isle/tools/isledecomp/isledecomp/compare/asm/swap.py
2024-01-13 15:09:03 -05:00

81 lines
2.5 KiB
Python

import re
REGISTER_LIST = set(
[
"ax",
"bp",
"bx",
"cx",
"di",
"dx",
"eax",
"ebp",
"ebx",
"ecx",
"edi",
"edx",
"esi",
"esp",
"si",
"sp",
]
)
WORDS = re.compile(r"\w+")
def get_registers(line: str):
to_replace = []
# use words regex to find all matching positions:
for match in WORDS.finditer(line):
reg = match.group(0)
if reg in REGISTER_LIST:
to_replace.append((reg, match.start()))
return to_replace
def replace_register(
lines: list[str], start_line: int, reg: str, replacement: str
) -> list[str]:
return [
line.replace(reg, replacement) if i >= start_line else line
for i, line in enumerate(lines)
]
# Is it possible to make new_asm the same as original_asm by swapping registers?
def can_resolve_register_differences(original_asm, new_asm):
# Split the ASM on spaces to get more granularity, and so
# that we don't modify the original arrays passed in.
original_asm = [part for line in original_asm for part in line.split()]
new_asm = [part for line in new_asm for part in line.split()]
# Swapping ain't gonna help if the lengths are different
if len(original_asm) != len(new_asm):
return False
# Look for the mismatching lines
for i, original_line in enumerate(original_asm):
new_line = new_asm[i]
if new_line != original_line:
# Find all the registers to replace
to_replace = get_registers(original_line)
for replace in to_replace:
(reg, reg_index) = replace
replacing_reg = new_line[reg_index : reg_index + len(reg)]
if replacing_reg in REGISTER_LIST:
if replacing_reg != reg:
# Do a three-way swap replacing in all the subsequent lines
temp_reg = "&" * len(reg)
new_asm = replace_register(new_asm, i, replacing_reg, temp_reg)
new_asm = replace_register(new_asm, i, reg, replacing_reg)
new_asm = replace_register(new_asm, i, temp_reg, reg)
else:
# No replacement to do, different code, bail out
return False
# Check if the lines are now the same
for i, original_line in enumerate(original_asm):
if new_asm[i] != original_line:
return False
return True