On Thu, Mar 7, 2019 at 8:46 AM Oleg Nesterov <oleg@xxxxxxxxxx> wrote:
>
> On 03/07, Arnd Bergmann wrote:
> >
> > We could use % everywhere,
>
> Yes.
>
> But again, why not simply use the "for (;;)" loops? Why we can't kill the
> supid switch(_NSIG_WORDS) tricks altogether?
>
> Oleg.
>
> --- x/include/linux/signal.h
> +++ x/include/linux/signal.h
> @@ -121,26 +121,9 @@
> #define _SIG_SET_BINOP(name, op) \
> static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \
> { \
> - unsigned long a0, a1, a2, a3, b0, b1, b2, b3; \
> - \
> - switch (_NSIG_WORDS) { \
> - case 4: \
> - a3 = a->sig[3]; a2 = a->sig[2]; \
> - b3 = b->sig[3]; b2 = b->sig[2]; \
> - r->sig[3] = op(a3, b3); \
> - r->sig[2] = op(a2, b2); \
> - /* fall through */ \
> - case 2: \
> - a1 = a->sig[1]; b1 = b->sig[1]; \
> - r->sig[1] = op(a1, b1); \
> - /* fall through */ \
> - case 1: \
> - a0 = a->sig[0]; b0 = b->sig[0]; \
> - r->sig[0] = op(a0, b0); \
> - break; \
> - default: \
> - BUILD_BUG(); \
> - } \
> + int i; \
> + for (i = 0; i < ARRAY_SIZE(r->sig); ++i) \
> + r->sig[i] = op(a->sig[i], b->sig[i]); \
> }
>
> #define _sig_or(x,y) ((x) | (y))
>
That looks much cleaner IMO.
--
Thanks,
~Nick Desaulniers
