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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 47bcf61b6608a260f9384457f901c40006c5efd6 / . / docs / ReleaseNotes.html
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Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]7 <title>LLVM 2.5 Release Notes</title>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]8</head>
9<body>
10
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]11<div class="doc_title">LLVM 2.5 Release Notes</div>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]12
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]13<ol>
14 <li><a href="#intro">Introduction</a></li>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]15 <li><a href="#subproj">Sub-project Status Update</a></li>
16 <li><a href="#whatsnew">What's New in LLVM?</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]17 <li><a href="GettingStarted.html">Installation Instructions</a></li>
18 <li><a href="#portability">Portability and Supported Platforms</a></li>
Dan Gohman0de549c2008-10-14 16:23:02 +0000[diff] [blame]19 <li><a href="#knownproblems">Known Problems</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]20 <li><a href="#additionalinfo">Additional Information</a></li>
21</ol>
22
23<div class="doc_author">
Dan Gohman0de549c2008-10-14 16:23:02 +0000[diff] [blame]24 <p>Written by the <a href="http://llvm.org">LLVM Team</a></p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]25</div>
26
27<!-- *********************************************************************** -->
28<div class="doc_section">
29 <a name="intro">Introduction</a>
30</div>
31<!-- *********************************************************************** -->
32
33<div class="doc_text">
34
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]35<p>This document contains the release notes for the LLVM Compiler
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]36Infrastructure, release 2.5. Here we describe the status of LLVM, including
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]37major improvements from the previous release and significant known problems.
38All LLVM releases may be downloaded from the <a
39href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]40
41<p>For more information about LLVM, including information about the latest
42release, please check out the <a href="http://llvm.org/">main LLVM
43web site</a>. If you have questions or comments, the <a
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]44href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM Developer's Mailing
45List</a> is a good place to send them.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]46
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]47<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]48main LLVM web page, this document applies to the <i>next</i> release, not the
Gabor Greif7c65c4f2008-10-14 11:00:32 +0000[diff] [blame]49current one. To see the release notes for a specific release, please see the
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]50<a href="http://llvm.org/releases/">releases page</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]51
52</div>
53
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]54<!-- Unfinished features in 2.5:
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]55 Machine LICM
56 Machine Sinking
Chris Lattnera53f4972009-02-25 06:34:50 +0000[diff] [blame]57 target-specific intrinsics
58 gold lto plugin
Chris Lattner56b64702009-02-25 07:32:53 +0000[diff] [blame]59 pre-alloc splitter, strong phi elim
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]60 llc -enable-value-prop, propagation of value info (sign/zero ext info) from
61 one MBB to another
Chris Lattnera53f4972009-02-25 06:34:50 +0000[diff] [blame]62 debug info for optimized code
Chris Lattner56b64702009-02-25 07:32:53 +0000[diff] [blame]63
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]64 -->
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]65
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]66 <!-- for announcement email:
Chris Lattnera53f4972009-02-25 06:34:50 +0000[diff] [blame]67 -->
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]68
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]69<!-- *********************************************************************** -->
70<div class="doc_section">
71 <a name="subproj">Sub-project Status Update</a>
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]72</div>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]73<!-- *********************************************************************** -->
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]74
75<div class="doc_text">
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]76<p>
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]77The LLVM 2.5 distribution currently consists of code from the core LLVM
Chris Lattnera3c683b2008-10-13 18:11:54 +0000[diff] [blame]78repository (which roughly includes the LLVM optimizers, code generators and
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]79supporting tools) and the llvm-gcc repository. In addition to this code, the
80LLVM Project includes other sub-projects that are in development. The two which
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]81are the most actively developed are the <a href="#clang">Clang Project</a> and
Nicolas Geoffray2b139382008-10-14 19:23:04 +0000[diff] [blame]82the <a href="#vmkit">VMKit Project</a>.
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]83</p>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]84
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]85</div>
86
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]87
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]88<!--=========================================================================-->
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]89<div class="doc_subsection">
Chris Lattnera3c683b2008-10-13 18:11:54 +0000[diff] [blame]90<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]91</div>
92
93<div class="doc_text">
94
95<p>The <a href="http://clang.llvm.org/">Clang project</a> is an effort to build
96a set of new 'LLVM native' front-end technologies for the LLVM optimizer
Chris Lattnerc97507b2009-02-25 05:09:54 +0000[diff] [blame]97and code generator. While Clang is not included in the LLVM 2.5 release, it
98is continuing to make major strides forward in all areas. Its C and Objective-C
99parsing and code generation support is now very solid. For example, it is
100capable of successfully building many real applications for X86-32 and X86-64,
101including the FreeBSD kernel. C++ is also making <a
102href="http://clang.llvm.org/cxx_status.html">incredible progress</a>, and work
103on templates has recently started.</p>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]104
Chris Lattnerc97507b2009-02-25 05:09:54 +0000[diff] [blame]105<p>While Clang is not yet production quality, it is progressing very nicely and
106is quite usable for building many C and Objective-C applications. If you are
107interested in fast compiles and good diagnostics, we encourage you to try it out
Chris Lattnera53f4972009-02-25 06:34:50 +0000[diff] [blame]108by <a href="http://clang.llvm.org/get_started.html">building from mainline</a>
Chris Lattnerc97507b2009-02-25 05:09:54 +0000[diff] [blame]109and reporting any issues you hit to the <a
110href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev">Clang front-end mailing
111list</a>.</p>
112
113<p>In the LLVM 2.5 time-frame, the Clang team has made many improvements:</p>
Bill Wendling385b0d32008-10-27 09:27:33 +0000[diff] [blame]114
Daniel Dunbarf3e35782008-10-14 23:25:09 +0000[diff] [blame]115<ul>
Chris Lattnerc97507b2009-02-25 05:09:54 +0000[diff] [blame]116<li>Clang now has a new driver, which is focused on providing a GCC-compatible
117 interface.</li>
118<li>The X86-64 ABI is now supported.</li>
119<li>Precompiled header support is now implemented.</li>
120<li>Objective-C support is significantly improved beyond LLVM 2.4, supporting
121 many features, such as Objective-C Garbage Collection.</li>
122<li>Many many bugs are fixed.</li>
Chris Lattnera3c683b2008-10-13 18:11:54 +0000[diff] [blame]123</div>
124
125<!--=========================================================================-->
126<div class="doc_subsection">
127<a name="clangsa">Clang Static Analyzer</a>
128</div>
129
130<div class="doc_text">
131
Ted Kremenek0437b2c2008-10-14 05:14:21 +0000[diff] [blame]132<p>The Clang project also includes an early stage static source code analysis
133tool for <a href="http://clang.llvm.org/StaticAnalysis.html">automatically
134finding bugs</a> in C and Objective-C programs. The tool performs a growing set
Chris Lattnerff170152008-10-14 06:02:29 +0000[diff] [blame]135of checks to find bugs that occur on a specific path within a program. Examples
Ted Kremenek0437b2c2008-10-14 05:14:21 +0000[diff] [blame]136of bugs the tool finds include logic errors such as null dereferences,
137violations of various API rules, dead code, and potential memory leaks in
Chris Lattnerff170152008-10-14 06:02:29 +0000[diff] [blame]138Objective-C programs. Since its inception, public feedback on the tool has been
139extremely positive, and conservative estimates put the number of real bugs it
140has found in industrial-quality software on the order of thousands.</p>
Chris Lattnerc2d84672008-10-14 00:52:49 +0000[diff] [blame]141
Ted Kremenek0437b2c2008-10-14 05:14:21 +0000[diff] [blame]142<p>The tool also provides a simple web GUI to inspect potential bugs found by
Chris Lattnerff170152008-10-14 06:02:29 +0000[diff] [blame]143the tool. While still early in development, the GUI illustrates some of the key
Ted Kremenek0437b2c2008-10-14 05:14:21 +0000[diff] [blame]144features of Clang: accurate source location information, which is used by the
145GUI to highlight specific code expressions that relate to a bug (including those
Bill Wendling385b0d32008-10-27 09:27:33 +0000[diff] [blame]146that span multiple lines); and built-in knowledge of macros, which is used to
Ted Kremenek0437b2c2008-10-14 05:14:21 +0000[diff] [blame]147perform inline expansion of macros within the GUI itself.</p>
148
Chris Lattnerff170152008-10-14 06:02:29 +0000[diff] [blame]149<p>The set of checks performed by the static analyzer is gradually expanding,
Bill Wendling385b0d32008-10-27 09:27:33 +0000[diff] [blame]150and future plans for the tool include full source-level inter-procedural
151analysis and deeper checks such as buffer overrun detection. There are many
152opportunities to extend and enhance the static analyzer, and anyone interested
153in working on this project is encouraged to get involved!</p>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]154
155</div>
156
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]157<!--=========================================================================-->
158<div class="doc_subsection">
Nicolas Geoffray2b139382008-10-14 19:23:04 +0000[diff] [blame]159<a name="vmkit">VMKit: JVM/CLI Virtual Machine Implementation</a>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]160</div>
161
162<div class="doc_text">
163<p>
Nicolas Geoffray2b139382008-10-14 19:23:04 +0000[diff] [blame]164The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation of
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]165a JVM and a CLI Virtual Machines (Microsoft .NET is an
166implementation of the CLI) using the Just-In-Time compiler of LLVM.</p>
167
Chris Lattner02408742009-02-25 05:45:05 +0000[diff] [blame]168<p>Following LLVM 2.5, VMKit has its first release ? that you can find on its
Nicolas Geoffray20cfdd42008-10-15 20:25:04 +0000[diff] [blame]169<a href="http://vmkit.llvm.org/releases/">webpage</a>. The release includes
170bug fixes, cleanup and new features. The major changes are:</p>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]171
Nicolas Geoffray2b139382008-10-14 19:23:04 +0000[diff] [blame]172<ul>
173
Chris Lattner47bcf612009-02-26 05:20:36 +0000[diff] [blame^]174<li>Ahead of Time compiler: compiles .class files to llvm .bc. VMKit uses this
175functionality to native compile the standard classes (eg java.lang.String).
176Users can compile AOT .class files into dynamic libraries and run them with the
177help of VMKit.</li>
178
179<li>New exception model: the dwarf exception model is very slow for
180exception-intensive applications, so the JVM has had a new implementation of
181exceptions which check at each function call if an exception happened. There is
182a low performance penalty on applications without exceptions, but it is a big
183gain for exception-intensive applications. For example the jack benchmark in
184Spec JVM98 is 6x faster (performance gain of 83%).</li>
185
186<li>New support for OSX/X64, Linux/X64 (with the Boehm GC), Linux/ppc32.</li>
Nicolas Geoffray2b139382008-10-14 19:23:04 +0000[diff] [blame]187
188</ul>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]189</div>
190
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]191
192<!-- *********************************************************************** -->
193<div class="doc_section">
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]194 <a name="whatsnew">What's New in LLVM?</a>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]195</div>
196<!-- *********************************************************************** -->
197
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]198<div class="doc_text">
199
Bill Wendling385b0d32008-10-27 09:27:33 +0000[diff] [blame]200<p>This release includes a huge number of bug fixes, performance tweaks, and
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]201minor improvements. Some of the major improvements and new features are listed
202in this section.
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]203</p>
204</div>
205
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]206<!--=========================================================================-->
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]207<div class="doc_subsection">
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]208<a name="majorfeatures">Major New Features</a>
209</div>
210
211<div class="doc_text">
212
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]213<p>LLVM 2.5 includes several major new capabilities:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]214
215<ul>
Duncan Sandse2cd8182009-02-25 11:37:39 +0000[diff] [blame]216<li><p>The code generator now supports arbitrary precision integers.
217Types like <tt>i33</tt> have long been valid in the LLVM IR, but previously
218could only be used with the interpreter.
219Now IR using such types can be compiled to native code on all targets.
220All operations are supported if the integer is not bigger than twice the
221target machine word size.
222Simple operations like loads, stores and shifts by a constant amount are
223supported for integers of any size.
224</p></li>
Chris Lattnera53f4972009-02-25 06:34:50 +0000[diff] [blame]225
226<!--
227Random stuff:
228
Chris Lattner56b64702009-02-25 07:32:53 +0000[diff] [blame]229xcore backend!
230fortran on darwin!
231
Chris Lattnera53f4972009-02-25 06:34:50 +0000[diff] [blame]232.ll parser rewrite.
233GCC inliner off.
234cmake mature?
235x86 backend FS/GS segment address spaces?
236nocapture
237memdep is faster / more aggressive.
Chris Lattner56b64702009-02-25 07:32:53 +0000[diff] [blame]238how to write a backend doc docs/WritingAnLLVMBackend.html
Chris Lattnera53f4972009-02-25 06:34:50 +0000[diff] [blame]239fastisel + exception handling
240vector widening <3 x float> -> <4 x float>
Chris Lattner56b64702009-02-25 07:32:53 +0000[diff] [blame]241arm port improvements? arm jit encoding stuff, constant island support?
Chris Lattner47bcf612009-02-26 05:20:36 +0000[diff] [blame^]242JIT TLS support on x86-32.
Chris Lattner56b64702009-02-25 07:32:53 +0000[diff] [blame]243mem2reg now faster on code with huge basic blocks
244stack protectors/stack canaries, -fstack-protector, controllable on a
245 per-function basis with attributes.
246shufflevector is generalized to allow different shuffle mask width than its
247 input vectors.
248loop optimizer improves floating point induction variables
249llvm/Analysis/DebugInfo.h classes, llvm-gcc and clang and codegen use them.
250asmprinters seperate from targets for jits
Chris Lattner47bcf612009-02-26 05:20:36 +0000[diff] [blame^]251PBQP register allocator now supports register coalescing.
252
Chris Lattnera53f4972009-02-25 06:34:50 +0000[diff] [blame]253-->
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]254
Chris Lattner5ba16862008-02-10 08:18:42 +0000[diff] [blame]255</ul>
256
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]257</div>
258
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]259
260<!--=========================================================================-->
261<div class="doc_subsection">
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]262<a name="llvm-gcc">llvm-gcc 4.2 Improvements</a>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]263</div>
264
265<div class="doc_text">
266
Chris Lattner4352cc82008-10-13 20:47:20 +0000[diff] [blame]267<p>LLVM fully supports the llvm-gcc 4.2 front-end, which marries the GCC
268front-ends and driver with the LLVM optimizer and code generator. It currently
269includes support for the C, C++, Objective-C, Ada, and Fortran front-ends.</p>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]270
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]271<ul>
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]272<li>?</li>
Gabor Greif0e49cc82008-06-09 06:06:18 +0000[diff] [blame]273</ul>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]274
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]275</div>
276
277
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]278<!--=========================================================================-->
279<div class="doc_subsection">
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]280<a name="coreimprovements">LLVM Core Improvements</a>
281</div>
282
283<div class="doc_text">
Bill Wendling385b0d32008-10-27 09:27:33 +0000[diff] [blame]284<p>New features include:</p>
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]285
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]286<ul>
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]287<li>?</li>
Chris Lattnerf7bae6d2008-10-13 20:59:32 +0000[diff] [blame]288
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]289</ul>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]290
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]291</div>
292
293<!--=========================================================================-->
294<div class="doc_subsection">
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]295<a name="optimizer">Optimizer Improvements</a>
296</div>
297
298<div class="doc_text">
299
Chris Lattnerea9c2242008-10-13 21:50:36 +0000[diff] [blame]300<p>In addition to a huge array of bug fixes and minor performance tweaks, this
301release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]302
303<ul>
304
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]305<li>?</li>
Chris Lattnerea9c2242008-10-13 21:50:36 +0000[diff] [blame]306
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]307</ul>
308
309</div>
310
311<!--=========================================================================-->
312<div class="doc_subsection">
313<a name="codegen">Code Generator Improvements</a>
314</div>
315
316<div class="doc_text">
317
Gabor Greifaa53e562008-10-14 11:31:14 +0000[diff] [blame]318<p>We have put a significant amount of work into the code generator infrastructure,
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]319which allows us to implement more aggressive algorithms and make it run
320faster:</p>
321
322<ul>
Duncan Sands335d5e42009-02-25 11:50:08 +0000[diff] [blame]323<li>The type legalization logic has been completely rewritten, and is now
324more powerful (it supports arbitrary precision integer types for example)
325and hopefully more correct.
326The type legalizer converts operations on types that are not natively
327supported by the target machine into equivalent code sequences that only use
328natively supported types.
329The old type legalizer is still available and will be used if
330<tt>-disable-legalize-types</tt> is passed to <tt>llc</tt>.
331</li>
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]332<li>?</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]333
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]334</ul>
335
336</div>
337
338
339<!--=========================================================================-->
340<div class="doc_subsection">
Chris Lattnercc64a322008-10-13 22:06:31 +0000[diff] [blame]341<a name="targetspecific">Target Specific Improvements</a>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]342</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]343
344<div class="doc_text">
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]345<p>New target-specific features include:
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]346</p>
347
348<ul>
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]349<li>?</li>
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]350</ul>
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]351
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]352</div>
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]353
354
355<!--=========================================================================-->
356<div class="doc_subsection">
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]357<a name="otherimprovements">Other Improvements</a>
358</div>
359
360<div class="doc_text">
361<p>New features include:
362</p>
363
364<ul>
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]365<li>?</li>
Tanya Lattnerc79f7542008-11-04 18:40:27 +0000[diff] [blame]366
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]367</ul>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]368
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]369</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]370
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]371<!--=========================================================================-->
372<div class="doc_subsection">
373<a name="changes">Major Changes and Removed Features</a>
374</div>
375
376<div class="doc_text">
377
Chris Lattnercc64a322008-10-13 22:06:31 +0000[diff] [blame]378<p>If you're already an LLVM user or developer with out-of-tree changes based
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]379on LLVM 2.4, this section lists some "gotchas" that you may run into upgrading
Chris Lattnercc64a322008-10-13 22:06:31 +0000[diff] [blame]380from the previous release.</p>
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]381
382<ul>
383
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]384<li>?</li>
Chris Lattnercc64a322008-10-13 22:06:31 +0000[diff] [blame]385</ul>
386
387
388<p>In addition, many APIs have changed in this release. Some of the major LLVM
389API changes are:</p>
390
391<ul>
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]392<li>?</li>
Devang Patel0e3da1a2008-10-14 20:03:43 +0000[diff] [blame]393</ul>
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]394
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]395<li>?</li>
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]396</ul>
397
398</div>
399
400
401
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]402<!-- *********************************************************************** -->
403<div class="doc_section">
404 <a name="portability">Portability and Supported Platforms</a>
405</div>
406<!-- *********************************************************************** -->
407
408<div class="doc_text">
409
410<p>LLVM is known to work on the following platforms:</p>
411
412<ul>
Chris Lattnerb1ad47c2008-11-10 05:40:34 +0000[diff] [blame]413<li>Intel and AMD machines (IA32, X86-64, AMD64, EMT-64) running Red Hat
414Linux, Fedora Core and FreeBSD (and probably other unix-like systems).</li>
415<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit
416and 64-bit modes.</li>
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]417<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]418<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
419 support is available for native builds with Visual C++).</li>
Gabor Greif5e75e652008-06-05 18:39:01 +0000[diff] [blame]420<li>Sun UltraSPARC workstations running Solaris 10.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]421<li>Alpha-based machines running Debian GNU/Linux.</li>
Gabor Greif5e75e652008-06-05 18:39:01 +0000[diff] [blame]422<li>Itanium-based (IA64) machines running Linux and HP-UX.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]423</ul>
424
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]425<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]426to the machine and operating system on which it is built. However, minor
427porting may be required to get LLVM to work on new platforms. We welcome your
428portability patches and reports of successful builds or error messages.</p>
429
430</div>
431
432<!-- *********************************************************************** -->
433<div class="doc_section">
434 <a name="knownproblems">Known Problems</a>
435</div>
436<!-- *********************************************************************** -->
437
438<div class="doc_text">
439
Chris Lattnerb1ad47c2008-11-10 05:40:34 +0000[diff] [blame]440<p>This section contains significant known problems with the LLVM system,
441listed by component. If you run into a problem, please check the <a
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]442href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
443there isn't already one.</p>
444
445</div>
446
447<!-- ======================================================================= -->
448<div class="doc_subsection">
449 <a name="experimental">Experimental features included with this release</a>
450</div>
451
452<div class="doc_text">
453
454<p>The following components of this LLVM release are either untested, known to
455be broken or unreliable, or are in early development. These components should
456not be relied on, and bugs should not be filed against them, but they may be
457useful to some people. In particular, if you would like to work on one of these
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]458components, please contact us on the <a
459href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]460
461<ul>
Gabor Greifaa53e562008-10-14 11:31:14 +0000[diff] [blame]462<li>The MSIL, IA64, Alpha, SPU, MIPS, and PIC16 backends are experimental.</li>
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]463<li>The llc "<tt>-filetype=asm</tt>" (the default) is the only supported
Chris Lattnerbd633de92008-02-06 06:30:34 +0000[diff] [blame]464 value for this option.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]465</ul>
466
467</div>
468
469<!-- ======================================================================= -->
470<div class="doc_subsection">
471 <a name="x86-be">Known problems with the X86 back-end</a>
472</div>
473
474<div class="doc_text">
475
476<ul>
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]477 <li>The X86 backend does not yet support
478 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
479 floating point stack</a>. It supports the 'f' and 't' constraints, but not
480 'u'.</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]481 <li>The X86 backend generates inefficient floating point code when configured
482 to generate code for systems that don't have SSE2.</li>
Duncan Sands8b4f3772008-06-08 19:38:43 +0000[diff] [blame]483 <li>Win64 code generation wasn't widely tested. Everything should work, but we
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]484 expect small issues to happen. Also, llvm-gcc cannot build mingw64 runtime
485 currently due
486 to <a href="http://llvm.org/PR2255">several</a>
Chris Lattnerf06141a2008-06-08 23:12:47 +0000[diff] [blame]487 <a href="http://llvm.org/PR2257">bugs</a> due to lack of support for the
488 'u' inline assembly constraint and X87 floating point inline assembly.</li>
Dan Gohman3882ecb2008-06-08 23:05:11 +0000[diff] [blame]489 <li>The X86-64 backend does not yet support the LLVM IR instruction
490 <tt>va_arg</tt>. Currently, the llvm-gcc front-end supports variadic
491 argument constructs on X86-64 by lowering them manually.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]492</ul>
493
494</div>
495
496<!-- ======================================================================= -->
497<div class="doc_subsection">
498 <a name="ppc-be">Known problems with the PowerPC back-end</a>
499</div>
500
501<div class="doc_text">
502
503<ul>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]504<li>The Linux PPC32/ABI support needs testing for the interpreter and static
505compilation, and lacks support for debug information.</li>
506</ul>
507
508</div>
509
510<!-- ======================================================================= -->
511<div class="doc_subsection">
512 <a name="arm-be">Known problems with the ARM back-end</a>
513</div>
514
515<div class="doc_text">
516
517<ul>
518<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sands1827fa62007-09-26 15:59:54 +0000[diff] [blame]519processors, thumb programs can crash or produce wrong
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]520results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
521<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
522</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]523<li>There is a bug in QEMU-ARM (&lt;= 0.9.0) which causes it to incorrectly
524 execute
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]525programs compiled with LLVM. Please use more recent versions of QEMU.</li>
526</ul>
527
528</div>
529
530<!-- ======================================================================= -->
531<div class="doc_subsection">
532 <a name="sparc-be">Known problems with the SPARC back-end</a>
533</div>
534
535<div class="doc_text">
536
537<ul>
538<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
539 support the 64-bit SPARC ABI (-m64).</li>
540</ul>
541
542</div>
543
544<!-- ======================================================================= -->
545<div class="doc_subsection">
Bruno Cardoso Lopes62d45d72008-10-25 14:56:26 +0000[diff] [blame]546 <a name="mips-be">Known problems with the MIPS back-end</a>
547</div>
548
549<div class="doc_text">
550
551<ul>
552<li>The O32 ABI is not fully supported.</li>
553<li>64-bit MIPS targets are not supported yet.</li>
554</ul>
555
556</div>
557
558<!-- ======================================================================= -->
559<div class="doc_subsection">
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]560 <a name="alpha-be">Known problems with the Alpha back-end</a>
561</div>
562
563<div class="doc_text">
564
565<ul>
566
567<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
568appropriate nops inserted to ensure restartability.</li>
569
570</ul>
571</div>
572
573<!-- ======================================================================= -->
574<div class="doc_subsection">
575 <a name="ia64-be">Known problems with the IA64 back-end</a>
576</div>
577
578<div class="doc_text">
579
580<ul>
Chris Lattnerf06141a2008-06-08 23:12:47 +0000[diff] [blame]581<li>The Itanium backend is highly experimental, and has a number of known
582 issues. We are looking for a maintainer for the Itanium backend. If you
Gabor Greif45fc8b12008-10-15 10:47:24 +0000[diff] [blame]583 are interested, please contact the LLVMdev mailing list.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]584</ul>
585
586</div>
587
588<!-- ======================================================================= -->
589<div class="doc_subsection">
590 <a name="c-be">Known problems with the C back-end</a>
591</div>
592
593<div class="doc_text">
594
595<ul>
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]596<li><a href="http://llvm.org/PR802">The C backend has only basic support for
597 inline assembly code</a>.</li>
Chris Lattnere0194462007-09-26 06:01:35 +0000[diff] [blame]598<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
599 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]600 C++ code compiled with llc or native compilers.</li>
Duncan Sandsbd0ad6e2008-02-10 13:40:55 +0000[diff] [blame]601<li>The C backend does not support all exception handling constructs.</li>
Duncan Sandse6e264c2009-02-25 11:51:54 +0000[diff] [blame]602<li>The C backend does not support arbitrary precision integers.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]603</ul>
604
605</div>
606
607
608<!-- ======================================================================= -->
609<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]610 <a name="c-fe">Known problems with the llvm-gcc C front-end</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]611</div>
612
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]613<div class="doc_text">
614
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]615<p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time
616Optimization</a> on most platforms "out-of-the-box". Please inquire on the
Gabor Greif45fc8b12008-10-15 10:47:24 +0000[diff] [blame]617LLVMdev mailing list if you are interested.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]618
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]619<p>The only major language feature of GCC not supported by llvm-gcc is
620 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
621 are only supported on some targets. For example, trampolines are only
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]622 supported on some targets (these are used when you take the address of a
623 nested function).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]624
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]625<p>If you run into GCC extensions which are not supported, please let us know.
626</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]627
628</div>
629
630<!-- ======================================================================= -->
631<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]632 <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]633</div>
634
635<div class="doc_text">
636
637<p>The C++ front-end is considered to be fully
638tested and works for a number of non-trivial programs, including LLVM
639itself, Qt, Mozilla, etc.</p>
640
641<ul>
Anton Korobeynikovd9a17932008-10-11 18:27:16 +0000[diff] [blame]642<li>Exception handling works well on the X86 and PowerPC targets. Currently
Chris Lattnerb1ad47c2008-11-10 05:40:34 +0000[diff] [blame]643 only Linux and Darwin targets are supported (both 32 and 64 bit).</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]644</ul>
645
646</div>
647
Chris Lattner6c8a1b82008-10-30 03:58:13 +0000[diff] [blame]648<!-- ======================================================================= -->
649<div class="doc_subsection">
650 <a name="fortran-fe">Known problems with the llvm-gcc Fortran front-end</a>
651</div>
652
653<div class="doc_text">
Gabor Greif1fc8fbc2008-11-04 21:50:59 +0000[diff] [blame]654<ul>
Chris Lattner6c8a1b82008-10-30 03:58:13 +0000[diff] [blame]655<li>Fortran support generally works, but there are still several unresolved bugs
656 in Bugzilla. Please see the tools/gfortran component for details.</li>
657
658<li>The Fortran front-end currently does not build on Darwin (without tweaks)
659 due to unresolved dependencies on the C front-end.</li>
Gabor Greif1fc8fbc2008-11-04 21:50:59 +0000[diff] [blame]660</ul>
Chris Lattner6c8a1b82008-10-30 03:58:13 +0000[diff] [blame]661</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]662
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]663<!-- ======================================================================= -->
664<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]665 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]666</div>
667
668<div class="doc_text">
669The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature
670technology and problems should be expected.
671<ul>
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]672<li>The Ada front-end currently only builds on X86-32. This is mainly due
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]673to lack of trampoline support (pointers to nested functions) on other platforms,
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]674however it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]675which does support trampolines.</li>
676<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
Duncan Sandsf73473e2009-02-25 11:59:06 +0000[diff] [blame]677This is due to lack of LLVM support for <tt>setjmp</tt>/<tt>longjmp</tt> style
678exception handling, which is used internally by the compiler.
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]679Workaround: configure with --disable-bootstrap.</li>
Duncan Sands2dbc2e82008-10-13 17:27:23 +0000[diff] [blame]680<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
681and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
Duncan Sandsf73473e2009-02-25 11:59:06 +0000[diff] [blame]682(c380004 also fails with gcc-4.2 mainline).
683If the compiler is built with checks disabled then <a href="http://llvm.org/PR2010">c393010</a>
684causes the compiler to go into an infinite loop, using up all system memory.</li>
Duncan Sands2dbc2e82008-10-13 17:27:23 +0000[diff] [blame]685<li>Some gcc specific Ada tests continue to crash the compiler.</li>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]686<li>The -E binder option (exception backtraces)
687<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
688crashing if an exception is raised. Workaround: do not use -E.</li>
689<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
690or finish at a non-byte offset</a> in a record. Workaround: do not pack records
691or use representation clauses that result in a field of a non-discrete type
692starting or finishing in the middle of a byte.</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]693<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
694'main' as generated by the Ada binder to be invalid</a>.
695Workaround: hand edit the file to use pointers for <tt>argv</tt> and
696<tt>envp</tt> rather than integers.</li>
697<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
698ignored</a>.</li>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]699</ul>
700</div>
701
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]702<!-- *********************************************************************** -->
703<div class="doc_section">
704 <a name="additionalinfo">Additional Information</a>
705</div>
706<!-- *********************************************************************** -->
707
708<div class="doc_text">
709
710<p>A wide variety of additional information is available on the <a
711href="http://llvm.org">LLVM web page</a>, in particular in the <a
712href="http://llvm.org/docs/">documentation</a> section. The web page also
713contains versions of the API documentation which is up-to-date with the
714Subversion version of the source code.
715You can access versions of these documents specific to this release by going
716into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
717
718<p>If you have any questions or comments about LLVM, please feel free to contact
719us via the <a href="http://llvm.org/docs/#maillist"> mailing
720lists</a>.</p>
721
722</div>
723
724<!-- *********************************************************************** -->
725
726<hr>
727<address>
728 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
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Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]730 <a href="http://validator.w3.org/check/referer"><img
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Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]732
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