mirror of
https://github.com/RPCSX/llvm.git
synced 2024-11-27 21:50:40 +00:00
e26cdbe1c7
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149972 91177308-0d34-0410-b5e6-96231b3b80d8
540 lines
17 KiB
HTML
540 lines
17 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
|
|
"http://www.w3.org/TR/html4/strict.dtd">
|
|
<html>
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
|
<link rel="stylesheet" href="llvm.css" type="text/css">
|
|
<title>LLVM 3.1 Release Notes</title>
|
|
</head>
|
|
<body>
|
|
|
|
<h1>LLVM 3.1 Release Notes</h1>
|
|
|
|
<div>
|
|
<img style="float:right" src="http://llvm.org/img/DragonSmall.png"
|
|
width="136" height="136" alt="LLVM Dragon Logo">
|
|
</div>
|
|
|
|
<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 3.1</a></li>
|
|
<li><a href="#whatsnew">What's New in LLVM?</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>
|
|
</div>
|
|
|
|
<h1 style="color:red">These are in-progress notes for the upcoming LLVM 3.1
|
|
release.<br>
|
|
You may prefer the
|
|
<a href="http://llvm.org/releases/3.0/docs/ReleaseNotes.html">LLVM 3.0
|
|
Release Notes</a>.</h1>
|
|
|
|
<!-- *********************************************************************** -->
|
|
<h2>
|
|
<a name="intro">Introduction</a>
|
|
</h2>
|
|
<!-- *********************************************************************** -->
|
|
|
|
<div>
|
|
|
|
<p>This document contains the release notes for the LLVM Compiler
|
|
Infrastructure, release 3.1. Here we describe the status of LLVM, including
|
|
major improvements from the previous release, improvements in various
|
|
subprojects of LLVM, and some of the current users of the code.
|
|
All LLVM releases may be downloaded from
|
|
the <a href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
|
|
|
|
<p>For more information about LLVM, including information about the latest
|
|
release, please check out the <a href="http://llvm.org/">main LLVM web
|
|
site</a>. If you have questions or comments,
|
|
the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM
|
|
Developer's Mailing List</a> is a good place to send them.</p>
|
|
|
|
<p>Note that if you are reading this file from a Subversion checkout or the main
|
|
LLVM web page, this document applies to the <i>next</i> release, not the
|
|
current one. To see the release notes for a specific release, please see the
|
|
<a href="http://llvm.org/releases/">releases page</a>.</p>
|
|
|
|
</div>
|
|
|
|
|
|
<!-- *********************************************************************** -->
|
|
<h2>
|
|
<a name="subproj">Sub-project Status Update</a>
|
|
</h2>
|
|
<!-- *********************************************************************** -->
|
|
|
|
<div>
|
|
|
|
<p>The LLVM 3.1 distribution currently consists of code from the core LLVM
|
|
repository (which roughly includes the LLVM optimizers, code generators and
|
|
supporting tools), and the Clang 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>
|
|
|
|
<!--=========================================================================-->
|
|
<h3>
|
|
<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
|
|
</h3>
|
|
|
|
<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 through expressive diagnostics, a high level of conformance to
|
|
language standards, fast compilation, and low memory use. Like LLVM, Clang
|
|
provides a modular, library-based architecture that makes it suitable for
|
|
creating or integrating with other development tools. Clang is considered a
|
|
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 3.1 time-frame, the Clang team has made many improvements:</p>
|
|
<ul>
|
|
<li>...</li>
|
|
</ul>
|
|
|
|
<p>For more details about the changes to Clang since the 2.9 release, see the
|
|
<a href="http://clang.llvm.org/docs/ReleaseNotes.html">Clang release notes</a>
|
|
</p>
|
|
|
|
|
|
<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 this is not intentional or a known
|
|
issue.</p>
|
|
|
|
</div>
|
|
|
|
<!--=========================================================================-->
|
|
<h3>
|
|
<a name="dragonegg">DragonEgg: GCC front-ends, LLVM back-end</a>
|
|
</h3>
|
|
|
|
<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
|
|
optimizers and code generators with LLVM's. It works with gcc-4.5 or gcc-4.6,
|
|
targets the x86-32 and x86-64 processor families, and has been successfully
|
|
used on the Darwin, FreeBSD, KFreeBSD, Linux and OpenBSD platforms. It fully
|
|
supports Ada, C, C++ and Fortran. It has partial support for Go, Java, Obj-C
|
|
and Obj-C++.</p>
|
|
|
|
<p>The 3.1 release has the following notable changes:</p>
|
|
|
|
<ul>
|
|
|
|
<li>...</li>
|
|
|
|
</ul>
|
|
|
|
</div>
|
|
|
|
<!--=========================================================================-->
|
|
<h3>
|
|
<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
|
|
</h3>
|
|
|
|
<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
|
|
target-specific hooks required by code generation and other runtime
|
|
components. For example, when compiling for a 32-bit target, converting a
|
|
double to a 64-bit unsigned integer is compiled into a runtime call to the
|
|
"__fixunsdfdi" function. The compiler-rt library provides highly optimized
|
|
implementations of this and other low-level routines (some are 3x faster than
|
|
the equivalent libgcc routines).</p>
|
|
|
|
<p>....</p>
|
|
|
|
</div>
|
|
|
|
<!--=========================================================================-->
|
|
<h3>
|
|
<a name="lldb">LLDB: Low Level Debugger</a>
|
|
</h3>
|
|
|
|
<div>
|
|
|
|
<p>LLDB is a ground-up implementation of a command line debugger, as well as a
|
|
debugger API that can be used from other applications. LLDB makes use of the
|
|
Clang parser to provide high-fidelity expression parsing (particularly for
|
|
C++) and uses the LLVM JIT for target support.</p>
|
|
|
|
<p>...</p>
|
|
|
|
</div>
|
|
|
|
<!--=========================================================================-->
|
|
<h3>
|
|
<a name="libc++">libc++: C++ Standard Library</a>
|
|
</h3>
|
|
|
|
<div>
|
|
|
|
<p>Like compiler_rt, libc++ is now <a href="DeveloperPolicy.html#license">dual
|
|
licensed</a> under the MIT and UIUC license, allowing it to be used more
|
|
permissively.</p>
|
|
|
|
<p>...</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.
|
|
|
|
<p>In the LLVM 3.1 time-frame, VMKit has had significant improvements on both
|
|
runtime and startup performance:</p>
|
|
|
|
<ul>
|
|
<li>...</li>
|
|
</ul>
|
|
|
|
</div>
|
|
|
|
</div>
|
|
|
|
<!-- *********************************************************************** -->
|
|
<h2>
|
|
<a name="externalproj">External Open Source Projects Using LLVM 3.1</a>
|
|
</h2>
|
|
<!-- *********************************************************************** -->
|
|
|
|
<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 3.1.</p>
|
|
|
|
... to be filled in right before the release ...
|
|
|
|
</div>
|
|
|
|
<!-- *********************************************************************** -->
|
|
<h2>
|
|
<a name="whatsnew">What's New in LLVM 3.1?</a>
|
|
</h2>
|
|
<!-- *********************************************************************** -->
|
|
|
|
<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>
|
|
|
|
<!--=========================================================================-->
|
|
<h3>
|
|
<a name="majorfeatures">Major New Features</a>
|
|
</h3>
|
|
|
|
<div>
|
|
|
|
<!-- Features that need text if they're finished for 3.1:
|
|
ARM EHABI
|
|
combiner-aa?
|
|
strong phi elim
|
|
loop dependence analysis
|
|
CorrelatedValuePropagation
|
|
lib/Transforms/IPO/MergeFunctions.cpp => consider for 3.1.
|
|
Integrated assembler on by default for arm/thumb?
|
|
|
|
-->
|
|
|
|
<!-- Near dead:
|
|
Analysis/RegionInfo.h + Dom Frontiers
|
|
SparseBitVector: used in LiveVar.
|
|
llvm/lib/Archive - replace with lib object?
|
|
-->
|
|
|
|
<p>LLVM 3.1 includes several major changes and big features:</p>
|
|
|
|
<ul>
|
|
<li><a href="../tools/clang/docs/AddressSanitizer.html">AddressSanitizer</a>,
|
|
a fast memory error detector.</li>
|
|
<li><a href="CodeGenerator.html#machineinstrbundle">MachineInstr Bundles</a>,
|
|
Support to model instruction bundling / packing.</li>
|
|
<li>....</li>
|
|
</ul>
|
|
|
|
</div>
|
|
|
|
|
|
<!--=========================================================================-->
|
|
<h3>
|
|
<a name="coreimprovements">LLVM IR and Core Improvements</a>
|
|
</h3>
|
|
|
|
<div>
|
|
|
|
<p>LLVM IR has several new features for better support of new targets and that
|
|
expose new optimization opportunities:</p>
|
|
|
|
<ul>
|
|
<li>IR support for half float</li>
|
|
<li>IR support for vectors of pointers, including vector GEPs.</li>
|
|
<li>The <tt>unwind</tt> instruction is now gone. With the introduction of
|
|
the new exception handling system in LLVM 3.0, the <tt>unwind</tt>
|
|
instruction became obsolete.</li>
|
|
<li>....</li>
|
|
</ul>
|
|
</div>
|
|
|
|
<!--=========================================================================-->
|
|
<h3>
|
|
<a name="optimizer">Optimizer Improvements</a>
|
|
</h3>
|
|
|
|
<div>
|
|
|
|
<p>In addition to many minor performance tweaks and bug fixes, this
|
|
release includes a few major enhancements and additions to the
|
|
optimizers:</p>
|
|
|
|
<ul>
|
|
<li>....</li>
|
|
</ul>
|
|
|
|
</div>
|
|
|
|
<!--=========================================================================-->
|
|
<h3>
|
|
<a name="mc">MC Level Improvements</a>
|
|
</h3>
|
|
|
|
<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,
|
|
and a number of other related areas that CPU instruction-set level tools work
|
|
in. For more information, please see
|
|
the <a href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html">Intro
|
|
to the LLVM MC Project Blog Post</a>.</p>
|
|
|
|
<ul>
|
|
<li>....</li>
|
|
</ul>
|
|
|
|
</div>
|
|
|
|
<!--=========================================================================-->
|
|
<h3>
|
|
<a name="codegen">Target Independent Code Generator Improvements</a>
|
|
</h3>
|
|
|
|
<div>
|
|
|
|
<p>We have changed the way that the Type Legalizer legalizes vectors.
|
|
The type legalizer now attempts to promote integer elements.
|
|
This enabled the implementation of vector-select.
|
|
Additionally, we see a performance boost on workloads which use vectors of chars and shorts, since they are now promoted
|
|
to 32-bit types, which are better supported by the SIMD instruction set.
|
|
Floating point types are still widened as before.</p>
|
|
|
|
|
|
<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>
|
|
<li>TableGen can now synthesize register classes that are only needed to
|
|
represent combinations of constraints from instructions and sub-registers.
|
|
The synthetic register classes inherit most of their properties form their
|
|
closest user-defined super-class.</li>
|
|
<li><code>MachineRegisterInfo</code> now allows the reserved registers to be
|
|
frozen when register allocation starts. Target hooks should use the
|
|
<code>MRI->canReserveReg(FramePtr)</code> method to avoid accidentally
|
|
disabling frame pointer elimination during register allocation.</li>
|
|
<li>A new kind of <code>MachineOperand</code> provides a compact
|
|
representation of large clobber lists on call instructions. The register
|
|
mask operand references a bit mask of preserved registers. Everything else is
|
|
clobbered.</li>
|
|
</ul>
|
|
</div>
|
|
|
|
<!--=========================================================================-->
|
|
<h3>
|
|
<a name="x86">X86-32 and X86-64 Target Improvements</a>
|
|
</h3>
|
|
|
|
<div>
|
|
|
|
<p>New features and major changes in the X86 target include:</p>
|
|
|
|
<ul>
|
|
<li>Bug fixes and improved support for AVX1</li>
|
|
<li>Support for AVX2 (still incomplete at this point)</li>
|
|
<li>....</li>
|
|
</ul>
|
|
|
|
</div>
|
|
|
|
<!--=========================================================================-->
|
|
<h3>
|
|
<a name="ARM">ARM Target Improvements</a>
|
|
</h3>
|
|
|
|
<div>
|
|
|
|
<p>New features of the ARM target include:</p>
|
|
|
|
<ul>
|
|
<li>The constant island pass now supports basic block and constant pool entry
|
|
alignments greater than 4 bytes.</li> </ul>
|
|
</div>
|
|
|
|
|
|
<!--=========================================================================-->
|
|
<h3>
|
|
<a name="MIPS">MIPS Target Improvements</a>
|
|
</h3>
|
|
|
|
<div>
|
|
|
|
<p>This release has seen major new work on just about every aspect of the MIPS
|
|
backend. Some of the major new features include:</p>
|
|
|
|
<ul>
|
|
<li>....</li>
|
|
</ul>
|
|
</div>
|
|
|
|
<!--=========================================================================-->
|
|
<h3>
|
|
<a name="OtherTS">Other Target Specific Improvements</a>
|
|
</h3>
|
|
|
|
<div>
|
|
|
|
<ul>
|
|
<li>....</li>
|
|
|
|
|
|
</ul>
|
|
|
|
</div>
|
|
|
|
<!--=========================================================================-->
|
|
<h3>
|
|
<a name="changes">Major Changes and Removed Features</a>
|
|
</h3>
|
|
|
|
<div>
|
|
|
|
<p>If you're already an LLVM user or developer with out-of-tree changes based on
|
|
LLVM 3.1, this section lists some "gotchas" that you may run into upgrading
|
|
from the previous release.</p>
|
|
|
|
<ul>
|
|
<li>LLVM 3.1 removes support for reading LLVM 2.9 bitcode files. Going forward,
|
|
we aim for all future versions of LLVM to read bitcode files and .ll files
|
|
produced by LLVM 3.0 and later.</li>
|
|
<li>....</li>
|
|
</ul>
|
|
|
|
</div>
|
|
|
|
<!--=========================================================================-->
|
|
<h3>
|
|
<a name="api_changes">Internal API Changes</a>
|
|
</h3>
|
|
|
|
<div>
|
|
|
|
<p>In addition, many APIs have changed in this release. Some of the major
|
|
LLVM API changes are:</p>
|
|
|
|
<ul>
|
|
<li>....</li>
|
|
</ul>
|
|
|
|
</div>
|
|
|
|
</div>
|
|
|
|
<!-- *********************************************************************** -->
|
|
<h2>
|
|
<a name="knownproblems">Known Problems</a>
|
|
</h2>
|
|
<!-- *********************************************************************** -->
|
|
|
|
<div>
|
|
|
|
<p>LLVM is generally a production quality compiler, and is used by a broad range
|
|
of applications and shipping in many products. That said, not every
|
|
subsystem is as mature as the aggregate, particularly the more obscure
|
|
targets. 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 or ask on the <a
|
|
href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev
|
|
list</a>.</p>
|
|
|
|
<p>Known problem areas include:</p>
|
|
|
|
<ul>
|
|
<li>The Alpha, Blackfin, CellSPU, MSP430, PTX, SystemZ and
|
|
XCore backends are experimental, and the Alpha, Blackfin and SystemZ
|
|
targets have already been removed from mainline.</li>
|
|
|
|
<li>The integrated assembler, disassembler, and JIT is not supported by
|
|
several targets. If an integrated assembler is not supported, then a
|
|
system assembler is required. For more details, see the <a
|
|
href="CodeGenerator.html#targetfeatures">Target Features Matrix</a>.
|
|
</li>
|
|
|
|
<li>The C backend has numerous problems and is not being actively maintained.
|
|
Depending on it for anything serious is not advised.</li>
|
|
</ul>
|
|
|
|
</div>
|
|
|
|
<!-- *********************************************************************** -->
|
|
<h2>
|
|
<a name="additionalinfo">Additional Information</a>
|
|
</h2>
|
|
<!-- *********************************************************************** -->
|
|
|
|
<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/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. You can access versions of these
|
|
documents specific to this release by going into the "<tt>llvm/doc/</tt>"
|
|
directory in the LLVM tree.</p>
|
|
|
|
<p>If you have any questions or comments about LLVM, please feel free to contact
|
|
us via the <a href="http://llvm.org/docs/#maillist"> mailing lists</a>.</p>
|
|
|
|
</div>
|
|
|
|
<!-- *********************************************************************** -->
|
|
|
|
<hr>
|
|
<address>
|
|
<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
|
|
src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
|
|
<a href="http://validator.w3.org/check/referer"><img
|
|
src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
|
|
|
|
<a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
|
|
Last modified: $Date$
|
|
</address>
|
|
|
|
</body>
|
|
</html>
|