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| author | Chandler Carruth <chandlerc@gmail.com> | 2014-01-24 02:24:47 +0000 |
|---|---|---|
| committer | Chandler Carruth <chandlerc@gmail.com> | 2014-01-24 02:24:47 +0000 |
| commit | 4296ce566202cf00ba2beeb3344db0ea20af0e6f (patch) | |
| tree | 85a39df99b2ceb1cc45835273f8910c586084e2a /lib/Transforms | |
| parent | 5950c6fa48fe607e253afab421fa286f5f8e44bf (diff) | |
| download | llvm-4296ce566202cf00ba2beeb3344db0ea20af0e6f.tar.gz llvm-4296ce566202cf00ba2beeb3344db0ea20af0e6f.tar.bz2 llvm-4296ce566202cf00ba2beeb3344db0ea20af0e6f.tar.xz | |
[LPM] Fix a logic error in LICM spotted by inspection.
We completely skipped promotion in LICM if the loop has a preheader or
dedicated exits, but not *both*. We hoist if there is a preheader, and
sink if there are dedicated exits, but either hoisting or sinking can
move loop invariant code out of the loop!
I have no idea if this has a practical consequence. If anyone has ideas
for a test case, let me know.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199966 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms')
| -rw-r--r-- | lib/Transforms/Scalar/LICM.cpp | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/Transforms/Scalar/LICM.cpp b/lib/Transforms/Scalar/LICM.cpp index f6c78b04f2..46d5ca3dca 100644 --- a/lib/Transforms/Scalar/LICM.cpp +++ b/lib/Transforms/Scalar/LICM.cpp @@ -273,7 +273,7 @@ bool LICM::runOnLoop(Loop *L, LPPassManager &LPM) { // Now that all loop invariants have been removed from the loop, promote any // memory references to scalars that we can. - if (!DisablePromotion && Preheader && L->hasDedicatedExits()) { + if (!DisablePromotion && (Preheader || L->hasDedicatedExits())) { SmallVector<BasicBlock *, 8> ExitBlocks; SmallVector<Instruction *, 8> InsertPts; |