Efficiency of memmove vs. generic typed copy

[Gabriel Dos Reis]

Our typed std::copy() is specialized for T*, where T is a POd, as a
forwarding function to generic memmove() from the C library. 
Do we have evidence that for the majority of the targets supported by
GCC, that is a win compared to the typed generic copy()
implementation that exposes alignment and other goodies to the optimizer?
On which targets do we know copy() wins?

-- Gaby