Decomp IntToFixedPoint64

asm/main_02001CB0.s

@@ -1,24 +1,8 @@
 	.include "asm/macros.inc"
-	.include "main_02001C80.inc"
+	.include "main_02001CB0.inc"
 
 	.text
 
-	arm_func_start IntToFixedPoint64
-IntToFixedPoint64: ; 0x02001C80
-	mov r2, #0x10000
-	rsb r2, r2, #0
-	and r3, r1, r2
-	mov r3, r3, lsr #0x10
-	str r3, [r0]
-	mov r3, r1, lsl #0x10
-	str r3, [r0, #4]
-	tst r1, #0x8000
-	ldrne r1, [r0]
-	orrne r1, r1, r2
-	strne r1, [r0]
-	bx lr
-	arm_func_end IntToFixedPoint64
-
 	arm_func_start FixedPoint64ToInt
 FixedPoint64ToInt: ; 0x02001CB0
 	ldmia r0, {r1, r2}

include/main_02001BB4.h

@@ -4,5 +4,6 @@
 #include "util.h"
 
 u32 sub_02001BB4(s32 x, s32 y);
+void IntToFixedPoint64(struct fixed_point_64* out, s32 x);
 
 #endif //PMDSKY_MAIN_02001BB4_H

include/util.h

@@ -32,6 +32,13 @@ struct fixed_point {
     s16 fractional;
 };
 
+// 64-bit signed fixed-point number with 16 fraction bits.
+// Represents the number ((upper << 16) + (lower >> 16) + (lower & 0xFFFF) * 2^-16)
+struct fixed_point_64 {
+    s32 upper;  // sign bit, plus the 31 most significant integer bits
+    u32 lower; // the 32 least significant bits (16 integer + 16 fraction)
+};
+
 // Compares two numbers and return the minimum
 #define MIN(A, B) ((A > B) ? B : A)
 

main.lsf

@@ -21,7 +21,7 @@ Static main
 	Object src/main_02001A54.o
 	Object asm/main_02001B0C.o
 	Object src/main_02001BB4.o
-	Object asm/main_02001C80.o
+	Object asm/main_02001CB0.o
 	Object src/main_0200224C.o
 	Object asm/main_020022C4.o
 	Object src/main_0200330C.o

src/main_02001BB4.c

@@ -61,3 +61,12 @@ u32 sub_02001BB4(s32 x, s32 y)
     
     return var_r8;
 }
+
+void IntToFixedPoint64(struct fixed_point_64* out, s32 x)
+{
+    out->upper = (u32) (x & ~0xFFFF) >> 0x10;
+    out->lower = x << 0x10;
+    if (x & 0x8000) {
+        out->upper = out->upper | ~0xFFFF;
+    }
+}