/* If-conversion for vectorizer.
- Copyright (C) 2004 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, 59 Temple Place - Suite 330, Boston, MA
-02111-1307, 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.
A short description of if-conversion:
- o Decide if a loop is if-convertable or not.
+ o Decide if a loop is if-convertible or not.
o Walk all loop basic blocks in breadth first order (BFS order).
o Remove conditional statements (at the end of basic block)
and propagate condition into destination basic blocks'
#include "system.h"
#include "coretypes.h"
#include "tm.h"
-#include "errors.h"
#include "tree.h"
-#include "c-common.h"
#include "flags.h"
#include "timevar.h"
#include "varray.h"
#include "tree-pass.h"
#include "target.h"
+
/* local function prototypes */
-static void 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_convertable_phi_p (struct loop *, basic_block, tree);
-static bool if_convertable_modify_expr_p (struct loop *, basic_block, tree);
-static bool if_convertable_stmt_p (struct loop *, basic_block, tree);
-static bool if_convertable_bb_p (struct loop *, basic_block, bool);
-static bool if_convertable_loop_p (struct loop *, bool);
+static unsigned int main_tree_if_conversion (void);
+static tree tree_if_convert_stmt (struct loop *loop, gimple, tree,
+ gimple_stmt_iterator *);
+static void tree_if_convert_cond_stmt (struct loop *, gimple, tree,
+ gimple_stmt_iterator *);
+static bool if_convertible_phi_p (struct loop *, basic_block, gimple);
+static bool if_convertible_gimple_assign_stmt_p (struct loop *, basic_block,
+ gimple);
+static bool if_convertible_stmt_p (struct loop *, basic_block, gimple);
+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 tree add_to_dst_predicate_list (struct loop * loop, edge,
+ tree, tree,
+ gimple_stmt_iterator *);
static void clean_predicate_lists (struct loop *loop);
-static basic_block find_phi_replacement_condition (basic_block, tree *,
- block_stmt_iterator *);
-static void replace_phi_with_cond_modify_expr (tree, tree, basic_block,
- block_stmt_iterator *);
+static basic_block find_phi_replacement_condition (struct loop *loop,
+ basic_block, tree *,
+ gimple_stmt_iterator *);
+static void replace_phi_with_cond_gimple_assign_stmt (gimple, tree,
+ basic_block,
+ gimple_stmt_iterator *);
static void process_phi_nodes (struct loop *);
static void combine_blocks (struct loop *);
-static tree ifc_temp_var (tree, tree);
+static gimple 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 (basic_block);
+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;
tree_if_conversion (struct loop *loop, bool for_vectorizer)
{
basic_block bb;
- block_stmt_iterator itr;
- tree cond;
+ gimple_stmt_iterator itr;
unsigned int i;
ifc_bbs = NULL;
/* if-conversion is not appropriate for all loops. First, check if loop is
- if-convertable or not. */
- if (!if_convertable_loop_p (loop, for_vectorizer))
+ if-convertible or not. */
+ if (!if_convertible_loop_p (loop, for_vectorizer))
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file,"-------------------------\n");
ifc_bbs = NULL;
}
free_dominance_info (CDI_POST_DOMINATORS);
- free_df ();
return false;
}
- cond = NULL_TREE;
-
/* Do actual work now. */
for (i = 0; i < loop->num_nodes; i++)
{
+ tree cond;
+
bb = ifc_bbs [i];
/* Update condition using predicate list. */
- cond = bb->aux;
+ 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 = bsi_start (bb); !bsi_end_p (itr); /* empty */)
+ for (itr = gsi_start_bb (bb); !gsi_end_p (itr); /* empty */)
{
- tree t = bsi_stmt (itr);
+ gimple t = gsi_stmt (itr);
cond = tree_if_convert_stmt (loop, t, cond, &itr);
- if (!bsi_end_p (itr))
- bsi_next (&itr);
+ if (!gsi_end_p (itr))
+ gsi_next (&itr);
}
/* If current bb has only one successor, then consider it as an
unconditional goto. */
- if (EDGE_COUNT (bb->succs) == 1)
+ if (single_succ_p (bb))
{
- basic_block bb_n = EDGE_SUCC (bb, 0)->dest;
- if (cond != NULL_TREE)
- add_to_predicate_list (bb_n, cond);
- cond = NULL_TREE;
+ 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);
}
}
clean_predicate_lists (loop);
free (ifc_bbs);
ifc_bbs = NULL;
- free_df ();
return true;
}
/* if-convert stmt T which is part of LOOP.
- If T is a MODIFY_EXPR than it is converted into conditional modify
+ 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. */
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:
- break;
-
- case MODIFY_EXPR:
- /* This modify_expr 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. */
+ case GIMPLE_LABEL:
break;
- case GOTO_EXPR:
- /* Unconditional goto */
- add_to_predicate_list (bb_for_stmt (TREE_OPERAND (t, 1)), cond);
- bsi_remove (bsi);
- cond = NULL_TREE;
+ 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. */
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.
+/* 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. BSI is the iterator
+ 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_expr (struct loop *loop, tree stmt, tree cond,
- block_stmt_iterator *bsi)
+tree_if_convert_cond_stmt (struct loop *loop, gimple stmt, tree cond,
+ gimple_stmt_iterator *gsi)
{
- tree c, c2, new_cond;
+ tree c, c2;
edge true_edge, false_edge;
- new_cond = NULL_TREE;
- gcc_assert (TREE_CODE (stmt) == COND_EXPR);
+ gcc_assert (gimple_code (stmt) == GIMPLE_COND);
- c = COND_EXPR_COND (stmt);
+ c = fold_build2 (gimple_cond_code (stmt), boolean_type_node,
+ gimple_cond_lhs (stmt), gimple_cond_rhs (stmt));
- /* Create temp. for condition. */
- if (!is_gimple_condexpr (c))
- {
- tree new_stmt;
- new_stmt = ifc_temp_var (TREE_TYPE (c), unshare_expr (c));
- bsi_insert_before (bsi, new_stmt, BSI_SAME_STMT);
- c = TREE_OPERAND (new_stmt, 0);
- }
-
- extract_true_false_edges_from_block (bb_for_stmt (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. */
- new_cond = add_to_dst_predicate_list (loop, true_edge->dest, cond,
- unshare_expr (c), bsi);
-
- if (!is_gimple_reg(c) && is_gimple_condexpr (c))
- {
- tree new_stmt;
- new_stmt = ifc_temp_var (TREE_TYPE (c), unshare_expr (c));
- bsi_insert_before (bsi, new_stmt, BSI_SAME_STMT);
- c = TREE_OPERAND (new_stmt, 0);
- }
+ /* 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 (unshare_expr (c));
- add_to_dst_predicate_list (loop, false_edge->dest, cond, c2, bsi);
+ 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 (bb_for_stmt (stmt)))
+ if (!bb_with_exit_edge_p (loop, gimple_bb (stmt)))
{
- bsi_remove (bsi);
+ gsi_remove (gsi, true);
cond = NULL_TREE;
}
return;
}
-/* Return true, iff PHI is if-convertable. 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-convertable
+ PHI is not if-convertible
- if it has more than 2 arguments.
- - Virtual PHI is immediately used in another PHI node. */
+ - Virtual PHI is immediately used in another PHI node.
+ - Virtual PHI on BB other than header. */
static bool
-if_convertable_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))))
{
- int j;
- dataflow_t df = get_immediate_uses (phi);
- int num_uses = num_immediate_uses (df);
- for (j = 0; j < num_uses; j++)
+ imm_use_iterator imm_iter;
+ use_operand_p use_p;
+
+ if (bb != loop->header)
{
- tree use = immediate_use (df, j);
- if (TREE_CODE (use) == 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-convertable.
- MODIFY_EXPR is not if-convertable if,
+/* Return true, if STMT is if-convertible.
+ GIMPLE_ASSIGN statement is not if-convertible if,
- It is not movable.
- It could trap.
- LHS is not var decl.
- MODIFY_EXPR 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_convertable_modify_expr_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;
+
+ if (!is_gimple_assign (stmt))
+ return false;
+
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)
+ lhs = gimple_assign_lhs (stmt);
+
+ /* 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 (TREE_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 (TREE_OPERAND (m_expr, 1)) == CALL_EXPR)
- {
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "CALL_EXPR \n");
- return false;
- }
-
- if (TREE_CODE (TREE_OPERAND (m_expr, 0)) != SSA_NAME
+ if (TREE_CODE (lhs) != SSA_NAME
&& bb != loop->header
- && !bb_with_exit_edge_p (bb))
+ && !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-convertable.
- Statement is if-convertable if,
- - It is if-convertable MODIFY_EXPR
- - IT is LABEL_EXPR, GOTO_EXPR or COND_EXPR.
+/* Return true, iff STMT is if-convertible.
+ Statement is if-convertible if,
+ - 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_convertable_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:
+ case GIMPLE_LABEL:
break;
- case MODIFY_EXPR:
+ case GIMPLE_ASSIGN:
- if (!if_convertable_modify_expr_p (loop, bb, stmt))
+ if (!if_convertible_gimple_assign_stmt_p (loop, bb, stmt))
return false;
break;
- case GOTO_EXPR:
- case COND_EXPR:
+ case GIMPLE_COND:
break;
default:
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;
}
-/* Return true, iff BB is if-convertable.
+/* Return true, iff BB is if-convertible.
Note: This routine does _not_ check basic block statements and phis.
- Basic block is not if-convertable if,
+ 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.
BB is inside loop LOOP. */
static bool
-if_convertable_bb_p (struct loop *loop, basic_block bb, bool exit_bb_seen)
+if_convertible_bb_p (struct loop *loop, basic_block bb, basic_block exit_bb)
{
edge e;
edge_iterator ei;
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "----------[%d]-------------\n", bb->index);
- if (exit_bb_seen)
+ if (exit_bb)
{
if (bb != loop->latch)
{
fprintf (dump_file, "non empty basic block after exit bb\n");
return false;
}
+ else if (bb == loop->latch
+ && bb != exit_bb
+ && !dominated_by_p (CDI_DOMINATORS, bb, exit_bb))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "latch is not dominated by exit_block\n");
+ return false;
+ }
}
/* Be less adventurous and handle only normal edges. */
return true;
}
-/* Return true, iff LOOP is if-convertable.
- LOOP is if-convertable if,
+/* 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 convertable. See above for
+ - 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). */
static bool
-if_convertable_loop_p (struct loop *loop, bool for_vectorizer ATTRIBUTE_UNUSED)
+if_convertible_loop_p (struct loop *loop, bool for_vectorizer ATTRIBUTE_UNUSED)
{
- tree phi;
basic_block bb;
- block_stmt_iterator itr;
+ gimple_stmt_iterator itr;
unsigned int i;
edge e;
edge_iterator ei;
- bool exit_bb_seen = false;
+ basic_block exit_bb = NULL;
/* Handle only inner most loop. */
if (!loop || loop->inner)
return false;
}
- flow_loop_scan (loop, LOOP_ALL);
-
/* If only one block, no need for if-conversion. */
if (loop->num_nodes <= 2)
{
}
/* More than one loop exit is too much to handle. */
- if (loop->num_exits > 1)
+ if (!single_exit (loop))
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "multiple exits\n");
/* If one of the loop header's edge is exit edge then do not apply
if-conversion. */
FOR_EACH_EDGE (e, ei, loop->header->succs)
- if ( e->flags & EDGE_LOOP_EXIT)
- return false;
-
- compute_immediate_uses (TDFA_USE_OPS|TDFA_USE_VOPS, NULL);
+ {
+ if (loop_exit_edge_p (loop, e))
+ return false;
+ }
calculate_dominance_info (CDI_DOMINATORS);
calculate_dominance_info (CDI_POST_DOMINATORS);
{
bb = ifc_bbs[i];
- if (!if_convertable_bb_p (loop, bb, exit_bb_seen))
+ 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_convertable_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_convertable_phi_p (loop, bb, phi))
+ itr = gsi_start_phis (bb);
+
+ /* Clear aux field of incoming edges to a bb with a phi node. */
+ if (!gsi_end_p (itr))
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ e->aux = NULL;
+
+ /* Check statements. */
+ 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 (bb))
- exit_bb_seen = true;
+ if (bb_with_exit_edge_p (loop, bb))
+ exit_bb = bb;
}
/* OK. Did not find any potential issues so go ahead in if-convert
static void
add_to_predicate_list (basic_block bb, tree new_cond)
{
- tree cond = bb->aux;
+ tree cond = (tree) bb->aux;
if (cond)
- cond = fold (build (TRUTH_OR_EXPR, boolean_type_node,
- unshare_expr (cond), new_cond));
+ cond = fold_build2 (TRUTH_OR_EXPR, boolean_type_node,
+ unshare_expr (cond), new_cond);
else
cond = new_cond;
existing condition. */
static tree
-add_to_dst_predicate_list (struct loop * loop, basic_block bb,
+add_to_dst_predicate_list (struct loop * loop, edge e,
tree prev_cond, tree cond,
- block_stmt_iterator *bsi)
+ gimple_stmt_iterator *gsi)
{
tree new_cond = NULL_TREE;
- if (!flow_bb_inside_loop_p (loop, bb))
+ 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
{
- tree tmp_stmt;
+ tree tmp;
+ gimple tmp_stmt = NULL;
+
+ prev_cond = force_gimple_operand_gsi (gsi, unshare_expr (prev_cond),
+ true, NULL, true, GSI_SAME_STMT);
+
+ cond = force_gimple_operand_gsi (gsi, unshare_expr (cond),
+ true, NULL, true, GSI_SAME_STMT);
+
+ /* 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;
+
/* new_cond == prev_cond AND cond */
- tree tmp = build (TRUTH_AND_EXPR, boolean_type_node,
- unshare_expr (prev_cond), 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 = TREE_OPERAND (tmp_stmt, 0);
+ gsi_insert_before (gsi, tmp_stmt, GSI_SAME_STMT);
+ new_cond = gimple_assign_lhs (tmp_stmt);
}
- add_to_predicate_list (bb, new_cond);
+ add_to_predicate_list (e->dest, 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)
{
-#ifdef ENABLE_CHECKING
- gcc_assert (loop->num_nodes == 2 || loop->num_nodes == 1);
-#endif
- loop->header->aux = NULL;
- loop->latch->aux = NULL;
+ 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;
+ 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
whose phi arguments are selected when cond is true. */
static basic_block
-find_phi_replacement_condition (basic_block bb, tree *cond,
- block_stmt_iterator *bsi)
+find_phi_replacement_condition (struct loop *loop,
+ basic_block bb, tree *cond,
+ gimple_stmt_iterator *gsi)
{
- edge e;
- basic_block p1 = NULL;
- basic_block p2 = NULL;
- basic_block true_bb = NULL;
+ edge first_edge, second_edge;
tree tmp_cond;
- edge_iterator ei;
- FOR_EACH_EDGE (e, ei, bb->preds)
+ gcc_assert (EDGE_COUNT (bb->preds) == 2);
+ first_edge = EDGE_PRED (bb, 0);
+ second_edge = EDGE_PRED (bb, 1);
+
+ /* Use condition based on following criteria:
+ 1)
+ S1: x = !c ? a : b;
+
+ 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)
+ S1: x = !(c == d)? a : b;
+
+ S21: t1 = c == d;
+ S22: x = t1 ? b : a;
+
+ S3: x = (c == d) ? b : a;
+
+ 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 = (tree) (first_edge->src)->aux;
+ gcc_assert (tmp_cond);
+
+ if (TREE_CODE (tmp_cond) == TRUTH_NOT_EXPR)
{
- if (p1 == NULL)
- p1 = e->src;
- else
- {
- gcc_assert (!p2);
- p2 = e->src;
- }
+ edge tmp_edge;
+
+ tmp_edge = first_edge;
+ first_edge = second_edge;
+ second_edge = tmp_edge;
}
- /* Use condition that is not TRUTH_NOT_EXPR in conditional modify expr. */
- tmp_cond = p1->aux;
- if (TREE_CODE (tmp_cond) == TRUTH_NOT_EXPR)
+ /* Check if FIRST_BB is loop header or not and make sure that
+ FIRST_BB does not dominate SECOND_BB. */
+ if (first_edge->src == loop->header
+ || dominated_by_p (CDI_DOMINATORS,
+ second_edge->src, first_edge->src))
{
- *cond = p2->aux;
- true_bb = p2;
+ *cond = (tree) (second_edge->src)->aux;
+
+ /* If there is a condition on an incoming edge,
+ AND it with 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)
+ /* We can be smart here and choose inverted
+ condition without switching bbs. */
+ *cond = invert_truthvalue (*cond);
+ else
+ /* Select non loop header bb. */
+ first_edge = second_edge;
}
else
{
- *cond = p1->aux;
- true_bb = p1;
+ /* FIRST_BB is not loop header */
+ *cond = (tree) (first_edge->src)->aux;
+
+ /* If there is a condition on an incoming edge,
+ AND it with the incoming bb predicate. */
+ if (first_edge->aux)
+ *cond = build2 (TRUTH_AND_EXPR, boolean_type_node,
+ *cond, (tree) first_edge->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. */
+ 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_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_after (bsi, new_stmt, BSI_SAME_STMT);
- bsi_next (bsi);
- *cond = TREE_OPERAND (new_stmt, 0);
+ gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT);
+ *cond = gimple_assign_lhs (new_stmt);
}
gcc_assert (*cond);
- return true_bb;
+ return first_edge->src;
}
*/
static void
-replace_phi_with_cond_modify_expr (tree phi, tree cond, basic_block true_bb,
- block_stmt_iterator *bsi)
+replace_phi_with_cond_gimple_assign_stmt (gimple phi, tree cond,
+ basic_block true_bb,
+ 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);
+ gcc_assert (gimple_code (phi) == GIMPLE_PHI);
/* If this is not filtered earlier, then now it is too late. */
- gcc_assert (PHI_NUM_ARGS (phi) == 2);
+ gcc_assert (gimple_phi_num_args (phi) == 2);
/* Find basic block and initialize iterator. */
- bb = bb_for_stmt (phi);
-
- 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 (PHI_ARG_EDGE(phi, 1)->src == true_bb)
+ 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. */
- rhs = build (COND_EXPR, TREE_TYPE (PHI_RESULT (phi)),
- unshare_expr (cond), unshare_expr (arg_0),
- unshare_expr (arg_1));
+ rhs = build3 (COND_EXPR, TREE_TYPE (PHI_RESULT (phi)),
+ unshare_expr (cond), unshare_expr (arg_0),
+ unshare_expr (arg_1));
- /* Create new MODIFY expression using RHS. */
- new_stmt = build (MODIFY_EXPR, TREE_TYPE (PHI_RESULT (phi)),
- unshare_expr (PHI_RESULT (phi)), rhs);
+ /* Create new GIMPLE_ASSIGN statement using RHS. */
+ new_stmt = gimple_build_assign (unshare_expr (PHI_RESULT (phi)), rhs);
/* Make new statement definition of the original phi result. */
- SSA_NAME_DEF_STMT (PHI_RESULT (phi)) = new_stmt;
-
- /* Set basic block and insert using iterator. */
- set_bb_for_stmt (new_stmt, bb);
-
- bsi_insert_after (bsi, new_stmt, BSI_SAME_STMT);
- bsi_next (bsi);
+ SSA_NAME_DEF_STMT (gimple_phi_result (phi)) = new_stmt;
- modify_stmt (new_stmt);
+ /* Insert using iterator. */
+ 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);
}
}
/* 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_start (bb);
+ phi_gsi = gsi_start_phis (bb);
+ gsi = gsi_after_labels (bb);
/* 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 (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_modify_expr (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_ann (bb)->phi_nodes = NULL;
+ set_phi_nodes (bb, NULL);
}
return;
}
basic_block bb, exit_bb, merge_target_bb;
unsigned int orig_loop_num_nodes = loop->num_nodes;
unsigned int i;
+ edge e;
+ edge_iterator ei;
/* 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. */
exit_bb = NULL;
+ for (i = 0; i < orig_loop_num_nodes; i++)
+ {
+ bb = ifc_bbs[i];
+ if (bb_with_exit_edge_p (loop, bb))
+ {
+ exit_bb = bb;
+ break;
+ }
+ }
+ gcc_assert (exit_bb != loop->latch);
- /* Merge basic blocks */
- merge_target_bb = loop->header;
for (i = 1; i < orig_loop_num_nodes; i++)
{
- edge e;
- block_stmt_iterator bsi;
- tree_stmt_iterator last;
-
bb = ifc_bbs[i];
- if (!exit_bb && bb_with_exit_edge_p (bb))
- exit_bb = bb;
-
- if (bb == exit_bb)
+ for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei));)
{
- edge new_e;
- edge_iterator ei;
+ if (e->src == exit_bb)
+ ei_next (&ei);
+ else
+ remove_edge (e);
+ }
+ }
+ if (exit_bb != NULL)
+ {
+ if (exit_bb != loop->header)
+ {
/* Connect this node with loop header. */
- new_e = make_edge (ifc_bbs[0], bb, EDGE_FALLTHRU);
- set_immediate_dominator (CDI_DOMINATORS, bb, ifc_bbs[0]);
+ make_edge (loop->header, exit_bb, EDGE_FALLTHRU);
+ set_immediate_dominator (CDI_DOMINATORS, exit_bb, loop->header);
+ }
- if (exit_bb != loop->latch)
- {
- /* Redirect non-exit edge to loop->latch. */
- FOR_EACH_EDGE (e, ei, bb->succs)
- if (!(e->flags & EDGE_LOOP_EXIT))
- {
- redirect_edge_and_branch (e, loop->latch);
- set_immediate_dominator (CDI_DOMINATORS, loop->latch, bb);
- }
- }
- continue;
+ /* Redirect non-exit edges to loop->latch. */
+ FOR_EACH_EDGE (e, ei, exit_bb->succs)
+ {
+ if (!loop_exit_edge_p (loop, e))
+ redirect_edge_and_branch (e, loop->latch);
}
+ set_immediate_dominator (CDI_DOMINATORS, loop->latch, exit_bb);
+ }
+ else
+ {
+ /* If the loop does not have exit then reconnect header and latch. */
+ make_edge (loop->header, loop->latch, EDGE_FALLTHRU);
+ set_immediate_dominator (CDI_DOMINATORS, loop->latch, loop->header);
+ }
- if (bb == loop->latch && empty_block_p (bb))
- continue;
+ merge_target_bb = loop->header;
+ for (i = 1; i < orig_loop_num_nodes; i++)
+ {
+ gimple_stmt_iterator gsi;
+ gimple_stmt_iterator last;
+
+ bb = ifc_bbs[i];
- /* It is time to remove this basic block. First remove edges. */
- while (EDGE_COUNT (bb->succs) > 0)
- ssa_remove_edge (EDGE_SUCC (bb, 0));
- while (EDGE_COUNT (bb->preds) > 0)
- ssa_remove_edge (EDGE_PRED (bb, 0));
+ if (bb == exit_bb || bb == loop->latch)
+ 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);
+ 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 = NULL;
-
- /* Update dominator info. */
- if (dom_computed[CDI_DOMINATORS])
- delete_from_dominance_info (CDI_DOMINATORS, bb);
- if (dom_computed[CDI_POST_DOMINATORS])
- delete_from_dominance_info (CDI_POST_DOMINATORS, bb);
-
- /* Remove basic block. */
- if (bb == loop->latch)
- loop->latch = merge_target_bb;
- remove_bb_from_loops (bb);
- expunge_block (bb);
+ 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
loops with two nodes only. FIXME: Use cleanup_tree_cfg(). */
if (exit_bb
- && loop->header != loop->latch
- && exit_bb != loop->latch
- && empty_block_p (loop->latch))
- {
- if (can_merge_blocks_p (loop->header, exit_bb))
- {
- remove_bb_from_loops (exit_bb);
- merge_blocks (loop->header, exit_bb);
- }
- }
+ && exit_bb != loop->header
+ && can_merge_blocks_p (loop->header, exit_bb))
+ merge_blocks (loop->header, exit_bb);
}
-/* Make new temp variable of type TYPE. Add MODIFY_EXPR to assign EXP
+/* Make a new temp variable of type TYPE. Add GIMPLE_ASSIGN to assign EXP
to the new variable. */
-static tree
+static gimple
ifc_temp_var (tree type, tree exp)
{
const char *name = "_ifc_";
- tree var, stmt, new_name;
-
- if (is_gimple_reg (exp))
- return exp;
+ tree var, new_name;
+ gimple stmt;
/* Create new temporary variable. */
var = create_tmp_var (type, name);
- add_referenced_tmp_var (var);
+ add_referenced_var (var);
/* Build new statement to assign EXP to new variable. */
- stmt = build (MODIFY_EXPR, type, var, exp);
+ stmt = gimple_build_assign (var, exp);
/* Get SSA name for the new variable and set make new statement
- its definition statment. */
+ its definition statement. */
new_name = make_ssa_name (var, stmt);
- TREE_OPERAND (stmt, 0) = new_name;
+ gimple_assign_set_lhs (stmt, new_name);
SSA_NAME_DEF_STMT (new_name) = stmt;
+ update_stmt (stmt);
return stmt;
}
gcc_assert (loop->num_nodes);
gcc_assert (loop->latch != EXIT_BLOCK_PTR);
- blocks = xcalloc (loop->num_nodes, sizeof (basic_block));
- visited = BITMAP_XMALLOC ();
+ blocks = XCNEWVEC (basic_block, loop->num_nodes);
+ visited = BITMAP_ALLOC (NULL);
blocks_in_bfs_order = get_loop_body_in_bfs_order (loop);
if (bb->flags & BB_IRREDUCIBLE_LOOP)
{
free (blocks_in_bfs_order);
- BITMAP_XFREE (visited);
+ BITMAP_FREE (visited);
free (blocks);
return NULL;
}
}
}
free (blocks_in_bfs_order);
- BITMAP_XFREE (visited);
+ BITMAP_FREE (visited);
return blocks;
}
-/* Return true if one of the basic block BB edge is loop exit. */
+/* Return true if one of the basic block BB edge is exit of LOOP. */
static bool
-bb_with_exit_edge_p (basic_block bb)
+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 (e->flags & EDGE_LOOP_EXIT)
+ if (loop_exit_edge_p (loop, e))
{
exit_edge_found = true;
break;
/* Tree if-conversion pass management. */
-static void
+static unsigned int
main_tree_if_conversion (void)
{
- unsigned i, loop_num;
+ loop_iterator li;
struct loop *loop;
- if (!current_loops)
- return;
+ if (number_of_loops () <= 1)
+ return 0;
- loop_num = current_loops->num;
- for (i = 0; i < loop_num; i++)
+ FOR_EACH_LOOP (li, loop, 0)
{
- loop = current_loops->parray[i];
- if (!loop)
- continue;
-
tree_if_conversion (loop, true);
}
-
+ return 0;
}
static bool
return flag_tree_vectorize != 0;
}
-struct tree_opt_pass pass_if_conversion =
+struct gimple_opt_pass pass_if_conversion =
{
- "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 */
- 0, /* properties_provided */
- 0, /* properties_destroyed */
- TODO_dump_func, /* todo_flags_start */
- TODO_dump_func
- | TODO_verify_ssa
- | TODO_verify_stmts
- | TODO_verify_flow, /* todo_flags_finish */
- 0 /* letter */
+ {
+ GIMPLE_PASS,
+ "ifcvt", /* name */
+ gate_tree_if_conversion, /* gate */
+ main_tree_if_conversion, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_NONE, /* tv_id */
+ PROP_cfg | PROP_ssa | PROP_alias, /* 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_flags_finish */
+ }
};
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