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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 78a130b68be45818d0d2daee4a835efb99e39efc / . / docs / ReleaseNotes.html
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Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]7 <title>LLVM 2.4 Release Notes</title>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]8</head>
9<body>
10
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]11<div class="doc_title">LLVM 2.4 Release Notes</div>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]12
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]13<ol>
14 <li><a href="#intro">Introduction</a></li>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame^]15 <li><a href="#subproj">Sub-project Status Update</a></li>
16 <li><a href="#whatsnew">What's New in LLVM?</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]17 <li><a href="GettingStarted.html">Installation Instructions</a></li>
18 <li><a href="#portability">Portability and Supported Platforms</a></li>
19 <li><a href="#knownproblems">Known Problems</a>
20 <li><a href="#additionalinfo">Additional Information</a></li>
21</ol>
22
23<div class="doc_author">
24 <p>Written by the <a href="http://llvm.org">LLVM Team</a><p>
25</div>
26
27<!-- *********************************************************************** -->
28<div class="doc_section">
29 <a name="intro">Introduction</a>
30</div>
31<!-- *********************************************************************** -->
32
33<div class="doc_text">
34
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]35<p>This document contains the release notes for the LLVM Compiler
36Infrastructure, release 2.4. Here we describe the status of LLVM, including
37major improvements from the previous release and significant known problems.
38All LLVM releases may be downloaded from the <a
39href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]40
41<p>For more information about LLVM, including information about the latest
42release, please check out the <a href="http://llvm.org/">main LLVM
43web site</a>. If you have questions or comments, the <a
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]44href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM Developer's Mailing
45List</a> is a good place to send them.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]46
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]47<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]48main 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>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]51
52</div>
53
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]54<!-- Unfinished features in 2.4:
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]55 Machine LICM
56 Machine Sinking
57 LegalizeDAGTypes
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]58 llc -enable-value-prop, propagation of value info (sign/zero ext info) from
59 one MBB to another
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]60 -->
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]61
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]62 <!-- for announcement email:
63 mention dev mtg
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]64 Xcode 3.1 and 3.1.1.
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]65 -->
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]66
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame^]67<!-- *********************************************************************** -->
68<div class="doc_section">
69 <a name="subproj">Sub-project Status Update</a>
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]70</div>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame^]71<!-- *********************************************************************** -->
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]72
73<div class="doc_text">
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]74<p>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame^]75The LLVM 2.4 distribution currently consists of code from the core LLVM
76repository (which roughly contains the LLVM optimizers, code generators and
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]77supporting tools) and the llvm-gcc repository. In addition to this code, the
78LLVM Project includes other sub-projects that are in development. The two which
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]79are the most actively developed are the <a href="#clang">Clang Project</a> and
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]80<a href="#vmkit">vmkit Project</a>.
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]81</p>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame^]82
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]83</div>
84
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame^]85
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]86<!--=========================================================================-->
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame^]87<div class="doc_subsection">
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]88<a name="clang">Clang</a>
89</div>
90
91<div class="doc_text">
92
93<p>The <a href="http://clang.llvm.org/">Clang project</a> is an effort to build
94a set of new 'LLVM native' front-end technologies for the LLVM optimizer
95and code generator. Clang is continuing to make major strides forward in all
96areas. Its C and Objective-C parsing support is very solid, and the code
97generation support is far enough along to build many C applications. While not
98yet production quality, it is progressing very nicely. In addition, C++
99front-end work has started to make significant progress.</p>
100
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]101<p>Codegen progress/state
102</p>
103
104<p>
105<a href="http://clang.llvm.org/StaticAnalysis.html">static analysis tool</a>
106</p>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]107
108</div>
109
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame^]110<!--=========================================================================-->
111<div class="doc_subsection">
112<a name="vmkit">vmkit</a>
113</div>
114
115<div class="doc_text">
116<p>
117The <a href="http://vmkit.llvm.org/">"vmkit" project</a> is an implementation of
118a JVM and a CLI Virtual Machines (Microsoft .NET is an
119implementation of the CLI) using the Just-In-Time compiler of LLVM.</p>
120
121<p>...</p>
122
123</div>
124
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]125
126<!-- *********************************************************************** -->
127<div class="doc_section">
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame^]128 <a name="whatsnew">What's New in LLVM?</a>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]129</div>
130<!-- *********************************************************************** -->
131
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]132<div class="doc_text">
133
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]134<p>This release includes a huge number of bug fixes, performance tweaks and
135minor improvements. Some of the major improvements and new features are listed
136in this section.
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]137</p>
138</div>
139
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]140<!--=========================================================================-->
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]141<div class="doc_subsection">
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]142<a name="majorfeatures">Major New Features</a>
143</div>
144
145<div class="doc_text">
146
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]147<p>LLVM 2.4 includes several major new capabilities:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]148
149<ul>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]150<li>
Chris Lattnera5a49382008-10-12 18:30:33 +0000[diff] [blame]151 <p>MRVs got generalized to FCAs. getresult is gone, ret with multiple values
152 is gone.</p>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]153 </li>
154
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]155<li><p>-O0 compile times overall much faster</p></li>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]156
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]157<li><p>Attrs changes?</p></li>
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]158
Chris Lattnera5a49382008-10-12 18:30:33 +0000[diff] [blame]159
160<li><p>Initial PIC16 port</p></li>
161
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]162<li><p> Support the rest of the atomic __sync builtins</p></li>
Chris Lattnera5a49382008-10-12 18:30:33 +0000[diff] [blame]163
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]164<li><p>...</p></li>
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]165
Chris Lattner5ba16862008-02-10 08:18:42 +0000[diff] [blame]166</ul>
167
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]168</div>
169
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]170
171<!--=========================================================================-->
172<div class="doc_subsection">
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]173<a name="llvm-gcc">llvm-gcc 4.2 Improvements</a>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]174</div>
175
176<div class="doc_text">
177
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]178<p>LLVM 2.4 fully supports the llvm-gcc 4.2 front-end, and includes support
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]179for the C, C++, Objective-C, Ada, and Fortran front-ends.</p>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]180
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]181<p>
182<ul>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]183<li>...</li>
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]184
Gabor Greif0e49cc82008-06-09 06:06:18 +0000[diff] [blame]185</ul>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]186
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]187</div>
188
189
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]190<!--=========================================================================-->
191<div class="doc_subsection">
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]192<a name="coreimprovements">LLVM Core Improvements</a>
193</div>
194
195<div class="doc_text">
196<p>New features include:
197</p>
198
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]199<ul>
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]200<li>vector shifts in the IR: no codegen support yet</li>
Chris Lattnera5a49382008-10-12 18:30:33 +0000[diff] [blame]201<li>use diet patch landed: saved 15% IR memory footprint</li>
202<li>LLVM IR now directly represents "common" linkage, instead of
203 representing it as a form of weak linkage.</li>
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]204<li>DebugInfoBuilder</li>
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]205<li>.ll printing format change: %3 = add i32 4, 2</li>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]206<li>...</li>
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]207</ul>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]208
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]209</div>
210
211<!--=========================================================================-->
212<div class="doc_subsection">
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]213<a name="optimizer">Optimizer Improvements</a>
214</div>
215
216<div class="doc_text">
217
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]218<p>In addition to a huge array of bug fixes and minor performance tweaks, the
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]219LLVM 2.4 optimizers support a few major enhancements:</p>
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]220
221<ul>
222
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]223<li>GVN now does local PRE?</li>
224
225<li>Matthijs' Dead argument elimination rewrite</li>
226
Chris Lattnera5a49382008-10-12 18:30:33 +0000[diff] [blame]227<li>Old-ADCE used control dependence and deleted output-free infinite loops.
228Added a new Loop deletion pass (for deleting output free provably-finite loops)
229and rewrote ADCE to be simpler faster, and not need control dependence.</li>
230
231<li>SparsePropagation framework for lattice-based dataflow solvers.</li>
232
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]233<li>Tail duplication was removed from the standard optimizer sequence.</li>
Chris Lattnera5a49382008-10-12 18:30:33 +0000[diff] [blame]234
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]235<li>Various helper functions (ComputeMaskedBits, ComputeNumSignBits, etc) were
236pulled out of instcombine and put into a new ValueTracking.h file, where they
237can be reused by other passes.</li>
238
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]239<li>MarkModRef etc</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]240</ul>
241
242</div>
243
244<!--=========================================================================-->
245<div class="doc_subsection">
246<a name="codegen">Code Generator Improvements</a>
247</div>
248
249<div class="doc_text">
250
251<p>We put a significant amount of work into the code generator infrastructure,
252which allows us to implement more aggressive algorithms and make it run
253faster:</p>
254
255<ul>
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]256<li>asm writers split out to their own library to avoid JITs having to link
257 them in.</li>
258<li>Big asm writer refactoring + TargetAsmInfo</li>
259<li>2-addr pass and coalescer can now remat trivial insts to avoid a copy.</li>
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]260<li>spiller to commute instructions in order to fold a reload</li>
261<li>Stack slot coloring?</li>
262<li>Live intervals renumbering? Is this useful to external people?</li>
263<li>'is as cheap as a move' instruction flag</li>
264<li>Improvements to selection dag viewing</li>
265<li>fast isel</li>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]266<li>Selection dag speedups</li>
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]267<li>asmwriter + raw_ostream -> fastah</li>
Chris Lattner72c8a252008-10-13 17:12:51 +0000[diff] [blame]268<li>Partitioned Boolean Quadratic Programming (PBQP) based register
269allocator.</li>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]270<li>...</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]271
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]272</ul>
273
274</div>
275
276
277<!--=========================================================================-->
278<div class="doc_subsection">
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]279<a name="x86specific">X86/X86-64 Specific Improvements</a>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]280</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]281
282<div class="doc_text">
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]283<p>New target-specific features include:
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]284</p>
285
286<ul>
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]287<li>Exception handling is supported by default on Linux/x86-64.</li>
Duncan Sandsd8745a92008-10-13 17:32:15 +0000[diff] [blame]288<li>Position Independent Code (PIC) is now supported on Linux/x86-64.</li>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]289<li>...</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]290
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]291</ul>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]292
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]293</div>
294
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]295<!--=========================================================================-->
296<div class="doc_subsection">
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]297<a name="targetspecific">Other Target Specific Improvements</a>
298</div>
299
300<div class="doc_text">
301<p>New target-specific features include:
302</p>
303
304<ul>
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]305<li>MIPS floating point support?</li>
Duncan Sandsd8745a92008-10-13 17:32:15 +0000[diff] [blame]306<li>PowerPC now supports trampolines.</li>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]307<li>....</li>
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]308</ul>
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]309
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]310</div>
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]311
312
313<!--=========================================================================-->
314<div class="doc_subsection">
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]315<a name="otherimprovements">Other Improvements</a>
316</div>
317
318<div class="doc_text">
319<p>New features include:
320</p>
321
322<ul>
Mikhail Glushenkovcc2d3012008-10-13 02:46:01 +0000[diff] [blame]323<li><tt>llvmc2</tt> (the generic compiler driver) gained plugin
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]324 support. It is now easier to experiment with <tt>llvmc2</tt> and
325 build your own tools based on it. </li>
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]326<li>raw_ostream + formatting</li>
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]327<li>Recycler + pool allocation stuff?</li>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]328<li>...</li>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]329</ul>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]330
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]331</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]332
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]333<!--=========================================================================-->
334<div class="doc_subsection">
335<a name="changes">Major Changes and Removed Features</a>
336</div>
337
338<div class="doc_text">
339
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame^]340<p>If you're already an LLVM user, this section lists some "gotchas" that you
341may run into upgrading from the previous release.</p>
342
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]343<p>The LLVM IR generated by llvm-gcc now doesn't name instructions. Use the
344 instnamer pass if you want them.</p>
345
346<li>LoadVN and GCSE are completely gone.</li>
347
348
349<p>LLVM API Changes:</p>
350
351<ul>
352
353<li>... Attributes changes ... </li>
354
355<li>The <tt>DbgStopPointInst</tt> methods <tt>getDirectory</tt> and
356<tt>getFileName</tt> now return <tt>Value*</tt> instead of strings. These can be
357converted to strings using <tt>llvm::GetConstantStringInfo</tt> defined via
358"llvm/Analysis/ValueTracking.h".</li>
359
360<li>API change: BinaryOperator::create -> Create (CmpInst, CastInst too)</li>
361<li>Various header files like "llvm/ADT/iterator" were given a .h suffix.
362 Change your code to #include "llvm/ADT/iterator.h" instead.</li>
363
364</ul>
365
366</div>
367
368
369
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]370<!-- *********************************************************************** -->
371<div class="doc_section">
372 <a name="portability">Portability and Supported Platforms</a>
373</div>
374<!-- *********************************************************************** -->
375
376<div class="doc_text">
377
378<p>LLVM is known to work on the following platforms:</p>
379
380<ul>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]381<li>Intel and AMD machines (IA32) running Red Hat Linux, Fedora Core and FreeBSD
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]382 (and probably other unix-like systems).</li>
Chris Lattnerbd633de92008-02-06 06:30:34 +0000[diff] [blame]383<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit and
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]384 64-bit modes.</li>
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]385<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]386<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
387 support is available for native builds with Visual C++).</li>
Gabor Greif5e75e652008-06-05 18:39:01 +0000[diff] [blame]388<li>Sun UltraSPARC workstations running Solaris 10.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]389<li>Alpha-based machines running Debian GNU/Linux.</li>
Gabor Greif5e75e652008-06-05 18:39:01 +0000[diff] [blame]390<li>Itanium-based (IA64) machines running Linux and HP-UX.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]391</ul>
392
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]393<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]394to the machine and operating system on which it is built. However, minor
395porting may be required to get LLVM to work on new platforms. We welcome your
396portability patches and reports of successful builds or error messages.</p>
397
398</div>
399
400<!-- *********************************************************************** -->
401<div class="doc_section">
402 <a name="knownproblems">Known Problems</a>
403</div>
404<!-- *********************************************************************** -->
405
406<div class="doc_text">
407
408<p>This section contains all known problems with the LLVM system, listed by
409component. As new problems are discovered, they will be added to these
410sections. If you run into a problem, please check the <a
411href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
412there isn't already one.</p>
413
414</div>
415
416<!-- ======================================================================= -->
417<div class="doc_subsection">
418 <a name="experimental">Experimental features included with this release</a>
419</div>
420
421<div class="doc_text">
422
423<p>The following components of this LLVM release are either untested, known to
424be broken or unreliable, or are in early development. These components should
425not be relied on, and bugs should not be filed against them, but they may be
426useful to some people. In particular, if you would like to work on one of these
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]427components, please contact us on the <a
428href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]429
430<ul>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]431<li>The MSIL, IA64, Alpha, SPU, and MIPS backends are experimental.</li>
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]432<li>The llc "<tt>-filetype=asm</tt>" (the default) is the only supported
Chris Lattnerbd633de92008-02-06 06:30:34 +0000[diff] [blame]433 value for this option.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]434</ul>
435
436</div>
437
438<!-- ======================================================================= -->
439<div class="doc_subsection">
440 <a name="x86-be">Known problems with the X86 back-end</a>
441</div>
442
443<div class="doc_text">
444
445<ul>
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]446 <li>The X86 backend does not yet support
447 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
448 floating point stack</a>. It supports the 'f' and 't' constraints, but not
449 'u'.</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]450 <li>The X86 backend generates inefficient floating point code when configured
451 to generate code for systems that don't have SSE2.</li>
Duncan Sands8b4f3772008-06-08 19:38:43 +0000[diff] [blame]452 <li>Win64 code generation wasn't widely tested. Everything should work, but we
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]453 expect small issues to happen. Also, llvm-gcc cannot build mingw64 runtime
454 currently due
455 to <a href="http://llvm.org/PR2255">several</a>
Chris Lattnerf06141a2008-06-08 23:12:47 +0000[diff] [blame]456 <a href="http://llvm.org/PR2257">bugs</a> due to lack of support for the
457 'u' inline assembly constraint and X87 floating point inline assembly.</li>
Dan Gohman3882ecb2008-06-08 23:05:11 +0000[diff] [blame]458 <li>The X86-64 backend does not yet support the LLVM IR instruction
459 <tt>va_arg</tt>. Currently, the llvm-gcc front-end supports variadic
460 argument constructs on X86-64 by lowering them manually.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]461</ul>
462
463</div>
464
465<!-- ======================================================================= -->
466<div class="doc_subsection">
467 <a name="ppc-be">Known problems with the PowerPC back-end</a>
468</div>
469
470<div class="doc_text">
471
472<ul>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]473<li>The Linux PPC32/ABI support needs testing for the interpreter and static
474compilation, and lacks support for debug information.</li>
475</ul>
476
477</div>
478
479<!-- ======================================================================= -->
480<div class="doc_subsection">
481 <a name="arm-be">Known problems with the ARM back-end</a>
482</div>
483
484<div class="doc_text">
485
486<ul>
487<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sands1827fa62007-09-26 15:59:54 +0000[diff] [blame]488processors, thumb programs can crash or produce wrong
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]489results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
490<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
491</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]492<li>There is a bug in QEMU-ARM (&lt;= 0.9.0) which causes it to incorrectly
493 execute
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]494programs compiled with LLVM. Please use more recent versions of QEMU.</li>
495</ul>
496
497</div>
498
499<!-- ======================================================================= -->
500<div class="doc_subsection">
501 <a name="sparc-be">Known problems with the SPARC back-end</a>
502</div>
503
504<div class="doc_text">
505
506<ul>
507<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
508 support the 64-bit SPARC ABI (-m64).</li>
509</ul>
510
511</div>
512
513<!-- ======================================================================= -->
514<div class="doc_subsection">
515 <a name="alpha-be">Known problems with the Alpha back-end</a>
516</div>
517
518<div class="doc_text">
519
520<ul>
521
522<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
523appropriate nops inserted to ensure restartability.</li>
524
525</ul>
526</div>
527
528<!-- ======================================================================= -->
529<div class="doc_subsection">
530 <a name="ia64-be">Known problems with the IA64 back-end</a>
531</div>
532
533<div class="doc_text">
534
535<ul>
Chris Lattnerf06141a2008-06-08 23:12:47 +0000[diff] [blame]536<li>The Itanium backend is highly experimental, and has a number of known
537 issues. We are looking for a maintainer for the Itanium backend. If you
538 are interested, please contact the llvmdev mailing list.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]539</ul>
540
541</div>
542
543<!-- ======================================================================= -->
544<div class="doc_subsection">
545 <a name="c-be">Known problems with the C back-end</a>
546</div>
547
548<div class="doc_text">
549
550<ul>
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]551<li><a href="http://llvm.org/PR802">The C backend has only basic support for
552 inline assembly code</a>.</li>
Chris Lattnere0194462007-09-26 06:01:35 +0000[diff] [blame]553<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
554 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]555 C++ code compiled with llc or native compilers.</li>
Duncan Sandsbd0ad6e2008-02-10 13:40:55 +0000[diff] [blame]556<li>The C backend does not support all exception handling constructs.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]557</ul>
558
559</div>
560
561
562<!-- ======================================================================= -->
563<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]564 <a name="c-fe">Known problems with the llvm-gcc C front-end</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]565</div>
566
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]567<div class="doc_text">
568
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]569<p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time
570Optimization</a> on most platforms "out-of-the-box". Please inquire on the
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]571llvmdev mailing list if you are interested.</p>
572
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]573<p>The only major language feature of GCC not supported by llvm-gcc is
574 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
575 are only supported on some targets. For example, trampolines are only
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]576 supported on some targets (these are used when you take the address of a
577 nested function).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]578
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]579<p>If you run into GCC extensions which are not supported, please let us know.
580</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]581
582</div>
583
584<!-- ======================================================================= -->
585<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]586 <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]587</div>
588
589<div class="doc_text">
590
591<p>The C++ front-end is considered to be fully
592tested and works for a number of non-trivial programs, including LLVM
593itself, Qt, Mozilla, etc.</p>
594
595<ul>
Anton Korobeynikovd9a17932008-10-11 18:27:16 +0000[diff] [blame]596<li>Exception handling works well on the X86 and PowerPC targets. Currently
597 only linux and darwin targets are supported (both 32 and 64 bit).</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]598</ul>
599
600</div>
601
602
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]603<!-- ======================================================================= -->
604<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]605 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]606</div>
607
608<div class="doc_text">
609The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature
610technology and problems should be expected.
611<ul>
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]612<li>The Ada front-end currently only builds on X86-32. This is mainly due
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]613to lack of trampoline support (pointers to nested functions) on other platforms,
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]614however it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]615which does support trampolines.</li>
616<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
617Workaround: configure with --disable-bootstrap.</li>
Duncan Sands2dbc2e82008-10-13 17:27:23 +0000[diff] [blame]618<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
619and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
620(c380004 also fails with gcc-4.2 mainline).</li>
621<li>Some gcc specific Ada tests continue to crash the compiler.</li>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]622<li>The -E binder option (exception backtraces)
623<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
624crashing if an exception is raised. Workaround: do not use -E.</li>
625<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
626or finish at a non-byte offset</a> in a record. Workaround: do not pack records
627or use representation clauses that result in a field of a non-discrete type
628starting or finishing in the middle of a byte.</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]629<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
630'main' as generated by the Ada binder to be invalid</a>.
631Workaround: hand edit the file to use pointers for <tt>argv</tt> and
632<tt>envp</tt> rather than integers.</li>
633<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
634ignored</a>.</li>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]635</ul>
636</div>
637
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]638<!-- *********************************************************************** -->
639<div class="doc_section">
640 <a name="additionalinfo">Additional Information</a>
641</div>
642<!-- *********************************************************************** -->
643
644<div class="doc_text">
645
646<p>A wide variety of additional information is available on the <a
647href="http://llvm.org">LLVM web page</a>, in particular in the <a
648href="http://llvm.org/docs/">documentation</a> section. The web page also
649contains versions of the API documentation which is up-to-date with the
650Subversion version of the source code.
651You can access versions of these documents specific to this release by going
652into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
653
654<p>If you have any questions or comments about LLVM, please feel free to contact
655us via the <a href="http://llvm.org/docs/#maillist"> mailing
656lists</a>.</p>
657
658</div>
659
660<!-- *********************************************************************** -->
661
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