wmemchr optimization and its throughput impact (original) (raw)

This include:

STL/stl/inc/xutility

Line 15 in313964b

Is used for wmemchr optimization, it was introcuded in 2024.

The <cwchar> brings in <intrin.h>, which we have always been avoided for throughput reasons. Probably it started bringing it in specifically for wmemchr optimization.

What should we do now? I see three opposite paths forward:

• Drop #include <cwchar> and current wmemchr optimizations. Will primarily affect ARM64.
• Get SDK fixed to use <intrin0.h>.
• Do nothing, accept throughput impact.