On Wed, Nov 10, 2010 at 18:11, Number Cruncher <number.cruncher@ntlworld.com> wrote:

Just some observations from a concerned user with a temperamental Open MPI program (1.4.3):

Fedora 14 (just released) includes glibc-2.12 which has optimized versions of memcpy, including a copy backward.
http://sourceware.org/git/?p=glibc.git;a=commitdiff;h=6fb8cbcb58a29fff73eb2101b34caa19a7f88eba

Is the memcpy-back code ever executed when called as memcpy()? I can't imagine why it would be, but it would make plenty of sense to use it inside memmove when the destination is at a higher address than the source.

Jed