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
|
# Copyright © 2022 degasus <markus@selfnet.de>
# This work is free. You can redistribute it and/or modify it under the
# terms of the Do What The Fuck You Want To Public License, Version 2,
# as published by Sam Hocevar. See http://www.wtfpl.net/ for more details.
from itertools import product
# The primitive instructions
OPS = {
'ir.BitwiseAnd({}, {})' : (2, 1, lambda a,b: a&b),
'ir.BitwiseOr({}, {})' : (2, 1, lambda a,b: a|b),
'ir.BitwiseXor({}, {})' : (2, 1, lambda a,b: a^b),
'ir.BitwiseNot({})' : (1, 0.1, lambda a: (~a) & 255), # Only tiny cost, as this can often inlined in other instructions
}
# Our database of combination of instructions
optimized_calls = {}
def cmp(lhs, rhs):
if lhs is None: # new entry
return True
if lhs[3] > rhs[3]: # costs
return True
if lhs[3] < rhs[3]: # costs
return False
if len(lhs[0]) > len(rhs[0]): # string len
return True
if len(lhs[0]) < len(rhs[0]): # string len
return False
if lhs[0] > rhs[0]: # string sorting
return True
if lhs[0] < rhs[0]: # string sorting
return False
assert lhs == rhs, "redundant instruction, bug in brute force"
return False
def register(imm, instruction, count, latency):
# Use the sum of instruction count and latency as costs to evaluate which combination is best
costs = count + latency
old = optimized_calls.get(imm, None)
new = (instruction, count, latency, costs)
# Update if new or better
if cmp(old, new):
optimized_calls[imm] = new
return True
return False
# Constants: 0, 1 (for free)
register(0, 'ir.Imm32(0)', 0, 0)
register(255, 'ir.Imm32(0xFFFFFFFF)', 0, 0)
# Inputs: a, b, c (for free)
ta = 0xF0
tb = 0xCC
tc = 0xAA
inputs = {
ta : 'a',
tb : 'b',
tc : 'c',
}
for imm, instruction in inputs.items():
register(imm, instruction, 0, 0)
register((~imm) & 255, 'ir.BitwiseNot({})'.format(instruction), 0.099, 0.099) # slightly cheaper NEG on inputs
# Try to combine two values from the db with an instruction.
# If it is better than the old method, update it.
while True:
registered = 0
calls_copy = optimized_calls.copy()
for OP, (argc, cost, f) in OPS.items():
for args in product(calls_copy.items(), repeat=argc):
# unpack(transponse) the arrays
imm = [arg[0] for arg in args]
value = [arg[1][0] for arg in args]
count = [arg[1][1] for arg in args]
latency = [arg[1][2] for arg in args]
registered += register(
f(*imm),
OP.format(*value),
sum(count) + cost,
max(latency) + cost)
if registered == 0:
# No update at all? So terminate
break
# Hacky output. Please improve me to output valid C++ instead.
s = """ case {imm}:
return {op};"""
for imm in range(256):
print(s.format(imm=imm, op=optimized_calls[imm][0]))
|
