frank@ladc.bull.com (Frank Mayhar) (10/06/89)
My installation of Gnu C on our XPS 100 is coming along. It's not quite
there yet, but I can see the light at the end of the tunnel. Thanks! to
all those who responded to my original request for help.
Now a new question. How would I go about adding an optimization to the
m68k.md file? Specifically, I want to optimize the following sequence:
L4:
cmp.b %d1,(%a0)+
beq.w L3
dbra %d0,L4
L3:
into:
L4:
cmp.b %d1,(%a0)+
dbeq %d0,L4
How would I go about doing that? Is it fairly simple? Very complicated?
Somewhere in between? I've read the information about the define_peephole
stuff, but I don't know enough about the internals of m68k.md or about the
compiler itself to keep from getting into trouble. (And, I would like to
come up with this before Christmas. :-)
Any takers?
--
Frank Mayhar frank@ladc.bull.com (..!{uunet,hacgate,rdahp}!ladcgw!frank)
Bull HN Information Systems Inc. Los Angeles Development Center
5250 W. Century Blvd., LA, CA 90045 Phone: (213) 216-6241