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| author | Dan Gohman <gohman@apple.com> | 2010-04-08 23:36:27 +0000 |
|---|---|---|
| committer | Dan Gohman <gohman@apple.com> | 2010-04-08 23:36:27 +0000 |
| commit | e60bb15982dc40517e078c3858fdc0716d43abb5 (patch) | |
| tree | 38b72394f7f363b0bf08bc23714087a942ded4fd /lib | |
| parent | dd98c4d1859a318e7586f87031db44b215476020 (diff) | |
| download | llvm-e60bb15982dc40517e078c3858fdc0716d43abb5.tar.gz llvm-e60bb15982dc40517e078c3858fdc0716d43abb5.tar.bz2 llvm-e60bb15982dc40517e078c3858fdc0716d43abb5.tar.xz | |
Avoid allocating a value of zero in a register if the initial formula
inputs happen to negate each other.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100828 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Transforms/Scalar/LoopStrengthReduce.cpp | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp index e50b13d63d..4669b60e8d 100644 --- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp +++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp @@ -262,11 +262,15 @@ void Formula::InitialMatch(const SCEV *S, Loop *L, SmallVector<const SCEV *, 4> Bad; DoInitialMatch(S, L, Good, Bad, SE, DT); if (!Good.empty()) { - BaseRegs.push_back(SE.getAddExpr(Good)); + const SCEV *Sum = SE.getAddExpr(Good); + if (!Sum->isZero()) + BaseRegs.push_back(Sum); AM.HasBaseReg = true; } if (!Bad.empty()) { - BaseRegs.push_back(SE.getAddExpr(Bad)); + const SCEV *Sum = SE.getAddExpr(Bad); + if (!Sum->isZero()) + BaseRegs.push_back(Sum); AM.HasBaseReg = true; } } |