[PATCH v6 2/4] powerpc/64: enhance memcmp() with VMX instruction for long bytes comparision

[Simon Guo]

Hi Segher,
On Mon, May 28, 2018 at 06:05:59AM -0500, Segher Boessenkool wrote:
> On Fri, May 25, 2018 at 12:07:34PM +0800, wei.guo.simon at gmail.com wrote:
> > +	/* save and restore cr0 */
> > +	mfocrf  r5,64
> > +	EXIT_VMX_OPS
> > +	mtocrf	64,r5
> > +	b	.LcmpAB_lightweight
> 
> That's cr1, not cr0.  You can use mcrf instead, it is cheaper (esp. if
> you have it in a non-volatile CR field before so you need only one, if any).
> 
You are right :) How about using mtcr/mfcr instead, I think they are
fast as well and more readable.

> > +	vcmpequb.  v7,v9,v10
> > +	bnl	cr6,.Ldiffoffset_vmx_diff_found
> 
> In other places you say  bf 24,...  Dunno which is more readable, but
> please pick one?
I will update to bnl for other cases.
> 
> 
> Segher

Thanks for your review.

BR,
- Simon