[FFmpeg-devel] the future of fastmemcpy.h

[Arpi]

Hi,

> On Tue, May 22, 2007 at 10:17:34PM +0200, Reimar Doeffinger wrote:
> > Hello,
> > On Tue, May 22, 2007 at 09:53:59PM +0200, Alex Beregszaszi wrote:
> > > > Ronald brought up the subject of the fastmemcpy.h #includes that we
> > > > continue to have in a few source files.  fastmemcpy.h is part of MPlayer
> > > > and not FFmpeg.  Is the #include just old cruft or worth keeping?
> > > > 
> > > 
> > > I thought today about moving fastmemcpy into libavutil.
> > 
> > Please don't without proper performance testing, it stops gcc from
> > replacing constant-size memcpys by an inlined builtin, causing both
> > valgrind problems and at least for lzo massive slowdown.
> 
> introduce a big_memcpy() and leave memcpy() as is ...
> 

or define such function in fastmemcpy.h:

inline void* memcpy(void* dst,void* src,size_t len){
	if(len<128)
		return __memcpy(dst,src,len);
	return fast_memcpy(dst,src,len);
}

but anyway simple memcpy() shouldnt be re-defined, instead
the functions using big copies should call fast_memcpy().

A'rpi