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gerrit-public.fairphone.software / toolchain / llvm-project / e549717d841fa5895c2583f3d68c60964b959691 / . / 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>
Misha Brukman0fdfcf12004-07-02 16:23:17 +0000[diff] [blame]108<li>LLVM now has first-class support for <a
109href="GarbageCollection.html">Accurate Garbage Collection</a>, enabling the use
110of aggressive copying and generational collectors.</li>
Chris Lattnereda4f472004-05-24 04:45:52 +0000[diff] [blame]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>
Misha Brukman0fdfcf12004-07-02 16:23:17 +0000[diff] [blame]118<li>The LLVM code generator is now being <a
119href="CodeGenerator.html">documented</a>.</li>
120<li>There is a new tool, llvm-bcanalyzer. This tool can compute basic
121statistics and bytecode density statistics on a module or function basis and
122also dump out bytecode in a textual format that is lower level than assembly
123(values are not resolved from slot numbers). It should only be of interest to
124(a) those who are working to improve the bytecode format and (b) those who
125really want to understand or document the details of the bytecode format.</li>
126<li>The <a href="BytecodeFormat.html">LLVM Bytecode file format</a> is now being
127documented.</li>
128<li>LLVM now provides an <a
129href="LangRef.html#i_isunordered">llvm.isunordered</a> intrinsic for efficient
130implementation 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>
Misha Brukman0fdfcf12004-07-02 16:23:17 +0000[diff] [blame]139<li>We now generate HTML documentation and man pages for the tools from a single
140source (perl-style POD files).</li>
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]141</ol>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]142
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]143</div>
144
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]145
146<!--=========================================================================-->
147<div class="doc_subsubsection">
148In this release, the following missing features were implemented:
149</div>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]150
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]151<div class="doc_text">
152
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]153<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]154<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
155more than 256 elements</a></li>
Misha Brukmane7050232004-04-19 03:01:01 +0000[diff] [blame]156<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
157non-instruction entities, such as global constant initializer</a></li>
Reid Spencer45e25d82004-05-09 23:32:39 +0000[diff] [blame]158<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
159with 64-bit pointers.</a></li>
Misha Brukmane7050232004-04-19 03:01:01 +0000[diff] [blame]160<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
161uses of external fns by immediate constant exprs</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]162</ol>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]163
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]164</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]165
166<!--=========================================================================-->
167<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]168<a name="qualityofimp">In this release, the following Quality of Implementation
169issues were fixed:</a>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]170</div>
171
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]172<div class="doc_text">
173
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]174<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]175<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
176bytecode onto your terminal</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]177<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
178for structure typedefs</a></li>
Chris Lattnerf10ccbf2004-05-24 04:53:32 +0000[diff] [blame]179<li>All documentation is now conformant to the HTML 4.01 (Strict) level.</li>
Chris Lattnerbd948cf2004-06-08 07:19:29 +0000[diff] [blame]180<li>The spurious "WARNING: Found global types that are not compatible" warning
181produced when linking C++ programs has been fixed.</li>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]182</ol>
183
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]184</div>
185
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]186<!--=========================================================================-->
187<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]188In this release, the following build problems were fixed:
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]189</div>
190
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]191<div class="doc_text">
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]192<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]193<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
194-disable/enable-povray and -disable-spec</a></li>
195<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
196work if you change PATH</a></li>
Chris Lattner47696122004-06-09 01:09:16 +0000[diff] [blame]197<li><a href="http://llvm.cs.uiuc.edu/PR364">[llvmgcc] llvmgcc does not compile
198with gcc 3.4</a></li>
Chris Lattner3daf9842004-06-18 17:57:29 +0000[diff] [blame]199<li><a href="http://llvm.cs.uiuc.edu/PR373">[llvmgcc] obstack.h relies on
200obsolete casts-as-lvalues GCC extension</a></li>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]201</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]202</div>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]203
204<!--=========================================================================-->
205<div class="doc_subsubsection">
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]206<a name="codequality">This release includes the following Code Quality
207improvements:</a>
Chris Lattner23257062004-05-23 20:42:08 +0000[diff] [blame]208</div>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]209
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]210<div class="doc_text">
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]211<ol>
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]212<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
213due to long operand of getelementptr</a></li>
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]214
215<li>The X86 backend now generates substantially better code for 64-bit integer
216and floating point operations.</li>
217
218<li>The -inline pass no longer inlines mutually recursive functions until it
219hits the inlining threshold.</li>
220
221<li>The -inline pass no longer misses obvious inlining opportunities just
222because the callee eventually calls into an external function.</li>
223
224<li>The -simplifycfg pass can now "if convert" simple statements into the new
225<tt>select</tt> instruction.</li>
226
227<li>The -loopsimplify pass can now break <a
228href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
229into multiple nested loops. This enables a variety of subsequent
230optimizations.</li>
231
232<li>The -adce pass can now eliminate calls to functions that do not not write to
233memory.</li>
234
235<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]236exception handlers).</li>
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]237
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]238<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
239"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
240operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
241&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
242
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]243<li>LLVM now has infrastructure for (simple and sparse conditional) constant
244propagation of function calls. It currently supports a few math library
245functions like sqrt/sin/cos/etc.</li>
Chris Lattner249b3552004-06-03 22:35:13 +0000[diff] [blame]246
247<li>The C backend now emits <a href="http://llvm.cs.uiuc.edu/PR334">Syntactic
248loops</a> in the code to help C compilers whose optimizers do not recognize
249loops formed from gotos (like GCC).</li>
Brian Gaeke522235e2004-06-11 02:15:39 +0000[diff] [blame]250
251<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR368">[sparcv9] null
252often spilled to constant pool</a>.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]253</ol>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]254</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]255
256<!--=========================================================================-->
257<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]258<a name="bugfix">In this release, the following bugs in the previous release
259were fixed:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]260</div>
261
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]262<div class="doc_text">
263
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]264<p>Bugs in the LLVM Core:</p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]265
266<ol>
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>
Reid Spencerb1076c42004-06-29 23:39:24 +0000[diff] [blame]273<li><a href="http://llvm.cs.uiuc.edu/PR315">[jit] abort, don't warn, when
274missing external functions encountered</a></li>
275<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
276asssertion</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]277<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
278code that unwinds</a></li>
279<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions
280of the same name, both having constant pools</a></li>
281<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
282physical register use of aliased definition</a></li>
Reid Spencerb1076c42004-06-29 23:39:24 +0000[diff] [blame]283<li><a href="http://llvm.cs.uiuc.edu/PR340">Verifier misses malformed switch
284instruction</a></li>
285<li><a href="http://llvm.cs.uiuc.edu/PR365">[asmwriter] Asm writer aborts if
286an instruction is not embedded into a function</a></li>
287<li><a href="http://llvm.cs.uiuc.edu/PR369">[X86] stackifier crash on floating
288point setcc X, X</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]289</ol>
290
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]291<p>Bugs in the C/C++ front-end:</p>
292
293<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]294<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
295indexing miscompiled</a></li>
Reid Spencerb1076c42004-06-29 23:39:24 +0000[diff] [blame]296<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
297enum type</a></li>
Chris Lattner2ef024b2004-06-19 01:11:02 +0000[diff] [blame]298<li><a href="http://llvm.cs.uiuc.edu/PR355">[llvmgcc] Errors handling function
299prototypes that take opaque structs by-value</a></li>
300<li><a href="http://llvm.cs.uiuc.edu/PR374">[llvmgcc] Crash compiling variable
301length array of structures</a></li>
Misha Brukman0fdfcf12004-07-02 16:23:17 +0000[diff] [blame]302<li><a href="http://llvm.cs.uiuc.edu/PR377">[llvmgcc] miscompilation of staticly
Reid Spencerb1076c42004-06-29 23:39:24 +0000[diff] [blame]303initialized unsigned bitfields</a></li>
Chris Lattnere5497172004-07-07 02:25:24 +0000[diff] [blame^]304<li><a href="http://llvm.cs.uiuc.edu/PR396">[llvm-gcc] Crash casting function to void</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]305</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]306</div>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]307
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]308<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]309<div class="doc_section">
310 <a name="portability">Portability and Supported Platforms</a>
311</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]312<!-- *********************************************************************** -->
313
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]314<div class="doc_text">
315
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]316<p>LLVM is known to work in the following platforms:</p>
317
318<ul>
319<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
320 other unix-like systems).</li>
321<li>Sun UltraSPARC workstations running Solaris 8.</li>
322<li>PowerPC-based Mac OS X boxes, running 10.3 and above (C backend and
323 interpreter only, no native codegen is available yet).</li>
324<li>Intel and AMD machines running on Win32 with the Cygwin libraries.</li>
325</ul>
326
Brian Gaekee3e557e2004-05-09 05:28:35 +0000[diff] [blame]327
328<p>The core LLVM infrastructure uses
329<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
330to the machine and operating system on which it is built. However, minor
331porting may be required to get LLVM to work on new platforms. We welcome your
332portability patches and reports of successful builds or error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]333
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]334<p>Note that the LLVM build system does not currently support directories with
335spaces on them when running on Win32/cygwin. We strongly recommend running
336LLVM and the C frontend out of a top-level directory without spaces (e.g.,
Chris Lattnerce1a3842004-06-01 19:41:30 +0000[diff] [blame]337<tt>/cygdrive/c/llvm</tt>). Also, make sure to install <b>all</b> of the
338cygwin packages. By default, many important tools are not installed that
339are needed by the LLVM build process or test suite (e.g., /bin/time).</p>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]340
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]341</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]342
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]343<!--=========================================================================-->
344<div class="doc_subsection">
345In this release, the following portability problems were fixed:
346</div>
347
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]348<div class="doc_text">
349
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]350<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]351<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
352on Mac OS X</a></li>
353<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
354understand abbreviated names in headers</a></li>
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]355</ol>
356
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]357</div>
358
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]359<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]360<div class="doc_section">
361 <a name="knownproblems">Known Problems</a>
362</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]363<!-- *********************************************************************** -->
364
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]365<div class="doc_text">
366
367<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]368component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]369sections. If you run into a problem, please check the <a
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]370href="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]371there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]372
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]373</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]374
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]375<!-- ======================================================================= -->
376<div class="doc_subsection">
377 <a name="experimental">Experimental features included with this release</a>
378</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]379
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]380<div class="doc_text">
381
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]382<p>The following components of this LLVM release are either untested, known to
383be broken or unreliable, or are in early development. These components should
384not be relied on, and bugs should not be filed against them, but they may be
385useful to some people. In particular, if you would like to work on one of these
386components, please contact us on the llvmdev list.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]387
388<ul>
389<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
Chris Lattner99583502004-06-28 00:44:45 +0000[diff] [blame]390 -ipmodref, -cee</tt></li>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]391
392<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
393 it should) and not thoroughly tested.</li>
394<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
395<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
396</ul>
397
398</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]399
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]400<!-- ======================================================================= -->
401<div class="doc_subsection">
402 <a name="core">Known problems with the LLVM Core</a>
403</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]404
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]405<div class="doc_text">
406
407<ul>
408
409<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
410work.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]411
412<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]413such, execution of a threaded program could cause these data structures to be
414corrupted.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]415
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]416<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]417
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]418<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]419table in the archive).</li>
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]420
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]421<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
422objects/archives in the order specified on the command line.</a></li>
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]423
424<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]425values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]426targets whose setjmp/longjmp libraries do not save and restore the entire
427register file.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]428</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]429</div>
430
431<!-- ======================================================================= -->
432<div class="doc_subsection">
433 <a name="c-fe">Known problems with the C front-end</a>
434</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]435
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]436<!-- _______________________________________________________________________ -->
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]437<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]438
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]439<div class="doc_text">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]440<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]441<li>C99 Variable sized arrays do not release stack memory when they go out of
442 scope. Thus, the following program may run out of stack space:
443<pre>
444 for (i = 0; i != 1000000; ++i) {
445 int X[n];
446 foo(X);
447 }
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]448</pre></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]449
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]450<li>Initialization of global union variables can only be done <a
451href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
452member</a>.</li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]453
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]454<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
455external function is re-declared as static</a></li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]456
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]457</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]458</div>
459
460<!-- _______________________________________________________________________ -->
461<div class="doc_subsubsection">
462 Notes
463</div>
464
465<div class="doc_text">
466
467<ul>
468
469<li>Inline assembly is not yet supported.</li>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]470
471<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]472support for floating point data types of any size other than 32 and 64
473bits.</li>
474
475<li>The following Unix system functionality has not been tested and may not
476work:
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]477 <ol>
478 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
479 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
480 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
481 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
482 - These functions have not been tested.
483 </ol></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]484
485<li>Although many GCC extensions are supported, some are not. In particular,
486 the following extensions are known to <b>not be</b> supported:
487 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]488 <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]489 <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>
490 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
491 <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]492 <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]493 <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>
494 <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]495 <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>
496 <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>
497 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
498 <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]499 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]500
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]501 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]502 attribute means that the LLVM compiler ignores the presence of the attribute,
503 but the code should still work. An unsupported attribute is one which is
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]504 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]505 the program.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]506
507 <ol>
508 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
509 Arrays whose length is computed at run time.<br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]510 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]511
512 <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]513
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]514 Declaring that functions have no side effects or that they can never
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]515 return.<br>
516
517 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
518 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
519 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
520
521 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
522 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
523 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
524
525 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
526 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
527 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]528
529 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
530 Specifying attributes of variables.<br>
531 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
532 <tt>deprecated</tt>, <tt>transparent_union</tt>,
533 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]534
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]535 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
536 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
537 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]538 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]539
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]540 <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]541 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]542 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]543
544 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
545 all target specific attributes.</li>
546
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]547 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
548 Other built-in functions.<br>
549 We support all builtins which have a C language equivalent (e.g.,
550 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
551 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Chris Lattnerb7c4bac2004-06-18 06:26:29 +0000[diff] [blame]552 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt>
553 (currently ignored). We also support builtins for ISO C99 floating
554 point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]555 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]556
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]557 <p>The following extensions <b>are</b> known to be supported:</p>
558
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]559 <ol>
Chris Lattnerd3dc8502004-03-16 08:54:07 +0000[diff] [blame]560 <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]561 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
562 <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]563 <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]564 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
565 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
566 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
567 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
568 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
569 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
570 <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>
571 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
572 <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]573 <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]574 <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]575 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
576or arrays as values.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]577 <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]578 <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]579 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
580 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
581 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
582 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
583 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
584 <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>
585 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
586 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
587 <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>
588 <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>
589 <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]590 <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]591 <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>
592 <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]593 </ol></li>
594
595</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]596
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]597<p>If you run into GCC extensions which have not been included in any of these
598lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]599
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]600</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]601
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]602<!-- ======================================================================= -->
603<div class="doc_subsection">
604 <a name="c++-fe">Known problems with the C++ front-end</a>
605</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]606
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]607<div class="doc_text">
608
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]609<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]610has not been tested as thoroughly as the C front-end. It has been tested and
611works for a number of non-trivial programs, but there may be lurking bugs.
612Please report any bugs or problems.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]613
614</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]615
616<!-- _______________________________________________________________________ -->
Chris Lattner141ebb62004-02-14 04:12:41 +0000[diff] [blame]617<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]618
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]619<div class="doc_text">
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]620
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]621<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]622<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]623 front-end</a>.</li>
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]624</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]625</div>
626
627<!-- _______________________________________________________________________ -->
628<div class="doc_subsubsection">
629 Notes
630</div>
631
632<div class="doc_text">
633
634<ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]635
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]636<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
637parser is significantly more standards compliant (and picky) than prior GCC
638versions. For more information, see the C++ section of the <a
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]639href="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]640
641<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]642 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]643 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]644 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]645 better than most compilers).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]646
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]647<li>The LLVM C++ front-end follows the <a
648 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
649 This document, which is not Itanium specific, specifies a standard for name
650 mangling, class layout, v-table layout, RTTI formats, and other C++
651 representation issues. Because we use this API, code generated by the LLVM
652 compilers should be binary compatible with machine code generated by other
653 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
654 <i>However</i>, the exception handling mechanism used by LLVM is very
655 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]656 interact correctly</b>. </li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]657
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]658</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]659
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]660</div>
661
662<!-- ======================================================================= -->
663<div class="doc_subsection">
664 <a name="x86-be">Known problems with the X86 back-end</a>
665</div>
666
667<div class="doc_text">
668
669<ul>
Reid Spencer006b3862004-06-19 18:24:05 +0000[diff] [blame]670 <li>Optimized (Release) versions of LLVM built with GCC 3.3.2 or 3.3.3 will
671 produce an llc tool that always enters an infinite loop due to what
672 appears to be an optimization bug (-O2 and -O3) in those versions of GCC.
673 This problem does not happen in GCC 3.3.1 nor GCC 3.4.0 nor does it happen if
674 you build a Debug version of LLVM. You are cautioned not to use GCC 3.3.2 or
675 GCC 3.3.3 to build Optimized versions of LLVM. It is unclear whether this problem
676 affects other backends but it is unlikely.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]677</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]678
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]679</div>
680
681<!-- ======================================================================= -->
682<div class="doc_subsection">
683 <a name="sparc-be">Known problems with the Sparc back-end</a>
684</div>
685
686<div class="doc_text">
687
688<ul>
Chris Lattner9e0b81c2004-03-19 19:22:28 +0000[diff] [blame]689<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]690</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]691
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]692</div>
693
694<!-- ======================================================================= -->
695<div class="doc_subsection">
696 <a name="c-be">Known problems with the C back-end</a>
697</div>
698
699<div class="doc_text">
700
701<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]702
703<li>The C back-end produces code that violates the ANSI C Type-Based Alias
704Analysis rules. As such, special options may be necessary to compile the code
705(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]706problem probably cannot be fixed.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]707
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]708<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]709cannot include special floating point numbers like Not-A-Number or
710Infinity.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]711
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]712<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]713supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]714frontends.</li>
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]715
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]716</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]717
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]718</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]719
720<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]721<div class="doc_section">
722 <a name="additionalinfo">Additional Information</a>
723</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]724<!-- *********************************************************************** -->
725
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]726<div class="doc_text">
727
728<p>A wide variety of additional information is available on the LLVM web page,
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]729including mailing lists and publications describing algorithms and components
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]730implemented in LLVM. The web page also contains versions of the API
731documentation which is up-to-date with the CVS version of the source code. You
732can access versions of these documents specific to this release by going into
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]733the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]734
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]735<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]736us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
737lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]738
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]739</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]740
741<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]742
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]743<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]744<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]745 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]746 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
747 <a href="http://validator.w3.org/check/referer"><img
748 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
749
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]750 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]751 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]752</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]753
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]754</body>
755</html>