Re: [RFA][PATCH][PR tree-optimization/64058] Improve and stabilize sorting of coalesce pairs

[Jeff Law <law at redhat dot com>]

On 03/15/2016 08:22 AM, Richard Biener wrote:
> > To work around the narrow API in the comparison function we have to either
> > store additional data in each node or have them available in globals.  The
> > former would be horribly wasteful, the latter is just ugly.  I choose the
> > latter in the lazy evaluation of the conflicts version.
>
> Works for me.
I'm going to take a look at Trevor's suggestion to use std::sort with a 
suitable class.  That may ultimately be cleaner.


> > > As far as a testcase goes we want to scan the dumps for the actual
> > > coalesces
> > > being done.  Might be a bit fragile though...
> >
> > I suspect that's going to be quite fragile and may have more target
> > dependencies than we'd like (due to branch costing and such).
>
> Yes.
>
> Otherwise -ENOPATCH.
Right.  I haven't written the part to count the number of unique bits 
across two bitmaps yet as exported function from bitmap.[ch] yet.  So no 
patch was included.  Off to do that now :-)

jeff