isa/microops/regop.isa

// Copyright (c) 2007-2008 The Hewlett-Packard Development Company
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Authors: Gabe Black

//////////////////////////////////////////////////////////////////////////
//
// RegOp Microop templates
//
//////////////////////////////////////////////////////////////////////////

def template MicroRegOpExecute {{
        Fault %(class_name)s::execute(%(CPU_exec_context)s *xc,
                Trace::InstRecord *traceData) const
        {
            Fault fault = NoFault;

            DPRINTF(X86, "The data size is %d\n", dataSize);
            %(op_decl)s;
            %(op_rd)s;

            if(%(cond_check)s)
            {
                %(code)s;
                %(flag_code)s;
            }
            else
            {
                %(else_code)s;
            }

            //Write the resulting state to the execution context
            if(fault == NoFault)
            {
                %(op_wb)s;
            }
            return fault;
        }
}};

def template MicroRegOpImmExecute {{
        Fault %(class_name)s::execute(%(CPU_exec_context)s *xc,
                Trace::InstRecord *traceData) const
        {
            Fault fault = NoFault;

            %(op_decl)s;
            %(op_rd)s;

            if(%(cond_check)s)
            {
                %(code)s;
                %(flag_code)s;
            }
            else
            {
                %(else_code)s;
            }

            //Write the resulting state to the execution context
            if(fault == NoFault)
            {
                %(op_wb)s;
            }
            return fault;
        }
}};

def template MicroRegOpDeclare {{
    class %(class_name)s : public %(base_class)s
    {
      protected:
        void buildMe();

      public:
        %(class_name)s(ExtMachInst _machInst,
                const char * instMnem,
                bool isMicro, bool isDelayed, bool isFirst, bool isLast,
                RegIndex _src1, RegIndex _src2, RegIndex _dest,
                uint8_t _dataSize, uint16_t _ext);

        %(class_name)s(ExtMachInst _machInst,
                const char * instMnem,
                RegIndex _src1, RegIndex _src2, RegIndex _dest,
                uint8_t _dataSize, uint16_t _ext);

        %(BasicExecDeclare)s
    };
}};

def template MicroRegOpImmDeclare {{

    class %(class_name)s : public %(base_class)s
    {
      protected:
        void buildMe();

      public:
        %(class_name)s(ExtMachInst _machInst,
                const char * instMnem,
                bool isMicro, bool isDelayed, bool isFirst, bool isLast,
                RegIndex _src1, uint16_t _imm8, RegIndex _dest,
                uint8_t _dataSize, uint16_t _ext);

        %(class_name)s(ExtMachInst _machInst,
                const char * instMnem,
                RegIndex _src1, uint16_t _imm8, RegIndex _dest,
                uint8_t _dataSize, uint16_t _ext);

        %(BasicExecDeclare)s
    };
}};

def template MicroRegOpConstructor {{

    inline void %(class_name)s::buildMe()
    {
        %(constructor)s;
    }

    inline %(class_name)s::%(class_name)s(
            ExtMachInst machInst, const char * instMnem,
            RegIndex _src1, RegIndex _src2, RegIndex _dest,
            uint8_t _dataSize, uint16_t _ext) :
        %(base_class)s(machInst, "%(mnemonic)s", instMnem,
                false, false, false, false,
                _src1, _src2, _dest, _dataSize, _ext,
                %(op_class)s)
    {
        buildMe();
    }

    inline %(class_name)s::%(class_name)s(
            ExtMachInst machInst, const char * instMnem,
            bool isMicro, bool isDelayed, bool isFirst, bool isLast,
            RegIndex _src1, RegIndex _src2, RegIndex _dest,
            uint8_t _dataSize, uint16_t _ext) :
        %(base_class)s(machInst, "%(mnemonic)s", instMnem,
                isMicro, isDelayed, isFirst, isLast,
                _src1, _src2, _dest, _dataSize, _ext,
                %(op_class)s)
    {
        buildMe();
    }
}};

def template MicroRegOpImmConstructor {{

    inline void %(class_name)s::buildMe()
    {
        %(constructor)s;
    }

    inline %(class_name)s::%(class_name)s(
            ExtMachInst machInst, const char * instMnem,
            RegIndex _src1, uint16_t _imm8, RegIndex _dest,
            uint8_t _dataSize, uint16_t _ext) :
        %(base_class)s(machInst, "%(mnemonic)s", instMnem,
                false, false, false, false,
                _src1, _imm8, _dest, _dataSize, _ext,
                %(op_class)s)
    {
        buildMe();
    }

    inline %(class_name)s::%(class_name)s(
            ExtMachInst machInst, const char * instMnem,
            bool isMicro, bool isDelayed, bool isFirst, bool isLast,
            RegIndex _src1, uint16_t _imm8, RegIndex _dest,
            uint8_t _dataSize, uint16_t _ext) :
        %(base_class)s(machInst, "%(mnemonic)s", instMnem,
                isMicro, isDelayed, isFirst, isLast,
                _src1, _imm8, _dest, _dataSize, _ext,
                %(op_class)s)
    {
        buildMe();
    }
}};

output header {{
    void
    divide(uint64_t dividend, uint64_t divisor,
            uint64_t &quotient, uint64_t &remainder);
}};

output decoder {{
    void
    divide(uint64_t dividend, uint64_t divisor,
            uint64_t &quotient, uint64_t &remainder)
    {
        //Check for divide by zero.
        if (divisor == 0)
            panic("Divide by zero!\\n");
        //If the divisor is bigger than the dividend, don't do anything.
        if (divisor <= dividend) {
            //Shift the divisor so it's msb lines up with the dividend.
            int dividendMsb = findMsbSet(dividend);
            int divisorMsb = findMsbSet(divisor);
            int shift = dividendMsb - divisorMsb;
            divisor <<= shift;
            //Compute what we'll add to the quotient if the divisor isn't
            //now larger than the dividend.
            uint64_t quotientBit = 1;
            quotientBit <<= shift;
            //If we need to step back a bit (no pun intended) because the
            //divisor got too to large, do that here. This is the "or two"
            //part of one or two bit division.
            if (divisor > dividend) {
                quotientBit >>= 1;
                divisor >>= 1;
            }
            //Decrement the remainder and increment the quotient.
            quotient += quotientBit;
            remainder -= divisor;
        }
    }
}};

let {{
    # Make these empty strings so that concatenating onto
    # them will always work.
    header_output = ""
    decoder_output = ""
    exec_output = ""

    immTemplates = (
            MicroRegOpImmDeclare,
            MicroRegOpImmConstructor,
            MicroRegOpImmExecute)

    regTemplates = (
            MicroRegOpDeclare,
            MicroRegOpConstructor,
            MicroRegOpExecute)

    class RegOpMeta(type):
        def buildCppClasses(self, name, Name, suffix, \
                code, flag_code, cond_check, else_code):

            # Globals to stick the output in
            global header_output
            global decoder_output
            global exec_output

            # Stick all the code together so it can be searched at once
            allCode = "|".join((code, flag_code, cond_check, else_code))

            # If op2 is used anywhere, make register and immediate versions
            # of this code.
            matcher = re.compile("(?<!\\w)(?P<prefix>s?)op2(?P<typeQual>\\.\\w+)?")
            match = matcher.search(allCode)
            if match:
                typeQual = ""
                if match.group("typeQual"):
                    typeQual = match.group("typeQual")
                src2_name = "%spsrc2%s" % (match.group("prefix"), typeQual)
                self.buildCppClasses(name, Name, suffix,
                        matcher.sub(src2_name, code),
                        matcher.sub(src2_name, flag_code),
                        matcher.sub(src2_name, cond_check),
                        matcher.sub(src2_name, else_code))
                self.buildCppClasses(name + "i", Name, suffix + "Imm",
                        matcher.sub("imm8", code),
                        matcher.sub("imm8", flag_code),
                        matcher.sub("imm8", cond_check),
                        matcher.sub("imm8", else_code))
                return

            # If there's something optional to do with flags, generate
            # a version without it and fix up this version to use it.
            if flag_code != "" or cond_check != "true":
                self.buildCppClasses(name, Name, suffix,
                        code, "", "true", else_code)
                suffix = "Flags" + suffix

            # If psrc1 or psrc2 is used, we need to actually insert code to
            # compute it.
            matcher = re.compile("(?<!\w)psrc1(?!\w)")
            if matcher.search(allCode):
                code = "uint64_t psrc1 = pick(SrcReg1, 0, dataSize);" + code
            matcher = re.compile("(?<!\w)psrc2(?!\w)")
            if matcher.search(allCode):
                code = "uint64_t psrc2 = pick(SrcReg2, 1, dataSize);" + code
            # Also make available versions which do sign extension
            matcher = re.compile("(?<!\w)spsrc1(?!\w)")
            if matcher.search(allCode):
                code = "int64_t spsrc1 = signedPick(SrcReg1, 0, dataSize);" + code
            matcher = re.compile("(?<!\w)spsrc2(?!\w)")
            if matcher.search(allCode):
                code = "int64_t spsrc2 = signedPick(SrcReg2, 1, dataSize);" + code

            base = "X86ISA::RegOp"

            # If imm8 shows up in the code, use the immediate templates, if
            # not, hopefully the register ones will be correct.
            templates = regTemplates
            matcher = re.compile("(?<!\w)imm8(?!\w)")
            if matcher.search(allCode):
                base += "Imm"
                templates = immTemplates

            # Get everything ready for the substitution
            iop = InstObjParams(name, Name + suffix, base,
                    {"code" : code,
                     "flag_code" : flag_code,
                     "cond_check" : cond_check,
                     "else_code" : else_code})

            # Generate the actual code (finally!)
            header_output += templates[0].subst(iop)
            decoder_output += templates[1].subst(iop)
            exec_output += templates[2].subst(iop)


        def __new__(mcls, Name, bases, dict):
            abstract = False
            name = Name.lower()
            if "abstract" in dict:
                abstract = dict['abstract']
                del dict['abstract']

            cls = super(RegOpMeta, mcls).__new__(mcls, Name, bases, dict)
            if not abstract:
                cls.className = Name
                cls.base_mnemonic = name
                code = cls.code
                flag_code = cls.flag_code
                cond_check = cls.cond_check
                else_code = cls.else_code

                # Set up the C++ classes
                mcls.buildCppClasses(cls, name, Name, "",
                        code, flag_code, cond_check, else_code)

                # Hook into the microassembler dict
                global microopClasses
                microopClasses[name] = cls

                allCode = "|".join((code, flag_code, cond_check, else_code))

                # If op2 is used anywhere, make register and immediate versions
                # of this code.
                matcher = re.compile("op2(?P<typeQual>\\.\\w+)?")
                if matcher.search(allCode):
                    microopClasses[name + 'i'] = cls
            return cls


    class RegOp(X86Microop):
        __metaclass__ = RegOpMeta
        # This class itself doesn't act as a microop
        abstract = True

        # Default template parameter values
        flag_code = ""
        cond_check = "true"
        else_code = ";"

        def __init__(self, dest, src1, op2, flags = None, dataSize = "env.dataSize"):
            self.dest = dest
            self.src1 = src1
            self.op2 = op2
            self.flags = flags
            self.dataSize = dataSize
            if flags is None:
                self.ext = 0
            else:
                if not isinstance(flags, (list, tuple)):
                    raise Exception, "flags must be a list or tuple of flags"
                self.ext = " | ".join(flags)
                self.className += "Flags"

        def getAllocator(self, *microFlags):
            className = self.className
            if self.mnemonic == self.base_mnemonic + 'i':
                className += "Imm"
            allocator = '''new %(class_name)s(machInst, mnemonic
                    %(flags)s, %(src1)s, %(op2)s, %(dest)s,
                    %(dataSize)s, %(ext)s)''' % {
                "class_name" : className,
                "flags" : self.microFlagsText(microFlags),
                "src1" : self.src1, "op2" : self.op2,
                "dest" : self.dest,
                "dataSize" : self.dataSize,
                "ext" : self.ext}
            return allocator

    class LogicRegOp(RegOp):
        abstract = True
        flag_code = '''
            //Don't have genFlags handle the OF or CF bits
            uint64_t mask = CFBit | ECFBit | OFBit;
            ccFlagBits = genFlags(ccFlagBits, ext & ~mask, DestReg, psrc1, op2);
            //If a logic microop wants to set these, it wants to set them to 0.
            ccFlagBits &= ~(CFBit & ext);
            ccFlagBits &= ~(ECFBit & ext);
            ccFlagBits &= ~(OFBit & ext);
        '''

    class FlagRegOp(RegOp):
        abstract = True
        flag_code = \
            "ccFlagBits = genFlags(ccFlagBits, ext, DestReg, psrc1, op2);"

    class SubRegOp(RegOp):
        abstract = True
        flag_code = \
            "ccFlagBits = genFlags(ccFlagBits, ext, DestReg, psrc1, ~op2, true);"

    class CondRegOp(RegOp):
        abstract = True
        cond_check = "checkCondition(ccFlagBits, ext)"

    class RdRegOp(RegOp):
        abstract = True
        def __init__(self, dest, src1=None, dataSize="env.dataSize"):
            if not src1:
                src1 = dest
            super(RdRegOp, self).__init__(dest, src1, "NUM_INTREGS", None, dataSize)

    class WrRegOp(RegOp):
        abstract = True
        def __init__(self, src1, src2, flags=None, dataSize="env.dataSize"):
            super(WrRegOp, self).__init__("NUM_INTREGS", src1, src2, flags, dataSize)

    class Add(FlagRegOp):
        code = 'DestReg = merge(DestReg, psrc1 + op2, dataSize);'

    class Or(LogicRegOp):
        code = 'DestReg = merge(DestReg, psrc1 | op2, dataSize);'

    class Adc(FlagRegOp):
        code = '''
            CCFlagBits flags = ccFlagBits;
            DestReg = merge(DestReg, psrc1 + op2 + flags.cf, dataSize);
            '''

    class Sbb(SubRegOp):
        code = '''
            CCFlagBits flags = ccFlagBits;
            DestReg = merge(DestReg, psrc1 - op2 - flags.cf, dataSize);
            '''

    class And(LogicRegOp):
        code = 'DestReg = merge(DestReg, psrc1 & op2, dataSize)'

    class Sub(SubRegOp):
        code = 'DestReg = merge(DestReg, psrc1 - op2, dataSize)'

    class Xor(LogicRegOp):
        code = 'DestReg = merge(DestReg, psrc1 ^ op2, dataSize)'

    # Neither of these is quite correct because it assumes that right shifting
    # a signed or unsigned value does sign or zero extension respectively.
    # The C standard says that what happens on a right shift with a 1 in the
    # MSB position is undefined. On x86 and under likely most compilers the
    # "right thing" happens, but this isn't a guarantee.
    class Mul1s(WrRegOp):
        code = '''
            ProdLow = psrc1 * op2;
            int halfSize = (dataSize * 8) / 2;
            int64_t spsrc1_h = spsrc1 >> halfSize;
            int64_t spsrc1_l = spsrc1 & mask(halfSize);
            int64_t spsrc2_h = sop2 >> halfSize;
            int64_t spsrc2_l = sop2 & mask(halfSize);
            ProdHi = ((spsrc1_l * spsrc2_h + spsrc1_h * spsrc2_l +
                      ((spsrc1_l * spsrc2_l) >> halfSize)) >> halfSize) +
                     spsrc1_h * spsrc2_h;
            '''

    class Mul1u(WrRegOp):
        code = '''
            ProdLow = psrc1 * op2;
            int halfSize = (dataSize * 8) / 2;
            uint64_t psrc1_h = psrc1 >> halfSize;
            uint64_t psrc1_l = psrc1 & mask(halfSize);
            uint64_t psrc2_h = op2 >> halfSize;
            uint64_t psrc2_l = op2 & mask(halfSize);
            ProdHi = ((psrc1_l * psrc2_h + psrc1_h * psrc2_l +
                      ((psrc1_l * psrc2_l) >> halfSize)) >> halfSize) +
                     psrc1_h * psrc2_h;
            '''

    class Mulel(RdRegOp):
        code = 'DestReg = merge(SrcReg1, ProdLow, dataSize);'

    class Muleh(RdRegOp):
        def __init__(self, dest, src1=None, flags=None, dataSize="env.dataSize"):
            if not src1:
                src1 = dest
            super(RdRegOp, self).__init__(dest, src1, "NUM_INTREGS", flags, dataSize)
        code = 'DestReg = merge(SrcReg1, ProdHi, dataSize);'
        flag_code = '''
            if (ProdHi)
                ccFlagBits = ccFlagBits | (ext & (CFBit | OFBit | ECFBit));
            else
                ccFlagBits = ccFlagBits & ~(ext & (CFBit | OFBit | ECFBit));
        '''

    # One or two bit divide
    class Div1(WrRegOp):
        code = '''
            //These are temporaries so that modifying them later won't make
            //the ISA parser think they're also sources.
            uint64_t quotient = 0;
            uint64_t remainder = psrc1;
            //Similarly, this is a temporary so changing it doesn't make it
            //a source.
            uint64_t divisor = op2;
            //This is a temporary just for consistency and clarity.
            uint64_t dividend = remainder;
            //Do the division.
            divide(dividend, divisor, quotient, remainder);
            //Record the final results.
            Remainder = remainder;
            Quotient = quotient;
            Divisor = divisor;
            '''

    # Step divide
    class Div2(RegOp):
        code = '''
            uint64_t dividend = Remainder;
            uint64_t divisor = Divisor;
            uint64_t quotient = Quotient;
            uint64_t remainder = dividend;
            int remaining = op2;
            //If we overshot, do nothing. This lets us unrool division loops a
            //little.
            if (remaining) {
                //Shift in bits from the low order portion of the dividend
                while(dividend < divisor && remaining) {
                    dividend = (dividend << 1) | bits(SrcReg1, remaining - 1);
                    quotient <<= 1;
                    remaining--;
                }
                remainder = dividend;
                //Do the division.
                divide(dividend, divisor, quotient, remainder);
            }
            //Keep track of how many bits there are still to pull in.
            DestReg = merge(DestReg, remaining, dataSize);
            //Record the final results
            Remainder = remainder;
            Quotient = quotient;
        '''
        flag_code = '''
            if (DestReg == 0)
                ccFlagBits = ccFlagBits | (ext & EZFBit);
            else
                ccFlagBits = ccFlagBits & ~(ext & EZFBit);
        '''

    class Divq(RdRegOp):
        code = 'DestReg = merge(SrcReg1, Quotient, dataSize);'

    class Divr(RdRegOp):
        code = 'DestReg = merge(SrcReg1, Remainder, dataSize);'

    class Mov(CondRegOp):
        code = 'DestReg = merge(SrcReg1, op2, dataSize)'
        else_code = 'DestReg=DestReg;'

    # Shift instructions

    class Sll(RegOp):
        code = '''
            uint8_t shiftAmt = (op2 & ((dataSize == 8) ? mask(6) : mask(5)));
            DestReg = merge(DestReg, psrc1 << shiftAmt, dataSize);
            '''
        flag_code = '''
            // If the shift amount is zero, no flags should be modified.
            if (shiftAmt) {
                //Zero out any flags we might modify. This way we only have to
                //worry about setting them.
                ccFlagBits = ccFlagBits & ~(ext & (CFBit | ECFBit | OFBit));
                int CFBits = 0;
                //Figure out if we -would- set the CF bits if requested.
                if (bits(SrcReg1, dataSize * 8 - shiftAmt))
                    CFBits = 1;
                //If some combination of the CF bits need to be set, set them.
                if ((ext & (CFBit | ECFBit)) && CFBits)
                    ccFlagBits = ccFlagBits | (ext & (CFBit | ECFBit));
                //Figure out what the OF bit should be.
                if ((ext & OFBit) && (CFBits ^ bits(DestReg, dataSize * 8 - 1)))
                    ccFlagBits = ccFlagBits | OFBit;
                //Use the regular mechanisms to calculate the other flags.
                ccFlagBits = genFlags(ccFlagBits, ext & ~(CFBit | ECFBit | OFBit),
                        DestReg, psrc1, op2);
            }
        '''

    class Srl(RegOp):
        code = '''
            uint8_t shiftAmt = (op2 & ((dataSize == 8) ? mask(6) : mask(5)));
            // Because what happens to the bits shift -in- on a right shift
            // is not defined in the C/C++ standard, we have to mask them out
            // to be sure they're zero.
            uint64_t logicalMask = mask(dataSize * 8 - shiftAmt);
            DestReg = merge(DestReg, (psrc1 >> shiftAmt) & logicalMask, dataSize);
            '''
        flag_code = '''
            // If the shift amount is zero, no flags should be modified.
            if (shiftAmt) {
                //Zero out any flags we might modify. This way we only have to
                //worry about setting them.
                ccFlagBits = ccFlagBits & ~(ext & (CFBit | ECFBit | OFBit));
                //If some combination of the CF bits need to be set, set them.
                if ((ext & (CFBit | ECFBit)) && bits(SrcReg1, shiftAmt - 1))
                    ccFlagBits = ccFlagBits | (ext & (CFBit | ECFBit));
                //Figure out what the OF bit should be.
                if ((ext & OFBit) && bits(SrcReg1, dataSize * 8 - 1))
                    ccFlagBits = ccFlagBits | OFBit;
                //Use the regular mechanisms to calculate the other flags.
                ccFlagBits = genFlags(ccFlagBits, ext & ~(CFBit | ECFBit | OFBit),
                        DestReg, psrc1, op2);
            }
        '''

    class Sra(RegOp):
        code = '''
            uint8_t shiftAmt = (op2 & ((dataSize == 8) ? mask(6) : mask(5)));
            // Because what happens to the bits shift -in- on a right shift
            // is not defined in the C/C++ standard, we have to sign extend
            // them manually to be sure.
            uint64_t arithMask =
                -bits(psrc1, dataSize * 8 - 1) << (dataSize * 8 - shiftAmt);
            DestReg = merge(DestReg, (psrc1 >> shiftAmt) | arithMask, dataSize);
            '''
        flag_code = '''
            // If the shift amount is zero, no flags should be modified.
            if (shiftAmt) {
                //Zero out any flags we might modify. This way we only have to
                //worry about setting them.
                ccFlagBits = ccFlagBits & ~(ext & (CFBit | ECFBit | OFBit));
                //If some combination of the CF bits need to be set, set them.
                if ((ext & (CFBit | ECFBit)) && bits(SrcReg1, shiftAmt - 1))
                    ccFlagBits = ccFlagBits | (ext & (CFBit | ECFBit));
                //Use the regular mechanisms to calculate the other flags.
                ccFlagBits = genFlags(ccFlagBits, ext & ~(CFBit | ECFBit | OFBit),
                        DestReg, psrc1, op2);
            }
        '''

    class Ror(RegOp):
        code = '''
            uint8_t shiftAmt =
                (op2 & ((dataSize == 8) ? mask(6) : mask(5)));
            if(shiftAmt)
            {
                uint64_t top = psrc1 << (dataSize * 8 - shiftAmt);
                uint64_t bottom = bits(psrc1, dataSize * 8, shiftAmt);
                DestReg = merge(DestReg, top | bottom, dataSize);
            }
            else
                DestReg = DestReg;
            '''
        flag_code = '''
            // If the shift amount is zero, no flags should be modified.
            if (shiftAmt) {
                //Zero out any flags we might modify. This way we only have to
                //worry about setting them.
                ccFlagBits = ccFlagBits & ~(ext & (CFBit | ECFBit | OFBit));
                //Find the most and second most significant bits of the result.
                int msb = bits(DestReg, dataSize * 8 - 1);
                int smsb = bits(DestReg, dataSize * 8 - 2);
                //If some combination of the CF bits need to be set, set them.
                if ((ext & (CFBit | ECFBit)) && msb)
                    ccFlagBits = ccFlagBits | (ext & (CFBit | ECFBit));
                //Figure out what the OF bit should be.
                if ((ext & OFBit) && (msb ^ smsb))
                    ccFlagBits = ccFlagBits | OFBit;
                //Use the regular mechanisms to calculate the other flags.
                ccFlagBits = genFlags(ccFlagBits, ext & ~(CFBit | ECFBit | OFBit),
                        DestReg, psrc1, op2);
            }
        '''

    class Rcr(RegOp):
        code = '''
            uint8_t shiftAmt =
                (op2 & ((dataSize == 8) ? mask(6) : mask(5)));
            if(shiftAmt)
            {
                CCFlagBits flags = ccFlagBits;
                uint64_t top = flags.cf << (dataSize * 8 - shiftAmt);
                if(shiftAmt > 1)
                    top |= psrc1 << (dataSize * 8 - shiftAmt - 1);
                uint64_t bottom = bits(psrc1, dataSize * 8, shiftAmt);
                DestReg = merge(DestReg, top | bottom, dataSize);
            }
            else
                DestReg = DestReg;
            '''
        flag_code = '''
            // If the shift amount is zero, no flags should be modified.
            if (shiftAmt) {
                //Zero out any flags we might modify. This way we only have to
                //worry about setting them.
                ccFlagBits = ccFlagBits & ~(ext & (CFBit | ECFBit | OFBit));
                //Figure out what the OF bit should be.
                if ((ext & OFBit) && ((ccFlagBits & CFBit) ^
                                      bits(SrcReg1, dataSize * 8 - 1)))
                    ccFlagBits = ccFlagBits | OFBit;
                //If some combination of the CF bits need to be set, set them.
                if ((ext & (CFBit | ECFBit)) && bits(SrcReg1, shiftAmt - 1))
                    ccFlagBits = ccFlagBits | (ext & (CFBit | ECFBit));
                //Use the regular mechanisms to calculate the other flags.
                ccFlagBits = genFlags(ccFlagBits, ext & ~(CFBit | ECFBit | OFBit),
                        DestReg, psrc1, op2);
            }
        '''

    class Rol(RegOp):
        code = '''
            uint8_t shiftAmt =
                (op2 & ((dataSize == 8) ? mask(6) : mask(5)));
            if(shiftAmt)
            {
                uint64_t top = psrc1 << shiftAmt;
                uint64_t bottom =
                    bits(psrc1, dataSize * 8 - 1, dataSize * 8 - shiftAmt);
                DestReg = merge(DestReg, top | bottom, dataSize);
            }
            else
                DestReg = DestReg;
            '''
        flag_code = '''
            // If the shift amount is zero, no flags should be modified.
            if (shiftAmt) {
                //Zero out any flags we might modify. This way we only have to
                //worry about setting them.
                ccFlagBits = ccFlagBits & ~(ext & (CFBit | ECFBit | OFBit));
                //The CF bits, if set, would be set to the lsb of the result.
                int lsb = DestReg & 0x1;
                int msb = bits(DestReg, dataSize * 8 - 1);
                //If some combination of the CF bits need to be set, set them.
                if ((ext & (CFBit | ECFBit)) && lsb)
                    ccFlagBits = ccFlagBits | (ext & (CFBit | ECFBit));
                //Figure out what the OF bit should be.
                if ((ext & OFBit) && (msb ^ lsb))
                    ccFlagBits = ccFlagBits | OFBit;
                //Use the regular mechanisms to calculate the other flags.
                ccFlagBits = genFlags(ccFlagBits, ext & ~(CFBit | ECFBit | OFBit),
                        DestReg, psrc1, op2);
            }
        '''

    class Rcl(RegOp):
        code = '''
            uint8_t shiftAmt =
                (op2 & ((dataSize == 8) ? mask(6) : mask(5)));
            if(shiftAmt)
            {
                CCFlagBits flags = ccFlagBits;
                uint64_t top = psrc1 << shiftAmt;
                uint64_t bottom = flags.cf << (shiftAmt - 1);
                if(shiftAmt > 1)
                    bottom |=
                        bits(psrc1, dataSize * 8 - 1,
                                   dataSize * 8 - shiftAmt + 1);
                DestReg = merge(DestReg, top | bottom, dataSize);
            }
            else
                DestReg = DestReg;
            '''
        flag_code = '''
            // If the shift amount is zero, no flags should be modified.
            if (shiftAmt) {
                //Zero out any flags we might modify. This way we only have to
                //worry about setting them.
                ccFlagBits = ccFlagBits & ~(ext & (CFBit | ECFBit | OFBit));
                int msb = bits(DestReg, dataSize * 8 - 1);
                int CFBits = bits(SrcReg1, dataSize * 8 - shiftAmt);
                //If some combination of the CF bits need to be set, set them.
                if ((ext & (CFBit | ECFBit)) && CFBits)
                    ccFlagBits = ccFlagBits | (ext & (CFBit | ECFBit));
                //Figure out what the OF bit should be.
                if ((ext & OFBit) && (msb ^ CFBits))
                    ccFlagBits = ccFlagBits | OFBit;
                //Use the regular mechanisms to calculate the other flags.
                ccFlagBits = genFlags(ccFlagBits, ext & ~(CFBit | ECFBit | OFBit),
                        DestReg, psrc1, op2);
            }
        '''

    class Wrip(WrRegOp, CondRegOp):
        code = 'RIP = psrc1 + sop2 + CSBase'
        else_code="RIP = RIP;"

    class Br(WrRegOp, CondRegOp):
        code = 'nuIP = psrc1 + op2;'
        else_code='nuIP = nuIP;'

    class Wruflags(WrRegOp):
        code = 'ccFlagBits = psrc1 ^ op2'

    class Rdip(RdRegOp):
        code = 'DestReg = RIP - CSBase'

    class Ruflags(RdRegOp):
        code = 'DestReg = ccFlagBits'

    class Ruflag(RegOp):
        code = '''
            int flag = bits(ccFlagBits, imm8);
            DestReg = merge(DestReg, flag, dataSize);
            ccFlagBits = (flag == 0) ? (ccFlagBits | EZFBit) :
                                       (ccFlagBits & ~EZFBit);
            '''
        def __init__(self, dest, imm, flags=None, \
                dataSize="env.dataSize"):
            super(Ruflag, self).__init__(dest, \
                    "NUM_INTREGS", imm, flags, dataSize)

    class Sext(RegOp):
        code = '''
            IntReg val = psrc1;
            // Mask the bit position so that it wraps.
            int bitPos = op2 & (dataSize * 8 - 1);
            int sign_bit = bits(val, bitPos, bitPos);
            uint64_t maskVal = mask(bitPos+1);
            val = sign_bit ? (val | ~maskVal) : (val & maskVal);
            DestReg = merge(DestReg, val, dataSize);
            '''
        flag_code = '''
            if (!sign_bit)
                ccFlagBits = ccFlagBits &
                    ~(ext & (CFBit | ECFBit | ZFBit | EZFBit));
            else
                ccFlagBits = ccFlagBits |
                    (ext & (CFBit | ECFBit | ZFBit | EZFBit));
            '''

    class Zext(RegOp):
        code = 'DestReg = bits(psrc1, op2, 0);'

    class Rdcr(RegOp):
        def __init__(self, dest, src1, flags=None, dataSize="env.dataSize"):
            super(Rdcr, self).__init__(dest, \
                    src1, "NUM_INTREGS", flags, dataSize)
        code = '''
            if (dest == 1 || (dest > 4 && dest < 8) || (dest > 8)) {
                fault = new InvalidOpcode();
            } else {
                DestReg = ControlSrc1;
            }
        '''

    class Wrcr(RegOp):
        def __init__(self, dest, src1, flags=None, dataSize="env.dataSize"):
            super(Wrcr, self).__init__(dest, \
                    src1, "NUM_INTREGS", flags, dataSize)
        code = '''
            if (dest == 1 || (dest > 4 && dest < 8) || (dest > 8)) {
                fault = new InvalidOpcode();
            } else {
                // There are *s in the line below so it doesn't confuse the
                // parser. They may be unnecessary.
                //Mis*cReg old*Val = pick(Cont*rolDest, 0, dat*aSize);
                MiscReg newVal = psrc1;

                // Check for any modifications that would cause a fault.
                switch(dest) {
                  case 0:
                    {
                        Efer efer = EferOp;
                        CR0 cr0 = newVal;
                        CR4 oldCr4 = CR4Op;
                        if (bits(newVal, 63, 32) ||
                                (!cr0.pe && cr0.pg) ||
                                (!cr0.cd && cr0.nw) ||
                                (cr0.pg && efer.lme && !oldCr4.pae))
                            fault = new GeneralProtection(0);
                    }
                    break;
                  case 2:
                    break;
                  case 3:
                    break;
                  case 4:
                    {
                        CR4 cr4 = newVal;
                        // PAE can't be disabled in long mode.
                        if (bits(newVal, 63, 11) ||
                                (machInst.mode.mode == LongMode && !cr4.pae))
                            fault = new GeneralProtection(0);
                    }
                    break;
                  case 8:
                    {
                        if (bits(newVal, 63, 4))
                            fault = new GeneralProtection(0);
                    }
                  default:
                    panic("Unrecognized control register %d.\\n", dest);
                }
                ControlDest = newVal;
            }
            '''

    # Microops for manipulating segmentation registers
    class SegOp(RegOp):
        abstract = True
        def __init__(self, dest, src1, flags=None, dataSize="env.dataSize"):
            super(SegOp, self).__init__(dest, \
                    src1, "NUM_INTREGS", flags, dataSize)

    class Wrbase(SegOp):
        code = '''
            SegBaseDest = psrc1;
        '''

    class Wrlimit(SegOp):
        code = '''
            SegLimitDest = psrc1;
        '''

    class Wrsel(SegOp):
        code = '''
            SegSelDest = psrc1;
        '''

    class Rdbase(SegOp):
        code = '''
            DestReg = SegBaseDest;
        '''

    class Rdlimit(SegOp):
        code = '''
            DestReg = SegLimitSrc1;
        '''

    class Rdsel(SegOp):
        code = '''
            DestReg = SegSelSrc1;
        '''

    class Chks(SegOp):
        code = '''
            // The selector is in source 1 and can be at most 16 bits.
            SegSelector selector = psrc1;

            // Compute the address of the descriptor and set DestReg to it.
            if (selector.ti) {
                // A descriptor in the LDT
                Addr target = (selector.si << 3) + LDTRBase;
                if (!LDTRSel || (selector.si << 3) + dataSize > LDTRLimit)
                    fault = new GeneralProtection(selector & mask(16));
                DestReg = target;
            } else {
                // A descriptor in the GDT
                Addr target = (selector.si << 3) + GDTRBase;
                if ((selector.si << 3) + dataSize > GDTRLimit)
                    fault = new GeneralProtection(selector & mask(16));
                DestReg = target;
            }
        '''
        flag_code = '''
            // Check for a NULL selector and set ZF,EZF appropriately.
            ccFlagBits = ccFlagBits & ~(ext & (ZFBit | EZFBit));
            if (!selector.si && !selector.ti)
                ccFlagBits = ccFlagBits | (ext & (ZFBit | EZFBit));
        '''

    class Wrdh(RegOp):
        code = '''

        '''

    class Wrtsc(WrRegOp):
        code = '''
            TscOp = psrc1;
        '''

    class Rdtsc(RdRegOp):
        code = '''
            DestReg = TscOp;
        '''

    class Wrdl(RegOp):
        code = '''
            SegDescriptor desc = SrcReg1;
            SegAttr attr = 0;
            attr.dpl = desc.dpl;
            attr.defaultSize = desc.d;
            if (!desc.s) {
                SegBaseDest = SegBaseDest;
                SegLimitDest = SegLimitDest;
                SegAttrDest = SegAttrDest;
                panic("System segment encountered.\\n");
            } else {
                if (!desc.p)
                    panic("Segment not present.\\n");
                if (desc.type.codeOrData) {
                    attr.readable = desc.type.r;
                    attr.longMode = desc.l;
                } else {
                    attr.expandDown = desc.type.e;
                    attr.readable = 1;
                    attr.writable = desc.type.w;
                }
                Addr base = desc.baseLow | (desc.baseHigh << 24);
                Addr limit = desc.limitLow | (desc.limitHigh << 16);
                if (desc.g)
                    limit = (limit << 12) | mask(12);
                SegBaseDest = base;
                SegLimitDest = limit;
                SegAttrDest = attr;
            }
        '''
}};