Re: [dpdk-dev] [PATCH] net/i40e: fix clang build error with 16B descriptors

[Ye Xiaolong <xiaolong.ye@intel.com>]

On 11/12, Bruce Richardson wrote:
>When compiling with 16B descriptor support enabled, clang compiles gave an
>error, complaining that the final parameter of _mm256_blend_epi32() had to
>be an immediate value (i.e. compile-time constant). While it appears that
>GCC was able to convert the constant variable value "fdir_blend_mask" into
>the blend call, clang was not doing so. To guarantee the use of an
>immediate we convert the variable value to a #define.
>
>Fixes: 7d087a0a8b8e ("net/i40e: support flow director on AVX Rx")
>Cc: harry.van.haaren@intel.com
>
>Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
>---
> drivers/net/i40e/i40e_rxtx_vec_avx2.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
>diff --git a/drivers/net/i40e/i40e_rxtx_vec_avx2.c b/drivers/net/i40e/i40e_rxtx_vec_avx2.c
>index b9f1a240c..3bcef1363 100644
>--- a/drivers/net/i40e/i40e_rxtx_vec_avx2.c
>+++ b/drivers/net/i40e/i40e_rxtx_vec_avx2.c
>@@ -529,6 +529,7 @@ _recv_raw_pkts_vec_avx2(struct i40e_rx_queue *rxq, struct rte_mbuf **rx_pkts,
> 			 * identifies an FDIR ID match, and zeros the RSS value
> 			 * in the mbuf on FDIR match to keep mbuf data clean.
> 			 */
>+#define FDIR_BLEND_MASK ((1 << 3) | (1 << 7))
> 
> 			/* Flags:
> 			 * - Take flags, shift bits to null out
>@@ -557,9 +558,8 @@ _recv_raw_pkts_vec_avx2(struct i40e_rx_queue *rxq, struct rte_mbuf **rx_pkts,
> 			 * otherwise the mb0_1 register RSS field is zeroed.
> 			 */
> 			const __m256i fdir_zero_mask = _mm256_setzero_si256();
>-			const uint32_t fdir_blend_mask = (1 << 3) | (1 << 7);
> 			__m256i tmp0_1 = _mm256_blend_epi32(fdir_zero_mask,
>-						fdir_mask, fdir_blend_mask);
>+						fdir_mask, FDIR_BLEND_MASK);
> 			__m256i fdir_mb0_1 = _mm256_and_si256(mb0_1, fdir_mask);
> 			mb0_1 = _mm256_andnot_si256(tmp0_1, mb0_1);
> 
>@@ -575,7 +575,7 @@ _recv_raw_pkts_vec_avx2(struct i40e_rx_queue *rxq, struct rte_mbuf **rx_pkts,
> 			__m256i tmp2_3 = _mm256_alignr_epi8(fdir_mask, fdir_mask, 12);
> 			__m256i fdir_mb2_3 = _mm256_and_si256(mb2_3, tmp2_3);
> 			tmp2_3 = _mm256_blend_epi32(fdir_zero_mask, tmp2_3,
>-						    fdir_blend_mask);
>+						    FDIR_BLEND_MASK);
> 			mb2_3 = _mm256_andnot_si256(tmp2_3, mb2_3);
> 			rx_pkts[i + 2]->hash.fdir.hi = _mm256_extract_epi32(fdir_mb2_3, 3);
> 			rx_pkts[i + 3]->hash.fdir.hi = _mm256_extract_epi32(fdir_mb2_3, 7);
>@@ -583,7 +583,7 @@ _recv_raw_pkts_vec_avx2(struct i40e_rx_queue *rxq, struct rte_mbuf **rx_pkts,
> 			__m256i tmp4_5 = _mm256_alignr_epi8(fdir_mask, fdir_mask, 8);
> 			__m256i fdir_mb4_5 = _mm256_and_si256(mb4_5, tmp4_5);
> 			tmp4_5 = _mm256_blend_epi32(fdir_zero_mask, tmp4_5,
>-						    fdir_blend_mask);
>+						    FDIR_BLEND_MASK);
> 			mb4_5 = _mm256_andnot_si256(tmp4_5, mb4_5);
> 			rx_pkts[i + 4]->hash.fdir.hi = _mm256_extract_epi32(fdir_mb4_5, 3);
> 			rx_pkts[i + 5]->hash.fdir.hi = _mm256_extract_epi32(fdir_mb4_5, 7);
>@@ -591,7 +591,7 @@ _recv_raw_pkts_vec_avx2(struct i40e_rx_queue *rxq, struct rte_mbuf **rx_pkts,
> 			__m256i tmp6_7 = _mm256_alignr_epi8(fdir_mask, fdir_mask, 4);
> 			__m256i fdir_mb6_7 = _mm256_and_si256(mb6_7, tmp6_7);
> 			tmp6_7 = _mm256_blend_epi32(fdir_zero_mask, tmp6_7,
>-						    fdir_blend_mask);
>+						    FDIR_BLEND_MASK);
> 			mb6_7 = _mm256_andnot_si256(tmp6_7, mb6_7);
> 			rx_pkts[i + 6]->hash.fdir.hi = _mm256_extract_epi32(fdir_mb6_7, 3);
> 			rx_pkts[i + 7]->hash.fdir.hi = _mm256_extract_epi32(fdir_mb6_7, 7);
>-- 
>2.21.0
>

Acked-by: Xiaolong Ye <xiaolong.ye@intel.com>

Applied to dpdk-next-net-intel, Thanks.