Merge enhancements and bug fixes from trunk.

FossilOrigin-Name: 9fb646f29c05bca5f677a2c7c4f45c36bfe0a0c6a88cb7968b4a0459bdd63bb2

1 files changed, 37 insertions, 19 deletions

diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index c3b8e8b53..bd67b8858 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -460,21 +460,22 @@ void sqlite3VdbeEndCoroutine(Vdbe *v, int regYield){
 ** 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(Vdbe *v){
-  Parse *p = v->pParse;
-  int i = p->nLabel++;
-  assert( v->magic==VDBE_MAGIC_INIT );
-  if( (i & (i-1))==0 ){
-    p->aLabel = sqlite3DbReallocOrFree(p->db, p->aLabel, 
-                                       (i*2+1)*sizeof(p->aLabel[0]));
-  }
-  if( p->aLabel ){
-    p->aLabel[i] = -1;
-  }
-  return ADDR(i);
+int sqlite3VdbeMakeLabel(Parse *pParse){
+  return --pParse->nLabel;
 }
 
 /*
@@ -482,18 +483,35 @@ int sqlite3VdbeMakeLabel(Vdbe *v){
 ** 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 = 10 - p->nLabel;
+  p->aLabel = sqlite3DbReallocOrFree(p->db, p->aLabel,
+                     nNewSize*sizeof(p->aLabel[0]));
+  if( p->aLabel==0 ){
+    p->nLabelAlloc = 0;
+  }else{
+#ifdef SQLITE_DEBUG
+    int i;
+    for(i=p->nLabelAlloc; i<nNewSize; i++) p->aLabel[i] = -1;
+#endif
+    p->nLabelAlloc = nNewSize;
+    p->aLabel[j] = v->nOp;
+  }
+}
 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 );
-  if( p->aLabel ){
 #ifdef SQLITE_DEBUG
-    if( p->db->flags & SQLITE_VdbeAddopTrace ){
-      printf("RESOLVE LABEL %d to %d\n", x, v->nOp);
-    }
+  if( p->db->flags & SQLITE_VdbeAddopTrace ){
+    printf("RESOLVE LABEL %d to %d\n", x, v->nOp);
+  }
 #endif
+  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;
   }
@@ -769,7 +787,7 @@ static void resolveP2Values(Vdbe *p, int *pMaxFuncArgs){
             ** 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;