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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / e2cd8187e4621ccabd25d1a49a8c66bc6bff6dad / . / 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 Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]174<li>?</li>
Nicolas Geoffray2b139382008-10-14 19:23:04 +0000[diff] [blame]175
176</ul>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]177</div>
178
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]179
180<!-- *********************************************************************** -->
181<div class="doc_section">
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]182 <a name="whatsnew">What's New in LLVM?</a>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]183</div>
184<!-- *********************************************************************** -->
185
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]186<div class="doc_text">
187
Bill Wendling385b0d32008-10-27 09:27:33 +0000[diff] [blame]188<p>This release includes a huge number of bug fixes, performance tweaks, and
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]189minor improvements. Some of the major improvements and new features are listed
190in this section.
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]191</p>
192</div>
193
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]194<!--=========================================================================-->
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]195<div class="doc_subsection">
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]196<a name="majorfeatures">Major New Features</a>
197</div>
198
199<div class="doc_text">
200
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]201<p>LLVM 2.5 includes several major new capabilities:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]202
203<ul>
Duncan Sandse2cd8182009-02-25 11:37:39 +0000[diff] [blame^]204<li><p>The code generator now supports arbitrary precision integers.
205Types like <tt>i33</tt> have long been valid in the LLVM IR, but previously
206could only be used with the interpreter.
207Now IR using such types can be compiled to native code on all targets.
208All operations are supported if the integer is not bigger than twice the
209target machine word size.
210Simple operations like loads, stores and shifts by a constant amount are
211supported for integers of any size.
212</p></li>
Chris Lattnera53f4972009-02-25 06:34:50 +0000[diff] [blame]213
214<!--
215Random stuff:
216
Chris Lattner56b64702009-02-25 07:32:53 +0000[diff] [blame]217xcore backend!
218fortran on darwin!
219
Chris Lattnera53f4972009-02-25 06:34:50 +0000[diff] [blame]220.ll parser rewrite.
221GCC inliner off.
222cmake mature?
223x86 backend FS/GS segment address spaces?
224nocapture
225memdep is faster / more aggressive.
Chris Lattner56b64702009-02-25 07:32:53 +0000[diff] [blame]226how to write a backend doc docs/WritingAnLLVMBackend.html
Chris Lattnera53f4972009-02-25 06:34:50 +0000[diff] [blame]227fastisel + exception handling
228vector widening <3 x float> -> <4 x float>
Chris Lattner56b64702009-02-25 07:32:53 +0000[diff] [blame]229arm port improvements? arm jit encoding stuff, constant island support?
230JIT TLS support on x86
231mem2reg now faster on code with huge basic blocks
232stack protectors/stack canaries, -fstack-protector, controllable on a
233 per-function basis with attributes.
234shufflevector is generalized to allow different shuffle mask width than its
235 input vectors.
236loop optimizer improves floating point induction variables
237llvm/Analysis/DebugInfo.h classes, llvm-gcc and clang and codegen use them.
238asmprinters seperate from targets for jits
Chris Lattnera53f4972009-02-25 06:34:50 +0000[diff] [blame]239-->
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]240
Chris Lattner5ba16862008-02-10 08:18:42 +0000[diff] [blame]241</ul>
242
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]243</div>
244
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]245
246<!--=========================================================================-->
247<div class="doc_subsection">
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]248<a name="llvm-gcc">llvm-gcc 4.2 Improvements</a>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]249</div>
250
251<div class="doc_text">
252
Chris Lattner4352cc82008-10-13 20:47:20 +0000[diff] [blame]253<p>LLVM fully supports the llvm-gcc 4.2 front-end, which marries the GCC
254front-ends and driver with the LLVM optimizer and code generator. It currently
255includes support for the C, C++, Objective-C, Ada, and Fortran front-ends.</p>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]256
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]257<ul>
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]258<li>?</li>
Gabor Greif0e49cc82008-06-09 06:06:18 +0000[diff] [blame]259</ul>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]260
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]261</div>
262
263
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]264<!--=========================================================================-->
265<div class="doc_subsection">
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]266<a name="coreimprovements">LLVM Core Improvements</a>
267</div>
268
269<div class="doc_text">
Bill Wendling385b0d32008-10-27 09:27:33 +0000[diff] [blame]270<p>New features include:</p>
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]271
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]272<ul>
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]273<li>?</li>
Chris Lattnerf7bae6d2008-10-13 20:59:32 +0000[diff] [blame]274
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]275</ul>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]276
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]277</div>
278
279<!--=========================================================================-->
280<div class="doc_subsection">
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]281<a name="optimizer">Optimizer Improvements</a>
282</div>
283
284<div class="doc_text">
285
Chris Lattnerea9c2242008-10-13 21:50:36 +0000[diff] [blame]286<p>In addition to a huge array of bug fixes and minor performance tweaks, this
287release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]288
289<ul>
290
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]291<li>?</li>
Chris Lattnerea9c2242008-10-13 21:50:36 +0000[diff] [blame]292
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]293</ul>
294
295</div>
296
297<!--=========================================================================-->
298<div class="doc_subsection">
299<a name="codegen">Code Generator Improvements</a>
300</div>
301
302<div class="doc_text">
303
Gabor Greifaa53e562008-10-14 11:31:14 +0000[diff] [blame]304<p>We have put a significant amount of work into the code generator infrastructure,
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]305which allows us to implement more aggressive algorithms and make it run
306faster:</p>
307
308<ul>
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]309<li>?</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]310
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]311</ul>
312
313</div>
314
315
316<!--=========================================================================-->
317<div class="doc_subsection">
Chris Lattnercc64a322008-10-13 22:06:31 +0000[diff] [blame]318<a name="targetspecific">Target Specific Improvements</a>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]319</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]320
321<div class="doc_text">
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]322<p>New target-specific features include:
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]323</p>
324
325<ul>
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]326<li>?</li>
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]327</ul>
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]328
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]329</div>
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]330
331
332<!--=========================================================================-->
333<div class="doc_subsection">
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]334<a name="otherimprovements">Other Improvements</a>
335</div>
336
337<div class="doc_text">
338<p>New features include:
339</p>
340
341<ul>
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]342<li>?</li>
Tanya Lattnerc79f7542008-11-04 18:40:27 +0000[diff] [blame]343
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]344</ul>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]345
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]346</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]347
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]348<!--=========================================================================-->
349<div class="doc_subsection">
350<a name="changes">Major Changes and Removed Features</a>
351</div>
352
353<div class="doc_text">
354
Chris Lattnercc64a322008-10-13 22:06:31 +0000[diff] [blame]355<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]356on LLVM 2.4, this section lists some "gotchas" that you may run into upgrading
Chris Lattnercc64a322008-10-13 22:06:31 +0000[diff] [blame]357from the previous release.</p>
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]358
359<ul>
360
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]361<li>?</li>
Chris Lattnercc64a322008-10-13 22:06:31 +0000[diff] [blame]362</ul>
363
364
365<p>In addition, many APIs have changed in this release. Some of the major LLVM
366API changes are:</p>
367
368<ul>
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]369<li>?</li>
Devang Patel0e3da1a2008-10-14 20:03:43 +0000[diff] [blame]370</ul>
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]371
Chris Lattner95d25072009-02-25 04:41:31 +0000[diff] [blame]372<li>?</li>
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]373</ul>
374
375</div>
376
377
378
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]379<!-- *********************************************************************** -->
380<div class="doc_section">
381 <a name="portability">Portability and Supported Platforms</a>
382</div>
383<!-- *********************************************************************** -->
384
385<div class="doc_text">
386
387<p>LLVM is known to work on the following platforms:</p>
388
389<ul>
Chris Lattnerb1ad47c2008-11-10 05:40:34 +0000[diff] [blame]390<li>Intel and AMD machines (IA32, X86-64, AMD64, EMT-64) running Red Hat
391Linux, Fedora Core and FreeBSD (and probably other unix-like systems).</li>
392<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit
393and 64-bit modes.</li>
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]394<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]395<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
396 support is available for native builds with Visual C++).</li>
Gabor Greif5e75e652008-06-05 18:39:01 +0000[diff] [blame]397<li>Sun UltraSPARC workstations running Solaris 10.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]398<li>Alpha-based machines running Debian GNU/Linux.</li>
Gabor Greif5e75e652008-06-05 18:39:01 +0000[diff] [blame]399<li>Itanium-based (IA64) machines running Linux and HP-UX.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]400</ul>
401
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]402<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]403to the machine and operating system on which it is built. However, minor
404porting may be required to get LLVM to work on new platforms. We welcome your
405portability patches and reports of successful builds or error messages.</p>
406
407</div>
408
409<!-- *********************************************************************** -->
410<div class="doc_section">
411 <a name="knownproblems">Known Problems</a>
412</div>
413<!-- *********************************************************************** -->
414
415<div class="doc_text">
416
Chris Lattnerb1ad47c2008-11-10 05:40:34 +0000[diff] [blame]417<p>This section contains significant known problems with the LLVM system,
418listed by component. If you run into a problem, please check the <a
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]419href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
420there isn't already one.</p>
421
422</div>
423
424<!-- ======================================================================= -->
425<div class="doc_subsection">
426 <a name="experimental">Experimental features included with this release</a>
427</div>
428
429<div class="doc_text">
430
431<p>The following components of this LLVM release are either untested, known to
432be broken or unreliable, or are in early development. These components should
433not be relied on, and bugs should not be filed against them, but they may be
434useful 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]435components, please contact us on the <a
436href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]437
438<ul>
Gabor Greifaa53e562008-10-14 11:31:14 +0000[diff] [blame]439<li>The MSIL, IA64, Alpha, SPU, MIPS, and PIC16 backends are experimental.</li>
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]440<li>The llc "<tt>-filetype=asm</tt>" (the default) is the only supported
Chris Lattnerbd633de92008-02-06 06:30:34 +0000[diff] [blame]441 value for this option.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]442</ul>
443
444</div>
445
446<!-- ======================================================================= -->
447<div class="doc_subsection">
448 <a name="x86-be">Known problems with the X86 back-end</a>
449</div>
450
451<div class="doc_text">
452
453<ul>
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]454 <li>The X86 backend does not yet support
455 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
456 floating point stack</a>. It supports the 'f' and 't' constraints, but not
457 'u'.</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]458 <li>The X86 backend generates inefficient floating point code when configured
459 to generate code for systems that don't have SSE2.</li>
Duncan Sands8b4f3772008-06-08 19:38:43 +0000[diff] [blame]460 <li>Win64 code generation wasn't widely tested. Everything should work, but we
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]461 expect small issues to happen. Also, llvm-gcc cannot build mingw64 runtime
462 currently due
463 to <a href="http://llvm.org/PR2255">several</a>
Chris Lattnerf06141a2008-06-08 23:12:47 +0000[diff] [blame]464 <a href="http://llvm.org/PR2257">bugs</a> due to lack of support for the
465 'u' inline assembly constraint and X87 floating point inline assembly.</li>
Dan Gohman3882ecb2008-06-08 23:05:11 +0000[diff] [blame]466 <li>The X86-64 backend does not yet support the LLVM IR instruction
467 <tt>va_arg</tt>. Currently, the llvm-gcc front-end supports variadic
468 argument constructs on X86-64 by lowering them manually.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]469</ul>
470
471</div>
472
473<!-- ======================================================================= -->
474<div class="doc_subsection">
475 <a name="ppc-be">Known problems with the PowerPC back-end</a>
476</div>
477
478<div class="doc_text">
479
480<ul>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]481<li>The Linux PPC32/ABI support needs testing for the interpreter and static
482compilation, and lacks support for debug information.</li>
483</ul>
484
485</div>
486
487<!-- ======================================================================= -->
488<div class="doc_subsection">
489 <a name="arm-be">Known problems with the ARM back-end</a>
490</div>
491
492<div class="doc_text">
493
494<ul>
495<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sands1827fa62007-09-26 15:59:54 +0000[diff] [blame]496processors, thumb programs can crash or produce wrong
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]497results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
498<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
499</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]500<li>There is a bug in QEMU-ARM (&lt;= 0.9.0) which causes it to incorrectly
501 execute
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]502programs compiled with LLVM. Please use more recent versions of QEMU.</li>
503</ul>
504
505</div>
506
507<!-- ======================================================================= -->
508<div class="doc_subsection">
509 <a name="sparc-be">Known problems with the SPARC back-end</a>
510</div>
511
512<div class="doc_text">
513
514<ul>
515<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
516 support the 64-bit SPARC ABI (-m64).</li>
517</ul>
518
519</div>
520
521<!-- ======================================================================= -->
522<div class="doc_subsection">
Bruno Cardoso Lopes62d45d72008-10-25 14:56:26 +0000[diff] [blame]523 <a name="mips-be">Known problems with the MIPS back-end</a>
524</div>
525
526<div class="doc_text">
527
528<ul>
529<li>The O32 ABI is not fully supported.</li>
530<li>64-bit MIPS targets are not supported yet.</li>
531</ul>
532
533</div>
534
535<!-- ======================================================================= -->
536<div class="doc_subsection">
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]537 <a name="alpha-be">Known problems with the Alpha back-end</a>
538</div>
539
540<div class="doc_text">
541
542<ul>
543
544<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
545appropriate nops inserted to ensure restartability.</li>
546
547</ul>
548</div>
549
550<!-- ======================================================================= -->
551<div class="doc_subsection">
552 <a name="ia64-be">Known problems with the IA64 back-end</a>
553</div>
554
555<div class="doc_text">
556
557<ul>
Chris Lattnerf06141a2008-06-08 23:12:47 +0000[diff] [blame]558<li>The Itanium backend is highly experimental, and has a number of known
559 issues. We are looking for a maintainer for the Itanium backend. If you
Gabor Greif45fc8b12008-10-15 10:47:24 +0000[diff] [blame]560 are interested, please contact the LLVMdev mailing list.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]561</ul>
562
563</div>
564
565<!-- ======================================================================= -->
566<div class="doc_subsection">
567 <a name="c-be">Known problems with the C back-end</a>
568</div>
569
570<div class="doc_text">
571
572<ul>
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]573<li><a href="http://llvm.org/PR802">The C backend has only basic support for
574 inline assembly code</a>.</li>
Chris Lattnere0194462007-09-26 06:01:35 +0000[diff] [blame]575<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
576 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]577 C++ code compiled with llc or native compilers.</li>
Duncan Sandsbd0ad6e2008-02-10 13:40:55 +0000[diff] [blame]578<li>The C backend does not support all exception handling constructs.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]579</ul>
580
581</div>
582
583
584<!-- ======================================================================= -->
585<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]586 <a name="c-fe">Known problems with the llvm-gcc C front-end</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]587</div>
588
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]589<div class="doc_text">
590
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]591<p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time
592Optimization</a> on most platforms "out-of-the-box". Please inquire on the
Gabor Greif45fc8b12008-10-15 10:47:24 +0000[diff] [blame]593LLVMdev mailing list if you are interested.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]594
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]595<p>The only major language feature of GCC not supported by llvm-gcc is
596 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
597 are only supported on some targets. For example, trampolines are only
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]598 supported on some targets (these are used when you take the address of a
599 nested function).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]600
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]601<p>If you run into GCC extensions which are not supported, please let us know.
602</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]603
604</div>
605
606<!-- ======================================================================= -->
607<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]608 <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]609</div>
610
611<div class="doc_text">
612
613<p>The C++ front-end is considered to be fully
614tested and works for a number of non-trivial programs, including LLVM
615itself, Qt, Mozilla, etc.</p>
616
617<ul>
Anton Korobeynikovd9a17932008-10-11 18:27:16 +0000[diff] [blame]618<li>Exception handling works well on the X86 and PowerPC targets. Currently
Chris Lattnerb1ad47c2008-11-10 05:40:34 +0000[diff] [blame]619 only Linux and Darwin targets are supported (both 32 and 64 bit).</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]620</ul>
621
622</div>
623
Chris Lattner6c8a1b82008-10-30 03:58:13 +0000[diff] [blame]624<!-- ======================================================================= -->
625<div class="doc_subsection">
626 <a name="fortran-fe">Known problems with the llvm-gcc Fortran front-end</a>
627</div>
628
629<div class="doc_text">
Gabor Greif1fc8fbc2008-11-04 21:50:59 +0000[diff] [blame]630<ul>
Chris Lattner6c8a1b82008-10-30 03:58:13 +0000[diff] [blame]631<li>Fortran support generally works, but there are still several unresolved bugs
632 in Bugzilla. Please see the tools/gfortran component for details.</li>
633
634<li>The Fortran front-end currently does not build on Darwin (without tweaks)
635 due to unresolved dependencies on the C front-end.</li>
Gabor Greif1fc8fbc2008-11-04 21:50:59 +0000[diff] [blame]636</ul>
Chris Lattner6c8a1b82008-10-30 03:58:13 +0000[diff] [blame]637</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]638
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]639<!-- ======================================================================= -->
640<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]641 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]642</div>
643
644<div class="doc_text">
645The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature
646technology and problems should be expected.
647<ul>
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]648<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]649to lack of trampoline support (pointers to nested functions) on other platforms,
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]650however 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]651which does support trampolines.</li>
652<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
653Workaround: configure with --disable-bootstrap.</li>
Duncan Sands2dbc2e82008-10-13 17:27:23 +0000[diff] [blame]654<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
655and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
656(c380004 also fails with gcc-4.2 mainline).</li>
657<li>Some gcc specific Ada tests continue to crash the compiler.</li>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]658<li>The -E binder option (exception backtraces)
659<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
660crashing if an exception is raised. Workaround: do not use -E.</li>
661<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
662or finish at a non-byte offset</a> in a record. Workaround: do not pack records
663or use representation clauses that result in a field of a non-discrete type
664starting or finishing in the middle of a byte.</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]665<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
666'main' as generated by the Ada binder to be invalid</a>.
667Workaround: hand edit the file to use pointers for <tt>argv</tt> and
668<tt>envp</tt> rather than integers.</li>
669<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
670ignored</a>.</li>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]671</ul>
672</div>
673
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]674<!-- *********************************************************************** -->
675<div class="doc_section">
676 <a name="additionalinfo">Additional Information</a>
677</div>
678<!-- *********************************************************************** -->
679
680<div class="doc_text">
681
682<p>A wide variety of additional information is available on the <a
683href="http://llvm.org">LLVM web page</a>, in particular in the <a
684href="http://llvm.org/docs/">documentation</a> section. The web page also
685contains versions of the API documentation which is up-to-date with the
686Subversion version of the source code.
687You can access versions of these documents specific to this release by going
688into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
689
690<p>If you have any questions or comments about LLVM, please feel free to contact
691us via the <a href="http://llvm.org/docs/#maillist"> mailing
692lists</a>.</p>
693
694</div>
695
696<!-- *********************************************************************** -->
697
698<hr>
699<address>
700 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman947321d2008-12-11 17:34:48 +0000[diff] [blame]701 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]702 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman947321d2008-12-11 17:34:48 +0000[diff] [blame]703 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]704
705 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
706 Last modified: $Date$
707</address>
708
709</body>
710</html>