Re: [PATCH][AArch64] Set default sched pressure algorithm

[Andrew Pinski]

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.

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.  */
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