https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102622
Aldy Hernandez <aldyh at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |aldyh at gcc dot gnu.org
--- Comment #4 from Aldy Hernandez <aldyh at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #3)
> (In reply to Andrew Pinski from comment #2)
> > Here is a slightly more reduced testcase (without the reasonable values):
>
> Looks like the store to var_22 was fully removed, I think this is not a
> vectorizer bug really, but rather some issue with jump threading ....
I'm getting an illegal instruction, so perhaps I don't have a machine with the
appropriate hardware. I even get the illegal instruction with
-fno-thread-jumps:
(base) abulafia:~/bld/t/gcc$ ./xg++ -B./ a.c -O3
-L/usr/lib/gcc/x86_64-redhat-linux/11/ -march=skylake-avx512
(base) abulafia:~/bld/t/gcc$ ./a.out
Illegal instruction (core dumped)
Can you try with -fno-thread-jumps to make sure its really the threader at
play?
If so, you could try to narrow it down to the problematic threading path with:
-fdbg-cnt=registered_jump_thread:N:N
where N is the number that causes the problem.
Once it's narrowed, I could look at the path and see if it's valid.
Thanks.
