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+ <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
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</head>
<li><a href="#quickstart">Getting Started Quickly (A Summary)</a>
<li><a href="#requirements">Requirements</a>
<ol>
- <li><a href="#hardware">Hardware</a>
- <li><a href="#software">Software</a>
+ <li><a href="#hardware">Hardware</a></li>
+ <li><a href="#software">Software</a></li>
+ <li><a href="#brokengcc">Broken versions of GCC and other tools</a></li>
</ol></li>
<li><a href="#starting">Getting Started with LLVM</a>
<ol>
- <li><a href="#terminology">Terminology and Notation</a>
- <li><a href="#environment">Setting Up Your Environment</a>
- <li><a href="#unpack">Unpacking the LLVM Archives</a>
- <li><a href="#checkout">Checkout LLVM from CVS</a>
- <li><a href="#installcf">Install the GCC Front End</a>
- <li><a href="#config">Local LLVM Configuration</a>
- <li><a href="#compile">Compiling the LLVM Suite Source Code</a>
- <li><a href="#objfiles">The Location of LLVM Object Files</a>
- <li><a href="#optionalconfig">Optional Configuration Items</a>
+ <li><a href="#terminology">Terminology and Notation</a></li>
+ <li><a href="#environment">Setting Up Your Environment</a></li>
+ <li><a href="#unpack">Unpacking the LLVM Archives</a></li>
+ <li><a href="#checkout">Checkout LLVM from Subversion</a></li>
+ <li><a href="#git_mirror">LLVM GIT mirror</a></li>
+ <li><a href="#installcf">Install the GCC Front End</a></li>
+ <li><a href="#config">Local LLVM Configuration</a></li>
+ <li><a href="#compile">Compiling the LLVM Suite Source Code</a></li>
+ <li><a href="#cross-compile">Cross-Compiling LLVM</a></li>
+ <li><a href="#objfiles">The Location of LLVM Object Files</a></li>
+ <li><a href="#optionalconfig">Optional Configuration Items</a></li>
</ol></li>
<li><a href="#layout">Program layout</a>
<ol>
- <li><a href="#cvsdir"><tt>CVS</tt> directories</a>
- <li><a href="#include"><tt>llvm/include</tt></a>
- <li><a href="#lib"><tt>llvm/lib</tt></a>
- <li><a href="#runtime"><tt>llvm/runtime</tt></a>
- <li><a href="#test"><tt>llvm/test</tt></a>
- <li><a href="#tools"><tt>llvm/tools</tt></a>
- <li><a href="#utils"><tt>llvm/utils</tt></a>
+ <li><a href="#examples"><tt>llvm/examples</tt></a></li>
+ <li><a href="#include"><tt>llvm/include</tt></a></li>
+ <li><a href="#lib"><tt>llvm/lib</tt></a></li>
+ <li><a href="#projects"><tt>llvm/projects</tt></a></li>
+ <li><a href="#runtime"><tt>llvm/runtime</tt></a></li>
+ <li><a href="#test"><tt>llvm/test</tt></a></li>
+ <li><a href="#test-suite"><tt>test-suite</tt></a></li>
+ <li><a href="#tools"><tt>llvm/tools</tt></a></li>
+ <li><a href="#utils"><tt>llvm/utils</tt></a></li>
</ol></li>
<li><a href="#tutorial">An Example Using the LLVM Tool Chain</a>
+ <ol>
+ <li><a href="#tutorial4">Example with llvm-gcc4</a></li>
+ </ol>
<li><a href="#problems">Common Problems</a>
<li><a href="#links">Links</a>
</ul>
<p>Welcome to LLVM! In order to get started, you first need to know some
basic information.</p>
-<p>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
-used to test the LLVM tools and the GCC front end.</p>
+<p>First, LLVM comes in three 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, bitcode analyzer and bitcode optimizer. It
+also contains basic regression tests that can be used to test the LLVM
+tools and the GCC front end.</p>
<p>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
-end is a modified version of GCC 3.4 (we track the GCC 3.4 development). Once
-compiled into LLVM bytecode, a program can be manipulated with the LLVM tools
+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 bitcode, a program can be manipulated with the LLVM tools
from the LLVM suite.</p>
+<p>
+There is a third, optional piece called Test Suite. It is a suite of programs
+with a testing harness that can be used to further test LLVM's functionality
+and performance.
+</p>
+
</div>
<!-- *********************************************************************** -->
<p>Here's the short story for getting up and running quickly with LLVM:</p>
<ol>
- <li>Install the GCC front end:
+ <li>Read the documentation.</li>
+ <li>Read the documentation.</li>
+ <li>Remember that you were warned twice about reading the documentation.</li>
+ <li>Install the llvm-gcc-4.2 front end if you intend to compile C or C++
+ (see <a href="#installcf">Install the GCC Front End</a> for details):</li>
<ol>
- <li><tt>cd <i>where-you-want-the-C-front-end-to-live</i></tt>
- <li><tt>gunzip --stdout cfrontend.<i>platform</i>.tar.gz | tar -xvf -</tt>
- <li><b>Sparc and MacOS X Only:</b><br>
- <tt>cd cfrontend/<i>platform</i><br>
- ./fixheaders</tt>
+ <li><tt>cd <i>where-you-want-the-C-front-end-to-live</i></tt></li>
+ <li><tt>gunzip --stdout llvm-gcc-4.2-<i>version</i>-<i>platform</i>.tar.gz | tar -xvf -</tt></li>
+ <li><tt><i>install-binutils-binary-from-MinGW</i></tt> (Windows only)</li>
+ <li>Note: If the binary extension is "<tt>.bz</tt>" use <tt>bunzip2</tt> instead of <tt>gunzip</tt>.</li>
+ <li>Note: On Windows, use <a href="http://www.7-zip.org">7-Zip</a> or a similar archiving tool.</li>
+ <li>Add <tt>llvm-gcc</tt>'s "<tt>bin</tt>" directory to your <tt>PATH</tt> environment variable.</li>
</ol></li>
- <li>Get the Source Code
+ <li>Get the LLVM Source Code
<ul>
- <li>With the distributed files:
+ <li>With the distributed files (or use <a href="#checkout">SVN</a>):
<ol>
<li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
<li><tt>gunzip --stdout llvm-<i>version</i>.tar.gz | tar -xvf -</tt>
- <li><tt>cd llvm</tt>
</ol></li>
- <li>With anonymous CVS access (or use a <a href="#mirror">mirror</a>):
+ </ul></li>
+
+ <li><b>[Optional]</b> Get the Test Suite Source Code
+ <ul>
+ <li>With the distributed files (or use <a href="#checkout">SVN</a>):
<ol>
- <li><tt>cd <i>where-you-want-llvm-to-live</i></tt></li>
- <li><tt>cvs -d
- :pserver:anon@llvm-cvs.cs.uiuc.edu:/var/cvs/llvm login</tt></li>
- <li>Hit the return key when prompted for the password.
- <li><tt>cvs -z3 -d :pserver:anon@llvm-cvs.cs.uiuc.edu:/var/cvs/llvm
- co llvm</tt></li>
- <li><tt>cd llvm</tt></li>
+ <li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
+ <li><tt>cd llvm/projects</tt>
+ <li><tt>gunzip --stdout llvm-test-<i>version</i>.tar.gz | tar -xvf -</tt>
+ <li><tt>mv llvm-test-<i>version</i> test-suite</tt>
</ol></li>
+
</ul></li>
+
<li>Configure the LLVM Build Environment
<ol>
- <li>Change directory to where you want to store the LLVM object
- files and run <tt>configure</tt> to configure the Makefiles and
- header files for the default platform. Useful options include:
+ <li><tt>cd <i>where-you-want-to-build-llvm</i></tt></li>
+ <li><tt><i>/path/to/llvm/</i>configure [options]</tt><br>
+ Some common options:
+
<ul>
+ <li><tt>--prefix=<i>directory</i></tt>
+ <p>Specify for <i>directory</i> the full pathname of where you
+ want the LLVM tools and libraries to be installed (default
+ <tt>/usr/local</tt>).</p></li>
<li><tt>--with-llvmgccdir=<i>directory</i></tt>
- <p>Specify the full pathname of where the LLVM GCC frontend is
- installed.</p></li>
+ <p>Optionally, specify for <i>directory</i> the full pathname of the
+ C/C++ front end installation to use with this LLVM configuration. If
+ not specified, the PATH will be searched. This is only needed if you
+ want to run test-suite or do some special kinds of LLVM builds.</p></li>
<li><tt>--enable-spec2000=<i>directory</i></tt>
<p>Enable the SPEC2000 benchmarks for testing. The SPEC2000
benchmarks should be available in
<li>Build the LLVM Suite:
<ol>
- <li>Set your LLVM_LIB_SEARCH_PATH environment variable.
- <li><tt>gmake -k |& tee gnumake.out
- # this is csh or tcsh syntax</tt>
+ <li><tt>gmake -k |& tee gnumake.out
+ # this is csh or tcsh syntax</tt></li>
+ <li>If you get an "internal compiler error (ICE)" or test failures, see
+ <a href="#brokengcc">below</a>.</li>
</ol>
</ol>
<p>LLVM is known to work on the following platforms:</p>
-<ul>
-
- <li>Linux on x86 (Pentium and above)
- <ul>
- <li>Approximately 1.02 GB of Free Disk Space
- <ul>
- <li>Source code: 45 MB</li>
- <li>Object code: 956 MB</li>
- <li>GCC front end: 40 MB</li>
- </ul></li>
- </ul>
- </li>
+<table cellpadding="3" summary="Known LLVM platforms">
+<tr>
+ <th>OS</th>
+ <th>Arch</th>
+ <th>Compilers</th>
+</tr>
+<tr>
+ <td>AuroraUX</td>
+ <td>x86<sup><a href="#pf_1">1</a></sup></td>
+ <td>GCC</td>
+</tr>
+<tr>
+ <td>Linux</td>
+ <td>x86<sup><a href="#pf_1">1</a></sup></td>
+ <td>GCC</td>
+</tr>
+<tr>
+ <td>Linux</td>
+ <td>amd64</td>
+ <td>GCC</td>
+</tr>
+<tr>
+ <td>Solaris</td>
+ <td>V9 (Ultrasparc)</td>
+ <td>GCC</td>
+</tr>
+<tr>
+ <td>FreeBSD</td>
+ <td>x86<sup><a href="#pf_1">1</a></sup></td>
+ <td>GCC</td>
+</tr>
+<tr>
+ <td>FreeBSD</td>
+ <td>amd64</td>
+ <td>GCC</td>
+</tr>
+<tr>
+ <td>MacOS X<sup><a href="#pf_2">2</a></sup></td>
+ <td>PowerPC</td>
+ <td>GCC</td>
+</tr>
+<tr>
+ <td>MacOS X<sup><a href="#pf_2">2</a>,<a href="#pf_9">9</a></sup></td>
+ <td>x86</td>
+ <td>GCC</td>
+</tr>
+<tr>
+ <td>Cygwin/Win32</td>
+ <td>x86<sup><a href="#pf_1">1</a>,<a href="#pf_8">8</a>,
+ <a href="#pf_11">11</a></sup></td>
+ <td>GCC 3.4.X, binutils 2.20</td>
+</tr>
+<tr>
+ <td>MinGW/Win32</td>
+ <td>x86<sup><a href="#pf_1">1</a>,<a href="#pf_6">6</a>,
+ <a href="#pf_8">8</a>, <a href="#pf_10">10</a></sup></td>
+ <td>GCC 3.4.X, binutils 2.20</td>
+</tr>
+</table>
- <li>Solaris on SparcV9 (Ultrasparc)
- <ul>
- <li>Approximately 1.75 GB of Free Disk Space
- <ul>
- <li>Source code: 45 MB</li>
- <li>Object code: 1705 MB</li>
- <li>GCC front end: 50 MB</li>
- </ul></li>
- </ul>
- </li>
+<p>LLVM has partial support for the following platforms:</p>
+
+<table summary="LLVM partial platform support">
+<tr>
+ <th>OS</th>
+ <th>Arch</th>
+ <th>Compilers</th>
+</tr>
+<tr>
+ <td>Windows</td>
+ <td>x86<sup><a href="#pf_1">1</a></sup></td>
+ <td>Visual Studio 2005 SP1 or higher<sup><a href="#pf_4">4</a>,<a href="#pf_5">5</a></sup></td>
+<tr>
+ <td>AIX<sup><a href="#pf_3">3</a>,<a href="#pf_4">4</a></sup></td>
+ <td>PowerPC</td>
+ <td>GCC</td>
+</tr>
+<tr>
+ <td>Linux<sup><a href="#pf_3">3</a>,<a href="#pf_5">5</a></sup></td>
+ <td>PowerPC</td>
+ <td>GCC</td>
+</tr>
+
+<tr>
+ <td>Linux<sup><a href="#pf_7">7</a></sup></td>
+ <td>Alpha</td>
+ <td>GCC</td>
+</tr>
+<tr>
+ <td>Linux<sup><a href="#pf_7">7</a></sup></td>
+ <td>Itanium (IA-64)</td>
+ <td>GCC</td>
+</tr>
+<tr>
+ <td>HP-UX<sup><a href="#pf_7">7</a></sup></td>
+ <td>Itanium (IA-64)</td>
+ <td>HP aCC</td>
+</tr>
+</table>
- <li>FreeBSD on x86 (Pentium and above)
- <ul>
- <li>Approximately 935 MB of Free Disk Space
- <ul>
- <li>Source code: 45 MB</li>
- <li>Object code: 850 MB</li>
- <li>GCC front end: 40 MB</li>
- </ul></li>
- </ul>
- </li>
+<p><b>Notes:</b></p>
- <li>MacOS X on PowerPC
- <ul>
- <li>No native code generation
- <li>Approximately 1.25 GB of Free Disk Space
- <ul>
- <li>Source code: 45 MB</li>
- <li>Object code: 1160 MB</li>
- <li>GCC front end: 40 MB</li>
- </ul></li>
- </ul>
+<div class="doc_notes">
+<ol>
+<li><a name="pf_1">Code generation supported for Pentium processors and
+up</a></li>
+<li><a name="pf_2">Code generation supported for 32-bit ABI only</a></li>
+<li><a name="pf_3">No native code generation</a></li>
+<li><a name="pf_4">Build is not complete: one or more tools do not link or function</a></li>
+<li><a name="pf_5">The GCC-based C/C++ frontend does not build</a></li>
+<li><a name="pf_6">The port is done using the MSYS shell.</a></li>
+<li><a name="pf_7">Native code generation exists but is not complete.</a></li>
+<li><a name="pf_8">Binutils 2.20 or later is required to build the assembler
+ generated by LLVM properly.</a></li>
+<li><a name="pf_9">XCode 2.5 and gcc 4.0.1</a> (Apple Build 5370) will trip
+ internal LLVM assert messages when compiled for Release at optimization
+ levels greater than 0 (i.e., <i>"-O1"</i> and higher).
+ Add <i>OPTIMIZE_OPTION="-O0"</i> to the build command line
+ if compiling for LLVM Release or bootstrapping the LLVM toolchain.</li>
+<li><a name="pf_10">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.</a></li>
+<li><a name="pf_11">In general, LLVM modules requiring dynamic linking can
+ not be built on Windows. However, you can build LLVM tools using
+ <i>"make tools-only"</i>.</li>
+</ol>
+</div>
- </li>
-</ul>
+<p>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 pass <tt>ONLY_TOOLS="tools you need"</tt> to make. The Release build
+requires considerably less space.</p>
<p>The LLVM suite <i>may</i> 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.</p>
<p>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.</p>
+to work on another platform, you can download a copy of the source and <a
+href="GCCFEBuildInstrs.html">try to compile it</a> on your platform.</p>
</div>
+<!-- ======================================================================= -->
+<div class="doc_subsection"><a name="software"><b>Software</b></a></div>
+<div class="doc_text">
+ <p>Compiling LLVM requires that you have several software packages
+ installed. The table below lists those required packages. The Package column
+ is the usual name for the software package that LLVM depends on. The Version
+ column provides "known to work" versions of the package. The Notes column
+ describes how LLVM uses the package and provides other details.</p>
+ <table summary="Packages required to compile LLVM">
+ <tr><th>Package</th><th>Version</th><th>Notes</th></tr>
+
+ <tr>
+ <td><a href="http://savannah.gnu.org/projects/make">GNU Make</a></td>
+ <td>3.79, 3.79.1</td>
+ <td>Makefile/build processor</td>
+ </tr>
+
+ <tr>
+ <td><a href="http://gcc.gnu.org">GCC</a></td>
+ <td>3.4.2</td>
+ <td>C/C++ compiler<sup><a href="#sf1">1</a></sup></td>
+ </tr>
+
+ <tr>
+ <td><a href="http://www.gnu.org/software/texinfo">TeXinfo</a></td>
+ <td>4.5</td>
+ <td>For building the CFE</td>
+ </tr>
+
+ <tr>
+ <td><a href="http://subversion.tigris.org/project_packages.html">SVN</a></td>
+ <td>≥1.3</td>
+ <td>Subversion access to LLVM<sup><a href="#sf2">2</a></sup></td>
+ </tr>
+
+ <tr>
+ <td><a href="http://savannah.gnu.org/projects/dejagnu">DejaGnu</a></td>
+ <td>1.4.2</td>
+ <td>Automated test suite<sup><a href="#sf3">3</a></sup></td>
+ </tr>
+
+ <tr>
+ <td><a href="http://www.tcl.tk/software/tcltk/">tcl</a></td>
+ <td>8.3, 8.4</td>
+ <td>Automated test suite<sup><a href="#sf3">3</a></sup></td>
+ </tr>
+
+ <tr>
+ <td><a href="http://expect.nist.gov/">expect</a></td>
+ <td>5.38.0</td>
+ <td>Automated test suite<sup><a href="#sf3">3</a></sup></td>
+ </tr>
+
+ <tr>
+ <td><a href="http://www.perl.com/download.csp">perl</a></td>
+ <td>≥5.6.0</td>
+ <td>Nightly tester, utilities</td>
+ </tr>
+
+ <tr>
+ <td><a href="http://savannah.gnu.org/projects/m4">GNU M4</a>
+ <td>1.4</td>
+ <td>Macro processor for configuration<sup><a href="#sf4">4</a></sup></td>
+ </tr>
+
+ <tr>
+ <td><a href="http://www.gnu.org/software/autoconf">GNU Autoconf</a></td>
+ <td>2.60</td>
+ <td>Configuration script builder<sup><a href="#sf4">4</a></sup></td>
+ </tr>
+
+ <tr>
+ <td><a href="http://www.gnu.org/software/automake">GNU Automake</a></td>
+ <td>1.9.6</td>
+ <td>aclocal macro generator<sup><a href="#sf4">4</a></sup></td>
+ </tr>
+
+ <tr>
+ <td><a href="http://savannah.gnu.org/projects/libtool">libtool</a></td>
+ <td>1.5.22</td>
+ <td>Shared library manager<sup><a href="#sf4">4</a></sup></td>
+ </tr>
+
+ </table>
+
+ <p><b>Notes:</b></p>
+ <div class="doc_notes">
+ <ol>
+ <li><a name="sf1">Only the C and C++ languages are needed so there's no
+ need to build the other languages for LLVM's purposes.</a> See
+ <a href="#brokengcc">below</a> for specific version info.</li>
+ <li><a name="sf2">You only need Subversion if you intend to build from the
+ latest LLVM sources. If you're working from a release distribution, you
+ don't need Subversion.</a></li>
+ <li><a name="sf3">Only needed if you want to run the automated test
+ suite in the <tt>llvm/test</tt> directory.</a></li>
+ <li><a name="sf4">If you want to make changes to the configure scripts,
+ you will need GNU autoconf (2.60), and consequently, GNU M4 (version 1.4
+ or higher). You will also need automake (1.9.6). We only use aclocal
+ from that package.</a></li>
+ </ol>
+ </div>
+
+ <p>Additionally, your compilation host is expected to have the usual
+ plethora of Unix utilities. Specifically:</p>
+ <ul>
+ <li><b>ar</b> - archive library builder</li>
+ <li><b>bzip2*</b> - bzip2 command for distribution generation</li>
+ <li><b>bunzip2*</b> - bunzip2 command for distribution checking</li>
+ <li><b>chmod</b> - change permissions on a file</li>
+ <li><b>cat</b> - output concatenation utility</li>
+ <li><b>cp</b> - copy files</li>
+ <li><b>date</b> - print the current date/time </li>
+ <li><b>echo</b> - print to standard output</li>
+ <li><b>egrep</b> - extended regular expression search utility</li>
+ <li><b>find</b> - find files/dirs in a file system</li>
+ <li><b>grep</b> - regular expression search utility</li>
+ <li><b>gzip*</b> - gzip command for distribution generation</li>
+ <li><b>gunzip*</b> - gunzip command for distribution checking</li>
+ <li><b>install</b> - install directories/files </li>
+ <li><b>mkdir</b> - create a directory</li>
+ <li><b>mv</b> - move (rename) files</li>
+ <li><b>ranlib</b> - symbol table builder for archive libraries</li>
+ <li><b>rm</b> - remove (delete) files and directories</li>
+ <li><b>sed</b> - stream editor for transforming output</li>
+ <li><b>sh</b> - Bourne shell for make build scripts</li>
+ <li><b>tar</b> - tape archive for distribution generation</li>
+ <li><b>test</b> - test things in file system</li>
+ <li><b>unzip*</b> - unzip command for distribution checking</li>
+ <li><b>zip*</b> - zip command for distribution generation</li>
+ </ul>
+</div>
+
<!-- ======================================================================= -->
<div class="doc_subsection">
- <a name="software"><b>Software</b></a>
+ <a name="brokengcc">Broken versions of GCC and other tools</a>
</div>
<div class="doc_text">
-<p>Compiling LLVM requires that you have several software packages
-installed:</p>
+<p>LLVM is very demanding of the host C++ compiler, and as such tends to expose
+bugs in the compiler. In particular, several versions of GCC crash when trying
+to compile LLVM. We routinely use GCC 3.3.3, 3.4.0, and Apple 4.0.1
+successfully with them (however, see important notes below). Other versions
+of GCC will probably work as well. GCC versions listed
+here are known to not work. If you are using one of these versions, please try
+to upgrade your GCC to something more recent. If you run into a problem with a
+version of GCC not listed here, please <a href="mailto:llvmdev@cs.uiuc.edu">let
+us know</a>. Please use the "<tt>gcc -v</tt>" command to find out which version
+of GCC you are using.
+</p>
-<ul>
- <li><a href="http://gcc.gnu.org">GCC 3.x with C and C++ language
- support</a></li>
+<p><b>GCC versions prior to 3.0</b>: GCC 2.96.x and before had several
+problems in the STL that effectively prevent it from compiling LLVM.
+</p>
- <li><a href="http://savannah.gnu.org/projects/make">GNU Make</a></li>
+<p><b>GCC 3.2.2 and 3.2.3</b>: These versions of GCC fails to compile LLVM with
+a bogus template error. This was fixed in later GCCs.</p>
+
+<p><b>GCC 3.3.2</b>: This version of GCC suffered from a <a
+href="http://gcc.gnu.org/PR13392">serious bug</a> which causes it to crash in
+the "<tt>convert_from_eh_region_ranges_1</tt>" GCC function.</p>
+
+<p><b>Cygwin GCC 3.3.3</b>: The version of GCC 3.3.3 commonly shipped with
+ Cygwin does not work. Please <a href="GCCFEBuildInstrs.html#cygwin">upgrade
+ to a newer version</a> if possible.</p>
+<p><b>SuSE GCC 3.3.3</b>: 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.</p>
+<p><b>GCC 3.4.0 on linux/x86 (32-bit)</b>: 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).</p>
+<p><b>GCC 3.4.2 on linux/x86 (32-bit)</b>: 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 ..."</p>
+<p><b>GCC 3.4.x on X86-64/amd64</b>: GCC <a href="http://llvm.org/PR1056">
+ miscompiles portions of LLVM</a>.</p>
+<p><b>GCC 3.4.4 (CodeSourcery ARM 2005q3-2)</b>: this compiler miscompiles LLVM
+ when building with optimizations enabled. It appears to work with
+ "<tt>make ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O1</tt>" or build a debug
+ build.</p>
+<p><b>IA-64 GCC 4.0.0</b>: The IA-64 version of GCC 4.0.0 is known to
+ miscompile LLVM.</p>
+<p><b>Apple Xcode 2.3</b>: GCC crashes when compiling LLVM at -O3 (which is the
+ default with ENABLE_OPTIMIZED=1. To work around this, build with
+ "ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O2".</p>
+<p><b>GCC 4.1.1</b>: GCC fails to build LLVM with template concept check errors
+ compiling some files. At the time of this writing, GCC mainline (4.2)
+ did not share the problem.</p>
+<p><b>GCC 4.1.1 on X86-64/amd64</b>: GCC <a href="http://llvm.org/PR1063">
+ miscompiles portions of LLVM</a> when compiling llvm itself into 64-bit
+ code. LLVM will appear to mostly work but will be buggy, e.g. failing
+ portions of its testsuite.</p>
+<p><b>GCC 4.1.2 on OpenSUSE</b>: Seg faults during libstdc++ build and on x86_64
+platforms compiling md5.c gets a mangled constant.</p>
+<p><b>GCC 4.1.2 (20061115 (prerelease) (Debian 4.1.1-21)) on Debian</b>: Appears
+to miscompile parts of LLVM 2.4. One symptom is ValueSymbolTable complaining
+about symbols remaining in the table on destruction.</p>
+<p><b>GCC 4.1.2 20071124 (Red Hat 4.1.2-42)</b>: Suffers from the same symptoms
+as the previous one. It appears to work with ENABLE_OPTIMIZED=0 (the default).</p>
+<p><b>Cygwin GCC 4.3.2 20080827 (beta) 2</b>:
+ Users <a href="http://llvm.org/PR4145">reported</a> various problems related
+ with link errors when using this GCC version.</p>
+<p><b>Debian GCC 4.3.2 on X86</b>: Crashes building some files in LLVM 2.6.</p>
+<p><b>GCC 4.3.3 (Debian 4.3.3-10) on ARM</b>: 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.</p>
+<p><b>GCC 4.3.5 and GCC 4.4.5 on ARM</b>: These can miscompile <tt>value >>
+1</tt> even at -O0. A test failure in <tt>test/Assembler/alignstack.ll</tt> is
+one symptom of the problem.
+<p><b>GNU ld 2.16.X</b>. 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
+erroneous and the linkage is correct. These messages disappear using ld
+2.17.</p>
+
+<p><b>GNU binutils 2.17</b>: Binutils 2.17 contains <a
+href="http://sourceware.org/bugzilla/show_bug.cgi?id=3111">a bug</a> 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).</p>
+
+<p><b>GNU Binutils 2.19.1 Gold</b>: This version of Gold contained
+<a href="http://sourceware.org/bugzilla/show_bug.cgi?id=9836">a bug</a>
+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.</p>
- <li><a href="http://www.gnu.org/software/flex">Flex</a></li>
+</div>
- <li><a href="http://www.gnu.org/software/bison/bison.html">Bison</a></li>
-</ul>
-<p>There are some additional tools that you may want to have when working with
-LLVM:</p>
-<ul>
- <li><A href="http://www.gnu.org/software/automake">GNU Automake</A></li>
- <li><A href="http://www.gnu.org/software/autoconf">GNU Autoconf</A></li>
- <li><A href="http://savannah.gnu.org/projects/m4">GNU M4</A>
-
- <p>If you want to make changes to the configure scripts, you will need GNU
- autoconf (2.57 or higher), and consequently, GNU M4 (version 1.4 or
- higher). You will also need automake. Any old version of
- automake from 1.4p5 on should work; we only use aclocal from that
- package.</p></li>
-
- <li><A href="http://www.codesourcery.com/qm/qmtest">QMTest 2.0.3</A></li>
- <li><A href="http://www.python.org">Python</A>
-
- <p>
- These are needed to use the LLVM test suite. Please note that newer
- versions of QMTest may not work with the LLVM test suite. QMTest 2.0.3
- can be retrieved from the QMTest CVS repository using the following
- commands:</p>
- <ul>
- <li><tt>cvs -d :pserver:anoncvs@cvs.codesourcery.com:/home/qm/Repository login</tt>
- </li>
- <li>When prompted, use <tt>anoncvs</tt> as the password.
- </li>
- <li><tt>cvs -d :pserver:anoncvs@cvs.codesourcery.com:/home/qm/Repository co -r release-2-0-3 qm</tt>
- </li>
- </ul>
- </li>
+<!-- *********************************************************************** -->
+<div class="doc_section">
+ <a name="starting"><b>Getting Started with LLVM</b></a>
+</div>
+<!-- *********************************************************************** -->
-</ul>
+<div class="doc_text">
<p>The remainder of this guide is meant to get you up and running with
-LLVM and to give you some basic information about the LLVM environment.
-A <a href="#starting">complete guide to installation</a> is provided in the
-next section.</p>
+LLVM and to give you some basic information about the LLVM environment.</p>
<p>The later sections of this guide describe the <a
href="#layout">general layout</a> of the the LLVM source tree, a <a
href="#tutorial">simple example</a> using the LLVM tool chain, and <a
href="#links">links</a> to find more information about LLVM or to get
help via e-mail.</p>
-
</div>
-<!-- *********************************************************************** -->
-<div class="doc_section">
- <a name="starting"><b>Getting Started with LLVM</b></a>
-</div>
-<!-- *********************************************************************** -->
-
<!-- ======================================================================= -->
<div class="doc_subsection">
<a name="terminology">Terminology and Notation</a>
<dt>SRC_ROOT
<dd>
This is the top level directory of the LLVM source tree.
- <p>
+ <br><br>
<dt>OBJ_ROOT
<dd>
This is the top level directory of the LLVM object tree (i.e. the
tree where object files and compiled programs will be placed. It
can be the same as SRC_ROOT).
- <p>
+ <br><br>
<dt>LLVMGCCDIR
<dd>
- This is the where the LLVM GCC Front End is installed.
+ This is where the LLVM GCC Front End is installed.
<p>
For the pre-built GCC front end binaries, the LLVMGCCDIR is
- <tt>cfrontend/<i>platform</i>/llvm-gcc</tt>.
+ <tt>llvm-gcc/<i>platform</i>/llvm-gcc</tt>.
</dl>
</div>
<div class="doc_text">
<p>
-In order to compile and use LLVM, you will need to set some environment
-variables. There are also some shell aliases which you may find useful.
-You can set these on the command line, or better yet, set them in your
-<tt>.cshrc</tt> or <tt>.profile</tt>.
+In order to compile and use LLVM, you may need to set some environment
+variables.
<dl>
- <dt><tt>LLVM_LIB_SEARCH_PATH</tt>=<tt><i>LLVMGCCDIR</i>/bytecode-libs</tt>
- <dd>
- This environment variable helps the LLVM GCC front end find bytecode
- libraries that it will need for compilation.
- <p>
-
- <dt>alias llvmgcc <i>LLVMGCCDIR</i><tt>/bin/gcc</tt>
- <dt>alias llvmg++ <i>LLVMGCCDIR</i><tt>/bin/g++</tt>
- <dd>
- This alias allows you to use the LLVM C and C++ front ends without putting
- them in your <tt>PATH</tt> or typing in their complete pathnames.
+ <dt><tt>LLVM_LIB_SEARCH_PATH</tt>=<tt>/path/to/your/bitcode/libs</tt></dt>
+ <dd>[Optional] This environment variable helps LLVM linking tools find the
+ 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 bitcode files
+ installed in its
+ <tt>lib</tt> directory.</dd>
</dl>
</div>
<p>
If you have the LLVM distribution, you will need to unpack it before you
can begin to compile it. LLVM is distributed as a set of two files: the LLVM
-suite and the LLVM GCC front end compiled for your platform. Each
-file is a TAR archive that is compressed with the gzip program.
+suite and the LLVM GCC front end compiled for your platform. There is an
+additional test suite that is optional. Each file is a TAR archive that is
+compressed with the gzip program.
</p>
-<p> The files are as follows:
+<p>The files are as follows, with <em>x.y</em> marking the version number:
<dl>
- <dt>llvm-1.2.tar.gz
- <dd>This is the source code to the LLVM suite.
- <p>
+ <dt><tt>llvm-x.y.tar.gz</tt></dt>
+ <dd>Source release for the LLVM libraries and tools.<br></dd>
- <dt>cfrontend-1.2.sparc-sun-solaris2.8.tar.gz
- <dd>This is the binary release of the GCC front end for Solaris/Sparc.
- <p>
+ <dt><tt>llvm-test-x.y.tar.gz</tt></dt>
+ <dd>Source release for the LLVM test-suite.</dd>
- <dt>cfrontend-1.2.i686-redhat-linux-gnu.tar.gz
- <dd>This is the binary release of the GCC front end for Linux/x86.
- <p>
+ <dt><tt>llvm-gcc-4.2-x.y.source.tar.gz</tt></dt>
+ <dd>Source release of the llvm-gcc-4.2 front end. See README.LLVM in the root
+ directory for build instructions.<br></dd>
- <dt>cfrontend-1.2.i386-unknown-freebsd5.1.tar.gz
- <dd>This is the binary release of the GCC front end for FreeBSD/x86.
- <p>
+ <dt><tt>llvm-gcc-4.2-x.y-platform.tar.gz</tt></dt>
+ <dd>Binary release of the llvm-gcc-4.2 front end for a specific platform.<br></dd>
- <dt>cfrontend-1.2.powerpc-apple-darwin7.0.0.tar.gz
- <dd>This is the binary release of the GCC front end for MacOS X/PPC.
</dl>
</div>
<!-- ======================================================================= -->
<div class="doc_subsection">
- <a name="checkout">Checkout LLVM from CVS</a>
+ <a name="checkout">Checkout LLVM from Subversion</a>
</div>
<div class="doc_text">
-<p>If you have access to our CVS repository, you can get a fresh copy of
-the entire source code. All you need to do is check it out from CVS as
+<p>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 Subversion as
follows:</p>
<ul>
-<li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
- <li><tt>cvs -d :pserver:anon@llvm-cvs.cs.uiuc.edu:/var/cvs/llvm login</tt>
- <li>Hit the return key when prompted for the password.
- <li><tt>cvs -z3 -d :pserver:anon@llvm-cvs.cs.uiuc.edu:/var/cvs/llvm co
- llvm</tt>
+ <li><tt>cd <i>where-you-want-llvm-to-live</i></tt></li>
+ <li>Read-Only: <tt>svn co http://llvm.org/svn/llvm-project/llvm/trunk llvm</tt></li>
+ <li>Read-Write:<tt>svn co https://user@llvm.org/svn/llvm-project/llvm/trunk
+ llvm</tt></li>
</ul>
+
<p>This will create an '<tt>llvm</tt>' directory in the current
directory and fully populate it with the LLVM source code, Makefiles,
test directories, and local copies of documentation files.</p>
<p>If you want to get a specific release (as opposed to the most recent
-revision), you can specify a label. The following releases have the following
-label:</p>
+revision), you can checkout it from the '<tt>tags</tt>' directory (instead of
+'<tt>trunk</tt>'). The following releases are located in the following
+subdirectories of the '<tt>tags</tt>' directory:</p>
<ul>
+<li>Release 2.8: <b>RELEASE_28</b></li>
+<li>Release 2.7: <b>RELEASE_27</b></li>
+<li>Release 2.6: <b>RELEASE_26</b></li>
+<li>Release 2.5: <b>RELEASE_25</b></li>
+<li>Release 2.4: <b>RELEASE_24</b></li>
+<li>Release 2.3: <b>RELEASE_23</b></li>
+<li>Release 2.2: <b>RELEASE_22</b></li>
+<li>Release 2.1: <b>RELEASE_21</b></li>
+<li>Release 2.0: <b>RELEASE_20</b></li>
+<li>Release 1.9: <b>RELEASE_19</b></li>
+<li>Release 1.8: <b>RELEASE_18</b></li>
+<li>Release 1.7: <b>RELEASE_17</b></li>
+<li>Release 1.6: <b>RELEASE_16</b></li>
+<li>Release 1.5: <b>RELEASE_15</b></li>
+<li>Release 1.4: <b>RELEASE_14</b></li>
+<li>Release 1.3: <b>RELEASE_13</b></li>
<li>Release 1.2: <b>RELEASE_12</b></li>
<li>Release 1.1: <b>RELEASE_11</b></li>
<li>Release 1.0: <b>RELEASE_1</b></li>
</ul>
-<p>If you would like to get the GCC front end source code, you can also get it
-from the CVS repository:</p>
+<p>If you would like to get the LLVM test suite (a separate package as of 1.4),
+you get it from the Subversion repository:</p>
+<div class="doc_code">
<pre>
- cvs -z3 -d :pserver:anon@llvm-cvs.cs.uiuc.edu:/var/cvs/llvm co llvm-gcc
+% cd llvm/projects
+% svn co http://llvm.org/svn/llvm-project/test-suite/trunk test-suite
</pre>
+</div>
+
+<p>By placing it in the <tt>llvm/projects</tt>, it will be automatically
+configured by the LLVM configure script as well as automatically updated when
+you run <tt>svn update</tt>.</p>
-<p>Please note that you must follow <a href="CFEBuildInstrs.html">these
-instructions</a> to successfully build the LLVM C front-end.</p>
+<p>If you would like to get the GCC front end source code, you can also get it
+and build it yourself. Please follow <a href="GCCFEBuildInstrs.html">these
+instructions</a> to successfully get and build the LLVM GCC front-end.</p>
</div>
<!-- ======================================================================= -->
-<div class="doc_subsubsection">
- <a name="mirrors">LLVM CVS Mirrors</a>
+<div class="doc_subsection">
+ <a name="git_mirror">GIT mirror</a>
</div>
<div class="doc_text">
-<p>If the main CVS server is overloaded or inaccessible, you can try one of
-these user-hosted mirrors:</p>
+<p>GIT mirrors are available for a number of LLVM subprojects. These mirrors
+ sync automatically with each Subversion commit and contain all necessary
+ git-svn marks (so, you can recreate git-svn metadata locally). Note that right
+ now mirrors reflect only <tt>trunk</tt> for each project. You can do the
+ read-only GIT clone of LLVM via:
+<pre>
+% git clone http://llvm.org/git/llvm.git
+</pre>
+</p>
-<ul>
-<li><a href="http://llvm.x10sys.com/">Mirror hosted by eXtensible Systems
-Inc.</a></li>
-</ul>
</div>
<!-- ======================================================================= -->
<div class="doc_text">
-<p>Before configuring and compiling the LLVM suite, you need to extract the LLVM
-GCC front end from the binary distribution. It is used for building the
-bytecode libraries later used by the GCC front end for linking programs, and its
-location must be specified when the LLVM suite is configured.</p>
+<p>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-suite and for compiling C/C++ programs. Note that
+you can optionally <a href="GCCFEBuildInstrs.html">build llvm-gcc yourself</a> after building the
+main LLVM repository.</p>
-<p>To install the GCC front end, do the following:</p>
+<p>To install the GCC front end, do the following (on Windows, use an archival tool
+like <a href="http://www.7-zip.org">7-zip</a> that understands gzipped tars):</p>
<ol>
<li><tt>cd <i>where-you-want-the-front-end-to-live</i></tt></li>
- <li><tt>gunzip --stdout cfrontend-<i>version</i>.<i>platform</i>.tar.gz | tar -xvf
+ <li><tt>gunzip --stdout llvm-gcc-4.2-<i>version</i>-<i>platform</i>.tar.gz | tar -xvf
-</tt></li>
</ol>
-<p>If you are using Solaris/Sparc or MacOS X/PPC, you will need to fix the
-header files:</p>
+<p>Once the binary is uncompressed, if you're using a *nix-based system, add a symlink for
+<tt>llvm-gcc</tt> and <tt>llvm-g++</tt> to some directory in your path. If you're using a
+Windows-based system, add the <tt>bin</tt> subdirectory of your front end installation directory
+to your <tt>PATH</tt> environment variable. For example, if you uncompressed the binary to
+<tt>c:\llvm-gcc</tt>, add <tt>c:\llvm-gcc\bin</tt> to your <tt>PATH</tt>.</p>
+
+<p>If you now want to build LLVM from source, when you configure LLVM, it will
+automatically detect <tt>llvm-gcc</tt>'s presence (if it is in your path) enabling its
+use in test-suite. Note that you can always build or install <tt>llvm-gcc</tt> at any
+point after building the main LLVM repository: just reconfigure llvm and
+test-suite will pick it up.
+</p>
-<p><tt>cd cfrontend/<i>platform</i><br>
- ./fixheaders</tt></p>
+<p>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
+<a href="http://mingw.org/">MinGW</a> 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.</p>
-<p>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.</p>
+<p>To install binutils on Windows:</p>
+
+<ol>
+ <li><tt><i>download GNU Binutils from <a href="http://sourceforge.net/projects/mingw/files/">MinGW Downloads</a></i></tt></li>
+ <li><tt>cd <i>where-you-uncompressed-the-front-end</i></tt></li>
+ <li><tt><i>uncompress archived binutils directories (not the tar file) into the current directory</i></tt></li>
+</ol>
-<p>In cases like these, you may want to try <a
-href="CFEBuildInstrs.html">building the GCC front end from source.</a> This is
-not for the faint of heart, so be forewarned.</p>
+<p>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
+<a href="GCCFEBuildInstrs.html">building the GCC front end from source</a>. Thankfully,
+this is much easier now than it was in the past.</p>
+
+<p>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.</p>
+
+<p>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
+<a href="http://llvm.org/docs/#maillist">mailing list</a>.</p>
</div>
<div class="doc_text">
-<p>Once checked out from the CVS repository, the LLVM suite source code must be
-configured via the <tt>configure</tt> script. This script sets variables in
-<tt>llvm/Makefile.config</tt> and <tt>llvm/include/Config/config.h</tt>. It
-also populates <i>OBJ_ROOT</i> with the Makefiles needed to begin building
-LLVM.</p>
+ <p>Once checked out from the Subversion repository, the LLVM suite source
+ code must be
+configured via the <tt>configure</tt> script. This script sets variables in the
+various <tt>*.in</tt> files, most notably <tt>llvm/Makefile.config</tt> and
+<tt>llvm/include/Config/config.h</tt>. It also populates <i>OBJ_ROOT</i> with
+the Makefiles needed to begin building LLVM.</p>
<p>The following environment variables are used by the <tt>configure</tt>
script to configure the build system:</p>
-<table border=1>
- <tr>
- <th>Variable</th>
- <th>Purpose</th>
- </tr>
-
+<table summary="LLVM configure script environment variables">
+ <tr><th>Variable</th><th>Purpose</th></tr>
<tr>
<td>CC</td>
<td>Tells <tt>configure</tt> which C compiler to use. By default,
<tt>PATH</tt>. Use this variable to override
<tt>configure</tt>'s default behavior.</td>
</tr>
-
<tr>
<td>CXX</td>
<td>Tells <tt>configure</tt> which C++ compiler to use. By default,
<p>The following options can be used to set or enable LLVM specific options:</p>
<dl>
- <dt><i>--with-llvmgccdir=LLVMGCCDIR</i>
+ <dt><i>--with-llvmgccdir</i></dt>
+ <dd>Path to the LLVM C/C++ FrontEnd to be used with this LLVM configuration.
+ The value of this option should specify the full pathname of the C/C++ Front
+ End to be used. If this option is not provided, the PATH will be searched for
+ a program named <i>llvm-gcc</i> and the C/C++ FrontEnd install directory will
+ be inferred from the path found. If the option is not given, and no llvm-gcc
+ can be found in the path then a warning will be produced by
+ <tt>configure</tt> indicating this situation. LLVM may still be built with
+ the <tt>tools-only</tt> target but attempting to build the runtime libraries
+ will fail as these libraries require llvm-gcc and llvm-g++. See
+ <a href="#installcf">Install the GCC Front End</a> for details on installing
+ the C/C++ Front End. See
+ <a href="GCCFEBuildInstrs.html">Bootstrapping the LLVM C/C++ Front-End</a>
+ for details on building the C/C++ Front End.</dd>
+ <dt><i>--with-tclinclude</i></dt>
+ <dd>Path to the tcl include directory under which <tt>tclsh</tt> can be
+ found. Use this if you have multiple tcl installations on your machine and you
+ want to use a specific one (8.x) for LLVM. LLVM only uses tcl for running the
+ dejagnu based test suite in <tt>llvm/test</tt>. If you don't specify this
+ option, the LLVM configure script will search for the tcl 8.4 and 8.3
+ releases.
+ <br><br>
+ </dd>
+ <dt><i>--enable-optimized</i></dt>
<dd>
- Path to the location where the LLVM GCC front end binaries and
- associated libraries were installed. This must be specified as an
- absolute pathname.
- <p>
- <dt><i>--enable-optimized</i>
+ 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).
+ <br><br>
+ </dd>
+ <dt><i>--enable-debug-runtime</i></dt>
<dd>
- 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).
- <p>
- <dt><i>--enable-jit</i>
+ Enables debug symbols in the runtime libraries. The default is to strip
+ debug symbols from the runtime libraries.
+ </dd>
+ <dt><i>--enable-jit</i></dt>
<dd>
Compile the Just In Time (JIT) compiler functionality. This is not
available
on all platforms. The default is dependent on platform, so it is best
to explicitly enable it if you want it.
- <p>
- <dt><i>--enable-spec2000</i>
- <dt><i>--enable-spec2000=<<tt>directory</tt>></i>
- <dd>
- Enable the use of SPEC2000 when testing LLVM. This is disabled by default
- (unless <tt>configure</tt> finds SPEC2000 installed). By specifying
- <tt>directory</tt>, you can tell configure where to find the SPEC2000
- benchmarks. If <tt>directory</tt> is left unspecified, <tt>configure</tt>
- uses the default value
- <tt>/home/vadve/shared/benchmarks/speccpu2000/benchspec</tt>.
- <p>
- <dt><i>--enable-spec95</i>
- <dt><i>--enable-spec95=<<tt>directory</tt>></i>
- <dd>
- Enable the use of SPEC95 when testing LLVM. It is similar to the
- <i>--enable-spec2000</i> option.
- <p>
- <dt><i>--enable-povray</i>
- <dt><i>--enable-povray=<<tt>directory</tt>></i>
- <dd>
- Enable the use of Povray as an external test. Versions of Povray written
- in C should work. This option is similar to the <i>--enable-spec2000</i>
- option.
+ <br><br>
+ </dd>
+ <dt><i>--enable-targets=</i><tt>target-option</tt></dt>
+ <dd>Controls which targets will be built and linked into llc. The default
+ value for <tt>target_options</tt> is "all" which builds and links all
+ available targets. The value "host-only" can be specified to build only a
+ 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: <br>
+ <tt>alpha, ia64, powerpc, skeleton, sparc, x86</tt>.
+ <br><br></dd>
+ <dt><i>--enable-doxygen</i></dt>
+ <dd>Look for the doxygen program and enable construction of doxygen based
+ documentation from the source code. This is disabled by default because
+ generating the documentation can take a long time and producess 100s of
+ megabytes of output.</dd>
+ <dt><i>--with-udis86</i></dt>
+ <dd>LLVM can use external disassembler library for various purposes (now it's
+ used only for examining code produced by JIT). This option will enable usage
+ of <a href="http://udis86.sourceforge.net/">udis86</a> x86 (both 32 and 64
+ bits) disassembler library.</dd>
</dl>
<p>To configure LLVM, follow these steps:</p>
<ol>
- <li>Change directory into the object root directory:
- <br>
- <tt>cd <i>OBJ_ROOT</i></tt>
- <p>
+ <li><p>Change directory into the object root directory:</p>
- <li>Run the <tt>configure</tt> script located in the LLVM source tree:
- <br>
- <tt><i>SRC_ROOT</i>/configure</tt>
- <p>
-</ol>
+ <div class="doc_code"><pre>% cd <i>OBJ_ROOT</i></pre></div></li>
-<p>In addition to running <tt>configure</tt>, you must set the
-<tt>LLVM_LIB_SEARCH_PATH</tt> environment variable in your startup scripts.
-This environment variable is used to locate "system" libraries like
-"<tt>-lc</tt>" and "<tt>-lm</tt>" when linking. This variable should be set to
-the absolute path of the <tt>bytecode-libs</tt> subdirectory of the GCC front
-end, or <i>LLVMGCCDIR</i>/<tt>bytecode-libs</tt>. For example, one might set
-<tt>LLVM_LIB_SEARCH_PATH</tt> to
-<tt>/home/vadve/lattner/local/x86/llvm-gcc/bytecode-libs</tt> for the x86
-version of the GCC front end on our research machines.</p>
+ <li><p>Run the <tt>configure</tt> script located in the LLVM source
+ tree:</p>
+
+ <div class="doc_code">
+ <pre>% <i>SRC_ROOT</i>/configure --prefix=/install/path [other options]</pre>
+ </div></li>
+</ol>
</div>
<dl>
<dt>Debug Builds
<dd>
- These builds are the default when one types <tt>gmake</tt> (unless the
- <tt>--enable-optimized</tt> option was used during configuration). The
- build system will compile the tools and libraries with debugging
- information.
- <p>
+ These builds are the default when one is using an Subversion checkout and
+ types <tt>gmake</tt> (unless the <tt>--enable-optimized</tt> 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 <tt>--disable-optimized</tt> option must be passed
+ to <tt>configure</tt>.
+ <br><br>
<dt>Release (Optimized) Builds
<dd>
<tt>gmake</tt> 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.
- <p>
+ Note that Release Builds are default when using an LLVM distribution.
+ <br><br>
<dt>Profile Builds
<dd>
<p>Once you have LLVM configured, you can build it by entering the
<i>OBJ_ROOT</i> directory and issuing the following command:</p>
-<p><tt>gmake</tt></p>
+<div class="doc_code"><pre>% gmake</pre></div>
-<p>If you have multiple processors in your machine, you may wish to use some of
+<p>If the build fails, please <a href="#brokengcc">check here</a> to see if you
+are using a version of GCC that is known not to compile LLVM.</p>
+
+<p>
+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:</p>
-<p><tt>gmake -j2</tt></p>
+<div class="doc_code"><pre>% gmake -j2</pre></div>
<p>There are several special targets which are useful when working with the LLVM
source code:</p>
<dd>
Removes all files generated by the build. This includes object files,
generated C/C++ files, libraries, and executables.
- <p>
+ <br><br>
- <dt><tt>gmake distclean</tt>
+ <dt><tt>gmake dist-clean</tt>
<dd>
- Removes everything that <tt>gmake clean</tt> does, but also removes
- files generated by <tt>configure</tt>. It attempts to return the
- source tree to the original state in which it was shipped.
- <p>
+ Removes everything that <tt>gmake clean</tt> does, but also removes files
+ generated by <tt>configure</tt>. It attempts to return the source tree to the
+ original state in which it was shipped.
+ <br><br>
<dt><tt>gmake install</tt>
<dd>
- Installs LLVM files into the proper location. For the most part,
- this does nothing, but it does install bytecode libraries into the
- GCC front end's bytecode library directory. If you need to update
- your bytecode libraries, this is the target to use once you've built
- them.
- <p>
+ Installs LLVM header files, libraries, tools, and documentation in a
+ hierarchy
+ under $PREFIX, specified with <tt>./configure --prefix=[dir]</tt>, which
+ defaults to <tt>/usr/local</tt>.
+ <br><br>
+
+ <dt><tt>gmake -C runtime install-bytecode</tt>
+ <dd>
+ Assuming you built LLVM into $OBJDIR, when this command is run, it will
+ 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.
+ <br><br>
</dl>
+<p>Please see the <a href="MakefileGuide.html">Makefile Guide</a> for further
+details on these <tt>make</tt> targets and descriptions of other targets
+available.</p>
+
<p>It is also possible to override default values from <tt>configure</tt> by
declaring variables on the command line. The following are some examples:</p>
<dt><tt>gmake ENABLE_OPTIMIZED=1</tt>
<dd>
Perform a Release (Optimized) build.
- <p>
+ <br><br>
+
+ <dt><tt>gmake ENABLE_OPTIMIZED=1 DISABLE_ASSERTIONS=1</tt>
+ <dd>
+ Perform a Release (Optimized) build without assertions enabled.
+ <br><br>
+
+ <dt><tt>gmake ENABLE_OPTIMIZED=0</tt>
+ <dd>
+ Perform a Debug build.
+ <br><br>
<dt><tt>gmake ENABLE_PROFILING=1</tt>
<dd>
Perform a Profiling build.
- <p>
+ <br><br>
<dt><tt>gmake VERBOSE=1</tt>
<dd>
Print what <tt>gmake</tt> is doing on standard output.
- <p>
+ <br><br>
+
+ <dt><tt>gmake TOOL_VERBOSE=1</tt></dt>
+ <dd>Ask each tool invoked by the makefiles to print out what it is doing on
+ the standard output. This also implies <tt>VERBOSE=1</tt>.
+ <br><br></dd>
</dl>
<p>Every directory in the LLVM object tree includes a <tt>Makefile</tt> to build
</div>
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="cross-compile">Cross-Compiling LLVM</a>
+</div>
+
+<div class="doc_text">
+ <p>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 <tt>--build</tt> and
+ <tt>--host</tt> options that are different. The values of these options must
+ be legal target triples that your GCC compiler supports.</p>
+
+ <p>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).</p>
+</div>
+
<!-- ======================================================================= -->
<div class="doc_subsection">
<a name="objfiles">The Location of LLVM Object Files</a>
<ul>
<li><p>Change directory to where the LLVM object files should live:</p>
- <p><tt>cd <i>OBJ_ROOT</i></tt></p></li>
+ <div class="doc_code"><pre>% cd <i>OBJ_ROOT</i></pre></div></li>
<li><p>Run the <tt>configure</tt> script found in the LLVM source
directory:</p>
- <p><tt><i>SRC_ROOT</i>/configure</tt></p></li>
+ <div class="doc_code"><pre>% <i>SRC_ROOT</i>/configure</pre></div></li>
</ul>
<p>The LLVM build will place files underneath <i>OBJ_ROOT</i> in directories
named after the build type:</p>
<dl>
- <dt>Debug Builds
+ <dt>Debug Builds with assertions enabled (the default)
<dd>
<dl>
<dt>Tools
- <dd><tt><i>OBJ_ROOT</i>/tools/Debug</tt>
+ <dd><tt><i>OBJ_ROOT</i>/Debug+Asserts/bin</tt>
<dt>Libraries
- <dd><tt><i>OBJ_ROOT</i>/lib/Debug</tt>
+ <dd><tt><i>OBJ_ROOT</i>/Debug+Asserts/lib</tt>
</dl>
- <p>
+ <br><br>
<dt>Release Builds
<dd>
<dl>
<dt>Tools
- <dd><tt><i>OBJ_ROOT</i>/tools/Release</tt>
+ <dd><tt><i>OBJ_ROOT</i>/Release/bin</tt>
<dt>Libraries
- <dd><tt><i>OBJ_ROOT</i>/lib/Release</tt>
+ <dd><tt><i>OBJ_ROOT</i>/Release/lib</tt>
</dl>
- <p>
+ <br><br>
<dt>Profile Builds
<dd>
<dl>
<dt>Tools
- <dd><tt><i>OBJ_ROOT</i>/tools/Profile</tt>
+ <dd><tt><i>OBJ_ROOT</i>/Profile/bin</tt>
<dt>Libraries
- <dd><tt><i>OBJ_ROOT</i>/lib/Profile</tt>
+ <dd><tt><i>OBJ_ROOT</i>/Profile/lib</tt>
</dl>
</dl>
<div class="doc_text">
<p>
-If you're running on a
linux system that supports the "<a
+If you're running on a
Linux system that supports the "<a
href="http://www.tat.physik.uni-tuebingen.de/~rguenth/linux/binfmt_misc.html">binfmt_misc</a>"
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):</p>
+<div class="doc_code">
<pre>
- $ 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
</pre>
+</div>
<p>
-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:</p>
</p>
+<div class="doc_code">
+<pre>
+$ sudo update-binfmts --install llvm /path/to/lli --magic 'BC'
+</pre>
</div>
+</div>
<!-- *********************************************************************** -->
<div class="doc_section">
<p>One useful source of information about the LLVM source base is the LLVM <a
href="http://www.doxygen.org">doxygen</a> documentation available at <tt><a
-href="http://llvm.cs.uiuc.edu/doxygen/">http://llvm.cs.uiuc.edu/doxygen/</a></tt>.
+href="http://llvm.org/doxygen/">http://llvm.org/doxygen/</a></tt>.
The following is a brief introduction to code layout:</p>
</div>
<!-- ======================================================================= -->
-<div class="doc_subsection">
- <a name="cvsdir"><tt>CVS</tt> directories</a>
-</div>
-
+<div class="doc_subsection"><a name="examples"><tt>llvm/examples</tt></a></div>
<div class="doc_text">
-
-<p>Every directory checked out of CVS will contain a <tt>CVS</tt> directory; for
-the most part these can just be ignored.</p>
-
+ <p>This directory contains some simple examples of how to use the LLVM IR and
+ JIT.</p>
</div>
<!-- ======================================================================= -->
-<div class="doc_subsection">
- <a name="include"><tt>llvm/include</tt></a>
-</div>
-
+<div class="doc_subsection"><a name="include"><tt>llvm/include</tt></a></div>
<div class="doc_text">
<p>This directory contains public header files exported from the LLVM
library. The three main subdirectories of this directory are:</p>
-<ol>
- <li><tt>llvm/include/llvm</tt> - This directory contains all of the LLVM
- specific header files. This directory also has subdirectories for
- different portions of LLVM: <tt>Analysis</tt>, <tt>CodeGen</tt>,
- <tt>Target</tt>, <tt>Transforms</tt>, etc...</li>
-
- <li><tt>llvm/include/Support</tt> - This directory contains generic
- support libraries that are independent of LLVM, but are used by LLVM.
- For example, some C++ STL utilities and a Command Line option processing
- library store their header files here.</li>
-
- <li><tt>llvm/include/Config</tt> - This directory contains header files
- configured by the <tt>configure</tt> script. They wrap "standard" UNIX
- and C header files. Source code can include these header files which
- automatically take care of the conditional #includes that the
- <tt>configure</tt> script generates.</li>
-</ol>
-
+<dl>
+ <dt><tt><b>llvm/include/llvm</b></tt></dt>
+ <dd>This directory contains all of the LLVM specific header files. This
+ directory also has subdirectories for different portions of LLVM:
+ <tt>Analysis</tt>, <tt>CodeGen</tt>, <tt>Target</tt>, <tt>Transforms</tt>,
+ etc...</dd>
+
+ <dt><tt><b>llvm/include/llvm/Support</b></tt></dt>
+ <dd>This directory contains generic support libraries that are provided with
+ LLVM but not necessarily specific to LLVM. For example, some C++ STL utilities
+ and a Command Line option processing library store their header files here.
+ </dd>
+
+ <dt><tt><b>llvm/include/llvm/Config</b></tt></dt>
+ <dd>This directory contains header files configured by the <tt>configure</tt>
+ script. They wrap "standard" UNIX and C header files. Source code can
+ include these header files which automatically take care of the conditional
+ #includes that the <tt>configure</tt> script generates.</dd>
+</dl>
</div>
<!-- ======================================================================= -->
-<div class="doc_subsection">
- <a name="lib"><tt>llvm/lib</tt></a>
-</div>
-
+<div class="doc_subsection"><a name="lib"><tt>llvm/lib</tt></a></div>
<div class="doc_text">
<p>This directory contains most of the source files of the LLVM system. In LLVM,
different <a href="#tools">tools</a>.</p>
<dl>
- <dt><tt>llvm/lib/VMCore/</tt><dd> This directory holds the core LLVM
- source files that implement core classes like Instruction and BasicBlock.
-
- <dt><tt>llvm/lib/AsmParser/</tt><dd> This directory holds the source code
- for the LLVM assembly language parser library.
+ <dt><tt><b>llvm/lib/VMCore/</b></tt></dt>
+ <dd> This directory holds the core LLVM source files that implement core
+ classes like Instruction and BasicBlock.</dd>
- <dt><tt>llvm/lib/ByteCode/</tt><dd> This directory holds code for reading
- and write LLVM bytecode.
+ <dt><tt><b>llvm/lib/AsmParser/</b></tt></dt>
+ <dd>This directory holds the source code for the LLVM assembly language parser
+ library.</dd>
- <dt><tt>llvm/lib/CWriter/</tt><dd> This directory implements the LLVM to C
- converter.
+ <dt><tt><b>llvm/lib/BitCode/</b></tt></dt>
+ <dd>This directory holds code for reading and write LLVM bitcode.</dd>
- <dt><tt>llvm/lib/Analysis/</tt><dd> This directory contains a variety of
+ <dt><tt><b>llvm/lib/Analysis/</b></tt><dd>This directory contains a variety of
different program analyses, such as Dominator Information, Call Graphs,
Induction Variables, Interval Identification, Natural Loop Identification,
- etc...
-
- <dt><tt>llvm/lib/Transforms/</tt><dd> This directory contains the source
- code for the LLVM to LLVM program transformations, such as Aggressive Dead
- Code Elimination, Sparse Conditional Constant Propagation, Inlining, Loop
- Invariant Code Motion, Dead Global Elimination, and many others...
-
- <dt><tt>llvm/lib/Target/</tt><dd> This directory contains files that
- describe various target architectures for code generation. For example,
- the llvm/lib/Target/SparcV9 directory holds the Sparc machine
- description.<br>
+ etc.</dd>
+
+ <dt><tt><b>llvm/lib/Transforms/</b></tt></dt>
+ <dd> This directory contains the source code for the LLVM to LLVM program
+ transformations, such as Aggressive Dead Code Elimination, Sparse Conditional
+ Constant Propagation, Inlining, Loop Invariant Code Motion, Dead Global
+ Elimination, and many others.</dd>
+
+ <dt><tt><b>llvm/lib/Target/</b></tt></dt>
+ <dd> This directory contains files that describe various target architectures
+ for code generation. For example, the <tt>llvm/lib/Target/X86</tt>
+ directory holds the X86 machine description while
+ <tt>llvm/lib/Target/CBackend</tt> implements the LLVM-to-C converter.</dd>
- <dt><tt>llvm/lib/CodeGen/</tt><dd> This directory contains the major parts
- of the code generator: Instruction Selector, Instruction Scheduling, and
- Register Allocation.
-
- <dt><tt>llvm/lib/Support/</tt><dd> This directory contains the source code
- that corresponds to the header files located in
- <tt>llvm/include/Support/</tt>.
+ <dt><tt><b>llvm/lib/CodeGen/</b></tt></dt>
+ <dd> This directory contains the major parts of the code generator: Instruction
+ Selector, Instruction Scheduling, and Register Allocation.</dd>
+
+ <dt><tt><b>llvm/lib/Debugger/</b></tt></dt>
+ <dd> This directory contains the source level debugger library that makes
+ it possible to instrument LLVM programs so that a debugger could identify
+ source code locations at which the program is executing.</dd>
+
+ <dt><tt><b>llvm/lib/ExecutionEngine/</b></tt></dt>
+ <dd> This directory contains libraries for executing LLVM bitcode directly
+ at runtime in both interpreted and JIT compiled fashions.</dd>
+
+ <dt><tt><b>llvm/lib/Support/</b></tt></dt>
+ <dd> This directory contains the source code that corresponds to the header
+ files located in <tt>llvm/include/Support/</tt>.</dd>
+
+ <dt><tt><b>llvm/lib/System/</b></tt></dt>
+ <dd>This directory contains the operating system abstraction layer that
+ shields LLVM from platform-specific coding.</dd>
</dl>
</div>
<!-- ======================================================================= -->
-<div class="doc_subsection">
- <a name="runtime"><tt>llvm/runtime</tt></a>
+<div class="doc_subsection"><a name="projects"><tt>llvm/projects</tt></a></div>
+<div class="doc_text">
+ <p>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 <tt>llvm/projects/sample</tt> for an example of how
+ to set up your own project.</p>
</div>
+<!-- ======================================================================= -->
+<div class="doc_subsection"><a name="runtime"><tt>llvm/runtime</tt></a></div>
<div class="doc_text">
-<p>This directory contains libraries which are compiled into LLVM bytecode and
+<p>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.</p>
</div>
<!-- ======================================================================= -->
-<div class="doc_subsection">
- <a name="test"><tt>llvm/test</tt></a>
-</div>
-
+<div class="doc_subsection"><a name="test"><tt>llvm/test</tt></a></div>
<div class="doc_text">
-
-<p>This directory contains regression tests and source code that is used to test
-the LLVM infrastructure.</p>
-
+ <p>This directory contains feature and regression tests and other basic sanity
+ checks on the LLVM infrastructure. These are intended to run quickly and cover
+ a lot of territory without being exhaustive.</p>
</div>
<!-- ======================================================================= -->
-<div class="doc_subsection">
- <a name="tools"><tt>llvm/tools</tt></a>
+<div class="doc_subsection"><a name="test-suite"><tt>test-suite</tt></a></div>
+<div class="doc_text">
+ <p>This is not a directory in the normal llvm module; it is a separate
+ Subversion
+ module that must be checked out (usually to <tt>projects/test-suite</tt>).
+ This
+ module contains a comprehensive correctness, performance, and benchmarking
+ test
+ suite for LLVM. It is a separate Subversion module because not every LLVM
+ user is
+ interested in downloading or building such a comprehensive test suite. For
+ further details on this test suite, please see the
+ <a href="TestingGuide.html">Testing Guide</a> document.</p>
</div>
+<!-- ======================================================================= -->
+<div class="doc_subsection"><a name="tools"><tt>llvm/tools</tt></a></div>
<div class="doc_text">
<p>The <b>tools</b> 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 <tt>tool_name --help</tt>. The
-following is a brief introduction to the most important tools:</p>
+always get help for a tool by typing <tt>tool_name -help</tt>. The
+following is a brief introduction to the most important tools. More detailed
+information is in the <a href="CommandGuide/index.html">Command Guide</a>.</p>
<dl>
- <dt><tt><b>analyze</b></tt> <dd><tt>analyze</tt> is used to run a specific
- analysis on an input LLVM bytecode file and print out the results. It is
- primarily useful for debugging analyses, or familiarizing yourself with
- what an analysis does.<p>
- <dt><tt><b>bugpoint</b></tt> <dd><tt>bugpoint</tt> is used to debug
+ <dt><tt><b>bugpoint</b></tt></dt>
+ <dd><tt>bugpoint</tt> is used to debug
optimization passes or code generation backends by narrowing down the
given test case to the minimum number of passes and/or instructions that
still cause a problem, whether it is a crash or miscompilation. See <a
href="HowToSubmitABug.html">HowToSubmitABug.html</a> for more information
- on using <tt>bugpoint</tt>.<p>
-
- <dt><tt><b>llvm-ar</b></tt> <dd>The archiver produces an archive containing
- the given LLVM bytecode files, optionally with an index for faster
- lookup.<p>
+ on using <tt>bugpoint</tt>.</dd>
+
+ <dt><tt><b>llvmc</b></tt></dt>
+ <dd>The LLVM Compiler Driver. This program can
+ 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. <tt>llvmc</tt> also takes care of processing the
+ dependent libraries found in bitcode. This reduces the need to get the
+ traditional <tt>-l<name></tt> options right on the command line. Please
+ note that this tool, while functional, is still experimental and not feature
+ complete.</dd>
+
+ <dt><tt><b>llvm-ar</b></tt></dt>
+ <dd>The archiver produces an archive containing
+ the given LLVM bitcode files, optionally with an index for faster
+ lookup.</dd>
- <dt><tt><b>llvm-as</b></tt> <dd>The assembler transforms the human readable
- LLVM assembly to LLVM bytecode.<p>
-
- <dt><tt><b>llvm-dis</b></tt><dd>The disassembler transforms the LLVM
- bytecode to human readable LLVM assembly.<p>
-
- <dt><tt><b>llvm-link</b></tt><dd> <tt>llvm-link</tt>, not surprisingly,
- links multiple LLVM modules into a single program.<p>
+ <dt><tt><b>llvm-as</b></tt></dt>
+ <dd>The assembler transforms the human readable LLVM assembly to LLVM
+ bitcode.</dd>
+
+ <dt><tt><b>llvm-dis</b></tt></dt>
+ <dd>The disassembler transforms the LLVM bitcode to human readable
+ LLVM assembly.</dd>
+
+ <dt><tt><b>llvm-ld</b></tt></dt>
+ <dd><tt>llvm-ld</tt> is a general purpose and extensible linker for LLVM.
+ This is the linker invoked by <tt>llvmc</tt>. It performs standard link time
+ optimizations and allows optimization modules to be loaded and run so that
+ language specific optimizations can be applied at link time.</dd>
+
+ <dt><tt><b>llvm-link</b></tt></dt>
+ <dd><tt>llvm-link</tt>, not surprisingly, links multiple LLVM modules into
+ a single program.</dd>
- <dt><tt><b>lli</b></tt><dd> <tt>lli</tt> is the LLVM interpreter, which
- can directly execute LLVM bytecode (although very slowly...). In addition
- to a simple interpreter, <tt>lli</tt> also has a tracing mode (entered by
- specifying <tt>-trace</tt> on the command line). Finally, for
- architectures that support it (currently only x86 and Sparc), by default,
- <tt>lli</tt> will function as a Just-In-Time compiler (if the
- functionality was compiled in), and will execute the code <i>much</i>
- faster than the interpreter.<p>
-
- <dt><tt><b>llc</b></tt><dd> <tt>llc</tt> is the LLVM backend compiler, which
- translates LLVM bytecode to a SPARC or x86 assembly file, or to C code (with
- the -march=c option).<p>
-
- <dt><tt><b>llvmgcc</b></tt><dd> <tt>llvmgcc</tt> is a GCC-based C frontend
- that has been retargeted to emit LLVM code as the machine code output. It
- works just like any other GCC compiler, taking the typical <tt>-c, -S, -E,
- -o</tt> options that are typically used. The source code for the
- <tt>llvmgcc</tt> tool is currently not included in the LLVM CVS tree
- because it is quite large and not very interesting.<p>
-
- <blockquote>
- <dl>
- <dt><tt><b>gccas</b></tt> <dd>This tool is invoked by the
- <tt>llvmgcc</tt> frontend as the "assembler" part of the compiler. This
- tool actually assembles LLVM assembly to LLVM bytecode,
- performs a variety of optimizations, and outputs LLVM bytecode. Thus
- when you invoke <tt>llvmgcc -c x.c -o x.o</tt>, you are causing
- <tt>gccas</tt> to be run, which writes the <tt>x.o</tt> file (which is
- an LLVM bytecode file that can be disassembled or manipulated just like
- any other bytecode file). The command line interface to <tt>gccas</tt>
- is designed to be as close as possible to the <b>system</b>
- `<tt>as</tt>' utility so that the gcc frontend itself did not have to be
- modified to interface to a "weird" assembler.<p>
-
- <dt><tt><b>gccld</b></tt> <dd><tt>gccld</tt> links together several LLVM
- bytecode files into one bytecode file and does some optimization. It is
- the linker invoked by the GCC frontend when multiple .o files need to be
- linked together. Like <tt>gccas</tt>, the command line interface of
- <tt>gccld</tt> is designed to match the system linker, to aid
- interfacing with the GCC frontend.</dl><p>
- </blockquote>
-
- <dt><tt><b>opt</b></tt><dd> <tt>opt</tt> reads LLVM bytecode, applies a
- series of LLVM to LLVM transformations (which are specified on the command
- line), and then outputs the resultant bytecode. The '<tt>opt --help</tt>'
- command is a good way to get a list of the program transformations
- available in LLVM.
-
+ <dt><tt><b>lli</b></tt></dt>
+ <dd><tt>lli</tt> is the LLVM interpreter, which
+ can directly execute LLVM bitcode (although very slowly...). For architectures
+ that support it (currently x86, Sparc, and PowerPC), by default, <tt>lli</tt>
+ will function as a Just-In-Time compiler (if the functionality was compiled
+ in), and will execute the code <i>much</i> faster than the interpreter.</dd>
+
+ <dt><tt><b>llc</b></tt></dt>
+ <dd> <tt>llc</tt> is the LLVM backend compiler, which
+ translates LLVM bitcode to a native code assembly file or to C code (with
+ the -march=c option).</dd>
+
+ <dt><tt><b>llvm-gcc</b></tt></dt>
+ <dd><tt>llvm-gcc</tt> 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
+ bitcode or assembly (with the <tt>-emit-llvm</tt> option) instead of the
+ usual machine code output. It works just like any other GCC compiler,
+ taking the typical <tt>-c, -S, -E, -o</tt> options that are typically used.
+ Additionally, the the source code for <tt>llvm-gcc</tt> is available as a
+ separate Subversion module.</dd>
+
+ <dt><tt><b>opt</b></tt></dt>
+ <dd><tt>opt</tt> reads LLVM bitcode, applies a series of LLVM to LLVM
+ transformations (which are specified on the command line), and then outputs
+ the resultant bitcode. The '<tt>opt -help</tt>' command is a good way to
+ get a list of the program transformations available in LLVM.<br>
+ <dd><tt>opt</tt> can also be used to run a specific analysis on an input
+ LLVM bitcode file and print out the results. It is primarily useful for
+ debugging analyses, or familiarizing yourself with what an analysis does.</dd>
</dl>
-
</div>
<!-- ======================================================================= -->
-<div class="doc_subsection">
- <a name="utils"><tt>llvm/utils</tt></a>
-</div>
-
+<div class="doc_subsection"><a name="utils"><tt>llvm/utils</tt></a></div>
<div class="doc_text">
<p>This directory contains utilities for working with LLVM source code, and some
are code generators for parts of LLVM infrastructure.</p>
<dl>
- <dt><tt><b>Burg/</b></tt> <dd><tt>Burg</tt> is an instruction selector
- generator -- it builds trees on which it then performs pattern-matching to
- select instructions according to the patterns the user has specified. Burg
- is currently used in the Sparc V9 backend.<p>
-
<dt><tt><b>codegen-diff</b></tt> <dd><tt>codegen-diff</tt> is a script
that finds differences between code that LLC generates and code that LLI
generates. This is a useful tool if you are debugging one of them,
assuming that the other generates correct output. For the full user
- manual, run <tt>`perldoc codegen-diff'</tt>.<p>
-
- <dt><tt><b>cvsupdate</b></tt> <dd><tt>cvsupdate</tt> is a script that will
- update your CVS tree, but produce a much cleaner and more organized output
- than simply running <tt>`cvs -z3 up -dP'</tt> will. For example, it will group
- together all the new and updated files and modified files in separate
- sections, so you can see at a glance what has changed. If you are at the
- top of your LLVM CVS tree, running <tt>utils/cvsupdate</tt> is the
- preferred way of updating the tree.<p>
+ manual, run <tt>`perldoc codegen-diff'</tt>.<br><br>
<dt><tt><b>emacs/</b></tt> <dd>The <tt>emacs</tt> directory contains
syntax-highlighting files which will work with Emacs and XEmacs editors,
providing syntax highlighting support for LLVM assembly files and TableGen
description files. For information on how to use the syntax files, consult
- the <tt>README</tt> file in that directory.<p>
+ the <tt>README</tt> file in that directory.<br><br>
<dt><tt><b>getsrcs.sh</b></tt> <dd>The <tt>getsrcs.sh</tt> script finds
and outputs all non-generated source files, which is useful if one wishes
to do a lot of development across directories and does not want to
individually find each file. One way to use it is to run, for example:
<tt>xemacs `utils/getsources.sh`</tt> from the top of your LLVM source
- tree.<p>
-
+ tree.<br><br>
+
+ <dt><tt><b>llvmgrep</b></tt></dt>
+ <dd>This little tool performs an "egrep -H -n" on each source file in LLVM and
+ passes to it a regular expression provided on <tt>llvmgrep</tt>'s command
+ line. This is a very efficient way of searching the source base for a
+ particular regular expression.</dd>
+
<dt><tt><b>makellvm</b></tt> <dd>The <tt>makellvm</tt> script compiles all
files in the current directory and then compiles and links the tool that
is the first argument. For example, assuming you are in the directory
<tt>llvm/lib/Target/Sparc</tt>, if <tt>makellvm</tt> is in your path,
simply running <tt>makellvm llc</tt> will make a build of the current
directory, switch to directory <tt>llvm/tools/llc</tt> and build it,
- causing a re-linking of LLC.<p>
+ causing a re-linking of LLC.<br><br>
- <dt><tt><b>NightlyTest.pl</b></tt> and
+ <dt><tt><b>NewNightlyTest.pl</b></tt> and
<tt><b>NightlyTestTemplate.html</b></tt> <dd>These files are used in a
cron script to generate nightly status reports of the functionality of
tools, and the results can be seen by following the appropriate link on
- the <a href="http://llvm.cs.uiuc.edu/">LLVM homepage</a>.<p>
+ the <a href="http://llvm.org/">LLVM homepage</a>.<br><br>
<dt><tt><b>TableGen/</b></tt> <dd>The <tt>TableGen</tt> directory contains
the tool used to generate register descriptions, instruction set
descriptions, and even assemblers from common TableGen description
- files.<p>
+ files.<br><br>
<dt><tt><b>vim/</b></tt> <dd>The <tt>vim</tt> directory contains
syntax-highlighting files which will work with the VIM editor, providing
syntax highlighting support for LLVM assembly files and TableGen
description files. For information on how to use the syntax files, consult
- the <tt>README</tt> file in that directory.<p>
+ the <tt>README</tt> file in that directory.<br><br>
</dl>
</div>
<!-- *********************************************************************** -->
+<div class="doc_text">
+<p>This section gives an example of using LLVM. llvm-gcc3 is now obsolete,
+so we only include instructions for llvm-gcc4.
+</p>
+
+<p><b>Note:</b> The <i>gcc4</i> frontend's invocation is <b><i>considerably different</i></b>
+from the previous <i>gcc3</i> frontend. In particular, the <i>gcc4</i> frontend <b><i>does not</i></b>
+create bitcode by default: <i>gcc4</i> produces native code. As the example below illustrates,
+the '--emit-llvm' flag is needed to produce LLVM bitcode output. For <i>makefiles</i> and
+<i>configure</i> scripts, the CFLAGS variable needs '--emit-llvm' to produce bitcode
+output.</p>
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection"><a name="tutorial4">Example with llvm-gcc4</a></div>
+
<div class="doc_text">
<ol>
- <li>First, create a simple C file, name it 'hello.c':
- <pre>
- #include <stdio.h>
- int main() {
- printf("hello world\n");
- return 0;
- }
- </pre></li>
-
- <li><p>Next, compile the C file into a LLVM bytecode file:</p>
- <p><tt>% llvmgcc hello.c -o hello</tt></p>
-
- <p>Note that you should have already built the tools and they have to be
- in your path, at least <tt>gccas</tt> and <tt>gccld</tt>.</p>
-
- <p>This will create two result files: <tt>hello</tt> and
- <tt>hello.bc</tt>. The <tt>hello.bc</tt> is the LLVM bytecode that
- corresponds the the compiled program and the library facilities that it
- required. <tt>hello</tt> is a simple shell script that runs the bytecode
- file with <tt>lli</tt>, making the result directly executable. Note that
- all LLVM optimizations are enabled by default, so there is no need for a
- "-O3" switch.</p></li>
-
- <li><p>Run the program. To make sure the program ran, execute one of the
- following commands:</p>
+ <li><p>First, create a simple C file, name it 'hello.c':</p>
+
+<div class="doc_code">
+<pre>
+#include <stdio.h>
+
+int main() {
+ printf("hello world\n");
+ return 0;
+}
+</pre></div></li>
+
+ <li><p>Next, compile the C file into a native executable:</p>
+
+ <div class="doc_code"><pre>% llvm-gcc hello.c -o hello</pre></div>
+
+ <p>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).</p></li>
+
+ <li><p>Next, compile the C file into a LLVM bitcode file:</p>
+
+ <div class="doc_code">
+ <pre>% llvm-gcc -O3 -emit-llvm hello.c -c -o hello.bc</pre></div>
+
+ <p>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 <a href="CommandGuide/index.html">standard LLVM tools</a> on
+ the bitcode file.</p>
+
+ <p>Unlike llvm-gcc3, llvm-gcc4 correctly responds to -O[0123] arguments.
+ </p></li>
+
+ <li><p>Run the program in both forms. To run the program, use:</p>
- <p><tt>% ./hello</tt></p>
+ <div class="doc_code"><pre>% ./hello</pre></div>
- <p>or</p>
+ <p>and</p>
+
+ <div class="doc_code"><pre>% lli hello.bc</pre></div>
- <p><tt>% lli hello.bc</tt></p></li>
+ <p>The second examples shows how to invoke the LLVM JIT, <a
+ href="CommandGuide/html/lli.html">lli</a>.</p></li>
<li><p>Use the <tt>llvm-dis</tt> utility to take a look at the LLVM assembly
code:</p>
- <p><tt>% llvm-dis < hello.bc | less</tt><p></li>
+<div class="doc_code">
+<pre>llvm-dis < hello.bc | less</pre>
+</div></li>
<li><p>Compile the program to native assembly using the LLC code
generator:</p>
- <p><tt>% llc hello.bc -o hello.s</tt></p>
+ <div class="doc_code"><pre>% llc hello.bc -o hello.s</pre></div></li>
<li><p>Assemble the native assembly language file into a program:</p>
- <p><b>Solaris:</b><tt>% /opt/SUNWspro/bin/cc -xarch=v9 hello.s -o hello.native</tt></p>
- <p><b>Others:</b><tt>% gcc hello.s -o hello.native</tt></p>
+<div class="doc_code">
+<pre>
+<b>Solaris:</b> % /opt/SUNWspro/bin/cc -xarch=v9 hello.s -o hello.native
+
+<b>Others:</b> % gcc hello.s -o hello.native
+</pre>
+</div></li>
<li><p>Execute the native code program:</p>
- <p><tt>% ./hello.native</tt></p></li>
+ <div class="doc_code"><pre>% ./hello.native</pre></div>
+
+ <p>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.</p>
+ </li>
</ol>
</div>
+
<!-- *********************************************************************** -->
<div class="doc_section">
<a name="problems">Common Problems</a>
<div class="doc_text">
-<p>This document is just an <b>introduction</b> to how to use LLVM to do
+<p>This document is just an <b>introduction</b> 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
out:</p>
<ul>
- <li><a href="http://llvm.cs.uiuc.edu/">LLVM homepage</a></li>
- <li><a href="http://llvm.cs.uiuc.edu/doxygen/">LLVM doxygen tree</a></li>
- <li><a href="http://llvm.cs.uiuc.edu/docs/Projects.html">Starting a Project
+ <li><a href="http://llvm.org/">LLVM homepage</a></li>
+ <li><a href="http://llvm.org/doxygen/">LLVM doxygen tree</a></li>
+ <li><a href="http://llvm.org/docs/Projects.html">Starting a Project
that Uses LLVM</a></li>
</ul>
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<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
- <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
+ <a href="http://llvm.x10sys.com/rspencer/">Reid Spencer</a><br>
+ <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
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