This patch adds dedicated vector costs for Neoverse V1.
Previously we just used the Cortex-A57 costs, which isn't
ideal given that Cortex-A57 doesn't support SVE.
gcc/
* config/aarch64/aarch64.c (neoversev1_advsimd_vector_cost)
(neoversev1_sve_vector_cost): New cost structures.
(neoversev1_vector_cost): Likewise.
(neoversev1_tunings): Use them. Enable use_new_vector_costs.
---
gcc/config/aarch64/aarch64.c | 95 +++++++++++++++++++++++++++++++++++-
1 file changed, 93 insertions(+), 2 deletions(-)
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 7f727413d01..2e9853e4c9b 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -1619,12 +1619,102 @@ static const struct tune_params neoversen1_tunings =
&generic_prefetch_tune
};
+static const advsimd_vec_cost neoversev1_advsimd_vector_cost =
+{
+ 2, /* int_stmt_cost */
+ 2, /* fp_stmt_cost */
+ 4, /* ld2_st2_permute_cost */
+ 4, /* ld3_st3_permute_cost */
+ 5, /* ld4_st4_permute_cost */
+ 3, /* permute_cost */
+ 4, /* reduc_i8_cost */
+ 4, /* reduc_i16_cost */
+ 2, /* reduc_i32_cost */
+ 2, /* reduc_i64_cost */
+ 6, /* reduc_f16_cost */
+ 3, /* reduc_f32_cost */
+ 2, /* reduc_f64_cost */
+ 2, /* store_elt_extra_cost */
+ /* This value is just inherited from the Cortex-A57 table. */
+ 8, /* vec_to_scalar_cost */
+ /* This depends very much on what the scalar value is and
+ where it comes from. E.g. some constants take two dependent
+ instructions or a load, while others might be moved from a GPR.
+ 4 seems to be a reasonable compromise in practice. */
+ 4, /* scalar_to_vec_cost */
+ 4, /* align_load_cost */
+ 4, /* unalign_load_cost */
+ /* Although stores have a latency of 2 and compete for the
+ vector pipes, in practice it's better not to model that. */
+ 1, /* unalign_store_cost */
+ 1 /* store_cost */
+};
+
+static const sve_vec_cost neoversev1_sve_vector_cost =
+{
+ {
+ 2, /* int_stmt_cost */
+ 2, /* fp_stmt_cost */
+ 4, /* ld2_st2_permute_cost */
+ 7, /* ld3_st3_permute_cost */
+ 8, /* ld4_st4_permute_cost */
+ 3, /* permute_cost */
+ /* Theoretically, a reduction involving 31 scalar ADDs could
+ complete in ~9 cycles and would have a cost of 31. [SU]ADDV
+ completes in 14 cycles, so give it a cost of 31 + 5. */
+ 36, /* reduc_i8_cost */
+ /* Likewise for 15 scalar ADDs (~5 cycles) vs. 12: 15 + 7. */
+ 22, /* reduc_i16_cost */
+ /* Likewise for 7 scalar ADDs (~3 cycles) vs. 10: 7 + 7. */
+ 14, /* reduc_i32_cost */
+ /* Likewise for 3 scalar ADDs (~2 cycles) vs. 10: 3 + 8. */
+ 11, /* reduc_i64_cost */
+ /* Theoretically, a reduction involving 15 scalar FADDs could
+ complete in ~9 cycles and would have a cost of 30. FADDV
+ completes in 13 cycles, so give it a cost of 30 + 4. */
+ 34, /* reduc_f16_cost */
+ /* Likewise for 7 scalar FADDs (~6 cycles) vs. 11: 14 + 5. */
+ 19, /* reduc_f32_cost */
+ /* Likewise for 3 scalar FADDs (~4 cycles) vs. 9: 6 + 5. */
+ 11, /* reduc_f64_cost */
+ 2, /* store_elt_extra_cost */
+ /* This value is just inherited from the Cortex-A57 table. */
+ 8, /* vec_to_scalar_cost */
+ /* See the comment above the Advanced SIMD versions. */
+ 4, /* scalar_to_vec_cost */
+ 4, /* align_load_cost */
+ 4, /* unalign_load_cost */
+ /* Although stores have a latency of 2 and compete for the
+ vector pipes, in practice it's better not to model that. */
+ 1, /* unalign_store_cost */
+ 1 /* store_cost */
+ },
+ 3, /* clast_cost */
+ 19, /* fadda_f16_cost */
+ 11, /* fadda_f32_cost */
+ 8, /* fadda_f64_cost */
+ 3 /* scatter_store_elt_cost */
+};
+
+/* Neoverse V1 costs for vector insn classes. */
+static const struct cpu_vector_cost neoversev1_vector_cost =
+{
+ 1, /* scalar_int_stmt_cost */
+ 2, /* scalar_fp_stmt_cost */
+ 4, /* scalar_load_cost */
+ 1, /* scalar_store_cost */
+ 1, /* cond_taken_branch_cost */
+ 1, /* cond_not_taken_branch_cost */
+ &neoversev1_advsimd_vector_cost, /* advsimd */
+ &neoversev1_sve_vector_cost /* sve */
+};
+
static const struct tune_params neoversev1_tunings =
{
&cortexa76_extra_costs,
&generic_addrcost_table,
&generic_regmove_cost,
- &cortexa57_vector_cost,
+ &neoversev1_vector_cost,
&generic_branch_cost,
&generic_approx_modes,
SVE_256, /* sve_width */
@@ -1641,7 +1731,8 @@ static const struct tune_params neoversev1_tunings =
2, /* min_div_recip_mul_df. */
0, /* max_case_values. */
tune_params::AUTOPREFETCHER_WEAK, /* autoprefetcher_model. */
- (AARCH64_EXTRA_TUNE_CSE_SVE_VL_CONSTANTS), /* tune_flags. */
+ (AARCH64_EXTRA_TUNE_CSE_SVE_VL_CONSTANTS
+ | AARCH64_EXTRA_TUNE_USE_NEW_VECTOR_COSTS), /* tune_flags. */
&generic_prefetch_tune
};
--
2.17.1
