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author | Owen Anderson <resistor@mac.com> | 2013-07-30 23:53:17 +0000 |
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committer | Owen Anderson <resistor@mac.com> | 2013-07-30 23:53:17 +0000 |
commit | 605b3427a9423c1e291a9e9ab94fd7202ca864ae (patch) | |
tree | 75919c6202ae38d5fa9d39d591c6141d52915d7d /lib/Transforms/InstCombine | |
parent | b0bee810e7f980ccb4c0ee56aed948716a51d0ab (diff) | |
download | llvm-605b3427a9423c1e291a9e9ab94fd7202ca864ae.tar.gz llvm-605b3427a9423c1e291a9e9ab94fd7202ca864ae.tar.bz2 llvm-605b3427a9423c1e291a9e9ab94fd7202ca864ae.tar.xz |
Preserve fast-math flags when folding (fsub x, (fneg y)) to (fadd x, y).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187462 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/InstCombine')
-rw-r--r-- | lib/Transforms/InstCombine/InstCombineAddSub.cpp | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/lib/Transforms/InstCombine/InstCombineAddSub.cpp index 1fa6897ddd..534feb8fad 100644 --- a/lib/Transforms/InstCombine/InstCombineAddSub.cpp +++ b/lib/Transforms/InstCombine/InstCombineAddSub.cpp @@ -1530,17 +1530,24 @@ Instruction *InstCombiner::visitFSub(BinaryOperator &I) { // If this is a 'B = x-(-A)', change to B = x+A, potentially looking // through FP extensions/truncations along the way. - if (Value *V = dyn_castFNegVal(Op1)) - return BinaryOperator::CreateFAdd(Op0, V); + if (Value *V = dyn_castFNegVal(Op1)) { + Instruction *NewI = BinaryOperator::CreateFAdd(Op0, V); + NewI->copyFastMathFlags(&I); + return NewI; + } if (FPTruncInst *FPTI = dyn_cast<FPTruncInst>(Op1)) { if (Value *V = dyn_castFNegVal(FPTI->getOperand(0))) { Value *NewTrunc = Builder->CreateFPTrunc(V, I.getType()); - return BinaryOperator::CreateFAdd(Op0, NewTrunc); + Instruction *NewI = BinaryOperator::CreateFAdd(Op0, NewTrunc); + NewI->copyFastMathFlags(&I); + return NewI; } } else if (FPExtInst *FPEI = dyn_cast<FPExtInst>(Op1)) { if (Value *V = dyn_castFNegVal(FPEI->getOperand(0))) { Value *NewExt = Builder->CreateFPExt(V, I.getType()); - return BinaryOperator::CreateFAdd(Op0, NewExt); + Instruction *NewI = BinaryOperator::CreateFAdd(Op0, NewExt); + NewI->copyFastMathFlags(&I); + return NewI; } } |