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

[Bruce Richardson]

On Wed, Apr 09, 2025 at 09:53:47AM +0000, Varghese, Vipin wrote:
> [Public]
> 
> Snipped
> 
> > > > > 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 at intel.com>
> 
> Hi Bruce,
> 
> From AMD end we have tested with gcc 12, and 13.
> We tried cross checking with and without patch for libraries such as `librte_net_ice and librte_net_i40e`.
> 
> We did not find much changes in the assembly code generated.
> I hope this is expected? Can you please share any pointers?\
> 
Yes, it's expected. This is a simplification/consolidation, not an attempt
to optimize in any way.

/Bruce