[Tarantool-patches] [PATCH v5 7/8] datetime: perf test for datetime parser

[Vladimir Davydov]

On Mon, Aug 16, 2021 at 02:59:41AM +0300, Timur Safin via Tarantool-patches wrote:
> It was told that if field `datetime.secs` would be `double` we should get
> better performance in LuaJIT instead of `uint64_t` type, which is used at the
> moment.
> 
> So we have created benchmark, which was comparing implementations of functions
> from `datetime.c` if we would use `double` or `int64_t` for `datetime.secs` field.
> 
> Despite expectations, based on prior experience with floaing-point on x86
> processors, comparison shows that `double` provides similar or
> sometimes better timings. And picture stays consistent be it SSE2, AVX1 or
> AVX2 code.
> 
> Part of #5941

I don't think this belongs in the repository. My understanding of the
perf tests committed to the repository (may be wrong) is that they are
supposed to be used to ensure there's no performance degradation of a
certain subsystem. Ideally, they should be run automatically after each
commit. The test added by this patch just checks what implementation of
datetime is faster - with double or int64_t.