Performance optimizations in the VDBE and especially to the OP_Next and

related opcodes.

FossilOrigin-Name: d78c5d89de4b840351b026c9db1952fc24e689d0

src/btree.c

@@ -4804,6 +4804,7 @@ int sqlite3BtreeNext(BtCursor *pCur, int *pRes){
   if( pCur->eState!=CURSOR_VALID ){
     rc = restoreCursorPosition(pCur);
     if( rc!=SQLITE_OK ){
+      *pRes = 0;
       return rc;
     }
     if( CURSOR_INVALID==pCur->eState ){
@@ -4838,7 +4839,10 @@ int sqlite3BtreeNext(BtCursor *pCur, int *pRes){
   if( idx>=pPage->nCell ){
     if( !pPage->leaf ){
       rc = moveToChild(pCur, get4byte(&pPage->aData[pPage->hdrOffset+8]));
-      if( rc ) return rc;
+      if( rc ){
+        *pRes = 0;
+        return rc;
+      }
       rc = moveToLeftmost(pCur);
       *pRes = 0;
       return rc;
@@ -4886,7 +4890,10 @@ int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
   if( pCur->eState!=CURSOR_VALID ){
     if( ALWAYS(pCur->eState>=CURSOR_REQUIRESEEK) ){
       rc = btreeRestoreCursorPosition(pCur);
-      if( rc!=SQLITE_OK ) return rc;
+      if( rc!=SQLITE_OK ){
+        *pRes = 0;
+        return rc;
+      }
     }
     if( CURSOR_INVALID==pCur->eState ){
       *pRes = 1;
@@ -4910,6 +4917,7 @@ int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
     int idx = pCur->aiIdx[pCur->iPage];
     rc = moveToChild(pCur, get4byte(findCell(pPage, idx)));
     if( rc ){
+      *pRes = 0;
       return rc;
     }
     rc = moveToRightmost(pCur);

src/vdbe.c

@@ -588,7 +588,7 @@ int sqlite3VdbeExec(
 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
   if( db->xProgress ){
     assert( 0 < db->nProgressOps );
-    nProgressLimit = (unsigned)p->aCounter[SQLITE_STMTSTATUS_VM_STEP-1];
+    nProgressLimit = (unsigned)p->aCounter[SQLITE_STMTSTATUS_VM_STEP];
     if( nProgressLimit==0 ){
       nProgressLimit = db->nProgressOps;
     }else{
@@ -1848,12 +1848,12 @@ case OP_Ge: {             /* same as TK_GE, jump, in1, in3 */
       ** then the result is always NULL.
       ** The jump is taken if the SQLITE_JUMPIFNULL bit is set.
       */
-      if( pOp->p5 & SQLITE_STOREP2 ){
+      if( pOp->p5 & SQLITE_JUMPIFNULL ){
+        pc = pOp->p2-1;
+      }else if( pOp->p5 & SQLITE_STOREP2 ){
         pOut = &aMem[pOp->p2];
         MemSetTypeFlag(pOut, MEM_Null);
         REGISTER_TRACE(pOp->p2, pOut);
-      }else if( pOp->p5 & SQLITE_JUMPIFNULL ){
-        pc = pOp->p2-1;
       }
       break;
     }
@@ -4438,7 +4438,7 @@ case OP_Sort: {        /* jump */
   sqlite3_sort_count++;
   sqlite3_search_count--;
 #endif
-  p->aCounter[SQLITE_STMTSTATUS_SORT-1]++;
+  p->aCounter[SQLITE_STMTSTATUS_SORT]++;
   /* Fall through into OP_Rewind */
 }
 /* Opcode: Rewind P1 P2 * * *
@@ -4517,7 +4517,7 @@ case OP_Next: {        /* jump */
   int res;
 
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
-  assert( pOp->p5<=ArraySize(p->aCounter) );
+  assert( pOp->p5<ArraySize(p->aCounter) );
   pC = p->apCsr[pOp->p1];
   if( pC==0 ){
     break;  /* See ticket #2273 */
@@ -4527,7 +4527,7 @@ case OP_Next: {        /* jump */
     assert( pOp->opcode==OP_SorterNext );
     rc = sqlite3VdbeSorterNext(db, pC, &res);
   }else{
-    res = 1;
+    /* res = 1; // Always initialized by the xAdvance() call */
     assert( pC->deferredMoveto==0 );
     assert( pC->pCursor );
     assert( pOp->opcode!=OP_Next || pOp->p4.xAdvance==sqlite3BtreeNext );
@@ -4538,7 +4538,7 @@ case OP_Next: {        /* jump */
   pC->cacheStatus = CACHE_STALE;
   if( res==0 ){
     pc = pOp->p2 - 1;
-    if( pOp->p5 ) p->aCounter[pOp->p5-1]++;
+    p->aCounter[pOp->p5]++;
 #ifdef SQLITE_TEST
     sqlite3_search_count++;
 #endif
@@ -6241,7 +6241,7 @@ vdbe_error_halt:
 vdbe_return:
   db->lastRowid = lastRowid;
   testcase( nVmStep>0 );
-  p->aCounter[SQLITE_STMTSTATUS_VM_STEP-1] += (int)nVmStep;
+  p->aCounter[SQLITE_STMTSTATUS_VM_STEP] += (int)nVmStep;
   sqlite3VdbeLeave(p);
   return rc;
 

src/vdbeInt.h

@@ -346,7 +346,7 @@ struct Vdbe {
   yDbMask btreeMask;      /* Bitmask of db->aDb[] entries referenced */
   yDbMask lockMask;       /* Subset of btreeMask that requires a lock */
   int iStatement;         /* Statement number (or 0 if has not opened stmt) */
-  int aCounter[4];        /* Counters used by sqlite3_stmt_status() */
+  u32 aCounter[5];        /* Counters used by sqlite3_stmt_status() */
 #ifndef SQLITE_OMIT_TRACE
   i64 startTime;          /* Time when query started - used for profiling */
 #endif

src/vdbeapi.c

@@ -1298,7 +1298,7 @@ sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt){
 */
 int sqlite3_stmt_status(sqlite3_stmt *pStmt, int op, int resetFlag){
   Vdbe *pVdbe = (Vdbe*)pStmt;
-  int v = pVdbe->aCounter[op-1];
-  if( resetFlag ) pVdbe->aCounter[op-1] = 0;
-  return v;
+  u32 v = pVdbe->aCounter[op];
+  if( resetFlag ) pVdbe->aCounter[op] = 0;
+  return (int)v;
 }