Re: beta gfortran 14.x.y (using -march=native and intrinsic repeat) gives a signal SIGILL
On 8/12/23 6:41 AM, Jorge D'Elia wrote: Hi Paul, - Mensaje original - De: "Paul Richard Thomas" Para: "Jerry" CC: "Jorge D'Elia" , "Gfortran List" , "Jorge D'Elia" Enviado: Sábado, 12 de Agosto 2023 3:56:44 Asunto: Re: beta gfortran 14.x.y (using -march=native and intrinsic repeat) gives a signal SIGILL Hi Jorge, There were some recent patches in this area IIRC. Jerry The tree dump is identical to mine, obtained with GNU Fortran (GCC) 14.0.0 20230809 (experimental), so I doubt that any recent patches are responsible. It seems so. Furthermore, I have the feeling that the problem is outside GFortran, between the use of -mtune=native versus -march=native. For example, $ gfortran --version GNU Fortran (GCC) 14.0.0 20230808 (experimental) $ ls -all total 4 drwxr-xr-x. 1 jdelia jdelia 16 Aug 12 10:06 . drwxr-xr-x. 1 jdelia jdelia 2782 Aug 12 10:05 .. -rwxr-xr-x. 1 jdelia jdelia 223 Aug 11 08:28 test.f90 $ gfortran -mtune=native -fcheck=all -std=f2018 -Wall -Werror -Wextra -g -fdump-tree-original -o test-mtune.exe test.f90 $ ls -all total 36 drwxr-xr-x. 1 jdelia jdelia 110 Aug 12 10:17 . drwxr-xr-x. 1 jdelia jdelia 2782 Aug 12 10:05 .. -rwxr-xr-x. 1 jdelia jdelia 223 Aug 11 08:28 test.f90 -rwxr-xr-x. 1 jdelia jdelia 26856 Aug 12 10:17 test-mtune.exe -rw-r--r--. 1 jdelia jdelia 1405 Aug 12 10:17 test-mtune-test.f90.005t.original $ mv test-mtune-test.f90.005t.original test-mtune.f90.005t.original $ ls -all total 36 drwxr-xr-x. 1 jdelia jdelia 100 Aug 12 10:19 . drwxr-xr-x. 1 jdelia jdelia 2782 Aug 12 10:05 .. -rwxr-xr-x. 1 jdelia jdelia 223 Aug 11 08:28 test.f90 -rwxr-xr-x. 1 jdelia jdelia 26856 Aug 12 10:17 test-mtune.exe -rw-r--r--. 1 jdelia jdelia 1405 Aug 12 10:17 test-mtune.f90.005t.original $ gfortran -march=native -fcheck=all -std=f2018 -Wall -Werror -Wextra -g -fdump-tree-original -o test-march.exe test.f90 $ ls -all total 68 drwxr-xr-x. 1 jdelia jdelia 194 Aug 12 10:19 . drwxr-xr-x. 1 jdelia jdelia 2782 Aug 12 10:05 .. -rwxr-xr-x. 1 jdelia jdelia 223 Aug 11 08:28 test.f90 -rwxr-xr-x. 1 jdelia jdelia 28064 Aug 12 10:19 test-march.exe -rw-r--r--. 1 jdelia jdelia 1405 Aug 12 10:19 test-march-test.f90.005t.original -rwxr-xr-x. 1 jdelia jdelia 26856 Aug 12 10:17 test-mtune.exe -rw-r--r--. 1 jdelia jdelia 1405 Aug 12 10:17 test-mtune.f90.005t.original $ mv test-march-test.f90.005t.original test-march.f90.005t.original $ ls -all total 68 drwxr-xr-x. 1 jdelia jdelia 184 Aug 12 10:19 . drwxr-xr-x. 1 jdelia jdelia 2782 Aug 12 10:05 .. -rwxr-xr-x. 1 jdelia jdelia 223 Aug 11 08:28 test.f90 -rwxr-xr-x. 1 jdelia jdelia 28064 Aug 12 10:19 test-march.exe -rw-r--r--. 1 jdelia jdelia 1405 Aug 12 10:19 test-march.f90.005t.original -rwxr-xr-x. 1 jdelia jdelia 26856 Aug 12 10:17 test-mtune.exe -rw-r--r--. 1 jdelia jdelia 1405 Aug 12 10:17 test-mtune.f90.005t.original $ diff test-mtune.f90.005t.original test-march.f90.005t.original # (nothing is shown, thus both tree dumps ares identical). $ test-mtune.exe cc : $ test-march.exe Program received signal SIGILL: Illegal instruction. Backtrace for this error: #0 0x15268845fb1f in ??? #1 0x4011c2 in test at /home/jdelia/TEST/test.f90:6 #2 0x4012ae in main at /home/jdelia/TEST/test.f90:8 Illegal instruction (core dumped) Being unable to reproduce the error, there is not much that I can do. Sorry Non problem. To avoid this error, for now we exclude the use of -march=native in our makefiles, and just use -mtune=native. Paul Thanks for your time. Regards. Jorge. -- I have not been able to reproduce it here. I tried on: gcc version 14.0.0 20230804 (experimental) (GCC) and gcc version 14.0.0 20230812 (experimental) (GCC) I wonder if you caught a version in between changes happening? $ lscpu Architecture:x86_64 CPU op-mode(s):32-bit, 64-bit Address sizes: 48 bits physical, 48 bits virtual Byte Order:Little Endian I started to draft a PR this morning, not sure. I know it is a pain to do, can you build a later version of gfortran and see if your results are different? Also, I have seen times where the libgfortran files were out of sync with the build because LD_LIBRARY_PATH was not pointing in the correct place. So check these things. Regards, Jerry
Re: beta gfortran 14.x.y (using -march=native and intrinsic repeat) gives a signal SIGILL
On Sat, Aug 12, 2023 at 10:41:10AM -0300, Jorge D'Elia via Fortran wrote: > > $ test-march.exe > > Program received signal SIGILL: Illegal instruction. > This, to me, suggests that the backend is emitting a wrong assembly language code. I suspect that you'll need to compare the generated assembly code between a working gfortran and the bad gfortran. It is also possible to get a listing of the actually options that -march=native activates. For example, % gfcx -o z -O -march=native --verbose a.f90 It is the options that begin with -m that matter. For my hardware I see 108 such options. With patients you can determine if one of these triggers the issues. One can also scan gcc/gcc/ChangeLog for changes to config/i386/i386.md. For example 2023-08-07 Jan Beulich * config/i386/i386.md (sse4_1_round2): Make "length_immediate" uniformly 1. * config/i386/mmx.md (mmx_pblendvb_v8qi): Likewise. (mmx_pblendvb_): Likewise. There are at least 10 commits on 2023-08-07 to this file. Finally, as a non-git user, you can always try git's bisection feature to identify where things go left. -- Steve
Re: beta gfortran 14.x.y (using -march=native and intrinsic repeat) gives a signal SIGILL
Hi Paul, - Mensaje original - > De: "Paul Richard Thomas" > Para: "Jerry" > CC: "Jorge D'Elia" , "Gfortran List" > , "Jorge D'Elia" > > Enviado: Sábado, 12 de Agosto 2023 3:56:44 > Asunto: Re: beta gfortran 14.x.y (using -march=native and intrinsic repeat) > gives a signal SIGILL > > Hi Jorge, > >> There were some recent patches in this area IIRC. >> >> Jerry > > The tree dump is identical to mine, obtained with GNU Fortran (GCC) > 14.0.0 20230809 (experimental), so I doubt that any recent patches are > responsible. It seems so. Furthermore, I have the feeling that the problem is outside GFortran, between the use of -mtune=native versus -march=native. For example, $ gfortran --version GNU Fortran (GCC) 14.0.0 20230808 (experimental) $ ls -all total 4 drwxr-xr-x. 1 jdelia jdelia 16 Aug 12 10:06 . drwxr-xr-x. 1 jdelia jdelia 2782 Aug 12 10:05 .. -rwxr-xr-x. 1 jdelia jdelia 223 Aug 11 08:28 test.f90 $ gfortran -mtune=native -fcheck=all -std=f2018 -Wall -Werror -Wextra -g -fdump-tree-original -o test-mtune.exe test.f90 $ ls -all total 36 drwxr-xr-x. 1 jdelia jdelia 110 Aug 12 10:17 . drwxr-xr-x. 1 jdelia jdelia 2782 Aug 12 10:05 .. -rwxr-xr-x. 1 jdelia jdelia 223 Aug 11 08:28 test.f90 -rwxr-xr-x. 1 jdelia jdelia 26856 Aug 12 10:17 test-mtune.exe -rw-r--r--. 1 jdelia jdelia 1405 Aug 12 10:17 test-mtune-test.f90.005t.original $ mv test-mtune-test.f90.005t.original test-mtune.f90.005t.original $ ls -all total 36 drwxr-xr-x. 1 jdelia jdelia 100 Aug 12 10:19 . drwxr-xr-x. 1 jdelia jdelia 2782 Aug 12 10:05 .. -rwxr-xr-x. 1 jdelia jdelia 223 Aug 11 08:28 test.f90 -rwxr-xr-x. 1 jdelia jdelia 26856 Aug 12 10:17 test-mtune.exe -rw-r--r--. 1 jdelia jdelia 1405 Aug 12 10:17 test-mtune.f90.005t.original $ gfortran -march=native -fcheck=all -std=f2018 -Wall -Werror -Wextra -g -fdump-tree-original -o test-march.exe test.f90 $ ls -all total 68 drwxr-xr-x. 1 jdelia jdelia 194 Aug 12 10:19 . drwxr-xr-x. 1 jdelia jdelia 2782 Aug 12 10:05 .. -rwxr-xr-x. 1 jdelia jdelia 223 Aug 11 08:28 test.f90 -rwxr-xr-x. 1 jdelia jdelia 28064 Aug 12 10:19 test-march.exe -rw-r--r--. 1 jdelia jdelia 1405 Aug 12 10:19 test-march-test.f90.005t.original -rwxr-xr-x. 1 jdelia jdelia 26856 Aug 12 10:17 test-mtune.exe -rw-r--r--. 1 jdelia jdelia 1405 Aug 12 10:17 test-mtune.f90.005t.original $ mv test-march-test.f90.005t.original test-march.f90.005t.original $ ls -all total 68 drwxr-xr-x. 1 jdelia jdelia 184 Aug 12 10:19 . drwxr-xr-x. 1 jdelia jdelia 2782 Aug 12 10:05 .. -rwxr-xr-x. 1 jdelia jdelia 223 Aug 11 08:28 test.f90 -rwxr-xr-x. 1 jdelia jdelia 28064 Aug 12 10:19 test-march.exe -rw-r--r--. 1 jdelia jdelia 1405 Aug 12 10:19 test-march.f90.005t.original -rwxr-xr-x. 1 jdelia jdelia 26856 Aug 12 10:17 test-mtune.exe -rw-r--r--. 1 jdelia jdelia 1405 Aug 12 10:17 test-mtune.f90.005t.original $ diff test-mtune.f90.005t.original test-march.f90.005t.original # (nothing is shown, thus both tree dumps ares identical). $ test-mtune.exe cc : $ test-march.exe Program received signal SIGILL: Illegal instruction. Backtrace for this error: #0 0x15268845fb1f in ??? #1 0x4011c2 in test at /home/jdelia/TEST/test.f90:6 #2 0x4012ae in main at /home/jdelia/TEST/test.f90:8 Illegal instruction (core dumped) > Being unable to reproduce the error, there is not much that I can do. > Sorry Non problem. To avoid this error, for now we exclude the use of -march=native in our makefiles, and just use -mtune=native. > Paul Thanks for your time. Regards. Jorge. --
Re: beta gfortran 14.x.y (using -march=native and intrinsic repeat) gives a signal SIGILL
Hi Jorge, > There were some recent patches in this area IIRC. > > Jerry The tree dump is identical to mine, obtained with GNU Fortran (GCC) 14.0.0 20230809 (experimental), so I doubt that any recent patches are responsible. Being unable to reproduce the error, there is not much that I can do. Sorry Paul
Re: beta gfortran 14.x.y (using -march=native and intrinsic repeat) gives a signal SIGILL
Dear Paul / Jerry,
- Mensaje original -
> De: "Paul Richard Thomas"
> Para: "Jerry D"
> CC: "Jorge D'Elia" , "Gfortran List" , "Jorge D'Elia"
>
> Enviado: Viernes, 11 de Agosto 2023 13:55:43
> Asunto: Re: beta gfortran 14.x.y (using -march=native and intrinsic repeat)
> gives a signal SIGILL
>
> 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 *) , (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 (_parm.0);
>{
> character(kind=1) str.1[38];
> character(kind=1) str.2[41];
>
> _gfortran_concat_string (38, (character(kind=1)[1:] *) ,
> 6, &" cc : "[1]{lb: 1 sz: 1}, 32, );
> _gfortran_concat_string (41, (character(kind=1)[1:] *) ,
> 38, (character(kind=1)[1:] *) , 3, &"end"[1]{lb: 1 sz: 1});
> _gfortran_transfer_character_write (_parm.0,
> (character(kind=1)[1:] *) , 41);
>}
>_gfortran_st_write_done (_parm.0);
> }
> }
>
> Note that repeat is reduced to the builtin memmove with 32 spaces going to cc.
Ok, then using:
$ gfortran --version
GNU Fortran (GCC) 14.0.0 20230808 (experimental)
$ gfortran -mtune=native -march=native -fcheck=all -std=f2018 -Wall -Werror
-Wextra -g -fdump-tree-original -o test.exe test.f90
$ cat test.f90.005t.original
__attribute__((fn spec (". ")))
void test ()
{
static logical(kind=4) is_recursive.0 = 0;
character(kind=1) cc[1:32];
try
{
if (is_recursive.0)
{
_gfortran_runtime_error_at (&"At line 1 of file test.f90"[1]{lb: 1
sz: 1}, &"Recursive call to nonrecursive procedure \'test\'"[1]{lb: 1 sz: 1});
}
is_recursive.0 = 1;
__builtin_memmove ((void *) , (void *) &"
"[1]{lb: 1 sz: 1}, 32);
{
struct __st_parameter_dt dt_parm.1;
dt_parm.1.common.filename = &"test.f90"[1]{lb: 1 sz: 1};
dt_parm.1.common.line = 7;
dt_parm.1.common.flags = 128;
dt_parm.1.common.unit = 6;
_gfortran_st_write (_parm.1);
{
character(kind=1) str.2[38];
_gfortran_concat_string (38, (character(kind=1)[1:] *) , 6, &"
cc : "[1]{lb: 1 sz: 1}, 32, );
_gfortran_transfer_character_write (_parm.1,
(character(kind=1)[1:] *) , 38);
}
_gfortran_st_write_done (_parm.1);
}
}
finally
{
is_recursive.0 = 0;
}
}
__attribute__((externally_visible))
integer(kind=4) main (integer(kind=4) argc, character(kind=1) * * argv)
{
static integer(kind=4) options.3[7] = {1282, 1947, 0, 1, 1, 1, 31};
_gfortran_set_args (argc, argv);
_gfortran_set_options (7, [0]);
test ();
return 0;
}
$ test.exe
Program received signal SIGILL: Illegal instruction.
Backtrace for this error:
#0 0x14aded839b1f in ???
#1 0x4011c2 in test
at /home/jdelia/TESTS/test.f90:6
#2 0x4012ae in main
at /home/jdelia/TESTS/test.f90:8
Illegal instruction (core dumped)
> Regards
> Paul
>
> On Fri, 11 Aug 2023 at 17:21, Jerry D via Fortran 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.
>
Re: beta gfortran 14.x.y (using -march=native and intrinsic repeat) gives a signal SIGILL
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 *) , (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 (_parm.0);
{
character(kind=1) str.1[38];
character(kind=1) str.2[41];
_gfortran_concat_string (38, (character(kind=1)[1:] *) ,
6, &" cc : "[1]{lb: 1 sz: 1}, 32, );
_gfortran_concat_string (41, (character(kind=1)[1:] *) ,
38, (character(kind=1)[1:] *) , 3, &"end"[1]{lb: 1 sz: 1});
_gfortran_transfer_character_write (_parm.0,
(character(kind=1)[1:] *) , 41);
}
_gfortran_st_write_done (_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 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 0x 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
>
Re: beta gfortran 14.x.y (using -march=native and intrinsic repeat) gives a signal SIGILL
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 0x 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
beta gfortran 14.x.y (using -march=native and intrinsic repeat) gives a signal SIGILL
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 0x 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)...
Regards.
Jorge.
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