Why can't CSE recognize const_int's in HIGH LO_SUM pair?
John David Anglin
dave@hiauly1.hia.nrc.ca
Mon Sep 10 20:12:00 GMT 2001
> > (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)
More information about the Gcc
mailing list