https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94655
Martin Sebor <msebor at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|RESOLVED |NEW
Resolution|DUPLICATE |---
--- Comment #7 from Martin Sebor <msebor at gcc dot gnu.org> ---
The root cause in this case or the solution are not the same as in bug 94675.
The MEM_REF type is the type of the access, so it's correct to rely on it for
the size of the access. The problem here is that the first MEM_REF pointer
operand doesn't point to the actual destination of the access: it points to one
member of the struct but as a result of adding the offset to it the access is
actually to the subsequent member. It's as if the final store in valid code
like this:
struct S { char i; char a[8], b[8]; };
void g (struct S *p)
{
typedef __attribute__ ((vector_size (8))) char V;
char *pa = p->a + 8;
char *pb = p->b;
*(V*)pb = (V) {0}; // pb points to p->b
}
were transformed into:
pa_2 = &MEM <char[8]> [(void *)p_1(D) + 9B];
MEM[(V *)pa_2] = { 0, 0, 0, 0, 0, 0, 0, 0 }; // but here store is into
(p->a + 9)
