+
+ bool isMemMode5() const {
+ if (!isMemory() || Mem.OffsetIsReg || Mem.OffsetRegShifted ||
+ Mem.Writeback || Mem.Negative)
+ return false;
+ // If there is an offset expression, make sure it's valid.
+ if (!Mem.Offset)
+ return true;
+ const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(Mem.Offset);
+ if (!CE)
+ return false;
+ // The offset must be a multiple of 4 in the range 0-1020.
+ int64_t Value = CE->getValue();
+ return ((Value & 0x3) == 0 && Value <= 1020 && Value >= -1020);
+ }
+
+ void addMemMode5Operands(MCInst &Inst, unsigned N) const {
+ assert(N == 2 && isMemMode5() && "Invalid number of operands!");
+
+ Inst.addOperand(MCOperand::CreateReg(Mem.BaseRegNum));
+ assert(!Mem.OffsetIsReg && "invalid mode 5 operand");
+
+ // FIXME: #-0 is encoded differently than #0. Does the parser preserve
+ // the difference?
+ if (Mem.Offset) {
+ const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(Mem.Offset);
+ assert(CE && "Non-constant mode 5 offset operand!");
+
+ // The MCInst offset operand doesn't include the low two bits (like
+ // the instruction encoding).
+ int64_t Offset = CE->getValue() / 4;
+ if (Offset >= 0)
+ Inst.addOperand(MCOperand::CreateImm(ARM_AM::getAM5Opc(ARM_AM::add,
+ Offset)));
+ else
+ Inst.addOperand(MCOperand::CreateImm(ARM_AM::getAM5Opc(ARM_AM::sub,
+ -Offset)));
+ } else {
+ Inst.addOperand(MCOperand::CreateImm(0));
+ }
+ }
+