https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69556
--- Comment #6 from rguenther at suse dot de <rguenther at suse dot de> --- On January 29, 2016 10:45:12 PM GMT+01:00, "glisse at gcc dot gnu.org" <gcc-bugzi...@gcc.gnu.org> wrote: >https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69556 > >--- Comment #5 from Marc Glisse <glisse at gcc dot gnu.org> --- >(In reply to rguent...@suse.de from comment #4) >> I think there is a misunderstanding. A replacement is still allowed >if it >> is a single operation as that replaces at least one other (the one we >are >> simplifying). This assumes equal cost of course which for divide vs. >Mult >> is not the case. So an explicit && single_use as in the patch below >is >> needed. > >The number of patterns that have to use an explicit single_use is >growing, >maybe we need a syntax like :S for "single_use, and I mean it, not like >:s". Heh. I hoped to avoid this and find some better way to cater to the different users of the machinery in the gcc 7 timeframe.
