From: Richard Sandiford <richard.sandiford@arm.com>
To: gcc-patches@gcc.gnu.org
Subject: [PATCH] vect: Keep scalar costs around longer
Date: Mon, 08 Nov 2021 10:46:29 +0000 [thread overview]
Message-ID: <mptsfw62ad6.fsf@arm.com> (raw)
The scalar costs for a loop are fleeting, with only the final
single_scalar_iteration_cost being kept for later comparison.
This patch replaces single_scalar_iteration_cost with the cost
structure, so that (with later patches) it's possible for targets
to examine other target-specific cost properties as well. This will
be done by passing the scalar costs to hooks where appropriate;
targets shouldn't try to read the information directly from
loop_vec_infos.
Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install?
Richard
gcc/
* tree-vectorizer.h (_loop_vec_info::scalar_costs): New member
variable.
(_loop_vec_info::single_scalar_iteration_cost): Delete.
(LOOP_VINFO_SINGLE_SCALAR_ITERATION_COST): Delete.
(vector_costs::total_cost): New function.
* tree-vect-loop.c (_loop_vec_info::_loop_vec_info): Update
after above changes.
(_loop_vec_info::~_loop_vec_info): Delete scalar_costs.
(vect_compute_single_scalar_iteration_cost): Store the costs
in loop_vinfo->scalar_costs.
(vect_estimate_min_profitable_iters): Get the scalar cost from
loop_vinfo->scalar_costs.
---
gcc/tree-vect-loop.c | 17 ++++++-----------
gcc/tree-vectorizer.h | 17 +++++++++++++----
2 files changed, 19 insertions(+), 15 deletions(-)
diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index c9ee2e15e35..887275a5071 100644
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -822,6 +822,7 @@ _loop_vec_info::_loop_vec_info (class loop *loop_in, vec_info_shared *shared)
num_iters_unchanged (NULL_TREE),
num_iters_assumptions (NULL_TREE),
vector_costs (nullptr),
+ scalar_costs (nullptr),
th (0),
versioning_threshold (0),
vectorization_factor (0),
@@ -839,7 +840,6 @@ _loop_vec_info::_loop_vec_info (class loop *loop_in, vec_info_shared *shared)
ivexpr_map (NULL),
scan_map (NULL),
slp_unrolling_factor (1),
- single_scalar_iteration_cost (0),
inner_loop_cost_factor (param_vect_inner_loop_cost_factor),
vectorizable (false),
can_use_partial_vectors_p (param_vect_partial_vector_usage != 0),
@@ -931,6 +931,7 @@ _loop_vec_info::~_loop_vec_info ()
delete ivexpr_map;
delete scan_map;
epilogue_vinfos.release ();
+ delete scalar_costs;
delete vector_costs;
/* When we release an epiloge vinfo that we do not intend to use
@@ -1292,20 +1293,15 @@ vect_compute_single_scalar_iteration_cost (loop_vec_info loop_vinfo)
}
/* Now accumulate cost. */
- vector_costs *target_cost_data = init_cost (loop_vinfo, true);
+ loop_vinfo->scalar_costs = init_cost (loop_vinfo, true);
stmt_info_for_cost *si;
int j;
FOR_EACH_VEC_ELT (LOOP_VINFO_SCALAR_ITERATION_COST (loop_vinfo),
j, si)
- (void) add_stmt_cost (target_cost_data, si->count,
+ (void) add_stmt_cost (loop_vinfo->scalar_costs, si->count,
si->kind, si->stmt_info, si->vectype,
si->misalign, si->where);
- unsigned prologue_cost = 0, body_cost = 0, epilogue_cost = 0;
- finish_cost (target_cost_data, &prologue_cost, &body_cost,
- &epilogue_cost);
- delete target_cost_data;
- LOOP_VINFO_SINGLE_SCALAR_ITERATION_COST (loop_vinfo)
- = prologue_cost + body_cost + epilogue_cost;
+ loop_vinfo->scalar_costs->finish_cost ();
}
@@ -3868,8 +3864,7 @@ vect_estimate_min_profitable_iters (loop_vec_info loop_vinfo,
TODO: Consider assigning different costs to different scalar
statements. */
- scalar_single_iter_cost
- = LOOP_VINFO_SINGLE_SCALAR_ITERATION_COST (loop_vinfo);
+ scalar_single_iter_cost = loop_vinfo->scalar_costs->total_cost ();
/* Add additional cost for the peeled instructions in prologue and epilogue
loop. (For fully-masked loops there will be no peeling.)
diff --git a/gcc/tree-vectorizer.h b/gcc/tree-vectorizer.h
index 0e3aad590e8..8dba3a34aa9 100644
--- a/gcc/tree-vectorizer.h
+++ b/gcc/tree-vectorizer.h
@@ -590,6 +590,9 @@ public:
/* The cost of the vector code. */
class vector_costs *vector_costs;
+ /* The cost of the scalar code. */
+ class vector_costs *scalar_costs;
+
/* Threshold of number of iterations below which vectorization will not be
performed. It is calculated from MIN_PROFITABLE_ITERS and
param_min_vect_loop_bound. */
@@ -721,9 +724,6 @@ public:
applied to the loop, i.e., no unrolling is needed, this is 1. */
poly_uint64 slp_unrolling_factor;
- /* Cost of a single scalar iteration. */
- int single_scalar_iteration_cost;
-
/* The factor used to over weight those statements in an inner loop
relative to the loop being vectorized. */
unsigned int inner_loop_cost_factor;
@@ -843,7 +843,6 @@ public:
#define LOOP_VINFO_SCALAR_LOOP_SCALING(L) (L)->scalar_loop_scaling
#define LOOP_VINFO_HAS_MASK_STORE(L) (L)->has_mask_store
#define LOOP_VINFO_SCALAR_ITERATION_COST(L) (L)->scalar_cost_vec
-#define LOOP_VINFO_SINGLE_SCALAR_ITERATION_COST(L) (L)->single_scalar_iteration_cost
#define LOOP_VINFO_ORIG_LOOP_INFO(L) (L)->orig_loop_info
#define LOOP_VINFO_SIMD_IF_COND(L) (L)->simd_if_cond
#define LOOP_VINFO_INNER_LOOP_COST_FACTOR(L) (L)->inner_loop_cost_factor
@@ -1438,6 +1437,7 @@ public:
unsigned int body_cost () const;
unsigned int epilogue_cost () const;
unsigned int outside_cost () const;
+ unsigned int total_cost () const;
protected:
unsigned int record_stmt_cost (stmt_vec_info, vect_cost_model_location,
@@ -1508,6 +1508,15 @@ vector_costs::outside_cost () const
return prologue_cost () + epilogue_cost ();
}
+/* Return the cost of the prologue, body and epilogue code
+ (in abstract units). */
+
+inline unsigned int
+vector_costs::total_cost () const
+{
+ return body_cost () + outside_cost ();
+}
+
#define VECT_MAX_COST 1000
/* The maximum number of intermediate steps required in multi-step type
--
2.25.1
next reply other threads:[~2021-11-08 10:46 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-08 10:46 Richard Sandiford [this message]
2021-11-08 11:02 ` Richard Biener
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