AMD's compiler does not respect alignment of types within unions. Within the struct
struct Foo{
int c;
union{ double b0; } b;
};
b0 does not have natural alignment (8 bytes). The Intel/nVidia compilers (LLVM) as well as gcc (all tested versions, as host compiler filling the buffer with data) aligns b0 properly. I am attaching test file which demonstrates the difference.
Dumping the part of the memory, I obtain with AMD:
b0 is at 4
b0 : ad 49 b2 d4 01 22 c6 c6
foo: 7d c3 94 25 ad 49 b2 d4 01 22 c6 c6
whereas with Intel/nVidia:
b0 is at 8
b0 : 01 22 c6 c6 21 ea b1 d4
foo: 7d c3 94 25 ad 49 b2 d4 01 22 c6 c6 21 ea b1 d4
