SQLite

          int addrPkConflict = sqlite3VdbeCurrentAddr(v)+pPk->nKeyCol;
          for(i=0; i<pPk->nKeyCol-1; i++){
            x = pPk->aiColumn[i];
            sqlite3VdbeAddOp3(v, OP_Ne, regOldData+1+x,
                              addrPkConflict, regIdx+x);
          }
          x = pPk->aiColumn[i];
          sqlite3VdbeAddOp3(v, OP_Eq, regOldData+1+x, addrUniqueOk, regIdx+i);
        }
      }else{
        /* For a UNIQUE index on a WITHOUT ROWID table, conflict only if the
        ** PRIMARY KEY value of the match is different from the old PRIMARY KEY
        ** value from before the update. */
        int addrConflict = sqlite3VdbeCurrentAddr(v)+pPk->nKeyCol;
        for(i=0; i<pPk->nKeyCol-1; i++){

    sqlite3VdbeMemRealify(pIn1);
  }
  break;
}
#endif /* !defined(SQLITE_OMIT_CAST) && !defined(SQLITE_OMIT_FLOATING_POINT) */

/* Opcode: Lt P1 P2 P3 P4 P5
** Synopsis: if r[P1]<r[P3] goto P3
**
** Compare the values in register P1 and P3.  If reg(P3)<reg(P1) then
** jump to address P2.  
**
** If the SQLITE_JUMPIFNULL bit of P5 is set and either reg(P1) or
** reg(P3) is NULL then take the jump.  If the SQLITE_JUMPIFNULL 
** bit is clear then fall through if either operand is NULL.

** store a boolean result (either 0, or 1, or NULL) in register P2.
**
** If the SQLITE_NULLEQ bit is set in P5, then NULL values are considered
** equal to one another, provided that they do not have their MEM_Cleared
** bit set.
*/
/* Opcode: Ne P1 P2 P3 P4 P5
** Synopsis: if r[P1]!=r[P3] goto P2
**
** This works just like the Lt opcode except that the jump is taken if
** the operands in registers P1 and P3 are not equal.  See the Lt opcode for
** additional information.
**
** If SQLITE_NULLEQ is set in P5 then the result of comparison is always either
** true or false and is never NULL.  If both operands are NULL then the result
** of comparison is false.  If either operand is NULL then the result is true.
** If neither operand is NULL the result is the same as it would be if
** the SQLITE_NULLEQ flag were omitted from P5.
*/
/* Opcode: Eq P1 P2 P3 P4 P5
** Synopsis: if r[P1]==r[P3] goto P2
**
** This works just like the Lt opcode except that the jump is taken if
** the operands in registers P1 and P3 are equal.
** See the Lt opcode for additional information.
**
** If SQLITE_NULLEQ is set in P5 then the result of comparison is always either
** true or false and is never NULL.  If both operands are NULL then the result
** of comparison is true.  If either operand is NULL then the result is false.
** If neither operand is NULL the result is the same as it would be if
** the SQLITE_NULLEQ flag were omitted from P5.
*/
/* Opcode: Le P1 P2 P3 P4 P5
** Synopsis: if r[P1]<=r[P3] goto P2
**
** This works just like the Lt opcode except that the jump is taken if
** the content of register P3 is less than or equal to the content of
** register P1.  See the Lt opcode for additional information.
*/
/* Opcode: Gt P1 P2 P3 P4 P5
** Synopsis: if r[P1]>r[P3] goto P2
**
** This works just like the Lt opcode except that the jump is taken if
** the content of register P3 is greater than the content of
** register P1.  See the Lt opcode for additional information.
*/
/* Opcode: Ge P1 P2 P3 P4 P5
** Synopsis: if r[P1]>=r[P3] goto P2
**
** This works just like the Lt opcode except that the jump is taken if
** the content of register P3 is greater than or equal to the content of
** register P1.  See the Lt opcode for additional information.
*/
case OP_Eq:               /* same as TK_EQ, jump, in1, in3 */
case OP_Ne:               /* same as TK_NE, jump, in1, in3 */