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gerrit-public.fairphone.software / toolchain / llvm-project / 91f297d4fe85b05b09589e98075f564d582ca192 / . / llvm / docs / ReleaseNotes.html
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Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]6 <title>LLVM 1.2 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
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]10<div class="doc_title">
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]11 LLVM 1.2 Release Notes
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]12</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]13
14<ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]15 <li><a href="#intro">Introduction</a></li>
16 <li><a href="#whatsnew">What's New?</a></li>
17 <li><a href="#portability">Portability and Supported Platforms</a></li>
18 <li><a href="#install-instructions">Installation Instructions</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]19 <li><a href="#knownproblems">Known Problems</a>
20 <ul>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]21 <li><a href="#experimental">Experimental features included with this release</a>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]22 <li><a href="#core">Known problems with the LLVM Core</a>
23 <li><a href="#c-fe">Known problems with the C Front-end</a>
24 <li><a href="#c++-fe">Known problems with the C++ Front-end</a>
25 <li><a href="#x86-be">Known problems with the X86 Back-end</a>
26 <li><a href="#sparc-be">Known problems with the Sparc Back-end</a>
27 <li><a href="#c-be">Known problems with the C back-end</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]28 </ul></li>
29 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]30</ol>
31
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]32<div class="doc_text">
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]33 <p><b>Written by the <a href="http://llvm.cs.uiuc.edu">LLVM team</a></b><p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]34</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]35
36<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]37<div class="doc_section">
38 <a name="intro">Introduction</a>
39</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]40<!-- *********************************************************************** -->
41
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]42<div class="doc_text">
43
44<p>This document contains the release notes for the LLVM compiler
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]45infrastructure, release 1.2. Here we describe the status of LLVM, including any
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]46known problems and bug fixes from the previous release. The most up-to-date
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]47version of this document can be found on the <a
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]48href="http://llvm.cs.uiuc.edu/releases/1.2/">LLVM 1.2 web site</a>. If you are
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]49not reading this on the LLVM web pages, you should probably go there because
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]50this document may be updated after the release.</p>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]51
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]52<p>For more information about LLVM, including information about potentially more
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]53current releases, please check out the <a href="http://llvm.cs.uiuc.edu">main
54web site</a>. If you have questions or comments, the <a
55href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]56list</a> is a good place to send them.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]57
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]58<p>Note that if you are reading this file from CVS, this document applies
59to the <i>next</i> release, not the current one. To see the release notes for
60the current or previous releases, see the <a
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]61href="http://llvm.cs.uiuc.edu/releases/">releases page</a>.</p>
62
63</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]64
65<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]66<div class="doc_section">
67 <a name="whatsnew">What's New?</a>
68</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]69<!-- *********************************************************************** -->
70
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]71<div class="doc_text">
72
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]73<p>
74This is the third public release of the LLVM compiler infrastructure. This
75release incorporates several <a href="#newfeatures">new features</a> (including
76exception handling support for the native code generators, the start of a
77source-level debugger, and profile guided optimizer components), many <a
78href="#qualityofimp">speedups</a> and <a href="#codequality">code quality</a>
79improvements, documentation improvements, and a small collection of important <a
80href="bugfix">bug fixes</a>. Overall, this is our highest quality release to
81date, and we encourage you to upgrade if you are using LLVM 1.0 or 1.1.
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]82</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]83
Chris Lattner28202352004-03-17 03:54:41 +0000[diff] [blame]84<p>
85At this time, LLVM is known to correctly compile and run all C &amp; C++ SPEC
86CPU2000 benchmarks, the Olden benchmarks, and the Ptrdist benchmarks. It has
87also been used to compile <b>many</b> other programs. LLVM now also works with
88a broad variety of C++ programs, though it has still received less testing than
89the C front-end.
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]90</p>
91
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]92<!--=========================================================================-->
93<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]94<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]95</div>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]96
97<ol>
Chris Lattner35630ad2004-02-08 21:20:42 +0000[diff] [blame]98<li><a href="SourceLevelDebugging.html">A new LLVM source-level debugger has been started.</a></li>
Chris Lattnere0f79a62004-02-23 03:51:34 +0000[diff] [blame]99<li>LLVM 1.2 encodes bytecode files for large programs in 10-30% less space.</li>
Chris Lattnerd2d7ccd2004-03-11 00:50:54 +0000[diff] [blame]100<li>LLVM can now feed profile information back into optimizers for Profile Guided Optimization, includes a simple basic block reordering pass, and supports edge profiling as well as function and block-level profiling.</li>
Chris Lattnere0f79a62004-02-23 03:51:34 +0000[diff] [blame]101<li>The LLVM JIT lazily initializes global variables, reducing startup time for programs with lots of globals (like C++ programs).</li>
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]102
103<li>The build and installation infrastructure in this release is dramatically
104improved. There is now an <a
105href="http://llvm.cs.uiuc.edu/PR105"><tt>autoconf/AutoRegen.sh</tt> script</a>
106that you can run to rebuild the <tt>configure</tt> script and its associated
107files as well as beta support for "<a
108href="http://llvm.cs.uiuc.edu/PR208">make</a> <a
109href="http://llvm.cs.uiuc.edu/PR220">install</a>" and <a
110href="http://llvm.cs.uiuc.edu/PR203">RPM package generation</a>.</li>
111
Chris Lattnere0f79a62004-02-23 03:51:34 +0000[diff] [blame]112<li>The "tblgen" tool is <a href="TableGenFundamentals.html">now documented</a>.</li>
Chris Lattnerd2d7ccd2004-03-11 00:50:54 +0000[diff] [blame]113<li>The target-independent code generator got several improvements:
Alkis Evlogimenos6cf43732004-02-27 05:26:23 +0000[diff] [blame]114<ul>
Chris Lattnerd2d7ccd2004-03-11 00:50:54 +0000[diff] [blame]115 <li>It can now fold spill code into instructions (on targets that support it).</li>
116 <li>A generic machine code spiller/rewriter was added. It provides an API for
117 global register allocators to eliminate virtual registers and add the
118 appropriate spill code.</li>
119 <li>The represenation of machine code basic blocks is more efficient and has
120 an easier to use interface.</li>
Alkis Evlogimenos6cf43732004-02-27 05:26:23 +0000[diff] [blame]121</ul>
122</li>
Chris Lattner7479e1e2004-02-24 03:50:24 +0000[diff] [blame]123<li><a href="http://llvm.cs.uiuc.edu/PR253">LLVM now no longer depends on the boost library</a>.</li>
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]124<li>The X86 backend now generates <b>substantially</b> better native code, and is faster.</li>
125<li>The C backend has been turned moved from the "llvm-dis" tool to the "llc"
126tool. You can activate it with "<tt>llc -march=c foo.bc -o foo.c</tt>".</li>
Chris Lattner19cfc402004-02-26 08:02:57 +0000[diff] [blame]127<li>LLVM includes a new interprocedural optimization that marks global variables
128"constant" when they are provably never written to.</li>
Chris Lattnerd2d7ccd2004-03-11 00:50:54 +0000[diff] [blame]129<li>LLVM now includes a new interprocedural optimization that converts small "by reference" arguments to "by value" arguments, which is often improve the performance of C++ programs substantially.</li>
Chris Lattner28202352004-03-17 03:54:41 +0000[diff] [blame]130<li>Bugpoint can now do a better job reducing miscompilation problems by
131reducing programs down to a particular loop nest, instead of just the function
132being miscompiled.</li>
133<li>The GCSE and LICM passes can now operate on side-effect-free function calls, for example hoisting calls to "<tt>strlen</tt>" and folding "<tt>cos</tt>" common subexpressions.</li>
134<li>LLVM has early support for a new <a
135href="LangRef.html#i_select"><tt>select</tt></a> instruction, though it is
136currently only supported by the C backend.</li>
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]137</ol>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]138
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]139
140<!--=========================================================================-->
141<div class="doc_subsubsection">
142In this release, the following missing features were implemented:
143</div>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]144
145<ol>
Chris Lattner28202352004-03-17 03:54:41 +0000[diff] [blame]146<li><a href="http://llvm.cs.uiuc.edu/PR16">Exception handling in the X86
147&amp; Sparc native code generators</a> is now supported</li>
148<li>The C/C++ front-end now support the GCC <tt>__builtin_return_address</tt> and <tt>__builtin_frame_address</tt> extensions. These are also supported by the X86 backend and by the C backend.</li>
Chris Lattnerc6acc102004-02-23 03:36:36 +0000[diff] [blame]149<li><a href="http://llvm.cs.uiuc.edu/PR249">[X86] Missing cast from ULong -> Double, cast FP -> bool and support for -9223372036854775808</a></li>
Chris Lattnerd3dc8502004-03-16 08:54:07 +0000[diff] [blame]150<li>The C/C++ front-end <a href="http://llvm.cs.uiuc.edu/PR273">now supports</a>
151the "<a href="http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html#Labels%20as%20Values">labels as values</a>" GCC extension, often used to build "threaded interpreters".</a></li>
152
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]153</ol>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]154
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]155
156<!--=========================================================================-->
157<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]158<a name="qualityofimp">In this release, the following Quality of Implementation issues were fixed:</a>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]159</div>
160
161<ol>
162
163<li><a href="http://llvm.cs.uiuc.edu/PR135">JIT should lazily initialize global variables</a></li>
Chris Lattner6448f892003-12-20 10:29:02 +0000[diff] [blame]164<li><a href="http://llvm.cs.uiuc.edu/PR192">[X86] X86 Backend never releases memory for machine code structures</a></li>
Chris Lattner4688edb2003-12-23 23:50:31 +0000[diff] [blame]165<li><a href="http://llvm.cs.uiuc.edu/PR196">[vmcore] OpaqueType objects memory leak</a></li>
Chris Lattner74339162004-01-08 17:20:50 +0000[diff] [blame]166<li><a href="http://llvm.cs.uiuc.edu/PR182">[llvmgcc] C front-end does not compile "extern inline" into linkonce</a></li>
Chris Lattnera38ebcc2004-01-15 17:59:29 +0000[diff] [blame]167<li><a href="http://llvm.cs.uiuc.edu/PR73">Bytecode format inconsistent</a></li>
Chris Lattner66c16d12004-02-05 17:31:37 +0000[diff] [blame]168<li><a href="http://llvm.cs.uiuc.edu/PR209">[loadvn/inline/scalarrepl] Slow optimizations with extremely large basic blocks</a></li>
Chris Lattner805e5e72004-02-09 21:16:16 +0000[diff] [blame]169<li><a href="http://llvm.cs.uiuc.edu/PR224">[asmparser] Really slow parsing of types with complex upreferences</a></li>
Chris Lattnere9fbbc22004-02-15 05:47:37 +0000[diff] [blame]170<li><a href="http://llvm.cs.uiuc.edu/PR205">[llvmgcc] C front-end does not emit 'zeroinitializer' when possible</a></li>
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]171<li><a href="http://llvm.cs.uiuc.edu/PR233">[llvmgcc] Structure copies result in a LOT of code</a></li>
Chris Lattner8579a6f2004-02-15 06:00:04 +0000[diff] [blame]172<li><a href="http://llvm.cs.uiuc.edu/PR239">LLVM is now much more memory efficient when handling large zero initialized arrays</a></li>
Chris Lattnerd68b5892004-03-10 21:43:47 +0000[diff] [blame]173<li><a href="http://llvm.cs.uiuc.edu/PR275">[llvmgcc] Local array initializers are expanded into large amounts of code</a></li>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]174</ol>
175
176<!--=========================================================================-->
177<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]178In this release, the following build problems were fixed:
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]179</div>
180
181<ol>
182<li><a href="http://llvm.cs.uiuc.edu/PR210">[build] Makefiles break if C frontend target string has unexpected value</a></li>
John Criswell47b48bf92004-01-26 21:03:54 +0000[diff] [blame]183<li><a href="http://llvm.cs.uiuc.edu/PR214">[build] hard-wired assumption that shared-library extension is ".so"</a></li>
Chris Lattner3d96eb62004-02-03 22:59:56 +0000[diff] [blame]184<li><A href="http://llvm.cs.uiuc.edu/PR222">make tools-only doesn't make lib/Support</a></li>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]185</ol>
186
187<!--=========================================================================-->
188<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]189<a name="codequality">In this release, the following Code Quality issues were fixed:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]190</div>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]191
192<ol>
Chris Lattner3d35e872003-12-19 06:31:56 +0000[diff] [blame]193<li><a href="http://llvm.cs.uiuc.edu/PR187">[loopsimplify] Many pointless phi nodes are created</a></li>
Chris Lattnerd5eec5e2004-02-15 00:23:15 +0000[diff] [blame]194<li><a href="http://llvm.cs.uiuc.edu/PR237">[x86] wierd stack/frame pointer manipulation</a></li>
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]195
196<li>The X86 backend now generate <tt>fchs</tt> to negate floating point numbers,
197compiles memcpy() into the <tt>rep movs</tt> instruction, and makes much better
198use of powerful addressing modes and instructions.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]199</ol>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]200
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]201
202<!--=========================================================================-->
203<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]204<a name="bugfix">In this release, the following bugs in the previous release were fixed:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]205</div>
206
207<p>Bugs in the LLVM Core:</p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]208
209<ol>
Misha Brukman34cba912003-12-15 22:48:12 +0000[diff] [blame]210<li><a href="http://llvm.cs.uiuc.edu/PR179">[licm] LICM promotes volatile memory
211locations to registers</a></li>
Chris Lattnerb3fdf832003-12-18 08:16:25 +0000[diff] [blame]212<li><a href="http://llvm.cs.uiuc.edu/PR191">[licm] Memory read after free causes
213infrequent crash</a></li>
Chris Lattner8e570bab2003-12-22 04:06:24 +0000[diff] [blame]214<li><a href="http://llvm.cs.uiuc.edu/PR194">[indvars] Induction variable
215canonicalization always makes 32-bit indvars</a></li>
Chris Lattner0b428c12003-12-22 23:56:37 +0000[diff] [blame]216<li><a href="http://llvm.cs.uiuc.edu/PR193">[constantmerge] Merging globals can
217cause use of invalid pointers!</a></li>
Chris Lattner1d199372004-01-20 19:16:50 +0000[diff] [blame]218<li><a href="http://llvm.cs.uiuc.edu/PR212">[bcreader] Bytecode reader misreads 'long -9223372036854775808'!</a></li>
Chris Lattner24fa5662004-02-09 21:22:51 +0000[diff] [blame]219<li><a href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=174">Tail duplication does not update SSA form correctly.</a></li>
Chris Lattnere2d61892004-02-01 22:52:12 +0000[diff] [blame]220<li><a href="http://llvm.cs.uiuc.edu/PR218">VMCore mishandles double -0.0</a></li>
Chris Lattnerd932cbf2004-02-02 19:40:06 +0000[diff] [blame]221<li><a href="http://llvm.cs.uiuc.edu/PR219">[X86] X86 backend code generates -0.0 as +0.0</a></li>
Chris Lattneraaaaec42004-02-05 21:16:42 +0000[diff] [blame]222<li><a href="http://llvm.cs.uiuc.edu/PR223">[loopsimplify] Loopsimplify incorrectly updates dominator information</a></li>
Chris Lattner35630ad2004-02-08 21:20:42 +0000[diff] [blame]223<li><a href="http://llvm.cs.uiuc.edu/PR225">[pruneeh] -pruneeh pass removes invoke instructions it shouldn't</a></li>
Chris Lattner6b3dea22004-02-10 05:19:54 +0000[diff] [blame]224<li><a href="http://llvm.cs.uiuc.edu/PR228">[sparc] Boolean constants are emitted as true and false</a></li>
Brian Gaeke11331e52004-02-26 00:08:25 +0000[diff] [blame]225<li><a href="http://llvm.cs.uiuc.edu/PR234">[interpreter] va_list values silently corrupted by function calls</a></li>
Chris Lattnerc68c6a62004-02-13 16:40:24 +0000[diff] [blame]226<li><a href="http://llvm.cs.uiuc.edu/PR235">Tablegen aborts on errors</a></li>
Chris Lattner963f2732004-02-13 17:03:01 +0000[diff] [blame]227<li><a href="http://llvm.cs.uiuc.edu/PR236">[inliner] Error inlining intrinsic calls into invoke instructions</a></li>
Chris Lattnerbe1c3002004-02-17 22:00:39 +0000[diff] [blame]228<li><a href="http://llvm.cs.uiuc.edu/PR245">Linking weak and strong global variables is dependent on link order</a></li>
John Criswellbbde7d62004-02-26 23:13:34 +0000[diff] [blame]229<li><a href="http://llvm.cs.uiuc.edu/PR258">Variables used to define non-printable FP constants are externally visible</a></li>
230<li><a href="http://llvm.cs.uiuc.edu/PR259">CBE gives linkonce functions wrong linkage semantics</a></li>
Brian Gaeke75a2efd2004-03-09 05:43:59 +0000[diff] [blame]231<li><a href="http://llvm.cs.uiuc.edu/PR274">[JIT] Programs cannot resolve the fstat function</a></li>
Chris Lattnerd68b5892004-03-10 21:43:47 +0000[diff] [blame]232<li><a href="http://llvm.cs.uiuc.edu/PR284">[indvars] Induction variable analysis violates LLVM invariants</a></li>
Chris Lattnere1f51612004-03-16 08:40:35 +0000[diff] [blame]233<li><a href="http://llvm.cs.uiuc.edu/PR296">[execution engines] Unhandled cast constant expression</a></li>
Chris Lattner91f297d2004-03-19 04:26:04 +0000[diff] [blame^]234<li><a href="http://llvm.cs.uiuc.edu/PR299">[Sparc] Code generator asserts on alloca of zero size type</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]235</ol>
236
237
Chris Lattner24fa5662004-02-09 21:22:51 +0000[diff] [blame]238
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]239<p>Bugs in the C/C++ front-end:</p>
240
241<ol>
Misha Brukman34cba912003-12-15 22:48:12 +0000[diff] [blame]242<li><a href="http://llvm.cs.uiuc.edu/PR186">Need weak linkage on memory
243management functions in libc runtime to allow them to be overriden</a></li>
Chris Lattner74339162004-01-08 17:20:50 +0000[diff] [blame]244<li><a href="http://llvm.cs.uiuc.edu/PR202">[llvm-gcc] asserts when an extern inline function is redefined</a></li>
Chris Lattner69fba002004-01-12 05:15:04 +0000[diff] [blame]245<li><a href="http://llvm.cs.uiuc.edu/PR204">[llvmg++] Dynamically initialized constants cannot be marked 'constant'</a></li>
Chris Lattner7bae4ce2004-02-02 17:48:56 +0000[diff] [blame]246<li><a href="http://llvm.cs.uiuc.edu/PR216">[llvmgcc] floating-point unary minus is incorrect for +0.0</a></li>
Chris Lattner8a630012004-02-03 08:03:41 +0000[diff] [blame]247<li><a href="http://llvm.cs.uiuc.edu/PR221">[llvm-gcc] miscompilation of 'X = Y = Z' with aggregate values</a></li>
Chris Lattnerf0cbbab2004-03-08 04:55:45 +0000[diff] [blame]248<li><a href="http://llvm.cs.uiuc.edu/PR272">[llvmgcc] Invalid code created for complex division operation</a></li>
Chris Lattner0536f8d2004-03-09 00:40:49 +0000[diff] [blame]249<li><a href="http://llvm.cs.uiuc.edu/PR268">[llvmgcc] Incorrect code generation for pointer subtraction</a></li>
Chris Lattnerc567f402004-03-09 00:59:15 +0000[diff] [blame]250<li><a href="http://llvm.cs.uiuc.edu/PR261">[llvmg++] Crash assigning pointers-to-members with casted types</a></li>
Chris Lattner0ea60172004-03-16 09:01:10 +0000[diff] [blame]251<li><a href="http://llvm.cs.uiuc.edu/PR291">[llvm-g++] Cleanups and gotos don't mix properly</a></li>
Chris Lattner64f25172004-03-16 21:55:23 +0000[diff] [blame]252<li><a href="http://llvm.cs.uiuc.edu/PR297">[llvmgcc] Crash on auto register variable with specific register specified</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]253</ol>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]254
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]255</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]256
257<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]258<div class="doc_section">
259 <a name="portability">Portability and Supported Platforms</a>
260</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]261<!-- *********************************************************************** -->
262
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]263<div class="doc_text">
264
265<p>LLVM has been extensively tested on Intel and AMD machines running Red
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]266Hat Linux and FreeBSD. It has also been tested on Sun UltraSPARC workstations running Solaris 8.
John Criswell604cd3c2003-12-12 19:54:20 +0000[diff] [blame]267Additionally,
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]268LLVM works on Mac OS X 10.3 and above, but only with the C backend or
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]269interpreter (no native backend for the PowerPC is available yet).
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]270The core LLVM infrastructure uses "autoconf" for portability, so hopefully we
Chris Lattner14b5d5a2003-11-08 05:22:09 +0000[diff] [blame]271work on more platforms than that. However, it is likely that we
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]272missed something and that minor porting is required to get LLVM to work on
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]273new platforms. We welcome portability patches and error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]274
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]275</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]276
277<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]278<div class="doc_section">
279 <a name="knownproblems">Known Problems</a>
280</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]281<!-- *********************************************************************** -->
282
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]283<div class="doc_text">
284
285<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]286component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]287sections. If you run into a problem, please check the <a
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]288href="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]289there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]290
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]291</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]292
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]293<!-- ======================================================================= -->
294<div class="doc_subsection">
295 <a name="experimental">Experimental features included with this release</a>
296</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]297
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]298<div class="doc_text">
299
300<p>
301The following components of this LLVM release are either untested, known to be
302broken or unreliable, or are in early development. These components should not
303be relied on, and bugs should not be filed against them, but they may be useful
304to some people. In particular, if you would like to work on one of these
305components, please contact us on the llvmdev list.
306</p>
307
308<ul>
309<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
310 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
311
312<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
313 it should) and not thoroughly tested.</li>
314<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
315<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
316</ul>
317
318</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]319
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]320<!-- ======================================================================= -->
321<div class="doc_subsection">
322 <a name="core">Known problems with the LLVM Core</a>
323</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]324
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]325<div class="doc_text">
326
327<ul>
328
329<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
330work.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]331
332<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]333such, execution of a threaded program could cause these data structures to be
334corrupted.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]335
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]336<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]337
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]338<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]339table in the archive).</li>
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]340
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]341<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]342more than 256 elements</a>.</li>
343
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]344<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link objects/archives in the order specified on the command line.</a></li>
345
346<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]347values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]348targets whose setjmp/longjmp libraries do not save and restore the entire
349register file.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]350</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]351</div>
352
353<!-- ======================================================================= -->
354<div class="doc_subsection">
355 <a name="c-fe">Known problems with the C front-end</a>
356</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]357
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]358<!-- _______________________________________________________________________ -->
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]359<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]360
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]361<div class="doc_text">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]362<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]363<li>C99 Variable sized arrays do not release stack memory when they go out of
364 scope. Thus, the following program may run out of stack space:
365<pre>
366 for (i = 0; i != 1000000; ++i) {
367 int X[n];
368 foo(X);
369 }
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]370</pre></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]371
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]372<li>
373Initialization of global union variables can only be done
374<a href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest
375union member</a>.
376</li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]377
378<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly external function is re-declared as static</a></li>
379
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]380</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]381</div>
382
383<!-- _______________________________________________________________________ -->
384<div class="doc_subsubsection">
385 Notes
386</div>
387
388<div class="doc_text">
389
390<ul>
391
392<li>Inline assembly is not yet supported.</li>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]393
394<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]395support for floating point data types of any size other than 32 and 64
396bits.</li>
397
398<li>The following Unix system functionality has not been tested and may not
399work:
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]400 <ol>
401 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
402 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
403 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
404 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
405 - These functions have not been tested.
406 </ol></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]407
408<li>Although many GCC extensions are supported, some are not. In particular,
409 the following extensions are known to <b>not be</b> supported:
410 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]411 <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]412 <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>
413 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
414 <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]415 <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]416 <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>
417 <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]418 <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>
419 <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>
420 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
421 <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]422 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]423
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]424 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]425 attribute means that the LLVM compiler ignores the presence of the attribute,
426 but the code should still work. An unsupported attribute is one which is
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]427 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]428 the program.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]429
430 <ol>
431 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
432 Arrays whose length is computed at run time.<br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]433 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]434
435 <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]436
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]437 Declaring that functions have no side effects or that they can never
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]438 return.<br>
439
440 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
441 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
442 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
443
444 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
445 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
446 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
447
448 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
449 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
450 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]451
452 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
453 Specifying attributes of variables.<br>
454 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
455 <tt>deprecated</tt>, <tt>transparent_union</tt>,
456 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]457
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]458 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
459 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
460 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]461 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]462
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]463 <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]464 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]465 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]466
467 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
468 all target specific attributes.</li>
469
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]470 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
471 Other built-in functions.<br>
472 We support all builtins which have a C language equivalent (e.g.,
473 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
474 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]475 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]476
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]477 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]478
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]479 <p>The following extensions <b>are</b> known to be supported:</p>
480
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]481 <ol>
Chris Lattnerd3dc8502004-03-16 08:54:07 +0000[diff] [blame]482 <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]483 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
484 <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>
485 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
486 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
487 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
488 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
489 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
490 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
491 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
492 <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>
493 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
494 <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]495 <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]496 <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]497 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
498or arrays as values.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]499 <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]500 <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]501 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
502 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
503 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
504 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
505 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
506 <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>
507 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
508 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
509 <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>
510 <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>
511 <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]512 <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]513 <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>
514 <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]515 </ol></li>
516
517</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]518
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]519<p>If you run into GCC extensions which have not been included in any of these
520lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]521
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]522</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]523
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]524<!-- ======================================================================= -->
525<div class="doc_subsection">
526 <a name="c++-fe">Known problems with the C++ front-end</a>
527</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]528
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]529<div class="doc_text">
530
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]531<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]532has not been tested as thoroughly as the C front-end. It has been tested and
533works for a number of non-trivial programs, but there may be lurking bugs.
534Please report any bugs or problems.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]535
536</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]537
538<!-- _______________________________________________________________________ -->
Chris Lattner141ebb62004-02-14 04:12:41 +0000[diff] [blame]539<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]540
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]541<div class="doc_text">
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]542
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]543<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]544<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]545 front-end</a>.</li>
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]546</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]547</div>
548
549<!-- _______________________________________________________________________ -->
550<div class="doc_subsubsection">
551 Notes
552</div>
553
554<div class="doc_text">
555
556<ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]557
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]558<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
559parser is significantly more standards compliant (and picky) than prior GCC
560versions. For more information, see the C++ section of the <a
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]561href="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]562
563<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]564 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]565 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]566 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]567 better than most compilers).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]568
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]569<li>The LLVM C++ front-end follows the <a
570 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
571 This document, which is not Itanium specific, specifies a standard for name
572 mangling, class layout, v-table layout, RTTI formats, and other C++
573 representation issues. Because we use this API, code generated by the LLVM
574 compilers should be binary compatible with machine code generated by other
575 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
576 <i>However</i>, the exception handling mechanism used by LLVM is very
577 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]578 interact correctly</b>. </li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]579
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]580</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]581
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]582</div>
583
584<!-- ======================================================================= -->
585<div class="doc_subsection">
586 <a name="x86-be">Known problems with the X86 back-end</a>
587</div>
588
589<div class="doc_text">
590
591<ul>
Chris Lattnerc5b7b242004-02-08 22:23:33 +0000[diff] [blame]592<li>None so far.
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]593</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]594
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]595</div>
596
597<!-- ======================================================================= -->
598<div class="doc_subsection">
599 <a name="sparc-be">Known problems with the Sparc back-end</a>
600</div>
601
602<div class="doc_text">
603
604<ul>
Chris Lattnerc5b7b242004-02-08 22:23:33 +0000[diff] [blame]605<li>None so far.
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]606</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]607
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]608</div>
609
610<!-- ======================================================================= -->
611<div class="doc_subsection">
612 <a name="c-be">Known problems with the C back-end</a>
613</div>
614
615<div class="doc_text">
616
617<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]618
619<li>The C back-end produces code that violates the ANSI C Type-Based Alias
620Analysis rules. As such, special options may be necessary to compile the code
621(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]622problem probably cannot be fixed.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]623
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]624<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]625cannot include special floating point numbers like Not-A-Number or
626Infinity.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]627
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]628<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]629supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]630frontends.</li>
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]631
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]632</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]633
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]634</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]635
636<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]637<div class="doc_section">
638 <a name="additionalinfo">Additional Information</a>
639</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]640<!-- *********************************************************************** -->
641
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]642<div class="doc_text">
643
644<p>A wide variety of additional information is available on the LLVM web page,
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]645including mailing lists and publications describing algorithms and components
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]646implemented in LLVM. The web page also contains versions of the API
647documentation which is up-to-date with the CVS version of the source code. You
648can access versions of these documents specific to this release by going into
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]649the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]650
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]651<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]652us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
653lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]654
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]655</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]656
657<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]658
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]659<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]660<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]661 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]662 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
663 <a href="http://validator.w3.org/check/referer"><img
664 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
665
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]666 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]667 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]668</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]669
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]670</body>
671</html>