[gcc r14-6882] aarch64: add 'AARCH64_EXTRA_TUNE_FULLY_PIPELINED_FMA'

[Di Zhao]

https://gcc.gnu.org/g:b041bd4ec2cff7b6cfa0b27fc631cba8a02975e4

commit r14-6882-gb041bd4ec2cff7b6cfa0b27fc631cba8a02975e4
Author: Di Zhao <dizhao@os.amperecomputing.com>
Date:   Tue Jan 2 12:35:03 2024 +0800

    aarch64: add 'AARCH64_EXTRA_TUNE_FULLY_PIPELINED_FMA'
    
    This patch adds a new tuning option
    'AARCH64_EXTRA_TUNE_FULLY_PIPELINED_FMA', to consider fully
    pipelined FMAs in reassociation. Also, set this option by default
    for Ampere CPUs.
    
    gcc/ChangeLog:
    
            * config/aarch64/aarch64-tuning-flags.def
            (AARCH64_EXTRA_TUNING_OPTION): New tuning option
            AARCH64_EXTRA_TUNE_FULLY_PIPELINED_FMA.
            * config/aarch64/aarch64.cc
            (aarch64_override_options_internal): Set
            param_fully_pipelined_fma according to tuning option.
            * config/aarch64/tuning_models/ampere1.h: Add
            AARCH64_EXTRA_TUNE_FULLY_PIPELINED_FMA to tune_flags.
            * config/aarch64/tuning_models/ampere1a.h: Likewise.
            * config/aarch64/tuning_models/ampere1b.h: Likewise.

Diff:
---
 gcc/config/aarch64/aarch64-tuning-flags.def | 2 ++
 gcc/config/aarch64/aarch64.cc               | 6 ++++++
 gcc/config/aarch64/tuning_models/ampere1.h  | 3 ++-
 gcc/config/aarch64/tuning_models/ampere1a.h | 3 ++-
 gcc/config/aarch64/tuning_models/ampere1b.h | 5 +++--
 5 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/gcc/config/aarch64/aarch64-tuning-flags.def b/gcc/config/aarch64/aarch64-tuning-flags.def
index f28a73839a6..1488a844886 100644
--- a/gcc/config/aarch64/aarch64-tuning-flags.def
+++ b/gcc/config/aarch64/aarch64-tuning-flags.def
@@ -49,4 +49,6 @@ AARCH64_EXTRA_TUNING_OPTION ("matched_vector_throughput", MATCHED_VECTOR_THROUGH
 
 AARCH64_EXTRA_TUNING_OPTION ("avoid_cross_loop_fma", AVOID_CROSS_LOOP_FMA)
 
+AARCH64_EXTRA_TUNING_OPTION ("fully_pipelined_fma", FULLY_PIPELINED_FMA)
+
 #undef AARCH64_EXTRA_TUNING_OPTION
diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
index 9858de6b171..298477d88bb 100644
--- a/gcc/config/aarch64/aarch64.cc
+++ b/gcc/config/aarch64/aarch64.cc
@@ -18321,6 +18321,12 @@ aarch64_override_options_internal (struct gcc_options *opts)
     SET_OPTION_IF_UNSET (opts, &global_options_set, param_avoid_fma_max_bits,
 			 512);
 
+  /* Consider fully pipelined FMA in reassociation.  */
+  if (aarch64_tune_params.extra_tuning_flags
+      & AARCH64_EXTRA_TUNE_FULLY_PIPELINED_FMA)
+    SET_OPTION_IF_UNSET (opts, &global_options_set, param_fully_pipelined_fma,
+			 1);
+
   aarch64_override_options_after_change_1 (opts);
 }
 
diff --git a/gcc/config/aarch64/tuning_models/ampere1.h b/gcc/config/aarch64/tuning_models/ampere1.h
index a144e8f94b3..ac215d3aaf9 100644
--- a/gcc/config/aarch64/tuning_models/ampere1.h
+++ b/gcc/config/aarch64/tuning_models/ampere1.h
@@ -104,7 +104,8 @@ static const struct tune_params ampere1_tunings =
   2,	/* min_div_recip_mul_df.  */
   0,	/* max_case_values.  */
   tune_params::AUTOPREFETCHER_WEAK,	/* autoprefetcher_model.  */
-  (AARCH64_EXTRA_TUNE_AVOID_CROSS_LOOP_FMA),	/* tune_flags.  */
+  (AARCH64_EXTRA_TUNE_AVOID_CROSS_LOOP_FMA
+   | AARCH64_EXTRA_TUNE_FULLY_PIPELINED_FMA), /* tune_flags.  */
   &ampere1_prefetch_tune,
   AARCH64_LDP_STP_POLICY_ALIGNED,   /* ldp_policy_model.  */
   AARCH64_LDP_STP_POLICY_ALIGNED    /* stp_policy_model.  */
diff --git a/gcc/config/aarch64/tuning_models/ampere1a.h b/gcc/config/aarch64/tuning_models/ampere1a.h
index f688ed08a79..00249600d22 100644
--- a/gcc/config/aarch64/tuning_models/ampere1a.h
+++ b/gcc/config/aarch64/tuning_models/ampere1a.h
@@ -56,7 +56,8 @@ static const struct tune_params ampere1a_tunings =
   2,	/* min_div_recip_mul_df.  */
   0,	/* max_case_values.  */
   tune_params::AUTOPREFETCHER_WEAK,	/* autoprefetcher_model.  */
-  (AARCH64_EXTRA_TUNE_AVOID_CROSS_LOOP_FMA),	/* tune_flags.  */
+  (AARCH64_EXTRA_TUNE_AVOID_CROSS_LOOP_FMA
+   | AARCH64_EXTRA_TUNE_FULLY_PIPELINED_FMA), /* tune_flags.  */
   &ampere1_prefetch_tune,
   AARCH64_LDP_STP_POLICY_ALIGNED,   /* ldp_policy_model.  */
   AARCH64_LDP_STP_POLICY_ALIGNED    /* stp_policy_model.  */
diff --git a/gcc/config/aarch64/tuning_models/ampere1b.h b/gcc/config/aarch64/tuning_models/ampere1b.h
index a98b6a980f7..15cc896143f 100644
--- a/gcc/config/aarch64/tuning_models/ampere1b.h
+++ b/gcc/config/aarch64/tuning_models/ampere1b.h
@@ -105,8 +105,9 @@ static const struct tune_params ampere1b_tunings =
   2,	/* min_div_recip_mul_df.  */
   0,	/* max_case_values.  */
   tune_params::AUTOPREFETCHER_STRONG,	/* autoprefetcher_model.  */
-  (AARCH64_EXTRA_TUNE_CHEAP_SHIFT_EXTEND |
-   AARCH64_EXTRA_TUNE_AVOID_CROSS_LOOP_FMA),	/* tune_flags.  */
+  (AARCH64_EXTRA_TUNE_CHEAP_SHIFT_EXTEND
+   | AARCH64_EXTRA_TUNE_AVOID_CROSS_LOOP_FMA
+   | AARCH64_EXTRA_TUNE_FULLY_PIPELINED_FMA), /* tune_flags.  */
   &ampere1b_prefetch_tune,
   AARCH64_LDP_STP_POLICY_ALIGNED,   /* ldp_policy_model.  */
   AARCH64_LDP_STP_POLICY_ALIGNED    /* stp_policy_model.  */