Re: [PATCH v4 00/11] remove component-specific logic for AVX builds

[Bruce Richardson <bruce.richardson@intel.com>]

On Wed, Mar 19, 2025 at 05:29:30PM +0000, Bruce Richardson wrote:
> A number of libs and drivers had special optimized AVX2 and AVX512 code
> paths for performance reasons, and these tended to have copy-pasted
> logic to build those files. Centralise that logic in the main
> drivers/ and lib/ meson.build files to avoid duplication.
> 
> v4: rebase on latest main branch
>     minor fixes following feedback
>     limit use of -march=skylake-avx512 to when we don't already have a
>       -march flag supporting AVX512.
> v3: add patch for event/dlb2 AVX512 handling.
>     add common code for libraries as well as drivers.
> v2: add patch 4 to remove use of unnecessary CC_AVX2_SUPPORT flag
> 
A related follow-up to this patchset. Checking with "godbolt.org", it
appears that both clang 3.6[1] and gcc 5[2] (the minimum called out compiler
versions in our docs[1]) support the set of AVX-512 compiler flags we use.
Therefore, it seems we can simplify our code further by removing the
"cc_has_avx512" variable.

/Bruce

PS: I'd also note that these minimum versions look to be ~10-year old
versions of compilers. I would expect end users to actually be using more
modern releases that these. Maybe we should look to update our compiler
minimum versions....

[1] https://godbolt.org/z/Ys9K6axMf
[2] https://godbolt.org/z/v6WP7d6Pf
[3] https://doc.dpdk.org/guides/linux_gsg/sys_reqs.html#compilation-of-the-dpdk