[dpdk-dev] [PATCH v6 1/6] lib/eal: implement the family of rte bit operation APIs
Honnappa Nagarahalli
Honnappa.Nagarahalli at arm.com
Mon Dec 23 06:45:13 CET 2019
>
> On Sat, 21 Dec 2019 16:07:23 +0000
> Honnappa Nagarahalli <Honnappa.Nagarahalli at arm.com> wrote:
>
> > Converting these into macros will help remove the size based duplication of
> APIs. I came up with the following macro:
> >
> > #define RTE_GET_BIT(nr, var, ret, memorder) \ ({ \
> > if (sizeof(var) == sizeof(uint32_t)) { \
> > uint32_t mask1 = 1U << (nr)%32; \
> > ret = __atomic_load_n(&var, (memorder)) & mask1;\
> > } \
> > else {\
> > uint64_t mask2 = 1UL << (nr)%64;\
> > ret = __atomic_load_n(&var, (memorder)) & mask2;\
> > } \
> > })
>
>
> Follow on if you want to do it as macros, then use typeof() to make the mask
> any size.
Yes, that makes it much simple
#define RTE_GET_BIT(nr, var, ret, memorder) \ ({ \
typeof(var) mask; \
if (sizeof(var) == sizeof(uint32_t)) { \
mask = 1U << (nr)%32; \
} else {\
mask = 1UL << (nr)%64;\
} \
ret = __atomic_load_n(&var, (memorder)) & mask;\
})
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