2003-11-22 00:38:41 +00:00
|
|
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
|
|
|
|
"http://www.w3.org/TR/html4/strict.dtd">
|
|
|
|
<html>
|
|
|
|
<head>
|
2004-11-18 18:38:58 +00:00
|
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
2003-11-22 00:38:41 +00:00
|
|
|
<link rel="stylesheet" href="llvm.css" type="text/css">
|
2009-02-25 04:41:31 +00:00
|
|
|
<title>LLVM 2.5 Release Notes</title>
|
2003-11-22 00:38:41 +00:00
|
|
|
</head>
|
|
|
|
<body>
|
|
|
|
|
2009-02-25 04:41:31 +00:00
|
|
|
<div class="doc_title">LLVM 2.5 Release Notes</div>
|
2008-10-13 02:08:34 +00:00
|
|
|
|
2003-10-02 04:57:28 +00:00
|
|
|
<ol>
|
2003-11-22 00:38:41 +00:00
|
|
|
<li><a href="#intro">Introduction</a></li>
|
2008-10-13 18:01:01 +00:00
|
|
|
<li><a href="#subproj">Sub-project Status Update</a></li>
|
2009-02-26 22:33:38 +00:00
|
|
|
<li><a href="#externalproj">External Projects Using LLVM 2.5</a></li>
|
2009-03-02 02:37:32 +00:00
|
|
|
<li><a href="#whatsnew">What's New in LLVM 2.5?</a></li>
|
2004-04-30 22:17:12 +00:00
|
|
|
<li><a href="GettingStarted.html">Installation Instructions</a></li>
|
2003-11-22 00:38:41 +00:00
|
|
|
<li><a href="#portability">Portability and Supported Platforms</a></li>
|
2008-10-14 16:23:02 +00:00
|
|
|
<li><a href="#knownproblems">Known Problems</a></li>
|
2003-11-22 00:38:41 +00:00
|
|
|
<li><a href="#additionalinfo">Additional Information</a></li>
|
2003-10-02 04:57:28 +00:00
|
|
|
</ol>
|
|
|
|
|
2004-05-23 21:07:27 +00:00
|
|
|
<div class="doc_author">
|
2008-10-14 16:23:02 +00:00
|
|
|
<p>Written by the <a href="http://llvm.org">LLVM Team</a></p>
|
2003-11-22 00:38:41 +00:00
|
|
|
</div>
|
2003-10-02 04:57:28 +00:00
|
|
|
|
|
|
|
<!-- *********************************************************************** -->
|
2003-11-22 00:38:41 +00:00
|
|
|
<div class="doc_section">
|
|
|
|
<a name="intro">Introduction</a>
|
|
|
|
</div>
|
2003-10-02 04:57:28 +00:00
|
|
|
<!-- *********************************************************************** -->
|
|
|
|
|
2003-11-22 00:38:41 +00:00
|
|
|
<div class="doc_text">
|
|
|
|
|
2008-10-13 17:57:36 +00:00
|
|
|
<p>This document contains the release notes for the LLVM Compiler
|
2009-02-25 04:41:31 +00:00
|
|
|
Infrastructure, release 2.5. Here we describe the status of LLVM, including
|
2008-10-13 17:57:36 +00:00
|
|
|
major improvements from the previous release and significant known problems.
|
2009-03-01 18:09:47 +00:00
|
|
|
All LLVM releases may be downloaded from the <a
|
2008-10-13 17:57:36 +00:00
|
|
|
href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
|
2003-10-02 16:38:05 +00:00
|
|
|
|
2004-12-07 08:04:13 +00:00
|
|
|
<p>For more information about LLVM, including information about the latest
|
2005-10-29 07:07:09 +00:00
|
|
|
release, please check out the <a href="http://llvm.org/">main LLVM
|
2003-10-07 21:38:31 +00:00
|
|
|
web site</a>. If you have questions or comments, the <a
|
2008-10-13 17:57:36 +00:00
|
|
|
href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM Developer's Mailing
|
|
|
|
List</a> is a good place to send them.</p>
|
2003-10-02 04:57:28 +00:00
|
|
|
|
2008-10-13 02:08:34 +00:00
|
|
|
<p>Note that if you are reading this file from a Subversion checkout or the
|
2007-09-21 03:54:09 +00:00
|
|
|
main LLVM web page, this document applies to the <i>next</i> release, not the
|
2008-10-14 11:00:32 +00:00
|
|
|
current one. To see the release notes for a specific release, please see the
|
2007-09-21 03:54:09 +00:00
|
|
|
<a href="http://llvm.org/releases/">releases page</a>.</p>
|
2003-11-22 00:38:41 +00:00
|
|
|
|
|
|
|
</div>
|
2003-10-02 04:57:28 +00:00
|
|
|
|
2009-02-25 04:41:31 +00:00
|
|
|
<!-- Unfinished features in 2.5:
|
2008-02-10 07:46:44 +00:00
|
|
|
Machine LICM
|
|
|
|
Machine Sinking
|
2009-02-25 06:34:50 +00:00
|
|
|
target-specific intrinsics
|
|
|
|
gold lto plugin
|
2009-02-25 07:32:53 +00:00
|
|
|
pre-alloc splitter, strong phi elim
|
2008-10-12 19:47:48 +00:00
|
|
|
llc -enable-value-prop, propagation of value info (sign/zero ext info) from
|
|
|
|
one MBB to another
|
2009-02-25 06:34:50 +00:00
|
|
|
debug info for optimized code
|
2009-02-26 07:29:17 +00:00
|
|
|
interpreter + libffi
|
2009-02-26 22:33:38 +00:00
|
|
|
postalloc scheduler: anti dependence breaking, hazard recognizer?
|
|
|
|
|
2009-03-02 02:37:32 +00:00
|
|
|
initial support for debug line numbers when optimization enabled, not useful in
|
|
|
|
2.5 but will be for 2.6.
|
|
|
|
|
2008-02-10 07:46:44 +00:00
|
|
|
-->
|
2008-10-13 02:08:34 +00:00
|
|
|
|
2008-10-12 19:47:48 +00:00
|
|
|
<!-- for announcement email:
|
2009-02-25 06:34:50 +00:00
|
|
|
-->
|
2008-02-10 07:46:44 +00:00
|
|
|
|
2008-10-13 18:01:01 +00:00
|
|
|
<!-- *********************************************************************** -->
|
|
|
|
<div class="doc_section">
|
|
|
|
<a name="subproj">Sub-project Status Update</a>
|
2006-04-18 06:18:36 +00:00
|
|
|
</div>
|
2008-10-13 18:01:01 +00:00
|
|
|
<!-- *********************************************************************** -->
|
2006-04-18 06:18:36 +00:00
|
|
|
|
2007-05-14 06:56:09 +00:00
|
|
|
<div class="doc_text">
|
2008-06-08 21:34:41 +00:00
|
|
|
<p>
|
2009-02-25 04:41:31 +00:00
|
|
|
The LLVM 2.5 distribution currently consists of code from the core LLVM
|
2009-03-02 04:28:18 +00:00
|
|
|
repository —which roughly includes the LLVM optimizers, code generators
|
|
|
|
and supporting tools — and the llvm-gcc repository. In addition to this
|
|
|
|
code, the LLVM Project includes other sub-projects that are in development. The
|
|
|
|
two which are the most actively developed are the <a href="#clang">Clang
|
|
|
|
Project</a> and the <a href="#vmkit">VMKit Project</a>.
|
|
|
|
</pp>
|
2008-06-05 06:57:39 +00:00
|
|
|
|
2008-06-08 21:58:17 +00:00
|
|
|
</div>
|
2008-06-05 06:57:39 +00:00
|
|
|
|
|
|
|
|
2008-06-08 21:58:17 +00:00
|
|
|
<!--=========================================================================-->
|
2008-10-13 18:01:01 +00:00
|
|
|
<div class="doc_subsection">
|
2008-10-13 18:11:54 +00:00
|
|
|
<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
|
2008-06-08 21:58:17 +00:00
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
|
|
|
|
<p>The <a href="http://clang.llvm.org/">Clang project</a> is an effort to build
|
2009-03-02 04:28:18 +00:00
|
|
|
a set of new 'LLVM native' front-end technologies for the LLVM optimizer and
|
|
|
|
code generator. While Clang is not included in the LLVM 2.5 release, it is
|
|
|
|
continuing to make major strides forward in all areas. Its C and Objective-C
|
2009-02-25 05:09:54 +00:00
|
|
|
parsing and code generation support is now very solid. For example, it is
|
2009-03-02 04:28:18 +00:00
|
|
|
capable of successfully building many real-world applications for X86-32
|
|
|
|
andX86-64,
|
2009-02-26 22:33:38 +00:00
|
|
|
including <a href="http://wiki.freebsd.org/BuildingFreeBSDWithClang">the FreeBSD
|
2009-03-02 04:28:18 +00:00
|
|
|
kernel</a>. C++ is also
|
|
|
|
making <a href="http://clang.llvm.org/cxx_status.html">incredible progress</a>,
|
|
|
|
and work on templates has recently started.</p>
|
2009-02-25 05:09:54 +00:00
|
|
|
|
|
|
|
<p>While Clang is not yet production quality, it is progressing very nicely and
|
|
|
|
is quite usable for building many C and Objective-C applications. If you are
|
|
|
|
interested in fast compiles and good diagnostics, we encourage you to try it out
|
2009-02-25 06:34:50 +00:00
|
|
|
by <a href="http://clang.llvm.org/get_started.html">building from mainline</a>
|
2009-03-01 18:09:47 +00:00
|
|
|
and reporting any issues you hit to the <a
|
2009-02-25 05:09:54 +00:00
|
|
|
href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev">Clang front-end mailing
|
|
|
|
list</a>.</p>
|
|
|
|
|
|
|
|
<p>In the LLVM 2.5 time-frame, the Clang team has made many improvements:</p>
|
2008-10-27 09:27:33 +00:00
|
|
|
|
2008-10-14 23:25:09 +00:00
|
|
|
<ul>
|
2009-02-25 05:09:54 +00:00
|
|
|
<li>Clang now has a new driver, which is focused on providing a GCC-compatible
|
2009-03-01 18:09:47 +00:00
|
|
|
interface.</li>
|
|
|
|
<li>The X86-64 ABI is now supported.</li>
|
|
|
|
<li>Precompiled header support is now implemented.</li>
|
2009-02-25 05:09:54 +00:00
|
|
|
<li>Objective-C support is significantly improved beyond LLVM 2.4, supporting
|
|
|
|
many features, such as Objective-C Garbage Collection.</li>
|
2009-03-02 02:37:32 +00:00
|
|
|
<li>Many many bugs are fixed and many features have been added.</li>
|
2009-03-02 04:28:18 +00:00
|
|
|
</ul>
|
2008-10-13 18:11:54 +00:00
|
|
|
</div>
|
|
|
|
|
|
|
|
<!--=========================================================================-->
|
|
|
|
<div class="doc_subsection">
|
|
|
|
<a name="clangsa">Clang Static Analyzer</a>
|
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
|
2009-02-27 07:01:32 +00:00
|
|
|
<p>Previously announced in the last LLVM release, the Clang project also
|
|
|
|
includes an early stage static source code analysis tool for <a
|
|
|
|
href="http://clang.llvm.org/StaticAnalysis.html">automatically finding bugs</a>
|
|
|
|
in C and Objective-C programs. The tool performs a growing set of checks to find
|
|
|
|
bugs that occur on a specific path within a program.</p>
|
|
|
|
|
|
|
|
<p>In the LLVM 2.5 time-frame there have been many significant improvements to
|
|
|
|
the analyzer's core path simulation engine and machinery for generating
|
|
|
|
path-based bug reports to end-users. Particularly noteworthy improvements
|
|
|
|
include experimental support for full field-sensitivity and reasoning about heap
|
|
|
|
objects as well as an improved value-constraints subengine that does a much
|
|
|
|
better job of reasoning about inequality relationships (e.g., <tt>x > 2</tt>)
|
|
|
|
between variables and constants.
|
|
|
|
|
|
|
|
<p>The set of checks performed by the static analyzer continue to expand, and
|
|
|
|
future plans for the tool include full source-level inter-procedural analysis
|
|
|
|
and deeper checks such as buffer overrun detection. There are many opportunities
|
|
|
|
to extend and enhance the static analyzer, and anyone interested in working on
|
|
|
|
this project is encouraged to get involved!</p>
|
2008-06-08 21:58:17 +00:00
|
|
|
|
|
|
|
</div>
|
|
|
|
|
2008-10-13 18:01:01 +00:00
|
|
|
<!--=========================================================================-->
|
|
|
|
<div class="doc_subsection">
|
2008-10-14 19:23:04 +00:00
|
|
|
<a name="vmkit">VMKit: JVM/CLI Virtual Machine Implementation</a>
|
2008-10-13 18:01:01 +00:00
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
<p>
|
2008-10-14 19:23:04 +00:00
|
|
|
The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation of
|
2008-10-13 18:01:01 +00:00
|
|
|
a JVM and a CLI Virtual Machines (Microsoft .NET is an
|
|
|
|
implementation of the CLI) using the Just-In-Time compiler of LLVM.</p>
|
|
|
|
|
2009-03-02 02:37:32 +00:00
|
|
|
<p>Following LLVM 2.5, VMKit has its first release that you can find on its
|
2008-10-15 20:25:04 +00:00
|
|
|
<a href="http://vmkit.llvm.org/releases/">webpage</a>. The release includes
|
|
|
|
bug fixes, cleanup and new features. The major changes are:</p>
|
2008-10-13 18:01:01 +00:00
|
|
|
|
2008-10-14 19:23:04 +00:00
|
|
|
<ul>
|
|
|
|
|
2009-02-26 05:20:36 +00:00
|
|
|
<li>Ahead of Time compiler: compiles .class files to llvm .bc. VMKit uses this
|
|
|
|
functionality to native compile the standard classes (eg java.lang.String).
|
|
|
|
Users can compile AOT .class files into dynamic libraries and run them with the
|
|
|
|
help of VMKit.</li>
|
|
|
|
|
|
|
|
<li>New exception model: the dwarf exception model is very slow for
|
|
|
|
exception-intensive applications, so the JVM has had a new implementation of
|
|
|
|
exceptions which check at each function call if an exception happened. There is
|
|
|
|
a low performance penalty on applications without exceptions, but it is a big
|
|
|
|
gain for exception-intensive applications. For example the jack benchmark in
|
|
|
|
Spec JVM98 is 6x faster (performance gain of 83%).</li>
|
|
|
|
|
|
|
|
<li>New support for OSX/X64, Linux/X64 (with the Boehm GC), Linux/ppc32.</li>
|
2008-10-14 19:23:04 +00:00
|
|
|
|
|
|
|
</ul>
|
2008-10-13 18:01:01 +00:00
|
|
|
</div>
|
|
|
|
|
2009-02-26 22:33:38 +00:00
|
|
|
<!-- *********************************************************************** -->
|
|
|
|
<div class="doc_section">
|
|
|
|
<a name="externalproj">External Projects Using LLVM 2.5</a>
|
|
|
|
</div>
|
|
|
|
<!-- *********************************************************************** -->
|
|
|
|
|
|
|
|
<!--=========================================================================-->
|
|
|
|
<div class="doc_subsection">
|
|
|
|
<a name="pure">Pure</a>
|
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
<p>
|
2009-03-02 02:37:32 +00:00
|
|
|
<a href="http://pure-lang.googlecode.com/">Pure</a>
|
|
|
|
is an algebraic/functional programming language based on term rewriting.
|
2009-02-26 22:33:38 +00:00
|
|
|
Programs are collections of equations which are used to evaluate expressions in
|
|
|
|
a symbolic fashion. Pure offers dynamic typing, eager and lazy evaluation,
|
2009-03-01 18:09:47 +00:00
|
|
|
lexical closures, a hygienic macro system (also based on term rewriting),
|
2009-02-26 22:33:38 +00:00
|
|
|
built-in list and matrix support (including list and matrix comprehensions) and
|
|
|
|
an easy-to-use C interface. The interpreter uses LLVM as a backend to
|
|
|
|
JIT-compile Pure programs to fast native code.</p>
|
|
|
|
|
|
|
|
<p>In addition to the usual algebraic data structures, Pure also has
|
|
|
|
MATLAB-style matrices in order to support numeric computations and signal
|
|
|
|
processing in an efficient way. Pure is mainly aimed at mathematical
|
|
|
|
applications right now, but it has been designed as a general purpose language.
|
|
|
|
The dynamic interpreter environment and the C interface make it possible to use
|
|
|
|
it as a kind of functional scripting language for many application areas.
|
|
|
|
</p>
|
|
|
|
</div>
|
|
|
|
|
|
|
|
|
|
|
|
<!--=========================================================================-->
|
|
|
|
<div class="doc_subsection">
|
|
|
|
<a name="ldc">LLVM D Compiler</a>
|
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
<p>
|
2009-03-02 02:37:32 +00:00
|
|
|
<a href="http://www.dsource.org/projects/ldc">LDC</a> is an implementation of
|
|
|
|
the D Programming Language using the LLVM optimizer and code generator.
|
|
|
|
LDC project works great with the LLVM 2.5 release. General improvmenets in this
|
|
|
|
cycle have included new inline asm constraint handling, better debug info
|
|
|
|
support, general bugfixes, and better x86-64 support. This has allowed
|
2009-02-26 22:33:38 +00:00
|
|
|
some major improvements in LDC, getting us much closer to being as
|
|
|
|
fully featured as the original DMD compiler from DigitalMars.
|
|
|
|
</p>
|
|
|
|
</div>
|
|
|
|
|
2009-02-28 18:58:01 +00:00
|
|
|
<!--=========================================================================-->
|
|
|
|
<div class="doc_subsection">
|
|
|
|
<a name="RoadsendPHP">Roadsend PHP</a>
|
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
2009-03-02 02:37:32 +00:00
|
|
|
<p><a href="http://code.roadsend.com/rphp">Roadsend PHP</a> (rphp) is an open
|
|
|
|
source compiler for the PHP programming language that uses LLVM for its
|
|
|
|
optimizer, JIT, and static compiler. This is a reimplementation of an earlier
|
|
|
|
project that is now based on the LLVM.</p>
|
2009-02-28 18:58:01 +00:00
|
|
|
</div>
|
2009-02-26 22:33:38 +00:00
|
|
|
|
2008-06-08 21:58:17 +00:00
|
|
|
|
|
|
|
<!-- *********************************************************************** -->
|
|
|
|
<div class="doc_section">
|
2009-03-02 02:37:32 +00:00
|
|
|
<a name="whatsnew">What's New in LLVM 2.5?</a>
|
2008-06-08 21:58:17 +00:00
|
|
|
</div>
|
|
|
|
<!-- *********************************************************************** -->
|
|
|
|
|
2008-06-08 22:59:35 +00:00
|
|
|
<div class="doc_text">
|
|
|
|
|
2008-10-27 09:27:33 +00:00
|
|
|
<p>This release includes a huge number of bug fixes, performance tweaks, and
|
2008-10-13 17:57:36 +00:00
|
|
|
minor improvements. Some of the major improvements and new features are listed
|
|
|
|
in this section.
|
2008-06-08 22:59:35 +00:00
|
|
|
</p>
|
|
|
|
</div>
|
|
|
|
|
2008-06-08 21:34:41 +00:00
|
|
|
<!--=========================================================================-->
|
|
|
|
<div class="doc_subsection">
|
|
|
|
<a name="majorfeatures">Major New Features</a>
|
|
|
|
</div>
|
2008-06-05 18:39:01 +00:00
|
|
|
|
2008-06-08 21:34:41 +00:00
|
|
|
<div class="doc_text">
|
2008-06-05 06:57:39 +00:00
|
|
|
|
2009-02-25 04:41:31 +00:00
|
|
|
<p>LLVM 2.5 includes several major new capabilities:</p>
|
2008-06-05 06:57:39 +00:00
|
|
|
|
2008-06-08 21:34:41 +00:00
|
|
|
<ul>
|
2009-03-02 02:37:32 +00:00
|
|
|
<li>LLVM 2.5 includes a brand new <a
|
|
|
|
href="http://en.wikipedia.org/wiki/XCore">XCore</a> backend.</li>
|
2009-02-25 06:34:50 +00:00
|
|
|
|
2009-03-02 02:37:32 +00:00
|
|
|
<li>llvm-gcc now generally supports the GFortan front-end, and the precompiled
|
|
|
|
release binaries now support Fortran, even on Mac OS/X.</li>
|
2009-02-25 06:34:50 +00:00
|
|
|
|
2009-03-02 02:37:32 +00:00
|
|
|
<li>CMake is now used by the <a href="GettingStartedVS.html">LLVM build process
|
|
|
|
on Windows</a>. It automatically generates Visual Studio project files (and
|
|
|
|
more) from a set of simple text files. This makes it much easier to
|
|
|
|
maintain. In time, we'd like to standardize on CMake for everything.</li>
|
2009-02-26 07:29:17 +00:00
|
|
|
|
2009-03-02 02:37:32 +00:00
|
|
|
<li>LLVM 2.5 now uses (and includes) Google Test for unit testing.</li>
|
2009-02-26 07:29:17 +00:00
|
|
|
|
2009-03-02 02:37:32 +00:00
|
|
|
<li>The LLVM native code generator now supports arbitrary precision integers.
|
|
|
|
Types like <tt>i33</tt> have long been valid in the LLVM IR, but were previously
|
|
|
|
only supported by the interpreter. Note that the C backend still does not
|
|
|
|
support these.</li>
|
2008-06-05 06:57:39 +00:00
|
|
|
|
2009-03-02 02:37:32 +00:00
|
|
|
<li>LLVM 2.5 no longer uses 'bison', so it is easier to build on Windows.</li>
|
2008-06-05 06:25:56 +00:00
|
|
|
</ul>
|
2008-02-06 18:00:06 +00:00
|
|
|
|
|
|
|
</div>
|
|
|
|
|
2008-06-05 06:25:56 +00:00
|
|
|
|
2008-02-06 18:00:06 +00:00
|
|
|
<!--=========================================================================-->
|
|
|
|
<div class="doc_subsection">
|
2008-06-08 21:34:41 +00:00
|
|
|
<a name="llvm-gcc">llvm-gcc 4.2 Improvements</a>
|
2008-02-06 18:00:06 +00:00
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
|
2008-10-13 20:47:20 +00:00
|
|
|
<p>LLVM fully supports the llvm-gcc 4.2 front-end, which marries the GCC
|
|
|
|
front-ends and driver with the LLVM optimizer and code generator. It currently
|
|
|
|
includes support for the C, C++, Objective-C, Ada, and Fortran front-ends.</p>
|
2008-02-06 18:00:06 +00:00
|
|
|
|
2008-06-08 22:59:35 +00:00
|
|
|
<ul>
|
2009-03-02 02:37:32 +00:00
|
|
|
<li>In this release, the GCC inliner is completely disabled. Previously the GCC
|
|
|
|
inliner was used to handle always-inline functions and other cases. This caused
|
|
|
|
problems with code size growth, and it is completely disabled in this
|
|
|
|
release.</li>
|
|
|
|
|
|
|
|
<li>llvm-gcc (and LLVM in general) now support code generation for stack
|
|
|
|
canaries, which is an effective form of <a
|
|
|
|
href="http://en.wikipedia.org/wiki/Stack-smashing_protection">buffer overflow
|
|
|
|
protection</a>. llvm-gcc supports this with the <tt>-fstack-protector</tt>
|
|
|
|
command line option (just like GCC). In LLVM IR, you can request code
|
|
|
|
generation for stack canaries with function attributes.
|
|
|
|
</li>
|
2008-06-09 06:06:18 +00:00
|
|
|
</ul>
|
2008-06-05 06:25:56 +00:00
|
|
|
|
2007-05-14 06:56:09 +00:00
|
|
|
</div>
|
|
|
|
|
2008-06-05 06:25:56 +00:00
|
|
|
|
2008-02-10 08:17:19 +00:00
|
|
|
<!--=========================================================================-->
|
|
|
|
<div class="doc_subsection">
|
2009-03-02 02:37:32 +00:00
|
|
|
<a name="coreimprovements">LLVM IR and Core Improvements</a>
|
2008-02-10 08:17:19 +00:00
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
2009-03-02 02:37:32 +00:00
|
|
|
<p>LLVM IR has several new features that are used by our existing front-ends and
|
|
|
|
can be useful if you are writing a front-end for LLVM:</p>
|
2008-02-10 08:17:19 +00:00
|
|
|
|
2008-06-08 22:59:35 +00:00
|
|
|
<ul>
|
2009-03-02 02:37:32 +00:00
|
|
|
<li>The <a href="LangRef.html#i_shufflevector">shufflevector</a> instruction
|
|
|
|
has been generalized to allow different shuffle mask width than its input
|
|
|
|
vectors. This allows you to use shufflevector to combine two
|
|
|
|
"<4 x float>" vectors into a "<8 x float>" for example.</li>
|
|
|
|
|
|
|
|
<li>LLVM IR now supports new intrinsics for computing and acting on <a
|
|
|
|
href="LangRef.html#int_overflow">overflow of integer operations</a>. This allows
|
|
|
|
efficient code generation for languages that must trap or throw an exception on
|
|
|
|
overflow. While these intrinsics work on all targets, they only generate
|
|
|
|
efficient code on X86 so far.</li>
|
|
|
|
|
|
|
|
<li>LLVM IR now supports a new <a href="LangRef.html#linkage">private
|
|
|
|
linkage</a> type to produce labels that are stripped by the assembler before it
|
|
|
|
produces a .o file (thus they are invisible to the linker).</li>
|
|
|
|
|
|
|
|
<li>LLVM IR supports two new attributes for better alias analysis. The <a
|
|
|
|
href="LangRef.html#paramattrs">noalias</a> attribute can now be used on the
|
|
|
|
return value of a function to indicate that it returns new memory (e.g.
|
|
|
|
'malloc', 'calloc', etc).</li>
|
|
|
|
|
|
|
|
<li>The new <a href="LangRef.html#paramattrs">nocapture</a> attribute can be
|
|
|
|
used on pointer arguments to functions that access through but do not return the
|
|
|
|
pointer in a data structure that out lives the call (e.g. 'strlen', 'memcpy',
|
|
|
|
and many others). The simplifylibcalls pass applies these attributes to
|
|
|
|
standard libc functions.</li>
|
|
|
|
|
|
|
|
<li>The parser for ".ll" files in lib/AsmParser is now completely rewritten as a
|
|
|
|
recursive descent parser. This parser produces better error messages (including
|
|
|
|
caret diagnostics) is less fragile (less likely to crash on strange things) does
|
|
|
|
not leak memory, is more efficient, and eliminates LLVM's last use of the
|
|
|
|
'bison' tool.</li>
|
|
|
|
|
|
|
|
<li>Debug information representation and manipulation internals have been
|
|
|
|
consolidated to use a new set of classes in
|
|
|
|
<tt>llvm/Analysis/DebugInfo.h</tt> classes. These routines are more
|
|
|
|
efficient, robust, and extensible and replace the older mechanisms.
|
|
|
|
llvm-gcc, clang, and the code generator now use them to create and process
|
|
|
|
debug information.</li>
|
2009-03-01 18:09:47 +00:00
|
|
|
|
2008-02-10 08:17:19 +00:00
|
|
|
</ul>
|
2008-10-13 02:08:34 +00:00
|
|
|
|
2008-02-10 08:17:19 +00:00
|
|
|
</div>
|
|
|
|
|
2007-09-21 03:54:09 +00:00
|
|
|
<!--=========================================================================-->
|
|
|
|
<div class="doc_subsection">
|
2008-02-10 07:46:44 +00:00
|
|
|
<a name="optimizer">Optimizer Improvements</a>
|
2007-09-21 03:54:09 +00:00
|
|
|
</div>
|
2007-05-18 06:33:02 +00:00
|
|
|
|
2006-04-18 06:18:36 +00:00
|
|
|
<div class="doc_text">
|
2007-09-21 03:54:09 +00:00
|
|
|
|
2008-10-13 21:50:36 +00:00
|
|
|
<p>In addition to a huge array of bug fixes and minor performance tweaks, this
|
|
|
|
release includes a few major enhancements and additions to the optimizers:</p>
|
2007-09-26 05:44:21 +00:00
|
|
|
|
2006-11-18 07:51:14 +00:00
|
|
|
<ul>
|
2007-05-16 23:25:46 +00:00
|
|
|
|
2009-03-02 02:37:32 +00:00
|
|
|
<li>The loop optimizer now improves floating point induction variables in
|
|
|
|
several ways, including adding shadow induction variables to avoid
|
|
|
|
"integer <-> floating point" conversions in loops when safe.</li>
|
|
|
|
|
|
|
|
<li>The "-mem2reg" pass is now much faster on code with huge basic blocks.</li>
|
|
|
|
|
|
|
|
<li>The "-jump-threading" pass is more powerful: it is iterative
|
|
|
|
and handles threading based on values with fully and partially redundant
|
|
|
|
loads.</li>
|
|
|
|
|
|
|
|
<li>The "-memdep" memory dependence analysis pass (used by GVN and memcpyopt) is
|
|
|
|
both faster and more aggressive.</li>
|
|
|
|
|
|
|
|
<li>The "-scalarrepl" scalar replacement of aggregates pass is more aggressive
|
|
|
|
about promoting unions to registers.</li>
|
2008-10-12 19:47:48 +00:00
|
|
|
|
2008-06-08 02:45:07 +00:00
|
|
|
</ul>
|
|
|
|
|
|
|
|
</div>
|
|
|
|
|
|
|
|
<!--=========================================================================-->
|
|
|
|
<div class="doc_subsection">
|
2009-03-02 03:24:11 +00:00
|
|
|
<a name="codegen">Target Independent Code Generator Improvements</a>
|
2008-06-08 02:45:07 +00:00
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
|
2009-03-01 18:09:47 +00:00
|
|
|
<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>
|
2008-06-08 02:45:07 +00:00
|
|
|
|
|
|
|
<ul>
|
2009-03-02 03:24:11 +00:00
|
|
|
<li>The <a href="WritingAnLLVMBackend.html">Writing an LLVM Compiler
|
|
|
|
Backend</a> document has been greatly expanded and is substantially more
|
|
|
|
complete.</li>
|
|
|
|
|
|
|
|
<li>The SelectionDAG type legalization logic has been completely rewritten, is
|
|
|
|
now more powerful (it supports arbitrary precision integer types for example),
|
|
|
|
and more correct in several corner cases. The type legalizer converts
|
|
|
|
operations on types that are not natively supported by the target machine into
|
|
|
|
equivalent code sequences that only use natively supported types. The old type
|
|
|
|
legalizer is still available (for now) and will be used if
|
|
|
|
<tt>-disable-legalize-types</tt> is passed to the code generator.
|
2009-02-25 11:50:08 +00:00
|
|
|
</li>
|
2009-03-02 02:37:32 +00:00
|
|
|
|
2009-03-02 03:24:11 +00:00
|
|
|
<li>The code generator now supports widening illegal vectors to larger legal
|
|
|
|
ones (for example, converting operations on <3 x float> to work on
|
|
|
|
<4 x float>) which is very important for common graphics
|
|
|
|
applications.</li>
|
2009-03-02 02:37:32 +00:00
|
|
|
|
2009-03-02 03:24:11 +00:00
|
|
|
<li>The assembly printers for each target are now split out into their own
|
|
|
|
libraries that are separate from the main code generation logic. This reduces
|
|
|
|
code size of JIT compilers by not requiring them to be linked in.</li>
|
2009-03-02 02:37:32 +00:00
|
|
|
|
2009-03-02 03:24:11 +00:00
|
|
|
<li>The 'fast' instruction selection path (used at -O0 and for fast JIT
|
|
|
|
compilers) now supports accelerating codegen for code that uses exception
|
|
|
|
handling constructs.</li>
|
|
|
|
|
|
|
|
<li>The optional PBQP register allocator now supports register coalescing.</li>
|
2006-11-18 07:51:14 +00:00
|
|
|
</ul>
|
2006-04-18 06:18:36 +00:00
|
|
|
</div>
|
|
|
|
|
2009-03-02 02:37:32 +00:00
|
|
|
<!--=========================================================================-->
|
|
|
|
<div class="doc_subsection">
|
|
|
|
<a name="x86">X86-32 and X86-64 Target Improvements</a>
|
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
<p>New features of the X86 target include:
|
|
|
|
</p>
|
|
|
|
|
|
|
|
<ul>
|
2009-03-02 03:24:11 +00:00
|
|
|
<li>The "<a href="LangRef.html#int_returnaddress">llvm.returnaddress</a>"
|
|
|
|
intrinsic (which is used to implement "__builtin_return_address") now supports
|
|
|
|
non-zero stack depths on X86.</li>
|
|
|
|
|
|
|
|
<li>The X86 backend now supports code generation of vector shift operations
|
|
|
|
using SSE instructions.</li>
|
|
|
|
|
|
|
|
<li>X86-64 code generation now takes advantage of red zone (unless
|
|
|
|
-mno-red-zone option is specified).</li>
|
|
|
|
|
|
|
|
<li>The X86 backend now supports using address space #256 in LLVM IR as a way of
|
|
|
|
performing memory references off the GS segment register. This allows a
|
|
|
|
front-end to take advantage of very low-level programming techniques when
|
|
|
|
targetting X86 CPUs. See test/CodeGen/X86/movgs.ll for a simple example.</li>
|
|
|
|
|
|
|
|
<li>The X86 backend now supports a <tt>-disable-mmx</tt> command line option to
|
|
|
|
prevent use of MMX even on chips that support it. This is important for cases
|
|
|
|
where code does not contain the proper "llvm.x86.mmx.emms" intrinsics.</li>
|
|
|
|
|
|
|
|
<li>The X86 JIT now detects the new Intel "<a
|
|
|
|
href="http://en.wikipedia.org/wiki/Intel_Core_i7">Core i7</a>" and <a
|
|
|
|
href="http://en.wikipedia.org/wiki/Intel_Atom">Atom</a>" chips,
|
|
|
|
auto-configuring itself appropriately for the features of these chips.</li>
|
|
|
|
|
|
|
|
<li>The JIT now supports exception handling constructs on Linux/X86-64 and
|
|
|
|
Darwin/x86-64.</li>
|
|
|
|
<li>The JIT supports Thread Local Storage (TLS) on Linux/X86-32 but not yet on
|
|
|
|
X86-64.</li>
|
2009-03-02 02:37:32 +00:00
|
|
|
</ul>
|
|
|
|
|
|
|
|
|
|
|
|
</div>
|
2007-09-21 03:54:09 +00:00
|
|
|
|
|
|
|
<!--=========================================================================-->
|
|
|
|
<div class="doc_subsection">
|
2009-02-26 07:32:11 +00:00
|
|
|
<a name="pic16">PIC16 Target Improvements</a>
|
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
<p>New features of the PIC16 target include:
|
|
|
|
</p>
|
|
|
|
|
|
|
|
<ul>
|
|
|
|
<li>Both direct and indirect load/stores work now.</li>
|
|
|
|
<li>Logical, bitwise and conditional operations now work for integer data
|
|
|
|
types.</li>
|
|
|
|
<li>Function calls involving basic types work now.</li>
|
|
|
|
<li>Support for integer arrays.</li>
|
|
|
|
<li>Compiler can now emit libcalls for operations not support by m/c insns.</li>
|
|
|
|
<li>Support for both data and rom address spaces.</li>
|
|
|
|
</ul>
|
|
|
|
|
|
|
|
<p>Things not yet supported:</p>
|
|
|
|
|
|
|
|
<ul>
|
|
|
|
<li>Floating point.</li>
|
|
|
|
<li>Passing/returning aggregate types to/from functions.</li>
|
|
|
|
<li>Variable arguments.</li>
|
|
|
|
<li>Indirect function calls.</li>
|
2009-03-02 03:24:11 +00:00
|
|
|
<li>Interrupts/programs.</li>
|
2009-02-26 07:32:11 +00:00
|
|
|
<li>Debug info.</li>
|
|
|
|
</ul>
|
|
|
|
|
|
|
|
</div>
|
|
|
|
|
|
|
|
|
2009-03-01 02:30:21 +00:00
|
|
|
<!--=========================================================================-->
|
|
|
|
<div class="doc_subsection">
|
|
|
|
<a name="llvmc">Improvements in LLVMC</a>
|
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
<p>New features include:</p>
|
|
|
|
|
|
|
|
<ul>
|
2009-03-01 18:09:47 +00:00
|
|
|
<li>Beginning with LLVM 2.5, <tt>llvmc2</tt> is known as
|
|
|
|
just <tt>llvmc</tt>. The old <tt>llvmc</tt> driver was removed.</li>
|
2009-03-01 02:30:21 +00:00
|
|
|
|
|
|
|
<li>The Clang plugin was substantially improved and is now enabled
|
2009-03-01 18:09:47 +00:00
|
|
|
by default. The command <tt>llvmc --clang</tt> can be now used as a
|
|
|
|
synonym to <tt>ccc</tt>.</li>
|
2009-03-01 02:30:21 +00:00
|
|
|
|
2009-03-01 18:09:47 +00:00
|
|
|
<li>There is now a <tt>--check-graph</tt> option which is supposed to catch
|
|
|
|
common errors like multiple default edges, mismatched output/input language
|
|
|
|
names and cycles. In general, these checks can't be done at compile-time
|
|
|
|
because of the need to support plugins.</li>
|
2009-03-01 02:30:21 +00:00
|
|
|
|
2009-03-01 18:09:47 +00:00
|
|
|
<li>Plugins are now more flexible and can refer to compilation graph nodes and
|
|
|
|
options defined in other plugins. To manage dependencies, a priority-sorting
|
|
|
|
mechanism was introduced. This change affects the TableGen file syntax; see the
|
|
|
|
documentation for details.</li>
|
2009-03-01 02:30:21 +00:00
|
|
|
|
2009-03-01 18:09:47 +00:00
|
|
|
<li>Hooks can now be provided with arguments. The syntax is "<tt>$CALL(MyHook,
|
|
|
|
'Arg1', 'Arg2', 'Arg #3')</tt>".</li>
|
2009-03-01 02:30:21 +00:00
|
|
|
|
2009-03-01 18:09:47 +00:00
|
|
|
<li>A new option type: multi-valued option, for options that take more than one
|
|
|
|
argument (for example, "<tt>-foo a b c</tt>").</li>
|
2009-03-01 02:30:21 +00:00
|
|
|
|
2009-03-01 18:09:47 +00:00
|
|
|
<li>New option properties: '<tt>one_or_more</tt>', '<tt>zero_or_more</tt>',
|
|
|
|
'<tt>hidden</tt>' and '<tt>really_hidden</tt>'.</li>
|
2009-03-01 02:30:21 +00:00
|
|
|
|
2009-03-01 18:09:47 +00:00
|
|
|
<li>The '<tt>case</tt>' expression gained an '<tt>error</tt>' action and
|
|
|
|
an '<tt>empty</tt>' test (equivalent to "<tt>(not (not_empty ...))</tt>").</li>
|
2009-03-01 02:30:21 +00:00
|
|
|
|
|
|
|
<li>Documentation now looks more consistent to the rest of the LLVM
|
|
|
|
docs. There is also a man page now.</li>
|
2009-03-01 18:09:47 +00:00
|
|
|
|
2009-03-01 02:30:21 +00:00
|
|
|
</ul>
|
2008-06-05 08:02:49 +00:00
|
|
|
|
2008-10-13 02:08:34 +00:00
|
|
|
</div>
|
2008-06-05 08:02:49 +00:00
|
|
|
|
|
|
|
|
2008-10-13 17:57:36 +00:00
|
|
|
<!--=========================================================================-->
|
|
|
|
<div class="doc_subsection">
|
|
|
|
<a name="changes">Major Changes and Removed Features</a>
|
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
|
2008-10-13 22:06:31 +00:00
|
|
|
<p>If you're already an LLVM user or developer with out-of-tree changes based
|
2009-02-25 04:41:31 +00:00
|
|
|
on LLVM 2.4, this section lists some "gotchas" that you may run into upgrading
|
2008-10-13 22:06:31 +00:00
|
|
|
from the previous release.</p>
|
2008-10-13 18:01:01 +00:00
|
|
|
|
2008-10-13 22:06:31 +00:00
|
|
|
<ul>
|
2008-10-13 17:57:36 +00:00
|
|
|
|
2009-03-02 03:24:11 +00:00
|
|
|
<li>llvm-gcc defaults to -fno-math-errno on all X86 targets.</li>
|
2008-10-13 22:06:31 +00:00
|
|
|
</ul>
|
2008-10-13 17:57:36 +00:00
|
|
|
|
2008-10-13 22:06:31 +00:00
|
|
|
|
|
|
|
<p>In addition, many APIs have changed in this release. Some of the major LLVM
|
|
|
|
API changes are:</p>
|
2008-10-13 17:57:36 +00:00
|
|
|
|
|
|
|
<ul>
|
2009-02-25 04:41:31 +00:00
|
|
|
<li>?</li>
|
2008-10-14 20:03:43 +00:00
|
|
|
</ul>
|
2009-02-25 04:41:31 +00:00
|
|
|
|
2009-03-02 04:28:18 +00:00
|
|
|
<ul>
|
2009-02-25 04:41:31 +00:00
|
|
|
<li>?</li>
|
2008-10-13 17:57:36 +00:00
|
|
|
</ul>
|
|
|
|
|
|
|
|
</div>
|
|
|
|
|
|
|
|
|
|
|
|
|
2003-10-02 16:38:05 +00:00
|
|
|
<!-- *********************************************************************** -->
|
2003-11-22 00:38:41 +00:00
|
|
|
<div class="doc_section">
|
|
|
|
<a name="portability">Portability and Supported Platforms</a>
|
|
|
|
</div>
|
2003-10-02 16:38:05 +00:00
|
|
|
<!-- *********************************************************************** -->
|
|
|
|
|
2003-11-22 00:38:41 +00:00
|
|
|
<div class="doc_text">
|
|
|
|
|
2004-12-08 20:35:47 +00:00
|
|
|
<p>LLVM is known to work on the following platforms:</p>
|
2004-06-01 18:22:41 +00:00
|
|
|
|
|
|
|
<ul>
|
2009-03-01 18:09:47 +00:00
|
|
|
<li>Intel and AMD machines (IA32, X86-64, AMD64, EMT-64) running Red Hat
|
2008-11-10 05:40:34 +00:00
|
|
|
Linux, Fedora Core and FreeBSD (and probably other unix-like systems).</li>
|
2009-03-01 18:09:47 +00:00
|
|
|
<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit
|
2008-11-10 05:40:34 +00:00
|
|
|
and 64-bit modes.</li>
|
2008-02-06 18:00:06 +00:00
|
|
|
<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
|
2004-12-07 08:04:13 +00:00
|
|
|
<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
|
|
|
|
support is available for native builds with Visual C++).</li>
|
2008-06-05 18:39:01 +00:00
|
|
|
<li>Sun UltraSPARC workstations running Solaris 10.</li>
|
2005-05-13 20:28:15 +00:00
|
|
|
<li>Alpha-based machines running Debian GNU/Linux.</li>
|
2008-06-05 18:39:01 +00:00
|
|
|
<li>Itanium-based (IA64) machines running Linux and HP-UX.</li>
|
2004-06-01 18:22:41 +00:00
|
|
|
</ul>
|
|
|
|
|
2008-06-05 06:57:39 +00:00
|
|
|
<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
|
2004-05-09 05:28:35 +00:00
|
|
|
to the machine and operating system on which it is built. However, minor
|
|
|
|
porting may be required to get LLVM to work on new platforms. We welcome your
|
|
|
|
portability patches and reports of successful builds or error messages.</p>
|
2003-10-02 04:57:28 +00:00
|
|
|
|
2003-11-22 00:38:41 +00:00
|
|
|
</div>
|
2003-10-02 04:57:28 +00:00
|
|
|
|
|
|
|
<!-- *********************************************************************** -->
|
2003-11-22 00:38:41 +00:00
|
|
|
<div class="doc_section">
|
|
|
|
<a name="knownproblems">Known Problems</a>
|
|
|
|
</div>
|
2003-10-02 04:57:28 +00:00
|
|
|
<!-- *********************************************************************** -->
|
|
|
|
|
2003-11-22 00:38:41 +00:00
|
|
|
<div class="doc_text">
|
|
|
|
|
2009-03-01 18:09:47 +00:00
|
|
|
<p>This section contains significant known problems with the LLVM system,
|
2008-11-10 05:40:34 +00:00
|
|
|
listed by component. If you run into a problem, please check the <a
|
2005-10-29 07:07:09 +00:00
|
|
|
href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
|
2003-12-12 21:22:16 +00:00
|
|
|
there isn't already one.</p>
|
2003-10-02 04:57:28 +00:00
|
|
|
|
2003-11-22 00:38:41 +00:00
|
|
|
</div>
|
2003-10-02 04:57:28 +00:00
|
|
|
|
2004-03-14 02:03:02 +00:00
|
|
|
<!-- ======================================================================= -->
|
|
|
|
<div class="doc_subsection">
|
|
|
|
<a name="experimental">Experimental features included with this release</a>
|
|
|
|
</div>
|
2003-10-02 04:57:28 +00:00
|
|
|
|
2004-03-14 02:03:02 +00:00
|
|
|
<div class="doc_text">
|
|
|
|
|
2004-05-12 21:46:05 +00:00
|
|
|
<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
|
|
|
|
not be relied on, and bugs should not be filed against them, but they may be
|
|
|
|
useful to some people. In particular, if you would like to work on one of these
|
2008-02-12 06:29:45 +00:00
|
|
|
components, please contact us on the <a
|
|
|
|
href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
|
2004-03-14 02:03:02 +00:00
|
|
|
|
|
|
|
<ul>
|
2008-10-14 11:31:14 +00:00
|
|
|
<li>The MSIL, IA64, Alpha, SPU, MIPS, and PIC16 backends are experimental.</li>
|
2008-06-08 20:18:35 +00:00
|
|
|
<li>The llc "<tt>-filetype=asm</tt>" (the default) is the only supported
|
2008-02-06 06:30:34 +00:00
|
|
|
value for this option.</li>
|
2004-03-14 02:03:02 +00:00
|
|
|
</ul>
|
|
|
|
|
|
|
|
</div>
|
2003-10-02 04:57:28 +00:00
|
|
|
|
2005-11-08 21:11:33 +00:00
|
|
|
<!-- ======================================================================= -->
|
|
|
|
<div class="doc_subsection">
|
2006-11-18 07:51:14 +00:00
|
|
|
<a name="x86-be">Known problems with the X86 back-end</a>
|
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
|
|
|
|
<ul>
|
2008-06-08 10:24:13 +00:00
|
|
|
<li>The X86 backend does not yet support
|
|
|
|
all <a href="http://llvm.org/PR879">inline assembly that uses the X86
|
|
|
|
floating point stack</a>. It supports the 'f' and 't' constraints, but not
|
|
|
|
'u'.</li>
|
2008-06-08 21:19:07 +00:00
|
|
|
<li>The X86 backend generates inefficient floating point code when configured
|
|
|
|
to generate code for systems that don't have SSE2.</li>
|
2008-06-08 19:38:43 +00:00
|
|
|
<li>Win64 code generation wasn't widely tested. Everything should work, but we
|
2008-06-08 10:24:13 +00:00
|
|
|
expect small issues to happen. Also, llvm-gcc cannot build mingw64 runtime
|
|
|
|
currently due
|
|
|
|
to <a href="http://llvm.org/PR2255">several</a>
|
2008-06-08 23:12:47 +00:00
|
|
|
<a href="http://llvm.org/PR2257">bugs</a> due to lack of support for the
|
|
|
|
'u' inline assembly constraint and X87 floating point inline assembly.</li>
|
2008-06-08 23:05:11 +00:00
|
|
|
<li>The X86-64 backend does not yet support the LLVM IR instruction
|
2009-03-02 02:37:32 +00:00
|
|
|
<tt>va_arg</tt>. Currently, the llvm-gcc and front-ends support variadic
|
2008-06-08 23:05:11 +00:00
|
|
|
argument constructs on X86-64 by lowering them manually.</li>
|
2006-11-18 07:51:14 +00:00
|
|
|
</ul>
|
|
|
|
|
|
|
|
</div>
|
|
|
|
|
|
|
|
<!-- ======================================================================= -->
|
|
|
|
<div class="doc_subsection">
|
|
|
|
<a name="ppc-be">Known problems with the PowerPC back-end</a>
|
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
|
|
|
|
<ul>
|
2007-05-15 09:21:28 +00:00
|
|
|
<li>The Linux PPC32/ABI support needs testing for the interpreter and static
|
2007-05-23 04:39:32 +00:00
|
|
|
compilation, and lacks support for debug information.</li>
|
2006-11-18 07:51:14 +00:00
|
|
|
</ul>
|
|
|
|
|
|
|
|
</div>
|
|
|
|
|
|
|
|
<!-- ======================================================================= -->
|
|
|
|
<div class="doc_subsection">
|
2007-05-14 06:56:09 +00:00
|
|
|
<a name="arm-be">Known problems with the ARM back-end</a>
|
2006-11-18 07:51:14 +00:00
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
|
|
|
|
<ul>
|
2007-05-23 04:39:32 +00:00
|
|
|
<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
|
2007-09-26 15:59:54 +00:00
|
|
|
processors, thumb programs can crash or produce wrong
|
2007-05-23 04:39:32 +00:00
|
|
|
results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
|
2007-05-14 06:56:09 +00:00
|
|
|
<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
|
|
|
|
</li>
|
2008-06-08 21:19:07 +00:00
|
|
|
<li>There is a bug in QEMU-ARM (<= 0.9.0) which causes it to incorrectly
|
|
|
|
execute
|
2007-05-23 04:39:32 +00:00
|
|
|
programs compiled with LLVM. Please use more recent versions of QEMU.</li>
|
2006-11-18 07:51:14 +00:00
|
|
|
</ul>
|
|
|
|
|
|
|
|
</div>
|
|
|
|
|
|
|
|
<!-- ======================================================================= -->
|
|
|
|
<div class="doc_subsection">
|
2007-05-14 06:56:09 +00:00
|
|
|
<a name="sparc-be">Known problems with the SPARC back-end</a>
|
2006-11-18 07:51:14 +00:00
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
|
|
|
|
<ul>
|
2007-05-14 06:56:09 +00:00
|
|
|
<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
|
|
|
|
support the 64-bit SPARC ABI (-m64).</li>
|
2006-11-18 07:51:14 +00:00
|
|
|
</ul>
|
|
|
|
|
|
|
|
</div>
|
|
|
|
|
2008-10-25 14:56:26 +00:00
|
|
|
<!-- ======================================================================= -->
|
|
|
|
<div class="doc_subsection">
|
|
|
|
<a name="mips-be">Known problems with the MIPS back-end</a>
|
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
|
|
|
|
<ul>
|
|
|
|
<li>The O32 ABI is not fully supported.</li>
|
|
|
|
<li>64-bit MIPS targets are not supported yet.</li>
|
|
|
|
</ul>
|
|
|
|
|
|
|
|
</div>
|
|
|
|
|
2006-11-18 07:51:14 +00:00
|
|
|
<!-- ======================================================================= -->
|
|
|
|
<div class="doc_subsection">
|
|
|
|
<a name="alpha-be">Known problems with the Alpha back-end</a>
|
2005-11-08 21:11:33 +00:00
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
|
|
|
|
<ul>
|
2006-11-18 07:51:14 +00:00
|
|
|
|
|
|
|
<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
|
|
|
|
appropriate nops inserted to ensure restartability.</li>
|
|
|
|
|
|
|
|
</ul>
|
|
|
|
</div>
|
|
|
|
|
|
|
|
<!-- ======================================================================= -->
|
|
|
|
<div class="doc_subsection">
|
|
|
|
<a name="ia64-be">Known problems with the IA64 back-end</a>
|
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
|
|
|
|
<ul>
|
2008-06-08 23:12:47 +00:00
|
|
|
<li>The Itanium backend is highly experimental, and has a number of known
|
|
|
|
issues. We are looking for a maintainer for the Itanium backend. If you
|
2008-10-15 10:47:24 +00:00
|
|
|
are interested, please contact the LLVMdev mailing list.</li>
|
2005-11-08 21:11:33 +00:00
|
|
|
</ul>
|
2006-11-18 07:51:14 +00:00
|
|
|
|
2005-11-08 21:11:33 +00:00
|
|
|
</div>
|
|
|
|
|
2006-11-18 07:51:14 +00:00
|
|
|
<!-- ======================================================================= -->
|
|
|
|
<div class="doc_subsection">
|
2007-05-14 06:56:09 +00:00
|
|
|
<a name="c-be">Known problems with the C back-end</a>
|
2006-11-18 07:51:14 +00:00
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
|
|
|
|
<ul>
|
2008-06-05 06:35:40 +00:00
|
|
|
<li><a href="http://llvm.org/PR802">The C backend has only basic support for
|
|
|
|
inline assembly code</a>.</li>
|
2007-09-26 06:01:35 +00:00
|
|
|
<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
|
|
|
|
C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
|
2008-06-08 20:18:35 +00:00
|
|
|
C++ code compiled with llc or native compilers.</li>
|
2008-02-10 13:40:55 +00:00
|
|
|
<li>The C backend does not support all exception handling constructs.</li>
|
2009-02-25 11:51:54 +00:00
|
|
|
<li>The C backend does not support arbitrary precision integers.</li>
|
2006-11-18 07:51:14 +00:00
|
|
|
</ul>
|
|
|
|
|
|
|
|
</div>
|
2005-11-08 21:11:33 +00:00
|
|
|
|
2003-11-22 00:38:41 +00:00
|
|
|
|
|
|
|
<!-- ======================================================================= -->
|
|
|
|
<div class="doc_subsection">
|
2008-06-05 06:35:40 +00:00
|
|
|
<a name="c-fe">Known problems with the llvm-gcc C front-end</a>
|
2003-11-22 00:38:41 +00:00
|
|
|
</div>
|
2003-10-02 05:07:23 +00:00
|
|
|
|
2003-11-22 00:38:41 +00:00
|
|
|
<div class="doc_text">
|
2006-03-03 00:34:26 +00:00
|
|
|
|
2008-02-06 18:00:06 +00:00
|
|
|
<p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time
|
|
|
|
Optimization</a> on most platforms "out-of-the-box". Please inquire on the
|
2008-10-15 10:47:24 +00:00
|
|
|
LLVMdev mailing list if you are interested.</p>
|
2006-11-18 07:51:14 +00:00
|
|
|
|
2008-06-05 06:35:40 +00:00
|
|
|
<p>The only major language feature of GCC not supported by llvm-gcc is
|
|
|
|
the <tt>__builtin_apply</tt> family of builtins. However, some extensions
|
|
|
|
are only supported on some targets. For example, trampolines are only
|
2008-06-08 20:18:35 +00:00
|
|
|
supported on some targets (these are used when you take the address of a
|
|
|
|
nested function).</p>
|
2007-09-26 15:59:54 +00:00
|
|
|
|
2008-06-05 06:35:40 +00:00
|
|
|
<p>If you run into GCC extensions which are not supported, please let us know.
|
|
|
|
</p>
|
2003-11-22 00:38:41 +00:00
|
|
|
|
|
|
|
</div>
|
|
|
|
|
|
|
|
<!-- ======================================================================= -->
|
|
|
|
<div class="doc_subsection">
|
2008-06-05 06:35:40 +00:00
|
|
|
<a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
|
2003-11-22 00:38:41 +00:00
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
|
2007-05-14 06:56:09 +00:00
|
|
|
<p>The C++ front-end is considered to be fully
|
2004-12-07 08:04:13 +00:00
|
|
|
tested and works for a number of non-trivial programs, including LLVM
|
2007-05-14 06:56:09 +00:00
|
|
|
itself, Qt, Mozilla, etc.</p>
|
2003-10-02 04:57:28 +00:00
|
|
|
|
2003-11-22 00:38:41 +00:00
|
|
|
<ul>
|
2008-10-11 18:27:16 +00:00
|
|
|
<li>Exception handling works well on the X86 and PowerPC targets. Currently
|
2008-11-10 05:40:34 +00:00
|
|
|
only Linux and Darwin targets are supported (both 32 and 64 bit).</li>
|
2003-11-22 00:38:41 +00:00
|
|
|
</ul>
|
2003-10-07 22:14:37 +00:00
|
|
|
|
2003-11-22 00:38:41 +00:00
|
|
|
</div>
|
2003-10-07 22:14:37 +00:00
|
|
|
|
2008-10-30 03:58:13 +00:00
|
|
|
<!-- ======================================================================= -->
|
|
|
|
<div class="doc_subsection">
|
|
|
|
<a name="fortran-fe">Known problems with the llvm-gcc Fortran front-end</a>
|
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
2008-11-04 21:50:59 +00:00
|
|
|
<ul>
|
2008-10-30 03:58:13 +00:00
|
|
|
<li>Fortran support generally works, but there are still several unresolved bugs
|
|
|
|
in Bugzilla. Please see the tools/gfortran component for details.</li>
|
2009-03-01 18:09:47 +00:00
|
|
|
|
2008-10-30 03:58:13 +00:00
|
|
|
<li>The Fortran front-end currently does not build on Darwin (without tweaks)
|
|
|
|
due to unresolved dependencies on the C front-end.</li>
|
2008-11-04 21:50:59 +00:00
|
|
|
</ul>
|
2008-10-30 03:58:13 +00:00
|
|
|
</div>
|
2006-04-18 06:18:36 +00:00
|
|
|
|
2008-02-12 06:29:45 +00:00
|
|
|
<!-- ======================================================================= -->
|
|
|
|
<div class="doc_subsection">
|
2008-06-05 06:35:40 +00:00
|
|
|
<a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
|
2008-02-12 06:29:45 +00:00
|
|
|
</div>
|
|
|
|
|
|
|
|
<div class="doc_text">
|
|
|
|
The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature
|
|
|
|
technology and problems should be expected.
|
|
|
|
<ul>
|
2008-06-08 20:18:35 +00:00
|
|
|
<li>The Ada front-end currently only builds on X86-32. This is mainly due
|
2008-02-12 06:29:45 +00:00
|
|
|
to lack of trampoline support (pointers to nested functions) on other platforms,
|
2008-06-08 20:18:35 +00:00
|
|
|
however it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
|
2008-02-12 06:29:45 +00:00
|
|
|
which does support trampolines.</li>
|
|
|
|
<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
|
2009-02-25 11:59:06 +00:00
|
|
|
This is due to lack of LLVM support for <tt>setjmp</tt>/<tt>longjmp</tt> style
|
|
|
|
exception handling, which is used internally by the compiler.
|
2008-02-12 06:29:45 +00:00
|
|
|
Workaround: configure with --disable-bootstrap.</li>
|
2008-10-13 17:27:23 +00:00
|
|
|
<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
|
|
|
|
and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
|
2009-02-25 11:59:06 +00:00
|
|
|
(c380004 also fails with gcc-4.2 mainline).
|
|
|
|
If the compiler is built with checks disabled then <a href="http://llvm.org/PR2010">c393010</a>
|
|
|
|
causes the compiler to go into an infinite loop, using up all system memory.</li>
|
2008-10-13 17:27:23 +00:00
|
|
|
<li>Some gcc specific Ada tests continue to crash the compiler.</li>
|
2008-02-12 06:29:45 +00:00
|
|
|
<li>The -E binder option (exception backtraces)
|
|
|
|
<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
|
|
|
|
crashing if an exception is raised. Workaround: do not use -E.</li>
|
|
|
|
<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
|
|
|
|
or finish at a non-byte offset</a> in a record. Workaround: do not pack records
|
|
|
|
or use representation clauses that result in a field of a non-discrete type
|
|
|
|
starting or finishing in the middle of a byte.</li>
|
2008-06-08 21:19:07 +00:00
|
|
|
<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
|
|
|
|
'main' as generated by the Ada binder to be invalid</a>.
|
|
|
|
Workaround: hand edit the file to use pointers for <tt>argv</tt> and
|
|
|
|
<tt>envp</tt> rather than integers.</li>
|
|
|
|
<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
|
|
|
|
ignored</a>.</li>
|
2008-02-12 06:29:45 +00:00
|
|
|
</ul>
|
|
|
|
</div>
|
|
|
|
|
2003-10-02 04:57:28 +00:00
|
|
|
<!-- *********************************************************************** -->
|
2003-11-22 00:38:41 +00:00
|
|
|
<div class="doc_section">
|
|
|
|
<a name="additionalinfo">Additional Information</a>
|
|
|
|
</div>
|
2003-10-02 04:57:28 +00:00
|
|
|
<!-- *********************************************************************** -->
|
|
|
|
|
2003-11-22 00:38:41 +00:00
|
|
|
<div class="doc_text">
|
|
|
|
|
2005-05-16 17:13:10 +00:00
|
|
|
<p>A wide variety of additional information is available on the <a
|
2007-05-18 00:44:29 +00:00
|
|
|
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
|
2007-07-09 08:04:31 +00:00
|
|
|
contains versions of the API documentation which is up-to-date with the
|
|
|
|
Subversion version of the source code.
|
2005-03-30 19:14:24 +00:00
|
|
|
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>
|
2003-10-02 04:57:28 +00:00
|
|
|
|
2003-11-22 00:38:41 +00:00
|
|
|
<p>If you have any questions or comments about LLVM, please feel free to contact
|
2005-10-29 07:07:09 +00:00
|
|
|
us via the <a href="http://llvm.org/docs/#maillist"> mailing
|
2003-12-12 21:22:16 +00:00
|
|
|
lists</a>.</p>
|
2003-10-02 04:57:28 +00:00
|
|
|
|
2003-11-22 00:38:41 +00:00
|
|
|
</div>
|
2003-10-02 04:57:28 +00:00
|
|
|
|
|
|
|
<!-- *********************************************************************** -->
|
|
|
|
|
2003-11-22 00:38:41 +00:00
|
|
|
<hr>
|
2003-11-22 01:23:39 +00:00
|
|
|
<address>
|
2003-12-21 22:53:21 +00:00
|
|
|
<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
|
2008-12-11 17:34:48 +00:00
|
|
|
src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
|
2003-11-22 01:23:39 +00:00
|
|
|
<a href="http://validator.w3.org/check/referer"><img
|
2008-12-11 17:34:48 +00:00
|
|
|
src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
|
2003-11-22 01:23:39 +00:00
|
|
|
|
2007-05-18 00:44:29 +00:00
|
|
|
<a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
|
2003-11-22 00:38:41 +00:00
|
|
|
Last modified: $Date$
|
2003-11-22 01:23:39 +00:00
|
|
|
</address>
|
2003-10-02 04:57:28 +00:00
|
|
|
|
2003-11-22 00:38:41 +00:00
|
|
|
</body>
|
|
|
|
</html>
|