[dpdk-stable] [PATCH 1/2] net/mlx5: remove redundant operations

[Ruifeng Wang]

Some operations on mask are redundant and can be removed.
The change yielded 1.6% performance gain on N1SDP.
On ThunderX2, slight performance uplift was also observed.

Fixes: 570acdb1da8a ("net/mlx5: add vectorized Rx/Tx burst for ARM")
Cc: stable at dpdk.org

Signed-off-by: Ruifeng Wang <ruifeng.wang at arm.com>
---
 drivers/net/mlx5/mlx5_rxtx_vec_neon.h | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_rxtx_vec_neon.h b/drivers/net/mlx5/mlx5_rxtx_vec_neon.h
index 2234fbe6b2..98a75b09c6 100644
--- a/drivers/net/mlx5/mlx5_rxtx_vec_neon.h
+++ b/drivers/net/mlx5/mlx5_rxtx_vec_neon.h
@@ -768,18 +768,11 @@ rxq_cq_process_v(struct mlx5_rxq_data *rxq, volatile struct mlx5_cqe *cq,
 					  comp_mask), 0)) /
 					  (sizeof(uint16_t) * 8);
 		/* D.6 mask out entries after the compressed CQE. */
-		mask = vcreate_u16(comp_idx < MLX5_VPMD_DESCS_PER_LOOP ?
-				   -1UL >> (comp_idx * sizeof(uint16_t) * 8) :
-				   0);
-		invalid_mask = vorr_u16(invalid_mask, mask);
+		invalid_mask = vorr_u16(invalid_mask, comp_mask);
 		/* D.7 count non-compressed valid CQEs. */
 		n = __builtin_clzl(vget_lane_u64(vreinterpret_u64_u16(
 				   invalid_mask), 0)) / (sizeof(uint16_t) * 8);
 		nocmp_n += n;
-		/* D.2 get the final invalid mask. */
-		mask = vcreate_u16(n < MLX5_VPMD_DESCS_PER_LOOP ?
-				   -1UL >> (n * sizeof(uint16_t) * 8) : 0);
-		invalid_mask = vorr_u16(invalid_mask, mask);
 		/* D.3 check error in opcode. */
 		opcode = vceq_u16(resp_err_check, opcode);
 		opcode = vbic_u16(opcode, invalid_mask);
-- 
2.25.1