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.
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,
+static tree add_to_dst_predicate_list (struct loop * loop, edge,
+ 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 bb;
block_stmt_iterator itr;
- tree cond;
unsigned int i;
ifc_bbs = NULL;
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. */
basic_block bb_n = single_succ (bb);
if (cond != NULL_TREE)
add_to_predicate_list (bb_n, cond);
- cond = NULL_TREE;
}
}
/* 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,
+ add_to_dst_predicate_list (loop, true_edge, 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);
+ add_to_dst_predicate_list (loop, false_edge, cond, c2, bsi);
/* Now this conditional statement is redundant. Remove it.
But, do not remove exit condition! Update exit condition
/* ??? Check data dependency for vectorizer. */
/* What about phi nodes ? */
- for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
+ phi = phi_nodes (bb);
+
+ /* Clear aux field of incoming edges to a bb with a phi node. */
+ if (phi)
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ e->aux = NULL;
+
+ /* Check statements. */
+ for (; phi; phi = PHI_CHAIN (phi))
if (!if_convertible_phi_p (loop, bb, phi))
return false;
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)
{
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)
{
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);
+
+ prev_cond = force_gimple_operand_bsi (bsi, unshare_expr (prev_cond),
+ true, NULL, true, BSI_SAME_STMT);
+
+ cond = force_gimple_operand_bsi (bsi, unshare_expr (cond),
+ true, NULL, true, BSI_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 */
tmp = build2 (TRUTH_AND_EXPR, boolean_type_node,
bsi_insert_before (bsi, tmp_stmt, BSI_SAME_STMT);
new_cond = GIMPLE_STMT_OPERAND (tmp_stmt, 0);
}
- 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)
{
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, tree *cond,
block_stmt_iterator *bsi)
{
- 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)
S3: x = (c == d) ? b : a;
S3 is preferred over S1 and S2*, Make 'b' first_bb and use
- its condition.
+ 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 = (first_edge->src)->aux;
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 = (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, 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 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;
+ {
+ /* FIRST_BB is not loop header */
+ *cond = (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, 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. */
- *cond = force_gimple_operand (*cond, &new_stmts, false, NULL_TREE);
- if (new_stmts)
- bsi_insert_before (bsi, new_stmts, BSI_SAME_STMT);
+ 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_bsi (bsi, unshare_expr (*cond),
+ false, NULL_TREE,
+ true, BSI_SAME_STMT);
if (!is_gimple_reg (*cond) && !is_gimple_condexpr (*cond))
{
tree new_stmt;
gcc_assert (*cond);
- return first_bb;
+ return first_edge->src;
}
/* Find basic block and initialize iterator. */
bb = bb_for_stmt (phi);
- new_stmt = NULL_TREE;
- arg_0 = NULL_TREE;
- arg_1 = NULL_TREE;
-
/* Use condition that is not TRUTH_NOT_EXPR in conditional modify expr. */
if (EDGE_PRED (bb, 1)->src == true_bb)
{
loop_iterator li;
struct loop *loop;
- if (!current_loops)
+ if (number_of_loops () <= 1)
return 0;
FOR_EACH_LOOP (li, loop, 0)
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