cfg merge part 17 - loop datastructure updates

Jan Hubicka jh@suse.cz
Sat Jun 1 01:40:00 GMT 2002


> On Fri, May 31, 2002 at 08:40:56PM +0200, Zdenek Dvorak wrote:
> > Here is the patch (also updated after bb renumbering removal).
> 
> Thanks.  Nearly ok.
> 
> > +       /* We could not redirect edges freely here. On the other hand,
> > + 	 we know that no abnormal edge enters this block, so we can simply
> > + 	 split the edge from entry block.  */
> 
> Actually, it is possible for the first block to be the target
> of an abnormal edge.  There could be a computed jump to a label
> at the beginning of the function.  But certainly that's not
> worth handling beyond not setting the header bit if we find one.

I think the comment is simply out of date. Now we don't use split_block,
but split_edge that will work even when first BB is reached by abnormal
edges too.  All we need to know is that the entry edge is normal (or
splittable, as it definitly isn't normal)

I am just installing the change, as Zdenek is currently away
(or leaving soon).

Thanks!
> 
> Ok with that change.
> 
> 
> 
> r~



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