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diff --git a/docs/OpenProjects.html b/docs/OpenProjects.html deleted file mode 100644 index bc574e5..0000000 --- a/docs/OpenProjects.html +++ /dev/null @@ -1,394 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" - "http://www.w3.org/TR/html4/strict.dtd"> -<html> -<head> - <title>Open LLVM Projects</title> - <link rel="stylesheet" href="llvm.css" type="text/css"> -</head> -<body> - -<div class="doc_title"> - Open LLVM Projects -</div> - -<ul> - <li><a href="#what">What is this?</a></li> - <li><a href="#improving">Improving the current system</a> - <ol> - <li><a href="#code-cleanups">Implementing Code Cleanup bugs</a></li> - <li><a href="#glibc">Port glibc to LLVM</a></li> - <li><a href="#programs">Compile programs with the LLVM Compiler</a></li> - <li><a href="#llvm_ir">Extend the LLVM intermediate representation</a></li> - <li><a href="#target">Target backend improvements</a></li> - <li><a href="#misc_imp">Miscellaneous Improvements</a></li> - </ol></li> - - <li><a href="#new">Adding new capabilities to LLVM</a> - <ol> - <li><a href="#newfeaturebugs">Implementing new feature PRs</a></li> - <li><a href="#pointeranalysis">Pointer and Alias Analysis</a></li> - <li><a href="#profileguided">Profile-Guided Optimization</a></li> - <li><a href="#xforms">New Transformations and Analyses</a></li> - <li><a href="#x86be">X86 Back-end Improvements</a></li> - <li><a href="#misc_new">Miscellaneous Additions</a></li> - </ol></li> -</ul> - -<div class="doc_author"> - <p>Written by the <a href="http://llvm.cs.uiuc.edu/">LLVM Team</a></p> -</div> - - -<!-- *********************************************************************** --> -<div class="doc_section"> - <a name="what">What is this?</a> -</div> -<!-- *********************************************************************** --> - -<div class="doc_text"> - -<p>This document is meant to be a sort of "big TODO list" for LLVM. Each -project in this document is something that would be useful for LLVM to have, and -would also be a great way to get familiar with the system. Some of these -projects are small and self-contained, which may be implemented in a couple of -days, others are larger. Several of these projects may lead to interesting -research projects in their own right. In any case, we welcome all -contributions.</p> - -<p>If you are thinking about tackling one of these projects, please send a mail -to the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM -Developer's</a> mailing list, so that we know the project is being worked on. -Additionally this is a good way to get more information about a specific project -or to suggest other projects to add to this page. -</p> - -<p>The projects in this page are open-ended. More specific projects are -filed as unassigned enhancements in the <a href="http://llvm.cs.uiuc.edu/bugs/"> -LLVM bug tracker</a>. See the <a href="http://llvm.cs.uiuc.edu/bugs/buglist.cgi?keywords_type=allwords&keywords=&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&bug_severity=enhancement&emailassigned_to1=1&emailtype1=substring&email1=unassigned">list of currently outstanding issues</a> if you wish to help improve LLVM.</p> - -</div> - -<!-- *********************************************************************** --> -<div class="doc_section"> - <a name="improving">Improving the current system</a> -</div> -<!-- *********************************************************************** --> - -<div class="doc_text"> - -<p>Improvements to the current infrastructure are always very welcome and tend -to be fairly straight-forward to implement. Here are some of the key areas that -can use improvement...</p> - -</div> - -<!-- ======================================================================= --> -<div class="doc_subsection"> - <a name="code-cleanups">Implementing Code Cleanup bugs</a> -</div> - -<div class="doc_text"> - -<p> -The <a href="http://llvm.cs.uiuc.edu/bugs/">LLVM bug tracker</a> occasionally -has <a - href="http://llvm.cs.uiuc.edu/bugs/buglist.cgi?short_desc_type=allwordssubstr&short_desc=&long_desc_type=allwordssubstr&long_desc=&bug_file_loc_type=allwordssubstr&bug_file_loc=&status_whiteboard_type=allwordssubstr&status_whiteboard=&keywords_type=allwords&keywords=code-cleanup&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&emailassigned_to1=1&emailtype1=substring&email1=&emailassigned_to2=1&emailreporter2=1&emailcc2=1&emailtype2=substring&email2=&bugidtype=include&bug_id=&votes=&changedin=&chfieldfrom=&chfieldto=Now&chfieldvalue=&cmdtype=doit&order=Bug+Number&field0-0-0=noop&type0-0-0=noop&value0-0-0=">"code-cleanup" bugs</a> filed in it. Taking one of these and fixing it is a good -way to get your feet wet in the LLVM code and discover how some of its components -work. -</p> - -</div> - -<!-- ======================================================================= --> -<div class="doc_subsection"> - <a name="glibc">Port glibc to LLVM</a> -</div> - -<div class="doc_text"> - -<p>It would be very useful to <a -href="http://www.gnu.org/software/libc/manual/html_node/Porting.html">port</a> <a -href="http://www.gnu.org/software/libc/">glibc</a> to LLVM. This would allow a -variety of interprocedural algorithms to be much more effective in the face of -library calls. The most important pieces to port are things like the string -library and the <tt>stdio</tt> related functions... low-level system calls like -'<tt>read</tt>' should stay unimplemented in LLVM.</p> - -</div> - -<!-- ======================================================================= --> -<div class="doc_subsection"> - <a name="programs">Compile programs with the LLVM Compiler</a> -</div> - -<div class="doc_text"> - -<p>We are always looking for new testcases and benchmarks for use with LLVM. In -particular, it is useful to try compiling your favorite C source code with LLVM. -If it doesn't compile, try to figure out why or report it to the <a -href="http://mail.cs.uiuc.edu/pipermail/llvmbugs/">llvm-bugs</a> list. If you -get the program to compile, it would be extremely useful to convert the build -system to be compatible with the LLVM Programs testsuite so that we can check it -into CVS and the automated tester can use it to track progress of the -compiler.</p> - -<p>When testing a code, try running it with a variety of optimizations, and with -all the back-ends: CBE, llc, and lli.</p> - -</div> - -<!-- ======================================================================= --> -<div class="doc_subsection"> - <a name="llvm_ir">Extend the LLVM intermediate representation</a> -</div> - -<div class="doc_text"> - -<ol> -<li>Add support for platform-independent prefetch support. The GCC <a - href="http://gcc.gnu.org/projects/prefetch.html">prefetch project</a> page - has a good survey of the prefetching capabilities of a variety of modern - processors.</li> - -</ol> - -</div> - -<!-- ======================================================================= --> -<div class="doc_subsection"> - <a name="target">Target backend improvements</a> -</div> - -<div class="doc_text"> - -<ol> - <li>Find benchmarks either using our <a - href="http://llvm.cs.uiuc.edu/testresults/">test results</a> or on your own, - where LLVM code generators do not produce optimal code or simply where another - compiler produces better code. Try to minimize the test case that - demonstrates the issue. Then, either <a - href="http://llvm.cs.uiuc.edu/bugs/">submit a bug</a> with your testcase and - the code that LLVM produces vs. the code that it <em>should</em> produce, or - even better, see if you can improve the code generator and submit a - patch.</li> -</ol> - -</div> - -<!-- ======================================================================= --> -<div class="doc_subsection"> - <a name="misc_imp">Miscellaneous Improvements</a> -</div> - -<div class="doc_text"> - -<ol> -<li>Rework the PassManager to be more flexible</li> - -<li>Some transformations and analyses only work on reducible flow graphs. It -would be nice to have a transformation which could be "required" by these passes -which makes irreducible graphs reducible. This can easily be accomplished -through code duplication. See <a -href="http://citeseer.nj.nec.com/janssen97making.html">Making Graphs Reducible -with Controlled Node Splitting</a> and perhaps <a -href="http://doi.acm.org/10.1145/262004.262005">Nesting of Reducible and -Irreducible Loops</a>.</li> - -</ol> - -</div> - -<!-- *********************************************************************** --> -<div class="doc_section"> - <a name="new">Adding new capabilities to LLVM</a> -</div> -<!-- *********************************************************************** --> - -<div class="doc_text"> - -<p>Sometimes creating new things is more fun than improving existing things. -These projects tend to be more involved and perhaps require more work, but can -also be very rewarding.</p> - -</div> - - -<!-- ======================================================================= --> -<div class="doc_subsection"> - <a name="newfeaturebugs">Implementing new feature PRs</a> -</div> - -<div class="doc_text"> - -<p>Many ideas for feature requests are stored in LLVM bugzilla. Just <a - href="http://llvm.cs.uiuc.edu/bugs/buglist.cgi?short_desc_type=allwordssubstr&short_desc=&long_desc_type=allwordssubstr&long_desc=&bug_file_loc_type=allwordssubstr&bug_file_loc=&status_whiteboard_type=allwordssubstr&status_whiteboard=&keywords_type=allwords&keywords=new-feature&bug_status=UNCONFIRMED&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&emailassigned_to1=1&emailtype1=substring&email1=&emailassigned_to2=1&emailreporter2=1&emailcc2=1&emailtype2=substring&email2=&bugidtype=include&bug_id=&votes=&changedin=&chfieldfrom=&chfieldto=Now&chfieldvalue=&cmdtype=doit&namedcmd=All+PRs&newqueryname=&order=Bug+Number&field0-0-0=noop&type0-0-0=noop&value0-0-0=">search for bugs with a "new-feature" keyword</a>.</p> - -</div> - -<!-- ======================================================================= --> -<div class="doc_subsection"> - <a name="pointeranalysis">Pointer and Alias Analysis</a> -</div> - -<div class="doc_text"> - -<p>We have a <a href="AliasAnalysis.html">strong base for development</a> of -both pointer analysis based optimizations as well as pointer analyses -themselves. It seems natural to want to take advantage of this...</p> - -<ol> -<li>Implement a flow-sensitive context-sensitive alias analysis algorithm<br> - - Pick one of the somewhat efficient algorithms, but strive for maximum - precision</li> - -<li>Implement a flow-sensitive context-insensitive alias analysis algorithm<br> - - Just an efficient local algorithm perhaps?</li> - -<li>Implement alias-analysis-based optimizations: - <ul> - <li>...</li> - </ul></li> -</ol> - -</div> - -<!-- ======================================================================= --> -<div class="doc_subsection"> - <a name="profileguided">Profile-Guided Optimization</a> -</div> - -<div class="doc_text"> - -<p>We now have a unified infrastructure for writing profile-guided -transformations, which will work either at offline-compile-time or in the JIT, -but we don't have many transformations. We would welcome new profile-guided -transformations as well as improvements to the current profiling system. -</p> - -<p>Ideas for profile-guided transformations:</p> - -<ol> -<li>Superblock formation (with many optimizations)</li> -<li>Loop unrolling/peeling</li> -<li>Profile directed inlining</li> -<li>Code layout</li> -<li>...</li> -</ol> - -<p>Improvements to the existing support:</p> - -<ol> -<li>The current block and edge profiling code that gets inserted is very simple -and inefficient. Through the use of control-dependence information, many fewer -counters could be inserted into the code. Also, if the execution count of a -loop is known to be a compile-time or runtime constant, all of the counters in -the loop could be avoided.</li> - -<li>You could implement one of the "static profiling" algorithms which analyze a -piece of code an make educated guesses about the relative execution frequencies -of various parts of the code.</li> - -<li>You could add path profiling support, or adapt the existing LLVM path -profiling code to work with the generic profiling interfaces.</li> -</ol> - -</div> - -<!-- ======================================================================= --> -<div class="doc_subsection"> - <a name="xforms">New Transformations and Analyses</a> -</div> - -<div class="doc_text"> - -<ol> -<li>Implement <a href="http://www.cs.purdue.edu/homes/vandrutj/">GVN-PRE</a>, a - powerful and simple Partial Redundancy Elimination algorithm for SSA form</li> -<li>Implement a Dependence Analysis Infrastructure<br> - - Design some way to represent and query dep analysis</li> -<li>Implement a strength reduction pass</li> -<li>Value range propagation pass</li> -</ol> - -</div> - -<!-- ======================================================================= --> -<div class="doc_section"> - <a name="x86be">X86 Back-end Improvements</a> -</div> - -<div class="doc_text"> - -<ol> -<li>Implement a better instruction selector</li> -<li>Implement support for the "switch" instruction without requiring the - lower-switches pass.</li> -<li>Implement interprocedural register allocation. The CallGraphSCCPass can be - used to implement a bottom-up analysis that will determine the *actual* - registers clobbered by a function. Use the pass to fine tune register usage - in callers based on *actual* registers used by the callee.</li> -</ol> - -</div> - -<!-- ======================================================================= --> -<div class="doc_section"> - <a name="misc_new">Miscellaneous Additions</a> -</div> - -<div class="doc_text"> - -<ol> -<li>Port the <a href="http://www-sop.inria.fr/mimosa/fp/Bigloo/">Bigloo</A> -Scheme compiler, from Manuel Serrano at INRIA Sophia-Antipolis, to -output LLVM bytecode. It seems that it can already output .NET -bytecode, JVM bytecode, and C, so LLVM would ostensibly be another good -candidate.</li> -<li>Write a new frontend for C/C++ <b>in</b> C++, giving us the ability to -directly use LLVM C++ classes from within a compiler rather than use -C-based wrapper functions a la llvm-gcc. One possible starting point is the <a -href="http://www.parashift.com/c++-faq-lite/compiler-dependencies.html#faq-37.11">C++ -yacc grammar by Ed Willink</a>.</li> -<li>Write a new frontend for some other language (Java? OCaml? Forth?)</li> -<li>Write a new backend for a target (IA64? MIPS? MMIX?)</li> -<li>Write a disassembler for machine code that would use TableGen to output -<tt>MachineInstr</tt>s for transformations, optimizations, etc.</li> -<li>Random test vector generator: Use a C grammar to generate random C code; -run it through llvm-gcc, then run a random set of passes on it using opt. -Try to crash opt. When opt crashes, use bugpoint to reduce the test case and -mail the result to yourself. Repeat ad infinitum.</li> -<li>Design a simple, recognizable logo.</li> -<li>Improve the usefulness and utility of the Skeleton target backend: -<ul> - <li>Convert the non-functional Skeleton target to become an abstract machine - target (choose some simple instructions, a register set, etc). This will - become a much more useful example of a backend since it would be a simple - but <em>functional</em> backend. Examples of such architectures include MIX, - MMIX, <a - href="http://www.cs.cinvestav.mx/SC/prof_personal/adiaz/vhdl/DLX/">DLX</a>, - or come up with your own!</li> - <li>Use the new Skeleton backend in the Interpreter: compile LLVM to Skeleton - target, and then interpret that code instead of LLVM. Performance win would - be the primary goal, as the number of registers would be a small constant - instead of unbounded, for example.</li> -</ul></li> -</ol> - -</div> - -<!-- *********************************************************************** --> - -<hr> -<address> - <a href="http://jigsaw.w3.org/css-validator/check/referer"><img - src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a> - <a href="http://validator.w3.org/check/referer"><img - src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a> - - <a href="mailto:sabre@nondot.org">Chris Lattner</a><br> - <a href="http://llvm.cs.uiuc.edu">LLVM Compiler Infrastructure</a><br> - Last modified: $Date$ -</address> - -</body> -</html> diff --git a/docs/index.html b/docs/index.html index e0eb24e..d17901c 100644 --- a/docs/index.html +++ b/docs/index.html @@ -128,10 +128,6 @@ Provides information on using the command line parsing library.</li> Details the LLVM coding standards and provides useful information on writing efficient C++ code.</li> -<li><a href="OpenProjects.html">Open Projects</a> - Look here if you are -interested in doing something with LLVM but aren't sure what needs to be -done.</li> - <li><a href="ExtendingLLVM.html">Extending LLVM</a> - Look here to see how to add instructions and intrinsics to LLVM.</li> |