SQLite

}
  
/* Opcode: String P1 P2 P3 P4 P5
** Synopsis: r[P2]='P4' (len=P1)
**
** The string value P4 of length P1 (bytes) is stored in register P2.
**
** If P3 is not zero and the content of register P3 is equal to P5, then
** the datatype of the register P2 is converted to BLOB.  The content is
** the same sequence of bytes, it is merely interpreted as a BLOB instead
** of a string, as if it had been CAST.  In other words:
**
** if( P3!=0 and reg[P3]==P5 ) reg[P2] := CAST(reg[P2] as BLOB)
*/
case OP_String: {          /* out2 */
  assert( pOp->p4.z!=0 );
  pOut = out2Prerelease(p, pOp);
  pOut->flags = MEM_Str|MEM_Static|MEM_Term;
  pOut->z = pOp->p4.z;
  pOut->n = pOp->p1;
  pOut->enc = encoding;
  UPDATE_MAX_BLOBSIZE(pOut);
#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
  if( pOp->p3>0 ){

    assert( pOp->p3<=(p->nMem+1 - p->nCursor) );
    pIn3 = &aMem[pOp->p3];
    assert( pIn3->flags & MEM_Int );
    if( pIn3->u.i==pOp->p5 ) pOut->flags = MEM_Blob|MEM_Static|MEM_Term;
  }
#endif
  break;
}

/* Opcode: Null P1 P2 P3 * *
** Synopsis:  r[P2..P3]=NULL

  pIn1->u.i--;
  VdbeBranchTaken(pIn1->u.i==0, 2);
  if( pIn1->u.i==0 ) goto jump_to_p2;
  break;
}

















/* Opcode: AggStep0 * P2 P3 P4 P5
** Synopsis: accum=r[P3] step(r[P2@P5])
**
** Execute the step function for an aggregate.  The
** function has P5 arguments.   P4 is a pointer to the FuncDef
** structure that specifies the function.  Register P3 is the
** accumulator.

      sqlite3VdbeGoto(v, pLevel->addrSkip);
      VdbeComment((v, "next skip-scan on %s", pLoop->u.btree.pIndex->zName));
      sqlite3VdbeJumpHere(v, pLevel->addrSkip);
      sqlite3VdbeJumpHere(v, pLevel->addrSkip-2);
    }
#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
    if( pLevel->addrLikeRep ){


      sqlite3VdbeAddOp2(v, OP_DecrJumpZero, (int)(pLevel->iLikeRepCntr>>1),



                        pLevel->addrLikeRep);
      VdbeCoverage(v);
    }
#endif
    if( pLevel->iLeftJoin ){
      addr = sqlite3VdbeAddOp1(v, OP_IfPos, pLevel->iLeftJoin); VdbeCoverage(v);
      assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0
           || (pLoop->wsFlags & WHERE_INDEXED)!=0 );

  int addrBrk;          /* Jump here to break out of the loop */
  int addrNxt;          /* Jump here to start the next IN combination */
  int addrSkip;         /* Jump here for next iteration of skip-scan */
  int addrCont;         /* Jump here to continue with the next loop cycle */
  int addrFirst;        /* First instruction of interior of the loop */
  int addrBody;         /* Beginning of the body of this loop */
#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
  u32 iLikeRepCntr;     /* LIKE range processing counter register (times 2) */
  int addrLikeRep;      /* LIKE range processing address */
#endif
  u8 iFrom;             /* Which entry in the FROM clause */
  u8 op, p3, p5;        /* Opcode, P3 & P5 of the opcode that ends the loop */
  int p1, p2;           /* Operands of the opcode used to ends the loop */
  union {               /* Information that depends on pWLoop->wsFlags */
    struct {

  }
  *pzAff = zAff;
  return regBase;
}

#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
/*
** If the most recently coded instruction is a constant range constraint
** (a string literal) that originated from the LIKE optimization, then 
** set P3 and P5 on the OP_String opcode so that the string will be cast
** to a BLOB at appropriate times.
**
** The LIKE optimization trys to evaluate "x LIKE 'abc%'" as a range
** expression: "x>='ABC' AND x<'abd'".  But this requires that the range
** scan loop run twice, once for strings and a second time for BLOBs.
** The OP_String opcodes on the second pass convert the upper and lower
** bound string contants to blobs.  This routine makes the necessary changes
** to the OP_String opcodes for that to happen.

  if( pTerm->wtFlags & TERM_LIKEOPT ){
    VdbeOp *pOp;
    assert( pLevel->iLikeRepCntr>0 );
    pOp = sqlite3VdbeGetOp(v, -1);
    assert( pOp!=0 );
    assert( pOp->opcode==OP_String8 
            || pTerm->pWC->pWInfo->pParse->db->mallocFailed );
    pOp->p3 = (int)(pLevel->iLikeRepCntr>>1);  /* Register holding counter */
    pOp->p5 = (u8)(pLevel->iLikeRepCntr&1);    /* ASC or DESC */
  }
}
#else
# define whereLikeOptimizationStringFixup(A,B,C)
#endif

#ifdef SQLITE_ENABLE_CURSOR_HINTS

    if( pLoop->wsFlags & WHERE_TOP_LIMIT ){
      pRangeEnd = pLoop->aLTerm[j++];
      nExtraReg = 1;
#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
      if( (pRangeEnd->wtFlags & TERM_LIKEOPT)!=0 ){
        assert( pRangeStart!=0 );                     /* LIKE opt constraints */
        assert( pRangeStart->wtFlags & TERM_LIKEOPT );   /* occur in pairs */
        pLevel->iLikeRepCntr = (u32)++pParse->nMem;
        sqlite3VdbeAddOp2(v, OP_Integer, 1, (int)pLevel->iLikeRepCntr);
        VdbeComment((v, "LIKE loop counter"));
        pLevel->addrLikeRep = sqlite3VdbeCurrentAddr(v);
        /* iLikeRepCntr actually stores 2x the counter register number.  The
        ** bottom bit indicates whether the search order is ASC or DESC. */
        testcase( bRev );
        testcase( pIdx->aSortOrder[nEq]==SQLITE_SO_DESC );

        assert( (bRev & ~1)==0 );
        pLevel->iLikeRepCntr <<=1;

        pLevel->iLikeRepCntr |= bRev ^ (pIdx->aSortOrder[nEq]==SQLITE_SO_DESC);
      }
#endif
      if( pRangeStart==0
       && (j = pIdx->aiColumn[nEq])>=0 
       && pIdx->pTable->aCol[j].notNull==0
      ){
        bSeekPastNull = 1;

    }
    pE = pTerm->pExpr;
    assert( pE!=0 );
    if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){
      continue;
    }
    if( pTerm->wtFlags & TERM_LIKECOND ){
      /* If the TERM_LIKECOND flag is set, that means that the range search
      ** is sufficient to guarantee that the LIKE operator is true, so we
      ** can skip the call to the like(A,B) function.  But this only works
      ** for strings.  So do not skip the call to the function on the pass
      ** that compares BLOBs. */
#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
      continue;
#else
      u32 x = pLevel->iLikeRepCntr;
      assert( x>0 );
      skipLikeAddr = sqlite3VdbeAddOp1(v, (x&1)? OP_IfNot : OP_If, (int)(x>>1));
      VdbeCoverage(v);
#endif
    }
    sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);
    if( skipLikeAddr ) sqlite3VdbeJumpHere(v, skipLikeAddr);
    pTerm->wtFlags |= TERM_CODED;
  }