<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
+ <meta encoding="utf8">
<link rel="stylesheet" href="llvm.css" type="text/css">
- <title>LLVM 2.8 Release Notes</title>
+ <title>LLVM 2.9 Release Notes</title>
</head>
<body>
-<div class="doc_title">LLVM 2.8 Release Notes</div>
+<div class="doc_title">LLVM 2.9 Release Notes</div>
<img align=right src="http://llvm.org/img/DragonSmall.png"
width="136" height="136" alt="LLVM Dragon Logo">
<ol>
<li><a href="#intro">Introduction</a></li>
<li><a href="#subproj">Sub-project Status Update</a></li>
- <li><a href="#externalproj">External Projects Using LLVM 2.8</a></li>
- <li><a href="#whatsnew">What's New in LLVM 2.8?</a></li>
+ <li><a href="#externalproj">External Projects Using LLVM 2.9</a></li>
+ <li><a href="#whatsnew">What's New in LLVM 2.9?</a></li>
<li><a href="GettingStarted.html">Installation Instructions</a></li>
<li><a href="#knownproblems">Known Problems</a></li>
<li><a href="#additionalinfo">Additional Information</a></li>
<p>Written by the <a href="http://llvm.org">LLVM Team</a></p>
</div>
-<!--
-<h1 style="color:red">These are in-progress notes for the upcoming LLVM 2.8
+<h1 style="color:red">These are in-progress notes for the upcoming LLVM 2.9
release.<br>
You may prefer the
-<a href="http://llvm.org/releases/2.7/docs/ReleaseNotes.html">LLVM 2.7
+<a href="http://llvm.org/releases/2.8/docs/ReleaseNotes.html">LLVM 2.8
Release Notes</a>.</h1>
--->
<!-- *********************************************************************** -->
<div class="doc_section">
<div class="doc_text">
<p>This document contains the release notes for the LLVM Compiler
-Infrastructure, release 2.8. Here we describe the status of LLVM, including
+Infrastructure, release 2.9. Here we describe the status of LLVM, including
major improvements from the previous release and significant known problems.
All LLVM releases may be downloaded from the <a
href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
<a href="http://llvm.org/releases/">releases page</a>.</p>
</div>
-
+
+<!-- NOTE: last release for llvm-gcc -->
<!--
Almost dead code.
- include/llvm/Analysis/LiveValues.h => Dan
- lib/Transforms/IPO/MergeFunctions.cpp => consider for 2.8.
- llvm/Analysis/PointerTracking.h => Edwin wants this, consider for 2.8.
- GEPSplitterPass
+ lib/Transforms/IPO/MergeFunctions.cpp => consider for 3.0.
-->
-<!-- Features that need text if they're finished for 2.9:
+<!-- Features that need text if they're finished for 3.0:
combiner-aa?
strong phi elim
loop dependence analysis
CorrelatedValuePropagation
-->
- <!-- Announcement, lldb, libc++ -->
-
- <!-- to write:
- MachineCSE tuned and on by default.
- llvm.dbg.value: variable debug info for optimized code
- MC Assembler backend is now real, does relaxation and is bitwise identical
- with darwin assembler in huge majority of all cases.
- new GHC calling convention
- New half float intrinsics LangRef.html#int_fp16
- Rewrote tblgen's type inference for backends to be more consistent and
- diagnose more target bugs. This also allows limited support for writing
- patterns for instructions that return multiple results, e.g. a virtual
- register and a flag result. Stuff that used 'parallel' before should use
- this.
- New ARM/Thumb disassembler support in MC.
- New SSEDomainFix pass:
- On Nehalem and newer CPUs there is a 2 cycle latency penalty on using a
- register in a different domain than where it was defined. Some instructions
- have equvivalents for different domains, like por/orps/orpd. The
- SSEDomainFix pass tries to minimize the number of domain crossings by
- changing between equvivalent opcodes where possible.
- Support for the Intel AES instructions in the assembler.
- memcpy, memmove, and memset now take address space qualified pointers + volatile.
- per-instruction debug info metadata is much faster and uses less space (new DebugLoc class).
- -ffunction-sections and -fdata-sections are supported on ELF targets.
- Now iterate function passes when a cgsccpassmanager detects a devirtualization
- -momit-leaf-frame-pointer now supported.
- New -regalloc=fast, =local got removed
- New -regalloc=default option that chooses a register allocator based on the -O optimization level.
- New "trap values" concept: http://llvm.org/docs/LangRef.html#trapvalues
- Improved trip count analysis for <= and >= loops, and uses sign overflow info.
- REMOVED: SCCVN pass.
- X86 backend attempts to promote 16-bit integer operations to 32-bits to avoid
- 0x66 prefixes, which are slow on some microarchitectures and bloat the code
- on others.
- X87 fp stackifier is global!
- LTO debug info support?
- NEON: Better performance for QQQQ (4-consecutive Q register) instructions. New reg sequence abstraction?
- New support for X86 "thiscall" calling convention (x86_thiscallcc in IR).
- ARM: Better scheduling (list-hybrid, hybrid?)
- New SubRegIndex tblgen class for targets -> jakob
- ARM: Tail call support.
- AVX support in the MC assembler. Full compiler support not done yet.
- Atomics now get legalized when not natively supported (jim g)
- ARM: General performance work and tuning.
- -->
-
-
<!-- *********************************************************************** -->
<div class="doc_section">
<a name="subproj">Sub-project Status Update</a>
<div class="doc_text">
<p>
-The LLVM 2.8 distribution currently consists of code from the core LLVM
+The LLVM 2.9 distribution currently consists of code from the core LLVM
repository (which roughly includes the LLVM optimizers, code generators
and supporting tools), the Clang repository and the llvm-gcc repository. In
addition to this code, the LLVM Project includes other sub-projects that are in
production-quality compiler for C, Objective-C, C++ and Objective-C++ on x86
(32- and 64-bit), and for darwin-arm targets.</p>
-<p>In the LLVM 2.8 time-frame, the Clang team has made many improvements:</p>
+<p>In the LLVM 2.9 time-frame, the Clang team has made many improvements:</p>
<ul>
-<li>Surely these guys have done something</li>
-<li>X86-64 abi improvements? Did they make it in?</li>
</ul>
</div>
future</a>!). The tool is very good at finding bugs that occur on specific
paths through code, such as on error conditions.</p>
-<p>The LLVM 2.8 release fixes a number of bugs and slightly improves precision
- over 2.7, but there are no major new features in the release.
-</p>
-
-</div>
-
-<!--=========================================================================-->
-<div class="doc_subsection">
-<a name="vmkit">VMKit: JVM/CLI Virtual Machine Implementation</a>
-</div>
-
-<div class="doc_text">
-<p>
-The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation of
-a JVM and a CLI Virtual Machine (Microsoft .NET is an
-implementation of the CLI) using LLVM for static and just-in-time
-compilation.</p>
-
-<p>With the release of LLVM 2.8, ...</p>
-
-</div>
-
-
-<!--=========================================================================-->
-<div class="doc_subsection">
-<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
-</div>
-
-<div class="doc_text">
-<p>
-The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
-is a simple library that provides an implementation of the low-level
-target-specific hooks required by code generation and other runtime components.
-For example, when compiling for a 32-bit target, converting a double to a 64-bit
-unsigned integer is compiled into a runtime call to the "__fixunsdfdi"
-function. The compiler-rt library provides highly optimized implementations of
-this and other low-level routines (some are 3x faster than the equivalent
-libgcc routines).</p>
-
-<p>
-All of the code in the compiler-rt project is available under the standard LLVM
-License, a "BSD-style" license. New in LLVM 2.8:
-
-Soft float support
+<p>The LLVM 2.9 release...
</p>
</div>
</div>
<div class="doc_text">
+NOTE: This should be written to be self-contained without referencing llvm-gcc.
+
<p>
<a href="http://dragonegg.llvm.org/">DragonEgg</a> is a port of llvm-gcc to
gcc-4.5. Unlike llvm-gcc, dragonegg in theory does not require any gcc-4.5
</p>
<p>
-The 2.8 release has the following notable changes:
+The 2.9 release has the following notable changes:
<ul>
-<li>The plugin loads faster due to exporting fewer symbols.</li>
-<li>Additional vector operations such as addps256 are now supported.</li>
-<li>Ada global variables with no initial value are no longer zero initialized,
-resulting in better optimization.</li>
-<li>The '-fplugin-arg-dragonegg-enable-gcc-optzns' flag now runs all gcc
-optimizers, rather than just a handful.</li>
-<li>Fortran programs using common variables now link correctly.</li>
-<li>GNU OMP constructs no longer crash the compiler.</li>
</ul>
-</p>
</div>
-
<!--=========================================================================-->
<div class="doc_subsection">
-<a name="lldb">LLDB: Low Level Debugger</a>
+<a name="vmkit">VMKit: JVM Virtual Machine Implementation</a>
</div>
<div class="doc_text">
<p>
-<a href="http://lldb.llvm.org/">LLDB</a> is</p>
-
-<p>
-</p>
+The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation of
+a Java Virtual Machine (Java VM or JVM) that uses LLVM for static and
+just-in-time compilation.
-<p>
-2.8 status here.
+UPDATE.
</p>
-
</div>
<!--=========================================================================-->
<div class="doc_subsection">
-<a name="libc++">libc++: C++ Standard Library</a>
+<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
</div>
<div class="doc_text">
<p>
-<a href="http://libc++.llvm.org/">libc++</a> is</p>
-
-<p>
-</p>
+The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
+is a simple library that provides an implementation of the low-level
+target-specific hooks required by code generation and other runtime components.
+For example, when compiling for a 32-bit target, converting a double to a 64-bit
+unsigned integer is compiled into a runtime call to the "__fixunsdfdi"
+function. The compiler-rt library provides highly optimized implementations of
+this and other low-level routines (some are 3x faster than the equivalent
+libgcc routines).</p>
<p>
-2.8 status here.
-</p>
-
-</div>
-
+All of the code in the compiler-rt project is available under the standard LLVM
+License, a "BSD-style" license.
-<!-- *********************************************************************** -->
-<div class="doc_section">
- <a name="externalproj">External Open Source Projects Using LLVM 2.8</a>
-</div>
-<!-- *********************************************************************** -->
+NEW: MIT License as well.
-<div class="doc_text">
+New in LLVM 2.9, UPDATE</p>
-<p>An exciting aspect of LLVM is that it is used as an enabling technology for
- a lot of other language and tools projects. This section lists some of the
- projects that have already been updated to work with LLVM 2.8.</p>
</div>
<!--=========================================================================-->
<div class="doc_subsection">
-<a name="tce">TTA-based Codesign Environment (TCE)</a>
+<a name="lldb">LLDB: Low Level Debugger</a>
</div>
<div class="doc_text">
<p>
-<a href="http://tce.cs.tut.fi/">TCE</a> is a toolset for designing
-application-specific processors (ASP) based on the Transport triggered
-architecture (TTA). The toolset provides a complete co-design flow from C/C++
-programs down to synthesizable VHDL and parallel program binaries. Processor
-customization points include the register files, function units, supported
-operations, and the interconnection network.</p>
-
-<p>TCE uses llvm-gcc/Clang and LLVM for C/C++ language support, target
-independent optimizations and also for parts of code generation. It generates
-new LLVM-based code generators "on the fly" for the designed TTA processors and
-loads them in to the compiler backend as runtime libraries to avoid per-target
-recompilation of larger parts of the compiler chain.</p>
-
-</div>
+<a href="http://lldb.llvm.org/">LLDB</a> is a brand new member of the LLVM
+umbrella of projects. LLDB is a next generation, high-performance debugger. It
+is built as a set of reusable components which highly leverage existing
+libraries in the larger LLVM Project, such as the Clang expression parser, the
+LLVM disassembler and the LLVM JIT.</p>
-<!--=========================================================================-->
-<div class="doc_subsection">
-<a name="Horizon">Horizon Bytecode Compiler</a>
-</div>
-
-<div class="doc_text">
<p>
-<a href="http://www.quokforge.org/projects/horizon">Horizon</a> is a bytecode
-language and compiler written on top of LLVM, intended for producing
-single-address-space managed code operating systems that
-run faster than the equivalent multiple-address-space C systems.
-More in-depth blurb is available on <a
-href="http://www.quokforge.org/projects/horizon/wiki/Wiki">the wiki</a>.</p>
+LLDB is in early development and not included as part of the LLVM 2.9 release,
+UPDATE!
-</div>
-
-<!--=========================================================================-->
-<div class="doc_subsection">
-<a name="clamav">Clam AntiVirus</a>
-</div>
-
-<div class="doc_text">
-<p>
-<a href=http://www.clamav.net>Clam AntiVirus</a> is an open source (GPL)
-anti-virus toolkit for UNIX, designed especially for e-mail scanning on mail
-gateways. Since version 0.96 it has <a
-href="http://vrt-sourcefire.blogspot.com/2010/09/introduction-to-clamavs-low-level.html">bytecode
-signatures</a> that allow writing detections for complex malware. It
-uses LLVM's JIT to speed up the execution of bytecode on
-X86,X86-64,PPC32/64, falling back to its own interpreter otherwise.
-The git version was updated to work with LLVM 2.8
+<!--
+but is mature enough to support basic debugging scenarios on Mac OS X in C,
+Objective-C and C++. We'd really like help extending and expanding LLDB to
+support new platforms, new languages, new architectures, and new features.-->
</p>
-<p>The <a
-href="http://git.clamav.net/gitweb?p=clamav-bytecode-compiler.git;a=blob_plain;f=docs/user/clambc-user.pdf">
-ClamAV bytecode compiler</a> uses Clang and LLVM to compile a C-like
-language, insert runtime checks, and generate ClamAV bytecode.</p>
-
</div>
<!--=========================================================================-->
<div class="doc_subsection">
-<a name="pure">Pure</a>
+<a name="libc++">libc++: C++ Standard Library</a>
</div>
<div class="doc_text">
<p>
-<a href="http://pure-lang.googlecode.com/">Pure</a>
-is an algebraic/functional
-programming language based on term rewriting. Programs are collections
-of equations which are used to evaluate expressions in a symbolic
-fashion. Pure offers dynamic typing, eager and lazy evaluation, lexical
-closures, a hygienic macro system (also based on term rewriting),
-built-in list and matrix support (including list and matrix
-comprehensions) and an easy-to-use C interface. The interpreter uses
-LLVM as a backend to JIT-compile Pure programs to fast native code.</p>
+<a href="http://libcxx.llvm.org/">libc++</a> is another new member of the LLVM
+family. It is an implementation of the C++ standard library, written from the
+ground up to specifically target the forthcoming C++'0X standard and focus on
+delivering great performance.</p>
-<p>Pure versions 0.44 and later have been tested and are known to work with
-LLVM 2.8 (and continue to work with older LLVM releases >= 2.5).</p>
+<p>
+As of the LLVM 2.9 release, UPDATE!
-</div>
+<!--libc++ is virtually feature complete, but would
+benefit from more testing and better integration with Clang++. It is also
+looking forward to the C++ committee finalizing the C++'0x standard.-->
+</p>
-<!--=========================================================================-->
-<div class="doc_subsection">
-<a name="GHC">Glasgow Haskell Compiler (GHC)</a>
</div>
-<div class="doc_text">
-<p>
-<a href="http://www.haskell.org/ghc/">GHC</a> is an open source,
-state-of-the-art programming suite for
-Haskell, a standard lazy functional programming language. It includes
-an optimizing static compiler generating good code for a variety of
-platforms, together with an interactive system for convenient, quick
-development.</p>
-
-<p>In addition to the existing C and native code generators, GHC 7.0 now
-supports an <a
-href="http://hackage.haskell.org/trac/ghc/wiki/Commentary/Compiler/Backends/LLVM">LLVM
-code generator</a>. GHC supports LLVM 2.7 and later.</p>
-</div>
<!--=========================================================================-->
<div class="doc_subsection">
-<a name="Clay">Clay Programming Language</a>
+<a name="klee">KLEE: A Symbolic Execution Virtual Machine</a>
</div>
<div class="doc_text">
<p>
-<a href="http://tachyon.in/clay/">Clay</a> is a new systems programming
-language that is specifically designed for generic programming. It makes
-generic programming very concise thanks to whole program type propagation. It
-uses LLVM as its backend.</p>
+<a href="http://klee.llvm.org/">KLEE</a> is a symbolic execution framework for
+programs in LLVM bitcode form. KLEE tries to symbolically evaluate "all" paths
+through the application and records state transitions that lead to fault
+states. This allows it to construct testcases that lead to faults and can even
+be used to verify some algorithms.
+</p>
+
+<p>UPDATE!</p>
</div>
-<!--=========================================================================-->
-<div class="doc_subsection">
-<a name="llvm-py">llvm-py Python Bindings for LLVM</a>
+
+<!-- *********************************************************************** -->
+<div class="doc_section">
+ <a name="externalproj">External Open Source Projects Using LLVM 2.9</a>
</div>
+<!-- *********************************************************************** -->
<div class="doc_text">
-<p>
-<a href="http://www.mdevan.org/llvm-py/">llvm-py</a> has been updated to work
-with LLVM 2.8. llvm-py provides Python bindings for LLVM, allowing you to write a
-compiler backend or a VM in Python.</p>
+<p>An exciting aspect of LLVM is that it is used as an enabling technology for
+ a lot of other language and tools projects. This section lists some of the
+ projects that have already been updated to work with LLVM 2.9.</p>
</div>
+
<!-- *********************************************************************** -->
<div class="doc_section">
- <a name="whatsnew">What's New in LLVM 2.8?</a>
+ <a name="whatsnew">What's New in LLVM 2.9?</a>
</div>
<!-- *********************************************************************** -->
</div>
-<!--=========================================================================-->
-<div class="doc_subsection">
-<a name="orgchanges">LLVM Community Changes</a>
-</div>
-
-<div class="doc_text">
-
-<p>In addition to changes to the code, between LLVM 2.7 and 2.8, a number of
-organization changes have happened:
-</p>
-
-<ul>
-<li>libc++ and lldb are new</li>
-<li>Debugging optimized code support.</li>
-</ul>
-</div>
-
<!--=========================================================================-->
<div class="doc_subsection">
<a name="majorfeatures">Major New Features</a>
<div class="doc_text">
-<p>LLVM 2.8 includes several major new capabilities:</p>
+<p>LLVM 2.9 includes several major new capabilities:</p>
<ul>
-<li>atomic lowering pass.</li>
-<li>RegionInfo pass: opt -regions analyze" or "opt -view-regions".
-<!-- Tobias Grosser --></li>
-<li>ARMGlobalMerge: <!-- Anton --> </li>
-<li>llvm-diff</li>
</ul>
</div>
expose new optimization opportunities:</p>
<ul>
-
-<li>LLVM 2.8 changes the internal order of operands in <a
- href="http://llvm.org/doxygen/classllvm_1_1InvokeInst.html"><tt>InvokeInst</tt></a>
- and <a href="http://llvm.org/doxygen/classllvm_1_1CallInst.html"><tt>CallInst</tt></a>.
- To be portable across releases, resort to <tt>CallSite</tt> and the
- high-level accessors, such as <tt>getCalledValue</tt> and <tt>setUnwindDest</tt>.
-</li>
-<li>
- You can no longer pass use_iterators directly to cast<> (and similar), because
- these routines tend to perform costly dereference operations more than once. You
- have to dereference the iterators yourself and pass them in.
-</li>
-<li>
- llvm.memcpy.*, llvm.memset.*, llvm.memmove.* (and possibly other?) intrinsics
- take an extra parameter now (i1 isVolatile), totaling 5 parameters.
- If you were creating these intrinsic calls and prototypes yourself (as opposed
- to using Intrinsic::getDeclaration), you can use UpgradeIntrinsicFunction/UpgradeIntrinsicCall
- to be portable accross releases.
- Note that you cannot use Intrinsic::getDeclaration() in a backwards compatible
- way (needs 2/3 types now, in 2.7 it needed just 1).
-</li>
-<li>
- SetCurrentDebugLocation takes a DebugLoc now instead of a MDNode.
- Change your code to use
- SetCurrentDebugLocation(DebugLoc::getFromDILocation(...)).
-</li>
-<li>
- VISIBILITY_HIDDEN is gone.
-</li>
-<li>
- The <tt>RegisterPass</tt> and <tt>RegisterAnalysisGroup</tt> templates are
- considered deprecated, but continue to function in LLVM 2.8. Clients are
- strongly advised to use the upcoming <tt>INITIALIZE_PASS()</tt> and
- <tt>INITIALIZE_AG_PASS()</tt> macros instead.
-<li>
- SMDiagnostic takes different parameters now. //FIXME: how to upgrade?
-</li>
-<li>
- The constructor for the Triple class no longer tries to understand odd triple
- specifications. Frontends should ensure that they only pass valid triples to
- LLVM. The Triple::normalize utility method has been added to help front-ends
- deal with funky triples.
-<li>
- Some APIs got renamed:
- <ul>
- <li>llvm_report_error -> report_fatal_error</li>
- <li>llvm_install_error_handler -> install_fatal_error_handler</li>
- <li>llvm::DwarfExceptionHandling -> llvm::JITExceptionHandling</li>
- </ul>
-</li>
</ul>
</div>
release includes a few major enhancements and additions to the optimizers:</p>
<ul>
-
-<li></li>
-
+ <li>TBAA.</li>
+ <li>LTO has been improved to use MC for parsing inline asm and now
+ can build large programs like Firefox 4 on both OS X and Linux.</li>
</ul>
-</div>
-
-
-<!--=========================================================================-->
-<div class="doc_subsection">
-<a name="executionengine">Interpreter and JIT Improvements</a>
-</div>
-
-<div class="doc_text">
-
-<ul>
-<li></li>
-
-</ul>
+<!--
+<p>In addition to these features that are done in 2.8, there is preliminary
+ support in the release for Type Based Alias Analysis
+ Preliminary work on TBAA but not usable in 2.8.
+ New CorrelatedValuePropagation pass, not on by default in 2.8 yet.
+-->
</div>
<div class="doc_text">
<p>
-FIXME: Rewrite.
-
-The LLVM Machine Code (aka MC) sub-project of LLVM was created to solve a number
+The LLVM Machine Code (aka MC) subsystem was created to solve a number
of problems in the realm of assembly, disassembly, object file format handling,
and a number of other related areas that CPU instruction-set level tools work
-in. It is a sub-project of LLVM which provides it with a number of advantages
-over other compilers that do not have tightly integrated assembly-level tools.
-For a gentle introduction, please see the <a
+in.</p>
+
+<ul>
+ <li>MC is now used by default for ELF systems on x86 and
+ x86-64.</li>
+ <li>MC supports and CodeGen uses the <tt>.loc</tt> directives for
+ producing line number debug info. This produces more compact line
+ tables.</li>
+ <li>MC supports the <tt>.cfi_*</tt> directives for producing DWARF
+ frame information, but it is still not used by CodeGen by default.</li>
+ <li>COFF support?</li>
+</ul>
+
+<p>For more information, please see the <a
href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html">Intro to the
LLVM MC Project Blog Post</a>.
</p>
-<p>2.8 status here. Basic correctness, some obscure missing instructions on
- mainline, on by default in clang.
- Entire compiler backend converted to use mcstreamer.
- </p>
</div>
-
<!--=========================================================================-->
<div class="doc_subsection">
<a name="codegen">Target Independent Code Generator Improvements</a>
it run faster:</p>
<ul>
-<li>MachO writer works.</li>
+<!-- SplitKit -->
+FastISel for ARM.
</ul>
</div>
</div>
<div class="doc_text">
-<p>New features of the X86 target include:
+<p>New features and major changes in the X86 target include:
</p>
<ul>
-<li>The X86 backend now supports holding X87 floating point stack values
- in registers across basic blocks, dramatically improving performance of code
- that uses long double, and when targetting CPUs that don't support SSE.</li>
-
</ul>
</div>
</p>
<ul>
-
-<li>
- All of the NEON load and store intrinsics (llvm.arm.neon.vld* and
- llvm.arm.neon.vst*) take an extra parameter to specify the alignment in bytes
- of the memory being accessed.
-</li>
-<li>
- The llvm.arm.neon.vaba intrinsic (vector absolute difference and
- accumulate) has been removed. This operation is now represented using
- the llvm.arm.neon.vabd intrinsic (vector absolute difference) followed by a
- vector add.
-</li>
-<li>
- The llvm.arm.neon.vabdl and llvm.arm.neon.vabal intrinsics (lengthening
- vector absolute difference with and without accumlation) have been removed.
- They are represented using the llvm.arm.neon.vabd intrinsic (vector absolute
- difference) followed by a vector zero-extend operation, and for vabal,
- a vector add.
-</li>
-<li>
- The llvm.arm.neon.vmovn intrinsic has been removed. Calls of this intrinsic
- are now replaced by vector truncate operations.
-</li>
-<li>
- The llvm.arm.neon.vmovls and llvm.arm.neon.vmovlu intrinsics have been
- removed. They are now represented as vector sign-extend (vmovls) and
- zero-extend (vmovlu) operations.
-</li>
-<li>
- The llvm.arm.neon.vaddl*, llvm.arm.neon.vaddw*, llvm.arm.neon.vsubl*, and
- llvm.arm.neon.vsubw* intrinsics (lengthening vector add and subtract) have
- been removed. They are replaced by vector add and vector subtract operations
- where one (vaddw, vsubw) or both (vaddl, vsubl) of the operands are either
- sign-extended or zero-extended.
-</li>
-<li>
- The llvm.arm.neon.vmulls, llvm.arm.neon.vmullu, llvm.arm.neon.vmlal*, and
- llvm.arm.neon.vmlsl* intrinsics (lengthening vector multiply with and without
- accumulation and subtraction) have been removed. These operations are now
- represented as vector multiplications where the operands are either
- sign-extended or zero-extended, followed by a vector add for vmlal or a
- vector subtract for vmlsl. Note that the polynomial vector multiply
- intrinsic, llvm.arm.neon.vmullp, remains unchanged.
-</li>
-
</ul>
</div>
+
<!--=========================================================================-->
<div class="doc_subsection">
-<a name="newapis">New Useful APIs</a>
+<a name="changes">Major Changes and Removed Features</a>
</div>
<div class="doc_text">
-<p>This release includes a number of new APIs that are used internally, which
- may also be useful for external clients.
-</p>
+<p>If you're already an LLVM user or developer with out-of-tree changes based
+on LLVM 2.8, this section lists some "gotchas" that you may run into upgrading
+from the previous release.</p>
<ul>
-<li></li>
</ul>
-</div>
-
-<!--=========================================================================-->
-<div class="doc_subsection">
-<a name="otherimprovements">Other Improvements and New Features</a>
-</div>
-
-<div class="doc_text">
-<p>Other miscellaneous features include:</p>
+<p>In addition, many APIs have changed in this release. Some of the major LLVM
+API changes are:</p>
<ul>
-<li></li>
</ul>
</div>
-
<!--=========================================================================-->
<div class="doc_subsection">
-<a name="changes">Major Changes and Removed Features</a>
+<a name="devtree_changes">Development Infrastructure Changes</a>
</div>
<div class="doc_text">
-<p>If you're already an LLVM user or developer with out-of-tree changes based
-on LLVM 2.7, this section lists some "gotchas" that you may run into upgrading
-from the previous release.</p>
-
-<ul>
-<li>.ll file doesn't produce #uses comments anymore, to get them, run a .bc file
- through "llvm-dis --show-annotations".</li>
-<li>MSIL Backend removed.</li>
-<li>ABCD and SSI passes removed.</li>
-<li>'Union' LLVM IR feature removed.</li>
-</ul>
-
-<p>In addition, many APIs have changed in this release. Some of the major LLVM
-API changes are:</p>
+<p>This section lists changes to the LLVM development infrastructure. This
+mostly impacts users who actively work on LLVM or follow development on
+mainline, but may also impact users who leverage the LLVM build infrastructure
+or are interested in LLVM qualification.</p>
<ul>
</ul>
-
</div>
-
<!-- *********************************************************************** -->
<div class="doc_section">
<a name="knownproblems">Known Problems</a>
href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
<ul>
-<li>The Alpha, SPU, MIPS, PIC16, Blackfin, MSP430, SystemZ and MicroBlaze
- backends are experimental.</li>
-<li><tt>llc</tt> "<tt>-filetype=asm</tt>" (the default) is the only
- supported value for this option. XXX Update me</li>
+<li>The Alpha, Blackfin, CellSPU, MicroBlaze, MSP430, MIPS, PTX, SystemZ
+ and XCore backends are experimental.</li>
+<li><tt>llc</tt> "<tt>-filetype=obj</tt>" is experimental on all targets
+ other than darwin-i386 and darwin-x86_64. FIXME: Not true on ELF anymore?</li>
+
</ul>
</div>
4.2. If you are interested in Fortran, we recommend that you consider using
<a href="#dragonegg">dragonegg</a> instead.</p>
-<p>The llvm-gcc 4.2 Ada compiler has basic functionality. However, this is not a
-mature technology, and problems should be expected. For example:</p>
-<ul>
-<li>The Ada front-end currently only builds on X86-32. This is mainly due
-to lack of trampoline support (pointers to nested functions) on other platforms.
-However, it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
-which does support trampolines.</li>
-<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
-This is due to lack of LLVM support for <tt>setjmp</tt>/<tt>longjmp</tt> style
-exception handling, which is used internally by the compiler.
-Workaround: configure with <tt>--disable-bootstrap</tt>.</li>
-<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
-and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
-(c380004 also fails with gcc-4.2 mainline).
-If the compiler is built with checks disabled then <a href="http://llvm.org/PR2010">c393010</a>
-causes the compiler to go into an infinite loop, using up all system memory.</li>
-<li>Some GCC specific Ada tests continue to crash the compiler.</li>
-<li>The <tt>-E</tt> binder option (exception backtraces)
-<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
-crashing if an exception is raised. Workaround: do not use <tt>-E</tt>.</li>
-<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
-or finish at a non-byte offset</a> in a record. Workaround: do not pack records
-or use representation clauses that result in a field of a non-discrete type
-starting or finishing in the middle of a byte.</li>
-<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
-'main' as generated by the Ada binder to be invalid</a>.
-Workaround: hand edit the file to use pointers for <tt>argv</tt> and
-<tt>envp</tt> rather than integers.</li>
-<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
-ignored</a>.</li>
-</ul>
+<p>The llvm-gcc 4.2 Ada compiler has basic functionality, but is no longer being
+actively maintained. If you are interested in Ada, we recommend that you
+consider using <a href="#dragonegg">dragonegg</a> instead.</p>
</div>
<!-- *********************************************************************** -->
projects / oota-llvm.git / blobdiff