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authorirar <irar@138bc75d-0d04-0410-961f-82ee72b054a4>2009-03-30 07:22:04 +0000
committerirar <irar@138bc75d-0d04-0410-961f-82ee72b054a4>2009-03-30 07:22:04 +0000
commitfb85abff92ed1f8489e517192319b5394c0ee529 (patch)
treeeb1de264e27b52e72961ef1403214ca950263b68 /gcc/tree-vect-loop-manip.c
parent0863a8f446cdaaa7c9b39b216c278f739a1920c8 (diff)
downloadgcc-fb85abff92ed1f8489e517192319b5394c0ee529.tar.gz
* tree-vect-loop-manip.c: New file.
* tree-vectorizer.c: Update documentation and included files. (vect_loop_location): Make extern. (rename_use_op): Move to tree-vect-loop-manip.c (rename_variables_in_bb, rename_variables_in_loop, slpeel_update_phis_for_duplicate_loop, slpeel_update_phi_nodes_for_guard1, slpeel_update_phi_nodes_for_guard2, slpeel_make_loop_iterate_ntimes, slpeel_tree_duplicate_loop_to_edge_cfg, slpeel_add_loop_guard, slpeel_can_duplicate_loop_p, slpeel_verify_cfg_after_peeling, set_prologue_iterations, slpeel_tree_peel_loop_to_edge, find_loop_location): Likewise. (new_stmt_vec_info): Move to tree-vect-stmts.c. (init_stmt_vec_info_vec, free_stmt_vec_info_vec, free_stmt_vec_info, get_vectype_for_scalar_type, vect_is_simple_use, supportable_widening_operation, supportable_narrowing_operation): Likewise. (bb_in_loop_p): Move to tree-vect-loop.c. (new_loop_vec_info, destroy_loop_vec_info, reduction_code_for_scalar_code, report_vect_op, vect_is_simple_reduction, vect_is_simple_iv_evolution): Likewise. (vect_can_force_dr_alignment_p): Move to tree-vect-data-refs.c. (vect_supportable_dr_alignment): Likewise. * tree-vectorizer.h (tree-data-ref.h): Include. (vect_loop_location): Declare. Reorganize function declarations according to the new file structure. * tree-vect-loop.c: New file. * tree-vect-analyze.c: Remove. Move functions to tree-vect-data-refs.c, tree-vect-stmts.c, tree-vect-slp.c, tree-vect-loop.c. * tree-vect-data-refs.c: New file. * tree-vect-patterns.c (timevar.h): Don't include. * tree-vect-stmts.c: New file. * tree-vect-transform.c: Remove. Move functions to tree-vect-stmts.c, tree-vect-slp.c, tree-vect-loop.c. * Makefile.in (OBJS-common): Remove tree-vect-analyze.o and tree-vect-transform.o. Add tree-vect-data-refs.o, tree-vect-stmts.o, tree-vect-loop.o, tree-vect-loop-manip.o, tree-vect-slp.o. (tree-vect-analyze.o): Remove. (tree-vect-transform.o): Likewise. (tree-vect-data-refs.o): Add rule. (tree-vect-stmts.o, tree-vect-loop.o, tree-vect-loop-manip.o, tree-vect-slp.o): Likewise. (tree-vect-patterns.o): Remove redundant dependencies. (tree-vectorizer.o): Likewise. * tree-vect-slp.c: New file. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@145280 138bc75d-0d04-0410-961f-82ee72b054a4
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diff --git a/gcc/tree-vect-loop-manip.c b/gcc/tree-vect-loop-manip.c
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+/* Vectorizer Specific Loop Manipulations
+ Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free Software
+ Foundation, Inc.
+ Contributed by Dorit Naishlos <dorit@il.ibm.com>
+ and Ira Rosen <irar@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/>. */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "ggc.h"
+#include "tree.h"
+#include "basic-block.h"
+#include "diagnostic.h"
+#include "tree-flow.h"
+#include "tree-dump.h"
+#include "cfgloop.h"
+#include "cfglayout.h"
+#include "expr.h"
+#include "toplev.h"
+#include "tree-scalar-evolution.h"
+#include "tree-vectorizer.h"
+#include "langhooks.h"
+
+/*************************************************************************
+ Simple Loop Peeling Utilities
+
+ Utilities to support loop peeling for vectorization purposes.
+ *************************************************************************/
+
+
+/* Renames the use *OP_P. */
+
+static void
+rename_use_op (use_operand_p op_p)
+{
+ tree new_name;
+
+ if (TREE_CODE (USE_FROM_PTR (op_p)) != SSA_NAME)
+ return;
+
+ new_name = get_current_def (USE_FROM_PTR (op_p));
+
+ /* Something defined outside of the loop. */
+ if (!new_name)
+ return;
+
+ /* An ordinary ssa name defined in the loop. */
+
+ SET_USE (op_p, new_name);
+}
+
+
+/* Renames the variables in basic block BB. */
+
+void
+rename_variables_in_bb (basic_block bb)
+{
+ gimple_stmt_iterator gsi;
+ gimple stmt;
+ use_operand_p use_p;
+ ssa_op_iter iter;
+ edge e;
+ edge_iterator ei;
+ struct loop *loop = bb->loop_father;
+
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ stmt = gsi_stmt (gsi);
+ FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_ALL_USES)
+ rename_use_op (use_p);
+ }
+
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ {
+ if (!flow_bb_inside_loop_p (loop, e->dest))
+ continue;
+ for (gsi = gsi_start_phis (e->dest); !gsi_end_p (gsi); gsi_next (&gsi))
+ rename_use_op (PHI_ARG_DEF_PTR_FROM_EDGE (gsi_stmt (gsi), e));
+ }
+}
+
+
+/* Renames variables in new generated LOOP. */
+
+void
+rename_variables_in_loop (struct loop *loop)
+{
+ unsigned i;
+ basic_block *bbs;
+
+ bbs = get_loop_body (loop);
+
+ for (i = 0; i < loop->num_nodes; i++)
+ rename_variables_in_bb (bbs[i]);
+
+ free (bbs);
+}
+
+
+/* Update the PHI nodes of NEW_LOOP.
+
+ NEW_LOOP is a duplicate of ORIG_LOOP.
+ AFTER indicates whether NEW_LOOP executes before or after ORIG_LOOP:
+ AFTER is true if NEW_LOOP executes after ORIG_LOOP, and false if it
+ executes before it. */
+
+static void
+slpeel_update_phis_for_duplicate_loop (struct loop *orig_loop,
+ struct loop *new_loop, bool after)
+{
+ tree new_ssa_name;
+ gimple phi_new, phi_orig;
+ tree def;
+ edge orig_loop_latch = loop_latch_edge (orig_loop);
+ edge orig_entry_e = loop_preheader_edge (orig_loop);
+ edge new_loop_exit_e = single_exit (new_loop);
+ edge new_loop_entry_e = loop_preheader_edge (new_loop);
+ edge entry_arg_e = (after ? orig_loop_latch : orig_entry_e);
+ gimple_stmt_iterator gsi_new, gsi_orig;
+
+ /*
+ step 1. For each loop-header-phi:
+ Add the first phi argument for the phi in NEW_LOOP
+ (the one associated with the entry of NEW_LOOP)
+
+ step 2. For each loop-header-phi:
+ Add the second phi argument for the phi in NEW_LOOP
+ (the one associated with the latch of NEW_LOOP)
+
+ step 3. Update the phis in the successor block of NEW_LOOP.
+
+ case 1: NEW_LOOP was placed before ORIG_LOOP:
+ The successor block of NEW_LOOP is the header of ORIG_LOOP.
+ Updating the phis in the successor block can therefore be done
+ along with the scanning of the loop header phis, because the
+ header blocks of ORIG_LOOP and NEW_LOOP have exactly the same
+ phi nodes, organized in the same order.
+
+ case 2: NEW_LOOP was placed after ORIG_LOOP:
+ The successor block of NEW_LOOP is the original exit block of
+ ORIG_LOOP - the phis to be updated are the loop-closed-ssa phis.
+ We postpone updating these phis to a later stage (when
+ loop guards are added).
+ */
+
+
+ /* Scan the phis in the headers of the old and new loops
+ (they are organized in exactly the same order). */
+
+ for (gsi_new = gsi_start_phis (new_loop->header),
+ gsi_orig = gsi_start_phis (orig_loop->header);
+ !gsi_end_p (gsi_new) && !gsi_end_p (gsi_orig);
+ gsi_next (&gsi_new), gsi_next (&gsi_orig))
+ {
+ phi_new = gsi_stmt (gsi_new);
+ phi_orig = gsi_stmt (gsi_orig);
+
+ /* step 1. */
+ def = PHI_ARG_DEF_FROM_EDGE (phi_orig, entry_arg_e);
+ add_phi_arg (phi_new, def, new_loop_entry_e);
+
+ /* step 2. */
+ def = PHI_ARG_DEF_FROM_EDGE (phi_orig, orig_loop_latch);
+ if (TREE_CODE (def) != SSA_NAME)
+ continue;
+
+ new_ssa_name = get_current_def (def);
+ if (!new_ssa_name)
+ {
+ /* This only happens if there are no definitions
+ inside the loop. use the phi_result in this case. */
+ new_ssa_name = PHI_RESULT (phi_new);
+ }
+
+ /* An ordinary ssa name defined in the loop. */
+ add_phi_arg (phi_new, new_ssa_name, loop_latch_edge (new_loop));
+
+ /* step 3 (case 1). */
+ if (!after)
+ {
+ gcc_assert (new_loop_exit_e == orig_entry_e);
+ SET_PHI_ARG_DEF (phi_orig,
+ new_loop_exit_e->dest_idx,
+ new_ssa_name);
+ }
+ }
+}
+
+
+/* Update PHI nodes for a guard of the LOOP.
+
+ Input:
+ - LOOP, GUARD_EDGE: LOOP is a loop for which we added guard code that
+ controls whether LOOP is to be executed. GUARD_EDGE is the edge that
+ originates from the guard-bb, skips LOOP and reaches the (unique) exit
+ bb of LOOP. This loop-exit-bb is an empty bb with one successor.
+ We denote this bb NEW_MERGE_BB because before the guard code was added
+ it had a single predecessor (the LOOP header), and now it became a merge
+ point of two paths - the path that ends with the LOOP exit-edge, and
+ the path that ends with GUARD_EDGE.
+ - NEW_EXIT_BB: New basic block that is added by this function between LOOP
+ and NEW_MERGE_BB. It is used to place loop-closed-ssa-form exit-phis.
+
+ ===> The CFG before the guard-code was added:
+ LOOP_header_bb:
+ loop_body
+ if (exit_loop) goto update_bb
+ else goto LOOP_header_bb
+ update_bb:
+
+ ==> The CFG after the guard-code was added:
+ guard_bb:
+ if (LOOP_guard_condition) goto new_merge_bb
+ else goto LOOP_header_bb
+ LOOP_header_bb:
+ loop_body
+ if (exit_loop_condition) goto new_merge_bb
+ else goto LOOP_header_bb
+ new_merge_bb:
+ goto update_bb
+ update_bb:
+
+ ==> The CFG after this function:
+ guard_bb:
+ if (LOOP_guard_condition) goto new_merge_bb
+ else goto LOOP_header_bb
+ LOOP_header_bb:
+ loop_body
+ if (exit_loop_condition) goto new_exit_bb
+ else goto LOOP_header_bb
+ new_exit_bb:
+ new_merge_bb:
+ goto update_bb
+ update_bb:
+
+ This function:
+ 1. creates and updates the relevant phi nodes to account for the new
+ incoming edge (GUARD_EDGE) into NEW_MERGE_BB. This involves:
+ 1.1. Create phi nodes at NEW_MERGE_BB.
+ 1.2. Update the phi nodes at the successor of NEW_MERGE_BB (denoted
+ UPDATE_BB). UPDATE_BB was the exit-bb of LOOP before NEW_MERGE_BB
+ 2. preserves loop-closed-ssa-form by creating the required phi nodes
+ at the exit of LOOP (i.e, in NEW_EXIT_BB).
+
+ There are two flavors to this function:
+
+ slpeel_update_phi_nodes_for_guard1:
+ Here the guard controls whether we enter or skip LOOP, where LOOP is a
+ prolog_loop (loop1 below), and the new phis created in NEW_MERGE_BB are
+ for variables that have phis in the loop header.
+
+ slpeel_update_phi_nodes_for_guard2:
+ Here the guard controls whether we enter or skip LOOP, where LOOP is an
+ epilog_loop (loop2 below), and the new phis created in NEW_MERGE_BB are
+ for variables that have phis in the loop exit.
+
+ I.E., the overall structure is:
+
+ loop1_preheader_bb:
+ guard1 (goto loop1/merge1_bb)
+ loop1
+ loop1_exit_bb:
+ guard2 (goto merge1_bb/merge2_bb)
+ merge1_bb
+ loop2
+ loop2_exit_bb
+ merge2_bb
+ next_bb
+
+ slpeel_update_phi_nodes_for_guard1 takes care of creating phis in
+ loop1_exit_bb and merge1_bb. These are entry phis (phis for the vars
+ that have phis in loop1->header).
+
+ slpeel_update_phi_nodes_for_guard2 takes care of creating phis in
+ loop2_exit_bb and merge2_bb. These are exit phis (phis for the vars
+ that have phis in next_bb). It also adds some of these phis to
+ loop1_exit_bb.
+
+ slpeel_update_phi_nodes_for_guard1 is always called before
+ slpeel_update_phi_nodes_for_guard2. They are both needed in order
+ to create correct data-flow and loop-closed-ssa-form.
+
+ Generally slpeel_update_phi_nodes_for_guard1 creates phis for variables
+ that change between iterations of a loop (and therefore have a phi-node
+ at the loop entry), whereas slpeel_update_phi_nodes_for_guard2 creates
+ phis for variables that are used out of the loop (and therefore have
+ loop-closed exit phis). Some variables may be both updated between
+ iterations and used after the loop. This is why in loop1_exit_bb we
+ may need both entry_phis (created by slpeel_update_phi_nodes_for_guard1)
+ and exit phis (created by slpeel_update_phi_nodes_for_guard2).
+
+ - IS_NEW_LOOP: if IS_NEW_LOOP is true, then LOOP is a newly created copy of
+ an original loop. i.e., we have:
+
+ orig_loop
+ guard_bb (goto LOOP/new_merge)
+ new_loop <-- LOOP
+ new_exit
+ new_merge
+ next_bb
+
+ If IS_NEW_LOOP is false, then LOOP is an original loop, in which case we
+ have:
+
+ new_loop
+ guard_bb (goto LOOP/new_merge)
+ orig_loop <-- LOOP
+ new_exit
+ new_merge
+ next_bb
+
+ The SSA names defined in the original loop have a current
+ reaching definition that that records the corresponding new
+ ssa-name used in the new duplicated loop copy.
+ */
+
+/* Function slpeel_update_phi_nodes_for_guard1
+
+ Input:
+ - GUARD_EDGE, LOOP, IS_NEW_LOOP, NEW_EXIT_BB - as explained above.
+ - DEFS - a bitmap of ssa names to mark new names for which we recorded
+ information.
+
+ In the context of the overall structure, we have:
+
+ loop1_preheader_bb:
+ guard1 (goto loop1/merge1_bb)
+LOOP-> loop1
+ loop1_exit_bb:
+ guard2 (goto merge1_bb/merge2_bb)
+ merge1_bb
+ loop2
+ loop2_exit_bb
+ merge2_bb
+ next_bb
+
+ For each name updated between loop iterations (i.e - for each name that has
+ an entry (loop-header) phi in LOOP) we create a new phi in:
+ 1. merge1_bb (to account for the edge from guard1)
+ 2. loop1_exit_bb (an exit-phi to keep LOOP in loop-closed form)
+*/
+
+static void
+slpeel_update_phi_nodes_for_guard1 (edge guard_edge, struct loop *loop,
+ bool is_new_loop, basic_block *new_exit_bb,
+ bitmap *defs)
+{
+ gimple orig_phi, new_phi;
+ gimple update_phi, update_phi2;
+ tree guard_arg, loop_arg;
+ basic_block new_merge_bb = guard_edge->dest;
+ edge e = EDGE_SUCC (new_merge_bb, 0);
+ basic_block update_bb = e->dest;
+ basic_block orig_bb = loop->header;
+ edge new_exit_e;
+ tree current_new_name;
+ tree name;
+ gimple_stmt_iterator gsi_orig, gsi_update;
+
+ /* Create new bb between loop and new_merge_bb. */
+ *new_exit_bb = split_edge (single_exit (loop));
+
+ new_exit_e = EDGE_SUCC (*new_exit_bb, 0);
+
+ for (gsi_orig = gsi_start_phis (orig_bb),
+ gsi_update = gsi_start_phis (update_bb);
+ !gsi_end_p (gsi_orig) && !gsi_end_p (gsi_update);
+ gsi_next (&gsi_orig), gsi_next (&gsi_update))
+ {
+ orig_phi = gsi_stmt (gsi_orig);
+ update_phi = gsi_stmt (gsi_update);
+
+ /* Virtual phi; Mark it for renaming. We actually want to call
+ mar_sym_for_renaming, but since all ssa renaming datastructures
+ are going to be freed before we get to call ssa_update, we just
+ record this name for now in a bitmap, and will mark it for
+ renaming later. */
+ name = PHI_RESULT (orig_phi);
+ if (!is_gimple_reg (SSA_NAME_VAR (name)))
+ bitmap_set_bit (vect_memsyms_to_rename, DECL_UID (SSA_NAME_VAR (name)));
+
+ /** 1. Handle new-merge-point phis **/
+
+ /* 1.1. Generate new phi node in NEW_MERGE_BB: */
+ new_phi = create_phi_node (SSA_NAME_VAR (PHI_RESULT (orig_phi)),
+ new_merge_bb);
+
+ /* 1.2. NEW_MERGE_BB has two incoming edges: GUARD_EDGE and the exit-edge
+ of LOOP. Set the two phi args in NEW_PHI for these edges: */
+ loop_arg = PHI_ARG_DEF_FROM_EDGE (orig_phi, EDGE_SUCC (loop->latch, 0));
+ guard_arg = PHI_ARG_DEF_FROM_EDGE (orig_phi, loop_preheader_edge (loop));
+
+ add_phi_arg (new_phi, loop_arg, new_exit_e);
+ add_phi_arg (new_phi, guard_arg, guard_edge);
+
+ /* 1.3. Update phi in successor block. */
+ gcc_assert (PHI_ARG_DEF_FROM_EDGE (update_phi, e) == loop_arg
+ || PHI_ARG_DEF_FROM_EDGE (update_phi, e) == guard_arg);
+ SET_PHI_ARG_DEF (update_phi, e->dest_idx, PHI_RESULT (new_phi));
+ update_phi2 = new_phi;
+
+
+ /** 2. Handle loop-closed-ssa-form phis **/
+
+ if (!is_gimple_reg (PHI_RESULT (orig_phi)))
+ continue;
+
+ /* 2.1. Generate new phi node in NEW_EXIT_BB: */
+ new_phi = create_phi_node (SSA_NAME_VAR (PHI_RESULT (orig_phi)),
+ *new_exit_bb);
+
+ /* 2.2. NEW_EXIT_BB has one incoming edge: the exit-edge of the loop. */
+ add_phi_arg (new_phi, loop_arg, single_exit (loop));
+
+ /* 2.3. Update phi in successor of NEW_EXIT_BB: */
+ gcc_assert (PHI_ARG_DEF_FROM_EDGE (update_phi2, new_exit_e) == loop_arg);
+ SET_PHI_ARG_DEF (update_phi2, new_exit_e->dest_idx, PHI_RESULT (new_phi));
+
+ /* 2.4. Record the newly created name with set_current_def.
+ We want to find a name such that
+ name = get_current_def (orig_loop_name)
+ and to set its current definition as follows:
+ set_current_def (name, new_phi_name)
+
+ If LOOP is a new loop then loop_arg is already the name we're
+ looking for. If LOOP is the original loop, then loop_arg is
+ the orig_loop_name and the relevant name is recorded in its
+ current reaching definition. */
+ if (is_new_loop)
+ current_new_name = loop_arg;
+ else
+ {
+ current_new_name = get_current_def (loop_arg);
+ /* current_def is not available only if the variable does not
+ change inside the loop, in which case we also don't care
+ about recording a current_def for it because we won't be
+ trying to create loop-exit-phis for it. */
+ if (!current_new_name)
+ continue;
+ }
+ gcc_assert (get_current_def (current_new_name) == NULL_TREE);
+
+ set_current_def (current_new_name, PHI_RESULT (new_phi));
+ bitmap_set_bit (*defs, SSA_NAME_VERSION (current_new_name));
+ }
+}
+
+
+/* Function slpeel_update_phi_nodes_for_guard2
+
+ Input:
+ - GUARD_EDGE, LOOP, IS_NEW_LOOP, NEW_EXIT_BB - as explained above.
+
+ In the context of the overall structure, we have:
+
+ loop1_preheader_bb:
+ guard1 (goto loop1/merge1_bb)
+ loop1
+ loop1_exit_bb:
+ guard2 (goto merge1_bb/merge2_bb)
+ merge1_bb
+LOOP-> loop2
+ loop2_exit_bb
+ merge2_bb
+ next_bb
+
+ For each name used out side the loop (i.e - for each name that has an exit
+ phi in next_bb) we create a new phi in:
+ 1. merge2_bb (to account for the edge from guard_bb)
+ 2. loop2_exit_bb (an exit-phi to keep LOOP in loop-closed form)
+ 3. guard2 bb (an exit phi to keep the preceding loop in loop-closed form),
+ if needed (if it wasn't handled by slpeel_update_phis_nodes_for_phi1).
+*/
+
+static void
+slpeel_update_phi_nodes_for_guard2 (edge guard_edge, struct loop *loop,
+ bool is_new_loop, basic_block *new_exit_bb)
+{
+ gimple orig_phi, new_phi;
+ gimple update_phi, update_phi2;
+ tree guard_arg, loop_arg;
+ basic_block new_merge_bb = guard_edge->dest;
+ edge e = EDGE_SUCC (new_merge_bb, 0);
+ basic_block update_bb = e->dest;
+ edge new_exit_e;
+ tree orig_def, orig_def_new_name;
+ tree new_name, new_name2;
+ tree arg;
+ gimple_stmt_iterator gsi;
+
+ /* Create new bb between loop and new_merge_bb. */
+ *new_exit_bb = split_edge (single_exit (loop));
+
+ new_exit_e = EDGE_SUCC (*new_exit_bb, 0);
+
+ for (gsi = gsi_start_phis (update_bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ update_phi = gsi_stmt (gsi);
+ orig_phi = update_phi;
+ orig_def = PHI_ARG_DEF_FROM_EDGE (orig_phi, e);
+ /* This loop-closed-phi actually doesn't represent a use
+ out of the loop - the phi arg is a constant. */
+ if (TREE_CODE (orig_def) != SSA_NAME)
+ continue;
+ orig_def_new_name = get_current_def (orig_def);
+ arg = NULL_TREE;
+
+ /** 1. Handle new-merge-point phis **/
+
+ /* 1.1. Generate new phi node in NEW_MERGE_BB: */
+ new_phi = create_phi_node (SSA_NAME_VAR (PHI_RESULT (orig_phi)),
+ new_merge_bb);
+
+ /* 1.2. NEW_MERGE_BB has two incoming edges: GUARD_EDGE and the exit-edge
+ of LOOP. Set the two PHI args in NEW_PHI for these edges: */
+ new_name = orig_def;
+ new_name2 = NULL_TREE;
+ if (orig_def_new_name)
+ {
+ new_name = orig_def_new_name;
+ /* Some variables have both loop-entry-phis and loop-exit-phis.
+ Such variables were given yet newer names by phis placed in
+ guard_bb by slpeel_update_phi_nodes_for_guard1. I.e:
+ new_name2 = get_current_def (get_current_def (orig_name)). */
+ new_name2 = get_current_def (new_name);
+ }
+
+ if (is_new_loop)
+ {
+ guard_arg = orig_def;
+ loop_arg = new_name;
+ }
+ else
+ {
+ guard_arg = new_name;
+ loop_arg = orig_def;
+ }
+ if (new_name2)
+ guard_arg = new_name2;
+
+ add_phi_arg (new_phi, loop_arg, new_exit_e);
+ add_phi_arg (new_phi, guard_arg, guard_edge);
+
+ /* 1.3. Update phi in successor block. */
+ gcc_assert (PHI_ARG_DEF_FROM_EDGE (update_phi, e) == orig_def);
+ SET_PHI_ARG_DEF (update_phi, e->dest_idx, PHI_RESULT (new_phi));
+ update_phi2 = new_phi;
+
+
+ /** 2. Handle loop-closed-ssa-form phis **/
+
+ /* 2.1. Generate new phi node in NEW_EXIT_BB: */
+ new_phi = create_phi_node (SSA_NAME_VAR (PHI_RESULT (orig_phi)),
+ *new_exit_bb);
+
+ /* 2.2. NEW_EXIT_BB has one incoming edge: the exit-edge of the loop. */
+ add_phi_arg (new_phi, loop_arg, single_exit (loop));
+
+ /* 2.3. Update phi in successor of NEW_EXIT_BB: */
+ gcc_assert (PHI_ARG_DEF_FROM_EDGE (update_phi2, new_exit_e) == loop_arg);
+ SET_PHI_ARG_DEF (update_phi2, new_exit_e->dest_idx, PHI_RESULT (new_phi));
+
+
+ /** 3. Handle loop-closed-ssa-form phis for first loop **/
+
+ /* 3.1. Find the relevant names that need an exit-phi in
+ GUARD_BB, i.e. names for which
+ slpeel_update_phi_nodes_for_guard1 had not already created a
+ phi node. This is the case for names that are used outside
+ the loop (and therefore need an exit phi) but are not updated
+ across loop iterations (and therefore don't have a
+ loop-header-phi).
+
+ slpeel_update_phi_nodes_for_guard1 is responsible for
+ creating loop-exit phis in GUARD_BB for names that have a
+ loop-header-phi. When such a phi is created we also record
+ the new name in its current definition. If this new name
+ exists, then guard_arg was set to this new name (see 1.2
+ above). Therefore, if guard_arg is not this new name, this
+ is an indication that an exit-phi in GUARD_BB was not yet
+ created, so we take care of it here. */
+ if (guard_arg == new_name2)
+ continue;
+ arg = guard_arg;
+
+ /* 3.2. Generate new phi node in GUARD_BB: */
+ new_phi = create_phi_node (SSA_NAME_VAR (PHI_RESULT (orig_phi)),
+ guard_edge->src);
+
+ /* 3.3. GUARD_BB has one incoming edge: */
+ gcc_assert (EDGE_COUNT (guard_edge->src->preds) == 1);
+ add_phi_arg (new_phi, arg, EDGE_PRED (guard_edge->src, 0));
+
+ /* 3.4. Update phi in successor of GUARD_BB: */
+ gcc_assert (PHI_ARG_DEF_FROM_EDGE (update_phi2, guard_edge)
+ == guard_arg);
+ SET_PHI_ARG_DEF (update_phi2, guard_edge->dest_idx, PHI_RESULT (new_phi));
+ }
+}
+
+
+/* Make the LOOP iterate NITERS times. This is done by adding a new IV
+ that starts at zero, increases by one and its limit is NITERS.
+
+ Assumption: the exit-condition of LOOP is the last stmt in the loop. */
+
+void
+slpeel_make_loop_iterate_ntimes (struct loop *loop, tree niters)
+{
+ tree indx_before_incr, indx_after_incr;
+ gimple cond_stmt;
+ gimple orig_cond;
+ edge exit_edge = single_exit (loop);
+ gimple_stmt_iterator loop_cond_gsi;
+ gimple_stmt_iterator incr_gsi;
+ bool insert_after;
+ tree init = build_int_cst (TREE_TYPE (niters), 0);
+ tree step = build_int_cst (TREE_TYPE (niters), 1);
+ LOC loop_loc;
+ enum tree_code code;
+
+ orig_cond = get_loop_exit_condition (loop);
+ gcc_assert (orig_cond);
+ loop_cond_gsi = gsi_for_stmt (orig_cond);
+
+ standard_iv_increment_position (loop, &incr_gsi, &insert_after);
+ create_iv (init, step, NULL_TREE, loop,
+ &incr_gsi, insert_after, &indx_before_incr, &indx_after_incr);
+
+ indx_after_incr = force_gimple_operand_gsi (&loop_cond_gsi, indx_after_incr,
+ true, NULL_TREE, true,
+ GSI_SAME_STMT);
+ niters = force_gimple_operand_gsi (&loop_cond_gsi, niters, true, NULL_TREE,
+ true, GSI_SAME_STMT);
+
+ code = (exit_edge->flags & EDGE_TRUE_VALUE) ? GE_EXPR : LT_EXPR;
+ cond_stmt = gimple_build_cond (code, indx_after_incr, niters, NULL_TREE,
+ NULL_TREE);
+
+ gsi_insert_before (&loop_cond_gsi, cond_stmt, GSI_SAME_STMT);
+
+ /* Remove old loop exit test: */
+ gsi_remove (&loop_cond_gsi, true);
+
+ loop_loc = find_loop_location (loop);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ if (loop_loc != UNKNOWN_LOC)
+ fprintf (dump_file, "\nloop at %s:%d: ",
+ LOC_FILE (loop_loc), LOC_LINE (loop_loc));
+ print_gimple_stmt (dump_file, cond_stmt, 0, TDF_SLIM);
+ }
+
+ loop->nb_iterations = niters;
+}
+
+
+/* Given LOOP this function generates a new copy of it and puts it
+ on E which is either the entry or exit of LOOP. */
+
+struct loop *
+slpeel_tree_duplicate_loop_to_edge_cfg (struct loop *loop, edge e)
+{
+ struct loop *new_loop;
+ basic_block *new_bbs, *bbs;
+ bool at_exit;
+ bool was_imm_dom;
+ basic_block exit_dest;
+ gimple phi;
+ tree phi_arg;
+ edge exit, new_exit;
+ gimple_stmt_iterator gsi;
+
+ at_exit = (e == single_exit (loop));
+ if (!at_exit && e != loop_preheader_edge (loop))
+ return NULL;
+
+ bbs = get_loop_body (loop);
+
+ /* Check whether duplication is possible. */
+ if (!can_copy_bbs_p (bbs, loop->num_nodes))
+ {
+ free (bbs);
+ return NULL;
+ }
+
+ /* Generate new loop structure. */
+ new_loop = duplicate_loop (loop, loop_outer (loop));
+ if (!new_loop)
+ {
+ free (bbs);
+ return NULL;
+ }
+
+ exit_dest = single_exit (loop)->dest;
+ was_imm_dom = (get_immediate_dominator (CDI_DOMINATORS,
+ exit_dest) == loop->header ?
+ true : false);
+
+ new_bbs = XNEWVEC (basic_block, loop->num_nodes);
+
+ exit = single_exit (loop);
+ copy_bbs (bbs, loop->num_nodes, new_bbs,
+ &exit, 1, &new_exit, NULL,
+ e->src);
+
+ /* Duplicating phi args at exit bbs as coming
+ also from exit of duplicated loop. */
+ for (gsi = gsi_start_phis (exit_dest); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ phi = gsi_stmt (gsi);
+ phi_arg = PHI_ARG_DEF_FROM_EDGE (phi, single_exit (loop));
+ if (phi_arg)
+ {
+ edge new_loop_exit_edge;
+
+ if (EDGE_SUCC (new_loop->header, 0)->dest == new_loop->latch)
+ new_loop_exit_edge = EDGE_SUCC (new_loop->header, 1);
+ else
+ new_loop_exit_edge = EDGE_SUCC (new_loop->header, 0);
+
+ add_phi_arg (phi, phi_arg, new_loop_exit_edge);
+ }
+ }
+
+ if (at_exit) /* Add the loop copy at exit. */
+ {
+ redirect_edge_and_branch_force (e, new_loop->header);
+ PENDING_STMT (e) = NULL;
+ set_immediate_dominator (CDI_DOMINATORS, new_loop->header, e->src);
+ if (was_imm_dom)
+ set_immediate_dominator (CDI_DOMINATORS, exit_dest, new_loop->header);
+ }
+ else /* Add the copy at entry. */
+ {
+ edge new_exit_e;
+ edge entry_e = loop_preheader_edge (loop);
+ basic_block preheader = entry_e->src;
+
+ if (!flow_bb_inside_loop_p (new_loop,
+ EDGE_SUCC (new_loop->header, 0)->dest))
+ new_exit_e = EDGE_SUCC (new_loop->header, 0);
+ else
+ new_exit_e = EDGE_SUCC (new_loop->header, 1);
+
+ redirect_edge_and_branch_force (new_exit_e, loop->header);
+ PENDING_STMT (new_exit_e) = NULL;
+ set_immediate_dominator (CDI_DOMINATORS, loop->header,
+ new_exit_e->src);
+
+ /* We have to add phi args to the loop->header here as coming
+ from new_exit_e edge. */
+ for (gsi = gsi_start_phis (loop->header);
+ !gsi_end_p (gsi);
+ gsi_next (&gsi))
+ {
+ phi = gsi_stmt (gsi);
+ phi_arg = PHI_ARG_DEF_FROM_EDGE (phi, entry_e);
+ if (phi_arg)
+ add_phi_arg (phi, phi_arg, new_exit_e);
+ }
+
+ redirect_edge_and_branch_force (entry_e, new_loop->header);
+ PENDING_STMT (entry_e) = NULL;
+ set_immediate_dominator (CDI_DOMINATORS, new_loop->header, preheader);
+ }
+
+ free (new_bbs);
+ free (bbs);
+
+ return new_loop;
+}
+
+
+/* Given the condition statement COND, put it as the last statement
+ of GUARD_BB; EXIT_BB is the basic block to skip the loop;
+ Assumes that this is the single exit of the guarded loop.
+ Returns the skip edge. */
+
+static edge
+slpeel_add_loop_guard (basic_block guard_bb, tree cond, basic_block exit_bb,
+ basic_block dom_bb)
+{
+ gimple_stmt_iterator gsi;
+ edge new_e, enter_e;
+ gimple cond_stmt;
+ gimple_seq gimplify_stmt_list = NULL;
+
+ enter_e = EDGE_SUCC (guard_bb, 0);
+ enter_e->flags &= ~EDGE_FALLTHRU;
+ enter_e->flags |= EDGE_FALSE_VALUE;
+ gsi = gsi_last_bb (guard_bb);
+
+ cond = force_gimple_operand (cond, &gimplify_stmt_list, true, NULL_TREE);
+ cond_stmt = gimple_build_cond (NE_EXPR,
+ cond, build_int_cst (TREE_TYPE (cond), 0),
+ NULL_TREE, NULL_TREE);
+ if (gimplify_stmt_list)
+ gsi_insert_seq_after (&gsi, gimplify_stmt_list, GSI_NEW_STMT);
+
+ gsi = gsi_last_bb (guard_bb);
+ gsi_insert_after (&gsi, cond_stmt, GSI_NEW_STMT);
+
+ /* Add new edge to connect guard block to the merge/loop-exit block. */
+ new_e = make_edge (guard_bb, exit_bb, EDGE_TRUE_VALUE);
+ set_immediate_dominator (CDI_DOMINATORS, exit_bb, dom_bb);
+ return new_e;
+}
+
+
+/* This function verifies that the following restrictions apply to LOOP:
+ (1) it is innermost
+ (2) it consists of exactly 2 basic blocks - header, and an empty latch.
+ (3) it is single entry, single exit
+ (4) its exit condition is the last stmt in the header
+ (5) E is the entry/exit edge of LOOP.
+ */
+
+bool
+slpeel_can_duplicate_loop_p (const struct loop *loop, const_edge e)
+{
+ edge exit_e = single_exit (loop);
+ edge entry_e = loop_preheader_edge (loop);
+ gimple orig_cond = get_loop_exit_condition (loop);
+ gimple_stmt_iterator loop_exit_gsi = gsi_last_bb (exit_e->src);
+
+ if (need_ssa_update_p ())
+ return false;
+
+ if (loop->inner
+ /* All loops have an outer scope; the only case loop->outer is NULL is for
+ the function itself. */
+ || !loop_outer (loop)
+ || loop->num_nodes != 2
+ || !empty_block_p (loop->latch)
+ || !single_exit (loop)
+ /* Verify that new loop exit condition can be trivially modified. */
+ || (!orig_cond || orig_cond != gsi_stmt (loop_exit_gsi))
+ || (e != exit_e && e != entry_e))
+ return false;
+
+ return true;
+}
+
+#ifdef ENABLE_CHECKING
+static void
+slpeel_verify_cfg_after_peeling (struct loop *first_loop,
+ struct loop *second_loop)
+{
+ basic_block loop1_exit_bb = single_exit (first_loop)->dest;
+ basic_block loop2_entry_bb = loop_preheader_edge (second_loop)->src;
+ basic_block loop1_entry_bb = loop_preheader_edge (first_loop)->src;
+
+ /* A guard that controls whether the second_loop is to be executed or skipped
+ is placed in first_loop->exit. first_loop->exit therefore has two
+ successors - one is the preheader of second_loop, and the other is a bb
+ after second_loop.
+ */
+ gcc_assert (EDGE_COUNT (loop1_exit_bb->succs) == 2);
+
+ /* 1. Verify that one of the successors of first_loop->exit is the preheader
+ of second_loop. */
+
+ /* The preheader of new_loop is expected to have two predecessors:
+ first_loop->exit and the block that precedes first_loop. */
+
+ gcc_assert (EDGE_COUNT (loop2_entry_bb->preds) == 2
+ && ((EDGE_PRED (loop2_entry_bb, 0)->src == loop1_exit_bb
+ && EDGE_PRED (loop2_entry_bb, 1)->src == loop1_entry_bb)
+ || (EDGE_PRED (loop2_entry_bb, 1)->src == loop1_exit_bb
+ && EDGE_PRED (loop2_entry_bb, 0)->src == loop1_entry_bb)));
+
+ /* Verify that the other successor of first_loop->exit is after the
+ second_loop. */
+ /* TODO */
+}
+#endif
+
+/* If the run time cost model check determines that vectorization is
+ not profitable and hence scalar loop should be generated then set
+ FIRST_NITERS to prologue peeled iterations. This will allow all the
+ iterations to be executed in the prologue peeled scalar loop. */
+
+static void
+set_prologue_iterations (basic_block bb_before_first_loop,
+ tree first_niters,
+ struct loop *loop,
+ unsigned int th)
+{
+ edge e;
+ basic_block cond_bb, then_bb;
+ tree var, prologue_after_cost_adjust_name;
+ gimple_stmt_iterator gsi;
+ gimple newphi;
+ edge e_true, e_false, e_fallthru;
+ gimple cond_stmt;
+ gimple_seq gimplify_stmt_list = NULL, stmts = NULL;
+ tree cost_pre_condition = NULL_TREE;
+ tree scalar_loop_iters =
+ unshare_expr (LOOP_VINFO_NITERS_UNCHANGED (loop_vec_info_for_loop (loop)));
+
+ e = single_pred_edge (bb_before_first_loop);
+ cond_bb = split_edge(e);
+
+ e = single_pred_edge (bb_before_first_loop);
+ then_bb = split_edge(e);
+ set_immediate_dominator (CDI_DOMINATORS, then_bb, cond_bb);
+
+ e_false = make_single_succ_edge (cond_bb, bb_before_first_loop,
+ EDGE_FALSE_VALUE);
+ set_immediate_dominator (CDI_DOMINATORS, bb_before_first_loop, cond_bb);
+
+ e_true = EDGE_PRED (then_bb, 0);
+ e_true->flags &= ~EDGE_FALLTHRU;
+ e_true->flags |= EDGE_TRUE_VALUE;
+
+ e_fallthru = EDGE_SUCC (then_bb, 0);
+
+ cost_pre_condition =
+ fold_build2 (LE_EXPR, boolean_type_node, scalar_loop_iters,
+ build_int_cst (TREE_TYPE (scalar_loop_iters), th));
+ cost_pre_condition =
+ force_gimple_operand (cost_pre_condition, &gimplify_stmt_list,
+ true, NULL_TREE);
+ cond_stmt = gimple_build_cond (NE_EXPR, cost_pre_condition,
+ build_int_cst (TREE_TYPE (cost_pre_condition),
+ 0), NULL_TREE, NULL_TREE);
+
+ gsi = gsi_last_bb (cond_bb);
+ if (gimplify_stmt_list)
+ gsi_insert_seq_after (&gsi, gimplify_stmt_list, GSI_NEW_STMT);
+
+ gsi = gsi_last_bb (cond_bb);
+ gsi_insert_after (&gsi, cond_stmt, GSI_NEW_STMT);
+
+ var = create_tmp_var (TREE_TYPE (scalar_loop_iters),
+ "prologue_after_cost_adjust");
+ add_referenced_var (var);
+ prologue_after_cost_adjust_name =
+ force_gimple_operand (scalar_loop_iters, &stmts, false, var);
+
+ gsi = gsi_last_bb (then_bb);
+ if (stmts)
+ gsi_insert_seq_after (&gsi, stmts, GSI_NEW_STMT);
+
+ newphi = create_phi_node (var, bb_before_first_loop);
+ add_phi_arg (newphi, prologue_after_cost_adjust_name, e_fallthru);
+ add_phi_arg (newphi, first_niters, e_false);
+
+ first_niters = PHI_RESULT (newphi);
+}
+
+
+/* Function slpeel_tree_peel_loop_to_edge.
+
+ Peel the first (last) iterations of LOOP into a new prolog (epilog) loop
+ that is placed on the entry (exit) edge E of LOOP. After this transformation
+ we have two loops one after the other - first-loop iterates FIRST_NITERS
+ times, and second-loop iterates the remainder NITERS - FIRST_NITERS times.
+ If the cost model indicates that it is profitable to emit a scalar
+ loop instead of the vector one, then the prolog (epilog) loop will iterate
+ for the entire unchanged scalar iterations of the loop.
+
+ Input:
+ - LOOP: the loop to be peeled.
+ - E: the exit or entry edge of LOOP.
+ If it is the entry edge, we peel the first iterations of LOOP. In this
+ case first-loop is LOOP, and second-loop is the newly created loop.
+ If it is the exit edge, we peel the last iterations of LOOP. In this
+ case, first-loop is the newly created loop, and second-loop is LOOP.
+ - NITERS: the number of iterations that LOOP iterates.
+ - FIRST_NITERS: the number of iterations that the first-loop should iterate.
+ - UPDATE_FIRST_LOOP_COUNT: specified whether this function is responsible
+ for updating the loop bound of the first-loop to FIRST_NITERS. If it
+ is false, the caller of this function may want to take care of this
+ (this can be useful if we don't want new stmts added to first-loop).
+ - TH: cost model profitability threshold of iterations for vectorization.
+ - CHECK_PROFITABILITY: specify whether cost model check has not occurred
+ during versioning and hence needs to occur during
+ prologue generation or whether cost model check
+ has not occurred during prologue generation and hence
+ needs to occur during epilogue generation.
+
+
+ Output:
+ The function returns a pointer to the new loop-copy, or NULL if it failed
+ to perform the transformation.
+
+ The function generates two if-then-else guards: one before the first loop,
+ and the other before the second loop:
+ The first guard is:
+ if (FIRST_NITERS == 0) then skip the first loop,
+ and go directly to the second loop.
+ The second guard is:
+ if (FIRST_NITERS == NITERS) then skip the second loop.
+
+ FORNOW only simple loops are supported (see slpeel_can_duplicate_loop_p).
+ FORNOW the resulting code will not be in loop-closed-ssa form.
+*/
+
+static struct loop*
+slpeel_tree_peel_loop_to_edge (struct loop *loop,
+ edge e, tree first_niters,
+ tree niters, bool update_first_loop_count,
+ unsigned int th, bool check_profitability)
+{
+ struct loop *new_loop = NULL, *first_loop, *second_loop;
+ edge skip_e;
+ tree pre_condition = NULL_TREE;
+ bitmap definitions;
+ basic_block bb_before_second_loop, bb_after_second_loop;
+ basic_block bb_before_first_loop;
+ basic_block bb_between_loops;
+ basic_block new_exit_bb;
+ edge exit_e = single_exit (loop);
+ LOC loop_loc;
+ tree cost_pre_condition = NULL_TREE;
+
+ if (!slpeel_can_duplicate_loop_p (loop, e))
+ return NULL;
+
+ /* We have to initialize cfg_hooks. Then, when calling
+ cfg_hooks->split_edge, the function tree_split_edge
+ is actually called and, when calling cfg_hooks->duplicate_block,
+ the function tree_duplicate_bb is called. */
+ gimple_register_cfg_hooks ();
+
+
+ /* 1. Generate a copy of LOOP and put it on E (E is the entry/exit of LOOP).
+ Resulting CFG would be:
+
+ first_loop:
+ do {
+ } while ...
+
+ second_loop:
+ do {
+ } while ...
+
+ orig_exit_bb:
+ */
+
+ if (!(new_loop = slpeel_tree_duplicate_loop_to_edge_cfg (loop, e)))
+ {
+ loop_loc = find_loop_location (loop);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ if (loop_loc != UNKNOWN_LOC)
+ fprintf (dump_file, "\n%s:%d: note: ",
+ LOC_FILE (loop_loc), LOC_LINE (loop_loc));
+ fprintf (dump_file, "tree_duplicate_loop_to_edge_cfg failed.\n");
+ }
+ return NULL;
+ }
+
+ if (e == exit_e)
+ {
+ /* NEW_LOOP was placed after LOOP. */
+ first_loop = loop;
+ second_loop = new_loop;
+ }
+ else
+ {
+ /* NEW_LOOP was placed before LOOP. */
+ first_loop = new_loop;
+ second_loop = loop;
+ }
+
+ definitions = ssa_names_to_replace ();
+ slpeel_update_phis_for_duplicate_loop (loop, new_loop, e == exit_e);
+ rename_variables_in_loop (new_loop);
+
+
+ /* 2. Add the guard code in one of the following ways:
+
+ 2.a Add the guard that controls whether the first loop is executed.
+ This occurs when this function is invoked for prologue or epilogue
+ generation and when the cost model check can be done at compile time.
+
+ Resulting CFG would be:
+
+ bb_before_first_loop:
+ if (FIRST_NITERS == 0) GOTO bb_before_second_loop
+ GOTO first-loop
+
+ first_loop:
+ do {
+ } while ...
+
+ bb_before_second_loop:
+
+ second_loop:
+ do {
+ } while ...
+
+ orig_exit_bb:
+
+ 2.b Add the cost model check that allows the prologue
+ to iterate for the entire unchanged scalar
+ iterations of the loop in the event that the cost
+ model indicates that the scalar loop is more
+ profitable than the vector one. This occurs when
+ this function is invoked for prologue generation
+ and the cost model check needs to be done at run
+ time.
+
+ Resulting CFG after prologue peeling would be:
+
+ if (scalar_loop_iterations <= th)
+ FIRST_NITERS = scalar_loop_iterations
+
+ bb_before_first_loop:
+ if (FIRST_NITERS == 0) GOTO bb_before_second_loop
+ GOTO first-loop
+
+ first_loop:
+ do {
+ } while ...
+
+ bb_before_second_loop:
+
+ second_loop:
+ do {
+ } while ...
+
+ orig_exit_bb:
+
+ 2.c Add the cost model check that allows the epilogue
+ to iterate for the entire unchanged scalar
+ iterations of the loop in the event that the cost
+ model indicates that the scalar loop is more
+ profitable than the vector one. This occurs when
+ this function is invoked for epilogue generation
+ and the cost model check needs to be done at run
+ time.
+
+ Resulting CFG after prologue peeling would be:
+
+ bb_before_first_loop:
+ if ((scalar_loop_iterations <= th)
+ ||
+ FIRST_NITERS == 0) GOTO bb_before_second_loop
+ GOTO first-loop
+
+ first_loop:
+ do {
+ } while ...
+
+ bb_before_second_loop:
+
+ second_loop:
+ do {
+ } while ...
+
+ orig_exit_bb:
+ */
+
+ bb_before_first_loop = split_edge (loop_preheader_edge (first_loop));
+ bb_before_second_loop = split_edge (single_exit (first_loop));
+
+ /* Epilogue peeling. */
+ if (!update_first_loop_count)
+ {
+ pre_condition =
+ fold_build2 (LE_EXPR, boolean_type_node, first_niters,
+ build_int_cst (TREE_TYPE (first_niters), 0));
+ if (check_profitability)
+ {
+ tree scalar_loop_iters
+ = unshare_expr (LOOP_VINFO_NITERS_UNCHANGED
+ (loop_vec_info_for_loop (loop)));
+ cost_pre_condition =
+ fold_build2 (LE_EXPR, boolean_type_node, scalar_loop_iters,
+ build_int_cst (TREE_TYPE (scalar_loop_iters), th));
+
+ pre_condition = fold_build2 (TRUTH_OR_EXPR, boolean_type_node,
+ cost_pre_condition, pre_condition);
+ }
+ }
+
+ /* Prologue peeling. */
+ else
+ {
+ if (check_profitability)
+ set_prologue_iterations (bb_before_first_loop, first_niters,
+ loop, th);
+
+ pre_condition =
+ fold_build2 (LE_EXPR, boolean_type_node, first_niters,
+ build_int_cst (TREE_TYPE (first_niters), 0));
+ }
+
+ skip_e = slpeel_add_loop_guard (bb_before_first_loop, pre_condition,
+ bb_before_second_loop, bb_before_first_loop);
+ slpeel_update_phi_nodes_for_guard1 (skip_e, first_loop,
+ first_loop == new_loop,
+ &new_exit_bb, &definitions);
+
+
+ /* 3. Add the guard that controls whether the second loop is executed.
+ Resulting CFG would be:
+
+ bb_before_first_loop:
+ if (FIRST_NITERS == 0) GOTO bb_before_second_loop (skip first loop)
+ GOTO first-loop
+
+ first_loop:
+ do {
+ } while ...
+
+ bb_between_loops:
+ if (FIRST_NITERS == NITERS) GOTO bb_after_second_loop (skip second loop)
+ GOTO bb_before_second_loop
+
+ bb_before_second_loop:
+
+ second_loop:
+ do {
+ } while ...
+
+ bb_after_second_loop:
+
+ orig_exit_bb:
+ */
+
+ bb_between_loops = new_exit_bb;
+ bb_after_second_loop = split_edge (single_exit (second_loop));
+
+ pre_condition =
+ fold_build2 (EQ_EXPR, boolean_type_node, first_niters, niters);
+ skip_e = slpeel_add_loop_guard (bb_between_loops, pre_condition,
+ bb_after_second_loop, bb_before_first_loop);
+ slpeel_update_phi_nodes_for_guard2 (skip_e, second_loop,
+ second_loop == new_loop, &new_exit_bb);
+
+ /* 4. Make first-loop iterate FIRST_NITERS times, if requested.
+ */
+ if (update_first_loop_count)
+ slpeel_make_loop_iterate_ntimes (first_loop, first_niters);
+
+ BITMAP_FREE (definitions);
+ delete_update_ssa ();
+
+ return new_loop;
+}
+
+/* Function vect_get_loop_location.
+
+ Extract the location of the loop in the source code.
+ If the loop is not well formed for vectorization, an estimated
+ location is calculated.
+ Return the loop location if succeed and NULL if not. */
+
+LOC
+find_loop_location (struct loop *loop)
+{
+ gimple stmt = NULL;
+ basic_block bb;
+ gimple_stmt_iterator si;
+
+ if (!loop)
+ return UNKNOWN_LOC;
+
+ stmt = get_loop_exit_condition (loop);
+
+ if (stmt && gimple_location (stmt) != UNKNOWN_LOC)
+ return gimple_location (stmt);
+
+ /* If we got here the loop is probably not "well formed",
+ try to estimate the loop location */
+
+ if (!loop->header)
+ return UNKNOWN_LOC;
+
+ bb = loop->header;
+
+ for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
+ {
+ stmt = gsi_stmt (si);
+ if (gimple_location (stmt) != UNKNOWN_LOC)
+ return gimple_location (stmt);
+ }
+
+ return UNKNOWN_LOC;
+}
+
+
+/* This function builds ni_name = number of iterations loop executes
+ on the loop preheader. */
+
+static tree
+vect_build_loop_niters (loop_vec_info loop_vinfo)
+{
+ tree ni_name, var;
+ gimple_seq stmts = NULL;
+ edge pe;
+ struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
+ tree ni = unshare_expr (LOOP_VINFO_NITERS (loop_vinfo));
+
+ var = create_tmp_var (TREE_TYPE (ni), "niters");
+ add_referenced_var (var);
+ ni_name = force_gimple_operand (ni, &stmts, false, var);
+
+ pe = loop_preheader_edge (loop);
+ if (stmts)
+ {
+ basic_block new_bb = gsi_insert_seq_on_edge_immediate (pe, stmts);
+ gcc_assert (!new_bb);
+ }
+
+ return ni_name;
+}
+
+
+/* This function generates the following statements:
+
+ ni_name = number of iterations loop executes
+ ratio = ni_name / vf
+ ratio_mult_vf_name = ratio * vf
+
+ and places them at the loop preheader edge. */
+
+static void
+vect_generate_tmps_on_preheader (loop_vec_info loop_vinfo,
+ tree *ni_name_ptr,
+ tree *ratio_mult_vf_name_ptr,
+ tree *ratio_name_ptr)
+{
+
+ edge pe;
+ basic_block new_bb;
+ gimple_seq stmts;
+ tree ni_name;
+ tree var;
+ tree ratio_name;
+ tree ratio_mult_vf_name;
+ struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
+ tree ni = LOOP_VINFO_NITERS (loop_vinfo);
+ int vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo);
+ tree log_vf;
+
+ pe = loop_preheader_edge (loop);
+
+ /* Generate temporary variable that contains
+ number of iterations loop executes. */
+
+ ni_name = vect_build_loop_niters (loop_vinfo);
+ log_vf = build_int_cst (TREE_TYPE (ni), exact_log2 (vf));
+
+ /* Create: ratio = ni >> log2(vf) */
+
+ ratio_name = fold_build2 (RSHIFT_EXPR, TREE_TYPE (ni_name), ni_name, log_vf);
+ if (!is_gimple_val (ratio_name))
+ {
+ var = create_tmp_var (TREE_TYPE (ni), "bnd");
+ add_referenced_var (var);
+
+ stmts = NULL;
+ ratio_name = force_gimple_operand (ratio_name, &stmts, true, var);
+ pe = loop_preheader_edge (loop);
+ new_bb = gsi_insert_seq_on_edge_immediate (pe, stmts);
+ gcc_assert (!new_bb);
+ }
+
+ /* Create: ratio_mult_vf = ratio << log2 (vf). */
+
+ ratio_mult_vf_name = fold_build2 (LSHIFT_EXPR, TREE_TYPE (ratio_name),
+ ratio_name, log_vf);
+ if (!is_gimple_val (ratio_mult_vf_name))
+ {
+ var = create_tmp_var (TREE_TYPE (ni), "ratio_mult_vf");
+ add_referenced_var (var);
+
+ stmts = NULL;
+ ratio_mult_vf_name = force_gimple_operand (ratio_mult_vf_name, &stmts,
+ true, var);
+ pe = loop_preheader_edge (loop);
+ new_bb = gsi_insert_seq_on_edge_immediate (pe, stmts);
+ gcc_assert (!new_bb);
+ }
+
+ *ni_name_ptr = ni_name;
+ *ratio_mult_vf_name_ptr = ratio_mult_vf_name;
+ *ratio_name_ptr = ratio_name;
+
+ return;
+}
+
+/* Function vect_can_advance_ivs_p
+
+ In case the number of iterations that LOOP iterates is unknown at compile
+ time, an epilog loop will be generated, and the loop induction variables
+ (IVs) will be "advanced" to the value they are supposed to take just before
+ the epilog loop. Here we check that the access function of the loop IVs
+ and the expression that represents the loop bound are simple enough.
+ These restrictions will be relaxed in the future. */
+
+bool
+vect_can_advance_ivs_p (loop_vec_info loop_vinfo)
+{
+ struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
+ basic_block bb = loop->header;
+ gimple phi;
+ gimple_stmt_iterator gsi;
+
+ /* Analyze phi functions of the loop header. */
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "vect_can_advance_ivs_p:");
+
+ for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ tree access_fn = NULL;
+ tree evolution_part;
+
+ phi = gsi_stmt (gsi);
+ if (vect_print_dump_info (REPORT_DETAILS))
+ {
+ fprintf (vect_dump, "Analyze phi: ");
+ print_gimple_stmt (vect_dump, phi, 0, TDF_SLIM);
+ }
+
+ /* Skip virtual phi's. The data dependences that are associated with
+ virtual defs/uses (i.e., memory accesses) are analyzed elsewhere. */
+
+ if (!is_gimple_reg (SSA_NAME_VAR (PHI_RESULT (phi))))
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "virtual phi. skip.");
+ continue;
+ }
+
+ /* Skip reduction phis. */
+
+ if (STMT_VINFO_DEF_TYPE (vinfo_for_stmt (phi)) == vect_reduction_def)
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "reduc phi. skip.");
+ continue;
+ }
+
+ /* Analyze the evolution function. */
+
+ access_fn = instantiate_parameters
+ (loop, analyze_scalar_evolution (loop, PHI_RESULT (phi)));
+
+ if (!access_fn)
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "No Access function.");
+ return false;
+ }
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ {
+ fprintf (vect_dump, "Access function of PHI: ");
+ print_generic_expr (vect_dump, access_fn, TDF_SLIM);
+ }
+
+ evolution_part = evolution_part_in_loop_num (access_fn, loop->num);
+
+ if (evolution_part == NULL_TREE)
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "No evolution.");
+ return false;
+ }
+
+ /* FORNOW: We do not transform initial conditions of IVs
+ which evolution functions are a polynomial of degree >= 2. */
+
+ if (tree_is_chrec (evolution_part))
+ return false;
+ }
+
+ return true;
+}
+
+
+/* Function vect_update_ivs_after_vectorizer.
+
+ "Advance" the induction variables of LOOP to the value they should take
+ after the execution of LOOP. This is currently necessary because the
+ vectorizer does not handle induction variables that are used after the
+ loop. Such a situation occurs when the last iterations of LOOP are
+ peeled, because:
+ 1. We introduced new uses after LOOP for IVs that were not originally used
+ after LOOP: the IVs of LOOP are now used by an epilog loop.
+ 2. LOOP is going to be vectorized; this means that it will iterate N/VF
+ times, whereas the loop IVs should be bumped N times.
+
+ Input:
+ - LOOP - a loop that is going to be vectorized. The last few iterations
+ of LOOP were peeled.
+ - NITERS - the number of iterations that LOOP executes (before it is
+ vectorized). i.e, the number of times the ivs should be bumped.
+ - UPDATE_E - a successor edge of LOOP->exit that is on the (only) path
+ coming out from LOOP on which there are uses of the LOOP ivs
+ (this is the path from LOOP->exit to epilog_loop->preheader).
+
+ The new definitions of the ivs are placed in LOOP->exit.
+ The phi args associated with the edge UPDATE_E in the bb
+ UPDATE_E->dest are updated accordingly.
+
+ Assumption 1: Like the rest of the vectorizer, this function assumes
+ a single loop exit that has a single predecessor.
+
+ Assumption 2: The phi nodes in the LOOP header and in update_bb are
+ organized in the same order.
+
+ Assumption 3: The access function of the ivs is simple enough (see
+ vect_can_advance_ivs_p). This assumption will be relaxed in the future.
+
+ Assumption 4: Exactly one of the successors of LOOP exit-bb is on a path
+ coming out of LOOP on which the ivs of LOOP are used (this is the path
+ that leads to the epilog loop; other paths skip the epilog loop). This
+ path starts with the edge UPDATE_E, and its destination (denoted update_bb)
+ needs to have its phis updated.
+ */
+
+static void
+vect_update_ivs_after_vectorizer (loop_vec_info loop_vinfo, tree niters,
+ edge update_e)
+{
+ struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
+ basic_block exit_bb = single_exit (loop)->dest;
+ gimple phi, phi1;
+ gimple_stmt_iterator gsi, gsi1;
+ basic_block update_bb = update_e->dest;
+
+ /* gcc_assert (vect_can_advance_ivs_p (loop_vinfo)); */
+
+ /* Make sure there exists a single-predecessor exit bb: */
+ gcc_assert (single_pred_p (exit_bb));
+
+ for (gsi = gsi_start_phis (loop->header), gsi1 = gsi_start_phis (update_bb);
+ !gsi_end_p (gsi) && !gsi_end_p (gsi1);
+ gsi_next (&gsi), gsi_next (&gsi1))
+ {
+ tree access_fn = NULL;
+ tree evolution_part;
+ tree init_expr;
+ tree step_expr;
+ tree var, ni, ni_name;
+ gimple_stmt_iterator last_gsi;
+
+ phi = gsi_stmt (gsi);
+ phi1 = gsi_stmt (gsi1);
+ if (vect_print_dump_info (REPORT_DETAILS))
+ {
+ fprintf (vect_dump, "vect_update_ivs_after_vectorizer: phi: ");
+ print_gimple_stmt (vect_dump, phi, 0, TDF_SLIM);
+ }
+
+ /* Skip virtual phi's. */
+ if (!is_gimple_reg (SSA_NAME_VAR (PHI_RESULT (phi))))
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "virtual phi. skip.");
+ continue;
+ }
+
+ /* Skip reduction phis. */
+ if (STMT_VINFO_DEF_TYPE (vinfo_for_stmt (phi)) == vect_reduction_def)
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "reduc phi. skip.");
+ continue;
+ }
+
+ access_fn = analyze_scalar_evolution (loop, PHI_RESULT (phi));
+ gcc_assert (access_fn);
+ STRIP_NOPS (access_fn);
+ evolution_part =
+ unshare_expr (evolution_part_in_loop_num (access_fn, loop->num));
+ gcc_assert (evolution_part != NULL_TREE);
+
+ /* FORNOW: We do not support IVs whose evolution function is a polynomial
+ of degree >= 2 or exponential. */
+ gcc_assert (!tree_is_chrec (evolution_part));
+
+ step_expr = evolution_part;
+ init_expr = unshare_expr (initial_condition_in_loop_num (access_fn,
+ loop->num));
+
+ if (POINTER_TYPE_P (TREE_TYPE (init_expr)))
+ ni = fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (init_expr),
+ init_expr,
+ fold_convert (sizetype,
+ fold_build2 (MULT_EXPR, TREE_TYPE (niters),
+ niters, step_expr)));
+ else
+ ni = fold_build2 (PLUS_EXPR, TREE_TYPE (init_expr),
+ fold_build2 (MULT_EXPR, TREE_TYPE (init_expr),
+ fold_convert (TREE_TYPE (init_expr),
+ niters),
+ step_expr),
+ init_expr);
+
+
+
+ var = create_tmp_var (TREE_TYPE (init_expr), "tmp");
+ add_referenced_var (var);
+
+ last_gsi = gsi_last_bb (exit_bb);
+ ni_name = force_gimple_operand_gsi (&last_gsi, ni, false, var,
+ true, GSI_SAME_STMT);
+
+ /* Fix phi expressions in the successor bb. */
+ SET_PHI_ARG_DEF (phi1, update_e->dest_idx, ni_name);
+ }
+}
+
+/* Return the more conservative threshold between the
+ min_profitable_iters returned by the cost model and the user
+ specified threshold, if provided. */
+
+static unsigned int
+conservative_cost_threshold (loop_vec_info loop_vinfo,
+ int min_profitable_iters)
+{
+ unsigned int th;
+ int min_scalar_loop_bound;
+
+ min_scalar_loop_bound = ((PARAM_VALUE (PARAM_MIN_VECT_LOOP_BOUND)
+ * LOOP_VINFO_VECT_FACTOR (loop_vinfo)) - 1);
+
+ /* Use the cost model only if it is more conservative than user specified
+ threshold. */
+ th = (unsigned) min_scalar_loop_bound;
+ if (min_profitable_iters
+ && (!min_scalar_loop_bound
+ || min_profitable_iters > min_scalar_loop_bound))
+ th = (unsigned) min_profitable_iters;
+
+ if (th && vect_print_dump_info (REPORT_COST))
+ fprintf (vect_dump, "Vectorization may not be profitable.");
+
+ return th;
+}
+
+/* Function vect_do_peeling_for_loop_bound
+
+ Peel the last iterations of the loop represented by LOOP_VINFO.
+ The peeled iterations form a new epilog loop. Given that the loop now
+ iterates NITERS times, the new epilog loop iterates
+ NITERS % VECTORIZATION_FACTOR times.
+
+ The original loop will later be made to iterate
+ NITERS / VECTORIZATION_FACTOR times (this value is placed into RATIO). */
+
+void
+vect_do_peeling_for_loop_bound (loop_vec_info loop_vinfo, tree *ratio)
+{
+ tree ni_name, ratio_mult_vf_name;
+ struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
+ struct loop *new_loop;
+ edge update_e;
+ basic_block preheader;
+ int loop_num;
+ bool check_profitability = false;
+ unsigned int th = 0;
+ int min_profitable_iters;
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "=== vect_do_peeling_for_loop_bound ===");
+
+ initialize_original_copy_tables ();
+
+ /* Generate the following variables on the preheader of original loop:
+
+ ni_name = number of iteration the original loop executes
+ ratio = ni_name / vf
+ ratio_mult_vf_name = ratio * vf */
+ vect_generate_tmps_on_preheader (loop_vinfo, &ni_name,
+ &ratio_mult_vf_name, ratio);
+
+ loop_num = loop->num;
+
+ /* If cost model check not done during versioning and
+ peeling for alignment. */
+ if (!VEC_length (gimple, LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo))
+ && !VEC_length (ddr_p, LOOP_VINFO_MAY_ALIAS_DDRS (loop_vinfo))
+ && !LOOP_PEELING_FOR_ALIGNMENT (loop_vinfo))
+ {
+ check_profitability = true;
+
+ /* Get profitability threshold for vectorized loop. */
+ min_profitable_iters = LOOP_VINFO_COST_MODEL_MIN_ITERS (loop_vinfo);
+
+ th = conservative_cost_threshold (loop_vinfo,
+ min_profitable_iters);
+ }
+
+ new_loop = slpeel_tree_peel_loop_to_edge (loop, single_exit (loop),
+ ratio_mult_vf_name, ni_name, false,
+ th, check_profitability);
+ gcc_assert (new_loop);
+ gcc_assert (loop_num == loop->num);
+#ifdef ENABLE_CHECKING
+ slpeel_verify_cfg_after_peeling (loop, new_loop);
+#endif
+
+ /* A guard that controls whether the new_loop is to be executed or skipped
+ is placed in LOOP->exit. LOOP->exit therefore has two successors - one
+ is the preheader of NEW_LOOP, where the IVs from LOOP are used. The other
+ is a bb after NEW_LOOP, where these IVs are not used. Find the edge that
+ is on the path where the LOOP IVs are used and need to be updated. */
+
+ preheader = loop_preheader_edge (new_loop)->src;
+ if (EDGE_PRED (preheader, 0)->src == single_exit (loop)->dest)
+ update_e = EDGE_PRED (preheader, 0);
+ else
+ update_e = EDGE_PRED (preheader, 1);
+
+ /* Update IVs of original loop as if they were advanced
+ by ratio_mult_vf_name steps. */
+ vect_update_ivs_after_vectorizer (loop_vinfo, ratio_mult_vf_name, update_e);
+
+ /* After peeling we have to reset scalar evolution analyzer. */
+ scev_reset ();
+
+ free_original_copy_tables ();
+}
+
+
+/* Function vect_gen_niters_for_prolog_loop
+
+ Set the number of iterations for the loop represented by LOOP_VINFO
+ to the minimum between LOOP_NITERS (the original iteration count of the loop)
+ and the misalignment of DR - the data reference recorded in
+ LOOP_VINFO_UNALIGNED_DR (LOOP_VINFO). As a result, after the execution of
+ this loop, the data reference DR will refer to an aligned location.
+
+ The following computation is generated:
+
+ If the misalignment of DR is known at compile time:
+ addr_mis = int mis = DR_MISALIGNMENT (dr);
+ Else, compute address misalignment in bytes:
+ addr_mis = addr & (vectype_size - 1)
+
+ prolog_niters = min (LOOP_NITERS, ((VF - addr_mis/elem_size)&(VF-1))/step)
+
+ (elem_size = element type size; an element is the scalar element whose type
+ is the inner type of the vectype)
+
+ When the step of the data-ref in the loop is not 1 (as in interleaved data
+ and SLP), the number of iterations of the prolog must be divided by the step
+ (which is equal to the size of interleaved group).
+
+ The above formulas assume that VF == number of elements in the vector. This
+ may not hold when there are multiple-types in the loop.
+ In this case, for some data-references in the loop the VF does not represent
+ the number of elements that fit in the vector. Therefore, instead of VF we
+ use TYPE_VECTOR_SUBPARTS. */
+
+static tree
+vect_gen_niters_for_prolog_loop (loop_vec_info loop_vinfo, tree loop_niters)
+{
+ struct data_reference *dr = LOOP_VINFO_UNALIGNED_DR (loop_vinfo);
+ struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
+ tree var;
+ gimple_seq stmts;
+ tree iters, iters_name;
+ edge pe;
+ basic_block new_bb;
+ gimple dr_stmt = DR_STMT (dr);
+ stmt_vec_info stmt_info = vinfo_for_stmt (dr_stmt);
+ tree vectype = STMT_VINFO_VECTYPE (stmt_info);
+ int vectype_align = TYPE_ALIGN (vectype) / BITS_PER_UNIT;
+ tree niters_type = TREE_TYPE (loop_niters);
+ int step = 1;
+ int element_size = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (DR_REF (dr))));
+ int nelements = TYPE_VECTOR_SUBPARTS (vectype);
+
+ if (STMT_VINFO_STRIDED_ACCESS (stmt_info))
+ step = DR_GROUP_SIZE (vinfo_for_stmt (DR_GROUP_FIRST_DR (stmt_info)));
+
+ pe = loop_preheader_edge (loop);
+
+ if (LOOP_PEELING_FOR_ALIGNMENT (loop_vinfo) > 0)
+ {
+ int byte_misalign = LOOP_PEELING_FOR_ALIGNMENT (loop_vinfo);
+ int elem_misalign = byte_misalign / element_size;
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "known alignment = %d.", byte_misalign);
+
+ iters = build_int_cst (niters_type,
+ (((nelements - elem_misalign) & (nelements - 1)) / step));
+ }
+ else
+ {
+ gimple_seq new_stmts = NULL;
+ tree start_addr = vect_create_addr_base_for_vector_ref (dr_stmt,
+ &new_stmts, NULL_TREE, loop);
+ tree ptr_type = TREE_TYPE (start_addr);
+ tree size = TYPE_SIZE (ptr_type);
+ tree type = lang_hooks.types.type_for_size (tree_low_cst (size, 1), 1);
+ tree vectype_size_minus_1 = build_int_cst (type, vectype_align - 1);
+ tree elem_size_log =
+ build_int_cst (type, exact_log2 (vectype_align/nelements));
+ tree nelements_minus_1 = build_int_cst (type, nelements - 1);
+ tree nelements_tree = build_int_cst (type, nelements);
+ tree byte_misalign;
+ tree elem_misalign;
+
+ new_bb = gsi_insert_seq_on_edge_immediate (pe, new_stmts);
+ gcc_assert (!new_bb);
+
+ /* Create: byte_misalign = addr & (vectype_size - 1) */
+ byte_misalign =
+ fold_build2 (BIT_AND_EXPR, type, fold_convert (type, start_addr), vectype_size_minus_1);
+
+ /* Create: elem_misalign = byte_misalign / element_size */
+ elem_misalign =
+ fold_build2 (RSHIFT_EXPR, type, byte_misalign, elem_size_log);
+
+ /* Create: (niters_type) (nelements - elem_misalign)&(nelements - 1) */
+ iters = fold_build2 (MINUS_EXPR, type, nelements_tree, elem_misalign);
+ iters = fold_build2 (BIT_AND_EXPR, type, iters, nelements_minus_1);
+ iters = fold_convert (niters_type, iters);
+ }
+
+ /* Create: prolog_loop_niters = min (iters, loop_niters) */
+ /* If the loop bound is known at compile time we already verified that it is
+ greater than vf; since the misalignment ('iters') is at most vf, there's
+ no need to generate the MIN_EXPR in this case. */
+ if (TREE_CODE (loop_niters) != INTEGER_CST)
+ iters = fold_build2 (MIN_EXPR, niters_type, iters, loop_niters);
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ {
+ fprintf (vect_dump, "niters for prolog loop: ");
+ print_generic_expr (vect_dump, iters, TDF_SLIM);
+ }
+
+ var = create_tmp_var (niters_type, "prolog_loop_niters");
+ add_referenced_var (var);
+ stmts = NULL;
+ iters_name = force_gimple_operand (iters, &stmts, false, var);
+
+ /* Insert stmt on loop preheader edge. */
+ if (stmts)
+ {
+ basic_block new_bb = gsi_insert_seq_on_edge_immediate (pe, stmts);
+ gcc_assert (!new_bb);
+ }
+
+ return iters_name;
+}
+
+
+/* Function vect_update_init_of_dr
+
+ NITERS iterations were peeled from LOOP. DR represents a data reference
+ in LOOP. This function updates the information recorded in DR to
+ account for the fact that the first NITERS iterations had already been
+ executed. Specifically, it updates the OFFSET field of DR. */
+
+static void
+vect_update_init_of_dr (struct data_reference *dr, tree niters)
+{
+ tree offset = DR_OFFSET (dr);
+
+ niters = fold_build2 (MULT_EXPR, sizetype,
+ fold_convert (sizetype, niters),
+ fold_convert (sizetype, DR_STEP (dr)));
+ offset = fold_build2 (PLUS_EXPR, sizetype, offset, niters);
+ DR_OFFSET (dr) = offset;
+}
+
+
+/* Function vect_update_inits_of_drs
+
+ NITERS iterations were peeled from the loop represented by LOOP_VINFO.
+ This function updates the information recorded for the data references in
+ the loop to account for the fact that the first NITERS iterations had
+ already been executed. Specifically, it updates the initial_condition of
+ the access_function of all the data_references in the loop. */
+
+static void
+vect_update_inits_of_drs (loop_vec_info loop_vinfo, tree niters)
+{
+ unsigned int i;
+ VEC (data_reference_p, heap) *datarefs = LOOP_VINFO_DATAREFS (loop_vinfo);
+ struct data_reference *dr;
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "=== vect_update_inits_of_dr ===");
+
+ for (i = 0; VEC_iterate (data_reference_p, datarefs, i, dr); i++)
+ vect_update_init_of_dr (dr, niters);
+}
+
+
+/* Function vect_do_peeling_for_alignment
+
+ Peel the first 'niters' iterations of the loop represented by LOOP_VINFO.
+ 'niters' is set to the misalignment of one of the data references in the
+ loop, thereby forcing it to refer to an aligned location at the beginning
+ of the execution of this loop. The data reference for which we are
+ peeling is recorded in LOOP_VINFO_UNALIGNED_DR. */
+
+void
+vect_do_peeling_for_alignment (loop_vec_info loop_vinfo)
+{
+ struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
+ tree niters_of_prolog_loop, ni_name;
+ tree n_iters;
+ struct loop *new_loop;
+ bool check_profitability = false;
+ unsigned int th = 0;
+ int min_profitable_iters;
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "=== vect_do_peeling_for_alignment ===");
+
+ initialize_original_copy_tables ();
+
+ ni_name = vect_build_loop_niters (loop_vinfo);
+ niters_of_prolog_loop = vect_gen_niters_for_prolog_loop (loop_vinfo, ni_name);
+
+
+ /* If cost model check not done during versioning. */
+ if (!VEC_length (gimple, LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo))
+ && !VEC_length (ddr_p, LOOP_VINFO_MAY_ALIAS_DDRS (loop_vinfo)))
+ {
+ check_profitability = true;
+
+ /* Get profitability threshold for vectorized loop. */
+ min_profitable_iters = LOOP_VINFO_COST_MODEL_MIN_ITERS (loop_vinfo);
+
+ th = conservative_cost_threshold (loop_vinfo,
+ min_profitable_iters);
+ }
+
+ /* Peel the prolog loop and iterate it niters_of_prolog_loop. */
+ new_loop =
+ slpeel_tree_peel_loop_to_edge (loop, loop_preheader_edge (loop),
+ niters_of_prolog_loop, ni_name, true,
+ th, check_profitability);
+
+ gcc_assert (new_loop);
+#ifdef ENABLE_CHECKING
+ slpeel_verify_cfg_after_peeling (new_loop, loop);
+#endif
+
+ /* Update number of times loop executes. */
+ n_iters = LOOP_VINFO_NITERS (loop_vinfo);
+ LOOP_VINFO_NITERS (loop_vinfo) = fold_build2 (MINUS_EXPR,
+ TREE_TYPE (n_iters), n_iters, niters_of_prolog_loop);
+
+ /* Update the init conditions of the access functions of all data refs. */
+ vect_update_inits_of_drs (loop_vinfo, niters_of_prolog_loop);
+
+ /* After peeling we have to reset scalar evolution analyzer. */
+ scev_reset ();
+
+ free_original_copy_tables ();
+}
+
+
+/* Function vect_create_cond_for_align_checks.
+
+ Create a conditional expression that represents the alignment checks for
+ all of data references (array element references) whose alignment must be
+ checked at runtime.
+
+ Input:
+ COND_EXPR - input conditional expression. New conditions will be chained
+ with logical AND operation.
+ LOOP_VINFO - two fields of the loop information are used.
+ LOOP_VINFO_PTR_MASK is the mask used to check the alignment.
+ LOOP_VINFO_MAY_MISALIGN_STMTS contains the refs to be checked.
+
+ Output:
+ COND_EXPR_STMT_LIST - statements needed to construct the conditional
+ expression.
+ The returned value is the conditional expression to be used in the if
+ statement that controls which version of the loop gets executed at runtime.
+
+ The algorithm makes two assumptions:
+ 1) The number of bytes "n" in a vector is a power of 2.
+ 2) An address "a" is aligned if a%n is zero and that this
+ test can be done as a&(n-1) == 0. For example, for 16
+ byte vectors the test is a&0xf == 0. */
+
+static void
+vect_create_cond_for_align_checks (loop_vec_info loop_vinfo,
+ tree *cond_expr,
+ gimple_seq *cond_expr_stmt_list)
+{
+ struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
+ VEC(gimple,heap) *may_misalign_stmts
+ = LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo);
+ gimple ref_stmt;
+ int mask = LOOP_VINFO_PTR_MASK (loop_vinfo);
+ tree mask_cst;
+ unsigned int i;
+ tree psize;
+ tree int_ptrsize_type;
+ char tmp_name[20];
+ tree or_tmp_name = NULL_TREE;
+ tree and_tmp, and_tmp_name;
+ gimple and_stmt;
+ tree ptrsize_zero;
+ tree part_cond_expr;
+
+ /* Check that mask is one less than a power of 2, i.e., mask is
+ all zeros followed by all ones. */
+ gcc_assert ((mask != 0) && ((mask & (mask+1)) == 0));
+
+ /* CHECKME: what is the best integer or unsigned type to use to hold a
+ cast from a pointer value? */
+ psize = TYPE_SIZE (ptr_type_node);
+ int_ptrsize_type
+ = lang_hooks.types.type_for_size (tree_low_cst (psize, 1), 0);
+
+ /* Create expression (mask & (dr_1 || ... || dr_n)) where dr_i is the address
+ of the first vector of the i'th data reference. */
+
+ for (i = 0; VEC_iterate (gimple, may_misalign_stmts, i, ref_stmt); i++)
+ {
+ gimple_seq new_stmt_list = NULL;
+ tree addr_base;
+ tree addr_tmp, addr_tmp_name;
+ tree or_tmp, new_or_tmp_name;
+ gimple addr_stmt, or_stmt;
+
+ /* create: addr_tmp = (int)(address_of_first_vector) */
+ addr_base =
+ vect_create_addr_base_for_vector_ref (ref_stmt, &new_stmt_list,
+ NULL_TREE, loop);
+ if (new_stmt_list != NULL)
+ gimple_seq_add_seq (cond_expr_stmt_list, new_stmt_list);
+
+ sprintf (tmp_name, "%s%d", "addr2int", i);
+ addr_tmp = create_tmp_var (int_ptrsize_type, tmp_name);
+ add_referenced_var (addr_tmp);
+ addr_tmp_name = make_ssa_name (addr_tmp, NULL);
+ addr_stmt = gimple_build_assign_with_ops (NOP_EXPR, addr_tmp_name,
+ addr_base, NULL_TREE);
+ SSA_NAME_DEF_STMT (addr_tmp_name) = addr_stmt;
+ gimple_seq_add_stmt (cond_expr_stmt_list, addr_stmt);
+
+ /* The addresses are OR together. */
+
+ if (or_tmp_name != NULL_TREE)
+ {
+ /* create: or_tmp = or_tmp | addr_tmp */
+ sprintf (tmp_name, "%s%d", "orptrs", i);
+ or_tmp = create_tmp_var (int_ptrsize_type, tmp_name);
+ add_referenced_var (or_tmp);
+ new_or_tmp_name = make_ssa_name (or_tmp, NULL);
+ or_stmt = gimple_build_assign_with_ops (BIT_IOR_EXPR,
+ new_or_tmp_name,
+ or_tmp_name, addr_tmp_name);
+ SSA_NAME_DEF_STMT (new_or_tmp_name) = or_stmt;
+ gimple_seq_add_stmt (cond_expr_stmt_list, or_stmt);
+ or_tmp_name = new_or_tmp_name;
+ }
+ else
+ or_tmp_name = addr_tmp_name;
+
+ } /* end for i */
+
+ mask_cst = build_int_cst (int_ptrsize_type, mask);
+
+ /* create: and_tmp = or_tmp & mask */
+ and_tmp = create_tmp_var (int_ptrsize_type, "andmask" );
+ add_referenced_var (and_tmp);
+ and_tmp_name = make_ssa_name (and_tmp, NULL);
+
+ and_stmt = gimple_build_assign_with_ops (BIT_AND_EXPR, and_tmp_name,
+ or_tmp_name, mask_cst);
+ SSA_NAME_DEF_STMT (and_tmp_name) = and_stmt;
+ gimple_seq_add_stmt (cond_expr_stmt_list, and_stmt);
+
+ /* Make and_tmp the left operand of the conditional test against zero.
+ if and_tmp has a nonzero bit then some address is unaligned. */
+ ptrsize_zero = build_int_cst (int_ptrsize_type, 0);
+ part_cond_expr = fold_build2 (EQ_EXPR, boolean_type_node,
+ and_tmp_name, ptrsize_zero);
+ if (*cond_expr)
+ *cond_expr = fold_build2 (TRUTH_AND_EXPR, boolean_type_node,
+ *cond_expr, part_cond_expr);
+ else
+ *cond_expr = part_cond_expr;
+}
+
+
+/* Function vect_vfa_segment_size.
+
+ Create an expression that computes the size of segment
+ that will be accessed for a data reference. The functions takes into
+ account that realignment loads may access one more vector.
+
+ Input:
+ DR: The data reference.
+ VECT_FACTOR: vectorization factor.
+
+ Return an expression whose value is the size of segment which will be
+ accessed by DR. */
+
+static tree
+vect_vfa_segment_size (struct data_reference *dr, tree vect_factor)
+{
+ tree segment_length = fold_build2 (MULT_EXPR, integer_type_node,
+ DR_STEP (dr), vect_factor);
+
+ if (vect_supportable_dr_alignment (dr) == dr_explicit_realign_optimized)
+ {
+ tree vector_size = TYPE_SIZE_UNIT
+ (STMT_VINFO_VECTYPE (vinfo_for_stmt (DR_STMT (dr))));
+
+ segment_length = fold_build2 (PLUS_EXPR, integer_type_node,
+ segment_length, vector_size);
+ }
+ return fold_convert (sizetype, segment_length);
+}
+
+
+/* Function vect_create_cond_for_alias_checks.
+
+ Create a conditional expression that represents the run-time checks for
+ overlapping of address ranges represented by a list of data references
+ relations passed as input.
+
+ Input:
+ COND_EXPR - input conditional expression. New conditions will be chained
+ with logical AND operation.
+ LOOP_VINFO - field LOOP_VINFO_MAY_ALIAS_STMTS contains the list of ddrs
+ to be checked.
+
+ Output:
+ COND_EXPR - conditional expression.
+ COND_EXPR_STMT_LIST - statements needed to construct the conditional
+ expression.
+
+
+ The returned value is the conditional expression to be used in the if
+ statement that controls which version of the loop gets executed at runtime.
+*/
+
+static void
+vect_create_cond_for_alias_checks (loop_vec_info loop_vinfo,
+ tree * cond_expr,
+ gimple_seq * cond_expr_stmt_list)
+{
+ struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
+ VEC (ddr_p, heap) * may_alias_ddrs =
+ LOOP_VINFO_MAY_ALIAS_DDRS (loop_vinfo);
+ tree vect_factor =
+ build_int_cst (integer_type_node, LOOP_VINFO_VECT_FACTOR (loop_vinfo));
+
+ ddr_p ddr;
+ unsigned int i;
+ tree part_cond_expr;
+
+ /* Create expression
+ ((store_ptr_0 + store_segment_length_0) < load_ptr_0)
+ || (load_ptr_0 + load_segment_length_0) < store_ptr_0))
+ &&
+ ...
+ &&
+ ((store_ptr_n + store_segment_length_n) < load_ptr_n)
+ || (load_ptr_n + load_segment_length_n) < store_ptr_n)) */
+
+ if (VEC_empty (ddr_p, may_alias_ddrs))
+ return;
+
+ for (i = 0; VEC_iterate (ddr_p, may_alias_ddrs, i, ddr); i++)
+ {
+ struct data_reference *dr_a, *dr_b;
+ gimple dr_group_first_a, dr_group_first_b;
+ tree addr_base_a, addr_base_b;
+ tree segment_length_a, segment_length_b;
+ gimple stmt_a, stmt_b;
+
+ dr_a = DDR_A (ddr);
+ stmt_a = DR_STMT (DDR_A (ddr));
+ dr_group_first_a = DR_GROUP_FIRST_DR (vinfo_for_stmt (stmt_a));
+ if (dr_group_first_a)
+ {
+ stmt_a = dr_group_first_a;
+ dr_a = STMT_VINFO_DATA_REF (vinfo_for_stmt (stmt_a));
+ }
+
+ dr_b = DDR_B (ddr);
+ stmt_b = DR_STMT (DDR_B (ddr));
+ dr_group_first_b = DR_GROUP_FIRST_DR (vinfo_for_stmt (stmt_b));
+ if (dr_group_first_b)
+ {
+ stmt_b = dr_group_first_b;
+ dr_b = STMT_VINFO_DATA_REF (vinfo_for_stmt (stmt_b));
+ }
+
+ addr_base_a =
+ vect_create_addr_base_for_vector_ref (stmt_a, cond_expr_stmt_list,
+ NULL_TREE, loop);
+ addr_base_b =
+ vect_create_addr_base_for_vector_ref (stmt_b, cond_expr_stmt_list,
+ NULL_TREE, loop);
+
+ segment_length_a = vect_vfa_segment_size (dr_a, vect_factor);
+ segment_length_b = vect_vfa_segment_size (dr_b, vect_factor);
+
+ if (vect_print_dump_info (REPORT_DR_DETAILS))
+ {
+ fprintf (vect_dump,
+ "create runtime check for data references ");
+ print_generic_expr (vect_dump, DR_REF (dr_a), TDF_SLIM);
+ fprintf (vect_dump, " and ");
+ print_generic_expr (vect_dump, DR_REF (dr_b), TDF_SLIM);
+ }
+
+
+ part_cond_expr =
+ fold_build2 (TRUTH_OR_EXPR, boolean_type_node,
+ fold_build2 (LT_EXPR, boolean_type_node,
+ fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (addr_base_a),
+ addr_base_a,
+ segment_length_a),
+ addr_base_b),
+ fold_build2 (LT_EXPR, boolean_type_node,
+ fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (addr_base_b),
+ addr_base_b,
+ segment_length_b),
+ addr_base_a));
+
+ if (*cond_expr)
+ *cond_expr = fold_build2 (TRUTH_AND_EXPR, boolean_type_node,
+ *cond_expr, part_cond_expr);
+ else
+ *cond_expr = part_cond_expr;
+ }
+ if (vect_print_dump_info (REPORT_VECTORIZED_LOOPS))
+ fprintf (vect_dump, "created %u versioning for alias checks.\n",
+ VEC_length (ddr_p, may_alias_ddrs));
+
+}
+
+
+/* Function vect_loop_versioning.
+
+ If the loop has data references that may or may not be aligned or/and
+ has data reference relations whose independence was not proven then
+ two versions of the loop need to be generated, one which is vectorized
+ and one which isn't. A test is then generated to control which of the
+ loops is executed. The test checks for the alignment of all of the
+ data references that may or may not be aligned. An additional
+ sequence of runtime tests is generated for each pairs of DDRs whose
+ independence was not proven. The vectorized version of loop is
+ executed only if both alias and alignment tests are passed.
+
+ The test generated to check which version of loop is executed
+ is modified to also check for profitability as indicated by the
+ cost model initially. */
+
+void
+vect_loop_versioning (loop_vec_info loop_vinfo)
+{
+ struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
+ struct loop *nloop;
+ tree cond_expr = NULL_TREE;
+ gimple_seq cond_expr_stmt_list = NULL;
+ basic_block condition_bb;
+ gimple_stmt_iterator gsi, cond_exp_gsi;
+ basic_block merge_bb;
+ basic_block new_exit_bb;
+ edge new_exit_e, e;
+ gimple orig_phi, new_phi;
+ tree arg;
+ unsigned prob = 4 * REG_BR_PROB_BASE / 5;
+ gimple_seq gimplify_stmt_list = NULL;
+ tree scalar_loop_iters = LOOP_VINFO_NITERS (loop_vinfo);
+ int min_profitable_iters = 0;
+ unsigned int th;
+
+ /* Get profitability threshold for vectorized loop. */
+ min_profitable_iters = LOOP_VINFO_COST_MODEL_MIN_ITERS (loop_vinfo);
+
+ th = conservative_cost_threshold (loop_vinfo,
+ min_profitable_iters);
+
+ cond_expr =
+ fold_build2 (GT_EXPR, boolean_type_node, scalar_loop_iters,
+ build_int_cst (TREE_TYPE (scalar_loop_iters), th));
+
+ cond_expr = force_gimple_operand (cond_expr, &cond_expr_stmt_list,
+ false, NULL_TREE);
+
+ if (VEC_length (gimple, LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo)))
+ vect_create_cond_for_align_checks (loop_vinfo, &cond_expr,
+ &cond_expr_stmt_list);
+
+ if (VEC_length (ddr_p, LOOP_VINFO_MAY_ALIAS_DDRS (loop_vinfo)))
+ vect_create_cond_for_alias_checks (loop_vinfo, &cond_expr,
+ &cond_expr_stmt_list);
+
+ cond_expr =
+ fold_build2 (NE_EXPR, boolean_type_node, cond_expr, integer_zero_node);
+ cond_expr =
+ force_gimple_operand (cond_expr, &gimplify_stmt_list, true, NULL_TREE);
+ gimple_seq_add_seq (&cond_expr_stmt_list, gimplify_stmt_list);
+
+ initialize_original_copy_tables ();
+ nloop = loop_version (loop, cond_expr, &condition_bb,
+ prob, prob, REG_BR_PROB_BASE - prob, true);
+ free_original_copy_tables();
+
+ /* Loop versioning violates an assumption we try to maintain during
+ vectorization - that the loop exit block has a single predecessor.
+ After versioning, the exit block of both loop versions is the same
+ basic block (i.e. it has two predecessors). Just in order to simplify
+ following transformations in the vectorizer, we fix this situation
+ here by adding a new (empty) block on the exit-edge of the loop,
+ with the proper loop-exit phis to maintain loop-closed-form. */
+
+ merge_bb = single_exit (loop)->dest;
+ gcc_assert (EDGE_COUNT (merge_bb->preds) == 2);
+ new_exit_bb = split_edge (single_exit (loop));
+ new_exit_e = single_exit (loop);
+ e = EDGE_SUCC (new_exit_bb, 0);
+
+ for (gsi = gsi_start_phis (merge_bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ orig_phi = gsi_stmt (gsi);
+ new_phi = create_phi_node (SSA_NAME_VAR (PHI_RESULT (orig_phi)),
+ new_exit_bb);
+ arg = PHI_ARG_DEF_FROM_EDGE (orig_phi, e);
+ add_phi_arg (new_phi, arg, new_exit_e);
+ SET_PHI_ARG_DEF (orig_phi, e->dest_idx, PHI_RESULT (new_phi));
+ }
+
+ /* End loop-exit-fixes after versioning. */
+
+ update_ssa (TODO_update_ssa);
+ if (cond_expr_stmt_list)
+ {
+ cond_exp_gsi = gsi_last_bb (condition_bb);
+ gsi_insert_seq_before (&cond_exp_gsi, cond_expr_stmt_list, GSI_SAME_STMT);
+ }
+}
+