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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 75d53d6bd06dbd0add54d5b0185ce6536d23c19f / . / docs / ReleaseNotes.html
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3<html>
4<head>
Reid Spencer6454ed32004-11-18 18:38:58 +0000[diff] [blame]5 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
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Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]7 <title>LLVM 2.4 Release Notes</title>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]8</head>
9<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]10
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]11<div class="doc_title">LLVM 2.4 Release Notes</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]12
13<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]14 <li><a href="#intro">Introduction</a></li>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]15 <li><a href="#changes">Major Changes and Sub-project Status</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]16 <li><a href="#whatsnew">What's New?</a></li>
Chris Lattner4b538b92004-04-30 22:17:12 +0000[diff] [blame]17 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]18 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]19 <li><a href="#knownproblems">Known Problems</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]20 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]21</ol>
22
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]23<div class="doc_author">
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]24 <p>Written by the <a href="http://llvm.org">LLVM Team</a><p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]25</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]26
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]27<!-- Done through Week-of-Mon-20080324.txt -->
28
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]29<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]30<div class="doc_section">
31 <a name="intro">Introduction</a>
32</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]33<!-- *********************************************************************** -->
34
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]35<div class="doc_text">
36
37<p>This document contains the release notes for the LLVM compiler
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]38infrastructure, release 2.4. Here we describe the status of LLVM, including
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]39major improvements from the previous release and any known problems. All LLVM
Chris Lattnercaf06342007-05-09 04:58:11 +0000[diff] [blame]40releases may be downloaded from the <a href="http://llvm.org/releases/">LLVM
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]41releases web site</a>.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]42
Chris Lattner7506b1d2004-12-07 08:04:13 +0000[diff] [blame]43<p>For more information about LLVM, including information about the latest
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]44release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]45web site</a>. If you have questions or comments, the <a
46href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]47list</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]48
Reid Spencer669ed452007-07-09 08:04:31 +0000[diff] [blame]49<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]50main LLVM web page, this document applies to the <i>next</i> release, not the
51current one. To see the release notes for a specific releases, please see the
52<a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]53
54</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]55
56<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]57<div class="doc_section">
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]58 <a name="changes">Major Changes and Sub-project Status</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]59</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]60<!-- *********************************************************************** -->
61
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]62<div class="doc_text">
63
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]64<p>This is the fifteenth public release of the LLVM Compiler Infrastructure.
65It includes a large number of features and refinements from LLVM 2.3.</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]66
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]67</div>
68
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]69<!-- Unfinished features in 2.4:
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]70 Machine LICM
71 Machine Sinking
72 LegalizeDAGTypes
73 -->
74
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]75<!--=========================================================================-->
Chris Lattner8a458762005-05-15 05:44:51 +0000[diff] [blame]76<div class="doc_subsection">
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]77<a name="changes">Major Changes in LLVM 2.4</a>
Chris Lattnerb4c68cd2008-02-10 07:04:35 +0000[diff] [blame]78</div>
79
80<div class="doc_text">
81
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]82<p>....</p>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000[diff] [blame]83
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]84<p>LLVM API Changes:</p>
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]85
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]86<ul>
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]87<li>....</li>
Daniel Dunbar43778b32008-10-11 21:26:56 +0000[diff] [blame]88
89<li>... Attributes changes ... </li>
90
Chris Lattnercce6d4b2008-10-12 18:30:33 +0000[diff] [blame]91<li>The <tt>DbgStopPointInst</tt> methods <tt>getDirectory</tt> and
92<tt>getFileName</tt> now return <tt>Value*</tt> instead of strings. These can be
93converted to strings using <tt>llvm::GetConstantStringInfo</tt> defined via
94"llvm/Analysis/ValueTracking.h".</li>
Daniel Dunbar43778b32008-10-11 21:26:56 +0000[diff] [blame]95
Chris Lattnercce6d4b2008-10-12 18:30:33 +0000[diff] [blame]96<li>API change: BinaryOperator::create -> Create (CmpInst, CastInst too)</li>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]97</ul>
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]98</div>
99
100<!--=========================================================================-->
101<div class="doc_subsection">
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]102<a name="otherprojects">Other LLVM Sub-Projects</a>
103</div>
104
105<div class="doc_text">
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]106<p>
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]107The core LLVM 2.4 distribution currently consists of code from the core LLVM
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]108repository (which roughly contains the LLVM optimizer, code generators and
109supporting tools) and the llvm-gcc repository. In addition to this code, the
110LLVM Project includes other sub-projects that are in development. The two which
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]111are the most actively developed are the <a href="#clang">Clang Project</a> and
112<a href="#vmkit">vmkit Project</a>.
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]113</p>
114</div>
115
116<!--=========================================================================-->
117<div class="doc_subsubsection">
118<a name="vmkit">vmkit</a>
119</div>
120
121<div class="doc_text">
122<p>
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]123The <a href="http://vmkit.llvm.org/">"vmkit" project</a> is an implementation of
124a JVM and a CLI Virtual Machines (Microsoft .NET is an
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]125implementation of the CLI) using the Just-In-Time compiler of LLVM.</p>
126
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]127<p>...</p>
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]128
129</div>
130
131<!--=========================================================================-->
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]132<div class="doc_subsubsection">
133<a name="clang">Clang</a>
134</div>
135
136<div class="doc_text">
137
138<p>The <a href="http://clang.llvm.org/">Clang project</a> is an effort to build
139a set of new 'LLVM native' front-end technologies for the LLVM optimizer
140and code generator. Clang is continuing to make major strides forward in all
141areas. Its C and Objective-C parsing support is very solid, and the code
142generation support is far enough along to build many C applications. While not
143yet production quality, it is progressing very nicely. In addition, C++
144front-end work has started to make significant progress.</p>
145
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]146<p>Codegen progress/state
147</p>
148
149<p>
150<a href="http://clang.llvm.org/StaticAnalysis.html">static analysis tool</a>
151</p>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]152
153</div>
154
155
156<!-- *********************************************************************** -->
157<div class="doc_section">
158 <a name="whatsnew">What's New?</a>
159</div>
160<!-- *********************************************************************** -->
161
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]162<div class="doc_text">
163
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]164<p>LLVM 2.4 includes a huge number of bug fixes, performance tweaks and minor
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]165improvements. Some of the major improvements and new features are listed in
166this section.
167</p>
168</div>
169
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]170<!--=========================================================================-->
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]171<div class="doc_subsection">
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]172<a name="majorfeatures">Major New Features</a>
173</div>
174
175<div class="doc_text">
176
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]177<p>LLVM 2.4 includes several major new capabilities:</p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]178
179<ul>
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]180<li>
Chris Lattnercce6d4b2008-10-12 18:30:33 +0000[diff] [blame]181 <p>MRVs got generalized to FCAs. getresult is gone, ret with multiple values
182 is gone.</p>
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]183 </li>
184
185<li><p>fast isel, -O0 compile times</p></li>
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]186
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]187<li><p>Attrs changes?</p></li>
Chris Lattnerbc5786b2008-06-05 06:57:39 +0000[diff] [blame]188
Chris Lattnercce6d4b2008-10-12 18:30:33 +0000[diff] [blame]189
190<li><p>Initial PIC16 port</p></li>
191
192<li><p> builtin sync_compare_and_swap builtins + intrinsics</p></li>
193
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]194<li><p>...</p></li>
Chris Lattnerbc5786b2008-06-05 06:57:39 +0000[diff] [blame]195
Chris Lattner8170c102008-02-10 08:18:42 +0000[diff] [blame]196</ul>
197
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]198</div>
199
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]200
201<!--=========================================================================-->
202<div class="doc_subsection">
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]203<a name="llvm-gcc">llvm-gcc 4.2 Improvements</a>
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]204</div>
205
206<div class="doc_text">
207
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]208<p>LLVM 2.4 fully supports the llvm-gcc 4.2 front-end, and includes support
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]209for the C, C++, Objective-C, Ada, and Fortran front-ends.</p>
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]210
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]211<p>
212<ul>
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]213<li>...</li>
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]214
Gabor Greifa3bd11d2008-06-09 06:06:18 +0000[diff] [blame]215</ul>
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]216
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]217</div>
218
219
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]220<!--=========================================================================-->
221<div class="doc_subsection">
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]222<a name="coreimprovements">LLVM Core Improvements</a>
223</div>
224
225<div class="doc_text">
226<p>New features include:
227</p>
228
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]229<ul>
Chris Lattnercce6d4b2008-10-12 18:30:33 +0000[diff] [blame]230<li>use diet patch landed: saved 15% IR memory footprint</li>
231<li>LLVM IR now directly represents "common" linkage, instead of
232 representing it as a form of weak linkage.</li>
233
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]234<li>...</li>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]235</ul>
236
237</div>
238
239<!--=========================================================================-->
240<div class="doc_subsection">
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]241<a name="optimizer">Optimizer Improvements</a>
242</div>
243
244<div class="doc_text">
245
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]246<p>In addition to a huge array of bug fixes and minor performance tweaks, the
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]247LLVM 2.4 optimizers support a few major enhancements:</p>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]248
249<ul>
250
Chris Lattnercce6d4b2008-10-12 18:30:33 +0000[diff] [blame]251<li>Old-ADCE used control dependence and deleted output-free infinite loops.
252Added a new Loop deletion pass (for deleting output free provably-finite loops)
253and rewrote ADCE to be simpler faster, and not need control dependence.</li>
254
255<li>SparsePropagation framework for lattice-based dataflow solvers.</li>
256
257<li>LoadVN and GCSE finally bit the dust?</li>
258
259<li>Tail duplication was is removed from the standard optimizer sequence.</li>
260
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]261</ul>
262
263</div>
264
265<!--=========================================================================-->
266<div class="doc_subsection">
267<a name="codegen">Code Generator Improvements</a>
268</div>
269
270<div class="doc_text">
271
272<p>We put a significant amount of work into the code generator infrastructure,
273which allows us to implement more aggressive algorithms and make it run
274faster:</p>
275
276<ul>
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]277<li>Selection dag speedups</li>
278<li>...</li>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]279
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]280</ul>
281
282</div>
283
284
285<!--=========================================================================-->
286<div class="doc_subsection">
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]287<a name="x86specific">X86/X86-64 Specific Improvements</a>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]288</div>
Chris Lattner60893e52007-05-18 06:33:02 +0000[diff] [blame]289
Chris Lattner738bd302006-04-18 06:32:08 +0000[diff] [blame]290<div class="doc_text">
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]291<p>New target-specific features include:
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]292</p>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]293
294<ul>
Anton Korobeynikov0021fc12008-10-11 18:27:16 +0000[diff] [blame]295<li>Exception handling is supported by default on x86-64 linux platform.</li>
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]296<li>...</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000[diff] [blame]297
Chris Lattnerbfb17ab2007-05-17 21:41:31 +0000[diff] [blame]298</ul>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]299
Chris Lattnerbfb17ab2007-05-17 21:41:31 +0000[diff] [blame]300</div>
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]301
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]302<!--=========================================================================-->
303<div class="doc_subsection">
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]304<a name="targetspecific">Other Target Specific Improvements</a>
305</div>
306
307<div class="doc_text">
308<p>New target-specific features include:
309</p>
310
311<ul>
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]312<li>....</li>
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]313</ul>
314
315</div>
316
317
318
319<!--=========================================================================-->
320<div class="doc_subsection">
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]321<a name="otherimprovements">Other Improvements</a>
322</div>
323
324<div class="doc_text">
325<p>New features include:
326</p>
327
328<ul>
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]329<li>...</li>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]330</ul>
331
332</div>
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]333
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]334<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]335<div class="doc_section">
336 <a name="portability">Portability and Supported Platforms</a>
337</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]338<!-- *********************************************************************** -->
339
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]340<div class="doc_text">
341
John Criswell0b5b5e92004-12-08 20:35:47 +0000[diff] [blame]342<p>LLVM is known to work on the following platforms:</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]343
344<ul>
Gabor Greif96a89c72008-06-05 18:39:01 +0000[diff] [blame]345<li>Intel and AMD machines (IA32) running Red Hat Linux, Fedora Core and FreeBSD
Reid Spencer00812e22005-05-17 02:47:27 +0000[diff] [blame]346 (and probably other unix-like systems).</li>
Chris Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame]347<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit and
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]348 64-bit modes.</li>
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]349<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]350<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
351 support is available for native builds with Visual C++).</li>
Gabor Greif96a89c72008-06-05 18:39:01 +0000[diff] [blame]352<li>Sun UltraSPARC workstations running Solaris 10.</li>
John Criswell9321fa82005-05-13 20:28:15 +0000[diff] [blame]353<li>Alpha-based machines running Debian GNU/Linux.</li>
Gabor Greif96a89c72008-06-05 18:39:01 +0000[diff] [blame]354<li>Itanium-based (IA64) machines running Linux and HP-UX.</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]355</ul>
356
Chris Lattnerbc5786b2008-06-05 06:57:39 +0000[diff] [blame]357<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]358to the machine and operating system on which it is built. However, minor
359porting may be required to get LLVM to work on new platforms. We welcome your
360portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]361
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]362</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]363
364<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]365<div class="doc_section">
366 <a name="knownproblems">Known Problems</a>
367</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]368<!-- *********************************************************************** -->
369
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]370<div class="doc_text">
371
372<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]373component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]374sections. If you run into a problem, please check the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]375href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]376there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]377
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]378</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]379
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]380<!-- ======================================================================= -->
381<div class="doc_subsection">
382 <a name="experimental">Experimental features included with this release</a>
383</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]384
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]385<div class="doc_text">
386
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]387<p>The following components of this LLVM release are either untested, known to
388be broken or unreliable, or are in early development. These components should
389not be relied on, and bugs should not be filed against them, but they may be
390useful to some people. In particular, if you would like to work on one of these
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]391components, please contact us on the <a
392href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]393
394<ul>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]395<li>The MSIL, IA64, Alpha, SPU, and MIPS backends are experimental.</li>
Duncan Sands27aff872008-06-08 20:18:35 +0000[diff] [blame]396<li>The llc "<tt>-filetype=asm</tt>" (the default) is the only supported
Chris Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame]397 value for this option.</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]398</ul>
399
400</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]401
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]402<!-- ======================================================================= -->
403<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]404 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]405</div>
406
407<div class="doc_text">
408
409<ul>
Anton Korobeynikova6094be2008-06-08 10:24:13 +0000[diff] [blame]410 <li>The X86 backend does not yet support
411 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
412 floating point stack</a>. It supports the 'f' and 't' constraints, but not
413 'u'.</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000[diff] [blame]414 <li>The X86 backend generates inefficient floating point code when configured
415 to generate code for systems that don't have SSE2.</li>
Duncan Sands47eff2b2008-06-08 19:38:43 +0000[diff] [blame]416 <li>Win64 code generation wasn't widely tested. Everything should work, but we
Anton Korobeynikova6094be2008-06-08 10:24:13 +0000[diff] [blame]417 expect small issues to happen. Also, llvm-gcc cannot build mingw64 runtime
418 currently due
419 to <a href="http://llvm.org/PR2255">several</a>
Chris Lattner04af7cb2008-06-08 23:12:47 +0000[diff] [blame]420 <a href="http://llvm.org/PR2257">bugs</a> due to lack of support for the
421 'u' inline assembly constraint and X87 floating point inline assembly.</li>
Dan Gohman8207ba92008-06-08 23:05:11 +0000[diff] [blame]422 <li>The X86-64 backend does not yet support the LLVM IR instruction
423 <tt>va_arg</tt>. Currently, the llvm-gcc front-end supports variadic
424 argument constructs on X86-64 by lowering them manually.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]425</ul>
426
427</div>
428
429<!-- ======================================================================= -->
430<div class="doc_subsection">
431 <a name="ppc-be">Known problems with the PowerPC back-end</a>
432</div>
433
434<div class="doc_text">
435
436<ul>
Nicolas Geoffraye4285dc2007-05-15 09:21:28 +0000[diff] [blame]437<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]438compilation, and lacks support for debug information.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]439</ul>
440
441</div>
442
443<!-- ======================================================================= -->
444<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]445 <a name="arm-be">Known problems with the ARM back-end</a>
446</div>
447
448<div class="doc_text">
449
450<ul>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]451<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000[diff] [blame]452processors, thumb programs can crash or produce wrong
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]453results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]454<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
455</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000[diff] [blame]456<li>There is a bug in QEMU-ARM (&lt;= 0.9.0) which causes it to incorrectly
457 execute
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]458programs compiled with LLVM. Please use more recent versions of QEMU.</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]459</ul>
460
461</div>
462
463<!-- ======================================================================= -->
464<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]465 <a name="sparc-be">Known problems with the SPARC back-end</a>
466</div>
467
468<div class="doc_text">
469
470<ul>
471<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
472 support the 64-bit SPARC ABI (-m64).</li>
473</ul>
474
475</div>
476
477<!-- ======================================================================= -->
478<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]479 <a name="alpha-be">Known problems with the Alpha back-end</a>
480</div>
481
482<div class="doc_text">
483
484<ul>
485
486<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
487appropriate nops inserted to ensure restartability.</li>
488
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]489</ul>
490</div>
491
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]492<!-- ======================================================================= -->
493<div class="doc_subsection">
494 <a name="ia64-be">Known problems with the IA64 back-end</a>
495</div>
496
497<div class="doc_text">
498
499<ul>
Chris Lattner04af7cb2008-06-08 23:12:47 +0000[diff] [blame]500<li>The Itanium backend is highly experimental, and has a number of known
501 issues. We are looking for a maintainer for the Itanium backend. If you
502 are interested, please contact the llvmdev mailing list.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]503</ul>
504
505</div>
506
507<!-- ======================================================================= -->
508<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]509 <a name="c-be">Known problems with the C back-end</a>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]510</div>
511
512<div class="doc_text">
513
514<ul>
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]515<li><a href="http://llvm.org/PR802">The C backend has only basic support for
516 inline assembly code</a>.</li>
Chris Lattner725a0d82007-09-26 06:01:35 +0000[diff] [blame]517<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
518 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Duncan Sands27aff872008-06-08 20:18:35 +0000[diff] [blame]519 C++ code compiled with llc or native compilers.</li>
Duncan Sandsf74c0cc2008-02-10 13:40:55 +0000[diff] [blame]520<li>The C backend does not support all exception handling constructs.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]521</ul>
522
523</div>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]524
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]525
526<!-- ======================================================================= -->
527<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]528 <a name="c-fe">Known problems with the llvm-gcc C front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]529</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]530
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]531<div class="doc_text">
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]532
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]533<p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time
534Optimization</a> on most platforms "out-of-the-box". Please inquire on the
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]535llvmdev mailing list if you are interested.</p>
Chris Lattnerd9ea0172006-08-08 17:27:28 +0000[diff] [blame]536
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]537<p>The only major language feature of GCC not supported by llvm-gcc is
538 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
539 are only supported on some targets. For example, trampolines are only
Duncan Sands27aff872008-06-08 20:18:35 +0000[diff] [blame]540 supported on some targets (these are used when you take the address of a
541 nested function).</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]542
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]543<p>If you run into GCC extensions which are not supported, please let us know.
544</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]545
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]546</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]547
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]548<!-- ======================================================================= -->
549<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]550 <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]551</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]552
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]553<div class="doc_text">
554
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]555<p>The C++ front-end is considered to be fully
Chris Lattner7506b1d2004-12-07 08:04:13 +0000[diff] [blame]556tested and works for a number of non-trivial programs, including LLVM
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]557itself, Qt, Mozilla, etc.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]558
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]559<ul>
Anton Korobeynikov0021fc12008-10-11 18:27:16 +0000[diff] [blame]560<li>Exception handling works well on the X86 and PowerPC targets. Currently
561 only linux and darwin targets are supported (both 32 and 64 bit).</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]562</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]563
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]564</div>
565
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]566
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]567<!-- ======================================================================= -->
568<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]569 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]570</div>
571
572<div class="doc_text">
573The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature
574technology and problems should be expected.
575<ul>
Duncan Sands27aff872008-06-08 20:18:35 +0000[diff] [blame]576<li>The Ada front-end currently only builds on X86-32. This is mainly due
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]577to lack of trampoline support (pointers to nested functions) on other platforms,
Duncan Sands27aff872008-06-08 20:18:35 +0000[diff] [blame]578however it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]579which does support trampolines.</li>
580<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
581Workaround: configure with --disable-bootstrap.</li>
582<li>The c380004 and <a href="http://llvm.org/PR2010">c393010</a> ACATS tests
Duncan Sands27aff872008-06-08 20:18:35 +0000[diff] [blame]583fail (c380004 also fails with gcc-4.2 mainline). When built at -O3, the
584<a href="http://llvm.org/PR2421">cxg2021</a> ACATS test also fails.</li>
585<li>Some gcc specific Ada tests continue to crash the compiler. The testsuite
586reports most tests as having failed even though they pass.</li>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]587<li>The -E binder option (exception backtraces)
588<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
589crashing if an exception is raised. Workaround: do not use -E.</li>
590<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
591or finish at a non-byte offset</a> in a record. Workaround: do not pack records
592or use representation clauses that result in a field of a non-discrete type
593starting or finishing in the middle of a byte.</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000[diff] [blame]594<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
595'main' as generated by the Ada binder to be invalid</a>.
596Workaround: hand edit the file to use pointers for <tt>argv</tt> and
597<tt>envp</tt> rather than integers.</li>
598<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
599ignored</a>.</li>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]600</ul>
601</div>
602
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]603<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]604<div class="doc_section">
605 <a name="additionalinfo">Additional Information</a>
606</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]607<!-- *********************************************************************** -->
608
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]609<div class="doc_text">
610
Chris Lattner416db102005-05-16 17:13:10 +0000[diff] [blame]611<p>A wide variety of additional information is available on the <a
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]612href="http://llvm.org">LLVM web page</a>, in particular in the <a
613href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencer669ed452007-07-09 08:04:31 +0000[diff] [blame]614contains versions of the API documentation which is up-to-date with the
615Subversion version of the source code.
Misha Brukman109d9e82005-03-30 19:14:24 +0000[diff] [blame]616You can access versions of these documents specific to this release by going
617into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]618
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]619<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]620us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]621lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]622
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]623</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]624
625<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]626
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]627<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]628<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]629 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]630 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
631 <a href="http://validator.w3.org/check/referer"><img
Chris Lattner8170c102008-02-10 08:18:42 +0000[diff] [blame]632 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]633
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]634 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]635 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]636</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]637
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]638</body>
639</html>