- return getOperandLatency(ItinData, DefTID, DefIdx, DefAlign,
- UseTID, UseIdx, UseAlign);
+ int Latency = getOperandLatency(ItinData, DefTID, DefIdx, DefAlign,
+ UseTID, UseIdx, UseAlign);
+
+ if (Latency > 1 &&
+ (Subtarget.isCortexA8() || Subtarget.isCortexA9())) {
+ // FIXME: Shifter op hack: no shift (i.e. [r +/- r]) or [r + r << 2]
+ // variants are one cycle cheaper.
+ switch (DefTID.getOpcode()) {
+ default: break;
+ case ARM::LDRrs:
+ case ARM::LDRBrs: {
+ unsigned ShOpVal =
+ cast<ConstantSDNode>(DefNode->getOperand(2))->getZExtValue();
+ unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
+ if (ShImm == 0 ||
+ (ShImm == 2 && ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl))
+ --Latency;
+ break;
+ }
+ case ARM::t2LDRs:
+ case ARM::t2LDRBs:
+ case ARM::t2LDRHs:
+ case ARM::t2LDRSHs: {
+ // Thumb2 mode: lsl only.
+ unsigned ShAmt =
+ cast<ConstantSDNode>(DefNode->getOperand(2))->getZExtValue();
+ if (ShAmt == 0 || ShAmt == 2)
+ --Latency;
+ break;
+ }
+ }
+ }
+
+ return Latency;