Decomp the fixed-point helper cluster at the end of main_020504BC.s

sub_02050EBC, SubFixedPoint, sub_02050F78, sub_02050FF8 and
BinToDecFixedPoint are the last five functions in asm/main_020504BC.s and
all operate on struct fixed_point (106 instructions). The next object in
main.lsf is src/number_util.o, which already holds their sibling
CeilFixedPoint, so extract_function.py merges rather than splits and
main.lsf is unchanged. They are landed in reverse address order so each
prepends above the last, leaving number_util.c in ascending address order
with CeilFixedPoint last.

sub_02050EBC and sub_02050F78 keep their sub_<addr> names - this is
decompilation, not identification.

A 4-byte struct fixed_point is passed and returned by value in r0, packed
as integer | fractional << 16. The stmdb sp!, {r0, r1, r2, r3} at entry is
MWCC giving the argument registers stack homes so a by-value struct
parameter can be addressed, and writing to the parameter reuses that home,
which is why SubFixedPoint and sub_02050EBC modify their first argument
and return it. The caller-side sub rX, sp, #4 idiom around these calls is
compiler-generated, not a source construct: src/dungeon_ai_movement.c
already emits it from a plain CeilFixedPoint(pokemon_info->belly).

None of the five blocks carries a region directive, so one source serves
all three regions.

Authored by Claude (Opus 5) under human direction. Confirmed by a matching
build: build/pmdsky.us/pmdsky.us.nds: OK.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

asm/include/main_020504BC.inc

@@ -1,10 +1,8 @@
 #pragma once
-.public _0209E6BD
-.public _022AB924
 .public ADVENTURE_LOG_PTR
 .public ARM9_UNKNOWN_DATA__NA_209E6BC
-.public ComputeSpecialCounters
 .public CONVERSION2_TYPE_TABLE
+.public ComputeSpecialCounters
 .public Copy16BitsFrom
 .public Copy16BitsTo
 .public CopyNStringFromId
@@ -16,3 +14,5 @@
 .public StrncpySimpleNoPad
 .public StrncpySimpleNoPadSafe
 .public TEAM_NAME
+.public _0209E6BD
+.public _022AB924

asm/main_020504BC.s

@@ -879,130 +879,3 @@ sub_02050E8C: ; 0x02050E8C
 	bl CopyBitsFrom
 	ldmia sp!, {r3, r4, r5, pc}
 	arm_func_end sub_02050E8C
-
-	arm_func_start sub_02050EBC
-sub_02050EBC: ; 0x02050EBC
-	stmdb sp!, {r0, r1, r2, r3}
-	ldrsh r3, [sp, #2]
-	ldrsh r0, [sp, #6]
-	ldrsh r2, [sp]
-	ldrsh r1, [sp, #4]
-	add r0, r3, r0
-	strh r0, [sp, #2]
-	ldrsh r0, [sp, #2]
-	add r1, r2, r1
-	strh r1, [sp]
-	cmp r0, #0x3e8
-	subge r0, r0, #0x3e8
-	ldrgesh r1, [sp]
-	strgeh r0, [sp, #2]
-	addge r0, r1, #1
-	strgeh r0, [sp]
-	ldrh r1, [sp, #2]
-	ldrh r0, [sp]
-	orr r0, r0, r1, lsl #16
-	add sp, sp, #0x10
-	bx lr
-	arm_func_end sub_02050EBC
-
-	arm_func_start SubFixedPoint
-SubFixedPoint: ; 0x02050F10
-	stmdb sp!, {r0, r1, r2, r3}
-	ldrsh r3, [sp, #2]
-	ldrsh r0, [sp, #6]
-	ldrsh r2, [sp]
-	ldrsh r1, [sp, #4]
-	sub r0, r3, r0
-	strh r0, [sp, #2]
-	ldrsh r0, [sp, #2]
-	sub r1, r2, r1
-	strh r1, [sp]
-	cmp r0, #0
-	addlt r0, r0, #0x3e8
-	ldrltsh r1, [sp]
-	strlth r0, [sp, #2]
-	sublt r0, r1, #1
-	strlth r0, [sp]
-	ldrsh r0, [sp]
-	cmp r0, #0
-	movlt r0, #0
-	strlth r0, [sp, #2]
-	strlth r0, [sp]
-	ldrh r1, [sp, #2]
-	ldrh r0, [sp]
-	orr r0, r0, r1, lsl #16
-	add sp, sp, #0x10
-	bx lr
-	arm_func_end SubFixedPoint
-
-	arm_func_start sub_02050F78
-sub_02050F78: ; 0x02050F78
-	stmdb sp!, {r0, r1, r2, r3}
-	stmdb sp!, {r3}
-	sub sp, sp, #4
-	ldrsh r1, [sp, #8]
-	ldrsh r0, [sp, #0xc]
-	cmp r1, r0
-	ldrgth r1, [sp, #0xe]
-	ldrgth r0, [sp, #0xc]
-	orrgt r0, r0, r1, lsl #16
-	bgt _02050FE8
-	ldrlth r1, [sp, #0xa]
-	ldrlth r0, [sp, #8]
-	orrlt r0, r0, r1, lsl #16
-	blt _02050FE8
-	ldrsh r1, [sp, #0xa]
-	ldrsh r0, [sp, #0xe]
-	cmp r1, r0
-	ldrgth r1, [sp, #0xc]
-	ldrgth r0, [sp, #0xe]
-	strgth r1, [sp]
-	strgth r0, [sp, #2]
-	ldrleh r1, [sp, #8]
-	ldrleh r0, [sp, #0xa]
-	strleh r1, [sp]
-	strleh r0, [sp, #2]
-	ldrh r1, [sp, #2]
-	ldrh r0, [sp]
-	orr r0, r0, r1, lsl #16
-_02050FE8:
-	add sp, sp, #4
-	ldmia sp!, {r3}
-	add sp, sp, #0x10
-	bx lr
-	arm_func_end sub_02050F78
-
-	arm_func_start sub_02050FF8
-sub_02050FF8: ; 0x02050FF8
-	stmdb sp!, {r3}
-	sub sp, sp, #4
-	strh r0, [sp]
-	ldrh r0, [sp]
-	mov r1, #0
-	strh r1, [sp, #2]
-	orr r0, r0, r1, lsl #16
-	add sp, sp, #4
-	ldmia sp!, {r3}
-	bx lr
-	arm_func_end sub_02050FF8
-
-	arm_func_start BinToDecFixedPoint
-BinToDecFixedPoint: ; 0x02051020
-	stmdb sp!, {r3}
-	sub sp, sp, #4
-	ldr r2, [r0, #4]
-	mov r1, #0x3e8
-	mov r0, r2, lsl #0x10
-	mov r0, r0, lsr #0x10
-	mul r1, r0, r1
-	mov r2, r2, lsr #0x10
-	mov r0, r1, lsr #0x10
-	strh r2, [sp]
-	strh r0, [sp, #2]
-	ldrh r1, [sp, #2]
-	ldrh r0, [sp]
-	orr r0, r0, r1, lsl #16
-	add sp, sp, #4
-	ldmia sp!, {r3}
-	bx lr
-	arm_func_end BinToDecFixedPoint

include/number_util.h

@@ -3,6 +3,11 @@
 
 #include "util.h"
 
+struct fixed_point sub_02050EBC(struct fixed_point a, struct fixed_point b);
+struct fixed_point SubFixedPoint(struct fixed_point a, struct fixed_point b);
+struct fixed_point sub_02050F78(struct fixed_point a, struct fixed_point b);
+struct fixed_point sub_02050FF8(s16 value);
+struct fixed_point BinToDecFixedPoint(struct fixed_point_64 *val);
 s32 CeilFixedPoint(struct fixed_point val_fp);
 
 #endif //PMDSKY_NUMBER_UTIL_H

src/number_util.c

@@ -1,5 +1,67 @@
 #include "number_util.h"
 
+struct fixed_point sub_02050EBC(struct fixed_point a, struct fixed_point b)
+{
+    a.fractional += b.fractional;
+    a.integer += b.integer;
+    if (a.fractional >= 1000)
+    {
+        a.integer++;
+        a.fractional -= 1000;
+    }
+    return a;
+}
+
+struct fixed_point SubFixedPoint(struct fixed_point a, struct fixed_point b)
+{
+    a.fractional -= b.fractional;
+    a.integer -= b.integer;
+    if (a.fractional < 0)
+    {
+        a.integer--;
+        a.fractional += 1000;
+    }
+    if (a.integer < 0)
+    {
+        a.fractional = 0;
+        a.integer = 0;
+    }
+    return a;
+}
+
+struct fixed_point sub_02050F78(struct fixed_point a, struct fixed_point b)
+{
+    struct fixed_point result;
+
+    if (a.integer > b.integer)
+        return b;
+    if (a.integer < b.integer)
+        return a;
+
+    if (a.fractional > b.fractional)
+        result = b;
+    else
+        result = a;
+
+    return result;
+}
+
+struct fixed_point sub_02050FF8(s16 value)
+{
+    struct fixed_point result;
+    result.integer = value;
+    result.fractional = 0;
+    return result;
+}
+
+struct fixed_point BinToDecFixedPoint(struct fixed_point_64 *val)
+{
+    struct fixed_point result;
+    result.integer = val->lower >> 16;
+    result.fractional = ((val->lower & 0xFFFF) * 1000) >> 16;
+    return result;
+}
+
 s32 CeilFixedPoint(struct fixed_point val_fp)
 {
     if (val_fp.integer == 0)