Strength reduce intrinsics with overflow into regular arithmetic operations if possible.
Some intrinsics, like s/uadd.with.overflow and umul.with.overflow, are already strength reduced.
This change adds other arithmetic intrinsics: s/usub.with.overflow, smul.with.overflow.
It completes the work on PR20194.
llvm-svn: 224417
diff --git a/llvm/lib/Transforms/InstCombine/InstCombine.h b/llvm/lib/Transforms/InstCombine/InstCombine.h
index 755de87..326bf8f 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombine.h
+++ b/llvm/lib/Transforms/InstCombine/InstCombine.h
@@ -285,6 +285,7 @@
bool WillNotOverflowUnsignedAdd(Value *LHS, Value *RHS, Instruction *CxtI);
bool WillNotOverflowSignedSub(Value *LHS, Value *RHS, Instruction *CxtI);
bool WillNotOverflowUnsignedSub(Value *LHS, Value *RHS, Instruction *CxtI);
+ bool WillNotOverflowSignedMul(Value *LHS, Value *RHS, Instruction *CxtI);
Value *EmitGEPOffset(User *GEP);
Instruction *scalarizePHI(ExtractElementInst &EI, PHINode *PN);
Value *EvaluateInDifferentElementOrder(Value *V, ArrayRef<int> Mask);