xref: /gem5/src/arch/arm/isa/formats/data.isa

// Copyright (c) 2010 ARM Limited
// All rights reserved
//
// The license below extends only to copyright in the software and shall
// not be construed as granting a license to any other intellectual
// property including but not limited to intellectual property relating
// to a hardware implementation of the functionality of the software
// licensed hereunder.  You may use the software subject to the license
// terms below provided that you ensure that this notice is replicated
// unmodified and in its entirety in all distributions of the software,
// modified or unmodified, in source code or in binary form.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met: redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer;
// redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution;
// neither the name of the copyright holders nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Authors: Gabe Black

def format ArmDataProcReg() {{
    pclr = '''
        return new %(className)ssRegPclr(machInst, %(dest)s,
                                        %(op1)s, rm, imm5,
                                        type);
    '''
    instDecode = '''
          case %(opcode)#x:
            if (immShift) {
                if (setCc) {
                    if (%(dest)s == INTREG_PC) {
                        %(pclr)s
                    } else {
                        return new %(className)sRegCc(machInst, %(dest)s,
                                                      %(op1)s, rm, imm5, type);
                    }
                } else {
                    return new %(className)sReg(machInst, %(dest)s, %(op1)s,
                                                 rm, imm5, type);
                }
            } else {
                if (setCc) {
                    return new %(className)sRegRegCc(machInst, %(dest)s,
                                                      %(op1)s, rm, rs, type);
                } else {
                    return new %(className)sRegReg(machInst, %(dest)s,
                                                    %(op1)s, rm, rs, type);
                }
            }
            break;
    '''

    def instCode(opcode, mnem, useDest = True, useOp1 = True):
        global pclr
        if useDest:
            dest = "rd"
        else:
            dest = "INTREG_ZERO"
        if useOp1:
            op1 = "rn"
        else:
            op1 = "INTREG_ZERO"
        global instDecode, pclrCode
        substDict = { "className": mnem.capitalize(),
                      "opcode": opcode,
                      "dest": dest,
                      "op1": op1 }
        if useDest:
            substDict["pclr"] = pclr % substDict
        else:
            substDict["pclr"] = ""
        return instDecode % substDict

    decode_block = '''
    {
        const bool immShift = (bits(machInst, 4) == 0);
        const bool setCc = (bits(machInst, 20) == 1);
        const uint32_t imm5 = bits(machInst, 11, 7);
        const ArmShiftType type = (ArmShiftType)(uint32_t)bits(machInst, 6, 5);
        const IntRegIndex rd = (IntRegIndex)(uint32_t)RD;
        const IntRegIndex rn = (IntRegIndex)(uint32_t)RN;
        const IntRegIndex rm = (IntRegIndex)(uint32_t)RM;
        const IntRegIndex rs = (IntRegIndex)(uint32_t)RS;
        switch (OPCODE) {
    '''
    decode_block += instCode(0x0, "and")
    decode_block += instCode(0x1, "eor")
    decode_block += instCode(0x2, "sub")
    decode_block += instCode(0x3, "rsb")
    decode_block += instCode(0x4, "add")
    decode_block += instCode(0x5, "adc")
    decode_block += instCode(0x6, "sbc")
    decode_block += instCode(0x7, "rsc")
    decode_block += instCode(0x8, "tst", useDest = False)
    decode_block += instCode(0x9, "teq", useDest = False)
    decode_block += instCode(0xa, "cmp", useDest = False)
    decode_block += instCode(0xb, "cmn", useDest = False)
    decode_block += instCode(0xc, "orr")
    decode_block += instCode(0xd, "mov", useOp1 = False)
    decode_block += instCode(0xe, "bic")
    decode_block += instCode(0xf, "mvn", useOp1 = False)
    decode_block += '''
          default:
            return new Unknown(machInst);
        }
    }
    '''
}};

def format ArmPackUnpackSatReverse() {{
    decode_block = '''
    {
        const uint32_t op1 = bits(machInst, 22, 20);
        const uint32_t a = bits(machInst, 19, 16);
        const uint32_t op2 = bits(machInst, 7, 5);
        if (bits(op2, 0) == 0) {
            const IntRegIndex rn =
                (IntRegIndex)(uint32_t)bits(machInst, 3, 0);
            const IntRegIndex rd =
                (IntRegIndex)(uint32_t)bits(machInst, 15, 12);
            const uint32_t satImm = bits(machInst, 20, 16);
            const uint32_t imm = bits(machInst, 11, 7);
            const ArmShiftType type =
                (ArmShiftType)(uint32_t)bits(machInst, 6, 5);
            if (op1 == 0) {
                return new WarnUnimplemented("pkh", machInst);
            } else if (bits(op1, 2, 1) == 1) {
                return new Ssat(machInst, rd, satImm + 1, rn, imm, type);
            } else if (bits(op1, 2, 1) == 3) {
                return new Usat(machInst, rd, satImm, rn, imm, type);
            }
            return new Unknown(machInst);
        }
        switch (op1) {
          case 0x0:
            if (op2 == 0x3) {
                const IntRegIndex rn =
                    (IntRegIndex)(uint32_t)bits(machInst, 19, 16);
                const IntRegIndex rd =
                    (IntRegIndex)(uint32_t)bits(machInst, 15, 12);
                const IntRegIndex rm =
                    (IntRegIndex)(uint32_t)bits(machInst, 3, 0);
                const uint32_t rotation =
                    (uint32_t)bits(machInst, 11, 10) << 3;
                if (a == 0xf) {
                    return new Sxtb16(machInst, rd, rotation, rm);
                } else {
                    return new Sxtab16(machInst, rd, rn, rm, rotation);
                }
            } else if (op2 == 0x5) {
                return new WarnUnimplemented("sel", machInst);
            }
            break;
          case 0x2:
            if (op2 == 0x1) {
                const IntRegIndex rn =
                    (IntRegIndex)(uint32_t)bits(machInst, 3, 0);
                const IntRegIndex rd =
                    (IntRegIndex)(uint32_t)bits(machInst, 15, 12);
                const uint32_t satImm = bits(machInst, 20, 16);
                return new Ssat16(machInst, rd, satImm + 1, rn);
            } else if (op2 == 0x3) {
                const IntRegIndex rn =
                    (IntRegIndex)(uint32_t)bits(machInst, 19, 16);
                const IntRegIndex rd =
                    (IntRegIndex)(uint32_t)bits(machInst, 15, 12);
                const IntRegIndex rm =
                    (IntRegIndex)(uint32_t)bits(machInst, 3, 0);
                const uint32_t rotation =
                    (uint32_t)bits(machInst, 11, 10) << 3;
                if (a == 0xf) {
                    return new Sxtb(machInst, rd, rotation, rm);
                } else {
                    return new Sxtab(machInst, rd, rn, rm, rotation);
                }
            }
            break;
          case 0x3:
            if (op2 == 0x1) {
                IntRegIndex rd = (IntRegIndex)(uint32_t)bits(machInst, 15, 12);
                IntRegIndex rm = (IntRegIndex)(uint32_t)bits(machInst, 3, 0);
                return new Rev(machInst, rd, rm);
            } else if (op2 == 0x3) {
                const IntRegIndex rn =
                    (IntRegIndex)(uint32_t)bits(machInst, 19, 16);
                const IntRegIndex rd =
                    (IntRegIndex)(uint32_t)bits(machInst, 15, 12);
                const IntRegIndex rm =
                    (IntRegIndex)(uint32_t)bits(machInst, 3, 0);
                const uint32_t rotation =
                    (uint32_t)bits(machInst, 11, 10) << 3;
                if (a == 0xf) {
                    return new Sxth(machInst, rd, rotation, rm);
                } else {
                    return new Sxtah(machInst, rd, rn, rm, rotation);
                }
            } else if (op2 == 0x5) {
                IntRegIndex rd = (IntRegIndex)(uint32_t)bits(machInst, 15, 12);
                IntRegIndex rm = (IntRegIndex)(uint32_t)bits(machInst, 3, 0);
                return new Rev16(machInst, rd, rm);
            }
            break;
          case 0x4:
            if (op2 == 0x3) {
                const IntRegIndex rn =
                    (IntRegIndex)(uint32_t)bits(machInst, 19, 16);
                const IntRegIndex rd =
                    (IntRegIndex)(uint32_t)bits(machInst, 15, 12);
                const IntRegIndex rm =
                    (IntRegIndex)(uint32_t)bits(machInst, 3, 0);
                const uint32_t rotation =
                    (uint32_t)bits(machInst, 11, 10) << 3;
                if (a == 0xf) {
                    return new Uxtb16(machInst, rd, rotation, rm);
                } else {
                    return new Uxtab16(machInst, rd, rn, rm, rotation);
                }
            }
            break;
          case 0x6:
            if (op2 == 0x1) {
                const IntRegIndex rn =
                    (IntRegIndex)(uint32_t)bits(machInst, 3, 0);
                const IntRegIndex rd =
                    (IntRegIndex)(uint32_t)bits(machInst, 15, 12);
                const uint32_t satImm = bits(machInst, 20, 16);
                return new Usat16(machInst, rd, satImm, rn);
            } else if (op2 == 0x3) {
                const IntRegIndex rn =
                    (IntRegIndex)(uint32_t)bits(machInst, 19, 16);
                const IntRegIndex rd =
                    (IntRegIndex)(uint32_t)bits(machInst, 15, 12);
                const IntRegIndex rm =
                    (IntRegIndex)(uint32_t)bits(machInst, 3, 0);
                const uint32_t rotation =
                    (uint32_t)bits(machInst, 11, 10) << 3;
                if (a == 0xf) {
                    return new Uxtb(machInst, rd, rotation, rm);
                } else {
                    return new Uxtab(machInst, rd, rn, rm, rotation);
                }
            }
            break;
          case 0x7:
            if (op2 == 0x1) {
                return new WarnUnimplemented("rbit", machInst);
            } else if (op2 == 0x3) {
                const IntRegIndex rn =
                    (IntRegIndex)(uint32_t)bits(machInst, 19, 16);
                const IntRegIndex rd =
                    (IntRegIndex)(uint32_t)bits(machInst, 15, 12);
                const IntRegIndex rm =
                    (IntRegIndex)(uint32_t)bits(machInst, 3, 0);
                const uint32_t rotation =
                    (uint32_t)bits(machInst, 11, 10) << 3;
                if (a == 0xf) {
                    return new Uxth(machInst, rd, rotation, rm);
                } else {
                    return new Uxtah(machInst, rd, rn, rm, rotation);
                }
            } else if (op2 == 0x5) {
                IntRegIndex rd = (IntRegIndex)(uint32_t)bits(machInst, 15, 12);
                IntRegIndex rm = (IntRegIndex)(uint32_t)bits(machInst, 3, 0);
                return new Revsh(machInst, rd, rm);
            }
            break;
        }
        return new Unknown(machInst);
    }
    '''
}};

def format ArmParallelAddSubtract() {{
    decode_block='''
    {
        const uint32_t op1 = bits(machInst, 21, 20);
        const uint32_t op2 = bits(machInst, 7, 5);
        const IntRegIndex rn = (IntRegIndex)(uint32_t)bits(machInst, 19, 16);
        const IntRegIndex rd = (IntRegIndex)(uint32_t)bits(machInst, 15, 12);
        const IntRegIndex rm = (IntRegIndex)(uint32_t)bits(machInst, 3, 0);
        if (bits(machInst, 22) == 0) {
            switch (op1) {
              case 0x1:
                switch (op2) {
                  case 0x0:
                    return new Sadd16RegCc(machInst, rd, rn, rm, 0, LSL);
                  case 0x1:
                    return new SasxRegCc(machInst, rd, rn, rm, 0, LSL);
                  case 0x2:
                    return new SsaxRegCc(machInst, rd, rn, rm, 0, LSL);
                  case 0x3:
                    return new Ssub16RegCc(machInst, rd, rn, rm, 0, LSL);
                  case 0x4:
                    return new Sadd8RegCc(machInst, rd, rn, rm, 0, LSL);
                  case 0x7:
                    return new Ssub8RegCc(machInst, rd, rn, rm, 0, LSL);
                }
                break;
              case 0x2:
                switch (op2) {
                  case 0x0:
                    return new Qadd16Reg(machInst, rd, rn, rm, 0, LSL);
                  case 0x1:
                    return new QasxReg(machInst, rd, rn, rm, 0, LSL);
                  case 0x2:
                    return new QsaxReg(machInst, rd, rn, rm, 0, LSL);
                  case 0x3:
                    return new Qsub16Reg(machInst, rd, rn, rm, 0, LSL);
                  case 0x4:
                    return new Qadd8Reg(machInst, rd, rn, rm, 0, LSL);
                  case 0x7:
                    return new Qsub8Reg(machInst, rd, rn, rm, 0, LSL);
                }
                break;
              case 0x3:
                switch (op2) {
                  case 0x0:
                    return new Shadd16Reg(machInst, rd, rn, rm, 0, LSL);
                  case 0x1:
                    return new ShasxReg(machInst, rd, rn, rm, 0, LSL);
                  case 0x2:
                    return new ShsaxReg(machInst, rd, rn, rm, 0, LSL);
                  case 0x3:
                    return new Shsub16Reg(machInst, rd, rn, rm, 0, LSL);
                  case 0x4:
                    return new Shadd8Reg(machInst, rd, rn, rm, 0, LSL);
                  case 0x7:
                    return new Shsub8Reg(machInst, rd, rn, rm, 0, LSL);
                }
                break;
            }
        } else {
            switch (op1) {
              case 0x1:
                switch (op2) {
                  case 0x0:
                    return new Uadd16RegCc(machInst, rd, rn, rm, 0, LSL);
                  case 0x1:
                    return new UasxRegCc(machInst, rd, rn, rm, 0, LSL);
                  case 0x2:
                    return new UsaxRegCc(machInst, rd, rn, rm, 0, LSL);
                  case 0x3:
                    return new Usub16RegCc(machInst, rd, rn, rm, 0, LSL);
                  case 0x4:
                    return new Uadd8RegCc(machInst, rd, rn, rm, 0, LSL);
                  case 0x7:
                    return new Usub8RegCc(machInst, rd, rn, rm, 0, LSL);
                }
                break;
              case 0x2:
                switch (op2) {
                  case 0x0:
                    return new Uqadd16Reg(machInst, rd, rn, rm, 0, LSL);
                  case 0x1:
                    return new UqasxReg(machInst, rd, rn, rm, 0, LSL);
                  case 0x2:
                    return new UqsaxReg(machInst, rd, rn, rm, 0, LSL);
                  case 0x3:
                    return new Uqsub16Reg(machInst, rd, rn, rm, 0, LSL);
                  case 0x4:
                    return new Uqadd8Reg(machInst, rd, rn, rm, 0, LSL);
                  case 0x7:
                    return new Uqsub8Reg(machInst, rd, rn, rm, 0, LSL);
                }
                break;
              case 0x3:
                switch (op2) {
                  case 0x0:
                    return new Uhadd16Reg(machInst, rd, rn, rm, 0, LSL);
                  case 0x1:
                    return new UhasxReg(machInst, rd, rn, rm, 0, LSL);
                  case 0x2:
                    return new UhsaxReg(machInst, rd, rn, rm, 0, LSL);
                  case 0x3:
                    return new Uhsub16Reg(machInst, rd, rn, rm, 0, LSL);
                  case 0x4:
                    return new Uhadd8Reg(machInst, rd, rn, rm, 0, LSL);
                  case 0x7:
                    return new Uhsub8Reg(machInst, rd, rn, rm, 0, LSL);
                }
                break;
            }
        }
        return new Unknown(machInst);
    }
    '''
}};

def format ArmDataProcImm() {{
    pclr = '''
        return new %(className)ssImmPclr(machInst, %(dest)s,
                                        %(op1)s, imm, false);
    '''
    adr = '''
        return new AdrImm(machInst, %(dest)s, %(add)s,
                                     imm, false);
    '''
    instDecode = '''
          case %(opcode)#x:
            if (setCc) {
                if (%(pclrInst)s && %(dest)s == INTREG_PC) {
                    %(pclr)s
                } else {
                    return new %(className)sImmCc(machInst, %(dest)s, %(op1)s,
                                                   imm, rotC);
                }
            } else {
                if (%(adrInst)s && %(op1)s == INTREG_PC) {
                    %(adr)s
                } else {
                    return new %(className)sImm(machInst, %(dest)s, %(op1)s,
                                                 imm, rotC);
                }
            }
            break;
    '''

    def instCode(opcode, mnem, useDest = True, useOp1 = True):
        global instDecode, pclr, adr
        if useDest:
            dest = "rd"
        else:
            dest = "INTREG_ZERO"
        if useOp1:
            op1 = "rn"
        else:
            op1 = "INTREG_ZERO"
        substDict = { "className": mnem.capitalize(),
                      "opcode": opcode,
                      "dest": dest,
                      "op1": op1,
                      "adr": "",
                      "adrInst": "false" }
        if useDest:
            substDict["pclrInst"] = "true"
            substDict["pclr"] = pclr % substDict
        else:
            substDict["pclrInst"] = "false"
            substDict["pclr"] = ""
        return instDecode % substDict

    def adrCode(opcode, mnem, add="1"):
        global instDecode, pclr, adr
        substDict = { "className": mnem.capitalize(),
                      "opcode": opcode,
                      "dest": "rd",
                      "op1": "rn",
                      "add": add,
                      "pclrInst": "true",
                      "adrInst": "true" }
        substDict["pclr"] = pclr % substDict
        substDict["adr"] = adr % substDict
        return instDecode % substDict

    decode_block = '''
    {
        const bool setCc = (bits(machInst, 20) == 1);
        const uint32_t unrotated = bits(machInst, 7, 0);
        const uint32_t rotation = (bits(machInst, 11, 8) << 1);
        const bool rotC = (rotation != 0);
        const uint32_t imm = rotate_imm(unrotated, rotation);
        const IntRegIndex rd = (IntRegIndex)(uint32_t)RD;
        const IntRegIndex rn = (IntRegIndex)(uint32_t)RN;
        switch (OPCODE) {
    '''
    decode_block += instCode(0x0, "and")
    decode_block += instCode(0x1, "eor")
    decode_block += adrCode(0x2, "sub", add="(IntRegIndex)0")
    decode_block += instCode(0x3, "rsb")
    decode_block += adrCode(0x4, "add", add="(IntRegIndex)1")
    decode_block += instCode(0x5, "adc")
    decode_block += instCode(0x6, "sbc")
    decode_block += instCode(0x7, "rsc")
    decode_block += instCode(0x8, "tst", useDest = False)
    decode_block += instCode(0x9, "teq", useDest = False)
    decode_block += instCode(0xa, "cmp", useDest = False)
    decode_block += instCode(0xb, "cmn", useDest = False)
    decode_block += instCode(0xc, "orr")
    decode_block += instCode(0xd, "mov", useOp1 = False)
    decode_block += instCode(0xe, "bic")
    decode_block += instCode(0xf, "mvn", useOp1 = False)
    decode_block += '''
          default:
            return new Unknown(machInst);
        }
    }
    '''
}};

def format ArmSatAddSub() {{
    decode_block = '''
    {
        IntRegIndex rn = (IntRegIndex)(uint32_t)bits(machInst, 19, 16);
        IntRegIndex rd = (IntRegIndex)(uint32_t)bits(machInst, 15, 12);
        IntRegIndex rm = (IntRegIndex)(uint32_t)bits(machInst, 3, 0);
        switch (OPCODE) {
          case 0x8:
            return new QaddRegCc(machInst, rd, rm, rn, 0, LSL);
          case 0x9:
            return new QsubRegCc(machInst, rd, rm, rn, 0, LSL);
          case 0xa:
            return new QdaddRegCc(machInst, rd, rm, rn, 0, LSL);
          case 0xb:
            return new QdsubRegCc(machInst, rd, rm, rn, 0, LSL);
          default:
            return new Unknown(machInst);
        }
    }
    '''
}};

def format Thumb32DataProcReg() {{
    decode_block = '''
    {
        const uint32_t op1 = bits(machInst, 23, 20);
        const IntRegIndex rn = (IntRegIndex)(uint32_t)bits(machInst, 19, 16);
        const uint32_t op2 = bits(machInst, 7, 4);
        if (bits(op1, 3) != 1) {
            if (op2 == 0) {
                IntRegIndex rd = (IntRegIndex)(uint32_t)bits(machInst, 11, 8);
                IntRegIndex rm = (IntRegIndex)(uint32_t)bits(machInst, 3, 0);
                switch (bits(op1, 2, 0)) {
                  case 0x0:
                    return new MovRegReg(machInst, rd,
                            INTREG_ZERO, rn, rm, LSL);
                  case 0x1:
                    return new MovRegRegCc(machInst, rd,
                            INTREG_ZERO, rn, rm, LSL);
                  case 0x2:
                    return new MovRegReg(machInst, rd,
                            INTREG_ZERO, rn, rm, LSR);
                  case 0x3:
                    return new MovRegRegCc(machInst, rd,
                            INTREG_ZERO, rn, rm, LSR);
                  case 0x4:
                    return new MovRegReg(machInst, rd,
                            INTREG_ZERO, rn, rm, ASR);
                  case 0x5:
                    return new MovRegRegCc(machInst, rd,
                            INTREG_ZERO, rn, rm, ASR);
                  case 0x6:
                    return new MovRegReg(machInst, rd,
                            INTREG_ZERO, rn, rm, ROR);
                  case 0x7:
                    return new MovRegRegCc(machInst, rd,
                            INTREG_ZERO, rn, rm, ROR);
                }
            }
            {
                const IntRegIndex rd =
                    (IntRegIndex)(uint32_t)bits(machInst, 11, 8);
                const IntRegIndex rm =
                    (IntRegIndex)(uint32_t)bits(machInst, 3, 0);
                const uint32_t rotation =
                    (uint32_t)bits(machInst, 5, 4) << 3;
                switch (bits(op1, 2, 0)) {
                  case 0x0:
                    if (rn == 0xf) {
                        return new Sxth(machInst, rd, rotation, rm);
                    } else {
                        return new Sxtah(machInst, rd, rn, rm, rotation);
                    }
                  case 0x1:
                    if (rn == 0xf) {
                        return new Uxth(machInst, rd, rotation, rm);
                    } else {
                        return new Uxtah(machInst, rd, rn, rm, rotation);
                    }
                  case 0x2:
                    if (rn == 0xf) {
                        return new Sxtb16(machInst, rd, rotation, rm);
                    } else {
                        return new Sxtab16(machInst, rd, rn, rm, rotation);
                    }
                  case 0x3:
                    if (rn == 0xf) {
                        return new Uxtb16(machInst, rd, rotation, rm);
                    } else {
                        return new Uxtab16(machInst, rd, rn, rm, rotation);
                    }
                  case 0x4:
                    if (rn == 0xf) {
                        return new Sxtb(machInst, rd, rotation, rm);
                    } else {
                        return new Sxtab(machInst, rd, rn, rm, rotation);
                    }
                  case 0x5:
                    if (rn == 0xf) {
                        return new Uxtb(machInst, rd, rotation, rm);
                    } else {
                        return new Uxtab(machInst, rd, rn, rm, rotation);
                    }
                  default:
                    return new Unknown(machInst);
                }
            }
        } else {
            if (bits(op2, 3) == 0) {
                const IntRegIndex rd =
                    (IntRegIndex)(uint32_t)bits(machInst, 11, 8);
                const IntRegIndex rm =
                    (IntRegIndex)(uint32_t)bits(machInst, 3, 0);
                if (bits(op2, 2) == 0x0) {
                    const uint32_t op1 = bits(machInst, 22, 20);
                    const uint32_t op2 = bits(machInst, 5, 4);
                    switch (op2) {
                      case 0x0:
                        switch (op1) {
                          case 0x1:
                            return new Sadd16RegCc(machInst, rd,
                                                   rn, rm, 0, LSL);
                          case 0x2:
                            return new SasxRegCc(machInst, rd,
                                                 rn, rm, 0, LSL);
                          case 0x6:
                            return new SsaxRegCc(machInst, rd,
                                                 rn, rm, 0, LSL);
                          case 0x5:
                            return new Ssub16RegCc(machInst, rd,
                                                   rn, rm, 0, LSL);
                          case 0x0:
                            return new Sadd8RegCc(machInst, rd,
                                                  rn, rm, 0, LSL);
                          case 0x4:
                            return new Ssub8RegCc(machInst, rd,
                                                  rn, rm, 0, LSL);
                        }
                        break;
                      case 0x1:
                        switch (op1) {
                          case 0x1:
                            return new Qadd16Reg(machInst, rd, rn, rm, 0, LSL);
                          case 0x2:
                            return new QasxReg(machInst, rd, rn, rm, 0, LSL);
                          case 0x6:
                            return new QsaxReg(machInst, rd, rn, rm, 0, LSL);
                          case 0x5:
                            return new Qsub16Reg(machInst, rd, rn, rm, 0, LSL);
                          case 0x0:
                            return new Qadd8Reg(machInst, rd, rn, rm, 0, LSL);
                          case 0x4:
                            return new Qsub8Reg(machInst, rd, rn, rm, 0, LSL);
                        }
                        break;
                      case 0x2:
                        switch (op1) {
                          case 0x1:
                            return new Shadd16Reg(machInst, rd, rn, rm, 0, LSL);
                          case 0x2:
                            return new ShasxReg(machInst, rd, rn, rm, 0, LSL);
                          case 0x6:
                            return new ShsaxReg(machInst, rd, rn, rm, 0, LSL);
                          case 0x5:
                            return new Shsub16Reg(machInst, rd, rn, rm, 0, LSL);
                          case 0x0:
                            return new Shadd8Reg(machInst, rd, rn, rm, 0, LSL);
                          case 0x4:
                            return new Shsub8Reg(machInst, rd, rn, rm, 0, LSL);
                        }
                        break;
                    }
                } else {
                    const uint32_t op1 = bits(machInst, 22, 20);
                    const uint32_t op2 = bits(machInst, 5, 4);
                    switch (op2) {
                      case 0x0:
                        switch (op1) {
                          case 0x1:
                            return new Uadd16RegCc(machInst, rd,
                                                   rn, rm, 0, LSL);
                          case 0x2:
                            return new UasxRegCc(machInst, rd,
                                                 rn, rm, 0, LSL);
                          case 0x6:
                            return new UsaxRegCc(machInst, rd,
                                                 rn, rm, 0, LSL);
                          case 0x5:
                            return new Usub16RegCc(machInst, rd,
                                                   rn, rm, 0, LSL);
                          case 0x0:
                            return new Uadd8RegCc(machInst, rd,
                                                  rn, rm, 0, LSL);
                          case 0x4:
                            return new Usub8RegCc(machInst, rd,
                                                  rn, rm, 0, LSL);
                        }
                        break;
                      case 0x1:
                        switch (op1) {
                          case 0x1:
                            return new Uqadd16Reg(machInst, rd, rn, rm, 0, LSL);
                          case 0x2:
                            return new UqasxReg(machInst, rd, rn, rm, 0, LSL);
                          case 0x6:
                            return new UqsaxReg(machInst, rd, rn, rm, 0, LSL);
                          case 0x5:
                            return new Uqsub16Reg(machInst, rd, rn, rm, 0, LSL);
                          case 0x0:
                            return new Uqadd8Reg(machInst, rd, rn, rm, 0, LSL);
                          case 0x4:
                            return new Uqsub8Reg(machInst, rd, rn, rm, 0, LSL);
                        }
                        break;
                      case 0x2:
                        switch (op1) {
                          case 0x1:
                            return new Uhadd16Reg(machInst, rd, rn, rm, 0, LSL);
                          case 0x2:
                            return new UhasxReg(machInst, rd, rn, rm, 0, LSL);
                          case 0x6:
                            return new UhsaxReg(machInst, rd, rn, rm, 0, LSL);
                          case 0x5:
                            return new Uhsub16Reg(machInst, rd, rn, rm, 0, LSL);
                          case 0x0:
                            return new Uhadd8Reg(machInst, rd, rn, rm, 0, LSL);
                          case 0x4:
                            return new Uhsub8Reg(machInst, rd, rn, rm, 0, LSL);
                        }
                        break;
                    }
                }
            } else if (bits(op1, 3, 2) == 0x2 && bits(op2, 3, 2) == 0x2) {
                const uint32_t op1 = bits(machInst, 21, 20);
                const uint32_t op2 = bits(machInst, 5, 4);
                switch (op1) {
                  case 0x0:
                    {
                        IntRegIndex rd =
                            (IntRegIndex)(uint32_t)bits(machInst, 11, 8);
                        IntRegIndex rm =
                            (IntRegIndex)(uint32_t)bits(machInst, 3, 0);
                        switch (op2) {
                          case 0x0:
                            return new QaddRegCc(machInst, rd,
                                                 rm, rn, 0, LSL);
                          case 0x1:
                            return new QdaddRegCc(machInst, rd,
                                                  rm, rn, 0, LSL);
                          case 0x2:
                            return new QsubRegCc(machInst, rd,
                                                 rm, rn, 0, LSL);
                          case 0x3:
                            return new QdsubRegCc(machInst, rd,
                                                  rm, rn, 0, LSL);
                        }
                    }
                    break;
                  case 0x1:
                    {
                        IntRegIndex rd =
                            (IntRegIndex)(uint32_t)bits(machInst, 11, 8);
                        IntRegIndex rm = rn;
                        switch (op2) {
                          case 0x0:
                            return new Rev(machInst, rd, rm);
                          case 0x1:
                            return new Rev16(machInst, rd, rm);
                          case 0x2:
                            return new WarnUnimplemented("rbit", machInst);
                          case 0x3:
                            return new Revsh(machInst, rd, rm);
                        }
                    }
                    break;
                  case 0x2:
                    if (op2 == 0) {
                        return new WarnUnimplemented("sel", machInst);
                    }
                    break;
                  case 0x3:
                    if (op2 == 0) {
                        return new WarnUnimplemented("clz", machInst);
                    }
                }
            }
            return new Unknown(machInst);
        }
    }
    '''
}};

def format Thumb16ShiftAddSubMoveCmp() {{
    decode_block = '''
    {
        const uint32_t imm5 = bits(machInst, 10, 6);
        const uint32_t imm3 = bits(machInst, 8, 6);
        const uint32_t imm8 = bits(machInst, 7, 0);
        const IntRegIndex rd = (IntRegIndex)(uint32_t)bits(machInst, 2, 0);
        const IntRegIndex rd8 = (IntRegIndex)(uint32_t)bits(machInst, 10, 8);
        const IntRegIndex rn = (IntRegIndex)(uint32_t)bits(machInst, 5, 3);
        const IntRegIndex rm = (IntRegIndex)(uint32_t)bits(machInst, 8, 6);
        switch (bits(machInst, 13, 11)) {
          case 0x0: // lsl
            return new MovRegCc(machInst, rd, INTREG_ZERO, rn, imm5, LSL);
          case 0x1: // lsr
            return new MovRegCc(machInst, rd, INTREG_ZERO, rn, imm5, LSR);
          case 0x2: // asr
            return new MovRegCc(machInst, rd, INTREG_ZERO, rn, imm5, ASR);
          case 0x3:
            switch (bits(machInst, 10, 9)) {
              case 0x0:
                return new AddRegCc(machInst, rd, rn, rm, 0, LSL);
              case 0x1:
                return new SubRegCc(machInst, rd, rn, rm, 0, LSL);
              case 0x2:
                return new AddImmCc(machInst, rd, rn, imm3, true);
              case 0x3:
                return new SubImmCc(machInst, rd, rn, imm3, true);
            }
          case 0x4:
            return new MovImmCc(machInst, rd8, INTREG_ZERO, imm8, false);
          case 0x5:
            return new CmpImmCc(machInst, INTREG_ZERO, rd8, imm8, true);
          case 0x6:
            return new AddImmCc(machInst, rd8, rd8, imm8, true);
          case 0x7:
            return new SubImmCc(machInst, rd8, rd8, imm8, true);
        }
    }
    '''
}};

def format Thumb16DataProcessing() {{
    decode_block = '''
    {
        const IntRegIndex rdn = (IntRegIndex)(uint32_t)bits(machInst, 2, 0);
        const IntRegIndex rm = (IntRegIndex)(uint32_t)bits(machInst, 5, 3);
        switch (bits(machInst, 9, 6)) {
          case 0x0:
            return new AndRegCc(machInst, rdn, rdn, rm, 0, LSL);
          case 0x1:
            return new EorRegCc(machInst, rdn, rdn, rm, 0, LSL);
          case 0x2: //lsl
            return new MovRegRegCc(machInst, rdn, INTREG_ZERO, rdn, rm, LSL);
          case 0x3: //lsr
            return new MovRegRegCc(machInst, rdn, INTREG_ZERO, rdn, rm, LSR);
          case 0x4: //asr
            return new MovRegRegCc(machInst, rdn, INTREG_ZERO, rdn, rm, ASR);
          case 0x5:
            return new AdcRegCc(machInst, rdn, rdn, rm, 0, LSL);
          case 0x6:
            return new SbcRegCc(machInst, rdn, rdn, rm, 0, LSL);
          case 0x7: // ror
            return new MovRegRegCc(machInst, rdn, INTREG_ZERO, rdn, rm, ROR);
          case 0x8:
            return new TstRegCc(machInst, INTREG_ZERO, rdn, rm, 0, LSL);
          case 0x9:
            return new RsbImmCc(machInst, rdn, rm, 0, true);
          case 0xa:
            return new CmpRegCc(machInst, INTREG_ZERO, rdn, rm, 0, LSL);
          case 0xb:
            return new CmnRegCc(machInst, INTREG_ZERO, rdn, rm, 0, LSL);
          case 0xc:
            return new OrrRegCc(machInst, rdn, rdn, rm, 0, LSL);
          case 0xd:
            return new MulCc(machInst, rdn, rm, rdn);
          case 0xe:
            return new BicRegCc(machInst, rdn, rdn, rm, 0, LSL);
          case 0xf:
            return new MvnRegCc(machInst, rdn, INTREG_ZERO, rm, 0, LSL);
        }
    }
    '''
}};

def format Thumb16SpecDataAndBx() {{
    decode_block = '''
    {
        const IntRegIndex rdn =
            (IntRegIndex)(uint32_t)(bits(machInst, 2, 0) |
                                    (bits(machInst, 7) << 3));
        const IntRegIndex rm = (IntRegIndex)(uint32_t)bits(machInst, 6, 3);
        switch (bits(machInst, 9, 8)) {
          case 0x0:
            return new AddReg(machInst, rdn, rdn, rm, 0, LSL);
          case 0x1:
            return new CmpRegCc(machInst, INTREG_ZERO, rdn, rm, 0, LSL);
          case 0x2:
            return new MovReg(machInst, rdn, INTREG_ZERO, rm, 0, LSL);
          case 0x3:
            if (bits(machInst, 7) == 0) {
                return new BxReg(machInst,
                                 (IntRegIndex)(uint32_t)bits(machInst, 6, 3),
                                 COND_UC);
            } else {
                return new BlxReg(machInst,
                                  (IntRegIndex)(uint32_t)bits(machInst, 6, 3),
                                  COND_UC);
            }
        }
    }
    '''
}};

def format Thumb16Adr() {{
    decode_block = '''
    {
        const IntRegIndex rd = (IntRegIndex)(uint32_t)bits(machInst, 10, 8);
        const uint32_t imm8 = bits(machInst, 7, 0) << 2;
        return new AdrImm(machInst, rd, (IntRegIndex)1, imm8, false);
    }
    '''
}};

def format Thumb16AddSp() {{
    decode_block = '''
    {
        const IntRegIndex rd = (IntRegIndex)(uint32_t)bits(machInst, 10, 8);
        const uint32_t imm8 = bits(machInst, 7, 0) << 2;
        return new AddImm(machInst, rd, INTREG_SP, imm8, true);
    }
    '''
}};

def format Thumb16Misc() {{
    decode_block = '''
    {
        switch (bits(machInst, 11, 8)) {
          case 0x0:
            if (bits(machInst, 7)) {
                return new SubImm(machInst, INTREG_SP, INTREG_SP,
                                   bits(machInst, 6, 0) << 2, true);
            } else {
                return new AddImm(machInst, INTREG_SP, INTREG_SP,
                                   bits(machInst, 6, 0) << 2, true);
            }
          case 0x1:
            return new Cbz(machInst,
                           (bits(machInst, 9) << 6) |
                           (bits(machInst, 7, 3) << 1),
                           (IntRegIndex)(uint32_t)bits(machInst, 2, 0));
          case 0x2:
            {
                const IntRegIndex rd =
                    (IntRegIndex)(uint32_t)bits(machInst, 2, 0);
                const IntRegIndex rm =
                    (IntRegIndex)(uint32_t)bits(machInst, 5, 3);
                switch (bits(machInst, 7, 6)) {
                  case 0x0:
                    return new Sxth(machInst, rd, 0, rm);
                  case 0x1:
                    return new Sxtb(machInst, rd, 0, rm);
                  case 0x2:
                    return new Uxth(machInst, rd, 0, rm);
                  case 0x3:
                    return new Uxtb(machInst, rd, 0, rm);
                }
            }
          case 0x3:
            return new Cbz(machInst,
                           (bits(machInst, 9) << 6) |
                           (bits(machInst, 7, 3) << 1),
                           (IntRegIndex)(uint32_t)bits(machInst, 2, 0));
          case 0x4:
          case 0x5:
            {
                const uint32_t m = bits(machInst, 8);
                const uint32_t regList = bits(machInst, 7, 0) | (m << 14);
                return new LdmStm(machInst, INTREG_SP, false, false, false,
                                  true, false, regList);
            }
          case 0x6:
            {
                const uint32_t opBits = bits(machInst, 7, 5);
                if (opBits == 2) {
                    return new WarnUnimplemented("setend", machInst);
                } else if (opBits == 3) {
                    return new WarnUnimplemented("cps", machInst);
                }
            }
          case 0x9:
            return new Cbnz(machInst,
                            (bits(machInst, 9) << 6) |
                            (bits(machInst, 7, 3) << 1),
                            (IntRegIndex)(uint32_t)bits(machInst, 2, 0));
          case 0xa:
            {
                IntRegIndex rd = (IntRegIndex)(uint32_t)bits(machInst, 2, 0);
                IntRegIndex rm = (IntRegIndex)(uint32_t)bits(machInst, 5, 3);
                switch (bits(machInst, 7, 6)) {
                  case 0x0:
                    return new Rev(machInst, rd, rm);
                  case 0x1:
                    return new Rev16(machInst, rd, rm);
                  case 0x3:
                    return new Revsh(machInst, rd, rm);
                  default:
                    break;
                }
            }
            break;
          case 0xb:
            return new Cbnz(machInst,
                            (bits(machInst, 9) << 6) |
                            (bits(machInst, 7, 3) << 1),
                            (IntRegIndex)(uint32_t)bits(machInst, 2, 0));
          case 0xc:
          case 0xd:
            {
                const uint32_t p = bits(machInst, 8);
                const uint32_t regList = bits(machInst, 7, 0) | (p << 15);
                return new LdmStm(machInst, INTREG_SP, true, true, false,
                                  true, true, regList);
            }
          case 0xe:
            return new WarnUnimplemented("bkpt", machInst);
          case 0xf:
            if (bits(machInst, 3, 0) != 0)
                return new WarnUnimplemented("it", machInst);
            switch (bits(machInst, 7, 4)) {
              case 0x0:
                return new WarnUnimplemented("nop", machInst);
              case 0x1:
                return new WarnUnimplemented("yield", machInst);
              case 0x2:
                return new WarnUnimplemented("wfe", machInst);
              case 0x3:
                return new WarnUnimplemented("wfi", machInst);
              case 0x4:
                return new WarnUnimplemented("sev", machInst);
              default:
                return new WarnUnimplemented("unallocated_hint", machInst);
            }
          default:
            break;
        }
        return new Unknown(machInst);
    }
    '''
}};

def format Thumb32DataProcModImm() {{

    def decInst(mnem, dest="rd", op1="rn"):
        return '''
            if (s) {
                return new %(mnem)sImmCc(machInst, %(dest)s,
                                          %(op1)s, imm, rotC);
            } else {
                return new %(mnem)sImm(machInst, %(dest)s,
                                        %(op1)s, imm, rotC);
            }
        ''' % {"mnem" : mnem, "dest" : dest, "op1" : op1}

    decode_block = '''
    {
        const uint32_t op = bits(machInst, 24, 21);
        const bool s = (bits(machInst, 20) == 1);
        const IntRegIndex rn = (IntRegIndex)(uint32_t)bits(machInst, 19, 16);
        const IntRegIndex rd = (IntRegIndex)(uint32_t)bits(machInst, 11, 8);
        const uint32_t ctrlImm = bits(machInst.instBits, 26) << 3 |
                                 bits(machInst, 14, 12);
        const bool rotC = ctrlImm > 3;
        const uint32_t dataImm = bits(machInst, 7, 0);
        const uint32_t imm = modified_imm(ctrlImm, dataImm);
        switch (op) {
          case 0x0:
            if (rd == INTREG_PC) {
                %(tst)s
            } else {
                %(and)s
            }
          case 0x1:
            %(bic)s
          case 0x2:
            if (rn == INTREG_PC) {
                %(mov)s
            } else {
                %(orr)s
            }
          case 0x3:
            if (rn == INTREG_PC) {
                %(mvn)s
            } else {
                %(orn)s
            }
          case 0x4:
            if (rd == INTREG_PC) {
                %(teq)s
            } else {
                %(eor)s
            }
          case 0x8:
            if (rd == INTREG_PC) {
                %(cmn)s
            } else {
                %(add)s
            }
          case 0xa:
            %(adc)s
          case 0xb:
            %(sbc)s
          case 0xd:
            if (rd == INTREG_PC) {
                %(cmp)s
            } else {
                %(sub)s
            }
          case 0xe:
            %(rsb)s
          default:
            return new Unknown(machInst);
        }
    }
    ''' % {
        "tst" : decInst("Tst", "INTREG_ZERO"),
        "and" : decInst("And"),
        "bic" : decInst("Bic"),
        "mov" : decInst("Mov", op1="INTREG_ZERO"),
        "orr" : decInst("Orr"),
        "mvn" : decInst("Mvn", op1="INTREG_ZERO"),
        "orn" : decInst("Orn"),
        "teq" : decInst("Teq", dest="INTREG_ZERO"),
        "eor" : decInst("Eor"),
        "cmn" : decInst("Cmn", dest="INTREG_ZERO"),
        "add" : decInst("Add"),
        "adc" : decInst("Adc"),
        "sbc" : decInst("Sbc"),
        "cmp" : decInst("Cmp", dest="INTREG_ZERO"),
        "sub" : decInst("Sub"),
        "rsb" : decInst("Rsb")
    }
}};

def format Thumb32DataProcPlainBin() {{
    decode_block = '''
    {
        const uint32_t op = bits(machInst, 24, 20);
        const IntRegIndex rn = (IntRegIndex)(uint32_t)bits(machInst, 19, 16);
        const IntRegIndex rd = (IntRegIndex)(uint32_t)bits(machInst, 11, 8);
        switch (op) {
          case 0x0:
            {
                const uint32_t imm = bits(machInst, 7, 0) |
                                     (bits(machInst, 14, 12) << 8) |
                                     (bits(machInst, 26) << 11);
                if (rn == 0xf) {
                    return new AdrImm(machInst, rd, (IntRegIndex)1,
                                      imm, false);
                } else {
                    return new AddImm(machInst, rd, rn, imm, true);
                }
            }
          case 0x4:
            {
                const uint32_t imm = bits(machInst, 7, 0) |
                                     (bits(machInst, 14, 12) << 8) |
                                     (bits(machInst, 26) << 11) |
                                     (bits(machInst, 19, 16) << 12);
                return new MovImm(machInst, rd, INTREG_ZERO, imm, true);
            }
          case 0xa:
            {
                const uint32_t imm = bits(machInst, 7, 0) |
                                     (bits(machInst, 14, 12) << 8) |
                                     (bits(machInst, 26) << 11);
                if (rn == 0xf) {
                    return new AdrImm(machInst, rd, (IntRegIndex)0,
                                      imm, false);
                } else {
                    return new SubImm(machInst, rd, rn, imm, true);
                }
            }
          case 0xc:
            {
                const uint32_t imm = bits(machInst, 7, 0) |
                                     (bits(machInst, 14, 12) << 8) |
                                     (bits(machInst, 26) << 11) |
                                     (bits(machInst, 19, 16) << 12);
                return new MovtImm(machInst, rd, rd, imm, true);
            }
          case 0x12:
            if (!(bits(machInst, 14, 12) || bits(machInst, 7, 6))) {
                const uint32_t satImm = bits(machInst, 4, 0);
                return new Ssat16(machInst, rd, satImm + 1, rn);
            }
            // Fall through on purpose...
          case 0x10:
            {
                const uint32_t satImm = bits(machInst, 4, 0);
                const uint32_t imm = bits(machInst, 7, 6) |
                                     (bits(machInst, 14, 12) << 2);
                const ArmShiftType type =
                    (ArmShiftType)(uint32_t)bits(machInst, 21, 20);
                return new Ssat(machInst, rd, satImm + 1, rn, imm, type);
            }
          case 0x14:
            return new WarnUnimplemented("sbfx", machInst);
          case 0x16:
            if (rn == 0xf) {
                return new WarnUnimplemented("bfc", machInst);
            } else {
                return new WarnUnimplemented("bfi", machInst);
            }
          case 0x1a:
            if (!(bits(machInst, 14, 12) || bits(machInst, 7, 6))) {
                const uint32_t satImm = bits(machInst, 4, 0);
                return new Usat16(machInst, rd, satImm, rn);
            }
            // Fall through on purpose...
          case 0x18:
            {
                const uint32_t satImm = bits(machInst, 4, 0);
                const uint32_t imm = bits(machInst, 7, 6) |
                                     (bits(machInst, 14, 12) << 2);
                const ArmShiftType type =
                    (ArmShiftType)(uint32_t)bits(machInst, 21, 20);
                return new Usat(machInst, rd, satImm, rn, imm, type);
            }
          case 0x1c:
            return new WarnUnimplemented("ubfx", machInst);
          default:
            return new Unknown(machInst);
        }
    }
    '''
}};

def format Thumb32DataProcShiftReg() {{

    def decInst(mnem, dest="rd", op1="rn"):
        return '''
            if (s) {
                return new %(mnem)sRegCc(machInst, %(dest)s,
                                          %(op1)s, rm, amt, type);
            } else {
                return new %(mnem)sReg(machInst, %(dest)s,
                                        %(op1)s, rm, amt, type);
            }
        ''' % {"mnem" : mnem, "dest" : dest, "op1" : op1}

    decode_block = '''
    {
        const uint32_t op = bits(machInst, 24, 21);
        const bool s = (bits(machInst, 20) == 1);
        const IntRegIndex rn = (IntRegIndex)(uint32_t)bits(machInst, 19, 16);
        const IntRegIndex rd = (IntRegIndex)(uint32_t)bits(machInst, 11, 8);
        const IntRegIndex rm = (IntRegIndex)(uint32_t)bits(machInst, 3, 0);
        const uint32_t amt = (bits(machInst, 14, 12) << 2) |
                              bits(machInst, 7, 6);
        const ArmShiftType type = (ArmShiftType)(uint32_t)bits(machInst, 5, 4);
        switch (op) {
          case 0x0:
            if (rd == INTREG_PC) {
                %(tst)s
            } else {
                %(and)s
            }
          case 0x1:
            %(bic)s
          case 0x2:
            if (rn == INTREG_PC) {
                %(mov)s
            } else {
                %(orr)s
            }
          case 0x3:
            if (rn == INTREG_PC) {
                %(mvn)s
            } else {
                %(orn)s
            }
          case 0x4:
            if (rd == INTREG_PC) {
                %(teq)s
            } else {
                %(eor)s
            }
          case 0x6:
            return new WarnUnimplemented("pkh", machInst);
          case 0x8:
            if (rd == INTREG_PC) {
                %(cmn)s
            } else {
                %(add)s
            }
          case 0xa:
            %(adc)s
          case 0xb:
            %(sbc)s
          case 0xd:
            if (rd == INTREG_PC) {
                %(cmp)s
            } else {
                %(sub)s
            }
          case 0xe:
            %(rsb)s
          default:
            return new Unknown(machInst);
        }
    }
    ''' % {
        "tst" : decInst("Tst", "INTREG_ZERO"),
        "and" : decInst("And"),
        "bic" : decInst("Bic"),
        "mov" : decInst("Mov", op1="INTREG_ZERO"),
        "orr" : decInst("Orr"),
        "mvn" : decInst("Mvn", op1="INTREG_ZERO"),
        "orn" : decInst("Orn"),
        "teq" : decInst("Teq", "INTREG_ZERO"),
        "eor" : decInst("Eor"),
        "cmn" : decInst("Cmn", "INTREG_ZERO"),
        "add" : decInst("Add"),
        "adc" : decInst("Adc"),
        "sbc" : decInst("Sbc"),
        "cmp" : decInst("Cmp", "INTREG_ZERO"),
        "sub" : decInst("Sub"),
        "rsb" : decInst("Rsb")
    }
}};