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Add a note to make sure the program is memory correct 

llvm-svn: 13464
This commit is contained in:
Chris Lattner 2004-05-11 19:34:27 +00:00
parent 1aaea06cbc
commit 415532491a
1 changed files with 9 additions and 3 deletions
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12
llvm/docs/HowToSubmitABug.html
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@ -230,9 +230,15 @@ from producing invalid LLVM code (i.e., code not in SSA form, using values
before defining them, etc.) which the verifier will check for after a pass
finishes its run.</p>
<p>To debug a miscompilation, you should choose which program you wish to run
the output through, e.g. C backend, the JIT, or LLC, and a selection of passes,
one of which may be causing the error, and run, for example:</p>
<p>If it looks like the LLVM compiler is miscompiling a program, the very first
thing to check is to make sure it is not using undefined behavior. In
particular, check to see if the program valgrinds clean, passes purify, or some
other memory checker tool. Many of the "LLVM bugs" that we have chased down
ended up being bugs in the program being compiled, not LLVM.</p>
<p>Once you determine that the program itself is not buggy, you should choose
which code generator you wish to compile the program with (e.g. C backend, the
JIT, or LLC) and optionally a series of LLVM passes to run. For example:</p>
<div class="doc_code">
<p><tt><b>bugpoint</b> -run-cbe [... optimization passes ...] file-to-test.bc