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gerrit-public.fairphone.software / toolchain / llvm-project / 89e761c19dca70028f90a190b6d3dfcb5ff5a6ea / . / 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 Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]7 <title>LLVM 1.7 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 Lattner578ab912005-11-08 21:29:17 +0000[diff] [blame]11<div class="doc_title">LLVM 1.7 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
26<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]27<div class="doc_section">
28 <a name="intro">Introduction</a>
29</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]30<!-- *********************************************************************** -->
31
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]32<div class="doc_text">
33
34<p>This document contains the release notes for the LLVM compiler
Chris Lattner578ab912005-11-08 21:29:17 +0000[diff] [blame]35infrastructure, release 1.7. Here we describe the status of LLVM, including any
Chris Lattner406bddf2005-05-15 05:44:51 +0000[diff] [blame]36known problems and major improvements from the previous release. The most
37up-to-date version of this document can be found on the <a
Chris Lattner578ab912005-11-08 21:29:17 +0000[diff] [blame]38href="http://llvm.org/releases/">LLVM releases web site</a>. If you are
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]39not reading this on the LLVM web pages, you should probably go there because
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]40this document may be updated after the release.</p>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]41
Chris Lattnerb5bb5972004-12-07 08:04:13 +0000[diff] [blame]42<p>For more information about LLVM, including information about the latest
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]43release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]44web site</a>. If you have questions or comments, the <a
45href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]46list</a> is a good place to send them.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]47
Chris Lattnerf3a7c242004-12-09 22:22:58 +0000[diff] [blame]48<p>Note that if you are reading this file from CVS or the main LLVM web page,
49this document applies to the <i>next</i> release, not the current one. To see
50the release notes for the current or previous releases, see the <a
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]51href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]52
53</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]54
55<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]56<div class="doc_section">
57 <a name="whatsnew">What's New?</a>
58</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]59<!-- *********************************************************************** -->
60
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]61<div class="doc_text">
62
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]63<p>This is the eighth public release of the LLVM Compiler Infrastructure. This
64release incorporates a large number of enhancements and new features,
65including vector support (Intel SSE and Altivec), a new GCC4.0-based
66C/C++ front-end, Objective C/C++ support, inline assembly support, and many
67other big features.
68</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]69
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]70</div>
71
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]72<!--=========================================================================-->
Chris Lattner406bddf2005-05-15 05:44:51 +0000[diff] [blame]73<div class="doc_subsection">
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]74<a name="newfeatures">New Features in LLVM 1.7</a>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]75</div>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]76
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]77<!--_________________________________________________________________________-->
78<div class="doc_subsubsection"><a name="llvmgcc4">GCC4.0-based llvm-gcc
79front-end</a></div>
80
81<div class="doc_text">
82
83<p>LLVM 1.8 includes a brand new llvm-gcc, based on GCC 4.0.1. This version
84of llvm-gcc solves many serious long-standing problems with llvm-gcc, including
85all of those blocked by the <a href="http://llvm.org/PR498">llvm-gcc 4 meta
86bug</a>. In addition, llvm-gcc4 implements support for many new features,
87including GCC inline assembly, generic vector support, SSE and Altivec
88intrinsics, and several new GCC attributes. In addition, llvm-gcc4 is
89significantly faster than llvm-gcc3, respects -O options, its -c/-S options
90correspond to GCC's (they emit native code).</p>
91
92<p>If you can use it, llvm-gcc4 is offers significant new functionality, and we
93hope that it will replace llvm-gcc3 completely in a future release.
94Unfortunately, it does not currently support C++ exception handling at all, and
95it only works on Apple Mac OS/X machines with X86 or PowerPC processors.
96</p>
97
98</div>
99
100<!--_________________________________________________________________________-->
101<div class="doc_subsubsection"><a name="inlineasm">Inline Assembly
102Support</a></div>
103
104<div class="doc_text">
105
106<p>The LLVM IR and llvm-gcc4 front-end now fully support arbitrary GCC <a
107href="LangRef.html#inlineasm">inline assembly</a>. The LLVM X86 and PowerPC
108code generators have initial support for it,
109being able to compile basic statements, but are missing some features. Please
110report any inline asm statements that crash the compiler or that are miscompiled
111as bugs.</p>
112
113</div>
114
115<!--_________________________________________________________________________-->
116<div class="doc_subsubsection"><a name="newsparc">New SPARC backend</a></div>
117
118<div class="doc_text">
119
120<p>LLVM 1.7 includes a new, fully functional, SPARC backend built in the
121target-independent code generator. This SPARC backend includes support for
122SPARC V8 and SPARC V9 subtargets (controlling whether V9 features can be used),
123and targets the 32-bit SPARC ABI.</p>
124
125<p>The LLVM 1.7 release is the last release that will include the LLVM "SparcV9"
126backend, which was the very first LLVM native code generator. In 1.8, it will
127be removed, replaced with the new SPARC backend.</p>
128
129</div>
130
131<!--_________________________________________________________________________-->
132<div class="doc_subsubsection"><a name="genvector">Generic Vector Support
133</a></div>
134
135<div class="doc_text">
136
137<p>LLVM now includes significantly extended support for SIMD vectors in its
138core instruction set. It now includes three new instructions for manipulating
139vectors: <a href="LangRef.html#i_extractelement"><tt>extractelement</tt></a>,
140<a href="LangRef.html#i_insertelement"><tt>insertelement</tt></a>, and
141<a href="LangRef.html#i_shufflevector"><tt>shufflevector</tt></a>. Further,
142many bugs in vector handling have been fixed, and vectors are now supported by
143the target-independent code generator. For example, if a vector operation is
144not supported by a particular target, it will be correctly broken down and
145executed as scalar operations.</p>
146
147<p>Because llvm-gcc3 does not support GCC generic vectors or vector intrinsics,
148so llvm-gcc4 must be used.</p>
149</div>
150
151
152<!--_________________________________________________________________________-->
153<div class="doc_subsubsection"><a name="ssealtivec">Intel SSE and PowerPC
154Altivec support
155</a></div>
156
157<div class="doc_text">
158
159<p>The LLVM X86 backend now supports Intel SSE 1, 2, and 3, and now uses scalar
160SSE operations to implement scalar floating point math when the target supports
161SSE1 (for floats) or SSE2 (for doubles). Vector SSE instructions are generated
162by llvm-gcc4 when the generic vector mechanism or specific SSE intrinsics are
163used.
164</p>
165
166<p>The LLVM PowerPC backend now supports the Altivec instruction set, including
167both GCC -maltivec and -faltivec modes. Altivec instructions are generated
168by llvm-gcc4 when the generic vector mechanism or specific Altivec intrinsics
169are used.
170</p>
171
172</div>
173
Chris Lattner89e761c2006-04-18 06:32:08 +0000[diff] [blame^]174<!--_________________________________________________________________________-->
175<div class="doc_subsubsection"><a name="othernew">Optimizer
176Improvements</a></div>
177
178<div class="doc_text">
179<ul>
180<li>The Loop Unswitching pass (<tt>-loop-unswitch</tt>) has had several bugs
181 fixed, has several new features, and is enabled by default in llvmgcc3
182 now.</li>
183<li>The Loop Strength Reduction pass (<tt>-loop-reduce</tt>) is now enabled for
184 the X86 backend.</li>
185<li>The Instruction Combining pass (<tt>-instcombine</tt>) now includes a
186 framework and implementation for simplifying code based on whether computed
187 bits are demanded or not.</li>
188<li>The Scalar Replacement of Aggregates pass (<tt>-scalarrepl</tt>) can now
189 promote simple unions to registers.</li>
190<li>Several LLVM passes are <a href="http://llvm.org/PR681">significantly
191faster</a>.</li>
192</ul>
193</div>
194
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]195
196<!--_________________________________________________________________________-->
197<div class="doc_subsubsection"><a name="othernew">Other New Features</a></div>
198
Chris Lattnera38fe5f2006-02-05 06:39:36 +0000[diff] [blame]199<div class="doc_text">
200<ul>
Chris Lattner89e761c2006-04-18 06:32:08 +0000[diff] [blame^]201<li>LLVM now supports first class global ctor/dtor initialization lists, no
202 longer forcing targets to use "__main".</li>
203<li>LLVM supports assigning globals and functions to a particular section
204 in the result executable using the GCC section attribute.</li>
205<li><a href="ExtendingLLVM.html">Adding intrinsics to LLVM</a> is now
206significantly easier.</li>
207<li>llvmgcc4 now fully supports C99 Variable Length Arrays, including dynamic
208 stack deallocation.</li>
209
Chris Lattnera38fe5f2006-02-05 06:39:36 +0000[diff] [blame]210</ul>
211</div>
John Criswell51e2a482005-06-29 16:22:34 +0000[diff] [blame]212
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]213
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]214<!--=========================================================================-->
215<div class="doc_subsection">
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]216<a name="changes">Significant Changes in LLVM 1.7</a>
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]217</div>
218
219<div class="doc_text">
220<ul>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]221<li>The LLVM intrinsics used to be overloaded based on type: for example,
222 <a href="LangRef.html#int_ctpop"><tt>llvm.ctpop</tt></a> could work with any
223 integer datatype. They are now separated into different intrinsics with
224 suffixes to denote their argument type (e.g. <tt>llvm.ctpop.i32</tt>)). Old
225 LLVM .ll and .bc files that use these intrinsics will continue to work with
226 new LLVM versions (they are transparently upgraded by the parsers), but will
227 cause a warning to be emitted.</li>
228<li>The <tt>llvm.readport</tt>, <tt>llvm.writeport</tt>, <tt>llvm.readio</tt>,
229 and <tt>llvm.writeio</tt> intrinsics have been removed. The first two
230 were ever only supported by the X86 backend, the last two were never
231 correctly supported by any target, and none were accessible through the
232 C front-end. Inline assembly support can now be used to
233 implement these operations.</li>
234<li>The <tt>llvm-db</tt> tool had basic support for stepping through code, which
235 used the JIT. This code has been removed, and DWARF emission support added
236 instead. <tt>llvm-db</tt> still exists in CVS if someone wanted to write a
237 <tt>ptrace</tt> backend for it.</li>
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]238</ul>
239</div>
240
241
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]242<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]243<div class="doc_section">
244 <a name="portability">Portability and Supported Platforms</a>
245</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]246<!-- *********************************************************************** -->
247
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]248<div class="doc_text">
249
John Criswell64307722004-12-08 20:35:47 +0000[diff] [blame]250<p>LLVM is known to work on the following platforms:</p>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]251
252<ul>
Reid Spencer9803b402005-05-17 02:47:27 +0000[diff] [blame]253 <li>Intel and AMD machines running Red Hat Linux, Fedora Core and FreeBSD
254 (and probably other unix-like systems).</li>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]255<li>Sun UltraSPARC workstations running Solaris 8.</li>
Chris Lattnerb5bb5972004-12-07 08:04:13 +0000[diff] [blame]256<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
257 support is available for native builds with Visual C++).</li>
Chris Lattner8ad30362005-10-29 05:14:01 +0000[diff] [blame]258<li>PowerPC and X86-based Mac OS X systems, running 10.2 and above.</li>
John Criswelld5234922005-05-13 20:28:15 +0000[diff] [blame]259<li>Alpha-based machines running Debian GNU/Linux.</li>
260<li>Itanium-based machines running Linux and HP-UX.</li>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]261</ul>
262
Brian Gaekee3e557e2004-05-09 05:28:35 +0000[diff] [blame]263<p>The core LLVM infrastructure uses
264<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
265to the machine and operating system on which it is built. However, minor
266porting may be required to get LLVM to work on new platforms. We welcome your
267portability patches and reports of successful builds or error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]268
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]269</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]270
271<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]272<div class="doc_section">
273 <a name="knownproblems">Known Problems</a>
274</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]275<!-- *********************************************************************** -->
276
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]277<div class="doc_text">
278
279<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]280component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]281sections. If you run into a problem, please check the <a
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]282href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]283there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]284
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]285</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]286
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]287<!-- ======================================================================= -->
288<div class="doc_subsection">
289 <a name="experimental">Experimental features included with this release</a>
290</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]291
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]292<div class="doc_text">
293
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]294<p>The following components of this LLVM release are either untested, known to
295be broken or unreliable, or are in early development. These components should
296not be relied on, and bugs should not be filed against them, but they may be
297useful to some people. In particular, if you would like to work on one of these
298components, please contact us on the llvmdev list.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]299
300<ul>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]301<li>The <tt>-cee</tt> pass is known to be buggy, and may be removed in in a
302 future release.</li>
Chris Lattnera38fe5f2006-02-05 06:39:36 +0000[diff] [blame]303<li>The IA64 code generator is experimental.</li>
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]304<li>The Alpha JIT is experimental.</li>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]305<li>"<tt>-filetype=asm</tt>" (the default) is the only supported value for the
306 <tt>-filetype</tt> llc option.</li>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]307</ul>
308
309</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]310
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]311<!-- ======================================================================= -->
312<div class="doc_subsection">
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]313 <a name="build">Known problems with the Build System</a>
314</div>
315
316<div class="doc_text">
317
318<ul>
319 <li>The <a href="http://llvm.org/PR656">configure script sometimes fails on Solaris/Sparc</a>. A work around is documented in <a href="http://llvm.org/PR656">PR656.</a></li>
320</ul>
321</div>
322
323
324<!-- ======================================================================= -->
325<div class="doc_subsection">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]326 <a name="core">Known problems with the LLVM Core</a>
327</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]328
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]329<div class="doc_text">
330
331<ul>
Misha Brukman96158092005-03-30 19:14:24 +0000[diff] [blame]332 <li>In the JIT, <tt>dlsym()</tt> on a symbol compiled by the JIT will not
333 work.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]334</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]335</div>
336
337<!-- ======================================================================= -->
338<div class="doc_subsection">
339 <a name="c-fe">Known problems with the C front-end</a>
340</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]341
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]342<!-- _______________________________________________________________________ -->
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]343<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]344
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]345<div class="doc_text">
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]346
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]347<p>
348llvm-gcc3 has many significant problems that are fixed by llvm-gcc4. See
349 those blocked on the <a href="http://llvm.org/PR498">llvm-gcc4 meta bug</a>.
350Two signicant ones include:</p>
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]351
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]352<ul>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]353<li>With llvm-gcc3,
354 C99 variable sized arrays do not release stack memory when they go out of
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]355 scope. Thus, the following program may run out of stack space:
356<pre>
357 for (i = 0; i != 1000000; ++i) {
358 int X[n];
359 foo(X);
360 }
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]361</pre></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]362
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]363<li>With llvm-gcc3, Initialization of global union variables can only be done <a
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]364href="http://llvm.org/PR162">with the largest union member</a>.</li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]365
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]366</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]367</div>
368
369<!-- _______________________________________________________________________ -->
370<div class="doc_subsubsection">
371 Notes
372</div>
373
374<div class="doc_text">
375
376<ul>
377
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]378<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]379support for floating point data types of any size other than 32 and 64
380bits.</li>
381
382<li>The following Unix system functionality has not been tested and may not
383work:
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]384 <ol>
385 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
386 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
387 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
388 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
389 - These functions have not been tested.
390 </ol></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]391
392<li>Although many GCC extensions are supported, some are not. In particular,
393 the following extensions are known to <b>not be</b> supported:
394 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]395 <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]396 <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>
397 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
398 <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]399 <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]400 <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>
401 <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]402 <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>
403 <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>
Tanya Lattner63371342004-12-08 18:25:34 +0000[diff] [blame]404 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread_002dLocal.html">Thread-Local</a>: Per-thread variables.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]405 <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]406 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]407
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]408 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]409 attribute means that the LLVM compiler ignores the presence of the attribute,
410 but the code should still work. An unsupported attribute is one which is
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]411 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]412 the program.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]413
414 <ol>
415 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
416 Arrays whose length is computed at run time.<br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]417 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]418
419 <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]420
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]421 Declaring that functions have no side effects or that they can never
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]422 return.<br>
423
424 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
John Criswell64307722004-12-08 20:35:47 +0000[diff] [blame]425 <tt>noreturn</tt>, <tt>constructor</tt>, <tt>destructor</tt>,
Chris Lattnerca18d192005-12-05 05:23:06 +0000[diff] [blame]426 <tt>unused</tt>, <tt>used</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]427 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
428
John Criswell64307722004-12-08 20:35:47 +0000[diff] [blame]429 <b>Ignored:</b> <tt>noinline</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]430 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
431 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
432
Chris Lattnerca18d192005-12-05 05:23:06 +0000[diff] [blame]433 <b>Unsupported:</b> <tt>section</tt>, <tt>alias</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]434 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
435 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]436
437 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
438 Specifying attributes of variables.<br>
439 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
440 <tt>deprecated</tt>, <tt>transparent_union</tt>,
Chris Lattnerca18d192005-12-05 05:23:06 +0000[diff] [blame]441 <tt>unused</tt>, <tt>used</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]442
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]443 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
444 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
445 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]446 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]447
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]448 <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]449 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]450 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]451
452 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
453 all target specific attributes.</li>
454
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]455 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
456 Other built-in functions.<br>
457 We support all builtins which have a C language equivalent (e.g.,
458 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
459 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Chris Lattnerb7c4bac2004-06-18 06:26:29 +0000[diff] [blame]460 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt>
461 (currently ignored). We also support builtins for ISO C99 floating
Chris Lattnerb34b2732005-05-07 02:21:21 +0000[diff] [blame]462 point comparison macros (e.g., <tt>__builtin_islessequal</tt>),
463 <tt>__builtin_prefetch</tt>, <tt>__builtin_popcount[ll]</tt>,
464 <tt>__builtin_clz[ll]</tt>, and <tt>__builtin_ctz[ll]</tt>.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]465 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]466
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]467 <p>The following extensions <b>are</b> known to be supported:</p>
468
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]469 <ol>
Chris Lattnerd3dc8502004-03-16 08:54:07 +0000[diff] [blame]470 <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]471 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
472 <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]473 <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]474 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
475 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
476 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
477 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
478 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
479 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
480 <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>
481 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
482 <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]483 <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]484 <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]485 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
486or arrays as values.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]487 <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]488 <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]489 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
490 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
491 <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]492 <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]493 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
494 <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>
495 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
496 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
497 <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>
498 <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>
499 <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]500 <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]501 <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>
502 <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]503 </ol></li>
504
505</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]506
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]507<p>If you run into GCC extensions which have not been included in any of these
508lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]509
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]510</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]511
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]512<!-- ======================================================================= -->
513<div class="doc_subsection">
514 <a name="c++-fe">Known problems with the C++ front-end</a>
515</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]516
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]517<div class="doc_text">
518
Reid Spencer55684c32004-12-07 08:39:08 +0000[diff] [blame]519<p>For this release, the C++ front-end is considered to be fully
Chris Lattnerb5bb5972004-12-07 08:04:13 +0000[diff] [blame]520tested and works for a number of non-trivial programs, including LLVM
521itself.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]522
523</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]524
525<!-- _______________________________________________________________________ -->
Chris Lattner141ebb62004-02-14 04:12:41 +0000[diff] [blame]526<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]527
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]528<div class="doc_text">
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]529
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]530<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]531<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]532 front-end</a>.</li>
Chris Lattner041e6c92004-07-17 02:04:41 +0000[diff] [blame]533
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]534</ul>
535
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]536</div>
537
538<!-- _______________________________________________________________________ -->
539<div class="doc_subsubsection">
540 Notes
541</div>
542
543<div class="doc_text">
544
545<ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]546
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]547<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]548 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]549 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]550 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]551 better than most compilers).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]552
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]553<li>The LLVM C++ front-end follows the <a
554 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
555 This document, which is not Itanium specific, specifies a standard for name
556 mangling, class layout, v-table layout, RTTI formats, and other C++
557 representation issues. Because we use this API, code generated by the LLVM
558 compilers should be binary compatible with machine code generated by other
559 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
560 <i>However</i>, the exception handling mechanism used by LLVM is very
561 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]562 interact correctly</b>. </li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]563
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]564</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]565
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]566</div>
567
568<!-- ======================================================================= -->
569<div class="doc_subsection">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]570 <a name="c-be">Known problems with the C back-end</a>
571</div>
572
573<div class="doc_text">
574
575<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]576
577<li>The C back-end produces code that violates the ANSI C Type-Based Alias
578Analysis rules. As such, special options may be necessary to compile the code
579(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]580problem probably cannot be fixed.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]581
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]582<li><a href="http://llvm.org/PR56">Zero arg vararg functions are not
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]583supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]584frontends.</li>
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]585
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]586<li>The C backend does not correctly implement the <a
587href="LangRef.html#i_stacksave"><tt>llvm.stacksave</tt></a> or
588<a href="LangRef.html#i_stackrestore"><tt>llvm.stackrestore</tt></a>
589intrinsics. This means that some code compiled by it can run out of stack
590space if they depend on these (e.g. C99 varargs).</li>
591
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]592</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]593
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]594</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]595
Andrew Lenharth2e18c622005-05-03 16:59:09 +0000[diff] [blame]596<!-- ======================================================================= -->
597<div class="doc_subsection">
Chris Lattner683a8472005-05-16 17:06:29 +0000[diff] [blame]598 <a name="x86-be">Known problems with the X86 back-end</a>
599</div>
600
601<div class="doc_text">
602
603<ul>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]604<li><a href="http://llvm.org/PR736">Indirect calls crash JIT on
605Darwin/x86</a>.</li>
Chris Lattner683a8472005-05-16 17:06:29 +0000[diff] [blame]606</ul>
607
608</div>
609
610<!-- ======================================================================= -->
611<div class="doc_subsection">
612 <a name="ppc-be">Known problems with the PowerPC back-end</a>
613</div>
614
615<div class="doc_text">
616
617<ul>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]618<li><a href="http://llvm.org/PR642">PowerPC backend does not correctly
619implement ordered FP comparisons</a>.</li>
Chris Lattner683a8472005-05-16 17:06:29 +0000[diff] [blame]620</ul>
621
622</div>
623
624<!-- ======================================================================= -->
625<div class="doc_subsection">
Andrew Lenharth2e18c622005-05-03 16:59:09 +0000[diff] [blame]626 <a name="alpha-be">Known problems with the Alpha back-end</a>
627</div>
628
629<div class="doc_text">
630
631<ul>
632
Chris Lattner683a8472005-05-16 17:06:29 +0000[diff] [blame]633<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
634appropriate nops inserted to ensure restartability.</li>
Andrew Lenharth2e18c622005-05-03 16:59:09 +0000[diff] [blame]635
Andrew Lenharth2e18c622005-05-03 16:59:09 +0000[diff] [blame]636</ul>
637
638</div>
639
Duraid Madina9a449002005-05-14 05:48:13 +0000[diff] [blame]640<!-- ======================================================================= -->
641<div class="doc_subsection">
642 <a name="ia64-be">Known problems with the IA64 back-end</a>
643</div>
644
645<div class="doc_text">
646
647<ul>
648
649<li>C++ programs are likely to fail on IA64, as calls to <tt>setjmp</tt> are
650made where the argument is not 16-byte aligned, as required on IA64. (Strictly
651speaking this is not a bug in the IA64 back-end; it will also be encountered
652when building C++ programs using the C back-end.)</li>
653
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]654<li>The C++ front-end does not use <a href="http://llvm.org/PR406">IA64
Chris Lattner683a8472005-05-16 17:06:29 +0000[diff] [blame]655ABI compliant layout of v-tables</a>. In particular, it just stores function
656pointers instead of function descriptors in the vtable. This bug prevents
657mixing C++ code compiled with LLVM with C++ objects compiled by other C++
658compilers.</li>
Duraid Madina9a449002005-05-14 05:48:13 +0000[diff] [blame]659
Chris Lattner683a8472005-05-16 17:06:29 +0000[diff] [blame]660<li>There are a few ABI violations which will lead to problems when mixing LLVM
661output with code built with other compilers, particularly for floating-point
662programs.</li>
663
664<li>Defining vararg functions is not supported (but calling them is ok).</li>
Duraid Madina9a449002005-05-14 05:48:13 +0000[diff] [blame]665
666</ul>
667
668</div>
669
Chris Lattnerb62a5f02005-05-15 16:01:20 +0000[diff] [blame]670<!-- ======================================================================= -->
671<div class="doc_subsection">
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]672 <a name="sparc-be">Known problems with the SPARC back-end</a>
Chris Lattnerb62a5f02005-05-15 16:01:20 +0000[diff] [blame]673</div>
674
675<div class="doc_text">
676
677<ul>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]678<li>None yet</li>
Chris Lattnerb62a5f02005-05-15 16:01:20 +0000[diff] [blame]679</ul>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]680
681</div>
682
683
684<!-- ======================================================================= -->
685<div class="doc_subsection">
686 <a name="sparcv9-be">Known problems with the SparcV9 back-end</a>
687</div>
688
689<div class="doc_text">
690
691<ul>
692<li><a href="http://llvm.org/PR60">[sparcv9] SparcV9 backend miscompiles
693several programs in the LLVM test suite</a></li>
694<li>The SparcV9 backend is slated to be removed before the LLVM 1.8
695 release.</li>
696</ul>
697
Chris Lattnerb62a5f02005-05-15 16:01:20 +0000[diff] [blame]698</div>
699
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]700<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]701<div class="doc_section">
702 <a name="additionalinfo">Additional Information</a>
703</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]704<!-- *********************************************************************** -->
705
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]706<div class="doc_text">
707
Chris Lattnercb5596d2005-05-16 17:13:10 +0000[diff] [blame]708<p>A wide variety of additional information is available on the <a
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]709href="http://llvm.org">LLVM web page</a>, including <a
710href="http://llvm.org/docs/">documentation</a> and <a
711href="http://llvm.org/pubs/">publications describing algorithms and
Misha Brukman96158092005-03-30 19:14:24 +0000[diff] [blame]712components implemented in LLVM</a>. The web page also contains versions of the
713API documentation which is up-to-date with the CVS version of the source code.
714You can access versions of these documents specific to this release by going
715into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]716
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]717<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]718us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]719lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]720
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]721</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]722
723<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]724
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]725<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]726<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]727 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
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729 <a href="http://validator.w3.org/check/referer"><img
730 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
731
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]732 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]733 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]734</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]735
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]736</body>
737</html>