<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 2.9 Release Notes</title>
+ <title>LLVM 3.0 Release Notes</title>
</head>
<body>
-<h1 class="doc_title">LLVM 2.9 Release Notes</h1>
+<h1>LLVM 3.0 Release Notes</h1>
<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 2.9</a></li>
- <li><a href="#whatsnew">What's New in LLVM 2.9?</a></li>
+ <li><a href="#externalproj">External Projects Using LLVM 3.0</a></li>
+ <li><a href="#whatsnew">What's New in LLVM 3.0?</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>
</ol>
<div class="doc_author">
- <p>Written by the <a href="http://llvm.org">LLVM Team</a></p>
+ <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 2.9
+<!--
+<h1 style="color:red">These are in-progress notes for the upcoming LLVM 3.0
release.<br>
You may prefer the
-<a href="http://llvm.org/releases/2.8/docs/ReleaseNotes.html">LLVM 2.8
+<a href="http://llvm.org/releases/2.9/docs/ReleaseNotes.html">LLVM 2.9
Release Notes</a>.</h1>
+ -->
<!-- *********************************************************************** -->
-<h1>
+<h2>
<a name="intro">Introduction</a>
-</h1>
+</h2>
<!-- *********************************************************************** -->
-<div class="doc_text">
+<div>
<p>This document contains the release notes for the LLVM Compiler
-Infrastructure, release 2.9. Here we describe the status of LLVM, including
+Infrastructure, release 3.0. 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>
-->
<!-- *********************************************************************** -->
-<h1>
+<h2>
<a name="subproj">Sub-project Status Update</a>
-</h1>
+</h2>
<!-- *********************************************************************** -->
-<div class="doc_text">
+<div>
<p>
-The LLVM 2.9 distribution currently consists of code from the core LLVM
+The LLVM 3.0 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
development. Here we include updates on these subprojects.
</p>
-</div>
-
-
<!--=========================================================================-->
-<h2>
+<h3>
<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<p><a href="http://clang.llvm.org/">Clang</a> is an LLVM front end for the C,
C++, and Objective-C languages. Clang aims to provide a better user experience
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 2.9 time-frame, the Clang team has made many improvements in C,
-C++ and Objective-C support. C++ support is now generally rock solid, has
-been exercised on a broad variety of code, and has several new <a
-href="http://clang.llvm.org/cxx_status.html#cxx0x">C++'0x features</a>
-implemented (such as rvalue references and variadic templates). LLVM 2.9 has
-also brought in a large range of bug fixes and minor features (e.g. __label__
-support), and is much more compatible with the Linux Kernel.</p>
+<p>In the LLVM 3.0 time-frame, the Clang team has made many improvements:</p>
-<p>If Clang rejects your code that is built with another compiler, please take a
+<p>If Clang rejects your code but another compiler accepts it, please take a
look at the <a href="http://clang.llvm.org/compatibility.html">language
-compatibility</a> guide to make sure the issue isn't intentional or a known
-issue.
+compatibility</a> guide to make sure this is not intentional or a known issue.
</p>
-<ul>
-</ul>
</div>
<!--=========================================================================-->
-<h2>
+<h3>
<a name="dragonegg">DragonEgg: GCC front-ends, LLVM back-end</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<p>
<a href="http://dragonegg.llvm.org/">DragonEgg</a> is a
<a href="http://gcc.gnu.org/wiki/plugins">gcc plugin</a> that replaces GCC's
</p>
<p>
-The 2.9 release has the following notable changes:
+The 3.0 release has the following notable changes:
<ul>
-<li>The plugin is much more stable when compiling Fortran.</li>
-<li>Inline assembly where an asm output is tied to an input of a different size
-is now supported in many more cases.</li>
-<li>Basic support for the __float128 type was added. It is now possible to
-generate LLVM IR from programs using __float128 but code generation does not
-work yet.</li>
-<li>Compiling Java programs no longer systematically crashes the plugin.</li>
+<!--
+<li></li>
+-->
</ul>
</div>
<!--=========================================================================-->
-<h2>
+<h3>
<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<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
this and other low-level routines (some are 3x faster than the equivalent
libgcc routines).</p>
-<p>In the LLVM 2.9 timeframe, compiler_rt has had several minor changes for
- better ARM support, and a fairly major license change. All of the code in the
- compiler-rt project is now <a href="DeveloperPolicy.html#license">dual
- licensed</a> under MIT and UIUC license, which allows you to use compiler-rt
- in applications without the binary copyright reproduction clause. If you
- prefer the LLVM/UIUC license, you are free to continue using it under that
- license as well.</p>
+<p>In the LLVM 3.0 timeframe,</p>
</div>
<!--=========================================================================-->
-<h2>
+<h3>
<a name="lldb">LLDB: Low Level Debugger</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<p>
<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
LLVM disassembler and the LLVM JIT.</p>
<p>
-LLDB is has advanced by leaps and bounds in the 2.9 timeframe. It is
+LLDB is has advanced by leaps and bounds in the 3.0 timeframe. It is
dramatically more stable and useful, and includes both a new <a
href="http://lldb.llvm.org/tutorial.html">tutorial</a> and a <a
href="http://lldb.llvm.org/lldb-gdb.html">side-by-side comparison with
</div>
<!--=========================================================================-->
-<h2>
+<h3>
<a name="libc++">libc++: C++ Standard Library</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<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
delivering great performance.</p>
<p>
-In the LLVM 2.9 timeframe, libc++ has had numerous bugs fixed, and is now being
-co-developed with Clang's C++'0x mode.</p>
+In the LLVM 3.0 timeframe,</p>
<p>
Like compiler_rt, libc++ is now <a href="DeveloperPolicy.html#license">dual
</div>
+<!--=========================================================================-->
+<h3>
+<a name="LLBrowse">LLBrowse: IR Browser</a>
+</h3>
+
+<div>
+<p>
+<a href="http://llvm.org/svn/llvm-project/llbrowse/trunk/doc/LLBrowse.html">
+ LLBrowse</a> is an interactive viewer for LLVM modules. It can load any LLVM
+ module and displays its contents as an expandable tree view, facilitating an
+ easy way to inspect types, functions, global variables, or metadata nodes. It
+ is fully cross-platform, being based on the popular wxWidgets GUI toolkit.
+</p>
+</div>
+<!--=========================================================================-->
+<h3>
+<a name="vmkit">VMKit</a>
+</h3>
+
+<div>
+<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. As of LLVM 3.0, VMKit now supports generational
+ garbage collectors. The garbage collectors are provided by the MMTk framework,
+ and VMKit can be configured to use one of the numerous implemented collectors
+ of MMTk.
+</p>
+</div>
+
+
<!--=========================================================================-->
<!--
-<h2>
+<h3>
<a name="klee">KLEE: A Symbolic Execution Virtual Machine</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<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
<p>UPDATE!</p>
</div>-->
+</div>
<!-- *********************************************************************** -->
-<h1>
- <a name="externalproj">External Open Source Projects Using LLVM 2.9</a>
-</h1>
+<h2>
+ <a name="externalproj">External Open Source Projects Using LLVM 3.0</a>
+</h2>
<!-- *********************************************************************** -->
-<div class="doc_text">
+<div>
<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>
+ projects that have already been updated to work with LLVM 3.0.</p>
+
+<!--=========================================================================-->
+<h3>Crack Programming Language</h3>
+
+<div>
+<p>
+<a href="http://code.google.com/p/crack-language/">Crack</a> aims to provide the
+ease of development of a scripting language with the performance of a compiled
+language. The language derives concepts from C++, Java and Python, incorporating
+object-oriented programming, operator overloading and strong typing.</p>
+</div>
+
+
+<!--=========================================================================-->
+<h3>TTA-based Codesign Environment (TCE)</h3>
+
+<div>
+<p>TCE 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 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>
+
+
+
+<!--=========================================================================-->
+<h3>PinaVM</h3>
+
+<div>
+<p><a href="http://gitorious.org/pinavm/pages/Home">PinaVM</a> is an open
+source, <a href="http://www.systemc.org/">SystemC</a> front-end. Unlike many
+other front-ends, PinaVM actually executes the elaboration of the
+program analyzed using LLVM's JIT infrastructure. It later enriches the
+bitcode with SystemC-specific information.</p>
</div>
+<!--=========================================================================-->
+<h3>Pure</h3>
+
+<div>
+<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. The interpreter uses LLVM as a backend to JIT-compile Pure
+ programs to fast native code. 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 interface to C and other
+ programming languages (including the ability to load LLVM bitcode
+ modules, and inline C, C++, Fortran and Faust code in Pure programs if
+ the corresponding LLVM-enabled compilers are installed).</p>
+
+<p>Pure version 0.47 has been tested and is known to work with LLVM 3.0
+ (and continues to work with older LLVM releases >= 2.5).</p>
+</div>
+<!--=========================================================================-->
+<h3 id="icedtea">IcedTea Java Virtual Machine Implementation</h3>
+<div>
+<p>
+<a href="http://icedtea.classpath.org/wiki/Main_Page">IcedTea</a> provides a
+harness to build OpenJDK using only free software build tools and to provide
+replacements for the not-yet free parts of OpenJDK. One of the extensions that
+IcedTea provides is a new JIT compiler named <a
+href="http://icedtea.classpath.org/wiki/ZeroSharkFaq">Shark</a> which uses LLVM
+to provide native code generation without introducing processor-dependent
+code.
+</p>
+
+<p> OpenJDK 7 b112, IcedTea6 1.9 and IcedTea7 1.13 and later have been tested
+and are known to work with LLVM 3.0 (and continue to work with older LLVM
+releases >= 2.6 as well).</p>
+</div>
+
+<!--=========================================================================-->
+<h3>Glasgow Haskell Compiler (GHC)</h3>
+
+<div>
+<p>GHC 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 LLVM code generator. GHC supports LLVM 2.7 and later.</p>
+</div>
+
+<!--=========================================================================-->
+<h3>Polly - Polyhedral optimizations for LLVM</h3>
+
+<div>
+<p>Polly is a project that aims to provide advanced memory access optimizations
+to better take advantage of SIMD units, cache hierarchies, multiple cores or
+even vector accelerators for LLVM. Built around an abstract mathematical
+description based on Z-polyhedra, it provides the infrastructure to develop
+advanced optimizations in LLVM and to connect complex external optimizers. In
+its first year of existence Polly already provides an exact value-based
+dependency analysis as well as basic SIMD and OpenMP code generation support.
+Furthermore, Polly can use PoCC(Pluto) an advanced optimizer for data-locality
+and parallelism.</p>
+</div>
+
+<!--=========================================================================-->
+<h3>Rubinius</h3>
+
+<div>
+ <p><a href="http://github.com/evanphx/rubinius">Rubinius</a> is an environment
+ for running Ruby code which strives to write as much of the implementation in
+ Ruby as possible. Combined with a bytecode interpreting VM, it uses LLVM to
+ optimize and compile ruby code down to machine code. Techniques such as type
+ feedback, method inlining, and deoptimization are all used to remove dynamism
+ from ruby execution and increase performance.</p>
+</div>
+
+
+<!--=========================================================================-->
+<h3>
+<a name="FAUST">FAUST Real-Time Audio Signal Processing Language</a>
+</h3>
+
+<div>
+<p>
+<a href="http://faust.grame.fr">FAUST</a> is a compiled language for real-time
+audio signal processing. The name FAUST stands for Functional AUdio STream. Its
+programming model combines two approaches: functional programming and block
+diagram composition. In addition with the C, C++, JAVA output formats, the
+Faust compiler can now generate LLVM bitcode, and works with LLVM 2.7-3.0.</p>
+
+</div>
+
+</div>
<!-- *********************************************************************** -->
-<h1>
- <a name="whatsnew">What's New in LLVM 2.9?</a>
-</h1>
+<h2>
+ <a name="whatsnew">What's New in LLVM 3.0?</a>
+</h2>
<!-- *********************************************************************** -->
-<div class="doc_text">
+<div>
<p>This release includes a huge number of bug fixes, performance tweaks and
minor improvements. Some of the major improvements and new features are listed
in this section.
</p>
-</div>
-
<!--=========================================================================-->
-<h2>
+<h3>
<a name="majorfeatures">Major New Features</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
-<p>LLVM 2.9 includes several major new capabilities:</p>
+<p>LLVM 3.0 includes several major new capabilities:</p>
<ul>
-
-<li>
- TBAA: On by default in clang. Disable it with -fno-strict-aliasing.
- Could be more aggressive for structs.
-</li>
-
-<li>New Nvidia PTX backend, not generally useful in 2.9 though.</li>
-
-<li>
-Much better debug info generated, particularly in optimized code situations.
-</li>
-<li>
-inline asm multiple alternative constraint support.
-</li>
+<!--
+<li></li>
+-->
-<li>
- New naming rules in coding standards: CodingStandards.html#ll_naming
-</li>
-
</ul>
</div>
<!--=========================================================================-->
-<h2>
+<h3>
<a name="coreimprovements">LLVM IR and Core Improvements</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<p>LLVM IR has several new features for better support of new targets and that
expose new optimization opportunities:</p>
<ul>
-<li>udiv, ashr, lshr, shl now have exact and nuw/nsw bits:
- PR8862 / LangRef.html</li>
-
- unnamed_addr + PR8927
-
- new 'hotpatch' attribute: LangRef.html#fnattrs
-
+<!--
+<li></li>
+-->
</ul>
</div>
<!--=========================================================================-->
-<h2>
+<h3>
<a name="optimizer">Optimizer Improvements</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<p>In addition to a large array of minor performance tweaks and bug fixes, this
release includes a few major enhancements and additions to the optimizers:</p>
<ul>
- <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>
-
-
- LoopIdiom: memset/memcpy formation and memset_pattern on darwin. Build with
- -ffreestanding or -fno-builtin if your memcpy is being compiled into infinite
- recursion.
-
- TargetLibraryInfo
-
- EarlyCSE pass.
- LoopInstSimplify pass.
-
-New <a href="WritingAnLLVMPass.html#RegionPass">RegionPass</a> infrastructure
- for region-based optimizations.
-
- Can optimize printf to iprintf when no floating point is used, for embedded
- targets with smaller iprintf implementation.
-
-Speedups to various mid-level passes:
- GVN is much faster on functions with deep dominator trees / lots of BBs.
- DomTree and DominatorFrontier are much faster to compute, and preserved by
- more passes (so they are computed less often)
- SRoA is also much faster and doesn't use DominanceFrontier.
-
-DSE is more aggressive with stores of different types: e.g. a large store
- following a small one to the same address.
-
-
-We now optimize various idioms for overflow detection into check of the flag
- register on various CPUs, e.g.:
- unsigned long t = a+b;
- if (t < a) ...
- into:
- addq %rdi, %rbx
- jno LBB0_2
-
-
-</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.
+<li></li>
-->
+</li>
+
+</ul>
</div>
<!--=========================================================================-->
-<h2>
+<h3>
<a name="mc">MC Level Improvements</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<p>
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,
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>
-
-
- MC Assembler: X86 now generates much better diagnostics for common errors,
- is much faster at matching instructions, is much more bug-compatible with
- the GAS assembler, and is now generally useful for a broad range of X86
- assembly.
-
-
- ELF MC support: on by default in clang. There are still known missing features
- for human written assembly.
-
-
- Some basic <a href="CodeGenerator.html#mc">internals documentation</a> for MC.
-
- MC Assembler support for .file and .loc.
-
- tblgen support for assembler aliases: <a
- href="CodeGenerator.html#na_instparsing">MnemonicAlias and InstAlias</a>
-
- Win32 PE-COFF support in the MC assembler has made a lot of progress in the 2.9
- timeframe, but is still not generally useful. Please see
- "http://llvm.org/bugs/showdependencytree.cgi?id=9100&hide_resolved=1" for open bugs?
-
-
- lib/Object and llvm-objdump
- Experimental format independent object file manipulation library.
- * Supports PE/COFF and ELF.
- * llvm-nm extended to work with object files. Exactly matches
- binutils-nm for the files I've tested.
- * llvm-objdump added with support for disassembly (no relocations displayed).
-
-
-
+<!--
+<li></li>
+-->
</ul>
<p>For more information, please see the <a
</div>
<!--=========================================================================-->
-<h2>
+<h3>
<a name="codegen">Target Independent Code Generator Improvements</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<p>We have put a significant amount of work into the code generator
infrastructure, which allows us to implement more aggressive algorithms and make
it run faster:</p>
<ul>
-<!-- SplitKit -->
-
-<li>The pre-register-allocation (preRA) instruction scheduler models register
- pressure much more accurately in some cases. This allows the adoption of more
- aggressive scheduling heuristics.
-</li>
-
- LiveDebugVariables is a new pass that keeps track of debugging information for
- user variables that are kept in registers in optimized builds.
-
-
-Scheduler now models operand latency and pipeline forwarding.
-
-Major regalloc rewrite, not on by default for 2.9 and not advised to use it.
- * New basic register allocator that can be used as a safe fallback when
- debugging. Enable with -regalloc=basic.
- * New infrastructure for live range splitting. SplitKit can break a live
- interval into smaller pieces while preserving SSA form, and SpillPlacement
- can help find the best split points. This is a work in progress so the API
- is changing quickly.
- * The inline spiller has learned to clean up after live range splitting. It
- can hoist spills out of loops, and it can eliminate redundant spills.
- Rematerialization works with live range splitting.
- * New greedy register allocator using live range splitting. This will be the
- default register allocator in the next LLVM release, but it is not turned on
- by default in 2.9.
-
-
-
+<!--
+<li></li>
+-->
</ul>
</div>
<!--=========================================================================-->
-<h2>
+<h3>
<a name="x86">X86-32 and X86-64 Target Improvements</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<p>New features and major changes in the X86 target include:
</p>
<ul>
-<li>
-X86: Reimplemented all of MMX to introduce a new LLVM IR x86_mmx type. Now
- random types like <2 x i32> are not iseld to mmx without emms. The
- -disable-mmx flag is gone now.
-</li>
-
- <li>
-X86 support for FS/GS relative loads and stores using address space 256/257 are
- reliable now.
- </li>
-
- <li>
-X86: Much better codegen for several cases using adc/sbb instead of cmovs for
- conditional increment and other idioms.
- </li>
-
- <li>
- The X86 backend has adopted a new preRA scheduling
- mode, "list-ilp", to shorten the height of instruction schedules
- without inducing register spills.
- </li>
+<li>The CRC32 intrinsics have been renamed. The intrinsics were previously
+ @llvm.x86.sse42.crc32.[8|16|32] and @llvm.x86.sse42.crc64.[8|64]. They have
+ been renamed to @llvm.x86.sse42.crc32.32.[8|16|32] and
+ @llvm.x86.sse42.crc32.64.[8|64].</li>
- MC assembler support for 3dNow! and 3DNowA instructions.
-
- <li>Several bugs have been fixed for Windows x64 code generator.</li>
</ul>
</div>
<!--=========================================================================-->
-<h2>
+<h3>
<a name="ARM">ARM Target Improvements</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<p>New features of the ARM target include:
</p>
<ul>
-<li>ARM Fast ISel</li>
-<li>ARM: New code placement pass.</li>
-<li>ARM: Improved code generation for Cortex-A8 and Cortex-A9 CPUs.</li>
-<li>ARM: __builtin_prefetch turns into prefetch instructions.</li>
-<li>Countless ARM microoptimizations.</li>
-
-<li> The ARM backend preRA scheduler now models machine resources at cycle
- granularity. This allows the scheduler to both accurately model
- instruction latency and avoid overcommitting functional units.</li>
-
-
+<!--
+<li></li>
+-->
</ul>
</div>
<!--=========================================================================-->
-<h2>
+<h3>
<a name="OtherTS">Other Target Specific Improvements</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<ul>
- PPC: Switched to MCInstPrinter, and MCCodeEmitter. Ready to implement support
- for directly writing out mach-o object files, but noone seems interested.
-
- MicroBlaze: major updates for aggressive delay slot filler, MC-based assembly
- printing, assembly instruction parsing, ELF .o file emission, and MC
- instruction disassembler.
-
- SPARC: Many improvements, including using the Y registers for multiplications
- and addition of a simple delay slot filler.
-
+<!--
+<li></li>
+-->
</ul>
</div>
<!--=========================================================================-->
-<h2>
+<h3>
<a name="changes">Major Changes and Removed Features</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<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
+on LLVM 2.9, this section lists some "gotchas" that you may run into upgrading
from the previous release.</p>
<ul>
- last release for llvm-gcc
-
-- DIBuilder provides simpler interface for front ends like Clang to encode debug info in LLVM IR.
- - This interface hides implementation details (e.g. DIDerivedType, existence of compile unit etc..) that any front end should not know about.
- For example, DIFactory DebugFactory;
- Ty = DebugFactory.CreateDerivedType(DW_TAG_volatile_type,
- findRegion(TYPE_CONTEXT(type)),
- StringRef(),
- getOrCreateFile(main_input_filename),
- 0 /*line no*/,
- NodeSizeInBits(type),
- NodeAlignInBits(type),
- 0 /*offset */,
- 0 /* flags */,
- MainTy);
- can be replaced by
- DbgTy = DBuilder.createQualifiedType(DW_TAG_volatile_type, MainTy);
-DIFactory is gone now.
-
-
-
-
-
-
- LoopIndexSplit pass was removed, unmaintained.
- LiveValues, SimplifyHalfPowrLibCalls, and GEPSplitter were removed.
- Removed the PartialSpecialization pass, it was unmaintained and buggy.
-
- DIFactory removed, use DIBuilder instead.
-
- Triple::normalize is new, llvm triples are always stored in normalized form internally.
-
- Triple x86_64--mingw64 is obsoleted. Use x86_64--mingw32 instead.
-
- PointerTracking has been removed from mainline, moved to ClamAV.
-
+<!--
+<li></li>
+-->
</ul>
</div>
<!--=========================================================================-->
-<h2>
+<h3>
<a name="api_changes">Internal API Changes</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<p>In addition, many APIs have changed in this release. Some of the major
LLVM API changes are:</p>
<ul>
-
- include/llvm/System merged into include/llvm/Support.
-
-
- APInt API changes, see PR5207.
-
- MVT::Flag renamed to MVT::Glue
-
-
- error_code + libsystem + PathV2 changes
- The system_error header from C++0x was added.
- * Use if (error_code ec = function()) to check for error conditions
- from functions which return it.
- * error_code::message returns a human readable description of the error.
-
- PathV1 has been deprecated in favor of PathV2 (sorry I didn't finish
- this before the release).
- * No Path class, use a r-value convertible to a twine instead.
- * Assumes all paths are UTF-8.
-
+<li>The biggest and most pervasive change is that llvm::Type's are no longer
+ returned or accepted as 'const' values. Instead, just pass around non-const
+ Type's.</li>
+
+<li><code>PHINode::reserveOperandSpace</code> has been removed. Instead, you
+ must specify how many operands to reserve space for when you create the
+ PHINode, by passing an extra argument into <code>PHINode::Create</code>.</li>
+
+<li>PHINodes no longer store their incoming BasicBlocks as operands. Instead,
+ the list of incoming BasicBlocks is stored separately, and can be accessed
+ with new functions <code>PHINode::block_begin</code>
+ and <code>PHINode::block_end</code>.</li>
+
+<li>Various functions now take an <code>ArrayRef</code> instead of either a pair
+ of pointers (or iterators) to the beginning and end of a range, or a pointer
+ and a length. Others now return an <code>ArrayRef</code> instead of a
+ reference to a <code>SmallVector</code> or <code>std::vector</code>. These
+ include:
+<ul>
+<!-- Please keep this list sorted. -->
+<li><code>CallInst::Create</code></li>
+<li><code>ComputeLinearIndex</code> (in <code>llvm/CodeGen/Analysis.h</code>)</li>
+<li><code>ConstantArray::get</code></li>
+<li><code>ConstantExpr::getExtractElement</code></li>
+<li><code>ConstantExpr::getGetElementPtr</code></li>
+<li><code>ConstantExpr::getInBoundsGetElementPtr</code></li>
+<li><code>ConstantExpr::getIndices</code></li>
+<li><code>ConstantExpr::getInsertElement</code></li>
+<li><code>ConstantExpr::getWithOperands</code></li>
+<li><code>ConstantFoldCall</code> (in <code>llvm/Analysis/ConstantFolding.h</code>)</li>
+<li><code>ConstantFoldInstOperands</code> (in <code>llvm/Analysis/ConstantFolding.h</code>)</li>
+<li><code>ConstantVector::get</code></li>
+<li><code>DIBuilder::createComplexVariable</code></li>
+<li><code>DIBuilder::getOrCreateArray</code></li>
+<li><code>ExtractValueInst::Create</code></li>
+<li><code>ExtractValueInst::getIndexedType</code></li>
+<li><code>ExtractValueInst::getIndices</code></li>
+<li><code>FindInsertedValue</code> (in <code>llvm/Analysis/ValueTracking.h</code>)</li>
+<li><code>gep_type_begin</code> (in <code>llvm/Support/GetElementPtrTypeIterator.h</code>)</li>
+<li><code>gep_type_end</code> (in <code>llvm/Support/GetElementPtrTypeIterator.h</code>)</li>
+<li><code>GetElementPtrInst::Create</code></li>
+<li><code>GetElementPtrInst::CreateInBounds</code></li>
+<li><code>GetElementPtrInst::getIndexedType</code></li>
+<li><code>InsertValueInst::Create</code></li>
+<li><code>InsertValueInst::getIndices</code></li>
+<li><code>InvokeInst::Create</code></li>
+<li><code>IRBuilder::CreateCall</code></li>
+<li><code>IRBuilder::CreateExtractValue</code></li>
+<li><code>IRBuilder::CreateGEP</code></li>
+<li><code>IRBuilder::CreateInBoundsGEP</code></li>
+<li><code>IRBuilder::CreateInsertValue</code></li>
+<li><code>IRBuilder::CreateInvoke</code></li>
+<li><code>MDNode::get</code></li>
+<li><code>MDNode::getIfExists</code></li>
+<li><code>MDNode::getTemporary</code></li>
+<li><code>MDNode::getWhenValsUnresolved</code></li>
+<li><code>SimplifyGEPInst</code> (in <code>llvm/Analysis/InstructionSimplify.h</code>)</li>
+<li><code>TargetData::getIndexedOffset</code></li>
+</ul></li>
+
+<li>All forms of <code>StringMap::getOrCreateValue</code> have been remove
+ except for the one which takes a <code>StringRef</code>.</li>
</ul>
</div>
+</div>
+
<!-- *********************************************************************** -->
-<h1>
+<h2>
<a name="knownproblems">Known Problems</a>
-</h1>
+</h2>
<!-- *********************************************************************** -->
-<div class="doc_text">
+<div>
<p>This section contains significant known problems with the LLVM system,
listed by component. If you run into a problem, please check the <a
href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
there isn't already one.</p>
-</div>
-
<!-- ======================================================================= -->
-<h2>
+<h3>
<a name="experimental">Experimental features included with this release</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<p>The following components of this LLVM release are either untested, known to
be broken or unreliable, or are in early development. These components should
<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>
+ other than darwin and ELF X86 systems.</li>
</ul>
</div>
<!-- ======================================================================= -->
-<h2>
+<h3>
<a name="x86-be">Known problems with the X86 back-end</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<ul>
<li>The X86 backend does not yet support
</div>
<!-- ======================================================================= -->
-<h2>
+<h3>
<a name="ppc-be">Known problems with the PowerPC back-end</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<ul>
<li>The Linux PPC32/ABI support needs testing for the interpreter and static
</div>
<!-- ======================================================================= -->
-<h2>
+<h3>
<a name="arm-be">Known problems with the ARM back-end</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<ul>
<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
</div>
<!-- ======================================================================= -->
-<h2>
+<h3>
<a name="sparc-be">Known problems with the SPARC back-end</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<ul>
<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not
</div>
<!-- ======================================================================= -->
-<h2>
+<h3>
<a name="mips-be">Known problems with the MIPS back-end</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<ul>
<li>64-bit MIPS targets are not supported yet.</li>
</div>
<!-- ======================================================================= -->
-<h2>
+<h3>
<a name="alpha-be">Known problems with the Alpha back-end</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<ul>
</div>
<!-- ======================================================================= -->
-<h2>
+<h3>
<a name="c-be">Known problems with the C back-end</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
<p>The C backend has numerous problems and is not being actively maintained.
Depending on it for anything serious is not advised.</p>
<!-- ======================================================================= -->
-<h2>
+<h3>
<a name="llvm-gcc">Known problems with the llvm-gcc front-end</a>
-</h2>
+</h3>
-<div class="doc_text">
+<div>
+
+<p><b>LLVM 3.0 will be the last release of llvm-gcc.</b></p>
<p>llvm-gcc is generally very stable for the C family of languages. The only
major language feature of GCC not supported by llvm-gcc is the
consider using <a href="#dragonegg">dragonegg</a> instead.</p>
</div>
+</div>
+
<!-- *********************************************************************** -->
-<h1>
+<h2>
<a name="additionalinfo">Additional Information</a>
-</h1>
+</h2>
<!-- *********************************************************************** -->
-<div class="doc_text">
+<div>
<p>A wide variety of additional information is available on the <a
-href="http://llvm.org">LLVM web page</a>, in particular in the <a
+href="http://llvm.org
/">LLVM web page</a>, in particular in the <a
href="http://llvm.org/docs/">documentation</a> section. The web page also
contains versions of the API documentation which is up-to-date with the
Subversion version of the source code.
projects / oota-llvm.git / blobdiff