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| author | Chris Lattner <sabre@nondot.org> | 2002-07-24 19:51:14 +0000 |
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| committer | Chris Lattner <sabre@nondot.org> | 2002-07-24 19:51:14 +0000 |
| commit | 7fe7f817e9e16c4773f5a4e3ba4c6144674d218e (patch) | |
| tree | 32d8a3d31146e02ec2442448ace761639aff4524 /docs | |
| parent | f6a1328e4ce44683615a9c2f285744dbc976ae84 (diff) | |
| download | external_llvm-7fe7f817e9e16c4773f5a4e3ba4c6144674d218e.zip external_llvm-7fe7f817e9e16c4773f5a4e3ba4c6144674d218e.tar.gz external_llvm-7fe7f817e9e16c4773f5a4e3ba4c6144674d218e.tar.bz2 | |
Major changes, expansions, clarifications and corrections.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@3046 91177308-0d34-0410-b5e6-96231b3b80d8
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| -rw-r--r-- | docs/GettingStarted.html | 441 |
1 files changed, 323 insertions, 118 deletions
diff --git a/docs/GettingStarted.html b/docs/GettingStarted.html index 465c006..c3c34d3 100644 --- a/docs/GettingStarted.html +++ b/docs/GettingStarted.html @@ -1,146 +1,351 @@ <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> - <title>Specification for LLVM system code</title> + <title>Getting Started with LLVM System</title> </head> <body> - <h1>Specification for LLVM system</h1> - <h1><a name="index">Index</a></h1> + <h1>Getting Started with the LLVM System</h1> <ul> - <li><a href="#cvs">Checkout LLVM from CVS</a> - <li><a href="#compilerun">Compile and Run</a> + <li><a href="#quickstart">Getting started with LLVM</a> + <ol> + <li><a href="#cvs">Checkout LLVM from CVS</a> + <li><a href="#environment">Set up your environment</a> + <li><a href="#compile">Compiling the Source Code</a> + </ol> <li><a href="#layout">Program layout</a> <ol> - <li><a href="#d&d">Depend and Debug directories</a></li> + <li><a href="#cvsdir">CVS directories</a> + <li><a href="#dd">Depend, Debug, & Release directories</a></li> <li><a href="#include">llvm/include</a> <li><a href="#lib">llvm/lib</a> <li><a href="#test">llvm/test</a> <li><a href="#tools">llvm/tools</a> </ol> - <li> <a href="#tutorial"> simple example for using tools</li> + <li><a href="#tutorial">An example using the LLVM tool chain</a> <li><a href="#links">Links</a> </ul> - <h2><a name="tools">Checkout LLVM from CVS</a></h2> - <p> - <dl> - <dt>cvs root directory:<dd> /home/vadve/vadve/Research/DynOpt/CVSRepository<br> - <dt>project name:<dd> llvm - </dl> + + + + <!--=====================================================================--> + <h2><a name="quickstart">Getting Started with LLVM</a></h2> + <!--=====================================================================--> + + <p>This guide is meant to get you up and running with LLVM as quickly as + possible. Once you get the basic system running you can choose an area to + dive into and learn more about. If you get stuck or something is missing + from this document, please email <a + href="mailto:sabre@nondot.org">Chris</a>.</p> + + + <!-------------------------------------------------------------------------> + <h3><a name="tools">Checkout LLVM from CVS</a></h3> + <!-------------------------------------------------------------------------> + + <p>First step is to get the actual source code. To do this, all you need to + do is check it out from CVS. From your home directory, just enter:</p> + + <p><tt>cvs -d /home/vadve/vadve/Research/DynOpt/CVSRepository checkout llvm</tt></p> + + <p>This will create an '<tt>llvm</tt>' directory in your home directory and fully + populate it with the source code for LLVM.</p> + + + <!-------------------------------------------------------------------------> + <h3><a name="tools">Set up your environment</a></h3> + <!-------------------------------------------------------------------------> - For those who are not familar with cvs, there are two steps you should do:<br> + <p>Now that you have the source code available, you should set up your + environment to be able to use the LLVM tools (once compiled) with as little + hassle as possible. To do this, we recommend that you add the following + lines to your <tt>.cshrc</tt> (or the corresponding lines to your + <tt>.profile</tt> if you use a bourne shell derivative): + + <pre> + # Make the C frontend easy to use... + alias llvmgcc /home/vadve/lattner/cvs/gcc_install/bin/gcc + + # Make the LLVM tools easy to use... + setenv PATH ~/llvm/tools/Debug:${PATH} + </pre> + + <p>The C compiler is not included in the CVS tree you just checked out, so + we just point to the cannonical location, and access it with the + <tt>llvmgcc</tt> command. The rest of the <a href="#tools">LLVM tools</a> + will be built into the llvm/tools/Debug directory inside of the sourcebase. + Adding them to your path will make it much easier to use them.</p> + + + + <!-------------------------------------------------------------------------> + <h3><a name="compile">Compiling the Source Code</a></h3> + <!-------------------------------------------------------------------------> + + <p>Every directory in the LLVM source tree includes a Makefile to build it, + and any subdirectories that it contains. These makefiles require that you + use <tt>gmake</tt>, instead of <tt>make</tt> to build them, but can + otherwise be used freely. To build the entire LLVM system, just enter the + top level <tt>llvm</tt> directory and type <tt>gmake</tt>. A few minutes + later you will hopefully have a freshly compiled toolchain waiting for you + in <tt>llvm/tools/Debug</tt>. If you want to look at the libraries that + were compiled, look in <tt>llvm/lib/Debug</tt>.</p> + + + <!--=====================================================================--> + <h2><a name="layout">Program Layout</a></h2> + <!--=====================================================================--> + + <p>One useful source of infomation about the LLVM sourcebase is the LLVM + doxygen 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> + + + <!-------------------------------------------------------------------------> + <h3><a name="cvsdir">CVS directories</a></h3> + <!-------------------------------------------------------------------------> + + Every directory checked out of CVS will contain a CVS directory, for the + most part these can just be ignored. + + + <!-------------------------------------------------------------------------> + <h3><a name="ddr">Depend, Debug, & Release directories</a></h3> + <!-------------------------------------------------------------------------> + + Most source directories contain two directories, Depend and Debug. The + Depend directory contains automatically generated dependance files which are + used during compilation to make sure that source files get rebuilt if a + header file they use is modified. The Debug directory holds the object + files, library files and executables that are used for building a debug + enabled build. The Release directory is created to hold the same files when + the <tt>ENABLE_OPTIMIZED=1</tt> flag is passed to <tt>gmake</tt>, causing an + optimized built to be performed. + + + <!-------------------------------------------------------------------------> + <h3><a name="include">llvm/include</a></h3> + <!-------------------------------------------------------------------------> + + This directory contains public header files exported from the LLVM + library. The two main subdirectories of this directory are: + <ol> - <li> - set CVSROOT. Add the following line into the .cshrc file in your home directory if you are using tcsh or csh:<br> - <i>setenv CVSROOT /home/vadve/vadve/Research/DynOpt/CVSRepository</i> - </li> - <li> - check out. Go to the directory you want to store LLVM, type <br> - <i>cvs checkout llvm</i> - </li> + <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... + + <li><tt>llvm/include/Support</tt> - This directory contains generic + support libraries that are independant of LLVM, but are used by LLVM. + For example, some C++ STL utilities and a Command Line option processing + library. </ol> - - note: the c front-end implementation is not in cvs. If you want to use it, you can use excutable in Chris Lattner's directory<br> - <dd><i>/home/vadve/lattner/cvs/gcc_install/bin/gcc</i><br> - a brief usage of this gcc and other tools are introduced later. To read it now, click <a href="#tutorial">here</a>. - - <h2><a name="compilerun">Compile and Run</a></h2> - There is a makefile in each directory. You can simple type <i>gmake</i> in the <b>~/llvm</b> directory to compile all the files or you can type <i>gmake</i> in the certain directory to compile all files and subdirectories in that directory.<br> - You might want to add the the following directory into your path:<br> - <dd><i>llvm/tools/Debug</i><br> - so you can run tools in any directory. If you are using csh or tcsh, add <br> - <dd><i>setenv PATH llvm/tools/Debug:${PATH}</i><br> - at the end of the file .cshrc in your home directory. - - </dl> - <h2><a name="layout">Program Layout</a></h2> - Many useful infomation can be obtained from the LLVM doxygen tree available at <a href="http://llvm.cs.uiuc.edu/doxygen/"><i>http://llvm.cs.uiuc.edu/doxygen/ </i><br></a> - The following is a brief introduction to code layout: - - <h3><a name="d&d">Depend and Debug directories</a></h3> - Most directories contain these two directories. The depend directory contains dependance files which will be used during complilation. The debug directory contains object files, library files or executables after compilation. - <h3><a name="include">llvm/include</a></h3> - This directory contains common head files supporting the LLVM library. Specific head files which are only used by certain directory are place in that directory instead of here. - <h3><a name="lib">llvm/lib</a></h3> - This directory contains most important files of LLVM system. <br> - <dl compact> - - <dt>llvm/lib/transforms/<dd> This directory contains files and directories for transforming one representation to another representation. - <dt>llvm/lib/Target/<dd> This directory contains files and directories for target machine. The files under llvm/lib/Target describe the common property for any target machine. The directory llvm/lib/Target/Sparc describe the sparc machine specification. <br> + + <!-------------------------------------------------------------------------> + <h3><a name="lib">llvm/lib</a></h3> + <!-------------------------------------------------------------------------> + + This directory contains most source files of LLVM system. In LLVM almost all + code exists in libraries, making it very easy to share code among the + different <a href="#tools">tools</a>.<p> + + <dl compact> + <dt><tt>llvm/lib/VMCore/</tt><dd> This directory holds the core LLVM + source files that implement core classes like Instruction and BasicBlock. + + <dt><tt>llvm/lib/AsmParser/</tt><dd> This directory holds the source code + for the LLVM assembly language parser library. + + <dt><tt>llvm/lib/ByteCode/</tt><dd> This directory holds code for reading + and write LLVM bytecode. + + <dt><tt>llvm/lib/CWrite/</tt><dd> This directory implements the LLVM to C + converter. + + <dt><tt>llvm/lib/Analysis/</tt><dd> This directory contains a variety of + different program analyses, such as Dominator Information, Call Graphs, + Induction Variables, Interval Identification, Natural Loop Identification, + etc... + + <dt><tt>llvm/lib/Transforms/</tt><dd> This directory contains the source + code for the LLVM to LLVM program transformations, such as Aggressive Dead + Code Elimination, Sparse Conditional Constant Propogation, Inlining, Loop + Invarient Code Motion, Dead Global Elimination, Pool Allocation, and many + others... + + <dt><tt>llvm/lib/Target/</tt><dd> This directory contains files that + describe various target architectures for code generation. For example, + the llvm/lib/Target/Sparc directory holds the Sparc machine + description.<br> - <dt>llvm/lib/Analysis/<dd> This directory contains files and directories for doing all kinds of data and control analysis. - <dt>llvm/lib/AsmParser/<dd> This directory contains files and directories for parsing the llvm assemly files. - <dt>llvm/lib/ByteCode/<dd> This directory contains files and directories for reading and write LLVM bytecode. - <dt>llvm/lib/CWrite/<dd> This directory contains files and directories for writing c files as output. - <dt>llvm/lib/CodeGen/<dd> This directory contains files and directories for instruction selection, instruction scheduling and register allocation. - <dt>llvm/lib/Reoptimizer<dd> This directory contains files and directories for all kinds of optimizations, e.g. dead code elimination, Loop Invariant Code Motion, etc. + <dt><tt>llvm/lib/CodeGen/</tt><dd> This directory contains the major parts + of the code generator: Instruction Selector, Instruction Scheduling, and + Register Allocation. + + <dt><tt>llvm/lib/Reoptimizer/</tt><dd> This directory holds code related + to the runtime reoptimizer framework that is currently under development. - <dt>llvm/lib/Support/<dd> This directory contains some files and directories supporting the library, e.g. commandline processor and statistic reporter. - <dt>llvm/lib/VMCore/<dd> This directory contains files and directories for implementing the virtual machine instruction set. - </dl> - <h3><a name="test">llvm/test</a></h3> - This directory contains llvm assembly and other files to test the llvm library. - - <h3><a name="tools">llvm/tools</a></h3> - <p> The <b>tools</b> directory contains many tools. You can always get help by typing <i>command_name --help </i>. The following is a brief introduction to each tool. + <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="test">llvm/test</a></h3> + <!-------------------------------------------------------------------------> + + <p>This directory contains regression tests and source code that is used to + test the LLVM infrastructure...</p> + + <!-------------------------------------------------------------------------> + <h3><a name="tools">llvm/tools</a></h3> + <!-------------------------------------------------------------------------> + + <p>The <b>tools</b> directory contains the executables built out of the + libraries above, which form the main part of the user interface. You can + always get help for a tool by typing <tt>tool_name --help</tt>. The + following is a brief introduction to the most important tools.</p> + <dl compact> - <dt><i>analyze</i><dd> ??? - <dt><i>as</i><dd>llvm .ll -> .bc assembler - <br>The assembler transfroms the human readable assembly to llvm bytecode. - <dt><i>dis</i><dd>llvm .bc -> .ll disassembler - <br>The disassembler transfroms the llvm bytecode to human readable assembly. - <dt><i>extract</i><dd> ??? - <dt><i>gccas</i><dd>llvm .ll -> .bc assembler - <br>The assembler transfroms the human readable assembly to llvm bytecode. - <dt><i>gccld</i><dd>many llvm bytecode -> llvm bytecode + optimizations - <br> gccld links many llvm bytecode files into one bytecode file and does some optimization. - <dt><i>link</i><dd>many llvm bytecode -> llvm bytecode - <br> <i>link</i> takes many llvm bytecode files and link them into one llvm bytecode file. - <dt><i>llc</i><dd>llvm bytecode -> SPARC assembly - <br> <i>llc</i> takes a llvm bytecode file and output a SPARC assembly file. - <dt><i>lli</i><dd>llvm interpreter - <br><i>lli</i> reads a llvm bytecode file and execute it. - <dt><i>opt</i><dd>llvm .bc -> .bc modular optimizer - <br> <i>opt</i> reads llvm bytecode and do certain optimization, then output llvm bytecode . - </dl> + <dt><tt><b>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>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 intepreter, <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> + + <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> + + <dt><tt><b>llvmgcc</b></tt><dd> <tt>llvmgcc</tt> is a GCC based C frontend + that has been retargeted to emit LLVM code as the machine code output. It + works just like any other GCC compiler, taking the typical <tt>-c, -S, -E, + -o</tt> options that are typically used. The source code for the + <tt>llvmgcc</tt> tool is currently not included in the LLVM cvs tree + because it is quite large and not very interesting.<p> + + <ol> + <dt><tt><b>gccas</b></tt><dd> This took is invoked by the + <tt>llvmgcc</tt> frontend as the "assembler" part of the compiler. This + tool actually assembles its input, 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 "wierd" + assembler.<p> + + <dt><tt><b>gccld</b></tt><dd> <tt>gccld</tt> links together several llvm + bytecode files into one bytecode file and does some optimization. It is + the linker invoked by the gcc frontend when multiple .o files need to be + linked together. Like <tt>gccas</tt> the command line interface of + <tt>gccld</tt> is designed to match the system linker, to aid + interfacing with the GCC frontend.<p> + </ol> + + <dt><tt><b>opt</b></tt><dd> <tt>opt</tt> reads llvm bytecode, applies a + series of LLVM to LLVM transformations (which are specified on the command + line), and then outputs the resultant bytecode. The '<tt>opt --help</tt>' + command is a good way to get a list of the program transformations + available in LLVM.<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> - <h2><a name="tutorial">tutorial for using tools</h2> - <ul> - <li>create a simple c file:<br> - <pre> - hello.c - - int main() { - printf("hello world\n"); - return 0; - } - </pre> - </li> - <li>compile the c file into a llvm bytecode file<br> - <i>% alias llvmgcc /home/vadve/lattner/cvs/gcc_install/bin/gcc</i><br> - <i>% llvmgcc hello.c </i><br> - there will be two output files: <b>a.out</b> and <b>a.out.bc</b>. The file <b>a.out</b> is a shell script and <b>a.out.bc</b> is the llvm bytecode. You can run a.out to excute or directly call the interpreter: <br> - % <i>lli a.out.bc</i><br> - <li> dissembler and assembler <br> - read llvm bytecode and output human readable llvm assembly<br> - %<i>dis a.out.bc -o hello.ll</i><br> - read human readable llvm assembly code and output llvm bytecode<br> - %<i>as hello.ll -o hello.bc</i> - </li> - <li> compile to sparc assembly<br> - <i>%llc hello.bc -o hello.s</i> - </li> - </ul> - <h2><a name="links">Links</a></h2> - <ul> - <li><a href="http://llvm.cs.uiuc.edu/">LLVM homepage</a></li> - <li><a href="http://tank.cs.uiuc.edu/doxygen/">LLVM doxygen tree</a></li> - </ul> - <hr> - If you have any question, please send an email to <a href="mailto:lattner@uiuc.edu">Lattner Chris Arthur</a> or <a href="mailto:gshi1@uiuc.edu">Guochun Shi</a>. <p> + <!--=====================================================================--> + <h2><a name="tutorial">An example using the LLVM tool chain</h2> + <!--=====================================================================--> + + <ol> + <li>First, create a simple C file, name it 'hello.c': + <pre> + #include <stdio.h> + int main() { + printf("hello world\n"); + return 0; + } + </pre> + + <li>Next, compile the C file into a LLVM bytecode file:<p> + + <tt>% llvmgcc hello.c -o hello</tt><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.<p> + + <li>Run the program. To make sure the program ran, execute one of the + following commands:<p> + + <tt>% ./hello</tt><p> + + or<p> + + <tt>% lli hello.bc</tt><p> + + <li>Use the <tt>dis</tt> utility to take a look at the LLVM assembly + code:<p> + + <tt>% dis < hello.bc | less</tt><p> + + <li>Compile the program to native Sparc assembly using the code + generator:<p> + + <tt>% llc hello.bc -o hello.s</tt><p> + + <li>Assemble the native sparc assemble file into a program:<p> + + <tt>% /opt/SUNWspro/bin/cc -xarch=v9 hello.s -o hello.sparc</tt><p> + + <li>Execute the native sparc program:<p> + + <tt>% ./hello.sparc</tt><p> + + </ol> + + + <!--=====================================================================--> + <h2><a name="links">Links</a></h2> + <!--=====================================================================--> + + <p>This document is just an <b>introduction</b> to how to use LLVM to do + some simple things... there are many more interesting and complicated things + that you can do that aren't documented here (but we'll gladly accept a patch + if you want to write something up!). For more information about LLVM, check + out:</p> + + <ul> + <li><a href="http://llvm.cs.uiuc.edu/">LLVM homepage</a></li> + <li><a href="http://tank.cs.uiuc.edu/doxygen/">LLVM doxygen tree</a></li> + </ul> + + <hr> + + If you have any questions or run into any snags (or you have any + additions...), please send an email to <a + href="mailto:sabre@nondot.org">Chris Lattner</a> or <a + href="mailto:gshi1@uiuc.edu">Guochun Shi</a>. <p> + <!-- Created: Mon Jul 1 02:29:02 CDT 2002 --> <!-- hhmts start --> -Last modified: Wed Jul 17 17:55:16 CDT 2002 +Last modified: Wed Jul 24 14:43:12 CDT 2002 <!-- hhmts end --> </body> </html> |