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gerrit-public.fairphone.software / toolchain / llvm-project / 4d918bbdd3518d0ccdf4a9d08bdbf6063508833e / . / llvm / docs / ReleaseNotes.html
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Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]7 <title>LLVM 1.8 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 Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]11<div class="doc_title">LLVM 1.8 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 Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]35infrastructure, release 1.8. 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
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]37up-to-date version of this document (corresponding to LLVM CVS) can be found
38on the <a
Chris Lattner578ab912005-11-08 21:29:17 +0000[diff] [blame]39href="http://llvm.org/releases/">LLVM releases web site</a>. If you are
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]40not reading this on the LLVM web pages, you should probably go there because
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]41this document may be updated after the release.</p>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]42
Chris Lattnerb5bb5972004-12-07 08:04:13 +0000[diff] [blame]43<p>For more information about LLVM, including information about the latest
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]44release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]45web site</a>. If you have questions or comments, the <a
46href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]47list</a> is a good place to send them.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]48
Chris Lattnerf3a7c242004-12-09 22:22:58 +0000[diff] [blame]49<p>Note that if you are reading this file from CVS or the main LLVM web page,
50this document applies to the <i>next</i> release, not the current one. To see
51the release notes for the current or previous releases, see the <a
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]52href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]53
54</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]55
56<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]57<div class="doc_section">
58 <a name="whatsnew">What's New?</a>
59</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]60<!-- *********************************************************************** -->
61
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]62<div class="doc_text">
63
Chris Lattner05a225b2006-08-09 04:08:52 +0000[diff] [blame]64<p>This is the nineth public release of the LLVM Compiler Infrastructure. This
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]65release incorporates a large number of enhancements and new features,
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]66including DWARF debugging support (C and C++ on Darwin/PPC), improved inline
67assembly support, a new <a href="http://llvm.org/nightlytest/">nightly
Chris Lattner05a225b2006-08-09 04:08:52 +0000[diff] [blame]68tester</a>, llvm-config enhancements, many bugs
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]69fixed, and performance and compile time improvements.
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]70</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]71
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]72</div>
73
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]74<!--=========================================================================-->
Chris Lattner406bddf2005-05-15 05:44:51 +0000[diff] [blame]75<div class="doc_subsection">
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]76<a name="newfeatures">New Features in LLVM 1.8</a>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]77</div>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]78
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]79<!--_________________________________________________________________________-->
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]80<div class="doc_subsubsection"><a name="dwarf">DWARF debugging
81support </a></div>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]82
83<div class="doc_text">
84
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]85<p>The llvm-gcc4 C front-end now generates debugging info for C and C++. This
86information is propagated through the compiler and the code generator can
87currently produce DWARF debugging information from it. DWARF is a standard
88debugging format used on many platforms, but currently LLVM only includes
89target support for Mac OS X targets for the 1.8 release.
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]90</p>
91
92</div>
93
94<!--_________________________________________________________________________-->
95<div class="doc_subsubsection"><a name="inlineasm">Inline Assembly
96Support</a></div>
97
98<div class="doc_text">
99
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]100<p>Inline assembly support is substantially improved in LLVM 1.8 over LLVM 1.7.
101Many unsupported features are now supported, and inline asm support in the X86
102backend is far better. llvm-gcc4 now supports global register variables as
103well.</p>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]104
105</div>
106
107<!--_________________________________________________________________________-->
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]108<div class="doc_subsubsection"><a name="loopopt">Loop Optimizer Improvements</a></div>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]109
110<div class="doc_text">
111
Chris Lattner05a225b2006-08-09 04:08:52 +0000[diff] [blame]112<p>The loop optimizer passes now uses "Loop-Closed SSA Form", which makes it
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]113easier to update SSA form as loop transformations change the code. An
114immediate benefit of this is that the loop unswitching pass can now unswitch
115loops in more cases.
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]116</p>
117
118</div>
119
Chris Lattner89e761c2006-04-18 06:32:08 +0000[diff] [blame]120<!--_________________________________________________________________________-->
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]121<div class="doc_subsubsection"><a name="jumptab">Jump Table Support for Switches
122</a></div>
Chris Lattner89e761c2006-04-18 06:32:08 +0000[diff] [blame]123
124<div class="doc_text">
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]125
126<p>The code generator now lowers switch statements to jump tables, providing
127significant performance boosts for applications (e.g. interpreters) whose
128performance is highly correlated to switch statement performance.</p>
129
Chris Lattner89e761c2006-04-18 06:32:08 +0000[diff] [blame]130</div>
131
Chris Lattner0b7fd712006-04-19 04:02:47 +0000[diff] [blame]132<!--_________________________________________________________________________-->
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]133<div class="doc_subsubsection"><a name="jitrelease">Deallocation of JIT'd
134Machine Code
135</a></div>
Chris Lattner0b7fd712006-04-19 04:02:47 +0000[diff] [blame]136
137<div class="doc_text">
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]138
139<p>The LLVM JIT now allows clients to deallocate machine code JIT'd to its code
140buffer. This is important for long living applications that depend on the JIT.
141</p>
142
Chris Lattner0b7fd712006-04-19 04:02:47 +0000[diff] [blame]143</div>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]144
145<!--_________________________________________________________________________-->
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]146<div class="doc_subsubsection"><a name="other">Other Improvements</a></div>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]147
Chris Lattnera38fe5f2006-02-05 06:39:36 +0000[diff] [blame]148<div class="doc_text">
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]149
150<p>This release includes many other improvements, including improvements to
151 the optimizers and code generators (improving the generated code) changes to
152 speed up the compiler in many ways (improving algorithms and fine tuning
153 code), and changes to reduce the code size of the compiler itself.</p>
154
155<p>More specific changes include:</p>
156
Chris Lattnera38fe5f2006-02-05 06:39:36 +0000[diff] [blame]157<ul>
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]158<li>LLVM 1.8 includes an initial ARM backend. This backend is in early
159 development stages.</li>
160<li>LLVM 1.8 now includes significantly better support for mingw and
161 cygwin.</li>
162<li>The <a href="CommandGuide/html/llvm-config.html">llvm-config</a> tool is
163 now built by default and has several new features.</li>
164<li>The X86 and PPC backends now use the correct platform ABI for passing
165 vectors as arguments to functions.</li>
166<li>The X86 backend now includes support for the Microsoft ML assembler
167 ("MASM").</li>
168<li>The PowerPC backend now pattern matches the 'rlwimi' instruction more
169 aggressively.</li>
170<li>Most of LLVM is now built with "-pedantic", ensuring better portability
171 to more C++ Compilers.</li>
172<li>The PowerPC backend now includes initial 64-bit support. The JIT is not
173 complete, and the static compiler has a couple of known bugs, but support
174 is mostly in place. LLVM 1.9 will include completed PPC-64 support. </li>
Chris Lattner89e761c2006-04-18 06:32:08 +0000[diff] [blame]175
Chris Lattnera38fe5f2006-02-05 06:39:36 +0000[diff] [blame]176</ul>
177</div>
John Criswell51e2a482005-06-29 16:22:34 +0000[diff] [blame]178
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]179<!--=========================================================================-->
180<div class="doc_subsection">
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]181<a name="changes">Significant Changes in LLVM 1.8</a>
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]182</div>
183
184<div class="doc_text">
185<ul>
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]186<li>The LLVM "SparcV9" backend (deprecated in LLVM 1.7) has been removed in
187LLVM 1.8. The LLVM "Sparc" backend replaces it.</li>
188<li>The --version option now prints more useful information, including the
189 build configuration for the tool.</li>
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]190</ul>
191</div>
192
193
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]194<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]195<div class="doc_section">
196 <a name="portability">Portability and Supported Platforms</a>
197</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]198<!-- *********************************************************************** -->
199
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]200<div class="doc_text">
201
John Criswell64307722004-12-08 20:35:47 +0000[diff] [blame]202<p>LLVM is known to work on the following platforms:</p>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]203
204<ul>
Reid Spencer9803b402005-05-17 02:47:27 +0000[diff] [blame]205 <li>Intel and AMD machines running Red Hat Linux, Fedora Core and FreeBSD
206 (and probably other unix-like systems).</li>
Chris Lattner4d918bb2006-08-09 04:10:32 +0000[diff] [blame^]207<li>Intel and AMD machines running on Win32 using MinGW libraries (native)</li>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]208<li>Sun UltraSPARC workstations running Solaris 8.</li>
Chris Lattnerb5bb5972004-12-07 08:04:13 +0000[diff] [blame]209<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
210 support is available for native builds with Visual C++).</li>
Chris Lattner8ad30362005-10-29 05:14:01 +0000[diff] [blame]211<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]212<li>Alpha-based machines running Debian GNU/Linux.</li>
213<li>Itanium-based machines running Linux and HP-UX.</li>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]214</ul>
215
Brian Gaekee3e557e2004-05-09 05:28:35 +0000[diff] [blame]216<p>The core LLVM infrastructure uses
217<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
218to the machine and operating system on which it is built. However, minor
219porting may be required to get LLVM to work on new platforms. We welcome your
220portability patches and reports of successful builds or error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]221
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]222</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]223
224<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]225<div class="doc_section">
226 <a name="knownproblems">Known Problems</a>
227</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]228<!-- *********************************************************************** -->
229
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]230<div class="doc_text">
231
232<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]233component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]234sections. If you run into a problem, please check the <a
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]235href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]236there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]237
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]238</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]239
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]240<!-- ======================================================================= -->
241<div class="doc_subsection">
242 <a name="experimental">Experimental features included with this release</a>
243</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]244
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]245<div class="doc_text">
246
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]247<p>The following components of this LLVM release are either untested, known to
248be broken or unreliable, or are in early development. These components should
249not be relied on, and bugs should not be filed against them, but they may be
250useful to some people. In particular, if you would like to work on one of these
Chris Lattner05a225b2006-08-09 04:08:52 +0000[diff] [blame]251components, please contact us on the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]252
253<ul>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]254<li>The <tt>-cee</tt> pass is known to be buggy, and may be removed in in a
255 future release.</li>
Chris Lattnera38fe5f2006-02-05 06:39:36 +0000[diff] [blame]256<li>The IA64 code generator is experimental.</li>
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]257<li>The Alpha JIT is experimental.</li>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]258<li>"<tt>-filetype=asm</tt>" (the default) is the only supported value for the
259 <tt>-filetype</tt> llc option.</li>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]260</ul>
261
262</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]263
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]264<!-- ======================================================================= -->
265<div class="doc_subsection">
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]266 <a name="build">Known problems with the Build System</a>
267</div>
268
269<div class="doc_text">
270
271<ul>
Chris Lattner64006062006-04-20 04:24:28 +0000[diff] [blame]272<li>none yet</li>
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]273</ul>
274</div>
275
276
277<!-- ======================================================================= -->
278<div class="doc_subsection">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]279 <a name="core">Known problems with the LLVM Core</a>
280</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]281
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]282<div class="doc_text">
283
284<ul>
Misha Brukman96158092005-03-30 19:14:24 +0000[diff] [blame]285 <li>In the JIT, <tt>dlsym()</tt> on a symbol compiled by the JIT will not
286 work.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]287</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]288</div>
289
290<!-- ======================================================================= -->
291<div class="doc_subsection">
292 <a name="c-fe">Known problems with the C front-end</a>
293</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]294
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]295<!-- _______________________________________________________________________ -->
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]296<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]297
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]298<div class="doc_text">
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]299
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]300<p>
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]301llvm-gcc3 has many significant problems that are fixed by llvm-gcc4.
Chris Lattnerc3e92b52006-04-19 04:12:01 +0000[diff] [blame]302Two major ones include:</p>
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]303
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]304<ul>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]305<li>With llvm-gcc3,
306 C99 variable sized arrays do not release stack memory when they go out of
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]307 scope. Thus, the following program may run out of stack space:
308<pre>
309 for (i = 0; i != 1000000; ++i) {
310 int X[n];
311 foo(X);
312 }
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]313</pre></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]314
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]315<li>With llvm-gcc3, Initialization of global union variables can only be done <a
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]316href="http://llvm.org/PR162">with the largest union member</a>.</li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]317
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]318</ul>
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]319
320<p>llvm-gcc4 is far more stable and produces better code than llvm-gcc3, but
321does not currently support Link-Time-Optimization or C++ Exception Handling,
322which llvm-gcc3 does.</p>
323
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]324</div>
325
326<!-- _______________________________________________________________________ -->
327<div class="doc_subsubsection">
328 Notes
329</div>
330
331<div class="doc_text">
332
333<ul>
334
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]335<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]336support for floating point data types of any size other than 32 and 64
337bits.</li>
338
339<li>The following Unix system functionality has not been tested and may not
340work:
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]341 <ol>
342 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
343 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
344 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
345 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
346 - These functions have not been tested.
347 </ol></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]348
349<li>Although many GCC extensions are supported, some are not. In particular,
350 the following extensions are known to <b>not be</b> supported:
351 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]352 <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]353 <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>
354 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
355 <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]356 <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]357 <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>
358 <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]359 <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>
360 <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]361 <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]362 <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]363 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]364
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]365 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]366 attribute means that the LLVM compiler ignores the presence of the attribute,
367 but the code should still work. An unsupported attribute is one which is
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]368 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]369 the program.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]370
371 <ol>
372 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
373 Arrays whose length is computed at run time.<br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]374 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]375
376 <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]377
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]378 Declaring that functions have no side effects or that they can never
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]379 return.<br>
380
381 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
John Criswell64307722004-12-08 20:35:47 +0000[diff] [blame]382 <tt>noreturn</tt>, <tt>constructor</tt>, <tt>destructor</tt>,
Chris Lattnerca18d192005-12-05 05:23:06 +0000[diff] [blame]383 <tt>unused</tt>, <tt>used</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]384 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
385
John Criswell64307722004-12-08 20:35:47 +0000[diff] [blame]386 <b>Ignored:</b> <tt>noinline</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]387 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
388 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
389
Chris Lattnerca18d192005-12-05 05:23:06 +0000[diff] [blame]390 <b>Unsupported:</b> <tt>section</tt>, <tt>alias</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]391 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
392 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]393
394 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
395 Specifying attributes of variables.<br>
396 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
397 <tt>deprecated</tt>, <tt>transparent_union</tt>,
Chris Lattnerca18d192005-12-05 05:23:06 +0000[diff] [blame]398 <tt>unused</tt>, <tt>used</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]399
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]400 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
401 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
402 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]403 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]404
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]405 <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]406 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]407 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]408
409 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
410 all target specific attributes.</li>
411
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]412 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
413 Other built-in functions.<br>
414 We support all builtins which have a C language equivalent (e.g.,
415 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
416 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Chris Lattnerb7c4bac2004-06-18 06:26:29 +0000[diff] [blame]417 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt>
418 (currently ignored). We also support builtins for ISO C99 floating
Chris Lattnerb34b2732005-05-07 02:21:21 +0000[diff] [blame]419 point comparison macros (e.g., <tt>__builtin_islessequal</tt>),
420 <tt>__builtin_prefetch</tt>, <tt>__builtin_popcount[ll]</tt>,
421 <tt>__builtin_clz[ll]</tt>, and <tt>__builtin_ctz[ll]</tt>.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]422 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]423
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]424 <p>The following extensions <b>are</b> known to be supported:</p>
425
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]426 <ol>
Chris Lattnerd3dc8502004-03-16 08:54:07 +0000[diff] [blame]427 <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]428 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
429 <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]430 <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]431 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
432 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
433 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
434 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
435 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
436 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
437 <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>
438 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
439 <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]440 <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]441 <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]442 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
443or arrays as values.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]444 <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]445 <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]446 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
447 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
448 <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]449 <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]450 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
451 <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>
452 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
453 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
454 <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>
455 <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>
456 <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]457 <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]458 <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>
459 <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]460 </ol></li>
461
462</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]463
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]464<p>If you run into GCC extensions which have not been included in any of these
465lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]466
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]467</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]468
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]469<!-- ======================================================================= -->
470<div class="doc_subsection">
471 <a name="c++-fe">Known problems with the C++ front-end</a>
472</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]473
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]474<div class="doc_text">
475
Reid Spencer55684c32004-12-07 08:39:08 +0000[diff] [blame]476<p>For this release, the C++ front-end is considered to be fully
Chris Lattnerb5bb5972004-12-07 08:04:13 +0000[diff] [blame]477tested and works for a number of non-trivial programs, including LLVM
478itself.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]479
480</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]481
482<!-- _______________________________________________________________________ -->
Chris Lattner141ebb62004-02-14 04:12:41 +0000[diff] [blame]483<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]484
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]485<div class="doc_text">
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]486
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]487<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]488<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]489 front-end</a>.</li>
Chris Lattner041e6c92004-07-17 02:04:41 +0000[diff] [blame]490
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]491</ul>
492
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]493</div>
494
495<!-- _______________________________________________________________________ -->
496<div class="doc_subsubsection">
497 Notes
498</div>
499
500<div class="doc_text">
501
502<ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]503
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]504<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]505 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]506 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]507 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]508 better than most compilers).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]509
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]510<li>The LLVM C++ front-end follows the <a
511 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
512 This document, which is not Itanium specific, specifies a standard for name
513 mangling, class layout, v-table layout, RTTI formats, and other C++
514 representation issues. Because we use this API, code generated by the LLVM
515 compilers should be binary compatible with machine code generated by other
516 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
517 <i>However</i>, the exception handling mechanism used by LLVM is very
518 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]519 interact correctly</b>. </li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]520
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]521</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]522
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]523</div>
524
525<!-- ======================================================================= -->
526<div class="doc_subsection">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]527 <a name="c-be">Known problems with the C back-end</a>
528</div>
529
530<div class="doc_text">
531
532<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]533
534<li>The C back-end produces code that violates the ANSI C Type-Based Alias
535Analysis rules. As such, special options may be necessary to compile the code
536(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]537problem probably cannot be fixed.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]538
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]539<li><a href="http://llvm.org/PR56">Zero arg vararg functions are not
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]540supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]541frontends.</li>
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]542
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]543<li>The C backend does not correctly implement the <a
544href="LangRef.html#i_stacksave"><tt>llvm.stacksave</tt></a> or
545<a href="LangRef.html#i_stackrestore"><tt>llvm.stackrestore</tt></a>
546intrinsics. This means that some code compiled by it can run out of stack
547space if they depend on these (e.g. C99 varargs).</li>
548
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]549</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]550
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]551</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]552
Andrew Lenharth2e18c622005-05-03 16:59:09 +0000[diff] [blame]553<!-- ======================================================================= -->
554<div class="doc_subsection">
Chris Lattner683a8472005-05-16 17:06:29 +0000[diff] [blame]555 <a name="x86-be">Known problems with the X86 back-end</a>
556</div>
557
558<div class="doc_text">
559
560<ul>
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]561<li>none yet.</li>
Chris Lattner683a8472005-05-16 17:06:29 +0000[diff] [blame]562</ul>
563
564</div>
565
566<!-- ======================================================================= -->
567<div class="doc_subsection">
568 <a name="ppc-be">Known problems with the PowerPC back-end</a>
569</div>
570
571<div class="doc_text">
572
573<ul>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]574<li><a href="http://llvm.org/PR642">PowerPC backend does not correctly
575implement ordered FP comparisons</a>.</li>
Chris Lattner683a8472005-05-16 17:06:29 +0000[diff] [blame]576</ul>
577
578</div>
579
580<!-- ======================================================================= -->
581<div class="doc_subsection">
Andrew Lenharth2e18c622005-05-03 16:59:09 +0000[diff] [blame]582 <a name="alpha-be">Known problems with the Alpha back-end</a>
583</div>
584
585<div class="doc_text">
586
587<ul>
588
Chris Lattner683a8472005-05-16 17:06:29 +0000[diff] [blame]589<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
590appropriate nops inserted to ensure restartability.</li>
Andrew Lenharth2e18c622005-05-03 16:59:09 +0000[diff] [blame]591
Andrew Lenharth2e18c622005-05-03 16:59:09 +0000[diff] [blame]592</ul>
593
594</div>
595
Duraid Madina9a449002005-05-14 05:48:13 +0000[diff] [blame]596<!-- ======================================================================= -->
597<div class="doc_subsection">
598 <a name="ia64-be">Known problems with the IA64 back-end</a>
599</div>
600
601<div class="doc_text">
602
603<ul>
604
605<li>C++ programs are likely to fail on IA64, as calls to <tt>setjmp</tt> are
606made where the argument is not 16-byte aligned, as required on IA64. (Strictly
607speaking this is not a bug in the IA64 back-end; it will also be encountered
608when building C++ programs using the C back-end.)</li>
609
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]610<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]611ABI compliant layout of v-tables</a>. In particular, it just stores function
612pointers instead of function descriptors in the vtable. This bug prevents
613mixing C++ code compiled with LLVM with C++ objects compiled by other C++
614compilers.</li>
Duraid Madina9a449002005-05-14 05:48:13 +0000[diff] [blame]615
Chris Lattner683a8472005-05-16 17:06:29 +0000[diff] [blame]616<li>There are a few ABI violations which will lead to problems when mixing LLVM
617output with code built with other compilers, particularly for floating-point
618programs.</li>
619
620<li>Defining vararg functions is not supported (but calling them is ok).</li>
Duraid Madina9a449002005-05-14 05:48:13 +0000[diff] [blame]621
622</ul>
623
624</div>
625
Chris Lattnerb62a5f02005-05-15 16:01:20 +0000[diff] [blame]626<!-- ======================================================================= -->
627<div class="doc_subsection">
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]628 <a name="sparc-be">Known problems with the SPARC back-end</a>
Chris Lattnerb62a5f02005-05-15 16:01:20 +0000[diff] [blame]629</div>
630
631<div class="doc_text">
632
633<ul>
Chris Lattnere9e46a72006-04-19 04:05:21 +0000[diff] [blame]634<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
635 support the 64-bit SPARC ABI (-m64).</li>
Chris Lattnerb62a5f02005-05-15 16:01:20 +0000[diff] [blame]636</ul>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]637
638</div>
639
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]640<!-- ======================================================================= -->
641<div class="doc_subsection">
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]642 <a name="arm-be">Known problems with the ARM back-end</a>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]643</div>
644
645<div class="doc_text">
646
647<ul>
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]648<li>The ARM backend is currently in early development stages, it is not
649ready for production use.</li>
Chris Lattner9f871732006-04-18 06:18:36 +0000[diff] [blame]650</ul>
651
Chris Lattnerb62a5f02005-05-15 16:01:20 +0000[diff] [blame]652</div>
653
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]654<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]655<div class="doc_section">
656 <a name="additionalinfo">Additional Information</a>
657</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]658<!-- *********************************************************************** -->
659
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]660<div class="doc_text">
661
Chris Lattnercb5596d2005-05-16 17:13:10 +0000[diff] [blame]662<p>A wide variety of additional information is available on the <a
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]663href="http://llvm.org">LLVM web page</a>, including <a
664href="http://llvm.org/docs/">documentation</a> and <a
665href="http://llvm.org/pubs/">publications describing algorithms and
Misha Brukman96158092005-03-30 19:14:24 +0000[diff] [blame]666components implemented in LLVM</a>. The web page also contains versions of the
667API documentation which is up-to-date with the CVS version of the source code.
668You can access versions of these documents specific to this release by going
669into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]670
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]671<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]672us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]673lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]674
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]675</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]676
677<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]678
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]679<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]680<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]681 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
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683 <a href="http://validator.w3.org/check/referer"><img
684 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
685
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]686 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]687 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]688</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]689
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]690</body>
691</html>