up through state_to_direction, which is nonmatching (help, registers are misbehaving)

asm/field_map_obj.s

@@ -1353,90 +1353,6 @@ sub_805FD08: @ 805FD08
 
 	.section .text_805fd18
 
-	thumb_func_start GetOppositeDirection
-GetOppositeDirection: @ 8060B90
-	push {r4,lr}
-	sub sp, 0x8
-	lsls r0, 24
-	lsrs r4, r0, 24
-	ldr r1, _08060BB4 @ =gUnknown_0837574F
-	mov r0, sp
-	movs r2, 0x8
-	bl memcpy
-	subs r1, r4, 0x1
-	lsls r0, r1, 24
-	lsrs r0, 24
-	cmp r0, 0x7
-	bhi _08060BB8
-	mov r2, sp
-	adds r0, r2, r1
-	ldrb r0, [r0]
-	b _08060BBA
-	.align 2, 0
-_08060BB4: .4byte gUnknown_0837574F
-_08060BB8:
-	adds r0, r4, 0
-_08060BBA:
-	add sp, 0x8
-	pop {r4}
-	pop {r1}
-	bx r1
-	thumb_func_end GetOppositeDirection
-
-	thumb_func_start zffu_offset_calc
-zffu_offset_calc: @ 8060BC4
-	lsls r0, 24
-	lsls r1, 24
-	lsrs r1, 24
-	ldr r2, _08060BD8 @ =gUnknown_08375757
-	lsrs r0, 22
-	subs r0, 0x5
-	adds r1, r0
-	adds r1, r2
-	ldrb r0, [r1]
-	bx lr
-	.align 2, 0
-_08060BD8: .4byte gUnknown_08375757
-	thumb_func_end zffu_offset_calc
-
-	thumb_func_start state_to_direction
-state_to_direction: @ 8060BDC
-	push {r4,lr}
-	lsls r0, 24
-	lsrs r4, r0, 24
-	lsls r1, 24
-	lsrs r1, 24
-	adds r0, r1, 0
-	lsls r2, 24
-	lsrs r2, 24
-	cmp r1, 0
-	beq _08060BFC
-	cmp r2, 0
-	beq _08060BFC
-	cmp r1, 0x4
-	bhi _08060BFC
-	cmp r2, 0x4
-	bls _08060C00
-_08060BFC:
-	movs r0, 0
-	b _08060C12
-_08060C00:
-	adds r1, r2, 0
-	bl zffu_offset_calc
-	ldr r2, _08060C18 @ =gUnknown_08375767
-	lsls r1, r4, 2
-	subs r1, 0x5
-	adds r0, r1
-	adds r0, r2
-	ldrb r0, [r0]
-_08060C12:
-	pop {r4}
-	pop {r1}
-	bx r1
-	.align 2, 0
-_08060C18: .4byte gUnknown_08375767
-	thumb_func_end state_to_direction
-
 	thumb_func_start FieldObjectExecSpecialAnim
 FieldObjectExecSpecialAnim: @ 8060C1C
 	push {r4,lr}

include/field_map_obj.h

@@ -76,6 +76,10 @@ extern const u8 gUnknown_08375574[4];
 extern const u8 gUnknown_08375584[4];
 
 extern const u8 gUnknown_0837567B[9];
+extern const u8 gUnknown_0837574F[8];
+
+extern const u8 gUnknown_08375757[4][4];
+extern const u8 gUnknown_08375767[4][4];
 
 extern const struct Coords16 gDirectionToVector[];
 

src/field_map_obj.c

@@ -4064,3 +4064,73 @@ u8 sub_8060B64(u8 index)
     }
     return directions[index];
 }
+
+u8 GetOppositeDirection(u8 direction)
+{
+    u8 directions[8];
+    memcpy(directions, gUnknown_0837574F, 8);
+    if (direction == 0 || direction > 8)
+    {
+        return direction;
+    }
+    return directions[direction - 1];
+}
+
+int zffu_offset_calc(u8 a0, u8 a1)
+{
+    return gUnknown_08375757[a0 - 1][a1 - 1];
+}
+
+#ifdef NONMATCHING
+u8 state_to_direction(u8 a0, u8 a1, u8 a2)
+{
+    int zffuOffset;
+    if (a1 == 0 || a2 == 0 || a1 > 4 || a2 > 4)
+    {
+        return 0;
+    }
+    zffuOffset = zffu_offset_calc(a1, a2);
+    return gUnknown_08375767[a0 - 1][zffuOffset - 1];
+}
+#else
+__attribute__((naked))
+u8 state_to_direction(u8 a0, u8 a1, u8 a2)
+{
+    asm(".syntax unified\n\
+	push {r4,lr}\n\
+	lsls r0, 24\n\
+	lsrs r4, r0, 24\n\
+	lsls r1, 24\n\
+	lsrs r1, 24\n\
+	adds r0, r1, 0\n\
+	lsls r2, 24\n\
+	lsrs r2, 24\n\
+	cmp r1, 0\n\
+	beq _08060BFC\n\
+	cmp r2, 0\n\
+	beq _08060BFC\n\
+	cmp r1, 0x4\n\
+	bhi _08060BFC\n\
+	cmp r2, 0x4\n\
+	bls _08060C00\n\
+_08060BFC:\n\
+	movs r0, 0\n\
+	b _08060C12\n\
+_08060C00:\n\
+	adds r1, r2, 0\n\
+	bl zffu_offset_calc\n\
+	ldr r2, _08060C18 @ =gUnknown_08375767\n\
+	lsls r1, r4, 2\n\
+	subs r1, 0x5\n\
+	adds r0, r1\n\
+	adds r0, r2\n\
+	ldrb r0, [r0]\n\
+_08060C12:\n\
+	pop {r4}\n\
+	pop {r1}\n\
+	bx r1\n\
+	.align 2, 0\n\
+_08060C18: .4byte gUnknown_08375767\n\
+.syntax divided\n");
+}
+#endif