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4<head>
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Chris Lattnerd8b33e02008-10-11 18:18:28 +0000[diff] [blame]7 <title>LLVM 2.4 Release Notes</title>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]8</head>
9<body>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]10
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000[diff] [blame]11<div class="doc_title">LLVM 2.4 Release Notes</div>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]12
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]13<ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]14 <li><a href="#intro">Introduction</a></li>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]15 <li><a href="#subproj">Sub-project Status Update</a></li>
16 <li><a href="#whatsnew">What's New in LLVM?</a></li>
Chris Lattner77a51732004-04-30 22:17:12 +0000[diff] [blame]17 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]18 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]19 <li><a href="#knownproblems">Known Problems</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]20 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]21</ol>
22
Chris Lattner020e1fc2004-05-23 21:07:27 +0000[diff] [blame]23<div class="doc_author">
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]24 <p>Written by the <a href="http://llvm.org">LLVM Team</a><p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]25</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]26
27<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]28<div class="doc_section">
29 <a name="intro">Introduction</a>
30</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]31<!-- *********************************************************************** -->
32
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]33<div class="doc_text">
34
Chris Lattner1e4d5bc2008-10-13 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>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]40
Chris Lattnerb5bb5972004-12-07 08:04:13 +0000[diff] [blame]41<p>For more information about LLVM, including information about the latest
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]42release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]43web site</a>. If you have questions or comments, the <a
Chris Lattner1e4d5bc2008-10-13 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>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]46
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]47<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattner0a1fd102007-09-21 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>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]51
52</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]53
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000[diff] [blame]54<!-- Unfinished features in 2.4:
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]55 Machine LICM
56 Machine Sinking
57 LegalizeDAGTypes
Chris Lattnerc4d68542008-10-12 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 Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]60 -->
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]61
Chris Lattnerc4d68542008-10-12 19:47:48 +0000[diff] [blame]62 <!-- for announcement email:
63 mention dev mtg
Chris Lattnere3df07e2008-10-12 22:57:58 +0000[diff] [blame]64 Xcode 3.1 and 3.1.1.
Chris Lattnerc4d68542008-10-12 19:47:48 +0000[diff] [blame]65 -->
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]66
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]67<!-- *********************************************************************** -->
68<div class="doc_section">
69 <a name="subproj">Sub-project Status Update</a>
Chris Lattner625a3d82008-06-08 21:34:41 +0000[diff] [blame]70</div>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]71<!-- *********************************************************************** -->
Chris Lattner625a3d82008-06-08 21:34:41 +0000[diff] [blame]72
73<div class="doc_text">
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]74<p>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]75The LLVM 2.4 distribution currently consists of code from the core LLVM
Chris Lattner44c09cd2008-10-13 18:11:54 +0000[diff] [blame]76repository (which roughly includes the LLVM optimizers, code generators and
Chris Lattnerc75fd522008-06-08 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 Lattnerd8b33e02008-10-11 18:18:28 +0000[diff] [blame]79are the most actively developed are the <a href="#clang">Clang Project</a> and
Duncan Sandsb34d5902008-10-13 18:33:28 +0000[diff] [blame]80the <a href="#vmkit">vmkit Project</a>.
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]81</p>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]82
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]83</div>
84
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]85
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]86<!--=========================================================================-->
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]87<div class="doc_subsection">
Chris Lattner44c09cd2008-10-13 18:11:54 +0000[diff] [blame]88<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
Chris Lattnerc75fd522008-06-08 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 Lattnerd8b33e02008-10-11 18:18:28 +0000[diff] [blame]101<p>Codegen progress/state
102</p>
103
Chris Lattner44c09cd2008-10-13 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 Lattnerd8b33e02008-10-11 18:18:28 +0000[diff] [blame]114<a href="http://clang.llvm.org/StaticAnalysis.html">static analysis tool</a>
Chris Lattner44c09cd2008-10-13 18:11:54 +0000[diff] [blame]115.</p>
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]116
117</div>
118
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]119<!--=========================================================================-->
120<div class="doc_subsection">
Chris Lattner44c09cd2008-10-13 18:11:54 +0000[diff] [blame]121<a name="vmkit">vmkit: JVM/CLI Virtual Machine Implementation</a>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]122</div>
123
124<div class="doc_text">
125<p>
Chris Lattner44c09cd2008-10-13 18:11:54 +0000[diff] [blame]126The <a href="http://vmkit.llvm.org/">vmkit project</a> is an implementation of
Chris Lattnerf5cd9862008-10-13 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 Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]134
135<!-- *********************************************************************** -->
136<div class="doc_section">
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]137 <a name="whatsnew">What's New in LLVM?</a>
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]138</div>
139<!-- *********************************************************************** -->
140
Chris Lattnerb7bc2aa2008-06-08 22:59:35 +0000[diff] [blame]141<div class="doc_text">
142
Chris Lattner1e4d5bc2008-10-13 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 Lattnerb7bc2aa2008-06-08 22:59:35 +0000[diff] [blame]146</p>
147</div>
148
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]149<!--=========================================================================-->
Chris Lattner625a3d82008-06-08 21:34:41 +0000[diff] [blame]150<div class="doc_subsection">
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000[diff] [blame]151<a name="majorfeatures">Major New Features</a>
152</div>
153
154<div class="doc_text">
155
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000[diff] [blame]156<p>LLVM 2.4 includes several major new capabilities:</p>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]157
158<ul>
Chris Lattner591ef272008-10-13 20:47:20 +0000[diff] [blame]159<li><p>The most visible end-user change in LLVM 2.4 is that it includes many
Chris Lattner25879d72008-10-13 21:50:36 +0000[diff] [blame^]160optimizations and changes to make -O0 compile times much faster. You should see
Chris Lattner591ef272008-10-13 20:47:20 +0000[diff] [blame]161improvements on the order of 30% or more faster than LLVM 2.3. There are many
162pieces to this change, described in more detail below. The speedups and new
163components can also be used for JIT compilers that want fast compilation as
164well.</p></li>
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000[diff] [blame]165
Chris Lattner591ef272008-10-13 20:47:20 +0000[diff] [blame]166<li><p>The biggest change to the LLVM IR is that Multiple Return Values (which
167were introduced in LLVM 2.3) have been generalized to full support for "First
168Class Aggregate" values in LLVM 2.4. This means that LLVM IR supports using
169structs and arrays as values in a function. This capability is mostly useful
170for front-end authors, who prefer to treat things like complex numbers, simple
171tuples, dope vectors, etc as Value*'s instead of as a tuple of Value*'s or as
172memory values.</p></li>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]173
Chris Lattner591ef272008-10-13 20:47:20 +0000[diff] [blame]174<li><p>LLVM 2.4 also includes an initial port for the PIC16 microprocessor. This
175is the LLVM targer that only has support for 8 bit registers, and a number of
176other crazy constraints. While the port is still in early development stages,
177it shows some interesting things you can do with LLVM.</p></li>
Chris Lattner618a99f2008-06-05 06:57:39 +0000[diff] [blame]178
Chris Lattner458e79f2008-02-10 08:18:42 +0000[diff] [blame]179</ul>
180
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]181</div>
182
Chris Lattnerb7112222008-06-05 06:25:56 +0000[diff] [blame]183
184<!--=========================================================================-->
185<div class="doc_subsection">
Chris Lattner625a3d82008-06-08 21:34:41 +0000[diff] [blame]186<a name="llvm-gcc">llvm-gcc 4.2 Improvements</a>
Chris Lattnerb7112222008-06-05 06:25:56 +0000[diff] [blame]187</div>
188
189<div class="doc_text">
190
Chris Lattner591ef272008-10-13 20:47:20 +0000[diff] [blame]191<p>LLVM fully supports the llvm-gcc 4.2 front-end, which marries the GCC
192front-ends and driver with the LLVM optimizer and code generator. It currently
193includes support for the C, C++, Objective-C, Ada, and Fortran front-ends.</p>
Chris Lattnerb7112222008-06-05 06:25:56 +0000[diff] [blame]194
Chris Lattnerb7bc2aa2008-06-08 22:59:35 +0000[diff] [blame]195<ul>
Chris Lattner0327f0b2008-10-13 20:59:32 +0000[diff] [blame]196<li>LLVM 2.4 supports the full set of atomic <tt>__sync_*</tt> builtins. LLVM
1972.3 only supported those used by OpenMP, but 2.4 supports them all. While
Chris Lattner25879d72008-10-13 21:50:36 +0000[diff] [blame^]198llvm-gcc supports all of these builtins, note that not all targets do. X86
199support them all in both 32-bit and 64-bit mode and PowerPC supports them all
200except for the 64-bit operations when in 32-bit mode.</li>
Chris Lattnerb7bc2aa2008-06-08 22:59:35 +0000[diff] [blame]201
Chris Lattner0327f0b2008-10-13 20:59:32 +0000[diff] [blame]202<li>llvm-gcc now supports an <tt>-flimited-precision</tt> option, which tells
203the compiler that it is ok to use low-precision approximations of certain libm
Chris Lattner591ef272008-10-13 20:47:20 +0000[diff] [blame]204functions (like tan, log, etc). This allows you to get high performance if you
205only need (say) 14-bits of precision.</li>
206
207<li>llvm-gcc now supports a C language extension known as "<a
208href="http://lists.cs.uiuc.edu/pipermail/cfe-dev/2008-August/002670.html">Blocks
209</a>. This feature is similar to nested functions and closures, but does not
210require stack trampolines (with most ABIs) and supports returning closures
211from functions that define them. Note that actually <em>using</em> Blocks
212requires a small runtime that is not included with llvm-gcc.</li>
213
214<li>llvm-gcc now supports a new <tt>-flto</tt> option. On systems that support
215transparent Link Time Optimization (currently Darwin systems with Xcode 3.1 and
216later) this allows the use of LTO with other optimization levels like -Os.
217Previously, LTO could only be used with -O4, which implied optimizations in
218-O3 that can increase code size.</li>
Gabor Greif7f39fb52008-06-09 06:06:18 +0000[diff] [blame]219</ul>
Chris Lattnerb7112222008-06-05 06:25:56 +0000[diff] [blame]220
Chris Lattnerb7112222008-06-05 06:25:56 +0000[diff] [blame]221</div>
222
223
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]224<!--=========================================================================-->
225<div class="doc_subsection">
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]226<a name="coreimprovements">LLVM Core Improvements</a>
227</div>
228
229<div class="doc_text">
230<p>New features include:
231</p>
232
Chris Lattnerb7112222008-06-05 06:25:56 +0000[diff] [blame]233<ul>
Chris Lattner0327f0b2008-10-13 20:59:32 +0000[diff] [blame]234<li>A major change to the "Use" class landed, which shrank it by 25%. Since
235this is a pervasive part of the LLVM, it ended up reducing the memory use of
236LLVM IR in general by 15% for most programs.</li>
237
238<li>Values with no names are now pretty printed by <tt>llvm-dis</tt> more
239nicely. They now print as "<tt>%3 = add i32 %A, 4</tt>" instead of
240"<tt>add i32 %A, 4 ; &lt;i32&gt;:3</tt>", which makes it much easier to read.
241</li>
242
243<li>LLVM 2.4 includes some changes for better vector support. First, the shift
244operations (<tt>shl</tt>, <tt>ashr</tt>, <tt>lshr</tt>) now all support vectors
245and do an element-by-element shift (shifts of the whole vector can be
246accomplished by bitcasting the vector to &lt;1 x i128&gt; for example). Second,
247there is support in development for vector comparisons. LLVM 2.4 actually
248supports two ways to do vector comparisons: the vicmp/vfcmp instructions and the
249icmp/fcmp instructions. The vicmp/vfcmp instructions are temporary and will be
250removed (do not use them). The icmp/fcmp instructions compare two vectors and
251return a vector of i1's for each result. Note that there is very little codegen
252support available for any of these IR features though.</li>
253
254<li>A new <tt>DebugInfoBuilder</tt> class is available, which makes it much
255easier for front-ends to create debug info descriptors, similar to the way that
256IRBuilder makes it easier to create LLVM IR.</li>
257
258<li>LLVM now supports "function attributes", which allows us to seperate return
259value attributes from function attributes. LLVM now supports attributes on a
260function itself, a return value, and its parameters. New supported function
261attributes include noinline/alwaysinline and the "opt-size" flag which says the
262function should be optimized for code size.</li>
263
Chris Lattner63969522008-10-12 18:30:33 +0000[diff] [blame]264<li>LLVM IR now directly represents "common" linkage, instead of
265 representing it as a form of weak linkage.</li>
Chris Lattner0327f0b2008-10-13 20:59:32 +0000[diff] [blame]266
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]267</ul>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]268
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]269</div>
270
271<!--=========================================================================-->
272<div class="doc_subsection">
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]273<a name="optimizer">Optimizer Improvements</a>
274</div>
275
276<div class="doc_text">
277
Chris Lattner25879d72008-10-13 21:50:36 +0000[diff] [blame^]278<p>In addition to a huge array of bug fixes and minor performance tweaks, this
279release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]280
281<ul>
282
Chris Lattner25879d72008-10-13 21:50:36 +0000[diff] [blame^]283<li>The Global Value Numbering (GVN) pass now does local Partial Redundancy
284Elimination (PRE) to eliminate some partially redundant expressions in cases
285where doing so won't grow code size.</li>
Chris Lattnerc4d68542008-10-12 19:47:48 +0000[diff] [blame]286
Chris Lattner25879d72008-10-13 21:50:36 +0000[diff] [blame^]287<li>LLVM 2.4 includes a new loop deletion pass (which removes output-free
288provably-finite loops) and a rewritten Aggressive Dead Code Elimination (ADCE)
289pass that no longer uses control dependence information. These changes speed up
290the optimizer and also prevents it from deleting output-free infinite
291loops.</li>
Chris Lattnerc4d68542008-10-12 19:47:48 +0000[diff] [blame]292
Duncan Sands8547c2d2008-10-13 18:42:43 +0000[diff] [blame]293<li>The new AddReadAttrs pass works out which functions are read-only or
294read-none (these correspond to 'pure' and 'const' in C) and marks them
295with the appropriate attribute.</li>
Chris Lattner25879d72008-10-13 21:50:36 +0000[diff] [blame^]296
297<li>LLVM 2.4 now includes a new SparsePropagation framework, which makes it
298trivial to build lattice-based dataflow solvers that operate over LLVM IR. Using
299this interface means that you just define objects to represent your lattice
300values and the transfer functions that operate on them. It handles the
301mechanics of worklist processing, liveness tracking, handling PHI nodes,
302etc.</li>
303
304<li>Various helper functions (ComputeMaskedBits, ComputeNumSignBits, etc) were
305pulled out of the Instruction Combining pass and put into a new
306<tt>ValueTracking.h</tt> header, where they can be reused by other passes.</li>
307
308<li>The tail duplication pass has been removed from the standard optimizer
309sequence used by llvm-gcc. This pass still exists, but the benefits it once
310provided are now achieved by other passes.</li>
311
Chris Lattner7795ea92008-06-08 02:45:07 +0000[diff] [blame]312</ul>
313
314</div>
315
316<!--=========================================================================-->
317<div class="doc_subsection">
318<a name="codegen">Code Generator Improvements</a>
319</div>
320
321<div class="doc_text">
322
323<p>We put a significant amount of work into the code generator infrastructure,
324which allows us to implement more aggressive algorithms and make it run
325faster:</p>
326
327<ul>
Chris Lattner25879d72008-10-13 21:50:36 +0000[diff] [blame^]328<li>The target-independent code generator supports (and the X86 backend
329 currently implements) a new interface for "fast" instruction selection. This
330 interface is optimized to produce code as quickly as possible, sacrificing
331 code quality to do it. This is used by default at -O0 or when using
332 "llc -fast" on X86. It is straight-forward to add support for
333 other targets if faster -O0 compilation is desired.</li>
334
335<li>In addition to the new 'fast' instruction selection path, many existing
336 pieces of the code generator have been optimized in significant ways.
337 SelectionDAG's are now pool allocated and use better algorithms in many
338 places, the ".s" file printers now use raw_ostream to emit text much faster,
339 etc. The end result of these improvements is that the compiler also takes
340 substantially less time to generate code that is just as good (and often
341 better) than before.</li>
342
343<li>Each target has been split to separate the .s file printing logic from the
344 rest of the target. This enables JIT compilers that don't link in the
345 (somewhat large) code and data tables used for printing a .s file.</li>
346
347<li>The code generator now includes a "stack slot coloring" pass, which packs
348 together individual spilled values into common stack slots. This reduces
349 the size of stack frames with many spills, which tends to increase L1 cache
350 effectiveness.</li>
351
352<li>Various pieces of the register allocator (e.g. the coalescer and two-address
353 operation elimination pass) now know how to rematerialize trivial operations
354 to avoid copies and include several other optimizations.</li>
355
356<li>The <a href="CodeGenerator.html#selectiondag_process">graphs</a> produced by
357 the <tt>llc -view-*-dags</tt> options are now significantly prettier and
358 easier to read.</li>
359
360<li>LLVM 2.4 includes a new register allocator based on Partitioned Boolean
361 Quadratic Programming (PBQP). This register allocator is still in
362 development, but is very simple and clean.</li>
Chris Lattner7795ea92008-06-08 02:45:07 +0000[diff] [blame]363
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]364</ul>
365
366</div>
367
368
369<!--=========================================================================-->
370<div class="doc_subsection">
Chris Lattner6cb64032008-06-05 08:02:49 +0000[diff] [blame]371<a name="x86specific">X86/X86-64 Specific Improvements</a>
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]372</div>
Chris Lattner727c3742007-05-18 06:33:02 +0000[diff] [blame]373
Chris Lattner89e761c2006-04-18 06:32:08 +0000[diff] [blame]374<div class="doc_text">
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]375<p>New target-specific features include:
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]376</p>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]377
378<ul>
Chris Lattnerc4d68542008-10-12 19:47:48 +0000[diff] [blame]379<li>Exception handling is supported by default on Linux/x86-64.</li>
Duncan Sands719f7782008-10-13 17:32:15 +0000[diff] [blame]380<li>Position Independent Code (PIC) is now supported on Linux/x86-64.</li>
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000[diff] [blame]381<li>...</li>
Chris Lattnerb076b002008-06-08 21:19:07 +0000[diff] [blame]382
Chris Lattner8ce1ba42007-05-17 21:41:31 +0000[diff] [blame]383</ul>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]384
Chris Lattner8ce1ba42007-05-17 21:41:31 +0000[diff] [blame]385</div>
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]386
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]387<!--=========================================================================-->
388<div class="doc_subsection">
Chris Lattner6cb64032008-06-05 08:02:49 +0000[diff] [blame]389<a name="targetspecific">Other Target Specific Improvements</a>
390</div>
391
392<div class="doc_text">
393<p>New target-specific features include:
394</p>
395
396<ul>
Chris Lattnere3df07e2008-10-12 22:57:58 +0000[diff] [blame]397<li>MIPS floating point support?</li>
Duncan Sands719f7782008-10-13 17:32:15 +0000[diff] [blame]398<li>PowerPC now supports trampolines.</li>
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000[diff] [blame]399<li>....</li>
Chris Lattner6cb64032008-06-05 08:02:49 +0000[diff] [blame]400</ul>
Chris Lattner6cb64032008-06-05 08:02:49 +0000[diff] [blame]401
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]402</div>
Chris Lattner6cb64032008-06-05 08:02:49 +0000[diff] [blame]403
404
405<!--=========================================================================-->
406<div class="doc_subsection">
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]407<a name="otherimprovements">Other Improvements</a>
408</div>
409
410<div class="doc_text">
411<p>New features include:
412</p>
413
414<ul>
Mikhail Glushenkovd3ec89e2008-10-13 02:46:01 +0000[diff] [blame]415<li><tt>llvmc2</tt> (the generic compiler driver) gained plugin
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]416 support. It is now easier to experiment with <tt>llvmc2</tt> and
417 build your own tools based on it. </li>
Chris Lattnerc4d68542008-10-12 19:47:48 +0000[diff] [blame]418<li>raw_ostream + formatting</li>
Chris Lattnere3df07e2008-10-12 22:57:58 +0000[diff] [blame]419<li>Recycler + pool allocation stuff?</li>
Chris Lattnerd8b33e02008-10-11 18:18:28 +0000[diff] [blame]420<li>...</li>
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]421</ul>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]422
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]423</div>
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]424
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]425<!--=========================================================================-->
426<div class="doc_subsection">
427<a name="changes">Major Changes and Removed Features</a>
428</div>
429
430<div class="doc_text">
431
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]432<p>If you're already an LLVM user, this section lists some "gotchas" that you
433may run into upgrading from the previous release.</p>
434
Duncan Sandsb34d5902008-10-13 18:33:28 +0000[diff] [blame]435<p>The LLVM IR generated by llvm-gcc no longer names all instructions.
436 Use the instnamer pass if you want everything named.</p>
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]437
Duncan Sandsb34d5902008-10-13 18:33:28 +0000[diff] [blame]438<li>The LoadVN and GCSE passes have been removed.</li>
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]439
440
441<p>LLVM API Changes:</p>
442
443<ul>
444
445<li>... Attributes changes ... </li>
446
447<li>The <tt>DbgStopPointInst</tt> methods <tt>getDirectory</tt> and
448<tt>getFileName</tt> now return <tt>Value*</tt> instead of strings. These can be
449converted to strings using <tt>llvm::GetConstantStringInfo</tt> defined via
450"llvm/Analysis/ValueTracking.h".</li>
451
452<li>API change: BinaryOperator::create -> Create (CmpInst, CastInst too)</li>
453<li>Various header files like "llvm/ADT/iterator" were given a .h suffix.
454 Change your code to #include "llvm/ADT/iterator.h" instead.</li>
455
456</ul>
457
458</div>
459
460
461
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]462<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]463<div class="doc_section">
464 <a name="portability">Portability and Supported Platforms</a>
465</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]466<!-- *********************************************************************** -->
467
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]468<div class="doc_text">
469
John Criswell64307722004-12-08 20:35:47 +0000[diff] [blame]470<p>LLVM is known to work on the following platforms:</p>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]471
472<ul>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]473<li>Intel and AMD machines (IA32) running Red Hat Linux, Fedora Core and FreeBSD
Reid Spencer9803b402005-05-17 02:47:27 +0000[diff] [blame]474 (and probably other unix-like systems).</li>
Chris Lattner7422bce2008-02-06 06:30:34 +0000[diff] [blame]475<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit and
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]476 64-bit modes.</li>
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000[diff] [blame]477<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]478<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
479 support is available for native builds with Visual C++).</li>
Gabor Greif80ae8a72008-06-05 18:39:01 +0000[diff] [blame]480<li>Sun UltraSPARC workstations running Solaris 10.</li>
John Criswelld5234922005-05-13 20:28:15 +0000[diff] [blame]481<li>Alpha-based machines running Debian GNU/Linux.</li>
Gabor Greif80ae8a72008-06-05 18:39:01 +0000[diff] [blame]482<li>Itanium-based (IA64) machines running Linux and HP-UX.</li>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]483</ul>
484
Chris Lattner618a99f2008-06-05 06:57:39 +0000[diff] [blame]485<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Brian Gaekee3e557e2004-05-09 05:28:35 +0000[diff] [blame]486to the machine and operating system on which it is built. However, minor
487porting may be required to get LLVM to work on new platforms. We welcome your
488portability patches and reports of successful builds or error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]489
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]490</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]491
492<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]493<div class="doc_section">
494 <a name="knownproblems">Known Problems</a>
495</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]496<!-- *********************************************************************** -->
497
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]498<div class="doc_text">
499
500<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]501component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]502sections. If you run into a problem, please check the <a
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]503href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]504there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]505
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]506</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]507
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]508<!-- ======================================================================= -->
509<div class="doc_subsection">
510 <a name="experimental">Experimental features included with this release</a>
511</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]512
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]513<div class="doc_text">
514
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]515<p>The following components of this LLVM release are either untested, known to
516be broken or unreliable, or are in early development. These components should
517not be relied on, and bugs should not be filed against them, but they may be
518useful to some people. In particular, if you would like to work on one of these
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]519components, please contact us on the <a
520href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]521
522<ul>
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]523<li>The MSIL, IA64, Alpha, SPU, and MIPS backends are experimental.</li>
Duncan Sands56448462008-06-08 20:18:35 +0000[diff] [blame]524<li>The llc "<tt>-filetype=asm</tt>" (the default) is the only supported
Chris Lattner7422bce2008-02-06 06:30:34 +0000[diff] [blame]525 value for this option.</li>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]526</ul>
527
528</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]529
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]530<!-- ======================================================================= -->
531<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]532 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]533</div>
534
535<div class="doc_text">
536
537<ul>
Anton Korobeynikov486c7d32008-06-08 10:24:13 +0000[diff] [blame]538 <li>The X86 backend does not yet support
539 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
540 floating point stack</a>. It supports the 'f' and 't' constraints, but not
541 'u'.</li>
Chris Lattnerb076b002008-06-08 21:19:07 +0000[diff] [blame]542 <li>The X86 backend generates inefficient floating point code when configured
543 to generate code for systems that don't have SSE2.</li>
Duncan Sands0bc15262008-06-08 19:38:43 +0000[diff] [blame]544 <li>Win64 code generation wasn't widely tested. Everything should work, but we
Anton Korobeynikov486c7d32008-06-08 10:24:13 +0000[diff] [blame]545 expect small issues to happen. Also, llvm-gcc cannot build mingw64 runtime
546 currently due
547 to <a href="http://llvm.org/PR2255">several</a>
Chris Lattner54d12102008-06-08 23:12:47 +0000[diff] [blame]548 <a href="http://llvm.org/PR2257">bugs</a> due to lack of support for the
549 'u' inline assembly constraint and X87 floating point inline assembly.</li>
Dan Gohman721b3722008-06-08 23:05:11 +0000[diff] [blame]550 <li>The X86-64 backend does not yet support the LLVM IR instruction
551 <tt>va_arg</tt>. Currently, the llvm-gcc front-end supports variadic
552 argument constructs on X86-64 by lowering them manually.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]553</ul>
554
555</div>
556
557<!-- ======================================================================= -->
558<div class="doc_subsection">
559 <a name="ppc-be">Known problems with the PowerPC back-end</a>
560</div>
561
562<div class="doc_text">
563
564<ul>
Nicolas Geoffray77d99502007-05-15 09:21:28 +0000[diff] [blame]565<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]566compilation, and lacks support for debug information.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]567</ul>
568
569</div>
570
571<!-- ======================================================================= -->
572<div class="doc_subsection">
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]573 <a name="arm-be">Known problems with the ARM back-end</a>
574</div>
575
576<div class="doc_text">
577
578<ul>
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]579<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sands47fc0a22007-09-26 15:59:54 +0000[diff] [blame]580processors, thumb programs can crash or produce wrong
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]581results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]582<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
583</li>
Chris Lattnerb076b002008-06-08 21:19:07 +0000[diff] [blame]584<li>There is a bug in QEMU-ARM (&lt;= 0.9.0) which causes it to incorrectly
585 execute
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]586programs compiled with LLVM. Please use more recent versions of QEMU.</li>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]587</ul>
588
589</div>
590
591<!-- ======================================================================= -->
592<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]593 <a name="sparc-be">Known problems with the SPARC back-end</a>
594</div>
595
596<div class="doc_text">
597
598<ul>
599<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
600 support the 64-bit SPARC ABI (-m64).</li>
601</ul>
602
603</div>
604
605<!-- ======================================================================= -->
606<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]607 <a name="alpha-be">Known problems with the Alpha back-end</a>
608</div>
609
610<div class="doc_text">
611
612<ul>
613
614<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
615appropriate nops inserted to ensure restartability.</li>
616
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]617</ul>
618</div>
619
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]620<!-- ======================================================================= -->
621<div class="doc_subsection">
622 <a name="ia64-be">Known problems with the IA64 back-end</a>
623</div>
624
625<div class="doc_text">
626
627<ul>
Chris Lattner54d12102008-06-08 23:12:47 +0000[diff] [blame]628<li>The Itanium backend is highly experimental, and has a number of known
629 issues. We are looking for a maintainer for the Itanium backend. If you
630 are interested, please contact the llvmdev mailing list.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]631</ul>
632
633</div>
634
635<!-- ======================================================================= -->
636<div class="doc_subsection">
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]637 <a name="c-be">Known problems with the C back-end</a>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]638</div>
639
640<div class="doc_text">
641
642<ul>
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000[diff] [blame]643<li><a href="http://llvm.org/PR802">The C backend has only basic support for
644 inline assembly code</a>.</li>
Chris Lattner8e061162007-09-26 06:01:35 +0000[diff] [blame]645<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
646 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Duncan Sands56448462008-06-08 20:18:35 +0000[diff] [blame]647 C++ code compiled with llc or native compilers.</li>
Duncan Sandse09506a2008-02-10 13:40:55 +0000[diff] [blame]648<li>The C backend does not support all exception handling constructs.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]649</ul>
650
651</div>
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]652
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]653
654<!-- ======================================================================= -->
655<div class="doc_subsection">
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000[diff] [blame]656 <a name="c-fe">Known problems with the llvm-gcc C front-end</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]657</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]658
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]659<div class="doc_text">
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]660
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000[diff] [blame]661<p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time
662Optimization</a> on most platforms "out-of-the-box". Please inquire on the
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]663llvmdev mailing list if you are interested.</p>
Chris Lattner44124232006-08-08 17:27:28 +0000[diff] [blame]664
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000[diff] [blame]665<p>The only major language feature of GCC not supported by llvm-gcc is
666 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
667 are only supported on some targets. For example, trampolines are only
Duncan Sands56448462008-06-08 20:18:35 +0000[diff] [blame]668 supported on some targets (these are used when you take the address of a
669 nested function).</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]670
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000[diff] [blame]671<p>If you run into GCC extensions which are not supported, please let us know.
672</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]673
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]674</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]675
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]676<!-- ======================================================================= -->
677<div class="doc_subsection">
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000[diff] [blame]678 <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]679</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]680
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]681<div class="doc_text">
682
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]683<p>The C++ front-end is considered to be fully
Chris Lattnerb5bb5972004-12-07 08:04:13 +0000[diff] [blame]684tested and works for a number of non-trivial programs, including LLVM
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]685itself, Qt, Mozilla, etc.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]686
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]687<ul>
Anton Korobeynikov28f08aa2008-10-11 18:27:16 +0000[diff] [blame]688<li>Exception handling works well on the X86 and PowerPC targets. Currently
689 only linux and darwin targets are supported (both 32 and 64 bit).</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]690</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]691
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]692</div>
693
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]694
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]695<!-- ======================================================================= -->
696<div class="doc_subsection">
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000[diff] [blame]697 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]698</div>
699
700<div class="doc_text">
701The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature
702technology and problems should be expected.
703<ul>
Duncan Sands56448462008-06-08 20:18:35 +0000[diff] [blame]704<li>The Ada front-end currently only builds on X86-32. This is mainly due
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]705to lack of trampoline support (pointers to nested functions) on other platforms,
Duncan Sands56448462008-06-08 20:18:35 +0000[diff] [blame]706however it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]707which does support trampolines.</li>
708<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
709Workaround: configure with --disable-bootstrap.</li>
Duncan Sandsaef747f2008-10-13 17:27:23 +0000[diff] [blame]710<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
711and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
712(c380004 also fails with gcc-4.2 mainline).</li>
713<li>Some gcc specific Ada tests continue to crash the compiler.</li>
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]714<li>The -E binder option (exception backtraces)
715<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
716crashing if an exception is raised. Workaround: do not use -E.</li>
717<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
718or finish at a non-byte offset</a> in a record. Workaround: do not pack records
719or use representation clauses that result in a field of a non-discrete type
720starting or finishing in the middle of a byte.</li>
Chris Lattnerb076b002008-06-08 21:19:07 +0000[diff] [blame]721<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
722'main' as generated by the Ada binder to be invalid</a>.
723Workaround: hand edit the file to use pointers for <tt>argv</tt> and
724<tt>envp</tt> rather than integers.</li>
725<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
726ignored</a>.</li>
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]727</ul>
728</div>
729
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]730<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]731<div class="doc_section">
732 <a name="additionalinfo">Additional Information</a>
733</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]734<!-- *********************************************************************** -->
735
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]736<div class="doc_text">
737
Chris Lattnercb5596d2005-05-16 17:13:10 +0000[diff] [blame]738<p>A wide variety of additional information is available on the <a
Chris Lattnere0c1df42007-05-18 00:44:29 +0000[diff] [blame]739href="http://llvm.org">LLVM web page</a>, in particular in the <a
740href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencerc7f87f22007-07-09 08:04:31 +0000[diff] [blame]741contains versions of the API documentation which is up-to-date with the
742Subversion version of the source code.
Misha Brukman96158092005-03-30 19:14:24 +0000[diff] [blame]743You can access versions of these documents specific to this release by going
744into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]745
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]746<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]747us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]748lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]749
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]750</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]751
752<!-- *********************************************************************** -->
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Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]754<hr>
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