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Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
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4<head>
Reid Spencer6454ed32004-11-18 18:38:58 +0000[diff] [blame]5 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]6 <link rel="stylesheet" href="llvm.css" type="text/css">
Dan Gohmanb44f6c62010-05-03 23:51:05 +0000[diff] [blame]7 <title>LLVM 2.8 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
Dan Gohmanb44f6c62010-05-03 23:51:05 +0000[diff] [blame]11<div class="doc_title">LLVM 2.8 Release Notes</div>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]12
Chris Lattner0e464a92010-03-17 04:02:39 +0000[diff] [blame]13<img align=right src="http://llvm.org/img/DragonSmall.png"
Gabor Greifee2187a2010-04-22 10:21:43 +0000[diff] [blame]14 width="136" height="136" alt="LLVM Dragon Logo">
Chris Lattner0e464a92010-03-17 04:02:39 +0000[diff] [blame]15
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]16<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]17 <li><a href="#intro">Introduction</a></li>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]18 <li><a href="#subproj">Sub-project Status Update</a></li>
Dan Gohmanb44f6c62010-05-03 23:51:05 +0000[diff] [blame]19 <li><a href="#externalproj">External Projects Using LLVM 2.8</a></li>
20 <li><a href="#whatsnew">What's New in LLVM 2.8?</a></li>
Chris Lattner4b538b92004-04-30 22:17:12 +0000[diff] [blame]21 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Dan Gohman44aa9212008-10-14 16:23:02 +0000[diff] [blame]22 <li><a href="#knownproblems">Known Problems</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]23 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]24</ol>
25
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]26<div class="doc_author">
Dan Gohman44aa9212008-10-14 16:23:02 +0000[diff] [blame]27 <p>Written by the <a href="http://llvm.org">LLVM Team</a></p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]28</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]29
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]30<!--
Chris Lattner7b91eda2010-04-22 05:41:35 +0000[diff] [blame]31<h1 style="color:red">These are in-progress notes for the upcoming LLVM 2.8
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000[diff] [blame]32release.<br>
33You may prefer the
Dan Gohmanb44f6c62010-05-03 23:51:05 +0000[diff] [blame]34<a href="http://llvm.org/releases/2.7/docs/ReleaseNotes.html">LLVM 2.7
35Release Notes</a>.</h1>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]36-->
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000[diff] [blame]37
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]38<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]39<div class="doc_section">
40 <a name="intro">Introduction</a>
41</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]42<!-- *********************************************************************** -->
43
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]44<div class="doc_text">
45
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]46<p>This document contains the release notes for the LLVM Compiler
Dan Gohman7ae3ac82010-05-03 23:52:21 +0000[diff] [blame]47Infrastructure, release 2.8. Here we describe the status of LLVM, including
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]48major improvements from the previous release and significant known problems.
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000[diff] [blame]49All LLVM releases may be downloaded from the <a
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]50href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]51
Chris Lattner7506b1d2004-12-07 08:04:13 +0000[diff] [blame]52<p>For more information about LLVM, including information about the latest
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]53release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]54web site</a>. If you have questions or comments, the <a
Chris Lattnerc66bfef2010-03-17 04:41:49 +0000[diff] [blame]55href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM Developer's
56Mailing List</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]57
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]58<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]59main LLVM web page, this document applies to the <i>next</i> release, not the
Gabor Greiffa933f82008-10-14 11:00:32 +0000[diff] [blame]60current one. To see the release notes for a specific release, please see the
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]61<a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]62
63</div>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]64
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]65
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]66<!--
67Almost dead code.
68 include/llvm/Analysis/LiveValues.h => Dan
69 lib/Transforms/IPO/MergeFunctions.cpp => consider for 2.8.
70 llvm/Analysis/PointerTracking.h => Edwin wants this, consider for 2.8.
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]71 GEPSplitterPass
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]72-->
73
74
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]75<!-- Features that need text if they're finished for 2.9:
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]76 combiner-aa?
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]77 strong phi elim
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]78 loop dependence analysis
Chris Lattner885b6612010-08-28 16:33:36 +0000[diff] [blame]79 TBAA
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]80 CorrelatedValuePropagation
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]81 -->
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]82
83 <!-- Announcement, lldb, libc++ -->
Chris Lattnerafa41632010-09-29 07:25:03 +0000[diff] [blame]84
85 <!-- to write:
86 MachineCSE tuned and on by default.
87 llvm.dbg.value: variable debug info for optimized code
88 MC Assembler backend is now real, does relaxation and is bitwise identical
89 with darwin assembler in huge majority of all cases.
90 new GHC calling convention
91 New half float intrinsics LangRef.html#int_fp16
92 Rewrote tblgen's type inference for backends to be more consistent and
93 diagnose more target bugs. This also allows limited support for writing
94 patterns for instructions that return multiple results, e.g. a virtual
95 register and a flag result. Stuff that used 'parallel' before should use
96 this.
97 New ARM/Thumb disassembler support in MC.
98 New SSEDomainFix pass:
99 On Nehalem and newer CPUs there is a 2 cycle latency penalty on using a
100 register in a different domain than where it was defined. Some instructions
101 have equvivalents for different domains, like por/orps/orpd. The
102 SSEDomainFix pass tries to minimize the number of domain crossings by
103 changing between equvivalent opcodes where possible.
104 Support for the Intel AES instructions in the assembler.
105 memcpy, memmove, and memset now take address space qualified pointers + volatile.
106
107 -->
108
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]109
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]110<!-- *********************************************************************** -->
111<div class="doc_section">
112 <a name="subproj">Sub-project Status Update</a>
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]113</div>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]114<!-- *********************************************************************** -->
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]115
116<div class="doc_text">
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]117<p>
Dan Gohmanb44f6c62010-05-03 23:51:05 +0000[diff] [blame]118The LLVM 2.8 distribution currently consists of code from the core LLVM
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]119repository (which roughly includes the LLVM optimizers, code generators
120and supporting tools), the Clang repository and the llvm-gcc repository. In
121addition to this code, the LLVM Project includes other sub-projects that are in
122development. Here we include updates on these subprojects.
Bill Wendling63d8c552009-03-02 04:28:57 +0000[diff] [blame]123</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]124
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]125</div>
126
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]127
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]128<!--=========================================================================-->
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]129<div class="doc_subsection">
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000[diff] [blame]130<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]131</div>
132
133<div class="doc_text">
134
Chris Lattner095539f2010-04-26 17:42:18 +0000[diff] [blame]135<p><a href="http://clang.llvm.org/">Clang</a> is an LLVM front end for the C,
136C++, and Objective-C languages. Clang aims to provide a better user experience
137through expressive diagnostics, a high level of conformance to language
138standards, fast compilation, and low memory use. Like LLVM, Clang provides a
139modular, library-based architecture that makes it suitable for creating or
140integrating with other development tools. Clang is considered a
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]141production-quality compiler for C, Objective-C, C++ and Objective-C++ on x86
142(32- and 64-bit), and for darwin-arm targets.</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]143
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]144<p>In the LLVM 2.8 time-frame, the Clang team has made many improvements:</p>
Bill Wendling741748a2008-10-27 09:27:33 +0000[diff] [blame]145
Daniel Dunbar13739432008-10-14 23:25:09 +0000[diff] [blame]146<ul>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]147<li>Surely these guys have done something</li>
Bill Wendling6bc15282009-03-02 04:28:18 +0000[diff] [blame]148</ul>
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000[diff] [blame]149</div>
150
151<!--=========================================================================-->
152<div class="doc_subsection">
153<a name="clangsa">Clang Static Analyzer</a>
154</div>
155
156<div class="doc_text">
157
Chris Lattner8cdd7932010-04-22 06:38:11 +0000[diff] [blame]158<p>The <a href="http://clang-analyzer.llvm.org/">Clang Static Analyzer</a>
159 project is an effort to use static source code analysis techniques to
160 automatically find bugs in C and Objective-C programs (and hopefully <a
161 href="http://clang-analyzer.llvm.org/dev_cxx.html">C++ in the
162 future</a>!). The tool is very good at finding bugs that occur on specific
163 paths through code, such as on error conditions.</p>
Chris Lattnercc042612008-10-14 00:52:49 +0000[diff] [blame]164
Chris Lattner2e38c7f2010-09-30 00:34:43 +0000[diff] [blame]165<p>The LLVM 2.8 release fixes a number of bugs and slightly improves precision
166 over 2.7, but there are no major new features in the release.
Chris Lattner8cdd7932010-04-22 06:38:11 +0000[diff] [blame]167</p>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]168
169</div>
170
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]171<!--=========================================================================-->
172<div class="doc_subsection">
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000[diff] [blame]173<a name="vmkit">VMKit: JVM/CLI Virtual Machine Implementation</a>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]174</div>
175
176<div class="doc_text">
177<p>
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000[diff] [blame]178The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation of
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]179a JVM and a CLI Virtual Machine (Microsoft .NET is an
180implementation of the CLI) using LLVM for static and just-in-time
181compilation.</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]182
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]183<p>With the release of LLVM 2.8, ...</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]184
185</div>
186
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]187
188<!--=========================================================================-->
189<div class="doc_subsection">
190<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
191</div>
192
193<div class="doc_text">
194<p>
195The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
196is a simple library that provides an implementation of the low-level
197target-specific hooks required by code generation and other runtime components.
198For example, when compiling for a 32-bit target, converting a double to a 64-bit
199unsigned integer is compiled into a runtime call to the "__fixunsdfdi"
200function. The compiler-rt library provides highly optimized implementations of
201this and other low-level routines (some are 3x faster than the equivalent
202libgcc routines).</p>
203
204<p>
205All of the code in the compiler-rt project is available under the standard LLVM
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]206License, a "BSD-style" license. New in LLVM 2.8:
207
208Soft float support
209</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]210
211</div>
212
213<!--=========================================================================-->
214<div class="doc_subsection">
Duncan Sands749fd832010-04-02 09:23:15 +0000[diff] [blame]215<a name="dragonegg">DragonEgg: llvm-gcc ported to gcc-4.5</a>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]216</div>
217
218<div class="doc_text">
219<p>
Duncan Sands749fd832010-04-02 09:23:15 +0000[diff] [blame]220<a href="http://dragonegg.llvm.org/">DragonEgg</a> is a port of llvm-gcc to
221gcc-4.5. Unlike llvm-gcc, which makes many intrusive changes to the underlying
222gcc-4.2 code, dragonegg in theory does not require any gcc-4.5 modifications
223whatsoever (currently one small patch is needed). This is thanks to the new
224<a href="http://gcc.gnu.org/wiki/plugins">gcc plugin architecture</a>, which
225makes it possible to modify the behaviour of gcc at runtime by loading a plugin,
226which is nothing more than a dynamic library which conforms to the gcc plugin
227interface. DragonEgg is a gcc plugin that causes the LLVM optimizers to be run
228instead of the gcc optimizers, and the LLVM code generators instead of the gcc
229code generators, just like llvm-gcc. To use it, you add
230"-fplugin=path/dragonegg.so" to the gcc-4.5 command line, and gcc-4.5 magically
231becomes llvm-gcc-4.5!
232</p>
233
234<p>
235DragonEgg is still a work in progress. Currently C works very well, while C++,
236Ada and Fortran work fairly well. All other languages either don't work at all,
237or only work poorly. For the moment only the x86-32 and x86-64 targets are
Duncan Sands51a51742010-04-20 19:40:58 +0000[diff] [blame]238supported, and only on linux and darwin (darwin needs an additional gcc patch).
Duncan Sands749fd832010-04-02 09:23:15 +0000[diff] [blame]239</p>
240
241<p>
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]2422.8 status here.
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]243</p>
244
245</div>
246
247
248<!--=========================================================================-->
249<div class="doc_subsection">
250<a name="mc">llvm-mc: Machine Code Toolkit</a>
251</div>
252
253<div class="doc_text">
254<p>
Chris Lattner8cdd7932010-04-22 06:38:11 +0000[diff] [blame]255The LLVM Machine Code (aka MC) sub-project of LLVM was created to solve a number
256of problems in the realm of assembly, disassembly, object file format handling,
257and a number of other related areas that CPU instruction-set level tools work
258in. It is a sub-project of LLVM which provides it with a number of advantages
259over other compilers that do not have tightly integrated assembly-level tools.
260For a gentle introduction, please see the <a
261href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html">Intro to the
262LLVM MC Project Blog Post</a>.
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]263</p>
264
Chris Lattnerafa41632010-09-29 07:25:03 +0000[diff] [blame]265<p>2.8 status here. Basic correctness, some obscure missing instructions on
266 mainline, on by default in clang.
267 Entire compiler backend converted to use mcstreamer.
268 </p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]269</div>
270
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]271<!--=========================================================================-->
272<div class="doc_subsection">
273<a name="lldb">LLDB: Low Level Debugger</a>
274</div>
275
276<div class="doc_text">
277<p>
278<a href="http://lldb.llvm.org/">LLDB</a> is</p>
279
280<p>
281</p>
282
283<p>
2842.8 status here.
285</p>
286
287</div>
288
289<!--=========================================================================-->
290<div class="doc_subsection">
291<a name="libc++">libc++: C++ Standard Library</a>
292</div>
293
294<div class="doc_text">
295<p>
296<a href="http://libc++.llvm.org/">libc++</a> is</p>
297
298<p>
299</p>
300
301<p>
3022.8 status here.
303</p>
304
305</div>
306
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]307
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame]308<!-- *********************************************************************** -->
309<div class="doc_section">
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]310 <a name="externalproj">External Open Source Projects Using LLVM 2.8</a>
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame]311</div>
312<!-- *********************************************************************** -->
313
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]314<div class="doc_text">
315
316<p>An exciting aspect of LLVM is that it is used as an enabling technology for
317 a lot of other language and tools projects. This section lists some of the
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]318 projects that have already been updated to work with LLVM 2.8.</p>
Chris Lattner7c8e7962010-04-26 17:38:10 +0000[diff] [blame]319</div>
320
Chris Lattner2e38c7f2010-09-30 00:34:43 +0000[diff] [blame]321<!--=========================================================================-->
322<div class="doc_subsection">
323<a name="tce">TTA-based Codesign Environment (TCE)</a>
324</div>
325
326<div class="doc_text">
327<p>
328<a href="http://tce.cs.tut.fi/">TCE</a> is a toolset for designing
329application-specific processors (ASP) based on the Transport triggered
330architecture (TTA). The toolset provides a complete co-design flow from C/C++
331programs down to synthesizable VHDL and parallel program binaries. Processor
332customization points include the register files, function units, supported
333operations, and the interconnection network.</p>
334
335<p>TCE uses llvm-gcc/Clang and LLVM for C/C++ language support, target
336independent optimizations and also for parts of code generation. It generates
337new LLVM-based code generators "on the fly" for the designed TTA processors and
338loads them in to the compiler backend as runtime libraries to avoid per-target
339recompilation of larger parts of the compiler chain.</p>
340
341</div>
342
343<!--=========================================================================-->
344<div class="doc_subsection">
345<a name="Horizon">Horizon Bytecode Compiler</a>
346</div>
347
348<div class="doc_text">
349<p>
350<a href="http://www.quokforge.org/projects/horizon">Horizon</a> is a bytecode
351language and compiler written on top of LLVM, intended for producing
352single-address-space managed code operating systems that
353run faster than the equivalent multiple-address-space C systems.
354More in-depth blurb is available on <a
355href="http://www.quokforge.org/projects/horizon/wiki/Wiki">the wiki</a>.</p>
356
357</div>
358
359<!--=========================================================================-->
360<div class="doc_subsection">
361<a name="clamav">Clam AntiVirus</a>
362</div>
363
364<div class="doc_text">
365<p>
366<a href=http://www.clamav.net>Clam AntiVirus</a> is an open source (GPL)
367anti-virus toolkit for UNIX, designed especially for e-mail scanning on mail
368gateways. Since version 0.96 it has <a
369href="http://vrt-sourcefire.blogspot.com/2010/09/introduction-to-clamavs-low-level.html">bytecode
370signatures</a> that allow writing detections for complex malware. It
371uses LLVM's JIT to speed up the execution of bytecode on
372X86,X86-64,PPC32/64, falling back to its own interpreter otherwise.
373The git version was updated to work with LLVM 2.8
374</p>
375
376<p>The <a
377href="http://git.clamav.net/gitweb?p=clamav-bytecode-compiler.git;a=blob_plain;f=docs/user/clambc-user.pdf">
378ClamAV bytecode compiler</a> uses Clang and LLVM to compile a C-like
379language, insert runtime checks, and generate ClamAV bytecode.</p>
380
381</div>
382
383<!--=========================================================================-->
384<div class="doc_subsection">
385<a name="pure">Pure</a>
386</div>
387
388<div class="doc_text">
389<p>
390<a href="http://pure-lang.googlecode.com/">Pure</a>
391is an algebraic/functional
392programming language based on term rewriting. Programs are collections
393of equations which are used to evaluate expressions in a symbolic
394fashion. Pure offers dynamic typing, eager and lazy evaluation, lexical
395closures, a hygienic macro system (also based on term rewriting),
396built-in list and matrix support (including list and matrix
397comprehensions) and an easy-to-use C interface. The interpreter uses
398LLVM as a backend to JIT-compile Pure programs to fast native code.</p>
399
400<p>Pure versions 0.44 and later have been tested and are known to work with
401LLVM 2.8 (and continue to work with older LLVM releases >= 2.5).</p>
402
403</div>
404
405<!--=========================================================================-->
406<div class="doc_subsection">
407<a name="GHC">Glasgow Haskell Compiler (GHC)</a>
408</div>
409
410<div class="doc_text">
411<p>
412<a href="http://www.haskell.org/ghc/">GHC</a> is an open source,
413state-of-the-art programming suite for
414Haskell, a standard lazy functional programming language. It includes
415an optimizing static compiler generating good code for a variety of
416platforms, together with an interactive system for convenient, quick
417development.</p>
418
419<p>In addition to the existing C and native code generators, GHC 7.0 now
420supports an <a
421href="http://hackage.haskell.org/trac/ghc/wiki/Commentary/Compiler/Backends/LLVM">LLVM
422code generator</a>. GHC supports LLVM 2.7 and later.</p>
423
424</div>
425
426<!--=========================================================================-->
427<div class="doc_subsection">
428<a name="Clay">Clay Programming Language</a>
429</div>
430
431<div class="doc_text">
432<p>
433<a href="http://www.haskell.org/ghc/">Clay</a> is a new systems programming
434language that is specifically designed for generic programming. It makes
435generic programming very concise thanks to whole program type propagation. It
436uses LLVM as its backend.</p>
437
438</div>
Chris Lattner3a1d4cf2010-04-22 21:34:16 +0000[diff] [blame]439
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]440<!-- *********************************************************************** -->
441<div class="doc_section">
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]442 <a name="whatsnew">What's New in LLVM 2.8?</a>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]443</div>
444<!-- *********************************************************************** -->
445
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]446<div class="doc_text">
447
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]448<p>This release includes a huge number of bug fixes, performance tweaks and
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]449minor improvements. Some of the major improvements and new features are listed
450in this section.
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]451</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]452
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]453</div>
454
455<!--=========================================================================-->
456<div class="doc_subsection">
457<a name="orgchanges">LLVM Community Changes</a>
458</div>
459
460<div class="doc_text">
461
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]462<p>In addition to changes to the code, between LLVM 2.7 and 2.8, a number of
Chris Lattnerb7c85b42010-04-21 05:17:40 +0000[diff] [blame]463organization changes have happened:
464</p>
465
466<ul>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]467<li>libc++ and lldb are new</li>
Chris Lattnerafa41632010-09-29 07:25:03 +0000[diff] [blame]468<li>Debugging optimized code support.</li>
Chris Lattnerb7c85b42010-04-21 05:17:40 +0000[diff] [blame]469</ul>
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]470</div>
471
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]472<!--=========================================================================-->
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]473<div class="doc_subsection">
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]474<a name="majorfeatures">Major New Features</a>
475</div>
476
477<div class="doc_text">
478
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]479<p>LLVM 2.8 includes several major new capabilities:</p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]480
481<ul>
Chris Lattner8dc5faf2010-09-05 20:49:45 +0000[diff] [blame]482<li>atomic lowering pass.</li>
483<li>RegionInfo pass: opt -regions analyze" or "opt -view-regions".
484<!-- Tobias Grosser --></li>
485<li>ARMGlobalMerge: <!-- Anton --> </li>
Chris Lattner702f2d42010-09-06 19:14:40 +0000[diff] [blame]486<li>llvm-diff</li>
Chris Lattner8170c102008-02-10 08:18:42 +0000[diff] [blame]487</ul>
Chris Lattnerdc910082010-03-17 06:41:58 +0000[diff] [blame]488
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]489</div>
490
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]491<!--=========================================================================-->
492<div class="doc_subsection">
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]493<a name="coreimprovements">LLVM IR and Core Improvements</a>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]494</div>
495
496<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]497<p>LLVM IR has several new features for better support of new targets and that
498expose new optimization opportunities:</p>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]499
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]500<ul>
Gabor Greif17b59fe2010-07-21 10:20:08 +0000[diff] [blame]501
502<li>LLVM 2.8 changes the internal order of operands in <a
503 href="http://llvm.org/doxygen/classllvm_1_1InvokeInst.html"><tt>InvokeInst</tt></a>
504 and <a href="http://llvm.org/doxygen/classllvm_1_1CallInst.html"><tt>CallInst</tt></a>.
505 To be portable across releases, resort to <tt>CallSite</tt> and the
Gabor Greif50fb3302010-07-21 10:22:41 +0000[diff] [blame]506 high-level accessors, such as <tt>getCalledValue</tt> and <tt>setUnwindDest</tt>.
Gabor Greif17b59fe2010-07-21 10:20:08 +0000[diff] [blame]507</li>
Gabor Greif05006e22010-07-26 18:48:07 +0000[diff] [blame]508<li>
509 You can no longer pass use_iterators directly to cast<> (and similar), because
510 these routines tend to perform costly dereference operations more than once. You
511 have to dereference the iterators yourself and pass them in.
512</li>
Torok Edwin7c46cf02010-08-04 12:43:22 +0000[diff] [blame]513<li>
514 llvm.memcpy.*, llvm.memset.*, llvm.memmove.* (and possibly other?) intrinsics
515 take an extra parameter now (i1 isVolatile), totaling 5 parameters.
516 If you were creating these intrinsic calls and prototypes yourself (as opposed
517 to using Intrinsic::getDeclaration), you can use UpgradeIntrinsicFunction/UpgradeIntrinsicCall
518 to be portable accross releases.
519 Note that you cannot use Intrinsic::getDeclaration() in a backwards compatible
520 way (needs 2/3 types now, in 2.7 it needed just 1).
521</li>
522<li>
523 SetCurrentDebugLocation takes a DebugLoc now instead of a MDNode.
524 Change your code to use
525 SetCurrentDebugLocation(DebugLoc::getFromDILocation(...)).
526</li>
527<li>
528 VISIBILITY_HIDDEN is gone.
529</li>
530<li>
Owen Anderson87ebbc02010-08-04 18:27:08 +0000[diff] [blame]531 The <tt>RegisterPass</tt> and <tt>RegisterAnalysisGroup</tt> templates are
532 considered deprecated, but continue to function in LLVM 2.8. Clients are
533 strongly advised to use the upcoming <tt>INITIALIZE_PASS()</tt> and
534 <tt>INITIALIZE_AG_PASS()</tt> macros instead.
535<li>
Torok Edwin7c46cf02010-08-04 12:43:22 +0000[diff] [blame]536 SMDiagnostic takes different parameters now. //FIXME: how to upgrade?
537</li>
538<li>
Duncan Sands12881e72010-08-30 10:57:54 +0000[diff] [blame]539 The constructor for the Triple class no longer tries to understand odd triple
540 specifications. Frontends should ensure that they only pass valid triples to
541 LLVM. The Triple::normalize utility method has been added to help front-ends
542 deal with funky triples.
543<li>
Torok Edwin7c46cf02010-08-04 12:43:22 +0000[diff] [blame]544 Some APIs got renamed:
545 <ul>
546 <li>llvm_report_error -&gt; report_fatal_error</li>
547 <li>llvm_install_error_handler -&gt; install_fatal_error_handler</li>
548 <li>llvm::DwarfExceptionHandling -&gt; llvm::JITExceptionHandling</li>
549 </ul>
550</li>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]551</ul>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]552
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]553</div>
554
555<!--=========================================================================-->
556<div class="doc_subsection">
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]557<a name="optimizer">Optimizer Improvements</a>
558</div>
559
560<div class="doc_text">
561
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]562<p>In addition to a large array of minor performance tweaks and bug fixes, this
Chris Lattnerf3013872008-10-13 21:50:36 +0000[diff] [blame]563release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]564
565<ul>
566
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]567<li></li>
Chris Lattnera54c1f72010-04-21 06:42:24 +0000[diff] [blame]568
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]569</ul>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]570
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]571</div>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]572
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]573
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]574<!--=========================================================================-->
575<div class="doc_subsection">
576<a name="executionengine">Interpreter and JIT Improvements</a>
577</div>
Chris Lattnerf3013872008-10-13 21:50:36 +0000[diff] [blame]578
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]579<div class="doc_text">
580
581<ul>
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]582<li></li>
Chris Lattnerb7c85b42010-04-21 05:17:40 +0000[diff] [blame]583
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]584</ul>
585
586</div>
587
588<!--=========================================================================-->
589<div class="doc_subsection">
Chris Lattner511433e2009-03-02 03:24:11 +0000[diff] [blame]590<a name="codegen">Target Independent Code Generator Improvements</a>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]591</div>
592
593<div class="doc_text">
594
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000[diff] [blame]595<p>We have put a significant amount of work into the code generator
596infrastructure, which allows us to implement more aggressive algorithms and make
597it run faster:</p>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]598
599<ul>
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]600<li>MachO writer works.</li>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]601</ul>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]602</div>
603
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]604<!--=========================================================================-->
605<div class="doc_subsection">
606<a name="x86">X86-32 and X86-64 Target Improvements</a>
607</div>
608
609<div class="doc_text">
610<p>New features of the X86 target include:
611</p>
612
613<ul>
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]614<li>The X86 backend now supports holding X87 floating point stack values
615 in registers across basic blocks, dramatically improving performance of code
616 that uses long double, and when targetting CPUs that don't support SSE.</li>
Chris Lattner511433e2009-03-02 03:24:11 +0000[diff] [blame]617
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]618</ul>
619
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]620</div>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]621
622<!--=========================================================================-->
623<div class="doc_subsection">
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]624<a name="ARM">ARM Target Improvements</a>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]625</div>
626
627<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]628<p>New features of the ARM target include:
629</p>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]630
631<ul>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]632
Bob Wilson5b2fb952010-09-13 17:37:55 +0000[diff] [blame]633<li>
634 All of the NEON load and store intrinsics (llvm.arm.neon.vld* and
635 llvm.arm.neon.vst*) take an extra parameter to specify the alignment in bytes
636 of the memory being accessed.
637</li>
638<li>
639 The llvm.arm.neon.vaba intrinsic (vector absolute difference and
640 accumulate) has been removed. This operation is now represented using
641 the llvm.arm.neon.vabd intrinsic (vector absolute difference) followed by a
642 vector add.
Bob Wilsone8472772010-09-13 17:39:35 +0000[diff] [blame]643</li>
Bob Wilson5b2fb952010-09-13 17:37:55 +0000[diff] [blame]644<li>
645 The llvm.arm.neon.vabdl and llvm.arm.neon.vabal intrinsics (lengthening
646 vector absolute difference with and without accumlation) have been removed.
647 They are represented using the llvm.arm.neon.vabd intrinsic (vector absolute
648 difference) followed by a vector zero-extend operation, and for vabal,
649 a vector add.
650</li>
651<li>
652 The llvm.arm.neon.vmovn intrinsic has been removed. Calls of this intrinsic
653 are now replaced by vector truncate operations.
654</li>
655<li>
656 The llvm.arm.neon.vmovls and llvm.arm.neon.vmovlu intrinsics have been
657 removed. They are now represented as vector sign-extend (vmovls) and
658 zero-extend (vmovlu) operations.
659</li>
660<li>
661 The llvm.arm.neon.vaddl*, llvm.arm.neon.vaddw*, llvm.arm.neon.vsubl*, and
662 llvm.arm.neon.vsubw* intrinsics (lengthening vector add and subtract) have
663 been removed. They are replaced by vector add and vector subtract operations
664 where one (vaddw, vsubw) or both (vaddl, vsubl) of the operands are either
665 sign-extended or zero-extended.
666</li>
667<li>
668 The llvm.arm.neon.vmulls, llvm.arm.neon.vmullu, llvm.arm.neon.vmlal*, and
669 llvm.arm.neon.vmlsl* intrinsics (lengthening vector multiply with and without
670 accumulation and subtraction) have been removed. These operations are now
671 represented as vector multiplications where the operands are either
672 sign-extended or zero-extended, followed by a vector add for vmlal or a
673 vector subtract for vmlsl. Note that the polynomial vector multiply
674 intrinsic, llvm.arm.neon.vmullp, remains unchanged.
675</li>
Bob Wilsone8472772010-09-13 17:39:35 +0000[diff] [blame]676
677</ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]678</div>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]679
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]680<!--=========================================================================-->
681<div class="doc_subsection">
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]682<a name="newapis">New Useful APIs</a>
683</div>
684
685<div class="doc_text">
686
687<p>This release includes a number of new APIs that are used internally, which
688 may also be useful for external clients.
689</p>
690
691<ul>
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]692<li></li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]693</ul>
694
695
696</div>
697
698<!--=========================================================================-->
699<div class="doc_subsection">
700<a name="otherimprovements">Other Improvements and New Features</a>
701</div>
702
703<div class="doc_text">
704<p>Other miscellaneous features include:</p>
705
706<ul>
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]707<li></li>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]708</ul>
709
710</div>
711
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]712
713<!--=========================================================================-->
714<div class="doc_subsection">
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]715<a name="changes">Major Changes and Removed Features</a>
716</div>
717
718<div class="doc_text">
719
Chris Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]720<p>If you're already an LLVM user or developer with out-of-tree changes based
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]721on LLVM 2.7, this section lists some "gotchas" that you may run into upgrading
Chris Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]722from the previous release.</p>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]723
724<ul>
Chris Lattner2295b5a2010-09-02 23:22:50 +0000[diff] [blame]725<li>.ll file doesn't produce #uses comments anymore, to get them, run a .bc file
726 through "llvm-dis --show-annotations".</li>
Chris Lattner885b6612010-08-28 16:33:36 +0000[diff] [blame]727<li>MSIL Backend removed.</li>
728<li>ABCD and SSI passes removed.</li>
729<li>'Union' LLVM IR feature removed.</li>
Chris Lattnerb7c85b42010-04-21 05:17:40 +0000[diff] [blame]730</ul>
Chris Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]731
732<p>In addition, many APIs have changed in this release. Some of the major LLVM
733API changes are:</p>
734
735<ul>
Devang Patelb34dd132008-10-14 20:03:43 +0000[diff] [blame]736</ul>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]737
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]738</div>
739
740
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]741<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]742<div class="doc_section">
743 <a name="knownproblems">Known Problems</a>
744</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]745<!-- *********************************************************************** -->
746
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]747<div class="doc_text">
748
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000[diff] [blame]749<p>This section contains significant known problems with the LLVM system,
Chris Lattnere18b32e2008-11-10 05:40:34 +0000[diff] [blame]750listed by component. If you run into a problem, please check the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]751href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]752there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]753
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]754</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]755
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]756<!-- ======================================================================= -->
757<div class="doc_subsection">
758 <a name="experimental">Experimental features included with this release</a>
759</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]760
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]761<div class="doc_text">
762
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]763<p>The following components of this LLVM release are either untested, known to
764be broken or unreliable, or are in early development. These components should
765not be relied on, and bugs should not be filed against them, but they may be
766useful 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]767components, please contact us on the <a
768href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]769
770<ul>
Chris Lattner885b6612010-08-28 16:33:36 +0000[diff] [blame]771<li>The Alpha, SPU, MIPS, PIC16, Blackfin, MSP430, SystemZ and MicroBlaze
Wesley Peck7c4a1212010-03-18 14:31:30 +0000[diff] [blame]772 backends are experimental.</li>
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]773<li><tt>llc</tt> "<tt>-filetype=asm</tt>" (the default) is the only
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]774 supported value for this option. XXX Update me</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]775</ul>
776
777</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]778
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]779<!-- ======================================================================= -->
780<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]781 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]782</div>
783
784<div class="doc_text">
785
786<ul>
Anton Korobeynikova6094be2008-06-08 10:24:13 +0000[diff] [blame]787 <li>The X86 backend does not yet support
788 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
789 floating point stack</a>. It supports the 'f' and 't' constraints, but not
790 'u'.</li>
Duncan Sands47eff2b2008-06-08 19:38:43 +0000[diff] [blame]791 <li>Win64 code generation wasn't widely tested. Everything should work, but we
John Criswell524a5dd2009-03-02 15:28:15 +0000[diff] [blame]792 expect small issues to happen. Also, llvm-gcc cannot build the mingw64
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]793 runtime currently due to lack of support for the 'u' inline assembly
794 constraint and for X87 floating point inline assembly.</li>
Dan Gohman8207ba92008-06-08 23:05:11 +0000[diff] [blame]795 <li>The X86-64 backend does not yet support the LLVM IR instruction
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]796 <tt>va_arg</tt>. Currently, front-ends support variadic
Dan Gohman8207ba92008-06-08 23:05:11 +0000[diff] [blame]797 argument constructs on X86-64 by lowering them manually.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]798</ul>
799
800</div>
801
802<!-- ======================================================================= -->
803<div class="doc_subsection">
804 <a name="ppc-be">Known problems with the PowerPC back-end</a>
805</div>
806
807<div class="doc_text">
808
809<ul>
Nicolas Geoffraye4285dc2007-05-15 09:21:28 +0000[diff] [blame]810<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]811compilation, and lacks support for debug information.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]812</ul>
813
814</div>
815
816<!-- ======================================================================= -->
817<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]818 <a name="arm-be">Known problems with the ARM back-end</a>
819</div>
820
821<div class="doc_text">
822
823<ul>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]824<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000[diff] [blame]825processors, thumb programs can crash or produce wrong
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]826results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
John Criswell524a5dd2009-03-02 15:28:15 +0000[diff] [blame]827<li>Compilation for ARM Linux OABI (old ABI) is supported but not fully tested.
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]828</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]829</ul>
830
831</div>
832
833<!-- ======================================================================= -->
834<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]835 <a name="sparc-be">Known problems with the SPARC back-end</a>
836</div>
837
838<div class="doc_text">
839
840<ul>
John Criswell524a5dd2009-03-02 15:28:15 +0000[diff] [blame]841<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]842 support the 64-bit SPARC ABI (-m64).</li>
843</ul>
844
845</div>
846
847<!-- ======================================================================= -->
848<div class="doc_subsection">
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000[diff] [blame]849 <a name="mips-be">Known problems with the MIPS back-end</a>
850</div>
851
852<div class="doc_text">
853
854<ul>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000[diff] [blame]855<li>64-bit MIPS targets are not supported yet.</li>
856</ul>
857
858</div>
859
860<!-- ======================================================================= -->
861<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]862 <a name="alpha-be">Known problems with the Alpha back-end</a>
863</div>
864
865<div class="doc_text">
866
867<ul>
868
869<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
870appropriate nops inserted to ensure restartability.</li>
871
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]872</ul>
873</div>
874
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]875<!-- ======================================================================= -->
876<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]877 <a name="c-be">Known problems with the C back-end</a>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]878</div>
879
880<div class="doc_text">
881
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]882<p>The C backend has numerous problems and is not being actively maintained.
883Depending on it for anything serious is not advised.</p>
884
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]885<ul>
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]886<li><a href="http://llvm.org/PR802">The C backend has only basic support for
887 inline assembly code</a>.</li>
Chris Lattner725a0d82007-09-26 06:01:35 +0000[diff] [blame]888<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
889 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Gabor Greif4906abe2009-03-02 12:02:51 +0000[diff] [blame]890 C++ code compiled with <tt>llc</tt> or native compilers.</li>
Duncan Sandsf74c0cc2008-02-10 13:40:55 +0000[diff] [blame]891<li>The C backend does not support all exception handling constructs.</li>
Duncan Sands50723a92009-02-25 11:51:54 +0000[diff] [blame]892<li>The C backend does not support arbitrary precision integers.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]893</ul>
894
895</div>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]896
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]897
898<!-- ======================================================================= -->
899<div class="doc_subsection">
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]900 <a name="llvm-gcc">Known problems with the llvm-gcc front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]901</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]902
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]903<div class="doc_text">
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]904
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]905<p>llvm-gcc is generally very stable for the C family of languages. The only
906 major language feature of GCC not supported by llvm-gcc is the
907 <tt>__builtin_apply</tt> family of builtins. However, some extensions
908 are only supported on some targets. For example, trampolines are only
909 supported on some targets (these are used when you take the address of a
910 nested function).</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]911
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]912<p>Fortran support generally works, but there are still several unresolved bugs
913 in <a href="http://llvm.org/bugs/">Bugzilla</a>. Please see the
914 tools/gfortran component for details. Note that llvm-gcc is missing major
915 Fortran performance work in the frontend and library that went into GCC after
916 4.2. If you are interested in Fortran, we recommend that you consider using
917 <a href="#dragonegg">dragonegg</a> instead.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]918
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]919<p>The llvm-gcc 4.2 Ada compiler has basic functionality. However, this is not a
920mature technology, and problems should be expected. For example:</p>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]921<ul>
Duncan Sands27aff872008-06-08 20:18:35 +0000[diff] [blame]922<li>The Ada front-end currently only builds on X86-32. This is mainly due
John Criswell524a5dd2009-03-02 15:28:15 +0000[diff] [blame]923to lack of trampoline support (pointers to nested functions) on other platforms.
924However, 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]925which does support trampolines.</li>
926<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]927This is due to lack of LLVM support for <tt>setjmp</tt>/<tt>longjmp</tt> style
928exception handling, which is used internally by the compiler.
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]929Workaround: configure with <tt>--disable-bootstrap</tt>.</li>
Duncan Sands978bcee2008-10-13 17:27:23 +0000[diff] [blame]930<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
931and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
Duncan Sands326a4982009-02-25 11:59:06 +0000[diff] [blame]932(c380004 also fails with gcc-4.2 mainline).
933If the compiler is built with checks disabled then <a href="http://llvm.org/PR2010">c393010</a>
934causes the compiler to go into an infinite loop, using up all system memory.</li>
Duncan Sandsdd3e6722009-03-02 16:35:57 +0000[diff] [blame]935<li>Some GCC specific Ada tests continue to crash the compiler.</li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]936<li>The <tt>-E</tt> binder option (exception backtraces)
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]937<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]938crashing if an exception is raised. Workaround: do not use <tt>-E</tt>.</li>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]939<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
940or finish at a non-byte offset</a> in a record. Workaround: do not pack records
941or use representation clauses that result in a field of a non-discrete type
942starting or finishing in the middle of a byte.</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000[diff] [blame]943<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
944'main' as generated by the Ada binder to be invalid</a>.
945Workaround: hand edit the file to use pointers for <tt>argv</tt> and
946<tt>envp</tt> rather than integers.</li>
947<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
948ignored</a>.</li>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]949</ul>
950</div>
951
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]952<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]953<div class="doc_section">
954 <a name="additionalinfo">Additional Information</a>
955</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]956<!-- *********************************************************************** -->
957
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]958<div class="doc_text">
959
Chris Lattner416db102005-05-16 17:13:10 +0000[diff] [blame]960<p>A wide variety of additional information is available on the <a
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]961href="http://llvm.org">LLVM web page</a>, in particular in the <a
962href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencer669ed452007-07-09 08:04:31 +0000[diff] [blame]963contains versions of the API documentation which is up-to-date with the
964Subversion version of the source code.
Misha Brukman109d9e82005-03-30 19:14:24 +0000[diff] [blame]965You can access versions of these documents specific to this release by going
966into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]967
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]968<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]969us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]970lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]971
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]972</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]973
974<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]975
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]976<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]977<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]978 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]979 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]980 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]981 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]982
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]983 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]984 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]985</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]986
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]987</body>
988</html>