Gitiles
Code Review Sign In
gerrit-public.fairphone.software / platform / external / llvm / ad64385129e2fd6799828ab44d947c2b2094f500 / . / docs / ReleaseNotes.html
blob: 77347b2f7f437bfe2541ef50b3e2fc2ebb93124a [file] [log] [blame]
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
2 "http://www.w3.org/TR/html4/strict.dtd">
3<html>
4<head>
5 <link rel="stylesheet" href="llvm.css" type="text/css">
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]6 <title>LLVM 1.2 Release Notes</title>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]7</head>
8<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]9
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]10<div class="doc_title">
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]11 LLVM 1.2 Release Notes
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]12</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]13
14<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]15 <li><a href="#intro">Introduction</a></li>
16 <li><a href="#whatsnew">What's New?</a></li>
17 <li><a href="#portability">Portability and Supported Platforms</a></li>
18 <li><a href="#install-instructions">Installation Instructions</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]19 <li><a href="#knownproblems">Known Problems</a>
20 <ul>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]21<!-- <li><a href="#portabilityprobs">Portability Problems</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>
26 <li><a href="#sparc-be">Known problems with the Sparc Back-end</a>
27 <li><a href="#c-be">Known problems with the C back-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]28 </ul></li>
29 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]30</ol>
31
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]32<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]33 <p><b>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a></b><p>
34</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]35
36<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]37<div class="doc_section">
38 <a name="intro">Introduction</a>
39</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]40<!-- *********************************************************************** -->
41
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]42<div class="doc_text">
43
44<p>This document contains the release notes for the LLVM compiler
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]45infrastructure, release 1.2. Here we describe the status of LLVM, including any
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]46known problems, and bug fixes from the previous release. The most up-to-date
47version of this document can be found on the <a
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]48href="http://llvm.cs.uiuc.edu/releases/1.2/">LLVM 1.2 web site</a>. If you are
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]49not reading this on the LLVM web pages, you should probably go there, because
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]50this document may be updated after the release.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]51
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]52<p>For more information about LLVM, including information about potentially more
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]53current releases, please check out the <a href="http://llvm.cs.uiuc.edu">main
54web site</a>. If you have questions or comments, the <a
55href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]56list</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]57
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]58<p>Note that if you are reading this file from CVS, this document applies
59to the <i>next</i> release, not the current one. To see the release notes for
60the current or previous releases, see the <a
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]61href="http://llvm.cs.uiuc.edu/releases/">releases page</a>.</p>
62
63</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]64
65<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]66<div class="doc_section">
67 <a name="whatsnew">What's New?</a>
68</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]69<!-- *********************************************************************** -->
70
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]71<div class="doc_text">
72
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]73<p>This is the third public release of the LLVM compiler infrastructure. OTHER
74OVERVIEW STUFF HERE.
75</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]76
Chris Lattner1124e2c2003-12-12 21:33:08 +0000[diff] [blame]77<p>At this time, LLVM is known to correctly compile and run all non-unwinding C
78&amp; C++ SPEC CPU2000 benchmarks, the Olden benchmarks, and the Ptrdist
79benchmarks. It has also been used to compile <b>many</b> other programs. LLVM
80now also works with a broad variety of C++ programs, though it has still
81received much less testing than the C front-end.
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]82</p>
83
84<p>
Chris Lattner1124e2c2003-12-12 21:33:08 +0000[diff] [blame]85The LLVM native code generators are very stable, but do not currently support
86unwinding (exception throwing or <tt>longjmp</tt>ing), which prevent them from
87working with programs like the <tt>253.perlbmk</tt> in SPEC CPU2000. The C
88backend and the rest of LLVM does support these programs however, so you can
89still use LLVM with them. Support for unwinding will be added in a future
90release.
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]91</p>
92
93
94<!--=========================================================================-->
95<div class="doc_subsubsection">
96This release implements the following new features:
97</div>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]98
99<ol>
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]100<li></li>
101<li></li>
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]102</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]103
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]104
105<!--=========================================================================-->
106<div class="doc_subsubsection">
107In this release, the following missing features were implemented:
108</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]109
110<ol>
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]111<li></li>
112<li></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]113</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]114
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]115
116<!--=========================================================================-->
117<div class="doc_subsubsection">
118In this release, the following Quality of Implementation issues were
119fixed:
120</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]121
122<ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]123
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]124<li></li>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]125
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]126<li></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]127</ol>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]128
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]129
130<!--=========================================================================-->
131<div class="doc_subsubsection">
132In this release, the following bugs in the previous release were fixed:
133</div>
134
135<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]136
137<ol>
Misha Brukmanad643852003-12-15 22:48:12 +0000[diff] [blame^]138<li><a href="http://llvm.cs.uiuc.edu/PR179">[licm] LICM promotes volatile memory
139locations to registers</a></li>
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]140
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]141</ol>
142
143
144<p>Bugs in the C/C++ front-end:</p>
145
146<ol>
Misha Brukmanad643852003-12-15 22:48:12 +0000[diff] [blame^]147<li><a href="http://llvm.cs.uiuc.edu/PR186">Need weak linkage on memory
148management functions in libc runtime to allow them to be overriden</a></li>
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]149<li></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]150</ol>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]151
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]152</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]153
154<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]155<div class="doc_section">
156 <a name="portability">Portability and Supported Platforms</a>
157</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]158<!-- *********************************************************************** -->
159
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]160<div class="doc_text">
161
162<p>LLVM has been extensively tested on Intel and AMD machines running Red
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]163Hat Linux and FreeBSD. It has also been tested on Sun UltraSPARC workstations running Solaris 8.
John Criswellbb1bad52003-12-12 19:54:20 +0000[diff] [blame]164Additionally,
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]165LLVM works on Mac OS/X 10.3 and above, but only with the C backend or
166interpreter (no native backend for the PowerPC is available yet).
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]167The core LLVM infrastructure uses "autoconf" for portability, so hopefully we
Chris Lattner3e2959e2003-11-08 05:22:09 +0000[diff] [blame]168work on more platforms than that. However, it is likely that we
169missed something, and that minor porting is required to get LLVM to work on
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]170new platforms. We welcome portability patches and error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]171
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]172</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]173
174<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]175<div class="doc_section">
176 <a name="knownproblems">Known Problems</a>
177</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]178<!-- *********************************************************************** -->
179
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]180<div class="doc_text">
181
182<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]183component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]184sections. If you run into a problem, please check the <a
185href="http://llvm.cs.uiuc.edu/bugs/">LLVM bug database</a>, and submit a bug if
186there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]187
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]188</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]189
190<!-- _______________________________________________________________________ -->
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]191<!--
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]192</ul><h4><a name="portability"><hr size=0>Portability Problems</h4><ul>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]193-->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]194
195
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]196<!-- ======================================================================= -->
197<div class="doc_subsection">
198 <a name="core">Known problems with the LLVM Core</a>
199</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]200
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]201<div class="doc_text">
202
203<ul>
204
205<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
206work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]207
208<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]209such, execution of a threaded program could cause these data structures to be
210corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]211
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]212<li>It is not possible to <tt>dlopen</tt> an LLVM bytecode file in the JIT.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]213
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]214<li>Linking in static archive files (.a files) is very slow (there is no symbol
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]215table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]216
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]217<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]218more than 256 elements</a>.</li>
219
220</ul>
221
222</div>
223
224<!-- ======================================================================= -->
225<div class="doc_subsection">
226 <a name="c-fe">Known problems with the C front-end</a>
227</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]228
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]229<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]230<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]231
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]232<div class="doc_text">
233
234<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]235
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]236<li>C99 Variable sized arrays do not release stack memory when they go out of
237 scope. Thus, the following program may run out of stack space:
238<pre>
239 for (i = 0; i != 1000000; ++i) {
240 int X[n];
241 foo(X);
242 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]243</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]244
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]245</ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]246
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]247</div>
248
249<!-- _______________________________________________________________________ -->
250<div class="doc_subsubsection">
251 Notes
252</div>
253
254<div class="doc_text">
255
256<ul>
257
258<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]259
260<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]261support for floating point data types of any size other than 32 and 64
262bits.</li>
263
264<li>The following Unix system functionality has not been tested and may not
265work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]266 <ol>
267 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
268 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
269 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
270 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
271 - These functions have not been tested.
272 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]273
274<li>Although many GCC extensions are supported, some are not. In particular,
275 the following extensions are known to <b>not be</b> supported:
276 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]277 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
278 <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>
279 <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>
280 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
281 <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>
282 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands</li>
283 <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>
284 <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>
285 <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>
286 <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>
287 <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>
288 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
289 <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]290 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]291
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]292 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]293 attribute means that the LLVM compiler ignores the presence of the attribute,
294 but the code should still work. An unsupported attribute is one which is
295 ignored by the LLVM compiler, which will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]296 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]297
298 <ol>
299 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
300 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]301 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]302
303 <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]304
305 Declaring that functions have no side effects, or that they can never
306 return.<br>
307
308 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
309 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
310 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
311
312 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
313 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
314 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
315
316 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
317 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
318 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]319
320 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
321 Specifying attributes of variables.<br>
322 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
323 <tt>deprecated</tt>, <tt>transparent_union</tt>,
324 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]325
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]326 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
327 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
328 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]329 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]330
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]331 <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]332 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]333 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]334
335 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
336 all target specific attributes.</li>
337
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]338 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
339 Other built-in functions.<br>
340 We support all builtins which have a C language equivalent (e.g.,
341 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
342 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]343 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]344
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]345 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]346
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]347 <p>The following extensions <b>are</b> known to be supported:</p>
348
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]349 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]350 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
351 <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>
352 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
353 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
354 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
355 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
356 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
357 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
358 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
359 <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>
360 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
361 <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]362 <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]363 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
364 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions or arrays as values.</li>
365 <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]366 <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]367 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
368 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
369 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
370 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
371 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
372 <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>
373 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
374 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
375 <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>
376 <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>
377 <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>
378 <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>
379 <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]380 </ol></li>
381
382</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]383
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]384<p>If you run into GCC extensions which have not been included in any of these
385lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]386
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]387</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]388
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]389<!-- ======================================================================= -->
390<div class="doc_subsection">
391 <a name="c++-fe">Known problems with the C++ front-end</a>
392</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]393
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]394<div class="doc_text">
395
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]396<p>For this release, the C++ front-end is considered to be fully functional, but
397has not been tested as thoroughly as the C front-end. It has been tested and
398works for a number of non-trivial programs, but there may be lurking bugs.
399Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]400
401</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]402
403<!-- _______________________________________________________________________ -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]404<div class="doc_subsubsection">
405 Bugs
406</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]407
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]408<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]409
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]410<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]411<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]412 front-end</a></li>
413</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]414
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]415</div>
416
417<!-- _______________________________________________________________________ -->
418<div class="doc_subsubsection">
419 Notes
420</div>
421
422<div class="doc_text">
423
424<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]425
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]426<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
427parser is significantly more standards compliant (and picky) than prior GCC
428versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]429href="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]430
431<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]432 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]433 function and in the <tt>setjmp</tt> receiver function may not be run.
434 Objects in intervening stack frames will be destroyed however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]435 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]436
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]437<li>The LLVM C++ front-end follows the <a
438 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
439 This document, which is not Itanium specific, specifies a standard for name
440 mangling, class layout, v-table layout, RTTI formats, and other C++
441 representation issues. Because we use this API, code generated by the LLVM
442 compilers should be binary compatible with machine code generated by other
443 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
444 <i>However</i>, the exception handling mechanism used by LLVM is very
445 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]446 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]447
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]448</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]449
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]450</div>
451
452<!-- ======================================================================= -->
453<div class="doc_subsection">
454 <a name="x86-be">Known problems with the X86 back-end</a>
455</div>
456
457<div class="doc_text">
458
459<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]460
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]461<li>The X86 code generator <a
Chris Lattner0d4379a2003-10-08 06:01:38 +0000[diff] [blame]462href="http://llvm.cs.uiuc.edu/PR16">does not currently
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]463support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]464or calls the C <tt>longjmp</tt> function will abort.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]465
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]466</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]467
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]468</div>
469
470<!-- ======================================================================= -->
471<div class="doc_subsection">
472 <a name="sparc-be">Known problems with the Sparc back-end</a>
473</div>
474
475<div class="doc_text">
476
477<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]478
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]479<li>The Sparc code generator <a
Chris Lattner0d4379a2003-10-08 06:01:38 +0000[diff] [blame]480href="http://llvm.cs.uiuc.edu/PR15">does not currently
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]481support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]482or calls the C <tt>longjmp</tt> function will abort.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]483
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]484</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]485
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]486</div>
487
488<!-- ======================================================================= -->
489<div class="doc_subsection">
490 <a name="c-be">Known problems with the C back-end</a>
491</div>
492
493<div class="doc_text">
494
495<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]496
497<li>The C back-end produces code that violates the ANSI C Type-Based Alias
498Analysis rules. As such, special options may be necessary to compile the code
499(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]500problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]501
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]502<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]503cannot include special floating point numbers like Not-A-Number or
504Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]505
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]506<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]507supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]508frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]509
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]510</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]511
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]512</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]513
514<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]515<div class="doc_section">
516 <a name="additionalinfo">Additional Information</a>
517</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]518<!-- *********************************************************************** -->
519
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]520<div class="doc_text">
521
522<p>A wide variety of additional information is available on the LLVM web page,
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]523including mailing lists publications describing algorithms and components
524implemented in LLVM. The web page also contains versions of the API
525documentation which is up-to-date with the CVS version of the source code. You
526can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]527the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]528
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]529<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]530us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
531lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]532
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]533</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]534
535<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]536
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]537<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]538<address>
539 <a href="http://jigsaw.w3.org/css-validator/"><img
540 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
541 <a href="http://validator.w3.org/check/referer"><img
542 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
543
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]544 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]545 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]546</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]547
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]548</body>
549</html>