[tz] localtime_r multiple times slower for Europe/Moscow timezone

[Guy Harris]

On Jan 11, 2023, at 12:07 AM, Guy Harris via tz <tz at iana.org> wrote:

> GNU libc's code does *not* save the results of the parse.  Its code to test whether the time is past the last transition's time is
> 
> 	else if (__glibc_unlikely (timer >= transitions[num_transitions - 1]))
> 
> which suggest that they assumed that this was an unlikely case.  There may have been a time when it was unlikely, but, with the current zic, this will, I think, be the case for any tzdb region that does not currently adjust the clocks, and there are quite a few of them.

Including China, India, Japan, and Russia, for starters.