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gerrit-public.fairphone.software / toolchain / llvm-project / 639a702db804c622299781b20c444f802246cdc0 / . / 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>
Misha Brukmana516e992004-07-12 16:55:41 +0000[diff] [blame]25 <li><a href="#sparcv9-be">Known problems with the SparcV9 Back-end</a>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]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 Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]74code</a> produced by all aspects of the LLVM compiler, adds many <a
75href="#newfeatures">new features</a>, <a href="#bugfix">fixes a few
76bugs</a>, and speeds up the compiler.</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++
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]79SPEC CPU95 &amp; 2000 benchmarks, the Olden benchmarks, and the Ptrdist
80benchmarks, and <b>many</b> other programs. LLVM now also works
81with a broad variety of C++ programs.</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]82
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]83</div>
84
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]85<!--=========================================================================-->
86<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]87<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]88</div>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]89
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]90<div class="doc_text">
91
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]92<ol>
Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]93<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]94now fully implemented and supported by all transformations, native code
95generators, and the interpreter.</li>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]96<li>Bugpoint can now narrow down code-generation bugs to a loop nest, where
97before it could only narrow them down to a function being miscompiled.</li>
Brian Gaekee307f8a72004-05-04 21:22:57 +0000[diff] [blame]98<li><a href="http://llvm.cs.uiuc.edu/PR40">Bugpoint can now debug arbitrary
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]99modes of llc</a> and lli, by passing them command line flags (e.g.
100<tt>-regalloc=linearscan</tt>).</li>
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]101<li>The Control Flow Graph in the native code generators is no longer
102constrained to be the same as the CFG for the LLVM input code.</li>
103<li>The LLVM induction variable analysis routines have been rewritten.</li>
104<li>LLVM now has new loop unrolling and loop unswitching passes.</li>
105<li>The induction variable substitution pass performs linear function test
106replacement and exit value replacement optimizations.</li>
Misha Brukman0fdfcf12004-07-02 16:23:17 +0000[diff] [blame]107<li>LLVM now has first-class support for <a
108href="GarbageCollection.html">Accurate Garbage Collection</a>, enabling the use
109of aggressive copying and generational collectors.</li>
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]110<li>LLVM now includes a simple implementation of <a
111href="AliasAnalysis.html#anders-aa">Andersen's interprocedural alias
112analysis</a> 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>
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]120<li>LLVM includes a new tool, <a
121href="CommandGuide/html/llvm-bcanalyzer.html">llvm-bcanalyzer</a>, This tool
122can compute various statistics and dump information about LLVM bytecode
123encoding.</li>
124<li>The <a href="BytecodeFormat.html">LLVM bytecode file format</a> is now
Misha Brukman0fdfcf12004-07-02 16:23:17 +0000[diff] [blame]125documented.</li>
126<li>LLVM now provides an <a
127href="LangRef.html#i_isunordered">llvm.isunordered</a> intrinsic for efficient
128implementation of unordered floating point comparisons.</li>
Chris Lattnerb7c4bac2004-06-18 06:26:29 +0000[diff] [blame]129<li>The llvmgcc front-end now supports the GCC builtins for ISO C99 floating
130point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]131<li>We now generate <a href="CommandGuide/">HTML documentation and man pages</a>
132for the tools from a single source (perl-style POD files).</li>
Chris Lattner47bafde2004-07-12 17:09:23 +0000[diff] [blame]133<li>The LLVM code generator can now dynamically load targets from shared
134objects.</li>
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]135<li>LLVM now includes a "skeleton" target, which makes it easier to get
136started porting LLVM to new architectures.</li>
137<li>The linear scan register allocator is now enabled by default in the
138target-independent code generator.</li>
139<li>LLVM now includes a dead store elimination pass.</li>
140<li>Bugpoint can now debug miscompilations that lead to the program going
141into an infinite loop.</li>
142<li>LLVM now provides interfaces to support ML-style pattern matching on the
143LLVM IR.</li>
144<li>LLVM now includes a <a
145href="AliasAnalysis.html#globalsmodref">context-sensitive mod/ref analysis</a>
146for global variables, which is now enabled by default in gccld.</li>
147<li>LLVM can now autogenerate assembly printers for code generators from the
148tablegen description of the target (before they were hand coded).</li>
Reid Spencer639a7022004-08-04 00:43:50 +0000[diff] [blame^]149<li>All LLVM tools will now respond to the
150<a href="http://llvm.cs.uiuc.edu/PR413"><tt>--version</tt> option</a> which
151will tell you the version of LLVM on which the tool is based.</li>
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]152</ol>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]153
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]154</div>
155
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]156
157<!--=========================================================================-->
158<div class="doc_subsubsection">
159In this release, the following missing features were implemented:
160</div>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]161
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]162<div class="doc_text">
163
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]164<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]165<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
166more than 256 elements</a></li>
Misha Brukmane7050232004-04-19 03:01:01 +0000[diff] [blame]167<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
168non-instruction entities, such as global constant initializer</a></li>
Reid Spencer45e25d82004-05-09 23:32:39 +0000[diff] [blame]169<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
170with 64-bit pointers.</a></li>
Misha Brukmane7050232004-04-19 03:01:01 +0000[diff] [blame]171<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
172uses of external fns by immediate constant exprs</a></li>
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]173<li><a href="http://llvm.cs.uiuc.edu/PR407">Can't add function passes that
174depend on immutable passes to the FunctionPassManager</a>.</li>
175<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
176understand abbreviated names in headers</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]177</ol>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]178
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]179</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]180
181<!--=========================================================================-->
182<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]183<a name="qualityofimp">In this release, the following Quality of Implementation
184issues were fixed:</a>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]185</div>
186
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]187<div class="doc_text">
188
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]189<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]190<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
191bytecode onto your terminal</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]192<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
193for structure typedefs</a></li>
Chris Lattnerf10ccbf2004-05-24 04:53:32 +0000[diff] [blame]194<li>All documentation is now conformant to the HTML 4.01 (Strict) level.</li>
Chris Lattnerbd948cf2004-06-08 07:19:29 +0000[diff] [blame]195<li>The spurious "WARNING: Found global types that are not compatible" warning
196produced when linking C++ programs has been fixed.</li>
Reid Spencer66522522004-07-07 21:06:28 +0000[diff] [blame]197<li><a href="http://llvm.cs.uiuc.edu/PR391">lli Doesn't Handle Exceptions From
198Bytecode Reader</a></li>
Reid Spencer4b7a38d2004-07-25 22:15:33 +0000[diff] [blame]199<li><a href="http://llvm.cs.uiuc.edu/PR392">Global Vars Have (Somewhat) Limited
200 Type Range</a></li>
Chris Lattnera4d8ce62004-07-15 02:59:24 +0000[diff] [blame]201<li><a href="http://llvm.cs.uiuc.edu/PR341">operator&lt;&lt; on a Value* now prints the address of the object instead of its contents.</a></li>
Reid Spencer4b7a38d2004-07-25 22:15:33 +0000[diff] [blame]202<li><a href="http://llvm.cs.uiuc.edu/PR402">Bytecode Enhancements
203 Needed</a></li>
Chris Lattner34cc6952004-07-15 04:30:35 +0000[diff] [blame]204<li><a href="http://llvm.cs.uiuc.edu/PR404">[loopsimplify] Loop simplify is really slow on 252.eon</a></li>
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]205<li><a href="Http://llvm.cs.uiuc.edu/PR122">[code-cleanup] SymbolTable
206 class cleanup, Type should not derive from Value, eliminate
207 ConstantPointerRef class</a>.</li>
208<li>The memory footprint of the LLVM IR has been reduced substantially.</li>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]209</ol>
210
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]211</div>
212
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]213<!--=========================================================================-->
214<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]215In this release, the following build problems were fixed:
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]216</div>
217
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]218<div class="doc_text">
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]219<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]220<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
221-disable/enable-povray and -disable-spec</a></li>
222<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
223work if you change PATH</a></li>
Chris Lattner47696122004-06-09 01:09:16 +0000[diff] [blame]224<li><a href="http://llvm.cs.uiuc.edu/PR364">[llvmgcc] llvmgcc does not compile
225with gcc 3.4</a></li>
Chris Lattner3daf9842004-06-18 17:57:29 +0000[diff] [blame]226<li><a href="http://llvm.cs.uiuc.edu/PR373">[llvmgcc] obstack.h relies on
227obsolete casts-as-lvalues GCC extension</a></li>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]228</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]229</div>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]230
231<!--=========================================================================-->
232<div class="doc_subsubsection">
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]233<a name="codequality">This release includes the following Code Quality
234improvements:</a>
Chris Lattner23257062004-05-23 20:42:08 +0000[diff] [blame]235</div>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]236
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]237<div class="doc_text">
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]238<ol>
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]239<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
240due to long operand of getelementptr</a></li>
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]241
242<li>The X86 backend now generates substantially better code for 64-bit integer
243and floating point operations.</li>
244
245<li>The -inline pass no longer inlines mutually recursive functions until it
246hits the inlining threshold.</li>
247
248<li>The -inline pass no longer misses obvious inlining opportunities just
249because the callee eventually calls into an external function.</li>
250
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]251<li>The -simplifycfg pass can now "if convert" simple statements into the
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]252<tt>select</tt> instruction.</li>
253
254<li>The -loopsimplify pass can now break <a
255href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
256into multiple nested loops. This enables a variety of subsequent
257optimizations.</li>
258
259<li>The -adce pass can now eliminate calls to functions that do not not write to
260memory.</li>
261
262<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]263exception handlers).</li>
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]264
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]265<li>The link-time optimizer now runs dead store elimination and uses a simple
266interprocedural alias analysis.</li>
267
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]268<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
269"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
270operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
271&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
272
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]273<li>LLVM now has infrastructure for (simple and sparse conditional) constant
274propagation of function calls. It currently supports a few math library
275functions like sqrt/sin/cos/etc.</li>
Chris Lattner249b3552004-06-03 22:35:13 +0000[diff] [blame]276
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]277<li>The C backend now emits <a href="http://llvm.cs.uiuc.edu/PR334">syntactic
Chris Lattner249b3552004-06-03 22:35:13 +0000[diff] [blame]278loops</a> in the code to help C compilers whose optimizers do not recognize
279loops formed from gotos (like GCC).</li>
Brian Gaeke522235e2004-06-11 02:15:39 +0000[diff] [blame]280
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]281<li>The SparcV9 backend no longers <a
282href="http://llvm.cs.uiuc.edu/PR368">spills the null constant to the constant
283pool</a>.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]284</ol>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]285</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]286
287<!--=========================================================================-->
288<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]289<a name="bugfix">In this release, the following bugs in the previous release
290were fixed:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]291</div>
292
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]293<div class="doc_text">
294
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]295<p>Bugs fixed in the LLVM Core:</p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]296
297<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]298<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
299incorrectly updates dominator information</a></li>
300<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
301breaks SSA form</a></li>
302<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
303to floating point cast</a></li>
Reid Spencerb1076c42004-06-29 23:39:24 +0000[diff] [blame]304<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
305asssertion</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]306<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
307code that unwinds</a></li>
Misha Brukmana516e992004-07-12 16:55:41 +0000[diff] [blame]308<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparcv9] LLC can't emit 2 functions
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]309of the same name, both having constant pools</a></li>
310<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
311physical register use of aliased definition</a></li>
Reid Spencerb1076c42004-06-29 23:39:24 +0000[diff] [blame]312<li><a href="http://llvm.cs.uiuc.edu/PR369">[X86] stackifier crash on floating
313point setcc X, X</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]314</ol>
315
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]316<p>Bugs in the C/C++ front-end:</p>
317
318<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]319<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
320indexing miscompiled</a></li>
Reid Spencerb1076c42004-06-29 23:39:24 +0000[diff] [blame]321<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
322enum type</a></li>
Chris Lattner2ef024b2004-06-19 01:11:02 +0000[diff] [blame]323<li><a href="http://llvm.cs.uiuc.edu/PR355">[llvmgcc] Errors handling function
324prototypes that take opaque structs by-value</a></li>
325<li><a href="http://llvm.cs.uiuc.edu/PR374">[llvmgcc] Crash compiling variable
326length array of structures</a></li>
Misha Brukman0fdfcf12004-07-02 16:23:17 +0000[diff] [blame]327<li><a href="http://llvm.cs.uiuc.edu/PR377">[llvmgcc] miscompilation of staticly
Reid Spencerb1076c42004-06-29 23:39:24 +0000[diff] [blame]328initialized unsigned bitfields</a></li>
Chris Lattnere5497172004-07-07 02:25:24 +0000[diff] [blame]329<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]330</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]331</div>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]332
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]333<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]334<div class="doc_section">
335 <a name="portability">Portability and Supported Platforms</a>
336</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]337<!-- *********************************************************************** -->
338
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]339<div class="doc_text">
340
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]341<p>LLVM is known to work in the following platforms:</p>
342
343<ul>
344<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
345 other unix-like systems).</li>
346<li>Sun UltraSPARC workstations running Solaris 8.</li>
347<li>PowerPC-based Mac OS X boxes, running 10.3 and above (C backend and
348 interpreter only, no native codegen is available yet).</li>
349<li>Intel and AMD machines running on Win32 with the Cygwin libraries.</li>
350</ul>
351
Brian Gaekee3e557e2004-05-09 05:28:35 +0000[diff] [blame]352
353<p>The core LLVM infrastructure uses
354<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
355to the machine and operating system on which it is built. However, minor
356porting may be required to get LLVM to work on new platforms. We welcome your
357portability patches and reports of successful builds or error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]358
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]359<p>Note that the LLVM build system does not currently support directories with
360spaces on them when running on Win32/cygwin. We strongly recommend running
361LLVM and the C frontend out of a top-level directory without spaces (e.g.,
Chris Lattnerce1a3842004-06-01 19:41:30 +0000[diff] [blame]362<tt>/cygdrive/c/llvm</tt>). Also, make sure to install <b>all</b> of the
363cygwin packages. By default, many important tools are not installed that
364are needed by the LLVM build process or test suite (e.g., /bin/time).</p>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]365
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]366</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]367
368<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]369<div class="doc_section">
370 <a name="knownproblems">Known Problems</a>
371</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]372<!-- *********************************************************************** -->
373
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]374<div class="doc_text">
375
376<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]377component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]378sections. If you run into a problem, please check the <a
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]379href="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]380there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]381
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]382</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]383
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]384<!-- ======================================================================= -->
385<div class="doc_subsection">
386 <a name="experimental">Experimental features included with this release</a>
387</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]388
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]389<div class="doc_text">
390
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]391<p>The following components of this LLVM release are either untested, known to
392be broken or unreliable, or are in early development. These components should
393not be relied on, and bugs should not be filed against them, but they may be
394useful to some people. In particular, if you would like to work on one of these
395components, please contact us on the llvmdev list.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]396
397<ul>
398<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
Chris Lattner99583502004-06-28 00:44:45 +0000[diff] [blame]399 -ipmodref, -cee</tt></li>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]400
401<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
402 it should) and not thoroughly tested.</li>
403<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
404<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
405</ul>
406
407</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]408
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]409<!-- ======================================================================= -->
410<div class="doc_subsection">
411 <a name="core">Known problems with the LLVM Core</a>
412</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]413
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]414<div class="doc_text">
415
416<ul>
417
418<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
419work.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]420
421<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]422such, execution of a threaded program could cause these data structures to be
423corrupted.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]424
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]425<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]426
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]427<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]428table in the archive).</li>
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]429
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]430<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
431objects/archives in the order specified on the command line.</a></li>
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]432
433<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]434values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]435targets whose setjmp/longjmp libraries do not save and restore the entire
436register file.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]437</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]438</div>
439
440<!-- ======================================================================= -->
441<div class="doc_subsection">
442 <a name="c-fe">Known problems with the C front-end</a>
443</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]444
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]445<!-- _______________________________________________________________________ -->
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]446<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]447
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]448<div class="doc_text">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]449<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]450<li>C99 Variable sized arrays do not release stack memory when they go out of
451 scope. Thus, the following program may run out of stack space:
452<pre>
453 for (i = 0; i != 1000000; ++i) {
454 int X[n];
455 foo(X);
456 }
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]457</pre></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]458
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]459<li>Initialization of global union variables can only be done <a
460href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
461member</a>.</li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]462
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]463<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
464external function is re-declared as static</a></li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]465
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]466</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]467</div>
468
469<!-- _______________________________________________________________________ -->
470<div class="doc_subsubsection">
471 Notes
472</div>
473
474<div class="doc_text">
475
476<ul>
477
478<li>Inline assembly is not yet supported.</li>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]479
480<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]481support for floating point data types of any size other than 32 and 64
482bits.</li>
483
484<li>The following Unix system functionality has not been tested and may not
485work:
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]486 <ol>
487 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
488 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
489 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
490 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
491 - These functions have not been tested.
492 </ol></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]493
494<li>Although many GCC extensions are supported, some are not. In particular,
495 the following extensions are known to <b>not be</b> supported:
496 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]497 <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]498 <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>
499 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
500 <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]501 <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]502 <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>
503 <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]504 <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>
505 <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>
506 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
507 <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]508 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]509
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]510 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]511 attribute means that the LLVM compiler ignores the presence of the attribute,
512 but the code should still work. An unsupported attribute is one which is
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]513 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]514 the program.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]515
516 <ol>
517 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
518 Arrays whose length is computed at run time.<br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]519 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]520
521 <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]522
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]523 Declaring that functions have no side effects or that they can never
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]524 return.<br>
525
526 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
527 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
528 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
529
530 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
531 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
532 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
533
534 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
535 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
536 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]537
538 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
539 Specifying attributes of variables.<br>
540 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
541 <tt>deprecated</tt>, <tt>transparent_union</tt>,
542 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]543
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]544 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
545 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
546 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]547 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]548
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]549 <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]550 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]551 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]552
553 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
554 all target specific attributes.</li>
555
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]556 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
557 Other built-in functions.<br>
558 We support all builtins which have a C language equivalent (e.g.,
559 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
560 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Chris Lattnerb7c4bac2004-06-18 06:26:29 +0000[diff] [blame]561 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt>
562 (currently ignored). We also support builtins for ISO C99 floating
563 point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]564 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]565
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]566 <p>The following extensions <b>are</b> known to be supported:</p>
567
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]568 <ol>
Chris Lattnerd3dc8502004-03-16 08:54:07 +0000[diff] [blame]569 <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]570 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
571 <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]572 <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]573 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
574 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
575 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
576 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
577 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
578 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
579 <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>
580 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
581 <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]582 <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]583 <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]584 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
585or arrays as values.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]586 <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]587 <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]588 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
589 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
590 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
591 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
592 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
593 <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>
594 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
595 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
596 <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>
597 <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>
598 <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]599 <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]600 <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>
601 <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]602 </ol></li>
603
604</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]605
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]606<p>If you run into GCC extensions which have not been included in any of these
607lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]608
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]609</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]610
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]611<!-- ======================================================================= -->
612<div class="doc_subsection">
613 <a name="c++-fe">Known problems with the C++ front-end</a>
614</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]615
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]616<div class="doc_text">
617
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]618<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]619has not been tested as thoroughly as the C front-end. It has been tested and
620works for a number of non-trivial programs, but there may be lurking bugs.
621Please report any bugs or problems.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]622
623</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]624
625<!-- _______________________________________________________________________ -->
Chris Lattner141ebb62004-02-14 04:12:41 +0000[diff] [blame]626<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]627
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]628<div class="doc_text">
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]629
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]630<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]631<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]632 front-end</a>.</li>
Chris Lattner041e6c92004-07-17 02:04:41 +0000[diff] [blame]633
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]634<li><b>IA-64 specific</b>: The C++ front-end does not use <a
635href="http://llvm.cs.uiuc.edu/PR406">IA64 ABI compliant layout of v-tables</a>.
Chris Lattner041e6c92004-07-17 02:04:41 +0000[diff] [blame]636In particular, it just stores function pointers instead of function
637descriptors in the vtable. This bug prevents mixing C++ code compiled with
Chris Lattner2fd93492004-08-02 20:29:51 +0000[diff] [blame]638LLVM with C++ objects compiled by other C++ compilers.</li>
Chris Lattner041e6c92004-07-17 02:04:41 +0000[diff] [blame]639
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]640</ul>
641
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]642</div>
643
644<!-- _______________________________________________________________________ -->
645<div class="doc_subsubsection">
646 Notes
647</div>
648
649<div class="doc_text">
650
651<ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]652
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]653<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
654parser is significantly more standards compliant (and picky) than prior GCC
655versions. For more information, see the C++ section of the <a
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]656href="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]657
658<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]659 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]660 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]661 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]662 better than most compilers).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]663
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]664<li>The LLVM C++ front-end follows the <a
665 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
666 This document, which is not Itanium specific, specifies a standard for name
667 mangling, class layout, v-table layout, RTTI formats, and other C++
668 representation issues. Because we use this API, code generated by the LLVM
669 compilers should be binary compatible with machine code generated by other
670 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
671 <i>However</i>, the exception handling mechanism used by LLVM is very
672 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]673 interact correctly</b>. </li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]674
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]675</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]676
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]677</div>
678
679<!-- ======================================================================= -->
680<div class="doc_subsection">
681 <a name="x86-be">Known problems with the X86 back-end</a>
682</div>
683
684<div class="doc_text">
685
686<ul>
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]687 <li>none yet</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]688</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]689
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]690</div>
691
692<!-- ======================================================================= -->
693<div class="doc_subsection">
Misha Brukmana516e992004-07-12 16:55:41 +0000[diff] [blame]694 <a name="sparcv9-be">Known problems with the SparcV9 back-end</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]695</div>
696
697<div class="doc_text">
698
699<ul>
Misha Brukmana516e992004-07-12 16:55:41 +0000[diff] [blame]700<li><a href="http://llvm.cs.uiuc.edu/PR60">[sparcv9] SparcV9 backend miscompiles
701several programs in the LLVM test suite</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]702</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]703
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]704</div>
705
706<!-- ======================================================================= -->
707<div class="doc_subsection">
708 <a name="c-be">Known problems with the C back-end</a>
709</div>
710
711<div class="doc_text">
712
713<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]714
715<li>The C back-end produces code that violates the ANSI C Type-Based Alias
716Analysis rules. As such, special options may be necessary to compile the code
717(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]718problem probably cannot be fixed.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]719
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]720<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]721cannot include special floating point numbers like Not-A-Number or
722Infinity.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]723
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]724<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]725supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]726frontends.</li>
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]727
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]728</ul>
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<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]733<div class="doc_section">
734 <a name="additionalinfo">Additional Information</a>
735</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]736<!-- *********************************************************************** -->
737
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]738<div class="doc_text">
739
740<p>A wide variety of additional information is available on the LLVM web page,
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]741including mailing lists and publications describing algorithms and components
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]742implemented in LLVM. The web page also contains versions of the API
743documentation which is up-to-date with the CVS version of the source code. You
744can access versions of these documents specific to this release by going into
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]745the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]746
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]747<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]748us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
749lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]750
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]751</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]752
753<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]754
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]755<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]756<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]757 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]758 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
759 <a href="http://validator.w3.org/check/referer"><img
760 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
761
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]762 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]763 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]764</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]765
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]766</body>
767</html>