From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Hemminger <stephen@networkplumber.org>
Subject: Re: [PATCH v2 4/7] vhost: do not use rte_memcpy for
 virtio_hdr copy
Date: Sun, 6 Mar 2016 20:20:00 -0800
Message-ID: <20160306202000.68ce5514@xeon-e3>
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Cc: dev@dpdk.org, Victor Kaplansky <vkaplans@redhat.com>,
 "Michael S. Tsirkin" <mst@redhat.com>
To: Yuanhan Liu <yuanhan.liu@linux.intel.com>
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On Thu, 18 Feb 2016 21:49:09 +0800
Yuanhan Liu <yuanhan.liu@linux.intel.com> wrote:

> +static inline void
> +copy_virtio_net_hdr(struct vhost_virtqueue *vq, uint64_t desc_addr,
> +		    struct virtio_net_hdr_mrg_rxbuf hdr)
> +{
> +	if (vq->vhost_hlen == sizeof(struct virtio_net_hdr_mrg_rxbuf)) {
> +		*(struct virtio_net_hdr_mrg_rxbuf *)(uintptr_t)desc_addr = hdr;
> +	} else {
> +		*(struct virtio_net_hdr *)(uintptr_t)desc_addr = hdr.hdr;
> +	}
> +}
> +

Don't use {} around single statements.
Since you are doing all this casting, why not just use regular old memcpy
which will be inlined by Gcc  into same instructions anyway.
And since are always casting the desc_addr, why not pass a type that
doesn't need the additional cast (like void *)