On Thu, Mar 26, 2020 at 2:06 AM Yangfei (Felix) <felix.y...@huawei.com> wrote: > > Hi! > > > -----Original Message----- > > From: Richard Biener [mailto:richard.guent...@gmail.com] > > Sent: Tuesday, March 24, 2020 10:14 PM > > To: Yangfei (Felix) <felix.y...@huawei.com> > > Cc: gcc-patches@gcc.gnu.org > > Subject: Re: [RFC] Should widening_mul should consider block frequency? > > > > > > As written in the PR I'd follow fma generation and restrict defs to the > > > > same > > BB. > > > > > > Thanks for the suggestion. That should be more consistent. > > > Attached please find the adapted patch. > > > Bootstrap and tested on both x86_64 and aarch64 Linux platform. > > > > OK with moving the BB check before the is_widening_mult_p call since it's > > way > > cheaper. > > That's a good point. I have attached the v2 patch. > Also did a spec2017 test on aarch64, no obvious impact witnessed with this. > Can you sponsor this patch please? My networking does not work well and I am > having some trouble pushing it : - (
Pushed. For the future can you please attach patches suitable for git am? Thanks, Richard. > git commit msg: > > widening_mul: restrict ops to be defined in the same basic-block when > convert plusminus to widen > > In the testcase for PR94269, widening_mul moves two multiply instructions > from outside the loop to inside > the loop, merging with two add instructions separately. This increases > the cost of the loop. Like FMA detection > in the same pass, simply restrict ops to be defined in the same > basic-block to avoid possibly moving multiply > to a different block with a higher execution frequency. > > 2020-03-26 Felix Yang <felix.y...@huawei.com> > > gcc/ > PR tree-optimization/94269 > * tree-ssa-math-opts.c (convert_plusminus_to_widen): Restrict this > operation to single basic block. > > gcc/testsuite/ > PR tree-optimization/94269 > * gcc.dg/pr94269.c: New test. > > change log: > > gcc: > +2020-03-26 Felix Yang <felix.y...@huawei.com> > + > + PR tree-optimization/94269 > + * tree-ssa-math-opts.c (convert_plusminus_to_widen): Restrict this > + operation to single basic block. > > gcc/testsuite: > +2020-03-26 Felix Yang <felix.y...@huawei.com> > + > + PR tree-optimization/94269 > + * gcc.dg/pr94269.c: New test. > +
