diff options
| -rw-r--r-- | lib/Target/ARM/ARMISelDAGToDAG.cpp | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/lib/Target/ARM/ARMISelDAGToDAG.cpp b/lib/Target/ARM/ARMISelDAGToDAG.cpp index c9642caef7..b0c040b39d 100644 --- a/lib/Target/ARM/ARMISelDAGToDAG.cpp +++ b/lib/Target/ARM/ARMISelDAGToDAG.cpp @@ -102,6 +102,29 @@ void ARMDAGToDAGISel::InstructionSelectBasicBlock(SelectionDAG &DAG) { bool ARMDAGToDAGISel::SelectAddrMode2(SDOperand Op, SDOperand N, SDOperand &Base, SDOperand &Offset, SDOperand &Opc) { + if (N.getOpcode() == ISD::MUL) { + if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(N.getOperand(1))) { + // X * [3,5,9] -> X + X * [2,4,8] etc. + int RHSC = (int)RHS->getValue(); + if (RHSC & 1) { + RHSC = RHSC & ~1; + ARM_AM::AddrOpc AddSub = ARM_AM::add; + if (RHSC < 0) { + AddSub = ARM_AM::sub; + RHSC = - RHSC; + } + if (isPowerOf2_32(RHSC)) { + unsigned ShAmt = Log2_32(RHSC); + Base = Offset = N.getOperand(0); + Opc = CurDAG->getTargetConstant(ARM_AM::getAM2Opc(AddSub, ShAmt, + ARM_AM::lsl), + MVT::i32); + return true; + } + } + } + } + if (N.getOpcode() != ISD::ADD && N.getOpcode() != ISD::SUB) { Base = N; if (N.getOpcode() == ISD::FrameIndex) { |