https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121954
Bug ID: 121954
Summary: Missing CLOBBER(eos) for temporary of function
return/arg
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: pinskia at gcc dot gnu.org
Target Milestone: ---
Take:
```
struct s1 {
int i[1024];
};
void f1(struct s1 *);
static inline struct s1 f(struct s1 a)
{
f1(&a);
return a;
}
void h();
struct s1 g(int a)
{
struct s1 b = {a};
struct s1 c = f(f(f(f(b))));
h();
struct s1 s = f(f(f(f(c))));
h();
return s;
}
```
The gimplifier produces:
```
D.4653 = f (b); [return slot optimization]
D.4654 = f (D.4653); [return slot optimization]
D.4655 = f (D.4654); [return slot optimization]
c = f (D.4655); [return slot optimization]
h ();
D.4656 = f (c); [return slot optimization]
D.4657 = f (D.4656); [return slot optimization]
D.4658 = f (D.4657); [return slot optimization]
<retval> = f (D.4658); [return slot optimization]
h ();
```
But there is no clobber generated for the temporaries that was created from the
function return/argument.
Right now this produces:
```
Partition 0: size 4096 align 8
D.4658
Partition 1: size 4096 align 8
D.4657
Partition 2: size 4096 align 8
D.4656
Partition 3: size 4096 align 8
D.4655
Partition 4: size 4096 align 8
D.4654
Partition 5: size 4096 align 8
D.4653
```
But there should be 3 paritions rather than 6.
