https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109661
--- Comment #4 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org>
---
Yeah, I'd come up with essentially the same fix locally. Was just trying
to see whether it is an ABI problem. And I think it is. For:
typedef unsigned long U __attribute__ ((aligned (16)));
typedef enum : U { V = 0 } W;
U
foo (int x0, int x1, int x2, int x3, int x4, int x5, int x6, int x7, U a, W b)
{
return a + b;
}
GCC aligns the b stack argument to 16 bytes:
ldr x1, [sp]
ldr x0, [sp, 16]
add x0, x1, x0
ret
whereas clang doesn't:
ldp x8, x9, [sp]
add x0, x9, x8
ret
The clang behaviour is correct, so we'll need to fix it on the GCC side.
(Neither compiler aligns for register arguments.)
