gem5/arch/mips/isa/operands.isa

def operand_types {{
    'sb' : ('signed int', 8),
    'ub' : ('unsigned int', 8),
    'sh' : ('signed int', 16),
    'uh' : ('unsigned int', 16),
    'sw' : ('signed int', 32),
    'uw' : ('unsigned int', 32),
    'sd' : ('signed int', 64),
    'ud' : ('unsigned int', 64),
    'sf' : ('float', 32),
    'df' : ('float', 64),
    'qf' : ('float', 128)
}};

def operands {{
    #General Purpose Integer Reg Operands
    'Rd': ('IntReg', 'uw', 'RD', 'IsInteger', 1),
    'Rs': ('IntReg', 'uw', 'RS', 'IsInteger', 2),
    'Rt': ('IntReg', 'uw', 'RT', 'IsInteger', 3),

    #Operands used for Link or Syscall Insts
    'R31': ('IntReg', 'uw','31','IsInteger', 4),
    'R2':  ('IntReg', 'uw','2', 'IsInteger', 5),

    #Special Integer Reg operands
    'HI':  ('IntReg', 'uw','32', 'IsInteger', 6),
    'LO':  ('IntReg', 'uw','33', 'IsInteger', 7),

    #Immediate Value operand
    'IntImm': ('IntReg', 'uw', 'INTIMM', 'IsInteger', 3),

    #Floating Point Reg Operands
    'Fd': ('FloatReg', 'sf', 'FD', 'IsFloating', 1),
    'Fs': ('FloatReg', 'sf', 'FS', 'IsFloating', 2),
    'Ft': ('FloatReg', 'sf', 'FT', 'IsFloating', 3),
    'Fr': ('FloatReg', 'sf', 'FR', 'IsFloating', 3),

    #Special Floating Point Control Reg Operands
    'FIR':  ('FloatReg', 'uw', '32', 'IsFloating', 1),
    'FCCR': ('FloatReg', 'uw', '33', 'IsFloating', 2),
    'FEXR': ('FloatReg', 'uw', '34', 'IsFloating', 3),
    'FENR': ('FloatReg', 'uw', '35', 'IsFloating', 3),
    'FCSR': ('FloatReg', 'uw', '36', 'IsFloating', 3),

     #Operands For Paired Singles FP Operations
    'Fd1': ('FloatReg', 'sf', 'FD', 'IsFloating', 4),
    'Fd2': ('FloatReg', 'sf', 'FD+1', 'IsFloating', 4),
    'Fs1': ('FloatReg', 'sf', 'FS', 'IsFloating', 5),
    'Fs2': ('FloatReg', 'sf', 'FS+1', 'IsFloating', 5),
    'Ft1': ('FloatReg', 'sf', 'FT', 'IsFloating', 6),
    'Ft2': ('FloatReg', 'sf', 'FT+1', 'IsFloating', 6),
    'Fr1': ('FloatReg', 'sf', 'FR', 'IsFloating', 7),
    'Fr2': ('FloatReg', 'sf', 'FR+1', 'IsFloating', 7),

    #Memory Operand
    'Mem': ('Mem', 'uw', None, ('IsMemRef', 'IsLoad', 'IsStore'), 4),

    #Program Counter Operands
    'NPC': ('NPC', 'uw', None, ( None, None, 'IsControl' ), 4),
    'NNPC':('NNPC', 'uw', None, ( None, None, 'IsControl' ), 4)
}};