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

[Vladimir Kozlov]

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.