isa/formats/unimp.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.
//
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// "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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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

////////////////////////////////////////////////////////////////////
//
// Unimplemented instructions
//

output header {{
    /**
     * Static instruction class for unimplemented instructions that
     * cause simulator termination.  Note that these are recognized
     * (legal) instructions that the simulator does not support; the
     * 'Unknown' class is used for unrecognized/illegal instructions.
     * This is a leaf class.
     */
    class FailUnimplemented : public MipsStaticInst
    {
      public:
        /// Constructor
        FailUnimplemented(const char *_mnemonic, MachInst _machInst)
            : MipsStaticInst(_mnemonic, _machInst, No_OpClass)
        {
            // don't call execute() (which panics) if we're on a
            // speculative path
            flags[IsNonSpeculative] = true;
        }

        %(BasicExecDeclare)s

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

    /**
     * Base class for unimplemented instructions that cause a warning
     * to be printed (but do not terminate simulation).  This
     * implementation is a little screwy in that it will print a
     * warning for each instance of a particular unimplemented machine
     * instruction, not just for each unimplemented opcode.  Should
     * probably make the 'warned' flag a static member of the derived
     * class.
     */
    class WarnUnimplemented : public MipsStaticInst
    {
      private:
        /// Have we warned on this instruction yet?
        mutable bool warned;

      public:
        /// Constructor
        WarnUnimplemented(const char *_mnemonic, MachInst _machInst)
            : MipsStaticInst(_mnemonic, _machInst, No_OpClass), warned(false)
        {
            // don't call execute() (which panics) if we're on a
            // speculative path
            flags[IsNonSpeculative] = true;
        }

        %(BasicExecDeclare)s

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

output decoder {{
    std::string
    FailUnimplemented::generateDisassembly(Addr pc,
                                           const SymbolTable *symtab) const
    {
        return csprintf("%-10s (unimplemented)", mnemonic);
    }

    std::string
    WarnUnimplemented::generateDisassembly(Addr pc,
                                           const SymbolTable *symtab) const
    {
#ifdef SS_COMPATIBLE_DISASSEMBLY
        return csprintf("%-10s", mnemonic);
#else
        return csprintf("%-10s (unimplemented)", mnemonic);
#endif
    }
}};

output exec {{
    Fault
    FailUnimplemented::execute(%(CPU_exec_context)s *xc,
                               Trace::InstRecord *traceData) const
    {
        panic("attempt to execute unimplemented instruction '%s' "
              "(inst 0x%08x, opcode 0x%x, binary:%s)", mnemonic, machInst, OPCODE,
              inst2string(machInst));
        return new UnimplementedOpcodeFault;
    }

    Fault
    WarnUnimplemented::execute(%(CPU_exec_context)s *xc,
                               Trace::InstRecord *traceData) const
    {
        if (!warned) {
            warn("instruction '%s' unimplemented\n", mnemonic);
            warned = true;
        }

        return NoFault;
    }
}};


def format FailUnimpl() {{
    iop = InstObjParams(name, 'FailUnimplemented')
    decode_block = BasicDecodeWithMnemonic.subst(iop)
}};

def format WarnUnimpl() {{
    iop = InstObjParams(name, 'WarnUnimplemented')
    decode_block = BasicDecodeWithMnemonic.subst(iop)
}};

output header {{
    /**
     * Static instruction class for unknown (illegal) instructions.
     * These cause simulator termination if they are executed in a
     * non-speculative mode.  This is a leaf class.
     */
    class Unknown : public MipsStaticInst
    {
      public:
        /// Constructor
        Unknown(MachInst _machInst)
            : MipsStaticInst("unknown", _machInst, No_OpClass)
        {
            // don't call execute() (which panics) if we're on a
            // speculative path
            flags[IsNonSpeculative] = true;
        }

        %(BasicExecDeclare)s

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