<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <link rel="stylesheet" href="llvm.css" type="text/css"> <title>LLVM 2.6 Release Notes</title> </head> <body> <div class="doc_title">LLVM 2.6 Release Notes</div> <ol> <li><a href="#intro">Introduction</a></li> <li><a href="#subproj">Sub-project Status Update</a></li> <li><a href="#externalproj">External Projects Using LLVM 2.6</a></li> <li><a href="#whatsnew">What's New in LLVM 2.6?</a></li> <li><a href="GettingStarted.html">Installation Instructions</a></li> <li><a href="#portability">Portability and Supported Platforms</a></li> <li><a href="#knownproblems">Known Problems</a></li> <li><a href="#additionalinfo">Additional Information</a></li> </ol> <div class="doc_author"> <p>Written by the <a href="http://llvm.org">LLVM Team</a></p> </div> <!-- *********************************************************************** --> <div class="doc_section"> <a name="intro">Introduction</a> </div> <!-- *********************************************************************** --> <div class="doc_text"> <p>This document contains the release notes for the LLVM Compiler Infrastructure, release 2.6. Here we describe the status of LLVM, including major improvements from the previous release and significant known problems. All LLVM releases may be downloaded from the <a href="http://llvm.org/releases/">LLVM releases web site</a>.</p> <p>For more information about LLVM, including information about the latest release, please check out the <a href="http://llvm.org/">main LLVM web site</a>. If you have questions or comments, the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM Developer's Mailing List</a> is a good place to send them.</p> <p>Note that if you are reading this file from a Subversion checkout or the main LLVM web page, this document applies to the <i>next</i> release, not the current one. To see the release notes for a specific release, please see the <a href="http://llvm.org/releases/">releases page</a>.</p> </div> <!-- Unfinished features in 2.5: Machine LICM Machine Sinking target-specific intrinsics gold lto plugin pre-alloc splitter, strong phi elim <tt>llc -enable-value-prop</tt>, propagation of value info (sign/zero ext info) from one MBB to another debug info for optimized code interpreter + libffi postalloc scheduler: anti dependence breaking, hazard recognizer? initial support for debug line numbers when optimization enabled, not useful in 2.5 but will be for 2.6. --> <!-- for announcement email: --> <!-- *********************************************************************** --> <div class="doc_section"> <a name="subproj">Sub-project Status Update</a> </div> <!-- *********************************************************************** --> <div class="doc_text"> <p> The LLVM 2.6 distribution currently consists of code from the core LLVM repository —which roughly includes the LLVM optimizers, code generators and supporting tools — and the llvm-gcc repository. In addition to this code, the LLVM Project includes other sub-projects that are in development. The two which are the most actively developed are the <a href="#clang">Clang Project</a> and the <a href="#vmkit">VMKit Project</a>. </p> </div> <!--=========================================================================--> <div class="doc_subsection"> <a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a> </div> <div class="doc_text"> <p>The <a href="http://clang.llvm.org/">Clang project</a> is an effort to build a set of new 'LLVM native' front-end technologies for the LLVM optimizer and code generator. While Clang is not included in the LLVM 2.6 release, it is continuing to make major strides forward in all areas. Its C and Objective-C parsing and code generation support is now very solid. For example, it is capable of successfully building many real-world applications for X86-32 and X86-64, including the <a href="http://wiki.freebsd.org/BuildingFreeBSDWithClang">FreeBSD kernel</a> and <a href="http://gcc.gnu.org/gcc-4.2/">gcc 4.2</a>. C++ is also making <a href="http://clang.llvm.org/cxx_status.html">incredible progress</a>, and work on templates has recently started. If you are interested in fast compiles and good diagnostics, we encourage you to try it out by <a href="http://clang.llvm.org/get_started.html">building from mainline</a> and reporting any issues you hit to the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev">Clang front-end mailing list</a>.</p> <p>In the LLVM 2.6 time-frame, the Clang team has made many improvements:</p> <ul> <li>Something wonderful!</li> <li>AuroraUX / FreeBSD & OpenBSD Toolchain support.</li> <li>Many many bugs are fixed and many features have been added.</li> </ul> </div> <!--=========================================================================--> <div class="doc_subsection"> <a name="clangsa">Clang Static Analyzer</a> </div> <div class="doc_text"> <p>Previously announced in the 2.4 LLVM release, the Clang project also includes an early stage static source code analysis tool for <a href="http://clang.llvm.org/StaticAnalysis.html">automatically finding bugs</a> in C and Objective-C programs. The tool performs a growing set of checks to find bugs that occur on a specific path within a program.</p> <p>In the LLVM 2.6 time-frame there have been many significant improvements to XYZ.</p> <p>The set of checks performed by the static analyzer continues to expand, and future plans for the tool include full source-level inter-procedural analysis and deeper checks such as buffer overrun detection. There are many opportunities to extend and enhance the static analyzer, and anyone interested in working on this project is encouraged to get involved!</p> </div> <!--=========================================================================--> <div class="doc_subsection"> <a name="vmkit">VMKit: JVM/CLI Virtual Machine Implementation</a> </div> <div class="doc_text"> <p> The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation of a JVM and a CLI Virtual Machines (Microsoft .NET is an implementation of the CLI) using the Just-In-Time compiler of LLVM.</p> <p>Following LLVM 2.6, VMKit has its XYZ release that you can find on its <a href="http://vmkit.llvm.org/releases/">webpage</a>. The release includes bug fixes, cleanup and new features. The major changes are:</p> <ul> <li>Something wonderful!</li> </ul> </div> <!-- *********************************************************************** --> <div class="doc_section"> <a name="externalproj">External Projects Using LLVM 2.6</a> </div> <!-- *********************************************************************** --> <!--=========================================================================--> <div class="doc_subsection"> <a name="pure">Pure</a> </div> <div class="doc_text"> <p> <a href="http://pure-lang.googlecode.com/">Pure</a> is an algebraic/functional programming language based on term rewriting. Programs are collections of equations which are used to evaluate expressions in a symbolic fashion. Pure offers dynamic typing, eager and lazy evaluation, lexical closures, a hygienic macro system (also based on term rewriting), built-in list and matrix support (including list and matrix comprehensions) and an easy-to-use C interface. The interpreter uses LLVM as a backend to JIT-compile Pure programs to fast native code.</p> <p>In addition to the usual algebraic data structures, Pure also has MATLAB-style matrices in order to support numeric computations and signal processing in an efficient way. Pure is mainly aimed at mathematical applications right now, but it has been designed as a general purpose language. The dynamic interpreter environment and the C interface make it possible to use it as a kind of functional scripting language for many application areas. </p> </div> <!--=========================================================================--> <div class="doc_subsection"> <a name="ldc">LLVM D Compiler</a> </div> <div class="doc_text"> <p> <a href="http://www.dsource.org/projects/ldc">LDC</a> is an implementation of the D Programming Language using the LLVM optimizer and code generator. The LDC project works great with the LLVM 2.6 release. General improvements in this cycle have included new inline asm constraint handling, better debug info support, general bugfixes, and better x86-64 support. This has allowed some major improvements in LDC, getting us much closer to being as fully featured as the original DMD compiler from DigitalMars. </p> </div> <!--=========================================================================--> <div class="doc_subsection"> <a name="RoadsendPHP">Roadsend PHP</a> </div> <div class="doc_text"> <p><a href="http://code.roadsend.com/rphp">Roadsend PHP</a> (rphp) is an open source implementation of the PHP programming language that uses LLVM for its optimizer, JIT, and static compiler. This is a reimplementation of an earlier project that is now based on LLVM.</p> </div> <!--=========================================================================--> <div class="doc_subsection"> <a name="Unladen Swallow">Unladen Swallow</a> </div> <div class="doc_text"> <p><a href="http://code.google.com/p/unladen-swallow/">Unladen Swallow</a> is a branch of <a href="http://python.org/">Python</a> intended to be fully compatible and significantly faster. It uses LLVM's optimization passes and JIT compiler.</p> </div> <!--=========================================================================--> <div class="doc_subsection"> <a name="Rubinius">Rubinius</a> </div> <div class="doc_text"> <p><a href="http://github.com/evanphx/rubinius">Rubinius</a> is a new virtual machine for Ruby. It leverages LLVM to dynamically compile Ruby code down to machine code using LLVM's JIT.</p> </div> <!-- *********************************************************************** --> <div class="doc_section"> <a name="whatsnew">What's New in LLVM 2.6?</a> </div> <!-- *********************************************************************** --> <div class="doc_text"> <p>This release includes a huge number of bug fixes, performance tweaks, and minor improvements. Some of the major improvements and new features are listed in this section. </p> </div> <!--=========================================================================--> <div class="doc_subsection"> <a name="majorfeatures">Major New Features</a> </div> <div class="doc_text"> <p>LLVM 2.6 includes several major new capabilities:</p> <ul> <li>Something wonderful!</li> <li>LLVM 2.6 includes a brand new experimental LLVM bindings to the Ada2005 programming language.</li> </ul> </div> <!--=========================================================================--> <div class="doc_subsection"> <a name="llvm-gcc">llvm-gcc 4.2 Improvements</a> </div> <div class="doc_text"> <p>LLVM fully supports the llvm-gcc 4.2 front-end, which marries the GCC front-ends and driver with the LLVM optimizer and code generator. It currently includes support for the C, C++, Objective-C, Ada, and Fortran front-ends.</p> <ul> <li>Something wonderful!</li> </ul> </div> <!--=========================================================================--> <div class="doc_subsection"> <a name="coreimprovements">LLVM IR and Core Improvements</a> </div> <div class="doc_text"> <p>LLVM IR has several new features that are used by our existing front-ends and can be useful if you are writing a front-end for LLVM:</p> <ul> <li>Something wonderful!</li> </ul> </div> <!--=========================================================================--> <div class="doc_subsection"> <a name="optimizer">Optimizer Improvements</a> </div> <div class="doc_text"> <p>In addition to a large array of bug fixes and minor performance tweaks, this release includes a few major enhancements and additions to the optimizers:</p> <ul> <li>Something wonderful!</li> </ul> </div> <!--=========================================================================--> <div class="doc_subsection"> <a name="codegen">Target Independent Code Generator Improvements</a> </div> <div class="doc_text"> <p>We have put a significant amount of work into the code generator infrastructure, which allows us to implement more aggressive algorithms and make it run faster:</p> <ul> <li>Something wonderful!</li> </ul> </div> <!--=========================================================================--> <div class="doc_subsection"> <a name="x86">X86-32 and X86-64 Target Improvements</a> </div> <div class="doc_text"> <p>New features of the X86 target include: </p> <ul> <li>Something wonderful!</li> </ul> </div> <!--=========================================================================--> <div class="doc_subsection"> <a name="pic16">PIC16 Target Improvements</a> </div> <div class="doc_text"> <p>New features of the PIC16 target include: </p> <ul> <li>Something wonderful!</li> </ul> <p>Things not yet supported:</p> <ul> <li>Floating point.</li> <li>Passing/returning aggregate types to and from functions.</li> <li>Variable arguments.</li> <li>Indirect function calls.</li> <li>Interrupts/programs.</li> <li>Debug info.</li> </ul> </div> <!--=========================================================================--> <div class="doc_subsection"> <a name="ARM">ARM Target Improvements</a> </div> <div class="doc_text"> <p>New features of the ARM target include: </p> <ul> <li>Preliminary support for processors, such as the Cortex-A8 and Cortex-A9, that implement version v7-A of the ARM architecture. The ARM backend now supports both the Thumb2 and Advanced SIMD (Neon) instruction sets. The AAPCS-VFP "hard float" calling conventions are also supported with the <tt>-float-abi=hard</tt> flag. These features are still somewhat experimental and subject to change. The Neon intrinsics, in particular, may change in future releases of LLVM. </li> </ul> </div> <!--=========================================================================--> <div class="doc_subsection"> <a name="llvmc">Improvements in LLVMC</a> </div> <div class="doc_text"> <p>New features include:</p> <ul> <li>Something wonderful!</li> </ul> </div> <!--=========================================================================--> <div class="doc_subsection"> <a name="changes">Major Changes and Removed Features</a> </div> <div class="doc_text"> <p>If you're already an LLVM user or developer with out-of-tree changes based on LLVM 2.5, this section lists some "gotchas" that you may run into upgrading from the previous release.</p> <ul> <li>Something horrible!</li> </ul> <p>In addition, many APIs have changed in this release. Some of the major LLVM API changes are:</p> <ul> <li>LLVM's global uniquing tables for <tt>Type</tt>s and <tt>Constant</tt>s have been privatized into members of an <tt>LLVMContext</tt>. A number of APIs now take an <tt>LLVMContext</tt> as a parameter. To smooth the transition for clients that will only ever use a single context, the new <tt>getGlobalContext()</tt> API can be used to access a default global context which can be passed in any and all cases where a context is required. <li>The <tt>getABITypeSize</tt> methods are now called <tt>getAllocSize</tt>.</li> <li>The <tt>Add</tt>, <tt>Sub</tt>, and <tt>Mul</tt> operators are no longer overloaded for floating-point types. Floating-point addition, subtraction, and multiplication are now represented with new operators <tt>FAdd</tt>, <tt>FSub</tt>, and <tt>FMul</tt>. In the <tt>IRBuilder</tt> API, <tt>CreateAdd</tt>, <tt>CreateSub</tt>, <tt>CreateMul</tt>, and <tt>CreateNeg</tt> should only be used for integer arithmetic now; <tt>CreateFAdd</tt>, <tt>CreateFSub</tt>, <tt>CreateFMul</tt>, and <tt>CreateFNeg</tt> should now be used for floating-point arithmetic.</li> <li>The DynamicLibrary class can no longer be constructed, its functionality has moved to static member functions.</li> <li><tt>raw_fd_ostream</tt>'s constructor for opening a given filename now takes an extra <tt>Force</tt> argument. If <tt>Force</tt> is set to <tt>false</tt>, an error will be reported if a file with the given name already exists. If <tt>Force</tt> is set to <tt>true</tt>, the file will be silently truncated (which is the behavior before this flag was added).</li> <li><tt>SCEVHandle</tt> no longer exists, because reference counting is no longer done for <tt>SCEV*</tt> objects, instead <tt>const SCEV*</tt> should be used.</li> <li>Many APIs, notably <tt>llvm::Value</tt>, now use the <tt>StringRef</tt> and <tt>Twine</tt> classes instead of passing <tt>const char*</tt> or <tt>std::string</tt>, as described in the <a href="ProgrammersManual.html#string_apis">Programmer's Manual</a>. Most clients should be unaffected by this transition, unless they are used to <tt>Value::getName()</tt> returning a string. Here are some tips on updating to 2.6: <ul> <li><tt>getNameStr()</tt> is still available, and matches the old behavior. Replacing <tt>getName()</tt> calls with this is an safe option, although more efficient alternatives are now possible.</li> <li>If you were just relying on <tt>getName()</tt> being able to be sent to a <tt>std::ostream</tt>, consider migrating to <tt>llvm::raw_ostream</tt>.</li> <li>If you were using <tt>getName().c_str()</tt> to get a <tt>const char*</tt> pointer to the name, you can use <tt>getName().data()</tt>. Note that this string (as before), may not be the entire name if the name containts embedded null characters.</li> <li>If you were using operator plus on the result of <tt>getName()</tt> and treating the result as an <tt>std::string</tt>, you can either uses <tt>Twine::str</tt> to get the result as an <tt>std::string</tt>, or could move to a <tt>Twine</tt> based design.</li> <li><tt>isName()</tt> should be replaced with comparison against <tt>getName()</tt> (this is now efficient). </ul> </li> <li>The registration interfaces for backend Targets has changed (what was previously TargetMachineRegistry). For backend authors, see the <a href="WritingAnLLVMBackend.html#TargetRegistration">Writing An LLVM Backend</a> guide. For clients, the notable API changes are: <ul> <li><tt>TargetMachineRegistry</tt> has been renamed to <tt>TargetRegistry</tt>.</li> <li>Clients should move to using the <tt>TargetRegistry::lookupTarget()</tt> function to find targets.</li> </ul> </li> <li>llvm-dis now fails if output file exists, instead of dumping to stdout. FIXME: describe any other tool changes due to the raw_fd_ostream change. FIXME: This is not an API change, maybe there should be a tool changes section?</li> <li>temporarely due to Context API change passes should call doInitialization() method of the pass they inherit from, otherwise Context is NULL. FIXME: remove this entry when this is no longer needed.<li> </ul> </div> <!-- *********************************************************************** --> <div class="doc_section"> <a name="portability">Portability and Supported Platforms</a> </div> <!-- *********************************************************************** --> <div class="doc_text"> <p>LLVM is known to work on the following platforms:</p> <ul> <li>Intel and AMD machines (IA32, X86-64, AMD64, EMT-64) running Red Hat Linux, Fedora Core, FreeBSD and AuroraUX (and probably other unix-like systems).</li> <li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit and 64-bit modes.</li> <li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li> <li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited support is available for native builds with Visual C++).</li> <li>Sun UltraSPARC workstations running Solaris 10.</li> <li>Alpha-based machines running Debian GNU/Linux.</li> </ul> <p>The core LLVM infrastructure uses GNU autoconf to adapt itself to the machine and operating system on which it is built. However, minor porting may be required to get LLVM to work on new platforms. We welcome your portability patches and reports of successful builds or error messages.</p> </div> <!-- *********************************************************************** --> <div class="doc_section"> <a name="knownproblems">Known Problems</a> </div> <!-- *********************************************************************** --> <div class="doc_text"> <p>This section contains significant known problems with the LLVM system, listed by component. If you run into a problem, please check the <a href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if there isn't already one.</p> <ul> <li>LLVM will not correctly compile on Solaris and/or OpenSolaris using the stock GCC 3.x.x series 'out the box', See: <a href="#brokengcc">Broken versions of GCC and other tools</a>. However, A <a href="http://pkg.auroraux.org/GCC">Modern GCC Build</a> for x86/x64 has been made available from the third party AuroraUX Project that has been meticulously tested for bootstrapping LLVM & Clang.</li> </ul> </div> <!-- ======================================================================= --> <div class="doc_subsection"> <a name="experimental">Experimental features included with this release</a> </div> <div class="doc_text"> <p>The following components of this LLVM release are either untested, known to be broken or unreliable, or are in early development. These components should not be relied on, and bugs should not be filed against them, but they may be useful to some people. In particular, if you would like to work on one of these components, please contact us on the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p> <ul> <li>The MSIL, Alpha, SPU, MIPS, and PIC16 backends are experimental.</li> <li>The <tt>llc</tt> "<tt>-filetype=asm</tt>" (the default) is the only supported value for this option.</li> </ul> </div> <!-- ======================================================================= --> <div class="doc_subsection"> <a name="x86-be">Known problems with the X86 back-end</a> </div> <div class="doc_text"> <ul> <li>The X86 backend does not yet support all <a href="http://llvm.org/PR879">inline assembly that uses the X86 floating point stack</a>. It supports the 'f' and 't' constraints, but not 'u'.</li> <li>The X86 backend generates inefficient floating point code when configured to generate code for systems that don't have SSE2.</li> <li>Win64 code generation wasn't widely tested. Everything should work, but we expect small issues to happen. Also, llvm-gcc cannot build the mingw64 runtime currently due to <a href="http://llvm.org/PR2255">several</a> <a href="http://llvm.org/PR2257">bugs</a> and due to lack of support for the 'u' inline assembly constraint and for X87 floating point inline assembly.</li> <li>The X86-64 backend does not yet support the LLVM IR instruction <tt>va_arg</tt>. Currently, the llvm-gcc and front-ends support variadic argument constructs on X86-64 by lowering them manually.</li> </ul> </div> <!-- ======================================================================= --> <div class="doc_subsection"> <a name="ppc-be">Known problems with the PowerPC back-end</a> </div> <div class="doc_text"> <ul> <li>The Linux PPC32/ABI support needs testing for the interpreter and static compilation, and lacks support for debug information.</li> </ul> </div> <!-- ======================================================================= --> <div class="doc_subsection"> <a name="arm-be">Known problems with the ARM back-end</a> </div> <div class="doc_text"> <ul> <li>Support for the Advanced SIMD (Neon) instruction set is still incomplete and not well tested. Some features may not work at all, and the code quality may be poor in some cases.</li> <li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6 processors, thumb programs can crash or produce wrong results (<a href="http://llvm.org/PR1388">PR1388</a>).</li> <li>Compilation for ARM Linux OABI (old ABI) is supported but not fully tested. </li> <li>There is a bug in QEMU-ARM (<= 0.9.0) which causes it to incorrectly execute programs compiled with LLVM. Please use more recent versions of QEMU.</li> </ul> </div> <!-- ======================================================================= --> <div class="doc_subsection"> <a name="sparc-be">Known problems with the SPARC back-end</a> </div> <div class="doc_text"> <ul> <li>The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not support the 64-bit SPARC ABI (-m64).</li> </ul> </div> <!-- ======================================================================= --> <div class="doc_subsection"> <a name="mips-be">Known problems with the MIPS back-end</a> </div> <div class="doc_text"> <ul> <li>The O32 ABI is not fully supported.</li> <li>64-bit MIPS targets are not supported yet.</li> </ul> </div> <!-- ======================================================================= --> <div class="doc_subsection"> <a name="alpha-be">Known problems with the Alpha back-end</a> </div> <div class="doc_text"> <ul> <li>On 21164s, some rare FP arithmetic sequences which may trap do not have the appropriate nops inserted to ensure restartability.</li> </ul> </div> <!-- ======================================================================= --> <div class="doc_subsection"> <a name="c-be">Known problems with the C back-end</a> </div> <div class="doc_text"> <ul> <li><a href="http://llvm.org/PR802">The C backend has only basic support for inline assembly code</a>.</li> <li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common C++ programs</a>, preventing intermixing between C++ compiled by the CBE and C++ code compiled with <tt>llc</tt> or native compilers.</li> <li>The C backend does not support all exception handling constructs.</li> <li>The C backend does not support arbitrary precision integers.</li> </ul> </div> <!-- ======================================================================= --> <div class="doc_subsection"> <a name="c-fe">Known problems with the llvm-gcc C front-end</a> </div> <div class="doc_text"> <p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time Optimization</a> on most platforms "out-of-the-box". Please inquire on the LLVMdev mailing list if you are interested.</p> <p>The only major language feature of GCC not supported by llvm-gcc is the <tt>__builtin_apply</tt> family of builtins. However, some extensions are only supported on some targets. For example, trampolines are only supported on some targets (these are used when you take the address of a nested function).</p> <p>If you run into GCC extensions which are not supported, please let us know. </p> </div> <!-- ======================================================================= --> <div class="doc_subsection"> <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a> </div> <div class="doc_text"> <p>The C++ front-end is considered to be fully tested and works for a number of non-trivial programs, including LLVM itself, Qt, Mozilla, etc.</p> <ul> <li>Exception handling works well on the X86 and PowerPC targets. Currently only Linux and Darwin targets are supported (both 32 and 64 bit).</li> </ul> </div> <!-- ======================================================================= --> <div class="doc_subsection"> <a name="fortran-fe">Known problems with the llvm-gcc Fortran front-end</a> </div> <div class="doc_text"> <ul> <li>Fortran support generally works, but there are still several unresolved bugs in Bugzilla. Please see the tools/gfortran component for details.</li> </ul> </div> <!-- ======================================================================= --> <div class="doc_subsection"> <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a> </div> <div class="doc_text"> The llvm-gcc 4.2 Ada compiler works fairly well; however, this is not a mature technology, and problems should be expected. <ul> <li>The Ada front-end currently only builds on X86-32. This is mainly due to lack of trampoline support (pointers to nested functions) on other platforms. However, it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a> which does support trampolines.</li> <li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>. This is due to lack of LLVM support for <tt>setjmp</tt>/<tt>longjmp</tt> style exception handling, which is used internally by the compiler. Workaround: configure with --disable-bootstrap.</li> <li>The c380004, <a href="http://llvm.org/PR2010">c393010</a> and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail (c380004 also fails with gcc-4.2 mainline). If the compiler is built with checks disabled then <a href="http://llvm.org/PR2010">c393010</a> causes the compiler to go into an infinite loop, using up all system memory.</li> <li>Some GCC specific Ada tests continue to crash the compiler.</li> <li>The -E binder option (exception backtraces) <a href="http://llvm.org/PR1982">does not work</a> and will result in programs crashing if an exception is raised. Workaround: do not use -E.</li> <li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start or finish at a non-byte offset</a> in a record. Workaround: do not pack records or use representation clauses that result in a field of a non-discrete type starting or finishing in the middle of a byte.</li> <li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers 'main' as generated by the Ada binder to be invalid</a>. Workaround: hand edit the file to use pointers for <tt>argv</tt> and <tt>envp</tt> rather than integers.</li> <li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is ignored</a>.</li> </ul> </div> <!-- *********************************************************************** --> <div class="doc_section"> <a name="additionalinfo">Additional Information</a> </div> <!-- *********************************************************************** --> <div class="doc_text"> <p>A wide variety of additional information is available on the <a href="http://llvm.org">LLVM web page</a>, in particular in the <a href="http://llvm.org/docs/">documentation</a> section. The web page also contains versions of the API documentation which is up-to-date with the Subversion version of the source code. You can access versions of these documents specific to this release by going into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p> <p>If you have any questions or comments about LLVM, please feel free to contact us via the <a href="http://llvm.org/docs/#maillist"> mailing lists</a>.</p> </div> <!-- *********************************************************************** --> <hr> <address> <a href="http://jigsaw.w3.org/css-validator/check/referer"><img src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a> <a href="http://validator.w3.org/check/referer"><img src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a> <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br> Last modified: $Date$ </address> </body> </html>