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 (basic_block, tree *,
+static basic_block find_phi_replacement_condition (struct loop *loop,
+ basic_block, tree *,
block_stmt_iterator *);
static void replace_phi_with_cond_modify_expr (tree, tree, basic_block,
block_stmt_iterator *);
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 (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;
ifc_bbs = NULL;
}
free_dominance_info (CDI_POST_DOMINATORS);
- free_df ();
return false;
}
/* 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;
+ basic_block bb_n = single_succ (bb);
if (cond != NULL_TREE)
add_to_predicate_list (bb_n, cond);
cond = NULL_TREE;
clean_predicate_lists (loop);
free (ifc_bbs);
ifc_bbs = NULL;
- free_df ();
return true;
}
tree_if_convert_cond_expr (struct loop *loop, tree stmt, tree cond,
block_stmt_iterator *bsi)
{
- tree c, c2, new_cond;
+ tree c, c2;
edge true_edge, false_edge;
- new_cond = NULL_TREE;
gcc_assert (TREE_CODE (stmt) == COND_EXPR);
c = COND_EXPR_COND (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),
&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);
- }
+ 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));
/* 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, bb_for_stmt (stmt)))
{
bsi_remove (bsi);
cond = NULL_TREE;
if (!is_gimple_reg (SSA_NAME_VAR (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;
+ FOR_EACH_IMM_USE_FAST (use_p, imm_iter, PHI_RESULT (phi))
{
- tree use = immediate_use (df, j);
- if (TREE_CODE (use) == PHI_NODE)
+ if (TREE_CODE (USE_STMT (use_p)) == PHI_NODE)
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "Difficult to handle this virtual phi.\n");
if (TREE_CODE (TREE_OPERAND (m_expr, 0)) != 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))
{
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 (!loop->single_exit)
{
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);
if (!if_convertible_phi_p (loop, bb, phi))
return false;
- if (bb_with_exit_edge_p (bb))
+ if (bb_with_exit_edge_p (loop, bb))
exit_bb_seen = true;
}
whose phi arguments are selected when cond is true. */
static basic_block
-find_phi_replacement_condition (basic_block bb, tree *cond,
+find_phi_replacement_condition (struct loop *loop,
+ basic_block bb, tree *cond,
block_stmt_iterator *bsi)
{
- edge e;
- basic_block p1 = NULL;
- basic_block p2 = NULL;
- basic_block true_bb = NULL;
+ basic_block first_bb = NULL;
+ basic_block second_bb = NULL;
tree tmp_cond;
- edge_iterator ei;
- FOR_EACH_EDGE (e, ei, bb->preds)
- {
- if (p1 == NULL)
- p1 = e->src;
- else
- {
- gcc_assert (!p2);
- p2 = e->src;
- }
- }
+ gcc_assert (EDGE_COUNT (bb->preds) == 2);
+ first_bb = (EDGE_PRED (bb, 0))->src;
+ second_bb = (EDGE_PRED (bb, 1))->src;
- /* Use condition that is not TRUTH_NOT_EXPR in conditional modify expr. */
- tmp_cond = p1->aux;
+ /* 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. */
+
+ /* Select condition that is not TRUTH_NOT_EXPR. */
+ tmp_cond = first_bb->aux;
if (TREE_CODE (tmp_cond) == TRUTH_NOT_EXPR)
{
- *cond = p2->aux;
- true_bb = p2;
+ basic_block tmp_bb;
+ tmp_bb = first_bb;
+ first_bb = second_bb;
+ second_bb = tmp_bb;
}
- else
+
+ /* Check if FIRST_BB is loop header or not. */
+ if (first_bb == loop->header)
{
- *cond = p1->aux;
- true_bb = p1;
+ 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));
+ }
+ else
+ {
+ /* Select non loop header condition. */
+ first_bb = second_bb;
+ *cond = first_bb->aux;
+ }
}
+ 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
gcc_assert (*cond);
- return true_bb;
+ return first_bb;
}
bsi_insert_after (bsi, new_stmt, BSI_SAME_STMT);
bsi_next (bsi);
- modify_stmt (new_stmt);
+ update_stmt (new_stmt);
if (dump_file && (dump_flags & TDF_DETAILS))
{
continue;
phi = phi_nodes (bb);
- bsi = bsi_start (bb);
+ bsi = bsi_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);
+ true_bb = find_phi_replacement_condition (loop, bb, &cond, &bsi);
while (phi)
{
basic_block bb, exit_bb, merge_target_bb;
unsigned int orig_loop_num_nodes = loop->num_nodes;
unsigned int i;
+ unsigned int n_exits;
+ get_loop_exit_edges (loop, &n_exits);
/* Process phi nodes to prepare blocks for merge. */
process_phi_nodes (loop);
bb = ifc_bbs[i];
- if (!exit_bb && bb_with_exit_edge_p (bb))
+ if (!exit_bb && bb_with_exit_edge_p (loop, bb))
exit_bb = bb;
if (bb == exit_bb)
{
- edge new_e;
edge_iterator ei;
/* Connect this node with loop header. */
- new_e = make_edge (ifc_bbs[0], bb, EDGE_FALLTHRU);
+ make_edge (ifc_bbs[0], bb, EDGE_FALLTHRU);
set_immediate_dominator (CDI_DOMINATORS, bb, ifc_bbs[0]);
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);
- }
+ {
+ if (!loop_exit_edge_p (loop, e))
+ {
+ redirect_edge_and_branch (e, loop->latch);
+ set_immediate_dominator (CDI_DOMINATORS, loop->latch, bb);
+ }
+ }
}
continue;
}
continue;
/* It is time to remove this basic block. First remove edges. */
- while (EDGE_COUNT (bb->succs) > 0)
- remove_edge (EDGE_SUCC (bb, 0));
while (EDGE_COUNT (bb->preds) > 0)
remove_edge (EDGE_PRED (bb, 0));
+ /* This is loop latch and loop does not have exit then do not
+ delete this basic block. Just remove its PREDS and reconnect
+ loop->header and loop->latch blocks. */
+ if (bb == loop->latch && n_exits == 0)
+ {
+ make_edge (loop->header, loop->latch, EDGE_FALLTHRU);
+ set_immediate_dominator (CDI_DOMINATORS, loop->latch, loop->header);
+ continue;
+ }
+
+ while (EDGE_COUNT (bb->succs) > 0)
+ remove_edge (EDGE_SUCC (bb, 0));
+
/* Remove labels and make stmts member of loop->header. */
for (bsi = bsi_start (bb); !bsi_end_p (bsi); )
{
gcc_assert (loop->latch != EXIT_BLOCK_PTR);
blocks = xcalloc (loop->num_nodes, sizeof (basic_block));
- visited = BITMAP_XMALLOC ();
+ 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;
struct tree_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 */
+ "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 */
+ 0, /* todo_flags_start */
+ TODO_dump_func | TODO_verify_loops | TODO_verify_stmts | TODO_verify_flow,
+ /* todo_flags_finish */
+ 0 /* letter */
};
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