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| author | Chen Zheng <czhengsz@cn.ibm.com> | 2019-04-09 16:34:31 +0000 |
|---|---|---|
| committer | Chen Zheng <czhengsz@cn.ibm.com> | 2019-04-09 16:34:31 +0000 |
| commit | 1383a9168948aabfd827220c9445ce0ce5765800 (patch) | |
| tree | 68a8036eec4a2c0bec8b402cf3b7a1107e856dbe /llvm/lib/Transforms/InstCombine | |
| parent | 366f4d45c0079e0d9b0c973aeaf459840629c0b1 (diff) | |
| download | bcm5719-llvm-1383a9168948aabfd827220c9445ce0ce5765800.tar.gz bcm5719-llvm-1383a9168948aabfd827220c9445ce0ce5765800.zip | |
[InstCombine] [InstCombine] Canonicalize (-X s/ Y) to -(X s/ Y).
Differential Revision: https://reviews.llvm.org/D60395
llvm-svn: 358017
Diffstat (limited to 'llvm/lib/Transforms/InstCombine')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp index cb8708446b2..2db6e849b19 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp @@ -1043,6 +1043,12 @@ Instruction *InstCombiner::visitSDiv(BinaryOperator &I) { Value *NarrowOp = Builder.CreateSDiv(Op0Src, NarrowDivisor); return new SExtInst(NarrowOp, Op0->getType()); } + + // -X / Y --> -(X / Y) + Value *Y; + if (match(&I, m_SDiv(m_OneUse(m_NSWSub(m_Zero(), m_Value(X))), m_Value(Y)))) + return BinaryOperator::CreateNSWNeg( + Builder.CreateSDiv(X, Y, I.getName(), I.isExact())); // -X / C --> X / -C (if the negation doesn't overflow). // TODO: This could be enhanced to handle arbitrary vector constants by |
