Slow memcmp for aligned strings on Pentium 3

[Jerry Quinn]

I just tried the same benchmark on a Pentium 4 out of curiosity.  Slightly
different results:

Memory compare int:
  10000
  130000
  Speed up: 0.076923
Memory compare 15 bytes:
  10000
  370000
  Speed up: 0.027027
Memory compare 16 bytes:
  20000
  330000
  Speed up: 0.060606
Memory compare 64 bytes:
  10000
  1040000
  Speed up: 0.009615
Memory compare 256 bytes:
  20000
  2300000
  Speed up: 0.008696


Perhaps this is to be expected since the routine uses shifts.

Jerry Quinn