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Chris Lattner38ab04c2009-02-25 04:41:31 +0000[diff] [blame]7 <title>LLVM 2.5 Release Notes</title>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]8</head>
9<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]10
Chris Lattner38ab04c2009-02-25 04:41:31 +0000[diff] [blame]11<div class="doc_title">LLVM 2.5 Release Notes</div>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]12
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]13<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]14 <li><a href="#intro">Introduction</a></li>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]15 <li><a href="#subproj">Sub-project Status Update</a></li>
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame^]16 <li><a href="#externalproj">External Projects Using LLVM 2.5</a></li>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]17 <li><a href="#whatsnew">What's New in LLVM?</a></li>
Chris Lattner4b538b92004-04-30 22:17:12 +0000[diff] [blame]18 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]19 <li><a href="#portability">Portability and Supported Platforms</a></li>
Dan Gohman44aa9212008-10-14 16:23:02 +0000[diff] [blame]20 <li><a href="#knownproblems">Known Problems</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]21 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]22</ol>
23
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]24<div class="doc_author">
Dan Gohman44aa9212008-10-14 16:23:02 +0000[diff] [blame]25 <p>Written by the <a href="http://llvm.org">LLVM Team</a></p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]26</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]27
28<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]29<div class="doc_section">
30 <a name="intro">Introduction</a>
31</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]32<!-- *********************************************************************** -->
33
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]34<div class="doc_text">
35
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]36<p>This document contains the release notes for the LLVM Compiler
Chris Lattner38ab04c2009-02-25 04:41:31 +0000[diff] [blame]37Infrastructure, release 2.5. Here we describe the status of LLVM, including
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]38major improvements from the previous release and significant known problems.
39All LLVM releases may be downloaded from the <a
40href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]41
Chris Lattner7506b1d2004-12-07 08:04:13 +0000[diff] [blame]42<p>For more information about LLVM, including information about the latest
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]43release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]44web site</a>. If you have questions or comments, the <a
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]45href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM Developer's Mailing
46List</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]47
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]48<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]49main LLVM web page, this document applies to the <i>next</i> release, not the
Gabor Greiffa933f82008-10-14 11:00:32 +0000[diff] [blame]50current one. To see the release notes for a specific release, please see the
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]51<a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]52
53</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]54
Chris Lattner38ab04c2009-02-25 04:41:31 +0000[diff] [blame]55<!-- Unfinished features in 2.5:
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]56 Machine LICM
57 Machine Sinking
Chris Lattner74c80df2009-02-25 06:34:50 +0000[diff] [blame]58 target-specific intrinsics
59 gold lto plugin
Chris Lattner99f375b2009-02-25 07:32:53 +0000[diff] [blame]60 pre-alloc splitter, strong phi elim
Chris Lattner547a3912008-10-12 19:47:48 +0000[diff] [blame]61 llc -enable-value-prop, propagation of value info (sign/zero ext info) from
62 one MBB to another
Chris Lattner74c80df2009-02-25 06:34:50 +0000[diff] [blame]63 debug info for optimized code
Chris Lattnerc1771e32009-02-26 07:29:17 +0000[diff] [blame]64 interpreter + libffi
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame^]65 postalloc scheduler: anti dependence breaking, hazard recognizer?
66
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]67 -->
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]68
Chris Lattner547a3912008-10-12 19:47:48 +0000[diff] [blame]69 <!-- for announcement email:
Chris Lattner74c80df2009-02-25 06:34:50 +0000[diff] [blame]70 -->
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]71
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]72<!-- *********************************************************************** -->
73<div class="doc_section">
74 <a name="subproj">Sub-project Status Update</a>
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]75</div>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]76<!-- *********************************************************************** -->
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]77
78<div class="doc_text">
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]79<p>
Chris Lattner38ab04c2009-02-25 04:41:31 +0000[diff] [blame]80The LLVM 2.5 distribution currently consists of code from the core LLVM
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000[diff] [blame]81repository (which roughly includes the LLVM optimizers, code generators and
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]82supporting tools) and the llvm-gcc repository. In addition to this code, the
83LLVM Project includes other sub-projects that are in development. The two which
Chris Lattner857fb132008-10-11 18:18:28 +0000[diff] [blame]84are the most actively developed are the <a href="#clang">Clang Project</a> and
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000[diff] [blame]85the <a href="#vmkit">VMKit Project</a>.
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]86</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]87
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]88</div>
89
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]90
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]91<!--=========================================================================-->
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]92<div class="doc_subsection">
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000[diff] [blame]93<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]94</div>
95
96<div class="doc_text">
97
98<p>The <a href="http://clang.llvm.org/">Clang project</a> is an effort to build
99a set of new 'LLVM native' front-end technologies for the LLVM optimizer
Chris Lattnerf40c40b2009-02-25 05:09:54 +0000[diff] [blame]100and code generator. While Clang is not included in the LLVM 2.5 release, it
101is continuing to make major strides forward in all areas. Its C and Objective-C
102parsing and code generation support is now very solid. For example, it is
103capable of successfully building many real applications for X86-32 and X86-64,
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame^]104including <a href="http://wiki.freebsd.org/BuildingFreeBSDWithClang">the FreeBSD
105kernel</a>. C++ is also making <a
Chris Lattnerf40c40b2009-02-25 05:09:54 +0000[diff] [blame]106href="http://clang.llvm.org/cxx_status.html">incredible progress</a>, and work
107on templates has recently started.</p>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]108
Chris Lattnerf40c40b2009-02-25 05:09:54 +0000[diff] [blame]109<p>While Clang is not yet production quality, it is progressing very nicely and
110is quite usable for building many C and Objective-C applications. If you are
111interested in fast compiles and good diagnostics, we encourage you to try it out
Chris Lattner74c80df2009-02-25 06:34:50 +0000[diff] [blame]112by <a href="http://clang.llvm.org/get_started.html">building from mainline</a>
Chris Lattnerf40c40b2009-02-25 05:09:54 +0000[diff] [blame]113and reporting any issues you hit to the <a
114href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev">Clang front-end mailing
115list</a>.</p>
116
117<p>In the LLVM 2.5 time-frame, the Clang team has made many improvements:</p>
Bill Wendling741748a2008-10-27 09:27:33 +0000[diff] [blame]118
Daniel Dunbar13739432008-10-14 23:25:09 +0000[diff] [blame]119<ul>
Chris Lattnerf40c40b2009-02-25 05:09:54 +0000[diff] [blame]120<li>Clang now has a new driver, which is focused on providing a GCC-compatible
121 interface.</li>
122<li>The X86-64 ABI is now supported.</li>
123<li>Precompiled header support is now implemented.</li>
124<li>Objective-C support is significantly improved beyond LLVM 2.4, supporting
125 many features, such as Objective-C Garbage Collection.</li>
126<li>Many many bugs are fixed.</li>
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000[diff] [blame]127</div>
128
129<!--=========================================================================-->
130<div class="doc_subsection">
131<a name="clangsa">Clang Static Analyzer</a>
132</div>
133
134<div class="doc_text">
135
Ted Kremenek3c3ec0c2008-10-14 05:14:21 +0000[diff] [blame]136<p>The Clang project also includes an early stage static source code analysis
137tool for <a href="http://clang.llvm.org/StaticAnalysis.html">automatically
138finding bugs</a> in C and Objective-C programs. The tool performs a growing set
Chris Lattnerc702d162008-10-14 06:02:29 +0000[diff] [blame]139of checks to find bugs that occur on a specific path within a program. Examples
Ted Kremenek3c3ec0c2008-10-14 05:14:21 +0000[diff] [blame]140of bugs the tool finds include logic errors such as null dereferences,
141violations of various API rules, dead code, and potential memory leaks in
Chris Lattnerc702d162008-10-14 06:02:29 +0000[diff] [blame]142Objective-C programs. Since its inception, public feedback on the tool has been
143extremely positive, and conservative estimates put the number of real bugs it
144has found in industrial-quality software on the order of thousands.</p>
Chris Lattnercc042612008-10-14 00:52:49 +0000[diff] [blame]145
Ted Kremenek3c3ec0c2008-10-14 05:14:21 +0000[diff] [blame]146<p>The tool also provides a simple web GUI to inspect potential bugs found by
Chris Lattnerc702d162008-10-14 06:02:29 +0000[diff] [blame]147the tool. While still early in development, the GUI illustrates some of the key
Ted Kremenek3c3ec0c2008-10-14 05:14:21 +0000[diff] [blame]148features of Clang: accurate source location information, which is used by the
149GUI to highlight specific code expressions that relate to a bug (including those
Bill Wendling741748a2008-10-27 09:27:33 +0000[diff] [blame]150that span multiple lines); and built-in knowledge of macros, which is used to
Ted Kremenek3c3ec0c2008-10-14 05:14:21 +0000[diff] [blame]151perform inline expansion of macros within the GUI itself.</p>
152
Chris Lattnerc702d162008-10-14 06:02:29 +0000[diff] [blame]153<p>The set of checks performed by the static analyzer is gradually expanding,
Bill Wendling741748a2008-10-27 09:27:33 +0000[diff] [blame]154and future plans for the tool include full source-level inter-procedural
155analysis and deeper checks such as buffer overrun detection. There are many
156opportunities to extend and enhance the static analyzer, and anyone interested
157in working on this project is encouraged to get involved!</p>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]158
159</div>
160
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]161<!--=========================================================================-->
162<div class="doc_subsection">
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000[diff] [blame]163<a name="vmkit">VMKit: JVM/CLI Virtual Machine Implementation</a>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]164</div>
165
166<div class="doc_text">
167<p>
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000[diff] [blame]168The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation of
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]169a JVM and a CLI Virtual Machines (Microsoft .NET is an
170implementation of the CLI) using the Just-In-Time compiler of LLVM.</p>
171
Chris Lattner1f859862009-02-25 05:45:05 +0000[diff] [blame]172<p>Following LLVM 2.5, VMKit has its first release ? that you can find on its
Nicolas Geoffray56d313d2008-10-15 20:25:04 +0000[diff] [blame]173<a href="http://vmkit.llvm.org/releases/">webpage</a>. The release includes
174bug fixes, cleanup and new features. The major changes are:</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]175
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000[diff] [blame]176<ul>
177
Chris Lattner75e26ca2009-02-26 05:20:36 +0000[diff] [blame]178<li>Ahead of Time compiler: compiles .class files to llvm .bc. VMKit uses this
179functionality to native compile the standard classes (eg java.lang.String).
180Users can compile AOT .class files into dynamic libraries and run them with the
181help of VMKit.</li>
182
183<li>New exception model: the dwarf exception model is very slow for
184exception-intensive applications, so the JVM has had a new implementation of
185exceptions which check at each function call if an exception happened. There is
186a low performance penalty on applications without exceptions, but it is a big
187gain for exception-intensive applications. For example the jack benchmark in
188Spec JVM98 is 6x faster (performance gain of 83%).</li>
189
190<li>New support for OSX/X64, Linux/X64 (with the Boehm GC), Linux/ppc32.</li>
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000[diff] [blame]191
192</ul>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]193</div>
194
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame^]195<!-- *********************************************************************** -->
196<div class="doc_section">
197 <a name="externalproj">External Projects Using LLVM 2.5</a>
198</div>
199<!-- *********************************************************************** -->
200
201<!--=========================================================================-->
202<div class="doc_subsection">
203<a name="pure">Pure</a>
204</div>
205
206<div class="doc_text">
207<p>
208http://pure-lang.googlecode.com/
209</p>
210
211<p>
212Pure is an algebraic/functional programming language based on term rewriting.
213Programs are collections of equations which are used to evaluate expressions in
214a symbolic fashion. Pure offers dynamic typing, eager and lazy evaluation,
215lexical closures, a hygienic macro system (also based on term rewriting),
216built-in list and matrix support (including list and matrix comprehensions) and
217an easy-to-use C interface. The interpreter uses LLVM as a backend to
218 JIT-compile Pure programs to fast native code.</p>
219
220<p>In addition to the usual algebraic data structures, Pure also has
221MATLAB-style matrices in order to support numeric computations and signal
222processing in an efficient way. Pure is mainly aimed at mathematical
223applications right now, but it has been designed as a general purpose language.
224The dynamic interpreter environment and the C interface make it possible to use
225it as a kind of functional scripting language for many application areas.
226</p>
227</div>
228
229
230<!--=========================================================================-->
231<div class="doc_subsection">
232<a name="ldc">LLVM D Compiler</a>
233</div>
234
235<div class="doc_text">
236<p>
237http://www.dsource.org/projects/ldc
238</p>
239
240<p>
241I'd like to inform that the LDC project (LLVM D
242Compiler) is working with release 2.5 of LLVM. In fact we've required
2432.5 in our trunk since the release was branched.
244The improvements in 2.5 have fixed a lot of problems with LDC, more
245specifically the new inline asm constraints, better debug info
246support, general bugfixes :) and better x86-64 support have allowed
247some major improvements in LDC, getting us much closer to being as
248fully featured as the original DMD compiler from DigitalMars.
249</p>
250</div>
251
252
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]253
254<!-- *********************************************************************** -->
255<div class="doc_section">
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]256 <a name="whatsnew">What's New in LLVM?</a>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]257</div>
258<!-- *********************************************************************** -->
259
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]260<div class="doc_text">
261
Bill Wendling741748a2008-10-27 09:27:33 +0000[diff] [blame]262<p>This release includes a huge number of bug fixes, performance tweaks, and
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]263minor improvements. Some of the major improvements and new features are listed
264in this section.
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]265</p>
266</div>
267
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]268<!--=========================================================================-->
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]269<div class="doc_subsection">
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]270<a name="majorfeatures">Major New Features</a>
271</div>
272
273<div class="doc_text">
274
Chris Lattner38ab04c2009-02-25 04:41:31 +0000[diff] [blame]275<p>LLVM 2.5 includes several major new capabilities:</p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]276
277<ul>
Duncan Sands8524cb92009-02-25 11:37:39 +0000[diff] [blame]278<li><p>The code generator now supports arbitrary precision integers.
279Types like <tt>i33</tt> have long been valid in the LLVM IR, but previously
280could only be used with the interpreter.
281Now IR using such types can be compiled to native code on all targets.
282All operations are supported if the integer is not bigger than twice the
283target machine word size.
284Simple operations like loads, stores and shifts by a constant amount are
285supported for integers of any size.
286</p></li>
Chris Lattner74c80df2009-02-25 06:34:50 +0000[diff] [blame]287
288<!--
289Random stuff:
290
Chris Lattnerc1771e32009-02-26 07:29:17 +0000[diff] [blame]291Pure project: http://code.google.com/p/pure-lang/
292
293
Chris Lattner99f375b2009-02-25 07:32:53 +0000[diff] [blame]294xcore backend!
295fortran on darwin!
296
Chris Lattnerc1771e32009-02-26 07:29:17 +0000[diff] [blame]297.ll parser rewrite, caret diags, better errors, less fragile (less likely to
298 crash on strange things). No longer depends on flex/bison.
Chris Lattnerd838fcd2009-02-26 06:47:09 +0000[diff] [blame]299GCC inliner off, llvm handles always-inline.
Chris Lattner74c80df2009-02-25 06:34:50 +0000[diff] [blame]300cmake mature?
Chris Lattnerc1771e32009-02-26 07:29:17 +0000[diff] [blame]301x86 backend GS segment -> addr space 256 (r62980)
Chris Lattner74c80df2009-02-25 06:34:50 +0000[diff] [blame]302nocapture
Chris Lattnerd838fcd2009-02-26 06:47:09 +0000[diff] [blame]303memdep (used by GVN and memcpyopt) is faster / more aggressive.
Chris Lattner99f375b2009-02-25 07:32:53 +0000[diff] [blame]304how to write a backend doc docs/WritingAnLLVMBackend.html
Chris Lattner74c80df2009-02-25 06:34:50 +0000[diff] [blame]305fastisel + exception handling
306vector widening <3 x float> -> <4 x float>
Chris Lattner99f375b2009-02-25 07:32:53 +0000[diff] [blame]307arm port improvements? arm jit encoding stuff, constant island support?
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame^]308JIT TLS support on x86-32 but not x86-64.
Chris Lattner99f375b2009-02-25 07:32:53 +0000[diff] [blame]309mem2reg now faster on code with huge basic blocks
310stack protectors/stack canaries, -fstack-protector, controllable on a
311 per-function basis with attributes.
312shufflevector is generalized to allow different shuffle mask width than its
313 input vectors.
314loop optimizer improves floating point induction variables
315llvm/Analysis/DebugInfo.h classes, llvm-gcc and clang and codegen use them.
Chris Lattnerc1771e32009-02-26 07:29:17 +0000[diff] [blame]316 DebugInfoBuilder gone.
Chris Lattner99f375b2009-02-25 07:32:53 +0000[diff] [blame]317asmprinters seperate from targets for jits
Chris Lattner75e26ca2009-02-26 05:20:36 +0000[diff] [blame]318PBQP register allocator now supports register coalescing.
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame^]319JIT supports exceptions on linux/x86-64 and linux/x86-64.
Chris Lattnerd838fcd2009-02-26 06:47:09 +0000[diff] [blame]320integer overflow intrinsics for [us](add/sub/mul). Supported on all targets,
321 but only generates efficient code on x86.
322X86 backend now supports -disable-mmx.
323noalias attribute on return value indicates that function returns new memory
324 (e.g. malloc).
Chris Lattnerd838fcd2009-02-26 06:47:09 +0000[diff] [blame]325llvmc2 renamed to llvmc
326Jump threading more powerful: it is iterative, handles threading based on values
327 with fully redundant and partially redundant loads.
328LSR improvements?
329ARM debug info support?
330unit test framework based on Google Test.
331
332vector shift support + X86 backend.
Chris Lattnerc1771e32009-02-26 07:29:17 +0000[diff] [blame]333x86 JIT now detects core i7 and atom, autoconfiguring itself appropriately.
334SROA is more aggressive about promoting unions.
335non-zero __builtin_return_address values on X86.
336x86-64 now uses red zone (unless -mno-red-zone option is specified).
337private linkage.
Chris Lattner75e26ca2009-02-26 05:20:36 +0000[diff] [blame]338
Chris Lattnerc1771e32009-02-26 07:29:17 +0000[diff] [blame]339llvm-gcc defaults to -fno-math-errno on all x86 targets.
340
341initial support for debug line numbers when optimization enabled, not useful in
342 2.5 but will be for 2.6.
Chris Lattner74c80df2009-02-25 06:34:50 +0000[diff] [blame]343-->
Chris Lattnerbc5786b2008-06-05 06:57:39 +0000[diff] [blame]344
Chris Lattner8170c102008-02-10 08:18:42 +0000[diff] [blame]345</ul>
346
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]347</div>
348
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]349
350<!--=========================================================================-->
351<div class="doc_subsection">
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]352<a name="llvm-gcc">llvm-gcc 4.2 Improvements</a>
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]353</div>
354
355<div class="doc_text">
356
Chris Lattnerb82eb062008-10-13 20:47:20 +0000[diff] [blame]357<p>LLVM fully supports the llvm-gcc 4.2 front-end, which marries the GCC
358front-ends and driver with the LLVM optimizer and code generator. It currently
359includes support for the C, C++, Objective-C, Ada, and Fortran front-ends.</p>
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]360
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]361<ul>
Chris Lattner38ab04c2009-02-25 04:41:31 +0000[diff] [blame]362<li>?</li>
Gabor Greifa3bd11d2008-06-09 06:06:18 +0000[diff] [blame]363</ul>
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]364
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]365</div>
366
367
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]368<!--=========================================================================-->
369<div class="doc_subsection">
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]370<a name="coreimprovements">LLVM Core Improvements</a>
371</div>
372
373<div class="doc_text">
Bill Wendling741748a2008-10-27 09:27:33 +0000[diff] [blame]374<p>New features include:</p>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]375
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]376<ul>
Chris Lattner38ab04c2009-02-25 04:41:31 +0000[diff] [blame]377<li>?</li>
Chris Lattner7752d1a2008-10-13 20:59:32 +0000[diff] [blame]378
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]379</ul>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]380
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]381</div>
382
383<!--=========================================================================-->
384<div class="doc_subsection">
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]385<a name="optimizer">Optimizer Improvements</a>
386</div>
387
388<div class="doc_text">
389
Chris Lattnerf3013872008-10-13 21:50:36 +0000[diff] [blame]390<p>In addition to a huge array of bug fixes and minor performance tweaks, this
391release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]392
393<ul>
394
Chris Lattner38ab04c2009-02-25 04:41:31 +0000[diff] [blame]395<li>?</li>
Chris Lattnerf3013872008-10-13 21:50:36 +0000[diff] [blame]396
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]397</ul>
398
399</div>
400
401<!--=========================================================================-->
402<div class="doc_subsection">
403<a name="codegen">Code Generator Improvements</a>
404</div>
405
406<div class="doc_text">
407
Gabor Greifa8b84902008-10-14 11:31:14 +0000[diff] [blame]408<p>We have put a significant amount of work into the code generator infrastructure,
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]409which allows us to implement more aggressive algorithms and make it run
410faster:</p>
411
412<ul>
Duncan Sands07636ea2009-02-25 11:50:08 +0000[diff] [blame]413<li>The type legalization logic has been completely rewritten, and is now
414more powerful (it supports arbitrary precision integer types for example)
415and hopefully more correct.
416The type legalizer converts operations on types that are not natively
417supported by the target machine into equivalent code sequences that only use
418natively supported types.
419The old type legalizer is still available and will be used if
420<tt>-disable-legalize-types</tt> is passed to <tt>llc</tt>.
421</li>
Chris Lattner38ab04c2009-02-25 04:41:31 +0000[diff] [blame]422<li>?</li>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]423
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]424</ul>
425
426</div>
427
428
429<!--=========================================================================-->
430<div class="doc_subsection">
Chris Lattner11398992009-02-26 07:32:11 +0000[diff] [blame]431<a name="pic16">PIC16 Target Improvements</a>
432</div>
433
434<div class="doc_text">
435<p>New features of the PIC16 target include:
436</p>
437
438<ul>
439<li>Both direct and indirect load/stores work now.</li>
440<li>Logical, bitwise and conditional operations now work for integer data
441types.</li>
442<li>Function calls involving basic types work now.</li>
443<li>Support for integer arrays.</li>
444<li>Compiler can now emit libcalls for operations not support by m/c insns.</li>
445<li>Support for both data and rom address spaces.</li>
446</li>
447</ul>
448
449<p>Things not yet supported:</p>
450
451<ul>
452<li>Floating point.</li>
453<li>Passing/returning aggregate types to/from functions.</li>
454<li>Variable arguments.</li>
455<li>Indirect function calls.</li>
456<li>Interrupts/prgrams.</li>
457<li>Debug info.</li>
458</li>
459</ul>
460
461</div>
462
463
464<!--=========================================================================-->
465<div class="doc_subsection">
466<a name="othertargetspecific">Other Target Specific Improvements</a>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]467</div>
Chris Lattner60893e52007-05-18 06:33:02 +0000[diff] [blame]468
Chris Lattner738bd302006-04-18 06:32:08 +0000[diff] [blame]469<div class="doc_text">
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]470<p>New target-specific features include:
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]471</p>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]472
473<ul>
Chris Lattner38ab04c2009-02-25 04:41:31 +0000[diff] [blame]474<li>?</li>
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]475</ul>
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]476
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]477</div>
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]478
479
480<!--=========================================================================-->
481<div class="doc_subsection">
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]482<a name="otherimprovements">Other Improvements</a>
483</div>
484
485<div class="doc_text">
486<p>New features include:
487</p>
488
489<ul>
Chris Lattner38ab04c2009-02-25 04:41:31 +0000[diff] [blame]490<li>?</li>
Tanya Lattnera7ec7062008-11-04 18:40:27 +0000[diff] [blame]491
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]492</ul>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]493
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]494</div>
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]495
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]496<!--=========================================================================-->
497<div class="doc_subsection">
498<a name="changes">Major Changes and Removed Features</a>
499</div>
500
501<div class="doc_text">
502
Chris Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]503<p>If you're already an LLVM user or developer with out-of-tree changes based
Chris Lattner38ab04c2009-02-25 04:41:31 +0000[diff] [blame]504on LLVM 2.4, this section lists some "gotchas" that you may run into upgrading
Chris Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]505from the previous release.</p>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]506
507<ul>
508
Chris Lattner38ab04c2009-02-25 04:41:31 +0000[diff] [blame]509<li>?</li>
Chris Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]510</ul>
511
512
513<p>In addition, many APIs have changed in this release. Some of the major LLVM
514API changes are:</p>
515
516<ul>
Chris Lattner38ab04c2009-02-25 04:41:31 +0000[diff] [blame]517<li>?</li>
Devang Patelb34dd132008-10-14 20:03:43 +0000[diff] [blame]518</ul>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]519
Chris Lattner38ab04c2009-02-25 04:41:31 +0000[diff] [blame]520<li>?</li>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]521</ul>
522
523</div>
524
525
526
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]527<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]528<div class="doc_section">
529 <a name="portability">Portability and Supported Platforms</a>
530</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]531<!-- *********************************************************************** -->
532
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]533<div class="doc_text">
534
John Criswell0b5b5e92004-12-08 20:35:47 +0000[diff] [blame]535<p>LLVM is known to work on the following platforms:</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]536
537<ul>
Chris Lattnere18b32e2008-11-10 05:40:34 +0000[diff] [blame]538<li>Intel and AMD machines (IA32, X86-64, AMD64, EMT-64) running Red Hat
539Linux, Fedora Core and FreeBSD (and probably other unix-like systems).</li>
540<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit
541and 64-bit modes.</li>
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]542<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]543<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
544 support is available for native builds with Visual C++).</li>
Gabor Greif96a89c72008-06-05 18:39:01 +0000[diff] [blame]545<li>Sun UltraSPARC workstations running Solaris 10.</li>
John Criswell9321fa82005-05-13 20:28:15 +0000[diff] [blame]546<li>Alpha-based machines running Debian GNU/Linux.</li>
Gabor Greif96a89c72008-06-05 18:39:01 +0000[diff] [blame]547<li>Itanium-based (IA64) machines running Linux and HP-UX.</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]548</ul>
549
Chris Lattnerbc5786b2008-06-05 06:57:39 +0000[diff] [blame]550<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]551to the machine and operating system on which it is built. However, minor
552porting may be required to get LLVM to work on new platforms. We welcome your
553portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]554
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]555</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]556
557<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]558<div class="doc_section">
559 <a name="knownproblems">Known Problems</a>
560</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]561<!-- *********************************************************************** -->
562
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]563<div class="doc_text">
564
Chris Lattnere18b32e2008-11-10 05:40:34 +0000[diff] [blame]565<p>This section contains significant known problems with the LLVM system,
566listed by component. If you run into a problem, please check the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]567href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]568there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]569
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]570</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]571
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]572<!-- ======================================================================= -->
573<div class="doc_subsection">
574 <a name="experimental">Experimental features included with this release</a>
575</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]576
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]577<div class="doc_text">
578
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]579<p>The following components of this LLVM release are either untested, known to
580be broken or unreliable, or are in early development. These components should
581not be relied on, and bugs should not be filed against them, but they may be
582useful to some people. In particular, if you would like to work on one of these
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]583components, please contact us on the <a
584href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]585
586<ul>
Gabor Greifa8b84902008-10-14 11:31:14 +0000[diff] [blame]587<li>The MSIL, IA64, Alpha, SPU, MIPS, and PIC16 backends are experimental.</li>
Duncan Sands27aff872008-06-08 20:18:35 +0000[diff] [blame]588<li>The llc "<tt>-filetype=asm</tt>" (the default) is the only supported
Chris Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame]589 value for this option.</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]590</ul>
591
592</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]593
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]594<!-- ======================================================================= -->
595<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]596 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]597</div>
598
599<div class="doc_text">
600
601<ul>
Anton Korobeynikova6094be2008-06-08 10:24:13 +0000[diff] [blame]602 <li>The X86 backend does not yet support
603 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
604 floating point stack</a>. It supports the 'f' and 't' constraints, but not
605 'u'.</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000[diff] [blame]606 <li>The X86 backend generates inefficient floating point code when configured
607 to generate code for systems that don't have SSE2.</li>
Duncan Sands47eff2b2008-06-08 19:38:43 +0000[diff] [blame]608 <li>Win64 code generation wasn't widely tested. Everything should work, but we
Anton Korobeynikova6094be2008-06-08 10:24:13 +0000[diff] [blame]609 expect small issues to happen. Also, llvm-gcc cannot build mingw64 runtime
610 currently due
611 to <a href="http://llvm.org/PR2255">several</a>
Chris Lattner04af7cb2008-06-08 23:12:47 +0000[diff] [blame]612 <a href="http://llvm.org/PR2257">bugs</a> due to lack of support for the
613 'u' inline assembly constraint and X87 floating point inline assembly.</li>
Dan Gohman8207ba92008-06-08 23:05:11 +0000[diff] [blame]614 <li>The X86-64 backend does not yet support the LLVM IR instruction
615 <tt>va_arg</tt>. Currently, the llvm-gcc front-end supports variadic
616 argument constructs on X86-64 by lowering them manually.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]617</ul>
618
619</div>
620
621<!-- ======================================================================= -->
622<div class="doc_subsection">
623 <a name="ppc-be">Known problems with the PowerPC back-end</a>
624</div>
625
626<div class="doc_text">
627
628<ul>
Nicolas Geoffraye4285dc2007-05-15 09:21:28 +0000[diff] [blame]629<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]630compilation, and lacks support for debug information.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]631</ul>
632
633</div>
634
635<!-- ======================================================================= -->
636<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]637 <a name="arm-be">Known problems with the ARM back-end</a>
638</div>
639
640<div class="doc_text">
641
642<ul>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]643<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000[diff] [blame]644processors, thumb programs can crash or produce wrong
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]645results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]646<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
647</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000[diff] [blame]648<li>There is a bug in QEMU-ARM (&lt;= 0.9.0) which causes it to incorrectly
649 execute
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]650programs compiled with LLVM. Please use more recent versions of QEMU.</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]651</ul>
652
653</div>
654
655<!-- ======================================================================= -->
656<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]657 <a name="sparc-be">Known problems with the SPARC back-end</a>
658</div>
659
660<div class="doc_text">
661
662<ul>
663<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
664 support the 64-bit SPARC ABI (-m64).</li>
665</ul>
666
667</div>
668
669<!-- ======================================================================= -->
670<div class="doc_subsection">
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000[diff] [blame]671 <a name="mips-be">Known problems with the MIPS back-end</a>
672</div>
673
674<div class="doc_text">
675
676<ul>
677<li>The O32 ABI is not fully supported.</li>
678<li>64-bit MIPS targets are not supported yet.</li>
679</ul>
680
681</div>
682
683<!-- ======================================================================= -->
684<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]685 <a name="alpha-be">Known problems with the Alpha back-end</a>
686</div>
687
688<div class="doc_text">
689
690<ul>
691
692<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
693appropriate nops inserted to ensure restartability.</li>
694
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]695</ul>
696</div>
697
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]698<!-- ======================================================================= -->
699<div class="doc_subsection">
700 <a name="ia64-be">Known problems with the IA64 back-end</a>
701</div>
702
703<div class="doc_text">
704
705<ul>
Chris Lattner04af7cb2008-06-08 23:12:47 +0000[diff] [blame]706<li>The Itanium backend is highly experimental, and has a number of known
707 issues. We are looking for a maintainer for the Itanium backend. If you
Gabor Greif3bd3a262008-10-15 10:47:24 +0000[diff] [blame]708 are interested, please contact the LLVMdev mailing list.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]709</ul>
710
711</div>
712
713<!-- ======================================================================= -->
714<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]715 <a name="c-be">Known problems with the C back-end</a>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]716</div>
717
718<div class="doc_text">
719
720<ul>
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]721<li><a href="http://llvm.org/PR802">The C backend has only basic support for
722 inline assembly code</a>.</li>
Chris Lattner725a0d82007-09-26 06:01:35 +0000[diff] [blame]723<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
724 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Duncan Sands27aff872008-06-08 20:18:35 +0000[diff] [blame]725 C++ code compiled with llc or native compilers.</li>
Duncan Sandsf74c0cc2008-02-10 13:40:55 +0000[diff] [blame]726<li>The C backend does not support all exception handling constructs.</li>
Duncan Sands50723a92009-02-25 11:51:54 +0000[diff] [blame]727<li>The C backend does not support arbitrary precision integers.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]728</ul>
729
730</div>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]731
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]732
733<!-- ======================================================================= -->
734<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]735 <a name="c-fe">Known problems with the llvm-gcc C front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]736</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]737
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]738<div class="doc_text">
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]739
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]740<p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time
741Optimization</a> on most platforms "out-of-the-box". Please inquire on the
Gabor Greif3bd3a262008-10-15 10:47:24 +0000[diff] [blame]742LLVMdev mailing list if you are interested.</p>
Chris Lattnerd9ea0172006-08-08 17:27:28 +0000[diff] [blame]743
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]744<p>The only major language feature of GCC not supported by llvm-gcc is
745 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
746 are only supported on some targets. For example, trampolines are only
Duncan Sands27aff872008-06-08 20:18:35 +0000[diff] [blame]747 supported on some targets (these are used when you take the address of a
748 nested function).</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]749
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]750<p>If you run into GCC extensions which are not supported, please let us know.
751</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]752
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]753</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]754
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]755<!-- ======================================================================= -->
756<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]757 <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]758</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]759
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]760<div class="doc_text">
761
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]762<p>The C++ front-end is considered to be fully
Chris Lattner7506b1d2004-12-07 08:04:13 +0000[diff] [blame]763tested and works for a number of non-trivial programs, including LLVM
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]764itself, Qt, Mozilla, etc.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]765
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]766<ul>
Anton Korobeynikov0021fc12008-10-11 18:27:16 +0000[diff] [blame]767<li>Exception handling works well on the X86 and PowerPC targets. Currently
Chris Lattnere18b32e2008-11-10 05:40:34 +0000[diff] [blame]768 only Linux and Darwin targets are supported (both 32 and 64 bit).</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]769</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]770
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]771</div>
772
Chris Lattner1eb4df62008-10-30 03:58:13 +0000[diff] [blame]773<!-- ======================================================================= -->
774<div class="doc_subsection">
775 <a name="fortran-fe">Known problems with the llvm-gcc Fortran front-end</a>
776</div>
777
778<div class="doc_text">
Gabor Greifba10fe02008-11-04 21:50:59 +0000[diff] [blame]779<ul>
Chris Lattner1eb4df62008-10-30 03:58:13 +0000[diff] [blame]780<li>Fortran support generally works, but there are still several unresolved bugs
781 in Bugzilla. Please see the tools/gfortran component for details.</li>
782
783<li>The Fortran front-end currently does not build on Darwin (without tweaks)
784 due to unresolved dependencies on the C front-end.</li>
Gabor Greifba10fe02008-11-04 21:50:59 +0000[diff] [blame]785</ul>
Chris Lattner1eb4df62008-10-30 03:58:13 +0000[diff] [blame]786</div>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]787
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]788<!-- ======================================================================= -->
789<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]790 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]791</div>
792
793<div class="doc_text">
794The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature
795technology and problems should be expected.
796<ul>
Duncan Sands27aff872008-06-08 20:18:35 +0000[diff] [blame]797<li>The Ada front-end currently only builds on X86-32. This is mainly due
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]798to lack of trampoline support (pointers to nested functions) on other platforms,
Duncan Sands27aff872008-06-08 20:18:35 +0000[diff] [blame]799however it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]800which does support trampolines.</li>
801<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
Duncan Sands326a4982009-02-25 11:59:06 +0000[diff] [blame]802This is due to lack of LLVM support for <tt>setjmp</tt>/<tt>longjmp</tt> style
803exception handling, which is used internally by the compiler.
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]804Workaround: configure with --disable-bootstrap.</li>
Duncan Sands978bcee2008-10-13 17:27:23 +0000[diff] [blame]805<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
806and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
Duncan Sands326a4982009-02-25 11:59:06 +0000[diff] [blame]807(c380004 also fails with gcc-4.2 mainline).
808If the compiler is built with checks disabled then <a href="http://llvm.org/PR2010">c393010</a>
809causes the compiler to go into an infinite loop, using up all system memory.</li>
Duncan Sands978bcee2008-10-13 17:27:23 +0000[diff] [blame]810<li>Some gcc specific Ada tests continue to crash the compiler.</li>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]811<li>The -E binder option (exception backtraces)
812<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
813crashing if an exception is raised. Workaround: do not use -E.</li>
814<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
815or finish at a non-byte offset</a> in a record. Workaround: do not pack records
816or use representation clauses that result in a field of a non-discrete type
817starting or finishing in the middle of a byte.</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000[diff] [blame]818<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
819'main' as generated by the Ada binder to be invalid</a>.
820Workaround: hand edit the file to use pointers for <tt>argv</tt> and
821<tt>envp</tt> rather than integers.</li>
822<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
823ignored</a>.</li>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]824</ul>
825</div>
826
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]827<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]828<div class="doc_section">
829 <a name="additionalinfo">Additional Information</a>
830</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]831<!-- *********************************************************************** -->
832
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]833<div class="doc_text">
834
Chris Lattner416db102005-05-16 17:13:10 +0000[diff] [blame]835<p>A wide variety of additional information is available on the <a
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]836href="http://llvm.org">LLVM web page</a>, in particular in the <a
837href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencer669ed452007-07-09 08:04:31 +0000[diff] [blame]838contains versions of the API documentation which is up-to-date with the
839Subversion version of the source code.
Misha Brukman109d9e82005-03-30 19:14:24 +0000[diff] [blame]840You can access versions of these documents specific to this release by going
841into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]842
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]843<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]844us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]845lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]846
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]847</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]848
849<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]850
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]851<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]852<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]853 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]854 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]855 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]856 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]857
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]858 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]859 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]860</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]861
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]862</body>
863</html>