On Fri, Nov 3, 2017 at 6:38 AM, Andrew Pinski <apin...@cavium.com> wrote: > On Fri, Nov 3, 2017 at 12:11 AM, Wilco Dijkstra <wilco.dijks...@arm.com> > wrote: >> The Arm backend sets the default sched-pressure algorithm to >> SCHED_PRESSURE_MODEL. Benchmarking on AArch64 shows this >> speeds up floating point performance on SPEC - eg. CactusBSSN improves >> by ~16%. The gains are mostly due to less spilling, so enable this on >> AArch64 >> by default. >> >> OK for commit? > > I am ok with this from my point of view. The rs6000, arm and s390 > back-ends all enable the same way. I suspect all RISC targets should > enable this way too.
I think all OOO execution capable CPUs should. Ideally this wouldn't be a choice between two models but the scheduler would take into account register pressure anyways. Or we should always schedule with sched-pressure during first scheduling. Richard. > Thanks, > Andrew > >> >> 2017-11-02 Wilco Dijkstra <wdijk...@arm.com> >> >> * config/aarch64/aarch64.c (aarch64_override_options_internal): >> Set PARAM_SCHED_PRESSURE_ALGORITHM to SCHED_PRESSURE_MODEL. >> >> -- >> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c >> index >> 34456e96497ac7b6d2f9931187ff05619e1934a4..750b0bc29c0963742d5d7bb4ae4619d93bec3e4a >> 100644 >> --- a/gcc/config/aarch64/aarch64.c >> +++ b/gcc/config/aarch64/aarch64.c >> @@ -9276,6 +9276,11 @@ aarch64_override_options_internal (struct gcc_options >> *opts) >> opts->x_param_values, >> global_options_set.x_param_values); >> >> + /* Use the alternative scheduling-pressure algorithm by default. */ >> + maybe_set_param_value (PARAM_SCHED_PRESSURE_ALGORITHM, >> SCHED_PRESSURE_MODEL, >> + opts->x_param_values, >> + global_options_set.x_param_values); >> + >> /* Enable sw prefetching at specified optimization level for >> CPUS that have prefetch. Lower optimization level threshold by 1 >> when profiling is enabled. */ > <div id="DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2"><br /> > <table style="border-top: 1px solid #D3D4DE;"> > <tr> > <td style="width: 55px; padding-top: 13px;"><a > href="http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail"; > target="_blank"><img > src="https://ipmcdn.avast.com/images/icons/icon-envelope-tick-green-avg-v1.png"; > alt="" width="46" height="29" style="width: 46px; height: 29px;" > /></a></td> > <td style="width: 470px; padding-top: 12px; color: #41424e; > font-size: 13px; font-family: Arial, Helvetica, sans-serif; > line-height: 18px;">Virus-free. <a > href="http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail"; > target="_blank" style="color: #4453ea;">www.avg.com</a> > </td> > </tr> > </table><a href="#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2" width="1" > height="1"></a></div>
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