Disassembly performance improvements (speed, RAM) (#478)

* Improve disasm.py RAM usage using `bisect`

This is based on AngheloAlf's work in PR #477, but uses the built-in
library `bisect` instead of adding an external dependency.

* Caching vrom_variables for ~25% faster disasm.py

tools/disasm/disasm.py

@@ -1,6 +1,7 @@
 #!/usr/bin/env python3
 
 import argparse, ast, math, os, re, struct
+import bisect
 from mips_isa import *
 from multiprocessing import Pool
 
@@ -88,11 +89,11 @@ multiply_referenced_rodata = set() # rodata with more than 1 reference outside o
 files = set()          # vram start of file
 
 vrom_variables = list() # (name,addr)
+vrom_addrs = set()     # set of addrs from vrom_variables, for faster lookup
 
 functions_ast = None
 variables_ast = None
-
-vars_cache = {} # (address: variable + addend)
+variable_addrs = None
 
 def proper_name(symbol, in_data=False, is_symbol=True):
     # hacks
@@ -116,7 +117,7 @@ def proper_name(symbol, in_data=False, is_symbol=True):
         return functions_ast[symbol][0]
     elif symbol in variables_ast.keys():
         return variables_ast[symbol][0]
-    elif symbol in [addr for _,addr in vrom_variables]:
+    elif symbol in vrom_addrs:
         # prefer "start" vrom symbols
         if symbol in [addr for name,addr in vrom_variables if "SegmentRomStart" in name]:
             return [name for name,addr in vrom_variables if "SegmentRomStart" in name and addr == symbol][0]
@@ -124,8 +125,15 @@ def proper_name(symbol, in_data=False, is_symbol=True):
             return [name for name,addr in vrom_variables if addr == symbol][0]
 
     # addends
-    if is_symbol and symbol in vars_cache.keys():
-        return vars_cache[symbol]
+    if is_symbol:
+        symbol_index = bisect.bisect(variable_addrs, symbol)
+        if symbol_index:
+            vram_addr = variable_addrs[symbol_index-1]
+            symbol_name, _, _, symbol_size = variables_ast[vram_addr]
+
+            if vram_addr < symbol < vram_addr + symbol_size:
+                return f"{symbol_name} + 0x{symbol-vram_addr:X}"
+
 
     # generated names
     if symbol in functions and not in_data:
@@ -142,7 +150,7 @@ def proper_name(symbol, in_data=False, is_symbol=True):
 
 def lookup_name(symbol, word):
     # hacks for vrom variables in data
-    if word in [addr for _,addr in vrom_variables]:
+    if word in vrom_addrs:
         if word == 0: # no makerom segment start
             return "0x00000000"
         if symbol in [0x801AE4A0, # effect table
@@ -1112,13 +1120,8 @@ with open("tools/disasm/functions.txt", "r") as infile:
 with open("tools/disasm/variables.txt", "r") as infile:
     variables_ast = ast.literal_eval(infile.read())
 
-# Precompute variable addends for all variables, this uses a lot of memory but the lookups later are fast
+# Find floats, doubles, and strings
 for var in sorted(variables_ast.keys()):
-    for i in range(var, var + variables_ast[var][3], 1):
-        addend = i - var
-        assert addend >= 0
-        vars_cache.update({i : f"{variables_ast[var][0]}" + (f" + 0x{addend:X}" if addend > 0 else "")})
-    # also add to floats, doubles & strings
     var_type = variables_ast[var][1]
 
     if var_type == "f64":
@@ -1164,6 +1167,9 @@ for segment in files_spec:
     if segment[3][-1][1] not in variables_ast:
         variables_ast.update({segment[3][-1][1] : (f"_{segment[0]}SegmentEnd","u8","[]",0x1)})
 
+# Construct variable_addrs, now that variable_addrs is fully constructed
+variable_addrs = sorted(variables_ast.keys())
+
 pool = Pool(jobs)
 # Find symbols for each segment
 for segment in files_spec:
@@ -1219,6 +1225,9 @@ for segment in files_spec:
                 i += 1
                 dmadata_entry = dmadata[i*0x10:(i+1)*0x10]
 
+# Construct vrom_addrs, now that vrom_variables is fully constructed
+vrom_addrs = {addr for _, addr in vrom_variables}
+
 def disassemble_makerom(segment):
     os.makedirs(f"{ASM_OUT}/makerom/", exist_ok=True)
     rom_header = segment[3][0][4]

tools/disasm/variables.txt

@@ -3890,13 +3890,7 @@
     0x801E3BB0:("D_801E3BB0","UNK_TYPE1","",0x1),
     0x801E3F40:("gJpegUCodeData","UNK_TYPE1","",0x1),
     0x801E3FA0:("D_801E3FA0","UNK_TYPE1","",0x1),
-    0x801E3FB0:("sEffTable","EffTables","",0x98e0),
-    0x801E4514:("D_801E4514","UNK_TYPE1","",0x1),
-    0x801E4E08:("D_801E4E08","UNK_TYPE1","",0x1),
-    0x801E531C:("D_801E531C","UNK_TYPE1","",0x1),
-    0x801E69E0:("D_801E69E0","UNK_TYPE1","",0x1),
-    0x801E9AA0:("D_801E9AA0","UNK_TYPE1","",0x1),
-    0x801ED4C0:("D_801ED4C0","UNK_TYPE1","",0x1),
+    0x801E3FB0:("sEffTable","EffTables","",0x98E0),
     0x801ED890:("D_801ED890","UNK_TYPE1","",0x1),
     0x801ED894:("D_801ED894","UNK_TYPE1","",0x1),
     0x801ED8A0:("D_801ED8A0","UNK_TYPE1","",0x1),