[Bug sanitizer/99168] inconsistent behavior on -O0 and -O2 with ASAN on

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99168

--- Comment #5 from Martin Liška <marxin at gcc dot gnu.org> ---
(In reply to zhan3299 from comment #4)
> (In reply to Martin Liška from comment #3)
> > Very interesting issue, the failure is caused by IPA ICF that merges 2
> > variables with different alignments. I've got a patch candidate.
> 
> Hi, just curious because I am also studying the source code of GCC.
> 
> Is this issue is about sanitizer or optimization?

It's bad optimization done by IPA ICF. The issue is gone with -fno-ipa-icf.