diff --git a/src/scroll.c b/src/scroll.c
index c4c43f77e..abb3c136d 100644
--- a/src/scroll.c
+++ b/src/scroll.c
@@ -419,64 +419,43 @@ void sub_080801BC(RoomControls* controls) {
 }
 
 u32 sub_08080278(void) {
-    u32 width;
-    u32 height;
-    u32 tilePos;
-    u16* bottomMapDataPtr;
-    u16* topMapDataPtr;
-    u32 result;
-    u16* bottomMapDataClonePtr;
-    u16* topMapDataClonePtr;
-    u32 indexX;
-    FORCE_REGISTER(u32 indexY, r10);
-    int iVar10;
-    u16* ptr1;
-    u32 tmp;
+    u16* ptr1 = (u16*)gUnk_02022830;
+    u16* mapBottomData = gMapBottom.mapData;
+    u16* mapTopData = gMapTop.mapData;
+    u16* mapBottomDataClone = gMapBottom.mapDataClone;
+    u16* mapTopDataClone = gMapTop.mapDataClone;
+    u32 width = gRoomControls.width >> 4;
+    u32 height = (gRoomControls.height >> 4) << 6;
 
-    ptr1 = (u16*)gUnk_02022830;
-    width = gRoomControls.width >> 4;
-    height = (gRoomControls.height >> 4) << 6;
-    result = 0;
-    indexY = 0;
-    if (result < height) {
-        iVar10 = 0;
-        do {
-            indexX = 0;
-            if (indexX < width) {
-                topMapDataPtr = (u16*)((int)gMapTop.mapData + iVar10);
-                topMapDataClonePtr = (u16*)((int)gMapTop.mapDataClone + iVar10);
-                bottomMapDataPtr = (u16*)((int)gMapBottom.mapData + iVar10);
-                bottomMapDataClonePtr = (u16*)((int)gMapBottom.mapDataClone + iVar10);
-                while (indexX < width) {
-                    tilePos = indexY + indexX;
-                    if ((bottomMapDataClonePtr[0] != bottomMapDataPtr[0]) && (bottomMapDataPtr[0] < 0x4000)) {
-                        ptr1[0] = tilePos | 0x4000;
-                        ptr1[1] = bottomMapDataPtr[0];
-                        ptr1 += 2;
-                        result++;
-                        if (result >= 0x600) {
-                            return result;
-                        }
+    u32 result;
+    u32 y, x;
+
+    for (result = 0, y = 0; y < height; y += 0x40) {
+        for (x = 0; x < width; x++) {
+            u32 tilePos = y + x;
+            if (mapBottomDataClone[tilePos] != mapBottomData[tilePos]) {
+                if (mapBottomData[tilePos] < 0x4000) {
+                    ptr1[0] = tilePos | 0x4000;
+                    ptr1[1] = mapBottomData[tilePos];
+                    ptr1 += 2;
+                    result++;
+                    if (result >= 0x600) {
+                        return result;
                     }
-                    if ((topMapDataClonePtr[0] != topMapDataPtr[0]) && (topMapDataPtr[0] < 0x4000)) {
-                        ptr1[0] = tilePos | 0x8000;
-                        ptr1[1] = topMapDataPtr[0];
-                        ptr1 += 2;
-                        result++;
-                        if (result >= 0x800) {
-                            return result;
-                        }
+                }
+            }
+            if (mapTopDataClone[tilePos] != mapTopData[tilePos]) {
+                if (mapTopData[tilePos] < 0x4000) {
+                    ptr1[0] = tilePos | 0x8000;
+                    ptr1[1] = mapTopData[tilePos];
+                    ptr1 += 2;
+                    result++;
+                    if (result >= 0x800) {
+                        return result;
                     }
-                    topMapDataPtr++;
-                    topMapDataClonePtr++;
-                    bottomMapDataPtr++;
-                    bottomMapDataClonePtr++;
-                    indexX++;
                 }
             }
-            iVar10 += 0x80;
-            indexY += 0x40;
-        } while (indexY < height);
+        }
     }
     return result;
 }