[Bug fortran/58913] Segmentation fault on real128 array

[Bug fortran/58913] Segmentation fault on real128 array

[kargl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58913

kargl at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kargl at gcc dot gnu.org
           Severity|major                       |normal

--- Comment #1 from kargl at gcc dot gnu.org ---
What operating system?  Where did you get gfortran?

Your program works for 4.7.4, 4.8.2, and trunk on
x86_64 FreeBSD

[Bug fortran/58913] Segmentation fault on real128 array

[kargl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58913

--- Comment #2 from kargl at gcc dot gnu.org ---
(In reply to kargl from comment #1)
> What operating system?  Where did you get gfortran?
> 
> Your program works for 4.7.4, 4.8.2, and trunk on
> x86_64 FreeBSD

I take it back.  Your program does not work as you
may have intended on my system. real128 from 
iso_fortran_env is set to 10 not the desired 16.

However, changing real128 to 16 works.

[Bug fortran/58913] Segmentation fault on real128 array

[rrodrigues at poli dot ufrj.br]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58913

--- Comment #3 from Rodrigo Rodrigues <rrodrigues at poli dot ufrj.br> ---
Windows 7 x86
I got gfortran from mingw.

Actually, real128 returns 16 in my machine. It is totally equivalent to 16
here.

[Bug fortran/58913] Segmentation fault on real128 array

[sgk at troutmask dot apl.washington.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58913

--- Comment #4 from Steve Kargl <sgk at troutmask dot apl.washington.edu> ---
On Tue, Oct 29, 2013 at 07:47:36PM +0000, rrodrigues at poli dot ufrj.br wrote:
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58913
> 
> --- Comment #3 from Rodrigo Rodrigues <rrodrigues at poli dot ufrj.br> ---
> Windows 7 x86
> I got gfortran from mingw.
> 

Can you add -g to the command line and get a backtrace
with gdb?

Can you post the file created with the -fdump-tree-original
option?

[Bug fortran/58913] Segmentation fault on real128 array

[rrodrigues at poli dot ufrj.br]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58913

--- Comment #5 from Rodrigo Rodrigues <rrodrigues at poli dot ufrj.br> ---
There is no compile error. Adding -g for running doesn't show any new
information, just the same:

Program received signal SIGSEGV: Segmentation Fault - invalid memory reference.

Backtrace for this error:
#0 ffffffff


The dump file have:

MAIN__ ()
{
  real(kind=16) a[2];

  {
    static real(kind=16) A.0[2] = {0.0, 1.0e+0};

    (void) (MEM[(c_char * {ref-all})&a] = MEM[(c_char * {ref-all})&A.0]);
    {
      struct __st_parameter_dt dt_parm.1;

      dt_parm.1.common.filename = &"main.f90"[1]{lb: 1 sz: 1};
      dt_parm.1.common.line = 5;
      dt_parm.1.common.flags = 128;
      dt_parm.1.common.unit = 6;
      _gfortran_st_write (&dt_parm.1);
      {
        struct array1_real(kind=16) parm.2;

        parm.2.dtype = 1049;
        parm.2.dim[0].lbound = 1;
        parm.2.dim[0].ubound = 2;
        parm.2.dim[0].stride = 1;
        parm.2.data = (void *) &a[0];
        parm.2.offset = -1;
        _gfortran_transfer_array_write (&dt_parm.1, &parm.2, 16, 0);
      }
      _gfortran_st_write_done (&dt_parm.1);
    }
  }
}


main (integer(kind=4) argc, character(kind=1) * * argv)
{
  static integer(kind=4) options.3[7] = {68, 1023, 0, 0, 1, 1, 0};

  _gfortran_set_args (argc, argv);
  _gfortran_set_options (7, &options.3[0]);
  MAIN__ ();
  return 0;
}

[Bug fortran/58913] Segmentation fault on real128 array

[sgk at troutmask dot apl.washington.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58913

--- Comment #6 from Steve Kargl <sgk at troutmask dot apl.washington.edu> ---
On Tue, Oct 29, 2013 at 08:02:08PM +0000, rrodrigues at poli dot ufrj.br wrote:
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58913
> 
> --- Comment #5 from Rodrigo Rodrigues <rrodrigues at poli dot ufrj.br> ---
> There is no compile error. Adding -g for running doesn't show any new
> information, just the same:
> 
> Program received signal SIGSEGV: Segmentation Fault
> - invalid memory reference.
> 
> Backtrace for this error:
> #0 ffffffff

You need to run the file within gdb to get a backtrace.
I don't use MingW so I'm not sure how to do this.  On
FreeBSD, one would do

% gfortran -o z a.f90
% gdb ./z
gdb> run
(segfault occurs)
gdb> bt
(trace of function calls)

> The dump file have:

A quick glance shows that the dump looks like what I have here.

> MAIN__ ()
> {

(snip)

>         _gfortran_transfer_array_write (&dt_parm.1, &parm.2, 16, 0);

What I hope gdb shows is that segfault occurs in this function.
This would then mean we have an OS specific issue.

[Bug fortran/58913] Segmentation fault on real128 array

[rrodrigues at poli dot ufrj.br]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58913

--- Comment #7 from Rodrigo Rodrigues <rrodrigues at poli dot ufrj.br> ---
Here goes the backtrack:

#0  0x00000000 in ?? ()
#1  0x0042d483 in output_float_FMT_G_16 (comp_d=<optimized out>, 
    zero_flag=<optimized out>, sign_bit=<optimized out>, 
    size=<optimized out>, buffer=<optimized out>, m=<optimized out>, 
    f=0x22fb6c, dtp=<optimized out>)
    at ../../../gcc-4.8.0-mingw/libgfortran/io/write_float.def:1112
#2  write_float (dtp=dtp@entry=0x22fcf8, f=f@entry=0x22fbbc, 
    source=source@entry=0x22fe70 "", len=len@entry=16, comp_d=comp_d@entry=1)
    at ../../../gcc-4.8.0-mingw/libgfortran/io/write_float.def:1259
#3  0x0041f78f in __gfortrani_write_real (dtp=dtp@entry=0x22fcf8, 
    source=source@entry=0x22fe70 "", length=length@entry=16)
    at ../../../gcc-4.8.0-mingw/libgfortran/io/write.c:1470
#4  0x00419dd4 in list_formatted_write_scalar (size=16, kind=16, p=0x22fe70, 
    type=BT_REAL, dtp=0x22fcf8)
    at ../../../gcc-4.8.0-mingw/libgfortran/io/write.c:1571
#5  __gfortrani_list_formatted_write (dtp=0x22fcf8, type=BT_REAL, p=0x22fe70, 
    kind=16, size=16, nelems=2)
    at ../../../gcc-4.8.0-mingw/libgfortran/io/write.c:1599
#6  0x0041704b in __gfortran_transfer_array (dtp=0x22fcf8, desc=0x22fe58, 
    kind=16, charlen=<optimized out>)
    at ../../../gcc-4.8.0-mingw/libgfortran/io/transfer.c:2170
#7  0x0040173d in MAIN__ ()
#8  0x00401786 in main ()

[Bug fortran/58913] Segmentation fault on real128 array

[sgk at troutmask dot apl.washington.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58913

--- Comment #8 from Steve Kargl <sgk at troutmask dot apl.washington.edu> ---
On Tue, Oct 29, 2013 at 08:39:15PM +0000, rrodrigues at poli dot ufrj.br wrote:
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58913
> 
> --- Comment #7 from Rodrigo Rodrigues <rrodrigues at poli dot ufrj.br> ---
> Here goes the backtrack:
> 
> #0  0x00000000 in ?? ()
> #1  0x0042d483 in output_float_FMT_G_16 (comp_d=<optimized out>, 
>     zero_flag=<optimized out>, sign_bit=<optimized out>, 
>     size=<optimized out>, buffer=<optimized out>, m=<optimized out>, 
>     f=0x22fb6c, dtp=<optimized out>)
>     at ../../../gcc-4.8.0-mingw/libgfortran/io/write_float.def:1112
> #2  write_float (dtp=dtp@entry=0x22fcf8, f=f@entry=0x22fbbc, 
>     source=source@entry=0x22fe70 "", len=len@entry=16, comp_d=comp_d@entry=1)
>     at ../../../gcc-4.8.0-mingw/libgfortran/io/write_float.def:1259

Unfortnately, your trace suggests to me that this is MingW 
specific.  I can't help beyond this point.  Prehaps, ping 
the MingW developers?

[Bug fortran/58913] Segmentation fault on real128 array

[rrodrigues at poli dot ufrj.br]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58913

--- Comment #9 from Rodrigo Rodrigues <rrodrigues at poli dot ufrj.br> ---
(In reply to Steve Kargl from comment #8)
> Unfortnately, your trace suggests to me that this is MingW 
> specific.  I can't help beyond this point.  Prehaps, ping 
> the MingW developers?

Yeah, I have to agree.

I've tested tonight on two linux machines: a x86 ubuntu with gfortran 4.8.1 and
real128=16 and a x64 xubuntu with gfortran 4.7.3 and real128=10. Both worked
and run properly.

I also tested on a win8 x86 machine, with gfortran 4.8.0 abd real128=16 and it
worked too. I don't remember where did I get gfortran for that machine, I don't
know if it was from MingW also... but I don't think so.

Well, I'll try to contact MingW developers. Thank you Steve.

[Bug fortran/58913] Segmentation fault on real128 array

[rrodrigues at poli dot ufrj.br]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58913

--- Comment #10 from Rodrigo Rodrigues <rrodrigues at poli dot ufrj.br> ---
(In reply to Steve Kargl from comment #8)
> On Tue, Oct 29, 2013 at 08:39:15PM +0000, rrodrigues at poli dot ufrj.br
> wrote:
> > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58913
> > 
> > --- Comment #7 from Rodrigo Rodrigues <rrodrigues at poli dot ufrj.br> ---
> > Here goes the backtrack:
> > 
> > #0  0x00000000 in ?? ()
> > #1  0x0042d483 in output_float_FMT_G_16 (comp_d=<optimized out>, 
> >     zero_flag=<optimized out>, sign_bit=<optimized out>, 
> >     size=<optimized out>, buffer=<optimized out>, m=<optimized out>, 
> >     f=0x22fb6c, dtp=<optimized out>)
> >     at ../../../gcc-4.8.0-mingw/libgfortran/io/write_float.def:1112
> > #2  write_float (dtp=dtp@entry=0x22fcf8, f=f@entry=0x22fbbc, 
> >     source=source@entry=0x22fe70 "", len=len@entry=16, comp_d=comp_d@entry=1)
> >     at ../../../gcc-4.8.0-mingw/libgfortran/io/write_float.def:1259
> 
> Unfortnately, your trace suggests to me that this is MingW 
> specific.  I can't help beyond this point.  Prehaps, ping 
> the MingW developers?

Well, as I got gfortran binaries from http://www.equation.com/
I've contacted the Equation Team and they confirmed that that is a platform
specific bug. They addressed this bug and recommended to not use real128 float
numbers.

So I think that this bug report can be closed here. Thank you for the
attention.

[Bug fortran/58913] Segmentation fault on real128 array

[kargl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58913

--- Comment #11 from kargl at gcc dot gnu.org ---
Remove myself from cc list.

[Bug fortran/58913] Segmentation fault on real128 array

[rrodrigues at poli dot ufrj.br]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58913

Rodrigo Rodrigues <rrodrigues at poli dot ufrj.br> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |INVALID

--- Comment #12 from Rodrigo Rodrigues <rrodrigues at poli dot ufrj.br> ---
Ok, marking as invalid and closing...