On Wed, 30 Oct 2019, Jiufu Guo wrote:
> Hi,
>
> In this patch, loop unroll adjust hook is introduced for powerpc. In this
> hook,
> we can do target related hueristic adjustment. For this patch, we tunned for
> O2 to unroll small loops with small unroll factor (2 times), for other
> optimization, default unroll factor is used.
>
> Bootstrapped and regtested on powerpc64le. Is this ok for trunk?
This looks good to me, needs ppc maintainer approval though.
Thanks,
Richard.
>
> Jiufu
> BR.
>
>
> gcc/
> 2019-10-30 Jiufu Guo <guoji...@linux.ibm.com>
>
> PR tree-optimization/88760
> * config/rs6000/rs6000.c (rs6000_option_override_internal): Remove
> code which changes PARAM_MAX_UNROLL_TIMES and PARAM_MAX_UNROLLED_INSNS.
> (TARGET_LOOP_UNROLL_ADJUST): Add loop unroll adjust hook.
> (rs6000_loop_unroll_adjust): New hook for loop unroll adjust. Unrolling
> small loop 2 times for -O2.
>
>
> gcc.testsuite/
> 2019-10-29 Jiufu Guo <guoji...@linux.ibm.com>
>
> PR tree-optimization/88760
> * gcc.dg/pr59643.c: Update back to r277550.
> * gcc.dg/unroll-8.c: Update cases.
> * gcc.dg/var-expand3.c: Update cases.
>
> ---
> gcc/config/rs6000/rs6000.c | 37 ++++++++++++++++++++++++++-----------
> gcc/testsuite/gcc.dg/pr59643.c | 3 ---
> gcc/testsuite/gcc.dg/unroll-8.c | 4 ++++
> gcc/testsuite/gcc.dg/var-expand3.c | 2 ++
> 4 files changed, 32 insertions(+), 14 deletions(-)
>
> diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
> index 9ed5151..183dceb 100644
> --- a/gcc/config/rs6000/rs6000.c
> +++ b/gcc/config/rs6000/rs6000.c
> @@ -1428,6 +1428,9 @@ static const struct attribute_spec
> rs6000_attribute_table[] =
> #undef TARGET_VECTORIZE_DESTROY_COST_DATA
> #define TARGET_VECTORIZE_DESTROY_COST_DATA rs6000_destroy_cost_data
>
> +#undef TARGET_LOOP_UNROLL_ADJUST
> +#define TARGET_LOOP_UNROLL_ADJUST rs6000_loop_unroll_adjust
> +
> #undef TARGET_INIT_BUILTINS
> #define TARGET_INIT_BUILTINS rs6000_init_builtins
> #undef TARGET_BUILTIN_DECL
> @@ -4540,20 +4543,11 @@ rs6000_option_override_internal (bool global_init_p)
> global_options.x_param_values,
> global_options_set.x_param_values);
>
> - /* unroll very small loops 2 time if no -funroll-loops. */
> + /* If funroll-loops is implicitly enabled, do not turn fweb or
> + frename-registers on implicitly. */
> if (!global_options_set.x_flag_unroll_loops
> && !global_options_set.x_flag_unroll_all_loops)
> {
> - maybe_set_param_value (PARAM_MAX_UNROLL_TIMES, 2,
> - global_options.x_param_values,
> - global_options_set.x_param_values);
> -
> - maybe_set_param_value (PARAM_MAX_UNROLLED_INSNS, 20,
> - global_options.x_param_values,
> - global_options_set.x_param_values);
> -
> - /* If fweb or frename-registers are not specificed in command-line,
> - do not turn them on implicitly. */
> if (!global_options_set.x_flag_web)
> global_options.x_flag_web = 0;
> if (!global_options_set.x_flag_rename_registers)
> @@ -5101,6 +5095,27 @@ rs6000_destroy_cost_data (void *data)
> free (data);
> }
>
> +/* This target hook implementation for TARGET_LOOP_UNROLL_ADJUST calculates
> + a new heristic number struct loop *loop should be unrolled. */
> +
> +static unsigned
> +rs6000_loop_unroll_adjust (unsigned nunroll, struct loop * loop)
> +{
> + /* For -O2, we only unroll small loops with small unroll factor. */
> + if (optimize == 2)
> + {
> + /* If the loop contains few insns, treated it as small loops.
> + TODO: Uing 10 hard code for now. Continue to refine, For example,
> + if loop constians only 1-2 insns, we may unroll more times(4).
> + And we may use PARAM to control kinds of loop size. */
> + if (loop->ninsns <= 10)
> + return MIN (2, nunroll);
> + else
> + return 0;
> + }
> + return nunroll;
> +}
> +
> /* Handler for the Mathematical Acceleration Subsystem (mass) interface to a
> library with vectorized intrinsics. */
>
> diff --git a/gcc/testsuite/gcc.dg/pr59643.c b/gcc/testsuite/gcc.dg/pr59643.c
> index 4446f6e..de78d60 100644
> --- a/gcc/testsuite/gcc.dg/pr59643.c
> +++ b/gcc/testsuite/gcc.dg/pr59643.c
> @@ -1,9 +1,6 @@
> /* PR tree-optimization/59643 */
> /* { dg-do compile } */
> /* { dg-options "-O3 -fdump-tree-pcom-details" } */
> -/* { dg-additional-options "--param max-unrolled-insns=400" { target {
> powerpc*-*-* } } } */
> -/* Implicit threashold of max-unrolled-insn on ppc at O3 is too small for the
> - loop of this case. */
>
> void
> foo (double *a, double *b, double *c, double d, double e, int n)
> diff --git a/gcc/testsuite/gcc.dg/unroll-8.c b/gcc/testsuite/gcc.dg/unroll-8.c
> index b16df67..b1d38a6 100644
> --- a/gcc/testsuite/gcc.dg/unroll-8.c
> +++ b/gcc/testsuite/gcc.dg/unroll-8.c
> @@ -4,6 +4,10 @@ struct a {int a[7];};
> int t(struct a *a, int n)
> {
> int i;
> +
> + /* Testing unroller message if arrary size is smaller than unroll factor.
> */
> + /* Using pragma unroll to make sure unroll factor is large enough. */
> + #pragma GCC unroll 8
> for (i=0;i<n;i++)
> a->a[i]++;
> }
> diff --git a/gcc/testsuite/gcc.dg/var-expand3.c
> b/gcc/testsuite/gcc.dg/var-expand3.c
> index dce6ec1..d2ca6df 100644
> --- a/gcc/testsuite/gcc.dg/var-expand3.c
> +++ b/gcc/testsuite/gcc.dg/var-expand3.c
> @@ -21,6 +21,8 @@ foo (int n)
>
> vaccum = vzero;
>
> + /* Using pragma unroll to make sure unroll enough times. */
> + #pragma GCC unroll 8
> for (i = 0; i < n; i++)
> {
> vp1 = vec_ld (i * 16, in1);
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
