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gerrit-public.fairphone.software / toolchain / llvm-project / 458e79fa723d00d5486b7f0ae2d4724c27dcfa77 / . / 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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4<head>
Reid Spencere4190fa2004-11-18 18:38:58 +0000[diff] [blame]5 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]6 <link rel="stylesheet" href="llvm.css" type="text/css">
Chris Lattner7422bce2008-02-06 06:30:34 +0000[diff] [blame]7 <title>LLVM 2.2 Release Notes</title>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]8</head>
9<body>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]10
Chris Lattner7422bce2008-02-06 06:30:34 +0000[diff] [blame]11<div class="doc_title">LLVM 2.2 Release Notes</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]12
13<ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]14 <li><a href="#intro">Introduction</a></li>
15 <li><a href="#whatsnew">What's New?</a></li>
Chris Lattner77a51732004-04-30 22:17:12 +0000[diff] [blame]16 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]17 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]18 <li><a href="#knownproblems">Known Problems</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]19 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]20</ol>
21
Chris Lattner020e1fc2004-05-23 21:07:27 +0000[diff] [blame]22<div class="doc_author">
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]23 <p>Written by the <a href="http://llvm.org">LLVM Team</a><p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]24</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]25
Chris Lattner0ec35042008-02-06 18:00:48 +0000[diff] [blame]26<h1><font color="red">THIS IS A WORK IN PROGRESS FOR THE LLVM 2.2
27RELEASE</font</h1>
28
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]29<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]30<div class="doc_section">
31 <a name="intro">Introduction</a>
32</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]33<!-- *********************************************************************** -->
34
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]35<div class="doc_text">
36
37<p>This document contains the release notes for the LLVM compiler
Chris Lattner7422bce2008-02-06 06:30:34 +0000[diff] [blame]38infrastructure, release 2.2. Here we describe the status of LLVM, including
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]39major improvements from the previous release and any known problems. All LLVM
Chris Lattner98a33492007-05-09 04:58:11 +0000[diff] [blame]40releases may be downloaded from the <a href="http://llvm.org/releases/">LLVM
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]41releases web site</a>.</p>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]42
Chris Lattnerb5bb5972004-12-07 08:04:13 +0000[diff] [blame]43<p>For more information about LLVM, including information about the latest
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]44release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]45web site</a>. If you have questions or comments, the <a
46href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]47list</a> is a good place to send them.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]48
Reid Spencerc7f87f22007-07-09 08:04:31 +0000[diff] [blame]49<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]50main LLVM web page, this document applies to the <i>next</i> release, not the
51current one. To see the release notes for a specific releases, please see the
52<a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]53
54</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]55
56<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]57<div class="doc_section">
58 <a name="whatsnew">What's New?</a>
59</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]60<!-- *********************************************************************** -->
61
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]62<div class="doc_text">
63
Chris Lattner7422bce2008-02-06 06:30:34 +0000[diff] [blame]64<p>This is the thirteenth public release of the LLVM Compiler Infrastructure.
65It includes many features and refinements from LLVM 2.1.</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]66
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]67</div>
68
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]69<!-- Unfinished features in 2.2:
70 Index Set Splitting not enabled by default
71 Machine LICM
72 Machine Sinking
73 LegalizeDAGTypes
74 -->
75
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]76<!--=========================================================================-->
Chris Lattner406bddf2005-05-15 05:44:51 +0000[diff] [blame]77<div class="doc_subsection">
Chris Lattnera2735862008-02-10 07:04:35 +0000[diff] [blame]78<a name="deprecation">Deprecated features in LLVM 2.2</a>
79</div>
80
81<div class="doc_text">
82
83<p>This is the last LLVM release to support llvm-gcc 4.0, llvm-upgrade, and
84llvmc in its current form. llvm-gcc 4.0 has been replaced with llvm-gcc 4.2.
85llvm-upgrade is useful for upgrading llvm 1.9 files to llvm 2.x syntax, but you
86can always use an old release to do this. llvmc is currently mostly useless in
87llvm 2.2, and will be redesigned or removed in llvm 2.3.</p>
88
89</div>
90
91<!--=========================================================================-->
92<div class="doc_subsection">
Chris Lattner7422bce2008-02-06 06:30:34 +0000[diff] [blame]93<a name="frontends">llvm-gcc 4.0, llvm-gcc 4.2, and clang</a>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]94</div>
95
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]96<div class="doc_text">
Chris Lattner727c3742007-05-18 06:33:02 +0000[diff] [blame]97
Chris Lattner7422bce2008-02-06 06:30:34 +0000[diff] [blame]98<p>LLVM 2.2 fully supports both the llvm-gcc 4.0 and llvm-gcc 4.2 front-ends (in
99LLVM 2.1, llvm-gcc 4.2 was beta). Since LLVM 2.1, the llvm-gcc 4.2 front-end
100has made leaps and bounds and is now at least as good as 4.0 in virtually every
101area, and is better in several areas (for example, exception handling
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]102correctness, support for Ada and FORTRAN). We strongly recommend that you
103migrate from llvm-gcc 4.0 to llvm-gcc 4.2 in this release cycle because
104<b>LLVM 2.2 is the last release that will support llvm-gcc 4.0</b>: LLVM 2.3
105will only support the llvm-gcc 4.2 front-end.</p>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]106
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000[diff] [blame]107<p>The <a href="http://clang.llvm.org/">clang project</a> is an effort to build
108a set of new 'llvm native' front-end technologies for the LLVM optimizer
109and code generator. Currently, its C and Objective-C support is maturing
110nicely, and it has advanced source-to-source analysis and transformation
111capabilities. If you are interested in building source-level tools for C and
112Objective-C (and eventually C++), you should take a look. However, note that
113clang is not an official part of the LLVM 2.2 release. If you are interested in
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]114this project, please see its <a href="http://clang.llvm.org/">web site</a>.</p>
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000[diff] [blame]115
116</div>
117
118<!--=========================================================================-->
119<div class="doc_subsection">
120<a name="majorfeatures">Major New Features</a>
121</div>
122
123<div class="doc_text">
124
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]125<p>LLVM 2.2 includes several major new capabilities:</p>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]126
127<ul>
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]128<li>Scott Michel contributed an SPU backend, which generates code for the
129vector coprocessors on the Cell processor. (Status?)</li>
Tanya Lattner6ee68ca2007-05-16 23:25:46 +0000[diff] [blame]130
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]131<li>llvm-gcc 4.2 has significantly improved support for the GCC Ada (GNAT) and
132FORTRAN (gfortran) frontends. Duncan has the llvm-gcc 4.2 GNAT front-end
133supporting almost all of the ACATS testsuite (except 2 tests?). The llvm-gcc
1344.2 gfortran front-end supports a broad range of FORTRAN code, but does <a
135href="http://llvm.org/PR1971">not support EQUIVALENCE yet</a>.</li>
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000[diff] [blame]136
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]137<li>Dale contributed full support for long double on x86/x86-64 (where it is 80
138bits) and on Darwin PPC/PPC64 (where it is 128 bits). In previous LLVM
139releases, llvm-gcc silently mapped long double to double.</li>
Chris Lattner20ed4ef552008-02-09 22:58:07 +0000[diff] [blame]140
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]141<li>Gordon Henriksen rewrote most of the <a href="GarbageCollection.html"
142>Accurate Garbage Collection</a> code in the code generator, making the
143generated code more efficient and adding support for the Ocaml garbage collector
144metadata format.</li>
145
146<li>Christopher Lamb contributed support for multiple address spaces in LLVM
147IR. This is useful for supporting targets that have 'near' vs 'far' pointers,
148'RAM' vs 'ROM' pointers, or that have non-local memory that can be accessed with
149special instructions.</li>
Chris Lattner20ed4ef552008-02-09 22:58:07 +0000[diff] [blame]150
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]151<li>LLVM now includes a new set of detailed <a
152href="tutorial/index.html">tutorials</a>, which explain how to implement a
153language with LLVM and shows how to use several important APIs.</li>
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]154
Chris Lattner458e79f2008-02-10 08:18:42 +0000[diff] [blame^]155</ul>
156
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]157</div>
158
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]159<!--=========================================================================-->
160<div class="doc_subsection">
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]161<a name="coreimprovements">LLVM Core Improvements</a>
162</div>
163
164<div class="doc_text">
165<p>New features include:
166</p>
167
168<ul>
169<li>Gordon contributed support for C and Ocaml Bindings for the basic LLVM IR
170construction routines as well as several other auxiliary APIs.</li>
171
172<li>Anton added readnone/readonly attributes for modeling function side effects.
173Duncan hooked up GCC's pure/const attributes to use them and enhanced mod/ref
174analysis to use them.</li>
175
176<li>Devang added LLVMFoldingBuilder, a version of LLVMBuilder that implicitly
177simplifies the code as it is constructed.</li>
178
179<li>Ted Kremenek added a framework for generic object serialization to bitcode
180files. This support is only used by clang right now for ASTs but is extensible
181and could be used for serializing arbitrary other data into bitcode files.</li>
182
183<li>Duncan improved TargetData to distinguish between the size/alignment of a
184type in a register, in memory according to the platform ABI, and in memory when
185we have a choice.</li>
186
187<li>Duncan moved parameter attributes off of FunctionType and onto functions
188and calls. This makes it much easier to add attributes to a function in a
189transformation pass.</li>
190
191<li>Dan Gohman added support for vector sin, cos, and pow intrinsics.</li>
192
193</ul>
194
195</div>
196
197<!--=========================================================================-->
198<div class="doc_subsection">
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]199<a name="codegen">Code Generator Improvements</a>
200</div>
201
202<div class="doc_text">
203
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]204<p>We put a significant amount of work into the code generator infrastructure,
205which allows us to implement more aggressive algorithms and make it run
206faster:</p>
Chris Lattner4734a352007-09-26 05:44:21 +0000[diff] [blame]207
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]208<ul>
209
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]210<li>Owen refactored the existing LLVM dominator and loop information code to
211allow it work on the machine code representation. He contributed support for
212dominator and loop information on machine code and merged the code for forward
213and backward dominator computation.</li>
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]214
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]215<li>Dan added support for emitting debug information with .file and .loc
216directives on that support it, instead of emitting large tables in the .s
217file.</li>
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000[diff] [blame]218
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]219<li>Evan extended the DAG scheduler to model physical register dependencies
220explicitly and have the BURR scheduler pick a correct schedule based on the
221dependencies. This reduces our use of the 'flag' operand hack.</li>
Chris Lattner47ce2b22008-02-06 18:32:06 +0000[diff] [blame]222
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]223<li>Evan added initial support for register coalescing of subregister
224references.</li>
225
226<li>Rafael Espindola implemented initial support for a new 'byval' attribute,
227which allows more efficient by-value argument passing in the LLVM IR. Evan
228finished support for it and enabled it in the X86 (32- and 64-bit) and C
229backends.</li>
230
231<li>The LLVM TargetInstrInfo class can now answer queries about the mod/ref and
232side-effect behavior of MachineInstr's. This information is inferred
233automatically by TableGen from .td files for all instructions with
234patterns.</li>
235
236<li>Evan implemented simple live interval splitting on basic block boundaries.
237This allows the register allocator to be more successful at keeping values in
238registers in some parts of a value's live range, even if they need to be spilled
239in some other block.</li>
240
241<li>The new MachineRegisterInfo.h class provides support for efficiently
242iterating over all defs/uses of a register, and this information is
243automatically kept up-to-date. This support is similar to the use_iterator in
244the LLVM IR level.</li>
245
246<li>The MachineInstr, MachineOperand and TargetInstrDesc classes are simpler,
247more consistent, and better documented.</li>
248</ul>
249
250</div>
251
252<!--=========================================================================-->
253<div class="doc_subsection">
254<a name="optimizer">Optimizer Improvements</a>
255</div>
256
257<div class="doc_text">
258
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]259<p>In addition to a huge array of bug fixes and minor performance tweaks, the
260LLVM 2.2 optimizers support a few major enhancements:</p>
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]261
262<ul>
263
264<li>Daniel Berlin and Curtis Dunham rewrote Andersen's alias analysis to be
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]265several orders of magnitude faster, and implemented Offline Variable
266Substitution and Lazy Cycle Detection. Note that Andersen's is not enabled in
267llvm-gcc by default, but can be accessed through 'opt'.</li>
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]268
269<li>Dan Gohman contributed several enhancements to Loop Strength Reduction (LSR)
270to make it more aggressive with SSE intrinsics.</li>
271
272<li>Evan added support for simple exit value substitution to LSR.</li>
273
Chris Lattner20ed4ef552008-02-09 22:58:07 +0000[diff] [blame]274<li>Evan enhanced LSR to support induction variable reuse when the induction
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]275variables have different widths.</li>
Chris Lattner20ed4ef552008-02-09 22:58:07 +0000[diff] [blame]276
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]277</ul>
278
279</div>
280
281
282<!--=========================================================================-->
283<div class="doc_subsection">
284<a name="targetspecific">Target Specific Improvements</a>
285</div>
Chris Lattner727c3742007-05-18 06:33:02 +0000[diff] [blame]286
Chris Lattner89e761c2006-04-18 06:32:08 +0000[diff] [blame]287<div class="doc_text">
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]288<p>New target-specific features include:
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]289</p>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]290
291<ul>
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]292<li>Evan contributed support to the X86 backend to model the mod/ref behavior
293of the EFLAGS register explicitly in all instructions. This gives more freedom
294to the scheduler, and is a more explicit way to model the instructions.</li>
295<li>Dale contributed support for exception handling on Darwin/x86-64 and
296Darwin/ppc.</li>
297<li>Evan turned on if-conversion by default for ARM, allowing LLVM to take
298advantage of its predication features.</li>
299<li>Bruno added PIC support to the MIPS backend, fixed many bugs and improved
300support for architecture variants.</li>
301<li>Arnold Schwaighofer added support for X86 tail calls (limitations?
302details?).</li>
303<li>Evan contributed several enhancements to Darwin/x86 debug information,
304and improvements at -O0 (details?).</li>
Chris Lattner8ce1ba42007-05-17 21:41:31 +0000[diff] [blame]305</ul>
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]306
Chris Lattner8ce1ba42007-05-17 21:41:31 +0000[diff] [blame]307</div>
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]308
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]309<!--=========================================================================-->
310<div class="doc_subsection">
311<a name="otherimprovements">Other Improvements</a>
312</div>
313
314<div class="doc_text">
315<p>New features include:
316</p>
317
318<ul>
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]319<li>Gordon expanded and updated the <a href="Passes.html">LLVM Analysis and
320Transformation Passes</a> reference to include descriptions for each pass.</li>
321
322<li>We rewrote the lexer and parser used by TableGen to make them simpler
323and cleaner. This gives tblgen support for 'caret diagnostics'. The .ll file
324lexer was also rewritten to support caret diagnostics but doesn't use this
325support yet.</li>
326
327<li>Dale has been grinding through the GCC testsuite, and marked many
328LLVM-incompatible tests as not-to-be-run (for example, if they are grepping
329through some GCC dump file that LLVM doesn't produce), he also found and fixed
330many LLVM bugs exposed by the testsuite.</li>
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]331</ul>
332
333</div>
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]334
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]335<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]336<div class="doc_section">
337 <a name="portability">Portability and Supported Platforms</a>
338</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]339<!-- *********************************************************************** -->
340
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]341<div class="doc_text">
342
John Criswell64307722004-12-08 20:35:47 +0000[diff] [blame]343<p>LLVM is known to work on the following platforms:</p>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]344
345<ul>
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]346<li>Intel and AMD machines running Red Hat Linux, Fedora Core and FreeBSD
Reid Spencer9803b402005-05-17 02:47:27 +0000[diff] [blame]347 (and probably other unix-like systems).</li>
Chris Lattner7422bce2008-02-06 06:30:34 +0000[diff] [blame]348<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit and
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]349 64-bit modes.</li>
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000[diff] [blame]350<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]351<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
352 support is available for native builds with Visual C++).</li>
353<li>Sun UltraSPARC workstations running Solaris 8.</li>
John Criswelld5234922005-05-13 20:28:15 +0000[diff] [blame]354<li>Alpha-based machines running Debian GNU/Linux.</li>
355<li>Itanium-based machines running Linux and HP-UX.</li>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]356</ul>
357
Brian Gaekee3e557e2004-05-09 05:28:35 +0000[diff] [blame]358<p>The core LLVM infrastructure uses
359<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
360to the machine and operating system on which it is built. However, minor
361porting may be required to get LLVM to work on new platforms. We welcome your
362portability patches and reports of successful builds or error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]363
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]364</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]365
366<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]367<div class="doc_section">
368 <a name="knownproblems">Known Problems</a>
369</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]370<!-- *********************************************************************** -->
371
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]372<div class="doc_text">
373
374<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]375component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]376sections. If you run into a problem, please check the <a
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]377href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]378there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]379
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]380</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]381
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]382<!-- ======================================================================= -->
383<div class="doc_subsection">
384 <a name="experimental">Experimental features included with this release</a>
385</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]386
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]387<div class="doc_text">
388
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]389<p>The following components of this LLVM release are either untested, known to
390be broken or unreliable, or are in early development. These components should
391not be relied on, and bugs should not be filed against them, but they may be
392useful to some people. In particular, if you would like to work on one of these
Chris Lattner05a225b2006-08-09 04:08:52 +0000[diff] [blame]393components, please contact us on the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]394
395<ul>
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000[diff] [blame]396<li>The <tt>-cee</tt> pass is known to be buggy and will be removed in
397 LLVM 2.3.</li>
Chris Lattner7422bce2008-02-06 06:30:34 +0000[diff] [blame]398<li>The MSIL, IA64, Alpha, and MIPS backends are experimental.</li>
399<li>The LLC "<tt>-filetype=asm</tt>" (the default) is the only supported
400 value for this option.</li>
401<li>The llvmc tool is not supported.</li>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]402</ul>
403
404</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]405
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]406<!-- ======================================================================= -->
407<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]408 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]409</div>
410
411<div class="doc_text">
412
413<ul>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]414<li>The X86 backend does not yet support <a href="http://llvm.org/PR879">inline
Chris Lattner98a33492007-05-09 04:58:11 +0000[diff] [blame]415 assembly that uses the X86 floating point stack</a>.</li>
Chris Lattner8e061162007-09-26 06:01:35 +0000[diff] [blame]416<li>The X86 backend occasionally has <a href="http://llvm.org/PR1649">alignment
417 problems</a> on operating systems that don't require 16-byte stack alignment
418 (including most non-darwin OS's like linux).</li>
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]419<li>The X86 backend generates inefficient floating point code when configured to
420 generate code for systems that don't have SSE2.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]421</ul>
422
423</div>
424
425<!-- ======================================================================= -->
426<div class="doc_subsection">
427 <a name="ppc-be">Known problems with the PowerPC back-end</a>
428</div>
429
430<div class="doc_text">
431
432<ul>
Nicolas Geoffray77d99502007-05-15 09:21:28 +0000[diff] [blame]433<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]434compilation, and lacks support for debug information.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]435</ul>
436
437</div>
438
439<!-- ======================================================================= -->
440<div class="doc_subsection">
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]441 <a name="arm-be">Known problems with the ARM back-end</a>
442</div>
443
444<div class="doc_text">
445
446<ul>
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]447<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sands47fc0a22007-09-26 15:59:54 +0000[diff] [blame]448processors, thumb programs can crash or produce wrong
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]449results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]450<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
451</li>
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]452<li>There is a bug in QEMU-ARM (&lt;= 0.9.0) which causes it to incorrectly execute
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]453programs compiled with LLVM. Please use more recent versions of QEMU.</li>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]454</ul>
455
456</div>
457
458<!-- ======================================================================= -->
459<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]460 <a name="sparc-be">Known problems with the SPARC back-end</a>
461</div>
462
463<div class="doc_text">
464
465<ul>
466<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
467 support the 64-bit SPARC ABI (-m64).</li>
468</ul>
469
470</div>
471
472<!-- ======================================================================= -->
473<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]474 <a name="alpha-be">Known problems with the Alpha back-end</a>
475</div>
476
477<div class="doc_text">
478
479<ul>
480
481<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
482appropriate nops inserted to ensure restartability.</li>
483
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]484</ul>
485</div>
486
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]487<!-- ======================================================================= -->
488<div class="doc_subsection">
489 <a name="ia64-be">Known problems with the IA64 back-end</a>
490</div>
491
492<div class="doc_text">
493
494<ul>
495
496<li>C++ programs are likely to fail on IA64, as calls to <tt>setjmp</tt> are
497made where the argument is not 16-byte aligned, as required on IA64. (Strictly
498speaking this is not a bug in the IA64 back-end; it will also be encountered
499when building C++ programs using the C back-end.)</li>
500
501<li>The C++ front-end does not use <a href="http://llvm.org/PR406">IA64
502ABI compliant layout of v-tables</a>. In particular, it just stores function
503pointers instead of function descriptors in the vtable. This bug prevents
504mixing C++ code compiled with LLVM with C++ objects compiled by other C++
505compilers.</li>
506
507<li>There are a few ABI violations which will lead to problems when mixing LLVM
508output with code built with other compilers, particularly for floating-point
509programs.</li>
510
511<li>Defining vararg functions is not supported (but calling them is ok).</li>
512
Chris Lattner98a33492007-05-09 04:58:11 +0000[diff] [blame]513<li>The Itanium backend has bitrotted somewhat.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]514</ul>
515
516</div>
517
518<!-- ======================================================================= -->
519<div class="doc_subsection">
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]520 <a name="c-be">Known problems with the C back-end</a>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]521</div>
522
523<div class="doc_text">
524
525<ul>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]526<li><a href="http://llvm.org/PR802">The C backend does not support inline
527 assembly code</a>.</li>
Chris Lattner8e061162007-09-26 06:01:35 +0000[diff] [blame]528<li><a href="http://llvm.org/PR1126">The C backend does not support vectors
529 yet</a>.</li>
Chris Lattner8e061162007-09-26 06:01:35 +0000[diff] [blame]530<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
531 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
532 C++ code compiled with LLC or native compilers.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]533</ul>
534
535</div>
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]536
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]537
538<!-- ======================================================================= -->
539<div class="doc_subsection">
540 <a name="c-fe">Known problems with the C front-end</a>
541</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]542
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]543<!-- _______________________________________________________________________ -->
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]544<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]545
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]546<div class="doc_text">
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]547
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000[diff] [blame]548<p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time
549Optimization</a> on most platforms "out-of-the-box". Please inquire on the
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]550llvmdev mailing list if you are interested.</p>
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]551
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]552</div>
553
554<!-- _______________________________________________________________________ -->
555<div class="doc_subsubsection">
556 Notes
557</div>
558
559<div class="doc_text">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]560<ul>
561
Chris Lattner2f131fe2007-05-17 22:02:24 +0000[diff] [blame]562<li><p>llvm-gcc does <b>not</b> support <tt>__builtin_apply</tt> yet.
563 See <a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</p>
564</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]565
Duncan Sandsea7a3262007-05-18 09:04:20 +0000[diff] [blame]566<li><p>llvm-gcc <b>partially</b> supports these GCC extensions:</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]567 <ol>
Duncan Sands47fc0a22007-09-26 15:59:54 +0000[diff] [blame]568 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html#Nested%20Functions">Nested Functions</a>:
569
570 As in Algol and Pascal, lexical scoping of functions.
571 Nested functions are supported, but llvm-gcc does not support
Duncan Sands755d9302007-09-26 16:24:52 +0000[diff] [blame]572 taking the address of a nested function (except on the X86-32 target)
Duncan Sands47fc0a22007-09-26 15:59:54 +0000[diff] [blame]573 or non-local gotos.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]574
575 <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]576
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]577 Declaring that functions have no side effects or that they can never
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]578 return.<br>
579
Anton Korobeynikovb8a47242007-11-16 11:12:01 +0000[diff] [blame]580 <b>Supported:</b> <tt>alias</tt>, <tt>always_inline</tt>, <tt>cdecl</tt>,
581 <tt>const</tt>, <tt>constructor</tt>, <tt>destructor</tt>,
Anton Korobeynikove7cbbfc2006-11-18 08:04:48 +0000[diff] [blame]582 <tt>deprecated</tt>, <tt>fastcall</tt>, <tt>format</tt>,
Anton Korobeynikovb8a47242007-11-16 11:12:01 +0000[diff] [blame]583 <tt>format_arg</tt>, <tt>non_null</tt>, <tt>noinline</tt>,
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]584 <tt>noreturn</tt>, <tt>nothrow</tt>, <tt>pure</tt>, <tt>regparm</tt>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]585 <tt>section</tt>, <tt>stdcall</tt>, <tt>unused</tt>, <tt>used</tt>,
586 <tt>visibility</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]587
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]588 <b>Ignored:</b> <tt>malloc</tt>,
Anton Korobeynikovb8a47242007-11-16 11:12:01 +0000[diff] [blame]589 <tt>no_instrument_function</tt></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]590 </ol>
Chris Lattner2f131fe2007-05-17 22:02:24 +0000[diff] [blame]591</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]592
Chris Lattner2f131fe2007-05-17 22:02:24 +0000[diff] [blame]593<li><p>llvm-gcc supports the vast majority of GCC extensions, including:</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]594
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]595 <ol>
Chris Lattner2f131fe2007-05-17 22:02:24 +0000[diff] [blame]596 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pragmas.html#Pragmas">Pragmas</a>: Pragmas accepted by GCC.</li>
597 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
598 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
599 Other built-in functions.</li>
600 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
601 Specifying attributes of variables.</li>
602 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html#Type%20Attributes">Type Attributes</a>: Specifying attributes of types.</li>
603 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread_002dLocal.html">Thread-Local</a>: Per-thread variables.</li>
604 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
605 Arrays whose length is computed at run time.</li>
Chris Lattnerd3dc8502004-03-16 08:54:07 +0000[diff] [blame]606 <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]607 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
608 <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]609 <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]610 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
611 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
612 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
613 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
614 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
615 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
616 <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>
617 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]618 <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>
619 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands.</li>
620 <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>
621 <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>
622 <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>
623 <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>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]624 <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]625 <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]626 <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]627 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
628or arrays as values.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]629 <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]630 <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]631 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
632 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
633 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
Tanya Lattner7591b822004-12-08 18:29:38 +0000[diff] [blame]634 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C_002b_002b-Comments.html#C_002b_002b-Comments">C++ Comments</a>: C++ comments are recognized.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]635 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
636 <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>
637 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
638 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
639 <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>
640 <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>
641 <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]642 <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]643 <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>
644 <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]645 </ol></li>
646
647</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]648
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]649<p>If you run into GCC extensions which have not been included in any of these
650lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]651
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]652</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]653
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]654<!-- ======================================================================= -->
655<div class="doc_subsection">
656 <a name="c++-fe">Known problems with the C++ front-end</a>
657</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]658
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]659<div class="doc_text">
660
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]661<p>The C++ front-end is considered to be fully
Chris Lattnerb5bb5972004-12-07 08:04:13 +0000[diff] [blame]662tested and works for a number of non-trivial programs, including LLVM
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]663itself, Qt, Mozilla, etc.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]664
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]665<ul>
Chris Lattner7422bce2008-02-06 06:30:34 +0000[diff] [blame]666<li>Exception handling only works well on the X86 and PowerPC targets.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]667</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]668
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]669</div>
670
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]671
Chris Lattnerb62a5f02005-05-15 16:01:20 +0000[diff] [blame]672
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]673<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]674<div class="doc_section">
675 <a name="additionalinfo">Additional Information</a>
676</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]677<!-- *********************************************************************** -->
678
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]679<div class="doc_text">
680
Chris Lattnercb5596d2005-05-16 17:13:10 +0000[diff] [blame]681<p>A wide variety of additional information is available on the <a
Chris Lattnere0c1df42007-05-18 00:44:29 +0000[diff] [blame]682href="http://llvm.org">LLVM web page</a>, in particular in the <a
683href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencerc7f87f22007-07-09 08:04:31 +0000[diff] [blame]684contains versions of the API documentation which is up-to-date with the
685Subversion version of the source code.
Misha Brukman96158092005-03-30 19:14:24 +0000[diff] [blame]686You can access versions of these documents specific to this release by going
687into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]688
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]689<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]690us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]691lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]692
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]693</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]694
695<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]696
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]697<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]698<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]699 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]700 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
701 <a href="http://validator.w3.org/check/referer"><img
Chris Lattner458e79f2008-02-10 08:18:42 +0000[diff] [blame^]702 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]703
Chris Lattnere0c1df42007-05-18 00:44:29 +0000[diff] [blame]704 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]705 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]706</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]707
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]708</body>
709</html>