I approve of this patch. I'm responsible for GCC for TX2 at Marvell. Andrew
Pinski should certainly chime in if he wants.
Joel
On 7/6/20, 10:48 AM, "Gcc-patches on behalf of Richard Sandiford"
<gcc-patches-boun...@gcc.gnu.org on behalf of richard.sandif...@arm.com> wrote:
External Email
----------------------------------------------------------------------
Anton Youdkevitch <anton.youdkevi...@bell-sw.com> writes:
> This patch changes some vector costs for TX2 so that
> more vectorizations beneficial for TX2 chip can happen.
>
> The new cost model makes the x264 benchmark of CPU2017
> 7% faster with no negative performance impact on other
> benchmarks.
>
> Bootstrapped on linux-aarch64
>
> 2020-07-06 Anton Youdkevitch <anton.youdkevi...@bell-sw.com>
> gcc/
> * config/aarch64/aarch64.c (thunderx2t99_regmove_cost):
> Change instruction cost
> (thunderx2t99_vector_cost): Likewise
OK if Andrew agrees.
Thanks,
Richard
>
> From 3440e019c05fe5b565041cad549c6eefa2004a2b Mon Sep 17 00:00:00 2001
> From: Anton Youdkevitch <anton.youdkevi...@bell-sw.com>
> Date: Tue, 26 May 2020 04:23:04 -0700
> Subject: [PATCH] Change costs for TX2 to expose more vectorization
opportunities
>
> Make the costs such that they do not exaclty reflect
> the actual instructions costs from the manual but make
> the codegen emit the code we want it to.
> ---
> gcc/config/aarch64/aarch64.c | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
> index e92c7e6..18c2251 100644
> --- a/gcc/config/aarch64/aarch64.c
> +++ b/gcc/config/aarch64/aarch64.c
> @@ -535,9 +535,9 @@ static const struct cpu_regmove_cost
thunderx2t99_regmove_cost =
> {
> 1, /* GP2GP */
> /* Avoid the use of int<->fp moves for spilling. */
> - 8, /* GP2FP */
> - 8, /* FP2GP */
> - 4 /* FP2FP */
> + 5, /* GP2FP */
> + 6, /* FP2GP */
> + 3, /* FP2FP */
> };
>
> static const struct cpu_regmove_cost thunderx3t110_regmove_cost =
> @@ -704,15 +704,15 @@ static const struct cpu_vector_cost
thunderx2t99_vector_cost =
> 6, /* scalar_fp_stmt_cost */
> 4, /* scalar_load_cost */
> 1, /* scalar_store_cost */
> - 5, /* vec_int_stmt_cost */
> - 6, /* vec_fp_stmt_cost */
> + 4, /* vec_int_stmt_cost */
> + 5, /* vec_fp_stmt_cost */
> 10, /* vec_permute_cost */
> 6, /* vec_to_scalar_cost */
> 5, /* scalar_to_vec_cost */
> - 8, /* vec_align_load_cost */
> - 8, /* vec_unalign_load_cost */
> - 4, /* vec_unalign_store_cost */
> - 4, /* vec_store_cost */
> + 4, /* vec_align_load_cost */
> + 4, /* vec_unalign_load_cost */
> + 1, /* vec_unalign_store_cost */
> + 1, /* vec_store_cost */
> 2, /* cond_taken_branch_cost */
> 1 /* cond_not_taken_branch_cost */
> };
