<p>Bitwise binary operators are used to do various forms of
-bit-twiddling in a program. They are generally very efficient
-instructions, and can commonly be strength reduced from other
-instructions. They require two operands, execute an operation on them,
-and produce a single value. The resulting value of the bitwise binary
-operators is always the same type as its first operand.</p>
+
+<h5>Syntax:</h5>
+
+<pre>
+ <resultval> = va_arg <va_list*> <arglist>, <argty>
+</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
+the "variable argument" area of a function call. It is used to implement the
+<tt>va_arg</tt> macro in C.</p>
+
+<h5>Arguments:</h5>
+
+<p>This instruction takes a <tt>va_list*</tt> value and the type of
+the argument. It returns a value of the specified argument type and
+increments the <tt>va_list</tt> to point to the next argument. The
+actual type of <tt>va_list</tt> is target specific.</p>
+
+<h5>Semantics:</h5>
+
+<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
+type from the specified <tt>va_list</tt> and causes the
+<tt>va_list</tt> to point to the next argument. For more information,
+see the variable argument handling <a href="#int_varargs">Intrinsic
+Functions</a>.</p>
+
+<p>It is legal for this instruction to be called in a function which does not
+take a variable number of arguments, for example, the <tt>vfprintf</tt>
+function.</p>
+
+<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
+href="#intrinsics">intrinsic function</a> because it takes a type as an
+argument.</p>
+
+<h5>Example:</h5>
+
+<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
+
</div>
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
-Instruction</a> </div>
+<div class="doc_subsubsection">
+ <a name="i_getresult">'<tt>getresult</tt>' Instruction</a>
+</div>
+
<div class="doc_text">
+
<h5>Syntax:</h5>
-<pre> <result> = and <ty> <var1>, <var2> <i>; yields {ty}:result</i>
+<pre>
+ <resultval> = getresult <type> <retval>, <index>
</pre>
+
<h5>Overview:</h5>
-<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
-its two operands.</p>
+
+<p> The '<tt>getresult</tt>' instruction is used to extract individual values
+from a '<tt><a href="#i_call">call</a></tt>'
+or '<tt><a href="#i_invoke">invoke</a></tt>' instruction that returns multiple
+results.</p>
+
<h5>Arguments:</h5>
-<p>The two arguments to the '<tt>and</tt>' instruction must be <a
- href="#t_integral">integral</a> values. Both arguments must have
-identical types.</p>
+
+<p>The '<tt>getresult</tt>' instruction takes a call or invoke value as its
+first argument, or an undef value. The value must have <a
+href="#t_struct">structure type</a>. The second argument is a constant
+unsigned index value which must be in range for the number of values returned
+by the call.</p>
+
<h5>Semantics:</h5>
-<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
-<p> </p>
-<div style="align: center">
-<table border="1" cellspacing="0" cellpadding="4">
- <tbody>
- <tr>
- <td>In0</td>
- <td>In1</td>
- <td>Out</td>
- </tr>
- <tr>
- <td>0</td>
- <td>0</td>
- <td>0</td>
- </tr>
- <tr>
- <td>0</td>
- <td>1</td>
- <td>0</td>
- </tr>
- <tr>
- <td>1</td>
- <td>0</td>
- <td>0</td>
- </tr>
- <tr>
- <td>1</td>
- <td>1</td>
- <td>1</td>
- </tr>
- </tbody>
-</table>
-</div>
+
+<p>The '<tt>getresult</tt>' instruction extracts the element identified by
+'<tt>index</tt>' from the aggregate value.</p>
+
<h5>Example:</h5>
-<pre> <result> = and int 4, %var <i>; yields {int}:result = 4 & %var</i>
- <result> = and int 15, 40 <i>; yields {int}:result = 8</i>
- <result> = and int 4, 8 <i>; yields {int}:result = 0</i>
+
+<pre>
+ %struct.A = type { i32, i8 }
+
+ %r = call %struct.A @foo()
+ %gr = getresult %struct.A %r, 0 <i>; yields i32:%gr</i>
+ %gr1 = getresult %struct.A %r, 1 <i>; yields i8:%gr1</i>
+ add i32 %gr, 42
+ add i8 %gr1, 41
+</pre>
+
+</div>
+
+<!-- *********************************************************************** -->
+<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
+<!-- *********************************************************************** -->
+
+<div class="doc_text">
+
+<p>LLVM supports the notion of an "intrinsic function". These functions have
+well known names and semantics and are required to follow certain restrictions.
+Overall, these intrinsics represent an extension mechanism for the LLVM
+language that does not require changing all of the transformations in LLVM when
+adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
+
+<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
+prefix is reserved in LLVM for intrinsic names; thus, function names may not
+begin with this prefix. Intrinsic functions must always be external functions:
+you cannot define the body of intrinsic functions. Intrinsic functions may
+only be used in call or invoke instructions: it is illegal to take the address
+of an intrinsic function. Additionally, because intrinsic functions are part
+of the LLVM language, it is required if any are added that they be documented
+here.</p>
+
+<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
+a family of functions that perform the same operation but on different data
+types. Because LLVM can represent over 8 million different integer types,
+overloading is used commonly to allow an intrinsic function to operate on any
+integer type. One or more of the argument types or the result type can be
+overloaded to accept any integer type. Argument types may also be defined as
+exactly matching a previous argument's type or the result type. This allows an
+intrinsic function which accepts multiple arguments, but needs all of them to
+be of the same type, to only be overloaded with respect to a single argument or
+the result.</p>
+
+<p>Overloaded intrinsics will have the names of its overloaded argument types
+encoded into its function name, each preceded by a period. Only those types
+which are overloaded result in a name suffix. Arguments whose type is matched
+against another type do not. For example, the <tt>llvm.ctpop</tt> function can
+take an integer of any width and returns an integer of exactly the same integer
+width. This leads to a family of functions such as
+<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
+Only one type, the return type, is overloaded, and only one type suffix is
+required. Because the argument's type is matched against the return type, it
+does not require its own name suffix.</p>
+
+<p>To learn how to add an intrinsic function, please see the
+<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
+</p>
+
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="int_varargs">Variable Argument Handling Intrinsics</a>
+</div>
+
+<div class="doc_text">
+
+<p>Variable argument support is defined in LLVM with the <a
+ href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
+intrinsic functions. These functions are related to the similarly
+named macros defined in the <tt><stdarg.h></tt> header file.</p>
+
+<p>All of these functions operate on arguments that use a
+target-specific value type "<tt>va_list</tt>". The LLVM assembly
+language reference manual does not define what this type is, so all
+transformations should be prepared to handle these functions regardless of
+the type used.</p>
+
+<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
+instruction and the variable argument handling intrinsic functions are
+used.</p>
+
+<div class="doc_code">
+<pre>
+define i32 @test(i32 %X, ...) {
+ ; Initialize variable argument processing
+ %ap = alloca i8*
+ %ap2 = bitcast i8** %ap to i8*
+ call void @llvm.va_start(i8* %ap2)
+
+ ; Read a single integer argument
+ %tmp = va_arg i8** %ap, i32
+
+ ; Demonstrate usage of llvm.va_copy and llvm.va_end
+ %aq = alloca i8*
+ %aq2 = bitcast i8** %aq to i8*
+ call void @llvm.va_copy(i8* %aq2, i8* %ap2)
+ call void @llvm.va_end(i8* %aq2)
+
+ ; Stop processing of arguments.
+ call void @llvm.va_end(i8* %ap2)
+ ret i32 %tmp
+}
+
+declare void @llvm.va_start(i8*)
+declare void @llvm.va_copy(i8*, i8*)
+declare void @llvm.va_end(i8*)
</pre>
</div>
+
+</div>
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
+<div class="doc_subsubsection">
+ <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
+</div>
+
+
<div class="doc_text">
<h5>Syntax:</h5>
-<pre> <result> = or <ty> <var1>, <var2> <i>; yields {ty}:result</i>
-</pre>
+<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
<h5>Overview:</h5>
-<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
-or of its two operands.</p>
+<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
+<tt>*<arglist></tt> for subsequent use by <tt><a
+href="#i_va_arg">va_arg</a></tt>.</p>
+
<h5>Arguments:</h5>
-<p>The two arguments to the '<tt>or</tt>' instruction must be <a
- href="#t_integral">integral</a> values. Both arguments must have
-identical types.</p>
+
+<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
+
<h5>Semantics:</h5>
-<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
-<p> </p>
-<div style="align: center">
-<table border="1" cellspacing="0" cellpadding="4">
- <tbody>
- <tr>
- <td>In0</td>
- <td>In1</td>
- <td>Out</td>
- </tr>
- <tr>
- <td>0</td>
- <td>0</td>
- <td>0</td>
- </tr>
- <tr>
- <td>0</td>
- <td>1</td>
- <td>1</td>
- </tr>
- <tr>
- <td>1</td>
- <td>0</td>
- <td>1</td>
- </tr>
- <tr>
- <td>1</td>
- <td>1</td>
- <td>1</td>
- </tr>
- </tbody>
-</table>
+
+<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
+macro available in C. In a target-dependent way, it initializes the
+<tt>va_list</tt> element to which the argument points, so that the next call to
+<tt>va_arg</tt> will produce the first variable argument passed to the function.
+Unlike the C <tt>va_start</tt> macro, this intrinsic does not need to know the
+last argument of the function as the compiler can figure that out.</p>
+
</div>
-<h5>Example:</h5>
-<pre> <result> = or int 4, %var <i>; yields {int}:result = 4 | %var</i>
- <result> = or int 15, 40 <i>; yields {int}:result = 47</i>
- <result> = or int 4, 8 <i>; yields {int}:result = 12</i>
-</pre>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
+</div>
+
+<div class="doc_text">
+<h5>Syntax:</h5>
+<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
+<h5>Overview:</h5>
+
+<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
+which has been initialized previously with <tt><a href="#int_va_start">llvm.va_start</a></tt>
+or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
+
+<h5>Arguments:</h5>
+
+<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
+
+<h5>Semantics:</h5>
+
+<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
+macro available in C. In a target-dependent way, it destroys the
+<tt>va_list</tt> element to which the argument points. Calls to <a
+href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
+<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
+<tt>llvm.va_end</tt>.</p>
+
</div>
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
-Instruction</a> </div>
+<div class="doc_subsubsection">
+ <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
+</div>
+
<div class="doc_text">
+
<h5>Syntax:</h5>
-<pre> <result> = xor <ty> <var1>, <var2> <i>; yields {ty}:result</i>
+
+<pre>
+ declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
</pre>
+
<h5>Overview:</h5>
-<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
-or of its two operands. The <tt>xor</tt> is used to implement the
-"one's complement" operation, which is the "~" operator in C.</p>
+
+<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
+from the source argument list to the destination argument list.</p>
+
<h5>Arguments:</h5>
-<p>The two arguments to the '<tt>xor</tt>' instruction must be <a
- href="#t_integral">integral</a> values. Both arguments must have
-identical types.</p>
+
+<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
+The second argument is a pointer to a <tt>va_list</tt> element to copy from.</p>
+
+
<h5>Semantics:</h5>
-<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
-<p> </p>
-<div style="align: center">
-<table border="1" cellspacing="0" cellpadding="4">
- <tbody>
- <tr>
- <td>In0</td>
- <td>In1</td>
- <td>Out</td>
- </tr>
- <tr>
- <td>0</td>
- <td>0</td>
- <td>0</td>
- </tr>
- <tr>
- <td>0</td>
- <td>1</td>
- <td>1</td>
- </tr>
- <tr>
- <td>1</td>
- <td>0</td>
- <td>1</td>
- </tr>
- <tr>
- <td>1</td>
- <td>1</td>
- <td>0</td>
- </tr>
- </tbody>
-</table>
+
+<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
+macro available in C. In a target-dependent way, it copies the source
+<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
+intrinsic is necessary because the <tt><a href="#int_va_start">
+llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
+example, memory allocation.</p>
+
</div>
-<p> </p>
-<h5>Example:</h5>
-<pre> <result> = xor int 4, %var <i>; yields {int}:result = 4 ^ %var</i>
- <result> = xor int 15, 40 <i>; yields {int}:result = 39</i>
- <result> = xor int 4, 8 <i>; yields {int}:result = 12</i>
- <result> = xor int %V, -1 <i>; yields {int}:result = ~%V</i>
-</pre>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
+</div>
+
+<div class="doc_text">
+
+<p>
+LLVM support for <a href="GarbageCollection.html">Accurate Garbage
+Collection</a> requires the implementation and generation of these intrinsics.
+These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
+stack</a>, as well as garbage collector implementations that require <a
+href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
+Front-ends for type-safe garbage collected languages should generate these
+intrinsics to make use of the LLVM garbage collectors. For more details, see <a
+href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
+</p>
+
+<p>The garbage collection intrinsics only operate on objects in the generic
+ address space (address space zero).</p>
+
</div>
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
-Instruction</a> </div>
+<div class="doc_subsubsection">
+ <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
+</div>
+
<div class="doc_text">
+
<h5>Syntax:</h5>
-<pre> <result> = shl <ty> <var1>, ubyte <var2> <i>; yields {ty}:result</i>
+
+<pre>
+ declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
</pre>
+
<h5>Overview:</h5>
-<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
-the left a specified number of bits.</p>
+
+<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
+the code generator, and allows some metadata to be associated with it.</p>
+
<h5>Arguments:</h5>
-<p>The first argument to the '<tt>shl</tt>' instruction must be an <a
- href="#t_integer">integer</a> type. The second argument must be an '<tt>ubyte</tt>'
-type.</p>
+
+<p>The first argument specifies the address of a stack object that contains the
+root pointer. The second pointer (which must be either a constant or a global
+value address) contains the meta-data to be associated with the root.</p>
+
<h5>Semantics:</h5>
-<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup>.</p>
-<h5>Example:</h5>
-<pre> <result> = shl int 4, ubyte %var <i>; yields {int}:result = 4 << %var</i>
- <result> = shl int 4, ubyte 2 <i>; yields {int}:result = 16</i>
- <result> = shl int 1, ubyte 10 <i>; yields {int}:result = 1024</i>
-</pre>
+
+<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
+location. At compile-time, the code generator generates information to allow
+the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
+intrinsic may only be used in a function which <a href="#gc">specifies a GC
+algorithm</a>.</p>
+
</div>
+
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_shr">'<tt>shr</tt>'
-Instruction</a> </div>
+<div class="doc_subsubsection">
+ <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
+</div>
+
<div class="doc_text">
+
<h5>Syntax:</h5>
-<pre> <result> = shr <ty> <var1>, ubyte <var2> <i>; yields {ty}:result</i>
+
+<pre>
+ declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
</pre>
+
<h5>Overview:</h5>
-<p>The '<tt>shr</tt>' instruction returns the first operand shifted to
-the right a specified number of bits.</p>
+
+<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
+locations, allowing garbage collector implementations that require read
+barriers.</p>
+
<h5>Arguments:</h5>
-<p>The first argument to the '<tt>shr</tt>' instruction must be an <a
- href="#t_integer">integer</a> type. The second argument must be an '<tt>ubyte</tt>'
-type.</p>
+
+<p>The second argument is the address to read from, which should be an address
+allocated from the garbage collector. The first object is a pointer to the
+start of the referenced object, if needed by the language runtime (otherwise
+null).</p>
+
<h5>Semantics:</h5>
-<p>If the first argument is a <a href="#t_signed">signed</a> type, the
-most significant bit is duplicated in the newly free'd bit positions.
-If the first argument is unsigned, zero bits shall fill the empty
-positions.</p>
-<h5>Example:</h5>
-<pre> <result> = shr int 4, ubyte %var <i>; yields {int}:result = 4 >> %var</i>
- <result> = shr uint 4, ubyte 1 <i>; yields {uint}:result = 2</i>
- <result> = shr int 4, ubyte 2 <i>; yields {int}:result = 1</i>
- <result> = shr sbyte 4, ubyte 3 <i>; yields {sbyte}:result = 0</i>
- <result> = shr sbyte -2, ubyte 1 <i>; yields {sbyte}:result = -1</i>
+
+<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
+instruction, but may be replaced with substantially more complex code by the
+garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
+may only be used in a function which <a href="#gc">specifies a GC
+algorithm</a>.</p>
+
+</div>
+
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
+</div>
+
+<div class="doc_text">
+
+<h5>Syntax:</h5>
+
+<pre>
+ declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
</pre>
+
+<h5>Overview:</h5>
+
+<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
+locations, allowing garbage collector implementations that require write
+barriers (such as generational or reference counting collectors).</p>
+
+<h5>Arguments:</h5>
+
+<p>The first argument is the reference to store, the second is the start of the
+object to store it to, and the third is the address of the field of Obj to
+store to. If the runtime does not require a pointer to the object, Obj may be
+null.</p>
+
+<h5>Semantics:</h5>
+
+<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
+instruction, but may be replaced with substantially more complex code by the
+garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
+may only be used in a function which <a href="#gc">specifies a GC
+algorithm</a>.</p>
+
</div>
+
+
+
<!-- ======================================================================= -->
-<div class="doc_subsection"> <a name="memoryops">Memory Access
-Operations</a></div>
+<div class="doc_subsection">
+ <a name="int_codegen">Code Generator Intrinsics</a>
+</div>
+
<div class="doc_text">
-<p>A key design point of an SSA-based representation is how it
-represents memory. In LLVM, no memory locations are in SSA form, which
-makes things very simple. This section describes how to read, write,
-allocate and free memory in LLVM.</p>
+<p>
+These intrinsics are provided by LLVM to expose special features that may only
+be implemented with code generator support.
+</p>
+
</div>
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_malloc">'<tt>malloc</tt>'
-Instruction</a> </div>
+<div class="doc_subsubsection">
+ <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
+</div>
+
<div class="doc_text">
+
<h5>Syntax:</h5>
-<pre> <result> = malloc <type>, uint <NumElements> <i>; yields {type*}:result</i>
- <result> = malloc <type> <i>; yields {type*}:result</i>
+<pre>
+ declare i8 *@llvm.returnaddress(i32 <level>)
</pre>
+
<h5>Overview:</h5>
-<p>The '<tt>malloc</tt>' instruction allocates memory from the system
-heap and returns a pointer to it.</p>
+
+<p>
+The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
+target-specific value indicating the return address of the current function
+or one of its callers.
+</p>
+
<h5>Arguments:</h5>
-<p>The '<tt>malloc</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
-bytes of memory from the operating system and returns a pointer of the
-appropriate type to the program. The second form of the instruction is
-a shorter version of the first instruction that defaults to allocating
-one element.</p>
-<p>'<tt>type</tt>' must be a sized type.</p>
+
+<p>
+The argument to this intrinsic indicates which function to return the address
+for. Zero indicates the calling function, one indicates its caller, etc. The
+argument is <b>required</b> to be a constant integer value.
+</p>
+
<h5>Semantics:</h5>
-<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
-a pointer is returned.</p>
-<h5>Example:</h5>
-<pre> %array = malloc [4 x ubyte ] <i>; yields {[%4 x ubyte]*}:array</i>
- %size = <a
- href="#i_add">add</a> uint 2, 2 <i>; yields {uint}:size = uint 4</i>
- %array1 = malloc ubyte, uint 4 <i>; yields {ubyte*}:array1</i>
- %array2 = malloc [12 x ubyte], uint %size <i>; yields {[12 x ubyte]*}:array2</i>
-</pre>
+<p>
+The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
+the return address of the specified call frame, or zero if it cannot be
+identified. The value returned by this intrinsic is likely to be incorrect or 0
+for arguments other than zero, so it should only be used for debugging purposes.
+</p>
+
+<p>
+Note that calling this intrinsic does not prevent function inlining or other
+aggressive transformations, so the value returned may not be that of the obvious
+source-language caller.
+</p>
</div>
+
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_free">'<tt>free</tt>'
-Instruction</a> </div>
+<div class="doc_subsubsection">
+ <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
+</div>
+
<div class="doc_text">
+
<h5>Syntax:</h5>
-<pre> free <type> <value> <i>; yields {void}</i>
+<pre>
+ declare i8 *@llvm.frameaddress(i32 <level>)
</pre>
+
<h5>Overview:</h5>
-<p>The '<tt>free</tt>' instruction returns memory back to the unused
-memory heap, to be reallocated in the future.</p>
-<p> </p>
+
+<p>
+The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
+target-specific frame pointer value for the specified stack frame.
+</p>
+
<h5>Arguments:</h5>
-<p>'<tt>value</tt>' shall be a pointer value that points to a value
-that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
-instruction.</p>
+
+<p>
+The argument to this intrinsic indicates which function to return the frame
+pointer for. Zero indicates the calling function, one indicates its caller,
+etc. The argument is <b>required</b> to be a constant integer value.
+</p>
+
<h5>Semantics:</h5>
-<p>Access to the memory pointed to by the pointer is not longer defined
-after this instruction executes.</p>
-<h5>Example:</h5>
-<pre> %array = <a href="#i_malloc">malloc</a> [4 x ubyte] <i>; yields {[4 x ubyte]*}:array</i>
- free [4 x ubyte]* %array
-</pre>
+
+<p>
+The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
+the frame address of the specified call frame, or zero if it cannot be
+identified. The value returned by this intrinsic is likely to be incorrect or 0
+for arguments other than zero, so it should only be used for debugging purposes.
+</p>
+
+<p>
+Note that calling this intrinsic does not prevent function inlining or other
+aggressive transformations, so the value returned may not be that of the obvious
+source-language caller.
+</p>
</div>
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_alloca">'<tt>alloca</tt>'
-Instruction</a> </div>
+<div class="doc_subsubsection">
+ <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
+</div>
+
<div class="doc_text">
+
<h5>Syntax:</h5>
-<pre> <result> = alloca <type>, uint <NumElements> <i>; yields {type*}:result</i>
- <result> = alloca <type> <i>; yields {type*}:result</i>
+<pre>
+ declare i8 *@llvm.stacksave()
</pre>
+
<h5>Overview:</h5>
-<p>The '<tt>alloca</tt>' instruction allocates memory on the current
-stack frame of the procedure that is live until the current function
-returns to its caller.</p>
-<h5>Arguments:</h5>
-<p>The the '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
-bytes of memory on the runtime stack, returning a pointer of the
-appropriate type to the program. The second form of the instruction is
-a shorter version of the first that defaults to allocating one element.</p>
-<p>'<tt>type</tt>' may be any sized type.</p>
+
+<p>
+The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
+the function stack, for use with <a href="#int_stackrestore">
+<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
+features like scoped automatic variable sized arrays in C99.
+</p>
+
<h5>Semantics:</h5>
-<p>Memory is allocated, a pointer is returned. '<tt>alloca</tt>'d
-memory is automatically released when the function returns. The '<tt>alloca</tt>'
-instruction is commonly used to represent automatic variables that must
-have an address available. When the function returns (either with the <tt><a
- href="#i_ret">ret</a></tt> or <tt><a href="#i_invoke">invoke</a></tt>
-instructions), the memory is reclaimed.</p>
-<h5>Example:</h5>
-<pre> %ptr = alloca int <i>; yields {int*}:ptr</i>
- %ptr = alloca int, uint 4 <i>; yields {int*}:ptr</i>
-</pre>
+
+<p>
+This intrinsic returns a opaque pointer value that can be passed to <a
+href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
+<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
+<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
+state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
+practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
+that were allocated after the <tt>llvm.stacksave</tt> was executed.
+</p>
+
</div>
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
-Instruction</a> </div>
+<div class="doc_subsubsection">
+ <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
+</div>
+
<div class="doc_text">
+
<h5>Syntax:</h5>
-<pre> <result> = load <ty>* <pointer><br> <result> = volatile load <ty>* <pointer><br></pre>
+<pre>
+ declare void @llvm.stackrestore(i8 * %ptr)
+</pre>
+
<h5>Overview:</h5>
-<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
-<h5>Arguments:</h5>
-<p>The argument to the '<tt>load</tt>' instruction specifies the memory
-
address to load from. The pointer must point to a <a
- href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
-marked as <tt>volatile</tt> then the optimizer is not allowed to modify
-the number or order of execution of this <tt>load</tt> with other
-volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
-instructions. </p>
+
+<p>
+The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
+
the function stack to the state it was in when the corresponding <a
+href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
+useful for implementing language features like scoped automatic variable sized
+arrays in C99.
+</p>
+
<h5>Semantics:</h5>
-<p>The location of memory pointed to is loaded.</p>
-<h5>Examples:</h5>
-<pre> %ptr = <a href="#i_alloca">alloca</a> int <i>; yields {int*}:ptr</i>
- <a
- href="#i_store">store</a> int 3, int* %ptr <i>; yields {void}</i>
- %val = load int* %ptr <i>; yields {int}:val = int 3</i>
-</pre>
+
+<p>
+See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
+</p>
+
</div>
+
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
-Instruction</a> </div>
+<div class="doc_subsubsection">
+ <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
+</div>
+
+<div class="doc_text">
+
<h5>Syntax:</h5>
-<pre> store <ty> <value>, <ty>* <pointer> <i>; yields {void}</i>
- volatile store <ty> <value>, <ty>* <pointer> <i>; yields {void}</i>
+<pre>
+ declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
</pre>
+
<h5>Overview:</h5>
-<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
+
+
+<p>
+The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
+a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
+no
+effect on the behavior of the program but can change its performance
+characteristics.
+</p>
+
<h5>Arguments:</h5>
-<p>There are two arguments to the '<tt>store</tt>' instruction: a value
-to store and an address to store it into. The type of the '<tt><pointer></tt>'
-operand must be a pointer to the type of the '<tt><value></tt>'
-operand. If the <tt>store</tt> is marked as <tt>volatile</tt> then the
-optimizer is not allowed to modify the number or order of execution of
-this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
- href="#i_store">store</a></tt> instructions.</p>
+
+<p>
+<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
+determining if the fetch should be for a read (0) or write (1), and
+<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
+locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
+<tt>locality</tt> arguments must be constant integers.
+</p>
+
<h5>Semantics:</h5>
-<p>The contents of memory are updated to contain '<tt><value></tt>'
-at the location specified by the '<tt><pointer></tt>' operand.</p>
-<h5>Example:</h5>
-<pre> %ptr = <a href="#i_alloca">alloca</a> int <i>; yields {int*}:ptr</i>
- <a
- href="#i_store">store</a> int 3, int* %ptr <i>; yields {void}</i>
- %val = load int* %ptr <i>; yields {int}:val = int 3</i>
-</pre>
+
+<p>
+This intrinsic does not modify the behavior of the program. In particular,
+prefetches cannot trap and do not produce a value. On targets that support this
+intrinsic, the prefetch can provide hints to the processor cache for better
+performance.
+</p>
+
+</div>
+
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
+ <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
</div>
<div class="doc_text">
+
<h5>Syntax:</h5>
<pre>
- <result> = getelementptr <ty>* <ptrval>{, <ty> <idx>}*
+ declare void @llvm.pcmarker(i32 <id>)
</pre>
<h5>Overview:</h5>
+
<p>
-The '<tt>getelementptr</tt>' instruction is used to get the address of a
-subelement of an aggregate data structure.</p>
+The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
+(PC) in a region of
+code to simulators and other tools. The method is target specific, but it is
+expected that the marker will use exported symbols to transmit the PC of the marker.
+The marker makes no guarantees that it will remain with any specific instruction
+after optimizations. It is possible that the presence of a marker will inhibit
+optimizations. The intended use is to be inserted after optimizations to allow
+correlations of simulation runs.
+</p>
<h5>Arguments:</h5>
-<p>This instruction takes a list of integer constants that indicate what
-elements of the aggregate object to index to. The actual types of the arguments
-provided depend on the type of the first pointer argument. The
-'<tt>getelementptr</tt>' instruction is used to index down through the type
-levels of a structure. When indexing into a structure, only <tt>uint</tt>
-integer constants are allowed. When indexing into an array or pointer
-<tt>int</tt> and <tt>long</tt> indexes are allowed of any sign.</p>
+<p>
+<tt>id</tt> is a numerical id identifying the marker.
+</p>
-<p>For example, let's consider a C code fragment and how it gets
-compiled to LLVM:</p>
+<h5>Semantics:</h5>
-<pre>
- struct RT {
- char A;
- int B[10][20];
- char C;
- };
- struct ST {
- int X;
- double Y;
- struct RT Z;
- };
+<p>
+This intrinsic does not modify the behavior of the program. Backends that do not
+support this intrinisic may ignore it.
+</p>
- int *foo(struct ST *s) {
- return &s[1].Z.B[5][13];
- }
-</pre>
+</div>
-<p>The LLVM code generated by the GCC frontend is:</p>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
+</div>
-<pre>
- %RT = type { sbyte, [10 x [20 x int]], sbyte }
- %ST = type { int, double, %RT }
+<div class="doc_text">
- int* "foo"(%ST* %s) {
- %reg = getelementptr %ST* %s, int 1, uint 2, uint 1, int 5, int 13<br>
- ret int* %reg
- }
+<h5>Syntax:</h5>
+<pre>
+ declare i64 @llvm.readcyclecounter( )
</pre>
-<h5>Semantics:</h5>
+<h5>Overview:</h5>
-<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
-on the pointer type that is being index into. <a href="#t_pointer">Pointer</a>
-and <a href="#t_array">array</a> types require <tt>uint</tt>, <tt>int</tt>,
-<tt>ulong</tt>, or <tt>long</tt> values, and <a href="#t_struct">structure</a>
-types require <tt>uint</tt> <b>constants</b>.</p>
-<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
-type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ int, double, %RT
-}</tt>' type, a structure. The second index indexes into the third element of
-the structure, yielding a '<tt>%RT</tt>' = '<tt>{ sbyte, [10 x [20 x int]],
-sbyte }</tt>' type, another structure. The third index indexes into the second
-element of the structure, yielding a '<tt>[10 x [20 x int]]</tt>' type, an
-array. The two dimensions of the array are subscripted into, yielding an
-'<tt>int</tt>' type. The '<tt>getelementptr</tt>' instruction return a pointer
-to this element, thus computing a value of '<tt>int*</tt>' type.</p>
+<p>
+The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
+counter register (or similar low latency, high accuracy clocks) on those targets
+that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
+As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
+should only be used for small timings.
+</p>
-<p>Note that it is perfectly legal to index partially through a
-structure, returning a pointer to an inner element. Because of this,
-the LLVM code for the given testcase is equivalent to:</p>
+<h5>Semantics:</h5>
-<pre>
- int* "foo"(%ST* %s) {
- %t1 = getelementptr %ST* %s, int 1 <i>; yields %ST*:%t1</i>
- %t2 = getelementptr %ST* %t1, int 0, uint 2 <i>; yields %RT*:%t2</i>
- %t3 = getelementptr %RT* %t2, int 0, uint 1 <i>; yields [10 x [20 x int]]*:%t3</i>
- %t4 = getelementptr [10 x [20 x int]]* %t3, int 0, int 5 <i>; yields [20 x int]*:%t4</i>
- %t5 = getelementptr [20 x int]* %t4, int 0, int 13 <i>; yields int*:%t5</i>
- ret int* %t5
- }
-</pre>
-<h5>Example:</h5>
-<pre>
- <i>; yields [12 x ubyte]*:aptr</i>
- %aptr = getelementptr {int, [12 x ubyte]}* %sptr, long 0, uint 1
-</pre>
+<p>
+When directly supported, reading the cycle counter should not modify any memory.
+Implementations are allowed to either return a application specific value or a
+system wide value. On backends without support, this is lowered to a constant 0.
+</p>
</div>
+
<!-- ======================================================================= -->
-<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
+<div class="doc_subsection">
+ <a name="int_libc">Standard C Library Intrinsics</a>
+</div>
+
<div class="doc_text">
-<p>The instructions in this category are the "miscellaneous"
-instructions, which defy better classification.</p>
+<p>
+LLVM provides intrinsics for a few important standard C library functions.
+These intrinsics allow source-language front-ends to pass information about the
+alignment of the pointer arguments to the code generator, providing opportunity
+for more efficient code generation.
+</p>
+
</div>
+
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_phi">'<tt>phi</tt>'
-Instruction</a> </div>
+<div class="doc_subsubsection">
+ <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
+</div>
+
<div class="doc_text">
+
<h5>Syntax:</h5>
-<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
+<pre>
+ declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
+ i32 <len>, i32 <align>)
+ declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
+ i64 <len>, i32 <align>)
+</pre>
+
<h5>Overview:</h5>
-<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
-the SSA graph representing the function.</p>
+
+<p>
+The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
+location to the destination location.
+</p>
+
+<p>
+Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
+intrinsics do not return a value, and takes an extra alignment argument.
+</p>
+
<h5>Arguments:</h5>
-<p>The type of the incoming values are specified with the first type
-field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
-as arguments, with one pair for each predecessor basic block of the
-current block. Only values of <a href="#t_firstclass">first class</a>
-type may be used as the value arguments to the PHI node. Only labels
-may be used as the label arguments.</p>
-<p>There must be no non-phi instructions between the start of a basic
-block and the PHI instructions: i.e. PHI instructions must be first in
-a basic block.</p>
+
+<p>
+The first argument is a pointer to the destination, the second is a pointer to
+the source. The third argument is an integer argument
+specifying the number of bytes to copy, and the fourth argument is the alignment
+of the source and destination locations.
+</p>
+
+<p>
+If the call to this intrinisic has an alignment value that is not 0 or 1, then
+the caller guarantees that both the source and destination pointers are aligned
+to that boundary.
+</p>
+
<h5>Semantics:</h5>
-<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the
-value specified by the parameter, depending on which basic block we
-came from in the last <a href="#terminators">terminator</a> instruction.</p>
-<h5>Example:</h5>
-<pre>Loop: ; Infinite loop that counts from 0 on up...<br> %indvar = phi uint [ 0, %LoopHeader ], [ %nextindvar, %Loop ]<br> %nextindvar = add uint %indvar, 1<br> br label %Loop<br></pre>
+
+<p>
+The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
+location to the destination location, which are not allowed to overlap. It
+copies "len" bytes of memory over. If the argument is known to be aligned to
+some boundary, this can be specified as the fourth argument, otherwise it should
+be set to 0 or 1.
+</p>
</div>
+
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_cast">'<tt>cast .. to</tt>' Instruction</a>
+ <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<h5>Syntax:</h5>
-
<pre>
- <result> = cast <ty> <value> to <ty2> <i>; yields ty2</i>
+ declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
+ i32 <len>, i32 <align>)
+ declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
+ i64 <len>, i32 <align>)
</pre>
<h5>Overview:</h5>
<p>
-The '<tt>cast</tt>' instruction is used as the primitive means to convert
-integers to floating point, change data type sizes, and break type safety (by
-casting pointers).
+The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
+location to the destination location. It is similar to the
+'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
</p>
-
-<h5>Arguments:</h5>
-
<p>
-The '<tt>cast</tt>' instruction takes a value to cast, which must be a first
-class value, and a type to cast it to, which must also be a <a
-href="#t_firstclass">first class</a> type.
+Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
+intrinsics do not return a value, and takes an extra alignment argument.
</p>
-<h5>Semantics:</h5>
+<h5>Arguments:</h5>
<p>
-This instruction follows the C rules for explicit casts when determining how the
-data being cast must change to fit in its new container.
+The first argument is a pointer to the destination, the second is a pointer to
+the source. The third argument is an integer argument
+specifying the number of bytes to copy, and the fourth argument is the alignment
+of the source and destination locations.
</p>
<p>
-When casting to bool, any value that would be considered true in the context of
-a C '<tt>if</tt>' condition is converted to the boolean '<tt>true</tt>' values,
-all else are '<tt>false</tt>'.
+If the call to this intrinisic has an alignment value that is not 0 or 1, then
+the caller guarantees that the source and destination pointers are aligned to
+that boundary.
</p>
+<h5>Semantics:</h5>
+
<p>
-When extending an integral value from a type of one signness to another (for
-example '<tt>sbyte</tt>' to '<tt>ulong</tt>'), the value is sign-extended if the
-<b>source</b> value is signed, and zero-extended if the source value is
-unsigned. <tt>bool</tt> values are always zero extended into either zero or
-one.
+The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
+location to the destination location, which may overlap. It
+copies "len" bytes of memory over. If the argument is known to be aligned to
+some boundary, this can be specified as the fourth argument, otherwise it should
+be set to 0 or 1.
</p>
-
-<h5>Example:</h5>
-
-<pre>
- %X = cast int 257 to ubyte <i>; yields ubyte:1</i>
- %Y = cast int 123 to bool <i>; yields bool:true</i>
-</pre>
</div>
+
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_select">'<tt>select</tt>' Instruction</a>
+ <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
</div>
<div class="doc_text">
<h5>Syntax:</h5>
-
<pre>
- <result> = select bool <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
+ declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
+ i32 <len>, i32 <align>)
+ declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
+ i64 <len>, i32 <align>)
</pre>
<h5>Overview:</h5>
<p>
-The '<tt>select</tt>' instruction is used to choose one value based on a
-condition, without branching.
+The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
+byte value.
</p>
+<p>
+Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
+does not return a value, and takes an extra alignment argument.
+</p>
<h5>Arguments:</h5>
<p>
-The '<tt>select</tt>' instruction requires a boolean value indicating the condition, and two values of the same <a href="#t_firstclass">first class</a> type.
+The first argument is a pointer to the destination to fill, the second is the
+byte value to fill it with, the third argument is an integer
+argument specifying the number of bytes to fill, and the fourth argument is the
+known alignment of destination location.
</p>
-<h5>Semantics:</h5>
-
<p>
-If the boolean condition evaluates to true, the instruction returns the first
-value argument, otherwise it returns the second value argument.
+If the call to this intrinisic has an alignment value that is not 0 or 1, then
+the caller guarantees that the destination pointer is aligned to that boundary.
</p>
-<h5>Example:</h5>
+<h5>Semantics:</h5>
-<pre>
- %X = select bool true, ubyte 17, ubyte 42 <i>; yields ubyte:17</i>
-</pre>
+<p>
+The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
+the
+destination location. If the argument is known to be aligned to some boundary,
+this can be specified as the fourth argument, otherwise it should be set to 0 or
+1.
+</p>
</div>
-
-
-
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_call">'<tt>call</tt>'
-Instruction</a> </div>
-<div class="doc_text">
-<h5>Syntax:</h5>
-<pre> <result> = call <ty>* <fnptrval>(<param list>)<br></pre>
-<h5>Overview:</h5>
-<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
-<h5>Arguments:</h5>
-<p>This instruction requires several arguments:</p>
-<ol>
- <li>
- <p>'<tt>ty</tt>': shall be the signature of the pointer to function
-value being invoked. The argument types must match the types implied
-by this signature.</p>
- </li>
- <li>
- <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a
-function to be invoked. In most cases, this is a direct function
-invocation, but indirect <tt>call</tt>s are just as possible,
-calling an arbitrary pointer to function values.</p>
- </li>
- <li>
- <p>'<tt>function args</tt>': argument list whose types match the
-function signature argument types. If the function signature
-indicates the function accepts a variable number of arguments, the
-extra arguments can be specified.</p>
- </li>
-</ol>
-<h5>Semantics:</h5>
-<p>The '<tt>call</tt>' instruction is used to cause control flow to
-transfer to a specified function, with its incoming arguments bound to
-the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
-instruction in the called function, control flow continues with the
-instruction after the function call, and the return value of the
-function is bound to the result argument. This is a simpler case of
-the <a href="#i_invoke">invoke</a> instruction.</p>
-<h5>Example:</h5>
-<pre> %retval = call int %test(int %argc)<br> call int(sbyte*, ...) *%printf(sbyte* %msg, int 12, sbyte 42);<br></pre>
-</div>
<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_vanext">'<tt>vanext</tt>'
-Instruction</a> </div>
-<div class="doc_text">
-<h5>Syntax:</h5>
-<pre> <resultarglist> = vanext <va_list> <arglist>, <argty><br></pre>
-<h5>Overview:</h5>
-<p>The '<tt>vanext</tt>' instruction is used to access arguments passed
-through the "variable argument" area of a function call. It is used to
-implement the <tt>va_arg</tt> macro in C.</p>
-<h5>Arguments:</h5>
-<p>This instruction takes a <tt>valist</tt> value and the type of the
-argument. It returns another <tt>valist</tt>.</p>
-<h5>Semantics:</h5>
-<p>The '<tt>vanext</tt>' instruction advances the specified <tt>valist</tt>
-past an argument of the specified type. In conjunction with the <a
- href="#i_vaarg"><tt>vaarg</tt></a> instruction, it is used to implement
-the <tt>va_arg</tt> macro available in C. For more information, see
-the variable argument handling <a href="#int_varargs">Intrinsic
-Functions</a>.</p>
-<p>It is legal for this instruction to be called in a function which
-does not take a variable number of arguments, for example, the <tt>vfprintf</tt>
-function.</p>
-<p><tt>vanext</tt> is an LLVM instruction instead of an <a
- href="#intrinsics">intrinsic function</a> because it takes an type as
-an argument.</p>
-<h5>Example:</h5>
-<p>See the <a href="#int_varargs">variable argument processing</a>
-section.</p>
+<div class="doc_subsubsection">
+ <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
</div>
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection"> <a name="i_vaarg">'<tt>vaarg</tt>'
-Instruction</a> </div>
+
<div class="doc_text">
+
<h5>Syntax:</h5>
-<pre> <resultval> = vaarg <va_list> <arglist>, <argty><br></pre>
-<h5>Overview:</h5>
-<p>The '<tt>vaarg</tt>' instruction is used to access arguments passed
-through the "variable argument" area of a function call. It is used to
-implement the <tt>va_arg</tt> macro in C.</p>
-<h5>Arguments:</h5>
-<p>This instruction takes a <tt>valist</tt> value and the type of the
-argument. It returns a value of the specified argument type.</p>
-<h5>Semantics:</h5>
-<p>The '<tt>vaarg</tt>' instruction loads an argument of the specified
-type from the specified <tt>va_list</tt>. In conjunction with the <a
- href="#i_vanext"><tt>vanext</tt></a> instruction, it is used to
-implement the <tt>va_arg</tt> macro available in C. For more
-information, see the variable argument handling <a href="#int_varargs">Intrinsic
-Functions</a>.</p>
-<p>It is legal for this instruction to be called in a function which
-does not take a variable number of arguments, for example, the <tt>vfprintf</tt>
-function.</p>
-<p><tt>vaarg</tt> is an LLVM instruction instead of an <a
- href="#intrinsics">intrinsic function</a> because it takes an type as
-an argument.</p>
-<h5>Example:</h5>
-<p>See the <a href="#int_varargs">variable argument processing</a>
-section.</p>
-</div>
+<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
+floating point or vector of floating point type. Not all targets support all
+types however.
+<pre>
+ declare float @llvm.sqrt.f32(float %Val)
+ declare double @llvm.sqrt.f64(double %Val)
+ declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
+ declare fp128 @llvm.sqrt.f128(fp128 %Val)
+ declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
+</pre>
-<!-- *********************************************************************** -->
-<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
-<!-- *********************************************************************** -->
+<h5>Overview:</h5>
-<div class="doc_text">
+<p>
+The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
+returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
+<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
+negative numbers other than -0.0 (which allows for better optimization, because
+there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
+defined to return -0.0 like IEEE sqrt.
+</p>
-<p>LLVM supports the notion of an "intrinsic function". These functions have
-well known names and semantics, and are required to follow certain
-restrictions. Overall, these instructions represent an extension mechanism for
-the LLVM language that does not require changing all of the transformations in
-LLVM to add to the language (or the bytecode reader/writer, the parser,
-etc...).</p>
+<h5>Arguments:</h5>
-<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix, this
-prefix is reserved in LLVM for intrinsic names, thus functions may not be named
-this. Intrinsic functions must always be external functions: you cannot define
-the body of intrinsic functions. Intrinsic functions may only be used in call
-or invoke instructions: it is illegal to take the address of an intrinsic
-function. Additionally, because intrinsic functions are part of the LLVM
-language, it is required that they all be documented here if any are added.</p>
+<p>
+The argument and return value are floating point numbers of the same type.
+</p>
+<h5>Semantics:</h5>
<p>
-Adding an intrinsic to LLVM is straight-forward if it is possible to express the
-concept in LLVM directly (ie, code generator support is not _required_). To do
-this, extend the default implementation of the IntrinsicLowering class to handle
-the intrinsic. Code generators use this class to lower intrinsics they do not
-understand to raw LLVM instructions that they do.
+This function returns the sqrt of the specified operand if it is a nonnegative
+floating point number.
</p>
-
</div>
-<!-- ======================================================================= -->
-<div class="doc_subsection">
- <a name="int_varargs">Variable Argument Handling Intrinsics</a>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
</div>
<div class="doc_text">
-<p>Variable argument support is defined in LLVM with the <a
- href="#i_vanext"><tt>vanext</tt></a> instruction and these three
-intrinsic functions. These functions are related to the similarly
-named macros defined in the <tt><stdarg.h></tt> header file.</p>
-
-<p>All of these functions operate on arguments that use a
-target-specific value type "<tt>va_list</tt>". The LLVM assembly
-language reference manual does not define what this type is, so all
-transformations should be prepared to handle intrinsics with any type
-used.</p>
+<h5>Syntax:</h5>
+<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
+floating point or vector of floating point type. Not all targets support all
+types however.
+<pre>
+ declare float @llvm.powi.f32(float %Val, i32 %power)
+ declare double @llvm.powi.f64(double %Val, i32 %power)
+ declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
+ declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
+ declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
+</pre>
-<p>This example shows how the <a href="#i_vanext"><tt>vanext</tt></a>
-instruction and the variable argument handling intrinsic functions are
-used.</p>
+<h5>Overview:</h5>
-<pre>
-int %test(int %X, ...) {
- ; Initialize variable argument processing
- %ap = call sbyte* %<a href="#i_va_start">llvm.va_start</a>()
+<p>
+The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
+specified (positive or negative) power. The order of evaluation of
+multiplications is not defined. When a vector of floating point type is
+used, the second argument remains a scalar integer value.
+</p>
- ; Read a single integer argument
- %tmp = vaarg sbyte* %ap, int
+<h5>Arguments:</h5>
- ; Advance to the next argument
- %ap2 = vanext sbyte* %ap, int
+<p>
+The second argument is an integer power, and the first is a value to raise to
+that power.
+</p>
- ; Demonstrate usage of llvm.va_copy and llvm.va_end
- %aq = call sbyte* %<a href="#i_va_copy">llvm.va_copy</a>(sbyte* %ap2)
- call void %<a href="#i_va_end">llvm.va_end</a>(sbyte* %aq)
+<h5>Semantics:</h5>
- ; Stop processing of arguments.
- call void %<a href="#i_va_end">llvm.va_end</a>(sbyte* %ap2)
- ret int %tmp
-}
-</pre>
+<p>
+This function returns the first value raised to the second power with an
+unspecified sequence of rounding operations.</p>
</div>
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
+ <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
</div>
-
<div class="doc_text">
+
<h5>Syntax:</h5>
-<pre> call va_list ()* %llvm.va_start()<br></pre>
+<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
+floating point or vector of floating point type. Not all targets support all
+types however.
+<pre>
+ declare float @llvm.sin.f32(float %Val)
+ declare double @llvm.sin.f64(double %Val)
+ declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
+ declare fp128 @llvm.sin.f128(fp128 %Val)
+ declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
+</pre>
+
<h5>Overview:</h5>
-<p>The '<tt>llvm.va_start</tt>' intrinsic returns a new <tt><arglist></tt>
-for subsequent use by the variable argument intrinsics.</p>
-<h5>Semantics:</h5>
-<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
-macro available in C. In a target-dependent way, it initializes and
-returns a <tt>va_list</tt> element, so that the next <tt>vaarg</tt>
-will produce the first variable argument passed to the function. Unlike
-the C <tt>va_start</tt> macro, this intrinsic does not need to know the
-last argument of the function, the compiler can figure that out.</p>
-<p>Note that this intrinsic function is only legal to be called from
-within the body of a variable argument function.</p>
-</div>
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection">
- <a name="i_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
-</div>
+<p>
+The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
+</p>
-<div class="doc_text">
-<h5>Syntax:</h5>
-<pre> call void (va_list)* %llvm.va_end(va_list <arglist>)<br></pre>
-<h5>Overview:</h5>
-<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt><arglist></tt>
-which has been initialized previously with <tt><a href="#i_va_start">llvm.va_start</a></tt>
-or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
<h5>Arguments:</h5>
-<p>The argument is a <tt>va_list</tt> to destroy.</p>
+
+<p>
+The argument and return value are floating point numbers of the same type.
+</p>
+
<h5>Semantics:</h5>
-<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
-macro available in C. In a target-dependent way, it destroys the <tt>va_list</tt>.
-Calls to <a href="#i_va_start"><tt>llvm.va_start</tt></a> and <a
- href="#i_va_copy"><tt>llvm.va_copy</tt></a> must be matched exactly
-with calls to <tt>llvm.va_end</tt>.</p>
+
+<p>
+This function returns the sine of the specified operand, returning the
+same values as the libm <tt>sin</tt> functions would, and handles error
+conditions in the same way.</p>
</div>
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
+ <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<h5>Syntax:</h5>
-
+<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
+floating point or vector of floating point type. Not all targets support all
+types however.
<pre>
- call va_list (va_list)* %llvm.va_copy(va_list <destarglist>)
+ declare float @llvm.cos.f32(float %Val)
+ declare double @llvm.cos.f64(double %Val)
+ declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
+ declare fp128 @llvm.cos.f128(fp128 %Val)
+ declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
</pre>
<h5>Overview:</h5>
-<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
-from the source argument list to the destination argument list.</p>
+<p>
+The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
+</p>
<h5>Arguments:</h5>
-<p>The argument is the <tt>va_list</tt> to copy.</p>
+<p>
+The argument and return value are floating point numbers of the same type.
+</p>
<h5>Semantics:</h5>
-<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
-macro available in C. In a target-dependent way, it copies the source
-<tt>va_list</tt> element into the returned list. This intrinsic is necessary
-because the <tt><a href="i_va_start">llvm.va_start</a></tt> intrinsic may be
-arbitrarily complex and require memory allocation, for example.</p>
-
-</div>
-
-<!-- ======================================================================= -->
-<div class="doc_subsection">
- <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
-</div>
-
-<div class="doc_text">
-
<p>
-LLVM support for <a href="GarbageCollection.html">Accurate Garbage
-Collection</a> requires the implementation and generation of these intrinsics.
-These intrinsics allow identification of <a href="#i_gcroot">GC roots on the
-stack</a>, as well as garbage collector implementations that require <a
-href="#i_gcread">read</a> and <a href="#i_gcwrite">write</a> barriers.
-Front-ends for type-safe garbage collected languages should generate these
-intrinsics to make use of the LLVM garbage collectors. For more details, see <a
-href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
-</p>
+This function returns the cosine of the specified operand, returning the
+same values as the libm <tt>cos</tt> functions would, and handles error
+conditions in the same way.</p>
</div>
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
+ <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<h5>Syntax:</h5>
-
+<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
+floating point or vector of floating point type. Not all targets support all
+types however.
<pre>
- call void (<ty>**, <ty2>*)* %llvm.gcroot(<ty>** %ptrloc, <ty2>* %metadata)
+ declare float @llvm.pow.f32(float %Val, float %Power)
+ declare double @llvm.pow.f64(double %Val, double %Power)
+ declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
+ declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
+ declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
</pre>
<h5>Overview:</h5>
-<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existance of a GC root to
-the code generator, and allows some metadata to be associated with it.</p>
+<p>
+The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
+specified (positive or negative) power.
+</p>
<h5>Arguments:</h5>
-<p>The first argument specifies the address of a stack object that contains the
-root pointer. The second pointer (which must be either a constant or a global
-value address) contains the meta-data to be associated with the root.</p>
+<p>
+The second argument is a floating point power, and the first is a value to
+raise to that power.
+</p>
<h5>Semantics:</h5>
-<p>At runtime, a call to this intrinsics stores a null pointer into the "ptrloc"
-location. At compile-time, the code generator generates information to allow
-the runtime to find the pointer at GC safe points.
-</p>
+<p>
+This function returns the first value raised to the second power,
+returning the
+same values as the libm <tt>pow</tt> functions would, and handles error
+conditions in the same way.</p>
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="int_manip">Bit Manipulation Intrinsics</a>
</div>
+<div class="doc_text">
+<p>
+LLVM provides intrinsics for a few important bit manipulation operations.
+These allow efficient code generation for some algorithms.
+</p>
+
+</div>
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
+ <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
</div>
<div class="doc_text">
<h5>Syntax:</h5>
-
+<p>This is an overloaded intrinsic function. You can use bswap on any integer
+type that is an even number of bytes (i.e. BitWidth % 16 == 0).
<pre>
- call sbyte* (sbyte**)* %llvm.gcread(sbyte** %Ptr)
+ declare i16 @llvm.bswap.i16(i16 <id>)
+ declare i32 @llvm.bswap.i32(i32 <id>)
+ declare i64 @llvm.bswap.i64(i64 <id>)
</pre>
<h5>Overview:</h5>
-<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
-locations, allowing garbage collector implementations that require read
-barriers.</p>
-
-<h5>Arguments:</h5>
-
-<p>The argument is the address to read from, which should be an address
-allocated from the garbage collector.</p>
+<p>
+The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
+values with an even number of bytes (positive multiple of 16 bits). These are
+useful for performing operations on data that is not in the target's native
+byte order.
+</p>
<h5>Semantics:</h5>
-<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
-instruction, but may be replaced with substantially more complex code by the
-garbage collector runtime, as needed.</p>
+<p>
+The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
+and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
+intrinsic returns an i32 value that has the four bytes of the input i32
+swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
+i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
+<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
+additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
+</p>
</div>
-
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
+ <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<h5>Syntax:</h5>
-
+<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
+width. Not all targets support all bit widths however.
<pre>
- call void (sbyte*, sbyte**)* %llvm.gcwrite(sbyte* %P1, sbyte** %P2)
+ declare i8 @llvm.ctpop.i8 (i8 <src>)
+ declare i16 @llvm.ctpop.i16(i16 <src>)
+ declare i32 @llvm.ctpop.i32(i32 <src>)
+ declare i64 @llvm.ctpop.i64(i64 <src>)
+ declare i256 @llvm.ctpop.i256(i256 <src>)
</pre>
<h5>Overview:</h5>
-<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
-locations, allowing garbage collector implementations that require write
-barriers (such as generational or reference counting collectors).</p>
+<p>
+The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
+value.
+</p>
<h5>Arguments:</h5>
-<p>The first argument is the reference to store, and the second is the heap
-location to store to.</p>
-
-<h5>Semantics:</h5>
-
-<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
-instruction, but may be replaced with substantially more complex code by the
-garbage collector runtime, as needed.</p>
-
-</div>
-
-
+<p>
+The only argument is the value to be counted. The argument may be of any
+integer type. The return type must match the argument type.
+</p>
-<!-- ======================================================================= -->
-<div class="doc_subsection">
- <a name="int_codegen">Code Generator Intrinsics</a>
-</div>
+<h5>Semantics:</h5>
-<div class="doc_text">
<p>
-These intrinsics are provided by LLVM to expose special features that may only
-be implemented with code generator support.
+The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
</p>
-
</div>
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
+ <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<h5>Syntax:</h5>
+<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
+integer bit width. Not all targets support all bit widths however.
<pre>
- call void* ()* %llvm.returnaddress(uint <level>)
+ declare i8 @llvm.ctlz.i8 (i8 <src>)
+ declare i16 @llvm.ctlz.i16(i16 <src>)
+ declare i32 @llvm.ctlz.i32(i32 <src>)
+ declare i64 @llvm.ctlz.i64(i64 <src>)
+ declare i256 @llvm.ctlz.i256(i256 <src>)
</pre>
<h5>Overview:</h5>
<p>
-The '<tt>llvm.returnaddress</tt>' intrinsic returns a target-specific value
-indicating the return address of the current function or one of its callers.
+The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
+leading zeros in a variable.
</p>
<h5>Arguments:</h5>
<p>
-The argument to this intrinsic indicates which function to return the address
-for. Zero indicates the calling function, one indicates its caller, etc. The
-argument is <b>required</b> to be a constant integer value.
+The only argument is the value to be counted. The argument may be of any
+integer type. The return type must match the argument type.
</p>
<h5>Semantics:</h5>
<p>
-The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
-the return address of the specified call frame, or zero if it cannot be
-identified. The value returned by this intrinsic is likely to be incorrect or 0
-for arguments other than zero, so it should only be used for debugging purposes.
-</p>
-
-<p>
-Note that calling this intrinsic does not prevent function inlining or other
-aggressive transformations, so the value returned may not that of the obvious
-source-language caller.
+The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
+in a variable. If the src == 0 then the result is the size in bits of the type
+of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
</p>
</div>
+
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
+ <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<h5>Syntax:</h5>
+<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
+integer bit width. Not all targets support all bit widths however.
<pre>
- call void* ()* %llvm.frameaddress(uint <level>)
+ declare i8 @llvm.cttz.i8 (i8 <src>)
+ declare i16 @llvm.cttz.i16(i16 <src>)
+ declare i32 @llvm.cttz.i32(i32 <src>)
+ declare i64 @llvm.cttz.i64(i64 <src>)
+ declare i256 @llvm.cttz.i256(i256 <src>)
</pre>
<h5>Overview:</h5>
<p>
-The '<tt>llvm.frameaddress</tt>' intrinsic returns the target-specific frame
-pointer value for the specified stack frame.
+The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
+trailing zeros.
</p>
<h5>Arguments:</h5>
<p>
-The argument to this intrinsic indicates which function to return the frame
-pointer for. Zero indicates the calling function, one indicates its caller,
-etc. The argument is <b>required</b> to be a constant integer value.
+The only argument is the value to be counted. The argument may be of any
+integer type. The return type must match the argument type.
</p>
<h5>Semantics:</h5>
<p>
-The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
-the frame address of the specified call frame, or zero if it cannot be
-identified. The value returned by this intrinsic is likely to be incorrect or 0
-for arguments other than zero, so it should only be used for debugging purposes.
-</p>
-
-<p>
-Note that calling this intrinsic does not prevent function inlining or other
-aggressive transformations, so the value returned may not that of the obvious
-source-language caller.
+The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
+in a variable. If the src == 0 then the result is the size in bits of the type
+of src. For example, <tt>llvm.cttz(2) = 1</tt>.
</p>
</div>
-<!-- ======================================================================= -->
-<div class="doc_subsection">
- <a name="int_os">Operating System Intrinsics</a>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
</div>
<div class="doc_text">
-<p>
-These intrinsics are provided by LLVM to support the implementation of
-operating system level code.
-</p>
+<h5>Syntax:</h5>
+<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
+on any integer bit width.
+<pre>
+ declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
+ declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
+</pre>
+
+<h5>Overview:</h5>
+<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
+range of bits from an integer value and returns them in the same bit width as
+the original value.</p>
+
+<h5>Arguments:</h5>
+<p>The first argument, <tt>%val</tt> and the result may be integer types of
+any bit width but they must have the same bit width. The second and third
+arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
+
+<h5>Semantics:</h5>
+<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
+of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
+<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
+operates in forward mode.</p>
+<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
+right by <tt>%loBit</tt> bits and then ANDing it with a mask with
+only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
+<ol>
+ <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
+ by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
+ <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
+ to determine the number of bits to retain.</li>
+ <li>A mask of the retained bits is created by shifting a -1 value.</li>
+ <li>The mask is ANDed with <tt>%val</tt> to produce the result.
+</ol>
+<p>In reverse mode, a similar computation is made except that the bits are
+returned in the reverse order. So, for example, if <tt>X</tt> has the value
+<tt>i16 0x0ACF (101011001111)</tt> and we apply
+<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
+<tt>i16 0x0026 (000000100110)</tt>.</p>
</div>
-<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_readport">'<tt>llvm.readport</tt>' Intrinsic</a>
+ <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<h5>Syntax:</h5>
+<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
+on any integer bit width.
<pre>
- call <integer type> (<integer type>)* %llvm.readport (<integer type> <address>)
+ declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
+ declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
</pre>
<h5>Overview:</h5>
-
-<p>
-The '<tt>llvm.readport</tt>' intrinsic reads data from the specified hardware
-I/O port.
-</p>
+<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
+of bits in an integer value with another integer value. It returns the integer
+with the replaced bits.</p>
<h5>Arguments:</h5>
+<p>The first argument, <tt>%val</tt> and the result may be integer types of
+any bit width but they must have the same bit width. <tt>%val</tt> is the value
+whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
+integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
+type since they specify only a bit index.</p>
+
+<h5>Semantics:</h5>
+<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
+of operation: forwards and reverse. If <tt>%lo</tt> is greater than
+<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
+operates in forward mode.</p>
+<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
+truncating it down to the size of the replacement area or zero extending it
+up to that size.</p>
+<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
+are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
+in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
+to the <tt>%hi</tt>th bit.
+<p>In reverse mode, a similar computation is made except that the bits are
+reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
+<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.
+<h5>Examples:</h5>
+<pre>
+ llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
+ llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
+ llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
+ llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
+ llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
+</pre>
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="int_debugger">Debugger Intrinsics</a>
+</div>
+<div class="doc_text">
<p>
-The argument to this intrinsic indicates the hardware I/O address from which
-to read the data. The address is in the hardware I/O address namespace (as
-opposed to being a memory location for memory mapped I/O).
+The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
+are described in the <a
+href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
+Debugging</a> document.
</p>
+</div>
-<h5>Semantics:</h5>
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="int_eh">Exception Handling Intrinsics</a>
+</div>
+
+<div class="doc_text">
+<p> The LLVM exception handling intrinsics (which all start with
+<tt>llvm.eh.</tt> prefix), are described in the <a
+href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
+Handling</a> document. </p>
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="int_trampoline">Trampoline Intrinsic</a>
+</div>
+
+<div class="doc_text">
<p>
-The '<tt>llvm.readport</tt>' intrinsic reads data from the hardware I/O port
-specified by <i>address</i> and returns the value. The address and return
-value must be integers, but the size is dependent upon the platform upon which
-the program is code generated. For example, on x86, the address must be an
-unsigned 16 bit value, and the return value must be 8, 16, or 32 bits.
+ This intrinsic makes it possible to excise one parameter, marked with
+ the <tt>nest</tt> attribute, from a function. The result is a callable
+ function pointer lacking the nest parameter - the caller does not need
+ to provide a value for it. Instead, the value to use is stored in
+ advance in a "trampoline", a block of memory usually allocated
+ on the stack, which also contains code to splice the nest value into the
+ argument list. This is used to implement the GCC nested function address
+ extension.
</p>
-
+<p>
+ For example, if the function is
+ <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
+ pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p>
+<pre>
+ %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
+ %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
+ %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
+ %fp = bitcast i8* %p to i32 (i32, i32)*
+</pre>
+ <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
+ to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
</div>
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_writeport">'<tt>llvm.writeport</tt>' Intrinsic</a>
+ <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
</div>
-
<div class="doc_text">
-
<h5>Syntax:</h5>
<pre>
- call void (<integer type>, <integer type>)* %llvm.writeport (<integer type> <value>, <integer type> <address>)
+declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
</pre>
-
<h5>Overview:</h5>
-
<p>
-The '<tt>llvm.writeport</tt>' intrinsic writes data to the specified hardware
-I/O port.
+ This fills the memory pointed to by <tt>tramp</tt> with code
+ and returns a function pointer suitable for executing it.
</p>
-
<h5>Arguments:</h5>
-
<p>
-The first argument is the value to write to the I/O port.
+ The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
+ pointers. The <tt>tramp</tt> argument must point to a sufficiently large
+ and sufficiently aligned block of memory; this memory is written to by the
+ intrinsic. Note that the size and the alignment are target-specific - LLVM
+ currently provides no portable way of determining them, so a front-end that
+ generates this intrinsic needs to have some target-specific knowledge.
+ The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
</p>
-
+<h5>Semantics:</h5>
<p>
-The second argument indicates the hardware I/O address to which data should be
-written. The address is in the hardware I/O address namespace (as opposed to
-being a memory location for memory mapped I/O).
+ The block of memory pointed to by <tt>tramp</tt> is filled with target
+ dependent code, turning it into a function. A pointer to this function is
+ returned, but needs to be bitcast to an
+ <a href="#int_trampoline">appropriate function pointer type</a>
+ before being called. The new function's signature is the same as that of
+ <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
+ removed. At most one such <tt>nest</tt> argument is allowed, and it must be
+ of pointer type. Calling the new function is equivalent to calling
+ <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
+ missing <tt>nest</tt> argument. If, after calling
+ <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
+ modified, then the effect of any later call to the returned function pointer is
+ undefined.
</p>
+</div>
-<h5>Semantics:</h5>
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
+</div>
+<div class="doc_text">
<p>
-The '<tt>llvm.writeport</tt>' intrinsic writes <i>value</i> to the I/O port
-specified by <i>address</i>. The address and value must be integers, but the
-size is dependent upon the platform upon which the program is code generated.
-For example, on x86, the address must be an unsigned 16 bit value, and the
-value written must be 8, 16, or 32 bits in length.
+ These intrinsic functions expand the "universal IR" of LLVM to represent
+ hardware constructs for atomic operations and memory synchronization. This
+ provides an interface to the hardware, not an interface to the programmer. It
+ is aimed at a low enough level to allow any programming models or APIs which
+ need atomic behaviors to map cleanly onto it. It is also modeled primarily on
+ hardware behavior. Just as hardware provides a "universal IR" for source
+ languages, it also provides a starting point for developing a "universal"
+ atomic operation and synchronization IR.
</p>
+<p>
+ These do <em>not</em> form an API such as high-level threading libraries,
+ software transaction memory systems, atomic primitives, and intrinsic
+ functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
+ application libraries. The hardware interface provided by LLVM should allow
+ a clean implementation of all of these APIs and parallel programming models.
+ No one model or paradigm should be selected above others unless the hardware
+ itself ubiquitously does so.
+</p>
</div>
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_readio">'<tt>llvm.readio</tt>' Intrinsic</a>
+ <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
</div>
-
<div class="doc_text">
-
<h5>Syntax:</h5>
<pre>
- call <result> (<ty>*)* %llvm.readio (<ty> * <pointer>)
-</pre>
+declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
+i1 <device> )
+</pre>
<h5>Overview:</h5>
-
<p>
-The '<tt>llvm.readio</tt>' intrinsic reads data from a memory mapped I/O
-address.
+ The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
+ specific pairs of memory access types.
</p>
-
<h5>Arguments:</h5>
-
<p>
-The argument to this intrinsic is a pointer indicating the memory address from
-which to read the data. The data must be a
-<a href="#t_firstclass">first class</a> type.
-</p>
+ The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
+ The first four arguments enables a specific barrier as listed below. The fith
+ argument specifies that the barrier applies to io or device or uncached memory.
+</p>
+ <ul>
+ <li><tt>ll</tt>: load-load barrier</li>
+ <li><tt>ls</tt>: load-store barrier</li>
+ <li><tt>sl</tt>: store-load barrier</li>
+ <li><tt>ss</tt>: store-store barrier</li>
+ <li><tt>device</tt>: barrier applies to device and uncached memory also.
+ </ul>
<h5>Semantics:</h5>
-
<p>
-The '<tt>llvm.readio</tt>' intrinsic reads data from a memory mapped I/O
-location specified by <i>pointer</i> and returns the value. The argument must
-be a pointer, and the return value must be a
-<a href="#t_firstclass">first class</a> type. However, certain architectures
-may not support I/O on all first class types. For example, 32 bit processors
-may only support I/O on data types that are 32 bits or less.
+ This intrinsic causes the system to enforce some ordering constraints upon
+ the loads and stores of the program. This barrier does not indicate
+ <em>when</em> any events will occur, it only enforces an <em>order</em> in
+ which they occur. For any of the specified pairs of load and store operations
+ (f.ex. load-load, or store-load), all of the first operations preceding the
+ barrier will complete before any of the second operations succeeding the
+ barrier begin. Specifically the semantics for each pairing is as follows:
</p>
-
+ <ul>
+ <li><tt>ll</tt>: All loads before the barrier must complete before any load
+ after the barrier begins.</li>
+
+ <li><tt>ls</tt>: All loads before the barrier must complete before any
+ store after the barrier begins.</li>
+ <li><tt>ss</tt>: All stores before the barrier must complete before any
+ store after the barrier begins.</li>
+ <li><tt>sl</tt>: All stores before the barrier must complete before any
+ load after the barrier begins.</li>
+ </ul>
<p>
-This intrinsic enforces an in-order memory model for llvm.readio and
-llvm.writeio calls on machines that use dynamic scheduling. Dynamically
-scheduled processors may execute loads and stores out of order, re-ordering at
-run time accesses to memory mapped I/O registers. Using these intrinsics
-ensures that accesses to memory mapped I/O registers occur in program order.
+ These semantics are applied with a logical "and" behavior when more than one
+ is enabled in a single memory barrier intrinsic.
</p>
+<p>
+ Backends may implement stronger barriers than those requested when they do not
+ support as fine grained a barrier as requested. Some architectures do not
+ need all types of barriers and on such architectures, these become noops.
+</p>
+<h5>Example:</h5>
+<pre>
+%ptr = malloc i32
+ store i32 4, %ptr
+%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
+ call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
+ <i>; guarantee the above finishes</i>
+ store i32 8, %ptr <i>; before this begins</i>
+</pre>
</div>
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_writeio">'<tt>llvm.writeio</tt>' Intrinsic</a>
+ <a name="int_atomic_lcs">'<tt>llvm.atomic.lcs.*</tt>' Intrinsic</a>
</div>
-
<div class="doc_text">
-
<h5>Syntax:</h5>
+<p>
+ This is an overloaded intrinsic. You can use <tt>llvm.atomic.lcs</tt> on any
+ integer bit width. Not all targets support all bit widths however.</p>
+
<pre>
- call void (<ty1>, <ty2>*)* %llvm.writeio (<ty1> <value>, <ty2> * <pointer>)
-</pre>
+declare i8 @llvm.atomic.lcs.i8( i8* <ptr>, i8 <cmp>, i8 <val> )
+declare i16 @llvm.atomic.lcs.i16( i16* <ptr>, i16 <cmp>, i16 <val> )
+declare i32 @llvm.atomic.lcs.i32( i32* <ptr>, i32 <cmp>, i32 <val> )
+declare i64 @llvm.atomic.lcs.i64( i64* <ptr>, i64 <cmp>, i64 <val> )
+</pre>
<h5>Overview:</h5>
-
<p>
-The '<tt>llvm.writeio</tt>' intrinsic writes data to the specified memory
-mapped I/O address.
+ This loads a value in memory and compares it to a given value. If they are
+ equal, it stores a new value into the memory.
</p>
-
<h5>Arguments:</h5>
-
<p>
-The first argument is the value to write to the memory mapped I/O location.
-The second argument is a pointer indicating the memory address to which the
-data should be written.
-</p>
-
-<h5>Semantics:</h5>
+ The <tt>llvm.atomic.lcs</tt> intrinsic takes three arguments. The result as
+ well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
+ same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
+ this integer type. While any bit width integer may be used, targets may only
+ lower representations they support in hardware.
-<p>
-The '<tt>llvm.writeio</tt>' intrinsic writes <i>value</i> to the memory mapped
-I/O address specified by <i>pointer</i>. The value must be a
-<a href="#t_firstclass">first class</a> type. However, certain architectures
-may not support I/O on all first class types. For example, 32 bit processors
-may only support I/O on data types that are 32 bits or less.
</p>
-
+<h5>Semantics:</h5>
<p>
-This intrinsic enforces an in-order memory model for llvm.readio and
-llvm.writeio calls on machines that use dynamic scheduling. Dynamically
-scheduled processors may execute loads and stores out of order, re-ordering at
-run time accesses to memory mapped I/O registers. Using these intrinsics
-ensures that accesses to memory mapped I/O registers occur in program order.
+ This entire intrinsic must be executed atomically. It first loads the value
+ in memory pointed to by <tt>ptr</tt> and compares it with the value
+ <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
+ loaded value is yielded in all cases. This provides the equivalent of an
+ atomic compare-and-swap operation within the SSA framework.
</p>
+<h5>Examples:</h5>
-</div>
-
+<pre>
+%ptr = malloc i32
+ store i32 4, %ptr
-<!-- ======================================================================= -->
-<div class="doc_subsection">
- <a name="int_libc">Standard C Library Intrinsics</a>
-</div>
+%val1 = add i32 4, 4
+%result1 = call i32 @llvm.atomic.lcs.i32( i32* %ptr, i32 4, %val1 )
+ <i>; yields {i32}:result1 = 4</i>
+%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
+%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
-<div class="doc_text">
-<p>
-LLVM provides intrinsics for a few important standard C library functions.
-These intrinsics allow source-language front-ends to pass information about the
-alignment of the pointer arguments to the code generator, providing opportunity
-for more efficient code generation.
-</p>
+%val2 = add i32 1, 1
+%result2 = call i32 @llvm.atomic.lcs.i32( i32* %ptr, i32 5, %val2 )
+ <i>; yields {i32}:result2 = 8</i>
+%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
+%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
+</pre>
</div>
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
+ <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
</div>
-
<div class="doc_text">
-
<h5>Syntax:</h5>
+
+<p>
+ This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
+ integer bit width. Not all targets support all bit widths however.</p>
<pre>
- call void (sbyte*, sbyte*, uint, uint)* %llvm.memcpy(sbyte* <dest>, sbyte* <src>,
- uint <len>, uint <align>)
-</pre>
+declare i8 @llvm.atomic.swap.i8( i8* <ptr>, i8 <val> )
+declare i16 @llvm.atomic.swap.i16( i16* <ptr>, i16 <val> )
+declare i32 @llvm.atomic.swap.i32( i32* <ptr>, i32 <val> )
+declare i64 @llvm.atomic.swap.i64( i64* <ptr>, i64 <val> )
+</pre>
<h5>Overview:</h5>
-
<p>
-The '<tt>llvm.memcpy</tt>' intrinsic copies a block of memory from the source
-location to the destination location.
+ This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
+ the value from memory. It then stores the value in <tt>val</tt> in the memory
+ at <tt>ptr</tt>.
</p>
+<h5>Arguments:</h5>
<p>
-Note that, unlike the standard libc function, the <tt>llvm.memcpy</tt> intrinsic
-does not return a value, and takes an extra alignment argument.
+ The <tt>llvm.atomic.ls</tt> intrinsic takes two arguments. Both the
+ <tt>val</tt> argument and the result must be integers of the same bit width.
+ The first argument, <tt>ptr</tt>, must be a pointer to a value of this
+ integer type. The targets may only lower integer representations they
+ support.
+</p>
+<h5>Semantics:</h5>
+<p>
+ This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
+ stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
+ equivalent of an atomic swap operation within the SSA framework.
+
</p>
+<h5>Examples:</h5>
+<pre>
+%ptr = malloc i32
+ store i32 4, %ptr
-<h5>Arguments:</h5>
+%val1 = add i32 4, 4
+%result1 = call i32 @llvm.atomic.swap.i32( i32* %ptr, i32 %val1 )
+ <i>; yields {i32}:result1 = 4</i>
+%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
+%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
+
+%val2 = add i32 1, 1
+%result2 = call i32 @llvm.atomic.swap.i32( i32* %ptr, i32 %val2 )
+ <i>; yields {i32}:result2 = 8</i>
+
+%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
+%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
+</pre>
+</div>
+
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="int_atomic_las">'<tt>llvm.atomic.las.*</tt>' Intrinsic</a>
+</div>
+<div class="doc_text">
+<h5>Syntax:</h5>
<p>
-The first argument is a pointer to the destination, the second is a pointer to
-the source. The third argument is an (arbitrarily sized) integer argument
-specifying the number of bytes to copy, and the fourth argument is the alignment
-of the source and destination locations.
-</p>
+ This is an overloaded intrinsic. You can use <tt>llvm.atomic.las</tt> on any
+ integer bit width. Not all targets support all bit widths however.</p>
+<pre>
+declare i8 @llvm.atomic.las.i8.( i8* <ptr>, i8 <delta> )
+declare i16 @llvm.atomic.las.i16.( i16* <ptr>, i16 <delta> )
+declare i32 @llvm.atomic.las.i32.( i32* <ptr>, i32 <delta> )
+declare i64 @llvm.atomic.las.i64.( i64* <ptr>, i64 <delta> )
+</pre>
+<h5>Overview:</h5>
<p>
-If the call to this intrinisic has an alignment value that is not 0 or 1, then
-the caller guarantees that the size of the copy is a multiple of the alignment
-and that both the source and destination pointers are aligned to that boundary.
+ This intrinsic adds <tt>delta</tt> to the value stored in memory at
+ <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
</p>
+<h5>Arguments:</h5>
+<p>
+ The intrinsic takes two arguments, the first a pointer to an integer value
+ and the second an integer value. The result is also an integer value. These
+ integer types can have any bit width, but they must all have the same bit
+ width. The targets may only lower integer representations they support.
+</p>
<h5>Semantics:</h5>
-
<p>
-The '<tt>llvm.memcpy</tt>' intrinsic copies a block of memory from the source
-location to the destination location, which are not allowed to overlap. It
-copies "len" bytes of memory over. If the argument is known to be aligned to
-some boundary, this can be specified as the fourth argument, otherwise it should
-be set to 0 or 1.
+ This intrinsic does a series of operations atomically. It first loads the
+ value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
+ to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
</p>
+
+<h5>Examples:</h5>
+<pre>
+%ptr = malloc i32
+ store i32 4, %ptr
+%result1 = call i32 @llvm.atomic.las.i32( i32* %ptr, i32 4 )
+ <i>; yields {i32}:result1 = 4</i>
+%result2 = call i32 @llvm.atomic.las.i32( i32* %ptr, i32 2 )
+ <i>; yields {i32}:result2 = 8</i>
+%result3 = call i32 @llvm.atomic.las.i32( i32* %ptr, i32 5 )
+ <i>; yields {i32}:result3 = 10</i>
+%memval = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
+</pre>
+</div>
+
+
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="int_general">General Intrinsics</a>
</div>
+<div class="doc_text">
+<p> This class of intrinsics is designed to be generic and has
+no specific purpose. </p>
+</div>
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
+ <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<h5>Syntax:</h5>
<pre>
- call void (sbyte*, sbyte*, uint, uint)* %llvm.memmove(sbyte* <dest>, sbyte* <src>,
- uint <len>, uint <align>)
+ declare void @llvm.var.annotation(i8* <val>, i8* <str>, i8* <str>, i32 <int> )
</pre>
<h5>Overview:</h5>
<p>
-The '<tt>llvm.memmove</tt>' intrinsic moves a block of memory from the source
-location to the destination location. It is similar to the '<tt>llvm.memcpy</tt>'
-intrinsic but allows the two memory locations to overlap.
-</p>
-
-<p>
-Note that, unlike the standard libc function, the <tt>llvm.memmove</tt> intrinsic
-does not return a value, and takes an extra alignment argument.
+The '<tt>llvm.var.annotation</tt>' intrinsic
</p>
<h5>Arguments:</h5>
<p>
-The first argument is a pointer to the destination, the second is a pointer to
-the source. The third argument is an (arbitrarily sized) integer argument
-specifying the number of bytes to copy, and the fourth argument is the alignment
-of the source and destination locations.
-</p>
-
-<p>
-If the call to this intrinisic has an alignment value that is not 0 or 1, then
-the caller guarantees that the size of the copy is a multiple of the alignment
-and that both the source and destination pointers are aligned to that boundary.
+The first argument is a pointer to a value, the second is a pointer to a
+global string, the third is a pointer to a global string which is the source
+file name, and the last argument is the line number.
</p>
<h5>Semantics:</h5>
<p>
-The '<tt>llvm.memmove</tt>' intrinsic copies a block of memory from the source
-location to the destination location, which may overlap. It
-copies "len" bytes of memory over. If the argument is known to be aligned to
-some boundary, this can be specified as the fourth argument, otherwise it should
-be set to 0 or 1.
+This intrinsic allows annotation of local variables with arbitrary strings.
+This can be useful for special purpose optimizations that want to look for these
+annotations. These have no other defined use, they are ignored by code
+generation and optimization.
</p>
</div>
-
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_memset">'<tt>llvm.memset</tt>' Intrinsic</a>
+ <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<h5>Syntax:</h5>
+<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
+any integer bit width.
+</p>
<pre>
- call void (sbyte*, ubyte, uint, uint)* %llvm.memset(sbyte* <dest>, ubyte <val>,
- uint <len>, uint <align>)
+ declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
+ declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
+ declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
+ declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
+ declare i256 @llvm.annotation.i256(i256 <val>, i8* <str>, i8* <str>, i32 <int> )
</pre>
<h5>Overview:</h5>
<p>
-The '<tt>llvm.memset</tt>' intrinsic fills a block of memory with a particular
-byte value.
-</p>
-
-<p>
-Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
-does not return a value, and takes an extra alignment argument.
+The '<tt>llvm.annotation</tt>' intrinsic.
</p>
<h5>Arguments:</h5>
<p>
-The first argument is a pointer to the destination to fill, the second is the
-byte value to fill it with, the third argument is an (arbitrarily sized) integer
-argument specifying the number of bytes to fill, and the fourth argument is the
-known alignment of destination location.
-</p>
-
-<p>
-If the call to this intrinisic has an alignment value that is not 0 or 1, then
-the caller guarantees that the size of the copy is a multiple of the alignment
-and that the destination pointer is aligned to that boundary.
+The first argument is an integer value (result of some expression),
+the second is a pointer to a global string, the third is a pointer to a global
+string which is the source file name, and the last argument is the line number.
+It returns the value of the first argument.
</p>
<h5>Semantics:</h5>
<p>
-The '<tt>llvm.memset</tt>' intrinsic fills "len" bytes of memory starting at the
-destination location. If the argument is known to be aligned to some boundary,
-this can be specified as the fourth argument, otherwise it should be set to 0 or
-1.
-</p>
+This intrinsic allows annotations to be put on arbitrary expressions
+with arbitrary strings. This can be useful for special purpose optimizations
+that want to look for these annotations. These have no other defined use, they
+are ignored by code generation and optimization.
</div>
-
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_isnan">'<tt>llvm.isnan</tt>' Intrinsic</a>
+ <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<h5>Syntax:</h5>
<pre>
- call bool (<float or double>)* %llvm.isnan(<float or double> Val)
+ declare void @llvm.trap()
</pre>
<h5>Overview:</h5>
<p>
-The '<tt>llvm.isnan</tt>' intrinsic returns true if the specific floating point
-value is a NAN.
+The '<tt>llvm.trap</tt>' intrinsic
</p>
<h5>Arguments:</h5>
<p>
-The argument is a floating point number.
+None
</p>
<h5>Semantics:</h5>
<p>
-If the argument is a SNAN or QNAN, it returns true, otherwise false.
-</p>
-</div>
-
-
-
-
-<!-- ======================================================================= -->
-<div class="doc_subsection">
- <a name="int_debugger">Debugger Intrinsics</a>
-</div>
-
-<div class="doc_text">
-<p>
-The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
-are described in the <a
-href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
-Debugging</a> document.
+This intrinsics is lowered to the target dependent trap instruction. If the
+target does not have a trap instruction, this intrinsic will be lowered to the
+call of the abort() function.
</p>
</div>
-
<!-- *********************************************************************** -->
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+ <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
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