[dpdk-dev] [PATCH 6/7] net/mlx5: optimize copy of Ethernet header

[Nelio Laranjeiro <nelio.laranjeiro@6wind.com>]

Use fewer instructions to copy the first two bytes of Ethernet headers to
work queue elements.

Signed-off-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
Acked-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
---
 drivers/net/mlx5/mlx5_rxtx.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index 0d0b807..4b8c197 100644
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -409,7 +409,7 @@ mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 		unsigned int ds = 0;
 		uintptr_t addr;
 		uint16_t pkt_inline_sz = MLX5_WQE_DWORD_SIZE;
-		uint8_t ehdr[2];
+		uint16_t ehdr;
 		uint8_t cs_flags = 0;
 #ifdef MLX5_PMD_SOFT_COUNTERS
 		uint32_t total_length = 0;
@@ -436,8 +436,8 @@ mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 			rte_prefetch0(*pkts);
 		addr = rte_pktmbuf_mtod(buf, uintptr_t);
 		length = DATA_LEN(buf);
-		ehdr[0] = ((uint8_t *)addr)[0];
-		ehdr[1] = ((uint8_t *)addr)[1];
+		ehdr = (((uint8_t *)addr)[1] << 8) |
+		       ((uint8_t *)addr)[0];
 #ifdef MLX5_PMD_SOFT_COUNTERS
 		total_length = length;
 #endif
@@ -600,8 +600,7 @@ mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 			0,
 			cs_flags,
 			0,
-			(ehdr[1] << 24) | (ehdr[0] << 16) |
-			htons(pkt_inline_sz),
+			(ehdr << 16) | htons(pkt_inline_sz),
 		};
 		txq->wqe_ci += (ds + 3) / 4;
 #ifdef MLX5_PMD_SOFT_COUNTERS
-- 
2.1.4