[PATCH 1/4] net/i40e: fix AVX-512 pointer copy on 32-bit

Bruce Richardson bruce.richardson at intel.com
Fri Sep 6 16:11:24 CEST 2024


The size of a pointer on 32-bit is only 4 rather than 8 bytes, so
copying 32 pointers only requires half the number of AVX-512 load store
operations.

Fixes: 5171b4ee6b6b ("net/i40e: optimize Tx by using AVX512")
Cc: stable at dpdk.org

Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
---
 drivers/net/i40e/i40e_rxtx_vec_avx512.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/i40e/i40e_rxtx_vec_avx512.c b/drivers/net/i40e/i40e_rxtx_vec_avx512.c
index 0238b03f8a..3b2750221b 100644
--- a/drivers/net/i40e/i40e_rxtx_vec_avx512.c
+++ b/drivers/net/i40e/i40e_rxtx_vec_avx512.c
@@ -799,6 +799,7 @@ i40e_tx_free_bufs_avx512(struct i40e_tx_queue *txq)
 		uint32_t copied = 0;
 		/* n is multiple of 32 */
 		while (copied < n) {
+#ifdef RTE_ARCH_64
 			const __m512i a = _mm512_load_si512(&txep[copied]);
 			const __m512i b = _mm512_load_si512(&txep[copied + 8]);
 			const __m512i c = _mm512_load_si512(&txep[copied + 16]);
@@ -808,6 +809,12 @@ i40e_tx_free_bufs_avx512(struct i40e_tx_queue *txq)
 			_mm512_storeu_si512(&cache_objs[copied + 8], b);
 			_mm512_storeu_si512(&cache_objs[copied + 16], c);
 			_mm512_storeu_si512(&cache_objs[copied + 24], d);
+#else
+			const __m512i a = _mm512_load_si512(&txep[copied]);
+			const __m512i b = _mm512_load_si512(&txep[copied + 16]);
+			_mm512_storeu_si512(&cache_objs[copied], a);
+			_mm512_storeu_si512(&cache_objs[copied + 16], b);
+#endif
 			copied += 32;
 		}
 		cache->len += n;
-- 
2.43.0



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