<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="#moduleasm">Module-Level Inline Assembly</a></li>
<li><a href="#datalayout">Data Layout</a></li>
<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="#i_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
- <li><a href="#i_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
- <li><a href="#i_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
- <li><a href="#i_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
- <li><a href="#i_readcyclecounter"><tt>llvm.readcyclecounter</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_libc">Standard C Library 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_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
- <li><a href="#i_powi">'<tt>llvm.powi.*</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>
</ol>
</li>
<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
<ol>
- <li><a href="#i_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</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>
until linked, if not linked, the symbol becomes null instead of being an
undefined reference.
</dd>
-</dl>
<dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
visible, meaning that it participates in linkage and can be used to resolve
external symbol references.
</dd>
+</dl>
<p>
The next two types of linkage are targeted for Microsoft Windows platform
<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>
<!-- ======================================================================= -->
<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 a global "constant," which indicates that the
-contents of the variable will <b>never</b> be modified (enabling better
+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>
</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="aliasstructure">Aliases</a>
+</div>
+<div class="doc_text">
+ <p>Aliases act as "second name" for the aliasee value (which can be either
+ function or global variable 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>
+
+ <pre>
+ @<Name> = [Linkage] [Visibility] alias <AliaseeTy> @<Aliasee>
+ </pre>
+
+</div>
+
+
+
<!-- ======================================================================= -->
<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
<div class="doc_text">
<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:<br/>
-<pre> target datalayout = "<i>layout specification</i>"
-</pre>
-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>
+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
<h5>Examples:</h5>
<table class="layout">
<tr class="layout">
- <td class="left">
- <tt>{ i32, i32, i32 }</tt><br/>
- <tt>{ float, i32 (i32) * }</tt><br/>
- </td>
- <td class="left">
- a triple of three <tt>i32</tt> values<br/>
- 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>.<br/>
- </td>
+ <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>
<h5>Examples:</h5>
<table class="layout">
<tr class="layout">
- <td class="left">
- <tt> < { i32, i32, i32 } > </tt><br/>
- <tt> < { float, i32 (i32) * } > </tt><br/>
- </td>
- <td class="left">
- a triple of three <tt>i32</tt> values<br/>
- 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>.<br/>
- </td>
+ <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>
<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>". V
Ector constants must have <a
+ i32 11, i32 74, i32 100 ></tt>". V
ector 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>
</p>
<pre>
- %X = call i32 asm "<a href="#i_bswap">bswap</a> $0", "=r,r"(i32 %Y)
+ %X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
</pre>
<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 %Test(i32 15) to label %Continue
- unwind label %TestCleanup <i>; {i32}:retval set</i>
+ %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 %Test(i32 15) to label %Continue
+ unwind label %TestCleanup <i>; {i32}:retval set</i>
</pre>
</div>
<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
operands.</p>
<h5>Arguments:</h5>
-<p>The two arguments to the '<tt>div</tt>' instruction must be
+<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
<a href="#t_floating">floating point</a> values. Both arguments must have
identical types. This instruction can also take <a href="#t_vector">vector</a>
-versions of the values in which case the elements must be floating point.</p>
+versions of floating point values.</p>
<h5>Semantics:</h5>
<p>The value produced is the floating point quotient of the two operands.</p>
<h5>Example:</h5>
<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.</p>
+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
<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.</p>
+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
<div class="doc_text">
<p>LLVM supports several instructions to represent vector operations in a
-target-independent manner. This instructions cover the element-access and
+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
<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>
+ <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>
<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
+<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.</p>
<h5>Arguments:</h5>
Instruction</a> </div>
<div class="doc_text">
<h5>Syntax:</h5>
-<pre> <result> = load <ty>* <pointer><br> <result> = volatile load <ty>* <pointer><br></pre>
+<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>
Instruction</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> 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 in which to store it. The type of the '<tt><pointer></tt>'
+to store and an address at which to store it. 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
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> types, require <tt>i32</tt>
+to 64-bits. <a href="#t_struct">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>'
<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>
+ %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
<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>
+ %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
</pre>
</div>
<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>
+ %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
</pre>
</div>
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>).</p>
+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</i>
- %Y = ptrtoint i32* %x to i64 <i>; yields zero extend on 32-bit</i>
+ %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>
<h5>Example:</h5>
<pre>
- %X = inttoptr i32 255 to i32* <i>; yields zero extend on 64-bit</i>
- %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit </i>
- %Y = inttoptr i16 0 to i32* <i>; yields zero extend on 32-bit</i>
+ %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>
<h5>Example:</h5>
<pre>
- %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
+ %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_text">
<h5>Syntax:</h5>
-<pre> <result> = icmp <cond> <ty> <var1>, <var2>
-<i>; yields {i1}:result</i>
+<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 operands.</p>
<h5>Arguments:</h5>
<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
-the condition code which indicates the kind of comparison to perform. It is not
-a value, just a keyword. The possibilities for the condition code are:
+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>
<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 treated as integers and then compared.</p>
+values are compared as if they were integers.</p>
<h5>Example:</h5>
<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
</div>
<div class="doc_text">
<h5>Syntax:</h5>
-<pre> <result> = fcmp <cond> <ty> <var1>, <var2>
-<i>; yields {i1}:result</i>
+<pre> <result> = fcmp <cond> <ty> <var1>, <var2> <i>; yields {i1}:result</i>
</pre>
<h5>Overview:</h5>
<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
of its floating point operands.</p>
<h5>Arguments:</h5>
<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
-the condition code which indicates the kind of comparison to perform. It is not
-a value, just a keyword. The possibilities for the condition code are:
+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>uno</tt>: unordered (either nans)</li>
<li><tt>true</tt>: no comparison, always returns true</li>
</ol>
-<p>In the preceding, <i>ordered</i> means that neither operand is a QNAN while
+<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>
-<p>In the foregoing, <i>ordered</i> means that neither operand is a QNAN and
-<i>unordered</i> means that either operand is a QNAN.</p>
<h5>Semantics:</h5>
<p>The '<tt>fcmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
the condition code given as <tt>cond</tt>. The comparison performed always
<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 type of the incoming values are specified with the first type
+<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>
block and the PHI instructions: i.e. PHI instructions must be first in
a basic block.</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>
+<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>Loop: ; Infinite loop that counts from 0 on up...<br> %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]<br> %nextindvar = add i32 %indvar, 1<br> br label %Loop<br></pre>
</div>
<pre>
%retval = call i32 %test(i32 %argc)
- call i32(i8 *, ...) *%printf(i8 * %msg, i32 12, i8 42);
+ call i32(i8 *, ...) *%printf(i8 * %msg, i32 12, i8 42);
%X = tail call i32 %foo()
%Y = tail call <a href="#callingconv">fastcc</a> i32 %foo()
</pre>
<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. Again, the
+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>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 to
-add to the language (or the bytecode reader/writer, the parser,
-etc...).</p>
+language that does not require changing all of the transformations in LLVM when
+adding to the language (or the bytecode 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, 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>Some intrinsic functions can be overloaded. That is, the intrinsic represents
+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. This is most frequent with the integer types. Since LLVM can represent
over 8 million different integer types, there is a way to declare an intrinsic
-that can be overloaded based on its arguments. Such intrinsics will have the
-names of the arbitrary types encoded into the intrinsic function name, each
+that can be overloaded based on its arguments. Such an intrinsic will have the
+names of its argument types encoded into its function name, each
preceded by a period. For example, the <tt>llvm.ctpop</tt> function can take an
integer of any width. This leads to a family of functions such as
<tt>i32 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i32 @llvm.ctpop.i29(i29 %val)</tt>.
<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>
+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
<pre>
define i32 @test(i32 %X, ...) {
; Initialize variable argument processing
- %ap = alloca i8 *
+ %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
+ %tmp = va_arg i8** %ap, i32
; Demonstrate usage of llvm.va_copy and llvm.va_end
- %aq = alloca i8 *
+ %aq = alloca i8*
%aq2 = bitcast i8** %aq to i8*
- call void @llvm.va_copy(i8 *%aq2, i8* %ap2)
+ call void @llvm.va_copy(i8* %aq2, i8* %ap2)
call void @llvm.va_end(i8* %aq2)
; Stop processing of arguments.
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
+ <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
</div>
<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 the argument points to, so that the next call to
+<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, the compiler can figure that out.</p>
+last argument of the function as the compiler can figure that out.</p>
</div>
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
+ <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<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="#i_va_start">llvm.va_start</a></tt>
+<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 <tt>va_list</tt> to destroy.</p>
+<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>.
-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>
+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_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
+ <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<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.va_copy</tt>' intrinsic copies the current argument position
+from the source argument list to the destination argument list.</p>
<h5>Arguments:</h5>
<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 destination 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>
+<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>
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
+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="#i_gcread">read</a> and <a href="#i_gcwrite">write</a> barriers.
+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>.
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
+ <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
+ <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
+ <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
+ <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
+ <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
+ <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<p>
The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
-the function stack, for use with <a href="#i_stackrestore">
+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>
<p>
This intrinsic returns a opaque pointer value that can be passed to <a
-href="#i_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
+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
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
+ <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<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="#i_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
+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>
-See the description for <a href="#i_stacksave"><tt>llvm.stacksave</tt></a>.
+See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
</p>
</div>
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
+ <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
+ <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
+ <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
+ <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
+ <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
+ <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
</div>
<div class="doc_text">
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
+ <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
+ <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
</div>
<div class="doc_text">
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="i_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
+ <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
</div>
<div class="doc_text">
<h5>Overview:</h5>
<p>
-The '<tt>llvm.bwsap</tt>' family of intrinsics is used to byte swap integer
+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.
<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="int_bit_and_reduce">'<tt>llvm.bit.and.reduce.*</tt>' Intrinsic</a>
-</div>
-
-<div class="doc_text">
-<h5>Syntax:</h5>
-<p>This is an overloaded intrinsic. You can use <tt>llvm.bit.and.reduce</tt> on
-any integer bit width.
-<pre>
- declare i1 @llvm.bit.and.reduce.i32(i32 %val)
- declare i1 @llvm.bit.and.reduce.i97(i97 %val)
-</pre>
-<h5>Overview:</h5>
-<p>The '<tt>llvm.bit.and.reduce</tt>' family of intrinsic functions applies the
-AND operator bitwise to each bit in <tt>%val</tt> until it yields the result.
-</p>
-
-<h5>Arguments:</h5>
-<p>The argument may be any bit width. The result is always a 1-bit integer.</p>
-
-<h5>Semantics:</h5>
-<p>The '<tt>llvm.bit.and.reduce</tt>' intrinsic is the equivalent of a test
-against <tt>-1</tt>. Only if all bits in <tt>%val</tt> are set will the result
-be 1, otherwise 0.</p>
-</div>
-
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection">
- <a name="int_bit_or_reduce">'<tt>llvm.bit.or.reduce.*</tt>' Intrinsic</a>
-</div>
-
-<div class="doc_text">
-<h5>Syntax:</h5>
-<p>This is an overloaded intrinsic. You can use <tt>llvm.bit.or.reduce</tt> on
-any integer bit width.
-<pre>
- declare i1 @llvm.bit.or.reduce.i32(i32 %val)
- declare i1 @llvm.bit.or.reduce.i97(i97 %val)
-</pre>
-<h5>Overview:</h5>
-<p>The '<tt>llvm.bit.or.reduce</tt>' family of intrinsic functions applies the
-OR operator bitwise to each bit in <tt>%val</tt> until it yields the result.
-</p>
-
-<h5>Arguments:</h5>
-<p>The argument may be any bit width. The result is always a 1-bit integer.</p>
-
-<h5>Semantics:</h5>
-<p>The '<tt>llvm.bit.or.reduce</tt>' intrinsic is the equivalent of a test
-against <tt>0</tt>. Only if all bits in <tt>%val</tt> are clear will the result
-be 0, otherwise 1.</p>
-</div>
-
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection">
- <a name="int_bit_xor_reduce">'<tt>llvm.bit.xor.reduce.*</tt>' Intrinsic</a>
+ <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
</div>
<div class="doc_text">
-<h5>Syntax:</h5>
-<p>This is an overloaded intrinsic. You can use <tt>llvm.bit.xor.reduce</tt> on
-any integer bit width.
-<pre>
- declare i1 @llvm.bit.xor.reduce.i32(i32 %val)
- declare i1 @llvm.bit.xor.reduce.i97(i97 %val)
-</pre>
-<h5>Overview:</h5>
-<p>The '<tt>llvm.bit.xor.reduce</tt>' family of intrinsic functions applies the
-XOR operator bitwise to each bit in <tt>%val</tt> until it yields the result.
-</p>
-<h5>Arguments:</h5>
-<p>The argument may be any bit width. The result is always a 1-bit integer.</p>
-
-<h5>Semantics:</h5>
-<p>The '<tt>llvm.bit.xor.reduce</tt>' computes its result by performing an XOR
-operation on the two lowest order bits in <tt>%val</tt>. That result is then
-XOR'd with the next bit in <tt>%val</tt> and this process continues until all
-bits in <tt>%val</tt> have been XOR'd with the result of the previous XORs. The
-resulting bit is returned.</p>
-</div>
-
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection">
- <a name="int_bit_nand_reduce">'<tt>llvm.bit.nand.reduce.*</tt>' Intrinsic</a>
-</div>
-
-<div class="doc_text">
<h5>Syntax:</h5>
-<p>This is an overloaded intrinsic. You can use <tt>llvm.bit.nand.reduce</tt> on
-any integer bit width.
-<pre>
- declare i1 @llvm.bit.nand.reduce.i32(i32 %val)
- declare i1 @llvm.bit.nand.reduce.i97(i97 %val)
-</pre>
-<h5>Overview:</h5>
-<p>The '<tt>llvm.bit.nand.reduce</tt>' family of intrinsic functions applies the
-NAND operator bitwise to each bit in <tt>%val</tt> until it yields the result.
-</p>
-
-<h5>Arguments:</h5>
-<p>The argument may be any bit width. The result is always a 1-bit integer.</p>
-
-<h5>Semantics:</h5>
-<p>The '<tt>llvm.bit.nand.reduce</tt>' intrinsic is the equivalent of taking the
-complement of the <tt>llvm.bit.and.reduce</tt> intrinsic. That is, it returns 0
-if <tt>%val</tt> is all ones (-1) and 1 otherwise.</p>
-</div>
-
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection">
- <a name="int_bit_nor_reduce">'<tt>llvm.bit.nor.reduce.*</tt>' Intrinsic</a>
-</div>
-
-<div class="doc_text">
-<h5>Syntax:</h5>
-<p>This is an overloaded intrinsic. You can use <tt>llvm.bit.nor.reduce</tt> on
-any integer bit width.
-<pre>
- declare i1 @llvm.bit.nor.reduce.i32(i32 %val)
- declare i1 @llvm.bit.nor.reduce.i97(i97 %val)
-</pre>
-<h5>Overview:</h5>
-<p>The '<tt>llvm.bit.nor.reduce</tt>' family of intrinsic functions applies the
-NOR operator bitwise to each bit in <tt>%val</tt> until it yields the result.
-</p>
-
-<h5>Arguments:</h5>
-<p>The argument may be any bit width. The result is always a 1-bit integer.</p>
-
-<h5>Semantics:</h5>
-<p>The '<tt>llvm.bit.nor.reduce</tt>' intrinsic is equivalent to the complement
-of the <tt>llvm.bit.or.reduce</tt> intrinsic. That is, it returns 1 if all bits
-in <tt>%val</tt> are 0, and 1 otherwise.</p>
-</div>
-
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection">
- <a name="int_bit_nxor_reduce">'<tt>llvm.bit.nxor.reduce.*</tt>' Intrinsic</a>
-</div>
-
-<div class="doc_text">
-<h5>Syntax:</h5>
-<p>This is an overloaded intrinsic. You can use <tt>llvm.bit.nxor.reduce</tt> on
-any integer bit width.
-<pre>
- declare i1 @llvm.bit.nxor.reduce.i32(i32 %val)
- declare i1 @llvm.bit.nxor.reduce.i97(i97 %val)
-</pre>
-<h5>Overview:</h5>
-<p>The '<tt>llvm.bit.nxor.reduce</tt>' family of intrinsic functions applies the
-AND operator bitwise to each bit in <tt>%val</tt> until it yields the result.
-</p>
-
-<h5>Arguments:</h5>
-<p>The argument may be any bit width. The result is always a 1-bit integer.</p>
-
-<h5>Semantics:</h5>
-<p>The '<tt>llvm.bit.nxor.reduce</tt>' intrinsic is the equivalent of the
-complement of the <tt>llvm.bit.xor.reduce</tt> intrinsic.</p>
-</div>
-
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection">
- <a name="int_bit_select">'<tt>llvm.bit.select.*</tt>' Intrinsic</a>
-</div>
-
-<div class="doc_text">
-<h5>Syntax:</h5>
-<p>This is an overloaded intrinsic. You can use <tt>llvm.bit.select</tt> on any
-integer bit width.
-<pre>
- declare i1 @llvm.bit.select.i17 (i17 %val, i32 %bit)
- declare i1 @llvm.bit.select.i29 (i29 %val, i32 %bit)
-</pre>
-
-<h5>Overview:</h5>
-<p>The '<tt>llvm.bit.select</tt>' family of intrinsic functions selects a
-specific bit from an integer value and returns it.</p>
-
-<h5>Arguments:</h5>
-<p>The two arguments may be any bit width. The result is always a 1-bit
-integer. The first argument, <tt>%val</tt> may be any bit width and is the
-value from which the bit is selected. The second argument, <tt>%bit</tt> must
-be an <tt>i32</tt> and is the bit index of the bit to be selected. Bits are
-numbered starting with 0 as the lowest ordered bit.</p>
-
-<h5>Semantics:</h5>
-<p>The '<tt>llvm.bit.select</tt>' intrinsic is the equivalent of shift and a
-truncate operation. The <tt>%val</tt> is shifted right by <tt>%bit</tt> bits and
-then truncated to a 1-bit integer.</p>
-</div>
-
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection">
- <a name="int_bit_set">'<tt>llvm.bit.set.*</tt>' Intrinsic</a>
-</div>
-
-<div class="doc_text">
-<h5>Syntax:</h5>
-<p>This is an overloaded intrinsic. You can use <tt>llvm.bit.set</tt> on any
-integer bit width.
-<pre>
- declare i17 @llvm.bit.set.i17.i17 (i17 %val, i32 %bit)
- declare i52 @llvm.bit.set.i52.i52 (i52 %val, i32 %bit)
-</pre>
-
-<h5>Overview:</h5>
-<p>
-The '<tt>llvm.bit.set</tt>' family of intrinsic functions sets a specific bit in
-a <tt>%val</tt> and returns the result.</p>
-
-<h5>Arguments:</h5>
-<p>The result and the first argument, <tt>%val</tt>, may be an integer of any
-bit width, but they must be the same bit width. The second argument must be an
-<tt>i32</tt>.</p>
-
-<h5>Semantics:</h5>
-<p>The '<tt>llvm.bit.set</tt>' intrinsic is the equivalent of creating a bit
-mask for the <tt>%bit</tt> requested in the width of <tt>%val</tt>, ORing that
-mask with <tt>%val</tt> and returning the result.</p>
-</div>
-
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection">
- <a name="int_bit_clear">'<tt>llvm.bit.clear.*</tt>' Intrinsic</a>
-</div>
-
-<div class="doc_text">
-
-<h5>Syntax:</h5>
-<p>This is an overloaded intrinsic. You can use <tt>llvm.bit.clear</tt> on any
-integer bit width.
-<pre>
- declare i17 @llvm.bit.clear.i17.i17 (i17 %val, i32 %bit)
- declare i29 @llvm.bit.clear.i29.i29 (i29 %val, i32 %bit)
-</pre>
-
-<h5>Overview:</h5>
-<p>The '<tt>llvm.bit.clear</tt>' family of intrinsic functions clears a specific
-bit in a value and returns the result.</p>
-
-<h5>Arguments:</h5>
-<p>The result and the first argument, <tt>%val</tt>, may be an integer of any
-bit width, but they must be the same bit width. The second argument must be an
-<tt>i32</tt>.</p>
-
-<h5>Semantics:</h5>
-<p>The '<tt>llvm.bit.clear</tt>' intrinsic is the equivalent of making a bit
-mask in the width of <tt>%val</tt> but with the bit at index <tt>%bit</tt> set
-to zero, ANDing that mask with <tt>%val</tt> and returning the result.</p>
-</div>
-
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection">
- <a name="int_bit_concat">'<tt>llvm.bit.concat.*</tt>' Intrinsic</a>
-</div>
-
-<div class="doc_text">
-
-<h5>Syntax:</h5>
-<p>This is an overloaded intrinsic. You can use <tt>llvm.bit.concat</tt> on any
-integer bit width.
-<pre>
- declare i32 @llvm.bit.concat.i32.i17.i15 (i17 %hi, i15 %lo)
- declare i29 @llvm.bit.concat.i29.i12.i15 (i12 %hi, i15 %lo)
-</pre>
-
-<h5>Overview:</h5>
-<p>The '<tt>llvm.bit.concat</tt>' family of intrinsic functions concatenates two
-integer values to produce a longer one.</p>
-
-<h5>Arguments:</h5>
-<p>The two arguments may be any bit width. The result must be an integer type
-whose bit width is the sum of the arguments' bit widths. The first argument,
-<tt>%hi</tt>, represents the bits that will occupy the high order bit locations
-in the concatenated result. The second argument, <tt>%lo</tt>, will occupy the
-lower order bit locations in the result.</p>
-
-<h5>Semantics:</h5>
-
-<p>The '<tt>llvm.bit.concat</tt>' intrinsic is the equivalent of two
-<tt>zext</tt> instructions, a <tt>shl</tt> and an <tt>or</tt>. The operation
-proceeds as follows:</p>
-<ol>
- <li>Each of the arguments is <tt>zext</tt>'d to the result bit width.</li>
- <li>The <tt>%hi</tt> argument is shift left by the width of the <tt>%lo</tt>
- argument (shifted into to high order bits).</li>
- <li>The shifted <tt>%hi</tt> value and <tt>%lo</tt> are <tt>or</tt>'d together
- to form the result.</li>
-</ol>
-</div>
-
-<!-- _______________________________________________________________________ -->
-<div class="doc_subsubsection">
- <a name="int_bit_part_select">'<tt>llvm.bit.part.select.*</tt>' Intrinsic</a>
-</div>
-
-<div class="doc_text">
-
-<h5>Syntax:</h5>
-<p>This is an overloaded intrinsic. You can use <tt>llvm.bit.part.select</tt>
+<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
on any integer bit width.
<pre>
- declare i17 @llvm.bit.part.select.i17.i17 (i17 %val, i32 %loBit, i32 %hiBit)
- declare i29 @llvm.bit.part.select.i29.i29 (i29 %val, i32 %loBit, i32 %hiBit)
+ declare i17 @llvm.part.select.i17.i17 (i17 %val, i32 %loBit, i32 %hiBit)
+ declare i29 @llvm.part.select.i29.i29 (i29 %val, i32 %loBit, i32 %hiBit)
</pre>
<h5>Overview:</h5>
-<p>The '<tt>llvm.bit.part.select</tt>' family of intrinsic functions selects a
+<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.</p>
+arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
<h5>Semantics:</h5>
-<p>The '<tt>llvm.bit.part.select</tt>' intrinsic is the equivalent of shifting
-<tt>%val</tt> right by <tt>%loBit</tt> bits and then ANDing it with a mask with
+<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
<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:</p>
+<ol>
+ <li>The bits selected wrap around to include both the highest and lowest bits.
+ For example, part.select(i16 X, 4, 7) selects bits from X with a mask of
+ 0x00F0 (forwards case) while part.select(i16 X, 8, 3) selects bits from X
+ with a mask of 0xFF0F.</li>
+ <li>The bits returned in the reverse case are reversed. So, if X has the value
+ 0x6ACF and we apply part.select(i16 X, 8, 3) to it, we get back the value
+ 0x0A6F.</li>
+</ol>
</div>
-<!-- _______________________________________________________________________ -->
<div class="doc_subsubsection">
- <a name="int_bit_part_set">'<tt>llvm.bit.part.set.*</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.bit.part.set</tt> on
-any integer bit width.
+<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
+on any integer bit width.
<pre>
- declare i17 @llvm.bit.part.set.i17.i17.i9 (i17 %val, i32 %bit, i9 %newbits)
- declare i29 @llvm.bit.part.set.i29.i29.i13(i29 %val, i32 %bit, i13 %newbits)
+ declare i17 @llvm.part.set.i17.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
+ declare i29 @llvm.part.set.i29.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
</pre>
<h5>Overview:</h5>
-<p>The '<tt>llvm.bit.part.set</tt>' family of intrinsic functions sets a range
-of bits in a given value to a new value and returns the result.</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 and the result may be an integer type of any bit width but
-they must have the same bit width. The second argument must be an <tt>i32</tt>.
-The third argument may be any any bit width less than or equal to the bit width
-of the first argument.</p>
+<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 '<tt>llvm.bit.part.set</tt>' intrinsic sets the value given by
-<tt>%newbits</tt> into <tt>%val</tt> at the bit index given by <tt>%bit</tt>.
-This is equivalent to the following sequence:</p>
-<ol>
- <li>The bits in <tt>%val</tt> starting at <tt>%bit</tt> and up to the width
- of <tt>%newbits</tt> are cleared by ANDing them with a zero mask.</li>
- <li>The bits in <tt>%newbits</tt> are shifted left by <tt>%bit</tt> bits.
- <li>The shifted <tt>%newbits</tt> value is OR'd into <tt>%val</tt> to produce
- the result.</li>
-</ol>
+<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 replaced
+wrap around to include both the highest and lowest bits. For example, if a
+16 bit value is being replaced then <tt>%lo=8</tt> and <tt>%hi=4</tt> would
+cause these bits to be set: <tt>0xFF1F</tt>.</p>
+<h5>Examples:</h5>
+<pre>
+ llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
+ llvm.part.set(0xFFFF, 0, 7, 4) -> 0x0060
+ llvm.part.set(0xFFFF, 0, 8, 3) -> 0x00F0
+ llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
+</pre>
</div>
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projects / oota-llvm.git / blobdiff