review (S) for 6953576: bottom_type for matched AddPNodes doesn't always agree with ideal

[Tom Rodriguez]

We talked about it but I never officially sent it out for review.  It's unchanged from what you saw earlier.  Thanks!

tom

On May 18, 2010, at 2:59 PM, Vladimir Kozlov wrote:

> Did not I review it already?
> Anyway it looks good.
> 
> Vladimir
> 
> Tom Rodriguez wrote:
>> http://cr.openjdk.java.net/~never/6953576/
>> 6953576: bottom_type for matched AddPNodes doesn't always agree with ideal
>> Reviewed-by:
>> 6715633 added an assert to make sure that the adr_type of nodes
>> doesn't change during matching.  If the address pieces are matched
>> separately this assert can fail because the logic in
>> AddPNode::mach_bottom_type isn't the equivalent to
>> AddPNode::bottom_type.  The fix is to simply capture the bottom_type
>> when transforming the nodes by making AddP matches inherit from
>> MachTypeNode.  This was originally discovered in the ia64 port but I
>> reproduced it by disabling the use of complex addressing modes to
>> force the matching AddPs separately.