Re: [dpdk-dev] [PATCH v2] net/virtio: fix compiling issue for vectorized NEON path

[Ruifeng Wang <Ruifeng.Wang@arm.com>]

> -----Original Message-----
> From: Joyce Kong <joyce.kong@arm.com>
> Sent: Tuesday, January 26, 2021 5:58 PM
> To: maxime.coquelin@redhat.com; david.marchand@redhat.com;
> i.maximets@ovn.org; Ruifeng Wang <Ruifeng.Wang@arm.com>; Honnappa
> Nagarahalli <Honnappa.Nagarahalli@arm.com>
> Cc: dev@dpdk.org; nd <nd@arm.com>; Subhi Masri <subhim@nvidia.com>
> Subject: [PATCH v2] net/virtio: fix compiling issue for vectorized NEON path
> 
> In file included from ../drivers/net/virtio/virtio_rxtx_packed.c:22:0:
> ../drivers/net/virtio/virtio_rxtx_packed_neon.h: In function
> ‘virtqueue_enqueue_batch_packed_vec’:
> ../drivers/net/virtio/virtio_rxtx_packed_neon.h:74:2: warning:
> implicit declaration of function ‘vreinterpretq_p128_u32’
> [-Wimplicit-function-declaration]
> poly128_t cmp1 = vreinterpretq_p128_u32(~vceqq_u32(ref_seg,
> def_ref_seg)); ^
> 
> The message shows ‘vreinterpretq_p128_u32’ intrinsic is not supported
> because an old version gcc (gcc 4.8.5) is used. So fix the issue with
> implementing the logic with other intrinsics.
> 
> Bugzilla ID: 621
> Fixes: 530887469350 ("net/virtio: add vectorized packed ring NEON Tx")
> Fixes: 5971ce5e2a59 ("net/virtio: add vectorized packed ring NEON Rx")
> 
> Reported-by: Subhi Masri <subhim@nvidia.com>
> Signed-off-by: Joyce Kong <joyce.kong@arm.com>
> ---
>  drivers/net/virtio/virtio_rxtx_packed_neon.h | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtio_rxtx_packed_neon.h
> b/drivers/net/virtio/virtio_rxtx_packed_neon.h
> index 01c77b712..00dd04277 100644
> --- a/drivers/net/virtio/virtio_rxtx_packed_neon.h
> +++ b/drivers/net/virtio/virtio_rxtx_packed_neon.h
> @@ -71,8 +71,8 @@ virtqueue_enqueue_batch_packed_vec(struct
> virtnet_tx *txvq,
>  	uint32x4_t def_ref_seg = vdupq_n_u32(0x10001);
>  	/* Check refcnt and nb_segs. */
>  	uint32x4_t ref_seg = vreinterpretq_u32_u8(vqtbl2q_u8(mbuf,
> ref_seg_msk));
> -	poly128_t cmp1 = vreinterpretq_p128_u32(~vceqq_u32(ref_seg,
> def_ref_seg));
> -	if (unlikely(cmp1))
> +	uint64x2_t cmp1 = vreinterpretq_u64_u32(~vceqq_u32(ref_seg,
> def_ref_seg));
> +	if (unlikely(vgetq_lane_u64(cmp1, 0) || vgetq_lane_u64(cmp1, 1)))
>  		return -1;
> 
>  	/* Check headroom is enough. */
> @@ -225,10 +225,10 @@ virtqueue_dequeue_batch_packed_vec(struct
> virtnet_rx *rxvq,
>  	if (vq->vq_packed.used_wrap_counter)
>  		v_used_flag = vdupq_n_u32(PACKED_FLAGS_MASK);
> 
> -	poly128_t desc_stats = vreinterpretq_p128_u32(~vceqq_u32(v_flag,
> v_used_flag));
> +	uint64x2_t desc_stats = vreinterpretq_u64_u32(~vceqq_u32(v_flag,
> +v_used_flag));
> 
>  	/* Check all descs are used. */
> -	if (desc_stats)
> +	if (unlikely(vgetq_lane_u64(desc_stats, 0) ||
> +vgetq_lane_u64(desc_stats, 1)))
>  		return -1;
> 
>  	/* Load 2 mbuf pointers per time. */
> --
> 2.30.0

Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>