Re: [Xen-devel] [RFC PATCH] p2m-pt: avoid get the pte falgs repeatedly.

["Li, Liang Z" <liang.z.li@xxxxxxxxx>]

> >>> On 17.11.16 at 09:24, <liang.z.li@xxxxxxxxx> wrote:
> > There are a lot of code try to get the pte flags repeatedly, why not
> > save the result and reuse it in the following code? It can help to
> > save some CPU cycles and make the code cleaner, no?
> >
> > I am not sure if this is the right direction, just change one place.
> 
> Did you compare generated code with and without this change? A compiler

No.  
> doing well optimization wise may produce better code in at least some of the
> cases: The calculation involved in lNe_get_flags() may be possible to
> completely elide, and hence your patch may increase register pressure /
> stack consumption due to the new variable. But of course a benefit of the
> change is better overall readability ...
> 
Good to know that it's worthy to make the change.

> In any event you'd need to address various style issues before such a patch
> could be accepted.

Of course, and I will try to change other places and resend the patch.

Thanks!
Liang
> 
> Jan


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