[Bug fortran/67779] New: Strange ordering with strings in extended object

[Bug fortran/67779] New: Strange ordering with strings in extended object

[arjen.markus895 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67779

            Bug ID: 67779
           Summary: Strange ordering with strings in extended object
           Product: gcc
           Version: 4.9.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: arjen.markus895 at gmail dot com
  Target Milestone: ---

Created attachment 36421
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36421&action=edit
Source file demonstrating the problem

The attached program constructs a small array of integers and strings and then
sorts them. The output is:
 Sorting ...
 Result:
           1
           2
           3
           4
           5
           6
           7
           8
           9
          10
 String = 10         
 String = 1          
 String = 2          
 String = 3          
 String = 4          
 String = 5          
 String = 6          
 String = 7          
 String = 8          
 String = 9           

What is unexpected is the fact that "String = 10" comes before "String = 1". I
have not been able to reduce the code (other than removing the derived type
with integers) and still exhibit the odd ordering. The ten integers show that
the quicksort routine does its job, though. When comparing the strings in a
small program, "String = 10" definitely comes after "String = 1" as I would
expect.

[Bug fortran/67779] Strange ordering with strings in extended object

[gerhard.steinmetz.fortran@t-online.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67779

Gerhard Steinmetz <gerhard.steinmetz.fortran@t-online.de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |gerhard.steinmetz.fortran@t
                   |                            |-online.de

--- Comment #1 from Gerhard Steinmetz <gerhard.steinmetz.fortran@t-online.de> ---
This differs :
   llt('9 ', '10') : F
   llt(' 9', '10') : T

Test : changing format '(a,i0)' to e.g. '(a,i2)'

$ a.out
 Sorting ...
 Result:
           1
           2
           3
           4
           5
           6
           7
           8
           9
          10
 String =  1
 String =  2
 String =  3
 String =  4
 String =  5
 String =  6
 String =  7
 String =  8
 String =  9
 String = 10

[Bug fortran/67779] Strange ordering with strings in extended object

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67779

Dominique d'Humieres <dominiq at lps dot ens.fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING
   Last reconfirmed|                            |2015-10-09
     Ever confirmed|0                           |1

--- Comment #2 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
> Test : changing format '(a,i0)' to e.g. '(a,i2)'

Confirmed. Closing as INVALID?

[Bug fortran/67779] Strange ordering with strings in extended object

[arjen.markus895 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67779

--- Comment #3 from Arjen Markus <arjen.markus895 at gmail dot com> ---
Let me clarify: 
the STRING "String = 10" should come after the STRING "String = 1 ". It is not
a matter of the numbers inside. If you compare these strings with LLT(), you
will see this.

[Bug fortran/67779] Strange ordering with strings in extended object

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67779

--- Comment #4 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
I have instrumented the test and found that 'String = 10         ', which at
the first position, is compared only once at the first call to quick sort, but
not for the other invocations of array(1:j). I am unable to understand why.

[Bug fortran/67779] Strange ordering with strings in extended object

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67779

--- Comment #5 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
Apparently there is a nasty bug somewhere: if I sort

           'String = 2          '
           'String = 9          '
           'String = 8          '
           'String = 7          '
           'String = 6          '
           'String = 5          '
           'String = 4          '
           'String = 3          '
           'String = 10         '
           'String = 1          '

I get

 String = 2          
 String = 1          
 String = 10         
 String = 3          
 String = 4          
 String = 5          
 String = 6          
 String = 7          
 String = 8          
 String = 9

[Bug fortran/67779] Strange ordering with strings in extended object

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67779

--- Comment #6 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
The problem is not limited to strings. If I add the following lines

        array(1)%value = 2
        array(9)%value = 10
        write( string_array(1)%value, '(a,i0)' ) "String = ", 2
        write( string_array(9)%value, '(a,i0)' ) "String = ", 10

the initial values are

           2 'String = 2          '
           9 'String = 9          '
           8 'String = 8          '
           7 'String = 7          '
           6 'String = 6          '
           5 'String = 5          '
           4 'String = 4          '
           3 'String = 3          '
          10 'String = 10         '
           1 'String = 1          '

and the "sorted" ones are

           2
           1
           3
           4
           5
           6
           7
           8
          10
           9
 String = 2          
 String = 1          
 String = 10         
 String = 3          
 String = 4          
 String = 5          
 String = 6          
 String = 7          
 String = 8          
 String = 9

[Bug fortran/67779] Strange ordering with strings in extended object

[arjen.markus895 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67779

--- Comment #7 from Arjen Markus <arjen.markus895 at gmail dot com> ---
Yes, I can confirm this - I also tried with the Intel Fortran compiler and that
sorts the integers and strings in the way one would expect.