RtlAreBitsClearEx

VOID __stdcall RtlAreBitsClearEx(_RTL_BITMAP_EX *BitMapHeader, UINT64 StartingIndex, UINT64 Length){
  unsigned __int64 *Buffer; 
  unsigned __int64 *v4; 
  unsigned __int64 *v5; 
  unsigned __int64 *i; 

  if( StartingIndex < BitMapHeader->SizeOfBitMap )
  {
    if( Length <= 1 )
    {
      if( Length == 1 )
        _bittest64((const signed __int64 *)BitMapHeader->Buffer, StartingIndex);
    }
    else if( BitMapHeader->SizeOfBitMap - StartingIndex >= Length )
    {
      Buffer = BitMapHeader->Buffer;
      v4 = &Buffer[StartingIndex >> 6];
      v5 = &Buffer[(StartingIndex + Length - 1) >> 6];
      if( v4 != v5 && (Buffer[StartingIndex >> 6] & (-1i64 << StartingIndex)) == 0 )
      {
        for( i = v4 + 1; i != v5; ++i )
        {
          if( *i )
            break;
        }
      }
    }
  }
}

Referenced by: