diff --git a/src/game/data/data_020df0.c b/src/game/data/data_020df0.c
index 31faf3616..818c83a44 100644
--- a/src/game/data/data_020df0.c
+++ b/src/game/data/data_020df0.c
@@ -7091,7 +7091,7 @@ bool g_PortalStack[20] = {0};
 s32 g_PortalStackIndex = 0x00000000;
 u32 g_PortalMode = 0x00000000;
 u32 var8007fcb0 = 0x00000190;
-u32 var8007fcb4 = 0x00000000;
+f32 var8007fcb4 = 0;
 u32 var8007fcb8 = 0x00000000;
 u32 var8007fcbc = 0x00000000;
 
diff --git a/src/game/game_157db0.c b/src/game/game_157db0.c
index 688dae2a7..26686cda7 100644
--- a/src/game/game_157db0.c
+++ b/src/game/game_157db0.c
@@ -15873,6 +15873,44 @@ glabel var7f1b76c4
 /*  f164f98:	27bd0048 */ 	addiu	$sp,$sp,0x48
 );
 
+// regalloc in callee-save registers
+// The empty if-statements below narrow it down to just two swapped registers
+//s32 func0f164e8c(struct coord *arg0, struct coord *arg1)
+//{
+//	s32 bestportalnum = -1;
+//	s32 count = 0;
+//	f32 bestthing = F32_MAX;
+//	f32 thisthing;
+//	s32 i;
+//
+//	for (i = 0; g_Portals[i].unk00; i++) {
+//		if (func00017e30(i, arg0, arg1)) {
+//			thisthing = var8007fcb4;
+//
+//			if (thisthing < 0) {
+//				thisthing = -thisthing;
+//			}
+//
+//			if (thisthing < bestthing) {
+//				bestportalnum = i;
+//				bestthing = thisthing;
+//				count++;
+//
+//				if (i);
+//				if (bestportalnum);
+//			}
+//		}
+//
+//		if (i);
+//		if (bestportalnum);
+//	}
+//
+//	if (count);
+//	if (bestportalnum);
+//
+//	return bestportalnum;
+//}
+
 GLOBAL_ASM(
 glabel func0f164f9c
 /*  f164f9c:	00001825 */ 	or	$v1,$zero,$zero
diff --git a/src/include/constants.h b/src/include/constants.h
index ca412317a..e8a15608d 100644
--- a/src/include/constants.h
+++ b/src/include/constants.h
@@ -8,6 +8,7 @@
 
 #define osSyncPrintf
 
+#define F32_MAX 3.4028234663853E+38 // 7f7fffff
 #define S32_MAX 2147483647
 #define U32_MAX 4294967295
 
diff --git a/src/include/game/data/data_020df0.h b/src/include/game/data/data_020df0.h
index a8fa54f79..b624bdc57 100644
--- a/src/include/game/data/data_020df0.h
+++ b/src/include/game/data/data_020df0.h
@@ -280,7 +280,7 @@ extern bool g_PortalStack[20];
 extern s32 g_PortalStackIndex;
 extern u32 g_PortalMode;
 extern u32 var8007fcb0;
-extern u32 var8007fcb4;
+extern f32 var8007fcb4;
 extern struct stagetableentry g_Stages[61];
 extern u32 var80081018;
 extern u32 var80081058;
diff --git a/src/include/lib/lib_16110.h b/src/include/lib/lib_16110.h
index 9a42f4812..47285b886 100644
--- a/src/include/lib/lib_16110.h
+++ b/src/include/lib/lib_16110.h
@@ -40,7 +40,7 @@ u32 func00017c2c(void);
 u32 func00017cbc(void);
 u32 func00017ce0(void);
 u32 func00017dc4(void);
-u32 func00017e30(void);
+bool func00017e30(s32 portalnum, struct coord *arg1, struct coord *arg2);
 u32 func00018148(void);
 void func000185d0(struct defaultobj *obj, s32 arg1);
 u32 func00018680(void);