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gerrit-public.fairphone.software / toolchain / llvm-project / b3fdf83d17bc437a9db16c69f374faef32438f66 / . / llvm / docs / ReleaseNotes.html
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Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]6 <title>LLVM 1.2 Release Notes</title>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]7</head>
8<body>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]9
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]10<div class="doc_title">
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]11 LLVM 1.2 Release Notes
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]12</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]13
14<ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]15 <li><a href="#intro">Introduction</a></li>
16 <li><a href="#whatsnew">What's New?</a></li>
17 <li><a href="#portability">Portability and Supported Platforms</a></li>
18 <li><a href="#install-instructions">Installation Instructions</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]19 <li><a href="#knownproblems">Known Problems</a>
20 <ul>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]21<!-- <li><a href="#portabilityprobs">Portability Problems</a> -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]22 <li><a href="#core">Known problems with the LLVM Core</a>
23 <li><a href="#c-fe">Known problems with the C Front-end</a>
24 <li><a href="#c++-fe">Known problems with the C++ Front-end</a>
25 <li><a href="#x86-be">Known problems with the X86 Back-end</a>
26 <li><a href="#sparc-be">Known problems with the Sparc Back-end</a>
27 <li><a href="#c-be">Known problems with the C back-end</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]28 </ul></li>
29 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]30</ol>
31
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]32<div class="doc_text">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]33 <p><b>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a></b><p>
34</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]35
36<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]37<div class="doc_section">
38 <a name="intro">Introduction</a>
39</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]40<!-- *********************************************************************** -->
41
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]42<div class="doc_text">
43
44<p>This document contains the release notes for the LLVM compiler
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]45infrastructure, release 1.2. Here we describe the status of LLVM, including any
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]46known problems, and bug fixes from the previous release. The most up-to-date
47version of this document can be found on the <a
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]48href="http://llvm.cs.uiuc.edu/releases/1.2/">LLVM 1.2 web site</a>. If you are
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]49not reading this on the LLVM web pages, you should probably go there, because
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]50this document may be updated after the release.</p>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]51
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]52<p>For more information about LLVM, including information about potentially more
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]53current releases, please check out the <a href="http://llvm.cs.uiuc.edu">main
54web site</a>. If you have questions or comments, the <a
55href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]56list</a> is a good place to send them.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]57
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]58<p>Note that if you are reading this file from CVS, this document applies
59to the <i>next</i> release, not the current one. To see the release notes for
60the current or previous releases, see the <a
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]61href="http://llvm.cs.uiuc.edu/releases/">releases page</a>.</p>
62
63</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]64
65<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]66<div class="doc_section">
67 <a name="whatsnew">What's New?</a>
68</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]69<!-- *********************************************************************** -->
70
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]71<div class="doc_text">
72
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]73<p>This is the third public release of the LLVM compiler infrastructure. OTHER
74OVERVIEW STUFF HERE.
75</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]76
Chris Lattner6f9e65e2003-12-12 21:33:08 +0000[diff] [blame]77<p>At this time, LLVM is known to correctly compile and run all non-unwinding C
78&amp; C++ SPEC CPU2000 benchmarks, the Olden benchmarks, and the Ptrdist
79benchmarks. It has also been used to compile <b>many</b> other programs. LLVM
80now also works with a broad variety of C++ programs, though it has still
81received much less testing than the C front-end.
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]82</p>
83
84<p>
Chris Lattner6f9e65e2003-12-12 21:33:08 +0000[diff] [blame]85The LLVM native code generators are very stable, but do not currently support
86unwinding (exception throwing or <tt>longjmp</tt>ing), which prevent them from
87working with programs like the <tt>253.perlbmk</tt> in SPEC CPU2000. The C
88backend and the rest of LLVM does support these programs however, so you can
89still use LLVM with them. Support for unwinding will be added in a future
90release.
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]91</p>
92
93
94<!--=========================================================================-->
95<div class="doc_subsubsection">
96This release implements the following new features:
97</div>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]98
99<ol>
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]100<li></li>
101<li></li>
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]102</ol>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]103
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]104
105<!--=========================================================================-->
106<div class="doc_subsubsection">
107In this release, the following missing features were implemented:
108</div>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]109
110<ol>
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]111<li></li>
112<li></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]113</ol>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]114
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]115
116<!--=========================================================================-->
117<div class="doc_subsubsection">
118In this release, the following Quality of Implementation issues were
119fixed:
120</div>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]121
122<ol>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]123
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]124<li></li>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]125
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]126<li></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]127</ol>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]128
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]129
130<!--=========================================================================-->
131<div class="doc_subsubsection">
132In this release, the following bugs in the previous release were fixed:
133</div>
134
135<p>Bugs in the LLVM Core:</p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]136
137<ol>
Misha Brukman34cba912003-12-15 22:48:12 +0000[diff] [blame]138<li><a href="http://llvm.cs.uiuc.edu/PR179">[licm] LICM promotes volatile memory
139locations to registers</a></li>
Chris Lattnerb3fdf832003-12-18 08:16:25 +0000[diff] [blame^]140<li><a href="http://llvm.cs.uiuc.edu/PR191">[licm] Memory read after free causes
141infrequent crash</a></li>
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]142
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]143</ol>
144
145
146<p>Bugs in the C/C++ front-end:</p>
147
148<ol>
Misha Brukman34cba912003-12-15 22:48:12 +0000[diff] [blame]149<li><a href="http://llvm.cs.uiuc.edu/PR186">Need weak linkage on memory
150management functions in libc runtime to allow them to be overriden</a></li>
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]151<li></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]152</ol>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]153
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]154</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]155
156<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]157<div class="doc_section">
158 <a name="portability">Portability and Supported Platforms</a>
159</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]160<!-- *********************************************************************** -->
161
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]162<div class="doc_text">
163
164<p>LLVM has been extensively tested on Intel and AMD machines running Red
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]165Hat Linux and FreeBSD. It has also been tested on Sun UltraSPARC workstations running Solaris 8.
John Criswell604cd3c2003-12-12 19:54:20 +0000[diff] [blame]166Additionally,
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]167LLVM works on Mac OS/X 10.3 and above, but only with the C backend or
168interpreter (no native backend for the PowerPC is available yet).
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]169The core LLVM infrastructure uses "autoconf" for portability, so hopefully we
Chris Lattner14b5d5a2003-11-08 05:22:09 +0000[diff] [blame]170work on more platforms than that. However, it is likely that we
171missed something, and that minor porting is required to get LLVM to work on
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]172new platforms. We welcome portability patches and error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]173
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]174</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]175
176<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]177<div class="doc_section">
178 <a name="knownproblems">Known Problems</a>
179</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]180<!-- *********************************************************************** -->
181
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]182<div class="doc_text">
183
184<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]185component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]186sections. If you run into a problem, please check the <a
187href="http://llvm.cs.uiuc.edu/bugs/">LLVM bug database</a>, and submit a bug if
188there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]189
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]190</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]191
192<!-- _______________________________________________________________________ -->
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]193<!--
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]194</ul><h4><a name="portability"><hr size=0>Portability Problems</h4><ul>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]195-->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]196
197
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]198<!-- ======================================================================= -->
199<div class="doc_subsection">
200 <a name="core">Known problems with the LLVM Core</a>
201</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]202
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]203<div class="doc_text">
204
205<ul>
206
207<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
208work.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]209
210<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]211such, execution of a threaded program could cause these data structures to be
212corrupted.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]213
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]214<li>It is not possible to <tt>dlopen</tt> an LLVM bytecode file in the JIT.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]215
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]216<li>Linking in static archive files (.a files) is very slow (there is no symbol
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]217table in the archive).</li>
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]218
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]219<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]220more than 256 elements</a>.</li>
221
222</ul>
223
224</div>
225
226<!-- ======================================================================= -->
227<div class="doc_subsection">
228 <a name="c-fe">Known problems with the C front-end</a>
229</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]230
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]231<!-- _______________________________________________________________________ -->
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]232<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]233
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]234<div class="doc_text">
235
236<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]237
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]238<li>C99 Variable sized arrays do not release stack memory when they go out of
239 scope. Thus, the following program may run out of stack space:
240<pre>
241 for (i = 0; i != 1000000; ++i) {
242 int X[n];
243 foo(X);
244 }
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]245</pre></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]246
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]247</ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]248
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]249</div>
250
251<!-- _______________________________________________________________________ -->
252<div class="doc_subsubsection">
253 Notes
254</div>
255
256<div class="doc_text">
257
258<ul>
259
260<li>Inline assembly is not yet supported.</li>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]261
262<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]263support for floating point data types of any size other than 32 and 64
264bits.</li>
265
266<li>The following Unix system functionality has not been tested and may not
267work:
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]268 <ol>
269 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
270 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
271 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
272 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
273 - These functions have not been tested.
274 </ol></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]275
276<li>Although many GCC extensions are supported, some are not. In particular,
277 the following extensions are known to <b>not be</b> supported:
278 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]279 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
280 <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>
281 <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>
282 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
283 <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>
284 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands</li>
285 <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>
286 <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>
287 <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>
288 <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>
289 <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>
290 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
291 <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]292 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]293
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]294 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]295 attribute means that the LLVM compiler ignores the presence of the attribute,
296 but the code should still work. An unsupported attribute is one which is
297 ignored by the LLVM compiler, which will cause a different interpretation of
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]298 the program.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]299
300 <ol>
301 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
302 Arrays whose length is computed at run time.<br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]303 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]304
305 <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]306
307 Declaring that functions have no side effects, or that they can never
308 return.<br>
309
310 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
311 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
312 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
313
314 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
315 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
316 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
317
318 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
319 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
320 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]321
322 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
323 Specifying attributes of variables.<br>
324 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
325 <tt>deprecated</tt>, <tt>transparent_union</tt>,
326 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]327
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]328 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
329 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
330 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]331 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]332
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]333 <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]334 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]335 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]336
337 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
338 all target specific attributes.</li>
339
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]340 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
341 Other built-in functions.<br>
342 We support all builtins which have a C language equivalent (e.g.,
343 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
344 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]345 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]346
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]347 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]348
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]349 <p>The following extensions <b>are</b> known to be supported:</p>
350
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]351 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]352 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
353 <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>
354 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
355 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
356 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
357 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
358 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
359 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
360 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
361 <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>
362 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
363 <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]364 <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]365 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
366 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions or arrays as values.</li>
367 <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]368 <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]369 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
370 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
371 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
372 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
373 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
374 <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>
375 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
376 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
377 <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>
378 <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>
379 <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>
380 <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>
381 <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]382 </ol></li>
383
384</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]385
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]386<p>If you run into GCC extensions which have not been included in any of these
387lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]388
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]389</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]390
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]391<!-- ======================================================================= -->
392<div class="doc_subsection">
393 <a name="c++-fe">Known problems with the C++ front-end</a>
394</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]395
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]396<div class="doc_text">
397
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]398<p>For this release, the C++ front-end is considered to be fully functional, but
399has not been tested as thoroughly as the C front-end. It has been tested and
400works for a number of non-trivial programs, but there may be lurking bugs.
401Please report any bugs or problems.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]402
403</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]404
405<!-- _______________________________________________________________________ -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]406<div class="doc_subsubsection">
407 Bugs
408</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]409
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]410<div class="doc_text">
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]411
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]412<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]413<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]414 front-end</a></li>
415</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]416
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]417</div>
418
419<!-- _______________________________________________________________________ -->
420<div class="doc_subsubsection">
421 Notes
422</div>
423
424<div class="doc_text">
425
426<ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]427
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]428<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
429parser is significantly more standards compliant (and picky) than prior GCC
430versions. For more information, see the C++ section of the <a
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]431href="http://gcc.gnu.org/gcc-3.4/changes.html">GCC 3.4 release notes</a>.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]432
433<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]434 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]435 function and in the <tt>setjmp</tt> receiver function may not be run.
436 Objects in intervening stack frames will be destroyed however (which is
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]437 better than most compilers).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]438
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]439<li>The LLVM C++ front-end follows the <a
440 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
441 This document, which is not Itanium specific, specifies a standard for name
442 mangling, class layout, v-table layout, RTTI formats, and other C++
443 representation issues. Because we use this API, code generated by the LLVM
444 compilers should be binary compatible with machine code generated by other
445 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
446 <i>However</i>, the exception handling mechanism used by LLVM is very
447 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]448 interact correctly</b>. </li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]449
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]450</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]451
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]452</div>
453
454<!-- ======================================================================= -->
455<div class="doc_subsection">
456 <a name="x86-be">Known problems with the X86 back-end</a>
457</div>
458
459<div class="doc_text">
460
461<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]462
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]463<li>The X86 code generator <a
Chris Lattnerc4788bb2003-10-08 06:01:38 +0000[diff] [blame]464href="http://llvm.cs.uiuc.edu/PR16">does not currently
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]465support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]466or calls the C <tt>longjmp</tt> function will abort.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]467
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]468</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]469
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]470</div>
471
472<!-- ======================================================================= -->
473<div class="doc_subsection">
474 <a name="sparc-be">Known problems with the Sparc back-end</a>
475</div>
476
477<div class="doc_text">
478
479<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]480
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]481<li>The Sparc code generator <a
Chris Lattnerc4788bb2003-10-08 06:01:38 +0000[diff] [blame]482href="http://llvm.cs.uiuc.edu/PR15">does not currently
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]483support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]484or calls the C <tt>longjmp</tt> function will abort.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]485
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]486</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]487
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]488</div>
489
490<!-- ======================================================================= -->
491<div class="doc_subsection">
492 <a name="c-be">Known problems with the C back-end</a>
493</div>
494
495<div class="doc_text">
496
497<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]498
499<li>The C back-end produces code that violates the ANSI C Type-Based Alias
500Analysis rules. As such, special options may be necessary to compile the code
501(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]502problem probably cannot be fixed.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]503
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]504<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]505cannot include special floating point numbers like Not-A-Number or
506Infinity.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]507
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]508<li><a href="http://llvm.cs.uiuc.edu/PR56">Zero arg vararg functions are not
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]509supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]510frontends.</li>
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]511
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]512</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]513
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]514</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]515
516<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]517<div class="doc_section">
518 <a name="additionalinfo">Additional Information</a>
519</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]520<!-- *********************************************************************** -->
521
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]522<div class="doc_text">
523
524<p>A wide variety of additional information is available on the LLVM web page,
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]525including mailing lists publications describing algorithms and components
526implemented in LLVM. The web page also contains versions of the API
527documentation which is up-to-date with the CVS version of the source code. You
528can access versions of these documents specific to this release by going into
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]529the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]530
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]531<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]532us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
533lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]534
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]535</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]536
537<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]538
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]539<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]540<address>
541 <a href="http://jigsaw.w3.org/css-validator/"><img
542 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
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545
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]546 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]547 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]548</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]549
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]550</body>
551</html>