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gerrit-public.fairphone.software / toolchain / llvm-project / 9958350f42a3c49ffecb8584e29c59b3597b1ff9 / . / llvm / docs / ReleaseNotes.html
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Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
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Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]6 <title>LLVM 1.3 Release Notes</title>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]7</head>
8<body>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]9
Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]10<div class="doc_title">LLVM 1.3 Release Notes</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]11
12<ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]13 <li><a href="#intro">Introduction</a></li>
14 <li><a href="#whatsnew">What's New?</a></li>
Chris Lattner77a51732004-04-30 22:17:12 +0000[diff] [blame]15 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]16 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]17 <li><a href="#knownproblems">Known Problems</a>
18 <ul>
Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]19 <li><a href="#experimental">Experimental features included in this
20 release</a>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]21 <li><a href="#core">Known problems with the LLVM Core</a>
22 <li><a href="#c-fe">Known problems with the C Front-end</a>
23 <li><a href="#c++-fe">Known problems with the C++ Front-end</a>
24 <li><a href="#x86-be">Known problems with the X86 Back-end</a>
25 <li><a href="#sparc-be">Known problems with the Sparc Back-end</a>
26 <li><a href="#c-be">Known problems with the C back-end</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]27 </ul></li>
28 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]29</ol>
30
Chris Lattner020e1fc2004-05-23 21:07:27 +0000[diff] [blame]31<div class="doc_author">
32 <p>Written by the <a href="http://llvm.cs.uiuc.edu">LLVM team</a><p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]33</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]34
35<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]36<div class="doc_section">
37 <a name="intro">Introduction</a>
38</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]39<!-- *********************************************************************** -->
40
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]41<div class="doc_text">
42
43<p>This document contains the release notes for the LLVM compiler
Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]44infrastructure, release 1.3. Here we describe the status of LLVM, including any
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]45known problems and bug fixes from the previous release. The most up-to-date
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]46version of this document can be found on the <a
Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]47href="http://llvm.cs.uiuc.edu/releases/1.3/">LLVM 1.3 web site</a>. If you are
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]48not reading this on the LLVM web pages, you should probably go there because
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]49this document may be updated after the release.</p>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]50
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]51<p>For more information about LLVM, including information about potentially more
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]52current releases, please check out the <a href="http://llvm.cs.uiuc.edu">main
53web site</a>. If you have questions or comments, the <a
54href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]55list</a> is a good place to send them.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]56
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]57<p>Note that if you are reading this file from CVS, this document applies
58to the <i>next</i> release, not the current one. To see the release notes for
59the current or previous releases, see the <a
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]60href="http://llvm.cs.uiuc.edu/releases/">releases page</a>.</p>
61
62</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]63
64<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]65<div class="doc_section">
66 <a name="whatsnew">What's New?</a>
67</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]68<!-- *********************************************************************** -->
69
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]70<div class="doc_text">
71
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]72<p>This is the fourth public release of the LLVM compiler infrastructure. This
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]73release primarily improves the <a href="#codequality">performance of the
Chris Lattnerb7c4bac2004-06-18 06:26:29 +0000[diff] [blame]74code</a> produced by all aspects of the LLVM compiler and adds many <a
75href="#newfeatures">new features</a>, and <a href="#bugfix">fixes a few
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]76bugs</a> as well.</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]77
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]78<p> At this time, LLVM is known to correctly compile and run all C &amp; C++
79SPEC CPU2000 benchmarks, the Olden benchmarks, and the Ptrdist benchmarks. It
80has also been used to compile <b>many</b> other programs. LLVM now also works
81with a broad variety of C++ programs, though it has still received less testing
82than the C front-end.</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]83
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]84</div>
85
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]86<!--=========================================================================-->
87<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]88<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]89</div>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]90
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]91<div class="doc_text">
92
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]93<ol>
Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]94<li>The LLVM <a href="LangRef.html#i_select"><tt>select</tt></a> instruction is
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]95now fully implemented and supported by all transformations, native code
96generators, and the interpreter.</li>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]97<li>Bugpoint can now narrow down code-generation bugs to a loop nest, where
98before it could only narrow them down to a function being miscompiled.</li>
Brian Gaekee307f8a72004-05-04 21:22:57 +0000[diff] [blame]99<li><a href="http://llvm.cs.uiuc.edu/PR40">Bugpoint can now debug arbitrary
100modes of llc</a> and lli, by passing them command line flags (e.g.,
101<tt>-regalloc=linearscan</tt>, <tt>-enable-correct-eh-support</tt>, etc.) </li>
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]102<li>The Control Flow Graph in the native code generators is no longer
103constrained to be the same as the CFG for the LLVM input code.</li>
104<li>The LLVM induction variable analysis routines have been rewritten.</li>
105<li>LLVM now has new loop unrolling and loop unswitching passes.</li>
106<li>The induction variable substitution pass performs linear function test
107replacement and exit value replacement optimizations.</li>
Chris Lattnereda4f472004-05-24 04:45:52 +0000[diff] [blame]108<li>LLVM now has first-class support for <a href="GarbageCollection.html">Accurate
109Garbage Collection</a>, enabling the use of aggressive copying and generational
110collectors.</li>
111<li>LLVM now includes an implementation of Andersen's interprocedural alias
112analysis algorithm.</li>
Chris Lattner57e7a4c2004-05-24 05:34:32 +0000[diff] [blame]113<li>Bugpoint can <a href="http://llvm.cs.uiuc.edu/PR327">extract individual
114basic blocks</a> to track down reduce miscompilation testcases.</li>
Brian Gaeke84c8bd02004-06-01 20:02:56 +0000[diff] [blame]115<li>LLVM and the C front-end now work under Win32 using the
116<a href="http://www.cygwin.com">Cygwin</a> runtime libraries.
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]117This includes the JIT compiler.</li>
Chris Lattnera7fac952004-06-04 00:40:11 +0000[diff] [blame]118<li>The LLVM code generator is now being <a
119 href="CodeGenerator.html">documented</a>.</li>
Reid Spencer850f85f2004-06-08 07:30:31 +0000[diff] [blame]120<li>There is a new tool, llvm-abcd, the Analysis of ByteCode Dumper (abcd).
121This tool can compute basic statistics and bytecode density statistics on a
122module or function basis and also dump out bytecode in a textual format that
123is lower level than assembly (values are not resolved from slot numbers).
124It should only be of interest to (a) those who are working to improve the
125bytecode format and (b) those who really want to understand or document the
126details of the bytecode format.</li>
127<li>The <a href="BytecodeFormat.html">LLVM Bytecode file format</a> is now
128 being documented.</li>
Chris Lattnerf64f7942004-06-15 21:50:46 +0000[diff] [blame]129<li>LLVM now provides an <a href="LangRef.html#i_isunordered">llvm.isunordered</a> intrinsic
Chris Lattner4e71aa82004-06-11 04:35:21 +0000[diff] [blame]130for efficient implementation of unordered floating point comparisons.</li>
Chris Lattnerb7c4bac2004-06-18 06:26:29 +0000[diff] [blame]131<li>The llvmgcc front-end now supports the GCC builtins for ISO C99 floating
132point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Reid Spencer3a4916e2004-06-23 06:33:15 +0000[diff] [blame]133<li>Now that there are more source files than can fit on a 32Kbyte command
134line (Linux's limit), there's a new utility for searching the sources. The
135llvmgrep tool in the utils directory combines an egrep and a find without
136passing filenames through the command line. This improves performance
137slightly. Simply run llvmgrep like you might egrep but leave off the file
138names.</li>
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]139</ol>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]140
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]141</div>
142
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]143
144<!--=========================================================================-->
145<div class="doc_subsubsection">
146In this release, the following missing features were implemented:
147</div>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]148
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]149<div class="doc_text">
150
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]151<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]152<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
153more than 256 elements</a></li>
Misha Brukmane7050232004-04-19 03:01:01 +0000[diff] [blame]154<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
155non-instruction entities, such as global constant initializer</a></li>
Reid Spencer45e25d82004-05-09 23:32:39 +0000[diff] [blame]156<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
157with 64-bit pointers.</a></li>
Misha Brukmane7050232004-04-19 03:01:01 +0000[diff] [blame]158<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
159uses of external fns by immediate constant exprs</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]160</ol>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]161
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]162</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]163
164<!--=========================================================================-->
165<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]166<a name="qualityofimp">In this release, the following Quality of Implementation
167issues were fixed:</a>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]168</div>
169
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]170<div class="doc_text">
171
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]172<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]173<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
174bytecode onto your terminal</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]175<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
176for structure typedefs</a></li>
Chris Lattnerf10ccbf2004-05-24 04:53:32 +0000[diff] [blame]177<li>All documentation is now conformant to the HTML 4.01 (Strict) level.</li>
Chris Lattnerbd948cf2004-06-08 07:19:29 +0000[diff] [blame]178<li>The spurious "WARNING: Found global types that are not compatible" warning
179produced when linking C++ programs has been fixed.</li>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]180</ol>
181
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]182</div>
183
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]184<!--=========================================================================-->
185<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]186In this release, the following build problems were fixed:
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]187</div>
188
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]189<div class="doc_text">
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]190<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]191<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
192-disable/enable-povray and -disable-spec</a></li>
193<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
194work if you change PATH</a></li>
Chris Lattner47696122004-06-09 01:09:16 +0000[diff] [blame]195<li><a href="http://llvm.cs.uiuc.edu/PR364">[llvmgcc] llvmgcc does not compile
196with gcc 3.4</a></li>
Chris Lattner3daf9842004-06-18 17:57:29 +0000[diff] [blame]197<li><a href="http://llvm.cs.uiuc.edu/PR373">[llvmgcc] obstack.h relies on
198obsolete casts-as-lvalues GCC extension</a></li>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]199</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]200</div>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]201
202<!--=========================================================================-->
203<div class="doc_subsubsection">
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]204<a name="codequality">This release includes the following Code Quality
205improvements:</a>
Chris Lattner23257062004-05-23 20:42:08 +0000[diff] [blame]206</div>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]207
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]208<div class="doc_text">
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]209<ol>
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]210<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
211due to long operand of getelementptr</a></li>
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]212
213<li>The X86 backend now generates substantially better code for 64-bit integer
214and floating point operations.</li>
215
216<li>The -inline pass no longer inlines mutually recursive functions until it
217hits the inlining threshold.</li>
218
219<li>The -inline pass no longer misses obvious inlining opportunities just
220because the callee eventually calls into an external function.</li>
221
222<li>The -simplifycfg pass can now "if convert" simple statements into the new
223<tt>select</tt> instruction.</li>
224
225<li>The -loopsimplify pass can now break <a
226href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
227into multiple nested loops. This enables a variety of subsequent
228optimizations.</li>
229
230<li>The -adce pass can now eliminate calls to functions that do not not write to
231memory.</li>
232
233<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]234exception handlers).</li>
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]235
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]236<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
237"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
238operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
239&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
240
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]241<li>LLVM now has infrastructure for (simple and sparse conditional) constant
242propagation of function calls. It currently supports a few math library
243functions like sqrt/sin/cos/etc.</li>
Chris Lattner249b3552004-06-03 22:35:13 +0000[diff] [blame]244
245<li>The C backend now emits <a href="http://llvm.cs.uiuc.edu/PR334">Syntactic
246loops</a> in the code to help C compilers whose optimizers do not recognize
247loops formed from gotos (like GCC).</li>
Brian Gaeke522235e2004-06-11 02:15:39 +0000[diff] [blame]248
249<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR368">[sparcv9] null
250often spilled to constant pool</a>.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]251</ol>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]252</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]253
254<!--=========================================================================-->
255<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]256<a name="bugfix">In this release, the following bugs in the previous release
257were fixed:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]258</div>
259
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]260<div class="doc_text">
261
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]262<p>Bugs in the LLVM Core:</p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]263
264<ol>
John Criswell6956afa2004-05-06 22:23:24 +0000[diff] [blame]265<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
266asssertion</a></li>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]267<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
268incorrectly updates dominator information</a></li>
269<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
270breaks SSA form</a></li>
271<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
272to floating point cast</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]273<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
274code that unwinds</a></li>
275<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions
276of the same name, both having constant pools</a></li>
277<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
278physical register use of aliased definition</a></li>
Chris Lattner8f7cf272004-05-21 16:48:20 +0000[diff] [blame]279<li><a href="http://llvm.cs.uiuc.edu/PR340">Verifier misses malformed switch instruction</a></li>
Chris Lattner3edb94b2004-06-01 21:52:45 +0000[diff] [blame]280<li><a href="http://llvm.cs.uiuc.edu/PR315">[jit] abort, don't warn, when missing external functions encountered</a></li>
Chris Lattner4e71aa82004-06-11 04:35:21 +0000[diff] [blame]281<li><a href="http://llvm.cs.uiuc.edu/PR369">[X86] stackifier crash on floating point setcc X, X</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]282</ol>
283
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]284<p>Bugs in the C/C++ front-end:</p>
285
286<ol>
Chris Lattnerb7a6a332004-06-20 19:08:50 +0000[diff] [blame]287<li><a href="http://llvm.cs.uiuc.edu/PR377">[llvmgcc] miscompilation of staticly initialized unsigned bitfields</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]288<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
289enum type</a></li>
290<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
291indexing miscompiled</a></li>
Chris Lattner2ef024b2004-06-19 01:11:02 +0000[diff] [blame]292<li><a href="http://llvm.cs.uiuc.edu/PR355">[llvmgcc] Errors handling function
293prototypes that take opaque structs by-value</a></li>
294<li><a href="http://llvm.cs.uiuc.edu/PR374">[llvmgcc] Crash compiling variable
295length array of structures</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]296</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]297</div>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]298
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]299<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]300<div class="doc_section">
301 <a name="portability">Portability and Supported Platforms</a>
302</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]303<!-- *********************************************************************** -->
304
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]305<div class="doc_text">
306
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]307<p>LLVM is known to work in the following platforms:</p>
308
309<ul>
310<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
311 other unix-like systems).</li>
312<li>Sun UltraSPARC workstations running Solaris 8.</li>
313<li>PowerPC-based Mac OS X boxes, running 10.3 and above (C backend and
314 interpreter only, no native codegen is available yet).</li>
315<li>Intel and AMD machines running on Win32 with the Cygwin libraries.</li>
316</ul>
317
Brian Gaekee3e557e2004-05-09 05:28:35 +0000[diff] [blame]318
319<p>The core LLVM infrastructure uses
320<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
321to the machine and operating system on which it is built. However, minor
322porting may be required to get LLVM to work on new platforms. We welcome your
323portability patches and reports of successful builds or error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]324
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]325<p>Note that the LLVM build system does not currently support directories with
326spaces on them when running on Win32/cygwin. We strongly recommend running
327LLVM and the C frontend out of a top-level directory without spaces (e.g.,
Chris Lattnerce1a3842004-06-01 19:41:30 +0000[diff] [blame]328<tt>/cygdrive/c/llvm</tt>). Also, make sure to install <b>all</b> of the
329cygwin packages. By default, many important tools are not installed that
330are needed by the LLVM build process or test suite (e.g., /bin/time).</p>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]331
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]332</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]333
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]334<!--=========================================================================-->
335<div class="doc_subsection">
336In this release, the following portability problems were fixed:
337</div>
338
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]339<div class="doc_text">
340
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]341<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]342<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
343on Mac OS X</a></li>
344<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
345understand abbreviated names in headers</a></li>
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]346</ol>
347
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]348</div>
349
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]350<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]351<div class="doc_section">
352 <a name="knownproblems">Known Problems</a>
353</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]354<!-- *********************************************************************** -->
355
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]356<div class="doc_text">
357
358<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]359component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]360sections. If you run into a problem, please check the <a
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]361href="http://llvm.cs.uiuc.edu/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]362there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]363
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]364</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]365
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]366<!-- ======================================================================= -->
367<div class="doc_subsection">
368 <a name="experimental">Experimental features included with this release</a>
369</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]370
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]371<div class="doc_text">
372
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]373<p>The following components of this LLVM release are either untested, known to
374be broken or unreliable, or are in early development. These components should
375not be relied on, and bugs should not be filed against them, but they may be
376useful to some people. In particular, if you would like to work on one of these
377components, please contact us on the llvmdev list.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]378
379<ul>
380<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
Chris Lattner99583502004-06-28 00:44:45 +0000[diff] [blame^]381 -ipmodref, -cee</tt></li>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]382
383<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
384 it should) and not thoroughly tested.</li>
385<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
386<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
387</ul>
388
389</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]390
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]391<!-- ======================================================================= -->
392<div class="doc_subsection">
393 <a name="core">Known problems with the LLVM Core</a>
394</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]395
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]396<div class="doc_text">
397
398<ul>
399
400<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
401work.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]402
403<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]404such, execution of a threaded program could cause these data structures to be
405corrupted.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]406
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]407<li>It is not possible to <tt>dlopen</tt> an LLVM bytecode file in the JIT.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]408
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]409<li>Linking in static archive files (.a files) is very slow (there is no symbol
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]410table in the archive).</li>
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]411
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]412<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
413objects/archives in the order specified on the command line.</a></li>
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]414
415<li><a href="http://llvm.cs.uiuc.edu/PR240">The lower-invoke pass does not mark
John Criswell5d6345a2004-03-12 21:29:42 +0000[diff] [blame]416values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]417targets whose setjmp/longjmp libraries do not save and restore the entire
418register file.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]419</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]420</div>
421
422<!-- ======================================================================= -->
423<div class="doc_subsection">
424 <a name="c-fe">Known problems with the C front-end</a>
425</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]426
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]427<!-- _______________________________________________________________________ -->
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]428<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]429
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]430<div class="doc_text">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]431<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]432<li>C99 Variable sized arrays do not release stack memory when they go out of
433 scope. Thus, the following program may run out of stack space:
434<pre>
435 for (i = 0; i != 1000000; ++i) {
436 int X[n];
437 foo(X);
438 }
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]439</pre></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]440
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]441<li>Initialization of global union variables can only be done <a
442href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
443member</a>.</li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]444
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]445<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
446external function is re-declared as static</a></li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]447
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]448</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]449</div>
450
451<!-- _______________________________________________________________________ -->
452<div class="doc_subsubsection">
453 Notes
454</div>
455
456<div class="doc_text">
457
458<ul>
459
460<li>Inline assembly is not yet supported.</li>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]461
462<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]463support for floating point data types of any size other than 32 and 64
464bits.</li>
465
466<li>The following Unix system functionality has not been tested and may not
467work:
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]468 <ol>
469 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
470 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
471 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
472 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
473 - These functions have not been tested.
474 </ol></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]475
476<li>Although many GCC extensions are supported, some are not. In particular,
477 the following extensions are known to <b>not be</b> supported:
478 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]479 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]480 <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>
481 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
482 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Extended%20Asm">Extended Asm</a>: Assembler instructions with C expressions as operands.</li>
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]483 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]484 <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>
485 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Explicit-Reg-Vars.html#Explicit%20Reg%20Vars">Explicit Reg Vars</a>: Defining variables residing in specified registers.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]486 <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>
487 <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>
488 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
489 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pragmas.html#Pragmas">Pragmas</a>: Pragmas accepted by GCC.</li>
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]490 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]491
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]492 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]493 attribute means that the LLVM compiler ignores the presence of the attribute,
494 but the code should still work. An unsupported attribute is one which is
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]495 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]496 the program.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]497
498 <ol>
499 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
500 Arrays whose length is computed at run time.<br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]501 Supported, but allocated stack space is not freed until the function returns (noted above).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]502
503 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html#Function%20Attributes">Function Attributes</a>:
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]504
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]505 Declaring that functions have no side effects or that they can never
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]506 return.<br>
507
508 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
509 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
510 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
511
512 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
513 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
514 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
515
516 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
517 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
518 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]519
520 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
521 Specifying attributes of variables.<br>
522 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
523 <tt>deprecated</tt>, <tt>transparent_union</tt>,
524 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]525
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]526 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
527 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
528 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]529 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]530
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]531 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html#Type%20Attributes">Type Attributes</a>: Specifying attributes of types.<br>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]532 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]533 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]534
535 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
536 all target specific attributes.</li>
537
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]538 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
539 Other built-in functions.<br>
540 We support all builtins which have a C language equivalent (e.g.,
541 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
542 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Chris Lattnerb7c4bac2004-06-18 06:26:29 +0000[diff] [blame]543 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt>
544 (currently ignored). We also support builtins for ISO C99 floating
545 point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]546 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]547
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]548 <p>The following extensions <b>are</b> known to be supported:</p>
549
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]550 <ol>
Chris Lattnerd3dc8502004-03-16 08:54:07 +0000[diff] [blame]551 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html#Labels%20as%20Values">Labels as Values</a>: Getting pointers to labels and computed gotos.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]552 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
553 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Typeof.html#Typeof">Typeof</a>: <code>typeof</code>: referring to the type of an expression.</li>
Tanya Lattnerce33a1b2004-06-22 03:48:17 +0000[diff] [blame]554 <li><a href="http://gcc.gnu.org/onlinedocs/gcc-3.4.0/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]555 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
556 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
557 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
558 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
559 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
560 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
561 <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>
562 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
563 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Subscripting.html#Subscripting">Subscripting</a>: Any array can be subscripted, even if not an lvalue.</li>
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]564 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pointer-Arith.html#Pointer%20Arith">Pointer Arith</a>: Arithmetic on <code>void</code>-pointers and function pointers.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]565 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]566 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
567or arrays as values.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]568 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html#Designated%20Inits">Designated Inits</a>: Labeling elements of initializers.</li>
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]569 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Cast-to-Union.html#Cast%20to%20Union">Cast to Union</a>: Casting to union type from any member of the union.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]570 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
571 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
572 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
573 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
574 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
575 <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>
576 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
577 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
578 <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>
579 <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>
580 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Names.html#Function%20Names">Function Names</a>: Printable strings which are the name of the current function.</li>
Chris Lattner3646dad2004-02-14 04:08:29 +0000[diff] [blame]581 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Return-Address.html#Return%20Address">Return Address</a>: Getting the return or frame address of a function.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]582 <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>
583 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html#Attribute%20Syntax">Attribute Syntax</a>: Formal syntax for attributes.</li>
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]584 </ol></li>
585
586</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]587
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]588<p>If you run into GCC extensions which have not been included in any of these
589lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]590
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]591</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]592
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]593<!-- ======================================================================= -->
594<div class="doc_subsection">
595 <a name="c++-fe">Known problems with the C++ front-end</a>
596</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]597
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]598<div class="doc_text">
599
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]600<p>For this release, the C++ front-end is considered to be fully functional but
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]601has not been tested as thoroughly as the C front-end. It has been tested and
602works for a number of non-trivial programs, but there may be lurking bugs.
603Please report any bugs or problems.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]604
605</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]606
607<!-- _______________________________________________________________________ -->
Chris Lattner141ebb62004-02-14 04:12:41 +0000[diff] [blame]608<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]609
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]610<div class="doc_text">
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]611
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]612<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]613<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]614 front-end</a>.</li>
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]615</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]616</div>
617
618<!-- _______________________________________________________________________ -->
619<div class="doc_subsubsection">
620 Notes
621</div>
622
623<div class="doc_text">
624
625<ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]626
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]627<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
628parser is significantly more standards compliant (and picky) than prior GCC
629versions. For more information, see the C++ section of the <a
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]630href="http://gcc.gnu.org/gcc-3.4/changes.html">GCC 3.4 release notes</a>.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]631
632<li>Destructors for local objects are not always run when a <tt>longjmp</tt> is
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]633 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]634 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]635 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]636 better than most compilers).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]637
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]638<li>The LLVM C++ front-end follows the <a
639 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
640 This document, which is not Itanium specific, specifies a standard for name
641 mangling, class layout, v-table layout, RTTI formats, and other C++
642 representation issues. Because we use this API, code generated by the LLVM
643 compilers should be binary compatible with machine code generated by other
644 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
645 <i>However</i>, the exception handling mechanism used by LLVM is very
646 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]647 interact correctly</b>. </li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]648
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]649</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]650
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]651</div>
652
653<!-- ======================================================================= -->
654<div class="doc_subsection">
655 <a name="x86-be">Known problems with the X86 back-end</a>
656</div>
657
658<div class="doc_text">
659
660<ul>
Reid Spencer006b3862004-06-19 18:24:05 +0000[diff] [blame]661 <li>Optimized (Release) versions of LLVM built with GCC 3.3.2 or 3.3.3 will
662 produce an llc tool that always enters an infinite loop due to what
663 appears to be an optimization bug (-O2 and -O3) in those versions of GCC.
664 This problem does not happen in GCC 3.3.1 nor GCC 3.4.0 nor does it happen if
665 you build a Debug version of LLVM. You are cautioned not to use GCC 3.3.2 or
666 GCC 3.3.3 to build Optimized versions of LLVM. It is unclear whether this problem
667 affects other backends but it is unlikely.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]668</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]669
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]670</div>
671
672<!-- ======================================================================= -->
673<div class="doc_subsection">
674 <a name="sparc-be">Known problems with the Sparc back-end</a>
675</div>
676
677<div class="doc_text">
678
679<ul>
Chris Lattner9e0b81c2004-03-19 19:22:28 +0000[diff] [blame]680<li>There are several programs in the LLVM testsuite that the Sparc code generator is known to miscompile.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]681</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]682
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]683</div>
684
685<!-- ======================================================================= -->
686<div class="doc_subsection">
687 <a name="c-be">Known problems with the C back-end</a>
688</div>
689
690<div class="doc_text">
691
692<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]693
694<li>The C back-end produces code that violates the ANSI C Type-Based Alias
695Analysis rules. As such, special options may be necessary to compile the code
696(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]697problem probably cannot be fixed.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]698
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]699<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]700cannot include special floating point numbers like Not-A-Number or
701Infinity.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]702
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]703<li><a href="http://llvm.cs.uiuc.edu/PR56">Zero arg vararg functions are not
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]704supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]705frontends.</li>
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]706
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]707</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]708
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]709</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]710
711<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]712<div class="doc_section">
713 <a name="additionalinfo">Additional Information</a>
714</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]715<!-- *********************************************************************** -->
716
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]717<div class="doc_text">
718
719<p>A wide variety of additional information is available on the LLVM web page,
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]720including mailing lists and publications describing algorithms and components
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]721implemented in LLVM. The web page also contains versions of the API
722documentation which is up-to-date with the CVS version of the source code. You
723can access versions of these documents specific to this release by going into
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]724the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]725
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]726<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]727us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
728lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]729
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]730</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]731
732<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]733
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]734<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]735<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]736 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]737 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
738 <a href="http://validator.w3.org/check/referer"><img
739 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
740
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]741 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]742 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]743</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]744
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]745</body>
746</html>