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Diffstat (limited to 'llvm/lib/Target/X86/X86ISelLowering.cpp')
-rw-r--r--llvm/lib/Target/X86/X86ISelLowering.cpp18
1 files changed, 14 insertions, 4 deletions
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index eea84a2..c32b1a6 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -3624,6 +3624,16 @@ X86TargetLowering::getJumpConditionMergingParams(Instruction::BinaryOps Opc,
match(Lhs, m_SpecificICmp(ICmpInst::ICMP_EQ, m_Value(), m_Value())) &&
match(Rhs, m_SpecificICmp(ICmpInst::ICMP_EQ, m_Value(), m_Value())))
BaseCost += 1;
+
+ // For OR conditions with EQ comparisons, prefer splitting into branches
+ // (unless CCMP is available). OR+EQ cannot be optimized via bitwise ops,
+ // unlike OR+NE which becomes (P|Q)!=0. Similarly, don't split signed
+ // comparisons (SLT, SGT) that can be optimized.
+ if (BaseCost >= 0 && !Subtarget.hasCCMP() && Opc == Instruction::Or &&
+ match(Lhs, m_SpecificICmp(ICmpInst::ICMP_EQ, m_Value(), m_Value())) &&
+ match(Rhs, m_SpecificICmp(ICmpInst::ICMP_EQ, m_Value(), m_Value())))
+ return {-1, -1, -1};
+
return {BaseCost, BrMergingLikelyBias.getValue(),
BrMergingUnlikelyBias.getValue()};
}
@@ -3787,7 +3797,7 @@ static bool isUndefOrZeroOrInRange(ArrayRef<int> Mask, int Low, int Hi) {
/// Return true if every element in Mask, is an in-place blend/select mask or is
/// undef.
-LLVM_ATTRIBUTE_UNUSED static bool isBlendOrUndef(ArrayRef<int> Mask) {
+[[maybe_unused]] static bool isBlendOrUndef(ArrayRef<int> Mask) {
unsigned NumElts = Mask.size();
for (auto [I, M] : enumerate(Mask))
if (!isUndefOrEqual(M, I) && !isUndefOrEqual(M, I + NumElts))
@@ -8096,7 +8106,7 @@ static SDValue LowerBUILD_VECTORvXi1(SDValue Op, const SDLoc &dl,
return DstVec;
}
-LLVM_ATTRIBUTE_UNUSED static bool isHorizOp(unsigned Opcode) {
+[[maybe_unused]] static bool isHorizOp(unsigned Opcode) {
switch (Opcode) {
case X86ISD::PACKSS:
case X86ISD::PACKUS:
@@ -20813,7 +20823,7 @@ SDValue X86TargetLowering::FP_TO_INTHelper(SDValue Op, SelectionDAG &DAG,
// for DAG type consistency we have to match the FP operand type.
APFloat Thresh(APFloat::IEEEsingle(), APInt(32, 0x5f000000));
- LLVM_ATTRIBUTE_UNUSED APFloat::opStatus Status = APFloat::opOK;
+ [[maybe_unused]] APFloat::opStatus Status = APFloat::opOK;
bool LosesInfo = false;
if (TheVT == MVT::f64)
// The rounding mode is irrelevant as the conversion should be exact.
@@ -22856,7 +22866,7 @@ static SDValue combineVectorSizedSetCCEquality(EVT VT, SDValue X, SDValue Y,
// be generated by the memcmp expansion pass with oversized integer compares
// (see PR33325).
bool IsOrXorXorTreeCCZero = isNullConstant(Y) && isOrXorXorTree(X);
- if (isNullConstant(Y) && !IsOrXorXorTreeCCZero)
+ if (isNullConstant(Y) && OpSize == 128 && !IsOrXorXorTreeCCZero)
return SDValue();
// Don't perform this combine if constructing the vector will be expensive.