[Bug tree-optimization/118954] [15 regression] Miscompile at -O3

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118954

--- Comment #9 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Sam James from comment #8)
> Sorry about that. It doesn't always hang because of uninit memory.
> 
> With Valgrind, I got r15-1757-g4d24159a1fcb15. Does that sound more
> reasonable?

Maybe. 

For the bisect you could add `-fdump-tree-dse4` and then `grep "Deleted dead
store" *.dse4` which might be a more reliable way. In the working case there
will be no matches.