http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60452
--- Comment #6 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
> But even if I try:
> int a;
> __attribute__((noinline, noclone)) void
> foo (int *e)
> {
> asm volatile ("" : : "r" (e) : "memory");
> }
>
> int
> main ()
> {
> int e[2] = { 0, 0 }, f = 0;
> if (a == 131072)
> f = e[a];
> foo (e);
> return f;
> }
> where we have:
> (mem:SI (plus:DI (reg/f:DI 20 frame)
> (const_int 524272 [0x7fff0])) [2 e+524288 S4 A128])
> instead and thus from MEM_EXPR we perhaps could find out that it is an out
> of bound access, we still always treat all frame based accesses (whatever
> the offset is) as non-trapping.
> So perhaps we need to handle known out of bound MEMs specially when we find
> that fact out (if we want to emit them into the RTL IL at all), one thing is
> expansion, another thing if say initially non-constant offset is later
> CSEd/forwprop etc. into constant out of bound offset.
>
> Thoughts?
Again quite an artificial testcase... What about adding a comparison of the
offset with the result of get_frame_size if the base register is SFP/HFP/SP?
