https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84777
--- Comment #9 from rguenther at suse dot de <rguenther at suse dot de> --- On Fri, 9 Mar 2018, linux at carewolf dot com wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84777 > > --- Comment #8 from Allan Jensen <linux at carewolf dot com> --- > Yes, those I say are missing are compared to -O2. I was investigating this in > relation to Qt. We either build these files with -O3, or with -Os for customer > that are binary size sensitive. Since some of the image handling routines are > quite heavy and have been written for auto-vectorization I was just checking > if > I could get it to work and the results with your patch are quite good: > > Normal sizes of qdrawhelper.o with -O3/-O2/-Os: > 277704 / 198984 / 168440 > > With -O2 -ftree-vectorize: 242224 > With -O2 -fopenmp: 219536 > With -Os -ftree-loop-vectorize: 168440 (no change) > With -Os -fopenmp: 177144 (with your patch) > > So most of the -Os benefit and still many of the central draw loops > auto-vectorized. That looks indeed good. We have enough infrastructure already to support a #pragma GCC vectorize as well (it was added for Ada) just nobody bothered to add C/C++ support. > Haven't benchmarked it yet though. I will test and post the patch, I think it makes sense.
