gem5/src/arch/x86/isa/microops/fpop.isa

// Copyright (c) 2007 The Hewlett-Packard Development Company
// All rights reserved.
//
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// Authors: Gabe Black

//////////////////////////////////////////////////////////////////////////
//
// FpOp Microop templates
//
//////////////////////////////////////////////////////////////////////////

def template MicroFpOpExecute {{
        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;
                %(top_code)s;
            }
            else
            {
                %(else_code)s;
            }

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

def template MicroFpOpDeclare {{
    class %(class_name)s : public %(base_class)s
    {
      public:
        %(class_name)s(ExtMachInst _machInst,
                const char * instMnem, uint64_t setFlags,
                InstRegIndex _src1, InstRegIndex _src2, InstRegIndex _dest,
                uint8_t _dataSize, int8_t _spm);

        %(BasicExecDeclare)s
    };
}};

def template MicroFpOpConstructor {{
    inline %(class_name)s::%(class_name)s(
            ExtMachInst machInst, const char * instMnem, uint64_t setFlags,
            InstRegIndex _src1, InstRegIndex _src2, InstRegIndex _dest,
            uint8_t _dataSize, int8_t _spm) :
        %(base_class)s(machInst, "%(mnemonic)s", instMnem, setFlags,
                _src1, _src2, _dest, _dataSize, _spm,
                %(op_class)s)
    {
        %(constructor)s;
    }
}};

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

    class FpOpMeta(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 there's something optional to do with flags, generate
            # a version without it and fix up this version to use it.
            if flag_code is not "" or cond_check is not "true":
                self.buildCppClasses(name, Name, suffix,
                        code, "", "true", else_code)
                suffix = "Flags" + suffix

            base = "X86ISA::FpOp"

            # Get everything ready for the substitution
            iop_top = InstObjParams(name, Name + suffix + "Top", base,
                    {"code" : code,
                     "flag_code" : flag_code,
                     "cond_check" : cond_check,
                     "else_code" : else_code,
                     "top_code" : "TOP = (TOP + spm + 8) % 8;"})
            iop = InstObjParams(name, Name + suffix, base,
                    {"code" : code,
                     "flag_code" : flag_code,
                     "cond_check" : cond_check,
                     "else_code" : else_code,
                     "top_code" : ";"})

            # Generate the actual code (finally!)
            header_output += MicroFpOpDeclare.subst(iop_top)
            decoder_output += MicroFpOpConstructor.subst(iop_top)
            exec_output += MicroFpOpExecute.subst(iop_top)
            header_output += MicroFpOpDeclare.subst(iop)
            decoder_output += MicroFpOpConstructor.subst(iop)
            exec_output += MicroFpOpExecute.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(FpOpMeta, mcls).__new__(mcls, Name, bases, dict)
            if not abstract:
                cls.className = Name
                cls.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

            return cls


    class FpOp(X86Microop):
        __metaclass__ = FpOpMeta
        # 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, src2, spm=0, \
                SetStatus=False, dataSize="env.dataSize"):
            self.dest = dest
            self.src1 = src1
            self.src2 = src2
            self.spm = spm
            self.dataSize = dataSize
            if SetStatus:
                self.className += "Flags"
            if spm:
                self.className += "Top"

        def getAllocator(self, microFlags):
            return '''new %(class_name)s(machInst, macrocodeBlock,
                    %(flags)s, %(src1)s, %(src2)s, %(dest)s,
                    %(dataSize)s, %(spm)d)''' % {
                "class_name" : self.className,
                "flags" : self.microFlagsText(microFlags),
                "src1" : self.src1, "src2" : self.src2,
                "dest" : self.dest,
                "dataSize" : self.dataSize,
                "spm" : self.spm}

    class Movfp(FpOp):
        def __init__(self, dest, src1, spm=0, \
                SetStatus=False, dataSize="env.dataSize"):
            super(Movfp, self).__init__(dest, src1, "InstRegIndex(0)", \
                    spm, SetStatus, dataSize)
        code = 'FpDestReg_uqw = FpSrcReg1_uqw;'
        else_code = 'FpDestReg_uqw = FpDestReg_uqw;'
        cond_check = "checkCondition(ccFlagBits | cfofBits | dfBit | \
                                     ecfBit | ezfBit, src2)"

    class Xorfp(FpOp):
        code = 'FpDestReg_uqw = FpSrcReg1_uqw ^ FpSrcReg2_uqw;'

    class Sqrtfp(FpOp):
        code = 'FpDestReg = sqrt(FpSrcReg2);'

    # Conversion microops
    class ConvOp(FpOp):
        abstract = True
        def __init__(self, dest, src1):
            super(ConvOp, self).__init__(dest, src1, \
                    "InstRegIndex(FLOATREG_MICROFP0)")

    # These probably shouldn't look at the ExtMachInst directly to figure
    # out what size to use and should instead delegate that to the macroop's
    # constructor. That would be more efficient, and it would make the
    # microops a little more modular.
    class cvtf_i2d(ConvOp):
        code = '''
            X86IntReg intReg = SSrcReg1;
            if (REX_W)
                FpDestReg = intReg.SR;
            else
                FpDestReg = intReg.SE;
            '''

    class cvtf_i2d_hi(ConvOp):
        code = 'FpDestReg = bits(SSrcReg1, 63, 32);'

    class cvtf_d2i(ConvOp):
        code = '''
            int64_t intSrcReg1 = static_cast<int64_t>(FpSrcReg1);
            if (REX_W)
                SDestReg = intSrcReg1;
            else
                SDestReg = merge(SDestReg, intSrcReg1, 4);
            '''

    # These need to consider size at some point. They'll always use doubles
    # for the moment.
    class addfp(FpOp):
        code = 'FpDestReg = FpSrcReg1 + FpSrcReg2;'

    class mulfp(FpOp):
        code = 'FpDestReg = FpSrcReg1 * FpSrcReg2;'

    class divfp(FpOp):
        code = 'FpDestReg = FpSrcReg1 / FpSrcReg2;'

    class subfp(FpOp):
        code = 'FpDestReg = FpSrcReg1 - FpSrcReg2;'

    class Compfp(FpOp):
        def __init__(self, src1, src2, spm=0, setStatus=False, \
                dataSize="env.dataSize"):
            super(Compfp, self).__init__("InstRegIndex(FLOATREG_MICROFP0)", \
                    src1, src2, spm, setStatus, dataSize)
        # This class sets the condition codes in rflags according to the
        # rules for comparing floating point.
        code = '''
            //               ZF PF CF
            // Unordered      1  1  1
            // Greater than   0  0  0
            // Less than      0  0  1
            // Equal          1  0  0
            //           OF = SF = AF = 0
            ccFlagBits = ccFlagBits & ~(SFBit | AFBit | ZFBit | PFBit);
            cfofBits = cfofBits & ~(OFBit | CFBit);

            if (std::isnan(FpSrcReg1) || std::isnan(FpSrcReg2)) {
                ccFlagBits = ccFlagBits | (ZFBit | PFBit);
                cfofBits = cfofBits | CFBit;
            }
            else if(FpSrcReg1 < FpSrcReg2)
                cfofBits = cfofBits | CFBit;
            else if(FpSrcReg1 == FpSrcReg2)
                ccFlagBits = ccFlagBits | ZFBit;
        '''
}};