gem5/arch/alpha/isa/mem.isa

// -*- mode:c++ -*-

// Copyright (c) 2003-2005 The Regents of The University of Michigan
// All rights reserved.
//
// 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
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output header {{
    /**
     * Base class for general Alpha memory-format instructions.
     */
    class Memory : public AlphaStaticInst
    {
      protected:

        /// Memory request flags.  See mem_req_base.hh.
        unsigned memAccessFlags;
        /// Pointer to EAComp object.
        const StaticInstPtr<AlphaISA> eaCompPtr;
        /// Pointer to MemAcc object.
        const StaticInstPtr<AlphaISA> memAccPtr;

        /// Constructor
        Memory(const char *mnem, MachInst _machInst, OpClass __opClass,
               StaticInstPtr<AlphaISA> _eaCompPtr = nullStaticInstPtr,
               StaticInstPtr<AlphaISA> _memAccPtr = nullStaticInstPtr)
            : AlphaStaticInst(mnem, _machInst, __opClass),
              memAccessFlags(0), eaCompPtr(_eaCompPtr), memAccPtr(_memAccPtr)
        {
        }

        std::string
        generateDisassembly(Addr pc, const SymbolTable *symtab) const;

      public:

        const StaticInstPtr<AlphaISA> &eaCompInst() const { return eaCompPtr; }
        const StaticInstPtr<AlphaISA> &memAccInst() const { return memAccPtr; }
    };

    /**
     * Base class for memory-format instructions using a 32-bit
     * displacement (i.e. most of them).
     */
    class MemoryDisp32 : public Memory
    {
      protected:
        /// Displacement for EA calculation (signed).
        int32_t disp;

        /// Constructor.
        MemoryDisp32(const char *mnem, MachInst _machInst, OpClass __opClass,
                     StaticInstPtr<AlphaISA> _eaCompPtr = nullStaticInstPtr,
                     StaticInstPtr<AlphaISA> _memAccPtr = nullStaticInstPtr)
            : Memory(mnem, _machInst, __opClass, _eaCompPtr, _memAccPtr),
              disp(MEMDISP)
        {
        }
    };


    /**
     * Base class for a few miscellaneous memory-format insts
     * that don't interpret the disp field: wh64, fetch, fetch_m, ecb.
     * None of these instructions has a destination register either.
     */
    class MemoryNoDisp : public Memory
    {
      protected:
        /// Constructor
        MemoryNoDisp(const char *mnem, MachInst _machInst, OpClass __opClass,
                     StaticInstPtr<AlphaISA> _eaCompPtr = nullStaticInstPtr,
                     StaticInstPtr<AlphaISA> _memAccPtr = nullStaticInstPtr)
            : Memory(mnem, _machInst, __opClass, _eaCompPtr, _memAccPtr)
        {
        }

        std::string
        generateDisassembly(Addr pc, const SymbolTable *symtab) const;
    };
}};


output decoder {{
    std::string
    Memory::generateDisassembly(Addr pc, const SymbolTable *symtab) const
    {
        return csprintf("%-10s %c%d,%d(r%d)", mnemonic,
                        flags[IsFloating] ? 'f' : 'r', RA, MEMDISP, RB);
    }

    std::string
    MemoryNoDisp::generateDisassembly(Addr pc, const SymbolTable *symtab) const
    {
        return csprintf("%-10s (r%d)", mnemonic, RB);
    }
}};

def format LoadAddress(code) {{
    iop = InstObjParams(name, Name, 'MemoryDisp32', CodeBlock(code))
    header_output = BasicDeclare.subst(iop)
    decoder_output = BasicConstructor.subst(iop)
    decode_block = BasicDecode.subst(iop)
    exec_output = BasicExecute.subst(iop)
}};


def template LoadStoreDeclare {{
    /**
     * Static instruction class for "%(mnemonic)s".
     */
    class %(class_name)s : public %(base_class)s
    {
      protected:

        /**
         * "Fake" effective address computation class for "%(mnemonic)s".
         */
        class EAComp : public %(base_class)s
        {
          public:
            /// Constructor
            EAComp(MachInst machInst);

            %(BasicExecDeclare)s
        };

        /**
         * "Fake" memory access instruction class for "%(mnemonic)s".
         */
        class MemAcc : public %(base_class)s
        {
          public:
            /// Constructor
            MemAcc(MachInst machInst);

            %(BasicExecDeclare)s
        };

      public:

        /// Constructor.
        %(class_name)s(MachInst machInst);

        %(BasicExecDeclare)s
    };
}};

def template LoadStoreConstructor {{
    /** TODO: change op_class to AddrGenOp or something (requires
     * creating new member of OpClass enum in op_class.hh, updating
     * config files, etc.). */
    inline %(class_name)s::EAComp::EAComp(MachInst machInst)
        : %(base_class)s("%(mnemonic)s (EAComp)", machInst, IntAluOp)
    {
        %(ea_constructor)s;
    }

    inline %(class_name)s::MemAcc::MemAcc(MachInst machInst)
        : %(base_class)s("%(mnemonic)s (MemAcc)", machInst, %(op_class)s)
    {
        %(memacc_constructor)s;
    }

    inline %(class_name)s::%(class_name)s(MachInst machInst)
         : %(base_class)s("%(mnemonic)s", machInst, %(op_class)s,
                          new EAComp(machInst), new MemAcc(machInst))
    {
        %(constructor)s;
    }
}};


def template EACompExecute {{
    Fault
    %(class_name)s::EAComp::execute(%(CPU_exec_context)s *xc,
                                   Trace::InstRecord *traceData) const
    {
        Addr EA;
        Fault fault = No_Fault;

        %(fp_enable_check)s;
        %(op_decl)s;
        %(op_rd)s;
        %(code)s;

        if (fault == No_Fault) {
            %(op_wb)s;
            xc->setEA(EA);
        }

        return fault;
    }
}};

def template MemAccExecute {{
    Fault
    %(class_name)s::MemAcc::execute(%(CPU_exec_context)s *xc,
                                   Trace::InstRecord *traceData) const
    {
        Addr EA;
        Fault fault = No_Fault;

        %(fp_enable_check)s;
        %(op_decl)s;
        %(op_nonmem_rd)s;
        EA = xc->getEA();

        if (fault == No_Fault) {
            %(op_mem_rd)s;
            %(code)s;
        }

        if (fault == No_Fault) {
            %(op_mem_wb)s;
        }

        if (fault == No_Fault) {
            %(postacc_code)s;
        }

        if (fault == No_Fault) {
            %(op_nonmem_wb)s;
        }

        return fault;
    }
}};


def template LoadStoreExecute {{
    Fault %(class_name)s::execute(%(CPU_exec_context)s *xc,
                                  Trace::InstRecord *traceData) const
    {
        Addr EA;
        Fault fault = No_Fault;

        %(fp_enable_check)s;
        %(op_decl)s;
        %(op_nonmem_rd)s;
        %(ea_code)s;

        if (fault == No_Fault) {
            %(op_mem_rd)s;
            %(memacc_code)s;
        }

        if (fault == No_Fault) {
            %(op_mem_wb)s;
        }

        if (fault == No_Fault) {
            %(postacc_code)s;
        }

        if (fault == No_Fault) {
            %(op_nonmem_wb)s;
        }

        return fault;
    }
}};


def template PrefetchExecute {{
    Fault %(class_name)s::execute(%(CPU_exec_context)s *xc,
                                  Trace::InstRecord *traceData) const
    {
        Addr EA;
        Fault fault = No_Fault;

        %(fp_enable_check)s;
        %(op_decl)s;
        %(op_nonmem_rd)s;
        %(ea_code)s;

        if (fault == No_Fault) {
            xc->prefetch(EA, memAccessFlags);
        }

        return No_Fault;
    }
}};

// load instructions use Ra as dest, so check for
// Ra == 31 to detect nops
def template LoadNopCheckDecode {{
 {
     AlphaStaticInst *i = new %(class_name)s(machInst);
     if (RA == 31) {
         i = makeNop(i);
     }
     return i;
 }
}};


// for some load instructions, Ra == 31 indicates a prefetch (not a nop)
def template LoadPrefetchCheckDecode {{
 {
     if (RA != 31) {
         return new %(class_name)s(machInst);
     }
     else {
         return new %(class_name)sPrefetch(machInst);
     }
 }
}};


let {{
def LoadStoreBase(name, Name, ea_code, memacc_code, postacc_code = '',
                  base_class = 'MemoryDisp32', flags = [],
                  decode_template = BasicDecode,
                  exec_template = LoadStoreExecute):
    # Segregate flags into instruction flags (handled by InstObjParams)
    # and memory access flags (handled here).

    # Would be nice to autogenerate this list, but oh well.
    valid_mem_flags = ['LOCKED', 'NO_FAULT', 'EVICT_NEXT', 'PF_EXCLUSIVE']
    mem_flags =  [f for f in flags if f in valid_mem_flags]
    inst_flags = [f for f in flags if f not in valid_mem_flags]

    # add hook to get effective addresses into execution trace output.
    ea_code += '\nif (traceData) { traceData->setAddr(EA); }\n'

    # generate code block objects
    ea_cblk = CodeBlock(ea_code)
    memacc_cblk = CodeBlock(memacc_code)
    postacc_cblk = CodeBlock(postacc_code)

    # Some CPU models execute the memory operation as an atomic unit,
    # while others want to separate them into an effective address
    # computation and a memory access operation.  As a result, we need
    # to generate three StaticInst objects.  Note that the latter two
    # are nested inside the larger "atomic" one.

    # generate InstObjParams for EAComp object
    ea_iop = InstObjParams(name, Name, base_class, ea_cblk, inst_flags)

    # generate InstObjParams for MemAcc object
    memacc_iop = InstObjParams(name, Name, base_class, memacc_cblk, inst_flags)
    # in the split execution model, the MemAcc portion is responsible
    # for the post-access code.
    memacc_iop.postacc_code = postacc_cblk.code

    # generate InstObjParams for unified execution
    cblk = CodeBlock(ea_code + memacc_code + postacc_code)
    iop = InstObjParams(name, Name, base_class, cblk, inst_flags)

    iop.ea_constructor = ea_cblk.constructor
    iop.ea_code = ea_cblk.code
    iop.memacc_constructor = memacc_cblk.constructor
    iop.memacc_code = memacc_cblk.code
    iop.postacc_code = postacc_cblk.code

    if mem_flags:
        s = '\n\tmemAccessFlags = ' + string.join(mem_flags, '|') + ';'
        iop.constructor += s
        memacc_iop.constructor += s

    # (header_output, decoder_output, decode_block, exec_output)
    return (LoadStoreDeclare.subst(iop), LoadStoreConstructor.subst(iop),
            decode_template.subst(iop),
            EACompExecute.subst(ea_iop)
            + MemAccExecute.subst(memacc_iop)
            + exec_template.subst(iop))
}};


def format LoadOrNop(ea_code, memacc_code, *flags) {{
    (header_output, decoder_output, decode_block, exec_output) = \
        LoadStoreBase(name, Name, ea_code, memacc_code, flags = flags,
                      decode_template = LoadNopCheckDecode)
}};


// Note that the flags passed in apply only to the prefetch version
def format LoadOrPrefetch(ea_code, memacc_code, *pf_flags) {{
    # declare the load instruction object and generate the decode block
    (header_output, decoder_output, decode_block, exec_output) = \
        LoadStoreBase(name, Name, ea_code, memacc_code,
                      decode_template = LoadPrefetchCheckDecode)

    # Declare the prefetch instruction object.

    # convert flags from tuple to list to make them mutable
    pf_flags = list(pf_flags) + ['IsMemRef', 'IsLoad', 'IsDataPrefetch', 'MemReadOp', 'NO_FAULT']

    (pf_header_output, pf_decoder_output, _, pf_exec_output) = \
        LoadStoreBase(name, Name + 'Prefetch', ea_code, '',
                      flags = pf_flags, exec_template = PrefetchExecute)

    header_output += pf_header_output
    decoder_output += pf_decoder_output
    exec_output += pf_exec_output
}};


def format Store(ea_code, memacc_code, *flags) {{
    (header_output, decoder_output, decode_block, exec_output) = \
        LoadStoreBase(name, Name, ea_code, memacc_code, flags = flags)
}};


def format StoreCond(ea_code, memacc_code, postacc_code, *flags) {{
    (header_output, decoder_output, decode_block, exec_output) = \
        LoadStoreBase(name, Name, ea_code, memacc_code, postacc_code,
                      flags = flags)
}};


// Use 'MemoryNoDisp' as base: for wh64, fetch, ecb
def format MiscPrefetch(ea_code, memacc_code, *flags) {{
    (header_output, decoder_output, decode_block, exec_output) = \
        LoadStoreBase(name, Name, ea_code, memacc_code, flags = flags,
                      base_class = 'MemoryNoDisp')
}};