[dpdk-dev] [PATCH] build: fix memcpy behaviour regression

[Han, YingyaX]

Tested-by: Han, Yingya <yingyax.han at intel.com>

Best Regards,
Yingya
-----Original Message-----
From: Richardson, Bruce <bruce.richardson at intel.com> 
Sent: Monday, October 12, 2020 10:52 PM
To: dev at dpdk.org
Cc: Han, YingyaX <yingyax.han at intel.com>; Ananyev, Konstantin <konstantin.ananyev at intel.com>; Tu, Lijuan <lijuan.tu at intel.com>; Richardson, Bruce <bruce.richardson at intel.com>
Subject: [PATCH] build: fix memcpy behaviour regression

When testing on some x86 platforms, code compiled with meson was observed running at a different power-license level to that compiled with make. This is due to the fact that meson auto-detects the instruction sets available on the system and enabled AVX512 rte_memcpy when AVX512 was available, while on make, a build time AVX-512 flag needed to be explicitly set to enable that AVX512 rte_memcpy code path.

In the absense of runtime path selection for rte_memcpy - which is complicated by it being a static inline function in a header file - we can fix this behaviour regression by similarly having a build-time option which must be set to enable the AVX-512 memcpy path.