diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 6fd1fe4b789..d57400bf4bf 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -2623,19 +2623,36 @@ SDOperand DAGCombiner::SimplifySetCC(MVT::ValueType VT, SDOperand N0, return DAG.getSetCC(VT, N0.getOperand(0), N1.getOperand(1), Cond); } } - - // Turn (X^C1) == C2 into X == C1^C2 iff X&~C1 = 0. Common for condcodes. - if (N0.getOpcode() == ISD::XOR) - if (ConstantSDNode *XORC = dyn_cast(N0.getOperand(1))) - if (ConstantSDNode *RHSC = dyn_cast(N1)) { + + if (ConstantSDNode *RHSC = dyn_cast(N1)) { + if (ConstantSDNode *LHSR = dyn_cast(N0.getOperand(1))) { + // Turn (X+C1) == C2 --> X == C2-C1 + if (N0.getOpcode() == ISD::ADD && N0.Val->hasOneUse()) { + return DAG.getSetCC(VT, N0.getOperand(0), + DAG.getConstant(RHSC->getValue()-LHSR->getValue(), + N0.getValueType()), Cond); + } + + // Turn (X^C1) == C2 into X == C1^C2 iff X&~C1 = 0. + if (N0.getOpcode() == ISD::XOR) // If we know that all of the inverted bits are zero, don't bother // performing the inversion. - if (TLI.MaskedValueIsZero(N0.getOperand(0), ~XORC->getValue())) + if (TLI.MaskedValueIsZero(N0.getOperand(0), ~LHSR->getValue())) return DAG.getSetCC(VT, N0.getOperand(0), - DAG.getConstant(XORC->getValue()^RHSC->getValue(), + DAG.getConstant(LHSR->getValue()^RHSC->getValue(), N0.getValueType()), Cond); + } + + // Turn (C1-X) == C2 --> X == C1-C2 + if (ConstantSDNode *SUBC = dyn_cast(N0.getOperand(0))) { + if (N0.getOpcode() == ISD::SUB && N0.Val->hasOneUse()) { + return DAG.getSetCC(VT, N0.getOperand(1), + DAG.getConstant(SUBC->getValue()-RHSC->getValue(), + N0.getValueType()), Cond); } - + } + } + // Simplify (X+Z) == X --> Z == 0 if (N0.getOperand(0) == N1) return DAG.getSetCC(VT, N0.getOperand(1),