Index: src/expr.c
==================================================================
--- src/expr.c
+++ src/expr.c
@@ -3610,10 +3610,15 @@
       int i;                 /* Loop counter */
       sqlite3 *db = pParse->db;  /* The database connection */
       u8 enc = ENC(db);      /* The text encoding used by this database */
       CollSeq *pColl = 0;    /* A collating sequence */
 
+      if( ConstFactorOk(pParse) && sqlite3ExprIsConstantNotJoin(pExpr) ){
+        /* SQL function can be expensive. So try to move constant functions
+        ** out of the inner loop, even if that means an extra OP_Copy. */
+        return sqlite3ExprCodeAtInit(pParse, pExpr, -1);
+      }
       assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
       if( ExprHasProperty(pExpr, EP_TokenOnly) ){
         pFarg = 0;
       }else{
         pFarg = pExpr->x.pList;
@@ -3990,28 +3995,44 @@
   return inReg;
 }
 
 /*
 ** Factor out the code of the given expression to initialization time.
+**
+** If regDest>=0 then the result is always stored in that register and the
+** result is not reusable.  If regDest<0 then this routine is free to 
+** store the value whereever it wants.  The register where the expression 
+** is stored is returned.  When regDest<0, two identical expressions will
+** code to the same register.
 */
-void sqlite3ExprCodeAtInit(
+int sqlite3ExprCodeAtInit(
   Parse *pParse,    /* Parsing context */
   Expr *pExpr,      /* The expression to code when the VDBE initializes */
-  int regDest,      /* Store the value in this register */
-  u8 reusable       /* True if this expression is reusable */
+  int regDest       /* Store the value in this register */
 ){
   ExprList *p;
   assert( ConstFactorOk(pParse) );
   p = pParse->pConstExpr;
+  if( regDest<0 && p ){
+    struct ExprList_item *pItem;
+    int i;
+    for(pItem=p->a, i=p->nExpr; i>0; pItem++, i--){
+      if( pItem->reusable && sqlite3ExprCompare(pItem->pExpr,pExpr,-1)==0 ){
+        return pItem->u.iConstExprReg;
+      }
+    }
+  }
   pExpr = sqlite3ExprDup(pParse->db, pExpr, 0);
   p = sqlite3ExprListAppend(pParse, p, pExpr);
   if( p ){
      struct ExprList_item *pItem = &p->a[p->nExpr-1];
+     pItem->reusable = regDest<0;
+     if( regDest<0 ) regDest = ++pParse->nMem;
      pItem->u.iConstExprReg = regDest;
-     pItem->reusable = reusable;
   }
   pParse->pConstExpr = p;
+  return regDest;
 }
 
 /*
 ** Generate code to evaluate an expression and store the results
 ** into a register.  Return the register number where the results
@@ -4030,23 +4051,12 @@
   pExpr = sqlite3ExprSkipCollate(pExpr);
   if( ConstFactorOk(pParse)
    && pExpr->op!=TK_REGISTER
    && sqlite3ExprIsConstantNotJoin(pExpr)
   ){
-    ExprList *p = pParse->pConstExpr;
-    int i;
     *pReg  = 0;
-    if( p ){
-      struct ExprList_item *pItem;
-      for(pItem=p->a, i=p->nExpr; i>0; pItem++, i--){
-        if( pItem->reusable && sqlite3ExprCompare(pItem->pExpr,pExpr,-1)==0 ){
-          return pItem->u.iConstExprReg;
-        }
-      }
-    }
-    r2 = ++pParse->nMem;
-    sqlite3ExprCodeAtInit(pParse, pExpr, r2, 1);
+    r2 = sqlite3ExprCodeAtInit(pParse, pExpr, -1);
   }else{
     int r1 = sqlite3GetTempReg(pParse);
     r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
     if( r2==r1 ){
       *pReg = r1;
@@ -4096,11 +4106,11 @@
 ** in register target.  If the expression is constant, then this routine
 ** might choose to code the expression at initialization time.
 */
 void sqlite3ExprCodeFactorable(Parse *pParse, Expr *pExpr, int target){
   if( pParse->okConstFactor && sqlite3ExprIsConstant(pExpr) ){
-    sqlite3ExprCodeAtInit(pParse, pExpr, target, 0);
+    sqlite3ExprCodeAtInit(pParse, pExpr, target);
   }else{
     sqlite3ExprCode(pParse, pExpr, target);
   }
 }
 
@@ -4168,11 +4178,11 @@
         n--;
       }else{
         sqlite3VdbeAddOp2(v, copyOp, j+srcReg-1, target+i);
       }
     }else if( (flags & SQLITE_ECEL_FACTOR)!=0 && sqlite3ExprIsConstant(pExpr) ){
-      sqlite3ExprCodeAtInit(pParse, pExpr, target+i, 0);
+      sqlite3ExprCodeAtInit(pParse, pExpr, target+i);
     }else{
       int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);
       if( inReg!=target+i ){
         VdbeOp *pOp;
         if( copyOp==OP_Copy

Index: src/sqliteInt.h
==================================================================
--- src/sqliteInt.h
+++ src/sqliteInt.h
@@ -3714,11 +3714,11 @@
 void sqlite3ExprCacheClear(Parse*);
 void sqlite3ExprCacheAffinityChange(Parse*, int, int);
 void sqlite3ExprCode(Parse*, Expr*, int);
 void sqlite3ExprCodeCopy(Parse*, Expr*, int);
 void sqlite3ExprCodeFactorable(Parse*, Expr*, int);
-void sqlite3ExprCodeAtInit(Parse*, Expr*, int, u8);
+int sqlite3ExprCodeAtInit(Parse*, Expr*, int);
 int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
 int sqlite3ExprCodeTarget(Parse*, Expr*, int);
 void sqlite3ExprCodeAndCache(Parse*, Expr*, int);
 int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int, u8);
 #define SQLITE_ECEL_DUP      0x01  /* Deep, not shallow copies */