Hi Pavan
Shouldn't the new APIs be tagged with the experimental tag as agreed?
Besides that,
Acked-by: Matan Azrad <ma...@mellanox.com>
From: Pavan Nikhilesh, Wednesday, April 4, 2018 1:16 PM
> Add 32b and 64b API's to align the given integer to the previous power of 2.
>
> Signed-off-by: Pavan Nikhilesh <pbhagavat...@caviumnetworks.com>
> ---
> v3 Changes:
> - Move commonly used code to rte_combine(32/64)ms1b so that it can be
> reused.
>
> v2 Changes:
> - Modified api name to `rte_align(32/64)prevpow2` from
> `rte_align(32/64)lowpow2`.
> - corrected fuction to return if the integer is already aligned to power of
> 2.
>
> lib/librte_eal/common/include/rte_common.h | 92
> ++++++++++++++++++++++++++----
> 1 file changed, 81 insertions(+), 11 deletions(-)
>
> diff --git a/lib/librte_eal/common/include/rte_common.h
> b/lib/librte_eal/common/include/rte_common.h
> index c7803e41c..7e147dcf2 100644
> --- a/lib/librte_eal/common/include/rte_common.h
> +++ b/lib/librte_eal/common/include/rte_common.h
> @@ -223,6 +223,51 @@ extern int RTE_BUILD_BUG_ON_detected_error; }
> while(0) #endif
>
> +/**
> + * Combines 32b inputs most significant set bits into the least
> + * significant bits to construct a value with the same MSBs as x
> + * but all 1's under it.
> + *
> + * @param x
> + * The integer whose MSBs need to be combined with its LSBs
> + * @return
> + * The combined value.
> + */
> +static inline uint32_t
> +rte_combine32ms1b(register uint32_t x)
> +{
> + x |= x >> 1;
> + x |= x >> 2;
> + x |= x >> 4;
> + x |= x >> 8;
> + x |= x >> 16;
> +
> + return x;
> +}
> +
> +/**
> + * Combines 64b inputs most significant set bits into the least
> + * significant bits to construct a value with the same MSBs as x
> + * but all 1's under it.
> + *
> + * @param v
> + * The integer whose MSBs need to be combined with its LSBs
> + * @return
> + * The combined value.
> + */
> +static inline uint64_t
> +rte_combine64ms1b(register uint64_t v)
> +{
> + v |= v >> 1;
> + v |= v >> 2;
> + v |= v >> 4;
> + v |= v >> 8;
> + v |= v >> 16;
> + v |= v >> 32;
> +
> + return v;
> +}
> +
> /*********** Macros to work with powers of 2 ********/
>
> /**
> @@ -250,15 +295,28 @@ static inline uint32_t rte_align32pow2(uint32_t x) {
> x--;
> - x |= x >> 1;
> - x |= x >> 2;
> - x |= x >> 4;
> - x |= x >> 8;
> - x |= x >> 16;
> + x = rte_combine32ms1b(x);
>
> return x + 1;
> }
>
> +/**
> + * Aligns input parameter to the previous power of 2
> + *
> + * @param x
> + * The integer value to algin
> + *
> + * @return
> + * Input parameter aligned to the previous power of 2
> + */
> +static inline uint32_t
> +rte_align32prevpow2(uint32_t x)
> +{
> + x = rte_combine32ms1b(x);
> +
> + return x - (x >> 1);
> +}
> +
> /**
> * Aligns 64b input parameter to the next power of 2
> *
> @@ -272,16 +330,28 @@ static inline uint64_t rte_align64pow2(uint64_t v) {
> v--;
> - v |= v >> 1;
> - v |= v >> 2;
> - v |= v >> 4;
> - v |= v >> 8;
> - v |= v >> 16;
> - v |= v >> 32;
> + v = rte_combine64ms1b(v);
>
> return v + 1;
> }
>
> +/**
> + * Aligns 64b input parameter to the previous power of 2
> + *
> + * @param v
> + * The 64b value to align
> + *
> + * @return
> + * Input parameter aligned to the previous power of 2
> + */
> +static inline uint64_t
> +rte_align64prevpow2(uint64_t v)
> +{
> + v = rte_combine64ms1b(v);
> +
> + return v - (v >> 1);
> +}
> +
> /*********** Macros for calculating min and max **********/
>
> /**
> --
> 2.16.3
