arithmetic.py

from . import encodings


#
# Add two integers.
#
# Add two numbers contained in registers and store them in a register.
#
@encodings.R
@encodings.opcode(0x07)
def ADD(state, rs1, rs2, rd):
    state.registers[rd] = state.registers[rs1] + state.registers[rs2]


@encodings.R
@encodings.opcode(0x0E)
def CMP(state, rs1, rs2, rd):
    x = state.registers[rs1]
    y = state.registers[rs2]

    state.ccr = x - y
    state.ccn = (state.ccr < 0)
    state.ccz = (state.ccr == 0)
    state.ccv = False


#
# Multiply two integers.
#
# Multiply two numbers contained in registers and store them in a register.
#
@encodings.R
@encodings.opcode(0x08)
def MUL(state, rs1, rs2, rd):
    state.registers[rd] = state.registers[rs1] * state.registers[rs2]


#
# Shift Left Logical
#
# Shift the number in %rs1 left by the number of bits in %rs2.
#
@encodings.R
@encodings.opcode(0x04)
def SLL(state, rs1, rs2, rd):
    state.registers[rd] = state.registers[rs1] << state.registers[rs2]


#
# Shift Right Logical
#
# Shift the number in %rs1 right by the number of bits in %rs2.
#
@encodings.R
@encodings.opcode(0x05)
def SRL(state, rs1, rs2, rd):
    state.registers[rd] = state.registers[rs1] >> state.registers[rs2]


#
# Subtract two integers.
#
# Subtract two numbers contained in registers and store them in a register.
#
@encodings.R
@encodings.opcode(0x06)
def SUB(state, rs1, rs2, rd):
    state.registers[rd] = state.registers[rs1] - state.registers[rs2]