Index: src/sqliteInt.h
==================================================================
--- src/sqliteInt.h
+++ src/sqliteInt.h
@@ -3066,11 +3066,11 @@
   int nTab;            /* Number of previously allocated VDBE cursors */
   int nMem;            /* Number of memory cells used so far */
   int szOpAlloc;       /* Bytes of memory space allocated for Vdbe.aOp[] */
   int iSelfTab;        /* Table associated with an index on expr, or negative
                        ** of the base register during check-constraint eval */
-  int nLabel;          /* Number of labels used */
+  int nLabel;          /* The *negative* of the number of labels used */
   int nLabelAlloc;     /* Number of slots in aLabel */
   int *aLabel;         /* Space to hold the labels */
   ExprList *pConstExpr;/* Constant expressions */
   Token constraintName;/* Name of the constraint currently being parsed */
   yDbMask writeMask;   /* Start a write transaction on these databases */

Index: src/vdbe.h
==================================================================
--- src/vdbe.h
+++ src/vdbe.h
@@ -154,16 +154,15 @@
 #   define COLNAME_N      2      /* Store the name and decltype */
 # endif
 #endif
 
 /*
-** The following macro converts a relative address in the p2 field
-** of a VdbeOp structure into a negative number so that 
-** sqlite3VdbeAddOpList() knows that the address is relative.  Calling
-** the macro again restores the address.
+** The following macro converts a label returned by sqlite3VdbeMakeLabel()
+** into an index into the Parse.aLabel[] array that contains the resolved
+** address of that label.
 */
-#define ADDR(X)  (-1-(X))
+#define ADDR(X)  (~(X))
 
 /*
 ** The makefile scans the vdbe.c source file and creates the "opcodes.h"
 ** header file that defines a number for each opcode used by the VDBE.
 */

Index: src/vdbeaux.c
==================================================================
--- src/vdbeaux.c
+++ src/vdbeaux.c
@@ -443,24 +443,35 @@
 ** the label into the resolved address.
 **
 ** The VDBE knows that a P2 value is a label because labels are
 ** always negative and P2 values are suppose to be non-negative.
 ** Hence, a negative P2 value is a label that has yet to be resolved.
+** (Later:) This is only true for opcodes that have the OPFLG_JUMP
+** property.
 **
-** Zero is returned if a malloc() fails.
+** Variable usage notes:
+**
+**     Parse.aLabel[x]     Stores the address that the x-th label resolves
+**                         into.  For testing (SQLITE_DEBUG), unresolved
+**                         labels stores -1, but that is not required.
+**     Parse.nLabelAlloc   Number of slots allocated to Parse.aLabel[]
+**     Parse.nLabel        The *negative* of the number of labels that have
+**                         been issued.  The negative is stored because
+**                         that gives a performance improvement over storing
+**                         the equivalent positive value.
 */
 int sqlite3VdbeMakeLabel(Parse *pParse){
-  return ADDR(pParse->nLabel++);
+  return --pParse->nLabel;
 }
 
 /*
 ** Resolve label "x" to be the address of the next instruction to
 ** be inserted.  The parameter "x" must have been obtained from
 ** a prior call to sqlite3VdbeMakeLabel().
 */
 static SQLITE_NOINLINE void resizeResolveLabel(Parse *p, Vdbe *v, int j){
-  int nNewSize = p->nLabel+10;
+  int nNewSize = 10 - p->nLabel;
   p->aLabel = sqlite3DbReallocOrFree(p->db, p->aLabel,
                      nNewSize*sizeof(p->aLabel[0]));
   if( p->aLabel==0 ){
     p->nLabelAlloc = 0;
   }else{
@@ -474,18 +485,18 @@
 }
 void sqlite3VdbeResolveLabel(Vdbe *v, int x){
   Parse *p = v->pParse;
   int j = ADDR(x);
   assert( v->magic==VDBE_MAGIC_INIT );
-  assert( j<p->nLabel );
+  assert( j<-p->nLabel );
   assert( j>=0 );
 #ifdef SQLITE_DEBUG
   if( p->db->flags & SQLITE_VdbeAddopTrace ){
     printf("RESOLVE LABEL %d to %d\n", x, v->nOp);
   }
 #endif
-  if( p->nLabelAlloc < p->nLabel ){
+  if( p->nLabelAlloc + p->nLabel < 0 ){
     resizeResolveLabel(p,v,j);
   }else{
     assert( p->aLabel[j]==(-1) ); /* Labels may only be resolved once */
     p->aLabel[j] = v->nOp;
   }
@@ -759,11 +770,11 @@
           if( pOp->p2<0 ){
             /* The mkopcodeh.tcl script has so arranged things that the only
             ** non-jump opcodes less than SQLITE_MX_JUMP_CODE are guaranteed to
             ** have non-negative values for P2. */
             assert( (sqlite3OpcodeProperty[pOp->opcode] & OPFLG_JUMP)!=0 );
-            assert( ADDR(pOp->p2)<pParse->nLabel );
+            assert( ADDR(pOp->p2)<-pParse->nLabel );
             pOp->p2 = aLabel[ADDR(pOp->p2)];
           }
           break;
         }
       }