https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110963
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #1)
> Confirmed.
> PRE seems to have missed an obvious redundant load here though:
Skipping partial redundancy for expression {mem_ref<0B>,addr_expr<&h>}@.MEM_21
(0008), no redundancy on to be optimized for speed edge
renaming 'main' into 'bar' fixes this:
Found partial redundancy for expression {mem_ref<0B>,addr_expr<&h>}@.MEM_22
(0007)
Created phi prephitmp_7 = PHI <_10(11), 0B(6)>
in block 7 (0007)
...
then the call to 'foo' is eliminated already in FRE5 (before the sinking pass
affected by r14-2946-g46c8c225455).
IMHO this isn't a bug worth pursuing.
Alternatively you can put __attribute__((hot)) on 'main' which we otherwise
consider cold. Maybe that's a good idea for future DCE regression searches?
Maybe we can consider the special case worthwhile also when optimizing for
size.
