In issue #1184, cppcheck found several issues in the printf formats
used to display integers, some of which are unsigned but which used to
still rely on "%d".
Dmitry reported this warning on FreeBSD since the introduction of -Wundef:
admin/halog/fgets2.c:38:30: warning: '__GLIBC__' is not defined, evaluates to 0 [-Wundef]
#if defined(__x86_64__) && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 15))
^
A defined() was missing.
There has been a USE_MEMCHR option for ages that was mostly never enabled
because it was unclear when glibc became faster. A quick look at the code
indicates that this arrived with the SSE implementation of memchr() which
arrived at commit 093ecf92998de2 between 2.14 and 2.15, so let's automatically
turn this on on x86_64 with glibc >= 2.15.
This results in ~6GB of logs read per second (20 million lines) and ~2.5GB/s
(8 million lines) parsed for errors or status codes classification, or 1 GB/s
(3 million lines) for time percentiles.