<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>Type Based Alias Analysis (TBAA) is now implemented and turned on by default
- in Clang. This allows substantially better load/store optimization in some
- cases. TBAA can be disabled by passing -fno-strict-aliasing.
-</li>
-
-<li>This release has seen a continued focus on quality of debug information.
- LLVM now generates much higher fidelity debug information, particularly when
- debugging optimized code.</li>
-
-<li>Inline assembly now supports multiple alternative constraints.</li>
-<li>A new backend for the NVIDIA PTX virtual ISA (used to target its GPUs) is
- under rapid development. It is not generally useful in 2.9, but is making
- rapid progress.</li>
+<!--
+<li></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>The <a href="LangRef.html#bitwiseops">udiv, ashr, lshr, and shl</a>
- instructions now have support exact and nuw/nsw bits to indicate that they
- don't overflow or shift out bits. This is useful for optimization of <a
- href="http://llvm.org/PR8862">pointer differences</a> and other cases.</li>
-
-<li>LLVM IR now supports the <a href="LangRef.html#globalvars">unnamed_addr</a>
- attribute to indicate that constant global variables with identical
- initializers can be merged. This fixed <a href="http://llvm.org/PR8927">an
- issue</a> where LLVM would incorrectly merge two globals which were supposed
- to have distinct addresses.</li>
-
-<li>The new <a href="LangRef.html#fnattrs">hotpatch attribute</a> has been added
- to allow runtime patching of functions.</li>
+<!--
+<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>Link Time Optimization (LTO) has been improved to use MC for parsing inline
- assembly and now can build large programs like Firefox 4 on both Mac OS X and
- Linux.</li>
-
-<li>The new -loop-idiom pass recognizes memset/memcpy loops (and memset_pattern
- on darwin), turning them into library calls, which are typically better
- optimized than inline code. If you are building a libc and notice that your
- memcpy and memset functions are compiled into infinite recursion, please build
- with -ffreestanding or -fno-builtin to disable this pass.</li>
-
-<li>A new -early-cse pass does a fast pass over functions to fold constants,
- simplify expressions, perform simple dead store elimination, and perform
- common subexpression elimination. It does a good job at catching some of the
- trivial redundancies that exist in unoptimized code, making later passes more
- effective.<,/li>
-
-<li>A new -loop-instsimplify pass is used to clean up loop bodies in the loop
- optimizer.</li>
-
-<li>The new TargetLibraryInfo interface allows mid-level optimizations to know
- whether the current target's runtime library has certain functions. For
- example, the optimizer can now transform integer-only printf calls to call
- iprintf, allowing reduced code size for embedded C libraries (e.g. newlib).
-</li>
-
-<li>LLVM has a new <a href="WritingAnLLVMPass.html#RegionPass">RegionPass</a>
- infrastructure for region-based optimizations.</li>
-
-<li>Several optimizer passes have been substantially sped up:
- GVN is much faster on functions with deep dominator trees and lots of basic
- blocks. The dominator tree and dominance frontier passes are much faster to
- compute, and preserved by more passes (so they are computed less often). The
- -scalar-repl pass is also much faster and doesn't use DominanceFrontier.
-</li>
-
-<li>The Dead Store Elimination pass is more aggressive optimizing stores of
- different types: e.g. a large store following a small one to the same address.
- The MemCpyOptimizer pass handles several new forms of memcpy elimination.</li>
-
-<li>LLVM now optimizes various idioms for overflow detection into check of the
- flag register on various CPUs. For example, we now compile:
-
- <pre>
- unsigned long t = a+b;
- if (t < a) ...
- </pre>
- into:
- <pre>
- addq %rdi, %rbx
- jno LBB0_2
- </pre>
+<!--
+<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>ELF MC support has matured enough for the integrated assembler to be turned
- on by default in Clang on X86-32 and X86-64 ELF systems.</li>
-
-<li>MC supports and CodeGen uses the <tt>.file</tt> and <tt>.loc</tt> directives
- for producing line number debug info. This produces more compact line
- tables and easier to read .s files.</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>The MC assembler 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.</li>
-
-<li>We now have some basic <a href="CodeGenerator.html#mc">internals
- documentation</a> for MC.</li>
-
-<li>.td files can now specify assembler aliases directly with the <a
- href="CodeGenerator.html#na_instparsing">MnemonicAlias and InstAlias</a>
- tblgen classes.</li>
-
-<li>LLVM now has an experimental format-independent object file manipulation
- library (lib/Object). It supports both PE/COFF and ELF. The llvm-nm tool has
- been extended to work with native object files, and the new llvm-objdump tool
- supports disassembly of object files (but no relocations are displayed yet).
-</li>
-
-<li>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.</li>
-
+<!--
+<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
-
- <li>
- New naming rules in coding standards: CodingStandards.html#ll_naming
- </li>
-
-
-
-- 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::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>IRBuilder::CreateCall</code></li>
+<li><code>IRBuilder::CreateExtractValue</code></li>
+<li><code>IRBuilder::CreateInsertValue</code></li>
+<li><code>IRBuilder::CreateInvoke</code></li>
+<li><code>InsertValueInst::Create</code></li>
+<li><code>InsertValueInst::getIndices</code></li>
+<li><code>InvokeInst::Create</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>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