Re: [dpdk-dev] [PATCH v3 1/3] net/i40e: remove devarg use-latest-supported-vec

[Ferruh Yigit]

On 1/14/2021 6:39 AM, Leyi Rong wrote:
As eal parameter --force-max-simd-bitwidth is already introduced,
to make it more clear when setting rx/tx function, remove
devarg use-latest-supported-vec support.
Signed-off-by: Leyi Rong <leyi.r...@intel.com>
Acked-by: Wenzhuo Lu <wenzhuo...@intel.com>

<...>

-static eth_rx_burst_t
-i40e_get_recommend_rx_vec(bool scatter)
+static inline bool
+get_avx_supported(bool request_avx512)
  {
-#if defined(RTE_ARCH_X86) && defined(CC_AVX2_SUPPORT)
-       /*
-        * since AVX frequency can be different to base frequency, limit
-        * use of AVX2 version to later plaforms, not all those that could
-        * theoretically run it.
-        */
-       if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX512F) &&
-                       rte_vect_get_max_simd_bitwidth() >= RTE_VECT_SIMD_256)
-               return scatter ? i40e_recv_scattered_pkts_vec_avx2 :
-                                i40e_recv_pkts_vec_avx2;
+#ifdef RTE_ARCH_X86
+       if (request_avx512) {
+               if (rte_vect_get_max_simd_bitwidth() >= RTE_VECT_SIMD_512 &&
+               rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX512F) == 1 &&
+               rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX512BW) == 1)
+#ifdef CC_AVX512_SUPPORT
+                       return true;
+#else
+               PMD_DRV_LOG(NOTICE,
+                       "AVX512 is not supported in build env");
+               return false;
+#endif
+       } else {
+               if (rte_vect_get_max_simd_bitwidth() >= RTE_VECT_SIMD_256 &&
+               rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX2) == 1 &&
+               rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX512F) == 1)
+#ifdef CC_AVX2_SUPPORT
+                       return true;
+#else
+               PMD_DRV_LOG(NOTICE,
+                       "AVX2 is not supported in build env");
+               return false;
  #endif
-       return scatter ? i40e_recv_scattered_pkts_vec :
-                        i40e_recv_pkts_vec;
+       }
+#endif /* RTE_ARCH_X86 */
+
+       return false;
  }

This was still causing build error for non x86, becuase of not used 
'request_avx512' variable, updated as below in next-net:

 diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
 index a4661cdd8377..ce2b0bc12ed9 100644
 --- a/drivers/net/i40e/i40e_rxtx.c
 +++ b/drivers/net/i40e/i40e_rxtx.c
 @@ -3122,6 +3122,8 @@ get_avx_supported(bool request_avx512)
                 return false;
  #endif
         }
 +#else
 +       RTE_SET_USED(request_avx512);
  #endif /* RTE_ARCH_X86 */

         return false;