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Chris Lattner78bf32b2004-12-09 22:22:58 +00007 <title>LLVM 1.5 Release Notes</title>
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9<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +000010
Chris Lattner78bf32b2004-12-09 22:22:58 +000011<div class="doc_title">LLVM 1.5 Release Notes</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000012
13<ol>
Misha Brukman500bc302003-11-22 00:38:41 +000014 <li><a href="#intro">Introduction</a></li>
15 <li><a href="#whatsnew">What's New?</a></li>
Chris Lattner4b538b92004-04-30 22:17:12 +000016 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +000017 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +000018 <li><a href="#knownproblems">Known Problems</a>
Misha Brukman500bc302003-11-22 00:38:41 +000019 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +000020</ol>
21
Chris Lattner7911ce22004-05-23 21:07:27 +000022<div class="doc_author">
Chris Lattner78bf32b2004-12-09 22:22:58 +000023 <p>Written by the <a href="http://llvm.cs.uiuc.edu">LLVM Team</a><p>
Misha Brukman500bc302003-11-22 00:38:41 +000024</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000025
26<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +000027<div class="doc_section">
28 <a name="intro">Introduction</a>
29</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000030<!-- *********************************************************************** -->
31
Misha Brukman500bc302003-11-22 00:38:41 +000032<div class="doc_text">
33
34<p>This document contains the release notes for the LLVM compiler
Chris Lattner78bf32b2004-12-09 22:22:58 +000035infrastructure, release 1.5. Here we describe the status of LLVM, including any
Chris Lattner7506b1d2004-12-07 08:04:13 +000036known problems and improvements from the previous release. The most up-to-date
Misha Brukman500bc302003-11-22 00:38:41 +000037version of this document can be found on the <a
Chris Lattner78bf32b2004-12-09 22:22:58 +000038href="http://llvm.cs.uiuc.edu/releases/1.5/">LLVM 1.5 web site</a>. If you are
John Criswelld000e1d2003-12-18 16:43:17 +000039not reading this on the LLVM web pages, you should probably go there because
Misha Brukman500bc302003-11-22 00:38:41 +000040this document may be updated after the release.</p>
Chris Lattner19092612003-10-02 16:38:05 +000041
Chris Lattner7506b1d2004-12-07 08:04:13 +000042<p>For more information about LLVM, including information about the latest
43release, please check out the <a href="http://llvm.cs.uiuc.edu">main LLVM
Chris Lattner47ad72c2003-10-07 21:38:31 +000044web site</a>. If you have questions or comments, the <a
45href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman500bc302003-11-22 00:38:41 +000046list</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +000047
Chris Lattner78bf32b2004-12-09 22:22:58 +000048<p>Note that if you are reading this file from CVS or the main LLVM web page,
49this document applies to the <i>next</i> release, not the current one. To see
50the release notes for the current or previous releases, see the <a
Misha Brukman500bc302003-11-22 00:38:41 +000051href="http://llvm.cs.uiuc.edu/releases/">releases page</a>.</p>
52
53</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000054
55<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +000056<div class="doc_section">
57 <a name="whatsnew">What's New?</a>
58</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000059<!-- *********************************************************************** -->
60
Misha Brukman500bc302003-11-22 00:38:41 +000061<div class="doc_text">
62
Chris Lattner78bf32b2004-12-09 22:22:58 +000063<p>This is the sixth public release of the LLVM compiler infrastructure.</p>
Chris Lattnera5099962003-12-06 20:22:41 +000064
Chris Lattner0bce6ac2004-12-10 16:27:34 +000065<p> At this time, LLVM is known to correctly compile a broad range of C and
Chris Lattner78bf32b2004-12-09 22:22:58 +000066C++ programs, including the SPEC CPU95 &amp; 2000 suite. TODO. It also includes
67bug fixes for those problems found since the 1.4 release.</p>
Chris Lattnera5099962003-12-06 20:22:41 +000068
Chris Lattner80453c92004-05-24 04:50:25 +000069</div>
70
Chris Lattnera5099962003-12-06 20:22:41 +000071<!--=========================================================================-->
72<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +000073<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnera5099962003-12-06 20:22:41 +000074</div>
Chris Lattner47ad72c2003-10-07 21:38:31 +000075
Chris Lattner80453c92004-05-24 04:50:25 +000076<div class="doc_text">
Chris Lattner47ad72c2003-10-07 21:38:31 +000077<ol>
Chris Lattner74d74cd2004-12-11 06:10:52 +000078 <li>LLVM now includes an <a href="http://llvm.cs.uiuc.edu/PR415">
Chris Lattnerda1f03c2005-01-22 18:45:35 +000079 Interprocedural Sparse Conditional Constant Propagation</a> pass, named
Chris Lattner74d74cd2004-12-11 06:10:52 +000080 -ipsccp, which is run by default at link-time.</li>
Chris Lattner75008d82005-02-01 01:33:52 +000081 <li>LLVM 1.5 is now about 15% faster than LLVM 1.4 and its core data structures
Chris Lattner2e12c742005-02-13 22:27:24 +000082 use about 30% less memory.</li>
83 <li>LLVM includes new experimental native code generators for SparcV8 and
84 Alpha.</li>
85 <li>Support for Microsoft Visual Studio is improved, and <a
Chris Lattnera5d803e2005-02-14 22:58:38 +000086 href="GettingStartedVS.html">now documented</a>.</li>
Chris Lattner55ee0312003-11-19 22:05:38 +000087</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +000088
Chris Lattner80453c92004-05-24 04:50:25 +000089</div>
90
Chris Lattnera5099962003-12-06 20:22:41 +000091
92<!--=========================================================================-->
93<div class="doc_subsubsection">
94In this release, the following missing features were implemented:
95</div>
Chris Lattner0ef19062003-11-08 04:28:55 +000096
Chris Lattner80453c92004-05-24 04:50:25 +000097<div class="doc_text">
98
Chris Lattner0ef19062003-11-08 04:28:55 +000099<ol>
Chris Lattner78bf32b2004-12-09 22:22:58 +0000100 <li></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000101</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000102
Chris Lattner80453c92004-05-24 04:50:25 +0000103</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000104
105<!--=========================================================================-->
106<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000107<a name="qualityofimp">In this release, the following Quality of Implementation
108issues were fixed:</a>
Chris Lattnere29ac162003-12-20 03:42:11 +0000109</div>
110
Chris Lattner80453c92004-05-24 04:50:25 +0000111<div class="doc_text">
112
Chris Lattnere29ac162003-12-20 03:42:11 +0000113<ol>
Chris Lattnerda1f03c2005-01-22 18:45:35 +0000114 <li><a href="http://llvm.cs.uiuc.edu/PR448">Building LLVM in optimized mode
115 should no longer cause GCC to hit swap in the PowerPC backend.</a></li>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000116</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000117</div>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000118
119<!--=========================================================================-->
120<div class="doc_subsubsection">
Chris Lattner6e1ef192004-05-02 04:19:15 +0000121<a name="codequality">This release includes the following Code Quality
122improvements:</a>
Chris Lattneraab56d42004-05-23 20:42:08 +0000123</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000124
Chris Lattner80453c92004-05-24 04:50:25 +0000125<div class="doc_text">
Chris Lattner89ca2b82003-10-27 17:06:39 +0000126<ol>
Chris Lattner78bf32b2004-12-09 22:22:58 +0000127 <li></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000128</ol>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000129</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000130
131<!--=========================================================================-->
132<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000133<a name="bugfix">In this release, the following bugs in the previous release
134were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000135</div>
136
Chris Lattner80453c92004-05-24 04:50:25 +0000137<div class="doc_text">
138
Chris Lattner47ad72c2003-10-07 21:38:31 +0000139
Chris Lattnerf54e9cb2005-02-14 16:57:55 +0000140<p>Bugs fixed in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000141<ol>
Chris Lattnerbfd24682004-12-29 04:39:50 +0000142 <li><a href="http://llvm.cs.uiuc.edu/PR491">[dse] DSE deletes stores that
143 are partially overwritten by smaller stores</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000144</ol>
145
Chris Lattnerf54e9cb2005-02-14 16:57:55 +0000146<p>Code Generator Bugs:</p>
147<ol>
148 <li><a href="http://llvm.cs.uiuc.edu/PR490">[cbackend] Logical constant
149 expressions (and/or/xor) not implemented</a></li>
150 <li><a href="http://llvm.cs.uiuc.edu/PR511">[cbackend] C backend does not
151 respect 'volatile'</a></li>
152</ol>
Chris Lattnera5099962003-12-06 20:22:41 +0000153
Chris Lattnerf54e9cb2005-02-14 16:57:55 +0000154<p>Bugs in the C/C++ front-end:</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000155<ol>
Chris Lattner8de9f232005-01-03 04:20:21 +0000156 <li><a href="http://llvm.cs.uiuc.edu/PR487">[llvmgcc] llvm-gcc incorrectly
157 rejects some constant initializers involving the addresses of array
158 elements</a></li>
Chris Lattnerf832f6a2005-02-11 19:29:52 +0000159 <li><a href="http://llvm.cs.uiuc.edu/PR501">[llvm-g++] Crash compiling
160 anonymous union</a></li>
Chris Lattnerf54e9cb2005-02-14 16:57:55 +0000161 <li><a href="http://llvm.cs.uiuc.edu/PR509">[llvm-g++] Do not use dynamic
162 initialization where static init will do</a></li>
Chris Lattner4a9dc292005-02-15 05:28:06 +0000163 <li><a href="http://llvm.cs.uiuc.edu/PR510">[llvmgcc] Field offset
164 miscalculated for some structure fields following bit fields</a></li>
Chris Lattner5ad907a2005-02-15 07:02:12 +0000165 <li><a href="http://llvm.cs.uiuc.edu/PR513">[llvm-g++] Temporary lifetimes
166 incorrect for short circuit logical operations</a></li>
Chris Lattnerc1f90a92005-02-19 07:29:25 +0000167 <li><a href="http://llvm.cs.uiuc.edu/PR517">[llvm-gcc] Crash compiling
168 bitfield &lt;-&gt; aggregate assignment</a></li>
Brian Gaekee77c8e72004-08-24 07:43:48 +0000169</ol>
170
Chris Lattner80453c92004-05-24 04:50:25 +0000171</div>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000172
Chris Lattner19092612003-10-02 16:38:05 +0000173<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000174<div class="doc_section">
175 <a name="portability">Portability and Supported Platforms</a>
176</div>
Chris Lattner19092612003-10-02 16:38:05 +0000177<!-- *********************************************************************** -->
178
Misha Brukman500bc302003-11-22 00:38:41 +0000179<div class="doc_text">
180
John Criswell0b5b5e92004-12-08 20:35:47 +0000181<p>LLVM is known to work on the following platforms:</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000182
183<ul>
184<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
185 other unix-like systems).</li>
186<li>Sun UltraSPARC workstations running Solaris 8.</li>
Chris Lattner7506b1d2004-12-07 08:04:13 +0000187<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
188 support is available for native builds with Visual C++).</li>
189<li>PowerPC-based Mac OS X systems, running 10.2 and above.</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000190</ul>
191
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000192<p>The core LLVM infrastructure uses
193<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
194to the machine and operating system on which it is built. However, minor
195porting may be required to get LLVM to work on new platforms. We welcome your
196portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000197
Misha Brukman500bc302003-11-22 00:38:41 +0000198</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000199
200<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000201<div class="doc_section">
202 <a name="knownproblems">Known Problems</a>
203</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000204<!-- *********************************************************************** -->
205
Misha Brukman500bc302003-11-22 00:38:41 +0000206<div class="doc_text">
207
208<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000209component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000210sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000211href="http://llvm.cs.uiuc.edu/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000212there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000213
Misha Brukman500bc302003-11-22 00:38:41 +0000214</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000215
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000216<!-- ======================================================================= -->
217<div class="doc_subsection">
218 <a name="experimental">Experimental features included with this release</a>
219</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000220
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000221<div class="doc_text">
222
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000223<p>The following components of this LLVM release are either untested, known to
224be broken or unreliable, or are in early development. These components should
225not be relied on, and bugs should not be filed against them, but they may be
226useful to some people. In particular, if you would like to work on one of these
227components, please contact us on the llvmdev list.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000228
229<ul>
Chris Lattner7506b1d2004-12-07 08:04:13 +0000230<li>The following passes are incomplete or buggy, and may be removed in future
Chris Lattner1fe848e2005-01-28 06:13:52 +0000231 releases: <tt>-cee, -branch-combine, -instloops, -paths, -pre</tt></li>
Chris Lattner7506b1d2004-12-07 08:04:13 +0000232<li>The <tt>llvm-db</tt> tool is in a very early stage of development, but can
233 be used to step through programs and inspect the stack.</li>
Chris Lattner0da7f492004-12-02 17:20:17 +0000234<li>The "iterative scan" register allocator (enabled with -regalloc=iterativescan)
235 is not stable.</li>
Chris Lattner2e12c742005-02-13 22:27:24 +0000236<li>The SparcV8 and Alpha ports are experimental.</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000237</ul>
238
239</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000240
Misha Brukman500bc302003-11-22 00:38:41 +0000241<!-- ======================================================================= -->
242<div class="doc_subsection">
243 <a name="core">Known problems with the LLVM Core</a>
244</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000245
Misha Brukman500bc302003-11-22 00:38:41 +0000246<div class="doc_text">
247
248<ul>
Reid Spencer4f86f9c2004-11-25 22:38:30 +0000249 <li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not work.
250 </li>
251 <li>The JIT does not use mutexes to protect its internal data structures. As
252 such, execution of a threaded program could cause these data structures to be
253 corrupted.
254 </li>
Reid Spencer4f86f9c2004-11-25 22:38:30 +0000255 <li><a href="http://llvm.cs.uiuc.edu/PR240">The lower-invoke pass does not
256 mark values live across a setjmp as volatile</a>. This missing feature
257 only affects targets whose setjmp/longjmp libraries do not save and restore
258 the entire register file.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000259</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000260</div>
261
262<!-- ======================================================================= -->
263<div class="doc_subsection">
264 <a name="c-fe">Known problems with the C front-end</a>
265</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000266
Chris Lattner79c3fe12003-10-02 04:57:28 +0000267<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000268<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000269
Misha Brukman500bc302003-11-22 00:38:41 +0000270<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000271<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000272<li>C99 Variable sized arrays do not release stack memory when they go out of
273 scope. Thus, the following program may run out of stack space:
274<pre>
275 for (i = 0; i != 1000000; ++i) {
276 int X[n];
277 foo(X);
278 }
Misha Brukman500bc302003-11-22 00:38:41 +0000279</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000280
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000281<li>Initialization of global union variables can only be done <a
Misha Brukman43ee2932004-12-04 00:45:09 +0000282href="http://llvm.cs.uiuc.edu/PR162">with the largest union member</a>.</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000283
John Criswelld000e1d2003-12-18 16:43:17 +0000284</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000285</div>
286
287<!-- _______________________________________________________________________ -->
288<div class="doc_subsubsection">
289 Notes
290</div>
291
292<div class="doc_text">
293
294<ul>
295
296<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000297
298<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000299support for floating point data types of any size other than 32 and 64
300bits.</li>
301
302<li>The following Unix system functionality has not been tested and may not
303work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000304 <ol>
305 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
306 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
307 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
308 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
309 - These functions have not been tested.
310 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000311
312<li>Although many GCC extensions are supported, some are not. In particular,
313 the following extensions are known to <b>not be</b> supported:
314 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000315 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000316 <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>
317 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
318 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Extended%20Asm">Extended Asm</a>: Assembler instructions with C expressions as operands.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000319 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000320 <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>
321 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Explicit-Reg-Vars.html#Explicit%20Reg%20Vars">Explicit Reg Vars</a>: Defining variables residing in specified registers.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000322 <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>
323 <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>
Tanya Lattner014e5f52004-12-08 18:25:34 +0000324 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread_002dLocal.html">Thread-Local</a>: Per-thread variables.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000325 <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 +0000326 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000327
Misha Brukman500bc302003-11-22 00:38:41 +0000328 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000329 attribute means that the LLVM compiler ignores the presence of the attribute,
330 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000331 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000332 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000333
334 <ol>
335 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
336 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000337 Supported, but allocated stack space is not freed until the function returns (noted above).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000338
339 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html#Function%20Attributes">Function Attributes</a>:
Misha Brukman500bc302003-11-22 00:38:41 +0000340
John Criswelld000e1d2003-12-18 16:43:17 +0000341 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000342 return.<br>
343
344 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
John Criswell0b5b5e92004-12-08 20:35:47 +0000345 <tt>noreturn</tt>, <tt>constructor</tt>, <tt>destructor</tt>,
346 <tt>unused</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000347 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
348
John Criswell0b5b5e92004-12-08 20:35:47 +0000349 <b>Ignored:</b> <tt>noinline</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000350 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
351 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
352
353 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
354 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
355 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000356
357 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
358 Specifying attributes of variables.<br>
359 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
360 <tt>deprecated</tt>, <tt>transparent_union</tt>,
361 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000362
Chris Lattner79c3fe12003-10-02 04:57:28 +0000363 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
364 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
365 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000366 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000367
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000368 <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 +0000369 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000370 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000371
372 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
373 all target specific attributes.</li>
374
Chris Lattner79c3fe12003-10-02 04:57:28 +0000375 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
376 Other built-in functions.<br>
377 We support all builtins which have a C language equivalent (e.g.,
378 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
379 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Chris Lattnerceebeb62004-06-18 06:26:29 +0000380 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt>
381 (currently ignored). We also support builtins for ISO C99 floating
382 point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000383 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000384
Misha Brukman500bc302003-11-22 00:38:41 +0000385 <p>The following extensions <b>are</b> known to be supported:</p>
386
Chris Lattner79c3fe12003-10-02 04:57:28 +0000387 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000388 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html#Labels%20as%20Values">Labels as Values</a>: Getting pointers to labels and computed gotos.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000389 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
390 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Typeof.html#Typeof">Typeof</a>: <code>typeof</code>: referring to the type of an expression.</li>
Tanya Lattnerca26c3e2004-06-22 03:48:17 +0000391 <li><a href="http://gcc.gnu.org/onlinedocs/gcc-3.4.0/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000392 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
393 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
394 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
395 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
396 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
397 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
398 <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>
399 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
400 <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 +0000401 <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 +0000402 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000403 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
404or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000405 <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 +0000406 <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 +0000407 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
408 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
409 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
Tanya Lattner78537e42004-12-08 18:29:38 +0000410 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C_002b_002b-Comments.html#C_002b_002b-Comments">C++ Comments</a>: C++ comments are recognized.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000411 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
412 <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>
413 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
414 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
415 <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>
416 <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>
417 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Names.html#Function%20Names">Function Names</a>: Printable strings which are the name of the current function.</li>
Chris Lattner25795bc2004-02-14 04:08:29 +0000418 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Return-Address.html#Return%20Address">Return Address</a>: Getting the return or frame address of a function.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000419 <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>
420 <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 +0000421 </ol></li>
422
423</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000424
Misha Brukman500bc302003-11-22 00:38:41 +0000425<p>If you run into GCC extensions which have not been included in any of these
426lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000427
Misha Brukman500bc302003-11-22 00:38:41 +0000428</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000429
Misha Brukman500bc302003-11-22 00:38:41 +0000430<!-- ======================================================================= -->
431<div class="doc_subsection">
432 <a name="c++-fe">Known problems with the C++ front-end</a>
433</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000434
Misha Brukman500bc302003-11-22 00:38:41 +0000435<div class="doc_text">
436
Reid Spencere09ca642004-12-07 08:39:08 +0000437<p>For this release, the C++ front-end is considered to be fully
Chris Lattner7506b1d2004-12-07 08:04:13 +0000438tested and works for a number of non-trivial programs, including LLVM
439itself.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000440
441</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000442
443<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000444<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000445
Misha Brukman500bc302003-11-22 00:38:41 +0000446<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000447
Misha Brukman500bc302003-11-22 00:38:41 +0000448<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000449<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
John Criswelld000e1d2003-12-18 16:43:17 +0000450 front-end</a>.</li>
Chris Lattner7962f712004-07-17 02:04:41 +0000451
Chris Lattnerd5713882004-08-02 20:28:44 +0000452<li><b>IA-64 specific</b>: The C++ front-end does not use <a
453href="http://llvm.cs.uiuc.edu/PR406">IA64 ABI compliant layout of v-tables</a>.
Chris Lattner7962f712004-07-17 02:04:41 +0000454In particular, it just stores function pointers instead of function
455descriptors in the vtable. This bug prevents mixing C++ code compiled with
Chris Lattner04db8082004-08-02 20:29:51 +0000456LLVM with C++ objects compiled by other C++ compilers.</li>
Chris Lattner7962f712004-07-17 02:04:41 +0000457
Chris Lattnerd5713882004-08-02 20:28:44 +0000458</ul>
459
Misha Brukman500bc302003-11-22 00:38:41 +0000460</div>
461
462<!-- _______________________________________________________________________ -->
463<div class="doc_subsubsection">
464 Notes
465</div>
466
467<div class="doc_text">
468
469<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000470
Chris Lattner79c3fe12003-10-02 04:57:28 +0000471<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
472parser is significantly more standards compliant (and picky) than prior GCC
473versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000474href="http://gcc.gnu.org/gcc-3.4/changes.html">GCC 3.4 release notes</a>.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000475
476<li>Destructors for local objects are not always run when a <tt>longjmp</tt> is
Chris Lattner19092612003-10-02 16:38:05 +0000477 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000478 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000479 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000480 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000481
Chris Lattner19092612003-10-02 16:38:05 +0000482<li>The LLVM C++ front-end follows the <a
483 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
484 This document, which is not Itanium specific, specifies a standard for name
485 mangling, class layout, v-table layout, RTTI formats, and other C++
486 representation issues. Because we use this API, code generated by the LLVM
487 compilers should be binary compatible with machine code generated by other
488 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
489 <i>However</i>, the exception handling mechanism used by LLVM is very
490 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000491 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000492
Misha Brukman500bc302003-11-22 00:38:41 +0000493</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000494
Misha Brukman500bc302003-11-22 00:38:41 +0000495</div>
496
497<!-- ======================================================================= -->
498<div class="doc_subsection">
499 <a name="x86-be">Known problems with the X86 back-end</a>
500</div>
501
502<div class="doc_text">
503
504<ul>
Chris Lattnerd5713882004-08-02 20:28:44 +0000505 <li>none yet</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000506</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000507
Misha Brukman500bc302003-11-22 00:38:41 +0000508</div>
509
510<!-- ======================================================================= -->
511<div class="doc_subsection">
Misha Brukmanadb1c392004-07-12 16:55:41 +0000512 <a name="sparcv9-be">Known problems with the SparcV9 back-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000513</div>
514
515<div class="doc_text">
516
517<ul>
Misha Brukmanadb1c392004-07-12 16:55:41 +0000518<li><a href="http://llvm.cs.uiuc.edu/PR60">[sparcv9] SparcV9 backend miscompiles
519several programs in the LLVM test suite</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000520</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000521
Misha Brukman500bc302003-11-22 00:38:41 +0000522</div>
523
524<!-- ======================================================================= -->
525<div class="doc_subsection">
Chris Lattnerf32a5f52004-11-07 01:55:32 +0000526 <a name="ppc-be">Known problems with the PowerPC back-end</a>
527</div>
528
529<div class="doc_text">
530
531<ul>
532<li>none yet</li>
533</ul>
534
535</div>
536
537<!-- ======================================================================= -->
538<div class="doc_subsection">
Misha Brukman500bc302003-11-22 00:38:41 +0000539 <a name="c-be">Known problems with the C back-end</a>
540</div>
541
542<div class="doc_text">
543
544<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000545
546<li>The C back-end produces code that violates the ANSI C Type-Based Alias
547Analysis rules. As such, special options may be necessary to compile the code
548(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000549problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000550
Chris Lattner2855ecd2003-11-04 20:06:53 +0000551<li><a href="http://llvm.cs.uiuc.edu/PR56">Zero arg vararg functions are not
Chris Lattner2af46052003-10-24 04:03:19 +0000552supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000553frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000554
Misha Brukman500bc302003-11-22 00:38:41 +0000555</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000556
Misha Brukman500bc302003-11-22 00:38:41 +0000557</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000558
559<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000560<div class="doc_section">
561 <a name="additionalinfo">Additional Information</a>
562</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000563<!-- *********************************************************************** -->
564
Misha Brukman500bc302003-11-22 00:38:41 +0000565<div class="doc_text">
566
567<p>A wide variety of additional information is available on the LLVM web page,
John Criswelld000e1d2003-12-18 16:43:17 +0000568including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 04:57:28 +0000569implemented in LLVM. The web page also contains versions of the API
570documentation which is up-to-date with the CVS version of the source code. You
571can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000572the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000573
Misha Brukman500bc302003-11-22 00:38:41 +0000574<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattner5eccca42003-12-12 21:22:16 +0000575us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
576lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000577
Misha Brukman500bc302003-11-22 00:38:41 +0000578</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000579
580<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000581
Misha Brukman500bc302003-11-22 00:38:41 +0000582<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000583<address>
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588
Misha Brukmane0c891c2003-11-22 01:00:11 +0000589 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000590 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000591</address>
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594</html>