<center><h1>Getting Started with the LLVM System<br><font size=3>By: <a
href="mailto:gshi1@uiuc.edu">Guochun Shi</a>,
<a href="mailto:sabre@nondot.org">Chris Lattner</a>,
- <a href="mailto:criswell@uiuc.edu">John Criswell</a>, and
+ <a href="mailto:criswell@uiuc.edu">John Criswell</a>,
+ <a href="http://misha.brukman.net">Misha Brukman</a>, and
<a href="http://www.cs.uiuc.edu/~vadve">Vikram Adve</a>
</font></h1></center>
<li><a href="#software">Software</a>
</ol>
</ol>
- <li><a href="#starting">Getting started with LLVM</a>
+ <li><a href="#quickstart">Getting Started Quickly (A Summary)</a>
+ <li><a href="#starting">Getting Started with LLVM</a>
<ol>
- <li><a href="#quickstart">Getting started quickly (a summary)</a>
<li><a href="#terminology">Terminology and Notation</tt></a>
- <li><a href="#environment">Setting up your environment</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="#config">Local LLVM Configuration</tt></a>
+ <li><a href="#installcf">Install the GCC Front End</a>
+ <li><a href="#config">Local LLVM Configuration</tt></a>
<li><a href="#compile">Compiling the LLVM Suite Source Code</a>
- <li><a href="#build">Building the LLVM C Front End</a>
- <li><a href="#objfiles">The location for object files</tt></a>
+ <li><a href="#objfiles">The Location of LLVM Object Files</tt></a>
</ol>
<li><a href="#layout">Program layout</a>
- <ol>
- <li><a href="#cvsdir">CVS directories</a>
- <li><a href="#include"><tt>llvm/include</tt></a>
- <li><a href="#lib"><tt>llvm/lib</tt></a>
- <li><a href="#test"><tt>llvm/test</tt></a>
- <li><a href="#tools"><tt>llvm/tools</tt></a>
- </ol>
- <li><a href="#tutorial">An example using the LLVM tool chain</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>
+ </ol>
+ <li><a href="#tutorial">An Example Using the LLVM Tool Chain</a>
+ <li><a href="#problems">Common Problems</a>
<li><a href="#links">Links</a>
</ul>
<center>
<h2><a name="overview"><b>Overview</b></a></h2>
</center>
+ <hr>
<!--=====================================================================-->
Welcome to LLVM! In order to get started, you first need to know some
to test the LLVM tools and the GCC front end.
<p>
The second piece is the GCC front end. This component provides a version
- of GCC that compiles C code into LLVM bytecode. Currently, the C 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.
+ 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 from the LLVM suite.
<!--=====================================================================-->
<h3><a name="requirements"><b>Requirements</b></a></h3>
<!--=====================================================================-->
LLVM is known to work on the following platforms:
<ul>
- <li> Linux on x86
+ <li> Linux on x86 (Pentium and above)
<ul>
- <li> Approximately 700 MB of Free Disk Space
+ <li> Approximately 760 MB of Free Disk Space
<ul>
<li>Source code: 30 MB
<li>Object code: 670 MB
+ <li>GCC front end: 60 MB
</ul>
</ul>
+
+ <p>
+
<li> Solaris on SparcV9 (Ultrasparc)
<ul>
- <li> Approximately 1.03 GB of Free Disk Space
+ <li> Approximately 1.24 GB of Free Disk Space
<ul>
<li>Source code: 30 MB
<li>Object code: 1000 MB
+ <li>GCC front end: 210 MB
</ul>
</ul>
</ul>
on other platforms, so it should be possible to generate and produce LLVM
bytecode on unsupported platforms (although bytecode generated on one
platform may not work on another platform). However, the code generators
- and Just In Time Compilers (JIT's) only generate SparcV9 or x86 machine
- code.
+ and Just-In-Time (JIT) compilers only generate SparcV9 or x86 machine code.
+ </p>
<!--=====================================================================-->
<h4><a name="software"><b>Software</b></a></h4>
<!--=====================================================================-->
<p>
+
+ Unpacking the distribution requires the following tools:
+ <dl compact>
+ <dt>
+ <A href="http://www.gnu.org/software/gzip/gzip.html">GNU Zip (gzip)</A>
+ <dt><A href="http://www.gnu.org/software/tar/tar.html">GNU Tar</A>
+ <dd>
+ These tools are needed to uncompress and unarchive the software.
+ Regular Solaris <tt>tar</tt> may work for unpacking the TAR archive but
+ is untested.
+ </dl>
+
Compiling LLVM requires that you have several different software packages
installed:
<dl compact>
- <dt> GCC
+ <dt> <A href="http://gcc.gnu.org">GCC</A>
<dd>
The GNU Compiler Collection must be installed with C and C++ language
support. GCC 3.2.x works, and GCC 3.x is generally supported.
Note that we currently do not support any other C++ compiler.
</p>
- <dt> GNU Make
+ <dt> <A href="http://savannah.gnu.org/projects/make">GNU Make</A>
<dd>
The LLVM build system relies upon GNU Make extensions. Therefore, you
will need GNU Make (sometimes known as gmake) to build LLVM.
<p>
- <dt> Flex and Bison
+ <dt> <A href="http://www.gnu.org/software/flex">Flex</A>
+ and
+ <A href="http://www.gnu.org/software/bison/bison.html">Bison</A>
<dd>
The LLVM source code is built using flex and bison. You will not be
able to configure and compile LLVM without them.
<p>
- <dt> GNU M4
+ <dt> <A href="http://savannah.gnu.org/projects/m4">GNU M4</A>
<dd>
If you are installing Bison on your machine for the first time, you
will need GNU M4 (version 1.4 or higher).
</p>
<ul>
- <li>GNU Autoconf
- <li>GNU M4
+ <li><A href="http://www.gnu.org/software/autoconf">GNU Autoconf</A>
+ <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 (2.53 or higher), and consequently, GNU M4 (version 1.4
or higher).
</p>
+
+ <li><A href="http://www.codesourcery.com/qm/qmtest">QMTest</A>
+ <li><A href="http://www.python.org">Python</A>
+ <p>
+ In order to run the tests in the LLVM test suite, you will need QMTest and
+ a version of the Python interpreter that works with QMTest.
</ul>
- <p>The <a href="starting">next section</a> of this guide is meant to get
- you up and running with LLVM and to give you some basic information about
- the LLVM environment. The <a href"#quickstart">first subsection</a> gives
- a short summary for those who are already familiar with the system and
- want to get started as quickly as possible.
+ <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.
+ The <a href"#quickstart">next section</a> gives a short summary for those
+ who are already familiar with the system and want to get started as quickly
+ as possible. A <a href="#starting">complete guide to installation</a> is
+ provided in the subsequent section.
<p>The later sections of this guide describe the <a
href="#layout">general layout</a> of the the LLVM source-tree, a <a
<!--=====================================================================-->
<center>
- <h2><a name="starting"><b>Getting Started</b></a></h2>
+ <h2><a name="quickstart"><b>Getting Started Quickly (A Summary)</b></a></h2>
</center>
- <!--=====================================================================-->
-
- <!--=====================================================================-->
- <h3><a name="quickstart"><b>Getting Started Quickly (A Summary)</b></a></h3>
+ <hr>
<!--=====================================================================-->
Here's the short story for getting up and running quickly with LLVM:
<ol>
- <li>Build the LLVM suite
+ <li>Install the GCC front end:
<ol>
- <li>Find the path to the CVS repository containing LLVM (we'll call this <i>CVSROOTDIR</i>).
- <li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
- <li><tt>cvs -d <i>CVSROOTDIR</i> checkout llvm</tt>
- <li><tt>cd llvm</tt>
- <li>Run <tt>configure</tt> to configure the Makefiles and header files.
- Useful options include:
- <ul>
- <li><tt>--with-objroot=<i>directory</i></tt>
- <br>
- Specify where object files should be placed during the build.
+ <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>
+ </ol>
- <li><tt>--with-llvmgccdir=<i>directory</i></tt>
- <br>
- Specify where the LLVM C frontend is going to be installed.
- </ul>
- <li>Set your LLVM_LIB_SEARCH_PATH environment variable.
- <li><tt>gmake -k |& tee gnumake.out
- # this is csh or tcsh syntax</tt>
+ <p>
+
+ <li>Get the Source Code
+ <ul>
+ <li>With the distributed files:
+ <ol>
+ <li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
+ <li><tt>gunzip --stdout llvm.tar.gz | tar -xvf -</tt>
+ <li><tt>cd llvm</tt>
+ </ol>
+
+ <p>
+
+ <li>With anonymous CVS access:
+ <ol>
+ <li>Find the path to the CVS repository containing LLVM (we'll
+ call this <i>CVSROOTDIR</i>).
+ <li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
+ <li><tt>cvs -d <i>CVSROOTDIR</i> checkout llvm</tt>
+ <li><tt>cd llvm</tt>
+ </ol>
+ </ul>
+ </ul>
+
+ <p>
+
+ <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:
+ <ul>
+ <li><tt>--with-llvmgccdir=<i>directory</i></tt>
+ <br>
+ Specify where the LLVM GCC frontend is installed.
+ <p>
+
+ <li><tt>--enable-spec2000=<i>directory</i></tt>
+ <br>
+ Enable the SPEC2000 benchmarks for testing. The SPEC2000
+ benchmarks should be available in <tt><i>directory</i></tt>.
+ </ul>
</ol>
+
<p>
- <li>Build the LLVM C Front End <b>(optional)</b>
+
+ <li>Build the LLVM Suite
<ol>
- <li>Create a directory for the object files to live.
- <li><tt>cd <i>object file directory</i></tt>
- <li>Run <tt><i>Pathname-to-where-the-source-code-lives</i>/configure --prefix=<i>LLVMGCCDIR</i></tt> to configure GCC.
- <li><tt>make bootstrap</tt>
- <li><tt>make install</tt>
+ <li>Set your LLVM_LIB_SEARCH_PATH environment variable.
+ <li><tt>gmake -k |& tee gnumake.out
+ # this is csh or tcsh syntax</tt>
</ol>
+
+ <p>
+
</ol>
- <p>See <a href="#environment">Setting up your environment</a> on tips to
+ <p>See <a href="#environment">Setting Up Your Environment</a> on tips to
simplify working with the LLVM front-end and compiled tools. See the
- other sub-sections below for other useful details in working with LLVM,
+ next section for other useful details in working with LLVM,
or go straight to <a href="#layout">Program Layout</a> to learn about the
layout of the source code tree.
+ <!--=====================================================================-->
+ <center>
+ <h2><a name="starting"><b>Getting Started with LLVM</b></a></h2>
+ </center>
+ <hr>
+ <!--=====================================================================-->
+
<!------------------------------------------------------------------------->
<h3><a name="terminology">Terminology and Notation</a></h3>
<!------------------------------------------------------------------------->
give you this path.
<p>
- <dt>OBJ_ROOT
+ <dt>SRC_ROOT
<dd>
- This is the top level directory for where the LLVM suite object files
- will be placed during the build.
+ This is the top level directory of the LLVM source tree.
<p>
- <dt>LLVMGCCDIR
+ <dt>OBJ_ROOT
<dd>
- This is the pathname to the location where the LLVM C Front End will
- be installed. Note that the C front end does not need to be installed
- during the LLVM suite build; you will just need to know where it will
- go for configuring the build system and running the test suite later.
+ 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>
- <dt>GCCSRC
+ <dt>LLVMGCCDIR
<dd>
- This is the pathname of the directory where the LLVM C front end source
- code can be found.
+ This is the where the LLVM GCC Front End is installed.
<p>
-
- <dt>GCCOBJ
- <dd>
- This is the pathname of the directory where the LLVM C front end object
- code will be placed during the build. It can be safely removed once
- the build is complete.
+ For the pre-built GCC front end binaries, the LLVMGCCDIR is
+ <tt>cfrontend/<i>platform</i>/llvm-gcc</tt>.
</dl>
<!------------------------------------------------------------------------->
- <h3><a name="environment">Setting up your environment</a></h3>
+ <h3><a name="environment">Setting Up Your Environment</a></h3>
<!------------------------------------------------------------------------->
<p>
<dl compact>
<dt><tt>LLVM_LIB_SEARCH_PATH</tt>=<tt><i>LLVMGCCDIR</i>/llvm-gcc/bytecode-libs</tt>
<dd>
- This environment variable helps the LLVM C front end find bytecode
+ This environment variable helps the LLVM GCC front end find bytecode
libraries that it will need for compilation.
<p>
- <dt><tt>PATH</tt>=<tt>${PATH}:<i>OBJ_ROOT</i>/llvm/tools/Debug</tt>
+ <dt>alias llvmgcc <i>LLVMGCCDIR</i><tt>/llvm-gcc/bin/gcc</tt>
+ <dt>alias llvmg++ <i>LLVMGCCDIR</i><tt>/llvm-gcc/bin/g++</tt>
<dd>
- Adding this directory to the end of your path will allow the
- compilation of the C front end to find the LLVM tools. The LLVM tools
- are needed for the C front end compile.
- <p>
+ 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.
+ </dl>
- <dt><tt>CC</tt>=<i>Pathname to your GCC compiler</i>
- <dd>
- The GCC compiler that you want to use must be the first C compiler in
- your <tt>PATH</tt>. Otherwise, set this variable so that
- <tt>configure</tt> will use the GCC compiler that you want to use.
- <p>
+ <!------------------------------------------------------------------------->
+ <h3><a name="unpack">Unpacking the LLVM Archives</a></h3>
+ <!------------------------------------------------------------------------->
- <dt><tt>CXX</tt>=<i>Pathname to your GCC C++ compiler</i>
- <dd>
- The GCC compiler that you want to use must be the first C++ compiler in
- your <tt>PATH</tt>. Otherwise, set this variable so that
- <tt>configure</tt> will use the GCC compiler that you want to use.
+ <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 three files. Each
+ file is a TAR archive that is compressed with the gzip program.
+ </p>
+
+ <p> The three files are as follows:
+ <dl compact>
+ <dt>llvm.tar.gz
+ <dd>This is the source code to the LLVM suite.
<p>
- <dt><tt>CVSROOT</tt>=<i>CVSROOT</i>
- <dd>
- This environment variable tells CVS where to find the CVS repository.
+ <dt>cfrontend.sparc.tar.gz
+ <dd>This is the binary release of the GCC front end for Solaris/Sparc.
<p>
- <dt>alias llvmgcc <i>LLVMGCCDIR</i><tt>/bin/llvm-gcc</tt>
- <dd>
- This alias allows you to use the LLVM C front end without putting it in
- your <tt>PATH</tt> or typing in its complete pathname.
+ <dt>cfrontend.x86.tar.gz
+ <dd>This is the binary release of the GCC front end for Linux/x86.
</dl>
<!------------------------------------------------------------------------->
<h3><a name="checkout">Checkout LLVM from CVS</a></h3>
<!------------------------------------------------------------------------->
- <p>To get a fresh copy of the entire source code, all you
- need to do is check it out from CVS as follows:
+ <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
+ follows:
<ul>
<li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
<li><tt>cvs -d <i>CVSROOTDIR</i> checkout llvm</tt></p>
test directories, and local copies of documentation files.</p>
<p>
- Note that the C front end is not included in the CVS repository. You
- should have either downloaded the source, or better yet, downloaded the
- binary distribution for your platform.
+ Note that the GCC front end is not included in the CVS repository. You
+ should have downloaded the binary distribution for your platform.
</p>
+ <!------------------------------------------------------------------------->
+ <h3><a name="installcf">Install the GCC Front End</a></h3>
+ <!------------------------------------------------------------------------->
+
+ <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>
+ To install the GCC front end, do the following:
+ <ol>
+ <li><tt>cd <i>where-you-want-the-front-end-to-live</i></tt>
+ <li><tt>gunzip --stdout cfrontend.<i>platform</i>.tar.gz | tar -xvf
+ -</tt>
+ </ol>
+
<!------------------------------------------------------------------------->
<h3><a name="config">Local LLVM Configuration</a></h3>
<!------------------------------------------------------------------------->
<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>.
+ <tt>llvm/include/Config/config.h</tt>. It also populates <i>OBJ_ROOT</i> with
+ the Makefiles needed to build LLVM.
<p>
- The following environment variables are used by <tt>configure</tt> to
- configure Makefile.config:
+ The following environment variables are used by the <tt>configure</tt>
+ script to configure the build system:
</p>
- <ul>
- <p><li><i>CXX</i> = Pathname of the C++ compiler to use.
- <p><li><i>CC</i> = Pathname of the C compiler to use.
- </ul>
+ <table border=1>
+ <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>configure</tt> will look for the first GCC C compiler in
+ <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,
+ <tt>configure</tt> will look for the first GCC C++ compiler in
+ <tt>PATH</tt>. Use this variable to override
+ <tt>configure</tt>'s default behavior.
+ </td>
+ </tr>
+ </table>
+ <p>
The following options can be used to set or enable LLVM specific options:
+ </p>
<dl compact>
- <dt><i>--with-objroot=OBJ_ROOT</i>
- <dd>
- Path to the directory where
- object files, libraries, and executables should be placed.
- If this is set to <tt>.</tt>, then the object files will be placed
- within the source code tree. If left unspecified, the default value is
- <tt>.</tt>.
- (See the Section on <a href=#objfiles>
- The location for LLVM object files</a>
- for more information.)
- <p>
<dt><i>--with-llvmgccdir=LLVMGCCDIR</i>
<dd>
Path to the location where the LLVM C front end binaries and
<p>
<dt><i>--enable-optimized</i>
<dd>
- Enables optimized compilation (debugging symbols are removed and GCC
- optimization flags are enabled). The default is to use an unoptimized
- build (also known as a debug build).
+ Enables optimized compilation by defaulat (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>
<dd>
Compile the Just In Time (JIT) 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>.
</dl>
+ <p>
+ To configure LLVM, follow these steps:
+ <ol>
+ <li>Change directory into the object root directory:
+ <br>
+ <tt>cd <i>OBJ_ROOT</i></tt>
+ <p>
+
+ <li>Run the <tt>configure</tt> script located in the LLVM source tree:
+ <br>
+ <tt><i>SRC_ROOT</i>/configure</tt>
+ <p>
+ </ol>
+ </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 for the bytecode-libs subdirectory of the C front-end
- install, or LLVMGCCDIR/llvm-gcc/bytecode-libs. For example, one might
+ to the absolute path for the bytecode-libs subdirectory of the GCC front end
+ install, or <i>LLVMGCCDIR</i>/llvm-gcc/bytecode-libs. 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
C front-end on our research machines.<p>
+ version of the
GCC front end on our research machines.<p>
<!------------------------------------------------------------------------->
<h3><a name="compile">Compiling the LLVM Suite Source Code</a></h3>
<dl compact>
<dt>Debug Builds
<dd>
- These builds are the default. They compile the tools and libraries
- with debugging information.
+ 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>
<dt>Release (Optimized) Builds
<dd>
These builds are enabled with the <tt>--enable-optimized</tt> option to
- <tt>configure</tt>. They compile the tools and libraries with GCC
- optimizer flags on and strip debugging information from the libraries
- and executables it generates.
+ <tt>configure</tt> or by specifying <tt>ENABLE_OPTIMIZED=1</tt> on the
+ <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>
<dt>Profile Builds
<dd>
These builds are for use with profiling. They compile profiling
information into the code for use with programs like <tt>gprof</tt>.
- Profile builds must be started by setting variables on the
- <tt>make</tt> command line.
+ Profile builds must be started by specifying <tt>ENABLE_PROFILING=1</tt>
+ on the <tt>gmake</tt> command line.
</dl>
- Once you have LLVM configured, you can build it by entering the top level
- <tt>llvm</tt> directory and issuing the following command:
+ Once you have LLVM configured, you can build it by entering the
+ <i>OBJ_ROOT</i> directory and issuing the following command:
<p>
- <tt>make</tt>
+ <tt>gmake</tt>
<p>
If you have multiple processors in your machine, you may wish to use some
</p>
<p>
- <tt>make -j2</tt>
+ <tt>gmake -j2</tt>
<p>
- There are several other targets which are useful when working with the LLVM
+ There are several special targets which are useful when working with the LLVM
source code:
<dl compact>
- <dt><tt>make clean</tt>
+ <dt><tt>gmake clean</tt>
<dd>
Removes all files generated by the build. This includes object files,
generated C/C++ files, libraries, and executables.
<p>
- <dt><tt>make distclean</tt>
+ <dt><tt>gmake distclean</tt>
<dd>
- Removes everything that <tt>make clean</tt> does, but also removes
+ 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>
+
+ <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>
+
</dl>
It is also possible to override default values from <tt>configure</tt> by
declaring variables on the command line. The following are some examples:
<dl compact>
- <dt><tt>make ENABLE_OPTIMIZED=1</tt>
+ <dt><tt>gmake ENABLE_OPTIMIZED=1</tt>
<dd>
Perform a Release (Optimized) build.
<p>
- <dt><tt>make ENABLE_PROFILING=1</tt>
+ <dt><tt>gmake ENABLE_PROFILING=1</tt>
<dd>
Perform a Profiling build.
<p>
- <dt><tt>make VERBOSE=1</tt>
+ <dt><tt>gmake VERBOSE=1</tt>
<dd>
- Print what <tt>make</tt> is doing on standard output.
+ Print what <tt>gmake</tt> is doing on standard output.
<p>
</dl>
- Every directory in the LLVM source tree includes a <tt>Makefile</tt> to
+ Every directory in the LLVM object tree includes a <tt>Makefile</tt> to
build it and any subdirectories that it contains. Entering any directory
- inside the LLVM source tree and typing <tt>make</tt> should rebuild
+ inside the LLVM object tree and typing <tt>gmake</tt> should rebuild
anything in or below that directory that is out of date.
<!------------------------------------------------------------------------->
- <h3><a name="build">Building the LLVM C Front End</a></h3>
+ <h3><a name="objfiles">The Location of LLVM Object Files</a></h3>
<!------------------------------------------------------------------------->
- <b>
<p>
- This step is optional if you have the C front end binary distrubtion for
- your platform.
- </p>
- </b>
-
- Now that you have the LLVM Suite built, you can build the C front end. For
- those of you that have built GCC before, the process is very similar.
+ The LLVM build system is capable of sharing a single LLVM source tree among
+ several LLVM builds. Hence, it is possible to build LLVM for several
+ different platforms or configurations using the same source tree.
<p>
- Be forewarned, though: the build system for the C front end is not as
- polished as the rest of the LLVM code, so there will be many warnings and
- errors that you will need to ignore for now:
-
- <ol>
- <li>Ensure that <tt><i>OBJ_ROOT</i>/llvm/tools/Debug</tt> is at the
- <i>end</i> of your <tt>PATH</tt> environment variable.
-
- <li><tt>cd <i>GCCOBJ</i></tt>
-
- <li>Configure the source code:
- <ul>
- <li>On Linux/x86, use
- <ul>
- <li><tt><i>GCCSRC</i>/configure --prefix=<i>LLVMGCCDIR</i>
- --enable-languages=c</tt>
- </ul>
-
- <li>On Solaris/Sparc, use
- <ul>
- <li><tt><i>GCCSRC</i>/configure --prefix=<i>LLVMGCCDIR</i>
- --enable-languages=c --target=sparcv9-sun-solaris2</tt>
- </ul>
- </ul>
-
- <li><tt>make bootstrap</tt>
-
- <li>The build will eventually fail. Don't worry; chances are good that
- everything that needed to build is built.
-
- <li><tt>make install</tt>
- </ol>
-
- At this point, you should have a working copy of the LLVM C front end
- installed in <i>LLVMGCCDIR</i>.
-
- <!------------------------------------------------------------------------->
- <h3><a name="objfiles">The location for LLVM object files</a></h3>
- <!------------------------------------------------------------------------->
-
- <p>The LLVM build system sends most output files generated during the build
- into the directory defined by the variable <i>OBJ_ROOT</i> in
- <tt>llvm/Makefile.config</tt>, which is set by the <i>--with-objroot</i>
- option in <tt>configure</tt>. This can be either just your normal LLVM
- source tree or some other directory writable by you. You may wish to put
- object files on a different filesystem either to keep them from being backed
- up or to speed up local builds.
-
- <p>
- If <i>OBJ_ROOT</i> is specified, then the build system will create a
- directory tree underneath it that resembles the source code's pathname
- relative to your home directory.
- </p>
+ This is accomplished in the typical autoconf manner:
+ <ul>
+ <li>Change directory to where the LLVM object files should live:
+ <p>
+ <tt>cd <i>OBJ_ROOT</i></tt>
- <p>
- For example, suppose that <i>OBJ_ROOT</i> is set to <tt>/tmp</tt> and the
- LLVM suite source code is located in <tt>/usr/home/joe/src/llvm</tt>, where
- <tt>/usr/home/joe</tt> is the home directory of a user named Joe. Then,
- the object files will be placed in <tt>/tmp/src/llvm</tt>.
- </p>
+ <li>Run the <tt>configure</tt> script found in the LLVM source directory:
+ <p>
+ <tt><i>SRC_ROOT</i>/configure</tt>
+ </ul>
<p>
The LLVM build will place files underneath <i>OBJ_ROOT</i> in directories
<dd>
<dl compact>
<dt>Tools
- <dd><tt><i>OBJ_ROOT</i>/llvm/tools/Debug</tt>
+ <dd><tt><i>OBJ_ROOT</i>/tools/Debug</tt>
<dt>Libraries
- <dd><tt><i>OBJ_ROOT</i>/llvm/lib/Debug</tt>
+ <dd><tt><i>OBJ_ROOT</i>/lib/Debug</tt>
</dl>
<p>
<dd>
<dl compact>
<dt>Tools
- <dd><tt><i>OBJ_ROOT</i>/llvm/tools/Release</tt>
+ <dd><tt><i>OBJ_ROOT</i>/tools/Release</tt>
<dt>Libraries
- <dd><tt><i>OBJ_ROOT</i>/llvm/lib/Release</tt>
+ <dd><tt><i>OBJ_ROOT</i>/lib/Release</tt>
</dl>
<p>
<dd>
<dl compact>
<dt>Tools
- <dd><tt><i>OBJ_ROOT</i>/llvm/tools/Profile</tt>
+ <dd><tt><i>OBJ_ROOT</i>/tools/Profile</tt>
<dt>Libraries
- <dd><tt><i>OBJ_ROOT</i>/llvm/lib/Profile</tt>
+ <dd><tt><i>OBJ_ROOT</i>/lib/Profile</tt>
</dl>
</dl>
<center>
<h2><a name="layout"><b>Program Layout</b></a></h2>
</center>
+ <hr>
<!--=====================================================================-->
- <p>One useful source of information about the LLVM source base is the LLVM <a
+ <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>. The
- following is a brief introduction to code layout:</p>
-
+ href="http://llvm.cs.uiuc.edu/doxygen/">http://llvm.cs.uiuc.edu/doxygen/</a></tt>.
+ The following is a brief introduction to code layout:
+ </p>
<!------------------------------------------------------------------------->
<h3><a name="cvsdir"><tt>CVS</tt> directories</a></h3>
<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>Reoptimizer</tt>, <tt>Target</tt>, <tt>Transforms</tt>, etc...
+ <tt>Target</tt>, <tt>Transforms</tt>, etc...
<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.
+ library store their header files here.
<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 configure
- script generates.
+ automatically take care of the conditional #includes that the
+ <tt>configure</tt> script generates.
</ol>
<!------------------------------------------------------------------------->
<!------------------------------------------------------------------------->
This directory contains most of the source files of the LLVM system. In
- LLVM almost all
+ LLVM, almost all
code exists in libraries, making it very easy to share code among the
different <a href="#tools">tools</a>.<p>
<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
- Invarient Code Motion, Dead Global Elimination, Pool Allocation, and many
- others...
+ Invarient 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,
of the code generator: Instruction Selector, Instruction Scheduling, and
Register Allocation.
- <dt><tt>llvm/lib/Reoptimizer/</tt><dd> This directory holds code related
- to the runtime reoptimizer framework that is currently under development.
-
<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>.
</dl>
+ <!------------------------------------------------------------------------->
+ <h3><a name="runtime"><tt>llvm/runtime</tt></a></h3>
+ <!------------------------------------------------------------------------->
+
+ <p>
+ This directory contains libraries which are compiled into LLVM bytecode 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>
+
+ <p>
+ Unlike the rest of the LLVM suite, this directory needs the LLVM GCC front end
+ to compile.
+ </p>
+
<!------------------------------------------------------------------------->
<h3><a name="test"><tt>llvm/test</tt></a></h3>
<!------------------------------------------------------------------------->
<p>This directory contains regression tests and source code that is used to
- test the LLVM infrastructure...</p>
+ test the LLVM infrastructure.
+ </p>
<!------------------------------------------------------------------------->
<h3><a name="tools"><tt>llvm/tools</tt></a></h3>
following is a brief introduction to the most important tools.</p>
<dl compact>
- <dt><tt><b>as</b></tt><dd>The assembler transforms the human readable
+ <dt>
+
+ <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
+ 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>
+
+ <dt><tt><b>llvm-as</b></tt><dd>The assembler transforms the human readable
LLVM assembly to LLVM bytecode.<p>
- <dt><tt><b>dis</b></tt><dd>The disassembler transforms the LLVM bytecode
- to human readable LLVM assembly. Additionally it can convert LLVM
- bytecode to C, which is enabled with the <tt>-c</tt> option.<p>
+ <dt><tt><b>llvm-dis</b></tt><dd>The disassembler transforms the LLVM
+ bytecode to human readable LLVM assembly. Additionally, it can convert
+
LLVM bytecode to C, which is enabled with the <tt>-c</tt> option.<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>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> is also has debugger and tracing
- modes (entered by specifying <tt>-debug</tt> or <tt>-trace</tt> on the
- command line, respectively).<p>
+ 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 assembly file.<p>
+ which translates LLVM bytecode to a SPARC
or x86 assembly file.<p>
- <dt><tt><b>llvmgcc</b></tt><dd> <tt>llvmgcc</tt> is a GCC based C frontend
+ <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
<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>
+ 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
+ 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.<p>
</ol>
command is a good way to get a list of the program transformations
available in LLVM.<p>
-
- <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>
+ </dl>
+ <!------------------------------------------------------------------------->
+ <h3><a name="utils"><tt>llvm/utils</tt></a></h3>
+ <!------------------------------------------------------------------------->
+
+ This directory contains utilities for working with LLVM sourcecode, and some
+ of the utilities are actually required as part of the build process because
+ they are code generators for parts of LLVM infrastructure.
+
+ <dl compact>
+ <td><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 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>
+
+ <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>
+
+ <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>
+
+ <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>
+
+ <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>
+
+ <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>
+
+ <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>
+
</dl>
-
+
<!--=====================================================================-->
- <h2><a name="tutorial">An example using the LLVM tool chain</h2>
+ <h2>
+ <center><a name="tutorial">An Example Using the LLVM Tool Chain</center>
+ </h2>
+ <hr>
<!--=====================================================================-->
<ol>
<tt>% lli hello.bc</tt><p>
- <li>Use the <tt>dis</tt> utility to take a look at the LLVM assembly
+ <li>Use the <tt>llvm-dis</tt> utility to take a look at the LLVM assembly
code:<p>
- <tt>% dis < hello.bc | less</tt><p>
+ <tt>%
llvm-dis < hello.bc | less</tt><p>
<li>Compile the program to native Sparc assembly using the code
- generator:<p>
+ generator
(assuming you are currently on a Sparc system):<p>
<tt>% llc hello.bc -o hello.s</tt><p>
<!--=====================================================================-->
- <h2><a name="help">Common Problems</a></h2>
+ <h2>
+ <center><a name="problems">Common Problems</a></center>
+ </h2>
+ <hr>
<!--=====================================================================-->
Below are common problems and their remedies:
<tt>configure</tt> to do its work without having to adjust your
<tt>PATH</tt> permanently.
</ol>
+
+ <dt><b>I've upgraded to a new version of LLVM, and I get strange build
+ errors.</b>
+ <dd>
+ Sometimes changes to the LLVM source code alters how the build system
+ works. Changes in libtool, autoconf, or header file dependencies are
+ especially prone to this sort of problem.
+ <p>
+ The best thing to try is to remove the old files and re-build. In most
+ cases, this takes care of the problem. To do this, just type <tt>make
+ clean</tt> and then <tt>make</tt> in the directory that fails to build.
+ <p>
+
</dl>
<!--=====================================================================-->
- <h2><a name="links">Links</a></h2>
+ <h2><center><a name="links">Links</a></center></h2>
+ <hr>
<!--=====================================================================-->
<p>This document is just an <b>introduction</b> to how to use LLVM to do
<!-- Created: Mon Jul 1 02:29:02 CDT 2002 -->
<!-- hhmts start -->
-Last modified: Tue Jun 3 22:06:43 CDT 2003
+Last modified: Mon Aug 11 13:52:22 CDT 2003
<!-- hhmts end -->
</body>
</html>
projects / oota-llvm.git / blobdiff