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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / d47691460770c886cf2fdafaf0f53e0cd101ccf1 / . / docs / ReleaseNotes.html
blob: 2573dc8821305b201f0d677dea7153f37c55bd18 [file] [log] [blame]
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
2 "http://www.w3.org/TR/html4/strict.dtd">
3<html>
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.
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]106 per-instruction debug info metadata is much faster and uses less space (new DebugLoc class).
107 -ffunction-sections and -fdata-sections are supported on ELF targets.
108 Now iterate function passes when a cgsccpassmanager detects a devirtualization
109 -momit-leaf-frame-pointer now supported.
110 New -regalloc=fast, =local got removed
111 New -regalloc=default option that chooses a register allocator based on the -O optimization level.
112 New "trap values" concept: http://llvm.org/docs/LangRef.html#trapvalues
113 Improved trip count analysis for <= and >= loops, and uses sign overflow info.
114 REMOVED: SCCVN pass.
115 X86 backend attempts to promote 16-bit integer operations to 32-bits to avoid
116 0x66 prefixes, which are slow on some microarchitectures and bloat the code
117 on others.
118 X87 fp stackifier is global!
119 LTO debug info support?
120 NEON: Better performance for QQQQ (4-consecutive Q register) instructions. New reg sequence abstraction?
121 New support for X86 "thiscall" calling convention (x86_thiscallcc in IR).
122 ARM: Better scheduling (list-hybrid, hybrid?)
123 New SubRegIndex tblgen class for targets -> jakob
124 ARM: Tail call support.
125 AVX support in the MC assembler. Full compiler support not done yet.
126 Atomics now get legalized when not natively supported (jim g)
127 ARM: General performance work and tuning.
Chris Lattnereb6f5932010-10-02 19:32:01 +0000[diff] [blame]128 Bottom up fast isel. Simple Load reuse. No more machinedce. Load folding at -O0?
129 New linker_private_weak and linker_private_weak_def_auto linkage types
130 compiler_rt softfloat support.
131 X86 ABI: <2 x float> in IR no longer maps onto MMX, it turns into <4 x float>
132 IR ABI: <3 x float> is passed as <4 x float> instead of 3 floats.
133 renamed "Release" -> "Release+Asserts"; "Release-Asserts" -> "Release etc.
134 New COPY instruction. copyRegToReg -> copyPhysReg, isMoveInstr is gone.
135 JumpThreading much more aggressive about implied value relations.
136 New RegionInfo pass "opt -regions analyze" or "opt -view-regions".
137 mc assembler supports macros.
138 RenderMachineFunction: -rendermf
139 SplitKit?
140 Evan: Teach bottom up pre-ra scheduler to track register pressure. Work in progress.
141 Evan: Add an ILP scheduler. On x86_64, this is a win for all tests in CFP2000. It also sped up 256.bzip2 by 16%.
142 RegisterPass<> -> INTIALIZE_PASS()
143 llvm-diff?
144 Preliminary work on TBAA but not usable in 2.8.
145 Atomic lowering patch: -loweratomic (see Passes.html#loweratomic)
146 compiler_rt now includes extensive a fairly testsuite for blocks language feature and the blocks runtime.
147 New OptimizeExts+OptimizeCmps -> PeepholeOptimizer pass
148 Triples are now stored in normalized form. Triple::normalize.
149 New LocalStackSlotAllocation.cpp pass (jimg)
150 New llvm.x86.int intrinsic (for int $42 and int3)
151 New CorrelatedValuePropagation pass, not on by default in 2.8 yet.
152 Verbose assembly decodes X86 shuffle instructions, e.g.:
153 insertps $113, %xmm3, %xmm0 ## xmm0 = zero,xmm0[1,2],xmm3[1]
154 unpcklps %xmm1, %xmm0 ## xmm0 = xmm0[0],xmm1[0],xmm0[1],xmm1[1]
155 pshufd $1, %xmm1, %xmm1 ## xmm1 = xmm1[1,0,0,0]
Chris Lattnerafa41632010-09-29 07:25:03 +0000[diff] [blame]156 -->
157
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]158
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]159<!-- *********************************************************************** -->
160<div class="doc_section">
161 <a name="subproj">Sub-project Status Update</a>
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]162</div>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]163<!-- *********************************************************************** -->
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]164
165<div class="doc_text">
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]166<p>
Dan Gohmanb44f6c62010-05-03 23:51:05 +0000[diff] [blame]167The LLVM 2.8 distribution currently consists of code from the core LLVM
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]168repository (which roughly includes the LLVM optimizers, code generators
169and supporting tools), the Clang repository and the llvm-gcc repository. In
170addition to this code, the LLVM Project includes other sub-projects that are in
171development. Here we include updates on these subprojects.
Bill Wendling63d8c552009-03-02 04:28:57 +0000[diff] [blame]172</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]173
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]174</div>
175
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]176
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]177<!--=========================================================================-->
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]178<div class="doc_subsection">
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000[diff] [blame]179<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]180</div>
181
182<div class="doc_text">
183
Chris Lattner095539f2010-04-26 17:42:18 +0000[diff] [blame]184<p><a href="http://clang.llvm.org/">Clang</a> is an LLVM front end for the C,
185C++, and Objective-C languages. Clang aims to provide a better user experience
186through expressive diagnostics, a high level of conformance to language
187standards, fast compilation, and low memory use. Like LLVM, Clang provides a
188modular, library-based architecture that makes it suitable for creating or
189integrating with other development tools. Clang is considered a
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]190production-quality compiler for C, Objective-C, C++ and Objective-C++ on x86
191(32- and 64-bit), and for darwin-arm targets.</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]192
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]193<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]194
Daniel Dunbar13739432008-10-14 23:25:09 +0000[diff] [blame]195<ul>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]196<li>Surely these guys have done something</li>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]197<li>X86-64 abi improvements? Did they make it in?</li>
Bill Wendling6bc15282009-03-02 04:28:18 +0000[diff] [blame]198</ul>
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000[diff] [blame]199</div>
200
201<!--=========================================================================-->
202<div class="doc_subsection">
203<a name="clangsa">Clang Static Analyzer</a>
204</div>
205
206<div class="doc_text">
207
Chris Lattner8cdd7932010-04-22 06:38:11 +0000[diff] [blame]208<p>The <a href="http://clang-analyzer.llvm.org/">Clang Static Analyzer</a>
209 project is an effort to use static source code analysis techniques to
210 automatically find bugs in C and Objective-C programs (and hopefully <a
211 href="http://clang-analyzer.llvm.org/dev_cxx.html">C++ in the
212 future</a>!). The tool is very good at finding bugs that occur on specific
213 paths through code, such as on error conditions.</p>
Chris Lattnercc042612008-10-14 00:52:49 +0000[diff] [blame]214
Chris Lattner2e38c7f2010-09-30 00:34:43 +0000[diff] [blame]215<p>The LLVM 2.8 release fixes a number of bugs and slightly improves precision
216 over 2.7, but there are no major new features in the release.
Chris Lattner8cdd7932010-04-22 06:38:11 +0000[diff] [blame]217</p>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]218
219</div>
220
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]221<!--=========================================================================-->
222<div class="doc_subsection">
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000[diff] [blame]223<a name="vmkit">VMKit: JVM/CLI Virtual Machine Implementation</a>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]224</div>
225
226<div class="doc_text">
227<p>
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000[diff] [blame]228The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation of
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]229a JVM and a CLI Virtual Machine (Microsoft .NET is an
230implementation of the CLI) using LLVM for static and just-in-time
231compilation.</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]232
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]233<p>With the release of LLVM 2.8, ...</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]234
235</div>
236
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]237
238<!--=========================================================================-->
239<div class="doc_subsection">
240<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
241</div>
242
243<div class="doc_text">
244<p>
245The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
246is a simple library that provides an implementation of the low-level
247target-specific hooks required by code generation and other runtime components.
248For example, when compiling for a 32-bit target, converting a double to a 64-bit
249unsigned integer is compiled into a runtime call to the "__fixunsdfdi"
250function. The compiler-rt library provides highly optimized implementations of
251this and other low-level routines (some are 3x faster than the equivalent
252libgcc routines).</p>
253
254<p>
255All of the code in the compiler-rt project is available under the standard LLVM
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]256License, a "BSD-style" license. New in LLVM 2.8:
257
258Soft float support
259</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]260
261</div>
262
263<!--=========================================================================-->
264<div class="doc_subsection">
Duncan Sands749fd832010-04-02 09:23:15 +0000[diff] [blame]265<a name="dragonegg">DragonEgg: llvm-gcc ported to gcc-4.5</a>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]266</div>
267
268<div class="doc_text">
269<p>
Duncan Sands749fd832010-04-02 09:23:15 +0000[diff] [blame]270<a href="http://dragonegg.llvm.org/">DragonEgg</a> is a port of llvm-gcc to
Duncan Sands4b1da2b2010-09-30 17:37:34 +0000[diff] [blame]271gcc-4.5. Unlike llvm-gcc, dragonegg in theory does not require any gcc-4.5
272modifications whatsoever (currently one small patch is needed) thanks to the
273new <a href="http://gcc.gnu.org/wiki/plugins">gcc plugin architecture</a>.
274DragonEgg is a gcc plugin that makes gcc-4.5 use the LLVM optimizers and code
275generators instead of gcc's, just like with llvm-gcc.
Duncan Sands749fd832010-04-02 09:23:15 +0000[diff] [blame]276</p>
277
278<p>
Duncan Sands4b1da2b2010-09-30 17:37:34 +0000[diff] [blame]279DragonEgg is still a work in progress, but it is able to compile a lot of code,
280for example all of gcc, LLVM and clang. Currently Ada, C, C++ and Fortran work
281well, while all other languages either don't work at all or only work poorly.
282For the moment only the x86-32 and x86-64 targets are supported, and only on
283linux and darwin (darwin may need additional gcc patches).
Duncan Sands749fd832010-04-02 09:23:15 +0000[diff] [blame]284</p>
285
286<p>
Duncan Sands4b1da2b2010-09-30 17:37:34 +0000[diff] [blame]287The 2.8 release has the following notable changes:
288<ul>
289<li>The plugin loads faster due to exporting fewer symbols.</li>
290<li>Additional vector operations such as addps256 are now supported.</li>
291<li>Ada global variables with no initial value are no longer zero initialized,
292resulting in better optimization.</li>
293<li>The '-fplugin-arg-dragonegg-enable-gcc-optzns' flag now runs all gcc
294optimizers, rather than just a handful.</li>
295<li>Fortran programs using common variables now link correctly.</li>
296<li>GNU OMP constructs no longer crash the compiler.</li>
297</ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]298</p>
299
300</div>
301
302
303<!--=========================================================================-->
304<div class="doc_subsection">
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]305<a name="lldb">LLDB: Low Level Debugger</a>
306</div>
307
308<div class="doc_text">
309<p>
310<a href="http://lldb.llvm.org/">LLDB</a> is</p>
311
312<p>
313</p>
314
315<p>
3162.8 status here.
317</p>
318
319</div>
320
321<!--=========================================================================-->
322<div class="doc_subsection">
323<a name="libc++">libc++: C++ Standard Library</a>
324</div>
325
326<div class="doc_text">
327<p>
328<a href="http://libc++.llvm.org/">libc++</a> is</p>
329
330<p>
331</p>
332
333<p>
3342.8 status here.
335</p>
336
337</div>
338
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]339
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame]340<!-- *********************************************************************** -->
341<div class="doc_section">
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]342 <a name="externalproj">External Open Source Projects Using LLVM 2.8</a>
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame]343</div>
344<!-- *********************************************************************** -->
345
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]346<div class="doc_text">
347
348<p>An exciting aspect of LLVM is that it is used as an enabling technology for
349 a lot of other language and tools projects. This section lists some of the
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]350 projects that have already been updated to work with LLVM 2.8.</p>
Chris Lattner7c8e7962010-04-26 17:38:10 +0000[diff] [blame]351</div>
352
Chris Lattner2e38c7f2010-09-30 00:34:43 +0000[diff] [blame]353<!--=========================================================================-->
354<div class="doc_subsection">
355<a name="tce">TTA-based Codesign Environment (TCE)</a>
356</div>
357
358<div class="doc_text">
359<p>
360<a href="http://tce.cs.tut.fi/">TCE</a> is a toolset for designing
361application-specific processors (ASP) based on the Transport triggered
362architecture (TTA). The toolset provides a complete co-design flow from C/C++
363programs down to synthesizable VHDL and parallel program binaries. Processor
364customization points include the register files, function units, supported
365operations, and the interconnection network.</p>
366
367<p>TCE uses llvm-gcc/Clang and LLVM for C/C++ language support, target
368independent optimizations and also for parts of code generation. It generates
369new LLVM-based code generators "on the fly" for the designed TTA processors and
370loads them in to the compiler backend as runtime libraries to avoid per-target
371recompilation of larger parts of the compiler chain.</p>
372
373</div>
374
375<!--=========================================================================-->
376<div class="doc_subsection">
377<a name="Horizon">Horizon Bytecode Compiler</a>
378</div>
379
380<div class="doc_text">
381<p>
382<a href="http://www.quokforge.org/projects/horizon">Horizon</a> is a bytecode
383language and compiler written on top of LLVM, intended for producing
384single-address-space managed code operating systems that
385run faster than the equivalent multiple-address-space C systems.
386More in-depth blurb is available on <a
387href="http://www.quokforge.org/projects/horizon/wiki/Wiki">the wiki</a>.</p>
388
389</div>
390
391<!--=========================================================================-->
392<div class="doc_subsection">
393<a name="clamav">Clam AntiVirus</a>
394</div>
395
396<div class="doc_text">
397<p>
398<a href=http://www.clamav.net>Clam AntiVirus</a> is an open source (GPL)
399anti-virus toolkit for UNIX, designed especially for e-mail scanning on mail
400gateways. Since version 0.96 it has <a
401href="http://vrt-sourcefire.blogspot.com/2010/09/introduction-to-clamavs-low-level.html">bytecode
402signatures</a> that allow writing detections for complex malware. It
403uses LLVM's JIT to speed up the execution of bytecode on
404X86,X86-64,PPC32/64, falling back to its own interpreter otherwise.
405The git version was updated to work with LLVM 2.8
406</p>
407
408<p>The <a
409href="http://git.clamav.net/gitweb?p=clamav-bytecode-compiler.git;a=blob_plain;f=docs/user/clambc-user.pdf">
410ClamAV bytecode compiler</a> uses Clang and LLVM to compile a C-like
411language, insert runtime checks, and generate ClamAV bytecode.</p>
412
413</div>
414
415<!--=========================================================================-->
416<div class="doc_subsection">
417<a name="pure">Pure</a>
418</div>
419
420<div class="doc_text">
421<p>
422<a href="http://pure-lang.googlecode.com/">Pure</a>
423is an algebraic/functional
424programming language based on term rewriting. Programs are collections
425of equations which are used to evaluate expressions in a symbolic
426fashion. Pure offers dynamic typing, eager and lazy evaluation, lexical
427closures, a hygienic macro system (also based on term rewriting),
428built-in list and matrix support (including list and matrix
429comprehensions) and an easy-to-use C interface. The interpreter uses
430LLVM as a backend to JIT-compile Pure programs to fast native code.</p>
431
432<p>Pure versions 0.44 and later have been tested and are known to work with
433LLVM 2.8 (and continue to work with older LLVM releases >= 2.5).</p>
434
435</div>
436
437<!--=========================================================================-->
438<div class="doc_subsection">
439<a name="GHC">Glasgow Haskell Compiler (GHC)</a>
440</div>
441
442<div class="doc_text">
443<p>
444<a href="http://www.haskell.org/ghc/">GHC</a> is an open source,
445state-of-the-art programming suite for
446Haskell, a standard lazy functional programming language. It includes
447an optimizing static compiler generating good code for a variety of
448platforms, together with an interactive system for convenient, quick
449development.</p>
450
451<p>In addition to the existing C and native code generators, GHC 7.0 now
452supports an <a
453href="http://hackage.haskell.org/trac/ghc/wiki/Commentary/Compiler/Backends/LLVM">LLVM
454code generator</a>. GHC supports LLVM 2.7 and later.</p>
455
456</div>
457
458<!--=========================================================================-->
459<div class="doc_subsection">
460<a name="Clay">Clay Programming Language</a>
461</div>
462
463<div class="doc_text">
464<p>
Chris Lattner97fe6452010-09-30 01:12:09 +0000[diff] [blame]465<a href="http://tachyon.in/clay/">Clay</a> is a new systems programming
Chris Lattner2e38c7f2010-09-30 00:34:43 +0000[diff] [blame]466language that is specifically designed for generic programming. It makes
467generic programming very concise thanks to whole program type propagation. It
468uses LLVM as its backend.</p>
469
470</div>
Chris Lattner3a1d4cf2010-04-22 21:34:16 +0000[diff] [blame]471
Chris Lattnere0518442010-10-01 06:34:49 +0000[diff] [blame]472<!--=========================================================================-->
473<div class="doc_subsection">
474<a name="llvm-py">llvm-py Python Bindings for LLVM</a>
475</div>
476
477<div class="doc_text">
478<p>
479<a href="http://www.mdevan.org/llvm-py/">llvm-py</a> has been updated to work
480with LLVM 2.8. llvm-py provides Python bindings for LLVM, allowing you to write a
481compiler backend or a VM in Python.</p>
482
483</div>
484
485
486
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]487<!-- *********************************************************************** -->
488<div class="doc_section">
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]489 <a name="whatsnew">What's New in LLVM 2.8?</a>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]490</div>
491<!-- *********************************************************************** -->
492
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]493<div class="doc_text">
494
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]495<p>This release includes a huge number of bug fixes, performance tweaks and
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]496minor improvements. Some of the major improvements and new features are listed
497in this section.
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]498</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]499
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]500</div>
501
502<!--=========================================================================-->
503<div class="doc_subsection">
504<a name="orgchanges">LLVM Community Changes</a>
505</div>
506
507<div class="doc_text">
508
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]509<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]510organization changes have happened:
511</p>
512
513<ul>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]514<li>libc++ and lldb are new</li>
Chris Lattnerafa41632010-09-29 07:25:03 +0000[diff] [blame]515<li>Debugging optimized code support.</li>
Chris Lattnerb7c85b42010-04-21 05:17:40 +0000[diff] [blame]516</ul>
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]517</div>
518
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]519<!--=========================================================================-->
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]520<div class="doc_subsection">
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]521<a name="majorfeatures">Major New Features</a>
522</div>
523
524<div class="doc_text">
525
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]526<p>LLVM 2.8 includes several major new capabilities:</p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]527
528<ul>
Chris Lattner8dc5faf2010-09-05 20:49:45 +0000[diff] [blame]529<li>atomic lowering pass.</li>
530<li>RegionInfo pass: opt -regions analyze" or "opt -view-regions".
531<!-- Tobias Grosser --></li>
532<li>ARMGlobalMerge: <!-- Anton --> </li>
Chris Lattner702f2d42010-09-06 19:14:40 +0000[diff] [blame]533<li>llvm-diff</li>
Chris Lattner8170c102008-02-10 08:18:42 +0000[diff] [blame]534</ul>
Chris Lattnerdc910082010-03-17 06:41:58 +0000[diff] [blame]535
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]536</div>
537
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]538<!--=========================================================================-->
539<div class="doc_subsection">
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]540<a name="coreimprovements">LLVM IR and Core Improvements</a>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]541</div>
542
543<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]544<p>LLVM IR has several new features for better support of new targets and that
545expose new optimization opportunities:</p>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]546
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]547<ul>
Gabor Greif17b59fe2010-07-21 10:20:08 +0000[diff] [blame]548
549<li>LLVM 2.8 changes the internal order of operands in <a
550 href="http://llvm.org/doxygen/classllvm_1_1InvokeInst.html"><tt>InvokeInst</tt></a>
551 and <a href="http://llvm.org/doxygen/classllvm_1_1CallInst.html"><tt>CallInst</tt></a>.
552 To be portable across releases, resort to <tt>CallSite</tt> and the
Gabor Greif50fb3302010-07-21 10:22:41 +0000[diff] [blame]553 high-level accessors, such as <tt>getCalledValue</tt> and <tt>setUnwindDest</tt>.
Gabor Greif17b59fe2010-07-21 10:20:08 +0000[diff] [blame]554</li>
Gabor Greif05006e22010-07-26 18:48:07 +0000[diff] [blame]555<li>
556 You can no longer pass use_iterators directly to cast<> (and similar), because
557 these routines tend to perform costly dereference operations more than once. You
558 have to dereference the iterators yourself and pass them in.
559</li>
Torok Edwin7c46cf02010-08-04 12:43:22 +0000[diff] [blame]560<li>
561 llvm.memcpy.*, llvm.memset.*, llvm.memmove.* (and possibly other?) intrinsics
562 take an extra parameter now (i1 isVolatile), totaling 5 parameters.
563 If you were creating these intrinsic calls and prototypes yourself (as opposed
564 to using Intrinsic::getDeclaration), you can use UpgradeIntrinsicFunction/UpgradeIntrinsicCall
565 to be portable accross releases.
566 Note that you cannot use Intrinsic::getDeclaration() in a backwards compatible
567 way (needs 2/3 types now, in 2.7 it needed just 1).
568</li>
569<li>
570 SetCurrentDebugLocation takes a DebugLoc now instead of a MDNode.
571 Change your code to use
572 SetCurrentDebugLocation(DebugLoc::getFromDILocation(...)).
573</li>
574<li>
575 VISIBILITY_HIDDEN is gone.
576</li>
577<li>
Owen Anderson87ebbc02010-08-04 18:27:08 +0000[diff] [blame]578 The <tt>RegisterPass</tt> and <tt>RegisterAnalysisGroup</tt> templates are
579 considered deprecated, but continue to function in LLVM 2.8. Clients are
580 strongly advised to use the upcoming <tt>INITIALIZE_PASS()</tt> and
581 <tt>INITIALIZE_AG_PASS()</tt> macros instead.
582<li>
Torok Edwin7c46cf02010-08-04 12:43:22 +0000[diff] [blame]583 SMDiagnostic takes different parameters now. //FIXME: how to upgrade?
584</li>
585<li>
Duncan Sands12881e72010-08-30 10:57:54 +0000[diff] [blame]586 The constructor for the Triple class no longer tries to understand odd triple
587 specifications. Frontends should ensure that they only pass valid triples to
588 LLVM. The Triple::normalize utility method has been added to help front-ends
589 deal with funky triples.
590<li>
Torok Edwin7c46cf02010-08-04 12:43:22 +0000[diff] [blame]591 Some APIs got renamed:
592 <ul>
593 <li>llvm_report_error -&gt; report_fatal_error</li>
594 <li>llvm_install_error_handler -&gt; install_fatal_error_handler</li>
595 <li>llvm::DwarfExceptionHandling -&gt; llvm::JITExceptionHandling</li>
596 </ul>
597</li>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]598</ul>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]599
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]600</div>
601
602<!--=========================================================================-->
603<div class="doc_subsection">
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]604<a name="optimizer">Optimizer Improvements</a>
605</div>
606
607<div class="doc_text">
608
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]609<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]610release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]611
612<ul>
613
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]614<li></li>
Chris Lattnera54c1f72010-04-21 06:42:24 +0000[diff] [blame]615
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]616</ul>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]617
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]618</div>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]619
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]620
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]621<!--=========================================================================-->
622<div class="doc_subsection">
623<a name="executionengine">Interpreter and JIT Improvements</a>
624</div>
Chris Lattnerf3013872008-10-13 21:50:36 +0000[diff] [blame]625
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]626<div class="doc_text">
627
628<ul>
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]629<li></li>
Chris Lattnerb7c85b42010-04-21 05:17:40 +0000[diff] [blame]630
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]631</ul>
632
633</div>
634
635<!--=========================================================================-->
636<div class="doc_subsection">
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]637<a name="mc">MC Level Improvements</a>
638</div>
639
640<div class="doc_text">
641<p>
642FIXME: Rewrite.
643
644The LLVM Machine Code (aka MC) sub-project of LLVM was created to solve a number
645of problems in the realm of assembly, disassembly, object file format handling,
646and a number of other related areas that CPU instruction-set level tools work
647in. It is a sub-project of LLVM which provides it with a number of advantages
648over other compilers that do not have tightly integrated assembly-level tools.
649For a gentle introduction, please see the <a
650href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html">Intro to the
651LLVM MC Project Blog Post</a>.
652</p>
653
654<p>2.8 status here. Basic correctness, some obscure missing instructions on
655 mainline, on by default in clang.
656 Entire compiler backend converted to use mcstreamer.
657 </p>
658</div>
659
660
661
662<!--=========================================================================-->
663<div class="doc_subsection">
Chris Lattner511433e2009-03-02 03:24:11 +0000[diff] [blame]664<a name="codegen">Target Independent Code Generator Improvements</a>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]665</div>
666
667<div class="doc_text">
668
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000[diff] [blame]669<p>We have put a significant amount of work into the code generator
670infrastructure, which allows us to implement more aggressive algorithms and make
671it run faster:</p>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]672
673<ul>
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]674<li>MachO writer works.</li>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]675</ul>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]676</div>
677
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]678<!--=========================================================================-->
679<div class="doc_subsection">
680<a name="x86">X86-32 and X86-64 Target Improvements</a>
681</div>
682
683<div class="doc_text">
684<p>New features of the X86 target include:
685</p>
686
687<ul>
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]688<li>The X86 backend now supports holding X87 floating point stack values
689 in registers across basic blocks, dramatically improving performance of code
690 that uses long double, and when targetting CPUs that don't support SSE.</li>
Chris Lattner511433e2009-03-02 03:24:11 +0000[diff] [blame]691
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]692</ul>
693
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]694</div>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]695
696<!--=========================================================================-->
697<div class="doc_subsection">
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]698<a name="ARM">ARM Target Improvements</a>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]699</div>
700
701<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]702<p>New features of the ARM target include:
703</p>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]704
705<ul>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]706
Bob Wilson5b2fb952010-09-13 17:37:55 +0000[diff] [blame]707<li>
708 All of the NEON load and store intrinsics (llvm.arm.neon.vld* and
709 llvm.arm.neon.vst*) take an extra parameter to specify the alignment in bytes
710 of the memory being accessed.
711</li>
712<li>
713 The llvm.arm.neon.vaba intrinsic (vector absolute difference and
714 accumulate) has been removed. This operation is now represented using
715 the llvm.arm.neon.vabd intrinsic (vector absolute difference) followed by a
716 vector add.
Bob Wilsone8472772010-09-13 17:39:35 +0000[diff] [blame]717</li>
Bob Wilson5b2fb952010-09-13 17:37:55 +0000[diff] [blame]718<li>
719 The llvm.arm.neon.vabdl and llvm.arm.neon.vabal intrinsics (lengthening
720 vector absolute difference with and without accumlation) have been removed.
721 They are represented using the llvm.arm.neon.vabd intrinsic (vector absolute
722 difference) followed by a vector zero-extend operation, and for vabal,
723 a vector add.
724</li>
725<li>
726 The llvm.arm.neon.vmovn intrinsic has been removed. Calls of this intrinsic
727 are now replaced by vector truncate operations.
728</li>
729<li>
730 The llvm.arm.neon.vmovls and llvm.arm.neon.vmovlu intrinsics have been
731 removed. They are now represented as vector sign-extend (vmovls) and
732 zero-extend (vmovlu) operations.
733</li>
734<li>
735 The llvm.arm.neon.vaddl*, llvm.arm.neon.vaddw*, llvm.arm.neon.vsubl*, and
736 llvm.arm.neon.vsubw* intrinsics (lengthening vector add and subtract) have
737 been removed. They are replaced by vector add and vector subtract operations
738 where one (vaddw, vsubw) or both (vaddl, vsubl) of the operands are either
739 sign-extended or zero-extended.
740</li>
741<li>
742 The llvm.arm.neon.vmulls, llvm.arm.neon.vmullu, llvm.arm.neon.vmlal*, and
743 llvm.arm.neon.vmlsl* intrinsics (lengthening vector multiply with and without
744 accumulation and subtraction) have been removed. These operations are now
745 represented as vector multiplications where the operands are either
746 sign-extended or zero-extended, followed by a vector add for vmlal or a
747 vector subtract for vmlsl. Note that the polynomial vector multiply
748 intrinsic, llvm.arm.neon.vmullp, remains unchanged.
749</li>
Bob Wilsone8472772010-09-13 17:39:35 +0000[diff] [blame]750
751</ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]752</div>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]753
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]754<!--=========================================================================-->
755<div class="doc_subsection">
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]756<a name="newapis">New Useful APIs</a>
757</div>
758
759<div class="doc_text">
760
761<p>This release includes a number of new APIs that are used internally, which
762 may also be useful for external clients.
763</p>
764
765<ul>
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]766<li></li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]767</ul>
768
769
770</div>
771
772<!--=========================================================================-->
773<div class="doc_subsection">
774<a name="otherimprovements">Other Improvements and New Features</a>
775</div>
776
777<div class="doc_text">
778<p>Other miscellaneous features include:</p>
779
780<ul>
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]781<li></li>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]782</ul>
783
784</div>
785
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]786
787<!--=========================================================================-->
788<div class="doc_subsection">
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]789<a name="changes">Major Changes and Removed Features</a>
790</div>
791
792<div class="doc_text">
793
Chris Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]794<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]795on LLVM 2.7, this section lists some "gotchas" that you may run into upgrading
Chris Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]796from the previous release.</p>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]797
798<ul>
Chris Lattner2295b5a2010-09-02 23:22:50 +0000[diff] [blame]799<li>.ll file doesn't produce #uses comments anymore, to get them, run a .bc file
800 through "llvm-dis --show-annotations".</li>
Chris Lattner885b6612010-08-28 16:33:36 +0000[diff] [blame]801<li>MSIL Backend removed.</li>
802<li>ABCD and SSI passes removed.</li>
803<li>'Union' LLVM IR feature removed.</li>
Chris Lattnerb7c85b42010-04-21 05:17:40 +0000[diff] [blame]804</ul>
Chris Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]805
806<p>In addition, many APIs have changed in this release. Some of the major LLVM
807API changes are:</p>
808
809<ul>
Devang Patelb34dd132008-10-14 20:03:43 +0000[diff] [blame]810</ul>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]811
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]812</div>
813
814
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]815<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]816<div class="doc_section">
817 <a name="knownproblems">Known Problems</a>
818</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]819<!-- *********************************************************************** -->
820
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]821<div class="doc_text">
822
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000[diff] [blame]823<p>This section contains significant known problems with the LLVM system,
Chris Lattnere18b32e2008-11-10 05:40:34 +0000[diff] [blame]824listed by component. If you run into a problem, please check the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]825href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]826there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]827
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]828</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]829
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]830<!-- ======================================================================= -->
831<div class="doc_subsection">
832 <a name="experimental">Experimental features included with this release</a>
833</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]834
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]835<div class="doc_text">
836
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]837<p>The following components of this LLVM release are either untested, known to
838be broken or unreliable, or are in early development. These components should
839not be relied on, and bugs should not be filed against them, but they may be
840useful 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]841components, please contact us on the <a
842href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]843
844<ul>
Chris Lattner885b6612010-08-28 16:33:36 +0000[diff] [blame]845<li>The Alpha, SPU, MIPS, PIC16, Blackfin, MSP430, SystemZ and MicroBlaze
Wesley Peck7c4a1212010-03-18 14:31:30 +0000[diff] [blame]846 backends are experimental.</li>
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]847<li><tt>llc</tt> "<tt>-filetype=asm</tt>" (the default) is the only
Chris Lattner922d00f2010-07-21 15:57:40 +0000[diff] [blame]848 supported value for this option. XXX Update me</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]849</ul>
850
851</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]852
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]853<!-- ======================================================================= -->
854<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]855 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]856</div>
857
858<div class="doc_text">
859
860<ul>
Anton Korobeynikova6094be2008-06-08 10:24:13 +0000[diff] [blame]861 <li>The X86 backend does not yet support
862 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
863 floating point stack</a>. It supports the 'f' and 't' constraints, but not
864 'u'.</li>
Duncan Sands47eff2b2008-06-08 19:38:43 +0000[diff] [blame]865 <li>Win64 code generation wasn't widely tested. Everything should work, but we
John Criswell524a5dd2009-03-02 15:28:15 +0000[diff] [blame]866 expect small issues to happen. Also, llvm-gcc cannot build the mingw64
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]867 runtime currently due to lack of support for the 'u' inline assembly
868 constraint and for X87 floating point inline assembly.</li>
Dan Gohman8207ba92008-06-08 23:05:11 +0000[diff] [blame]869 <li>The X86-64 backend does not yet support the LLVM IR instruction
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]870 <tt>va_arg</tt>. Currently, front-ends support variadic
Dan Gohman8207ba92008-06-08 23:05:11 +0000[diff] [blame]871 argument constructs on X86-64 by lowering them manually.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]872</ul>
873
874</div>
875
876<!-- ======================================================================= -->
877<div class="doc_subsection">
878 <a name="ppc-be">Known problems with the PowerPC back-end</a>
879</div>
880
881<div class="doc_text">
882
883<ul>
Nicolas Geoffraye4285dc2007-05-15 09:21:28 +0000[diff] [blame]884<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]885compilation, and lacks support for debug information.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]886</ul>
887
888</div>
889
890<!-- ======================================================================= -->
891<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]892 <a name="arm-be">Known problems with the ARM back-end</a>
893</div>
894
895<div class="doc_text">
896
897<ul>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]898<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000[diff] [blame]899processors, thumb programs can crash or produce wrong
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]900results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
John Criswell524a5dd2009-03-02 15:28:15 +0000[diff] [blame]901<li>Compilation for ARM Linux OABI (old ABI) is supported but not fully tested.
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]902</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]903</ul>
904
905</div>
906
907<!-- ======================================================================= -->
908<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]909 <a name="sparc-be">Known problems with the SPARC back-end</a>
910</div>
911
912<div class="doc_text">
913
914<ul>
John Criswell524a5dd2009-03-02 15:28:15 +0000[diff] [blame]915<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]916 support the 64-bit SPARC ABI (-m64).</li>
917</ul>
918
919</div>
920
921<!-- ======================================================================= -->
922<div class="doc_subsection">
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000[diff] [blame]923 <a name="mips-be">Known problems with the MIPS back-end</a>
924</div>
925
926<div class="doc_text">
927
928<ul>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000[diff] [blame]929<li>64-bit MIPS targets are not supported yet.</li>
930</ul>
931
932</div>
933
934<!-- ======================================================================= -->
935<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]936 <a name="alpha-be">Known problems with the Alpha back-end</a>
937</div>
938
939<div class="doc_text">
940
941<ul>
942
943<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
944appropriate nops inserted to ensure restartability.</li>
945
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]946</ul>
947</div>
948
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]949<!-- ======================================================================= -->
950<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]951 <a name="c-be">Known problems with the C back-end</a>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]952</div>
953
954<div class="doc_text">
955
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]956<p>The C backend has numerous problems and is not being actively maintained.
957Depending on it for anything serious is not advised.</p>
958
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]959<ul>
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]960<li><a href="http://llvm.org/PR802">The C backend has only basic support for
961 inline assembly code</a>.</li>
Chris Lattner725a0d82007-09-26 06:01:35 +0000[diff] [blame]962<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
963 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Gabor Greif4906abe2009-03-02 12:02:51 +0000[diff] [blame]964 C++ code compiled with <tt>llc</tt> or native compilers.</li>
Duncan Sandsf74c0cc2008-02-10 13:40:55 +0000[diff] [blame]965<li>The C backend does not support all exception handling constructs.</li>
Duncan Sands50723a92009-02-25 11:51:54 +0000[diff] [blame]966<li>The C backend does not support arbitrary precision integers.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]967</ul>
968
969</div>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]970
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]971
972<!-- ======================================================================= -->
973<div class="doc_subsection">
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]974 <a name="llvm-gcc">Known problems with the llvm-gcc front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]975</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]976
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]977<div class="doc_text">
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]978
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]979<p>llvm-gcc is generally very stable for the C family of languages. The only
980 major language feature of GCC not supported by llvm-gcc is the
981 <tt>__builtin_apply</tt> family of builtins. However, some extensions
982 are only supported on some targets. For example, trampolines are only
983 supported on some targets (these are used when you take the address of a
984 nested function).</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]985
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]986<p>Fortran support generally works, but there are still several unresolved bugs
987 in <a href="http://llvm.org/bugs/">Bugzilla</a>. Please see the
988 tools/gfortran component for details. Note that llvm-gcc is missing major
989 Fortran performance work in the frontend and library that went into GCC after
990 4.2. If you are interested in Fortran, we recommend that you consider using
991 <a href="#dragonegg">dragonegg</a> instead.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]992
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]993<p>The llvm-gcc 4.2 Ada compiler has basic functionality. However, this is not a
994mature technology, and problems should be expected. For example:</p>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]995<ul>
Duncan Sands27aff872008-06-08 20:18:35 +0000[diff] [blame]996<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]997to lack of trampoline support (pointers to nested functions) on other platforms.
998However, 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]999which does support trampolines.</li>
1000<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]1001This is due to lack of LLVM support for <tt>setjmp</tt>/<tt>longjmp</tt> style
1002exception handling, which is used internally by the compiler.
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]1003Workaround: configure with <tt>--disable-bootstrap</tt>.</li>
Duncan Sands978bcee2008-10-13 17:27:23 +0000[diff] [blame]1004<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
1005and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
Duncan Sands326a4982009-02-25 11:59:06 +0000[diff] [blame]1006(c380004 also fails with gcc-4.2 mainline).
1007If the compiler is built with checks disabled then <a href="http://llvm.org/PR2010">c393010</a>
1008causes the compiler to go into an infinite loop, using up all system memory.</li>
Duncan Sandsdd3e6722009-03-02 16:35:57 +0000[diff] [blame]1009<li>Some GCC specific Ada tests continue to crash the compiler.</li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]1010<li>The <tt>-E</tt> binder option (exception backtraces)
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]1011<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]1012crashing if an exception is raised. Workaround: do not use <tt>-E</tt>.</li>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]1013<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
1014or finish at a non-byte offset</a> in a record. Workaround: do not pack records
1015or use representation clauses that result in a field of a non-discrete type
1016starting or finishing in the middle of a byte.</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000[diff] [blame]1017<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
1018'main' as generated by the Ada binder to be invalid</a>.
1019Workaround: hand edit the file to use pointers for <tt>argv</tt> and
1020<tt>envp</tt> rather than integers.</li>
1021<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
1022ignored</a>.</li>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]1023</ul>
1024</div>
1025
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1026<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1027<div class="doc_section">
1028 <a name="additionalinfo">Additional Information</a>
1029</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1030<!-- *********************************************************************** -->
1031
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1032<div class="doc_text">
1033
Chris Lattner416db102005-05-16 17:13:10 +0000[diff] [blame]1034<p>A wide variety of additional information is available on the <a
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]1035href="http://llvm.org">LLVM web page</a>, in particular in the <a
1036href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencer669ed452007-07-09 08:04:31 +0000[diff] [blame]1037contains versions of the API documentation which is up-to-date with the
1038Subversion version of the source code.
Misha Brukman109d9e82005-03-30 19:14:24 +0000[diff] [blame]1039You can access versions of these documents specific to this release by going
1040into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1041
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1042<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]1043us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]1044lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1045
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1046</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1047
1048<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1049
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1050<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]1051<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]1052 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]1053 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]1054 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]1055 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]1056
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]1057 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1058 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]1059</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1060
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1061</body>
1062</html>