simplify a transformation by making it more general.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83792 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 06a5660..e9ffb73 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -2783,39 +2783,21 @@
// we know the bool is either zero or one, so this is a 'masking' multiply.
// See if we can simplify things based on how the boolean was originally
// formed.
- CastInst *BoolCast = 0;
- if (ZExtInst *CI = dyn_cast<ZExtInst>(Op0))
- if (CI->getOperand(0)->getType() == Type::getInt1Ty(*Context))
- BoolCast = CI;
- if (!BoolCast)
- if (ZExtInst *CI = dyn_cast<ZExtInst>(I.getOperand(1)))
+ {
+ Value *BoolCast = 0, *OtherOp = 0;
+ if (ZExtInst *CI = dyn_cast<ZExtInst>(Op0))
if (CI->getOperand(0)->getType() == Type::getInt1Ty(*Context))
- BoolCast = CI;
- if (BoolCast) {
- if (ICmpInst *SCI = dyn_cast<ICmpInst>(BoolCast->getOperand(0))) {
- Value *SCIOp0 = SCI->getOperand(0), *SCIOp1 = SCI->getOperand(1);
- const Type *SCOpTy = SCIOp0->getType();
- bool TIS = false;
-
- // If the icmp is true iff the sign bit of X is set, then convert this
- // multiply into a shift/and combination.
- if (isa<ConstantInt>(SCIOp1) &&
- isSignBitCheck(SCI->getPredicate(), cast<ConstantInt>(SCIOp1), TIS) &&
- TIS) {
- // Shift the X value right to turn it into "all signbits".
- Constant *Amt = ConstantInt::get(SCIOp0->getType(),
- SCOpTy->getPrimitiveSizeInBits()-1);
- Value *V = Builder->CreateAShr(SCIOp0, Amt,
- BoolCast->getOperand(0)->getName()+".mask");
-
- // If the multiply type is not the same as the source type, sign extend
- // or truncate to the multiply type.
- if (I.getType() != V->getType())
- V = Builder->CreateIntCast(V, I.getType(), true);
-
- Value *OtherOp = Op0 == BoolCast ? I.getOperand(1) : Op0;
- return BinaryOperator::CreateAnd(V, OtherOp);
- }
+ BoolCast = CI, OtherOp = I.getOperand(1);
+ if (!BoolCast)
+ if (ZExtInst *CI = dyn_cast<ZExtInst>(I.getOperand(1)))
+ if (CI->getOperand(0)->getType() == Type::getInt1Ty(*Context))
+ BoolCast = CI, OtherOp = Op0;
+
+ if (BoolCast) {
+ // X * Y (where Y is 0 or 1) -> X & (0-Y)
+ Value *V = Builder->CreateSub(Constant::getNullValue(I.getType()),
+ BoolCast, "tmp");
+ return BinaryOperator::CreateAnd(V, OtherOp);
}
}