[Gnu-arch-users] hackerlab str_ functions performance

[Jani Monoses]

Hello

hackerlab's str_cmp, str_length and str_cpy are among the top CPU users when
running changes and inventory at least, totalling 40% of tla cpu time.
        
            %
14664    20.3263  str_cmp
9685     13.4247  str_length
9178     12.7220  is_simple_anchored_regexp
5442      7.5434  rx_dfa_advance_to_final
5265      7.2980  str_cpy

a similar topic was raised a while ago related to mem_set0.
This crude patch changes them to calling glibc's routines and yields about a
15-20% speedup(not much) 

the head of profile output changes to

14686    20.6924  is_simple_anchored_regexp
8642     12.1765  rx_dfa_advance_to_final
4459      6.2827  hash_key
3094      4.3594  mem_move
2474      3.4858  rx_regmatch

Most of the times tla is I/O bound so these optimizations might not be that
important though.

Jani