| commit | 2ad913b3428b634f46d6606a150c5d180b528197 | [log] [tgz] |
|---|---|---|
| author | Chris Lattner <sabre@nondot.org> | Sat May 19 00:43:44 2007 +0000 |
| committer | Chris Lattner <sabre@nondot.org> | Sat May 19 00:43:44 2007 +0000 |
| tree | 80981541884fb490f3b6b558e12f9b1b8c291952 | |
| parent | 35fbae2b6d47932126d1f9bfeaa76ce1a9dbd292 [diff] |
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37246 91177308-0d34-0410-b5e6-96231b3b80d8