On Mon, Aug 16, 2021 at 2:09 PM Hongtao Liu <crazylht@xxxxxxxxx> wrote: > > On Mon, Aug 16, 2021 at 2:00 PM Hongtao Liu <crazylht@xxxxxxxxx> wrote: > > > > On Mon, Aug 16, 2021 at 11:23 AM Kewen.Lin via Gcc-help > > <gcc-help@xxxxxxxxxxx> wrote: > > > > > > on 2021/8/4 下午4:31, Richard Biener wrote: > > > > On Wed, 4 Aug 2021, Richard Sandiford wrote: > > > > > > > >> Hongtao Liu <crazylht@xxxxxxxxx> writes: > > > >>> On Tue, May 18, 2021 at 4:27 AM Richard Sandiford via Gcc-help > > > >>> <gcc-help@xxxxxxxxxxx> wrote: > > > >>>> > > > >>>> Jan Hubicka <hubicka@xxxxxx> writes: > > > >>>>> Hi, > > > >>>>> here are updated scores. > > > >>>>> https://lnt.opensuse.org/db_default/v4/SPEC/latest_runs_report?younger_in_days=14&older_in_days=0&all_elf_detail_stats=on&min_percentage_change=0.001&revisions=9388fc7bf0da61a8104e8501e5965120e9159e12%2Cea21f32198432a490dd490696322838d94b3d3b2%2C4f5431c5768bbba81a422f6fed6a6e2454c700ee%2C&include_user_branches=on > > > >>>>> compares > > > >>>>> base: mainline > > > >>>>> 1st column: mainline with very cheap vectorization at -O2 and -O3 > > > >>>>> 2nd column: mainline with cheap vectorization at -O2 and -O3. > > > >>>>> > > > >>>>> The short story is: > > > >>>>> > > > >>>>> 1) -O2 generic performance > > > >>>>> kabylake (Intel): > > > >>>>> very cheap > > > >>>>> SPEC/SPEC2006/FP/total ~ 8.32% > > > >>>>> SPEC/SPEC2006/total -0.38% 4.74% > > > >>>>> SPEC/SPEC2006/INT/total -0.91% -0.14% > > > >>>>> > > > >>>>> SPEC/SPEC2017/INT/total 4.71% 7.11% > > > >>>>> SPEC/SPEC2017/total 2.22% 6.52% > > > >>>>> SPEC/SPEC2017/FP/total 0.34% 6.06% > > > >>>>> zen > > > >>>>> SPEC/SPEC2006/FP/total 0.61% 10.23% > > > >>>>> SPEC/SPEC2006/total 0.26% 6.27% > > > >>>>> SPEC/SPEC2006/INT/total 34.006 -0.24% 0.90% > > > >>>>> > > > >>>>> SPEC/SPEC2017/INT/total 3.937 5.34% 7.80% > > > >>>>> SPEC/SPEC2017/total 3.02% 6.55% > > > >>>>> SPEC/SPEC2017/FP/total 1.26% 5.60% > > > >>>>> > > > >>>>> 2) -O2 size: > > > >>>>> -0.78% (very cheap) 6.51% (cheap) for spec2k2006 > > > >>>>> -0.32% (very cheap) 6.75% (cheap) for spec2k2017 > > > >>>>> 3) build times: > > > >>>>> 0%, 0.16%, 0.71%, 0.93% (very cheap) 6.05% 4.80% 6.75% 7.15% (cheap) for spec2k2006 > > > >>>>> 0.39% 0.57% 0.71% (very cheap) 5.40% 6.23% 8.44% (cheap) for spec2k2017 > > > >>>>> here I simply copied data from different configuratoins > > > >>>>> > > > >>>>> So for SPEC i would say that most of compile time costs are derrived > > > >>>>> from code size growth which is a problem with cheap model but not with > > > >>>>> very cheap. Very cheap indeed results in code size improvements and > > > >>>>> compile time impact is probably somewhere around 0.5% > > > >>>>> > > > >>>>> So from these scores alone this would seem that vectorization makes > > > >>>>> sense at -O2 with very cheap model to me (I am sure we have other > > > >>>>> optimizations with worse benefits to compile time tradeoffs). > > > >>>> > > > >>>> Thanks for running these. > > > >>>> > > > >>>> The biggest issue I know of for enabling very-cheap at -O2 is: > > > >>>> > > > >>>> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100089 > > > >>>> > > > >>>> Perhaps we could get around that by (hopefully temporarily) disabling > > > >>>> BB SLP within loop vectorisation for the very-cheap model. This would > > > >>>> purely be a workaround and we should remove it once the PR is fixed. > > > >>>> (It would even be a compile-time win in the meantime :-)) Fixed by commit r12-3103-g819b7c3a339e3bdaf85cd55954c5536bd98aae09 Author: liuhongt <hongtao.liu@xxxxxxxxx> Date: Wed Aug 4 16:39:31 2021 +0800 Disable slp in loop vectorizer when cost model is very-cheap. Performance impact for the commit with option: -march=x86-64 -O2 -ftree-vectorize -fvect-cost-model=very-cheap SPEC2017 fprate 503.bwaves_r BuildSame 507.cactuBSSN_r -0.04 508.namd_r 0.14 510.parest_r -0.54 511.povray_r 0.10 519.lbm_r BuildSame 521.wrf_r 0.64 526.blender_r -0.32 527.cam4_r 0.17 538.imagick_r 0.09 544.nab_r BuildSame 549.fotonik3d_r BuildSame 554.roms_r BuildSame 997.specrand_fr -0.09 Geometric mean: 0.02 SPEC2017 intrate 500.perlbench_r 0.26 502.gcc_r 0.21 505.mcf_r -0.09 520.omnetpp_r BuildSame 523.xalancbmk_r BuildSame 525.x264_r -0.41 531.deepsjeng_r BuildSame 541.leela_r 0.13 548.exchange2_r BuildSame 557.xz_r BuildSame 999.specrand_ir BuildSame Geometric mean: 0.02 EEMBC: no regression, only improvement or build the same, the below is improved benchmarks. mp2decoddata1 7.59 mp2decoddata2 31.80 mp2decoddata3 12.15 mp2decoddata4 11.16 mp2decoddata5 11.19 mp2decoddata1 7.06 mp2decoddata2 24.12 mp2decoddata3 10.83 mp2decoddata4 10.04 mp2decoddata5 10.07 gcc/ChangeLog: PR tree-optimization/100089 * tree-vectorizer.c (try_vectorize_loop_1): Disable slp in loop vectorizer when cost model is very-cheap. -- BR, Hongtao
