[Bug middle-end/112572] [14 regression] LLVM miscompiled since r14-5355-g3cd3a09b3f91a1

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112572

--- Comment #17 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
It looks like another pass after vzeroupper depends on REG_DEAD/REG_UNUSED to
be correct but a different pass before that pass messes it up ...
I am still trying to figure out which pass is making the bad change.
Note vzeroupper does seems to be the same/correct but the updated
REG_DEAD/REG_UNUSED notes mess up the passes afterwards ...