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gerrit-public.fairphone.software / toolchain / llvm-project / 07e95680fde47691c6dd1ce4a9fa20191bf65249 / . / llvm / docs / ReleaseNotes.html
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4<head>
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Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]6 <link rel="stylesheet" href="llvm.css" type="text/css">
Chris Lattner7fad44b2009-02-25 04:41:31 +0000[diff] [blame]7 <title>LLVM 2.5 Release Notes</title>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]8</head>
9<body>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]10
Chris Lattner7fad44b2009-02-25 04:41:31 +0000[diff] [blame]11<div class="doc_title">LLVM 2.5 Release Notes</div>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]12
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]13<ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]14 <li><a href="#intro">Introduction</a></li>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]15 <li><a href="#subproj">Sub-project Status Update</a></li>
Chris Lattner53e06f92009-02-26 22:33:38 +0000[diff] [blame]16 <li><a href="#externalproj">External Projects Using LLVM 2.5</a></li>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]17 <li><a href="#whatsnew">What's New in LLVM?</a></li>
Chris Lattner77a51732004-04-30 22:17:12 +0000[diff] [blame]18 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]19 <li><a href="#portability">Portability and Supported Platforms</a></li>
Dan Gohmanad888912008-10-14 16:23:02 +0000[diff] [blame]20 <li><a href="#knownproblems">Known Problems</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]21 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]22</ol>
23
Chris Lattner020e1fc2004-05-23 21:07:27 +0000[diff] [blame]24<div class="doc_author">
Dan Gohmanad888912008-10-14 16:23:02 +0000[diff] [blame]25 <p>Written by the <a href="http://llvm.org">LLVM Team</a></p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]26</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]27
28<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]29<div class="doc_section">
30 <a name="intro">Introduction</a>
31</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]32<!-- *********************************************************************** -->
33
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]34<div class="doc_text">
35
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]36<p>This document contains the release notes for the LLVM Compiler
Chris Lattner7fad44b2009-02-25 04:41:31 +0000[diff] [blame]37Infrastructure, release 2.5. Here we describe the status of LLVM, including
Chris Lattner1e4d5bc2008-10-13 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 Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]41
Chris Lattnerb5bb5972004-12-07 08:04:13 +0000[diff] [blame]42<p>For more information about LLVM, including information about the latest
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]43release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]44web site</a>. If you have questions or comments, the <a
Chris Lattner1e4d5bc2008-10-13 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 Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]47
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]48<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]49main LLVM web page, this document applies to the <i>next</i> release, not the
Gabor Greif355f81c2008-10-14 11:00:32 +0000[diff] [blame]50current one. To see the release notes for a specific release, please see the
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]51<a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]52
53</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]54
Chris Lattner7fad44b2009-02-25 04:41:31 +0000[diff] [blame]55<!-- Unfinished features in 2.5:
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]56 Machine LICM
57 Machine Sinking
Chris Lattnerd02da042009-02-25 06:34:50 +0000[diff] [blame]58 target-specific intrinsics
59 gold lto plugin
Chris Lattner3ab27b72009-02-25 07:32:53 +0000[diff] [blame]60 pre-alloc splitter, strong phi elim
Chris Lattnerc4d68542008-10-12 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 Lattnerd02da042009-02-25 06:34:50 +0000[diff] [blame]63 debug info for optimized code
Chris Lattner07bf7e92009-02-26 07:29:17 +0000[diff] [blame]64 interpreter + libffi
Chris Lattner53e06f92009-02-26 22:33:38 +0000[diff] [blame]65 postalloc scheduler: anti dependence breaking, hazard recognizer?
66
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]67 -->
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]68
Chris Lattnerc4d68542008-10-12 19:47:48 +0000[diff] [blame]69 <!-- for announcement email:
Chris Lattnerd02da042009-02-25 06:34:50 +0000[diff] [blame]70 -->
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]71
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]72<!-- *********************************************************************** -->
73<div class="doc_section">
74 <a name="subproj">Sub-project Status Update</a>
Chris Lattner625a3d82008-06-08 21:34:41 +0000[diff] [blame]75</div>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]76<!-- *********************************************************************** -->
Chris Lattner625a3d82008-06-08 21:34:41 +0000[diff] [blame]77
78<div class="doc_text">
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]79<p>
Chris Lattner7fad44b2009-02-25 04:41:31 +0000[diff] [blame]80The LLVM 2.5 distribution currently consists of code from the core LLVM
Chris Lattner44c09cd2008-10-13 18:11:54 +0000[diff] [blame]81repository (which roughly includes the LLVM optimizers, code generators and
Chris Lattnerc75fd522008-06-08 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 Lattnerd8b33e02008-10-11 18:18:28 +0000[diff] [blame]84are the most actively developed are the <a href="#clang">Clang Project</a> and
Nicolas Geoffraye5ec9322008-10-14 19:23:04 +0000[diff] [blame]85the <a href="#vmkit">VMKit Project</a>.
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]86</p>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]87
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]88</div>
89
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]90
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]91<!--=========================================================================-->
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]92<div class="doc_subsection">
Chris Lattner44c09cd2008-10-13 18:11:54 +0000[diff] [blame]93<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
Chris Lattnerc75fd522008-06-08 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 Lattnerf70a0242009-02-25 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 Lattner53e06f92009-02-26 22:33:38 +0000[diff] [blame]104including <a href="http://wiki.freebsd.org/BuildingFreeBSDWithClang">the FreeBSD
105kernel</a>. C++ is also making <a
Chris Lattnerf70a0242009-02-25 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 Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]108
Chris Lattnerf70a0242009-02-25 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 Lattnerd02da042009-02-25 06:34:50 +0000[diff] [blame]112by <a href="http://clang.llvm.org/get_started.html">building from mainline</a>
Chris Lattnerf70a0242009-02-25 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 Wendlingef362462008-10-27 09:27:33 +0000[diff] [blame]118
Daniel Dunbarc11b40f2008-10-14 23:25:09 +0000[diff] [blame]119<ul>
Chris Lattnerf70a0242009-02-25 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 Lattner44c09cd2008-10-13 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 Kremenekc11fae82009-02-27 07:01:32 +0000[diff] [blame]136<p>Previously announced in the last LLVM release, the Clang project also
137includes an early stage static source code analysis tool for <a
138href="http://clang.llvm.org/StaticAnalysis.html">automatically finding bugs</a>
139in C and Objective-C programs. The tool performs a growing set of checks to find
140bugs that occur on a specific path within a program.</p>
Chris Lattnerbcffa5a2008-10-14 00:52:49 +0000[diff] [blame]141
Ted Kremenekc11fae82009-02-27 07:01:32 +0000[diff] [blame]142<p>In the LLVM 2.5 time-frame there have been many significant improvements to
143the analyzer's core path simulation engine and machinery for generating
144path-based bug reports to end-users. Particularly noteworthy improvements
145include experimental support for full field-sensitivity and reasoning about heap
146objects as well as an improved value-constraints subengine that does a much
147better job of reasoning about inequality relationships (e.g., <tt>x &gt; 2</tt>)
148between variables and constants.
Ted Kremenek3db01842008-10-14 05:14:21 +0000[diff] [blame]149
Ted Kremenekc11fae82009-02-27 07:01:32 +0000[diff] [blame]150<p>The set of checks performed by the static analyzer continue to expand, and
151future plans for the tool include full source-level inter-procedural analysis
152and deeper checks such as buffer overrun detection. There are many opportunities
153to extend and enhance the static analyzer, and anyone interested in working on
154this project is encouraged to get involved!</p>
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]155
156</div>
157
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]158<!--=========================================================================-->
159<div class="doc_subsection">
Nicolas Geoffraye5ec9322008-10-14 19:23:04 +0000[diff] [blame]160<a name="vmkit">VMKit: JVM/CLI Virtual Machine Implementation</a>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]161</div>
162
163<div class="doc_text">
164<p>
Nicolas Geoffraye5ec9322008-10-14 19:23:04 +0000[diff] [blame]165The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation of
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]166a JVM and a CLI Virtual Machines (Microsoft .NET is an
167implementation of the CLI) using the Just-In-Time compiler of LLVM.</p>
168
Chris Lattnerb39faaa2009-02-25 05:45:05 +0000[diff] [blame]169<p>Following LLVM 2.5, VMKit has its first release ? that you can find on its
Nicolas Geoffray54efd492008-10-15 20:25:04 +0000[diff] [blame]170<a href="http://vmkit.llvm.org/releases/">webpage</a>. The release includes
171bug fixes, cleanup and new features. The major changes are:</p>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]172
Nicolas Geoffraye5ec9322008-10-14 19:23:04 +0000[diff] [blame]173<ul>
174
Chris Lattnerd38d5e82009-02-26 05:20:36 +0000[diff] [blame]175<li>Ahead of Time compiler: compiles .class files to llvm .bc. VMKit uses this
176functionality to native compile the standard classes (eg java.lang.String).
177Users can compile AOT .class files into dynamic libraries and run them with the
178help of VMKit.</li>
179
180<li>New exception model: the dwarf exception model is very slow for
181exception-intensive applications, so the JVM has had a new implementation of
182exceptions which check at each function call if an exception happened. There is
183a low performance penalty on applications without exceptions, but it is a big
184gain for exception-intensive applications. For example the jack benchmark in
185Spec JVM98 is 6x faster (performance gain of 83%).</li>
186
187<li>New support for OSX/X64, Linux/X64 (with the Boehm GC), Linux/ppc32.</li>
Nicolas Geoffraye5ec9322008-10-14 19:23:04 +0000[diff] [blame]188
189</ul>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]190</div>
191
Chris Lattner53e06f92009-02-26 22:33:38 +0000[diff] [blame]192<!-- *********************************************************************** -->
193<div class="doc_section">
194 <a name="externalproj">External Projects Using LLVM 2.5</a>
195</div>
196<!-- *********************************************************************** -->
197
198<!--=========================================================================-->
199<div class="doc_subsection">
200<a name="pure">Pure</a>
201</div>
202
203<div class="doc_text">
204<p>
205http://pure-lang.googlecode.com/
206</p>
207
208<p>
209Pure is an algebraic/functional programming language based on term rewriting.
210Programs are collections of equations which are used to evaluate expressions in
211a symbolic fashion. Pure offers dynamic typing, eager and lazy evaluation,
212lexical closures, a hygienic macro system (also based on term rewriting),
213built-in list and matrix support (including list and matrix comprehensions) and
214an easy-to-use C interface. The interpreter uses LLVM as a backend to
215 JIT-compile Pure programs to fast native code.</p>
216
217<p>In addition to the usual algebraic data structures, Pure also has
218MATLAB-style matrices in order to support numeric computations and signal
219processing in an efficient way. Pure is mainly aimed at mathematical
220applications right now, but it has been designed as a general purpose language.
221The dynamic interpreter environment and the C interface make it possible to use
222it as a kind of functional scripting language for many application areas.
223</p>
224</div>
225
226
227<!--=========================================================================-->
228<div class="doc_subsection">
229<a name="ldc">LLVM D Compiler</a>
230</div>
231
232<div class="doc_text">
233<p>
234http://www.dsource.org/projects/ldc
235</p>
236
237<p>
238I'd like to inform that the LDC project (LLVM D
239Compiler) is working with release 2.5 of LLVM. In fact we've required
2402.5 in our trunk since the release was branched.
241The improvements in 2.5 have fixed a lot of problems with LDC, more
242specifically the new inline asm constraints, better debug info
243support, general bugfixes :) and better x86-64 support have allowed
244some major improvements in LDC, getting us much closer to being as
245fully featured as the original DMD compiler from DigitalMars.
246</p>
247</div>
248
Chris Lattnerfb23a962009-02-28 18:58:01 +0000[diff] [blame]249<!--=========================================================================-->
250<div class="doc_subsection">
251<a name="RoadsendPHP">Roadsend PHP</a>
252</div>
253
254<div class="doc_text">
255<p>http://code.roadsend.com/rphp</p>
256
257<p>Roadsend PHP is using LLVM for code generation. This is an open source
258project.
259</p>
260</div>
Chris Lattner53e06f92009-02-26 22:33:38 +0000[diff] [blame]261
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]262
263<!-- *********************************************************************** -->
264<div class="doc_section">
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]265 <a name="whatsnew">What's New in LLVM?</a>
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]266</div>
267<!-- *********************************************************************** -->
268
Chris Lattnerb7bc2aa2008-06-08 22:59:35 +0000[diff] [blame]269<div class="doc_text">
270
Bill Wendlingef362462008-10-27 09:27:33 +0000[diff] [blame]271<p>This release includes a huge number of bug fixes, performance tweaks, and
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]272minor improvements. Some of the major improvements and new features are listed
273in this section.
Chris Lattnerb7bc2aa2008-06-08 22:59:35 +0000[diff] [blame]274</p>
275</div>
276
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]277<!--=========================================================================-->
Chris Lattner625a3d82008-06-08 21:34:41 +0000[diff] [blame]278<div class="doc_subsection">
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000[diff] [blame]279<a name="majorfeatures">Major New Features</a>
280</div>
281
282<div class="doc_text">
283
Chris Lattner7fad44b2009-02-25 04:41:31 +0000[diff] [blame]284<p>LLVM 2.5 includes several major new capabilities:</p>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]285
286<ul>
Duncan Sandsd9c35572009-02-25 11:37:39 +0000[diff] [blame]287<li><p>The code generator now supports arbitrary precision integers.
288Types like <tt>i33</tt> have long been valid in the LLVM IR, but previously
289could only be used with the interpreter.
290Now IR using such types can be compiled to native code on all targets.
291All operations are supported if the integer is not bigger than twice the
292target machine word size.
293Simple operations like loads, stores and shifts by a constant amount are
294supported for integers of any size.
295</p></li>
Chris Lattnerd02da042009-02-25 06:34:50 +0000[diff] [blame]296
297<!--
298Random stuff:
299
Chris Lattner07bf7e92009-02-26 07:29:17 +0000[diff] [blame]300Pure project: http://code.google.com/p/pure-lang/
301
302
Chris Lattner3ab27b72009-02-25 07:32:53 +0000[diff] [blame]303xcore backend!
304fortran on darwin!
305
Chris Lattner07bf7e92009-02-26 07:29:17 +0000[diff] [blame]306.ll parser rewrite, caret diags, better errors, less fragile (less likely to
307 crash on strange things). No longer depends on flex/bison.
Chris Lattner7354ec42009-02-26 06:47:09 +0000[diff] [blame]308GCC inliner off, llvm handles always-inline.
Chris Lattnerd02da042009-02-25 06:34:50 +0000[diff] [blame]309cmake mature?
Chris Lattner07bf7e92009-02-26 07:29:17 +0000[diff] [blame]310x86 backend GS segment -> addr space 256 (r62980)
Chris Lattnerd02da042009-02-25 06:34:50 +0000[diff] [blame]311nocapture
Chris Lattner7354ec42009-02-26 06:47:09 +0000[diff] [blame]312memdep (used by GVN and memcpyopt) is faster / more aggressive.
Chris Lattner3ab27b72009-02-25 07:32:53 +0000[diff] [blame]313how to write a backend doc docs/WritingAnLLVMBackend.html
Chris Lattnerd02da042009-02-25 06:34:50 +0000[diff] [blame]314fastisel + exception handling
315vector widening <3 x float> -> <4 x float>
Chris Lattner3ab27b72009-02-25 07:32:53 +0000[diff] [blame]316arm port improvements? arm jit encoding stuff, constant island support?
Chris Lattner53e06f92009-02-26 22:33:38 +0000[diff] [blame]317JIT TLS support on x86-32 but not x86-64.
Chris Lattner3ab27b72009-02-25 07:32:53 +0000[diff] [blame]318mem2reg now faster on code with huge basic blocks
319stack protectors/stack canaries, -fstack-protector, controllable on a
320 per-function basis with attributes.
321shufflevector is generalized to allow different shuffle mask width than its
322 input vectors.
323loop optimizer improves floating point induction variables
324llvm/Analysis/DebugInfo.h classes, llvm-gcc and clang and codegen use them.
Chris Lattner07bf7e92009-02-26 07:29:17 +0000[diff] [blame]325 DebugInfoBuilder gone.
Chris Lattner3ab27b72009-02-25 07:32:53 +0000[diff] [blame]326asmprinters seperate from targets for jits
Chris Lattnerd38d5e82009-02-26 05:20:36 +0000[diff] [blame]327PBQP register allocator now supports register coalescing.
Chris Lattner53e06f92009-02-26 22:33:38 +0000[diff] [blame]328JIT supports exceptions on linux/x86-64 and linux/x86-64.
Chris Lattner7354ec42009-02-26 06:47:09 +0000[diff] [blame]329integer overflow intrinsics for [us](add/sub/mul). Supported on all targets,
330 but only generates efficient code on x86.
331X86 backend now supports -disable-mmx.
332noalias attribute on return value indicates that function returns new memory
333 (e.g. malloc).
Chris Lattner7354ec42009-02-26 06:47:09 +0000[diff] [blame]334llvmc2 renamed to llvmc
335Jump threading more powerful: it is iterative, handles threading based on values
336 with fully redundant and partially redundant loads.
337LSR improvements?
338ARM debug info support?
339unit test framework based on Google Test.
340
341vector shift support + X86 backend.
Chris Lattner07bf7e92009-02-26 07:29:17 +0000[diff] [blame]342x86 JIT now detects core i7 and atom, autoconfiguring itself appropriately.
343SROA is more aggressive about promoting unions.
344non-zero __builtin_return_address values on X86.
345x86-64 now uses red zone (unless -mno-red-zone option is specified).
346private linkage.
Chris Lattnerd38d5e82009-02-26 05:20:36 +0000[diff] [blame]347
Chris Lattner07bf7e92009-02-26 07:29:17 +0000[diff] [blame]348llvm-gcc defaults to -fno-math-errno on all x86 targets.
349
350initial support for debug line numbers when optimization enabled, not useful in
351 2.5 but will be for 2.6.
Chris Lattnerd02da042009-02-25 06:34:50 +0000[diff] [blame]352-->
Chris Lattner618a99f2008-06-05 06:57:39 +0000[diff] [blame]353
Chris Lattner458e79f2008-02-10 08:18:42 +0000[diff] [blame]354</ul>
355
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]356</div>
357
Chris Lattnerb7112222008-06-05 06:25:56 +0000[diff] [blame]358
359<!--=========================================================================-->
360<div class="doc_subsection">
Chris Lattner625a3d82008-06-08 21:34:41 +0000[diff] [blame]361<a name="llvm-gcc">llvm-gcc 4.2 Improvements</a>
Chris Lattnerb7112222008-06-05 06:25:56 +0000[diff] [blame]362</div>
363
364<div class="doc_text">
365
Chris Lattner591ef272008-10-13 20:47:20 +0000[diff] [blame]366<p>LLVM fully supports the llvm-gcc 4.2 front-end, which marries the GCC
367front-ends and driver with the LLVM optimizer and code generator. It currently
368includes support for the C, C++, Objective-C, Ada, and Fortran front-ends.</p>
Chris Lattnerb7112222008-06-05 06:25:56 +0000[diff] [blame]369
Chris Lattnerb7bc2aa2008-06-08 22:59:35 +0000[diff] [blame]370<ul>
Chris Lattner7fad44b2009-02-25 04:41:31 +0000[diff] [blame]371<li>?</li>
Gabor Greif7f39fb52008-06-09 06:06:18 +0000[diff] [blame]372</ul>
Chris Lattnerb7112222008-06-05 06:25:56 +0000[diff] [blame]373
Chris Lattnerb7112222008-06-05 06:25:56 +0000[diff] [blame]374</div>
375
376
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]377<!--=========================================================================-->
378<div class="doc_subsection">
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]379<a name="coreimprovements">LLVM Core Improvements</a>
380</div>
381
382<div class="doc_text">
Bill Wendlingef362462008-10-27 09:27:33 +0000[diff] [blame]383<p>New features include:</p>
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]384
Chris Lattnerb7112222008-06-05 06:25:56 +0000[diff] [blame]385<ul>
Chris Lattner7fad44b2009-02-25 04:41:31 +0000[diff] [blame]386<li>?</li>
Chris Lattner0327f0b2008-10-13 20:59:32 +0000[diff] [blame]387
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]388</ul>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]389
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]390</div>
391
392<!--=========================================================================-->
393<div class="doc_subsection">
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]394<a name="optimizer">Optimizer Improvements</a>
395</div>
396
397<div class="doc_text">
398
Chris Lattner25879d72008-10-13 21:50:36 +0000[diff] [blame]399<p>In addition to a huge array of bug fixes and minor performance tweaks, this
400release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]401
402<ul>
403
Chris Lattner7fad44b2009-02-25 04:41:31 +0000[diff] [blame]404<li>?</li>
Chris Lattner25879d72008-10-13 21:50:36 +0000[diff] [blame]405
Chris Lattner7795ea92008-06-08 02:45:07 +0000[diff] [blame]406</ul>
407
408</div>
409
410<!--=========================================================================-->
411<div class="doc_subsection">
412<a name="codegen">Code Generator Improvements</a>
413</div>
414
415<div class="doc_text">
416
Gabor Greif20564a02008-10-14 11:31:14 +0000[diff] [blame]417<p>We have put a significant amount of work into the code generator infrastructure,
Chris Lattner7795ea92008-06-08 02:45:07 +0000[diff] [blame]418which allows us to implement more aggressive algorithms and make it run
419faster:</p>
420
421<ul>
Duncan Sands966fd262009-02-25 11:50:08 +0000[diff] [blame]422<li>The type legalization logic has been completely rewritten, and is now
423more powerful (it supports arbitrary precision integer types for example)
424and hopefully more correct.
425The type legalizer converts operations on types that are not natively
426supported by the target machine into equivalent code sequences that only use
427natively supported types.
428The old type legalizer is still available and will be used if
429<tt>-disable-legalize-types</tt> is passed to <tt>llc</tt>.
430</li>
Chris Lattner7fad44b2009-02-25 04:41:31 +0000[diff] [blame]431<li>?</li>
Chris Lattner7795ea92008-06-08 02:45:07 +0000[diff] [blame]432
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]433</ul>
434
435</div>
436
437
438<!--=========================================================================-->
439<div class="doc_subsection">
Chris Lattner6b8bf782009-02-26 07:32:11 +0000[diff] [blame]440<a name="pic16">PIC16 Target Improvements</a>
441</div>
442
443<div class="doc_text">
444<p>New features of the PIC16 target include:
445</p>
446
447<ul>
448<li>Both direct and indirect load/stores work now.</li>
449<li>Logical, bitwise and conditional operations now work for integer data
450types.</li>
451<li>Function calls involving basic types work now.</li>
452<li>Support for integer arrays.</li>
453<li>Compiler can now emit libcalls for operations not support by m/c insns.</li>
454<li>Support for both data and rom address spaces.</li>
455</li>
456</ul>
457
458<p>Things not yet supported:</p>
459
460<ul>
461<li>Floating point.</li>
462<li>Passing/returning aggregate types to/from functions.</li>
463<li>Variable arguments.</li>
464<li>Indirect function calls.</li>
465<li>Interrupts/prgrams.</li>
466<li>Debug info.</li>
467</li>
468</ul>
469
470</div>
471
472
473<!--=========================================================================-->
474<div class="doc_subsection">
475<a name="othertargetspecific">Other Target Specific Improvements</a>
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]476</div>
Chris Lattner727c3742007-05-18 06:33:02 +0000[diff] [blame]477
Chris Lattner89e761c2006-04-18 06:32:08 +0000[diff] [blame]478<div class="doc_text">
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]479<p>New target-specific features include:
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]480</p>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]481
482<ul>
Chris Lattner7fad44b2009-02-25 04:41:31 +0000[diff] [blame]483<li>?</li>
Chris Lattner6cb64032008-06-05 08:02:49 +0000[diff] [blame]484</ul>
Chris Lattner6cb64032008-06-05 08:02:49 +0000[diff] [blame]485
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]486</div>
Chris Lattner6cb64032008-06-05 08:02:49 +0000[diff] [blame]487
Chris Lattnerc92d7692009-03-01 02:30:21 +0000[diff] [blame]488<!--=========================================================================-->
489<div class="doc_subsection">
490<a name="llvmc">Improvements in LLVMC</a>
491</div>
492
493<div class="doc_text">
494<p>New features include:</p>
495
496<ul>
497<li>Beginning with LLVM 2.5, llvmc2 is known as just 'llvmc'. The
498 old llvmc driver was removed.</li>
499
500<li>The Clang plugin was substantially improved and is now enabled
501 by default. The command 'llvmc --clang' can be now used as a
502 synonym to 'ccc'.</li>
503
504<li>There is now a '--check-graph' option which is supposed to
505 catch common errors like multiple default edges, mismatched
506 output/input language names and cycles. In general, these
507 checks can't be done at compile-time because of the need to
508 support plugins.</li>
509
510<li>Plugins are now more flexible and can refer to compilation
511 graph nodes and options defined in other plugins. To manage
512 dependencies, a priority-sorting mechanism was introduced. This
513 change affects the '.td' file syntax; see the documentation for
514 details.</li>
515
516<li>Hooks can now be provided with arguments. The syntax
517 is "$CALL(MyHook, 'Arg1', 'Arg2', 'Arg #3')".</li>
518
519<li>A new option type: multi-valued option, for options that take
520 more than one argument (for example, "-foo a b c").</li>
521
522<li>New option properties: 'one_or_more', 'zero_or_more', 'hidden'
523 and 'really_hidden'.</li>
524
525<li>The 'case' expression gained an 'error' action and an 'empty'
526 test (equivalent to '(not (not_empty ...))').</li>
527
528<li>Documentation now looks more consistent to the rest of the LLVM
529 docs. There is also a man page now.</li>
530
531</ul>
532
533</div>
534
Chris Lattner6cb64032008-06-05 08:02:49 +0000[diff] [blame]535
536<!--=========================================================================-->
537<div class="doc_subsection">
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]538<a name="otherimprovements">Other Improvements</a>
539</div>
540
541<div class="doc_text">
542<p>New features include:
543</p>
544
545<ul>
Chris Lattner7fad44b2009-02-25 04:41:31 +0000[diff] [blame]546<li>?</li>
Tanya Lattner81edfc12008-11-04 18:40:27 +0000[diff] [blame]547
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]548</ul>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]549
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]550</div>
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]551
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]552<!--=========================================================================-->
553<div class="doc_subsection">
554<a name="changes">Major Changes and Removed Features</a>
555</div>
556
557<div class="doc_text">
558
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]559<p>If you're already an LLVM user or developer with out-of-tree changes based
Chris Lattner7fad44b2009-02-25 04:41:31 +0000[diff] [blame]560on LLVM 2.4, this section lists some "gotchas" that you may run into upgrading
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]561from the previous release.</p>
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]562
563<ul>
564
Chris Lattner7fad44b2009-02-25 04:41:31 +0000[diff] [blame]565<li>?</li>
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]566</ul>
567
568
569<p>In addition, many APIs have changed in this release. Some of the major LLVM
570API changes are:</p>
571
572<ul>
Chris Lattner7fad44b2009-02-25 04:41:31 +0000[diff] [blame]573<li>?</li>
Devang Pateldbf83832008-10-14 20:03:43 +0000[diff] [blame]574</ul>
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]575
Chris Lattner7fad44b2009-02-25 04:41:31 +0000[diff] [blame]576<li>?</li>
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]577</ul>
578
579</div>
580
581
582
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]583<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]584<div class="doc_section">
585 <a name="portability">Portability and Supported Platforms</a>
586</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]587<!-- *********************************************************************** -->
588
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]589<div class="doc_text">
590
John Criswell64307722004-12-08 20:35:47 +0000[diff] [blame]591<p>LLVM is known to work on the following platforms:</p>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]592
593<ul>
Chris Lattner2a092392008-11-10 05:40:34 +0000[diff] [blame]594<li>Intel and AMD machines (IA32, X86-64, AMD64, EMT-64) running Red Hat
595Linux, Fedora Core and FreeBSD (and probably other unix-like systems).</li>
596<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit
597and 64-bit modes.</li>
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000[diff] [blame]598<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]599<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
600 support is available for native builds with Visual C++).</li>
Gabor Greif80ae8a72008-06-05 18:39:01 +0000[diff] [blame]601<li>Sun UltraSPARC workstations running Solaris 10.</li>
John Criswelld5234922005-05-13 20:28:15 +0000[diff] [blame]602<li>Alpha-based machines running Debian GNU/Linux.</li>
Gabor Greif80ae8a72008-06-05 18:39:01 +0000[diff] [blame]603<li>Itanium-based (IA64) machines running Linux and HP-UX.</li>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]604</ul>
605
Chris Lattner618a99f2008-06-05 06:57:39 +0000[diff] [blame]606<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Brian Gaekee3e557e2004-05-09 05:28:35 +0000[diff] [blame]607to the machine and operating system on which it is built. However, minor
608porting may be required to get LLVM to work on new platforms. We welcome your
609portability patches and reports of successful builds or error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]610
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]611</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]612
613<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]614<div class="doc_section">
615 <a name="knownproblems">Known Problems</a>
616</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]617<!-- *********************************************************************** -->
618
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]619<div class="doc_text">
620
Chris Lattner2a092392008-11-10 05:40:34 +0000[diff] [blame]621<p>This section contains significant known problems with the LLVM system,
622listed by component. If you run into a problem, please check the <a
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]623href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]624there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]625
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]626</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]627
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]628<!-- ======================================================================= -->
629<div class="doc_subsection">
630 <a name="experimental">Experimental features included with this release</a>
631</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]632
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]633<div class="doc_text">
634
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]635<p>The following components of this LLVM release are either untested, known to
636be broken or unreliable, or are in early development. These components should
637not be relied on, and bugs should not be filed against them, but they may be
638useful to some people. In particular, if you would like to work on one of these
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]639components, please contact us on the <a
640href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]641
642<ul>
Gabor Greif20564a02008-10-14 11:31:14 +0000[diff] [blame]643<li>The MSIL, IA64, Alpha, SPU, MIPS, and PIC16 backends are experimental.</li>
Duncan Sands56448462008-06-08 20:18:35 +0000[diff] [blame]644<li>The llc "<tt>-filetype=asm</tt>" (the default) is the only supported
Chris Lattner7422bce2008-02-06 06:30:34 +0000[diff] [blame]645 value for this option.</li>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]646</ul>
647
648</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]649
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]650<!-- ======================================================================= -->
651<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]652 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]653</div>
654
655<div class="doc_text">
656
657<ul>
Anton Korobeynikov486c7d32008-06-08 10:24:13 +0000[diff] [blame]658 <li>The X86 backend does not yet support
659 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
660 floating point stack</a>. It supports the 'f' and 't' constraints, but not
661 'u'.</li>
Chris Lattnerb076b002008-06-08 21:19:07 +0000[diff] [blame]662 <li>The X86 backend generates inefficient floating point code when configured
663 to generate code for systems that don't have SSE2.</li>
Duncan Sands0bc15262008-06-08 19:38:43 +0000[diff] [blame]664 <li>Win64 code generation wasn't widely tested. Everything should work, but we
Anton Korobeynikov486c7d32008-06-08 10:24:13 +0000[diff] [blame]665 expect small issues to happen. Also, llvm-gcc cannot build mingw64 runtime
666 currently due
667 to <a href="http://llvm.org/PR2255">several</a>
Chris Lattner54d12102008-06-08 23:12:47 +0000[diff] [blame]668 <a href="http://llvm.org/PR2257">bugs</a> due to lack of support for the
669 'u' inline assembly constraint and X87 floating point inline assembly.</li>
Dan Gohman721b3722008-06-08 23:05:11 +0000[diff] [blame]670 <li>The X86-64 backend does not yet support the LLVM IR instruction
671 <tt>va_arg</tt>. Currently, the llvm-gcc front-end supports variadic
672 argument constructs on X86-64 by lowering them manually.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]673</ul>
674
675</div>
676
677<!-- ======================================================================= -->
678<div class="doc_subsection">
679 <a name="ppc-be">Known problems with the PowerPC back-end</a>
680</div>
681
682<div class="doc_text">
683
684<ul>
Nicolas Geoffray77d99502007-05-15 09:21:28 +0000[diff] [blame]685<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]686compilation, and lacks support for debug information.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]687</ul>
688
689</div>
690
691<!-- ======================================================================= -->
692<div class="doc_subsection">
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]693 <a name="arm-be">Known problems with the ARM back-end</a>
694</div>
695
696<div class="doc_text">
697
698<ul>
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]699<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sands47fc0a22007-09-26 15:59:54 +0000[diff] [blame]700processors, thumb programs can crash or produce wrong
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]701results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]702<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
703</li>
Chris Lattnerb076b002008-06-08 21:19:07 +0000[diff] [blame]704<li>There is a bug in QEMU-ARM (&lt;= 0.9.0) which causes it to incorrectly
705 execute
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]706programs compiled with LLVM. Please use more recent versions of QEMU.</li>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]707</ul>
708
709</div>
710
711<!-- ======================================================================= -->
712<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]713 <a name="sparc-be">Known problems with the SPARC back-end</a>
714</div>
715
716<div class="doc_text">
717
718<ul>
719<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
720 support the 64-bit SPARC ABI (-m64).</li>
721</ul>
722
723</div>
724
725<!-- ======================================================================= -->
726<div class="doc_subsection">
Bruno Cardoso Lopes24eb3de2008-10-25 14:56:26 +0000[diff] [blame]727 <a name="mips-be">Known problems with the MIPS back-end</a>
728</div>
729
730<div class="doc_text">
731
732<ul>
733<li>The O32 ABI is not fully supported.</li>
734<li>64-bit MIPS targets are not supported yet.</li>
735</ul>
736
737</div>
738
739<!-- ======================================================================= -->
740<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]741 <a name="alpha-be">Known problems with the Alpha back-end</a>
742</div>
743
744<div class="doc_text">
745
746<ul>
747
748<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
749appropriate nops inserted to ensure restartability.</li>
750
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]751</ul>
752</div>
753
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]754<!-- ======================================================================= -->
755<div class="doc_subsection">
756 <a name="ia64-be">Known problems with the IA64 back-end</a>
757</div>
758
759<div class="doc_text">
760
761<ul>
Chris Lattner54d12102008-06-08 23:12:47 +0000[diff] [blame]762<li>The Itanium backend is highly experimental, and has a number of known
763 issues. We are looking for a maintainer for the Itanium backend. If you
Gabor Greife4544f72008-10-15 10:47:24 +0000[diff] [blame]764 are interested, please contact the LLVMdev mailing list.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]765</ul>
766
767</div>
768
769<!-- ======================================================================= -->
770<div class="doc_subsection">
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]771 <a name="c-be">Known problems with the C back-end</a>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]772</div>
773
774<div class="doc_text">
775
776<ul>
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000[diff] [blame]777<li><a href="http://llvm.org/PR802">The C backend has only basic support for
778 inline assembly code</a>.</li>
Chris Lattner8e061162007-09-26 06:01:35 +0000[diff] [blame]779<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
780 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Duncan Sands56448462008-06-08 20:18:35 +0000[diff] [blame]781 C++ code compiled with llc or native compilers.</li>
Duncan Sandse09506a2008-02-10 13:40:55 +0000[diff] [blame]782<li>The C backend does not support all exception handling constructs.</li>
Duncan Sands3aa36732009-02-25 11:51:54 +0000[diff] [blame]783<li>The C backend does not support arbitrary precision integers.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]784</ul>
785
786</div>
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]787
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]788
789<!-- ======================================================================= -->
790<div class="doc_subsection">
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000[diff] [blame]791 <a name="c-fe">Known problems with the llvm-gcc C front-end</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]792</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]793
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]794<div class="doc_text">
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]795
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000[diff] [blame]796<p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time
797Optimization</a> on most platforms "out-of-the-box". Please inquire on the
Gabor Greife4544f72008-10-15 10:47:24 +0000[diff] [blame]798LLVMdev mailing list if you are interested.</p>
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]799
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000[diff] [blame]800<p>The only major language feature of GCC not supported by llvm-gcc is
801 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
802 are only supported on some targets. For example, trampolines are only
Duncan Sands56448462008-06-08 20:18:35 +0000[diff] [blame]803 supported on some targets (these are used when you take the address of a
804 nested function).</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]805
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000[diff] [blame]806<p>If you run into GCC extensions which are not supported, please let us know.
807</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]808
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]809</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]810
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]811<!-- ======================================================================= -->
812<div class="doc_subsection">
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000[diff] [blame]813 <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]814</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]815
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]816<div class="doc_text">
817
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]818<p>The C++ front-end is considered to be fully
Chris Lattnerb5bb5972004-12-07 08:04:13 +0000[diff] [blame]819tested and works for a number of non-trivial programs, including LLVM
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]820itself, Qt, Mozilla, etc.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]821
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]822<ul>
Anton Korobeynikov28f08aa2008-10-11 18:27:16 +0000[diff] [blame]823<li>Exception handling works well on the X86 and PowerPC targets. Currently
Chris Lattner2a092392008-11-10 05:40:34 +0000[diff] [blame]824 only Linux and Darwin targets are supported (both 32 and 64 bit).</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]825</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]826
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]827</div>
828
Chris Lattner7292fb12008-10-30 03:58:13 +0000[diff] [blame]829<!-- ======================================================================= -->
830<div class="doc_subsection">
831 <a name="fortran-fe">Known problems with the llvm-gcc Fortran front-end</a>
832</div>
833
834<div class="doc_text">
Gabor Greife5f9d672008-11-04 21:50:59 +0000[diff] [blame]835<ul>
Chris Lattner7292fb12008-10-30 03:58:13 +0000[diff] [blame]836<li>Fortran support generally works, but there are still several unresolved bugs
837 in Bugzilla. Please see the tools/gfortran component for details.</li>
838
839<li>The Fortran front-end currently does not build on Darwin (without tweaks)
840 due to unresolved dependencies on the C front-end.</li>
Gabor Greife5f9d672008-11-04 21:50:59 +0000[diff] [blame]841</ul>
Chris Lattner7292fb12008-10-30 03:58:13 +0000[diff] [blame]842</div>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]843
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]844<!-- ======================================================================= -->
845<div class="doc_subsection">
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000[diff] [blame]846 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]847</div>
848
849<div class="doc_text">
850The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature
851technology and problems should be expected.
852<ul>
Duncan Sands56448462008-06-08 20:18:35 +0000[diff] [blame]853<li>The Ada front-end currently only builds on X86-32. This is mainly due
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]854to lack of trampoline support (pointers to nested functions) on other platforms,
Duncan Sands56448462008-06-08 20:18:35 +0000[diff] [blame]855however it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]856which does support trampolines.</li>
857<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
Duncan Sandsd34bf762009-02-25 11:59:06 +0000[diff] [blame]858This is due to lack of LLVM support for <tt>setjmp</tt>/<tt>longjmp</tt> style
859exception handling, which is used internally by the compiler.
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]860Workaround: configure with --disable-bootstrap.</li>
Duncan Sandsaef747f2008-10-13 17:27:23 +0000[diff] [blame]861<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
862and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
Duncan Sandsd34bf762009-02-25 11:59:06 +0000[diff] [blame]863(c380004 also fails with gcc-4.2 mainline).
864If the compiler is built with checks disabled then <a href="http://llvm.org/PR2010">c393010</a>
865causes the compiler to go into an infinite loop, using up all system memory.</li>
Duncan Sandsaef747f2008-10-13 17:27:23 +0000[diff] [blame]866<li>Some gcc specific Ada tests continue to crash the compiler.</li>
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]867<li>The -E binder option (exception backtraces)
868<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
869crashing if an exception is raised. Workaround: do not use -E.</li>
870<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
871or finish at a non-byte offset</a> in a record. Workaround: do not pack records
872or use representation clauses that result in a field of a non-discrete type
873starting or finishing in the middle of a byte.</li>
Chris Lattnerb076b002008-06-08 21:19:07 +0000[diff] [blame]874<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
875'main' as generated by the Ada binder to be invalid</a>.
876Workaround: hand edit the file to use pointers for <tt>argv</tt> and
877<tt>envp</tt> rather than integers.</li>
878<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
879ignored</a>.</li>
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]880</ul>
881</div>
882
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]883<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]884<div class="doc_section">
885 <a name="additionalinfo">Additional Information</a>
886</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]887<!-- *********************************************************************** -->
888
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]889<div class="doc_text">
890
Chris Lattnercb5596d2005-05-16 17:13:10 +0000[diff] [blame]891<p>A wide variety of additional information is available on the <a
Chris Lattnere0c1df42007-05-18 00:44:29 +0000[diff] [blame]892href="http://llvm.org">LLVM web page</a>, in particular in the <a
893href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencerc7f87f22007-07-09 08:04:31 +0000[diff] [blame]894contains versions of the API documentation which is up-to-date with the
895Subversion version of the source code.
Misha Brukman96158092005-03-30 19:14:24 +0000[diff] [blame]896You can access versions of these documents specific to this release by going
897into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]898
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]899<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]900us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]901lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]902
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]903</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]904
905<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]906
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]907<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]908<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]909 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]910 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]911 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]912 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]913
Chris Lattnere0c1df42007-05-18 00:44:29 +0000[diff] [blame]914 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]915 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]916</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]917
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]918</body>
919</html>