[InstCombine] allow zext(bool) + C --> select bool, C+1, C for vector types
The backend should be prepared for this transform after:
https://reviews.llvm.org/rL311731
llvm-svn: 315701
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
index bcd60bc..e12bff0 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
@@ -953,6 +953,19 @@
static Instruction *foldAddWithConstant(BinaryOperator &Add,
InstCombiner::BuilderTy &Builder) {
Value *Op0 = Add.getOperand(0), *Op1 = Add.getOperand(1);
+ Constant *Op1C;
+ if (!match(Op1, m_Constant(Op1C)))
+ return nullptr;
+
+ Value *X;
+ Type *Ty = Add.getType();
+ if (match(Op0, m_ZExt(m_Value(X))) &&
+ X->getType()->getScalarSizeInBits() == 1) {
+ // zext(bool) + C -> bool ? C + 1 : C
+ Constant *One = ConstantInt::get(Ty, 1);
+ return SelectInst::Create(X, ConstantExpr::getAdd(Op1C, One), Op1);
+ }
+
const APInt *C;
if (!match(Op1, m_APInt(C)))
return nullptr;
@@ -968,12 +981,9 @@
return BinaryOperator::CreateXor(Op0, Op1);
}
- Value *X;
- const APInt *C2;
- Type *Ty = Add.getType();
-
// Is this add the last step in a convoluted sext?
// add(zext(xor i16 X, -32768), -32768) --> sext X
+ const APInt *C2;
if (match(Op0, m_ZExt(m_Xor(m_Value(X), m_APInt(C2)))) &&
C2->isMinSignedValue() && C2->sext(Ty->getScalarSizeInBits()) == *C)
return CastInst::Create(Instruction::SExt, X, Ty);
@@ -1031,13 +1041,8 @@
return X;
// FIXME: This should be moved into the above helper function to allow these
- // transforms for splat vectors.
+ // transforms for general constant or constant splat vectors.
if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
- // zext(bool) + C -> bool ? C + 1 : C
- if (ZExtInst *ZI = dyn_cast<ZExtInst>(LHS))
- if (ZI->getSrcTy()->isIntegerTy(1))
- return SelectInst::Create(ZI->getOperand(0), AddOne(CI), CI);
-
Value *XorLHS = nullptr; ConstantInt *XorRHS = nullptr;
if (match(LHS, m_Xor(m_Value(XorLHS), m_ConstantInt(XorRHS)))) {
uint32_t TySizeBits = I.getType()->getScalarSizeInBits();