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| author | Chris Lattner <sabre@nondot.org> | 2007-05-19 00:43:44 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2007-05-19 00:43:44 +0000 |
| commit | b08cbbd737e3b900a287e619f52bf0f593b6b7e7 (patch) | |
| tree | 16c848d19de5b43aaca85ab67b3c62da4510dc14 /llvm/lib/CodeGen/UnreachableBlockElim.cpp | |
| parent | bde968823a888b9401987872d94c56b72107c476 (diff) | |
| download | bcm5719-llvm-b08cbbd737e3b900a287e619f52bf0f593b6b7e7.tar.gz bcm5719-llvm-b08cbbd737e3b900a287e619f52bf0f593b6b7e7.zip | |
Disable the (A == (B-A)) -> 2*A == B xform when the sub has multiple uses (in
this case, the xform introduces an extra operation). This compiles
PowerPC/compare-duplicate.ll into:
_test:
subf r2, r3, r4
cmplw cr0, r2, r3
bne cr0, LBB1_2 ;F
instead of:
_test:
slwi r2, r3, 1
subf r3, r3, r4
cmplw cr0, r4, r2
bne cr0, LBB1_2 ;F
This is target independent of course.
llvm-svn: 37246
Diffstat (limited to 'llvm/lib/CodeGen/UnreachableBlockElim.cpp')
0 files changed, 0 insertions, 0 deletions
