SQLite

    iKey = sqlite3VdbeIntValue(pIn3); /* Get the integer key value */
    newType = pIn3->flags; /* Record the type after applying numeric affinity */
    pIn3->flags = flags3;  /* But convert the type back to its original */

    /* If the P3 value could not be converted into an integer without
    ** loss of information, then special processing is required... */
    if( (newType & (MEM_Int|MEM_IntReal))==0 ){
      int c;
      if( (newType & MEM_Real)==0 ){
        if( (newType & MEM_Null) || oc>=OP_SeekGE ){
          VdbeBranchTaken(1,2);
          goto jump_to_p2;
        }else{
          rc = sqlite3BtreeLast(pC->uc.pCursor, &res);
          if( rc!=SQLITE_OK ) goto abort_due_to_error;
          goto seek_not_found;
        }

      }
      c = sqlite3IntFloatCompare(iKey, pIn3->u.r);

      /* If the approximation iKey is larger than the actual real search
      ** term, substitute >= for > and < for <=. e.g. if the search term
      ** is 4.9 and the integer approximation 5:
      **
      **        (x >  4.9)    ->     (x >= 5)
      **        (x <= 4.9)    ->     (x <  5)
      */
      if( c>0 ){
        assert( OP_SeekGE==(OP_SeekGT-1) );
        assert( OP_SeekLT==(OP_SeekLE-1) );
        assert( (OP_SeekLE & 0x0001)==(OP_SeekGT & 0x0001) );
        if( (oc & 0x0001)==(OP_SeekGT & 0x0001) ) oc--;
      }

      /* If the approximation iKey is smaller than the actual real search
      ** term, substitute <= for < and > for >=.  */
      else if( c<0 ){
        assert( OP_SeekLE==(OP_SeekLT+1) );
        assert( OP_SeekGT==(OP_SeekGE+1) );
        assert( (OP_SeekLT & 0x0001)==(OP_SeekGE & 0x0001) );
        if( (oc & 0x0001)==(OP_SeekLT & 0x0001) ) oc++;
      }
    }
    rc = sqlite3BtreeTableMoveto(pC->uc.pCursor, (u64)iKey, 0, &res);

void sqlite3VdbeMemSetZeroBlob(Mem*,int);
#ifdef SQLITE_DEBUG
int sqlite3VdbeMemIsRowSet(const Mem*);
#endif
int sqlite3VdbeMemSetRowSet(Mem*);
int sqlite3VdbeMemMakeWriteable(Mem*);
int sqlite3VdbeMemStringify(Mem*, u8, u8);
int sqlite3IntFloatCompare(i64,double);
i64 sqlite3VdbeIntValue(Mem*);
int sqlite3VdbeMemIntegerify(Mem*);
double sqlite3VdbeRealValue(Mem*);
int sqlite3VdbeBooleanValue(Mem*, int ifNull);
void sqlite3VdbeIntegerAffinity(Mem*);
int sqlite3VdbeMemRealify(Mem*);
int sqlite3VdbeMemNumerify(Mem*);

}

/*
** Do a comparison between a 64-bit signed integer and a 64-bit floating-point
** number.  Return negative, zero, or positive if the first (i64) is less than,
** equal to, or greater than the second (double).
*/
int sqlite3IntFloatCompare(i64 i, double r){
  if( sizeof(LONGDOUBLE_TYPE)>8 ){
    LONGDOUBLE_TYPE x = (LONGDOUBLE_TYPE)i;
    testcase( x<r );
    testcase( x>r );
    testcase( x==r );
    if( x<r ) return -1;
    if( x>r ) return +1;  /*NO_TEST*/ /* work around bugs in gcov */

} {1}
do_execsql_test where-26.7 {
  SELECT '-1'>=0 AND '-1'<=t0.c0 FROM t0;
} {1}
do_execsql_test where-26.8 {
  SELECT '-1'>=0 AND '-1'<=t1.c0 FROM t1;
} {1}

# 2021-07-19 https://sqlite.org/forum/forumpost/2bdb86a068
# Lose of precision when doing comparisons between integer and
# floating point values that are near 9223372036854775807 in the
# OP_SeekGE opcode (and similar).
#
reset_db
do_execsql_test where-27.1 {
  CREATE TABLE t1(a INTEGER PRIMARY KEY);
  INSERT INTO t1(a) VALUES(9223372036854775807);
  SELECT 1 FROM t1 WHERE a>=(9223372036854775807+1);
} {}
do_execsql_test where-27.2 {
  SELECT a>=9223372036854775807+1 FROM t1;
} {0}

finish_test