/* If-conversion for vectorizer.
- Copyright (C) 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009
+ Free Software Foundation, Inc.
Contributed by Devang Patel <dpatel@apple.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 2, or (at your option) any later
+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
for more details.
You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING. If not, write to the Free
-Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
-02110-1301, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
-/* This pass implements tree level if-conversion transformation of loops.
- Initial goal is to help vectorizer vectorize loops with conditions.
+/* This pass implements a tree level if-conversion of loops. Its
+ initial goal is to help the vectorizer to vectorize loops with
+ conditions.
A short description of if-conversion:
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
-#include "c-common.h"
#include "flags.h"
#include "timevar.h"
-#include "varray.h"
#include "rtl.h"
#include "basic-block.h"
#include "diagnostic.h"
#include "tree-pass.h"
#include "target.h"
-/* local function prototypes */
-static unsigned int main_tree_if_conversion (void);
-static tree tree_if_convert_stmt (struct loop *loop, tree, tree,
- block_stmt_iterator *);
-static void tree_if_convert_cond_expr (struct loop *, tree, tree,
- block_stmt_iterator *);
-static bool if_convertible_phi_p (struct loop *, basic_block, tree);
-static bool if_convertible_gimple_modify_stmt_p (struct loop *, basic_block,
- tree);
-static bool if_convertible_stmt_p (struct loop *, basic_block, tree);
-static bool if_convertible_bb_p (struct loop *, basic_block, basic_block);
-static bool if_convertible_loop_p (struct loop *, bool);
-static void add_to_predicate_list (basic_block, tree);
-static tree add_to_dst_predicate_list (struct loop * loop, basic_block, tree, tree,
- block_stmt_iterator *);
-static void clean_predicate_lists (struct loop *loop);
-static basic_block find_phi_replacement_condition (struct loop *loop,
- basic_block, tree *,
- block_stmt_iterator *);
-static void replace_phi_with_cond_gimple_modify_stmt (tree, tree, basic_block,
- block_stmt_iterator *);
-static void process_phi_nodes (struct loop *);
-static void combine_blocks (struct loop *);
-static tree ifc_temp_var (tree, tree);
-static bool pred_blocks_visited_p (basic_block, bitmap *);
-static basic_block * get_loop_body_in_if_conv_order (const struct loop *loop);
-static bool bb_with_exit_edge_p (struct loop *, basic_block);
-
/* List of basic blocks in if-conversion-suitable order. */
static basic_block *ifc_bbs;
-/* Main entry point.
- Apply if-conversion to the LOOP. Return true if successful otherwise return
- false. If false is returned then loop remains unchanged.
- FOR_VECTORIZER is a boolean flag. It indicates whether if-conversion is used
- for vectorizer or not. If it is used for vectorizer, additional checks are
- used. (Vectorization checks are not yet implemented). */
+/* Make a new temp variable of type TYPE. Add GIMPLE_ASSIGN to assign EXP
+ to the new variable. */
-static bool
-tree_if_conversion (struct loop *loop, bool for_vectorizer)
+static gimple
+ifc_temp_var (tree type, tree exp)
{
- basic_block bb;
- block_stmt_iterator itr;
- tree cond;
- unsigned int i;
+ const char *name = "_ifc_";
+ tree var, new_name;
+ gimple stmt;
- ifc_bbs = NULL;
+ /* Create new temporary variable. */
+ var = create_tmp_var (type, name);
+ add_referenced_var (var);
- /* if-conversion is not appropriate for all loops. First, check if loop is
- if-convertible or not. */
- if (!if_convertible_loop_p (loop, for_vectorizer))
- {
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file,"-------------------------\n");
- if (ifc_bbs)
- {
- free (ifc_bbs);
- ifc_bbs = NULL;
- }
- free_dominance_info (CDI_POST_DOMINATORS);
- return false;
- }
+ /* Build new statement to assign EXP to new variable. */
+ stmt = gimple_build_assign (var, exp);
- cond = NULL_TREE;
+ /* Get SSA name for the new variable and set make new statement
+ its definition statement. */
+ new_name = make_ssa_name (var, stmt);
+ gimple_assign_set_lhs (stmt, new_name);
+ SSA_NAME_DEF_STMT (new_name) = stmt;
+ update_stmt (stmt);
- /* Do actual work now. */
- for (i = 0; i < loop->num_nodes; i++)
+ return stmt;
+}
+
+/* Add condition COND into predicate list of basic block BB. */
+
+static void
+add_to_predicate_list (basic_block bb, tree new_cond)
+{
+ tree cond = (tree) bb->aux;
+
+ if (cond)
+ cond = fold_build2_loc (EXPR_LOCATION (cond),
+ TRUTH_OR_EXPR, boolean_type_node,
+ unshare_expr (cond), new_cond);
+ else
+ cond = new_cond;
+
+ bb->aux = cond;
+}
+
+/* Add condition COND into BB's predicate list. PREV_COND is
+ existing condition. */
+
+static tree
+add_to_dst_predicate_list (struct loop *loop, edge e,
+ tree prev_cond, tree cond,
+ gimple_stmt_iterator *gsi)
+{
+ tree new_cond = NULL_TREE;
+
+ if (!flow_bb_inside_loop_p (loop, e->dest))
+ return NULL_TREE;
+
+ if (prev_cond == boolean_true_node || !prev_cond)
+ new_cond = unshare_expr (cond);
+ else
{
- bb = ifc_bbs [i];
+ tree tmp;
+ gimple tmp_stmt = NULL;
- /* Update condition using predicate list. */
- cond = bb->aux;
+ prev_cond = force_gimple_operand_gsi (gsi, unshare_expr (prev_cond),
+ true, NULL, true, GSI_SAME_STMT);
- /* Process all statements in this basic block.
- Remove conditional expression, if any, and annotate
- destination basic block(s) appropriately. */
- for (itr = bsi_start (bb); !bsi_end_p (itr); /* empty */)
- {
- tree t = bsi_stmt (itr);
- cond = tree_if_convert_stmt (loop, t, cond, &itr);
- if (!bsi_end_p (itr))
- bsi_next (&itr);
- }
+ cond = force_gimple_operand_gsi (gsi, unshare_expr (cond),
+ true, NULL, true, GSI_SAME_STMT);
- /* If current bb has only one successor, then consider it as an
- unconditional goto. */
- if (single_succ_p (bb))
- {
- basic_block bb_n = single_succ (bb);
- if (cond != NULL_TREE)
- add_to_predicate_list (bb_n, cond);
- cond = NULL_TREE;
- }
+ /* Add the condition to aux field of the edge. In case edge
+ destination is a PHI node, this condition will be ANDed with
+ block predicate to construct complete condition. */
+ e->aux = cond;
+
+ tmp = build2 (TRUTH_AND_EXPR, boolean_type_node,
+ unshare_expr (prev_cond), cond);
+ tmp_stmt = ifc_temp_var (boolean_type_node, tmp);
+ gsi_insert_before (gsi, tmp_stmt, GSI_SAME_STMT);
+ new_cond = gimple_assign_lhs (tmp_stmt);
}
- /* Now, all statements are if-converted and basic blocks are
- annotated appropriately. Combine all basic block into one huge
- basic block. */
- combine_blocks (loop);
+ add_to_predicate_list (e->dest, new_cond);
+ return new_cond;
+}
- /* clean up */
- clean_predicate_lists (loop);
- free (ifc_bbs);
- ifc_bbs = NULL;
+/* Return true if one of the basic block BB edge is exit of LOOP. */
- return true;
+static bool
+bb_with_exit_edge_p (struct loop *loop, basic_block bb)
+{
+ edge e;
+ edge_iterator ei;
+ bool exit_edge_found = false;
+
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ if (loop_exit_edge_p (loop, e))
+ {
+ exit_edge_found = true;
+ break;
+ }
+
+ return exit_edge_found;
+}
+
+/* STMT is a GIMPLE_COND. Update two destination's predicate list.
+ Remove COND_EXPR, if it is not the loop exit condition. Otherwise
+ update loop exit condition appropriately. GSI is the iterator
+ used to traverse statement list. STMT is part of loop LOOP. */
+
+static void
+tree_if_convert_cond_stmt (struct loop *loop, gimple stmt, tree cond,
+ gimple_stmt_iterator *gsi)
+{
+ tree c2;
+ edge true_edge, false_edge;
+ location_t loc = gimple_location (stmt);
+ tree c = fold_build2_loc (loc, gimple_cond_code (stmt), boolean_type_node,
+ gimple_cond_lhs (stmt), gimple_cond_rhs (stmt));
+
+ extract_true_false_edges_from_block (gimple_bb (stmt),
+ &true_edge, &false_edge);
+
+ /* Add new condition into destination's predicate list. */
+
+ /* If C is true, then TRUE_EDGE is taken. */
+ add_to_dst_predicate_list (loop, true_edge, cond, c, gsi);
+
+ /* If C is false, then FALSE_EDGE is taken. */
+ c2 = invert_truthvalue_loc (loc, unshare_expr (c));
+ add_to_dst_predicate_list (loop, false_edge, cond, c2, gsi);
+
+ /* Now this conditional statement is redundant. Remove it.
+ But, do not remove exit condition! Update exit condition
+ using new condition. */
+ if (!bb_with_exit_edge_p (loop, gimple_bb (stmt)))
+ {
+ gsi_remove (gsi, true);
+ cond = NULL_TREE;
+ }
+ return;
}
-/* if-convert stmt T which is part of LOOP.
- If T is a GIMPLE_MODIFY_STMT than it is converted into conditional modify
+/* If-convert stmt T which is part of LOOP.
+ If T is a GIMPLE_ASSIGN then it is converted into conditional modify
expression using COND. For conditional expressions, add condition in the
destination basic block's predicate list and remove conditional
- expression itself. BSI is the iterator used to traverse statements of
- loop. It is used here when it is required to delete current statement. */
+ expression itself. BSI is the iterator used to traverse statements of
+ loop. It is used here when it is required to delete current statement. */
static tree
-tree_if_convert_stmt (struct loop * loop, tree t, tree cond,
- block_stmt_iterator *bsi)
+tree_if_convert_stmt (struct loop *loop, gimple t, tree cond,
+ gimple_stmt_iterator *gsi)
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "------if-convert stmt\n");
- print_generic_stmt (dump_file, t, TDF_SLIM);
+ print_gimple_stmt (dump_file, t, 0, TDF_SLIM);
print_generic_stmt (dump_file, cond, TDF_SLIM);
}
- switch (TREE_CODE (t))
+ switch (gimple_code (t))
{
/* Labels are harmless here. */
- case LABEL_EXPR:
+ case GIMPLE_LABEL:
break;
- case GIMPLE_MODIFY_STMT:
- /* This GIMPLE_MODIFY_STMT is killing previous value of LHS. Appropriate
- value will be selected by PHI node based on condition. It is possible
+ case GIMPLE_DEBUG:
+ /* ??? Should there be conditional GIMPLE_DEBUG_BINDs? */
+ if (gimple_debug_bind_p (gsi_stmt (*gsi)))
+ {
+ gimple_debug_bind_reset_value (gsi_stmt (*gsi));
+ update_stmt (gsi_stmt (*gsi));
+ }
+ break;
+
+ case GIMPLE_ASSIGN:
+ /* This GIMPLE_ASSIGN is killing previous value of LHS. Appropriate
+ value will be selected by PHI node based on condition. It is possible
that before this transformation, PHI nodes was selecting default
- value and now it will use this new value. This is OK because it does
- not change validity the program. */
+ value and now it will use this new value. This is OK because it does
+ not change the validity of the program. */
break;
- case COND_EXPR:
+ case GIMPLE_COND:
/* Update destination blocks' predicate list and remove this
condition expression. */
- tree_if_convert_cond_expr (loop, t, cond, bsi);
+ tree_if_convert_cond_stmt (loop, t, cond, gsi);
cond = NULL_TREE;
break;
return cond;
}
-/* STMT is COND_EXPR. Update two destination's predicate list.
- Remove COND_EXPR, if it is not the loop exit condition. Otherwise
- update loop exit condition appropriately. BSI is the iterator
- used to traverse statement list. STMT is part of loop LOOP. */
-
-static void
-tree_if_convert_cond_expr (struct loop *loop, tree stmt, tree cond,
- block_stmt_iterator *bsi)
-{
- tree c, c2;
- edge true_edge, false_edge;
-
- gcc_assert (TREE_CODE (stmt) == COND_EXPR);
-
- c = COND_EXPR_COND (stmt);
-
- extract_true_false_edges_from_block (bb_for_stmt (stmt),
- &true_edge, &false_edge);
-
- /* Add new condition into destination's predicate list. */
-
- /* If 'c' is true then TRUE_EDGE is taken. */
- add_to_dst_predicate_list (loop, true_edge->dest, cond,
- unshare_expr (c), bsi);
-
- /* If 'c' is false then FALSE_EDGE is taken. */
- c2 = invert_truthvalue (unshare_expr (c));
- add_to_dst_predicate_list (loop, false_edge->dest, cond, c2, bsi);
-
- /* Now this conditional statement is redundant. Remove it.
- But, do not remove exit condition! Update exit condition
- using new condition. */
- if (!bb_with_exit_edge_p (loop, bb_for_stmt (stmt)))
- {
- bsi_remove (bsi, true);
- cond = NULL_TREE;
- }
- return;
-}
-
-/* Return true, iff PHI is if-convertible. PHI is part of loop LOOP
+/* Return true, iff PHI is if-convertible. PHI is part of loop LOOP
and it belongs to basic block BB.
PHI is not if-convertible
- - if it has more than 2 arguments.
- - Virtual PHI is immediately used in another PHI node. */
+ - if it has more than 2 arguments,
+ - virtual PHI is immediately used in another PHI node,
+ - virtual PHI on BB other than header. */
static bool
-if_convertible_phi_p (struct loop *loop, basic_block bb, tree phi)
+if_convertible_phi_p (struct loop *loop, basic_block bb, gimple phi)
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "-------------------------\n");
- print_generic_stmt (dump_file, phi, TDF_SLIM);
+ print_gimple_stmt (dump_file, phi, 0, TDF_SLIM);
}
- if (bb != loop->header && PHI_NUM_ARGS (phi) != 2)
+ if (bb != loop->header && gimple_phi_num_args (phi) != 2)
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "More than two phi node args.\n");
return false;
}
- if (!is_gimple_reg (SSA_NAME_VAR (PHI_RESULT (phi))))
+ if (!is_gimple_reg (SSA_NAME_VAR (gimple_phi_result (phi))))
{
imm_use_iterator imm_iter;
use_operand_p use_p;
- FOR_EACH_IMM_USE_FAST (use_p, imm_iter, PHI_RESULT (phi))
+
+ if (bb != loop->header)
{
- if (TREE_CODE (USE_STMT (use_p)) == PHI_NODE)
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Virtual phi not on loop header.\n");
+ return false;
+ }
+ FOR_EACH_IMM_USE_FAST (use_p, imm_iter, gimple_phi_result (phi))
+ {
+ if (gimple_code (USE_STMT (use_p)) == GIMPLE_PHI)
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "Difficult to handle this virtual phi.\n");
return true;
}
-/* Return true, if M_EXPR is if-convertible.
- GIMPLE_MODIFY_STMT is not if-convertible if,
- - It is not movable.
- - It could trap.
+/* Return true when STMT is if-convertible.
+
+ GIMPLE_ASSIGN statement is not if-convertible if,
+ - it is not movable,
+ - it could trap,
- LHS is not var decl.
- GIMPLE_MODIFY_STMT is part of block BB, which is inside loop LOOP.
-*/
+ GIMPLE_ASSIGN is part of block BB, which is inside loop LOOP. */
static bool
-if_convertible_gimple_modify_stmt_p (struct loop *loop, basic_block bb,
- tree m_expr)
+if_convertible_gimple_assign_stmt_p (struct loop *loop, basic_block bb,
+ gimple stmt)
{
+ tree lhs = gimple_assign_lhs (stmt);
+
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "-------------------------\n");
- print_generic_stmt (dump_file, m_expr, TDF_SLIM);
+ print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
}
- /* Be conservative and do not handle immovable expressions. */
- if (movement_possibility (m_expr) == MOVE_IMPOSSIBLE)
+ /* Some of these constrains might be too conservative. */
+ if (stmt_ends_bb_p (stmt)
+ || gimple_has_volatile_ops (stmt)
+ || (TREE_CODE (lhs) == SSA_NAME
+ && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
+ || gimple_has_side_effects (stmt))
{
if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "stmt is movable. Don't take risk\n");
+ fprintf (dump_file, "stmt not suitable for ifcvt\n");
return false;
}
/* See if it needs speculative loading or not. */
if (bb != loop->header
- && tree_could_trap_p (GIMPLE_STMT_OPERAND (m_expr, 1)))
+ && gimple_assign_rhs_could_trap_p (stmt))
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "tree could trap...\n");
return false;
}
- if (TREE_CODE (GIMPLE_STMT_OPERAND (m_expr, 1)) == CALL_EXPR)
- {
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "CALL_EXPR \n");
- return false;
- }
-
- if (TREE_CODE (GIMPLE_STMT_OPERAND (m_expr, 0)) != SSA_NAME
+ if (TREE_CODE (lhs) != SSA_NAME
&& bb != loop->header
&& !bb_with_exit_edge_p (loop, bb))
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "LHS is not var\n");
- print_generic_stmt (dump_file, m_expr, TDF_SLIM);
+ print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
}
return false;
}
-
return true;
}
/* Return true, iff STMT is if-convertible.
Statement is if-convertible if,
- - It is if-convertible GIMPLE_MODIFY_STMT
- - IT is LABEL_EXPR or COND_EXPR.
+ - it is if-convertible GIMPLE_ASSGIN,
+ - it is GIMPLE_LABEL or GIMPLE_COND.
STMT is inside block BB, which is inside loop LOOP. */
static bool
-if_convertible_stmt_p (struct loop *loop, basic_block bb, tree stmt)
+if_convertible_stmt_p (struct loop *loop, basic_block bb, gimple stmt)
{
- switch (TREE_CODE (stmt))
+ switch (gimple_code (stmt))
{
- case LABEL_EXPR:
- break;
+ case GIMPLE_LABEL:
+ case GIMPLE_DEBUG:
+ case GIMPLE_COND:
+ return true;
- case GIMPLE_MODIFY_STMT:
-
- if (!if_convertible_gimple_modify_stmt_p (loop, bb, stmt))
- return false;
- break;
-
- case COND_EXPR:
- break;
+ case GIMPLE_ASSIGN:
+ return if_convertible_gimple_assign_stmt_p (loop, bb, stmt);
default:
/* Don't know what to do with 'em so don't do anything. */
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "don't know what to do\n");
- print_generic_stmt (dump_file, stmt, TDF_SLIM);
+ print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
}
return false;
break;
/* Return true, iff BB is if-convertible.
Note: This routine does _not_ check basic block statements and phis.
- Basic block is not if-convertible if,
- - Basic block is non-empty and it is after exit block (in BFS order).
- - Basic block is after exit block but before latch.
- - Basic block edge(s) is not normal.
+ Basic block is not if-convertible if:
+ - basic block is non-empty and it is after exit block (in BFS order),
+ - basic block is after exit block but before latch,
+ - basic block edge(s) is not normal.
EXIT_BB_SEEN is true if basic block with exit edge is already seen.
BB is inside loop LOOP. */
fprintf (dump_file, "non empty basic block after exit bb\n");
return false;
}
- else if (bb == loop->latch
+ else if (bb == loop->latch
&& bb != exit_bb
&& !dominated_by_p (CDI_DOMINATORS, bb, exit_bb))
{
return true;
}
+/* Return TRUE iff, all pred blocks of BB are visited.
+ Bitmap VISITED keeps history of visited blocks. */
+
+static bool
+pred_blocks_visited_p (basic_block bb, bitmap *visited)
+{
+ edge e;
+ edge_iterator ei;
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ if (!bitmap_bit_p (*visited, e->src->index))
+ return false;
+
+ return true;
+}
+
+/* Get body of a LOOP in suitable order for if-conversion. It is
+ caller's responsibility to deallocate basic block list.
+ If-conversion suitable order is, breadth first sort (BFS) order
+ with an additional constraint: select a block only if all its
+ predecessors are already selected. */
+
+static basic_block *
+get_loop_body_in_if_conv_order (const struct loop *loop)
+{
+ basic_block *blocks, *blocks_in_bfs_order;
+ basic_block bb;
+ bitmap visited;
+ unsigned int index = 0;
+ unsigned int visited_count = 0;
+
+ gcc_assert (loop->num_nodes);
+ gcc_assert (loop->latch != EXIT_BLOCK_PTR);
+
+ blocks = XCNEWVEC (basic_block, loop->num_nodes);
+ visited = BITMAP_ALLOC (NULL);
+
+ blocks_in_bfs_order = get_loop_body_in_bfs_order (loop);
+
+ index = 0;
+ while (index < loop->num_nodes)
+ {
+ bb = blocks_in_bfs_order [index];
+
+ if (bb->flags & BB_IRREDUCIBLE_LOOP)
+ {
+ free (blocks_in_bfs_order);
+ BITMAP_FREE (visited);
+ free (blocks);
+ return NULL;
+ }
+
+ if (!bitmap_bit_p (visited, bb->index))
+ {
+ if (pred_blocks_visited_p (bb, &visited)
+ || bb == loop->header)
+ {
+ /* This block is now visited. */
+ bitmap_set_bit (visited, bb->index);
+ blocks[visited_count++] = bb;
+ }
+ }
+
+ index++;
+
+ if (index == loop->num_nodes
+ && visited_count != loop->num_nodes)
+ /* Not done yet. */
+ index = 0;
+ }
+ free (blocks_in_bfs_order);
+ BITMAP_FREE (visited);
+ return blocks;
+}
+
/* Return true, iff LOOP is if-convertible.
- LOOP is if-convertible if,
- - It is innermost.
- - It has two or more basic blocks.
- - It has only one exit.
- - Loop header is not the exit edge.
- - If its basic blocks and phi nodes are if convertible. See above for
+ LOOP is if-convertible if:
+ - it is innermost,
+ - it has two or more basic blocks,
+ - it has only one exit,
+ - loop header is not the exit edge,
+ - if its basic blocks and phi nodes are if convertible. See above for
more info.
- FOR_VECTORIZER enables vectorizer specific checks. For example, support
- for vector conditions, data dependency checks etc.. (Not implemented yet). */
+ FOR_VECTORIZER enables vectorizer specific checks, for example, support
+ for vector conditions, data dependency checks, etc.
+ (Not implemented yet). */
+
+static bool
+pred_blocks_visited_p (basic_block bb, bitmap *visited)
+{
+ edge e;
+ edge_iterator ei;
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ if (!bitmap_bit_p (*visited, e->src->index))
+ return false;
+
+ return true;
+}
+
+/* Get body of a LOOP in suitable order for if-conversion. It is
+ caller's responsibility to deallocate basic block list.
+ If-conversion suitable order is, breadth first sort (BFS) order
+ with an additional constraint: select a block only if all its
+ predecessors are already selected. */
+
+static basic_block *
+get_loop_body_in_if_conv_order (const struct loop *loop)
+{
+ basic_block *blocks, *blocks_in_bfs_order;
+ basic_block bb;
+ bitmap visited;
+ unsigned int index = 0;
+ unsigned int visited_count = 0;
+
+ gcc_assert (loop->num_nodes);
+ gcc_assert (loop->latch != EXIT_BLOCK_PTR);
+
+ blocks = XCNEWVEC (basic_block, loop->num_nodes);
+ visited = BITMAP_ALLOC (NULL);
+
+ blocks_in_bfs_order = get_loop_body_in_bfs_order (loop);
+
+ index = 0;
+ while (index < loop->num_nodes)
+ {
+ bb = blocks_in_bfs_order [index];
+
+ if (bb->flags & BB_IRREDUCIBLE_LOOP)
+ {
+ free (blocks_in_bfs_order);
+ BITMAP_FREE (visited);
+ free (blocks);
+ return NULL;
+ }
+
+ if (!bitmap_bit_p (visited, bb->index))
+ {
+ if (pred_blocks_visited_p (bb, &visited)
+ || bb == loop->header)
+ {
+ /* This block is now visited. */
+ bitmap_set_bit (visited, bb->index);
+ blocks[visited_count++] = bb;
+ }
+ }
+
+ index++;
+
+ if (index == loop->num_nodes
+ && visited_count != loop->num_nodes)
+ /* Not done yet. */
+ index = 0;
+ }
+ free (blocks_in_bfs_order);
+ BITMAP_FREE (visited);
+ return blocks;
+}
+
+/* Return true when LOOP is if-convertible.
+ LOOP is if-convertible if:
+ - it is innermost,
+ - it has two or more basic blocks,
+ - it has only one exit,
+ - loop header is not the exit edge,
+ - if its basic blocks and phi nodes are if convertible. */
static bool
-if_convertible_loop_p (struct loop *loop, bool for_vectorizer ATTRIBUTE_UNUSED)
+if_convertible_loop_p (struct loop *loop)
{
- tree phi;
basic_block bb;
- block_stmt_iterator itr;
+ gimple_stmt_iterator itr;
unsigned int i;
edge e;
edge_iterator ei;
if (!if_convertible_bb_p (loop, bb, exit_bb))
return false;
- /* Check statements. */
- for (itr = bsi_start (bb); !bsi_end_p (itr); bsi_next (&itr))
- if (!if_convertible_stmt_p (loop, bb, bsi_stmt (itr)))
+ for (itr = gsi_start_bb (bb); !gsi_end_p (itr); gsi_next (&itr))
+ if (!if_convertible_stmt_p (loop, bb, gsi_stmt (itr)))
return false;
- /* ??? Check data dependency for vectorizer. */
- /* What about phi nodes ? */
- for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
- if (!if_convertible_phi_p (loop, bb, phi))
+ itr = gsi_start_phis (bb);
+
+ if (!gsi_end_p (itr))
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ e->aux = NULL;
+
+ for (; !gsi_end_p (itr); gsi_next (&itr))
+ if (!if_convertible_phi_p (loop, bb, gsi_stmt (itr)))
return false;
if (bb_with_exit_edge_p (loop, bb))
exit_bb = bb;
}
- /* OK. Did not find any potential issues so go ahead in if-convert
- this loop. Now there is no looking back. */
if (dump_file)
fprintf (dump_file,"Applying if-conversion\n");
return true;
}
-/* Add condition COND into predicate list of basic block BB. */
-
-static void
-add_to_predicate_list (basic_block bb, tree new_cond)
-{
- tree cond = bb->aux;
-
- if (cond)
- cond = fold_build2 (TRUTH_OR_EXPR, boolean_type_node,
- unshare_expr (cond), new_cond);
- else
- cond = new_cond;
-
- bb->aux = cond;
-}
-
-/* Add condition COND into BB's predicate list. PREV_COND is
- existing condition. */
-
-static tree
-add_to_dst_predicate_list (struct loop * loop, basic_block bb,
- tree prev_cond, tree cond,
- block_stmt_iterator *bsi)
-{
- tree new_cond = NULL_TREE;
-
- if (!flow_bb_inside_loop_p (loop, bb))
- return NULL_TREE;
-
- if (prev_cond == boolean_true_node || !prev_cond)
- new_cond = unshare_expr (cond);
- else
- {
- tree tmp;
- tree tmp_stmt = NULL_TREE;
- tree tmp_stmts1 = NULL_TREE;
- tree tmp_stmts2 = NULL_TREE;
- prev_cond = force_gimple_operand (unshare_expr (prev_cond),
- &tmp_stmts1, true, NULL);
- if (tmp_stmts1)
- bsi_insert_before (bsi, tmp_stmts1, BSI_SAME_STMT);
-
- cond = force_gimple_operand (unshare_expr (cond),
- &tmp_stmts2, true, NULL);
- if (tmp_stmts2)
- bsi_insert_before (bsi, tmp_stmts2, BSI_SAME_STMT);
-
- /* new_cond == prev_cond AND cond */
- tmp = build2 (TRUTH_AND_EXPR, boolean_type_node,
- unshare_expr (prev_cond), cond);
- tmp_stmt = ifc_temp_var (boolean_type_node, tmp);
- bsi_insert_before (bsi, tmp_stmt, BSI_SAME_STMT);
- new_cond = GIMPLE_STMT_OPERAND (tmp_stmt, 0);
- }
- add_to_predicate_list (bb, new_cond);
- return new_cond;
-}
-
-/* During if-conversion aux field from basic block is used to hold predicate
- list. Clean each basic block's predicate list for the given LOOP. */
+/* During if-conversion aux field from basic block structure is used to hold
+ predicate list. Clean each basic block's predicate list for the given LOOP.
+ Also clean aux field of successor edges, used to hold true and false
+ condition from conditional expression. */
static void
clean_predicate_lists (struct loop *loop)
{
basic_block *bb;
unsigned int i;
+ edge e;
+ edge_iterator ei;
+
bb = get_loop_body (loop);
for (i = 0; i < loop->num_nodes; i++)
- bb[i]->aux = NULL;
-
+ {
+ bb[i]->aux = NULL;
+ FOR_EACH_EDGE (e, ei, bb[i]->succs)
+ e->aux = NULL;
+ }
free (bb);
}
/* Basic block BB has two predecessors. Using predecessor's aux field, set
- appropriate condition COND for the PHI node replacement. Return true block
+ appropriate condition COND for the PHI node replacement. Return true block
whose phi arguments are selected when cond is true. */
static basic_block
-find_phi_replacement_condition (struct loop *loop,
+find_phi_replacement_condition (struct loop *loop,
basic_block bb, tree *cond,
- block_stmt_iterator *bsi)
+ gimple_stmt_iterator *gsi)
{
- basic_block first_bb = NULL;
- basic_block second_bb = NULL;
- tree tmp_cond, new_stmts;
+ edge first_edge, second_edge;
+ tree tmp_cond;
gcc_assert (EDGE_COUNT (bb->preds) == 2);
- first_bb = (EDGE_PRED (bb, 0))->src;
- second_bb = (EDGE_PRED (bb, 1))->src;
+ first_edge = EDGE_PRED (bb, 0);
+ second_edge = EDGE_PRED (bb, 1);
/* Use condition based on following criteria:
1)
S2: x = c ? b : a;
S2 is preferred over S1. Make 'b' first_bb and use its condition.
-
+
2) Do not make loop header first_bb.
3)
S3: x = (c == d) ? b : a;
- S3 is preferred over S1 and S2*, Make 'b' first_bb and use
- its condition.
+ S3 is preferred over S1 and S2*, Make 'b' first_bb and use
+ its condition.
4) If pred B is dominated by pred A then use pred B's condition.
See PR23115. */
/* Select condition that is not TRUTH_NOT_EXPR. */
- tmp_cond = first_bb->aux;
+ tmp_cond = (tree) (first_edge->src)->aux;
+ gcc_assert (tmp_cond);
+
if (TREE_CODE (tmp_cond) == TRUTH_NOT_EXPR)
{
- basic_block tmp_bb;
- tmp_bb = first_bb;
- first_bb = second_bb;
- second_bb = tmp_bb;
+ edge tmp_edge;
+
+ tmp_edge = first_edge;
+ first_edge = second_edge;
+ second_edge = tmp_edge;
}
/* Check if FIRST_BB is loop header or not and make sure that
FIRST_BB does not dominate SECOND_BB. */
- if (first_bb == loop->header
- || dominated_by_p (CDI_DOMINATORS, second_bb, first_bb))
+ if (first_edge->src == loop->header
+ || dominated_by_p (CDI_DOMINATORS,
+ second_edge->src, first_edge->src))
{
- tmp_cond = second_bb->aux;
- if (TREE_CODE (tmp_cond) == TRUTH_NOT_EXPR)
- {
- /* Select non loop header condition but do not switch basic blocks. */
- *cond = invert_truthvalue (unshare_expr (tmp_cond));
- }
+ *cond = (tree) (second_edge->src)->aux;
+
+ /* If there is a condition on an incoming edge, add it to the
+ incoming bb predicate. */
+ if (second_edge->aux)
+ *cond = build2 (TRUTH_AND_EXPR, boolean_type_node,
+ *cond, (tree) second_edge->aux);
+
+ if (TREE_CODE (*cond) == TRUTH_NOT_EXPR)
+ *cond = invert_truthvalue (*cond);
else
- {
- /* Select non loop header condition. */
- first_bb = second_bb;
- *cond = first_bb->aux;
- }
+ /* Select non loop header bb. */
+ first_edge = second_edge;
}
else
- /* FIRST_BB is not loop header */
- *cond = first_bb->aux;
-
- /* Create temp. for the condition. Vectorizer prefers to have gimple
- value as condition. Various targets use different means to communicate
- condition in vector compare operation. Using gimple value allows compiler
- to emit vector compare and select RTL without exposing compare's result. */
- *cond = force_gimple_operand (*cond, &new_stmts, false, NULL_TREE);
- if (new_stmts)
- bsi_insert_before (bsi, new_stmts, BSI_SAME_STMT);
+ {
+ *cond = (tree) (first_edge->src)->aux;
+
+ /* If there is a condition on an incoming edge, add it to the
+ incoming bb predicate. */
+ if (first_edge->aux)
+ *cond = build2 (TRUTH_AND_EXPR, boolean_type_node,
+ *cond, (tree) first_edge->aux);
+ }
+
+ /* Gimplify the condition: the vectorizer prefers to have gimple
+ values as conditions. Various targets use different means to
+ communicate conditions in vector compare operations. Using a
+ gimple value allows the compiler to emit vector compare and
+ select RTL without exposing compare's result. */
+ *cond = force_gimple_operand_gsi (gsi, unshare_expr (*cond),
+ false, NULL_TREE,
+ true, GSI_SAME_STMT);
if (!is_gimple_reg (*cond) && !is_gimple_condexpr (*cond))
{
- tree new_stmt;
+ gimple new_stmt;
new_stmt = ifc_temp_var (TREE_TYPE (*cond), unshare_expr (*cond));
- bsi_insert_before (bsi, new_stmt, BSI_SAME_STMT);
- *cond = GIMPLE_STMT_OPERAND (new_stmt, 0);
+ gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT);
+ *cond = gimple_assign_lhs (new_stmt);
}
gcc_assert (*cond);
- return first_bb;
+ return first_edge->src;
}
+/* Replace PHI node with conditional modify expr using COND. This
+ routine does not handle PHI nodes with more than two arguments.
-/* Replace PHI node with conditional modify expr using COND.
- This routine does not handle PHI nodes with more than two arguments.
For example,
S1: A = PHI <x1(1), x2(5)
is converted into,
S2: A = cond ? x1 : x2;
- S2 is inserted at the top of basic block's statement list.
- When COND is true, phi arg from TRUE_BB is selected.
-*/
+
+ The generated code is inserted at GSI that points to the top of
+ basic block's statement list. When COND is true, phi arg from
+ TRUE_BB is selected. */
static void
-replace_phi_with_cond_gimple_modify_stmt (tree phi, tree cond,
+replace_phi_with_cond_gimple_assign_stmt (gimple phi, tree cond,
basic_block true_bb,
- block_stmt_iterator *bsi)
+ gimple_stmt_iterator *gsi)
{
- tree new_stmt;
+ gimple new_stmt;
basic_block bb;
tree rhs;
tree arg_0, arg_1;
- gcc_assert (TREE_CODE (phi) == PHI_NODE);
-
- /* If this is not filtered earlier, then now it is too late. */
- gcc_assert (PHI_NUM_ARGS (phi) == 2);
-
- /* Find basic block and initialize iterator. */
- bb = bb_for_stmt (phi);
+ gcc_assert (gimple_code (phi) == GIMPLE_PHI
+ && gimple_phi_num_args (phi) == 2);
- new_stmt = NULL_TREE;
- arg_0 = NULL_TREE;
- arg_1 = NULL_TREE;
+ bb = gimple_bb (phi);
/* Use condition that is not TRUTH_NOT_EXPR in conditional modify expr. */
if (EDGE_PRED (bb, 1)->src == true_bb)
{
- arg_0 = PHI_ARG_DEF (phi, 1);
- arg_1 = PHI_ARG_DEF (phi, 0);
+ arg_0 = gimple_phi_arg_def (phi, 1);
+ arg_1 = gimple_phi_arg_def (phi, 0);
}
else
{
- arg_0 = PHI_ARG_DEF (phi, 0);
- arg_1 = PHI_ARG_DEF (phi, 1);
+ arg_0 = gimple_phi_arg_def (phi, 0);
+ arg_1 = gimple_phi_arg_def (phi, 1);
}
/* Build new RHS using selected condition and arguments. */
unshare_expr (cond), unshare_expr (arg_0),
unshare_expr (arg_1));
- /* Create new MODIFY expression using RHS. */
- new_stmt = build2 (GIMPLE_MODIFY_STMT, TREE_TYPE (PHI_RESULT (phi)),
- unshare_expr (PHI_RESULT (phi)), rhs);
-
- /* Make new statement definition of the original phi result. */
- SSA_NAME_DEF_STMT (PHI_RESULT (phi)) = new_stmt;
-
- /* Insert using iterator. */
- bsi_insert_before (bsi, new_stmt, BSI_SAME_STMT);
+ new_stmt = gimple_build_assign (unshare_expr (PHI_RESULT (phi)), rhs);
+ SSA_NAME_DEF_STMT (gimple_phi_result (phi)) = new_stmt;
+ gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT);
update_stmt (new_stmt);
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "new phi replacement stmt\n");
- print_generic_stmt (dump_file, new_stmt, TDF_SLIM);
+ print_gimple_stmt (dump_file, new_stmt, 0, TDF_SLIM);
}
}
-/* Process phi nodes for the given LOOP. Replace phi nodes with cond
- modify expr. */
+/* Process phi nodes for the given LOOP. Replace phi nodes with
+ conditional modify expressions. */
static void
process_phi_nodes (struct loop *loop)
unsigned int orig_loop_num_nodes = loop->num_nodes;
unsigned int i;
- /* Replace phi nodes with cond. modify expr. */
for (i = 1; i < orig_loop_num_nodes; i++)
{
- tree phi, cond;
- block_stmt_iterator bsi;
+ gimple phi;
+ tree cond = NULL_TREE;
+ gimple_stmt_iterator gsi, phi_gsi;
basic_block true_bb = NULL;
bb = ifc_bbs[i];
if (bb == loop->header)
continue;
- phi = phi_nodes (bb);
- bsi = bsi_after_labels (bb);
+ phi_gsi = gsi_start_phis (bb);
+ gsi = gsi_after_labels (bb);
- /* BB has two predecessors. Using predecessor's aux field, set
+ /* BB has two predecessors. Using predecessor's aux field, set
appropriate condition for the PHI node replacement. */
- if (phi)
- true_bb = find_phi_replacement_condition (loop, bb, &cond, &bsi);
+ if (!gsi_end_p (phi_gsi))
+ true_bb = find_phi_replacement_condition (loop, bb, &cond, &gsi);
- while (phi)
+ while (!gsi_end_p (phi_gsi))
{
- tree next = PHI_CHAIN (phi);
- replace_phi_with_cond_gimple_modify_stmt (phi, cond, true_bb, &bsi);
+ phi = gsi_stmt (phi_gsi);
+ replace_phi_with_cond_gimple_assign_stmt (phi, cond, true_bb, &gsi);
release_phi_node (phi);
- phi = next;
+ gsi_next (&phi_gsi);
}
- bb->phi_nodes = NULL;
+ set_phi_nodes (bb, NULL);
}
- return;
}
-/* Combine all basic block from the given LOOP into one or two super
- basic block. Replace PHI nodes with conditional modify expression. */
+/* Combine all the basic blocks from LOOP into one or two super basic
+ blocks. Replace PHI nodes with conditional modify expressions. */
static void
combine_blocks (struct loop *loop)
/* Process phi nodes to prepare blocks for merge. */
process_phi_nodes (loop);
- /* Merge basic blocks. First remove all the edges in the loop, except
- for those from the exit block. */
+ /* Merge basic blocks: first remove all the edges in the loop,
+ except for those from the exit block. */
exit_bb = NULL;
for (i = 0; i < orig_loop_num_nodes; i++)
{
{
if (exit_bb != loop->header)
{
- /* Connect this node with loop header. */
+ /* Connect this node to loop header. */
make_edge (loop->header, exit_bb, EDGE_FALLTHRU);
set_immediate_dominator (CDI_DOMINATORS, exit_bb, loop->header);
}
}
else
{
- /* If the loop does not have exit then reconnect header and latch. */
+ /* If the loop does not have an exit, reconnect header and latch. */
make_edge (loop->header, loop->latch, EDGE_FALLTHRU);
set_immediate_dominator (CDI_DOMINATORS, loop->latch, loop->header);
}
merge_target_bb = loop->header;
for (i = 1; i < orig_loop_num_nodes; i++)
{
- block_stmt_iterator bsi;
- tree_stmt_iterator last;
+ gimple_stmt_iterator gsi;
+ gimple_stmt_iterator last;
bb = ifc_bbs[i];
continue;
/* Remove labels and make stmts member of loop->header. */
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); )
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); )
{
- if (TREE_CODE (bsi_stmt (bsi)) == LABEL_EXPR)
- bsi_remove (&bsi, true);
+ if (gimple_code (gsi_stmt (gsi)) == GIMPLE_LABEL)
+ gsi_remove (&gsi, true);
else
{
- set_bb_for_stmt (bsi_stmt (bsi), merge_target_bb);
- bsi_next (&bsi);
+ gimple_set_bb (gsi_stmt (gsi), merge_target_bb);
+ gsi_next (&gsi);
}
}
/* Update stmt list. */
- last = tsi_last (merge_target_bb->stmt_list);
- tsi_link_after (&last, bb->stmt_list, TSI_NEW_STMT);
- bb->stmt_list = alloc_stmt_list ();
+ last = gsi_last_bb (merge_target_bb);
+ gsi_insert_seq_after (&last, bb_seq (bb), GSI_NEW_STMT);
+ set_bb_seq (bb, NULL);
delete_basic_block (bb);
}
/* Now if possible, merge loop header and block with exit edge.
- This reduces number of basic blocks to 2. Auto vectorizer addresses
+ This reduces number of basic blocks to 2. Auto vectorizer addresses
loops with two nodes only. FIXME: Use cleanup_tree_cfg(). */
if (exit_bb
&& exit_bb != loop->header
merge_blocks (loop->header, exit_bb);
}
-/* Make new temp variable of type TYPE. Add GIMPLE_MODIFY_STMT to assign EXP
- to the new variable. */
-
-static tree
-ifc_temp_var (tree type, tree exp)
-{
- const char *name = "_ifc_";
- tree var, stmt, new_name;
-
- if (is_gimple_reg (exp))
- return exp;
-
- /* Create new temporary variable. */
- var = create_tmp_var (type, name);
- add_referenced_var (var);
-
- /* Build new statement to assign EXP to new variable. */
- stmt = build2 (GIMPLE_MODIFY_STMT, type, var, exp);
-
- /* Get SSA name for the new variable and set make new statement
- its definition statement. */
- new_name = make_ssa_name (var, stmt);
- GIMPLE_STMT_OPERAND (stmt, 0) = new_name;
- SSA_NAME_DEF_STMT (new_name) = stmt;
-
- return stmt;
-}
-
-
-/* Return TRUE iff, all pred blocks of BB are visited.
- Bitmap VISITED keeps history of visited blocks. */
+/* Main entry point. Apply if-conversion to the LOOP. Return true if
+ successful otherwise return false. If false is returned then loop
+ remains unchanged. FOR_VECTORIZER is a boolean flag. It indicates
+ whether if-conversion is used for vectorizer or not. If it is used
+ for vectorizer, additional checks are used. (Vectorization checks
+ are not yet implemented). */
static bool
-pred_blocks_visited_p (basic_block bb, bitmap *visited)
-{
- edge e;
- edge_iterator ei;
- FOR_EACH_EDGE (e, ei, bb->preds)
- if (!bitmap_bit_p (*visited, e->src->index))
- return false;
-
- return true;
-}
-
-/* Get body of a LOOP in suitable order for if-conversion.
- It is caller's responsibility to deallocate basic block
- list. If-conversion suitable order is, BFS order with one
- additional constraint. Select block in BFS block, if all
- pred are already selected. */
-
-static basic_block *
-get_loop_body_in_if_conv_order (const struct loop *loop)
+tree_if_conversion (struct loop *loop, bool for_vectorizer)
{
- basic_block *blocks, *blocks_in_bfs_order;
basic_block bb;
- bitmap visited;
- unsigned int index = 0;
- unsigned int visited_count = 0;
-
- gcc_assert (loop->num_nodes);
- gcc_assert (loop->latch != EXIT_BLOCK_PTR);
-
- blocks = XCNEWVEC (basic_block, loop->num_nodes);
- visited = BITMAP_ALLOC (NULL);
+ gimple_stmt_iterator itr;
+ unsigned int i;
- blocks_in_bfs_order = get_loop_body_in_bfs_order (loop);
+ ifc_bbs = NULL;
- index = 0;
- while (index < loop->num_nodes)
+ /* If-conversion is not appropriate for all loops. First, check if
+ loop is if-convertible or not. */
+ if (!if_convertible_loop_p (loop, for_vectorizer))
{
- bb = blocks_in_bfs_order [index];
-
- if (bb->flags & BB_IRREDUCIBLE_LOOP)
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,"-------------------------\n");
+ if (ifc_bbs)
{
- free (blocks_in_bfs_order);
- BITMAP_FREE (visited);
- free (blocks);
- return NULL;
+ free (ifc_bbs);
+ ifc_bbs = NULL;
}
- if (!bitmap_bit_p (visited, bb->index))
+ free_dominance_info (CDI_POST_DOMINATORS);
+ return false;
+ }
+
+ /* Do actual work now. */
+ for (i = 0; i < loop->num_nodes; i++)
+ {
+ tree cond;
+
+ bb = ifc_bbs [i];
+
+ /* Update condition using predicate list. */
+ cond = (tree) bb->aux;
+
+ /* Process all statements in this basic block.
+ Remove conditional expression, if any, and annotate
+ destination basic block(s) appropriately. */
+ for (itr = gsi_start_bb (bb); !gsi_end_p (itr); /* empty */)
{
- if (pred_blocks_visited_p (bb, &visited)
- || bb == loop->header)
- {
- /* This block is now visited. */
- bitmap_set_bit (visited, bb->index);
- blocks[visited_count++] = bb;
- }
+ gimple t = gsi_stmt (itr);
+ cond = tree_if_convert_stmt (loop, t, cond, &itr);
+ if (!gsi_end_p (itr))
+ gsi_next (&itr);
}
- index++;
- if (index == loop->num_nodes
- && visited_count != loop->num_nodes)
+
+ /* If current bb has only one successor, then consider it as an
+ unconditional goto. */
+ if (single_succ_p (bb))
{
- /* Not done yet. */
- index = 0;
+ basic_block bb_n = single_succ (bb);
+
+ /* Successor bb inherits predicate of its predecessor. If there
+ is no predicate in predecessor bb, then consider successor bb
+ as always executed. */
+ if (cond == NULL_TREE)
+ cond = boolean_true_node;
+
+ add_to_predicate_list (bb_n, cond);
}
}
- free (blocks_in_bfs_order);
- BITMAP_FREE (visited);
- return blocks;
-}
-
-/* Return true if one of the basic block BB edge is exit of LOOP. */
-static bool
-bb_with_exit_edge_p (struct loop *loop, basic_block bb)
-{
- edge e;
- edge_iterator ei;
- bool exit_edge_found = false;
+ /* Now, all statements are if-converted and basic blocks are
+ annotated appropriately. Combine all basic block into one huge
+ basic block. */
+ combine_blocks (loop);
- FOR_EACH_EDGE (e, ei, bb->succs)
- if (loop_exit_edge_p (loop, e))
- {
- exit_edge_found = true;
- break;
- }
+ /* clean up */
+ clean_predicate_lists (loop);
+ free (ifc_bbs);
+ ifc_bbs = NULL;
- return exit_edge_found;
+ return true;
}
/* Tree if-conversion pass management. */
static unsigned int
main_tree_if_conversion (void)
{
- unsigned i, loop_num;
+ loop_iterator li;
struct loop *loop;
- if (!current_loops)
+ if (number_of_loops () <= 1)
return 0;
- loop_num = current_loops->num;
- for (i = 0; i < loop_num; i++)
- {
- loop = current_loops->parray[i];
- if (!loop)
- continue;
+ FOR_EACH_LOOP (li, loop, 0)
+ tree_if_conversion (loop);
- tree_if_conversion (loop, true);
- }
return 0;
}
return flag_tree_vectorize != 0;
}
-struct tree_opt_pass pass_if_conversion =
+struct gimple_opt_pass pass_if_conversion =
{
+ {
+ GIMPLE_PASS,
"ifcvt", /* name */
gate_tree_if_conversion, /* gate */
main_tree_if_conversion, /* execute */
NULL, /* sub */
NULL, /* next */
0, /* static_pass_number */
- 0, /* tv_id */
- PROP_cfg | PROP_ssa | PROP_alias, /* properties_required */
+ TV_NONE, /* tv_id */
+ PROP_cfg | PROP_ssa, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- TODO_dump_func | TODO_verify_loops | TODO_verify_stmts | TODO_verify_flow,
+ TODO_dump_func | TODO_verify_stmts | TODO_verify_flow
/* todo_flags_finish */
- 0 /* letter */
+ }
};
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