X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=docs%2FGettingStarted.html;h=8bb1ac41e4fd443959a017d6f4532ce00b7676f2;hb=0dd27da1841ca50d00aad3465f4f9b6a646fd64e;hp=e2ee70abc9e44fbf65f9389f731d7bdc80399a04;hpb=98044e4a622e2cdc05b22f5d221d4c6504838d25;p=oota-llvm.git diff --git a/docs/GettingStarted.html b/docs/GettingStarted.html index e2ee70abc9e..8bb1ac41e4f 100644 --- a/docs/GettingStarted.html +++ b/docs/GettingStarted.html @@ -17,37 +17,37 @@
  • Getting Started Quickly (A Summary)
  • Requirements
      -
    1. Hardware -
    2. Software -
    3. Broken versions of GCC and other tools +
    4. Hardware
      5. +
    5. Software
      6. +
    6. Broken versions of GCC and other tools
  • Getting Started with LLVM
      -
    1. Terminology and Notation -
    2. Setting Up Your Environment -
    3. Unpacking the LLVM Archives -
    4. Checkout LLVM from Subversion -
    5. Install the GCC Front End -
    6. Local LLVM Configuration -
    7. Compiling the LLVM Suite Source Code -
    8. Cross-Compiling LLVM -
    9. The Location of LLVM Object Files -
    10. Optional Configuration Items +
    11. Terminology and Notation
      12. +
    12. Setting Up Your Environment
      13. +
    13. Unpacking the LLVM Archives
      14. +
    14. Checkout LLVM from Subversion
      15. +
    15. Install the GCC Front End
      16. +
    16. Local LLVM Configuration
      17. +
    17. Compiling the LLVM Suite Source Code
      18. +
    18. Cross-Compiling LLVM
      19. +
    19. The Location of LLVM Object Files
      20. +
    20. Optional Configuration Items
  • Program layout
      -
    1. llvm/examples -
    2. llvm/include -
    3. llvm/lib -
    4. llvm/projects -
    5. llvm/runtime -
    6. llvm/test -
    7. llvm-test -
    8. llvm/tools -
    9. llvm/utils -
    10. llvm/win32 +
    11. llvm/examples
      12. +
    12. llvm/include
      13. +
    13. llvm/lib
      14. +
    14. llvm/projects
      15. +
    15. llvm/runtime
      16. +
    16. llvm/test
      17. +
    17. llvm-test
      18. +
    18. llvm/tools
      19. +
    19. llvm/utils
      20. +
    20. llvm/win32
  • An Example Using the LLVM Tool Chain @@ -82,14 +82,14 @@ basic information.

    First, LLVM comes in two pieces. The first piece is the LLVM suite. This contains all of the tools, libraries, and header files needed to use the low -level virtual machine. It contains an assembler, disassembler, bytecode -analyzer and bytecode optimizer. It also contains a test suite that can be +level virtual machine. It contains an assembler, disassembler, bitcode +analyzer and bitcode optimizer. It also contains a test suite that can be used to test the LLVM tools and the GCC front end.

    The second piece is the GCC front end. This component provides a version of -GCC that compiles C and C++ code into LLVM bytecode. Currently, the GCC front +GCC that compiles C and C++ code into LLVM bitcode. Currently, the GCC front end uses the GCC parser to convert code to LLVM. Once -compiled into LLVM bytecode, a program can be manipulated with the LLVM tools +compiled into LLVM bitcode, a program can be manipulated with the LLVM tools from the LLVM suite.

    @@ -114,14 +114,15 @@ and performance.

  • Read the documentation.
  • Read the documentation.
  • Remember that you were warned twice about reading the documentation.
    • -
  • Install the GCC front end if you intend to compile C or C++: +
  • Install the llvm-gcc-4.2 front end if you intend to compile C or C++ + (see Install the GCC Front End for details):
    1. cd where-you-want-the-C-front-end-to-live
      2. -
    2. gunzip --stdout llvm-gcc.platform.tar.gz | tar -xvf - -
      3. -
    3. cd llvm-gcc3.4/platform (llvm-gcc3.4 only)
      - ./fixheaders
      4. -
    4. Add llvm-gcc's "bin" directory to your PATH variable.
      5. +
    5. gunzip --stdout llvm-gcc-4.2-version-platform.tar.gz | tar -xvf -
      6. +
    6. install-binutils-binary-from-MinGW (Windows only)
      7. +
    7. Note: If the binary extension is ".bz" use bunzip2 instead of gunzip.
      8. +
    8. Note: On Windows, use 7-Zip or a similar archiving tool.
      9. +
    9. Add llvm-gcc's "bin" directory to your PATH environment variable.
  • Get the LLVM Source Code @@ -160,7 +161,8 @@ and performance.
  • --with-llvmgccdir=directory

    Optionally, specify for directory the full pathname of the C/C++ front end installation to use with this LLVM configuration. If - not specified, the PATH will be searched.

    • + not specified, the PATH will be searched. This is only needed if you + want to run the testsuite or do some special kinds of LLVM builds.

  • --enable-spec2000=directory

    Enable the SPEC2000 benchmarks for testing. The SPEC2000 benchmarks should be available in @@ -215,11 +217,21 @@ software you will need.

    Arch Compilers + + AuroraUX + x861 + GCC + Linux x861 GCC + + Linux + amd64 + GCC + Solaris V9 (Ultrasparc) @@ -236,25 +248,21 @@ software you will need.

    GCC - MacOS X2 + MacOS X2,9 x86 GCC - Cygwin/Win32 - x861,8 - GCC 3.4.X, binutils 2.15 + x861,8, + 11 + GCC 3.4.X, binutils 2.20 MinGW/Win32 - x861,6,8 - GCC 3.4.X, binutils 2.15 - - - Linux - amd643 - GCC + x861,6, + 8, 10 + GCC 3.4.X, binutils 2.20 @@ -269,7 +277,7 @@ software you will need.

    Windows x861 - Visual Studio .NET4,5 + Visual Studio 2005 SP1 or higher4,5 AIX3,4 PowerPC @@ -306,39 +314,44 @@ software you will need.

    up
  • Code generation supported for 32-bit ABI only
  • No native code generation
    • -
  • Build is not complete: one or more tools don't link
    • +
  • Build is not complete: one or more tools do not link or function
  • The GCC-based C/C++ frontend does not build
    • -
  • The port is done using the MSYS shell. -Download and install -bison (excl. M4.exe) and flex in that order. Build binutils-2.15 from source, -if necessary. Bison & flex can be also grabbed from GNUWin32 sf.net -project.
    • +
  • The port is done using the MSYS shell.
  • Native code generation exists but is not complete.
    • -
  • Binutils up to post-2.17 has bug in bfd/cofflink.c - preventing LLVM from building correctly. Several workarounds have been - introduced into LLVM build system, but the bug can occur anytime in the - future. We highly recommend that you rebuild your current binutils with the - patch from - Binutils bugzilla, if it wasn't already applied.
    • +
  • Binutils 2.20 or later is required to build the assembler + generated by LLVM properly.
    • +
  • XCode 2.5 and gcc 4.0.1 (Apple Build 5370) will trip + internal LLVM assert messages when compiled for Release at optimization + levels greater than 0 (i.e., "-O1" and higher). + Add OPTIMIZE_OPTION="-O0" to the build command line + if compiling for LLVM Release or bootstrapping the LLVM toolchain.
    • +
  • For MSYS/MinGW on Windows, be sure to install the MSYS + version of the perl package, and be sure it appears in your path + before any Windows-based versions such as Strawberry Perl and + ActivePerl, as these have Windows-specifics that will cause the + build to fail.
    • +
  • In general, LLVM modules requiring dynamic linking can + not be built on Windows. However, you can build LLVM tools using + "make tools-only".

    • Note that you will need about 1-3 GB of space for a full LLVM build in Debug mode, depending on the system (it is so large because of all the debugging information and the fact that the libraries are statically linked into multiple -tools). If you do not need many of the tools and you are space-conscious, -you can disable them individually in llvm/tools/Makefile. The Release -build requires considerably less space.

    +tools). If you do not need many of the tools and you are space-conscious, you +can pass ONLY_TOOLS="tools you need" to make. The Release build +requires considerably less space.

    The LLVM suite may compile on other platforms, but it is not guaranteed to do so. If compilation is successful, the LLVM utilities should be -able to assemble, disassemble, analyze, and optimize LLVM bytecode. Code +able to assemble, disassemble, analyze, and optimize LLVM bitcode. Code generation should work as well, although the generated native code may not work on your platform.

    The GCC front end is not very portable at the moment. If you want to get it to work on another platform, you can download a copy of the source and try to compile it on your platform.

    +href="GCCFEBuildInstrs.html">try to compile it on your platform.

    @@ -371,18 +384,6 @@ href="CFEBuildInstrs.html">try to compile it on your platform.

    For building the CFE - - Flex - 2.5.4 - LEX compiler - - - - Bison - 1.28, 1.35, 1.75, 1.875d, 2.0, or 2.1
    (not 1.85 or 1.875) - YACC compiler - - SVN ≥1.3 @@ -421,19 +422,19 @@ href="CFEBuildInstrs.html">try to compile it on your platform.

    GNU Autoconf - 2.59 + 2.60 Configuration script builder4 GNU Automake - 1.9.2 + 1.9.6 aclocal macro generator4 libtool - 1.5.10 + 1.5.22 Shared library manager4 @@ -469,7 +470,6 @@ href="CFEBuildInstrs.html">try to compile it on your platform.

  • date - print the current date/time
  • echo - print to standard output
  • egrep - extended regular expression search utility
    • -
  • etags - C/C++ tag file creator for vim/emacs
  • find - find files/dirs in a file system
  • grep - regular expression search utility
  • gzip* - gzip command for distribution generation
    • @@ -511,28 +511,33 @@ of GCC you are using. problems in the STL that effectively prevent it from compiling LLVM.

    -

    GCC 3.2.2: This version of GCC fails to compile LLVM.

    +

    GCC 3.2.2 and 3.2.3: These versions of GCC fails to compile LLVM with +a bogus template error. This was fixed in later GCCs.

    GCC 3.3.2: This version of GCC suffered from a serious bug which causes it to crash in the "convert_from_eh_region_ranges_1" GCC function.

    Cygwin GCC 3.3.3: The version of GCC 3.3.3 commonly shipped with - Cygwin does not work. Please upgrade + Cygwin does not work. Please upgrade to a newer version if possible.

    SuSE GCC 3.3.3: The version of GCC 3.3.3 shipped with SuSE 9.1 (and possibly others) does not compile LLVM correctly (it appears that exception handling is broken in some cases). Please download the FSF 3.3.3 or upgrade to a newer version of GCC.

    -

    GCC 3.4.0 on linux/x86 (32-bit): GCC miscompiles portions of the +

    GCC 3.4.0 on linux/x86 (32-bit): GCC miscompiles portions of the code generator, causing an infinite loop in the llvm-gcc build when built with optimizations enabled (i.e. a release build).

    -

    GCC 3.4.2 on linux/x86 (32-bit): GCC miscompiles portions of the +

    GCC 3.4.2 on linux/x86 (32-bit): GCC miscompiles portions of the code generator at -O3, as with 3.4.0. However gcc 3.4.2 (unlike 3.4.0) correctly compiles LLVM at -O2. A work around is to build release LLVM builds with "make ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O2 ..."

    -

    GCC 3.4.x on X86-64/amd64: GCC +

    GCC 3.4.x on X86-64/amd64: GCC miscompiles portions of LLVM.

    +

    GCC 3.4.4 (CodeSourcery ARM 2005q3-2): this compiler miscompiles LLVM + when building with optimizations enabled. It appears to work with + "make ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O1" or build a debug + build.

    IA-64 GCC 4.0.0: The IA-64 version of GCC 4.0.0 is known to miscompile LLVM.

    Apple Xcode 2.3: GCC crashes when compiling LLVM at -O3 (which is the @@ -547,6 +552,18 @@ the "convert_from_eh_region_ranges_1" GCC function.

    portions of its testsuite.

    GCC 4.1.2 on OpenSUSE: Seg faults during libstdc++ build and on x86_64 platforms compiling md5.c gets a mangled constant.

    +

    GCC 4.1.2 (20061115 (prerelease) (Debian 4.1.1-21)) on Debian: Appears +to miscompile parts of LLVM 2.4. One symptom is ValueSymbolTable complaining +about symbols remaining in the table on destruction.

    +

    GCC 4.1.2 20071124 (Red Hat 4.1.2-42): Suffers from the same symptoms +as the previous one. It appears to work with ENABLE_OPTIMIZED=0 (the default).

    +

    Cygwin GCC 4.3.2 20080827 (beta) 2: + Users reported various problems related + with link errors when using this GCC version.

    +

    Debian GCC 4.3.2 on X86: Crashes building some files in LLVM 2.6.

    +

    GCC 4.3.3 (Debian 4.3.3-10) on ARM: Miscompiles parts of LLVM 2.6 +when optimizations are turned on. The symptom is an infinite loop in +FoldingSetImpl::RemoveNode while running the code generator.

    GNU ld 2.16.X. Some 2.16.X versions of the ld linker will produce very long warning messages complaining that some ".gnu.linkonce.t.*" symbol was defined in a discarded section. You can safely ignore these messages as they are @@ -558,6 +575,12 @@ href="http://sourceware.org/bugzilla/show_bug.cgi?id=3111">a bug which causes huge link times (minutes instead of seconds) when building LLVM. We recommend upgrading to a newer version (2.17.50.0.4 or later).

    +

    GNU Binutils 2.19.1 Gold: This version of Gold contained +a bug +which causes intermittent failures when building LLVM with position independent +code. The symptom is an error about cyclic dependencies. We recommend +upgrading to a newer version of Gold.

    + @@ -629,11 +652,11 @@ In order to compile and use LLVM, you may need to set some environment variables.
    -
    LLVM_LIB_SEARCH_PATH=/path/to/your/bytecode/libs
    +
    LLVM_LIB_SEARCH_PATH=/path/to/your/bitcode/libs
    [Optional] This environment variable helps LLVM linking tools find the - locations of your bytecode libraries. It is provided only as a + locations of your bitcode libraries. It is provided only as a convenience since you can specify the paths using the -L options of the - tools and the C/C++ front-end will automatically use the bytecode files + tools and the C/C++ front-end will automatically use the bitcode files installed in its lib directory.
    @@ -658,24 +681,20 @@ compressed with the gzip program.

    The files are as follows, with x.y marking the version number:

    llvm-x.y.tar.gz
    -
    Source release for the LLVM libraries and tools.
    +
    Source release for the LLVM libraries and tools.
    llvm-test-x.y.tar.gz
    Source release for the LLVM test suite.
    -
    llvm-gcc4-x.y.source.tar.gz
    -
    Source release of the llvm-gcc4 front end. See README.LLVM in the root - directory for build instructions.
    +
    llvm-gcc-4.2-x.y.source.tar.gz
    +
    Source release of the llvm-gcc-4.2 front end. See README.LLVM in the root + directory for build instructions.
    -
    llvm-gcc4-x.y-platform.tar.gz
    -
    Binary release of the llvm-gcc4 front end for a specific platform.
    +
    llvm-gcc-4.2-x.y-platform.tar.gz
    +
    Binary release of the llvm-gcc-4.2 front end for a specific platform.
    -

    It is also possible to download the sources of the llvm-gcc4 front end from a -read-only subversion mirror at -svn://anonsvn.opensource.apple.com/svn/llvm/trunk.

    - @@ -686,7 +705,7 @@ svn://anonsvn.opensource.apple.com/svn/llvm/trunk.

    If you have access to our Subversion repository, you can get a fresh copy of -the entire source code. All you need to do is check it out from Subvresion as +the entire source code. All you need to do is check it out from Subversion as follows:

    @@ -742,36 +772,66 @@ instructions to successfully get and build the LLVM GCC front-end.

    -

    Before configuring and compiling the LLVM suite, you can optionally extract the -LLVM GCC front end from the binary distribution. It is used for running the -llvm-test testsuite and for compiling C/C++ programs. Note that you can optionally -build llvm-gcc yourself after building the +

    Before configuring and compiling the LLVM suite (or if you want to use just the LLVM +GCC front end) you can optionally extract the front end from the binary distribution. +It is used for running the llvm-test testsuite and for compiling C/C++ programs. Note that +you can optionally build llvm-gcc yourself after building the main LLVM repository.

    -

    To install the GCC front end, do the following:

    +

    To install the GCC front end, do the following (on Windows, use an archival tool +like 7-zip that understands gzipped tars):

    1. cd where-you-want-the-front-end-to-live
      2. -
    2. gunzip --stdout llvmgcc-version.platform.tar.gz | tar -xvf +
    3. gunzip --stdout llvm-gcc-4.2-version-platform.tar.gz | tar -xvf -
    -

    Once the binary is uncompressed, you should add a symlink for llvm-gcc and -llvm-g++ to some directory in your path. When you configure LLVM, it will -automatically detect llvm-gcc's presence (if it is in your path) enabling its -use in llvm-test. Note that you can always build or install llvm-gcc at any -pointer after building the main LLVM repository: just reconfigure llvm and +

    Once the binary is uncompressed, if you're using a *nix-based system, add a symlink for +llvm-gcc and llvm-g++ to some directory in your path. If you're using a +Windows-based system, add the bin subdirectory of your front end installation directory +to your PATH environment variable. For example, if you uncompressed the binary to +c:\llvm-gcc, add c:\llvm-gcc\bin to your PATH.

    + +

    If you now want to build LLVM from source, when you configure LLVM, it will +automatically detect llvm-gcc's presence (if it is in your path) enabling its +use in llvm-test. Note that you can always build or install llvm-gcc at any +point after building the main LLVM repository: just reconfigure llvm and llvm-test will pick it up.

    -

    The binary versions of the GCC front end may not suit all of your needs. For -example, the binary distribution may include an old version of a system header -file, not "fix" a header file that needs to be fixed for GCC, or it may be -linked with libraries not available on your system.

    +

    As a convenience for Windows users, the front end binaries for MinGW/x86 include +versions of the required w32api and mingw-runtime binaries. The last remaining step for +Windows users is to simply uncompress the binary binutils package from +MinGW into your front end installation directory. While the +front end installation steps are not quite the same as a typical manual MinGW installation, +they should be similar enough to those who have previously installed MinGW on Windows systems.

    + +

    To install binutils on Windows:

    + +
      +
    1. download GNU Binutils from MinGW Downloads
      2. +
    2. cd where-you-uncompressed-the-front-end
      3. +
    3. uncompress archived binutils directories (not the tar file) into the current directory
      4. +
    -

    In cases like these, you may want to try building the GCC front end from source. This is -much easier now than it was in the past.

    +

    The binary versions of the LLVM GCC front end may not suit all of your needs. For +example, the binary distribution may include an old version of a system header +file, not "fix" a header file that needs to be fixed for GCC, or it may be linked with +libraries not available on your system. In cases like these, you may want to try +building the GCC front end from source. Thankfully, +this is much easier now than it was in the past.

    + +

    We also do not currently support updating of the GCC front end by manually overlaying +newer versions of the w32api and mingw-runtime binary packages that may become available +from MinGW. At this time, it's best to think of the MinGW LLVM GCC front end binary as +a self-contained convenience package that requires Windows users to simply download and +uncompress the GNU Binutils binary package from the MinGW project.

    + +

    Regardless of your platform, if you discover that installing the LLVM GCC front end +binaries is not as easy as previously described, or you would like to suggest improvements, +please let us know how you would like to see things improved by dropping us a note on our +mailing list.

    @@ -825,7 +885,7 @@ script to configure the build system:

    will fail as these libraries require llvm-gcc and llvm-g++. See Install the GCC Front End for details on installing the C/C++ Front End. See - Bootstrapping the LLVM C/C++ Front-End + Bootstrapping the LLVM C/C++ Front-End for details on building the C/C++ Front End.
    --with-tclinclude
    Path to the tcl include directory under which tclsh can be @@ -838,9 +898,11 @@ script to configure the build system:

    --enable-optimized
    - Enables optimized compilation by default (debugging symbols are removed - and GCC optimization flags are enabled). The default is to use an - unoptimized build (also known as a debug build). + Enables optimized compilation (debugging symbols are removed + and GCC optimization flags are enabled). Note that this is the default + setting if you are using the LLVM distribution. The default behavior + of an Subversion checkout is to use an unoptimized build (also known as a + debug build).

    --enable-debug-runtime
    @@ -863,7 +925,7 @@ script to configure the build system:

    native compiler (no cross-compiler targets available). The "native" target is selected as the target of the build host. You can also specify a comma separated list of target names that you want available in llc. The target - names use all lower case. The current set of targets is:
    + names use all lower case. The current set of targets is:
    alpha, ia64, powerpc, skeleton, sparc, x86.

    --enable-doxygen
    @@ -881,15 +943,16 @@ script to configure the build system:

    To configure LLVM, follow these steps:

      -
    1. Change directory into the object root directory: -
      - cd OBJ_ROOT -

      +

    2. Change directory into the object root directory:

      -
    3. Run the configure script located in the LLVM source tree: -
      - SRC_ROOT/configure --prefix=/install/path [other options] -

      + 
      % cd OBJ_ROOT
      4. + +

    4. Run the configure script located in the LLVM source + tree:

      + +
      + 
      % SRC_ROOT/configure --prefix=/install/path [other options]
      +
    @@ -907,10 +970,12 @@ builds:

    Debug Builds
    - These builds are the default when one types gmake (unless the - --enable-optimized option was used during configuration). The - build system will compile the tools and libraries with debugging - information. + These builds are the default when one is using an Subversion checkout and + types gmake (unless the --enable-optimized option was + used during configuration). The build system will compile the tools and + libraries with debugging information. To get a Debug Build using the + LLVM distribution the --disable-optimized option must be passed + to configure.

    Release (Optimized) Builds @@ -920,6 +985,7 @@ builds:

    gmake command line. For these builds, the build system will compile the tools and libraries with GCC optimizations enabled and strip debugging information from the libraries and executables it generates. + Note that Release Builds are default when using an LLVM distribution.

    Profile Builds @@ -933,7 +999,7 @@ builds:

    Once you have LLVM configured, you can build it by entering the OBJ_ROOT directory and issuing the following command:

    -

    gmake

    +
    % gmake

    If the build fails, please check here to see if you are using a version of GCC that is known not to compile LLVM.

    @@ -943,7 +1009,7 @@ If you have multiple processors in your machine, you may wish to use some of the parallel build options provided by GNU Make. For example, you could use the command:

    -

    gmake -j2

    +
    % gmake -j2

    There are several special targets which are useful when working with the LLVM source code:

    @@ -973,8 +1039,8 @@ source code:

    gmake -C runtime install-bytecode
    Assuming you built LLVM into $OBJDIR, when this command is run, it will - install bytecode libraries into the GCC front end's bytecode library - directory. If you need to update your bytecode libraries, + install bitcode libraries into the GCC front end's bitcode library + directory. If you need to update your bitcode libraries, this is the target to use once you've built them.

    @@ -996,6 +1062,11 @@ declaring variables on the command line. The following are some examples:

    Perform a Release (Optimized) build without assertions enabled.

    + +
    gmake ENABLE_OPTIMIZED=0 +
    + Perform a Debug build. +

    gmake ENABLE_PROFILING=1
    @@ -1026,43 +1097,16 @@ that directory that is out of date.

    -

    It is possible to cross-compile LLVM. That is, you can create LLVM - executables and libraries for a platform different than the one one which you - are compiling. To do this, a few additional steps are - required. 1 To cross-compile LLVM, use - these instructions:

    -
      -
    1. Configure and build LLVM as a native compiler. You will need - just TableGen from that build. -
        -
      • If you have $LLVM_OBJ_ROOT=$LLVM_SRC_ROOT just execute - make -C utils/TableGen after configuring.
        • -
      • Otherwise you will need to monitor building process and terminate - it just after TableGen was built.
        • -
      -
      2. -
    2. Copy the TableGen binary to somewhere safe (out of your build tree). -
      3. -
    3. Configure LLVM to build with a cross-compiler. To do this, supply the - configure script with --build and --host options that - are different. The values of these options must be legal target triples - that your GCC compiler supports.
      4. -
    4. Put the saved TableGen executable into the - into $LLVM_OBJ_ROOT/{BUILD_TYPE}/bin directory (e.g. into - .../Release/bin for a Release build).
      5. -
    5. Build LLVM as usual.
      6. -
    -

    The result of such a build will produce executables that are not executable - on your build host (--build option) but can be executed on your compile host +

    It is possible to cross-compile LLVM itself. That is, you can create LLVM + executables and libraries to be hosted on a platform different from the + platform where they are build (a Canadian Cross build). To configure a + cross-compile, supply the configure script with --build and + --host options that are different. The values of these options must + be legal target triples that your GCC compiler supports.

    + +

    The result of such a build is executables that are not runnable on + on the build host (--build option) but can be executed on the compile host (--host option).

    -

    Notes:

    -
    -
      -
    1. Cross-compiling was tested only with Linux as - build platform and Windows as host using mingw32 cross-compiler. Other - combinations have not been tested.
      2. -
    -
    @@ -1081,12 +1125,12 @@ platforms or configurations using the same source tree.

    The LLVM build will place files underneath OBJ_ROOT in directories @@ -1134,28 +1178,32 @@ named after the build type:

    If you're running on a Linux system that supports the " - binfmt_misc" +href="http://www.tat.physik.uni-tuebingen.de/~rguenth/linux/binfmt_misc.html">binfmt_misc" module, and you have root access on the system, you can set your system up to -execute LLVM bytecode files directly. To do this, use commands like this (the +execute LLVM bitcode files directly. To do this, use commands like this (the first command may not be required if you are already using the module):

    -   $ mount -t binfmt_misc none /proc/sys/fs/binfmt_misc
-   $ echo ':llvm:M::llvm::/path/to/lli:' > /proc/sys/fs/binfmt_misc/register
-   $ chmod u+x hello.bc                (if needed)
-   $ ./hello.bc
+$ mount -t binfmt_misc none /proc/sys/fs/binfmt_misc
+$ echo ':llvm:M::BC::/path/to/lli:' > /proc/sys/fs/binfmt_misc/register
+$ chmod u+x hello.bc   (if needed)
+$ ./hello.bc

    -This allows you to execute LLVM bytecode files directly. Thanks to Jack -Cummings for pointing this out! +This allows you to execute LLVM bitcode files directly. On Debian, you +can also use this command instead of the 'echo' command above:

    +
    +
    +$ sudo update-binfmts --install llvm /path/to/lli --magic 'BC'
+
    +
    @@ -1224,8 +1272,8 @@ different tools.

    This directory holds the source code for the LLVM assembly language parser library.
    -
    llvm/lib/ByteCode/
    -
    This directory holds code for reading and write LLVM bytecode.
    +
    llvm/lib/BitCode/
    +
    This directory holds code for reading and write LLVM bitcode.
    llvm/lib/Analysis/
    This directory contains a variety of different program analyses, such as Dominator Information, Call Graphs, @@ -1254,7 +1302,7 @@ different tools.

    source code locations at which the program is executing.
    llvm/lib/ExecutionEngine/
    -
    This directory contains libraries for executing LLVM bytecode directly +
    This directory contains libraries for executing LLVM bitcode directly at runtime in both interpreted and JIT compiled fashions.
    llvm/lib/Support/
    @@ -1274,15 +1322,14 @@ different tools.

    This directory contains projects that are not strictly part of LLVM but are shipped with LLVM. This is also the directory where you should create your own LLVM-based projects. See llvm/projects/sample for an example of how - to set up your own project. See llvm/projects/Stacker for a fully - functional example of a compiler front end.

    + to set up your own project.

    llvm/runtime
    -

    This directory contains libraries which are compiled into LLVM bytecode and +

    This directory contains libraries which are compiled into LLVM bitcode and used when linking programs with the GCC front end. Most of these libraries are skeleton versions of real libraries; for example, libc is a stripped down version of glibc.

    @@ -1322,7 +1369,7 @@ end to compile.

    The tools directory contains the executables built out of the libraries above, which form the main part of the user interface. You can -always get help for a tool by typing tool_name --help. The +always get help for a tool by typing tool_name -help. The following is a brief introduction to the most important tools. More detailed information is in the Command Guide.

    @@ -1341,22 +1388,22 @@ information is in the Command Guide.

    be configured to utilize both LLVM and non-LLVM compilation tools to enable pre-processing, translation, optimization, assembly, and linking of programs all from one command line. llvmc also takes care of processing the - dependent libraries found in bytecode. This reduces the need to get the + dependent libraries found in bitcode. This reduces the need to get the traditional -l<name> options right on the command line. Please note that this tool, while functional, is still experimental and not feature complete.
    llvm-ar
    The archiver produces an archive containing - the given LLVM bytecode files, optionally with an index for faster + the given LLVM bitcode files, optionally with an index for faster lookup.
    llvm-as
    The assembler transforms the human readable LLVM assembly to LLVM - bytecode.
    + bitcode.
    llvm-dis
    -
    The disassembler transforms the LLVM bytecode to human readable +
    The disassembler transforms the LLVM bitcode to human readable LLVM assembly.
    llvm-ld
    @@ -1371,35 +1418,32 @@ information is in the Command Guide.

    lli
    lli is the LLVM interpreter, which - can directly execute LLVM bytecode (although very slowly...). In addition - to a simple interpreter, lli also has a tracing mode (entered by - specifying -trace on the command line). Finally, for - architectures that support it (currently x86, Sparc, and PowerPC), by default, - lli will function as a Just-In-Time compiler (if the - functionality was compiled in), and will execute the code much - faster than the interpreter.
    + can directly execute LLVM bitcode (although very slowly...). For architectures + that support it (currently x86, Sparc, and PowerPC), by default, lli + will function as a Just-In-Time compiler (if the functionality was compiled + in), and will execute the code much faster than the interpreter.
    llc
    llc is the LLVM backend compiler, which - translates LLVM bytecode to a native code assembly file or to C code (with + translates LLVM bitcode to a native code assembly file or to C code (with the -march=c option).
    llvm-gcc
    llvm-gcc is a GCC-based C frontend that has been retargeted to use LLVM as its backend instead of GCC's RTL backend. It can also emit LLVM - byte code or assembly (with the -emit-llvm option) instead of the + bitcode or assembly (with the -emit-llvm option) instead of the usual machine code output. It works just like any other GCC compiler, taking the typical -c, -S, -E, -o options that are typically used. Additionally, the the source code for llvm-gcc is available as a separate Subversion module.
    opt
    -
    opt reads LLVM bytecode, applies a series of LLVM to LLVM +
    opt reads LLVM bitcode, applies a series of LLVM to LLVM transformations (which are specified on the command line), and then outputs - the resultant bytecode. The 'opt --help' command is a good way to - get a list of the program transformations available in LLVM.
    + the resultant bitcode. The 'opt -help' command is a good way to + get a list of the program transformations available in LLVM.
    opt can also be used to run a specific analysis on an input - LLVM bytecode file and print out the results. It is primarily useful for + LLVM bitcode file and print out the results. It is primarily useful for debugging analyses, or familiarizing yourself with what an analysis does.
    @@ -1484,14 +1528,14 @@ are code generators for parts of LLVM infrastructure.

    This section gives an example of using LLVM. llvm-gcc3 is now obsolete, -so we only include instructiosn for llvm-gcc4. +so we only include instructions for llvm-gcc4.

    Note: The gcc4 frontend's invocation is considerably different from the previous gcc3 frontend. In particular, the gcc4 frontend does not -create bytecode by default: gcc4 produces native code. As the example below illustrates, -the '--emit-llvm' flag is needed to produce LLVM bytecode output. For makefiles and -configure scripts, the CFLAGS variable needs '--emit-llvm' to produce bytecode +create bitcode by default: gcc4 produces native code. As the example below illustrates, +the '--emit-llvm' flag is needed to produce LLVM bitcode output. For makefiles and +configure scripts, the CFLAGS variable needs '--emit-llvm' to produce bitcode output.

    @@ -1501,41 +1545,46 @@ output.

      -
    1. First, create a simple C file, name it 'hello.c': - 
      -   #include <stdio.h>
-   int main() {
-     printf("hello world\n");
-     return 0;
-   }
-
      2. +

    2. First, create a simple C file, name it 'hello.c':

      + +
      +
      +#include <stdio.h>
+
+int main() {
+  printf("hello world\n");
+  return 0;
+}
+

    3. Next, compile the C file into a native executable:

      -

      % llvm-gcc hello.c -o hello

      + 
      % llvm-gcc hello.c -o hello

      Note that llvm-gcc works just like GCC by default. The standard -S and -c arguments work as usual (producing a native .s or .o file, - respectively).

      + respectively).

      4. + +

    4. Next, compile the C file into a LLVM bitcode file:

      -

    5. Next, compile the C file into a LLVM bytecode file:

      -

      % llvm-gcc -O3 -emit-llvm hello.c -c -o hello.bc

      +
      + 
      % llvm-gcc -O3 -emit-llvm hello.c -c -o hello.bc

      The -emit-llvm option can be used with the -S or -c options to emit an LLVM ".ll" or ".bc" file (respectively) for the code. This allows you to use the standard LLVM tools on - the bytecode file.

      + the bitcode file.

      Unlike llvm-gcc3, llvm-gcc4 correctly responds to -O[0123] arguments.

    6. Run the program in both forms. To run the program, use:

      -

      % ./hello

      + 
      % ./hello

      and

      -

      % lli hello.bc

      + 
      % lli hello.bc

      The second examples shows how to invoke the LLVM JIT, lli.

      7. @@ -1543,21 +1592,28 @@ output.

    7. Use the llvm-dis utility to take a look at the LLVM assembly code:

      -

      % llvm-dis < hello.bc | less

      8. +
      +
      llvm-dis < hello.bc | less
      +

    8. Compile the program to native assembly using the LLC code generator:

      -

      % llc hello.bc -o hello.s

      + 
      % llc hello.bc -o hello.s

    9. Assemble the native assembly language file into a program:

      -

      Solaris:% /opt/SUNWspro/bin/cc -xarch=v9 hello.s -o hello.native

      -

      Others:% gcc hello.s -o hello.native

      +
      +
      +Solaris: % /opt/SUNWspro/bin/cc -xarch=v9 hello.s -o hello.native
+
+Others:  % gcc hello.s -o hello.native
+
      +

    10. Execute the native code program:

      -

      % ./hello.native

      + 
      % ./hello.native

      Note that using llvm-gcc to compile directly to native code (i.e. when the -emit-llvm option is not present) does steps 6/7/8 for you.

      @@ -1590,7 +1646,7 @@ Asked Questions page.

      -

      This document is just an introduction to how to use LLVM to do +

      This document is just an introduction on how to use LLVM to do some simple things... there are many more interesting and complicated things that you can do that aren't documented here (but we'll gladly accept a patch if you want to write something up!). For more information about LLVM, check @@ -1610,9 +1666,9 @@ out:

      Valid CSS! + src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"> Valid HTML 4.01! + src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"> Chris Lattner
      Reid Spencer