On Friday, 6 January 2012 at 20:26:37 UTC, Walter Bright wrote:
On 1/6/2012 11:16 AM, Brad Roberts wrote:
However, a counter example, it'd be a lot easier to write a
memcpy routine that uses them
without having to resort to asm code under this theoretical
model.
I would seriously argue that individuals not attempt to write
their own memcpy.
Agner Fog states in his optimization manuals that the glibc
routines are fairly unoptimized. He provides his own versions,
however they are GPL.
Why? Because the C one has had probably thousands of
programmers looking at it for the last 30 years. You're not
going to spend 5 minutes, or even 5 days, and make it faster.
This assumes that hardware never changes. New memcpy
implementations can take advantage of large registers in newer
CPUs for higher speeds.
