[Bug rtl-optimization/90378] [9/10 regression] -Os -flto miscompiles 454.calculix after r266385 on Arm

[clyon at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90378

--- Comment #10 from Christophe Lyon <clyon at gcc dot gnu.org> ---
I checked the stack settings on the ARMv7 and ARMv8 machines:
ARMv7: beced000-bed0e000 rw-p 00000000 00:00 0          [stack]
ARMv8: fff12000-fff33000 rw-p 00000000 00:00 0          [stack]

In both cases ulimit -a says:
stack size              (kbytes, -s) 8192


I recompiled with "-Os -flto  -g -mthumb" (ie. I added -g) and execution
sometimes reaches iteration 2, sometimes not.

Using gdb I got a bit more info:
Program received signal SIGSEGV, Segmentation fault.
_int_free (av=0xc59a20, p=<optimized out>, have_lock=12975032) at malloc.c:4088
4088    malloc.c: No such file or directory.

But this is random too, another run gave:
Program received signal SIGSEGV, Segmentation fault.
__brk (addr=0x1) at ../sysdeps/unix/sysv/linux/arm/brk.c:31
31      ../sysdeps/unix/sysv/linux/arm/brk.c: No such file or directory.


Other runs from the same gdb gave no backtrace at all, and at least one of them
reached iteration 4.