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gerrit-public.fairphone.software / toolchain / llvm-project / b769690ab31a4d60afff30f8007378fb87b497b7 / . / llvm / docs / ReleaseNotes.html
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4<head>
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Chris Lattner163c3262004-08-16 00:20:18 +0000[diff] [blame]7 <title>LLVM 1.4 Release Notes</title>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]8</head>
9<body>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]10
Chris Lattner163c3262004-08-16 00:20:18 +0000[diff] [blame]11<div class="doc_title">LLVM 1.4 Release Notes</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]12
13<ol>
Misha Brukman80731b92003-11-22 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 Lattner77a51732004-04-30 22:17:12 +0000[diff] [blame]16 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]17 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]18 <li><a href="#knownproblems">Known Problems</a>
19 <ul>
Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]20 <li><a href="#experimental">Experimental features included in this
21 release</a>
Chris Lattner3d482502003-10-02 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 Brukmana516e992004-07-12 16:55:41 +0000[diff] [blame]26 <li><a href="#sparcv9-be">Known problems with the SparcV9 Back-end</a>
Chris Lattnerdf925ce2004-11-07 01:55:32 +0000[diff] [blame]27 <li><a href="#ppc-be">Known problems with the PowerPC Back-end</a>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]28 <li><a href="#c-be">Known problems with the C back-end</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]29 </ul></li>
30 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]31</ol>
32
Chris Lattner020e1fc2004-05-23 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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]35</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]36
37<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]38<div class="doc_section">
39 <a name="intro">Introduction</a>
40</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]41<!-- *********************************************************************** -->
42
Misha Brukman80731b92003-11-22 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 Lattner163c3262004-08-16 00:20:18 +0000[diff] [blame]46infrastructure, release 1.4. Here we describe the status of LLVM, including any
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]47known problems and bug fixes from the previous release. The most up-to-date
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]48version of this document can be found on the <a
Chris Lattner163c3262004-08-16 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 Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]50not reading this on the LLVM web pages, you should probably go there because
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]51this document may be updated after the release.</p>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]52
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]53<p>For more information about LLVM, including information about potentially more
Chris Lattnere7525b52003-10-07 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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]57list</a> is a good place to send them.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]58
Chris Lattnere76e9ab2003-12-12 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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]62href="http://llvm.cs.uiuc.edu/releases/">releases page</a>.</p>
63
64</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]65
66<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]67<div class="doc_section">
68 <a name="whatsnew">What's New?</a>
69</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]70<!-- *********************************************************************** -->
71
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]72<div class="doc_text">
73
Chris Lattner163c3262004-08-16 00:20:18 +0000[diff] [blame]74<p>This is the fifth public release of the LLVM compiler infrastructure.</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]75
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]76<p> At this time, LLVM is known to correctly compile and run all C &amp; C++
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]77SPEC CPU95 &amp; 2000 benchmarks, the Olden benchmarks, and the Ptrdist
Chris Lattner55266332004-10-16 18:35:57 +0000[diff] [blame]78benchmarks, and <b>many</b> other C and C++ programs.</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]79
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]80</div>
81
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]82<!--=========================================================================-->
83<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]84<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]85</div>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]86
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]87<div class="doc_text">
88
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]89<ol>
Misha Brukmanbbd150e2004-10-16 19:13:58 +0000[diff] [blame]90 <li>The test/Programs hierarchy <a href="http://llvm.cs.uiuc.edu/PR257">has
Chris Lattner55266332004-10-16 18:35:57 +0000[diff] [blame]91 been moved out of the main LLVM tree</a> into a separate CVS repo and
Reid Spencere4190fa2004-11-18 18:38:58 +0000[diff] [blame]92 tarball. This shrinks the distribution size of LLVM itself dramatically.
93 </li>
Chris Lattner55266332004-10-16 18:35:57 +0000[diff] [blame]94 <li>LLVM now optimizes global variables significantly more than it did
95 before.</li>
96 <li>LLVM now includes the new '<tt>undef</tt>' value and <a
97 href="LangRef.html#i_unreachable"><tt>unreachable</tt></a> instruction,
98 which give the optimizer more information about the behavior of the
99 program.</li>
Reid Spencere4190fa2004-11-18 18:38:58 +0000[diff] [blame]100 <li>The LLVM makefiles have been improved to build LLVM much faster (2x) and
101 includes new targets (like dist-check, uninstall). One important change is
102 associated with <a href="http://llvm.cs.uiuc.edu/PR456>PR456">PR456</a>.
103 The libraries and tools will now be built into
104 <tt>$builddir/Debug/{bin,lib}</tt> instead of
105 <tt>$builddir/tools/Debug</tt> and <tt>$builddir/lib/Debug</tt>. Similarly
106 for <tt>Release</tt> and <tt>Profile</tt> builds.
107 </li>
Chris Lattnerd5f52882004-11-17 18:19:32 +0000[diff] [blame]108 <li>The LLVM source code is much more compatible with Microsoft Visual C++,
109 including the JIT and runtime-code generation, though the entire system
110 may not work with it.</li>
Chris Lattner24874312004-11-18 21:25:11 +0000[diff] [blame]111 <li>llvmgcc and llvmg++ now emit source line number information when '-g' is
112 passed in. This information can be used with llvm-db or other tools and
113 passes.</li>
Chris Lattnerb7696902004-11-22 22:09:58 +0000[diff] [blame^]114 <li>The target-to-JIT interfaces <a href="http://llvm.cs.uiuc.edu/PR283">are
115 now much simpler</a> and more powerful.</li>
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]116</ol>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]117
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]118</div>
119
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]120
121<!--=========================================================================-->
122<div class="doc_subsubsection">
123In this release, the following missing features were implemented:
124</div>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]125
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]126<div class="doc_text">
127
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]128<ol>
Reid Spencere4190fa2004-11-18 18:38:58 +0000[diff] [blame]129 <li><a href="http://llvm.cs.uiuc.edu/PR419">JIT interface should support
Misha Brukmanbbd150e2004-10-16 19:13:58 +0000[diff] [blame]130 arbitrary calls</a></li>
Reid Spencere4190fa2004-11-18 18:38:58 +0000[diff] [blame]131 <li>The <tt>llvm-ar</tt> tool was previously incomplete and didn't properly
132 support other ar(1) implementations. This has been corrected. <tt>llvm-ar</tt>
133 now fully supports all archive editing functions, table of contents listing,
134 extraction, and printing. It can also read BSD4.4/MacOSX and SVR4 style
135 archives. See <a
136 href="http://llvm.cs.uiuc.edu/docs/CommandGuide/html/llvm-ar.html">llvm-ar</a>
137 for details.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]138</ol>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]139
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]140</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]141
142<!--=========================================================================-->
143<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]144<a name="qualityofimp">In this release, the following Quality of Implementation
145issues were fixed:</a>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]146</div>
147
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]148<div class="doc_text">
149
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]150<ol>
Chris Lattner99e41112004-10-09 19:19:57 +0000[diff] [blame]151<li><a href="http://llvm.cs.uiuc.edu/PR426">[llvmg++] Tons of warnings are spewed when
Chris Lattner615ffb82004-08-20 00:36:23 +0000[diff] [blame]152 linking to libstdc++</a></li>
Chris Lattner99e41112004-10-09 19:19:57 +0000[diff] [blame]153<li><a href="http://llvm.cs.uiuc.edu/PR352">include/{Support,Config} ->
Chris Lattner2249dd12004-09-19 19:21:26 +0000[diff] [blame]154 include/llvm/{Support,Config}</a></li>
Reid Spencerb4e3ec82004-11-22 18:40:51 +0000[diff] [blame]155 <li>The names of the libraries generated by compiling LLVM source have been
156 changed to ensure they do not conflict with other packages upon installation.
157 Each LLVM library is now prefixed with LLVM and uses mixed clase. For example,
158 the library <tt>libasmparser.a</tt> in 1.3 has become
159 <tt>libLLVMAsmParser.a</tt> in release 1.4.</li>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]160</ol>
161
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]162</div>
163
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]164<!--=========================================================================-->
165<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]166In this release, the following build problems were fixed:
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]167</div>
168
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]169<div class="doc_text">
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]170<ol>
Chris Lattner163c3262004-08-16 00:20:18 +0000[diff] [blame]171<li></li>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]172</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]173</div>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]174
175<!--=========================================================================-->
176<div class="doc_subsubsection">
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]177<a name="codequality">This release includes the following Code Quality
178improvements:</a>
Chris Lattner23257062004-05-23 20:42:08 +0000[diff] [blame]179</div>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]180
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]181<div class="doc_text">
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]182<ol>
Chris Lattnerb84e1c52004-10-09 19:37:02 +0000[diff] [blame]183<li><a href="http://llvm.cs.uiuc.edu/PR362">Ugly code generated for
Chris Lattner2249dd12004-09-19 19:21:26 +0000[diff] [blame]184 std::min/std::max</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]185</ol>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]186</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]187
188<!--=========================================================================-->
189<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]190<a name="bugfix">In this release, the following bugs in the previous release
191were fixed:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]192</div>
193
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]194<div class="doc_text">
195
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]196<p>Bugs fixed in the LLVM Core:</p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]197
198<ol>
Chris Lattner99e41112004-10-09 19:19:57 +0000[diff] [blame]199<li><a href="http://llvm.cs.uiuc.edu/PR420">[licm] LICM invalidates alias analysis info
Chris Lattner59d448f2004-09-15 01:09:25 +0000[diff] [blame]200 and uses broken information</a> (optimizer crash)</li>
Chris Lattner99e41112004-10-09 19:19:57 +0000[diff] [blame]201<li><a href="http://llvm.cs.uiuc.edu/PR422">[asmwriter] Asmwriter is really slow for
Chris Lattner59d448f2004-09-15 01:09:25 +0000[diff] [blame]202 functions with lots of values</a></li>
Chris Lattner99e41112004-10-09 19:19:57 +0000[diff] [blame]203<li><a href="http://llvm.cs.uiuc.edu/PR423">[anders-aa] Andersen's AA is completely
Chris Lattnera10ed3b2004-08-16 05:46:57 +0000[diff] [blame]204 broken in LLVM 1.3</a></li>
Chris Lattner99e41112004-10-09 19:19:57 +0000[diff] [blame]205<li><a href="http://llvm.cs.uiuc.edu/PR430">[bcwriter] Empty compaction tables
Reid Spencer7d0a1232004-08-27 00:48:26 +0000[diff] [blame]206 defined</a></li>
Chris Lattnerbff64722004-10-25 22:13:02 +0000[diff] [blame]207<li><a href="http://llvm.cs.uiuc.edu/PR227">[X86] llc output for functions w/certain
208 names tickles GNU 'as' bugs</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]209</ol>
210
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]211<p>Bugs in the C/C++ front-end:</p>
212
213<ol>
Chris Lattner99e41112004-10-09 19:19:57 +0000[diff] [blame]214<li><a href="http://llvm.cs.uiuc.edu/PR445">[llvmg++] not enough templates are instantiated</a></li>
215<li><a href="http://llvm.cs.uiuc.edu/PR450">[llvmg++] Extern const globals cannot be
Chris Lattner2426ff92004-10-05 00:23:02 +0000[diff] [blame]216marked 'constant' if they have nontrivial ctors or dtors</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]217</ol>
Brian Gaeke730d8d62004-08-24 07:43:48 +0000[diff] [blame]218
219<p>Bugs fixed in the Sparc V9 back-end:</p>
220
221<ol>
Chris Lattner99e41112004-10-09 19:19:57 +0000[diff] [blame]222<li><a href="http://llvm.cs.uiuc.edu/PR428">[sparcv9] regalloc assertion
Brian Gaeke730d8d62004-08-24 07:43:48 +0000[diff] [blame]223 failure with certain indirect calls</a></li>
224</ol>
225
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]226</div>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]227
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]228<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]229<div class="doc_section">
230 <a name="portability">Portability and Supported Platforms</a>
231</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]232<!-- *********************************************************************** -->
233
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]234<div class="doc_text">
235
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]236<p>LLVM is known to work in the following platforms:</p>
237
238<ul>
239<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
240 other unix-like systems).</li>
241<li>Sun UltraSPARC workstations running Solaris 8.</li>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]242<li>Intel and AMD machines running on Win32 with the Cygwin libraries.</li>
Chris Lattnerd21e3d02004-08-05 21:53:13 +0000[diff] [blame]243<li>PowerPC-based Mac OS X boxes, running 10.2 and above. Note that no JIT
244support is available yet, and LLC support is beta. The C backend can be used
245to produce stable code for this platform.</li>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]246</ul>
247
Brian Gaekee3e557e2004-05-09 05:28:35 +0000[diff] [blame]248<p>The core LLVM infrastructure uses
249<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
250to the machine and operating system on which it is built. However, minor
251porting may be required to get LLVM to work on new platforms. We welcome your
252portability patches and reports of successful builds or error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]253
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]254<p>Note that the LLVM build system does not currently support directories with
255spaces on them when running on Win32/cygwin. We strongly recommend running
256LLVM and the C frontend out of a top-level directory without spaces (e.g.,
Chris Lattnerce1a3842004-06-01 19:41:30 +0000[diff] [blame]257<tt>/cygdrive/c/llvm</tt>). Also, make sure to install <b>all</b> of the
258cygwin packages. By default, many important tools are not installed that
Chris Lattnera752fce2004-08-16 20:20:46 +0000[diff] [blame]259are needed by the LLVM build process or test suite (e.g., /bin/time). Finally,
260please make sure that there are no directories with spaces in them in your
261PATH environment variable.</p>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]262
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]263</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]264
265<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]266<div class="doc_section">
267 <a name="knownproblems">Known Problems</a>
268</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]269<!-- *********************************************************************** -->
270
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]271<div class="doc_text">
272
273<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]274component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]275sections. If you run into a problem, please check the <a
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]276href="http://llvm.cs.uiuc.edu/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]277there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]278
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]279</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]280
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]281<!-- ======================================================================= -->
282<div class="doc_subsection">
283 <a name="experimental">Experimental features included with this release</a>
284</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]285
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]286<div class="doc_text">
287
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]288<p>The following components of this LLVM release are either untested, known to
289be broken or unreliable, or are in early development. These components should
290not be relied on, and bugs should not be filed against them, but they may be
291useful to some people. In particular, if you would like to work on one of these
292components, please contact us on the llvmdev list.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]293
294<ul>
Misha Brukman467ea6b2004-08-05 21:04:03 +0000[diff] [blame]295<li>The PowerPC backend is incomplete and is known to miscompile several SPEC
296benchmarks. The file <tt>llvm/lib/Target/PowerPC/README.txt</tt> has
297details.</li>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]298<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
Chris Lattner09f3ac92004-09-14 16:43:13 +0000[diff] [blame]299 -ipmodref, -cee, -branch-combine, -instloops, -paths</tt></li>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]300<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
301 it should) and not thoroughly tested.</li>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]302<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
303</ul>
304
305</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]306
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]307<!-- ======================================================================= -->
308<div class="doc_subsection">
309 <a name="core">Known problems with the LLVM Core</a>
310</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]311
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]312<div class="doc_text">
313
314<ul>
315
316<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
317work.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]318
319<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]320such, execution of a threaded program could cause these data structures to be
321corrupted.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]322
Chris Lattnerc0171082004-08-08 03:33:07 +0000[diff] [blame]323<li>Linking in static archive files (.a files) is slow (there is no symbol
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]324table in the archive).</li>
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]325
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]326<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
327objects/archives in the order specified on the command line.</a></li>
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]328
329<li><a href="http://llvm.cs.uiuc.edu/PR240">The lower-invoke pass does not mark
John Criswell5d6345a2004-03-12 21:29:42 +0000[diff] [blame]330values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]331targets whose setjmp/longjmp libraries do not save and restore the entire
332register file.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]333</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]334</div>
335
336<!-- ======================================================================= -->
337<div class="doc_subsection">
338 <a name="c-fe">Known problems with the C front-end</a>
339</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]340
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]341<!-- _______________________________________________________________________ -->
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]342<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]343
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]344<div class="doc_text">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]345<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]346<li>C99 Variable sized arrays do not release stack memory when they go out of
347 scope. Thus, the following program may run out of stack space:
348<pre>
349 for (i = 0; i != 1000000; ++i) {
350 int X[n];
351 foo(X);
352 }
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]353</pre></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]354
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]355<li>Initialization of global union variables can only be done <a
356href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
357member</a>.</li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]358
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]359<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
360external function is re-declared as static</a></li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]361
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]362</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]363</div>
364
365<!-- _______________________________________________________________________ -->
366<div class="doc_subsubsection">
367 Notes
368</div>
369
370<div class="doc_text">
371
372<ul>
373
374<li>Inline assembly is not yet supported.</li>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]375
376<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]377support for floating point data types of any size other than 32 and 64
378bits.</li>
379
380<li>The following Unix system functionality has not been tested and may not
381work:
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]382 <ol>
383 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
384 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
385 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
386 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
387 - These functions have not been tested.
388 </ol></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]389
390<li>Although many GCC extensions are supported, some are not. In particular,
391 the following extensions are known to <b>not be</b> supported:
392 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]393 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]394 <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>
395 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
396 <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 Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]397 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]398 <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>
399 <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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]400 <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>
401 <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>
402 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
403 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pragmas.html#Pragmas">Pragmas</a>: Pragmas accepted by GCC.</li>
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]404 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]405
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]406 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]407 attribute means that the LLVM compiler ignores the presence of the attribute,
408 but the code should still work. An unsupported attribute is one which is
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]409 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]410 the program.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]411
412 <ol>
413 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
414 Arrays whose length is computed at run time.<br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]415 Supported, but allocated stack space is not freed until the function returns (noted above).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]416
417 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html#Function%20Attributes">Function Attributes</a>:
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]418
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]419 Declaring that functions have no side effects or that they can never
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]420 return.<br>
421
422 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
423 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
424 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
425
426 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
427 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
428 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
429
430 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
431 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
432 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]433
434 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
435 Specifying attributes of variables.<br>
436 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
437 <tt>deprecated</tt>, <tt>transparent_union</tt>,
438 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]439
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]440 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
441 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
442 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]443 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]444
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]445 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html#Type%20Attributes">Type Attributes</a>: Specifying attributes of types.<br>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]446 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]447 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]448
449 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
450 all target specific attributes.</li>
451
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]452 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
453 Other built-in functions.<br>
454 We support all builtins which have a C language equivalent (e.g.,
455 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
456 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Chris Lattnerb7c4bac2004-06-18 06:26:29 +0000[diff] [blame]457 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt>
458 (currently ignored). We also support builtins for ISO C99 floating
459 point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]460 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]461
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]462 <p>The following extensions <b>are</b> known to be supported:</p>
463
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]464 <ol>
Chris Lattnerd3dc8502004-03-16 08:54:07 +0000[diff] [blame]465 <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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]466 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
467 <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 Lattnerce33a1b2004-06-22 03:48:17 +0000[diff] [blame]468 <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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]469 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
470 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
471 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
472 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
473 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
474 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
475 <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>
476 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
477 <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 Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]478 <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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]479 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]480 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
481or arrays as values.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]482 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html#Designated%20Inits">Designated Inits</a>: Labeling elements of initializers.</li>
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]483 <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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]484 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
485 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
486 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
487 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
488 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
489 <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>
490 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
491 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
492 <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>
493 <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>
494 <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 Lattner3646dad2004-02-14 04:08:29 +0000[diff] [blame]495 <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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]496 <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>
497 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html#Attribute%20Syntax">Attribute Syntax</a>: Formal syntax for attributes.</li>
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]498 </ol></li>
499
500</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]501
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]502<p>If you run into GCC extensions which have not been included in any of these
503lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]504
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]505</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]506
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]507<!-- ======================================================================= -->
508<div class="doc_subsection">
509 <a name="c++-fe">Known problems with the C++ front-end</a>
510</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]511
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]512<div class="doc_text">
513
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]514<p>For this release, the C++ front-end is considered to be fully functional but
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]515has not been tested as thoroughly as the C front-end. It has been tested and
516works for a number of non-trivial programs, but there may be lurking bugs.
517Please report any bugs or problems.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]518
519</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]520
521<!-- _______________________________________________________________________ -->
Chris Lattner141ebb62004-02-14 04:12:41 +0000[diff] [blame]522<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]523
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]524<div class="doc_text">
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]525
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]526<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]527<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]528 front-end</a>.</li>
Chris Lattner041e6c92004-07-17 02:04:41 +0000[diff] [blame]529
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]530<li><b>IA-64 specific</b>: The C++ front-end does not use <a
531href="http://llvm.cs.uiuc.edu/PR406">IA64 ABI compliant layout of v-tables</a>.
Chris Lattner041e6c92004-07-17 02:04:41 +0000[diff] [blame]532In particular, it just stores function pointers instead of function
533descriptors in the vtable. This bug prevents mixing C++ code compiled with
Chris Lattner2fd93492004-08-02 20:29:51 +0000[diff] [blame]534LLVM with C++ objects compiled by other C++ compilers.</li>
Chris Lattner041e6c92004-07-17 02:04:41 +0000[diff] [blame]535
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]536</ul>
537
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]538</div>
539
540<!-- _______________________________________________________________________ -->
541<div class="doc_subsubsection">
542 Notes
543</div>
544
545<div class="doc_text">
546
547<ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]548
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]549<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
550parser is significantly more standards compliant (and picky) than prior GCC
551versions. For more information, see the C++ section of the <a
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]552href="http://gcc.gnu.org/gcc-3.4/changes.html">GCC 3.4 release notes</a>.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]553
554<li>Destructors for local objects are not always run when a <tt>longjmp</tt> is
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]555 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]556 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]557 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]558 better than most compilers).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]559
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]560<li>The LLVM C++ front-end follows the <a
561 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
562 This document, which is not Itanium specific, specifies a standard for name
563 mangling, class layout, v-table layout, RTTI formats, and other C++
564 representation issues. Because we use this API, code generated by the LLVM
565 compilers should be binary compatible with machine code generated by other
566 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
567 <i>However</i>, the exception handling mechanism used by LLVM is very
568 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]569 interact correctly</b>. </li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]570
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]571</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]572
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]573</div>
574
575<!-- ======================================================================= -->
576<div class="doc_subsection">
577 <a name="x86-be">Known problems with the X86 back-end</a>
578</div>
579
580<div class="doc_text">
581
582<ul>
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]583 <li>none yet</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]584</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]585
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]586</div>
587
588<!-- ======================================================================= -->
589<div class="doc_subsection">
Misha Brukmana516e992004-07-12 16:55:41 +0000[diff] [blame]590 <a name="sparcv9-be">Known problems with the SparcV9 back-end</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]591</div>
592
593<div class="doc_text">
594
595<ul>
Misha Brukmana516e992004-07-12 16:55:41 +0000[diff] [blame]596<li><a href="http://llvm.cs.uiuc.edu/PR60">[sparcv9] SparcV9 backend miscompiles
597several programs in the LLVM test suite</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]598</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]599
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]600</div>
601
602<!-- ======================================================================= -->
603<div class="doc_subsection">
Chris Lattnerdf925ce2004-11-07 01:55:32 +0000[diff] [blame]604 <a name="ppc-be">Known problems with the PowerPC back-end</a>
605</div>
606
607<div class="doc_text">
608
609<ul>
610<li>none yet</li>
611</ul>
612
613</div>
614
615<!-- ======================================================================= -->
616<div class="doc_subsection">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]617 <a name="c-be">Known problems with the C back-end</a>
618</div>
619
620<div class="doc_text">
621
622<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]623
624<li>The C back-end produces code that violates the ANSI C Type-Based Alias
625Analysis rules. As such, special options may be necessary to compile the code
626(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]627problem probably cannot be fixed.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]628
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]629<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]630cannot include special floating point numbers like Not-A-Number or
631Infinity.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]632
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]633<li><a href="http://llvm.cs.uiuc.edu/PR56">Zero arg vararg functions are not
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]634supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]635frontends.</li>
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]636
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]637</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]638
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]639</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]640
641<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]642<div class="doc_section">
643 <a name="additionalinfo">Additional Information</a>
644</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]645<!-- *********************************************************************** -->
646
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]647<div class="doc_text">
648
649<p>A wide variety of additional information is available on the LLVM web page,
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]650including mailing lists and publications describing algorithms and components
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]651implemented in LLVM. The web page also contains versions of the API
652documentation which is up-to-date with the CVS version of the source code. You
653can access versions of these documents specific to this release by going into
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]654the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]655
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]656<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]657us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
658lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]659
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]660</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]661
662<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]663
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]664<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]665<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]666 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]667 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
668 <a href="http://validator.w3.org/check/referer"><img
669 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
670
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]671 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]672 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]673</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]674
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]675</body>
676</html>