+bool ARMAsmParser::
+processInstruction(MCInst &Inst,
+ const SmallVectorImpl<MCParsedAsmOperand*> &Operands) {
+ switch (Inst.getOpcode()) {
+ // Handle the MOV complex aliases.
+ case ARM::ASRi:
+ case ARM::LSRi:
+ case ARM::LSLi:
+ case ARM::RORi: {
+ ARM_AM::ShiftOpc ShiftTy;
+ unsigned Amt = Inst.getOperand(2).getImm();
+ switch(Inst.getOpcode()) {
+ default: llvm_unreachable("unexpected opcode!");
+ case ARM::ASRi: ShiftTy = ARM_AM::asr; break;
+ case ARM::LSRi: ShiftTy = ARM_AM::lsr; break;
+ case ARM::LSLi: ShiftTy = ARM_AM::lsl; break;
+ case ARM::RORi: ShiftTy = ARM_AM::ror; break;
+ }
+ // A shift by zero is a plain MOVr, not a MOVsi.
+ unsigned Opc = Amt == 0 ? ARM::MOVr : ARM::MOVsi;
+ unsigned Shifter = ARM_AM::getSORegOpc(ShiftTy, Amt);
+ MCInst TmpInst;
+ TmpInst.setOpcode(Opc);
+ TmpInst.addOperand(Inst.getOperand(0)); // Rd
+ TmpInst.addOperand(Inst.getOperand(1)); // Rn
+ if (Opc == ARM::MOVsi)
+ TmpInst.addOperand(MCOperand::CreateImm(Shifter)); // Shift value and ty
+ TmpInst.addOperand(Inst.getOperand(3)); // CondCode
+ TmpInst.addOperand(Inst.getOperand(4));
+ TmpInst.addOperand(Inst.getOperand(5)); // cc_out
+ Inst = TmpInst;
+ return true;
+ }
+ case ARM::LDMIA_UPD:
+ // If this is a load of a single register via a 'pop', then we should use
+ // a post-indexed LDR instruction instead, per the ARM ARM.
+ if (static_cast<ARMOperand*>(Operands[0])->getToken() == "pop" &&
+ Inst.getNumOperands() == 5) {
+ MCInst TmpInst;
+ TmpInst.setOpcode(ARM::LDR_POST_IMM);
+ TmpInst.addOperand(Inst.getOperand(4)); // Rt
+ TmpInst.addOperand(Inst.getOperand(0)); // Rn_wb
+ TmpInst.addOperand(Inst.getOperand(1)); // Rn
+ TmpInst.addOperand(MCOperand::CreateReg(0)); // am2offset
+ TmpInst.addOperand(MCOperand::CreateImm(4));
+ TmpInst.addOperand(Inst.getOperand(2)); // CondCode
+ TmpInst.addOperand(Inst.getOperand(3));
+ Inst = TmpInst;
+ return true;
+ }
+ break;
+ case ARM::STMDB_UPD:
+ // If this is a store of a single register via a 'push', then we should use
+ // a pre-indexed STR instruction instead, per the ARM ARM.
+ if (static_cast<ARMOperand*>(Operands[0])->getToken() == "push" &&
+ Inst.getNumOperands() == 5) {
+ MCInst TmpInst;
+ TmpInst.setOpcode(ARM::STR_PRE_IMM);
+ TmpInst.addOperand(Inst.getOperand(0)); // Rn_wb
+ TmpInst.addOperand(Inst.getOperand(4)); // Rt
+ TmpInst.addOperand(Inst.getOperand(1)); // addrmode_imm12
+ TmpInst.addOperand(MCOperand::CreateImm(-4));
+ TmpInst.addOperand(Inst.getOperand(2)); // CondCode
+ TmpInst.addOperand(Inst.getOperand(3));
+ Inst = TmpInst;
+ }
+ break;
+ case ARM::tADDi8:
+ // If the immediate is in the range 0-7, we want tADDi3 iff Rd was
+ // explicitly specified. From the ARM ARM: "Encoding T1 is preferred
+ // to encoding T2 if <Rd> is specified and encoding T2 is preferred
+ // to encoding T1 if <Rd> is omitted."
+ if (Inst.getOperand(3).getImm() < 8 && Operands.size() == 6) {
+ Inst.setOpcode(ARM::tADDi3);
+ return true;
+ }
+ break;
+ case ARM::tSUBi8:
+ // If the immediate is in the range 0-7, we want tADDi3 iff Rd was
+ // explicitly specified. From the ARM ARM: "Encoding T1 is preferred
+ // to encoding T2 if <Rd> is specified and encoding T2 is preferred
+ // to encoding T1 if <Rd> is omitted."
+ if (Inst.getOperand(3).getImm() < 8 && Operands.size() == 6) {
+ Inst.setOpcode(ARM::tSUBi3);
+ return true;
+ }
+ break;
+ case ARM::tB:
+ // A Thumb conditional branch outside of an IT block is a tBcc.
+ if (Inst.getOperand(1).getImm() != ARMCC::AL && !inITBlock()) {
+ Inst.setOpcode(ARM::tBcc);
+ return true;
+ }
+ break;
+ case ARM::t2B:
+ // A Thumb2 conditional branch outside of an IT block is a t2Bcc.
+ if (Inst.getOperand(1).getImm() != ARMCC::AL && !inITBlock()){
+ Inst.setOpcode(ARM::t2Bcc);
+ return true;
+ }
+ break;
+ case ARM::t2Bcc:
+ // If the conditional is AL or we're in an IT block, we really want t2B.
+ if (Inst.getOperand(1).getImm() == ARMCC::AL || inITBlock()) {
+ Inst.setOpcode(ARM::t2B);
+ return true;
+ }
+ break;
+ case ARM::tBcc:
+ // If the conditional is AL, we really want tB.
+ if (Inst.getOperand(1).getImm() == ARMCC::AL) {
+ Inst.setOpcode(ARM::tB);
+ return true;
+ }
+ break;
+ case ARM::tLDMIA: {
+ // If the register list contains any high registers, or if the writeback
+ // doesn't match what tLDMIA can do, we need to use the 32-bit encoding
+ // instead if we're in Thumb2. Otherwise, this should have generated
+ // an error in validateInstruction().
+ unsigned Rn = Inst.getOperand(0).getReg();
+ bool hasWritebackToken =
+ (static_cast<ARMOperand*>(Operands[3])->isToken() &&
+ static_cast<ARMOperand*>(Operands[3])->getToken() == "!");
+ bool listContainsBase;
+ if (checkLowRegisterList(Inst, 3, Rn, 0, listContainsBase) ||
+ (!listContainsBase && !hasWritebackToken) ||
+ (listContainsBase && hasWritebackToken)) {
+ // 16-bit encoding isn't sufficient. Switch to the 32-bit version.
+ assert (isThumbTwo());
+ Inst.setOpcode(hasWritebackToken ? ARM::t2LDMIA_UPD : ARM::t2LDMIA);
+ // If we're switching to the updating version, we need to insert
+ // the writeback tied operand.
+ if (hasWritebackToken)
+ Inst.insert(Inst.begin(),
+ MCOperand::CreateReg(Inst.getOperand(0).getReg()));
+ return true;
+ }
+ break;
+ }
+ case ARM::tSTMIA_UPD: {
+ // If the register list contains any high registers, we need to use
+ // the 32-bit encoding instead if we're in Thumb2. Otherwise, this
+ // should have generated an error in validateInstruction().
+ unsigned Rn = Inst.getOperand(0).getReg();
+ bool listContainsBase;
+ if (checkLowRegisterList(Inst, 4, Rn, 0, listContainsBase)) {
+ // 16-bit encoding isn't sufficient. Switch to the 32-bit version.
+ assert (isThumbTwo());
+ Inst.setOpcode(ARM::t2STMIA_UPD);
+ return true;
+ }
+ break;
+ }
+ case ARM::tPOP: {
+ bool listContainsBase;
+ // If the register list contains any high registers, we need to use
+ // the 32-bit encoding instead if we're in Thumb2. Otherwise, this
+ // should have generated an error in validateInstruction().
+ if (!checkLowRegisterList(Inst, 2, 0, ARM::PC, listContainsBase))
+ return false;
+ assert (isThumbTwo());
+ Inst.setOpcode(ARM::t2LDMIA_UPD);
+ // Add the base register and writeback operands.
+ Inst.insert(Inst.begin(), MCOperand::CreateReg(ARM::SP));
+ Inst.insert(Inst.begin(), MCOperand::CreateReg(ARM::SP));
+ return true;
+ }
+ case ARM::tPUSH: {
+ bool listContainsBase;
+ if (!checkLowRegisterList(Inst, 2, 0, ARM::LR, listContainsBase))
+ return false;
+ assert (isThumbTwo());
+ Inst.setOpcode(ARM::t2STMDB_UPD);
+ // Add the base register and writeback operands.
+ Inst.insert(Inst.begin(), MCOperand::CreateReg(ARM::SP));
+ Inst.insert(Inst.begin(), MCOperand::CreateReg(ARM::SP));
+ return true;
+ }
+ case ARM::t2MOVi: {
+ // If we can use the 16-bit encoding and the user didn't explicitly
+ // request the 32-bit variant, transform it here.
+ if (isARMLowRegister(Inst.getOperand(0).getReg()) &&
+ Inst.getOperand(1).getImm() <= 255 &&
+ ((!inITBlock() && Inst.getOperand(2).getImm() == ARMCC::AL &&
+ Inst.getOperand(4).getReg() == ARM::CPSR) ||
+ (inITBlock() && Inst.getOperand(4).getReg() == 0)) &&
+ (!static_cast<ARMOperand*>(Operands[2])->isToken() ||
+ static_cast<ARMOperand*>(Operands[2])->getToken() != ".w")) {
+ // The operands aren't in the same order for tMOVi8...
+ MCInst TmpInst;
+ TmpInst.setOpcode(ARM::tMOVi8);
+ TmpInst.addOperand(Inst.getOperand(0));
+ TmpInst.addOperand(Inst.getOperand(4));
+ TmpInst.addOperand(Inst.getOperand(1));
+ TmpInst.addOperand(Inst.getOperand(2));
+ TmpInst.addOperand(Inst.getOperand(3));
+ Inst = TmpInst;
+ return true;
+ }
+ break;
+ }
+ case ARM::t2MOVr: {
+ // If we can use the 16-bit encoding and the user didn't explicitly
+ // request the 32-bit variant, transform it here.
+ if (isARMLowRegister(Inst.getOperand(0).getReg()) &&
+ isARMLowRegister(Inst.getOperand(1).getReg()) &&
+ Inst.getOperand(2).getImm() == ARMCC::AL &&
+ Inst.getOperand(4).getReg() == ARM::CPSR &&
+ (!static_cast<ARMOperand*>(Operands[2])->isToken() ||
+ static_cast<ARMOperand*>(Operands[2])->getToken() != ".w")) {
+ // The operands aren't the same for tMOV[S]r... (no cc_out)
+ MCInst TmpInst;
+ TmpInst.setOpcode(Inst.getOperand(4).getReg() ? ARM::tMOVSr : ARM::tMOVr);
+ TmpInst.addOperand(Inst.getOperand(0));
+ TmpInst.addOperand(Inst.getOperand(1));
+ TmpInst.addOperand(Inst.getOperand(2));
+ TmpInst.addOperand(Inst.getOperand(3));
+ Inst = TmpInst;
+ return true;
+ }
+ break;
+ }
+ case ARM::t2SXTH:
+ case ARM::t2SXTB:
+ case ARM::t2UXTH:
+ case ARM::t2UXTB: {
+ // If we can use the 16-bit encoding and the user didn't explicitly
+ // request the 32-bit variant, transform it here.
+ if (isARMLowRegister(Inst.getOperand(0).getReg()) &&
+ isARMLowRegister(Inst.getOperand(1).getReg()) &&
+ Inst.getOperand(2).getImm() == 0 &&
+ (!static_cast<ARMOperand*>(Operands[2])->isToken() ||
+ static_cast<ARMOperand*>(Operands[2])->getToken() != ".w")) {
+ unsigned NewOpc;
+ switch (Inst.getOpcode()) {
+ default: llvm_unreachable("Illegal opcode!");
+ case ARM::t2SXTH: NewOpc = ARM::tSXTH; break;
+ case ARM::t2SXTB: NewOpc = ARM::tSXTB; break;
+ case ARM::t2UXTH: NewOpc = ARM::tUXTH; break;
+ case ARM::t2UXTB: NewOpc = ARM::tUXTB; break;
+ }
+ // The operands aren't the same for thumb1 (no rotate operand).
+ MCInst TmpInst;
+ TmpInst.setOpcode(NewOpc);
+ TmpInst.addOperand(Inst.getOperand(0));
+ TmpInst.addOperand(Inst.getOperand(1));
+ TmpInst.addOperand(Inst.getOperand(3));
+ TmpInst.addOperand(Inst.getOperand(4));
+ Inst = TmpInst;
+ return true;
+ }
+ break;
+ }
+ case ARM::t2IT: {
+ // The mask bits for all but the first condition are represented as
+ // the low bit of the condition code value implies 't'. We currently
+ // always have 1 implies 't', so XOR toggle the bits if the low bit
+ // of the condition code is zero. The encoding also expects the low
+ // bit of the condition to be encoded as bit 4 of the mask operand,
+ // so mask that in if needed
+ MCOperand &MO = Inst.getOperand(1);
+ unsigned Mask = MO.getImm();
+ unsigned OrigMask = Mask;
+ unsigned TZ = CountTrailingZeros_32(Mask);
+ if ((Inst.getOperand(0).getImm() & 1) == 0) {
+ assert(Mask && TZ <= 3 && "illegal IT mask value!");
+ for (unsigned i = 3; i != TZ; --i)
+ Mask ^= 1 << i;
+ } else
+ Mask |= 0x10;
+ MO.setImm(Mask);
+
+ // Set up the IT block state according to the IT instruction we just
+ // matched.
+ assert(!inITBlock() && "nested IT blocks?!");
+ ITState.Cond = ARMCC::CondCodes(Inst.getOperand(0).getImm());
+ ITState.Mask = OrigMask; // Use the original mask, not the updated one.
+ ITState.CurPosition = 0;
+ ITState.FirstCond = true;
+ break;
+ }
+ }