El 10/03/2024 a las 22:40, Ivan Matek via Boost-users escribió:
Hi,
I have some small maps where I am pretty sure SIMD tricks that are
amazing in general will just slow down the lookups since I never
lookup items not in the map and map is so small that benefits of not
looking up into the big array and trashing the cache are miniscule.
I know I can force compiler to not support SIMD with march, but I want
to keep the SIMD optimizaitons for rest of the code, including large
boost unordered objects.
Hi Ivan,
Boost.Unordered support can be disabled by globally defining the macro
BOOST_UNORDERED_DISABLE_SSE2, but this is probably not a solution for
you because:
* It disables SSE2 for *all* flat containers in Boost.Unordered.
* The alternative implementation to SSE2 is likely to be slower anyway.
May I suggest that you use boost::unordered_map instead of
boost::unordered_flat_map
for those small maps and see if this improves the performance of your
program?
Best,
Joaquín M López Muñoz
_______________________________________________
Boost-users mailing list
Boost-users@lists.boost.org
https://lists.boost.org/mailman/listinfo.cgi/boost-users