[Bug middle-end/78995] A strange copy error caused by O3 optimization

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78995

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |RESOLVED
         Resolution|---                         |INVALID

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
static inline void
rte_memcpy(void *dst, const void *src, size_t n)
{
        uintptr_t dstu = (uintptr_t)dst;
        uintptr_t srcu = (uintptr_t)src;

    *(uint32_t *)dstu = *(const uint32_t *)srcu;

this is violating strict aliasing rules as you are copying

typedef unsigned short  WORD;

struct TFieldHeader
{
    WORD FieldID;
    WORD Size;
};