Misha Brukman | 500bc30 | 2003-11-22 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 Spencer | 6454ed3 | 2004-11-18 18:38:58 +0000 | [diff] [blame] | 5 | <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 6 | <link rel="stylesheet" href="llvm.css" type="text/css"> |
Chris Lattner | 857fb13 | 2008-10-11 18:18:28 +0000 | [diff] [blame] | 7 | <title>LLVM 2.4 Release Notes</title> |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 8 | </head> |
| 9 | <body> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 10 | |
Chris Lattner | 857fb13 | 2008-10-11 18:18:28 +0000 | [diff] [blame] | 11 | <div class="doc_title">LLVM 2.4 Release Notes</div> |
Mikhail Glushenkov | ea65d7d | 2008-10-13 02:08:34 +0000 | [diff] [blame] | 12 | |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 13 | <ol> |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 14 | <li><a href="#intro">Introduction</a></li> |
Chris Lattner | 96a445e | 2008-10-13 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 Lattner | 4b538b9 | 2004-04-30 22:17:12 +0000 | [diff] [blame] | 17 | <li><a href="GettingStarted.html">Installation Instructions</a></li> |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 18 | <li><a href="#portability">Portability and Supported Platforms</a></li> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 19 | <li><a href="#knownproblems">Known Problems</a> |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 20 | <li><a href="#additionalinfo">Additional Information</a></li> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 21 | </ol> |
| 22 | |
Chris Lattner | 7911ce2 | 2004-05-23 21:07:27 +0000 | [diff] [blame] | 23 | <div class="doc_author"> |
Chris Lattner | c463b27 | 2005-10-29 07:07:09 +0000 | [diff] [blame] | 24 | <p>Written by the <a href="http://llvm.org">LLVM Team</a><p> |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 25 | </div> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 26 | |
| 27 | <!-- *********************************************************************** --> |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 28 | <div class="doc_section"> |
| 29 | <a name="intro">Introduction</a> |
| 30 | </div> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 31 | <!-- *********************************************************************** --> |
| 32 | |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 33 | <div class="doc_text"> |
| 34 | |
Chris Lattner | f6662f9 | 2008-10-13 17:57:36 +0000 | [diff] [blame] | 35 | <p>This document contains the release notes for the LLVM Compiler |
| 36 | Infrastructure, release 2.4. Here we describe the status of LLVM, including |
| 37 | major improvements from the previous release and significant known problems. |
| 38 | All LLVM releases may be downloaded from the <a |
| 39 | href="http://llvm.org/releases/">LLVM releases web site</a>.</p> |
Chris Lattner | 1909261 | 2003-10-02 16:38:05 +0000 | [diff] [blame] | 40 | |
Chris Lattner | 7506b1d | 2004-12-07 08:04:13 +0000 | [diff] [blame] | 41 | <p>For more information about LLVM, including information about the latest |
Chris Lattner | c463b27 | 2005-10-29 07:07:09 +0000 | [diff] [blame] | 42 | release, please check out the <a href="http://llvm.org/">main LLVM |
Chris Lattner | 47ad72c | 2003-10-07 21:38:31 +0000 | [diff] [blame] | 43 | web site</a>. If you have questions or comments, the <a |
Chris Lattner | f6662f9 | 2008-10-13 17:57:36 +0000 | [diff] [blame] | 44 | href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM Developer's Mailing |
| 45 | List</a> is a good place to send them.</p> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 46 | |
Mikhail Glushenkov | ea65d7d | 2008-10-13 02:08:34 +0000 | [diff] [blame] | 47 | <p>Note that if you are reading this file from a Subversion checkout or the |
Chris Lattner | 8497764 | 2007-09-21 03:54:09 +0000 | [diff] [blame] | 48 | main LLVM web page, this document applies to the <i>next</i> release, not the |
| 49 | current 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 Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 51 | |
| 52 | </div> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 53 | |
Chris Lattner | 857fb13 | 2008-10-11 18:18:28 +0000 | [diff] [blame] | 54 | <!-- Unfinished features in 2.4: |
Chris Lattner | acce85d | 2008-02-10 07:46:44 +0000 | [diff] [blame] | 55 | Machine LICM |
| 56 | Machine Sinking |
| 57 | LegalizeDAGTypes |
Chris Lattner | 547a391 | 2008-10-12 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 Lattner | acce85d | 2008-02-10 07:46:44 +0000 | [diff] [blame] | 60 | --> |
Mikhail Glushenkov | ea65d7d | 2008-10-13 02:08:34 +0000 | [diff] [blame] | 61 | |
Chris Lattner | 547a391 | 2008-10-12 19:47:48 +0000 | [diff] [blame] | 62 | <!-- for announcement email: |
| 63 | mention dev mtg |
Chris Lattner | cdb0e4c | 2008-10-12 22:57:58 +0000 | [diff] [blame] | 64 | Xcode 3.1 and 3.1.1. |
Chris Lattner | 547a391 | 2008-10-12 19:47:48 +0000 | [diff] [blame] | 65 | --> |
Chris Lattner | acce85d | 2008-02-10 07:46:44 +0000 | [diff] [blame] | 66 | |
Chris Lattner | 96a445e | 2008-10-13 18:01:01 +0000 | [diff] [blame] | 67 | <!-- *********************************************************************** --> |
| 68 | <div class="doc_section"> |
| 69 | <a name="subproj">Sub-project Status Update</a> |
Chris Lattner | ea34f64 | 2008-06-08 21:34:41 +0000 | [diff] [blame] | 70 | </div> |
Chris Lattner | 96a445e | 2008-10-13 18:01:01 +0000 | [diff] [blame] | 71 | <!-- *********************************************************************** --> |
Chris Lattner | ea34f64 | 2008-06-08 21:34:41 +0000 | [diff] [blame] | 72 | |
| 73 | <div class="doc_text"> |
Chris Lattner | 8348b47 | 2008-06-08 21:58:17 +0000 | [diff] [blame] | 74 | <p> |
Chris Lattner | 96a445e | 2008-10-13 18:01:01 +0000 | [diff] [blame] | 75 | The LLVM 2.4 distribution currently consists of code from the core LLVM |
Chris Lattner | fb97b2d | 2008-10-13 18:11:54 +0000 | [diff] [blame] | 76 | repository (which roughly includes the LLVM optimizers, code generators and |
Chris Lattner | 8348b47 | 2008-06-08 21:58:17 +0000 | [diff] [blame] | 77 | supporting tools) and the llvm-gcc repository. In addition to this code, the |
| 78 | LLVM Project includes other sub-projects that are in development. The two which |
Chris Lattner | 857fb13 | 2008-10-11 18:18:28 +0000 | [diff] [blame] | 79 | are the most actively developed are the <a href="#clang">Clang Project</a> and |
Duncan Sands | bf8c4f2 | 2008-10-13 18:33:28 +0000 | [diff] [blame] | 80 | the <a href="#vmkit">vmkit Project</a>. |
Chris Lattner | 8348b47 | 2008-06-08 21:58:17 +0000 | [diff] [blame] | 81 | </p> |
Chris Lattner | 96a445e | 2008-10-13 18:01:01 +0000 | [diff] [blame] | 82 | |
Chris Lattner | 8348b47 | 2008-06-08 21:58:17 +0000 | [diff] [blame] | 83 | </div> |
| 84 | |
Chris Lattner | 96a445e | 2008-10-13 18:01:01 +0000 | [diff] [blame] | 85 | |
Chris Lattner | 8348b47 | 2008-06-08 21:58:17 +0000 | [diff] [blame] | 86 | <!--=========================================================================--> |
Chris Lattner | 96a445e | 2008-10-13 18:01:01 +0000 | [diff] [blame] | 87 | <div class="doc_subsection"> |
Chris Lattner | fb97b2d | 2008-10-13 18:11:54 +0000 | [diff] [blame] | 88 | <a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a> |
Chris Lattner | 8348b47 | 2008-06-08 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 |
| 94 | a set of new 'LLVM native' front-end technologies for the LLVM optimizer |
| 95 | and code generator. Clang is continuing to make major strides forward in all |
| 96 | areas. Its C and Objective-C parsing support is very solid, and the code |
| 97 | generation support is far enough along to build many C applications. While not |
| 98 | yet production quality, it is progressing very nicely. In addition, C++ |
| 99 | front-end work has started to make significant progress.</p> |
| 100 | |
Chris Lattner | 857fb13 | 2008-10-11 18:18:28 +0000 | [diff] [blame] | 101 | <p>Codegen progress/state |
| 102 | </p> |
| 103 | |
Chris Lattner | fb97b2d | 2008-10-13 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 Lattner | 857fb13 | 2008-10-11 18:18:28 +0000 | [diff] [blame] | 114 | <a href="http://clang.llvm.org/StaticAnalysis.html">static analysis tool</a> |
Chris Lattner | fb97b2d | 2008-10-13 18:11:54 +0000 | [diff] [blame] | 115 | .</p> |
Chris Lattner | 8348b47 | 2008-06-08 21:58:17 +0000 | [diff] [blame] | 116 | |
| 117 | </div> |
| 118 | |
Chris Lattner | 96a445e | 2008-10-13 18:01:01 +0000 | [diff] [blame] | 119 | <!--=========================================================================--> |
| 120 | <div class="doc_subsection"> |
Chris Lattner | fb97b2d | 2008-10-13 18:11:54 +0000 | [diff] [blame] | 121 | <a name="vmkit">vmkit: JVM/CLI Virtual Machine Implementation</a> |
Chris Lattner | 96a445e | 2008-10-13 18:01:01 +0000 | [diff] [blame] | 122 | </div> |
| 123 | |
| 124 | <div class="doc_text"> |
| 125 | <p> |
Chris Lattner | fb97b2d | 2008-10-13 18:11:54 +0000 | [diff] [blame] | 126 | The <a href="http://vmkit.llvm.org/">vmkit project</a> is an implementation of |
Chris Lattner | 96a445e | 2008-10-13 18:01:01 +0000 | [diff] [blame] | 127 | a JVM and a CLI Virtual Machines (Microsoft .NET is an |
| 128 | implementation of the CLI) using the Just-In-Time compiler of LLVM.</p> |
| 129 | |
| 130 | <p>...</p> |
| 131 | |
| 132 | </div> |
| 133 | |
Chris Lattner | 8348b47 | 2008-06-08 21:58:17 +0000 | [diff] [blame] | 134 | |
| 135 | <!-- *********************************************************************** --> |
| 136 | <div class="doc_section"> |
Chris Lattner | 96a445e | 2008-10-13 18:01:01 +0000 | [diff] [blame] | 137 | <a name="whatsnew">What's New in LLVM?</a> |
Chris Lattner | 8348b47 | 2008-06-08 21:58:17 +0000 | [diff] [blame] | 138 | </div> |
| 139 | <!-- *********************************************************************** --> |
| 140 | |
Chris Lattner | f8e0b4e | 2008-06-08 22:59:35 +0000 | [diff] [blame] | 141 | <div class="doc_text"> |
| 142 | |
Chris Lattner | f6662f9 | 2008-10-13 17:57:36 +0000 | [diff] [blame] | 143 | <p>This release includes a huge number of bug fixes, performance tweaks and |
| 144 | minor improvements. Some of the major improvements and new features are listed |
| 145 | in this section. |
Chris Lattner | f8e0b4e | 2008-06-08 22:59:35 +0000 | [diff] [blame] | 146 | </p> |
| 147 | </div> |
| 148 | |
Chris Lattner | 8348b47 | 2008-06-08 21:58:17 +0000 | [diff] [blame] | 149 | <!--=========================================================================--> |
Chris Lattner | ea34f64 | 2008-06-08 21:34:41 +0000 | [diff] [blame] | 150 | <div class="doc_subsection"> |
Chris Lattner | 252b83d | 2008-02-06 18:00:06 +0000 | [diff] [blame] | 151 | <a name="majorfeatures">Major New Features</a> |
| 152 | </div> |
| 153 | |
| 154 | <div class="doc_text"> |
| 155 | |
Chris Lattner | 857fb13 | 2008-10-11 18:18:28 +0000 | [diff] [blame] | 156 | <p>LLVM 2.4 includes several major new capabilities:</p> |
Chris Lattner | f3e5bc6 | 2007-05-14 06:56:09 +0000 | [diff] [blame] | 157 | |
| 158 | <ul> |
Chris Lattner | b82eb06 | 2008-10-13 20:47:20 +0000 | [diff] [blame^] | 159 | <li><p>The most visible end-user change in LLVM 2.4 is that it includes many |
| 160 | optimizations and changes ot make -O0 compile times much faster. You should see |
| 161 | improvements on the order of 30% or more faster than LLVM 2.3. There are many |
| 162 | pieces to this change, described in more detail below. The speedups and new |
| 163 | components can also be used for JIT compilers that want fast compilation as |
| 164 | well.</p></li> |
Chris Lattner | 857fb13 | 2008-10-11 18:18:28 +0000 | [diff] [blame] | 165 | |
Chris Lattner | b82eb06 | 2008-10-13 20:47:20 +0000 | [diff] [blame^] | 166 | <li><p>The biggest change to the LLVM IR is that Multiple Return Values (which |
| 167 | were introduced in LLVM 2.3) have been generalized to full support for "First |
| 168 | Class Aggregate" values in LLVM 2.4. This means that LLVM IR supports using |
| 169 | structs and arrays as values in a function. This capability is mostly useful |
| 170 | for front-end authors, who prefer to treat things like complex numbers, simple |
| 171 | tuples, dope vectors, etc as Value*'s instead of as a tuple of Value*'s or as |
| 172 | memory values.</p></li> |
Mikhail Glushenkov | ea65d7d | 2008-10-13 02:08:34 +0000 | [diff] [blame] | 173 | |
Chris Lattner | b82eb06 | 2008-10-13 20:47:20 +0000 | [diff] [blame^] | 174 | <li><p>LLVM 2.4 also includes an initial port for the PIC16 microprocessor. This |
| 175 | is the LLVM targer that only has support for 8 bit registers, and a number of |
| 176 | other crazy constraints. While the port is still in early development stages, |
| 177 | it shows some interesting things you can do with LLVM.</p></li> |
Chris Lattner | bc5786b | 2008-06-05 06:57:39 +0000 | [diff] [blame] | 178 | |
Chris Lattner | 8170c10 | 2008-02-10 08:18:42 +0000 | [diff] [blame] | 179 | </ul> |
| 180 | |
Chris Lattner | f3e5bc6 | 2007-05-14 06:56:09 +0000 | [diff] [blame] | 181 | </div> |
| 182 | |
Chris Lattner | 791f77b | 2008-06-05 06:25:56 +0000 | [diff] [blame] | 183 | |
| 184 | <!--=========================================================================--> |
| 185 | <div class="doc_subsection"> |
Chris Lattner | ea34f64 | 2008-06-08 21:34:41 +0000 | [diff] [blame] | 186 | <a name="llvm-gcc">llvm-gcc 4.2 Improvements</a> |
Chris Lattner | 791f77b | 2008-06-05 06:25:56 +0000 | [diff] [blame] | 187 | </div> |
| 188 | |
| 189 | <div class="doc_text"> |
| 190 | |
Chris Lattner | b82eb06 | 2008-10-13 20:47:20 +0000 | [diff] [blame^] | 191 | <p>LLVM fully supports the llvm-gcc 4.2 front-end, which marries the GCC |
| 192 | front-ends and driver with the LLVM optimizer and code generator. It currently |
| 193 | includes support for the C, C++, Objective-C, Ada, and Fortran front-ends.</p> |
Chris Lattner | 791f77b | 2008-06-05 06:25:56 +0000 | [diff] [blame] | 194 | |
Chris Lattner | f8e0b4e | 2008-06-08 22:59:35 +0000 | [diff] [blame] | 195 | <ul> |
Chris Lattner | b82eb06 | 2008-10-13 20:47:20 +0000 | [diff] [blame^] | 196 | <li>LLVM 2.4 supports the full set of atomic __sync builtins. LLVM 2.3 only |
| 197 | supported those used by OpenMP, but 2.4 supports them all. Not all targets |
| 198 | support all builtins, but X86 and PowerPC do.</li> |
Chris Lattner | f8e0b4e | 2008-06-08 22:59:35 +0000 | [diff] [blame] | 199 | |
Chris Lattner | b82eb06 | 2008-10-13 20:47:20 +0000 | [diff] [blame^] | 200 | <li>llvm-gcc now supports an -flimited-precision option, which tells the |
| 201 | compiler that it is ok to use low-precision approximations of certain libm |
| 202 | functions (like tan, log, etc). This allows you to get high performance if you |
| 203 | only need (say) 14-bits of precision.</li> |
| 204 | |
| 205 | <li>llvm-gcc now supports a C language extension known as "<a |
| 206 | href="http://lists.cs.uiuc.edu/pipermail/cfe-dev/2008-August/002670.html">Blocks |
| 207 | </a>. This feature is similar to nested functions and closures, but does not |
| 208 | require stack trampolines (with most ABIs) and supports returning closures |
| 209 | from functions that define them. Note that actually <em>using</em> Blocks |
| 210 | requires a small runtime that is not included with llvm-gcc.</li> |
| 211 | |
| 212 | <li>llvm-gcc now supports a new <tt>-flto</tt> option. On systems that support |
| 213 | transparent Link Time Optimization (currently Darwin systems with Xcode 3.1 and |
| 214 | later) this allows the use of LTO with other optimization levels like -Os. |
| 215 | Previously, LTO could only be used with -O4, which implied optimizations in |
| 216 | -O3 that can increase code size.</li> |
Gabor Greif | a3bd11d | 2008-06-09 06:06:18 +0000 | [diff] [blame] | 217 | </ul> |
Chris Lattner | 791f77b | 2008-06-05 06:25:56 +0000 | [diff] [blame] | 218 | |
Chris Lattner | 791f77b | 2008-06-05 06:25:56 +0000 | [diff] [blame] | 219 | </div> |
| 220 | |
| 221 | |
Chris Lattner | 8497764 | 2007-09-21 03:54:09 +0000 | [diff] [blame] | 222 | <!--=========================================================================--> |
| 223 | <div class="doc_subsection"> |
Chris Lattner | f304ffc | 2008-02-10 08:17:19 +0000 | [diff] [blame] | 224 | <a name="coreimprovements">LLVM Core Improvements</a> |
| 225 | </div> |
| 226 | |
| 227 | <div class="doc_text"> |
| 228 | <p>New features include: |
| 229 | </p> |
| 230 | |
Chris Lattner | 791f77b | 2008-06-05 06:25:56 +0000 | [diff] [blame] | 231 | <ul> |
Chris Lattner | cdb0e4c | 2008-10-12 22:57:58 +0000 | [diff] [blame] | 232 | <li>vector shifts in the IR: no codegen support yet</li> |
Chris Lattner | cce6d4b | 2008-10-12 18:30:33 +0000 | [diff] [blame] | 233 | <li>use diet patch landed: saved 15% IR memory footprint</li> |
| 234 | <li>LLVM IR now directly represents "common" linkage, instead of |
| 235 | representing it as a form of weak linkage.</li> |
Chris Lattner | 547a391 | 2008-10-12 19:47:48 +0000 | [diff] [blame] | 236 | <li>DebugInfoBuilder</li> |
Chris Lattner | cdb0e4c | 2008-10-12 22:57:58 +0000 | [diff] [blame] | 237 | <li>.ll printing format change: %3 = add i32 4, 2</li> |
Duncan Sands | bf8c4f2 | 2008-10-13 18:33:28 +0000 | [diff] [blame] | 238 | <li>opt-size, noinline, alwaysinline function attributes</li> |
Chris Lattner | b82eb06 | 2008-10-13 20:47:20 +0000 | [diff] [blame^] | 239 | <li>Attrs: function, return, param.</p></li> |
Chris Lattner | 857fb13 | 2008-10-11 18:18:28 +0000 | [diff] [blame] | 240 | <li>...</li> |
Chris Lattner | f304ffc | 2008-02-10 08:17:19 +0000 | [diff] [blame] | 241 | </ul> |
Mikhail Glushenkov | ea65d7d | 2008-10-13 02:08:34 +0000 | [diff] [blame] | 242 | |
Chris Lattner | f304ffc | 2008-02-10 08:17:19 +0000 | [diff] [blame] | 243 | </div> |
| 244 | |
| 245 | <!--=========================================================================--> |
| 246 | <div class="doc_subsection"> |
Chris Lattner | acce85d | 2008-02-10 07:46:44 +0000 | [diff] [blame] | 247 | <a name="optimizer">Optimizer Improvements</a> |
| 248 | </div> |
| 249 | |
| 250 | <div class="doc_text"> |
| 251 | |
Mikhail Glushenkov | ea65d7d | 2008-10-13 02:08:34 +0000 | [diff] [blame] | 252 | <p>In addition to a huge array of bug fixes and minor performance tweaks, the |
Chris Lattner | 857fb13 | 2008-10-11 18:18:28 +0000 | [diff] [blame] | 253 | LLVM 2.4 optimizers support a few major enhancements:</p> |
Chris Lattner | acce85d | 2008-02-10 07:46:44 +0000 | [diff] [blame] | 254 | |
| 255 | <ul> |
| 256 | |
Chris Lattner | 547a391 | 2008-10-12 19:47:48 +0000 | [diff] [blame] | 257 | <li>GVN now does local PRE?</li> |
| 258 | |
| 259 | <li>Matthijs' Dead argument elimination rewrite</li> |
| 260 | |
Chris Lattner | cce6d4b | 2008-10-12 18:30:33 +0000 | [diff] [blame] | 261 | <li>Old-ADCE used control dependence and deleted output-free infinite loops. |
| 262 | Added a new Loop deletion pass (for deleting output free provably-finite loops) |
| 263 | and rewrote ADCE to be simpler faster, and not need control dependence.</li> |
| 264 | |
| 265 | <li>SparsePropagation framework for lattice-based dataflow solvers.</li> |
| 266 | |
Chris Lattner | cdb0e4c | 2008-10-12 22:57:58 +0000 | [diff] [blame] | 267 | <li>Tail duplication was removed from the standard optimizer sequence.</li> |
Chris Lattner | cce6d4b | 2008-10-12 18:30:33 +0000 | [diff] [blame] | 268 | |
Chris Lattner | 547a391 | 2008-10-12 19:47:48 +0000 | [diff] [blame] | 269 | <li>Various helper functions (ComputeMaskedBits, ComputeNumSignBits, etc) were |
| 270 | pulled out of instcombine and put into a new ValueTracking.h file, where they |
| 271 | can be reused by other passes.</li> |
| 272 | |
Duncan Sands | 1050d73 | 2008-10-13 18:42:43 +0000 | [diff] [blame] | 273 | <li>The new AddReadAttrs pass works out which functions are read-only or |
| 274 | read-none (these correspond to 'pure' and 'const' in C) and marks them |
| 275 | with the appropriate attribute.</li> |
Chris Lattner | 0b83220 | 2008-06-08 02:45:07 +0000 | [diff] [blame] | 276 | </ul> |
| 277 | |
| 278 | </div> |
| 279 | |
| 280 | <!--=========================================================================--> |
| 281 | <div class="doc_subsection"> |
| 282 | <a name="codegen">Code Generator Improvements</a> |
| 283 | </div> |
| 284 | |
| 285 | <div class="doc_text"> |
| 286 | |
| 287 | <p>We put a significant amount of work into the code generator infrastructure, |
| 288 | which allows us to implement more aggressive algorithms and make it run |
| 289 | faster:</p> |
| 290 | |
| 291 | <ul> |
Chris Lattner | cdb0e4c | 2008-10-12 22:57:58 +0000 | [diff] [blame] | 292 | <li>asm writers split out to their own library to avoid JITs having to link |
| 293 | them in.</li> |
| 294 | <li>Big asm writer refactoring + TargetAsmInfo</li> |
| 295 | <li>2-addr pass and coalescer can now remat trivial insts to avoid a copy.</li> |
Chris Lattner | 547a391 | 2008-10-12 19:47:48 +0000 | [diff] [blame] | 296 | <li>spiller to commute instructions in order to fold a reload</li> |
| 297 | <li>Stack slot coloring?</li> |
| 298 | <li>Live intervals renumbering? Is this useful to external people?</li> |
| 299 | <li>'is as cheap as a move' instruction flag</li> |
| 300 | <li>Improvements to selection dag viewing</li> |
| 301 | <li>fast isel</li> |
Chris Lattner | 857fb13 | 2008-10-11 18:18:28 +0000 | [diff] [blame] | 302 | <li>Selection dag speedups</li> |
Chris Lattner | 547a391 | 2008-10-12 19:47:48 +0000 | [diff] [blame] | 303 | <li>asmwriter + raw_ostream -> fastah</li> |
Chris Lattner | 59b5ce4 | 2008-10-13 17:12:51 +0000 | [diff] [blame] | 304 | <li>Partitioned Boolean Quadratic Programming (PBQP) based register |
| 305 | allocator.</li> |
Chris Lattner | 857fb13 | 2008-10-11 18:18:28 +0000 | [diff] [blame] | 306 | <li>...</li> |
Chris Lattner | 0b83220 | 2008-06-08 02:45:07 +0000 | [diff] [blame] | 307 | |
Chris Lattner | 8497764 | 2007-09-21 03:54:09 +0000 | [diff] [blame] | 308 | </ul> |
| 309 | |
| 310 | </div> |
| 311 | |
| 312 | |
| 313 | <!--=========================================================================--> |
| 314 | <div class="doc_subsection"> |
Chris Lattner | 77d29b1 | 2008-06-05 08:02:49 +0000 | [diff] [blame] | 315 | <a name="x86specific">X86/X86-64 Specific Improvements</a> |
Chris Lattner | 8497764 | 2007-09-21 03:54:09 +0000 | [diff] [blame] | 316 | </div> |
Chris Lattner | 60893e5 | 2007-05-18 06:33:02 +0000 | [diff] [blame] | 317 | |
Chris Lattner | 738bd30 | 2006-04-18 06:32:08 +0000 | [diff] [blame] | 318 | <div class="doc_text"> |
Chris Lattner | f304ffc | 2008-02-10 08:17:19 +0000 | [diff] [blame] | 319 | <p>New target-specific features include: |
Chris Lattner | f3e5bc6 | 2007-05-14 06:56:09 +0000 | [diff] [blame] | 320 | </p> |
Chris Lattner | 2629922 | 2006-11-18 07:51:14 +0000 | [diff] [blame] | 321 | |
| 322 | <ul> |
Chris Lattner | 547a391 | 2008-10-12 19:47:48 +0000 | [diff] [blame] | 323 | <li>Exception handling is supported by default on Linux/x86-64.</li> |
Duncan Sands | bbf379a | 2008-10-13 17:32:15 +0000 | [diff] [blame] | 324 | <li>Position Independent Code (PIC) is now supported on Linux/x86-64.</li> |
Chris Lattner | 857fb13 | 2008-10-11 18:18:28 +0000 | [diff] [blame] | 325 | <li>...</li> |
Chris Lattner | e6e1b35 | 2008-06-08 21:19:07 +0000 | [diff] [blame] | 326 | |
Chris Lattner | bfb17ab | 2007-05-17 21:41:31 +0000 | [diff] [blame] | 327 | </ul> |
Mikhail Glushenkov | ea65d7d | 2008-10-13 02:08:34 +0000 | [diff] [blame] | 328 | |
Chris Lattner | bfb17ab | 2007-05-17 21:41:31 +0000 | [diff] [blame] | 329 | </div> |
Chris Lattner | c5d658a | 2006-03-03 00:34:26 +0000 | [diff] [blame] | 330 | |
Chris Lattner | 8497764 | 2007-09-21 03:54:09 +0000 | [diff] [blame] | 331 | <!--=========================================================================--> |
| 332 | <div class="doc_subsection"> |
Chris Lattner | 77d29b1 | 2008-06-05 08:02:49 +0000 | [diff] [blame] | 333 | <a name="targetspecific">Other Target Specific Improvements</a> |
| 334 | </div> |
| 335 | |
| 336 | <div class="doc_text"> |
| 337 | <p>New target-specific features include: |
| 338 | </p> |
| 339 | |
| 340 | <ul> |
Chris Lattner | cdb0e4c | 2008-10-12 22:57:58 +0000 | [diff] [blame] | 341 | <li>MIPS floating point support?</li> |
Duncan Sands | bbf379a | 2008-10-13 17:32:15 +0000 | [diff] [blame] | 342 | <li>PowerPC now supports trampolines.</li> |
Chris Lattner | 857fb13 | 2008-10-11 18:18:28 +0000 | [diff] [blame] | 343 | <li>....</li> |
Chris Lattner | 77d29b1 | 2008-06-05 08:02:49 +0000 | [diff] [blame] | 344 | </ul> |
Chris Lattner | 77d29b1 | 2008-06-05 08:02:49 +0000 | [diff] [blame] | 345 | |
Mikhail Glushenkov | ea65d7d | 2008-10-13 02:08:34 +0000 | [diff] [blame] | 346 | </div> |
Chris Lattner | 77d29b1 | 2008-06-05 08:02:49 +0000 | [diff] [blame] | 347 | |
| 348 | |
| 349 | <!--=========================================================================--> |
| 350 | <div class="doc_subsection"> |
Chris Lattner | 8497764 | 2007-09-21 03:54:09 +0000 | [diff] [blame] | 351 | <a name="otherimprovements">Other Improvements</a> |
| 352 | </div> |
| 353 | |
| 354 | <div class="doc_text"> |
| 355 | <p>New features include: |
| 356 | </p> |
| 357 | |
| 358 | <ul> |
Mikhail Glushenkov | 49feb45 | 2008-10-13 02:46:01 +0000 | [diff] [blame] | 359 | <li><tt>llvmc2</tt> (the generic compiler driver) gained plugin |
Mikhail Glushenkov | ea65d7d | 2008-10-13 02:08:34 +0000 | [diff] [blame] | 360 | support. It is now easier to experiment with <tt>llvmc2</tt> and |
| 361 | build your own tools based on it. </li> |
Chris Lattner | 547a391 | 2008-10-12 19:47:48 +0000 | [diff] [blame] | 362 | <li>raw_ostream + formatting</li> |
Chris Lattner | cdb0e4c | 2008-10-12 22:57:58 +0000 | [diff] [blame] | 363 | <li>Recycler + pool allocation stuff?</li> |
Chris Lattner | 857fb13 | 2008-10-11 18:18:28 +0000 | [diff] [blame] | 364 | <li>...</li> |
Chris Lattner | 8497764 | 2007-09-21 03:54:09 +0000 | [diff] [blame] | 365 | </ul> |
Mikhail Glushenkov | ea65d7d | 2008-10-13 02:08:34 +0000 | [diff] [blame] | 366 | |
Chris Lattner | 8497764 | 2007-09-21 03:54:09 +0000 | [diff] [blame] | 367 | </div> |
Chris Lattner | c5d658a | 2006-03-03 00:34:26 +0000 | [diff] [blame] | 368 | |
Chris Lattner | f6662f9 | 2008-10-13 17:57:36 +0000 | [diff] [blame] | 369 | <!--=========================================================================--> |
| 370 | <div class="doc_subsection"> |
| 371 | <a name="changes">Major Changes and Removed Features</a> |
| 372 | </div> |
| 373 | |
| 374 | <div class="doc_text"> |
| 375 | |
Chris Lattner | 96a445e | 2008-10-13 18:01:01 +0000 | [diff] [blame] | 376 | <p>If you're already an LLVM user, this section lists some "gotchas" that you |
| 377 | may run into upgrading from the previous release.</p> |
| 378 | |
Duncan Sands | bf8c4f2 | 2008-10-13 18:33:28 +0000 | [diff] [blame] | 379 | <p>The LLVM IR generated by llvm-gcc no longer names all instructions. |
| 380 | Use the instnamer pass if you want everything named.</p> |
Chris Lattner | f6662f9 | 2008-10-13 17:57:36 +0000 | [diff] [blame] | 381 | |
Duncan Sands | bf8c4f2 | 2008-10-13 18:33:28 +0000 | [diff] [blame] | 382 | <li>The LoadVN and GCSE passes have been removed.</li> |
Chris Lattner | f6662f9 | 2008-10-13 17:57:36 +0000 | [diff] [blame] | 383 | |
| 384 | |
| 385 | <p>LLVM API Changes:</p> |
| 386 | |
| 387 | <ul> |
| 388 | |
| 389 | <li>... Attributes changes ... </li> |
| 390 | |
| 391 | <li>The <tt>DbgStopPointInst</tt> methods <tt>getDirectory</tt> and |
| 392 | <tt>getFileName</tt> now return <tt>Value*</tt> instead of strings. These can be |
| 393 | converted to strings using <tt>llvm::GetConstantStringInfo</tt> defined via |
| 394 | "llvm/Analysis/ValueTracking.h".</li> |
| 395 | |
| 396 | <li>API change: BinaryOperator::create -> Create (CmpInst, CastInst too)</li> |
| 397 | <li>Various header files like "llvm/ADT/iterator" were given a .h suffix. |
| 398 | Change your code to #include "llvm/ADT/iterator.h" instead.</li> |
| 399 | |
| 400 | </ul> |
| 401 | |
| 402 | </div> |
| 403 | |
| 404 | |
| 405 | |
Chris Lattner | 1909261 | 2003-10-02 16:38:05 +0000 | [diff] [blame] | 406 | <!-- *********************************************************************** --> |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 407 | <div class="doc_section"> |
| 408 | <a name="portability">Portability and Supported Platforms</a> |
| 409 | </div> |
Chris Lattner | 1909261 | 2003-10-02 16:38:05 +0000 | [diff] [blame] | 410 | <!-- *********************************************************************** --> |
| 411 | |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 412 | <div class="doc_text"> |
| 413 | |
John Criswell | 0b5b5e9 | 2004-12-08 20:35:47 +0000 | [diff] [blame] | 414 | <p>LLVM is known to work on the following platforms:</p> |
Chris Lattner | 4654bdb | 2004-06-01 18:22:41 +0000 | [diff] [blame] | 415 | |
| 416 | <ul> |
Mikhail Glushenkov | ea65d7d | 2008-10-13 02:08:34 +0000 | [diff] [blame] | 417 | <li>Intel and AMD machines (IA32) running Red Hat Linux, Fedora Core and FreeBSD |
Reid Spencer | 00812e2 | 2005-05-17 02:47:27 +0000 | [diff] [blame] | 418 | (and probably other unix-like systems).</li> |
Chris Lattner | 000c73b | 2008-02-06 06:30:34 +0000 | [diff] [blame] | 419 | <li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit and |
Chris Lattner | 2629922 | 2006-11-18 07:51:14 +0000 | [diff] [blame] | 420 | 64-bit modes.</li> |
Chris Lattner | 252b83d | 2008-02-06 18:00:06 +0000 | [diff] [blame] | 421 | <li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li> |
Chris Lattner | 57a460e | 2007-05-23 04:39:32 +0000 | [diff] [blame] | 422 | <li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited |
| 423 | support is available for native builds with Visual C++).</li> |
Gabor Greif | 96a89c7 | 2008-06-05 18:39:01 +0000 | [diff] [blame] | 424 | <li>Sun UltraSPARC workstations running Solaris 10.</li> |
John Criswell | 9321fa8 | 2005-05-13 20:28:15 +0000 | [diff] [blame] | 425 | <li>Alpha-based machines running Debian GNU/Linux.</li> |
Gabor Greif | 96a89c7 | 2008-06-05 18:39:01 +0000 | [diff] [blame] | 426 | <li>Itanium-based (IA64) machines running Linux and HP-UX.</li> |
Chris Lattner | 4654bdb | 2004-06-01 18:22:41 +0000 | [diff] [blame] | 427 | </ul> |
| 428 | |
Chris Lattner | bc5786b | 2008-06-05 06:57:39 +0000 | [diff] [blame] | 429 | <p>The core LLVM infrastructure uses GNU autoconf to adapt itself |
Brian Gaeke | b0fd761 | 2004-05-09 05:28:35 +0000 | [diff] [blame] | 430 | to the machine and operating system on which it is built. However, minor |
| 431 | porting may be required to get LLVM to work on new platforms. We welcome your |
| 432 | portability patches and reports of successful builds or error messages.</p> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 433 | |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 434 | </div> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 435 | |
| 436 | <!-- *********************************************************************** --> |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 437 | <div class="doc_section"> |
| 438 | <a name="knownproblems">Known Problems</a> |
| 439 | </div> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 440 | <!-- *********************************************************************** --> |
| 441 | |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 442 | <div class="doc_text"> |
| 443 | |
| 444 | <p>This section contains all known problems with the LLVM system, listed by |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 445 | component. As new problems are discovered, they will be added to these |
Chris Lattner | 5eccca4 | 2003-12-12 21:22:16 +0000 | [diff] [blame] | 446 | sections. If you run into a problem, please check the <a |
Chris Lattner | c463b27 | 2005-10-29 07:07:09 +0000 | [diff] [blame] | 447 | href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if |
Chris Lattner | 5eccca4 | 2003-12-12 21:22:16 +0000 | [diff] [blame] | 448 | there isn't already one.</p> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 449 | |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 450 | </div> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 451 | |
Chris Lattner | f5ee170 | 2004-03-14 02:03:02 +0000 | [diff] [blame] | 452 | <!-- ======================================================================= --> |
| 453 | <div class="doc_subsection"> |
| 454 | <a name="experimental">Experimental features included with this release</a> |
| 455 | </div> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 456 | |
Chris Lattner | f5ee170 | 2004-03-14 02:03:02 +0000 | [diff] [blame] | 457 | <div class="doc_text"> |
| 458 | |
Misha Brukman | 6df9e2c | 2004-05-12 21:46:05 +0000 | [diff] [blame] | 459 | <p>The following components of this LLVM release are either untested, known to |
| 460 | be broken or unreliable, or are in early development. These components should |
| 461 | not be relied on, and bugs should not be filed against them, but they may be |
| 462 | useful to some people. In particular, if you would like to work on one of these |
Chris Lattner | 2b659ef | 2008-02-12 06:29:45 +0000 | [diff] [blame] | 463 | components, please contact us on the <a |
| 464 | href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p> |
Chris Lattner | f5ee170 | 2004-03-14 02:03:02 +0000 | [diff] [blame] | 465 | |
| 466 | <ul> |
Chris Lattner | 2b659ef | 2008-02-12 06:29:45 +0000 | [diff] [blame] | 467 | <li>The MSIL, IA64, Alpha, SPU, and MIPS backends are experimental.</li> |
Duncan Sands | 27aff87 | 2008-06-08 20:18:35 +0000 | [diff] [blame] | 468 | <li>The llc "<tt>-filetype=asm</tt>" (the default) is the only supported |
Chris Lattner | 000c73b | 2008-02-06 06:30:34 +0000 | [diff] [blame] | 469 | value for this option.</li> |
Chris Lattner | f5ee170 | 2004-03-14 02:03:02 +0000 | [diff] [blame] | 470 | </ul> |
| 471 | |
| 472 | </div> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 473 | |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 474 | <!-- ======================================================================= --> |
| 475 | <div class="doc_subsection"> |
Chris Lattner | 2629922 | 2006-11-18 07:51:14 +0000 | [diff] [blame] | 476 | <a name="x86-be">Known problems with the X86 back-end</a> |
John Criswell | c0c186d | 2005-11-08 21:11:33 +0000 | [diff] [blame] | 477 | </div> |
| 478 | |
| 479 | <div class="doc_text"> |
| 480 | |
| 481 | <ul> |
Anton Korobeynikov | a6094be | 2008-06-08 10:24:13 +0000 | [diff] [blame] | 482 | <li>The X86 backend does not yet support |
| 483 | all <a href="http://llvm.org/PR879">inline assembly that uses the X86 |
| 484 | floating point stack</a>. It supports the 'f' and 't' constraints, but not |
| 485 | 'u'.</li> |
Chris Lattner | e6e1b35 | 2008-06-08 21:19:07 +0000 | [diff] [blame] | 486 | <li>The X86 backend generates inefficient floating point code when configured |
| 487 | to generate code for systems that don't have SSE2.</li> |
Duncan Sands | 47eff2b | 2008-06-08 19:38:43 +0000 | [diff] [blame] | 488 | <li>Win64 code generation wasn't widely tested. Everything should work, but we |
Anton Korobeynikov | a6094be | 2008-06-08 10:24:13 +0000 | [diff] [blame] | 489 | expect small issues to happen. Also, llvm-gcc cannot build mingw64 runtime |
| 490 | currently due |
| 491 | to <a href="http://llvm.org/PR2255">several</a> |
Chris Lattner | 04af7cb | 2008-06-08 23:12:47 +0000 | [diff] [blame] | 492 | <a href="http://llvm.org/PR2257">bugs</a> due to lack of support for the |
| 493 | 'u' inline assembly constraint and X87 floating point inline assembly.</li> |
Dan Gohman | 8207ba9 | 2008-06-08 23:05:11 +0000 | [diff] [blame] | 494 | <li>The X86-64 backend does not yet support the LLVM IR instruction |
| 495 | <tt>va_arg</tt>. Currently, the llvm-gcc front-end supports variadic |
| 496 | argument constructs on X86-64 by lowering them manually.</li> |
Chris Lattner | 2629922 | 2006-11-18 07:51:14 +0000 | [diff] [blame] | 497 | </ul> |
| 498 | |
| 499 | </div> |
| 500 | |
| 501 | <!-- ======================================================================= --> |
| 502 | <div class="doc_subsection"> |
| 503 | <a name="ppc-be">Known problems with the PowerPC back-end</a> |
| 504 | </div> |
| 505 | |
| 506 | <div class="doc_text"> |
| 507 | |
| 508 | <ul> |
Nicolas Geoffray | e4285dc | 2007-05-15 09:21:28 +0000 | [diff] [blame] | 509 | <li>The Linux PPC32/ABI support needs testing for the interpreter and static |
Chris Lattner | 57a460e | 2007-05-23 04:39:32 +0000 | [diff] [blame] | 510 | compilation, and lacks support for debug information.</li> |
Chris Lattner | 2629922 | 2006-11-18 07:51:14 +0000 | [diff] [blame] | 511 | </ul> |
| 512 | |
| 513 | </div> |
| 514 | |
| 515 | <!-- ======================================================================= --> |
| 516 | <div class="doc_subsection"> |
Chris Lattner | f3e5bc6 | 2007-05-14 06:56:09 +0000 | [diff] [blame] | 517 | <a name="arm-be">Known problems with the ARM back-end</a> |
| 518 | </div> |
| 519 | |
| 520 | <div class="doc_text"> |
| 521 | |
| 522 | <ul> |
Chris Lattner | 57a460e | 2007-05-23 04:39:32 +0000 | [diff] [blame] | 523 | <li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6 |
Duncan Sands | c90d68b | 2007-09-26 15:59:54 +0000 | [diff] [blame] | 524 | processors, thumb programs can crash or produce wrong |
Chris Lattner | 57a460e | 2007-05-23 04:39:32 +0000 | [diff] [blame] | 525 | results (<a href="http://llvm.org/PR1388">PR1388</a>).</li> |
Chris Lattner | f3e5bc6 | 2007-05-14 06:56:09 +0000 | [diff] [blame] | 526 | <li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested. |
| 527 | </li> |
Chris Lattner | e6e1b35 | 2008-06-08 21:19:07 +0000 | [diff] [blame] | 528 | <li>There is a bug in QEMU-ARM (<= 0.9.0) which causes it to incorrectly |
| 529 | execute |
Chris Lattner | 57a460e | 2007-05-23 04:39:32 +0000 | [diff] [blame] | 530 | programs compiled with LLVM. Please use more recent versions of QEMU.</li> |
Chris Lattner | f3e5bc6 | 2007-05-14 06:56:09 +0000 | [diff] [blame] | 531 | </ul> |
| 532 | |
| 533 | </div> |
| 534 | |
| 535 | <!-- ======================================================================= --> |
| 536 | <div class="doc_subsection"> |
Chris Lattner | 2629922 | 2006-11-18 07:51:14 +0000 | [diff] [blame] | 537 | <a name="sparc-be">Known problems with the SPARC back-end</a> |
| 538 | </div> |
| 539 | |
| 540 | <div class="doc_text"> |
| 541 | |
| 542 | <ul> |
| 543 | <li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not |
| 544 | support the 64-bit SPARC ABI (-m64).</li> |
| 545 | </ul> |
| 546 | |
| 547 | </div> |
| 548 | |
| 549 | <!-- ======================================================================= --> |
| 550 | <div class="doc_subsection"> |
Chris Lattner | 2629922 | 2006-11-18 07:51:14 +0000 | [diff] [blame] | 551 | <a name="alpha-be">Known problems with the Alpha back-end</a> |
| 552 | </div> |
| 553 | |
| 554 | <div class="doc_text"> |
| 555 | |
| 556 | <ul> |
| 557 | |
| 558 | <li>On 21164s, some rare FP arithmetic sequences which may trap do not have the |
| 559 | appropriate nops inserted to ensure restartability.</li> |
| 560 | |
John Criswell | c0c186d | 2005-11-08 21:11:33 +0000 | [diff] [blame] | 561 | </ul> |
| 562 | </div> |
| 563 | |
Chris Lattner | 2629922 | 2006-11-18 07:51:14 +0000 | [diff] [blame] | 564 | <!-- ======================================================================= --> |
| 565 | <div class="doc_subsection"> |
| 566 | <a name="ia64-be">Known problems with the IA64 back-end</a> |
| 567 | </div> |
| 568 | |
| 569 | <div class="doc_text"> |
| 570 | |
| 571 | <ul> |
Chris Lattner | 04af7cb | 2008-06-08 23:12:47 +0000 | [diff] [blame] | 572 | <li>The Itanium backend is highly experimental, and has a number of known |
| 573 | issues. We are looking for a maintainer for the Itanium backend. If you |
| 574 | are interested, please contact the llvmdev mailing list.</li> |
Chris Lattner | 2629922 | 2006-11-18 07:51:14 +0000 | [diff] [blame] | 575 | </ul> |
| 576 | |
| 577 | </div> |
| 578 | |
| 579 | <!-- ======================================================================= --> |
| 580 | <div class="doc_subsection"> |
Chris Lattner | f3e5bc6 | 2007-05-14 06:56:09 +0000 | [diff] [blame] | 581 | <a name="c-be">Known problems with the C back-end</a> |
Chris Lattner | 2629922 | 2006-11-18 07:51:14 +0000 | [diff] [blame] | 582 | </div> |
| 583 | |
| 584 | <div class="doc_text"> |
| 585 | |
| 586 | <ul> |
Chris Lattner | 5733b27 | 2008-06-05 06:35:40 +0000 | [diff] [blame] | 587 | <li><a href="http://llvm.org/PR802">The C backend has only basic support for |
| 588 | inline assembly code</a>.</li> |
Chris Lattner | 725a0d8 | 2007-09-26 06:01:35 +0000 | [diff] [blame] | 589 | <li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common |
| 590 | C++ programs</a>, preventing intermixing between C++ compiled by the CBE and |
Duncan Sands | 27aff87 | 2008-06-08 20:18:35 +0000 | [diff] [blame] | 591 | C++ code compiled with llc or native compilers.</li> |
Duncan Sands | f74c0cc | 2008-02-10 13:40:55 +0000 | [diff] [blame] | 592 | <li>The C backend does not support all exception handling constructs.</li> |
Chris Lattner | 2629922 | 2006-11-18 07:51:14 +0000 | [diff] [blame] | 593 | </ul> |
| 594 | |
| 595 | </div> |
John Criswell | c0c186d | 2005-11-08 21:11:33 +0000 | [diff] [blame] | 596 | |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 597 | |
| 598 | <!-- ======================================================================= --> |
| 599 | <div class="doc_subsection"> |
Chris Lattner | 5733b27 | 2008-06-05 06:35:40 +0000 | [diff] [blame] | 600 | <a name="c-fe">Known problems with the llvm-gcc C front-end</a> |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 601 | </div> |
Chris Lattner | 47588f9 | 2003-10-02 05:07:23 +0000 | [diff] [blame] | 602 | |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 603 | <div class="doc_text"> |
Chris Lattner | c5d658a | 2006-03-03 00:34:26 +0000 | [diff] [blame] | 604 | |
Chris Lattner | 252b83d | 2008-02-06 18:00:06 +0000 | [diff] [blame] | 605 | <p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time |
| 606 | Optimization</a> on most platforms "out-of-the-box". Please inquire on the |
Chris Lattner | f3e5bc6 | 2007-05-14 06:56:09 +0000 | [diff] [blame] | 607 | llvmdev mailing list if you are interested.</p> |
Chris Lattner | d9ea017 | 2006-08-08 17:27:28 +0000 | [diff] [blame] | 608 | |
Chris Lattner | 5733b27 | 2008-06-05 06:35:40 +0000 | [diff] [blame] | 609 | <p>The only major language feature of GCC not supported by llvm-gcc is |
| 610 | the <tt>__builtin_apply</tt> family of builtins. However, some extensions |
| 611 | are only supported on some targets. For example, trampolines are only |
Duncan Sands | 27aff87 | 2008-06-08 20:18:35 +0000 | [diff] [blame] | 612 | supported on some targets (these are used when you take the address of a |
| 613 | nested function).</p> |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 614 | |
Chris Lattner | 5733b27 | 2008-06-05 06:35:40 +0000 | [diff] [blame] | 615 | <p>If you run into GCC extensions which are not supported, please let us know. |
| 616 | </p> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 617 | |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 618 | </div> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 619 | |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 620 | <!-- ======================================================================= --> |
| 621 | <div class="doc_subsection"> |
Chris Lattner | 5733b27 | 2008-06-05 06:35:40 +0000 | [diff] [blame] | 622 | <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a> |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 623 | </div> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 624 | |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 625 | <div class="doc_text"> |
| 626 | |
Chris Lattner | f3e5bc6 | 2007-05-14 06:56:09 +0000 | [diff] [blame] | 627 | <p>The C++ front-end is considered to be fully |
Chris Lattner | 7506b1d | 2004-12-07 08:04:13 +0000 | [diff] [blame] | 628 | tested and works for a number of non-trivial programs, including LLVM |
Chris Lattner | f3e5bc6 | 2007-05-14 06:56:09 +0000 | [diff] [blame] | 629 | itself, Qt, Mozilla, etc.</p> |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 630 | |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 631 | <ul> |
Anton Korobeynikov | 0021fc1 | 2008-10-11 18:27:16 +0000 | [diff] [blame] | 632 | <li>Exception handling works well on the X86 and PowerPC targets. Currently |
| 633 | only linux and darwin targets are supported (both 32 and 64 bit).</li> |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 634 | </ul> |
Chris Lattner | fcc54b3 | 2003-10-07 22:14:37 +0000 | [diff] [blame] | 635 | |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 636 | </div> |
| 637 | |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 638 | |
Chris Lattner | 2b659ef | 2008-02-12 06:29:45 +0000 | [diff] [blame] | 639 | <!-- ======================================================================= --> |
| 640 | <div class="doc_subsection"> |
Chris Lattner | 5733b27 | 2008-06-05 06:35:40 +0000 | [diff] [blame] | 641 | <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a> |
Chris Lattner | 2b659ef | 2008-02-12 06:29:45 +0000 | [diff] [blame] | 642 | </div> |
| 643 | |
| 644 | <div class="doc_text"> |
| 645 | The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature |
| 646 | technology and problems should be expected. |
| 647 | <ul> |
Duncan Sands | 27aff87 | 2008-06-08 20:18:35 +0000 | [diff] [blame] | 648 | <li>The Ada front-end currently only builds on X86-32. This is mainly due |
Chris Lattner | 2b659ef | 2008-02-12 06:29:45 +0000 | [diff] [blame] | 649 | to lack of trampoline support (pointers to nested functions) on other platforms, |
Duncan Sands | 27aff87 | 2008-06-08 20:18:35 +0000 | [diff] [blame] | 650 | however it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a> |
Chris Lattner | 2b659ef | 2008-02-12 06:29:45 +0000 | [diff] [blame] | 651 | which does support trampolines.</li> |
| 652 | <li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>. |
| 653 | Workaround: configure with --disable-bootstrap.</li> |
Duncan Sands | 978bcee | 2008-10-13 17:27:23 +0000 | [diff] [blame] | 654 | <li>The c380004, <a href="http://llvm.org/PR2010">c393010</a> |
| 655 | and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail |
| 656 | (c380004 also fails with gcc-4.2 mainline).</li> |
| 657 | <li>Some gcc specific Ada tests continue to crash the compiler.</li> |
Chris Lattner | 2b659ef | 2008-02-12 06:29:45 +0000 | [diff] [blame] | 658 | <li>The -E binder option (exception backtraces) |
| 659 | <a href="http://llvm.org/PR1982">does not work</a> and will result in programs |
| 660 | crashing if an exception is raised. Workaround: do not use -E.</li> |
| 661 | <li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start |
| 662 | or finish at a non-byte offset</a> in a record. Workaround: do not pack records |
| 663 | or use representation clauses that result in a field of a non-discrete type |
| 664 | starting or finishing in the middle of a byte.</li> |
Chris Lattner | e6e1b35 | 2008-06-08 21:19:07 +0000 | [diff] [blame] | 665 | <li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers |
| 666 | 'main' as generated by the Ada binder to be invalid</a>. |
| 667 | Workaround: hand edit the file to use pointers for <tt>argv</tt> and |
| 668 | <tt>envp</tt> rather than integers.</li> |
| 669 | <li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is |
| 670 | ignored</a>.</li> |
Chris Lattner | 2b659ef | 2008-02-12 06:29:45 +0000 | [diff] [blame] | 671 | </ul> |
| 672 | </div> |
| 673 | |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 674 | <!-- *********************************************************************** --> |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 675 | <div class="doc_section"> |
| 676 | <a name="additionalinfo">Additional Information</a> |
| 677 | </div> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 678 | <!-- *********************************************************************** --> |
| 679 | |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 680 | <div class="doc_text"> |
| 681 | |
Chris Lattner | 416db10 | 2005-05-16 17:13:10 +0000 | [diff] [blame] | 682 | <p>A wide variety of additional information is available on the <a |
Chris Lattner | b4b0ce7 | 2007-05-18 00:44:29 +0000 | [diff] [blame] | 683 | href="http://llvm.org">LLVM web page</a>, in particular in the <a |
| 684 | href="http://llvm.org/docs/">documentation</a> section. The web page also |
Reid Spencer | 669ed45 | 2007-07-09 08:04:31 +0000 | [diff] [blame] | 685 | contains versions of the API documentation which is up-to-date with the |
| 686 | Subversion version of the source code. |
Misha Brukman | 109d9e8 | 2005-03-30 19:14:24 +0000 | [diff] [blame] | 687 | You can access versions of these documents specific to this release by going |
| 688 | into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 689 | |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 690 | <p>If you have any questions or comments about LLVM, please feel free to contact |
Chris Lattner | c463b27 | 2005-10-29 07:07:09 +0000 | [diff] [blame] | 691 | us via the <a href="http://llvm.org/docs/#maillist"> mailing |
Chris Lattner | 5eccca4 | 2003-12-12 21:22:16 +0000 | [diff] [blame] | 692 | lists</a>.</p> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 693 | |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 694 | </div> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 695 | |
| 696 | <!-- *********************************************************************** --> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 697 | |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 698 | <hr> |
Misha Brukman | 2061e89 | 2003-11-22 01:23:39 +0000 | [diff] [blame] | 699 | <address> |
Misha Brukman | 38847d5 | 2003-12-21 22:53:21 +0000 | [diff] [blame] | 700 | <a href="http://jigsaw.w3.org/css-validator/check/referer"><img |
Misha Brukman | 2061e89 | 2003-11-22 01:23:39 +0000 | [diff] [blame] | 701 | src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a> |
| 702 | <a href="http://validator.w3.org/check/referer"><img |
Chris Lattner | 8170c10 | 2008-02-10 08:18:42 +0000 | [diff] [blame] | 703 | src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a> |
Misha Brukman | 2061e89 | 2003-11-22 01:23:39 +0000 | [diff] [blame] | 704 | |
Chris Lattner | b4b0ce7 | 2007-05-18 00:44:29 +0000 | [diff] [blame] | 705 | <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br> |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 706 | Last modified: $Date$ |
Misha Brukman | 2061e89 | 2003-11-22 01:23:39 +0000 | [diff] [blame] | 707 | </address> |
Chris Lattner | 79c3fe1 | 2003-10-02 04:57:28 +0000 | [diff] [blame] | 708 | |
Misha Brukman | 500bc30 | 2003-11-22 00:38:41 +0000 | [diff] [blame] | 709 | </body> |
| 710 | </html> |