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9<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +000010
Chris Lattnerc30c5c72005-11-08 21:29:17 +000011<div class="doc_title">LLVM 1.7 Release Notes</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000012
13<ol>
Misha Brukman500bc302003-11-22 00:38:41 +000014 <li><a href="#intro">Introduction</a></li>
15 <li><a href="#whatsnew">What's New?</a></li>
Chris Lattner4b538b92004-04-30 22:17:12 +000016 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +000017 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +000018 <li><a href="#knownproblems">Known Problems</a>
Misha Brukman500bc302003-11-22 00:38:41 +000019 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +000020</ol>
21
Chris Lattner7911ce22004-05-23 21:07:27 +000022<div class="doc_author">
Chris Lattnerc463b272005-10-29 07:07:09 +000023 <p>Written by the <a href="http://llvm.org">LLVM Team</a><p>
Misha Brukman500bc302003-11-22 00:38:41 +000024</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000025
26<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +000027<div class="doc_section">
28 <a name="intro">Introduction</a>
29</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000030<!-- *********************************************************************** -->
31
Misha Brukman500bc302003-11-22 00:38:41 +000032<div class="doc_text">
33
34<p>This document contains the release notes for the LLVM compiler
Chris Lattnerc30c5c72005-11-08 21:29:17 +000035infrastructure, release 1.7. Here we describe the status of LLVM, including any
Chris Lattner8a458762005-05-15 05:44:51 +000036known problems and major improvements from the previous release. The most
37up-to-date version of this document can be found on the <a
Chris Lattnerc30c5c72005-11-08 21:29:17 +000038href="http://llvm.org/releases/">LLVM releases web site</a>. If you are
John Criswelld000e1d2003-12-18 16:43:17 +000039not reading this on the LLVM web pages, you should probably go there because
Misha Brukman500bc302003-11-22 00:38:41 +000040this document may be updated after the release.</p>
Chris Lattner19092612003-10-02 16:38:05 +000041
Chris Lattner7506b1d2004-12-07 08:04:13 +000042<p>For more information about LLVM, including information about the latest
Chris Lattnerc463b272005-10-29 07:07:09 +000043release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattner47ad72c2003-10-07 21:38:31 +000044web site</a>. If you have questions or comments, the <a
45href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman500bc302003-11-22 00:38:41 +000046list</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +000047
Chris Lattner78bf32b2004-12-09 22:22:58 +000048<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 Lattnerc463b272005-10-29 07:07:09 +000051href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman500bc302003-11-22 00:38:41 +000052
53</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000054
55<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +000056<div class="doc_section">
57 <a name="whatsnew">What's New?</a>
58</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000059<!-- *********************************************************************** -->
60
Misha Brukman500bc302003-11-22 00:38:41 +000061<div class="doc_text">
62
Chris Lattnerc463b272005-10-29 07:07:09 +000063<p>This is the seventh public release of the LLVM Compiler Infrastructure. This
64release incorporates a large number of enhancements and additions (primarily in
65the code generator), which combine to improve the quality of the code generated
66by LLVM by up to 30% in some cases. This release is also the first release to
Chris Lattnerf2548362005-11-03 22:33:48 +000067have first-class support for Mac OS X: all of the major bugs have been shaken
Chris Lattnerc463b272005-10-29 07:07:09 +000068out and it is now as well supported as Linux on X86.</p>
Chris Lattnera5099962003-12-06 20:22:41 +000069
Chris Lattner80453c92004-05-24 04:50:25 +000070</div>
71
Chris Lattnera5099962003-12-06 20:22:41 +000072<!--=========================================================================-->
Chris Lattner8a458762005-05-15 05:44:51 +000073<div class="doc_subsection">
Chris Lattnerc30c5c72005-11-08 21:29:17 +000074<a name="newfeatures">New Features in LLVM 1.7cvs</a>
Chris Lattner80453c92004-05-24 04:50:25 +000075</div>
Brian Gaeke6b31beb2004-01-16 21:55:04 +000076
Chris Lattner58504a62006-02-05 06:39:36 +000077<div class="doc_text">
78<ul>
79<li>New SPARC backend.</li>
80</ul>
81</div>
John Criswelle531ec52005-06-29 16:22:34 +000082
Chris Lattner19092612003-10-02 16:38:05 +000083<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +000084<div class="doc_section">
85 <a name="portability">Portability and Supported Platforms</a>
86</div>
Chris Lattner19092612003-10-02 16:38:05 +000087<!-- *********************************************************************** -->
88
Misha Brukman500bc302003-11-22 00:38:41 +000089<div class="doc_text">
90
John Criswell0b5b5e92004-12-08 20:35:47 +000091<p>LLVM is known to work on the following platforms:</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +000092
93<ul>
Reid Spencer00812e22005-05-17 02:47:27 +000094 <li>Intel and AMD machines running Red Hat Linux, Fedora Core and FreeBSD
95 (and probably other unix-like systems).</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +000096<li>Sun UltraSPARC workstations running Solaris 8.</li>
Chris Lattner7506b1d2004-12-07 08:04:13 +000097<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
98 support is available for native builds with Visual C++).</li>
Chris Lattnerfeaf9602005-10-29 05:14:01 +000099<li>PowerPC and X86-based Mac OS X systems, running 10.2 and above.</li>
John Criswell9321fa82005-05-13 20:28:15 +0000100<li>Alpha-based machines running Debian GNU/Linux.</li>
101<li>Itanium-based machines running Linux and HP-UX.</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000102</ul>
103
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000104<p>The core LLVM infrastructure uses
105<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
106to the machine and operating system on which it is built. However, minor
107porting may be required to get LLVM to work on new platforms. We welcome your
108portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000109
Misha Brukman500bc302003-11-22 00:38:41 +0000110</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000111
112<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000113<div class="doc_section">
114 <a name="knownproblems">Known Problems</a>
115</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000116<!-- *********************************************************************** -->
117
Misha Brukman500bc302003-11-22 00:38:41 +0000118<div class="doc_text">
119
120<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000121component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000122sections. If you run into a problem, please check the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000123href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000124there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000125
Misha Brukman500bc302003-11-22 00:38:41 +0000126</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000127
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000128<!-- ======================================================================= -->
129<div class="doc_subsection">
130 <a name="experimental">Experimental features included with this release</a>
131</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000132
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000133<div class="doc_text">
134
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000135<p>The following components of this LLVM release are either untested, known to
136be broken or unreliable, or are in early development. These components should
137not be relied on, and bugs should not be filed against them, but they may be
138useful to some people. In particular, if you would like to work on one of these
139components, please contact us on the llvmdev list.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000140
141<ul>
Chris Lattner7506b1d2004-12-07 08:04:13 +0000142<li>The following passes are incomplete or buggy, and may be removed in future
Chris Lattner15dd16e2006-01-16 01:05:00 +0000143 releases: <tt>-cee</tt></li>
Chris Lattner7506b1d2004-12-07 08:04:13 +0000144<li>The <tt>llvm-db</tt> tool is in a very early stage of development, but can
145 be used to step through programs and inspect the stack.</li>
Chris Lattner58504a62006-02-05 06:39:36 +0000146<li>The IA64 code generator is experimental.</li>
Chris Lattnerc463b272005-10-29 07:07:09 +0000147<li>The Alpha JIT is experimental.</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000148</ul>
149
150</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000151
Misha Brukman500bc302003-11-22 00:38:41 +0000152<!-- ======================================================================= -->
153<div class="doc_subsection">
John Criswellc0c186d2005-11-08 21:11:33 +0000154 <a name="build">Known problems with the Build System</a>
155</div>
156
157<div class="doc_text">
158
159<ul>
160 <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>
161</ul>
162</div>
163
164
165<!-- ======================================================================= -->
166<div class="doc_subsection">
Misha Brukman500bc302003-11-22 00:38:41 +0000167 <a name="core">Known problems with the LLVM Core</a>
168</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000169
Misha Brukman500bc302003-11-22 00:38:41 +0000170<div class="doc_text">
171
172<ul>
Misha Brukman109d9e82005-03-30 19:14:24 +0000173 <li>In the JIT, <tt>dlsym()</tt> on a symbol compiled by the JIT will not
174 work.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000175</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000176</div>
177
178<!-- ======================================================================= -->
179<div class="doc_subsection">
180 <a name="c-fe">Known problems with the C front-end</a>
181</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000182
Chris Lattner79c3fe12003-10-02 04:57:28 +0000183<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000184<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000185
Misha Brukman500bc302003-11-22 00:38:41 +0000186<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000187<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000188<li>C99 Variable sized arrays do not release stack memory when they go out of
189 scope. Thus, the following program may run out of stack space:
190<pre>
191 for (i = 0; i != 1000000; ++i) {
192 int X[n];
193 foo(X);
194 }
Misha Brukman500bc302003-11-22 00:38:41 +0000195</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000196
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000197<li>Initialization of global union variables can only be done <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000198href="http://llvm.org/PR162">with the largest union member</a>.</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000199
John Criswelld000e1d2003-12-18 16:43:17 +0000200</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000201</div>
202
203<!-- _______________________________________________________________________ -->
204<div class="doc_subsubsection">
205 Notes
206</div>
207
208<div class="doc_text">
209
210<ul>
211
212<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000213
214<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000215support for floating point data types of any size other than 32 and 64
216bits.</li>
217
218<li>The following Unix system functionality has not been tested and may not
219work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000220 <ol>
221 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
222 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
223 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
224 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
225 - These functions have not been tested.
226 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000227
228<li>Although many GCC extensions are supported, some are not. In particular,
229 the following extensions are known to <b>not be</b> supported:
230 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000231 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000232 <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>
233 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
234 <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 Criswelld000e1d2003-12-18 16:43:17 +0000235 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000236 <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>
237 <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 Brukman500bc302003-11-22 00:38:41 +0000238 <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>
239 <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 Lattner014e5f52004-12-08 18:25:34 +0000240 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread_002dLocal.html">Thread-Local</a>: Per-thread variables.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000241 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pragmas.html#Pragmas">Pragmas</a>: Pragmas accepted by GCC.</li>
Misha Brukmane0c891c2003-11-22 01:00:11 +0000242 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000243
Misha Brukman500bc302003-11-22 00:38:41 +0000244 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000245 attribute means that the LLVM compiler ignores the presence of the attribute,
246 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000247 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000248 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000249
250 <ol>
251 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
252 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000253 Supported, but allocated stack space is not freed until the function returns (noted above).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000254
255 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html#Function%20Attributes">Function Attributes</a>:
Misha Brukman500bc302003-11-22 00:38:41 +0000256
John Criswelld000e1d2003-12-18 16:43:17 +0000257 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000258 return.<br>
259
260 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
John Criswell0b5b5e92004-12-08 20:35:47 +0000261 <tt>noreturn</tt>, <tt>constructor</tt>, <tt>destructor</tt>,
Chris Lattneraef8c642005-12-05 05:23:06 +0000262 <tt>unused</tt>, <tt>used</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000263 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
264
John Criswell0b5b5e92004-12-08 20:35:47 +0000265 <b>Ignored:</b> <tt>noinline</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000266 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
267 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
268
Chris Lattneraef8c642005-12-05 05:23:06 +0000269 <b>Unsupported:</b> <tt>section</tt>, <tt>alias</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000270 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
271 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000272
273 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
274 Specifying attributes of variables.<br>
275 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
276 <tt>deprecated</tt>, <tt>transparent_union</tt>,
Chris Lattneraef8c642005-12-05 05:23:06 +0000277 <tt>unused</tt>, <tt>used</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000278
Chris Lattner79c3fe12003-10-02 04:57:28 +0000279 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
280 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
281 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000282 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000283
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000284 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html#Type%20Attributes">Type Attributes</a>: Specifying attributes of types.<br>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000285 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000286 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000287
288 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
289 all target specific attributes.</li>
290
Chris Lattner79c3fe12003-10-02 04:57:28 +0000291 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
292 Other built-in functions.<br>
293 We support all builtins which have a C language equivalent (e.g.,
294 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
295 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Chris Lattnerceebeb62004-06-18 06:26:29 +0000296 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt>
297 (currently ignored). We also support builtins for ISO C99 floating
Chris Lattner7939b782005-05-07 02:21:21 +0000298 point comparison macros (e.g., <tt>__builtin_islessequal</tt>),
299 <tt>__builtin_prefetch</tt>, <tt>__builtin_popcount[ll]</tt>,
300 <tt>__builtin_clz[ll]</tt>, and <tt>__builtin_ctz[ll]</tt>.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000301 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000302
Misha Brukman500bc302003-11-22 00:38:41 +0000303 <p>The following extensions <b>are</b> known to be supported:</p>
304
Chris Lattner79c3fe12003-10-02 04:57:28 +0000305 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000306 <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 Brukman500bc302003-11-22 00:38:41 +0000307 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
308 <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 Lattnerca26c3e2004-06-22 03:48:17 +0000309 <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 Brukman500bc302003-11-22 00:38:41 +0000310 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
311 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
312 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
313 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
314 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
315 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
316 <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>
317 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
318 <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 Brukmanc4b7bee2003-12-12 04:37:31 +0000319 <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 Brukman500bc302003-11-22 00:38:41 +0000320 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000321 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
322or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000323 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html#Designated%20Inits">Designated Inits</a>: Labeling elements of initializers.</li>
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000324 <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 Brukman500bc302003-11-22 00:38:41 +0000325 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
326 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
327 <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 Lattner78537e42004-12-08 18:29:38 +0000328 <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 Brukman500bc302003-11-22 00:38:41 +0000329 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
330 <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>
331 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
332 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
333 <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>
334 <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>
335 <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 Lattner25795bc2004-02-14 04:08:29 +0000336 <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 Brukman500bc302003-11-22 00:38:41 +0000337 <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>
338 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html#Attribute%20Syntax">Attribute Syntax</a>: Formal syntax for attributes.</li>
Misha Brukmane0c891c2003-11-22 01:00:11 +0000339 </ol></li>
340
341</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000342
Misha Brukman500bc302003-11-22 00:38:41 +0000343<p>If you run into GCC extensions which have not been included in any of these
344lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000345
Misha Brukman500bc302003-11-22 00:38:41 +0000346</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000347
Misha Brukman500bc302003-11-22 00:38:41 +0000348<!-- ======================================================================= -->
349<div class="doc_subsection">
350 <a name="c++-fe">Known problems with the C++ front-end</a>
351</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000352
Misha Brukman500bc302003-11-22 00:38:41 +0000353<div class="doc_text">
354
Reid Spencere09ca642004-12-07 08:39:08 +0000355<p>For this release, the C++ front-end is considered to be fully
Chris Lattner7506b1d2004-12-07 08:04:13 +0000356tested and works for a number of non-trivial programs, including LLVM
357itself.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000358
359</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000360
361<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000362<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000363
Misha Brukman500bc302003-11-22 00:38:41 +0000364<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000365
Misha Brukman500bc302003-11-22 00:38:41 +0000366<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000367<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
John Criswelld000e1d2003-12-18 16:43:17 +0000368 front-end</a>.</li>
Chris Lattner7962f712004-07-17 02:04:41 +0000369
Chris Lattnerd5713882004-08-02 20:28:44 +0000370</ul>
371
Misha Brukman500bc302003-11-22 00:38:41 +0000372</div>
373
374<!-- _______________________________________________________________________ -->
375<div class="doc_subsubsection">
376 Notes
377</div>
378
379<div class="doc_text">
380
381<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000382
Chris Lattner79c3fe12003-10-02 04:57:28 +0000383<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
384parser is significantly more standards compliant (and picky) than prior GCC
385versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000386href="http://gcc.gnu.org/gcc-3.4/changes.html">GCC 3.4 release notes</a>.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000387
388<li>Destructors for local objects are not always run when a <tt>longjmp</tt> is
Chris Lattner19092612003-10-02 16:38:05 +0000389 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000390 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000391 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000392 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000393
Chris Lattner19092612003-10-02 16:38:05 +0000394<li>The LLVM C++ front-end follows the <a
395 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
396 This document, which is not Itanium specific, specifies a standard for name
397 mangling, class layout, v-table layout, RTTI formats, and other C++
398 representation issues. Because we use this API, code generated by the LLVM
399 compilers should be binary compatible with machine code generated by other
400 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
401 <i>However</i>, the exception handling mechanism used by LLVM is very
402 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000403 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000404
Misha Brukman500bc302003-11-22 00:38:41 +0000405</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000406
Misha Brukman500bc302003-11-22 00:38:41 +0000407</div>
408
409<!-- ======================================================================= -->
410<div class="doc_subsection">
Misha Brukman500bc302003-11-22 00:38:41 +0000411 <a name="c-be">Known problems with the C back-end</a>
412</div>
413
414<div class="doc_text">
415
416<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000417
418<li>The C back-end produces code that violates the ANSI C Type-Based Alias
419Analysis rules. As such, special options may be necessary to compile the code
420(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000421problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000422
Chris Lattnerc463b272005-10-29 07:07:09 +0000423<li><a href="http://llvm.org/PR56">Zero arg vararg functions are not
Chris Lattner2af46052003-10-24 04:03:19 +0000424supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000425frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000426
Misha Brukman500bc302003-11-22 00:38:41 +0000427</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000428
Misha Brukman500bc302003-11-22 00:38:41 +0000429</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000430
Andrew Lenharth30a1f8f2005-05-03 16:59:09 +0000431<!-- ======================================================================= -->
432<div class="doc_subsection">
Chris Lattnerf9b1f462005-05-16 17:06:29 +0000433 <a name="x86-be">Known problems with the X86 back-end</a>
434</div>
435
436<div class="doc_text">
437
438<ul>
Chris Lattnerc463b272005-10-29 07:07:09 +0000439<li><a href="http://llvm.org/PR566">Memory Mapped I/O Intrinsics do not fence
440memory</a></li>
Chris Lattnerf9b1f462005-05-16 17:06:29 +0000441</ul>
442
443</div>
444
445<!-- ======================================================================= -->
446<div class="doc_subsection">
447 <a name="ppc-be">Known problems with the PowerPC back-end</a>
448</div>
449
450<div class="doc_text">
451
452<ul>
453<li>None yet</li>
454</ul>
455
456</div>
457
458<!-- ======================================================================= -->
459<div class="doc_subsection">
460 <a name="sparcv9-be">Known problems with the SparcV9 back-end</a>
461</div>
462
463<div class="doc_text">
464
465<ul>
Chris Lattnerc463b272005-10-29 07:07:09 +0000466<li><a href="http://llvm.org/PR60">[sparcv9] SparcV9 backend miscompiles
Chris Lattnerf9b1f462005-05-16 17:06:29 +0000467several programs in the LLVM test suite</a></li>
468</ul>
469
470</div>
471
472<!-- ======================================================================= -->
473<div class="doc_subsection">
Andrew Lenharth30a1f8f2005-05-03 16:59:09 +0000474 <a name="alpha-be">Known problems with the Alpha back-end</a>
475</div>
476
477<div class="doc_text">
478
479<ul>
480
Chris Lattnerf9b1f462005-05-16 17:06:29 +0000481<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
482appropriate nops inserted to ensure restartability.</li>
Andrew Lenharth30a1f8f2005-05-03 16:59:09 +0000483
Andrew Lenharth30a1f8f2005-05-03 16:59:09 +0000484</ul>
485
486</div>
487
Duraid Madina2e36d6e2005-05-14 05:48:13 +0000488<!-- ======================================================================= -->
489<div class="doc_subsection">
490 <a name="ia64-be">Known problems with the IA64 back-end</a>
491</div>
492
493<div class="doc_text">
494
495<ul>
496
497<li>C++ programs are likely to fail on IA64, as calls to <tt>setjmp</tt> are
498made where the argument is not 16-byte aligned, as required on IA64. (Strictly
499speaking this is not a bug in the IA64 back-end; it will also be encountered
500when building C++ programs using the C back-end.)</li>
501
Chris Lattnerc463b272005-10-29 07:07:09 +0000502<li>The C++ front-end does not use <a href="http://llvm.org/PR406">IA64
Chris Lattnerf9b1f462005-05-16 17:06:29 +0000503ABI compliant layout of v-tables</a>. In particular, it just stores function
504pointers instead of function descriptors in the vtable. This bug prevents
505mixing C++ code compiled with LLVM with C++ objects compiled by other C++
506compilers.</li>
Duraid Madina2e36d6e2005-05-14 05:48:13 +0000507
Chris Lattnerf9b1f462005-05-16 17:06:29 +0000508<li>There are a few ABI violations which will lead to problems when mixing LLVM
509output with code built with other compilers, particularly for floating-point
510programs.</li>
511
512<li>Defining vararg functions is not supported (but calling them is ok).</li>
Duraid Madina2e36d6e2005-05-14 05:48:13 +0000513
514</ul>
515
516</div>
517
Chris Lattner98a493c2005-05-15 16:01:20 +0000518<!-- ======================================================================= -->
519<div class="doc_subsection">
Chris Lattner58504a62006-02-05 06:39:36 +0000520 <a name="sparcv8">Known problems with the SPARC back-end</a>
Chris Lattner98a493c2005-05-15 16:01:20 +0000521</div>
522
523<div class="doc_text">
524
525<ul>
Chris Lattner58504a62006-02-05 06:39:36 +0000526<li>This backend lacks a JIT compiler.</li>
Chris Lattner98a493c2005-05-15 16:01:20 +0000527</ul>
Chris Lattner98a493c2005-05-15 16:01:20 +0000528</div>
529
Chris Lattner79c3fe12003-10-02 04:57:28 +0000530<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000531<div class="doc_section">
532 <a name="additionalinfo">Additional Information</a>
533</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000534<!-- *********************************************************************** -->
535
Misha Brukman500bc302003-11-22 00:38:41 +0000536<div class="doc_text">
537
Chris Lattner416db102005-05-16 17:13:10 +0000538<p>A wide variety of additional information is available on the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000539href="http://llvm.org">LLVM web page</a>, including <a
540href="http://llvm.org/docs/">documentation</a> and <a
541href="http://llvm.org/pubs/">publications describing algorithms and
Misha Brukman109d9e82005-03-30 19:14:24 +0000542components implemented in LLVM</a>. The web page also contains versions of the
543API documentation which is up-to-date with the CVS version of the source code.
544You can access versions of these documents specific to this release by going
545into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000546
Misha Brukman500bc302003-11-22 00:38:41 +0000547<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerc463b272005-10-29 07:07:09 +0000548us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner5eccca42003-12-12 21:22:16 +0000549lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000550
Misha Brukman500bc302003-11-22 00:38:41 +0000551</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000552
553<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000554
Misha Brukman500bc302003-11-22 00:38:41 +0000555<hr>
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Chris Lattnerc463b272005-10-29 07:07:09 +0000562 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
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