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mnems = """
nop
rot
nrt
dup
swp
ovr
drp
tck
nip
equ
neq
add
sub
mul
div
neg
slt
ult
sle
ule
lod
sto
psh
pop
""".split()
mnems.extend(['???']*(64-len(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")
# print(mnems)
import sys
import collections
pc = 0
labels = {}
local_labels = {}
# map of labelname -> (dest, ifn)
label_wants = collections.defaultdict(set)
local_label_wants = collections.defaultdict(set)
output = bytearray()
class Wrong(Exception):
def __init__(self, lineno, msg):
self.lineno = lineno
self.msg = msg
def __str__(self):
return f"{self.lineno}: {self.msg}"
def assemble_line(args, lineno):
match args:
case ["c", label] if label in labels:
emit_call(labels[label])
case ["c", label]:
label_wants[label].add((pc,call_instr))
emit(0)
case ['b', label] if label in local_labels:
emit_obranch(local_labels[label])
case ['b', label]:
local_label_wants[label].add((pc, obranch_instr))
case ['j', label] if label in local_labels:
emit_jump(local_labels[label])
case ['j', label]:
local_label_wants[label].add((pc, jump_instr))
case ["i", i1]:
assemble_line(["i", i1, "nop"], lineno)
case ["i", i1, i2]:
opc1 = mnems.index(i1)
opc2 = mnems.index(i2)
emit_instrs(opc1, opc2)
case ["l", val]:
emit_lit(int(val))
case [':', label]:
if label in labels:
raise Wrong(lineno, "label defined twice "+label)
labels[label] = pc
for (dest, ifn) in label_wants[label]:
put_at(dest, ifn(pc, dest))
del label_wants[label]
local_labels.clear()
for u,v in local_label_wants.items():
raise Wrong(lineno, "unfulfilled local label "+u)
local_label_wants.clear()
case ['%', label]:
if label in local_labels:
raise Wrong(lineno, "local label defined twice "+label)
local_labels[label] = pc
for (dest, ifn) in local_label_wants[label]:
put_at(dest, ifn(pc, dest))
del local_label_wants[label]
case []: pass
case _:
raise Wrong(lineno, "unknown wordtype")
def emit_call(addr):
emit(call_instr(addr))
def emit_instrs(opc1, opc2):
emit(instrs_instr(opc1, opc2))
def emit_lit(val):
emit(lit_instr(val))
def emit_obranch(addr):
emit(obranch_instr(addr, origin=pc))
def emit_jump(addr):
emit(jump_instr(addr, origin=pc))
def emit(word):
output.extend(word.to_bytes(2))
global pc
pc += 2
def put_at(addr, word):
output[addr:addr+1] = word.to_bytes(2)
def lit_instr(val):
return (val&0b1111111111111) | 0b0110000000000000
def instrs_instr(opc1, opc2):
return (opc1 << 7) | opc2
def call_instr(addr,*_):
return (addr>>1)|0b1000000000000000
def obranch_instr(target, origin):
rel = target - origin + 2048
return (rel&0b111111111111)|0b0101000000000000
def jump_instr(target, origin):
rel = target - origin + 2048
return (rel&0b111111111111)|0b0100000000000000
import sys
def main():
for ix, line in enumerate(sys.stdin):
line = line.strip()
args = line.split()
assemble_line(args, ix+1)
for u,v in label_wants.items():
print("unfulfilled global label",u, file=sys.stderr)
sys.stdout.buffer.write(output)
if __name__ == "__main__": main()
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