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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / df284a74ec6729a9f4af1a6269487c892e07d6d1 / . / docs / ReleaseNotes.html
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Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
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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">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]6 <link rel="stylesheet" href="llvm.css" type="text/css">
Chris Lattner5c3389a2004-08-16 00:20:18 +0000[diff] [blame]7 <title>LLVM 1.4 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 Lattner5c3389a2004-08-16 00:20:18 +0000[diff] [blame]11<div class="doc_title">LLVM 1.4 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>
15 <li><a href="#whatsnew">What's New?</a></li>
Chris Lattner4b538b92004-04-30 22:17:12 +0000[diff] [blame]16 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]17 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]18 <li><a href="#knownproblems">Known Problems</a>
19 <ul>
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]20 <li><a href="#experimental">Experimental features included in this
21 release</a>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]22 <li><a href="#core">Known problems with the LLVM Core</a>
23 <li><a href="#c-fe">Known problems with the C Front-end</a>
24 <li><a href="#c++-fe">Known problems with the C++ Front-end</a>
25 <li><a href="#x86-be">Known problems with the X86 Back-end</a>
Misha Brukmanadb1c392004-07-12 16:55:41 +0000[diff] [blame]26 <li><a href="#sparcv9-be">Known problems with the SparcV9 Back-end</a>
Chris Lattnerf32a5f52004-11-07 01:55:32 +0000[diff] [blame]27 <li><a href="#ppc-be">Known problems with the PowerPC Back-end</a>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]28 <li><a href="#c-be">Known problems with the C back-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]29 </ul></li>
30 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]31</ol>
32
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]33<div class="doc_author">
34 <p>Written by the <a href="http://llvm.cs.uiuc.edu">LLVM team</a><p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]35</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]36
37<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]38<div class="doc_section">
39 <a name="intro">Introduction</a>
40</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]41<!-- *********************************************************************** -->
42
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]43<div class="doc_text">
44
45<p>This document contains the release notes for the LLVM compiler
Chris Lattner5c3389a2004-08-16 00:20:18 +0000[diff] [blame]46infrastructure, release 1.4. Here we describe the status of LLVM, including any
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]47known problems and bug fixes from the previous release. The most up-to-date
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]48version of this document can be found on the <a
Chris Lattner5c3389a2004-08-16 00:20:18 +0000[diff] [blame]49href="http://llvm.cs.uiuc.edu/releases/1.4/">LLVM 1.4 web site</a>. If you are
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]50not reading this on the LLVM web pages, you should probably go there because
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]51this document may be updated after the release.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]52
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]53<p>For more information about LLVM, including information about potentially more
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]54current releases, please check out the <a href="http://llvm.cs.uiuc.edu">main
55web site</a>. If you have questions or comments, the <a
56href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]57list</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]58
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]59<p>Note that if you are reading this file from CVS, this document applies
60to the <i>next</i> release, not the current one. To see the release notes for
61the current or previous releases, see the <a
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]62href="http://llvm.cs.uiuc.edu/releases/">releases page</a>.</p>
63
64</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]65
66<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]67<div class="doc_section">
68 <a name="whatsnew">What's New?</a>
69</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]70<!-- *********************************************************************** -->
71
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]72<div class="doc_text">
73
Chris Lattner5c3389a2004-08-16 00:20:18 +0000[diff] [blame]74<p>This is the fifth public release of the LLVM compiler infrastructure.</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]75
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]76<p> At this time, LLVM is known to correctly compile and run all C &amp; C++
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]77SPEC CPU95 &amp; 2000 benchmarks, the Olden benchmarks, and the Ptrdist
Chris Lattner9b3b04f2004-10-16 18:35:57 +0000[diff] [blame]78benchmarks, and <b>many</b> other C and C++ programs.</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]79
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]80</div>
81
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]82<!--=========================================================================-->
83<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]84<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]85</div>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]86
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]87<div class="doc_text">
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]88<ol>
Chris Lattnera4bcecf2004-11-27 19:24:06 +0000[diff] [blame]89 <li>LLVM now includes a JIT for the PowerPC target.</li>
Reid Spencer4f86f9c2004-11-25 22:38:30 +0000[diff] [blame]90 <li>LLVM now optimizes global variables significantly more than it did
91 before.
Reid Spencer6454ed32004-11-18 18:38:58 +0000[diff] [blame]92 </li>
Reid Spencer4f86f9c2004-11-25 22:38:30 +0000[diff] [blame]93 <li>LLVM now includes the new '<tt>undef</tt>' value and
94 <a href="LangRef.html#i_unreachable"><tt>unreachable</tt></a> instruction,
95 which give the optimizer more information about the behavior of the
96 program.
97 </li>
98 <li>llvmgcc and llvmg++ now emit source line number information when '-g' is
99 passed in. This information can be used with llvm-db or other tools and
100 passes.
101 </li>
102 <li>The test/Programs hierarchy <a href="http://llvm.cs.uiuc.edu/PR257">has
103 been moved out of the main LLVM tree</a> into a separate CVS repository and
104 tarball. This shrinks the distribution size of LLVM itself significantly.
105 </li>
106 <li>Bytecode compression with bzip2 has been implemented. All bytecode files
107 generated by LLVM will now be compressed by default. Compression can be
108 disabled with the <tt>-disable-compression</tt> option to the tools that can
109 generate bytecode files.
110 </li>
111 <li>A generic <a href="http://llvm.cs.uiuc.edu/PR353">compiler driver</a> and
112 an associated <a href="CommandGuide/html/llvm-ld.html">generic linker</a> have
113 been implemented. The compiler driver is generic because it can be configured
114 to pre-process, translate, optimize, assemble, and link code from any source
115 language. This aids compiler writers because all that is needed is a
116 source-to-bytecode or source-to-assembly translator and a configuration file.
117 The linker is generic because it allows dynamically loadable optimization
118 modules to be executed for link-time optimization. Language specific
119 link-time optimization modules can be created and executed automatically.
120 </li>
121 <li>The <a href="http://llvm.cs.uiuc.edu/PR263">dependent libraries</a>
122 feature has been implemented. This allows front end compilers to indicate in
123 the bytecode which libraries the bytecode needs to be linked with. Both the
124 C/C++ front end and Stacker support generating the required libraries. The
125 Linker now supports using this information to ensure required libaries are
126 linked into the module. This minimizes the need to use the <tt>-l</tt> option
127 when using <a href="CommandGuide/html/llvmc.html"><tt>llvmc</tt></a>
128 </li>
129 <li>The LLVM makefiles have been improved to build LLVM faster (2x) and
130 includes new targets (like dist-check, uninstall). One important change is
131 associated with <a href="http://llvm.cs.uiuc.edu/PR456">PR456</a>. The
132 libraries and tools will now be built into <tt>$builddir/Debug/{bin,lib}</tt>
133 instead of <tt>$builddir/tools/Debug</tt> and <tt>$builddir/lib/Debug</tt>.
134 Similarly for <tt>Release</tt> and <tt>Profile</tt> builds.
Reid Spencer6454ed32004-11-18 18:38:58 +0000[diff] [blame]135 </li>
Chris Lattner7c8dd7f2004-11-17 18:19:32 +0000[diff] [blame]136 <li>The LLVM source code is much more compatible with Microsoft Visual C++,
Reid Spencer4f86f9c2004-11-25 22:38:30 +0000[diff] [blame]137 including the JIT and runtime-code generation, though the entire system
138 may not work with it.
139 </li>
Chris Lattnere55cb542004-11-22 22:09:58 +0000[diff] [blame]140 <li>The target-to-JIT interfaces <a href="http://llvm.cs.uiuc.edu/PR283">are
Reid Spencer4f86f9c2004-11-25 22:38:30 +0000[diff] [blame]141 now much simpler</a> and more powerful.
142 </li>
Chris Lattnera4bcecf2004-11-27 19:24:06 +0000[diff] [blame]143 <li>zlib and libpng are <a href="http://llvm.cs.uiuc.edu/PR417">no longer
144 included in the main LLVM tarball</a>.</li>
Chris Lattner748e58b2004-11-27 19:50:58 +0000[diff] [blame]145 <li>The LLVM code generator now generates asm writers for the target from
146 an abstract target description, instead of requiring them to be hand
147 written.</li>
Chris Lattnerb7c00752004-11-27 21:29:43 +0000[diff] [blame]148 <li>LLVM regression and feature tests can now be run with DejaGNU.</li>
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]149</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]150
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]151</div>
152
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]153
154<!--=========================================================================-->
155<div class="doc_subsubsection">
156In this release, the following missing features were implemented:
157</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]158
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]159<div class="doc_text">
160
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]161<ol>
Reid Spencer6454ed32004-11-18 18:38:58 +0000[diff] [blame]162 <li><a href="http://llvm.cs.uiuc.edu/PR419">JIT interface should support
Reid Spencer4f86f9c2004-11-25 22:38:30 +0000[diff] [blame]163 arbitrary calls</a>
164 </li>
Reid Spencer6454ed32004-11-18 18:38:58 +0000[diff] [blame]165 <li>The <tt>llvm-ar</tt> tool was previously incomplete and didn't properly
166 support other ar(1) implementations. This has been corrected. <tt>llvm-ar</tt>
167 now fully supports all archive editing functions, table of contents listing,
168 extraction, and printing. It can also read BSD4.4/MacOSX and SVR4 style
Reid Spencer4f86f9c2004-11-25 22:38:30 +0000[diff] [blame]169 archives. See <a href="CommandGuide/html/llvm-ar.html">llvm-ar</a> for
170 details.
171 </li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]172</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]173
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]174</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]175
176<!--=========================================================================-->
177<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]178<a name="qualityofimp">In this release, the following Quality of Implementation
179issues were fixed:</a>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]180</div>
181
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]182<div class="doc_text">
183
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]184<ol>
Reid Spencer4f86f9c2004-11-25 22:38:30 +0000[diff] [blame]185 <li><a href="http://llvm.cs.uiuc.edu/PR426">[llvmg++] Tons of warnings
186 are spewed when linking to libstdc++</a>
187 </li>
188 <li><a href="http://llvm.cs.uiuc.edu/PR352">include/{Support,Config} ->
189 include/llvm/{Support,Config}</a>
190 </li>
Reid Spencerccbc9cf2004-11-22 18:40:51 +0000[diff] [blame]191 <li>The names of the libraries generated by compiling LLVM source have been
192 changed to ensure they do not conflict with other packages upon installation.
193 Each LLVM library is now prefixed with LLVM and uses mixed clase. For example,
194 the library <tt>libasmparser.a</tt> in 1.3 has become
Reid Spencer4f86f9c2004-11-25 22:38:30 +0000[diff] [blame]195 <tt>libLLVMAsmParser.a</tt> in release 1.4.
196 </li>
Chris Lattnerc33bf812004-11-27 21:33:28 +0000[diff] [blame]197 <li><a href="http://llvm.cs.uiuc.edu/PR459">[llvmg++] C++ frontend is expanding
198 lots of unused inline functions</a></li>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]199</ol>
200
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]201</div>
202
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]203<!--=========================================================================-->
204<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]205In this release, the following build problems were fixed:
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]206</div>
207
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]208<div class="doc_text">
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]209<ol>
Reid Spencer7409d1c2004-11-25 06:07:42 +0000[diff] [blame]210 <li><a href="http://llvm.cs.uiuc.edu/PR256">[autoconf] further standardizing
211 autoconf usage</a>. Various improvements in the configure.ac script were
Reid Spencer4f86f9c2004-11-25 22:38:30 +0000[diff] [blame]212 made as well as the makefile system.
213 </li>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]214</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]215</div>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]216
217<!--=========================================================================-->
218<div class="doc_subsubsection">
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]219<a name="codequality">This release includes the following Code Quality
220improvements:</a>
Chris Lattneraab56d42004-05-23 20:42:08 +0000[diff] [blame]221</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]222
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]223<div class="doc_text">
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]224<ol>
Reid Spencer4f86f9c2004-11-25 22:38:30 +0000[diff] [blame]225 <li><a href="http://llvm.cs.uiuc.edu/PR362">Ugly code generated for
226 std::min/std::max</a>
227 </li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]228</ol>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]229</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]230
231<!--=========================================================================-->
232<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]233<a name="bugfix">In this release, the following bugs in the previous release
234were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]235</div>
236
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]237<div class="doc_text">
238
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]239<p>Bugs fixed in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]240
241<ol>
Reid Spencer4f86f9c2004-11-25 22:38:30 +0000[diff] [blame]242 <li><a href="http://llvm.cs.uiuc.edu/PR420">[licm] LICM invalidates alias
243 analysis info and uses broken information</a> (optimizer crash)</li>
244 <li><a href="http://llvm.cs.uiuc.edu/PR422">[asmwriter] Asmwriter is really
245 slow for functions with lots of values</a></li>
246 <li><a href="http://llvm.cs.uiuc.edu/PR423">[anders-aa] Andersen's AA is
247 completely broken in LLVM 1.3</a></li>
248 <li><a href="http://llvm.cs.uiuc.edu/PR430">[bcwriter] Empty compaction
249 tables defined</a></li>
250 <li><a href="http://llvm.cs.uiuc.edu/PR227">[X86] llc output for functions
251 w/certain names tickles GNU 'as' bugs</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]252</ol>
253
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]254<p>Bugs in the C/C++ front-end:</p>
255
256<ol>
Reid Spencer4f86f9c2004-11-25 22:38:30 +0000[diff] [blame]257 <li><a href="http://llvm.cs.uiuc.edu/PR445">[llvmg++] not enough templates are
258 instantiated</a></li>
259 <li><a href="http://llvm.cs.uiuc.edu/PR450">[llvmg++] Extern const globals
260 cannot be marked 'constant' if they have nontrivial ctors or dtors</a></li>
261 <li><a href="http://llvm.cs.uiuc.edu/PR461">[llvmgcc] Crash compiling unnamed
Chris Lattner4df69b82004-11-25 06:31:42 +0000[diff] [blame]262 bitfield which does not increase struct size</a></li>
Chris Lattner748e58b2004-11-27 19:50:58 +0000[diff] [blame]263 <li><a href="http://llvm.cs.uiuc.edu/PR424">[llvmgcc] llvmgcc emits invalid
264 constant exprs</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]265</ol>
Brian Gaekee77c8e72004-08-24 07:43:48 +0000[diff] [blame]266
267<p>Bugs fixed in the Sparc V9 back-end:</p>
268
269<ol>
Reid Spencer4f86f9c2004-11-25 22:38:30 +0000[diff] [blame]270 <li><a href="http://llvm.cs.uiuc.edu/PR428">[sparcv9] regalloc assertion
Brian Gaekee77c8e72004-08-24 07:43:48 +0000[diff] [blame]271 failure with certain indirect calls</a></li>
272</ol>
273
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]274</div>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]275
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]276<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]277<div class="doc_section">
278 <a name="portability">Portability and Supported Platforms</a>
279</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]280<!-- *********************************************************************** -->
281
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]282<div class="doc_text">
283
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]284<p>LLVM is known to work in the following platforms:</p>
285
286<ul>
287<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
288 other unix-like systems).</li>
289<li>Sun UltraSPARC workstations running Solaris 8.</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]290<li>Intel and AMD machines running on Win32 with the Cygwin libraries.</li>
Chris Lattner4f7ac4c2004-11-25 06:33:10 +0000[diff] [blame]291<li>PowerPC-based Mac OS X boxes, running 10.2 and above.</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]292</ul>
293
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]294<p>The core LLVM infrastructure uses
295<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
296to the machine and operating system on which it is built. However, minor
297porting may be required to get LLVM to work on new platforms. We welcome your
298portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]299
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]300<p>Note that the LLVM build system does not currently support directories with
301spaces on them when running on Win32/cygwin. We strongly recommend running
302LLVM and the C frontend out of a top-level directory without spaces (e.g.,
Chris Lattner74032a52004-06-01 19:41:30 +0000[diff] [blame]303<tt>/cygdrive/c/llvm</tt>). Also, make sure to install <b>all</b> of the
304cygwin packages. By default, many important tools are not installed that
Chris Lattner5aff3552004-08-16 20:20:46 +0000[diff] [blame]305are needed by the LLVM build process or test suite (e.g., /bin/time). Finally,
306please make sure that there are no directories with spaces in them in your
307PATH environment variable.</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]308
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]309</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]310
311<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]312<div class="doc_section">
313 <a name="knownproblems">Known Problems</a>
314</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]315<!-- *********************************************************************** -->
316
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]317<div class="doc_text">
318
319<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]320component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]321sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]322href="http://llvm.cs.uiuc.edu/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]323there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]324
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]325</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]326
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]327<!-- ======================================================================= -->
328<div class="doc_subsection">
329 <a name="experimental">Experimental features included with this release</a>
330</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]331
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]332<div class="doc_text">
333
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]334<p>The following components of this LLVM release are either untested, known to
335be broken or unreliable, or are in early development. These components should
336not be relied on, and bugs should not be filed against them, but they may be
337useful to some people. In particular, if you would like to work on one of these
338components, please contact us on the llvmdev list.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]339
340<ul>
341<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
Chris Lattner9934f972004-09-14 16:43:13 +0000[diff] [blame]342 -ipmodref, -cee, -branch-combine, -instloops, -paths</tt></li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]343<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
344 it should) and not thoroughly tested.</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]345<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
346</ul>
347
348</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]349
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]350<!-- ======================================================================= -->
351<div class="doc_subsection">
352 <a name="core">Known problems with the LLVM Core</a>
353</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]354
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]355<div class="doc_text">
356
357<ul>
Reid Spencer4f86f9c2004-11-25 22:38:30 +0000[diff] [blame]358 <li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not work.
359 </li>
360 <li>The JIT does not use mutexes to protect its internal data structures. As
361 such, execution of a threaded program could cause these data structures to be
362 corrupted.
363 </li>
364 <li>Linking in static archive files (.a files) is slow by default because
365 there is no symbol table in the archive. To remedy this, run
366 <a href="CommandGuide/html/llvm-ranlib.html"><tt>llvm-ranlib</tt></a> on the
367 archive to add an LLVM symbol table.
368 </li>
369 <li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
370 objects/archives in the order specified on the command line.</a>
371 </li>
372 <li><a href="http://llvm.cs.uiuc.edu/PR240">The lower-invoke pass does not
373 mark values live across a setjmp as volatile</a>. This missing feature
374 only affects targets whose setjmp/longjmp libraries do not save and restore
375 the entire register file.</li>
Reid Spencer043e4b12004-11-25 22:43:58 +0000[diff] [blame]376 <li><a href="http://llvm.cs.uiuc.edu/PR427">[bytecode] Assertion on V1
377 Bytecode Files</a>. This bug won't be fixed because V1 bytecode had its own
378 problems, no one is using V1 bytecode any more, and the fix is non-trivial.
379 </li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]380</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]381</div>
382
383<!-- ======================================================================= -->
384<div class="doc_subsection">
385 <a name="c-fe">Known problems with the C front-end</a>
386</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]387
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]388<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]389<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]390
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]391<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]392<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]393<li>C99 Variable sized arrays do not release stack memory when they go out of
394 scope. Thus, the following program may run out of stack space:
395<pre>
396 for (i = 0; i != 1000000; ++i) {
397 int X[n];
398 foo(X);
399 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]400</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]401
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]402<li>Initialization of global union variables can only be done <a
403href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
404member</a>.</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]405
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]406<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
407external function is re-declared as static</a></li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]408
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]409</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]410</div>
411
412<!-- _______________________________________________________________________ -->
413<div class="doc_subsubsection">
414 Notes
415</div>
416
417<div class="doc_text">
418
419<ul>
420
421<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]422
423<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]424support for floating point data types of any size other than 32 and 64
425bits.</li>
426
427<li>The following Unix system functionality has not been tested and may not
428work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]429 <ol>
430 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
431 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
432 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
433 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
434 - These functions have not been tested.
435 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]436
437<li>Although many GCC extensions are supported, some are not. In particular,
438 the following extensions are known to <b>not be</b> supported:
439 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]440 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]441 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html#Nested%20Functions">Nested Functions</a>: As in Algol and Pascal, lexical scoping of functions.</li>
442 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
443 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Extended%20Asm">Extended Asm</a>: Assembler instructions with C expressions as operands.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]444 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]445 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Asm-Labels.html#Asm%20Labels">Asm Labels</a>: Specifying the assembler name to use for a C symbol.</li>
446 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Explicit-Reg-Vars.html#Explicit%20Reg%20Vars">Explicit Reg Vars</a>: Defining variables residing in specified registers.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]447 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Vector-Extensions.html#Vector%20Extensions">Vector Extensions</a>: Using vector instructions through built-in functions.</li>
448 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Target-Builtins.html#Target%20Builtins">Target Builtins</a>: Built-in functions specific to particular targets.</li>
449 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
450 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pragmas.html#Pragmas">Pragmas</a>: Pragmas accepted by GCC.</li>
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]451 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]452
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]453 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]454 attribute means that the LLVM compiler ignores the presence of the attribute,
455 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]456 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]457 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]458
459 <ol>
460 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
461 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]462 Supported, but allocated stack space is not freed until the function returns (noted above).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]463
464 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html#Function%20Attributes">Function Attributes</a>:
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]465
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]466 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]467 return.<br>
468
469 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
470 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
471 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
472
473 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
474 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
475 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
476
477 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
478 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
479 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]480
481 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
482 Specifying attributes of variables.<br>
483 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
484 <tt>deprecated</tt>, <tt>transparent_union</tt>,
485 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]486
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]487 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
488 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
489 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]490 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]491
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]492 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html#Type%20Attributes">Type Attributes</a>: Specifying attributes of types.<br>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]493 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]494 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]495
496 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
497 all target specific attributes.</li>
498
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]499 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
500 Other built-in functions.<br>
501 We support all builtins which have a C language equivalent (e.g.,
502 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
503 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Chris Lattnerceebeb62004-06-18 06:26:29 +0000[diff] [blame]504 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt>
505 (currently ignored). We also support builtins for ISO C99 floating
506 point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]507 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]508
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]509 <p>The following extensions <b>are</b> known to be supported:</p>
510
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]511 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]512 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html#Labels%20as%20Values">Labels as Values</a>: Getting pointers to labels and computed gotos.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]513 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
514 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Typeof.html#Typeof">Typeof</a>: <code>typeof</code>: referring to the type of an expression.</li>
Tanya Lattnerca26c3e2004-06-22 03:48:17 +0000[diff] [blame]515 <li><a href="http://gcc.gnu.org/onlinedocs/gcc-3.4.0/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]516 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
517 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
518 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
519 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
520 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
521 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
522 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variadic-Macros.html#Variadic%20Macros">Variadic Macros</a>: Macros with a variable number of arguments.</li>
523 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
524 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Subscripting.html#Subscripting">Subscripting</a>: Any array can be subscripted, even if not an lvalue.</li>
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]525 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pointer-Arith.html#Pointer%20Arith">Pointer Arith</a>: Arithmetic on <code>void</code>-pointers and function pointers.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]526 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]527 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
528or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]529 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html#Designated%20Inits">Designated Inits</a>: Labeling elements of initializers.</li>
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]530 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Cast-to-Union.html#Cast%20to%20Union">Cast to Union</a>: Casting to union type from any member of the union.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]531 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
532 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
533 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
534 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
535 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
536 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Character-Escapes.html#Character%20Escapes">Character Escapes</a>: <code>\e</code> stands for the character &lt;ESC&gt;.</li>
537 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
538 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
539 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alternate-Keywords.html#Alternate%20Keywords">Alternate Keywords</a>:<code>__const__</code>, <code>__asm__</code>, etc., for header files.</li>
540 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Incomplete-Enums.html#Incomplete%20Enums">Incomplete Enums</a>: <code>enum foo;</code>, with details to follow.</li>
541 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Names.html#Function%20Names">Function Names</a>: Printable strings which are the name of the current function.</li>
Chris Lattner25795bc2004-02-14 04:08:29 +0000[diff] [blame]542 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Return-Address.html#Return%20Address">Return Address</a>: Getting the return or frame address of a function.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]543 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Unnamed-Fields.html#Unnamed%20Fields">Unnamed Fields</a>: Unnamed struct/union fields within structs/unions.</li>
544 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html#Attribute%20Syntax">Attribute Syntax</a>: Formal syntax for attributes.</li>
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]545 </ol></li>
546
547</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]548
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]549<p>If you run into GCC extensions which have not been included in any of these
550lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]551
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]552</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]553
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]554<!-- ======================================================================= -->
555<div class="doc_subsection">
556 <a name="c++-fe">Known problems with the C++ front-end</a>
557</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]558
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]559<div class="doc_text">
560
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]561<p>For this release, the C++ front-end is considered to be fully functional but
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]562has not been tested as thoroughly as the C front-end. It has been tested and
563works for a number of non-trivial programs, but there may be lurking bugs.
564Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]565
566</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]567
568<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]569<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]570
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]571<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]572
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]573<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]574<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]575 front-end</a>.</li>
Chris Lattner7962f712004-07-17 02:04:41 +0000[diff] [blame]576
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]577<li><b>IA-64 specific</b>: The C++ front-end does not use <a
578href="http://llvm.cs.uiuc.edu/PR406">IA64 ABI compliant layout of v-tables</a>.
Chris Lattner7962f712004-07-17 02:04:41 +0000[diff] [blame]579In particular, it just stores function pointers instead of function
580descriptors in the vtable. This bug prevents mixing C++ code compiled with
Chris Lattner04db8082004-08-02 20:29:51 +0000[diff] [blame]581LLVM with C++ objects compiled by other C++ compilers.</li>
Chris Lattner7962f712004-07-17 02:04:41 +0000[diff] [blame]582
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]583</ul>
584
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]585</div>
586
587<!-- _______________________________________________________________________ -->
588<div class="doc_subsubsection">
589 Notes
590</div>
591
592<div class="doc_text">
593
594<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]595
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]596<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
597parser is significantly more standards compliant (and picky) than prior GCC
598versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]599href="http://gcc.gnu.org/gcc-3.4/changes.html">GCC 3.4 release notes</a>.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]600
601<li>Destructors for local objects are not always run when a <tt>longjmp</tt> is
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]602 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]603 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]604 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]605 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]606
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]607<li>The LLVM C++ front-end follows the <a
608 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
609 This document, which is not Itanium specific, specifies a standard for name
610 mangling, class layout, v-table layout, RTTI formats, and other C++
611 representation issues. Because we use this API, code generated by the LLVM
612 compilers should be binary compatible with machine code generated by other
613 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
614 <i>However</i>, the exception handling mechanism used by LLVM is very
615 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]616 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]617
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]618</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]619
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]620</div>
621
622<!-- ======================================================================= -->
623<div class="doc_subsection">
624 <a name="x86-be">Known problems with the X86 back-end</a>
625</div>
626
627<div class="doc_text">
628
629<ul>
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]630 <li>none yet</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]631</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]632
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]633</div>
634
635<!-- ======================================================================= -->
636<div class="doc_subsection">
Misha Brukmanadb1c392004-07-12 16:55:41 +0000[diff] [blame]637 <a name="sparcv9-be">Known problems with the SparcV9 back-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]638</div>
639
640<div class="doc_text">
641
642<ul>
Misha Brukmanadb1c392004-07-12 16:55:41 +0000[diff] [blame]643<li><a href="http://llvm.cs.uiuc.edu/PR60">[sparcv9] SparcV9 backend miscompiles
644several programs in the LLVM test suite</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]645</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]646
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]647</div>
648
649<!-- ======================================================================= -->
650<div class="doc_subsection">
Chris Lattnerf32a5f52004-11-07 01:55:32 +0000[diff] [blame]651 <a name="ppc-be">Known problems with the PowerPC back-end</a>
652</div>
653
654<div class="doc_text">
655
656<ul>
657<li>none yet</li>
658</ul>
659
660</div>
661
662<!-- ======================================================================= -->
663<div class="doc_subsection">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]664 <a name="c-be">Known problems with the C back-end</a>
665</div>
666
667<div class="doc_text">
668
669<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]670
671<li>The C back-end produces code that violates the ANSI C Type-Based Alias
672Analysis rules. As such, special options may be necessary to compile the code
673(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]674problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]675
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]676<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]677cannot include special floating point numbers like Not-A-Number or
678Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]679
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]680<li><a href="http://llvm.cs.uiuc.edu/PR56">Zero arg vararg functions are not
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]681supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]682frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]683
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]684</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]685
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]686</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]687
688<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]689<div class="doc_section">
690 <a name="additionalinfo">Additional Information</a>
691</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]692<!-- *********************************************************************** -->
693
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]694<div class="doc_text">
695
696<p>A wide variety of additional information is available on the LLVM web page,
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]697including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]698implemented in LLVM. The web page also contains versions of the API
699documentation which is up-to-date with the CVS version of the source code. You
700can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]701the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]702
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]703<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]704us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
705lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]706
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]707</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]708
709<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]710
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]711<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]712<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]713 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]714 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
715 <a href="http://validator.w3.org/check/referer"><img
716 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
717
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]718 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]719 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]720</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]721
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]722</body>
723</html>