<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="#cross-compile">Cross-Compiling LLVM</a>
<li><a href="#objfiles">The Location of LLVM Object Files</a>
<li><a href="#optionalconfig">Optional Configuration Items</a>
</ol></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>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
+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>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
+end uses the GCC parser to convert code to LLVM. Once
compiled into LLVM bytecode, a program can be manipulated with the LLVM tools
from the LLVM suite.</p>
<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 GCC front end:
+ <li>Install the GCC front end if you intend to compile C or C++:
<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.<i>platform</i>.tar.gz | tar -xvf -</tt>
+ </li>
+ <li><tt>cd llvm-gcc3.4/<i>platform</i> (llvm-gcc3.4 only)<br>
+ ./fixheaders</tt></li>
+ <li>Add llvm-gcc's "bin" directory to your PATH 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">CVS</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">CVS</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>cvs up -P -d</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>
</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.</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>
<li><tt>gmake -k |& tee gnumake.out
# this is csh or tcsh syntax</tt></li>
- <li>If you get an "internal compiler error (ICE)" see <a href="#brokengcc">below</a>.</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>
-<table cellpadding="3">
+<table cellpadding="3" summary="Known LLVM platforms">
<tr>
<th>OS</th>
<th>Arch</th>
</tr>
<tr>
<td>Linux</td>
- <td>x86<sup>1</sup></td>
+ <td>x86<sup><a href="#pf_1">1</a></sup></td>
<td>GCC</td>
</tr>
<tr>
</tr>
<tr>
<td>FreeBSD</td>
- <td>x86<sup>1</sup></td>
+ <td>x86<sup><a href="#pf_1">1</a></sup></td>
<td>GCC</td>
</tr>
<tr>
- <td>MacOS X<sup>2</sup></td>
+ <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></sup></td>
+ <td>x86</td>
+ <td>GCC</td>
+
+</tr>
<tr>
<td>Cygwin/Win32</td>
- <td>x86<sup>1</sup></td>
+ <td>x86<sup><a href="#pf_1">1</a>,<a href="#pf_8">8</a></sup></td>
+ <td>GCC 3.4.X, binutils 2.15</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></sup></td>
+ <td>GCC 3.4.X, binutils 2.15</td>
+</tr>
+<tr>
+ <td>Linux</td>
+ <td>amd64<sup><a href="#pf_3">3</a></sup></td>
<td>GCC</td>
</tr>
</table>
<p>LLVM has partial support for the following platforms:</p>
-<table>
+<table summary="LLVM partial platform support">
<tr>
<th>OS</th>
<th>Arch</th>
</tr>
<tr>
<td>Windows</td>
- <td>x86<sup>1</sup></td>
- <td>Visual Studio .NET<sup>4,5</sup>, MinGW</td>
+ <td>x86<sup><a href="#pf_1">1</a></sup></td>
+ <td>Visual Studio .NET<sup><a href="#pf_4">4</a>,<a href="#pf_5">5</a></sup></td>
<tr>
- <td>AIX<sup>3,4</sup></td>
+ <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>3,5</sup></td>
+ <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>
-<p>
-Notes:<br>
-<sup>1</sup> Code generation supported for Pentium processors and up<br>
-<sup>2</sup> Code generation supported for 32-bit ABI only<br>
-<sup>3</sup> No native code generation<br>
-<sup>4</sup> Build is not complete: one or more tools don't link<br>
-<sup>5</sup> The GCC-based C/C++ frontend does not build<br>
-</p>
+<p><b>Notes:</b></p>
+
+<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 don't link</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>
+<a href="http://www.mingw.org/MinGWiki/">Download</a> 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.</li>
+<li><a name="pf_7">Native code generation exists but is not complete.</a></li>
+<li><a name="pf_8">Binutils</a> 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 <a href="http://sourceware.org/bugzilla/show_bug.cgi?id=2659">
+ Binutils bugzilla</a>, if it wasn't already applied.</li>
+</ol>
+</div>
<p>Note that you will need about 1-3 GB of space for a full LLVM build in Debug
-mode, depending on the system (because of all the debug info), and the libraries
-appear in more than one of the tools that get linked, so there is some
-duplication. If you do not need many of the tools and you are space-conscious,
+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 <tt>llvm/tools/Makefile</tt>. The Release
build requires considerably less space.</p>
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>
+ <table summary="Packages required to compile LLVM">
<tr><th>Package</th><th>Version</th><th>Notes</th></tr>
<tr>
<tr>
<td><a href="http://gcc.gnu.org">GCC</a></td>
<td>3.4.2</td>
- <td>C/C++ compiler (<a href="#Note3">Note 3</a>)</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>
<tr>
<td><a href="http://www.gnu.org/software/bison/bison.html">Bison</a></td>
- <td>1.35</td>
+ <td>1.28, 1.35, 1.75, 1.875d, 2.0, or 2.1<br>(not 1.85 or 1.875)</td>
<td>YACC compiler</td>
</tr>
+ <tr>
+ <td><a href="https://www.cvshome.org/downloads.html">CVS</a></td>
+ <td>≥1.11</td>
+ <td>CVS 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 (<a href="#Note2">Note 2</a>)</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 (<a href="#Note2">Note 2</a>)</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 (<a href="#Note2">Note 2</a>)</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 (<a href="#Note1">Note 1</a>)</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>2.59</td>
- <td>Configuration script builder (<a href="#Note1">Note 1</a>)</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>1.9.2</td>
- <td>aclocal macro generator (<a href="#Note1">Note 1</a>)</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>
+ <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>1.5.10</td>
- <td>Shared library manager (<a href="#Note1">Note 1</a>)</td>
- </tr>
-
- <tr>
- <td><a href="https://www.cvshome.org/downloads.html">CVS</a></td>
- <td>≥1.11</td>
- <td>CVS access to LLVM (<a href="#Note4">Note 4</a>)</td>
+ <td>Shared library manager<sup><a href="#sf4">4</a></sup></td>
</tr>
</table>
- <p>Notes:</p>
+ <p><b>Notes:</b></p>
+ <div class="doc_notes">
<ol>
- <li><a name="Note1">If you want to make changes to the configure scripts,
- you will need GNU autoconf (2.59), and consequently, GNU M4 (version 1.4
- or higher). You will also need automake (1.9.2). We only use aclocal
- from that package.</a></li>
- <li><a name="Note2">Only needed if you want to run the automated test
- suite in the <tt>test</tt> directory.</a></li>
- </li>
- <li><a name="Note3">Only the C and C++ languages are needed so there's no
+ <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="Note4">You only need CVS if you intend to build from the
+ <a href="#brokengcc">below</a> for specific version info.</li>
+ <li><a name="sf2">You only need CVS if you intend to build from the
latest LLVM sources. If you're working from a release distribution, you
don't need CVS.</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 (2.59), and consequently, GNU M4 (version 1.4
+ or higher). You will also need automake (1.9.2). 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>
<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 and GCC 3.4.0 and have had success
-with them. Other versions of GCC will probably work as well. GCC versions listed
+to compile LLVM. We routinely use GCC 3.3.3, 3.4.0, and Apple 4.0.1
+successfully with them (however, see 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
<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="CFEBuildInstrs.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.x</b> on X86-64/amd64</b>: GCC <a href="http://llvm.org/PR1056">
+ miscompiles portions of LLVM</a>.</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>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>
</div>
<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>
- These aliases allow 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/bytecode/libs</tt></dt>
+ <dd>[Optional] This environment variable helps LLVM linking tools find the
+ locations of your bytecode 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
+ 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><tt>llvm-1.4.tar.gz</tt></dt>
- <dd>This is the source code for the LLVM libraries and tools.<br/></dd>
-
- <dt><tt>llvm-test-1.4.tar.gz</tt></dt>
- <dd>This is the source code for the LLVM test suite.</tt></dd>
+ <dt><tt>llvm-x.y.tar.gz</tt></dt>
+ <dd>Source release for the LLVM libraries and tools.<br/></dd>
- <dt><tt>cfrontend-1.4.source.tar.gz</tt></dt>
- <dd>This is the source release of the GCC front end.<br/></dd>
+ <dt><tt>llvm-test-x.y.tar.gz</tt></dt>
+ <dd>Source release for the LLVM test suite.</dd>
- <dt><tt>cfrontend-1.4.sparc-sun-solaris2.8.tar.gz</tt></dt>
- <dd>This is the binary release of the GCC front end for Solaris/Sparc.
- <br/></dd>
+ <dt><tt>llvm-gcc4-x.y.source.tar.gz</tt></dt>
+ <dd>Source release of the llvm-gcc4 front end. See README.LLVM in the root
+ directory for build instructions.<br/></dd>
- <dt><tt>cfrontend-1.4.i686-redhat-linux-gnu.tar.gz</tt></dt>
- <dd>This is the binary release of the GCC front end for Linux/x86.<br/></dd>
+ <dt><tt>llvm-gcc4-x.y-platform.tar.gz</tt></dt>
+ <dd>Binary release of the llvm-gcc4 front end for a specific platform.<br/></dd>
- <dt><tt>cfrontend-1.4.i386-unknown-freebsd5.1.tar.gz</tt></dt>
- <dd>This is the binary release of the GCC front end for FreeBSD/x86.<br/></dd>
-
- <dt><tt>cfrontend-1.4.powerpc-apple-darwin7.0.0.tar.gz</tt></dt>
- <dd>This is the binary release of the GCC front end for MacOS X/PPC.<br/></dd>
</dl>
+<p>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. </p>
+
</div>
<!-- ======================================================================= -->
<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><tt>cvs -d :pserver:anon@llvm.org:/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
+ <li><tt>cvs -z3 -d :pserver:anon@llvm.org:/var/cvs/llvm co
llvm</tt>
</ul>
<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>
+labels:</p>
<ul>
+<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>
you get it from the CVS repository:</p>
<pre>
cd llvm/projects
- cvs -z3 -d :pserver:anon@llvm-cvs.cs.uiuc.edu:/var/cvs/llvm co llvm-test
+ cvs -z3 -d :pserver:anon@llvm.org:/var/cvs/llvm co llvm-test
</pre>
<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>cvs update</tt>.</p>
-<p>If you would like to get the GCC front end source code, you can also get it
-from the CVS repository:</p>
-
-<pre>
- cvs -z3 -d :pserver:anon@llvm-cvs.cs.uiuc.edu:/var/cvs/llvm co llvm-gcc
-</pre>
-
-<p>Please note that you must follow <a href="CFEBuildInstrs.html">these
-instructions</a> to successfully build the LLVM GCC front-end.</p>
-
-</div>
-
-<!-- ======================================================================= -->
-<div class="doc_subsubsection">
- <a name="mirrors">LLVM CVS Mirrors</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>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="CFEBuildInstrs.html">these
+instructions</a> to successfully get and build the LLVM GCC front-end.</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, 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
+<a href="CFEBuildInstrs.html">build llvm-gcc yourself</a> after building the
+main LLVM repository.</p>
<p>To install the GCC front end, do the following:</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 llvmgcc-<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><tt>cd cfrontend/<i>platform</i><br>
- ./fixheaders</tt></p>
+<p>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
+llvm-test will pick it up.
+</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
<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>
+much easier now than it was in the past.</p>
</div>
<p>The following environment variables are used by the <tt>configure</tt>
script to configure the build system:</p>
-<table>
+<table summary="LLVM configure script environment variables">
<tr><th>Variable</th><th>Purpose</th></tr>
<tr>
<td>CC</td>
<p>The following options can be used to set or enable LLVM specific options:</p>
<dl>
- <dt><i>--with-llvmgccdir=LLVMGCCDIR</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></p>
- </dd>
+ <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="CFEBuildInstrs.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 the <tt>tclsh</tt> can be
+ <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 tcl 8.4 and 8.3 releases.
- <p></p>
+ 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>
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></p>
+ <br><br>
+ </dd>
+ <dt><i>--enable-debug-runtime</i></dt>
+ <dd>
+ 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>
available
on all platforms. The default is dependent on platform, so it is best
to explicitly enable it if you want it.
- <p></p>
+ <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>
<li>Change directory into the object root directory:
<br>
<tt>cd <i>OBJ_ROOT</i></tt>
- <p>
+ <br><br>
<li>Run the <tt>configure</tt> script located in the LLVM source tree:
<br>
<tt><i>SRC_ROOT</i>/configure --prefix=/install/path [other options]</tt>
- <p>
+ <br><br>
</ol>
-<p>In addition to running <tt>configure</tt>, you must set the
-<tt>LLVM_LIB_SEARCH_PATH</tt> environment variable in your startup shell
-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>
-
</div>
<!-- ======================================================================= -->
<tt>--enable-optimized</tt> option was used during configuration). The
build system will compile the tools and libraries with debugging
information.
- <p>
+ <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>
+ <br><br>
<dt>Profile Builds
<dd>
<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 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>
+ <br><br>
<dt><tt>gmake install</tt>
<dd>
hierarchy
under $PREFIX, specified with <tt>./configure --prefix=[dir]</tt>, which
defaults to <tt>/usr/local</tt>.
- <p>
-
+ <br><br>
+
<dt><tt>gmake -C runtime install-bytecode</tt>
<dd>
Assuming you built LLVM into $OBJDIR, when this command is run, it will
install bytecode libraries into the GCC front end's bytecode library
directory. If you need to update your bytecode libraries,
this is the target to use once you've built them.
- <p>
+ <br><br>
</dl>
<p>Please see the <a href="MakefileGuide.html">Makefile Guide</a> for further
<dt><tt>gmake ENABLE_OPTIMIZED=1</tt>
<dd>
Perform a Release (Optimized) build.
- <p>
+ <br><br>
+
+ <dt><tt>gmake ENABLE_OPTIMIZED=1 DISABLE_ASSERTIONS=1</tt>
+ <dd>
+ Perform a Release (Optimized) build without assertions enabled.
+ <br><br>
<dt><tt>gmake ENABLE_PROFILING=1</tt>
<dd>
Perform a Profiling build.
- <p>
+ <br><br>
<dt><tt>gmake VERBOSE=1</tt>
<dd>
Print what <tt>gmake</tt> is doing on standard output.
- <p>
+ <br><br>
<dt><tt>gmake TOOL_VERBOSE=1</tt></dt>
<dd>Ask each tool invoked by the makefiles to print out what it is doing on
the standard output. This also implies <tt>VERBOSE=1</tt>.
- <p></dd>
+ <br><br></dd>
</dl>
<p>Every directory in the LLVM object tree includes a <tt>Makefile</tt> to build
</div>
+<!-- ======================================================================= -->
+<div class="doc_subsection">
+ <a name="cross-compile">Cross-Compiling LLVM</a>
+</div>
+
+<div class="doc_text">
+ <p>It is possible to cross-compile LLVM. That is, you can create LLVM
+ executables and libraries for a platform different than the one one which you
+ are compiling. To do this, a few additional steps are
+ required. <sup><a href="#ccn_1">1</a></sup> To cross-compile LLVM, use
+ these instructions:</p>
+ <ol>
+ <li>Configure and build LLVM as a native compiler. You will need
+ just <tt>TableGen</tt> from that build.
+ <ul>
+ <li>If you have <tt>$LLVM_OBJ_ROOT=$LLVM_SRC_ROOT</tt> just execute
+ <tt>make -C utils/TableGen</tt> after configuring.</li>
+ <li>Otherwise you will need to monitor building process and terminate
+ it just after <tt>TableGen</tt> was built.</li>
+ </ul>
+ </li>
+ <li>Copy the TableGen binary to somewhere safe (out of your build tree).
+ </li>
+ <li>Configure LLVM to build with a cross-compiler. To do this, supply the
+ configure script with <tt>--build</tt> and <tt>--host</tt> options that
+ are different. The values of these options must be legal target triples
+ that your GCC compiler supports.</li>
+ <li>Put the saved <tt>TableGen</tt> executable into the
+ into <tt>$LLVM_OBJ_ROOT/{BUILD_TYPE}/bin</tt> directory (e.g. into
+ <tt>.../Release/bin</tt> for a Release build).</li>
+ <li>Build LLVM as usual.</li>
+ </ol>
+ <p>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
+ (--host option).</p>
+ <p><b>Notes:</b></p>
+ <div class="doc_notes">
+ <ol>
+ <li><a name="ccn_1">Cross-compiling</a> was tested only with Linux as
+ build platform and Windows as host using mingw32 cross-compiler. Other
+ combinations have not been tested.</li>
+ </ol>
+ </div>
+</div>
+
<!-- ======================================================================= -->
<div class="doc_subsection">
<a name="objfiles">The Location of LLVM Object Files</a>
<dt>Libraries
<dd><tt><i>OBJ_ROOT</i>/Debug/lib</tt>
</dl>
- <p>
+ <br><br>
<dt>Release Builds
<dd>
<dt>Libraries
<dd><tt><i>OBJ_ROOT</i>/Release/lib</tt>
</dl>
- <p>
+ <br><br>
<dt>Profile Builds
<dd>
<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
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
+ $ echo ':llvm:M::llvm::/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
<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>
<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/SparcV9</tt>
- directory holds the Sparc machine description while
- <tt>llvm/lib/Target/CBackend</tt> implements the LLVM-to-C converter</dd>
+ 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><b>llvm/lib/CodeGen/</b></tt></dt>
<dd> This directory contains the major parts of the code generator: Instruction
module contains a comprehensive correctness, performance, and benchmarking
test
suite for LLVM. It is a separate CVS module because not every LLVM user is
- interested in downloading or building such a comprehensive test. For further
- details on this test suite, please see the
+ 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>
information is in the <a href="CommandGuide/index.html">Command Guide</a>.</p>
<dl>
- <dt><tt><b>analyze</b></tt></dt>
- <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.</dd>
<dt><tt><b>bugpoint</b></tt></dt>
<dd><tt>bugpoint</tt> is used to debug
all from one command line. <tt>llvmc</tt> also takes care of processing the
dependent libraries found in bytecode. This reduces the need to get the
traditional <tt>-l<name></tt> options right on the command line. Please
- note that this tool is new in 1.4 and considered experimental. It will be
- fully supported in 1.5.</dd>
+ 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
LLVM assembly.</dd>
<dt><tt><b>llvm-ld</b></tt></dt>
- <dd><tt>llvm-ld</tt> is very similar to gccld and provides a general purpose
- and extensible linker for LLVM. This is the linker invoked by <tt>llvmc</tt>.
- It allows optimization modules to be loaded so that language specific
- optimizations can be applied at link time. Please note that this tool is new
- in LLVM 1.4 and still considered experimental. It will be fully supported in
- LLVM 1.5.</dd>
+ <dd><tt>llvm-ld</tt> is a general purpose and extensible linker for LLVM.
+ This is the linker invoked by <tt>llvmc</tt>. It performsn 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
<dt><tt><b>llc</b></tt></dt>
<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
+ translates LLVM bytecode to a native code assembly file or to C code (with
the -march=c option).</dd>
- <dt><tt><b>llvmgcc</b></tt></dt>
- <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.
- <blockquote>
- <dl>
- <dt><tt><b>gccas</b></tt></dt>
- <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.</dd>
-
- <dt><tt><b>gccld</b></tt></dt>
- <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.</dd>
- </dl>
- </blockquote>
- </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
+ byte code 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 CVS module.</dd>
<dt><tt><b>opt</b></tt></dt>
- <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.</dd>
+ <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.<br/>
+ <dd><tt>opt</tt> 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
+ debugging analyses, or familiarizing yourself with what an analysis does.</dd>
</dl>
</div>
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>
+ manual, run <tt>`perldoc codegen-diff'</tt>.<br><br>
<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
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>
+ preferred way of updating the tree.<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
<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
<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 instructiosn 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 bytecode by default: <i>gcc4</i> produces native code. As the example below illustrates,
+the '--emit-llvm' flag is needed to produce LLVM bytecode output. For <i>makefiles</i> and
+<i>configure</i> scripts, the CFLAGS variable needs '--emit-llvm' to produce bytecode
+output.</p>
+</div>
+
+<!-- ======================================================================= -->
+<div class="doc_subsection"><a name="tutorial4">Example with llvm-gcc4</a></div>
+
<div class="doc_text">
<ol>
}
</pre></li>
+ <li><p>Next, compile the C file into a native executable:</p>
+
+ <p><tt>% llvm-gcc hello.c -o hello</tt></p>
+
+ <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><p>Next, compile the C file into a LLVM bytecode file:</p>
- <p><tt>% llvmgcc hello.c -o hello</tt></p>
+ <p><tt>% llvm-gcc -O3 -emit-llvm hello.c -c -o hello.bc</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>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 bytecode file.</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>
+ <p>Unlike llvm-gcc3, llvm-gcc4 correctly responds to -O[0123] arguments.
+ </p></li>
- <li><p>Run the program. To make sure the program ran, execute one of the
- following commands:</p>
+ <li><p>Run the program in both forms. To run the program, use:</p>
<p><tt>% ./hello</tt></p>
- <p>or</p>
+ <p>and</p>
+
+ <p><tt>% lli hello.bc</tt></p>
- <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>
+ <p><tt>% llvm-dis < hello.bc | less</tt><br><br></li>
<li><p>Compile the program to native assembly using the LLC code
generator:</p>
<li><p>Execute the native code program:</p>
- <p><tt>% ./hello.native</tt></p></li>
+ <p><tt>% ./hello.native</tt></p>
+
+ <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>
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>
<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
<a href="http://llvm.x10sys.com/rspencer/">Reid Spencer</a><br>
- <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
+ <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Last modified: $Date$
</address>
</body>
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