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From: Thomas Monjalon <thomas@monjalon.net>
To: Andy Green <andy@warmcat.com>
Cc: dev@dpdk.org
Date: Sun, 13 May 2018 18:59:34 +0200
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Subject: Re: [dpdk-dev] [PATCH v3 17/24] rte_byteorder.h: explicit cast for
	return promotion
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12/05/2018 04:00, Andy Green:
> --- a/lib/librte_eal/common/include/generic/rte_byteorder.h
> +++ b/lib/librte_eal/common/include/generic/rte_byteorder.h
> @@ -123,7 +123,7 @@ typedef uint64_t rte_le64_t; /**< 64-bit little-endian value. */
>  static inline uint16_t
>  rte_constant_bswap16(uint16_t x)
>  {
> -	return RTE_STATIC_BSWAP16(x);
> +	return (uint16_t)RTE_STATIC_BSWAP16((uint16_t)x);
>  }

x is already uint16_t, and RTE_STATIC_BSWAP16 is already casting to uint16_t.
So why these casts are needed?
And why not in rte_constant_bswap32/64?