RE: [PATCH] add slice by 8 algorithm to crc32.c

[Bob Pearson]

> -----Original Message-----
> From: George Spelvin [mailto:linux@xxxxxxxxxxx]
> Sent: Monday, August 08, 2011 5:52 AM
> To: joakim.tjernlund@xxxxxxxxxxxx; linux@xxxxxxxxxxx
> Cc: akpm@xxxxxxxxxxxxxxxxxxxx; fzago@xxxxxxxxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; rpearson@xxxxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH] add slice by 8 algorithm to crc32.c
> 
> > I prefer to keep the current code which (at the time) generated good
code
> > for at least ppc:
> > 	/* Align it */
> > 	if (unlikely((long)buf & 3 && len)) {
> > 		do {
> > 			DO_CRC(*buf++);
> > 		} while ((--len) && ((long)buf)&3);
> > 	}
> 
> Ah, I was looking at fzago's initial patch; I hadn't realized you'd
> tweaked it.  That's pretty much what I was talking about.

Frank actually deserves none of the 'blame' for this effort. He is much more
experienced in sending in patches to linux-kernel than I am and helped me to
prepare and send the first version of the patch.

> 
> Would
>  	if (unlikely((long)buf & 3) && len) {
> 
> give the compiler better hints?  len != 0 is awfully
> likely, actually.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/