https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114574
--- Comment #31 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I've tried to construct a wrong-code testcase, but so far haven't been
successful.
In e.g.
struct S { int s; } s;
struct T { long l; } t;
const struct S *
foo (const struct S **p, const struct T **q)
{
*p = &s;
*q = &t;
return *p;
}
fre1 optimizes the return *p to return &s;
So I've tried
[[gnu::always_inline]] static inline const void *
foo (void *x, bool y)
{
const struct S **p = (const struct S **) x;
struct S { int s; };
static struct S s;
if (y)
*p = &s;
return *p;
}
[[gnu::always_inline]] static inline void
bar (void *x)
{
const struct S **q = (const struct S **) x;
struct S { int s; };
static struct S s;
*q = &s;
}
const void *
baz (void *x, void *y)
{
foo (x, true);
bar (y);
return foo (x, false);
}
where without the posted patch I think the TYPE_CANONICAL on const struct S*
should be wrong in the bar function, but strangely we don't optimize it.
