Re: [PATCH] net/mlx5: remove non constant size from type cast

[Tyler Retzlaff <roretzla@linux.microsoft.com>]

ping

this one seems pretty obvious, maintainers could you please take a look?

thanks

On Mon, Nov 13, 2023 at 09:20:38AM -0800, Tyler Retzlaff wrote:
> Placing a non-constant size in the subscript [size] of a type cast is
> causing unnecessary generation of a VLA. Remove size and just provide []
> indicating the type is an array of unspecified size.
> 
> Signed-off-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
> ---
>  drivers/net/mlx5/mlx5_rxq.c | 5 ++---
>  drivers/net/mlx5/mlx5_txq.c | 2 +-
>  2 files changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/mlx5/mlx5_rxq.c b/drivers/net/mlx5/mlx5_rxq.c
> index 88b2dc5..f0ab77d 100644
> --- a/drivers/net/mlx5/mlx5_rxq.c
> +++ b/drivers/net/mlx5/mlx5_rxq.c
> @@ -1951,9 +1951,8 @@ struct mlx5_rxq_ctrl *
>  	tmpl->rxq.mp = rx_seg[0].mp;
>  	tmpl->rxq.elts_n = log2above(desc);
>  	tmpl->rxq.rq_repl_thresh = MLX5_VPMD_RXQ_RPLNSH_THRESH(desc_n);
> -	tmpl->rxq.elts = (struct rte_mbuf *(*)[desc_n])(tmpl + 1);
> -	tmpl->rxq.mprq_bufs =
> -		(struct mlx5_mprq_buf *(*)[desc])(*tmpl->rxq.elts + desc_n);
> +	tmpl->rxq.elts = (struct rte_mbuf *(*)[])(tmpl + 1);
> +	tmpl->rxq.mprq_bufs = (struct mlx5_mprq_buf *(*)[])(*tmpl->rxq.elts + desc_n);
>  	tmpl->rxq.idx = idx;
>  	if (conf->share_group > 0) {
>  		tmpl->rxq.shared = 1;
> diff --git a/drivers/net/mlx5/mlx5_txq.c b/drivers/net/mlx5/mlx5_txq.c
> index b584055..3d219c4 100644
> --- a/drivers/net/mlx5/mlx5_txq.c
> +++ b/drivers/net/mlx5/mlx5_txq.c
> @@ -64,7 +64,7 @@
>  	const uint16_t elts_m = elts_n - 1;
>  	uint16_t elts_head = txq_ctrl->txq.elts_head;
>  	uint16_t elts_tail = txq_ctrl->txq.elts_tail;
> -	struct rte_mbuf *(*elts)[elts_n] = &txq_ctrl->txq.elts;
> +	struct rte_mbuf *(*elts)[] = &txq_ctrl->txq.elts;
>  
>  	DRV_LOG(DEBUG, "port %u Tx queue %u freeing WRs",
>  		PORT_ID(txq_ctrl->priv), txq_ctrl->txq.idx);
> -- 
> 1.8.3.1