Hi Pavan
Please see some comments below.
From: Pavan Nikhilesh, Saturday, February 17, 2018 12:50 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>
> ---
> lib/librte_eal/common/include/rte_common.h | 36
> ++++++++++++++++++++++++++++++
> 1 file changed, 36 insertions(+)
>
> diff --git a/lib/librte_eal/common/include/rte_common.h
> b/lib/librte_eal/common/include/rte_common.h
> index c7803e41c..126914f07 100644
> --- a/lib/librte_eal/common/include/rte_common.h
> +++ b/lib/librte_eal/common/include/rte_common.h
> @@ -259,6 +259,24 @@ rte_align32pow2(uint32_t 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
I think the zero case(x=0) result should be documented.
> + */
> +static inline uint32_t
> +rte_align32lowpow2(uint32_t x)
What do you think about " rte_align32prevpow2"?
> +{
> + x = rte_align32pow2(x);
In case of x is power of 2 number(already aligned), looks like the
result here is x and the final result is (x >> 1)?
Is it as you expect?
> + x--;
> +
> + return x - (x >> 1);
Why can't the implementation just be:
return rte_align32pow2(x) >> 1;
If the above is correct, Are you sure we need this API?
> +}
> +
> /**
> * Aligns 64b input parameter to the next power of 2
> *
> @@ -282,6 +300,24 @@ rte_align64pow2(uint64_t 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_align64lowpow2(uint64_t v)
> +{
> + v = rte_align64pow2(v);
> + v--;
> +
> + return v - (v >> 1);
> +}
> +
Same comments for 64b API.
> /*********** Macros for calculating min and max **********/
>
> /**
> --
> 2.16.1
If it is a new API, I think it should be added to the map file and to be tagged
as experimental. No?
Matan
