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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 275d1e036edb828acdbc5b818c7dddaa7003713d / . / docs / ReleaseNotes.html
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Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]7 <title>LLVM 2.4 Release Notes</title>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]8</head>
9<body>
10
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]11<div class="doc_title">LLVM 2.4 Release Notes</div>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]12
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]13<ol>
14 <li><a href="#intro">Introduction</a></li>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]15 <li><a href="#subproj">Sub-project Status Update</a></li>
16 <li><a href="#whatsnew">What's New in LLVM?</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]17 <li><a href="GettingStarted.html">Installation Instructions</a></li>
18 <li><a href="#portability">Portability and Supported Platforms</a></li>
19 <li><a href="#knownproblems">Known Problems</a>
20 <li><a href="#additionalinfo">Additional Information</a></li>
21</ol>
22
23<div class="doc_author">
24 <p>Written by the <a href="http://llvm.org">LLVM Team</a><p>
25</div>
26
27<!-- *********************************************************************** -->
28<div class="doc_section">
29 <a name="intro">Introduction</a>
30</div>
31<!-- *********************************************************************** -->
32
33<div class="doc_text">
34
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]35<p>This document contains the release notes for the LLVM Compiler
36Infrastructure, release 2.4. Here we describe the status of LLVM, including
37major improvements from the previous release and significant known problems.
38All LLVM releases may be downloaded from the <a
39href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]40
41<p>For more information about LLVM, including information about the latest
42release, please check out the <a href="http://llvm.org/">main LLVM
43web site</a>. If you have questions or comments, the <a
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]44href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM Developer's Mailing
45List</a> is a good place to send them.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]46
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]47<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]48main LLVM web page, this document applies to the <i>next</i> release, not the
49current one. To see the release notes for a specific releases, please see the
50<a href="http://llvm.org/releases/">releases page</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]51
52</div>
53
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]54<!-- Unfinished features in 2.4:
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]55 Machine LICM
56 Machine Sinking
57 LegalizeDAGTypes
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]58 llc -enable-value-prop, propagation of value info (sign/zero ext info) from
59 one MBB to another
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]60 -->
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]61
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]62 <!-- for announcement email:
63 mention dev mtg
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]64 Xcode 3.1 and 3.1.1.
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]65 -->
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]66
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]67<!-- *********************************************************************** -->
68<div class="doc_section">
69 <a name="subproj">Sub-project Status Update</a>
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]70</div>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]71<!-- *********************************************************************** -->
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]72
73<div class="doc_text">
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]74<p>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]75The LLVM 2.4 distribution currently consists of code from the core LLVM
Chris Lattnera3c683b2008-10-13 18:11:54 +0000[diff] [blame]76repository (which roughly includes the LLVM optimizers, code generators and
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]77supporting tools) and the llvm-gcc repository. In addition to this code, the
78LLVM Project includes other sub-projects that are in development. The two which
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]79are the most actively developed are the <a href="#clang">Clang Project</a> and
Duncan Sands275d1e02008-10-13 18:33:28 +0000[diff] [blame^]80the <a href="#vmkit">vmkit Project</a>.
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]81</p>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]82
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]83</div>
84
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]85
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]86<!--=========================================================================-->
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]87<div class="doc_subsection">
Chris Lattnera3c683b2008-10-13 18:11:54 +0000[diff] [blame]88<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]89</div>
90
91<div class="doc_text">
92
93<p>The <a href="http://clang.llvm.org/">Clang project</a> is an effort to build
94a set of new 'LLVM native' front-end technologies for the LLVM optimizer
95and code generator. Clang is continuing to make major strides forward in all
96areas. Its C and Objective-C parsing support is very solid, and the code
97generation support is far enough along to build many C applications. While not
98yet production quality, it is progressing very nicely. In addition, C++
99front-end work has started to make significant progress.</p>
100
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]101<p>Codegen progress/state
102</p>
103
Chris Lattnera3c683b2008-10-13 18:11:54 +0000[diff] [blame]104</div>
105
106<!--=========================================================================-->
107<div class="doc_subsection">
108<a name="clangsa">Clang Static Analyzer</a>
109</div>
110
111<div class="doc_text">
112
113<p>The
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]114<a href="http://clang.llvm.org/StaticAnalysis.html">static analysis tool</a>
Chris Lattnera3c683b2008-10-13 18:11:54 +0000[diff] [blame]115.</p>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]116
117</div>
118
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]119<!--=========================================================================-->
120<div class="doc_subsection">
Chris Lattnera3c683b2008-10-13 18:11:54 +0000[diff] [blame]121<a name="vmkit">vmkit: JVM/CLI Virtual Machine Implementation</a>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]122</div>
123
124<div class="doc_text">
125<p>
Chris Lattnera3c683b2008-10-13 18:11:54 +0000[diff] [blame]126The <a href="http://vmkit.llvm.org/">vmkit project</a> is an implementation of
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]127a JVM and a CLI Virtual Machines (Microsoft .NET is an
128implementation of the CLI) using the Just-In-Time compiler of LLVM.</p>
129
130<p>...</p>
131
132</div>
133
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]134
135<!-- *********************************************************************** -->
136<div class="doc_section">
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]137 <a name="whatsnew">What's New in LLVM?</a>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]138</div>
139<!-- *********************************************************************** -->
140
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]141<div class="doc_text">
142
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]143<p>This release includes a huge number of bug fixes, performance tweaks and
144minor improvements. Some of the major improvements and new features are listed
145in this section.
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]146</p>
147</div>
148
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]149<!--=========================================================================-->
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]150<div class="doc_subsection">
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]151<a name="majorfeatures">Major New Features</a>
152</div>
153
154<div class="doc_text">
155
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]156<p>LLVM 2.4 includes several major new capabilities:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]157
158<ul>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]159<li>
Chris Lattnera5a49382008-10-12 18:30:33 +0000[diff] [blame]160 <p>MRVs got generalized to FCAs. getresult is gone, ret with multiple values
161 is gone.</p>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]162 </li>
163
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]164<li><p>-O0 compile times overall much faster</p></li>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]165
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]166<li><p>Attrs changes?</p></li>
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]167
Chris Lattnera5a49382008-10-12 18:30:33 +0000[diff] [blame]168
169<li><p>Initial PIC16 port</p></li>
170
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]171<li><p> Support the rest of the atomic __sync builtins</p></li>
Chris Lattnera5a49382008-10-12 18:30:33 +0000[diff] [blame]172
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]173<li><p>...</p></li>
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]174
Chris Lattner5ba16862008-02-10 08:18:42 +0000[diff] [blame]175</ul>
176
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]177</div>
178
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]179
180<!--=========================================================================-->
181<div class="doc_subsection">
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]182<a name="llvm-gcc">llvm-gcc 4.2 Improvements</a>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]183</div>
184
185<div class="doc_text">
186
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]187<p>LLVM 2.4 fully supports the llvm-gcc 4.2 front-end, and includes support
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]188for the C, C++, Objective-C, Ada, and Fortran front-ends.</p>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]189
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]190<p>
191<ul>
Duncan Sands275d1e02008-10-13 18:33:28 +0000[diff] [blame^]192<li>block-pointers<li>
193<li>alpha?<li>
194<li>-flimited-precision</li>
195<li>-flto</li>
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]196
Gabor Greif0e49cc82008-06-09 06:06:18 +0000[diff] [blame]197</ul>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]198
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]199</div>
200
201
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]202<!--=========================================================================-->
203<div class="doc_subsection">
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]204<a name="coreimprovements">LLVM Core Improvements</a>
205</div>
206
207<div class="doc_text">
208<p>New features include:
209</p>
210
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]211<ul>
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]212<li>vector shifts in the IR: no codegen support yet</li>
Chris Lattnera5a49382008-10-12 18:30:33 +0000[diff] [blame]213<li>use diet patch landed: saved 15% IR memory footprint</li>
214<li>LLVM IR now directly represents "common" linkage, instead of
215 representing it as a form of weak linkage.</li>
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]216<li>DebugInfoBuilder</li>
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]217<li>.ll printing format change: %3 = add i32 4, 2</li>
Duncan Sands275d1e02008-10-13 18:33:28 +0000[diff] [blame^]218<li>opt-size, noinline, alwaysinline function attributes</li>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]219<li>...</li>
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]220</ul>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]221
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]222</div>
223
224<!--=========================================================================-->
225<div class="doc_subsection">
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]226<a name="optimizer">Optimizer Improvements</a>
227</div>
228
229<div class="doc_text">
230
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]231<p>In addition to a huge array of bug fixes and minor performance tweaks, the
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]232LLVM 2.4 optimizers support a few major enhancements:</p>
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]233
234<ul>
235
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]236<li>GVN now does local PRE?</li>
237
238<li>Matthijs' Dead argument elimination rewrite</li>
239
Chris Lattnera5a49382008-10-12 18:30:33 +0000[diff] [blame]240<li>Old-ADCE used control dependence and deleted output-free infinite loops.
241Added a new Loop deletion pass (for deleting output free provably-finite loops)
242and rewrote ADCE to be simpler faster, and not need control dependence.</li>
243
244<li>SparsePropagation framework for lattice-based dataflow solvers.</li>
245
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]246<li>Tail duplication was removed from the standard optimizer sequence.</li>
Chris Lattnera5a49382008-10-12 18:30:33 +0000[diff] [blame]247
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]248<li>Various helper functions (ComputeMaskedBits, ComputeNumSignBits, etc) were
249pulled out of instcombine and put into a new ValueTracking.h file, where they
250can be reused by other passes.</li>
251
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]252<li>MarkModRef etc</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]253</ul>
254
255</div>
256
257<!--=========================================================================-->
258<div class="doc_subsection">
259<a name="codegen">Code Generator Improvements</a>
260</div>
261
262<div class="doc_text">
263
264<p>We put a significant amount of work into the code generator infrastructure,
265which allows us to implement more aggressive algorithms and make it run
266faster:</p>
267
268<ul>
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]269<li>asm writers split out to their own library to avoid JITs having to link
270 them in.</li>
271<li>Big asm writer refactoring + TargetAsmInfo</li>
272<li>2-addr pass and coalescer can now remat trivial insts to avoid a copy.</li>
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]273<li>spiller to commute instructions in order to fold a reload</li>
274<li>Stack slot coloring?</li>
275<li>Live intervals renumbering? Is this useful to external people?</li>
276<li>'is as cheap as a move' instruction flag</li>
277<li>Improvements to selection dag viewing</li>
278<li>fast isel</li>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]279<li>Selection dag speedups</li>
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]280<li>asmwriter + raw_ostream -> fastah</li>
Chris Lattner72c8a252008-10-13 17:12:51 +0000[diff] [blame]281<li>Partitioned Boolean Quadratic Programming (PBQP) based register
282allocator.</li>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]283<li>...</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]284
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]285</ul>
286
287</div>
288
289
290<!--=========================================================================-->
291<div class="doc_subsection">
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]292<a name="x86specific">X86/X86-64 Specific Improvements</a>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]293</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]294
295<div class="doc_text">
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]296<p>New target-specific features include:
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]297</p>
298
299<ul>
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]300<li>Exception handling is supported by default on Linux/x86-64.</li>
Duncan Sandsd8745a92008-10-13 17:32:15 +0000[diff] [blame]301<li>Position Independent Code (PIC) is now supported on Linux/x86-64.</li>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]302<li>...</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]303
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]304</ul>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]305
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]306</div>
307
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]308<!--=========================================================================-->
309<div class="doc_subsection">
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]310<a name="targetspecific">Other Target Specific Improvements</a>
311</div>
312
313<div class="doc_text">
314<p>New target-specific features include:
315</p>
316
317<ul>
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]318<li>MIPS floating point support?</li>
Duncan Sandsd8745a92008-10-13 17:32:15 +0000[diff] [blame]319<li>PowerPC now supports trampolines.</li>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]320<li>....</li>
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]321</ul>
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]322
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]323</div>
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]324
325
326<!--=========================================================================-->
327<div class="doc_subsection">
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]328<a name="otherimprovements">Other Improvements</a>
329</div>
330
331<div class="doc_text">
332<p>New features include:
333</p>
334
335<ul>
Mikhail Glushenkovcc2d3012008-10-13 02:46:01 +0000[diff] [blame]336<li><tt>llvmc2</tt> (the generic compiler driver) gained plugin
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]337 support. It is now easier to experiment with <tt>llvmc2</tt> and
338 build your own tools based on it. </li>
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]339<li>raw_ostream + formatting</li>
Chris Lattner548493b2008-10-12 22:57:58 +0000[diff] [blame]340<li>Recycler + pool allocation stuff?</li>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]341<li>...</li>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]342</ul>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]343
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]344</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]345
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]346<!--=========================================================================-->
347<div class="doc_subsection">
348<a name="changes">Major Changes and Removed Features</a>
349</div>
350
351<div class="doc_text">
352
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]353<p>If you're already an LLVM user, this section lists some "gotchas" that you
354may run into upgrading from the previous release.</p>
355
Duncan Sands275d1e02008-10-13 18:33:28 +0000[diff] [blame^]356<p>The LLVM IR generated by llvm-gcc no longer names all instructions.
357 Use the instnamer pass if you want everything named.</p>
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]358
Duncan Sands275d1e02008-10-13 18:33:28 +0000[diff] [blame^]359<li>The LoadVN and GCSE passes have been removed.</li>
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]360
361
362<p>LLVM API Changes:</p>
363
364<ul>
365
366<li>... Attributes changes ... </li>
367
368<li>The <tt>DbgStopPointInst</tt> methods <tt>getDirectory</tt> and
369<tt>getFileName</tt> now return <tt>Value*</tt> instead of strings. These can be
370converted to strings using <tt>llvm::GetConstantStringInfo</tt> defined via
371"llvm/Analysis/ValueTracking.h".</li>
372
373<li>API change: BinaryOperator::create -> Create (CmpInst, CastInst too)</li>
374<li>Various header files like "llvm/ADT/iterator" were given a .h suffix.
375 Change your code to #include "llvm/ADT/iterator.h" instead.</li>
376
377</ul>
378
379</div>
380
381
382
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]383<!-- *********************************************************************** -->
384<div class="doc_section">
385 <a name="portability">Portability and Supported Platforms</a>
386</div>
387<!-- *********************************************************************** -->
388
389<div class="doc_text">
390
391<p>LLVM is known to work on the following platforms:</p>
392
393<ul>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]394<li>Intel and AMD machines (IA32) running Red Hat Linux, Fedora Core and FreeBSD
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]395 (and probably other unix-like systems).</li>
Chris Lattnerbd633de92008-02-06 06:30:34 +0000[diff] [blame]396<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit and
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]397 64-bit modes.</li>
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]398<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]399<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
400 support is available for native builds with Visual C++).</li>
Gabor Greif5e75e652008-06-05 18:39:01 +0000[diff] [blame]401<li>Sun UltraSPARC workstations running Solaris 10.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]402<li>Alpha-based machines running Debian GNU/Linux.</li>
Gabor Greif5e75e652008-06-05 18:39:01 +0000[diff] [blame]403<li>Itanium-based (IA64) machines running Linux and HP-UX.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]404</ul>
405
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]406<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]407to the machine and operating system on which it is built. However, minor
408porting may be required to get LLVM to work on new platforms. We welcome your
409portability patches and reports of successful builds or error messages.</p>
410
411</div>
412
413<!-- *********************************************************************** -->
414<div class="doc_section">
415 <a name="knownproblems">Known Problems</a>
416</div>
417<!-- *********************************************************************** -->
418
419<div class="doc_text">
420
421<p>This section contains all known problems with the LLVM system, listed by
422component. As new problems are discovered, they will be added to these
423sections. If you run into a problem, please check the <a
424href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
425there isn't already one.</p>
426
427</div>
428
429<!-- ======================================================================= -->
430<div class="doc_subsection">
431 <a name="experimental">Experimental features included with this release</a>
432</div>
433
434<div class="doc_text">
435
436<p>The following components of this LLVM release are either untested, known to
437be broken or unreliable, or are in early development. These components should
438not be relied on, and bugs should not be filed against them, but they may be
439useful to some people. In particular, if you would like to work on one of these
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]440components, please contact us on the <a
441href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]442
443<ul>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]444<li>The MSIL, IA64, Alpha, SPU, and MIPS backends are experimental.</li>
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]445<li>The llc "<tt>-filetype=asm</tt>" (the default) is the only supported
Chris Lattnerbd633de92008-02-06 06:30:34 +0000[diff] [blame]446 value for this option.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]447</ul>
448
449</div>
450
451<!-- ======================================================================= -->
452<div class="doc_subsection">
453 <a name="x86-be">Known problems with the X86 back-end</a>
454</div>
455
456<div class="doc_text">
457
458<ul>
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]459 <li>The X86 backend does not yet support
460 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
461 floating point stack</a>. It supports the 'f' and 't' constraints, but not
462 'u'.</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]463 <li>The X86 backend generates inefficient floating point code when configured
464 to generate code for systems that don't have SSE2.</li>
Duncan Sands8b4f3772008-06-08 19:38:43 +0000[diff] [blame]465 <li>Win64 code generation wasn't widely tested. Everything should work, but we
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]466 expect small issues to happen. Also, llvm-gcc cannot build mingw64 runtime
467 currently due
468 to <a href="http://llvm.org/PR2255">several</a>
Chris Lattnerf06141a2008-06-08 23:12:47 +0000[diff] [blame]469 <a href="http://llvm.org/PR2257">bugs</a> due to lack of support for the
470 'u' inline assembly constraint and X87 floating point inline assembly.</li>
Dan Gohman3882ecb2008-06-08 23:05:11 +0000[diff] [blame]471 <li>The X86-64 backend does not yet support the LLVM IR instruction
472 <tt>va_arg</tt>. Currently, the llvm-gcc front-end supports variadic
473 argument constructs on X86-64 by lowering them manually.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]474</ul>
475
476</div>
477
478<!-- ======================================================================= -->
479<div class="doc_subsection">
480 <a name="ppc-be">Known problems with the PowerPC back-end</a>
481</div>
482
483<div class="doc_text">
484
485<ul>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]486<li>The Linux PPC32/ABI support needs testing for the interpreter and static
487compilation, and lacks support for debug information.</li>
488</ul>
489
490</div>
491
492<!-- ======================================================================= -->
493<div class="doc_subsection">
494 <a name="arm-be">Known problems with the ARM back-end</a>
495</div>
496
497<div class="doc_text">
498
499<ul>
500<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sands1827fa62007-09-26 15:59:54 +0000[diff] [blame]501processors, thumb programs can crash or produce wrong
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]502results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
503<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
504</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]505<li>There is a bug in QEMU-ARM (&lt;= 0.9.0) which causes it to incorrectly
506 execute
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]507programs compiled with LLVM. Please use more recent versions of QEMU.</li>
508</ul>
509
510</div>
511
512<!-- ======================================================================= -->
513<div class="doc_subsection">
514 <a name="sparc-be">Known problems with the SPARC back-end</a>
515</div>
516
517<div class="doc_text">
518
519<ul>
520<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
521 support the 64-bit SPARC ABI (-m64).</li>
522</ul>
523
524</div>
525
526<!-- ======================================================================= -->
527<div class="doc_subsection">
528 <a name="alpha-be">Known problems with the Alpha back-end</a>
529</div>
530
531<div class="doc_text">
532
533<ul>
534
535<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
536appropriate nops inserted to ensure restartability.</li>
537
538</ul>
539</div>
540
541<!-- ======================================================================= -->
542<div class="doc_subsection">
543 <a name="ia64-be">Known problems with the IA64 back-end</a>
544</div>
545
546<div class="doc_text">
547
548<ul>
Chris Lattnerf06141a2008-06-08 23:12:47 +0000[diff] [blame]549<li>The Itanium backend is highly experimental, and has a number of known
550 issues. We are looking for a maintainer for the Itanium backend. If you
551 are interested, please contact the llvmdev mailing list.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]552</ul>
553
554</div>
555
556<!-- ======================================================================= -->
557<div class="doc_subsection">
558 <a name="c-be">Known problems with the C back-end</a>
559</div>
560
561<div class="doc_text">
562
563<ul>
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]564<li><a href="http://llvm.org/PR802">The C backend has only basic support for
565 inline assembly code</a>.</li>
Chris Lattnere0194462007-09-26 06:01:35 +0000[diff] [blame]566<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
567 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]568 C++ code compiled with llc or native compilers.</li>
Duncan Sandsbd0ad6e2008-02-10 13:40:55 +0000[diff] [blame]569<li>The C backend does not support all exception handling constructs.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]570</ul>
571
572</div>
573
574
575<!-- ======================================================================= -->
576<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]577 <a name="c-fe">Known problems with the llvm-gcc C front-end</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]578</div>
579
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]580<div class="doc_text">
581
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]582<p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time
583Optimization</a> on most platforms "out-of-the-box". Please inquire on the
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]584llvmdev mailing list if you are interested.</p>
585
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]586<p>The only major language feature of GCC not supported by llvm-gcc is
587 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
588 are only supported on some targets. For example, trampolines are only
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]589 supported on some targets (these are used when you take the address of a
590 nested function).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]591
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]592<p>If you run into GCC extensions which are not supported, please let us know.
593</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]594
595</div>
596
597<!-- ======================================================================= -->
598<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]599 <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]600</div>
601
602<div class="doc_text">
603
604<p>The C++ front-end is considered to be fully
605tested and works for a number of non-trivial programs, including LLVM
606itself, Qt, Mozilla, etc.</p>
607
608<ul>
Anton Korobeynikovd9a17932008-10-11 18:27:16 +0000[diff] [blame]609<li>Exception handling works well on the X86 and PowerPC targets. Currently
610 only linux and darwin targets are supported (both 32 and 64 bit).</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]611</ul>
612
613</div>
614
615
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]616<!-- ======================================================================= -->
617<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]618 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]619</div>
620
621<div class="doc_text">
622The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature
623technology and problems should be expected.
624<ul>
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]625<li>The Ada front-end currently only builds on X86-32. This is mainly due
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]626to lack of trampoline support (pointers to nested functions) on other platforms,
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]627however it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]628which does support trampolines.</li>
629<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
630Workaround: configure with --disable-bootstrap.</li>
Duncan Sands2dbc2e82008-10-13 17:27:23 +0000[diff] [blame]631<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
632and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
633(c380004 also fails with gcc-4.2 mainline).</li>
634<li>Some gcc specific Ada tests continue to crash the compiler.</li>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]635<li>The -E binder option (exception backtraces)
636<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
637crashing if an exception is raised. Workaround: do not use -E.</li>
638<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
639or finish at a non-byte offset</a> in a record. Workaround: do not pack records
640or use representation clauses that result in a field of a non-discrete type
641starting or finishing in the middle of a byte.</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]642<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
643'main' as generated by the Ada binder to be invalid</a>.
644Workaround: hand edit the file to use pointers for <tt>argv</tt> and
645<tt>envp</tt> rather than integers.</li>
646<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
647ignored</a>.</li>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]648</ul>
649</div>
650
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]651<!-- *********************************************************************** -->
652<div class="doc_section">
653 <a name="additionalinfo">Additional Information</a>
654</div>
655<!-- *********************************************************************** -->
656
657<div class="doc_text">
658
659<p>A wide variety of additional information is available on the <a
660href="http://llvm.org">LLVM web page</a>, in particular in the <a
661href="http://llvm.org/docs/">documentation</a> section. The web page also
662contains versions of the API documentation which is up-to-date with the
663Subversion version of the source code.
664You can access versions of these documents specific to this release by going
665into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
666
667<p>If you have any questions or comments about LLVM, please feel free to contact
668us via the <a href="http://llvm.org/docs/#maillist"> mailing
669lists</a>.</p>
670
671</div>
672
673<!-- *********************************************************************** -->
674
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