https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93946
--- Comment #18 from sandra at gcc dot gnu.org ---
Hmmm, it looks to me like things are going wrong in the tree fre1 pass too. I
commented out the redundant zero store in the test case to see what would
happen, like
long __attribute__((noipa))
foo (struct bb *bv, void *ptr)
{
struct aa *a = ptr;
struct bb *b = ptr;
bv->b.u.f = 1;
a->a.u.i = 0;
/* b->b.u.f = 0; */
return bv->b.u.f;
}
fre1 gets this as input:
__attribute__((noipa, noinline, noclone, no_icf))
foo (struct bb * bv, void * ptr)
{
struct bb * b;
struct aa * a;
long int _8;
<bb 2> :
bv_5(D)->b.u.f = 1;
MEM[(struct aa *)ptr_1(D)].a.u.i = 0;
_8 = bv_5(D)->b.u.f;
return _8;
}
and produces this output:
__attribute__((noipa, noinline, noclone, no_icf))
foo (struct bb * bv, void * ptr)
{
struct bb * b;
struct aa * a;
<bb 2> :
bv_5(D)->b.u.f = 1;
MEM[(struct aa *)ptr_1(D)].a.u.i = 0;
return 1;
}
This is with -O2.
Again, it seems like something is not realizing that pointer parameters can be
aliased no matter what their types are. Or perhaps that is just a symptom of
some other underlying bug. :-S
