gem5/src/arch/arm/isa/formats/unimp.isa

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

// Copyright (c) 2010 ARM Limited
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// Copyright (c) 2007-2008 The Florida State University
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// Authors: Stephen Hines

////////////////////////////////////////////////////////////////////
//
// 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 ArmStaticInst
    {
      public:
        /// Constructor
        FailUnimplemented(const char *_mnemonic, ExtMachInst _machInst)
            : ArmStaticInst(_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 ArmStaticInst
    {
      private:
        /// Have we warned on this instruction yet?
        mutable bool warned;

      public:
        /// Constructor
        WarnUnimplemented(const char *_mnemonic, ExtMachInst _machInst)
            : ArmStaticInst(_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
    {
        return csprintf("%-10s (unimplemented)", mnemonic);
    }
}};

output exec {{
    Fault
    FailUnimplemented::execute(%(CPU_exec_context)s *xc,
                               Trace::InstRecord *traceData) const
    {
#if FULL_SYSTEM
        return new UndefinedInstruction;
#else
        return new UndefinedInstruction(machInst, false, mnemonic);
#endif
    }

    Fault
    WarnUnimplemented::execute(%(CPU_exec_context)s *xc,
                               Trace::InstRecord *traceData) const
    {
        if (!warned) {
            warn("\tinstruction '%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)
}};