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