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Chris Lattnerf3a7c242004-12-09 22:22:58 +00007 <title>LLVM 1.5 Release Notes</title>
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9<body>
Chris Lattner3d482502003-10-02 04:57:28 +000010
Chris Lattnerf3a7c242004-12-09 22:22:58 +000011<div class="doc_title">LLVM 1.5 Release Notes</div>
Chris Lattner3d482502003-10-02 04:57:28 +000012
13<ol>
Misha Brukman80731b92003-11-22 00:38:41 +000014 <li><a href="#intro">Introduction</a></li>
15 <li><a href="#whatsnew">What's New?</a></li>
Chris Lattner77a51732004-04-30 22:17:12 +000016 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +000017 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +000018 <li><a href="#knownproblems">Known Problems</a>
Misha Brukman80731b92003-11-22 00:38:41 +000019 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +000020</ol>
21
Chris Lattner020e1fc2004-05-23 21:07:27 +000022<div class="doc_author">
Chris Lattnerf3a7c242004-12-09 22:22:58 +000023 <p>Written by the <a href="http://llvm.cs.uiuc.edu">LLVM Team</a><p>
Misha Brukman80731b92003-11-22 00:38:41 +000024</div>
Chris Lattner3d482502003-10-02 04:57:28 +000025
26<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +000027<div class="doc_section">
28 <a name="intro">Introduction</a>
29</div>
Chris Lattner3d482502003-10-02 04:57:28 +000030<!-- *********************************************************************** -->
31
Misha Brukman80731b92003-11-22 00:38:41 +000032<div class="doc_text">
33
34<p>This document contains the release notes for the LLVM compiler
Chris Lattnerf3a7c242004-12-09 22:22:58 +000035infrastructure, release 1.5. Here we describe the status of LLVM, including any
Chris Lattnerb5bb5972004-12-07 08:04:13 +000036known problems and improvements from the previous release. The most up-to-date
Misha Brukman80731b92003-11-22 00:38:41 +000037version of this document can be found on the <a
Chris Lattnerf3a7c242004-12-09 22:22:58 +000038href="http://llvm.cs.uiuc.edu/releases/1.5/">LLVM 1.5 web site</a>. If you are
John Criswell86a3a482003-12-18 16:43:17 +000039not reading this on the LLVM web pages, you should probably go there because
Misha Brukman80731b92003-11-22 00:38:41 +000040this document may be updated after the release.</p>
Chris Lattner62495762003-10-02 16:38:05 +000041
Chris Lattnerb5bb5972004-12-07 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 Lattnere7525b52003-10-07 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 Brukman80731b92003-11-22 00:38:41 +000046list</a> is a good place to send them.</p>
Chris Lattner3d482502003-10-02 04:57:28 +000047
Chris Lattnerf3a7c242004-12-09 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 Brukman80731b92003-11-22 00:38:41 +000051href="http://llvm.cs.uiuc.edu/releases/">releases page</a>.</p>
52
53</div>
Chris Lattner3d482502003-10-02 04:57:28 +000054
55<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +000056<div class="doc_section">
57 <a name="whatsnew">What's New?</a>
58</div>
Chris Lattner3d482502003-10-02 04:57:28 +000059<!-- *********************************************************************** -->
60
Misha Brukman80731b92003-11-22 00:38:41 +000061<div class="doc_text">
62
Chris Lattnerf3a7c242004-12-09 22:22:58 +000063<p>This is the sixth public release of the LLVM compiler infrastructure.</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +000064
Chris Lattner7c0241c2004-12-10 16:27:34 +000065<p> At this time, LLVM is known to correctly compile a broad range of C and
Chris Lattnerf3a7c242004-12-09 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 Lattnerba7bd472003-12-06 20:22:41 +000068
Chris Lattner21a90402004-05-24 04:50:25 +000069</div>
70
Chris Lattnerba7bd472003-12-06 20:22:41 +000071<!--=========================================================================-->
72<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +000073<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +000074</div>
Chris Lattnere7525b52003-10-07 21:38:31 +000075
Chris Lattner21a90402004-05-24 04:50:25 +000076<div class="doc_text">
Chris Lattnere7525b52003-10-07 21:38:31 +000077<ol>
Chris Lattner7bf2e542004-12-11 06:10:52 +000078 <li>LLVM now includes an <a href="http://llvm.cs.uiuc.edu/PR415">
Chris Lattner64d9d2b2005-01-22 18:45:35 +000079 Interprocedural Sparse Conditional Constant Propagation</a> pass, named
Chris Lattner7bf2e542004-12-11 06:10:52 +000080 -ipsccp, which is run by default at link-time.</li>
Chris Lattnerf87e05b2005-02-01 01:33:52 +000081 <li>LLVM 1.5 is now about 15% faster than LLVM 1.4 and its core data structures
Chris Lattnere14babd2005-02-13 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 Lattnerbe895ed2005-02-14 22:58:38 +000086 href="GettingStartedVS.html">now documented</a>.</li>
Chris Lattner592db402003-11-19 22:05:38 +000087</ol>
Chris Lattner4491de62003-11-08 04:28:55 +000088
Chris Lattner21a90402004-05-24 04:50:25 +000089</div>
90
Chris Lattnerba7bd472003-12-06 20:22:41 +000091
92<!--=========================================================================-->
93<div class="doc_subsubsection">
94In this release, the following missing features were implemented:
95</div>
Chris Lattner4491de62003-11-08 04:28:55 +000096
Chris Lattner21a90402004-05-24 04:50:25 +000097<div class="doc_text">
98
Chris Lattner4491de62003-11-08 04:28:55 +000099<ol>
Chris Lattnerf3a7c242004-12-09 22:22:58 +0000100 <li></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000101</ol>
Chris Lattnere7525b52003-10-07 21:38:31 +0000102
Chris Lattner21a90402004-05-24 04:50:25 +0000103</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000104
105<!--=========================================================================-->
106<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000107<a name="qualityofimp">In this release, the following Quality of Implementation
108issues were fixed:</a>
Chris Lattner4df78f02003-12-20 03:42:11 +0000109</div>
110
Chris Lattner21a90402004-05-24 04:50:25 +0000111<div class="doc_text">
112
Chris Lattner4df78f02003-12-20 03:42:11 +0000113<ol>
Chris Lattner64d9d2b2005-01-22 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 Gaeke8b05e4f2004-01-16 21:55:04 +0000116</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000117</div>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000118
119<!--=========================================================================-->
120<div class="doc_subsubsection">
Chris Lattner2ad48782004-05-02 04:19:15 +0000121<a name="codequality">This release includes the following Code Quality
122improvements:</a>
Chris Lattner23257062004-05-23 20:42:08 +0000123</div>
Chris Lattner639579c2003-10-27 17:06:39 +0000124
Chris Lattner21a90402004-05-24 04:50:25 +0000125<div class="doc_text">
Chris Lattner639579c2003-10-27 17:06:39 +0000126<ol>
Chris Lattnerf3a7c242004-12-09 22:22:58 +0000127 <li></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000128</ol>
Reid Spencer3e58f582004-05-23 17:23:13 +0000129</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000130
131<!--=========================================================================-->
132<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000133<a name="bugfix">In this release, the following bugs in the previous release
134were fixed:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000135</div>
136
Chris Lattner21a90402004-05-24 04:50:25 +0000137<div class="doc_text">
138
Chris Lattnere7525b52003-10-07 21:38:31 +0000139
Chris Lattner1c75b252005-02-14 16:57:55 +0000140<p>Bugs fixed in the LLVM Core:</p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000141<ol>
Chris Lattnerb5c253a2004-12-29 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 Lattnerba7bd472003-12-06 20:22:41 +0000144</ol>
145
Chris Lattner1c75b252005-02-14 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 Lattnerba7bd472003-12-06 20:22:41 +0000153
Chris Lattner1c75b252005-02-14 16:57:55 +0000154<p>Bugs in the C/C++ front-end:</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000155<ol>
Chris Lattnere1329f42005-01-03 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 Lattner2a38aea2005-02-11 19:29:52 +0000159 <li><a href="http://llvm.cs.uiuc.edu/PR501">[llvm-g++] Crash compiling
160 anonymous union</a></li>
Chris Lattner1c75b252005-02-14 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 Lattner1f031b22005-02-15 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 Lattner385a4732005-02-15 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 Lattner48c23142005-02-19 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>
Chris Lattner6a3ae642005-02-19 17:13:20 +0000169 <li><a href="http://llvm.cs.uiuc.edu/PR520">[llvm-g++] Error compiling
170 virtrual function thunk with an unnamed argument</a></li>
Brian Gaeke730d8d62004-08-24 07:43:48 +0000171</ol>
172
Chris Lattner21a90402004-05-24 04:50:25 +0000173</div>
Reid Spencer3e58f582004-05-23 17:23:13 +0000174
Chris Lattner62495762003-10-02 16:38:05 +0000175<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000176<div class="doc_section">
177 <a name="portability">Portability and Supported Platforms</a>
178</div>
Chris Lattner62495762003-10-02 16:38:05 +0000179<!-- *********************************************************************** -->
180
Misha Brukman80731b92003-11-22 00:38:41 +0000181<div class="doc_text">
182
John Criswell64307722004-12-08 20:35:47 +0000183<p>LLVM is known to work on the following platforms:</p>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000184
185<ul>
186<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
187 other unix-like systems).</li>
188<li>Sun UltraSPARC workstations running Solaris 8.</li>
Chris Lattnerb5bb5972004-12-07 08:04:13 +0000189<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
190 support is available for native builds with Visual C++).</li>
191<li>PowerPC-based Mac OS X systems, running 10.2 and above.</li>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000192</ul>
193
Brian Gaekee3e557e2004-05-09 05:28:35 +0000194<p>The core LLVM infrastructure uses
195<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
196to the machine and operating system on which it is built. However, minor
197porting may be required to get LLVM to work on new platforms. We welcome your
198portability patches and reports of successful builds or error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000199
Misha Brukman80731b92003-11-22 00:38:41 +0000200</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000201
202<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000203<div class="doc_section">
204 <a name="knownproblems">Known Problems</a>
205</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000206<!-- *********************************************************************** -->
207
Misha Brukman80731b92003-11-22 00:38:41 +0000208<div class="doc_text">
209
210<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000211component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000212sections. If you run into a problem, please check the <a
John Criswell86a3a482003-12-18 16:43:17 +0000213href="http://llvm.cs.uiuc.edu/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattnerb84f3322003-12-12 21:22:16 +0000214there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000215
Misha Brukman80731b92003-11-22 00:38:41 +0000216</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000217
Chris Lattnerb911de42004-03-14 02:03:02 +0000218<!-- ======================================================================= -->
219<div class="doc_subsection">
220 <a name="experimental">Experimental features included with this release</a>
221</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000222
Chris Lattnerb911de42004-03-14 02:03:02 +0000223<div class="doc_text">
224
Misha Brukmanfa50a222004-05-12 21:46:05 +0000225<p>The following components of this LLVM release are either untested, known to
226be broken or unreliable, or are in early development. These components should
227not be relied on, and bugs should not be filed against them, but they may be
228useful to some people. In particular, if you would like to work on one of these
229components, please contact us on the llvmdev list.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000230
231<ul>
Chris Lattnerb5bb5972004-12-07 08:04:13 +0000232<li>The following passes are incomplete or buggy, and may be removed in future
Chris Lattner38389b12005-01-28 06:13:52 +0000233 releases: <tt>-cee, -branch-combine, -instloops, -paths, -pre</tt></li>
Chris Lattnerb5bb5972004-12-07 08:04:13 +0000234<li>The <tt>llvm-db</tt> tool is in a very early stage of development, but can
235 be used to step through programs and inspect the stack.</li>
Chris Lattnerfa835102004-12-02 17:20:17 +0000236<li>The "iterative scan" register allocator (enabled with -regalloc=iterativescan)
237 is not stable.</li>
Chris Lattnere14babd2005-02-13 22:27:24 +0000238<li>The SparcV8 and Alpha ports are experimental.</li>
Chris Lattnerb911de42004-03-14 02:03:02 +0000239</ul>
240
241</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000242
Misha Brukman80731b92003-11-22 00:38:41 +0000243<!-- ======================================================================= -->
244<div class="doc_subsection">
245 <a name="core">Known problems with the LLVM Core</a>
246</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000247
Misha Brukman80731b92003-11-22 00:38:41 +0000248<div class="doc_text">
249
250<ul>
Reid Spencer493d9c22004-11-25 22:38:30 +0000251 <li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not work.
252 </li>
253 <li>The JIT does not use mutexes to protect its internal data structures. As
254 such, execution of a threaded program could cause these data structures to be
255 corrupted.
256 </li>
Reid Spencer493d9c22004-11-25 22:38:30 +0000257 <li><a href="http://llvm.cs.uiuc.edu/PR240">The lower-invoke pass does not
258 mark values live across a setjmp as volatile</a>. This missing feature
259 only affects targets whose setjmp/longjmp libraries do not save and restore
260 the entire register file.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000261</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000262</div>
263
264<!-- ======================================================================= -->
265<div class="doc_subsection">
266 <a name="c-fe">Known problems with the C front-end</a>
267</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000268
Chris Lattner3d482502003-10-02 04:57:28 +0000269<!-- _______________________________________________________________________ -->
Chris Lattner5a8a7282003-12-14 05:03:43 +0000270<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000271
Misha Brukman80731b92003-11-22 00:38:41 +0000272<div class="doc_text">
Misha Brukman80731b92003-11-22 00:38:41 +0000273<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000274<li>C99 Variable sized arrays do not release stack memory when they go out of
275 scope. Thus, the following program may run out of stack space:
276<pre>
277 for (i = 0; i != 1000000; ++i) {
278 int X[n];
279 foo(X);
280 }
Misha Brukman80731b92003-11-22 00:38:41 +0000281</pre></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000282
Misha Brukmanfa50a222004-05-12 21:46:05 +0000283<li>Initialization of global union variables can only be done <a
Misha Brukman68ef9a92004-12-04 00:45:09 +0000284href="http://llvm.cs.uiuc.edu/PR162">with the largest union member</a>.</li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000285
John Criswell86a3a482003-12-18 16:43:17 +0000286</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000287</div>
288
289<!-- _______________________________________________________________________ -->
290<div class="doc_subsubsection">
291 Notes
292</div>
293
294<div class="doc_text">
295
296<ul>
297
298<li>Inline assembly is not yet supported.</li>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000299
300<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman80731b92003-11-22 00:38:41 +0000301support for floating point data types of any size other than 32 and 64
302bits.</li>
303
304<li>The following Unix system functionality has not been tested and may not
305work:
Misha Brukman7cb4e382003-11-22 01:00:11 +0000306 <ol>
307 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
308 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
309 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
310 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
311 - These functions have not been tested.
312 </ol></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000313
314<li>Although many GCC extensions are supported, some are not. In particular,
315 the following extensions are known to <b>not be</b> supported:
316 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000317 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000318 <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>
319 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
320 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Extended%20Asm">Extended Asm</a>: Assembler instructions with C expressions as operands.</li>
John Criswell86a3a482003-12-18 16:43:17 +0000321 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000322 <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>
323 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Explicit-Reg-Vars.html#Explicit%20Reg%20Vars">Explicit Reg Vars</a>: Defining variables residing in specified registers.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000324 <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>
325 <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 Lattner63371342004-12-08 18:25:34 +0000326 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread_002dLocal.html">Thread-Local</a>: Per-thread variables.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000327 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pragmas.html#Pragmas">Pragmas</a>: Pragmas accepted by GCC.</li>
Misha Brukman7cb4e382003-11-22 01:00:11 +0000328 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000329
Misha Brukman80731b92003-11-22 00:38:41 +0000330 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner3d482502003-10-02 04:57:28 +0000331 attribute means that the LLVM compiler ignores the presence of the attribute,
332 but the code should still work. An unsupported attribute is one which is
John Criswell86a3a482003-12-18 16:43:17 +0000333 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman80731b92003-11-22 00:38:41 +0000334 the program.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000335
336 <ol>
337 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
338 Arrays whose length is computed at run time.<br>
Misha Brukman80731b92003-11-22 00:38:41 +0000339 Supported, but allocated stack space is not freed until the function returns (noted above).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000340
341 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html#Function%20Attributes">Function Attributes</a>:
Misha Brukman80731b92003-11-22 00:38:41 +0000342
John Criswell86a3a482003-12-18 16:43:17 +0000343 Declaring that functions have no side effects or that they can never
Misha Brukman80731b92003-11-22 00:38:41 +0000344 return.<br>
345
346 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
John Criswell64307722004-12-08 20:35:47 +0000347 <tt>noreturn</tt>, <tt>constructor</tt>, <tt>destructor</tt>,
348 <tt>unused</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000349 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
350
John Criswell64307722004-12-08 20:35:47 +0000351 <b>Ignored:</b> <tt>noinline</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000352 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
353 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
354
355 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
356 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
357 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000358
359 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
360 Specifying attributes of variables.<br>
361 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
362 <tt>deprecated</tt>, <tt>transparent_union</tt>,
363 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000364
Chris Lattner3d482502003-10-02 04:57:28 +0000365 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
366 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
367 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000368 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000369
Misha Brukman8395d732003-12-12 04:37:31 +0000370 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html#Type%20Attributes">Type Attributes</a>: Specifying attributes of types.<br>
Chris Lattner3d482502003-10-02 04:57:28 +0000371 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukman8395d732003-12-12 04:37:31 +0000372 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000373
374 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
375 all target specific attributes.</li>
376
Chris Lattner3d482502003-10-02 04:57:28 +0000377 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
378 Other built-in functions.<br>
379 We support all builtins which have a C language equivalent (e.g.,
380 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
381 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Chris Lattnerb7c4bac2004-06-18 06:26:29 +0000382 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt>
383 (currently ignored). We also support builtins for ISO C99 floating
384 point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000385 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000386
Misha Brukman80731b92003-11-22 00:38:41 +0000387 <p>The following extensions <b>are</b> known to be supported:</p>
388
Chris Lattner3d482502003-10-02 04:57:28 +0000389 <ol>
Chris Lattnerd3dc8502004-03-16 08:54:07 +0000390 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html#Labels%20as%20Values">Labels as Values</a>: Getting pointers to labels and computed gotos.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000391 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
392 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Typeof.html#Typeof">Typeof</a>: <code>typeof</code>: referring to the type of an expression.</li>
Tanya Lattnerce33a1b2004-06-22 03:48:17 +0000393 <li><a href="http://gcc.gnu.org/onlinedocs/gcc-3.4.0/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000394 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
395 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
396 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
397 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
398 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
399 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
400 <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>
401 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
402 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Subscripting.html#Subscripting">Subscripting</a>: Any array can be subscripted, even if not an lvalue.</li>
Misha Brukman8395d732003-12-12 04:37:31 +0000403 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pointer-Arith.html#Pointer%20Arith">Pointer Arith</a>: Arithmetic on <code>void</code>-pointers and function pointers.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000404 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
John Criswell86a3a482003-12-18 16:43:17 +0000405 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
406or arrays as values.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000407 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html#Designated%20Inits">Designated Inits</a>: Labeling elements of initializers.</li>
Misha Brukman8395d732003-12-12 04:37:31 +0000408 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Cast-to-Union.html#Cast%20to%20Union">Cast to Union</a>: Casting to union type from any member of the union.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000409 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
410 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
411 <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 Lattner7591b822004-12-08 18:29:38 +0000412 <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 Brukman80731b92003-11-22 00:38:41 +0000413 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
414 <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>
415 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
416 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
417 <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>
418 <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>
419 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Names.html#Function%20Names">Function Names</a>: Printable strings which are the name of the current function.</li>
Chris Lattner3646dad2004-02-14 04:08:29 +0000420 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Return-Address.html#Return%20Address">Return Address</a>: Getting the return or frame address of a function.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000421 <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>
422 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html#Attribute%20Syntax">Attribute Syntax</a>: Formal syntax for attributes.</li>
Misha Brukman7cb4e382003-11-22 01:00:11 +0000423 </ol></li>
424
425</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000426
Misha Brukman80731b92003-11-22 00:38:41 +0000427<p>If you run into GCC extensions which have not been included in any of these
428lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000429
Misha Brukman80731b92003-11-22 00:38:41 +0000430</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000431
Misha Brukman80731b92003-11-22 00:38:41 +0000432<!-- ======================================================================= -->
433<div class="doc_subsection">
434 <a name="c++-fe">Known problems with the C++ front-end</a>
435</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000436
Misha Brukman80731b92003-11-22 00:38:41 +0000437<div class="doc_text">
438
Reid Spencer55684c32004-12-07 08:39:08 +0000439<p>For this release, the C++ front-end is considered to be fully
Chris Lattnerb5bb5972004-12-07 08:04:13 +0000440tested and works for a number of non-trivial programs, including LLVM
441itself.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000442
443</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000444
445<!-- _______________________________________________________________________ -->
Chris Lattner141ebb62004-02-14 04:12:41 +0000446<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000447
Misha Brukman80731b92003-11-22 00:38:41 +0000448<div class="doc_text">
Chris Lattner3d482502003-10-02 04:57:28 +0000449
Misha Brukman80731b92003-11-22 00:38:41 +0000450<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000451<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
John Criswell86a3a482003-12-18 16:43:17 +0000452 front-end</a>.</li>
Chris Lattner041e6c92004-07-17 02:04:41 +0000453
Chris Lattner5cd40922004-08-02 20:28:44 +0000454<li><b>IA-64 specific</b>: The C++ front-end does not use <a
455href="http://llvm.cs.uiuc.edu/PR406">IA64 ABI compliant layout of v-tables</a>.
Chris Lattner041e6c92004-07-17 02:04:41 +0000456In particular, it just stores function pointers instead of function
457descriptors in the vtable. This bug prevents mixing C++ code compiled with
Chris Lattner2fd93492004-08-02 20:29:51 +0000458LLVM with C++ objects compiled by other C++ compilers.</li>
Chris Lattner041e6c92004-07-17 02:04:41 +0000459
Chris Lattner5cd40922004-08-02 20:28:44 +0000460</ul>
461
Misha Brukman80731b92003-11-22 00:38:41 +0000462</div>
463
464<!-- _______________________________________________________________________ -->
465<div class="doc_subsubsection">
466 Notes
467</div>
468
469<div class="doc_text">
470
471<ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000472
Chris Lattner3d482502003-10-02 04:57:28 +0000473<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
474parser is significantly more standards compliant (and picky) than prior GCC
475versions. For more information, see the C++ section of the <a
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000476href="http://gcc.gnu.org/gcc-3.4/changes.html">GCC 3.4 release notes</a>.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000477
478<li>Destructors for local objects are not always run when a <tt>longjmp</tt> is
Chris Lattner62495762003-10-02 16:38:05 +0000479 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000480 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswell86a3a482003-12-18 16:43:17 +0000481 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman80731b92003-11-22 00:38:41 +0000482 better than most compilers).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000483
Chris Lattner62495762003-10-02 16:38:05 +0000484<li>The LLVM C++ front-end follows the <a
485 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
486 This document, which is not Itanium specific, specifies a standard for name
487 mangling, class layout, v-table layout, RTTI formats, and other C++
488 representation issues. Because we use this API, code generated by the LLVM
489 compilers should be binary compatible with machine code generated by other
490 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
491 <i>However</i>, the exception handling mechanism used by LLVM is very
492 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman80731b92003-11-22 00:38:41 +0000493 interact correctly</b>. </li>
Chris Lattner3d482502003-10-02 04:57:28 +0000494
Misha Brukman80731b92003-11-22 00:38:41 +0000495</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000496
Misha Brukman80731b92003-11-22 00:38:41 +0000497</div>
498
499<!-- ======================================================================= -->
500<div class="doc_subsection">
501 <a name="x86-be">Known problems with the X86 back-end</a>
502</div>
503
504<div class="doc_text">
505
506<ul>
Chris Lattner5cd40922004-08-02 20:28:44 +0000507 <li>none yet</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000508</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000509
Misha Brukman80731b92003-11-22 00:38:41 +0000510</div>
511
512<!-- ======================================================================= -->
513<div class="doc_subsection">
Misha Brukmana516e992004-07-12 16:55:41 +0000514 <a name="sparcv9-be">Known problems with the SparcV9 back-end</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000515</div>
516
517<div class="doc_text">
518
519<ul>
Misha Brukmana516e992004-07-12 16:55:41 +0000520<li><a href="http://llvm.cs.uiuc.edu/PR60">[sparcv9] SparcV9 backend miscompiles
521several programs in the LLVM test suite</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000522</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000523
Misha Brukman80731b92003-11-22 00:38:41 +0000524</div>
525
526<!-- ======================================================================= -->
527<div class="doc_subsection">
Chris Lattnerdf925ce2004-11-07 01:55:32 +0000528 <a name="ppc-be">Known problems with the PowerPC back-end</a>
529</div>
530
531<div class="doc_text">
532
533<ul>
534<li>none yet</li>
535</ul>
536
537</div>
538
539<!-- ======================================================================= -->
540<div class="doc_subsection">
Misha Brukman80731b92003-11-22 00:38:41 +0000541 <a name="c-be">Known problems with the C back-end</a>
542</div>
543
544<div class="doc_text">
545
546<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000547
548<li>The C back-end produces code that violates the ANSI C Type-Based Alias
549Analysis rules. As such, special options may be necessary to compile the code
550(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman80731b92003-11-22 00:38:41 +0000551problem probably cannot be fixed.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000552
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000553<li><a href="http://llvm.cs.uiuc.edu/PR56">Zero arg vararg functions are not
Chris Lattnerb28c3282003-10-24 04:03:19 +0000554supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman80731b92003-11-22 00:38:41 +0000555frontends.</li>
Chris Lattnerb28c3282003-10-24 04:03:19 +0000556
Misha Brukman80731b92003-11-22 00:38:41 +0000557</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000558
Misha Brukman80731b92003-11-22 00:38:41 +0000559</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000560
561<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000562<div class="doc_section">
563 <a name="additionalinfo">Additional Information</a>
564</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000565<!-- *********************************************************************** -->
566
Misha Brukman80731b92003-11-22 00:38:41 +0000567<div class="doc_text">
568
569<p>A wide variety of additional information is available on the LLVM web page,
John Criswell86a3a482003-12-18 16:43:17 +0000570including mailing lists and publications describing algorithms and components
Chris Lattner3d482502003-10-02 04:57:28 +0000571implemented in LLVM. The web page also contains versions of the API
572documentation which is up-to-date with the CVS version of the source code. You
573can access versions of these documents specific to this release by going into
Misha Brukman80731b92003-11-22 00:38:41 +0000574the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000575
Misha Brukman80731b92003-11-22 00:38:41 +0000576<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerb84f3322003-12-12 21:22:16 +0000577us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
578lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000579
Misha Brukman80731b92003-11-22 00:38:41 +0000580</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000581
582<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000583
Misha Brukman80731b92003-11-22 00:38:41 +0000584<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000585<address>
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Misha Brukman68aab3b2003-11-22 01:23:39 +0000587 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
588 <a href="http://validator.w3.org/check/referer"><img
589 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
590
Misha Brukman7cb4e382003-11-22 01:00:11 +0000591 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000592 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000593</address>
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596</html>