https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94338
--- Comment #5 from huaixin chang <huaixin....@alibaba-inc.com> ---
(In reply to Richard Biener from comment #2)
> I think the testcase is ill-formed and should be diagnosed in some form.
> IIRC there's some documented behavior (that's not implemented) that
> __aligned__
> only increases alignment unless __packed__ is used. With __packed__ the
> testcase behaves as expected I think.
>
> Note __attribute__((__aligned__(4))) applies to 'A', not its type.
Yes, I missed this and quoted wrong document for this case.
>
> Not sure if behavior changes if you use a typedef that is aligned to 4.
If a use a typedef that is aligned to 4 like this:
typedef struct {
long a __attribute__((__aligned__(128)));
long b __attribute__((__aligned__(128)));
} foo __attribute__((__aligned(4)));
foo A;
Or align variable A to 4 only like this:
typedef struct {
long a __attribute__((__aligned__(128)));
long b __attribute__((__aligned__(128)));
} foo;
foo A __attribute__((__aligned(4)));
I will get warned while compiling and alignment is as expected.
