1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
|
#!/usr/bin/env python3
from mnems import mnems
# 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(0x8000)
case ['b', label] if label in local_labels:
emit_obranch(local_labels[label])
case ['b', label]:
local_label_wants[label].add((pc, obranch_instr))
emit(0x5000)
case ['j', label] if label in local_labels:
emit_jump(local_labels[label])
case ['j', label]:
local_label_wants[label].add((pc, jump_instr))
emit(0x4000)
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,16))
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):
oldlen = len(output)
output.extend(word.to_bytes(2))
global pc
pc += 2
assert len(output) == 2 + oldlen, "beeite"
def put_at(addr, word):
assert addr % 2 == 0, "ooeu"
output[addr:addr+2] = 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()
|
