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Re: Why can't CSE recognize const_int's in HIGH LO_SUM pair?


>   > 	(set (reg T) (const_int 0x10000))
>   > 	(set (reg A) (plus (reg T) (const_int 1)))
>   > 	(set (reg B) (plus (reg T) (const_int 2)))
>   > 
>   > Now consider A and B loaded on two different paths.  Code motion can
>   > then pull T up into the dominator.
> But recall that we don't do this right now on the PA due to implementation
> issues.

I was planning on trying to implement this later this week.  At the moment,
I am pounding nails helping with a new house for my sister.

It is clear that either the above, or just

(set (reg A) (const_int)) 

is better than the current high/lo_sum.  However, I don't see a consensis
from the discussion as to which approach is better.

Dave
-- 
J. David Anglin                                  dave.anglin@nrc.ca
National Research Council of Canada              (613) 990-0752 (FAX: 952-6605)


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