diff options
Diffstat (limited to 'lib/Transforms')
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineAddSub.cpp | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/lib/Transforms/InstCombine/InstCombineAddSub.cpp index 0aa301b..8d4677b 100644 --- a/lib/Transforms/InstCombine/InstCombineAddSub.cpp +++ b/lib/Transforms/InstCombine/InstCombineAddSub.cpp @@ -1528,9 +1528,21 @@ Instruction *InstCombiner::visitFSub(BinaryOperator &I) { if (Instruction *NV = FoldOpIntoSelect(I, SI)) return NV; - // If this is a 'B = x-(-A)', change to B = x+A... + // 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 (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); + } + } else if (FPExtInst *FPEI = dyn_cast<FPExtInst>(Op1)) { + if (Value *V = dyn_castFNegVal(FPEI->getOperand(0))) { + Value *NewTrunc = Builder->CreateFPExt(V, I.getType()); + return BinaryOperator::CreateFAdd(Op0, NewTrunc); + } + } if (I.hasUnsafeAlgebra()) { if (Value *V = FAddCombine(Builder).simplify(&I)) |