Performance optimization in the sqlite3VdbeChangeP4() routine of the

code generator.

FossilOrigin-Name: 28bd8d5fc541464b69886b7e886939035b42a869

manifest

@@ -1,5 +1,5 @@
-C Fix\sduplicate\stest\snumber\sin\s'waloverwrite'.
-D 2016-01-11T22:43:04.382
+C Performance\soptimization\sin\sthe\ssqlite3VdbeChangeP4()\sroutine\sof\sthe\ncode\sgenerator.
+D 2016-01-11T22:58:50.164
 F Makefile.in 7c8cc4c2f0179efc6fa9492141d1fb65f4807054
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc e45d8b9b56dfa3f2cd860b2c28bd9d304513b042
@@ -402,7 +402,7 @@ F src/vdbe.c 6572d00eefeaa0b14b325fdf3a409920ec3fee82
 F src/vdbe.h efb7a8c1459e31f3ea4377824c6a7e4cb5068637
 F src/vdbeInt.h 42eefa4f9e7432b9968d321b44e48821ec13b189
 F src/vdbeapi.c 020681b943e77766b32ae1cddf86d7831b7374ca
-F src/vdbeaux.c 5d8c7c04e0f677033efb1292248a5f9056bbc34c
+F src/vdbeaux.c f2e6b4fae037db04323be8de7bcd266375746471
 F src/vdbeblob.c fdc4a81605ae7a35ae94a55bd768b66d6be16f15
 F src/vdbemem.c fdd1578e47bea61390d472de53c565781d81e045
 F src/vdbesort.c a7ec02da4494c59dfd071126dd3726be5a11459d
@@ -412,7 +412,7 @@ F src/vxworks.h c18586c8edc1bddbc15c004fa16aeb1e1342b4fb
 F src/wal.c 92ca9e7923c337c497e4c9aa7edac800e269a1d8
 F src/wal.h 907943dfdef10b583e81906679a347e0ec6f1b1b
 F src/walker.c 0f142b5bd3ed2041fc52d773880748b212e63354
-F src/where.c c6d3d2f6af57d574a7365ee2b225a5024f2a6bec
+F src/where.c bb69654f841ae7af0a20cc6fb8f0ac57901c31be
 F src/whereInt.h 78b6b4de94db84aecbdc07fe3e38f648eb391e9a
 F src/wherecode.c dfbfe198e418b01f208b489e088edd230c91a4e7
 F src/whereexpr.c eebba8340c90de73b3d3bbe8c43b84559b8e6e2c
@@ -1407,7 +1407,7 @@ F tool/vdbe_profile.tcl 246d0da094856d72d2c12efec03250d71639d19f
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 48bd54594752d5be3337f12c72f28d2080cb630b
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P ecc98bef43c2fd07d64e4efddf340929a875ebac
-R bffff77db2267e7f44f05491f1b6c72d
-U mistachkin
-Z 70102cc7ed23bad282b82f2981075253
+P f5fb82686697e5fa1937323b1c1b35cf90ad0302
+R 5cc83036f9c9da1fadf85dd4abd0f133
+U drh
+Z a8c9a7d6a102c57d4a0aed7eac3aa290

manifest.uuid

@@ -1 +1 @@
-f5fb82686697e5fa1937323b1c1b35cf90ad0302
+28bd8d5fc541464b69886b7e886939035b42a869

src/vdbeaux.c

@@ -305,8 +305,7 @@ int sqlite3VdbeAddOp4Dup8(
 */
 void sqlite3VdbeAddParseSchemaOp(Vdbe *p, int iDb, char *zWhere){
   int j;
-  int addr = sqlite3VdbeAddOp3(p, OP_ParseSchema, iDb, 0, 0);
-  sqlite3VdbeChangeP4(p, addr, zWhere, P4_DYNAMIC);
+  sqlite3VdbeAddOp4(p, OP_ParseSchema, iDb, 0, 0, zWhere, P4_DYNAMIC);
   for(j=0; j<p->db->nDb; j++) sqlite3VdbeUsesBtree(p, j);
 }
 
@@ -805,7 +804,7 @@ static void vdbeFreeOpArray(sqlite3 *db, Op *aOp, int nOp){
   if( aOp ){
     Op *pOp;
     for(pOp=aOp; pOp<&aOp[nOp]; pOp++){
-      freeP4(db, pOp->p4type, pOp->p4.p);
+      if( pOp->p4type ) freeP4(db, pOp->p4type, pOp->p4.p);
 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
       sqlite3DbFree(db, pOp->zComment);
 #endif     
@@ -867,16 +866,34 @@ int sqlite3VdbeDeletePriorOpcode(Vdbe *p, u8 op){
 **
 ** If addr<0 then change P4 on the most recently inserted instruction.
 */
+static void SQLITE_NOINLINE vdbeChangeP4Full(
+  Vdbe *p,
+  Op *pOp,
+  const char *zP4,
+  int n
+){
+  if( pOp->p4type ){
+    freeP4(p->db, pOp->p4type, pOp->p4.p);
+    pOp->p4type = 0;
+    pOp->p4.p = 0;
+  }
+  if( n<0 ){
+    sqlite3VdbeChangeP4(p, (int)(pOp - p->aOp), zP4, n);
+  }else{
+    if( n==0 ) n = sqlite3Strlen30(zP4);
+    pOp->p4.z = sqlite3DbStrNDup(p->db, zP4, n);
+    pOp->p4type = P4_DYNAMIC;
+  }
+}
 void sqlite3VdbeChangeP4(Vdbe *p, int addr, const char *zP4, int n){
   Op *pOp;
   sqlite3 *db;
   assert( p!=0 );
   db = p->db;
   assert( p->magic==VDBE_MAGIC_INIT );
-  if( p->aOp==0 || db->mallocFailed ){
-    if( n!=P4_VTAB ){
-      freeP4(db, n, (void*)*(char**)&zP4);
-    }
+  assert( p->aOp!=0 || db->mallocFailed );
+  if( db->mallocFailed ){
+    if( n!=P4_VTAB ) freeP4(db, n, (void*)*(char**)&zP4);
     return;
   }
   assert( p->nOp>0 );
@@ -885,43 +902,20 @@ void sqlite3VdbeChangeP4(Vdbe *p, int addr, const char *zP4, int n){
     addr = p->nOp - 1;
   }
   pOp = &p->aOp[addr];
-  assert( pOp->p4type==P4_NOTUSED
-       || pOp->p4type==P4_INT32
-       || pOp->p4type==P4_KEYINFO );
-  freeP4(db, pOp->p4type, pOp->p4.p);
-  pOp->p4.p = 0;
+  if( n>=0 || pOp->p4type ){
+    vdbeChangeP4Full(p, pOp, zP4, n);
+    return;
+  }
   if( n==P4_INT32 ){
     /* Note: this cast is safe, because the origin data point was an int
     ** that was cast to a (const char *). */
     pOp->p4.i = SQLITE_PTR_TO_INT(zP4);
     pOp->p4type = P4_INT32;
-  }else if( zP4==0 ){
-    pOp->p4.p = 0;
-    pOp->p4type = P4_NOTUSED;
-  }else if( n==P4_KEYINFO ){
-    pOp->p4.p = (void*)zP4;
-    pOp->p4type = P4_KEYINFO;
-#ifdef SQLITE_ENABLE_CURSOR_HINTS
-  }else if( n==P4_EXPR ){
-    /* Responsibility for deleting the Expr tree is handed over to the
-    ** VDBE by this operation.  The caller should have already invoked
-    ** sqlite3ExprDup() or whatever other routine is needed to make a 
-    ** private copy of the tree. */
-    pOp->p4.pExpr = (Expr*)zP4;
-    pOp->p4type = P4_EXPR;
-#endif
-  }else if( n==P4_VTAB ){
-    pOp->p4.p = (void*)zP4;
-    pOp->p4type = P4_VTAB;
-    sqlite3VtabLock((VTable *)zP4);
-    assert( ((VTable *)zP4)->db==p->db );
-  }else if( n<0 ){
+  }else if( zP4!=0 ){
+    assert( n<0 );
     pOp->p4.p = (void*)zP4;
     pOp->p4type = (signed char)n;
-  }else{
-    if( n==0 ) n = sqlite3Strlen30(zP4);
-    pOp->p4.z = sqlite3DbStrNDup(p->db, zP4, n);
-    pOp->p4type = P4_DYNAMIC;
+    if( n==P4_VTAB ) sqlite3VtabLock((VTable*)zP4);
   }
 }
 

src/where.c

@@ -4318,8 +4318,7 @@ WhereInfo *sqlite3WhereBegin(
         Bitmask b = pTabItem->colUsed;
         int n = 0;
         for(; b; b=b>>1, n++){}
-        sqlite3VdbeChangeP4(v, sqlite3VdbeCurrentAddr(v)-1, 
-                            SQLITE_INT_TO_PTR(n), P4_INT32);
+        sqlite3VdbeChangeP4(v, -1, SQLITE_INT_TO_PTR(n), P4_INT32);
         assert( n<=pTab->nCol );
       }
 #ifdef SQLITE_ENABLE_CURSOR_HINTS