Re: [RFC PATCH] build: reduce use of AVX compiler flags

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

On Tue, Mar 25, 2025 at 05:22:15PM +0000, Bruce Richardson wrote:
> When doing a build for a target that already has the instruction sets
> for AVX2/AVX512 enabled, skip emitting the AVX compiler flags, or the
> skylake-avx512 '-march' flags, as they are unnecessary. Instead, when
> the default flags produce the desired output, just use them unmodified.
> 
> Depends-on: series-34915 ("remove component-specific logic for AVX builds")
> 
> Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> ---
> 
> This patchset depends on the previous AVX rework. However, sending it
> separately as a new RFC because it effectively increases the minimum
> compiler versions needed for x86 builds - from GCC 5 to 6, and
> Clang 3.6 to 3.9.
> 
> For now, I've just documented that as an additional note in the GSG that
> these versions are recommended, but it would be simpler if we could just
> set them as the required minimum baseline (at least in the docs).
> 
> Feedback on these compiler version requirements welcome.
>

+techboard

Ping for a little bit of feedback for this. Are we ok to bump the minimum
compiler versions as described above, or will I continue with the approach
in this RFC of keeping the minimum and just recommending the higher
versions for x86 platforms?

For reference GCC 6.1 was released April 2016[1], and, Clang 3.9 was
released Sept 2016[2]

/Bruce

[1] https://gcc.gnu.org/gcc-6/
[2] https://releases.llvm.org/