https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105728
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Component|c |ipa
Last reconfirmed| |2022-05-27
Ever confirmed|0 |1
Keywords| |missed-optimization
CC| |hubicka at gcc dot gnu.org,
| |marxin at gcc dot gnu.org,
| |rguenth at gcc dot gnu.org
Status|UNCONFIRMED |NEW
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
the dummy1/dummy2 optimizations could eventually be done by DCE if we knew that
'removeme' is only ever accessed from 'dummy1' / 'dummy2', in that case we
could consider the variable local and since there's no data dependence on it
we could elide it.
Don't we track that already in IPA? I think local passes cannot rely on
IPA references? We also need to consider
void foo (int *);
int dummy1()
{
static int removeme = 0;
static int *p = &removeme;
foo (p);
if (removeme)
{
return 0;
}
removeme = 1;
return 0;
}
thus global CTORs (the above will see the init in dummy1(), but not sure
whether we can rely on that?)
