On Wed, 25 Nov 2015, Jakub Jelinek wrote:
The same is true whether we write it b > a or (a - b) > a (I don't think PRE
+ SCCVN avoid increasing register pressure).
So, I'd really prefer doing x-y>x to y>x only for single use.
Ok (for now).
Do you plan to work on that (my match.pd experience is smaller than yours),
or should I add to my todo list?
Are we talking stage 3 or next stage 1? If you want something for stage 3,
I think you'll have to do it, it shouldn't be much longer than
(for cmp (gt le)
(simplify
(cmp (minus:s @0 @1) @0)
(if (TYPE_UNSIGNED (TREE_TYPE (@0)))
(cmp @1 @0))))
and a similar one for x<y-x. (I don't think TYPE_UNSIGNED needs protection
against floats or whatever, but I could be wrong)
--
Marc Glisse
