Gitiles
Code Review Sign In
gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / a3c683b53782f06b26f25d902420d8d5e782487a / . / docs / ReleaseNotes.html
blob: f8363a22d9bce9df8f0116c60c71f0e99d92b2c3 [file] [log] [blame]
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
2 "http://www.w3.org/TR/html4/strict.dtd">
3<html>
4<head>
5 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
6 <link rel="stylesheet" href="llvm.css" type="text/css">
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
Chris Lattnera3c683b2008-10-13 18:11:54 +0000[diff] [blame^]76repository (which roughly includes 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 Lattnera3c683b2008-10-13 18:11:54 +0000[diff] [blame^]88<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]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
Chris Lattnera3c683b2008-10-13 18:11:54 +0000[diff] [blame^]104</div>
105
106<!--=========================================================================-->
107<div class="doc_subsection">
108<a name="clangsa">Clang Static Analyzer</a>
109</div>
110
111<div class="doc_text">
112
113<p>The
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]114<a href="http://clang.llvm.org/StaticAnalysis.html">static analysis tool</a>
Chris Lattnera3c683b2008-10-13 18:11:54 +0000[diff] [blame^]115.</p>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]116
117</div>
118
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]119<!--=========================================================================-->
120<div class="doc_subsection">
Chris Lattnera3c683b2008-10-13 18:11:54 +0000[diff] [blame^]121<a name="vmkit">vmkit: JVM/CLI Virtual Machine Implementation</a>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]122</div>
123
124<div class="doc_text">
125<p>
Chris Lattnera3c683b2008-10-13 18:11:54 +0000[diff] [blame^]126The <a href="http://vmkit.llvm.org/">vmkit project</a> is an implementation of
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]127a JVM and a CLI Virtual Machines (Microsoft .NET is an
128implementation of the CLI) using the Just-In-Time compiler of LLVM.</p>
129
130<p>...</p>
131
132</div>
133
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]134
135<!-- *********************************************************************** -->
136<div class="doc_section">
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]137 <a name="whatsnew">What's New in LLVM?</a>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]138</div>
139<!-- *********************************************************************** -->
140
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]141<div class="doc_text">
142
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]143<p>This release includes a huge number of bug fixes, performance tweaks and
144minor improvements. Some of the major improvements and new features are listed
145in this section.
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]146</p>
147</div>
148
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]149<!--=========================================================================-->
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]150<div class="doc_subsection">
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]151<a name="majorfeatures">Major New Features</a>
152</div>
153
154<div class="doc_text">
155
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]156<p>LLVM 2.4 includes several major new capabilities:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]157
158<ul>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]159<li>
Chris Lattnera5a49382008-10-12 18:30:33 +0000[diff] [blame]160 <p>MRVs got generalized to FCAs. getresult is gone, ret with multiple values
161 is gone.</p>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]162 </li>
163
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]164<li><p>-O0 compile times overall much faster</p></li>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]165
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]166<li><p>Attrs changes?</p></li>
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]167
Chris Lattnera5a49382008-10-12 18:30:33 +0000[diff] [blame]168
169<li><p>Initial PIC16 port</p></li>
170
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]171<li><p> Support the rest of the atomic __sync builtins</p></li>
Chris Lattnera5a49382008-10-12 18:30:33 +0000[diff] [blame]172
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]173<li><p>...</p></li>
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]174
Chris Lattner5ba16862008-02-10 08:18:42 +0000[diff] [blame]175</ul>
176
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]177</div>
178
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]179
180<!--=========================================================================-->
181<div class="doc_subsection">
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]182<a name="llvm-gcc">llvm-gcc 4.2 Improvements</a>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]183</div>
184
185<div class="doc_text">
186
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]187<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]188for the C, C++, Objective-C, Ada, and Fortran front-ends.</p>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]189
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]190<p>
191<ul>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]192<li>...</li>
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]193
Gabor Greif0e49cc82008-06-09 06:06:18 +0000[diff] [blame]194</ul>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]195
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]196</div>
197
198
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]199<!--=========================================================================-->
200<div class="doc_subsection">
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]201<a name="coreimprovements">LLVM Core Improvements</a>
202</div>
203
204<div class="doc_text">
205<p>New features include:
206</p>
207
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]208<ul>
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]209<li>vector shifts in the IR: no codegen support yet</li>
Chris Lattnera5a49382008-10-12 18:30:33 +0000[diff] [blame]210<li>use diet patch landed: saved 15% IR memory footprint</li>
211<li>LLVM IR now directly represents "common" linkage, instead of
212 representing it as a form of weak linkage.</li>
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]213<li>DebugInfoBuilder</li>
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]214<li>.ll printing format change: %3 = add i32 4, 2</li>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]215<li>...</li>
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]216</ul>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]217
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]218</div>
219
220<!--=========================================================================-->
221<div class="doc_subsection">
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]222<a name="optimizer">Optimizer Improvements</a>
223</div>
224
225<div class="doc_text">
226
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]227<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]228LLVM 2.4 optimizers support a few major enhancements:</p>
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]229
230<ul>
231
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]232<li>GVN now does local PRE?</li>
233
234<li>Matthijs' Dead argument elimination rewrite</li>
235
Chris Lattnera5a49382008-10-12 18:30:33 +0000[diff] [blame]236<li>Old-ADCE used control dependence and deleted output-free infinite loops.
237Added a new Loop deletion pass (for deleting output free provably-finite loops)
238and rewrote ADCE to be simpler faster, and not need control dependence.</li>
239
240<li>SparsePropagation framework for lattice-based dataflow solvers.</li>
241
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]242<li>Tail duplication was removed from the standard optimizer sequence.</li>
Chris Lattnera5a49382008-10-12 18:30:33 +0000[diff] [blame]243
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]244<li>Various helper functions (ComputeMaskedBits, ComputeNumSignBits, etc) were
245pulled out of instcombine and put into a new ValueTracking.h file, where they
246can be reused by other passes.</li>
247
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]248<li>MarkModRef etc</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]249</ul>
250
251</div>
252
253<!--=========================================================================-->
254<div class="doc_subsection">
255<a name="codegen">Code Generator Improvements</a>
256</div>
257
258<div class="doc_text">
259
260<p>We put a significant amount of work into the code generator infrastructure,
261which allows us to implement more aggressive algorithms and make it run
262faster:</p>
263
264<ul>
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]265<li>asm writers split out to their own library to avoid JITs having to link
266 them in.</li>
267<li>Big asm writer refactoring + TargetAsmInfo</li>
268<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]269<li>spiller to commute instructions in order to fold a reload</li>
270<li>Stack slot coloring?</li>
271<li>Live intervals renumbering? Is this useful to external people?</li>
272<li>'is as cheap as a move' instruction flag</li>
273<li>Improvements to selection dag viewing</li>
274<li>fast isel</li>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]275<li>Selection dag speedups</li>
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]276<li>asmwriter + raw_ostream -> fastah</li>
Chris Lattner72c8a252008-10-13 17:12:51 +0000[diff] [blame]277<li>Partitioned Boolean Quadratic Programming (PBQP) based register
278allocator.</li>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]279<li>...</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]280
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]281</ul>
282
283</div>
284
285
286<!--=========================================================================-->
287<div class="doc_subsection">
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]288<a name="x86specific">X86/X86-64 Specific Improvements</a>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]289</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]290
291<div class="doc_text">
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]292<p>New target-specific features include:
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]293</p>
294
295<ul>
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]296<li>Exception handling is supported by default on Linux/x86-64.</li>
Duncan Sandsd8745a92008-10-13 17:32:15 +0000[diff] [blame]297<li>Position Independent Code (PIC) is now supported on Linux/x86-64.</li>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]298<li>...</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]299
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]300</ul>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]301
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]302</div>
303
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]304<!--=========================================================================-->
305<div class="doc_subsection">
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]306<a name="targetspecific">Other Target Specific Improvements</a>
307</div>
308
309<div class="doc_text">
310<p>New target-specific features include:
311</p>
312
313<ul>
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]314<li>MIPS floating point support?</li>
Duncan Sandsd8745a92008-10-13 17:32:15 +0000[diff] [blame]315<li>PowerPC now supports trampolines.</li>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]316<li>....</li>
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]317</ul>
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]318
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]319</div>
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]320
321
322<!--=========================================================================-->
323<div class="doc_subsection">
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]324<a name="otherimprovements">Other Improvements</a>
325</div>
326
327<div class="doc_text">
328<p>New features include:
329</p>
330
331<ul>
Mikhail Glushenkovcc2d3012008-10-13 02:46:01 +0000[diff] [blame]332<li><tt>llvmc2</tt> (the generic compiler driver) gained plugin
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]333 support. It is now easier to experiment with <tt>llvmc2</tt> and
334 build your own tools based on it. </li>
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]335<li>raw_ostream + formatting</li>
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]336<li>Recycler + pool allocation stuff?</li>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]337<li>...</li>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]338</ul>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]339
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]340</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]341
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]342<!--=========================================================================-->
343<div class="doc_subsection">
344<a name="changes">Major Changes and Removed Features</a>
345</div>
346
347<div class="doc_text">
348
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]349<p>If you're already an LLVM user, this section lists some "gotchas" that you
350may run into upgrading from the previous release.</p>
351
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]352<p>The LLVM IR generated by llvm-gcc now doesn't name instructions. Use the
353 instnamer pass if you want them.</p>
354
355<li>LoadVN and GCSE are completely gone.</li>
356
357
358<p>LLVM API Changes:</p>
359
360<ul>
361
362<li>... Attributes changes ... </li>
363
364<li>The <tt>DbgStopPointInst</tt> methods <tt>getDirectory</tt> and
365<tt>getFileName</tt> now return <tt>Value*</tt> instead of strings. These can be
366converted to strings using <tt>llvm::GetConstantStringInfo</tt> defined via
367"llvm/Analysis/ValueTracking.h".</li>
368
369<li>API change: BinaryOperator::create -> Create (CmpInst, CastInst too)</li>
370<li>Various header files like "llvm/ADT/iterator" were given a .h suffix.
371 Change your code to #include "llvm/ADT/iterator.h" instead.</li>
372
373</ul>
374
375</div>
376
377
378
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]379<!-- *********************************************************************** -->
380<div class="doc_section">
381 <a name="portability">Portability and Supported Platforms</a>
382</div>
383<!-- *********************************************************************** -->
384
385<div class="doc_text">
386
387<p>LLVM is known to work on the following platforms:</p>
388
389<ul>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]390<li>Intel and AMD machines (IA32) running Red Hat Linux, Fedora Core and FreeBSD
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]391 (and probably other unix-like systems).</li>
Chris Lattnerbd633de92008-02-06 06:30:34 +0000[diff] [blame]392<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]393 64-bit modes.</li>
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]394<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]395<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
396 support is available for native builds with Visual C++).</li>
Gabor Greif5e75e652008-06-05 18:39:01 +0000[diff] [blame]397<li>Sun UltraSPARC workstations running Solaris 10.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]398<li>Alpha-based machines running Debian GNU/Linux.</li>
Gabor Greif5e75e652008-06-05 18:39:01 +0000[diff] [blame]399<li>Itanium-based (IA64) machines running Linux and HP-UX.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]400</ul>
401
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]402<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]403to the machine and operating system on which it is built. However, minor
404porting may be required to get LLVM to work on new platforms. We welcome your
405portability patches and reports of successful builds or error messages.</p>
406
407</div>
408
409<!-- *********************************************************************** -->
410<div class="doc_section">
411 <a name="knownproblems">Known Problems</a>
412</div>
413<!-- *********************************************************************** -->
414
415<div class="doc_text">
416
417<p>This section contains all known problems with the LLVM system, listed by
418component. As new problems are discovered, they will be added to these
419sections. If you run into a problem, please check the <a
420href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
421there isn't already one.</p>
422
423</div>
424
425<!-- ======================================================================= -->
426<div class="doc_subsection">
427 <a name="experimental">Experimental features included with this release</a>
428</div>
429
430<div class="doc_text">
431
432<p>The following components of this LLVM release are either untested, known to
433be broken or unreliable, or are in early development. These components should
434not be relied on, and bugs should not be filed against them, but they may be
435useful 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]436components, please contact us on the <a
437href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]438
439<ul>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]440<li>The MSIL, IA64, Alpha, SPU, and MIPS backends are experimental.</li>
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]441<li>The llc "<tt>-filetype=asm</tt>" (the default) is the only supported
Chris Lattnerbd633de92008-02-06 06:30:34 +0000[diff] [blame]442 value for this option.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]443</ul>
444
445</div>
446
447<!-- ======================================================================= -->
448<div class="doc_subsection">
449 <a name="x86-be">Known problems with the X86 back-end</a>
450</div>
451
452<div class="doc_text">
453
454<ul>
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]455 <li>The X86 backend does not yet support
456 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
457 floating point stack</a>. It supports the 'f' and 't' constraints, but not
458 'u'.</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]459 <li>The X86 backend generates inefficient floating point code when configured
460 to generate code for systems that don't have SSE2.</li>
Duncan Sands8b4f3772008-06-08 19:38:43 +0000[diff] [blame]461 <li>Win64 code generation wasn't widely tested. Everything should work, but we
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]462 expect small issues to happen. Also, llvm-gcc cannot build mingw64 runtime
463 currently due
464 to <a href="http://llvm.org/PR2255">several</a>
Chris Lattnerf06141a2008-06-08 23:12:47 +0000[diff] [blame]465 <a href="http://llvm.org/PR2257">bugs</a> due to lack of support for the
466 'u' inline assembly constraint and X87 floating point inline assembly.</li>
Dan Gohman3882ecb2008-06-08 23:05:11 +0000[diff] [blame]467 <li>The X86-64 backend does not yet support the LLVM IR instruction
468 <tt>va_arg</tt>. Currently, the llvm-gcc front-end supports variadic
469 argument constructs on X86-64 by lowering them manually.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]470</ul>
471
472</div>
473
474<!-- ======================================================================= -->
475<div class="doc_subsection">
476 <a name="ppc-be">Known problems with the PowerPC back-end</a>
477</div>
478
479<div class="doc_text">
480
481<ul>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]482<li>The Linux PPC32/ABI support needs testing for the interpreter and static
483compilation, and lacks support for debug information.</li>
484</ul>
485
486</div>
487
488<!-- ======================================================================= -->
489<div class="doc_subsection">
490 <a name="arm-be">Known problems with the ARM back-end</a>
491</div>
492
493<div class="doc_text">
494
495<ul>
496<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sands1827fa62007-09-26 15:59:54 +0000[diff] [blame]497processors, thumb programs can crash or produce wrong
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]498results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
499<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
500</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]501<li>There is a bug in QEMU-ARM (&lt;= 0.9.0) which causes it to incorrectly
502 execute
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]503programs compiled with LLVM. Please use more recent versions of QEMU.</li>
504</ul>
505
506</div>
507
508<!-- ======================================================================= -->
509<div class="doc_subsection">
510 <a name="sparc-be">Known problems with the SPARC back-end</a>
511</div>
512
513<div class="doc_text">
514
515<ul>
516<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
517 support the 64-bit SPARC ABI (-m64).</li>
518</ul>
519
520</div>
521
522<!-- ======================================================================= -->
523<div class="doc_subsection">
524 <a name="alpha-be">Known problems with the Alpha back-end</a>
525</div>
526
527<div class="doc_text">
528
529<ul>
530
531<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
532appropriate nops inserted to ensure restartability.</li>
533
534</ul>
535</div>
536
537<!-- ======================================================================= -->
538<div class="doc_subsection">
539 <a name="ia64-be">Known problems with the IA64 back-end</a>
540</div>
541
542<div class="doc_text">
543
544<ul>
Chris Lattnerf06141a2008-06-08 23:12:47 +0000[diff] [blame]545<li>The Itanium backend is highly experimental, and has a number of known
546 issues. We are looking for a maintainer for the Itanium backend. If you
547 are interested, please contact the llvmdev mailing list.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]548</ul>
549
550</div>
551
552<!-- ======================================================================= -->
553<div class="doc_subsection">
554 <a name="c-be">Known problems with the C back-end</a>
555</div>
556
557<div class="doc_text">
558
559<ul>
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]560<li><a href="http://llvm.org/PR802">The C backend has only basic support for
561 inline assembly code</a>.</li>
Chris Lattnere0194462007-09-26 06:01:35 +0000[diff] [blame]562<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
563 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]564 C++ code compiled with llc or native compilers.</li>
Duncan Sandsbd0ad6e2008-02-10 13:40:55 +0000[diff] [blame]565<li>The C backend does not support all exception handling constructs.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]566</ul>
567
568</div>
569
570
571<!-- ======================================================================= -->
572<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]573 <a name="c-fe">Known problems with the llvm-gcc C front-end</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]574</div>
575
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]576<div class="doc_text">
577
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]578<p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time
579Optimization</a> on most platforms "out-of-the-box". Please inquire on the
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]580llvmdev mailing list if you are interested.</p>
581
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]582<p>The only major language feature of GCC not supported by llvm-gcc is
583 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
584 are only supported on some targets. For example, trampolines are only
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]585 supported on some targets (these are used when you take the address of a
586 nested function).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]587
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]588<p>If you run into GCC extensions which are not supported, please let us know.
589</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]590
591</div>
592
593<!-- ======================================================================= -->
594<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]595 <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]596</div>
597
598<div class="doc_text">
599
600<p>The C++ front-end is considered to be fully
601tested and works for a number of non-trivial programs, including LLVM
602itself, Qt, Mozilla, etc.</p>
603
604<ul>
Anton Korobeynikovd9a17932008-10-11 18:27:16 +0000[diff] [blame]605<li>Exception handling works well on the X86 and PowerPC targets. Currently
606 only linux and darwin targets are supported (both 32 and 64 bit).</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]607</ul>
608
609</div>
610
611
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]612<!-- ======================================================================= -->
613<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]614 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]615</div>
616
617<div class="doc_text">
618The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature
619technology and problems should be expected.
620<ul>
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]621<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]622to lack of trampoline support (pointers to nested functions) on other platforms,
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]623however 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]624which does support trampolines.</li>
625<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
626Workaround: configure with --disable-bootstrap.</li>
Duncan Sands2dbc2e82008-10-13 17:27:23 +0000[diff] [blame]627<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
628and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
629(c380004 also fails with gcc-4.2 mainline).</li>
630<li>Some gcc specific Ada tests continue to crash the compiler.</li>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]631<li>The -E binder option (exception backtraces)
632<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
633crashing if an exception is raised. Workaround: do not use -E.</li>
634<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
635or finish at a non-byte offset</a> in a record. Workaround: do not pack records
636or use representation clauses that result in a field of a non-discrete type
637starting or finishing in the middle of a byte.</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]638<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
639'main' as generated by the Ada binder to be invalid</a>.
640Workaround: hand edit the file to use pointers for <tt>argv</tt> and
641<tt>envp</tt> rather than integers.</li>
642<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
643ignored</a>.</li>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]644</ul>
645</div>
646
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]647<!-- *********************************************************************** -->
648<div class="doc_section">
649 <a name="additionalinfo">Additional Information</a>
650</div>
651<!-- *********************************************************************** -->
652
653<div class="doc_text">
654
655<p>A wide variety of additional information is available on the <a
656href="http://llvm.org">LLVM web page</a>, in particular in the <a
657href="http://llvm.org/docs/">documentation</a> section. The web page also
658contains versions of the API documentation which is up-to-date with the
659Subversion version of the source code.
660You can access versions of these documents specific to this release by going
661into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
662
663<p>If you have any questions or comments about LLVM, please feel free to contact
664us via the <a href="http://llvm.org/docs/#maillist"> mailing
665lists</a>.</p>
666
667</div>
668
669<!-- *********************************************************************** -->
670
671<hr>
672<address>
673 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
674 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
675 <a href="http://validator.w3.org/check/referer"><img
Chris Lattner5ba16862008-02-10 08:18:42 +0000[diff] [blame]676 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]677
678 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
679 Last modified: $Date$
680</address>
681
682</body>
683</html>