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| author | Bob Wilson <bob.wilson@apple.com> | 2010-02-12 01:30:21 +0000 |
|---|---|---|
| committer | Bob Wilson <bob.wilson@apple.com> | 2010-02-12 01:30:21 +0000 |
| commit | fe61fb1e1082c81653ed78efd6d471592a2e57ad (patch) | |
| tree | df0bb339b5cb79a8d22e66430b920e47fae100a5 /lib/Bitcode/Writer/BitcodeWriter.cpp | |
| parent | ccfa1db5380fd3089fc68f3ed9ccfe6a41d7a309 (diff) | |
Add a new pass on machine instructions to optimize away PHI cycles that
reduce down to a single value. InstCombine already does this transformation
but DAG legalization may introduce new opportunities. This has turned out to
be important for ARM where 64-bit values are split up during type legalization:
InstCombine is not able to remove the PHI cycles on the 64-bit values but
the separate 32-bit values can be optimized. I measured the compile time
impact of this (running llc on 176.gcc) and it was not significant.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95951 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Bitcode/Writer/BitcodeWriter.cpp')
0 files changed, 0 insertions, 0 deletions