https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102570
Bug ID: 102570
Summary: missed fully redudant with internal function of
add_overflow in FRE
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: pinskia at gcc dot gnu.org
Target Milestone: ---
Take:
bool f1(unsigned x, unsigned y, unsigned *res)
{
bool t = __builtin_add_overflow(x, y, res);
unsigned res1;
bool t1 = __builtin_add_overflow(x, y, &res1);
*res -= res1;
return t==t1;
}
This should be optimized at fre1 but currently takes into DOM to optimize it to
just *res = 0; return 1;
FRE does not handle some of the internal functions.
Note this is different from PR 102569 but related.
