Add a new OP_SeekRowid opcode, that combines the functions of OP_MustBeInt
and OP_NotExists.  This makes the code slightly smaller and faster.

FossilOrigin-Name: ffe80a1bfa014943a614fc6993c1749b9bfec4c1
diff --git a/src/expr.c b/src/expr.c
index 9e3b664..156db96 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -2222,8 +2222,7 @@
     if( eType==IN_INDEX_ROWID ){
       /* In this case, the RHS is the ROWID of table b-tree
       */
-      sqlite3VdbeAddOp2(v, OP_MustBeInt, r1, destIfFalse); VdbeCoverage(v);
-      sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, destIfFalse, r1);
+      sqlite3VdbeAddOp3(v, OP_SeekRowid, pExpr->iTable, destIfFalse, r1);
       VdbeCoverage(v);
     }else{
       /* In this case, the RHS is an index b-tree.
diff --git a/src/pragma.c b/src/pragma.c
index 330e999..56823c7 100644
--- a/src/pragma.c
+++ b/src/pragma.c
@@ -1334,12 +1334,10 @@
             sqlite3VdbeAddOp3(v, OP_Column, 0, iKey, regRow);
             sqlite3ColumnDefault(v, pTab, iKey, regRow);
             sqlite3VdbeAddOp2(v, OP_IsNull, regRow, addrOk); VdbeCoverage(v);
-            sqlite3VdbeAddOp2(v, OP_MustBeInt, regRow, 
-               sqlite3VdbeCurrentAddr(v)+3); VdbeCoverage(v);
           }else{
             sqlite3VdbeAddOp2(v, OP_Rowid, 0, regRow);
           }
-          sqlite3VdbeAddOp3(v, OP_NotExists, i, 0, regRow); VdbeCoverage(v);
+          sqlite3VdbeAddOp3(v, OP_SeekRowid, i, 0, regRow); VdbeCoverage(v);
           sqlite3VdbeGoto(v, addrOk);
           sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-2);
         }else{
diff --git a/src/vdbe.c b/src/vdbe.c
index d512c0b..d4392a8 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -4023,6 +4023,30 @@
   break;
 }
 
+/* Opcode: SeekRowid P1 P2 P3 * *
+** Synopsis: intkey=r[P3]
+**
+** P1 is the index of a cursor open on an SQL table btree (with integer
+** keys).  If register P3 does not contain an integer or if P1 does not
+** contain a record with rowid P3 then jump immediately to P2.  
+** Or, if P2 is 0, raise an SQLITE_CORRUPT error. If P1 does contain
+** a record with rowid P3 then 
+** leave the cursor pointing at that record and fall through to the next
+** instruction.
+**
+** The OP_NotExists opcode performs the same operation, but with OP_NotExists
+** the P3 register must be guaranteed to contain an integer value.  With this
+** opcode, register P3 might not contain an integer.
+**
+** The OP_NotFound opcode performs the same operation on index btrees
+** (with arbitrary multi-value keys).
+**
+** This opcode leaves the cursor in a state where it cannot be advanced
+** in either direction.  In other words, the Next and Prev opcodes will
+** not work following this opcode.
+**
+** See also: Found, NotFound, NoConflict, SeekRowid
+*/
 /* Opcode: NotExists P1 P2 P3 * *
 ** Synopsis: intkey=r[P3]
 **
@@ -4033,6 +4057,10 @@
 ** leave the cursor pointing at that record and fall through to the next
 ** instruction.
 **
+** The OP_SeekRowid opcode performs the same operation but also allows the
+** P3 register to contain a non-integer value, in which case the jump is
+** always taken.  This opcode requires that P3 always contain an integer.
+**
 ** The OP_NotFound opcode performs the same operation on index btrees
 ** (with arbitrary multi-value keys).
 **
@@ -4040,15 +4068,22 @@
 ** in either direction.  In other words, the Next and Prev opcodes will
 ** not work following this opcode.
 **
-** See also: Found, NotFound, NoConflict
+** See also: Found, NotFound, NoConflict, SeekRowid
 */
-case OP_NotExists: {        /* jump, in3 */
+case OP_SeekRowid: {        /* jump, in3 */
   VdbeCursor *pC;
   BtCursor *pCrsr;
   int res;
   u64 iKey;
 
   pIn3 = &aMem[pOp->p3];
+  if( (pIn3->flags & MEM_Int)==0 ){
+    applyAffinity(pIn3, SQLITE_AFF_NUMERIC, encoding);
+    if( (pIn3->flags & MEM_Int)==0 ) goto jump_to_p2;
+  }
+  /* Fall through into OP_NotExists */
+case OP_NotExists:          /* jump, in3 */
+  pIn3 = &aMem[pOp->p3];
   assert( pIn3->flags & MEM_Int );
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
   pC = p->apCsr[pOp->p1];
@@ -4250,10 +4285,12 @@
 ** sqlite3_last_insert_rowid() function (otherwise it is unmodified).
 **
 ** If the OPFLAG_USESEEKRESULT flag of P5 is set and if the result of
-** the last seek operation (OP_NotExists) was a success, then this
+** the last seek operation (OP_NotExists or OP_SeekRowid) was a success,
+** then this
 ** operation will not attempt to find the appropriate row before doing
 ** the insert but will instead overwrite the row that the cursor is
-** currently pointing to.  Presumably, the prior OP_NotExists opcode
+** currently pointing to.  Presumably, the prior OP_NotExists or
+** OP_SeekRowid opcode
 ** has already positioned the cursor correctly.  This is an optimization
 ** that boosts performance by avoiding redundant seeks.
 **
@@ -4611,8 +4648,9 @@
   pCrsr = pC->uc.pCursor;
 
   /* The OP_RowKey and OP_RowData opcodes always follow OP_NotExists or
-  ** OP_Rewind/Op_Next with no intervening instructions that might invalidate
-  ** the cursor.  If this where not the case, on of the following assert()s
+  ** OP_SeekRowid or OP_Rewind/Op_Next with no intervening instructions
+  ** that might invalidate the cursor.
+  ** If this where not the case, on of the following assert()s
   ** would fail.  Should this ever change (because of changes in the code
   ** generator) then the fix would be to insert a call to
   ** sqlite3VdbeCursorMoveto().
diff --git a/src/wherecode.c b/src/wherecode.c
index 054b1b1..83ee48a 100644
--- a/src/wherecode.c
+++ b/src/wherecode.c
@@ -971,8 +971,7 @@
     iRowidReg = codeEqualityTerm(pParse, pTerm, pLevel, 0, bRev, iReleaseReg);
     if( iRowidReg!=iReleaseReg ) sqlite3ReleaseTempReg(pParse, iReleaseReg);
     addrNxt = pLevel->addrNxt;
-    sqlite3VdbeAddOp2(v, OP_MustBeInt, iRowidReg, addrNxt); VdbeCoverage(v);
-    sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addrNxt, iRowidReg);
+    sqlite3VdbeAddOp3(v, OP_SeekRowid, iCur, addrNxt, iRowidReg);
     VdbeCoverage(v);
     sqlite3ExprCacheAffinityChange(pParse, iRowidReg, 1);
     sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);