memcpy verses memmove

What is the difference between memcpy and memmove? Which is more
expensive?

re: memcpy verses memmove

rinku24@yahoo.com wrote:[color=blue]
> What is the difference between memcpy and memmove? Which is more
> expensive?
>[/color]

memmove is ever so slightly more expensive because it does a check of
wether it needs to do a copy forward or copy backward.

On some systems, memcpy is the same routine as memmove.

re: memcpy verses memmove

<rinku24@yahoo.com> wrote in message
news:1108348259.203256.55320@o13g2000cwo.googlegro ups.com...[color=blue]
> What is the difference between memcpy and memmove? Which is more
> expensive?[/color]

memcpy expects that source and destination areas do not overlap.
It is undefined behaviour to give memcpy overlapping areas (and in C99,
memcpy has "restrict" qualifiers on both sides).
memmove behaves correctly in case of overlapping areas, but it is
potentially more expensive.

Hope it helps,
Ruslan Abdikeev.