[dpdk-dev] [RFC PATCH] build/pkg-config: remove machine arch flag

[Bruce Richardson]

On Wed, Jun 14, 2023 at 12:33:10PM -0700, Stephen Hemminger wrote:
> On Fri, 11 Dec 2020 15:51:11 +0000
> Bruce Richardson <bruce.richardson at intel.com> wrote:
> 
> > Traditionally any apps built using DPDK had to support the same
> > instruction sets as supported when the DPDK SDK itself was built, since
> > that was "leaked" through to the end-app and DPDK headers via
> > RTE_MACHINE_CPUFLAG_* values. Therefore, when converting over to meson
> > for app build correctness the "-march=" flag was included in the
> > pkg-config cflags output.
> > 
> > However, since the DPDK-specific CPU flags are now obsolete, and we
> > instead check directly for compiler-defined flags, we should no longer
> > need to force the exact same architecture match in all cases. To
> > faciliate such flexibility, a new pkg_config_machine_args array - which
> > defaults to the existing machine_args array has been defined. The
> > individual architectures - x86, arm and ppc - can choose if and how to
> > override this value themselves.
> > 
> > For x86, since SSE4.2 is the minimum instruction-set level needed to run
> > DPDK, and since some header files assume that minimum level of
> > instruction set support, we override the "-march=" value with "-msse4"
> > for the pkg-config file. This allows end applications to set their own
> > "march" value while still ensuring valid DPDK compilation.
> > 
> > Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
> 
> This looks fine, and can see no negatives in the comments.
> Could you rebase and resubmit a new version if still relevant?
> 
There seemed to be a general lack of interest in it, sadly, so not sure
I'll resubmit.