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Overview
Comment:Simplified VDBE code for the vector NOT IN null-scanning loop.
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SHA1: 7ae504e62e9bbbbd85a676f3c3922b7fd0cc73d2
User & Date: drh 2016-08-24 21:54:47.055
Context
2016-08-25
14:00
Add notes on the implementation of the IN operator. (check-in: d256b2caeb user: drh tags: rowvalue)
2016-08-24
21:54
Simplified VDBE code for the vector NOT IN null-scanning loop. (check-in: 7ae504e62e user: drh tags: rowvalue)
21:24
Improved extended comments of comparison operators when the SQLITE_STOREP2 flags is set on P5. No changes to non-debug code. (check-in: bbc1b01616 user: drh tags: rowvalue)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/expr.c.
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    }else{
      /* In this case, the RHS is an index b-tree. Apply the comparison
      ** affinities to each value on the LHS of the operator.  */
      sqlite3VdbeAddOp4(v, OP_Affinity, r1, nVector, 0, zAff, nVector);
      
      if( nVector>1 && destIfNull!=destIfFalse ){
        int iIdx = pExpr->iTable;
        int addr;
        int addrNext;


        /* Search the index for the key. */
        addr = sqlite3VdbeAddOp4Int(v, OP_Found, iIdx, 0, r1, nVector);
        VdbeCoverage(v);

        /* At this point the specified key is not present in the index, 
        ** so the result of the IN(..) operator must be either NULL or
        ** 0. The vdbe code generated below figures out which.  */
        addrNext = 1+sqlite3VdbeAddOp2(v, OP_Rewind, iIdx, destIfFalse);
        VdbeCoverage(v);


        for(i=0; i<nVector; i++){
          Expr *p;
          CollSeq *pColl;
          int r2 = sqlite3GetTempReg(pParse);
          p = sqlite3VectorFieldSubexpr(pLeft, i);
          pColl = sqlite3ExprCollSeq(pParse, p);

          sqlite3VdbeAddOp3(v, OP_Column, iIdx, i, r2);
          sqlite3VdbeAddOp4(v, OP_Eq, r1+i, 0, r2, (void*)pColl,P4_COLLSEQ);
          sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);
          VdbeCoverage(v);
          sqlite3VdbeAddOp2(v, OP_Next, iIdx, addrNext);
          VdbeCoverage(v);
          sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);
          sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-3);
          sqlite3ReleaseTempReg(pParse, r2);
        }
        sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull);





        /* The key was found in the index. If it contains any NULL values,
        ** then the result of the IN(...) operator is NULL. Otherwise, the
        ** result is 1.  */
        sqlite3VdbeJumpHere(v, addr);
        for(i=0; i<nVector; i++){
          Expr *p = sqlite3VectorFieldSubexpr(pExpr->pLeft, i);
          if( sqlite3ExprCanBeNull(p) ){
            sqlite3VdbeAddOp2(v, OP_IsNull, r1+aiMap[i], destIfNull);
            VdbeCoverage(v);
          }
        }








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    }else{
      /* In this case, the RHS is an index b-tree. Apply the comparison
      ** affinities to each value on the LHS of the operator.  */
      sqlite3VdbeAddOp4(v, OP_Affinity, r1, nVector, 0, zAff, nVector);
      
      if( nVector>1 && destIfNull!=destIfFalse ){
        int iIdx = pExpr->iTable;
        int addrTop;
        int addrNext;
        int addrFound;

        /* Search the index for the key. */
        addrFound = sqlite3VdbeAddOp4Int(v, OP_Found, iIdx, 0, r1, nVector);
        VdbeCoverage(v);

        /* At this point the specified key is not present in the index, 
        ** so the result of the IN(..) operator must be either NULL or
        ** 0. The vdbe code generated below figures out which.  */
        addrTop = 1+sqlite3VdbeAddOp2(v, OP_Rewind, iIdx, destIfFalse);
        VdbeCoverage(v);
        addrNext = sqlite3VdbeMakeLabel(v);

        for(i=0; i<nVector; i++){
          Expr *p;
          CollSeq *pColl;
          int r2 = sqlite3GetTempReg(pParse);
          p = sqlite3VectorFieldSubexpr(pLeft, i);
          pColl = sqlite3ExprCollSeq(pParse, p);

          sqlite3VdbeAddOp3(v, OP_Column, iIdx, i, r2);
          sqlite3VdbeAddOp4(v, OP_Ne, r1+i, addrNext, r2,

                            (void*)pColl, P4_COLLSEQ);

          VdbeCoverage(v);


          sqlite3ReleaseTempReg(pParse, r2);
        }
        sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull);
        sqlite3VdbeResolveLabel(v, addrNext);
        sqlite3VdbeAddOp2(v, OP_Next, iIdx, addrTop);
        VdbeCoverage(v);
        sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);

        /* The key was found in the index. If it contains any NULL values,
        ** then the result of the IN(...) operator is NULL. Otherwise, the
        ** result is 1.  */
        sqlite3VdbeJumpHere(v, addrFound);
        for(i=0; i<nVector; i++){
          Expr *p = sqlite3VectorFieldSubexpr(pExpr->pLeft, i);
          if( sqlite3ExprCanBeNull(p) ){
            sqlite3VdbeAddOp2(v, OP_IsNull, r1+aiMap[i], destIfNull);
            VdbeCoverage(v);
          }
        }
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