[U-Boot] [PATCH 1/3] memcpy: use 32-bit copies if possible

[Mike Frysinger]

On Thursday 08 October 2009 01:23:05 Chris Moore wrote:
> Alessandro Rubini a écrit :
> > --- a/lib_generic/string.c
> > +++ b/lib_generic/string.c
> > @@ -449,7 +449,16 @@ char * bcopy(const char * src, char * dest, int
> > count) void * memcpy(void * dest,const void *src,size_t count)
> >  {
> >  	char *tmp = (char *) dest, *s = (char *) src;
> > +	u32 *d32 = (u32 *)dest, *s32 = (u32 *) src;
> >
> > +	/* if both are aligned, use 32-bit copy */
> > +	if ( (((int)dest & 3) | ((int)src & 3) | (count & 3)) == 0 ) {
> 
> This can be factorized as (a & 3) | (b & 3) | (c & 3) is equivalent to
> (a | b | c) & 3.
> GCC is pretty smart but I doubt that it will pick this up :(

last time i looked (gcc-4.1 and gcc-4.3), it worked fine
-mike
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