On Tue, Nov 14, 2017 at 6:00 PM, Luis Machado <[email protected]> wrote:
> Disabling software prefetching and switching the autoprefetcher to weak
> improves
> CPU2017 rate and speed benchmarks for both int and fp sets on Falkor.
>
> SPECrate 2017 fp is up 0.38%
> SPECspeed 2017 fp is up 0.54%
> SPECrate 2017 int is up 3.02%
> SPECspeed 2017 int is up 3.16%
>
> There are only a couple individual regressions. The biggest one being about 4%
> in parest.
>
> For SPEC2006, we've noticed the following:
>
> SPECint is up 0.91%
> SPECfp is stable
>
> In the case of SPEC2006 we noticed both a big regression in mcf (about 20%)
> and a big improvement for hmmer (about 40%).
>
> Since the overall result is positive, we would like to make these new tuning
> settings the default for Falkor.
>
> We may revisit the software prefetcher setting in the future, in case we
> can adjust it enough so it provides us a good balance between improvements and
> regressions (mcf). But for now it is best if it stays off.
>
> I understand the freeze is happening soon, so it would be great to have this
> in before then.
>
> OK?
>
> Thanks,
> Luis
>
> 2017-11-14 Luis Machado <[email protected]>
>
> * config/aarch64/aarch64.c (qdf24xx_prefetch_tune): Remove.
> (qdf24xx_tunings): Replace qdf24xx_prefetch_tune with
> generic_prefetch_tune and tune_params::AUTOPREFETCHER_STRONG with
> tune_params::AUTOPREFETCHER_WEAK.
> ---
> gcc/ChangeLog | 7 +++++++
> gcc/config/aarch64/aarch64.c | 13 ++-----------
> 2 files changed, 9 insertions(+), 11 deletions(-)
>
> diff --git a/gcc/ChangeLog b/gcc/ChangeLog
> index b80a421..4dbfda0 100644
> --- a/gcc/ChangeLog
> +++ b/gcc/ChangeLog
> @@ -1,3 +1,10 @@
> +2017-11-14 Luis Machado <[email protected]>
> +
> + * config/aarch64/aarch64.c (qdf24xx_prefetch_tune): Remove.
> + (qdf24xx_tunings): Replace qdf24xx_prefetch_tune with
> + generic_prefetch_tune and tune_params::AUTOPREFETCHER_STRONG with
> + tune_params::AUTOPREFETCHER_WEAK.
> +
> 2017-11-14 Carl Love <[email protected]>
>
> * config/rs6000/rs6000.c (swap_endian_selector_for_mode): Remove
> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
> index 0c67e2b..171a230 100644
> --- a/gcc/config/aarch64/aarch64.c
> +++ b/gcc/config/aarch64/aarch64.c
> @@ -502,15 +502,6 @@ static const cpu_prefetch_tune exynosm1_prefetch_tune =
> -1 /* default_opt_level */
> };
>
> -static const cpu_prefetch_tune qdf24xx_prefetch_tune =
> -{
> - 4, /* num_slots */
> - 32, /* l1_cache_size */
> - 64, /* l1_cache_line_size */
> - 1024, /* l2_cache_size */
> - 3 /* default_opt_level */
I think the best thing is to leave this tuning structure in place and
just change default_opt_level to -1 to disable it at -O3.
Thanks,
Andrew
> -};
> -
> static const cpu_prefetch_tune thunderxt88_prefetch_tune =
> {
> 8, /* num_slots */
> @@ -817,9 +808,9 @@ static const struct tune_params qdf24xx_tunings =
> 2, /* min_div_recip_mul_sf. */
> 2, /* min_div_recip_mul_df. */
> 0, /* max_case_values. */
> - tune_params::AUTOPREFETCHER_STRONG, /* autoprefetcher_model. */
> + tune_params::AUTOPREFETCHER_WEAK, /* autoprefetcher_model. */
> (AARCH64_EXTRA_TUNE_NONE), /* tune_flags. */
> - &qdf24xx_prefetch_tune
> + &generic_prefetch_tune
> };
>
> /* Tuning structure for the Qualcomm Saphira core. Default to falkor values
> --
> 2.7.4
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