From: Richard Sandiford <richard.sandiford@arm.com>
To: gcc-patches@gcc.gnu.org
Subject: [PATCH 7/8] aarch64: Restrict issue heuristics to inner vector loop
Date: Tue, 03 Aug 2021 13:06:23 +0100 [thread overview]
Message-ID: <mptim0mbum8.fsf@arm.com> (raw)
In-Reply-To: <mptlf5id9bw.fsf@arm.com> (Richard Sandiford's message of "Tue, 03 Aug 2021 13:03:15 +0100")
The AArch64 vector costs try to take issue rates into account.
However, when vectorising an outer loop, we lumped the inner
and outer operations together, which is somewhat meaningless.
This patch restricts the heuristic to the inner loop.
gcc/
* config/aarch64/aarch64.c (aarch64_add_stmt_cost): Only
record issue information for operations that occur in the
innermost loop.
---
gcc/config/aarch64/aarch64.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 19045ef6944..19625eb048d 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -15392,6 +15392,10 @@ aarch64_add_stmt_cost (class vec_info *vinfo, void *data, int count,
fractional_cost stmt_cost
= aarch64_builtin_vectorization_cost (kind, vectype, misalign);
+ bool in_inner_loop_p = (where == vect_body
+ && stmt_info
+ && stmt_in_inner_loop_p (vinfo, stmt_info));
+
/* Do one-time initialization based on the vinfo. */
loop_vec_info loop_vinfo = dyn_cast<loop_vec_info> (vinfo);
bb_vec_info bb_vinfo = dyn_cast<bb_vec_info> (vinfo);
@@ -15438,14 +15442,15 @@ aarch64_add_stmt_cost (class vec_info *vinfo, void *data, int count,
stmt_cost = aarch64_adjust_stmt_cost (kind, stmt_info, vectype,
stmt_cost);
- /* If we're recording a nonzero vector loop body cost, also estimate
- the operations that would need to be issued by all relevant
- implementations of the loop. */
+ /* If we're recording a nonzero vector loop body cost for the
+ innermost loop, also estimate the operations that would need
+ to be issued by all relevant implementations of the loop. */
auto *issue_info = aarch64_tune_params.vec_costs->issue_info;
if (loop_vinfo
&& issue_info
&& costs->vec_flags
&& where == vect_body
+ && (!LOOP_VINFO_LOOP (loop_vinfo)->inner || in_inner_loop_p)
&& vectype
&& stmt_cost != 0)
{
@@ -15489,8 +15494,7 @@ aarch64_add_stmt_cost (class vec_info *vinfo, void *data, int count,
/* Statements in an inner loop relative to the loop being
vectorized are weighted more heavily. The value here is
arbitrary and could potentially be improved with analysis. */
- if (where == vect_body && stmt_info
- && stmt_in_inner_loop_p (vinfo, stmt_info))
+ if (in_inner_loop_p)
{
gcc_assert (loop_vinfo);
count *= LOOP_VINFO_INNER_LOOP_COST_FACTOR (loop_vinfo); /* FIXME */
next prev parent reply other threads:[~2021-08-03 12:06 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-03 12:03 [PATCH 0/8] aarch64 vector cost tweaks Richard Sandiford
2021-08-03 12:03 ` [PATCH 1/8] aarch64: Turn sve_width tuning field into a bitmask Richard Sandiford
2021-08-03 12:04 ` [PATCH 2/8] aarch64: Add a simple fixed-point class for costing Richard Sandiford
2021-08-03 12:04 ` [PATCH 3/8] aarch64: Split out aarch64_adjust_body_cost_sve Richard Sandiford
2021-08-03 12:05 ` [PATCH 4/8] aarch64: Add gather_load_xNN_cost tuning fields Richard Sandiford
2021-08-03 12:05 ` [PATCH 5/8] aarch64: Tweak the cost of elementwise stores Richard Sandiford
2021-08-04 11:43 ` Richard Biener
2021-08-05 12:04 ` [PATCH] vect: Move costing helpers from aarch64 code Richard Sandiford
2021-08-05 12:11 ` Richard Biener
2021-08-05 13:06 ` Richard Sandiford
2021-08-03 12:06 ` [PATCH 6/8] aarch64: Tweak MLA vector costs Richard Sandiford
2021-08-04 11:45 ` Richard Biener
2021-08-04 12:14 ` Richard Sandiford
2021-08-04 12:19 ` Richard Sandiford
2021-08-03 12:06 ` Richard Sandiford [this message]
2021-08-03 12:06 ` [PATCH 8/8] aarch64: Add -mtune=neoverse-512tvb Richard Sandiford
2021-08-17 14:37 ` Richard Sandiford
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