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Unify fields in ISA description in

Juhani Krekelä 7 months ago
  1. 57


@ -1,29 +1,33 @@
#!/usr/bin/env python
from collections import namedtuple
import enum
Opcode = namedtuple('Opcode', ('mnemonic', 'rx', 'ry', 'addr', 'immediate'))
class rfield(enum.Enum):
none, reg, imm_flag = range(3)
Opcode = namedtuple('Opcode', ('mnemonic', 'rx', 'ry', 'addr'))
opcodes = [
Opcode('halt', rx=False, ry=False, addr=False, immediate=False),
Opcode('ret', rx=False, ry=False, addr=False, immediate=False),
Opcode('shl', rx=True, ry=False, addr=False, immediate=False),
Opcode('shr', rx=True, ry=False, addr=False, immediate=False),
Opcode('rol', rx=True, ry=False, addr=False, immediate=False),
Opcode('ror', rx=True, ry=False, addr=False, immediate=False),
Opcode('nand', rx=True, ry=True, addr=False, immediate=False),
Opcode('and', rx=True, ry=True, addr=False, immediate=False),
Opcode('or', rx=True, ry=True, addr=False, immediate=False),
Opcode('xor', rx=True, ry=True, addr=False, immediate=False),
Opcode('load', rx=True, ry=False, addr=True, immediate=True),
Opcode('store', rx=False, ry=True, addr=True, immediate=False),
Opcode('breq', rx=True, ry=True, addr=True, immediate=False),
Opcode('brneq', rx=True, ry=True, addr=True, immediate=False),
Opcode('cleq', rx=True, ry=True, addr=True, immediate=False),
Opcode('clneq', rx=True, ry=True, addr=True, immediate=False),
Opcode('halt', rx=rfield.none, ry=rfield.none, addr=False),
Opcode('ret', rx=rfield.none, ry=rfield.none, addr=False),
Opcode('shl', rx=rfield.reg, ry=rfield.none, addr=False),
Opcode('shr', rx=rfield.reg, ry=rfield.none, addr=False),
Opcode('rol', rx=rfield.reg, ry=rfield.none, addr=False),
Opcode('ror', rx=rfield.reg, ry=rfield.none, addr=False),
Opcode('nand', rx=rfield.reg, ry=rfield.reg, addr=False),
Opcode('and', rx=rfield.reg, ry=rfield.reg, addr=False),
Opcode('or', rx=rfield.reg, ry=rfield.reg, addr=False),
Opcode('xor', rx=rfield.reg, ry=rfield.reg, addr=False),
Opcode('load', rx=rfield.reg, ry=rfield.imm_flag, addr=True),
Opcode('store', rx=rfield.none, ry=rfield.reg, addr=True),
Opcode('breq', rx=rfield.reg, ry=rfield.reg, addr=True),
Opcode('brneq', rx=rfield.reg, ry=rfield.reg, addr=True),
Opcode('cleq', rx=rfield.reg, ry=rfield.reg, addr=True),
Opcode('clneq', rx=rfield.reg, ry=rfield.reg, addr=True),
Instruction = namedtuple('Instruction', ['opcode', 'rx', 'ry', 'addr', 'immediate'])
@ -42,11 +46,12 @@ def segment(binary, origin):
rx = (byte >> 2) & 3
ry = byte & 3
immediate = opcodes[opcode].immediate and ry == 3
immediate = opcodes[opcode].ry == rfield.imm_flag and ry == 3
valid = True
if not opcodes[opcode].rx and rx != 0: valid = False
if not opcodes[opcode].ry and not immediate and ry != 0: valid = False
if opcodes[opcode].rx == rfield.none and rx != 0: valid = False
if opcodes[opcode].ry == rfield.none and ry != 0: valid = False
if opcodes[opcode].ry == rfield.imm_flag and ry not in (0, 3): valid = False
if opcodes[opcode].addr and not immediate and ip + 2 >= len(binary): valid = False
if immediate and ip + 1 >= len(binary): valid = False
@ -80,9 +85,9 @@ def disasm(binary, origin = 0):
mnemonic = opcodes[contents.opcode].mnemonic
fields = []
if opcodes[contents.opcode].rx:
if opcodes[contents.opcode].rx == rfield.reg:
if opcodes[contents.opcode].ry:
if opcodes[contents.opcode].ry == rfield.reg:
if contents.immediate is not None: