> On 3 Mar 2025, at 19:58, Wilco Dijkstra <[email protected]> wrote:
>
>
> Enable the early scheduler on AArch64 for O3/Ofast. This means GCC15 benefits
> from much faster build times with -O2, but avoids the regressions in lbm which
> is very sensitive to minor scheduling changes due to long FMA chains. We can
> then revisit this for GCC16.
>
I’m in favour of this.
So ok for me if no objections within 24h.
Thanks,
Kyrill
> gcc:
> PR target/118351
> * common/config/aarch64/aarch64-common.cc: Enable early scheduling with
> -O3 and higher.
>
> ---
>
> diff --git a/gcc/common/config/aarch64/aarch64-common.cc
> b/gcc/common/config/aarch64/aarch64-common.cc
> index
> 3d694f16d1fd84e142254a4880c91a7f053e72aa..3044336923415d9414b6c66e66d872612ead24cd
> 100644
> --- a/gcc/common/config/aarch64/aarch64-common.cc
> +++ b/gcc/common/config/aarch64/aarch64-common.cc
> @@ -54,8 +54,10 @@ static const struct default_options
> aarch_option_optimization_table[] =
> { OPT_LEVELS_FAST, OPT_fomit_frame_pointer, NULL, 1 },
> /* Enable -fsched-pressure by default when optimizing. */
> { OPT_LEVELS_1_PLUS, OPT_fsched_pressure, NULL, 1 },
> - /* Disable early scheduling due to high compile-time overheads. */
> + /* Except for -O3 and higher, disable early scheduling due to high
> + compile-time overheads. */
> { OPT_LEVELS_ALL, OPT_fschedule_insns, NULL, 0 },
> + { OPT_LEVELS_3_PLUS, OPT_fschedule_insns, NULL, 1 },
> /* Enable redundant extension instructions removal at -O2 and higher. */
> { OPT_LEVELS_2_PLUS, OPT_free, NULL, 1 },
> { OPT_LEVELS_2_PLUS, OPT_mearly_ra_, NULL, AARCH64_EARLY_RA_ALL },
>
