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Date: Wed, 2 Aug 2017 11:20:43 +0800
From: Peter Xu <peterx@redhat.com>
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Subject: Re: [Qemu-devel] [RFC 04/29] bitmap: introduce bitmap_invert()
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To: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: qemu-devel@nongnu.org, Laurent Vivier <lvivier@redhat.com>, Alexey Perevalov <a.perevalov@samsung.com>, Juan Quintela <quintela@redhat.com>, Andrea Arcangeli <aarcange@redhat.com>

On Tue, Aug 01, 2017 at 09:40:09AM +0100, Dr. David Alan Gilbert wrote:
> * Peter Xu (peterx@redhat.com) wrote:
> > On Mon, Jul 31, 2017 at 06:11:56PM +0100, Dr. David Alan Gilbert wrote:
> > > * Peter Xu (peterx@redhat.com) wrote:
> > > > It is used to invert the whole bitmap.
> > > 
> > > Would it be easier to change bitmap_complement to use ^
> > > in it's macro and slow_bitmap_complement, and then you could call it
> > > with src==dst  to do the same thing with just that small change?
> > 
> > Or, I can directly use that and drop this patch. :-)
> 
> Yes, that's fine - note the only difference I see is what happens to the
> bits in the last word after the end of the count; your code leaves them
> as is, the complement code will zero them on the destination I think.

I see.  I believe both should work since bitmap users should not
use those bits after all (considering those bits are outside range of
valid bits when declaring the bitmap).  Thanks,

-- 
Peter Xu