diff options
Diffstat (limited to 'llvm/lib/Target/SystemZ')
| -rw-r--r-- | llvm/lib/Target/SystemZ/SystemZISelLowering.cpp | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp b/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp index 6a34fec7ee1..ffd842d49a3 100644 --- a/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp +++ b/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp @@ -911,6 +911,29 @@ static unsigned CCMaskForCondCode(ISD::CondCode CC) { } // If a comparison described by IsUnsigned, CCMask, CmpOp0 and CmpOp1 +// can be converted to a comparison against zero, adjust the operands +// as necessary. +static void adjustZeroCmp(SelectionDAG &DAG, bool &IsUnsigned, + SDValue &CmpOp0, SDValue &CmpOp1, + unsigned &CCMask) { + if (IsUnsigned) + return; + + ConstantSDNode *ConstOp1 = dyn_cast<ConstantSDNode>(CmpOp1.getNode()); + if (!ConstOp1) + return; + + int64_t Value = ConstOp1->getSExtValue(); + if ((Value == -1 && CCMask == SystemZ::CCMASK_CMP_GT) || + (Value == -1 && CCMask == SystemZ::CCMASK_CMP_LE) || + (Value == 1 && CCMask == SystemZ::CCMASK_CMP_LT) || + (Value == 1 && CCMask == SystemZ::CCMASK_CMP_GE)) { + CCMask ^= SystemZ::CCMASK_CMP_EQ; + CmpOp1 = DAG.getConstant(0, CmpOp1.getValueType()); + } +} + +// If a comparison described by IsUnsigned, CCMask, CmpOp0 and CmpOp1 // is suitable for CLI(Y), CHHSI or CLHHSI, adjust the operands as necessary. static void adjustSubwordCmp(SelectionDAG &DAG, bool &IsUnsigned, SDValue &CmpOp0, SDValue &CmpOp1, @@ -954,7 +977,7 @@ static void adjustSubwordCmp(SelectionDAG &DAG, bool &IsUnsigned, if (Value == 0 && CCMask == SystemZ::CCMASK_CMP_LT) // Test whether the high bit of the byte is set. Value = 127, CCMask = SystemZ::CCMASK_CMP_GT, IsUnsigned = true; - else if (SignedValue == -1 && CCMask == SystemZ::CCMASK_CMP_GT) + else if (Value == 0 && CCMask == SystemZ::CCMASK_CMP_GE) // Test whether the high bit of the byte is clear. Value = 128, CCMask = SystemZ::CCMASK_CMP_LT, IsUnsigned = true; else @@ -1045,6 +1068,7 @@ static SDValue emitCmp(SelectionDAG &DAG, SDValue CmpOp0, SDValue CmpOp1, IsUnsigned = CCMask & SystemZ::CCMASK_CMP_UO; CCValid = SystemZ::CCMASK_ICMP; CCMask &= CCValid; + adjustZeroCmp(DAG, IsUnsigned, CmpOp0, CmpOp1, CCMask); adjustSubwordCmp(DAG, IsUnsigned, CmpOp0, CmpOp1, CCMask); if (preferUnsignedComparison(DAG, CmpOp0, CmpOp1, CCMask)) IsUnsigned = true; |
