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#!/usr/bin/env python3
import sys
from mnems import mnems
def opws(kw):
for k in range(16):
mnems.append(kw + str(k))
opws("mark") # who is mark
opws("loc")
opws("ret")
opws("lit")
def dpc(addr):
print(f"{addr:04x} | ",end='')
def uuu(b):
u=bin(b)[2:].zfill(16)
for x in range(0,len(u),4):
yield u[x:x+4]
def fbin(b):
return '_'.join(uuu(b))
pc = 0
MASK_CALL = 0b1000_0000_0000_0000
MASK_LIT = 0b0110_0000_0000_0000
MASK_JMP = 0b0100_0000_0000_0000
def maskeq(x, m):
# must be called in the right order
return (x&m)==m
def main():
while True:
global pc
bys = sys.stdin.buffer.read(2)
if len(bys) < 2: break
word = int.from_bytes(bys, 'big')
dpc(pc)
dpc(word)
if maskeq(word, MASK_CALL):
disasm_call(word)
elif maskeq(word, MASK_LIT):
disasm_lit(word)
elif maskeq(word, MASK_JMP):
disasm_br(word, pc)
else:
disasm_i(word)
pc += 2
def disasm_call(word):
addr = word & 0b0111_1111_1111_1111
addr = addr << 1
print(f"c {addr:04x}")
def disasm_lit(word):
val = word & 0b0001_1111_1111_1111
print(f"l {val:04x}")
def disasm_br(word, pc):
is_cond = (word & 0b0001_0000_0000_0000) != 0
char = 'b' if is_cond else 'j'
rel = (word & 0b0000_1111_1111_1111) - 2048
target = rel + pc
print(f"{char} {rel:+05x} ={target:04x}")
def disasm_i(word):
opc1 = (word&0b0011_1111_1000_0000)>>7
opc2 = (word&0b0000_0000_0111_1111)
mnem1 = mnems[opc1]
mnem2 = mnems[opc2]
if mnem2 == "nop": mnem2 = ""
print(f"i {mnem1} {mnem2}")
if __name__ == "__main__":
main()
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