On 12/4/2014 8:20 PM, Thomas Monjalon wrote: > 2014-12-04 10:28, Qiu, Michael: >> On 12/4/2014 5:01 PM, Thomas Monjalon wrote: >>> 2014-12-04 02:28, Qiu, Michael: >>>> On 12/4/2014 5:26 AM, Thomas Monjalon wrote: >>>>> There is no standard to check endianness. >>>>> So we need to try different checks. >>>>> Previous trials were done in testpmd (see commits >>>>> 51f694dd40f56 and 64741f237cf29) without full success. >>>>> This one is not guaranteed to work everywhere so it could >>>>> evolve when exceptions are found. >>> [...] >>>>> #include <stdint.h> >>>>> +#ifdef RTE_EXEC_ENV_BSDAPP >>>>> +#include <sys/endian.h> >>>>> +#else >>>>> +#include <endian.h> >>>>> +#endif >>>>> + >>>>> +/* >>>>> + * Compile-time endianness detection >>>>> + */ >>>>> +#define RTE_BIG_ENDIAN 1 >>>>> +#define RTE_LITTLE_ENDIAN 2 >>>>> +#if defined __BYTE_ORDER >>>>> +#if __BYTE_ORDER == __BIG_ENDIAN >>>>> +#define RTE_BYTE_ORDER RTE_BIG_ENDIAN >>>>> +#elif __BYTE_ORDER == __LITTLE_ENDIAN >>>>> +#define RTE_BYTE_ORDER RTE_LITTLE_ENDIAN >>>>> +#endif /* __BYTE_ORDER */ >>>>> +#elif defined __BYTE_ORDER__ >>>>> +#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ >>>>> +#define RTE_BYTE_ORDER RTE_BIG_ENDIAN >>>>> +#elif __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ >>>>> +#define RTE_BYTE_ORDER RTE_LITTLE_ENDIAN >>>>> +#endif /* __BYTE_ORDER__ */ >>>>> +#elif defined __BIG_ENDIAN__ >>>>> +#define RTE_BYTE_ORDER RTE_BIG_ENDIAN >>>>> +#elif defined __LITTLE_ENDIAN__ >>>>> +#define RTE_BYTE_ORDER RTE_LITTLE_ENDIAN >>>>> +#endif >>>> What do you think about : >>>> >>>> +/* >>>> + * Compile-time endianness detection >>>> + */ >>>> +#define RTE_BIG_ENDIAN 1 >>>> +#define RTE_LITTLE_ENDIAN 2 >>>> +if defined __BYTE_ORDER__ /* Prefer gcc build-in macros */ >>>> +#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ >>>> +#define RTE_BYTE_ORDER RTE_BIG_ENDIAN >>>> +#elif __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ >>>> +#define RTE_BYTE_ORDER RTE_LITTLE_ENDIAN >>>> +#endif /* __BYTE_ORDER__ */ >>>> +#else >>>> +#if defined RTE_EXEC_ENV_BSDAPP >>>> +#include <sys/endian.h> >>>> +#else >>>> +#include <endian.h> >>>> +#endif >>>> +#if defined __BYTE_ORDER >>>> +#if __BYTE_ORDER == __BIG_ENDIAN >>>> +#define RTE_BYTE_ORDER RTE_BIG_ENDIAN >>>> +#elif __BYTE_ORDER == __LITTLE_ENDIAN >>>> +#define RTE_BYTE_ORDER RTE_LITTLE_ENDIAN >>>> +#endif /* __BYTE_ORDER */ >>>> +#elif defined __BIG_ENDIAN__ >>>> +#define RTE_BYTE_ORDER RTE_BIG_ENDIAN >>>> +#elif defined __LITTLE_ENDIAN__ >>>> +#define RTE_BYTE_ORDER RTE_LITTLE_ENDIAN >>>> +#endif >>>> +#endif >>> Please, could you give more explanations about your proposal? >>> Why not always try to include endian.h? >> I assume that if gcc can handler why we need include that file? > Separating include on top is easier to read, and I'm not sure it won't > be needed for __BYTE_ORDER__ with some toolchains. > >> Also it seems that only old version could have this issue, newer >> versions has build in this marcos. >> >> So that's why I prefer "__BYTE_ORDER__" for high priority. > I have no problem with reversing this priority. > >>> Why giving high priority to __BYTE_ORDER__? > Any other comment? May I apply with above change?
Acked-by: Michael Qiu <michael.qiu at intel.com>
