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gerrit-public.fairphone.software / toolchain / llvm-project / 656db16db47615dffe96c4200cdd5b914c51d894 / . / llvm / docs / ReleaseNotes.html
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Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
2 "http://www.w3.org/TR/html4/strict.dtd">
3<html>
4<head>
Reid Spencere4190fa2004-11-18 18:38:58 +0000[diff] [blame]5 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]6 <link rel="stylesheet" href="llvm.css" type="text/css">
Jeffrey Yasskin0830b972010-01-28 01:14:43 +0000[diff] [blame]7 <title>LLVM 2.7 Release Notes</title>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]8</head>
9<body>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]10
Jeffrey Yasskin0830b972010-01-28 01:14:43 +0000[diff] [blame]11<div class="doc_title">LLVM 2.7 Release Notes</div>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]12
Chris Lattnerc871bac2010-03-17 04:02:39 +0000[diff] [blame]13<img align=right src="http://llvm.org/img/DragonSmall.png"
14 width="136" height="136">
15
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]16<ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]17 <li><a href="#intro">Introduction</a></li>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]18 <li><a href="#subproj">Sub-project Status Update</a></li>
Jeffrey Yasskin0830b972010-01-28 01:14:43 +0000[diff] [blame]19 <li><a href="#externalproj">External Projects Using LLVM 2.7</a></li>
20 <li><a href="#whatsnew">What's New in LLVM 2.7?</a></li>
Chris Lattner77a51732004-04-30 22:17:12 +0000[diff] [blame]21 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]22 <li><a href="#portability">Portability and Supported Platforms</a></li>
Dan Gohmanad888912008-10-14 16:23:02 +0000[diff] [blame]23 <li><a href="#knownproblems">Known Problems</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]24 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]25</ol>
26
Chris Lattner020e1fc2004-05-23 21:07:27 +0000[diff] [blame]27<div class="doc_author">
Dan Gohmanad888912008-10-14 16:23:02 +0000[diff] [blame]28 <p>Written by the <a href="http://llvm.org">LLVM Team</a></p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]29</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]30
Chris Lattner06971182010-04-13 06:37:00 +0000[diff] [blame]31<!--
Chris Lattner656db162010-04-22 05:41:35 +0000[diff] [blame^]32<h1 style="color:red">These are in-progress notes for the upcoming LLVM 2.8
Jeffrey Yasskin0830b972010-01-28 01:14:43 +0000[diff] [blame]33release.<br>
34You may prefer the
Chris Lattner656db162010-04-22 05:41:35 +0000[diff] [blame^]35<a href="http://llvm.org/releases/2.6/docs/ReleaseNotes.html">LLVM 2.7
Chris Lattner06971182010-04-13 06:37:00 +0000[diff] [blame]36Release Notes</a>.</h1>-->
Jeffrey Yasskin0830b972010-01-28 01:14:43 +0000[diff] [blame]37
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]38<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]39<div class="doc_section">
40 <a name="intro">Introduction</a>
41</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]42<!-- *********************************************************************** -->
43
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]44<div class="doc_text">
45
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]46<p>This document contains the release notes for the LLVM Compiler
Jeffrey Yasskin0830b972010-01-28 01:14:43 +0000[diff] [blame]47Infrastructure, release 2.7. Here we describe the status of LLVM, including
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]48major improvements from the previous release and significant known problems.
Mikhail Glushenkov25422542009-03-01 18:09:47 +0000[diff] [blame]49All LLVM releases may be downloaded from the <a
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]50href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]51
Chris Lattnerb5bb5972004-12-07 08:04:13 +0000[diff] [blame]52<p>For more information about LLVM, including information about the latest
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]53release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]54web site</a>. If you have questions or comments, the <a
Chris Lattner0b1c9a52010-03-17 04:41:49 +0000[diff] [blame]55href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM Developer's
56Mailing List</a> is a good place to send them.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]57
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]58<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]59main LLVM web page, this document applies to the <i>next</i> release, not the
Gabor Greif355f81c2008-10-14 11:00:32 +0000[diff] [blame]60current one. To see the release notes for a specific release, please see the
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]61<a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]62
63</div>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]64
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]65
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]66<!--
67Almost dead code.
68 include/llvm/Analysis/LiveValues.h => Dan
69 lib/Transforms/IPO/MergeFunctions.cpp => consider for 2.8.
70 llvm/Analysis/PointerTracking.h => Edwin wants this, consider for 2.8.
Chris Lattner06971182010-04-13 06:37:00 +0000[diff] [blame]71 ABCD, GEPSplitterPass
Chris Lattner89ea59d2010-01-16 21:25:13 +0000[diff] [blame]72 MSIL backend?
Chris Lattner10a3cc42010-03-17 06:41:58 +0000[diff] [blame]73 lib/Transforms/Utils/SSI.cpp -> ABCD depends on it.
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]74-->
75
76
Jeffrey Yasskin0830b972010-01-28 01:14:43 +0000[diff] [blame]77<!-- Features that need text if they're finished for 2.7:
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]78 strong phi elim
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]79 llvm.dbg.value: variable debug info for optimized code
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]80 loop dependence analysis
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]81 -->
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]82
Chris Lattnerc4d68542008-10-12 19:47:48 +0000[diff] [blame]83 <!-- for announcement email:
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]84 Logo web page.
85 llvm devmtg
86 compiler_rt
87 KLEE web page at klee.llvm.org
88 Many new papers added to /pubs/
Chris Lattner10a3cc42010-03-17 06:41:58 +0000[diff] [blame]89 Mention gcc plugin.
Chris Lattnerd02da042009-02-25 06:34:50 +0000[diff] [blame]90 -->
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]91
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]92<!-- *********************************************************************** -->
93<div class="doc_section">
94 <a name="subproj">Sub-project Status Update</a>
Chris Lattner625a3d82008-06-08 21:34:41 +0000[diff] [blame]95</div>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]96<!-- *********************************************************************** -->
Chris Lattner625a3d82008-06-08 21:34:41 +0000[diff] [blame]97
98<div class="doc_text">
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]99<p>
Jeffrey Yasskin0830b972010-01-28 01:14:43 +0000[diff] [blame]100The LLVM 2.7 distribution currently consists of code from the core LLVM
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]101repository (which roughly includes the LLVM optimizers, code generators
102and supporting tools), the Clang repository and the llvm-gcc repository. In
103addition to this code, the LLVM Project includes other sub-projects that are in
104development. Here we include updates on these subprojects.
Bill Wendlingf170d2e2009-03-02 04:28:57 +0000[diff] [blame]105</p>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]106
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]107</div>
108
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]109
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]110<!--=========================================================================-->
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]111<div class="doc_subsection">
Chris Lattner44c09cd2008-10-13 18:11:54 +0000[diff] [blame]112<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]113</div>
114
115<div class="doc_text">
116
Jeffrey Yasskin0830b972010-01-28 01:14:43 +0000[diff] [blame]117<p>The <a href="http://clang.llvm.org/">Clang project</a> is ...</p>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]118
Jeffrey Yasskin0830b972010-01-28 01:14:43 +0000[diff] [blame]119<p>In the LLVM 2.7 time-frame, the Clang team has made many improvements:</p>
Bill Wendlingef362462008-10-27 09:27:33 +0000[diff] [blame]120
Daniel Dunbarc11b40f2008-10-14 23:25:09 +0000[diff] [blame]121<ul>
Daniel Dunbareb4bc7f2010-03-25 16:09:18 +0000[diff] [blame]122<li>FIXME: C++! Include a link to cxx_compatibility.html</li>
123
124<li>FIXME: Static Analyzer improvements?</li>
125
126<li>CIndex API and Python bindings: Clang now includes a C API as part of the
127CIndex library. Although we make make some changes to the API in the future, it
128is intended to be stable and has been designed for use by external projects. See
129the Clang
130doxygen <a href="http://clang.llvm.org/doxygen/group__CINDEX.html">CIndex</a>
131documentation for more details. The CIndex API also includings an preliminary
132set of Python bindings.</li>
133
134<li>ARM Support: Clang now has ABI support for both the Darwin and Linux ARM
135ABIs. Coupled with many improvements to the LLVM ARM backend, Clang is now
136suitable for use as a a beta quality ARM compiler.</li>
Bill Wendling87adbe42009-03-02 04:28:18 +0000[diff] [blame]137</ul>
Chris Lattner44c09cd2008-10-13 18:11:54 +0000[diff] [blame]138</div>
139
140<!--=========================================================================-->
141<div class="doc_subsection">
142<a name="clangsa">Clang Static Analyzer</a>
143</div>
144
145<div class="doc_text">
146
Jeffrey Yasskin0830b972010-01-28 01:14:43 +0000[diff] [blame]147<p>Previously announced in the 2.4, 2.5, and 2.6 LLVM releases, the Clang project also
Ted Kremenekc11fae82009-02-27 07:01:32 +0000[diff] [blame]148includes an early stage static source code analysis tool for <a
149href="http://clang.llvm.org/StaticAnalysis.html">automatically finding bugs</a>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]150in C and Objective-C programs. The tool performs checks to find
Ted Kremenekc11fae82009-02-27 07:01:32 +0000[diff] [blame]151bugs that occur on a specific path within a program.</p>
Chris Lattnerbcffa5a2008-10-14 00:52:49 +0000[diff] [blame]152
Chris Lattnerc871bac2010-03-17 04:02:39 +0000[diff] [blame]153<p>In the LLVM 2.7 time-frame, the analyzer core has sprouted legs and...</p>
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]154
155</div>
156
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]157<!--=========================================================================-->
158<div class="doc_subsection">
Nicolas Geoffraye5ec9322008-10-14 19:23:04 +0000[diff] [blame]159<a name="vmkit">VMKit: JVM/CLI Virtual Machine Implementation</a>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]160</div>
161
162<div class="doc_text">
163<p>
Nicolas Geoffraye5ec9322008-10-14 19:23:04 +0000[diff] [blame]164The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation of
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]165a JVM and a CLI Virtual Machine (Microsoft .NET is an
166implementation of the CLI) using LLVM for static and just-in-time
167compilation.</p>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]168
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]169<p>
Chris Lattneref2e5732010-03-29 18:34:13 +0000[diff] [blame]170With the release of LLVM 2.7, VMKit has shifted to a great framework for writing
171virtual machines. VMKit now offers precise and efficient garbage collection with
172multi-threading support, thanks to the MMTk memory management toolkit, as well
173as just in time and ahead of time compilation with LLVM. The major changes in
174VMKit 0.27 are:</p>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]175
Nicolas Geoffraye5ec9322008-10-14 19:23:04 +0000[diff] [blame]176<ul>
177
Chris Lattneref2e5732010-03-29 18:34:13 +0000[diff] [blame]178<li>Garbage collection: VMKit now uses the MMTk toolkit for garbage collectors.
179 The first collector to be ported is the MarkSweep collector, which is precise,
180 and drastically improves the performance of VMKit.</li>
181<li>Line number information in the JVM: by using the debug metadata of LLVM, the
182 JVM now supports precise line number information, useful when printing a stack
183 trace.</li>
184<li>Interface calls in the JVM: we implemented a variant of the Interface Method
185 Table technique for interface calls in the JVM.
186</li>
Nicolas Geoffraye5ec9322008-10-14 19:23:04 +0000[diff] [blame]187
188</ul>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]189</div>
190
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]191
192<!--=========================================================================-->
193<div class="doc_subsection">
194<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
195</div>
196
197<div class="doc_text">
198<p>
199The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
200is a simple library that provides an implementation of the low-level
201target-specific hooks required by code generation and other runtime components.
202For example, when compiling for a 32-bit target, converting a double to a 64-bit
203unsigned integer is compiled into a runtime call to the "__fixunsdfdi"
204function. The compiler-rt library provides highly optimized implementations of
205this and other low-level routines (some are 3x faster than the equivalent
206libgcc routines).</p>
207
208<p>
209All of the code in the compiler-rt project is available under the standard LLVM
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]210License, a "BSD-style" license. New in LLVM 2.7: compiler_rt now
211supports ARM targets.</p>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]212
213</div>
214
215<!--=========================================================================-->
216<div class="doc_subsection">
Duncan Sands92452b92010-04-02 09:23:15 +0000[diff] [blame]217<a name="dragonegg">DragonEgg: llvm-gcc ported to gcc-4.5</a>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]218</div>
219
220<div class="doc_text">
221<p>
Duncan Sands92452b92010-04-02 09:23:15 +0000[diff] [blame]222<a href="http://dragonegg.llvm.org/">DragonEgg</a> is a port of llvm-gcc to
223gcc-4.5. Unlike llvm-gcc, which makes many intrusive changes to the underlying
224gcc-4.2 code, dragonegg in theory does not require any gcc-4.5 modifications
225whatsoever (currently one small patch is needed). This is thanks to the new
226<a href="http://gcc.gnu.org/wiki/plugins">gcc plugin architecture</a>, which
227makes it possible to modify the behaviour of gcc at runtime by loading a plugin,
228which is nothing more than a dynamic library which conforms to the gcc plugin
229interface. DragonEgg is a gcc plugin that causes the LLVM optimizers to be run
230instead of the gcc optimizers, and the LLVM code generators instead of the gcc
231code generators, just like llvm-gcc. To use it, you add
232"-fplugin=path/dragonegg.so" to the gcc-4.5 command line, and gcc-4.5 magically
233becomes llvm-gcc-4.5!
234</p>
235
236<p>
237DragonEgg is still a work in progress. Currently C works very well, while C++,
238Ada and Fortran work fairly well. All other languages either don't work at all,
239or only work poorly. For the moment only the x86-32 and x86-64 targets are
Duncan Sands4dd125e2010-04-20 19:40:58 +0000[diff] [blame]240supported, and only on linux and darwin (darwin needs an additional gcc patch).
Duncan Sands92452b92010-04-02 09:23:15 +0000[diff] [blame]241</p>
242
243<p>
Duncan Sandsfe291172010-04-21 13:51:48 +0000[diff] [blame]244DragonEgg is a new project which is seeing its first release with llvm-2.7.
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]245</p>
246
247</div>
248
249
250<!--=========================================================================-->
251<div class="doc_subsection">
252<a name="mc">llvm-mc: Machine Code Toolkit</a>
253</div>
254
255<div class="doc_text">
256<p>
Jeffrey Yasskin0830b972010-01-28 01:14:43 +0000[diff] [blame]257The LLVM Machine Code (MC) Toolkit project is ...
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]258</p>
259
Chris Lattner1dcca8b2010-04-21 06:23:40 +0000[diff] [blame]260<p>
261MC Disassembler (with blog post), MCInstPrinter. Many X86 backend and AsmPrinter simplifications
262Can transcode from GAS to intel syntax with "llvm-mc foo.s -output-asm-variant=1"
263</p>
264
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]265</div>
266
267
Chris Lattner53e06f92009-02-26 22:33:38 +0000[diff] [blame]268<!-- *********************************************************************** -->
269<div class="doc_section">
Jeffrey Yasskin0830b972010-01-28 01:14:43 +0000[diff] [blame]270 <a name="externalproj">External Open Source Projects Using LLVM 2.7</a>
Chris Lattner53e06f92009-02-26 22:33:38 +0000[diff] [blame]271</div>
272<!-- *********************************************************************** -->
273
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]274<div class="doc_text">
275
276<p>An exciting aspect of LLVM is that it is used as an enabling technology for
277 a lot of other language and tools projects. This section lists some of the
Jeffrey Yasskin0830b972010-01-28 01:14:43 +0000[diff] [blame]278 projects that have already been updated to work with LLVM 2.7.</p>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]279</div>
280
Chris Lattner53e06f92009-02-26 22:33:38 +0000[diff] [blame]281<!--=========================================================================-->
282<div class="doc_subsection">
283<a name="pure">Pure</a>
284</div>
285
286<div class="doc_text">
287<p>
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]288<a href="http://pure-lang.googlecode.com/">Pure</a>
289is an algebraic/functional programming language based on term rewriting.
Chris Lattner53e06f92009-02-26 22:33:38 +0000[diff] [blame]290Programs are collections of equations which are used to evaluate expressions in
291a symbolic fashion. Pure offers dynamic typing, eager and lazy evaluation,
Mikhail Glushenkov25422542009-03-01 18:09:47 +0000[diff] [blame]292lexical closures, a hygienic macro system (also based on term rewriting),
Chris Lattner53e06f92009-02-26 22:33:38 +0000[diff] [blame]293built-in list and matrix support (including list and matrix comprehensions) and
294an easy-to-use C interface. The interpreter uses LLVM as a backend to
295 JIT-compile Pure programs to fast native code.</p>
296
Chris Lattner6aba4862010-03-17 17:25:49 +0000[diff] [blame]297<p>Pure versions 0.43 and later have been tested and are known to work with
298LLVM 2.7 (and continue to work with older LLVM releases >= 2.5).</p>
299
Chris Lattner53e06f92009-02-26 22:33:38 +0000[diff] [blame]300</div>
301
Chris Lattnerfb23a962009-02-28 18:58:01 +0000[diff] [blame]302<!--=========================================================================-->
303<div class="doc_subsection">
304<a name="RoadsendPHP">Roadsend PHP</a>
305</div>
306
307<div class="doc_text">
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]308<p>
309<a href="http://code.roadsend.com/rphp">Roadsend PHP</a> (rphp) is an open
Chris Lattner0c72d8f2009-03-02 19:07:24 +0000[diff] [blame]310source implementation of the PHP programming
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]311language that uses LLVM for its optimizer, JIT and static compiler. This is a
Chris Lattnerc871bac2010-03-17 04:02:39 +0000[diff] [blame]312reimplementation of an earlier project that is now based on LLVM.
Chris Lattner6aba4862010-03-17 17:25:49 +0000[diff] [blame]313</p>
Chris Lattnerfb23a962009-02-28 18:58:01 +0000[diff] [blame]314</div>
Chris Lattner53e06f92009-02-26 22:33:38 +0000[diff] [blame]315
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]316<!--=========================================================================-->
317<div class="doc_subsection">
318<a name="UnladenSwallow">Unladen Swallow</a>
319</div>
320
321<div class="doc_text">
322<p>
323<a href="http://code.google.com/p/unladen-swallow/">Unladen Swallow</a> is a
324branch of <a href="http://python.org/">Python</a> intended to be fully
325compatible and significantly faster. It uses LLVM's optimization passes and JIT
Chris Lattner5b59a732010-03-18 06:52:15 +0000[diff] [blame]326compiler.
Chris Lattnerc871bac2010-03-17 04:02:39 +0000[diff] [blame]327</p>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]328</div>
329
330<!--=========================================================================-->
331<div class="doc_subsection">
Chris Lattnerb4a02792010-03-29 17:50:39 +0000[diff] [blame]332<a name="tce">TTA-based Codesign Environment (TCE)</a>
333</div>
334
335<div class="doc_text">
336<p>
337<a href="http://tce.cs.tut.fi/">TCE</a> is a toolset for designing
338application-specific processors (ASP) based on the Transport triggered
339architecture (TTA). The toolset provides a complete co-design flow from C/C++
340programs down to synthesizable VHDL and parallel program binaries. Processor
341customization points include the register files, function units, supported
342operations, and the interconnection network.</p>
343
344<p>TCE uses llvm-gcc/Clang and LLVM for C/C++ language support, target
345independent optimizations and also for parts of code generation. It generates
346new LLVM-based code generators "on the fly" for the designed TTA processors and
347loads them in to the compiler backend as runtime libraries to avoid per-target
348recompilation of larger parts of the compiler chain.</p>
349
350</div>
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]351
John Criswell9003e0f2010-04-06 14:52:14 +0000[diff] [blame]352<!--=========================================================================-->
353<div class="doc_subsection">
354<a name="safecode">SAFECode Compiler</a>
355</div>
356
357<div class="doc_text">
358<p>
359<a href="http://safecode.cs.illinois.edu">SAFECode</a> is a memory safe C
360compiler built using LLVM. It takes standard, unannotated C code, analyzes the
361code to ensure that memory accesses and array indexing operations are safe, and
362instruments the code with run-time checks when safety cannot be proven
363statically.
364</p>
365</div>
366
367
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]368<!-- *********************************************************************** -->
369<div class="doc_section">
Jeffrey Yasskin0830b972010-01-28 01:14:43 +0000[diff] [blame]370 <a name="whatsnew">What's New in LLVM 2.7?</a>
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]371</div>
372<!-- *********************************************************************** -->
373
Chris Lattnerb7bc2aa2008-06-08 22:59:35 +0000[diff] [blame]374<div class="doc_text">
375
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]376<p>This release includes a huge number of bug fixes, performance tweaks and
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]377minor improvements. Some of the major improvements and new features are listed
378in this section.
Chris Lattnerb7bc2aa2008-06-08 22:59:35 +0000[diff] [blame]379</p>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]380
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]381<p>In addition to changes to the code, between LLVM 2.6 and 2.7, a number of
382organization changes have happened:
383</p>
384
385<ul>
Chris Lattner656db162010-04-22 05:41:35 +0000[diff] [blame^]386<li>LLVM has a new <a href="http://llvm.org/Logo.html">official logo</a>!</li>
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]387
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]388<li>Ted Kremenek and Doug Gregor have stepped forward as <a
389 href="http://llvm.org/docs/DeveloperPolicy.html#owners">Code Owners</a> of the
390 Clang static analyzer and the Clang Frontend, respectively.</li>
Chris Lattner1dcca8b2010-04-21 06:23:40 +0000[diff] [blame]391
392<li>LLVM now has an <a href="http://blog.llvm.org">official Blog</a> at
393 <a href="http://blog.llvm.org">http://blog.llvm.org</a>. This is a great way
394 to learn about new LLVM-related features as they are implemented. Several
395 features in this release are already explained on the blog.</li>
396
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]397<li>The LLVM web pages are now checked into the SVN server, in the "www",
398 "www-pubs" and "www-releases" SVN modules. Previously they were hidden in a
Chris Lattner656db162010-04-22 05:41:35 +0000[diff] [blame^]399 largely inaccessible old CVS server.</li>
Chris Lattner1dcca8b2010-04-21 06:23:40 +0000[diff] [blame]400
401<li><a href="http://llvm.org">llvm.org</a> is now hosted on a new (and much
402 faster) server. It is still graciously hosted at the University of Illinois
403 of Urbana Champaign.</li>
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]404</ul>
Chris Lattnerb7bc2aa2008-06-08 22:59:35 +0000[diff] [blame]405</div>
406
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]407<!--=========================================================================-->
Chris Lattner625a3d82008-06-08 21:34:41 +0000[diff] [blame]408<div class="doc_subsection">
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000[diff] [blame]409<a name="majorfeatures">Major New Features</a>
410</div>
411
412<div class="doc_text">
413
Jeffrey Yasskin0830b972010-01-28 01:14:43 +0000[diff] [blame]414<p>LLVM 2.7 includes several major new capabilities:</p>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]415
416<ul>
Chris Lattner656db162010-04-22 05:41:35 +0000[diff] [blame^]417<li>2.7 includes initial support for the <a
Chris Lattner1dcca8b2010-04-21 06:23:40 +0000[diff] [blame]418 href="http://en.wikipedia.org/wiki/MicroBlaze">MicroBlaze</a> target.
419 MicroBlaze is a soft processor core designed for Xilinx FPGAs.</li>
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]420
Chris Lattner656db162010-04-22 05:41:35 +0000[diff] [blame^]421<li>2.7 includes a new LLVM IR "extensible metadata" feature. This feature
Chris Lattner1dcca8b2010-04-21 06:23:40 +0000[diff] [blame]422 supports many different use cases, including allowing front-end authors to
423 encode source level information into LLVM IR, which is consumed by later
424 language-specific passes. This is a great way to do high-level optimizations
425 like devirtualization, type-based alias analysis, etc. See the <a
426 href="http://blog.llvm.org/2010/04/extensible-metadata-in-llvm-ir.html">
427 Extensible Metadata Blog Post</a> for more information.</li>
428
Chris Lattner656db162010-04-22 05:41:35 +0000[diff] [blame^]429<li>2.7 encodes <a href="SourceLevelDebugging.html">debug information</a>
Chris Lattner1dcca8b2010-04-21 06:23:40 +0000[diff] [blame]430in a completely new way, built on extensible metadata. The new implementation
431is much more memory efficient and paves the way for improvements to optimized
432code debugging experience.</li>
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]433
Chris Lattner656db162010-04-22 05:41:35 +0000[diff] [blame^]434<li>2.7 now directly supports taking the address of a label and doing an
Chris Lattner1dcca8b2010-04-21 06:23:40 +0000[diff] [blame]435 indirect branch through a pointer. This is particularly useful for
436 interpreter loops, and is used to implement the GCC "address of label"
437 extension. For more information, see the <a
438href="http://blog.llvm.org/2010/01/address-of-label-and-indirect-branches.html">
439Address of Label and Indirect Branches in LLVM IR Blog Post</a>.
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]440
Chris Lattner656db162010-04-22 05:41:35 +0000[diff] [blame^]441<li>2.7 is the first release to start supporting APIs for assembling and
Chris Lattner1dcca8b2010-04-21 06:23:40 +0000[diff] [blame]442 disassembling target machine code. These APIs are useful for a variety of
443 low level clients, and are surfaced in the new "enhanced disassembly" API.
444 For more information see the <a
445 href="http://blog.llvm.org/2010/01/x86-disassembler.html">The X86
446 Disassembler Blog Post</a> for more information.</li>
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]447
Chris Lattner656db162010-04-22 05:41:35 +0000[diff] [blame^]448<li>2.7 includes major parts of the work required by the new MC Project,
Chris Lattner1dcca8b2010-04-21 06:23:40 +0000[diff] [blame]449 which aims to rework our handling of low-level machine code. A few targets
450 have been refactored to support it, and work is underway to support a native
451 assembler in LLVM. This work is not complete in LLVM 2.7, but you has made
452 substantially more progress on LLVM mainline. You can read more about this
453 in the <a href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html">
454 Intro to the LLVM MC Project Blog Post</a>.
455</li>
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]456
Chris Lattner458e79f2008-02-10 08:18:42 +0000[diff] [blame]457</ul>
Chris Lattner10a3cc42010-03-17 06:41:58 +0000[diff] [blame]458
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]459</div>
460
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]461<!--=========================================================================-->
462<div class="doc_subsection">
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]463<a name="coreimprovements">LLVM IR and Core Improvements</a>
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]464</div>
465
466<div class="doc_text">
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]467<p>LLVM IR has several new features for better support of new targets and that
468expose new optimization opportunities:</p>
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]469
Chris Lattnerb7112222008-06-05 06:25:56 +0000[diff] [blame]470<ul>
Chris Lattner656db162010-04-22 05:41:35 +0000[diff] [blame^]471<li>LLVM IR now supports a 16-bit "half float" data type through <a
472 href="LangRef.html#int_fp16">two new intrinsics</a> and APFloat support.</li>
473<li>LLVM IR supports two new <a href="LangRef.html#fnattrs">function
Chris Lattner1dcca8b2010-04-21 06:23:40 +0000[diff] [blame]474 attributes</a>: inlinehint and alignstack(n). The former is a hint to the
Chris Lattner656db162010-04-22 05:41:35 +0000[diff] [blame^]475 optimizer that a function was declared 'inline' and thus the inliner should
476 weight it higher when considering inlining it. The later
Chris Lattner1dcca8b2010-04-21 06:23:40 +0000[diff] [blame]477 indicates to the code generator that the function diverges from the platform
478 ABI on stack alignment.</li>
479<li>The new <a href="LangRef.html#int_objectsize">llvm.objectsize</a> intrinsic
480 allows the optimizer to infer the sizes of memory objects in some cases.
Chris Lattner656db162010-04-22 05:41:35 +0000[diff] [blame^]481 This intrinsic is used to implement the GCC <tt>__builtin_object_size</tt>
Chris Lattner1dcca8b2010-04-21 06:23:40 +0000[diff] [blame]482 extension.</li>
483<li>LLVM 2.7 has pre-alpha support for <a
484 href="http://llvm.org/docs/LangRef.html#t_union">unions in LLVM IR</a>.
485 Unfortuantely, this support is not really usable in 2.7, so if you're
486 interested in pushing it forward, please help contribute to LLVM mainline.</li>
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]487</li>
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]488</ul>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]489
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]490</div>
491
492<!--=========================================================================-->
493<div class="doc_subsection">
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]494<a name="optimizer">Optimizer Improvements</a>
495</div>
496
497<div class="doc_text">
498
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]499<p>In addition to a large array of minor performance tweaks and bug fixes, this
Chris Lattner25879d72008-10-13 21:50:36 +0000[diff] [blame]500release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]501
502<ul>
503
Chris Lattner656db162010-04-22 05:41:35 +0000[diff] [blame^]504<li>The inliner reuses now merges arrays stack objects in different callees when
505 inlining multiple call sites into one function. This reduces the stack size
506 of the resultant function.</li>
507<li>The -basicaa alias analysis pass (which is the default) has been improved to
508 be less dependent on "type safe" pointers. It can now look through bitcasts
509 and other constructs more aggressively, allowing better load/store
510 optimization.</li>
511<li>The load elimination optimization in the GVN Pass [<a
512href="http://blog.llvm.org/2009/12/introduction-to-load-elimination-in-gvn.html">intro
513 blog post</a>] has been substantially improved to be more aggressive about
514 partial redundancy elimination and do more aggressive phi translation. Please
515 see the <a
516 href="http://blog.llvm.org/2009/12/advanced-topics-in-redundant-load.html">
517 Advanced Topics in Redundant Load Elimination with a Focus on PHI Translation
518 Blog Post</a> for more details.</li>
519<li>The module <a href="LangRef.html#datalayout">target data string</a> now
520 includes a notion of what the 'native' integer data types a for the target,
521 which allows various optimizations to use. This helps mid-level
522 optimizations avoid promoting complex sequences of operations to data types
523 that are not natively supported (e.g. converting i32 operations to i64 on
524 a 32-bit chip).</li>
525<li>The mid-level optimizer is now conservative when operating on a module with
526 no target data. Previously, it would default to SparcV9 settings, which is
527 not what most people expected.</li>
Chris Lattnera668b452010-04-21 06:42:24 +0000[diff] [blame]528<li>Jump threading is now much more aggressive at simplifying correlated
Chris Lattner656db162010-04-22 05:41:35 +0000[diff] [blame^]529 conditionals and threading blocks with otherwise complex logic. It has
530 subsumed the old "Conditional Propagation" pass, and -condprop has been
531 removed from LLVM 2.7.</li>
532<li>The -instcombine pass has been refactored from being one huge file to being
533 a library of its own. Internally, it uses a customized IRBuilder to clean
534 it up and simplify it.</li>
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]535
Chris Lattner656db162010-04-22 05:41:35 +0000[diff] [blame^]536<li>The optimal edge profiling pass is reliable and much more complete than in
537 2.6. It can be used with the llvm-prof tool but isn't wired up to the
538 llvm-gcc and clang command line options yet.</li>
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]539
Chris Lattner656db162010-04-22 05:41:35 +0000[diff] [blame^]540<li>A new experimental alias analysis implementation, -scev-aa, has been added.
541 It uses LLVM's Scalar Evolution implementation to do symbolic analysis of
542 pointer offset expressions to disambiguate pointers. It can catch a few
543 cases that basicaa cannot, particularly in complex loop nests.</li>
Chris Lattnera668b452010-04-21 06:42:24 +0000[diff] [blame]544
Chris Lattner656db162010-04-22 05:41:35 +0000[diff] [blame^]545<li>As usual, there are countless minor optimization improvements and bug fixes,
546 and the default pass ordering has been tweaked for improved optimization
547 effectiveness.</li>
Chris Lattnera668b452010-04-21 06:42:24 +0000[diff] [blame]548
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]549</ul>
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]550
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]551</div>
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]552
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]553
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]554<!--=========================================================================-->
555<div class="doc_subsection">
556<a name="executionengine">Interpreter and JIT Improvements</a>
557</div>
Chris Lattner25879d72008-10-13 21:50:36 +0000[diff] [blame]558
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]559<div class="doc_text">
560
561<ul>
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]562<li>The JIT now supports generating debug information, which is compatible with
563the new GDB 7.0 (and later) interfaces for registering debug info for
564dynamically generated code.</li>
565
Jeffrey Yasskin9fb8ce82010-01-29 19:10:38 +0000[diff] [blame]566<li>The JIT now <a
567href="http://llvm.org/viewvc/llvm-project?view=rev&revision=85295">defaults
568to compiling eagerly</a> to avoid a race condition in the lazy JIT.
569Clients that still want the lazy JIT can switch it on by calling
570<tt>ExecutionEngine::DisableLazyCompilation(false)</tt>.</li>
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]571
Jeffrey Yasskine0913882010-02-11 01:07:39 +0000[diff] [blame]572<li>It is now possible to create more than one JIT instance in the same process.
573These JITs can generate machine code in parallel,
574although <a href="http://llvm.org/docs/ProgrammersManual.html#jitthreading">you
575still have to obey the other threading restrictions</a>.</li>
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]576
Chris Lattner7795ea92008-06-08 02:45:07 +0000[diff] [blame]577</ul>
578
579</div>
580
581<!--=========================================================================-->
582<div class="doc_subsection">
Chris Lattnerd434bfb2009-03-02 03:24:11 +0000[diff] [blame]583<a name="codegen">Target Independent Code Generator Improvements</a>
Chris Lattner7795ea92008-06-08 02:45:07 +0000[diff] [blame]584</div>
585
586<div class="doc_text">
587
Mikhail Glushenkov25422542009-03-01 18:09:47 +0000[diff] [blame]588<p>We have put a significant amount of work into the code generator
589infrastructure, which allows us to implement more aggressive algorithms and make
590it run faster:</p>
Chris Lattner7795ea92008-06-08 02:45:07 +0000[diff] [blame]591
592<ul>
Chris Lattner1dcca8b2010-04-21 06:23:40 +0000[diff] [blame]593<li>New instruction selector [blog post?].</li>
Chris Lattnera668b452010-04-21 06:42:24 +0000[diff] [blame]594<li>New LSR with "full strength reduction" mode. Description?</li>
595<li>Code generator MC'ized except for debug info and EH.</li>
596<li>New CodeGen Level CSE</li>
597<li>Combiner-AA improvements, why not on by default?</li>
598<li>Pre-regalloc tail duplication</li>
599<li>Codegen level OptimizeExtsPass pass, takes advantage of x86 subregs. </li>
600<li>Support for the GCC option -fno-schedule-insns</li>
601<li>Non-temporal load/store, only implemented on X86, see LangRef.html#i_load.</li>
602<li>MachineSSAUpdater.h</li>
603<li>X86 and XCore supports returning arbitrary return values, returning too many values is
604 supported by returning through a hidden pointer.</li>
605<li>verbose-asm now produces information about spill slots and loop nests</li>
606<li>GHC Haskell ABI / calling conv support.</li>
607<li>Many improvements to debug info</li>
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]608</ul>
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]609</div>
610
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]611<!--=========================================================================-->
612<div class="doc_subsection">
613<a name="x86">X86-32 and X86-64 Target Improvements</a>
614</div>
615
616<div class="doc_text">
617<p>New features of the X86 target include:
618</p>
619
620<ul>
Chris Lattnera668b452010-04-21 06:42:24 +0000[diff] [blame]621<li>The X86 backend now optimizes tails calls much more aggressively for
622 functions that use the standard C calling convention.</li>
623<li>The X86 backend now models scalar SSE registers as subregs of the SSE vector
624 registers, making the code generator more aggressive in cases where scalars
625 and vector types are mixed.</li>
Chris Lattnerd434bfb2009-03-02 03:24:11 +0000[diff] [blame]626
Chris Lattnera668b452010-04-21 06:42:24 +0000[diff] [blame]627<li>PostRA scheduler for X86? FIXME: is this on by default in 2.7?</li>
Chris Lattnerd434bfb2009-03-02 03:24:11 +0000[diff] [blame]628
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]629</ul>
630
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]631</div>
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]632
633<!--=========================================================================-->
634<div class="doc_subsection">
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]635<a name="ARM">ARM Target Improvements</a>
Chris Lattnerc92d7692009-03-01 02:30:21 +0000[diff] [blame]636</div>
637
638<div class="doc_text">
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]639<p>New features of the ARM target include:
640</p>
Chris Lattnerc92d7692009-03-01 02:30:21 +0000[diff] [blame]641
642<ul>
Chris Lattnerc92d7692009-03-01 02:30:21 +0000[diff] [blame]643
Chris Lattner1dcca8b2010-04-21 06:23:40 +0000[diff] [blame]644<li>The ARM backend now generates instructions in unified assembly syntax.</li>
645
646<li>llvm-gcc now has complete support for the ARM v7 NEON instruction set. This
647 support differs slightly from the GCC implementation. Please see the
648 <a
649href="http://blog.llvm.org/2010/04/arm-advanced-simd-neon-intrinsics-and.html">
650 ARM Advanced SIMD (NEON) Intrinsics and Types in LLVM Blog Post</a> for
651 helpful information if migrating code from GCC to LLVM-GCC.</li>
652
653<li>The ARM and Thumb code generators now using register scavenging for stack
654 object address materialization.(FIXME: WHAT BENEFIT DOES THIS PROVIDE?)</li>
655
656<li>The ARM backend now has good support for ARMv4 targets, and has been tested
657 on StrongARM hardware. Previously, LLVM only supported ARMv4T and
658 newer chips.</li>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]659</ul>
Chris Lattnerc92d7692009-03-01 02:30:21 +0000[diff] [blame]660
Chris Lattnerc92d7692009-03-01 02:30:21 +0000[diff] [blame]661
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]662</div>
Chris Lattnerc92d7692009-03-01 02:30:21 +0000[diff] [blame]663
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]664<!--=========================================================================-->
665<div class="doc_subsection">
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]666<a name="newapis">New Useful APIs</a>
667</div>
668
669<div class="doc_text">
670
671<p>This release includes a number of new APIs that are used internally, which
672 may also be useful for external clients.
673</p>
674
675<ul>
Chris Lattner656db162010-04-22 05:41:35 +0000[diff] [blame^]676<li>The optimizer uses the new CodeMetrics class to measure the size of code.
677 Various passes that use thing (like the inliner, loop unswitcher, etc) all
678 use this to make more accurate estimates of the code size impact of various
679 optimizations.</li>
680<li>A new <a href="http://llvm.org/doxygen/InstructionSimplify_8h-source.html">
681 llvm/Analysis/InstructionSimplify.h</a> interface available for doing
682 symbolic simplification of instructions (e.g. <tt>a+0</tt> -&gt; <tt>a</tt>)
683 without requiring the instruction to exist. This centralizes a lot of
684 ad-hoc symbolic manipulation code scattered in various passes.</li>
685<li>The optimizer now uses a new <a
686 href="http://llvm.org/doxygen/SSAUpdater_8h-source.html">SSAUpdater</a>
687 class which efficiently supports
688 doing unstructured SSA update operations. This centralized a bunch of code
689 scattered through various passes (e.g. jump threading, lcssa, loop rotate,
690 etc) for doing this sort of thing. The code generator has an similar
691 <a href="http://llvm.org/doxygen/MachineSSAUpdater_8h-source.html">
692 MachineSSAUpdater</a> class.</li>
693<li>The <a href="http://llvm.org/doxygen/Regex_8h-source.html">
694 llvm/Support/Regex.h</a> header exposes a platform independent regular
Chris Lattner1dcca8b2010-04-21 06:23:40 +0000[diff] [blame]695 expression API. Building on this, the <a
696 href="TestingGuide.html#FileCheck">FileCheck</a> utility now supports
697 regular exressions.</li>
698<li>raw_ostream now supports a circular "debug stream" accessed with "dbgs()".
699 By default, this stream works the same way as "errs()", but if you pass
700 <tt>-debug-buffer-size=1000</tt> to opt, the debug stream is capped to a
701 fixed sized circular buffer and the output is printed at the end of the
702 program's execution. This is helpful if you have a long lived compiler
703 process and you're interested in seeing snapshots in time.</li>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]704</ul>
705
706
707</div>
708
709<!--=========================================================================-->
710<div class="doc_subsection">
711<a name="otherimprovements">Other Improvements and New Features</a>
712</div>
713
714<div class="doc_text">
715<p>Other miscellaneous features include:</p>
716
717<ul>
Chris Lattner1dcca8b2010-04-21 06:23:40 +0000[diff] [blame]718<li>You can now build LLVM as a big dynamic library (e.g. "libllvm2.7.so"). To
719 get this, configure LLVM with the --enable-shared option.</li>
720
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]721<li>LLVM command line tools now overwrite their output by default, before they
722 would only do this with -f. This makes them more convenient to use, and
723 behave more like standard unix tools.</li>
724
725<li>The opt and llc tools now autodetect whether their input is a .ll or .bc
726 file, and automatically do the right thing. This means you don't need to
727 explicitly use the llvm-as tool for most things.</li>
Chris Lattnerc92d7692009-03-01 02:30:21 +0000[diff] [blame]728</ul>
729
730</div>
731
Chris Lattner6cb64032008-06-05 08:02:49 +0000[diff] [blame]732
733<!--=========================================================================-->
734<div class="doc_subsection">
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]735<a name="changes">Major Changes and Removed Features</a>
736</div>
737
738<div class="doc_text">
739
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]740<p>If you're already an LLVM user or developer with out-of-tree changes based
Jeffrey Yasskin0830b972010-01-28 01:14:43 +0000[diff] [blame]741on LLVM 2.6, this section lists some "gotchas" that you may run into upgrading
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]742from the previous release.</p>
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]743
744<ul>
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]745
746<li>
747The Andersen's alias analysis ("anders-aa") pass, the Predicate Simplifier
748("predsimplify") pass, the LoopVR pass, the GVNPRE pass, and the random sampling
749profiling ("rsprofiling") passes have all been removed. They were not being
750actively maintained and had substantial problems. If you are interested in
751these components, you are welcome to ressurect them from SVN, fix the
752correctness problems, and resubmit them to mainline.</li>
753
754<li>LLVM now defaults to building most libraries with RTTI turned off, providing
755a code size reduction. Packagers who are interested in building LLVM to support
756plugins that require RTTI information should build with "make REQUIRE_RTTI=1"
757and should read the new <a href="Packaging.html">Advice on Packaging LLVM</a>
758document.</li>
759
Jeffrey Yasskin914050b2010-02-09 23:03:44 +0000[diff] [blame]760<li>The LLVM interpreter now defaults to <em>not</em> using <tt>libffi</tt> even
761if you have it installed. This makes it more likely that an LLVM built on one
762system will work when copied to a similar system. To use <tt>libffi</tt>,
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]763configure with <tt>--enable-libffi</tt></li>.
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]764
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]765<li>Debug information uses a completely different representation, an LLVM 2.6
766.bc file should work with LLVM 2.7, but debug info won't come forward.</li>
767
768<li>The LLVM 2.6 (and earlier) "malloc" and "free" instructions got removed,
769 along with LowerAllocations pass. Now you should just use a call to the
770 malloc and free functions in libc. These calls are optimized as well as
771 the old instructions were.</li>
772</ul>
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]773
774<p>In addition, many APIs have changed in this release. Some of the major LLVM
775API changes are:</p>
776
777<ul>
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]778<li>Just about everything has been converted to use raw_ostream instead of
779 std::ostream.</li>
780<li>llvm/ADT/iterator.h has been removed, just use &lt;iterator&gt;
781 instead.</li>
782<li>The Streams.h file and "DOUT" got removed, use "DEBUG(errs() &lt;&lt; ...);"
783 instead.</li>
Jeffrey Yasskin4a8b1da2010-01-28 01:41:20 +0000[diff] [blame]784<li><tt>ModuleProvider</tt> has been <a
785href="http://llvm.org/viewvc/llvm-project?view=rev&revision=94686">removed</a>
786and its methods moved to <tt>Module</tt> and <tt>GlobalValue</tt>.
787Most clients can remove uses of <tt>ExistingModuleProvider</tt>,
788replace <tt>getBitcodeModuleProvider</tt> with
789<tt>getLazyBitcodeModule</tt>, and pass their <tt>Module</tt> to
790functions that used to accept <tt>ModuleProvider</tt>. Clients who
791wrote their own <tt>ModuleProvider</tt>s will need to derive from
792<tt>GVMaterializer</tt> instead and use
793<tt>Module::setMaterializer</tt> to attach it to a
794<tt>Module</tt>.</li>
795
796<li><tt>GhostLinkage</tt> has given up the ghost.
797<tt>GlobalValue</tt>s that have not yet been read from their backing
798storage have the same linkage they will have after being read in.
799Clients must replace calls to
800<tt>GlobalValue::hasNotBeenReadFromBitcode</tt> with
801<tt>GlobalValue::isMaterializable</tt>.</li>
Daniel Dunbar1e96fca2010-02-10 04:09:52 +0000[diff] [blame]802
Daniel Dunbar3e255da2010-02-14 01:47:19 +0000[diff] [blame]803<li>The <tt>llvm/Support/DataTypes.h</tt> header has moved
804to <tt>llvm/System/DataTypes.h</tt>.</li>
805
Duncan Sands80c430a2010-02-17 17:20:17 +0000[diff] [blame]806<li>The <tt>isInteger</tt>, <tt>isIntOrIntVector</tt>, <tt>isFloatingPoint</tt>,
807<tt>isFPOrFPVector</tt> and <tt>isFPOrFPVector</tt> methods have been renamed
808<tt>isIntegerTy</tt>, <tt>isIntOrIntVectorTy</tt>, <tt>isFloatingPointTy</tt>,
809<tt>isFPOrFPVectorTy</tt> and <tt>isFPOrFPVectorTy</tt> respectively.</li>
Devang Pateldbf83832008-10-14 20:03:43 +0000[diff] [blame]810</ul>
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]811
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]812</div>
813
814
815
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]816<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]817<div class="doc_section">
818 <a name="portability">Portability and Supported Platforms</a>
819</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]820<!-- *********************************************************************** -->
821
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]822<div class="doc_text">
823
John Criswell64307722004-12-08 20:35:47 +0000[diff] [blame]824<p>LLVM is known to work on the following platforms:</p>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]825
826<ul>
Mikhail Glushenkov25422542009-03-01 18:09:47 +0000[diff] [blame]827<li>Intel and AMD machines (IA32, X86-64, AMD64, EMT-64) running Red Hat
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]828 Linux, Fedora Core, FreeBSD and AuroraUX (and probably other unix-like
829 systems).</li>
Mikhail Glushenkov25422542009-03-01 18:09:47 +0000[diff] [blame]830<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]831 and 64-bit modes.</li>
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000[diff] [blame]832<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]833<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
834 support is available for native builds with Visual C++).</li>
Chris Lattner51948622009-10-16 16:30:58 +0000[diff] [blame]835<li>Sun x86 and AMD64 machines running Solaris 10, OpenSolaris 0906.</li>
John Criswelld5234922005-05-13 20:28:15 +0000[diff] [blame]836<li>Alpha-based machines running Debian GNU/Linux.</li>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]837</ul>
838
Chris Lattner618a99f2008-06-05 06:57:39 +0000[diff] [blame]839<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Brian Gaekee3e557e2004-05-09 05:28:35 +0000[diff] [blame]840to the machine and operating system on which it is built. However, minor
841porting may be required to get LLVM to work on new platforms. We welcome your
842portability patches and reports of successful builds or error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]843
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]844</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]845
846<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]847<div class="doc_section">
848 <a name="knownproblems">Known Problems</a>
849</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]850<!-- *********************************************************************** -->
851
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]852<div class="doc_text">
853
Mikhail Glushenkov25422542009-03-01 18:09:47 +0000[diff] [blame]854<p>This section contains significant known problems with the LLVM system,
Chris Lattner2a092392008-11-10 05:40:34 +0000[diff] [blame]855listed by component. If you run into a problem, please check the <a
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]856href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]857there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]858
Chris Lattner6aba4862010-03-17 17:25:49 +0000[diff] [blame]859<ul>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]860<li>LLVM will not correctly compile on Solaris and/or OpenSolaris
861using the stock GCC 3.x.x series 'out the box',
Chris Lattner6e41c792009-11-03 21:50:09 +0000[diff] [blame]862See: <a href="GettingStarted.html#brokengcc">Broken versions of GCC and other tools</a>.
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]863However, A <a href="http://pkg.auroraux.org/GCC">Modern GCC Build</a>
864for x86/x86-64 has been made available from the third party AuroraUX Project
865that has been meticulously tested for bootstrapping LLVM &amp; Clang.</li>
866</ul>
867
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]868</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]869
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]870<!-- ======================================================================= -->
871<div class="doc_subsection">
872 <a name="experimental">Experimental features included with this release</a>
873</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]874
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]875<div class="doc_text">
876
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]877<p>The following components of this LLVM release are either untested, known to
878be broken or unreliable, or are in early development. These components should
879not be relied on, and bugs should not be filed against them, but they may be
880useful to some people. In particular, if you would like to work on one of these
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]881components, please contact us on the <a
882href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]883
884<ul>
Wesley Peck3aa84e52010-03-18 14:31:30 +0000[diff] [blame]885<li>The MSIL, Alpha, SPU, MIPS, PIC16, Blackfin, MSP430, SystemZ and MicroBlaze
886 backends are experimental.</li>
Bill Wendling89cd82f2009-03-02 07:54:14 +0000[diff] [blame]887<li>The <tt>llc</tt> "<tt>-filetype=asm</tt>" (the default) is the only
Chris Lattner0b1c9a52010-03-17 04:41:49 +0000[diff] [blame]888 supported value for this option. The MachO writer is experimental, and
889 works much better in mainline SVN.</li>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]890</ul>
891
892</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]893
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]894<!-- ======================================================================= -->
895<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]896 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]897</div>
898
899<div class="doc_text">
900
901<ul>
Anton Korobeynikov486c7d32008-06-08 10:24:13 +0000[diff] [blame]902 <li>The X86 backend does not yet support
903 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
904 floating point stack</a>. It supports the 'f' and 't' constraints, but not
905 'u'.</li>
Chris Lattnerb076b002008-06-08 21:19:07 +0000[diff] [blame]906 <li>The X86 backend generates inefficient floating point code when configured
907 to generate code for systems that don't have SSE2.</li>
Duncan Sands0bc15262008-06-08 19:38:43 +0000[diff] [blame]908 <li>Win64 code generation wasn't widely tested. Everything should work, but we
John Criswellea03c9d2009-03-02 15:28:15 +0000[diff] [blame]909 expect small issues to happen. Also, llvm-gcc cannot build the mingw64
910 runtime currently due
Anton Korobeynikov486c7d32008-06-08 10:24:13 +0000[diff] [blame]911 to <a href="http://llvm.org/PR2255">several</a>
John Criswellea03c9d2009-03-02 15:28:15 +0000[diff] [blame]912 <a href="http://llvm.org/PR2257">bugs</a> and due to lack of support for
913 the
914 'u' inline assembly constraint and for X87 floating point inline assembly.</li>
Dan Gohman721b3722008-06-08 23:05:11 +0000[diff] [blame]915 <li>The X86-64 backend does not yet support the LLVM IR instruction
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]916 <tt>va_arg</tt>. Currently, the llvm-gcc and front-ends support variadic
Dan Gohman721b3722008-06-08 23:05:11 +0000[diff] [blame]917 argument constructs on X86-64 by lowering them manually.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]918</ul>
919
920</div>
921
922<!-- ======================================================================= -->
923<div class="doc_subsection">
924 <a name="ppc-be">Known problems with the PowerPC back-end</a>
925</div>
926
927<div class="doc_text">
928
929<ul>
Nicolas Geoffray77d99502007-05-15 09:21:28 +0000[diff] [blame]930<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]931compilation, and lacks support for debug information.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]932</ul>
933
934</div>
935
936<!-- ======================================================================= -->
937<div class="doc_subsection">
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]938 <a name="arm-be">Known problems with the ARM back-end</a>
939</div>
940
941<div class="doc_text">
942
943<ul>
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]944<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sands47fc0a22007-09-26 15:59:54 +0000[diff] [blame]945processors, thumb programs can crash or produce wrong
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]946results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
John Criswellea03c9d2009-03-02 15:28:15 +0000[diff] [blame]947<li>Compilation for ARM Linux OABI (old ABI) is supported but not fully tested.
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]948</li>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]949</ul>
950
951</div>
952
953<!-- ======================================================================= -->
954<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]955 <a name="sparc-be">Known problems with the SPARC back-end</a>
956</div>
957
958<div class="doc_text">
959
960<ul>
John Criswellea03c9d2009-03-02 15:28:15 +0000[diff] [blame]961<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]962 support the 64-bit SPARC ABI (-m64).</li>
963</ul>
964
965</div>
966
967<!-- ======================================================================= -->
968<div class="doc_subsection">
Bruno Cardoso Lopes24eb3de2008-10-25 14:56:26 +0000[diff] [blame]969 <a name="mips-be">Known problems with the MIPS back-end</a>
970</div>
971
972<div class="doc_text">
973
974<ul>
Bruno Cardoso Lopes24eb3de2008-10-25 14:56:26 +0000[diff] [blame]975<li>64-bit MIPS targets are not supported yet.</li>
976</ul>
977
978</div>
979
980<!-- ======================================================================= -->
981<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]982 <a name="alpha-be">Known problems with the Alpha back-end</a>
983</div>
984
985<div class="doc_text">
986
987<ul>
988
989<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
990appropriate nops inserted to ensure restartability.</li>
991
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]992</ul>
993</div>
994
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]995<!-- ======================================================================= -->
996<div class="doc_subsection">
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]997 <a name="c-be">Known problems with the C back-end</a>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]998</div>
999
1000<div class="doc_text">
1001
1002<ul>
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000[diff] [blame]1003<li><a href="http://llvm.org/PR802">The C backend has only basic support for
1004 inline assembly code</a>.</li>
Chris Lattner8e061162007-09-26 06:01:35 +0000[diff] [blame]1005<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
1006 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Gabor Greif75b2f762009-03-02 12:02:51 +0000[diff] [blame]1007 C++ code compiled with <tt>llc</tt> or native compilers.</li>
Duncan Sandse09506a2008-02-10 13:40:55 +0000[diff] [blame]1008<li>The C backend does not support all exception handling constructs.</li>
Duncan Sands3aa36732009-02-25 11:51:54 +0000[diff] [blame]1009<li>The C backend does not support arbitrary precision integers.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]1010</ul>
1011
1012</div>
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]1013
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]1014
1015<!-- ======================================================================= -->
1016<div class="doc_subsection">
Chris Lattner0b1c9a52010-03-17 04:41:49 +0000[diff] [blame]1017 <a name="c-fe">Known problems with the llvm-gcc C and C++ front-end</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]1018</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]1019
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]1020<div class="doc_text">
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]1021
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000[diff] [blame]1022<p>The only major language feature of GCC not supported by llvm-gcc is
1023 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
1024 are only supported on some targets. For example, trampolines are only
Duncan Sands56448462008-06-08 20:18:35 +0000[diff] [blame]1025 supported on some targets (these are used when you take the address of a
1026 nested function).</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]1027
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000[diff] [blame]1028<p>If you run into GCC extensions which are not supported, please let us know.
1029</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]1030
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]1031</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]1032
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]1033<!-- ======================================================================= -->
1034<div class="doc_subsection">
Chris Lattner7292fb12008-10-30 03:58:13 +0000[diff] [blame]1035 <a name="fortran-fe">Known problems with the llvm-gcc Fortran front-end</a>
1036</div>
1037
1038<div class="doc_text">
Gabor Greife5f9d672008-11-04 21:50:59 +0000[diff] [blame]1039<ul>
Chris Lattner7292fb12008-10-30 03:58:13 +0000[diff] [blame]1040<li>Fortran support generally works, but there are still several unresolved bugs
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]1041 in <a href="http://llvm.org/bugs/">Bugzilla</a>. Please see the
1042 tools/gfortran component for details.</li>
Gabor Greife5f9d672008-11-04 21:50:59 +0000[diff] [blame]1043</ul>
Chris Lattner7292fb12008-10-30 03:58:13 +0000[diff] [blame]1044</div>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]1045
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]1046<!-- ======================================================================= -->
1047<div class="doc_subsection">
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000[diff] [blame]1048 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]1049</div>
1050
1051<div class="doc_text">
John Criswellea03c9d2009-03-02 15:28:15 +0000[diff] [blame]1052The llvm-gcc 4.2 Ada compiler works fairly well; however, this is not a mature
1053technology, and problems should be expected.
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]1054<ul>
Duncan Sands56448462008-06-08 20:18:35 +0000[diff] [blame]1055<li>The Ada front-end currently only builds on X86-32. This is mainly due
John Criswellea03c9d2009-03-02 15:28:15 +0000[diff] [blame]1056to lack of trampoline support (pointers to nested functions) on other platforms.
1057However, it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]1058which does support trampolines.</li>
1059<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
Duncan Sandsd34bf762009-02-25 11:59:06 +0000[diff] [blame]1060This is due to lack of LLVM support for <tt>setjmp</tt>/<tt>longjmp</tt> style
1061exception handling, which is used internally by the compiler.
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]1062Workaround: configure with <tt>--disable-bootstrap</tt>.</li>
Duncan Sandsaef747f2008-10-13 17:27:23 +0000[diff] [blame]1063<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
1064and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
Duncan Sandsd34bf762009-02-25 11:59:06 +0000[diff] [blame]1065(c380004 also fails with gcc-4.2 mainline).
1066If the compiler is built with checks disabled then <a href="http://llvm.org/PR2010">c393010</a>
1067causes the compiler to go into an infinite loop, using up all system memory.</li>
Duncan Sands2dbb00e2009-03-02 16:35:57 +0000[diff] [blame]1068<li>Some GCC specific Ada tests continue to crash the compiler.</li>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]1069<li>The <tt>-E</tt> binder option (exception backtraces)
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]1070<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]1071crashing if an exception is raised. Workaround: do not use <tt>-E</tt>.</li>
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]1072<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
1073or finish at a non-byte offset</a> in a record. Workaround: do not pack records
1074or use representation clauses that result in a field of a non-discrete type
1075starting or finishing in the middle of a byte.</li>
Chris Lattnerb076b002008-06-08 21:19:07 +0000[diff] [blame]1076<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
1077'main' as generated by the Ada binder to be invalid</a>.
1078Workaround: hand edit the file to use pointers for <tt>argv</tt> and
1079<tt>envp</tt> rather than integers.</li>
1080<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
1081ignored</a>.</li>
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]1082</ul>
1083</div>
1084
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]1085<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]1086<div class="doc_section">
1087 <a name="additionalinfo">Additional Information</a>
1088</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]1089<!-- *********************************************************************** -->
1090
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]1091<div class="doc_text">
1092
Chris Lattnercb5596d2005-05-16 17:13:10 +0000[diff] [blame]1093<p>A wide variety of additional information is available on the <a
Chris Lattnere0c1df42007-05-18 00:44:29 +0000[diff] [blame]1094href="http://llvm.org">LLVM web page</a>, in particular in the <a
1095href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencerc7f87f22007-07-09 08:04:31 +0000[diff] [blame]1096contains versions of the API documentation which is up-to-date with the
1097Subversion version of the source code.
Misha Brukman96158092005-03-30 19:14:24 +0000[diff] [blame]1098You can access versions of these documents specific to this release by going
1099into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]1100
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]1101<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]1102us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]1103lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]1104
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]1105</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]1106
1107<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]1108
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]1109<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]1110<address>
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Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]1115
Chris Lattnere0c1df42007-05-18 00:44:29 +0000[diff] [blame]1116 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]1117 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]1118</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]1119
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]1120</body>
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