<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>
-</div>
-
+ projects that have already been updated to work with LLVM 3.0.</p>
<!--=========================================================================-->
-<h2>Crack Programming Language</h2>
+<h3>Crack Programming Language</h3>
-<div class="doc_text">
+<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
<!--=========================================================================-->
-<h2>TTA-based Codesign Environment (TCE)</h2>
+<h3>TTA-based Codesign Environment (TCE)</h3>
-<div class="doc_text">
+<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
<!--=========================================================================-->
-<h2>PinaVM</h2>
+<h3>PinaVM</h3>
-<div class="doc_text">
+<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
</div>
<!--=========================================================================-->
-<h2>Pure</h2>
+<h3>Pure</h3>
-<div class="doc_text">
+<div>
<p><a href="http://pure-lang.googlecode.com/">Pure</a> is an
algebraic/functional
programming language based on term rewriting. Programs are collections
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 2.9
+<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>
<!--=========================================================================-->
-<h2 id="icedtea">IcedTea Java Virtual Machine Implementation</h2>
+<h3 id="icedtea">IcedTea Java Virtual Machine Implementation</h3>
-<div class="doc_text">
+<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
</p>
<p> OpenJDK 7 b112, IcedTea6 1.9 and IcedTea7 1.13 and later have been tested
-and are known to work with LLVM 2.9 (and continue to work with older LLVM
+and are known to work with LLVM 3.0 (and continue to work with older LLVM
releases >= 2.6 as well).</p>
</div>
<!--=========================================================================-->
-<h2>Glasgow Haskell Compiler (GHC)</h2>
+<h3>Glasgow Haskell Compiler (GHC)</h3>
-<div class="doc_text">
+<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
</div>
<!--=========================================================================-->
-<h2>Polly - Polyhedral optimizations for LLVM</h2>
+<h3>Polly - Polyhedral optimizations for LLVM</h3>
-<div class="doc_text">
+<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
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
-from the previous release.</p>
+<p>If you're already an LLVM user or developer with out-of-tree changes based 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>The <code>LLVMC</code> front end code was removed while separating
+ out language independence.</li>
+ <li>The <code>LowerSetJmp</code> pass wasn't used effectively by any
+ target and has been removed.</li>
+ <li>The old <code>TailDup</code> pass was not used in the standard pipeline
+ and was unable to update ssa form, so it has been removed.
+ <li>The syntax of volatile loads and stores in IR has been changed to
+ "<code>load volatile</code>"/"<code>store volatile</code>". The old
+ syntax ("<code>volatile load</code>"/"<code>volatile store</code>")
+ is still accepted, but is now considered deprecated.</li>
+</ul>
+<h4>Windows (32-bit)</h4>
+<div>
+<ul>
+ <li>On Win32(MinGW32 and MSVC), Windows 2000 will not be supported.
+ Windows XP or higher is required.</li>
</ul>
+</div>
</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>
+ 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>
+
+<li>The <code>LLVMBuildUnwind</code> function from the C API was removed. The
+ LLVM <code>unwind</code> instruction has been deprecated for a long time and
+ isn't used by the current front-ends. So this was removed during the
+ exception handling rewrite.</li>
+
+<li>The <code>LLVMAddLowerSetJmpPass</code> function from the C API was removed
+ because the <code>LowerSetJmp</code> pass was removed.</li>
+
+<li>The <code>DIBuilder</code> interface used by front ends to encode debugging
+ information in the LLVM IR now expects clients to use <code>DIBuilder::finalize()</code>
+ at the end of translation unit to complete debugging information encoding.</li>
+
+<li>The way the type system works has been rewritten: <code>PATypeHolder</code>
+and <code>OpaqueType</code> are gone, and all APIs deal with <code>Type*</code>
+instead of <code>const Type*</code>.
+If you need to create recursive structures, then create a named structure,
+and use <code>setBody()</code> when all its elements are built.
+Type merging and refining is gone too: named structures are not
+merged with other structures, even if their layout is identical.
+(of course anonymous structures are still uniqued by layout).
+</li>
+
+<li>TargetSelect.h moved to Support/ from Target/</li>
+
+<li>UpgradeIntrinsicCall no longer upgrades pre-2.9 intrinsic calls
+(for example <code>llvm.memset.i32</code>).</li>
+
+<li>It is mandatory to initialize all out-of-tree passes too and their dependencies now with
+<code>INITIALIZE_PASS{BEGIN,END,}</code> and <code>INITIALIZE_{PASS,AG}_DEPENDENCY</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>
-<div class="doc_text">
+<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