https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78995
--- Comment #4 from feiz <zhangfei1 at cffex dot com.cn> ---
(In reply to Richard Biener from comment #2)
> 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;
> };
Well, that's right. I add the compile option -fno-strict-aliasing, and it
works.
To get a better performance, I got the rte_memcpy code from dpdk codes to
replace memcpy in our project.
Very thanks for your help. And I have one more question about this.
I check some instruction about aliasing, like
"Strict aliasing is an assumption, made by the C (or C++) compiler, that
dereferencing pointers to objects of different types will never refer to the
same memory location (i.e. alias eachother.)".
I am confused, we always use the following actions, does this safe?
char buf[1024];
struct A {
int a;
int b;
};
struct p * = (struct A*)buf;
p->a =01;
p->b = 02;
