diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Target/XCore/XCoreISelLowering.cpp | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/lib/Target/XCore/XCoreISelLowering.cpp b/lib/Target/XCore/XCoreISelLowering.cpp index 7cbfe3edc6..bf1a457627 100644 --- a/lib/Target/XCore/XCoreISelLowering.cpp +++ b/lib/Target/XCore/XCoreISelLowering.cpp @@ -1345,6 +1345,33 @@ SDValue XCoreTargetLowering::PerformDAGCombine(SDNode *N, } } break; + case XCoreISD::LMUL: { + SDValue N0 = N->getOperand(0); + SDValue N1 = N->getOperand(1); + SDValue N2 = N->getOperand(2); + SDValue N3 = N->getOperand(3); + ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0); + ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1); + EVT VT = N0.getValueType(); + // Canonicalize multiplicative constant to RHS. If both multiplicative + // operands are constant canonicalize smallest to RHS. + if ((N0C && !N1C) || + (N0C && N1C && N0C->getZExtValue() < N1C->getZExtValue())) + return DAG.getNode(XCoreISD::LMUL, dl, DAG.getVTList(VT, VT), N1, N0, N2, N3); + + // lmul(x, 0, a, b) + if (N1C && N1C->isNullValue()) { + // If the high result is unused fold to add(a, b) + if (N->hasNUsesOfValue(0, 0)) { + SDValue Lo = DAG.getNode(ISD::ADD, dl, VT, N2, N3); + SDValue Ops [] = { Lo, Lo }; + return DAG.getMergeValues(Ops, 2, dl); + } + // Otherwise fold to ladd(a, b, 0) + return DAG.getNode(XCoreISD::LADD, dl, DAG.getVTList(VT, VT), N2, N3, N1); + } + } + break; case ISD::ADD: { // Fold 32 bit expressions such as add(add(mul(x,y),a),b) -> // lmul(x, y, a, b). The high result of lmul will be ignored. |