Always compute all the bits in ComputeMaskedBits.
This allows us to keep passing reduced masks to SimplifyDemandedBits, but
know about all the bits if SimplifyDemandedBits fails. This allows instcombine
to simplify cases like the one in the included testcase.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154011 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 69a6036..e80bb87 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -8099,8 +8099,8 @@
unsigned BitWidth = Op0.getValueSizeInBits();
unsigned AndBitWidth = And.getValueSizeInBits();
if (BitWidth > AndBitWidth) {
- APInt Mask = APInt::getAllOnesValue(BitWidth), Zeros, Ones;
- DAG.ComputeMaskedBits(Op0, Mask, Zeros, Ones);
+ APInt Zeros, Ones;
+ DAG.ComputeMaskedBits(Op0, Zeros, Ones);
if (Zeros.countLeadingOnes() < BitWidth - AndBitWidth)
return SDValue();
}
@@ -12620,11 +12620,11 @@
//===----------------------------------------------------------------------===//
void X86TargetLowering::computeMaskedBitsForTargetNode(const SDValue Op,
- const APInt &Mask,
APInt &KnownZero,
APInt &KnownOne,
const SelectionDAG &DAG,
unsigned Depth) const {
+ unsigned BitWidth = KnownZero.getBitWidth();
unsigned Opc = Op.getOpcode();
assert((Opc >= ISD::BUILTIN_OP_END ||
Opc == ISD::INTRINSIC_WO_CHAIN ||
@@ -12633,7 +12633,7 @@
"Should use MaskedValueIsZero if you don't know whether Op"
" is a target node!");
- KnownZero = KnownOne = APInt(Mask.getBitWidth(), 0); // Don't know anything.
+ KnownZero = KnownOne = APInt(BitWidth, 0); // Don't know anything.
switch (Opc) {
default: break;
case X86ISD::ADD:
@@ -12652,8 +12652,7 @@
break;
// Fallthrough
case X86ISD::SETCC:
- KnownZero |= APInt::getHighBitsSet(Mask.getBitWidth(),
- Mask.getBitWidth() - 1);
+ KnownZero |= APInt::getHighBitsSet(BitWidth, BitWidth - 1);
break;
case ISD::INTRINSIC_WO_CHAIN: {
unsigned IntId = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
@@ -12678,8 +12677,7 @@
case Intrinsic::x86_sse2_pmovmskb_128: NumLoBits = 16; break;
case Intrinsic::x86_avx2_pmovmskb: NumLoBits = 32; break;
}
- KnownZero = APInt::getHighBitsSet(Mask.getBitWidth(),
- Mask.getBitWidth() - NumLoBits);
+ KnownZero = APInt::getHighBitsSet(BitWidth, BitWidth - NumLoBits);
break;
}
}