On Thu, Apr 14, 2016 at 12:25 PM, Jakub Jelinek <ja...@redhat.com> wrote:
> On Thu, Apr 14, 2016 at 12:19:26PM +0100, Ramana Radhakrishnan wrote:
>> Is this a valid example for what you have in mind ?
>>
>> struct baz
>> {
>> char a[1024];
>> };
>> struct foo : baz
>> {
>> };
>>
>> int bar (struct foo b, int x)
>
> No, I meant say:
> struct A {};
> struct B { A a[1024]; };
> int bar (struct B b, int c)
> {
> return c;
> }
> int baz (int a, int b, int c, int d, int e, int f, int g, struct B h, int i)
> {
> return g + i;
> }
>
> Strangely, we warn about this with -Wabi=9 even on x86_64-linux on both
> testcases, while only on baz it actually changes code generation.
>
Seems to be treated as passing a 1 byte quantity before the change.
Note you need one more parameter on aarch64 to force struct B into the
stack.
IIRC the same problem should happen on AArch32 as well but I haven't
tried that yet.
regards
Ramana
