On Fri, 28 Jul 2006, Johannes Schindelin wrote:
>
> +/* a and b may not overlap! */
> +static void memswap(void *a, void *b, unsigned int len)
This is disgusting.
Especially since it's also slow as hell.
> + memswap(p->new_name, p->old_name, sizeof(char *));
> + memswap(&p->new_mode, &p->old_mode, sizeof(unsigned int));
> + memswap(&p->is_new, &p->is_delete, sizeof(int));
> + memswap(&p->lines_added, &p->lines_deleted, sizeof(int));
> + memswap(p->old_sha1_prefix, p->new_sha1_prefix, 41);
> +
> + for (; frag; frag = frag->next) {
> + memswap(&frag->newpos, &frag->oldpos, sizeof(int));
> + memswap(&frag->newlines, &frag->oldlines, sizeof(int));
All but one of those are register sizes, so doing a horribly ugly
"memswap()"to do them is truly nasty, when you could have done
#define swap(a,b) myswap((a),(b),sizeof(a))
#define myswap(a,b,size) do { \
unsigned char mytmp[size]; \
memcpy(tmp, &a, size); \
memcpy(&a, &b, size); \
memcpy(&b, mytmp, size); \
} while (0)
and it would have worked MUCH more efficiently, since any sane compiler
would immediately have noticed that you're doing word-sized copies, and
optimized the hell out of it.
(Untested, of course).
Linus
-
: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html