/* Vectorizer
Copyright (C) 2003-2013 Free Software Foundation, Inc.
Contributed by Dorit Naishlos <dorit@il.ibm.com>
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
/* Loop and basic block vectorizer.
This file contains drivers for the three vectorizers:
(1) loop vectorizer (inter-iteration parallelism),
(2) loop-aware SLP (intra-iteration parallelism) (invoked by the loop
vectorizer)
(3) BB vectorizer (out-of-loops), aka SLP
The rest of the vectorizer's code is organized as follows:
- tree-vect-loop.c - loop specific parts such as reductions, etc. These are
used by drivers (1) and (2).
- tree-vect-loop-manip.c - vectorizer's loop control-flow utilities, used by
drivers (1) and (2).
- tree-vect-slp.c - BB vectorization specific analysis and transformation,
used by drivers (2) and (3).
- tree-vect-stmts.c - statements analysis and transformation (used by all).
- tree-vect-data-refs.c - vectorizer specific data-refs analysis and
manipulations (used by all).
- tree-vect-patterns.c - vectorizable code patterns detector (used by all)
Here's a poor attempt at illustrating that:
tree-vectorizer.c:
loop_vect() loop_aware_slp() slp_vect()
| / \ /
| / \ /
tree-vect-loop.c tree-vect-slp.c
| \ \ / / |
| \ \/ / |
| \ /\ / |
| \ / \ / |
tree-vect-stmts.c tree-vect-data-refs.c
\ /
tree-vect-patterns.c
*/
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "dumpfile.h"
#include "tm.h"
#include "ggc.h"
#include "tree.h"
#include "tree-pretty-print.h"
#include "tree-flow.h"
#include "cfgloop.h"
#include "tree-vectorizer.h"
#include "tree-pass.h"
/* Loop or bb location. */
LOC vect_location;
/* Vector mapping GIMPLE stmt to stmt_vec_info. */
vec<vec_void_p> stmt_vec_info_vec;
/* Function vectorize_loops.
Entry point to loop vectorization phase. */
unsigned
vectorize_loops (void)
{
unsigned int i;
unsigned int num_vectorized_loops = 0;
unsigned int vect_loops_num;
loop_iterator li;
struct loop *loop;
vect_loops_num = number_of_loops (cfun);
/* Bail out if there are no loops. */
if (vect_loops_num <= 1)
return 0;
init_stmt_vec_info_vec ();
/* ----------- Analyze loops. ----------- */
/* If some loop was duplicated, it gets bigger number
than all previously defined loops. This fact allows us to run
only over initial loops skipping newly generated ones. */
FOR_EACH_LOOP (li, loop, 0)
if (optimize_loop_nest_for_speed_p (loop))
{
loop_vec_info loop_vinfo;
vect_location = find_loop_location (loop);
if (LOCATION_LOCUS (vect_location) != UNKNOWN_LOC
&& dump_enabled_p ())
dump_printf (MSG_NOTE, "\nAnalyzing loop at %s:%d\n",
LOC_FILE (vect_location), LOC_LINE (vect_location));
loop_vinfo = vect_analyze_loop (loop);
loop->aux = loop_vinfo;
if (!loop_vinfo || !LOOP_VINFO_VECTORIZABLE_P (loop_vinfo))
continue;
if (LOCATION_LOCUS (vect_location) != UNKNOWN_LOC
&& dump_enabled_p ())
dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, vect_location,
"Vectorized loop\n");
vect_transform_loop (loop_vinfo);
num_vectorized_loops++;
}
vect_location = UNKNOWN_LOC;
statistics_counter_event (cfun, "Vectorized loops", num_vectorized_loops);
if (dump_enabled_p ()
|| (num_vectorized_loops > 0 && dump_enabled_p ()))
dump_printf_loc (MSG_NOTE, vect_location,
"vectorized %u loops in function.\n",
num_vectorized_loops);
/* ----------- Finalize. ----------- */
for (i = 1; i < vect_loops_num; i++)
{
loop_vec_info loop_vinfo;
loop = get_loop (cfun, i);
if (!loop)
continue;
loop_vinfo = (loop_vec_info) loop->aux;
destroy_loop_vec_info (loop_vinfo, true);
loop->aux = NULL;
}
free_stmt_vec_info_vec ();
if (num_vectorized_loops > 0)
{
/* If we vectorized any loop only virtual SSA form needs to be updated.
??? Also while we try hard to update loop-closed SSA form we fail
to properly do this in some corner-cases (see PR56286). */
rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa_only_virtuals);
return TODO_cleanup_cfg;
}
return 0;
}
/* Entry point to basic block SLP phase. */
static unsigned int
execute_vect_slp (void)
{
basic_block bb;
init_stmt_vec_info_vec ();
FOR_EACH_BB (bb)
{
vect_location = find_bb_location (bb);
if (vect_slp_analyze_bb (bb))
{
vect_slp_transform_bb (bb);
if (dump_enabled_p ())
dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, vect_location,
"Vectorized basic-block\n");
}
}
free_stmt_vec_info_vec ();
return 0;
}
static bool
gate_vect_slp (void)
{
/* Apply SLP either if the vectorizer is on and the user didn't specify
whether to run SLP or not, or if the SLP flag was set by the user. */
return ((flag_tree_vectorize != 0 && flag_tree_slp_vectorize != 0)
|| flag_tree_slp_vectorize == 1);
}
namespace {
const pass_data pass_data_slp_vectorize =
{
GIMPLE_PASS, /* type */
"slp", /* name */
OPTGROUP_LOOP | OPTGROUP_VEC, /* optinfo_flags */
true, /* has_gate */
true, /* has_execute */
TV_TREE_SLP_VECTORIZATION, /* tv_id */
( PROP_ssa | PROP_cfg ), /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
( TODO_verify_ssa | TODO_update_ssa
| TODO_verify_stmts ), /* todo_flags_finish */
};
class pass_slp_vectorize : public gimple_opt_pass
{
public:
pass_slp_vectorize(gcc::context *ctxt)
: gimple_opt_pass(pass_data_slp_vectorize, ctxt)
{}
/* opt_pass methods: */
bool gate () { return gate_vect_slp (); }
unsigned int execute () { return execute_vect_slp (); }
}; // class pass_slp_vectorize
} // anon namespace
gimple_opt_pass *
make_pass_slp_vectorize (gcc::context *ctxt)
{
return new pass_slp_vectorize (ctxt);
}
/* Increase alignment of global arrays to improve vectorization potential.
TODO:
- Consider also structs that have an array field.
- Use ipa analysis to prune arrays that can't be vectorized?
This should involve global alignment analysis and in the future also
array padding. */
static unsigned int
increase_alignment (void)
{
struct varpool_node *vnode;
vect_location = UNKNOWN_LOC;
/* Increase the alignment of all global arrays for vectorization. */
FOR_EACH_DEFINED_VARIABLE (vnode)
{
tree vectype, decl = vnode->symbol.decl;
tree t;
unsigned int alignment;
t = TREE_TYPE(decl);
if (TREE_CODE (t) != ARRAY_TYPE)
continue;
vectype = get_vectype_for_scalar_type (strip_array_types (t));
if (!vectype)
continue;
alignment = TYPE_ALIGN (vectype);
if (DECL_ALIGN (decl) >= alignment)
continue;
if (vect_can_force_dr_alignment_p (decl, alignment))
{
DECL_ALIGN (decl) = TYPE_ALIGN (vectype);
DECL_USER_ALIGN (decl) = 1;
dump_printf (MSG_NOTE, "Increasing alignment of decl: ");
dump_generic_expr (MSG_NOTE, TDF_SLIM, decl);
dump_printf (MSG_NOTE, "\n");
}
}
return 0;
}
static bool
gate_increase_alignment (void)
{
return flag_section_anchors && flag_tree_vectorize;
}
namespace {
const pass_data pass_data_ipa_increase_alignment =
{
SIMPLE_IPA_PASS, /* type */
"increase_alignment", /* name */
OPTGROUP_LOOP | OPTGROUP_VEC, /* optinfo_flags */
true, /* has_gate */
true, /* has_execute */
TV_IPA_OPT, /* tv_id */
0, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
0, /* todo_flags_finish */
};
class pass_ipa_increase_alignment : public simple_ipa_opt_pass
{
public:
pass_ipa_increase_alignment(gcc::context *ctxt)
: simple_ipa_opt_pass(pass_data_ipa_increase_alignment, ctxt)
{}
/* opt_pass methods: */
bool gate () { return gate_increase_alignment (); }
unsigned int execute () { return increase_alignment (); }
}; // class pass_ipa_increase_alignment
} // anon namespace
simple_ipa_opt_pass *
make_pass_ipa_increase_alignment (gcc::context *ctxt)
{
return new pass_ipa_increase_alignment (ctxt);
}