diff options
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 14 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/zext-bool-add-sub.ll | 31 |
2 files changed, 39 insertions, 6 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 5b9659e..c93994f 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -2101,13 +2101,10 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) { if (SimplifyDemandedInstructionBits(I)) return &I; - // zext(i1) - 1 -> select i1, 0, -1 + // zext(bool) + C -> bool ? C + 1 : C if (ZExtInst *ZI = dyn_cast<ZExtInst>(LHS)) - if (CI->isAllOnesValue() && - ZI->getOperand(0)->getType() == Type::Int1Ty) - return SelectInst::Create(ZI->getOperand(0), - Context->getNullValue(I.getType()), - Context->getAllOnesValue(I.getType())); + if (ZI->getSrcTy() == Type::Int1Ty) + return SelectInst::Create(ZI->getOperand(0), AddOne(CI, Context), CI); } if (isa<PHINode>(LHS)) @@ -2525,6 +2522,11 @@ Instruction *InstCombiner::visitSub(BinaryOperator &I) { if (SelectInst *SI = dyn_cast<SelectInst>(Op1)) if (Instruction *R = FoldOpIntoSelect(I, SI, this)) return R; + + // C - zext(bool) -> bool ? C - 1 : C + if (ZExtInst *ZI = dyn_cast<ZExtInst>(Op1)) + if (ZI->getSrcTy() == Type::Int1Ty) + return SelectInst::Create(ZI->getOperand(0), SubOne(C, Context), C); } if (I.getType() == Type::Int1Ty) diff --git a/test/Transforms/InstCombine/zext-bool-add-sub.ll b/test/Transforms/InstCombine/zext-bool-add-sub.ll new file mode 100644 index 0000000..105fa17 --- /dev/null +++ b/test/Transforms/InstCombine/zext-bool-add-sub.ll @@ -0,0 +1,31 @@ +; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep {zext } | count 0 + +define i32 @a(i1 %x) { +entry: + %y = zext i1 %x to i32 + %res = add i32 %y, 1 + ret i32 %res +} + +define i32 @b(i1 %x) { +entry: + %y = zext i1 %x to i32 + %res = add i32 %y, -1 + ret i32 %res +} + +define i32 @c(i1 %x) { +entry: + %y = zext i1 %x to i32 + %res = sub i32 0, %y + ret i32 %res +} + +define i32 @d(i1 %x) { +entry: + %y = zext i1 %x to i32 + %res = sub i32 3, %y + ret i32 %res +} + + |