Re: [PATCH v5 0/3] add portable version of __builtin_add_overflow

[David Marchand <david.marchand@redhat.com>]

On Wed, Jun 4, 2025 at 12:29 PM Morten Brørup <mb@smartsharesystems.com> wrote:
> > I am not a fan of adding such public API, an internal API would be
> > enough.
> > Do you plan to add more helpers for math operations?
> >
> > For the current helper, the only user is a driver (base code).
> > Can't we just wrap a __builtin_add_overflow (under #ifdef msvc) in the
> > osdep.h header?
>
> We already have public APIs for bit operations in rte_bitops.h.
> This math API follows the same principle; and math operations - just like bit operations - might be useful for DPDK applications, so let's keep it public.

This comparison is poor.

There are many users of bitops in dpdk, and *public* headers needed it.

Here, we have one single function in a driver implementation.
And this code is unused (__builtin_add_overflow -> check_add_overflow
-> ice_get_pfa_module_tlv -> ice_get_link_default_override ->
ice_cfg_phy_fec, with no intree user).


>
> The only issue I have with these (incl. the bit operations) are that they are in the EAL library, although they have absolutely nothing to do with hardware or O/S abstraction, so they really should be in a "utils" library.
> But that's another story, so let's not burden Andre with that.

Orthogonal to the question.


-- 
David Marchand