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Chris Lattnerd8b33e02008-10-11 18:18:28 +00007 <title>LLVM 2.4 Release Notes</title>
Misha Brukman80731b92003-11-22 00:38:41 +00008</head>
9<body>
Chris Lattner3d482502003-10-02 04:57:28 +000010
Chris Lattnerd8b33e02008-10-11 18:18:28 +000011<div class="doc_title">LLVM 2.4 Release Notes</div>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +000012
Chris Lattner3d482502003-10-02 04:57:28 +000013<ol>
Misha Brukman80731b92003-11-22 00:38:41 +000014 <li><a href="#intro">Introduction</a></li>
Chris Lattnerc75fd522008-06-08 21:58:17 +000015 <li><a href="#changes">Major Changes and Sub-project Status</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +000016 <li><a href="#whatsnew">What's New?</a></li>
Chris Lattner77a51732004-04-30 22:17:12 +000017 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +000018 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +000019 <li><a href="#knownproblems">Known Problems</a>
Misha Brukman80731b92003-11-22 00:38:41 +000020 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +000021</ol>
22
Chris Lattner020e1fc2004-05-23 21:07:27 +000023<div class="doc_author">
Chris Lattnera69595e2005-10-29 07:07:09 +000024 <p>Written by the <a href="http://llvm.org">LLVM Team</a><p>
Misha Brukman80731b92003-11-22 00:38:41 +000025</div>
Chris Lattner3d482502003-10-02 04:57:28 +000026
27<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +000028<div class="doc_section">
29 <a name="intro">Introduction</a>
30</div>
Chris Lattner3d482502003-10-02 04:57:28 +000031<!-- *********************************************************************** -->
32
Misha Brukman80731b92003-11-22 00:38:41 +000033<div class="doc_text">
34
35<p>This document contains the release notes for the LLVM compiler
Chris Lattnerd8b33e02008-10-11 18:18:28 +000036infrastructure, release 2.4. Here we describe the status of LLVM, including
Chris Lattnerbee7b322007-05-23 04:39:32 +000037major improvements from the previous release and any known problems. All LLVM
Chris Lattner98a33492007-05-09 04:58:11 +000038releases may be downloaded from the <a href="http://llvm.org/releases/">LLVM
Chris Lattnerbee7b322007-05-23 04:39:32 +000039releases web site</a>.</p>
Chris Lattner62495762003-10-02 16:38:05 +000040
Chris Lattnerb5bb5972004-12-07 08:04:13 +000041<p>For more information about LLVM, including information about the latest
Chris Lattnera69595e2005-10-29 07:07:09 +000042release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattnere7525b52003-10-07 21:38:31 +000043web site</a>. If you have questions or comments, the <a
44href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman80731b92003-11-22 00:38:41 +000045list</a> is a good place to send them.</p>
Chris Lattner3d482502003-10-02 04:57:28 +000046
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +000047<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattner0a1fd102007-09-21 03:54:09 +000048main LLVM web page, this document applies to the <i>next</i> release, not the
49current one. To see the release notes for a specific releases, please see the
50<a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman80731b92003-11-22 00:38:41 +000051
52</div>
Chris Lattner3d482502003-10-02 04:57:28 +000053
54<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +000055<div class="doc_section">
Chris Lattnerc75fd522008-06-08 21:58:17 +000056 <a name="changes">Major Changes and Sub-project Status</a>
Misha Brukman80731b92003-11-22 00:38:41 +000057</div>
Chris Lattner3d482502003-10-02 04:57:28 +000058<!-- *********************************************************************** -->
59
Misha Brukman80731b92003-11-22 00:38:41 +000060<div class="doc_text">
61
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +000062<p>This is the fifteenth public release of the LLVM Compiler Infrastructure.
Chris Lattnerd8b33e02008-10-11 18:18:28 +000063It includes a large number of features and refinements from LLVM 2.3.</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +000064
Chris Lattner21a90402004-05-24 04:50:25 +000065</div>
66
Chris Lattnerd8b33e02008-10-11 18:18:28 +000067<!-- Unfinished features in 2.4:
Chris Lattner2b8a52e2008-02-10 07:46:44 +000068 Machine LICM
69 Machine Sinking
70 LegalizeDAGTypes
Chris Lattnerc4d68542008-10-12 19:47:48 +000071 llc -enable-value-prop, propagation of value info (sign/zero ext info) from
72 one MBB to another
Chris Lattner2b8a52e2008-02-10 07:46:44 +000073 -->
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +000074
Chris Lattnerc4d68542008-10-12 19:47:48 +000075 <!-- for announcement email:
76 mention dev mtg
Chris Lattnere3df07e2008-10-12 22:57:58 +000077 Xcode 3.1 and 3.1.1.
Chris Lattnerc4d68542008-10-12 19:47:48 +000078 -->
Chris Lattner2b8a52e2008-02-10 07:46:44 +000079
Chris Lattnerba7bd472003-12-06 20:22:41 +000080<!--=========================================================================-->
Chris Lattner406bddf2005-05-15 05:44:51 +000081<div class="doc_subsection">
Chris Lattnerd8b33e02008-10-11 18:18:28 +000082<a name="changes">Major Changes in LLVM 2.4</a>
Chris Lattnera2735862008-02-10 07:04:35 +000083</div>
84
85<div class="doc_text">
86
Chris Lattnerc4d68542008-10-12 19:47:48 +000087<p>The LLVM IR generated by llvm-gcc now doesn't name instructions. Use the
88 instnamer pass if you want them.</p>
89
Chris Lattnere3df07e2008-10-12 22:57:58 +000090<li>LoadVN and GCSE are completely gone.</li>
Chris Lattnerc4d68542008-10-12 19:47:48 +000091
Chris Lattnerb076b002008-06-08 21:19:07 +000092
Chris Lattner7795ea92008-06-08 02:45:07 +000093<p>LLVM API Changes:</p>
Chris Lattner6cb64032008-06-05 08:02:49 +000094
Chris Lattner7795ea92008-06-08 02:45:07 +000095<ul>
Chris Lattnerd8b33e02008-10-11 18:18:28 +000096<li>....</li>
Daniel Dunbara4a08132008-10-11 21:26:56 +000097
98<li>... Attributes changes ... </li>
99
Chris Lattner63969522008-10-12 18:30:33 +0000100<li>The <tt>DbgStopPointInst</tt> methods <tt>getDirectory</tt> and
101<tt>getFileName</tt> now return <tt>Value*</tt> instead of strings. These can be
102converted to strings using <tt>llvm::GetConstantStringInfo</tt> defined via
103"llvm/Analysis/ValueTracking.h".</li>
Daniel Dunbara4a08132008-10-11 21:26:56 +0000104
Chris Lattner63969522008-10-12 18:30:33 +0000105<li>API change: BinaryOperator::create -> Create (CmpInst, CastInst too)</li>
Chris Lattnerc4d68542008-10-12 19:47:48 +0000106<li>Various header files like "llvm/ADT/iterator" were given a .h suffix.
107 Change your code to #include "llvm/ADT/iterator.h" instead.</li>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000108
Chris Lattner7795ea92008-06-08 02:45:07 +0000109</ul>
Chris Lattnere3df07e2008-10-12 22:57:58 +0000110
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000111</div>
112
113<!--=========================================================================-->
114<div class="doc_subsection">
Chris Lattner625a3d82008-06-08 21:34:41 +0000115<a name="otherprojects">Other LLVM Sub-Projects</a>
116</div>
117
118<div class="doc_text">
Chris Lattnerc75fd522008-06-08 21:58:17 +0000119<p>
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000120The core LLVM 2.4 distribution currently consists of code from the core LLVM
Chris Lattnerc75fd522008-06-08 21:58:17 +0000121repository (which roughly contains the LLVM optimizer, code generators and
122supporting tools) and the llvm-gcc repository. In addition to this code, the
123LLVM Project includes other sub-projects that are in development. The two which
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000124are the most actively developed are the <a href="#clang">Clang Project</a> and
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000125<a href="#vmkit">vmkit Project</a>.
Chris Lattnerc75fd522008-06-08 21:58:17 +0000126</p>
127</div>
128
129<!--=========================================================================-->
130<div class="doc_subsubsection">
131<a name="vmkit">vmkit</a>
132</div>
133
134<div class="doc_text">
135<p>
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000136The <a href="http://vmkit.llvm.org/">"vmkit" project</a> is an implementation of
137a JVM and a CLI Virtual Machines (Microsoft .NET is an
Chris Lattnerc75fd522008-06-08 21:58:17 +0000138implementation of the CLI) using the Just-In-Time compiler of LLVM.</p>
139
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000140<p>...</p>
Chris Lattner625a3d82008-06-08 21:34:41 +0000141
142</div>
143
144<!--=========================================================================-->
Chris Lattnerc75fd522008-06-08 21:58:17 +0000145<div class="doc_subsubsection">
146<a name="clang">Clang</a>
147</div>
148
149<div class="doc_text">
150
151<p>The <a href="http://clang.llvm.org/">Clang project</a> is an effort to build
152a set of new 'LLVM native' front-end technologies for the LLVM optimizer
153and code generator. Clang is continuing to make major strides forward in all
154areas. Its C and Objective-C parsing support is very solid, and the code
155generation support is far enough along to build many C applications. While not
156yet production quality, it is progressing very nicely. In addition, C++
157front-end work has started to make significant progress.</p>
158
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000159<p>Codegen progress/state
160</p>
161
162<p>
163<a href="http://clang.llvm.org/StaticAnalysis.html">static analysis tool</a>
164</p>
Chris Lattnerc75fd522008-06-08 21:58:17 +0000165
166</div>
167
168
169<!-- *********************************************************************** -->
170<div class="doc_section">
171 <a name="whatsnew">What's New?</a>
172</div>
173<!-- *********************************************************************** -->
174
Chris Lattnerb7bc2aa2008-06-08 22:59:35 +0000175<div class="doc_text">
176
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000177<p>LLVM 2.4 includes a huge number of bug fixes, performance tweaks and minor
Chris Lattnerb7bc2aa2008-06-08 22:59:35 +0000178improvements. Some of the major improvements and new features are listed in
179this section.
180</p>
181</div>
182
Chris Lattnerc75fd522008-06-08 21:58:17 +0000183<!--=========================================================================-->
Chris Lattner625a3d82008-06-08 21:34:41 +0000184<div class="doc_subsection">
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000185<a name="majorfeatures">Major New Features</a>
186</div>
187
188<div class="doc_text">
189
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000190<p>LLVM 2.4 includes several major new capabilities:</p>
Chris Lattner97beb512007-05-14 06:56:09 +0000191
192<ul>
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000193<li>
Chris Lattner63969522008-10-12 18:30:33 +0000194 <p>MRVs got generalized to FCAs. getresult is gone, ret with multiple values
195 is gone.</p>
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000196 </li>
197
Chris Lattnerc4d68542008-10-12 19:47:48 +0000198<li><p>-O0 compile times overall much faster</p></li>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000199
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000200<li><p>Attrs changes?</p></li>
Chris Lattner618a99f2008-06-05 06:57:39 +0000201
Chris Lattner63969522008-10-12 18:30:33 +0000202
203<li><p>Initial PIC16 port</p></li>
204
Chris Lattnerc4d68542008-10-12 19:47:48 +0000205<li><p> Support the rest of the atomic __sync builtins</p></li>
Chris Lattner63969522008-10-12 18:30:33 +0000206
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000207<li><p>...</p></li>
Chris Lattner618a99f2008-06-05 06:57:39 +0000208
Chris Lattner458e79f2008-02-10 08:18:42 +0000209</ul>
210
Chris Lattner97beb512007-05-14 06:56:09 +0000211</div>
212
Chris Lattnerb7112222008-06-05 06:25:56 +0000213
214<!--=========================================================================-->
215<div class="doc_subsection">
Chris Lattner625a3d82008-06-08 21:34:41 +0000216<a name="llvm-gcc">llvm-gcc 4.2 Improvements</a>
Chris Lattnerb7112222008-06-05 06:25:56 +0000217</div>
218
219<div class="doc_text">
220
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000221<p>LLVM 2.4 fully supports the llvm-gcc 4.2 front-end, and includes support
Chris Lattnerb7bc2aa2008-06-08 22:59:35 +0000222for the C, C++, Objective-C, Ada, and Fortran front-ends.</p>
Chris Lattnerb7112222008-06-05 06:25:56 +0000223
Chris Lattnerb7bc2aa2008-06-08 22:59:35 +0000224<p>
225<ul>
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000226<li>...</li>
Chris Lattnerb7bc2aa2008-06-08 22:59:35 +0000227
Gabor Greif7f39fb52008-06-09 06:06:18 +0000228</ul>
Chris Lattnerb7112222008-06-05 06:25:56 +0000229
Chris Lattnerb7112222008-06-05 06:25:56 +0000230</div>
231
232
Chris Lattner0a1fd102007-09-21 03:54:09 +0000233<!--=========================================================================-->
234<div class="doc_subsection">
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000235<a name="coreimprovements">LLVM Core Improvements</a>
236</div>
237
238<div class="doc_text">
239<p>New features include:
240</p>
241
Chris Lattnerb7112222008-06-05 06:25:56 +0000242<ul>
Chris Lattnere3df07e2008-10-12 22:57:58 +0000243<li>vector shifts in the IR: no codegen support yet</li>
Chris Lattner63969522008-10-12 18:30:33 +0000244<li>use diet patch landed: saved 15% IR memory footprint</li>
245<li>LLVM IR now directly represents "common" linkage, instead of
246 representing it as a form of weak linkage.</li>
Chris Lattnerc4d68542008-10-12 19:47:48 +0000247<li>DebugInfoBuilder</li>
Chris Lattnere3df07e2008-10-12 22:57:58 +0000248<li>.ll printing format change: %3 = add i32 4, 2</li>
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000249<li>...</li>
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000250</ul>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000251
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000252</div>
253
254<!--=========================================================================-->
255<div class="doc_subsection">
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000256<a name="optimizer">Optimizer Improvements</a>
257</div>
258
259<div class="doc_text">
260
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000261<p>In addition to a huge array of bug fixes and minor performance tweaks, the
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000262LLVM 2.4 optimizers support a few major enhancements:</p>
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000263
264<ul>
265
Chris Lattnerc4d68542008-10-12 19:47:48 +0000266<li>GVN now does local PRE?</li>
267
268<li>Matthijs' Dead argument elimination rewrite</li>
269
Chris Lattner63969522008-10-12 18:30:33 +0000270<li>Old-ADCE used control dependence and deleted output-free infinite loops.
271Added a new Loop deletion pass (for deleting output free provably-finite loops)
272and rewrote ADCE to be simpler faster, and not need control dependence.</li>
273
274<li>SparsePropagation framework for lattice-based dataflow solvers.</li>
275
Chris Lattnere3df07e2008-10-12 22:57:58 +0000276<li>Tail duplication was removed from the standard optimizer sequence.</li>
Chris Lattner63969522008-10-12 18:30:33 +0000277
Chris Lattnerc4d68542008-10-12 19:47:48 +0000278<li>Various helper functions (ComputeMaskedBits, ComputeNumSignBits, etc) were
279pulled out of instcombine and put into a new ValueTracking.h file, where they
280can be reused by other passes.</li>
281
Chris Lattnere3df07e2008-10-12 22:57:58 +0000282<li>MarkModRef etc</li>
Chris Lattner7795ea92008-06-08 02:45:07 +0000283</ul>
284
285</div>
286
287<!--=========================================================================-->
288<div class="doc_subsection">
289<a name="codegen">Code Generator Improvements</a>
290</div>
291
292<div class="doc_text">
293
294<p>We put a significant amount of work into the code generator infrastructure,
295which allows us to implement more aggressive algorithms and make it run
296faster:</p>
297
298<ul>
Chris Lattnere3df07e2008-10-12 22:57:58 +0000299<li>asm writers split out to their own library to avoid JITs having to link
300 them in.</li>
301<li>Big asm writer refactoring + TargetAsmInfo</li>
302<li>2-addr pass and coalescer can now remat trivial insts to avoid a copy.</li>
Chris Lattnerc4d68542008-10-12 19:47:48 +0000303<li>spiller to commute instructions in order to fold a reload</li>
304<li>Stack slot coloring?</li>
305<li>Live intervals renumbering? Is this useful to external people?</li>
306<li>'is as cheap as a move' instruction flag</li>
307<li>Improvements to selection dag viewing</li>
308<li>fast isel</li>
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000309<li>Selection dag speedups</li>
Chris Lattnerc4d68542008-10-12 19:47:48 +0000310<li>asmwriter + raw_ostream -> fastah</li>
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000311<li>...</li>
Chris Lattner7795ea92008-06-08 02:45:07 +0000312
Chris Lattner0a1fd102007-09-21 03:54:09 +0000313</ul>
314
315</div>
316
317
318<!--=========================================================================-->
319<div class="doc_subsection">
Chris Lattner6cb64032008-06-05 08:02:49 +0000320<a name="x86specific">X86/X86-64 Specific Improvements</a>
Chris Lattner0a1fd102007-09-21 03:54:09 +0000321</div>
Chris Lattner727c3742007-05-18 06:33:02 +0000322
Chris Lattner89e761c2006-04-18 06:32:08 +0000323<div class="doc_text">
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000324<p>New target-specific features include:
Chris Lattner97beb512007-05-14 06:56:09 +0000325</p>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000326
327<ul>
Chris Lattnerc4d68542008-10-12 19:47:48 +0000328<li>Exception handling is supported by default on Linux/x86-64.</li>
329<li>Position Independent Code (PIC) is now support on Linux/x86-64.</li>
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000330<li>...</li>
Chris Lattnerb076b002008-06-08 21:19:07 +0000331
Chris Lattner8ce1ba42007-05-17 21:41:31 +0000332</ul>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000333
Chris Lattner8ce1ba42007-05-17 21:41:31 +0000334</div>
Chris Lattner72a269f2006-03-03 00:34:26 +0000335
Chris Lattner0a1fd102007-09-21 03:54:09 +0000336<!--=========================================================================-->
337<div class="doc_subsection">
Chris Lattner6cb64032008-06-05 08:02:49 +0000338<a name="targetspecific">Other Target Specific Improvements</a>
339</div>
340
341<div class="doc_text">
342<p>New target-specific features include:
343</p>
344
345<ul>
Chris Lattnere3df07e2008-10-12 22:57:58 +0000346<li>MIPS floating point support?</li>
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000347<li>....</li>
Chris Lattner6cb64032008-06-05 08:02:49 +0000348</ul>
Chris Lattner6cb64032008-06-05 08:02:49 +0000349
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000350</div>
Chris Lattner6cb64032008-06-05 08:02:49 +0000351
352
353<!--=========================================================================-->
354<div class="doc_subsection">
Chris Lattner0a1fd102007-09-21 03:54:09 +0000355<a name="otherimprovements">Other Improvements</a>
356</div>
357
358<div class="doc_text">
359<p>New features include:
360</p>
361
362<ul>
Mikhail Glushenkovd3ec89e2008-10-13 02:46:01 +0000363<li><tt>llvmc2</tt> (the generic compiler driver) gained plugin
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000364 support. It is now easier to experiment with <tt>llvmc2</tt> and
365 build your own tools based on it. </li>
Chris Lattnerc4d68542008-10-12 19:47:48 +0000366<li>raw_ostream + formatting</li>
Chris Lattnere3df07e2008-10-12 22:57:58 +0000367<li>Recycler + pool allocation stuff?</li>
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000368<li>...</li>
Chris Lattner0a1fd102007-09-21 03:54:09 +0000369</ul>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000370
Chris Lattner0a1fd102007-09-21 03:54:09 +0000371</div>
Chris Lattner72a269f2006-03-03 00:34:26 +0000372
Chris Lattner62495762003-10-02 16:38:05 +0000373<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000374<div class="doc_section">
375 <a name="portability">Portability and Supported Platforms</a>
376</div>
Chris Lattner62495762003-10-02 16:38:05 +0000377<!-- *********************************************************************** -->
378
Misha Brukman80731b92003-11-22 00:38:41 +0000379<div class="doc_text">
380
John Criswell64307722004-12-08 20:35:47 +0000381<p>LLVM is known to work on the following platforms:</p>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000382
383<ul>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000384<li>Intel and AMD machines (IA32) running Red Hat Linux, Fedora Core and FreeBSD
Reid Spencer9803b402005-05-17 02:47:27 +0000385 (and probably other unix-like systems).</li>
Chris Lattner7422bce2008-02-06 06:30:34 +0000386<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit and
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000387 64-bit modes.</li>
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000388<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Chris Lattnerbee7b322007-05-23 04:39:32 +0000389<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
390 support is available for native builds with Visual C++).</li>
Gabor Greif80ae8a72008-06-05 18:39:01 +0000391<li>Sun UltraSPARC workstations running Solaris 10.</li>
John Criswelld5234922005-05-13 20:28:15 +0000392<li>Alpha-based machines running Debian GNU/Linux.</li>
Gabor Greif80ae8a72008-06-05 18:39:01 +0000393<li>Itanium-based (IA64) machines running Linux and HP-UX.</li>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000394</ul>
395
Chris Lattner618a99f2008-06-05 06:57:39 +0000396<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Brian Gaekee3e557e2004-05-09 05:28:35 +0000397to the machine and operating system on which it is built. However, minor
398porting may be required to get LLVM to work on new platforms. We welcome your
399portability patches and reports of successful builds or error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000400
Misha Brukman80731b92003-11-22 00:38:41 +0000401</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000402
403<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000404<div class="doc_section">
405 <a name="knownproblems">Known Problems</a>
406</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000407<!-- *********************************************************************** -->
408
Misha Brukman80731b92003-11-22 00:38:41 +0000409<div class="doc_text">
410
411<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000412component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000413sections. If you run into a problem, please check the <a
Chris Lattnera69595e2005-10-29 07:07:09 +0000414href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattnerb84f3322003-12-12 21:22:16 +0000415there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000416
Misha Brukman80731b92003-11-22 00:38:41 +0000417</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000418
Chris Lattnerb911de42004-03-14 02:03:02 +0000419<!-- ======================================================================= -->
420<div class="doc_subsection">
421 <a name="experimental">Experimental features included with this release</a>
422</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000423
Chris Lattnerb911de42004-03-14 02:03:02 +0000424<div class="doc_text">
425
Misha Brukmanfa50a222004-05-12 21:46:05 +0000426<p>The following components of this LLVM release are either untested, known to
427be broken or unreliable, or are in early development. These components should
428not be relied on, and bugs should not be filed against them, but they may be
429useful to some people. In particular, if you would like to work on one of these
Chris Lattnere38ac152008-02-12 06:29:45 +0000430components, please contact us on the <a
431href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000432
433<ul>
Chris Lattnere38ac152008-02-12 06:29:45 +0000434<li>The MSIL, IA64, Alpha, SPU, and MIPS backends are experimental.</li>
Duncan Sands56448462008-06-08 20:18:35 +0000435<li>The llc "<tt>-filetype=asm</tt>" (the default) is the only supported
Chris Lattner7422bce2008-02-06 06:30:34 +0000436 value for this option.</li>
Chris Lattnerb911de42004-03-14 02:03:02 +0000437</ul>
438
439</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000440
Misha Brukman80731b92003-11-22 00:38:41 +0000441<!-- ======================================================================= -->
442<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000443 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswell3bdbd302005-11-08 21:11:33 +0000444</div>
445
446<div class="doc_text">
447
448<ul>
Anton Korobeynikov486c7d32008-06-08 10:24:13 +0000449 <li>The X86 backend does not yet support
450 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
451 floating point stack</a>. It supports the 'f' and 't' constraints, but not
452 'u'.</li>
Chris Lattnerb076b002008-06-08 21:19:07 +0000453 <li>The X86 backend generates inefficient floating point code when configured
454 to generate code for systems that don't have SSE2.</li>
Duncan Sands0bc15262008-06-08 19:38:43 +0000455 <li>Win64 code generation wasn't widely tested. Everything should work, but we
Anton Korobeynikov486c7d32008-06-08 10:24:13 +0000456 expect small issues to happen. Also, llvm-gcc cannot build mingw64 runtime
457 currently due
458 to <a href="http://llvm.org/PR2255">several</a>
Chris Lattner54d12102008-06-08 23:12:47 +0000459 <a href="http://llvm.org/PR2257">bugs</a> due to lack of support for the
460 'u' inline assembly constraint and X87 floating point inline assembly.</li>
Dan Gohman721b3722008-06-08 23:05:11 +0000461 <li>The X86-64 backend does not yet support the LLVM IR instruction
462 <tt>va_arg</tt>. Currently, the llvm-gcc front-end supports variadic
463 argument constructs on X86-64 by lowering them manually.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000464</ul>
465
466</div>
467
468<!-- ======================================================================= -->
469<div class="doc_subsection">
470 <a name="ppc-be">Known problems with the PowerPC back-end</a>
471</div>
472
473<div class="doc_text">
474
475<ul>
Nicolas Geoffray77d99502007-05-15 09:21:28 +0000476<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattnerbee7b322007-05-23 04:39:32 +0000477compilation, and lacks support for debug information.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000478</ul>
479
480</div>
481
482<!-- ======================================================================= -->
483<div class="doc_subsection">
Chris Lattner97beb512007-05-14 06:56:09 +0000484 <a name="arm-be">Known problems with the ARM back-end</a>
485</div>
486
487<div class="doc_text">
488
489<ul>
Chris Lattnerbee7b322007-05-23 04:39:32 +0000490<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sands47fc0a22007-09-26 15:59:54 +0000491processors, thumb programs can crash or produce wrong
Chris Lattnerbee7b322007-05-23 04:39:32 +0000492results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
Chris Lattner97beb512007-05-14 06:56:09 +0000493<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
494</li>
Chris Lattnerb076b002008-06-08 21:19:07 +0000495<li>There is a bug in QEMU-ARM (&lt;= 0.9.0) which causes it to incorrectly
496 execute
Chris Lattnerbee7b322007-05-23 04:39:32 +0000497programs compiled with LLVM. Please use more recent versions of QEMU.</li>
Chris Lattner97beb512007-05-14 06:56:09 +0000498</ul>
499
500</div>
501
502<!-- ======================================================================= -->
503<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000504 <a name="sparc-be">Known problems with the SPARC back-end</a>
505</div>
506
507<div class="doc_text">
508
509<ul>
510<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
511 support the 64-bit SPARC ABI (-m64).</li>
512</ul>
513
514</div>
515
516<!-- ======================================================================= -->
517<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000518 <a name="alpha-be">Known problems with the Alpha back-end</a>
519</div>
520
521<div class="doc_text">
522
523<ul>
524
525<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
526appropriate nops inserted to ensure restartability.</li>
527
John Criswell3bdbd302005-11-08 21:11:33 +0000528</ul>
529</div>
530
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000531<!-- ======================================================================= -->
532<div class="doc_subsection">
533 <a name="ia64-be">Known problems with the IA64 back-end</a>
534</div>
535
536<div class="doc_text">
537
538<ul>
Chris Lattner54d12102008-06-08 23:12:47 +0000539<li>The Itanium backend is highly experimental, and has a number of known
540 issues. We are looking for a maintainer for the Itanium backend. If you
541 are interested, please contact the llvmdev mailing list.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000542</ul>
543
544</div>
545
546<!-- ======================================================================= -->
547<div class="doc_subsection">
Chris Lattner97beb512007-05-14 06:56:09 +0000548 <a name="c-be">Known problems with the C back-end</a>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000549</div>
550
551<div class="doc_text">
552
553<ul>
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000554<li><a href="http://llvm.org/PR802">The C backend has only basic support for
555 inline assembly code</a>.</li>
Chris Lattner8e061162007-09-26 06:01:35 +0000556<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
557 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Duncan Sands56448462008-06-08 20:18:35 +0000558 C++ code compiled with llc or native compilers.</li>
Duncan Sandse09506a2008-02-10 13:40:55 +0000559<li>The C backend does not support all exception handling constructs.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000560</ul>
561
562</div>
John Criswell3bdbd302005-11-08 21:11:33 +0000563
Misha Brukman80731b92003-11-22 00:38:41 +0000564
565<!-- ======================================================================= -->
566<div class="doc_subsection">
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000567 <a name="c-fe">Known problems with the llvm-gcc C front-end</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000568</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000569
Misha Brukman80731b92003-11-22 00:38:41 +0000570<div class="doc_text">
Chris Lattner72a269f2006-03-03 00:34:26 +0000571
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000572<p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time
573Optimization</a> on most platforms "out-of-the-box". Please inquire on the
Chris Lattner97beb512007-05-14 06:56:09 +0000574llvmdev mailing list if you are interested.</p>
Chris Lattner44124232006-08-08 17:27:28 +0000575
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000576<p>The only major language feature of GCC not supported by llvm-gcc is
577 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
578 are only supported on some targets. For example, trampolines are only
Duncan Sands56448462008-06-08 20:18:35 +0000579 supported on some targets (these are used when you take the address of a
580 nested function).</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000581
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000582<p>If you run into GCC extensions which are not supported, please let us know.
583</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000584
Misha Brukman80731b92003-11-22 00:38:41 +0000585</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000586
Misha Brukman80731b92003-11-22 00:38:41 +0000587<!-- ======================================================================= -->
588<div class="doc_subsection">
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000589 <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000590</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000591
Misha Brukman80731b92003-11-22 00:38:41 +0000592<div class="doc_text">
593
Chris Lattner97beb512007-05-14 06:56:09 +0000594<p>The C++ front-end is considered to be fully
Chris Lattnerb5bb5972004-12-07 08:04:13 +0000595tested and works for a number of non-trivial programs, including LLVM
Chris Lattner97beb512007-05-14 06:56:09 +0000596itself, Qt, Mozilla, etc.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000597
Misha Brukman80731b92003-11-22 00:38:41 +0000598<ul>
Anton Korobeynikov28f08aa2008-10-11 18:27:16 +0000599<li>Exception handling works well on the X86 and PowerPC targets. Currently
600 only linux and darwin targets are supported (both 32 and 64 bit).</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000601</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000602
Misha Brukman80731b92003-11-22 00:38:41 +0000603</div>
604
Misha Brukman80731b92003-11-22 00:38:41 +0000605
Chris Lattnere38ac152008-02-12 06:29:45 +0000606<!-- ======================================================================= -->
607<div class="doc_subsection">
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000608 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattnere38ac152008-02-12 06:29:45 +0000609</div>
610
611<div class="doc_text">
612The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature
613technology and problems should be expected.
614<ul>
Duncan Sands56448462008-06-08 20:18:35 +0000615<li>The Ada front-end currently only builds on X86-32. This is mainly due
Chris Lattnere38ac152008-02-12 06:29:45 +0000616to lack of trampoline support (pointers to nested functions) on other platforms,
Duncan Sands56448462008-06-08 20:18:35 +0000617however it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
Chris Lattnere38ac152008-02-12 06:29:45 +0000618which does support trampolines.</li>
619<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
620Workaround: configure with --disable-bootstrap.</li>
621<li>The c380004 and <a href="http://llvm.org/PR2010">c393010</a> ACATS tests
Duncan Sands56448462008-06-08 20:18:35 +0000622fail (c380004 also fails with gcc-4.2 mainline). When built at -O3, the
623<a href="http://llvm.org/PR2421">cxg2021</a> ACATS test also fails.</li>
624<li>Some gcc specific Ada tests continue to crash the compiler. The testsuite
625reports most tests as having failed even though they pass.</li>
Chris Lattnere38ac152008-02-12 06:29:45 +0000626<li>The -E binder option (exception backtraces)
627<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
628crashing if an exception is raised. Workaround: do not use -E.</li>
629<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
630or finish at a non-byte offset</a> in a record. Workaround: do not pack records
631or use representation clauses that result in a field of a non-discrete type
632starting or finishing in the middle of a byte.</li>
Chris Lattnerb076b002008-06-08 21:19:07 +0000633<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
634'main' as generated by the Ada binder to be invalid</a>.
635Workaround: hand edit the file to use pointers for <tt>argv</tt> and
636<tt>envp</tt> rather than integers.</li>
637<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
638ignored</a>.</li>
Chris Lattnere38ac152008-02-12 06:29:45 +0000639</ul>
640</div>
641
Chris Lattner3d482502003-10-02 04:57:28 +0000642<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000643<div class="doc_section">
644 <a name="additionalinfo">Additional Information</a>
645</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000646<!-- *********************************************************************** -->
647
Misha Brukman80731b92003-11-22 00:38:41 +0000648<div class="doc_text">
649
Chris Lattnercb5596d2005-05-16 17:13:10 +0000650<p>A wide variety of additional information is available on the <a
Chris Lattnere0c1df42007-05-18 00:44:29 +0000651href="http://llvm.org">LLVM web page</a>, in particular in the <a
652href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencerc7f87f22007-07-09 08:04:31 +0000653contains versions of the API documentation which is up-to-date with the
654Subversion version of the source code.
Misha Brukman96158092005-03-30 19:14:24 +0000655You can access versions of these documents specific to this release by going
656into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000657
Misha Brukman80731b92003-11-22 00:38:41 +0000658<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnera69595e2005-10-29 07:07:09 +0000659us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattnerb84f3322003-12-12 21:22:16 +0000660lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000661
Misha Brukman80731b92003-11-22 00:38:41 +0000662</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000663
664<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000665
Misha Brukman80731b92003-11-22 00:38:41 +0000666<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000667<address>
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670 <a href="http://validator.w3.org/check/referer"><img
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Misha Brukman68aab3b2003-11-22 01:23:39 +0000672
Chris Lattnere0c1df42007-05-18 00:44:29 +0000673 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000674 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000675</address>
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