I wonder why the development 14.0.0 doesn't exhibit this behaviour?
Could you please rerun with the compile options -g -fdump-tree-original .
The later should generate a file *.original with the content:
void test ()
{
character(kind=1) cc[1:32];
__builtin_memmove ((void *) &cc, (void *) &"
"[1]{lb: 1 sz: 1}, 32);
{
struct __st_parameter_dt dt_parm.0;
dt_parm.0.common.filename = &"test_repeat.f90"[1]{lb: 1 sz: 1};
dt_parm.0.common.line = 7;
dt_parm.0.common.flags = 128;
dt_parm.0.common.unit = 6;
_gfortran_st_write (&dt_parm.0);
{
character(kind=1) str.1[38];
character(kind=1) str.2[41];
_gfortran_concat_string (38, (character(kind=1)[1:] *) &str.1,
6, &" cc : "[1]{lb: 1 sz: 1}, 32, &cc);
_gfortran_concat_string (41, (character(kind=1)[1:] *) &str.2,
38, (character(kind=1)[1:] *) &str.1, 3, &"end"[1]{lb: 1 sz: 1});
_gfortran_transfer_character_write (&dt_parm.0,
(character(kind=1)[1:] *) &str.2, 41);
}
_gfortran_st_write_done (&dt_parm.0);
}
}
Note that repeat is reduced to the builtin memmove with 32 spaces going to cc.
Regards
Paul
On Fri, 11 Aug 2023 at 17:21, Jerry D via Fortran <[email protected]> wrote:
>
> On 8/11/23 5:34 AM, Jorge D'Elia via Fortran wrote:
> > Dear GFortran developers,
> >
> > With the beta gfortran 14.x.y versions we are noticing some runtime
> > errors in a production code.
> >
> > One type of runtime errors is related to the concurrent use of the
> > intrinsic "repeat" when the source code is compiled with the
> > flag -march=native, please, see below:
> >
> > $ cat test.f90
> > program test
> > implicit none
> > integer , parameter :: iin = kind (1)
> > integer (iin), parameter :: pp = 32
> > character (len=pp) :: cc
> > cc (1:pp) = repeat (" ",pp)
> > write (*,*)" cc : " // cc
> > end program test
> >
> > $ gfortran --version
> > GNU Fortran (GCC) 14.0.0 20230808 (experimental)
> > Copyright (C) 2023 Free Software Foundation, Inc.
> > This is free software; see the source for copying conditions. There is NO
> > warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
> >
> > a) Compiling with the flag -mtune=native only, without -march=native, the
> > test is ok:
> >
> > $ gfortran -mtune=native -fcheck=all -std=f2018 -Wall -Werror -Wextra -Og
> > -o test.exe test.f90
> > $ test.exe
> > cc :
> >
> > b) However, compiling with the flag -march=native:
> >
> > $ gfortran -march=native -fcheck=all -std=f2018 -Wall -Werror -Wextra -Og
> > -o test.exe test.f90
> > $ test.exe
> >
> > Program received signal SIGILL: Illegal instruction.
> >
> > Backtrace for this error:
> > #0 0x14fae277fb1f in ???
> > #1 0x4011ad in ???
> > #2 0x401272 in ???
> > #3 0x14fae276a50f in ???
> > #4 0x14fae276a5c8 in ???
> > #5 0x4010c4 in ???
> > #6 0xffffffffffffffff in ???
> > Illegal instruction (core dumped)
> >
> > On the other hand, compiling with the system version (GNU Fortran (GCC)
> > 12.3.1 20230508 (Red Hat 12.3.1-1)) or replacing the intrinsic repeat
> > with:
> >
> > do kk = 1, pp
> > cc (kk:kk) = " "
> > end do
> >
> > both tests are ok. The error occurs on any of Intel or AMD computers,
> > e.g. in the present case:
> >
> > $ lscpu
> > Architecture: x86_64
> > CPU op-mode(s): 32-bit, 64-bit
> > Address sizes: 46 bits physical, 48 bits virtual
> > Byte Order: Little Endian
> > CPU(s): 6
> > On-line CPU(s) list: 0-5
> > Vendor ID: GenuineIntel
> > Model name: Intel(R) Core(TM) i7-3930K CPU @ 3.20GHz
> > CPU family: 6
> > Model: 45
> > Thread(s) per core: 1
> > Core(s) per socket: 6
> > Socket(s): 1
> > Stepping: 7
> > BogoMIPS: 6400.22
> > Caches (sum of all):
> > L1d: 192 KiB (6 instances)
> > L1i: 192 KiB (6 instances)
> > L2: 1.5 MiB (6 instances)
> > L3: 12 MiB (1 instance)
> > NUMA:
> > NUMA node(s): 1
> > NUMA node0 CPU(s): 0-5
> >
> >
> > By the way, I do not know if the -march=native flag or the intrinsic
> > repeat would be of deprecated use (or not)...
>
> Regardless, we should never segfault. Thanks for the code example. We
> need to get a bug report opened on this. I am on travel this morning,
> but if I have time i will do so this afternnon if someone else does not
> beat me to it.
>
> There were some recent patches in this area IIRC.
>
> Jerry
>
