Index: src/btree.c
==================================================================
--- src/btree.c
+++ src/btree.c
@@ -5420,12 +5420,11 @@
     *pRC = rc;
     return;
   }
   endPtr = &data[pPage->cellOffset + 2*pPage->nCell - 2];
   while( ptr<endPtr ){
-    ptr[0] = ptr[2];
-    ptr[1] = ptr[3];
+    *(u16*)ptr = *(u16*)&ptr[2];
     ptr += 2;
   }
   pPage->nCell--;
   put2byte(&data[hdr+3], pPage->nCell);
   pPage->nFree += 2;
@@ -5462,10 +5461,11 @@
   int end;          /* First byte past the last cell pointer in data[] */
   int ins;          /* Index in data[] where new cell pointer is inserted */
   int cellOffset;   /* Address of first cell pointer in data[] */
   u8 *data;         /* The content of the whole page */
   u8 *ptr;          /* Used for moving information around in data[] */
+  u8 *endPtr;       /* End of the loop */
 
   int nSkip = (iChild ? 4 : 0);
 
   if( *pRC ) return;
 
@@ -5512,13 +5512,15 @@
     pPage->nFree -= (u16)(2 + sz);
     memcpy(&data[idx+nSkip], pCell+nSkip, sz-nSkip);
     if( iChild ){
       put4byte(&data[idx], iChild);
     }
-    for(j=end, ptr=&data[j]; j>ins; j-=2, ptr-=2){
-      ptr[0] = ptr[-2];
-      ptr[1] = ptr[-1];
+    ptr = &data[end];
+    endPtr = &data[ins];
+    while( ptr>endPtr ){
+      *(u16*)ptr = *(u16*)&ptr[-2];
+      ptr -= 2;
     }
     put2byte(&data[ins], idx);
     put2byte(&data[pPage->hdrOffset+3], pPage->nCell);
 #ifndef SQLITE_OMIT_AUTOVACUUM
     if( pPage->pBt->autoVacuum ){
@@ -5559,14 +5561,15 @@
   assert( get2byteNotZero(&data[hdr+5])==nUsable );
 
   pCellptr = &data[pPage->cellOffset + nCell*2];
   cellbody = nUsable;
   for(i=nCell-1; i>=0; i--){
+    u16 sz = aSize[i];
     pCellptr -= 2;
-    cellbody -= aSize[i];
+    cellbody -= sz;
     put2byte(pCellptr, cellbody);
-    memcpy(&data[cellbody], apCell[i], aSize[i]);
+    memcpy(&data[cellbody], apCell[i], sz);
   }
   put2byte(&data[hdr+3], nCell);
   put2byte(&data[hdr+5], cellbody);
   pPage->nFree -= (nCell*2 + nUsable - cellbody);
   pPage->nCell = (u16)nCell;