/* If-conversion for vectorizer.
- Copyright (C) 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
Contributed by Devang Patel <dpatel@apple.com>
This file is part of GCC.
#include "target.h"
/* local function prototypes */
-static void main_tree_if_conversion (void);
+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_modify_expr_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,
+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, tree *,
block_stmt_iterator *);
-static void replace_phi_with_cond_modify_expr (tree, tree, basic_block,
+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 *);
{
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;
}
}
}
/* 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_MODIFY_STMT than 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
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_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
+ 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:
/* 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
}
/* Return true, if M_EXPR is if-convertible.
- MODIFY_EXPR is not if-convertible if,
+ GIMPLE_MODIFY_STMT 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_MODIFY_STMT is part of block BB, which is inside loop LOOP.
*/
static bool
-if_convertible_modify_expr_p (struct loop *loop, basic_block bb, tree m_expr)
+if_convertible_gimple_modify_stmt_p (struct loop *loop, basic_block bb,
+ tree m_expr)
{
+ tree lhs, rhs;
+
+ if (TREE_CODE (m_expr) != GIMPLE_MODIFY_STMT)
+ return false;
+
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "-------------------------\n");
print_generic_stmt (dump_file, m_expr, TDF_SLIM);
}
- /* Be conservative and do not handle immovable expressions. */
- if (movement_possibility (m_expr) == MOVE_IMPOSSIBLE)
+ lhs = GIMPLE_STMT_OPERAND (m_expr, 0);
+ rhs = GIMPLE_STMT_OPERAND (m_expr, 1);
+
+ /* Some of these constrains might be too conservative. */
+ if (stmt_ends_bb_p (m_expr) || stmt_ann (m_expr)->has_volatile_ops
+ || (TREE_CODE (lhs) == SSA_NAME
+ && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
+ || TREE_SIDE_EFFECTS (rhs))
{
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)))
+ && tree_could_trap_p (GIMPLE_STMT_OPERAND (m_expr, 1)))
{
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 (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 (TREE_OPERAND (m_expr, 0)) != SSA_NAME
+ if (TREE_CODE (GIMPLE_STMT_OPERAND (m_expr, 0)) != SSA_NAME
&& bb != loop->header
&& !bb_with_exit_edge_p (loop, bb))
{
/* Return true, iff STMT is if-convertible.
Statement is if-convertible if,
- - It is if-convertible MODIFY_EXPR
+ - It is if-convertible GIMPLE_MODIFY_STMT
- IT is LABEL_EXPR or COND_EXPR.
STMT is inside block BB, which is inside loop LOOP. */
case LABEL_EXPR:
break;
- case MODIFY_EXPR:
+ case GIMPLE_MODIFY_STMT:
- if (!if_convertible_modify_expr_p (loop, bb, stmt))
+ if (!if_convertible_gimple_modify_stmt_p (loop, bb, stmt))
return false;
break;
}
/* More than one loop exit is too much to handle. */
- if (!loop->single_exit)
+ if (!single_exit (loop))
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "multiple exits\n");
/* ??? 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)
if (tmp_stmts2)
bsi_insert_before (bsi, tmp_stmts2, 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,
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);
+ 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;
+ edge first_edge, second_edge;
+ tree tmp_cond, new_stmts;
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);
if (!is_gimple_reg (*cond) && !is_gimple_condexpr (*cond))
{
tree 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);
+ bsi_insert_before (bsi, new_stmt, BSI_SAME_STMT);
+ *cond = GIMPLE_STMT_OPERAND (new_stmt, 0);
}
gcc_assert (*cond);
- return first_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_modify_stmt (tree phi, tree cond,
+ basic_block true_bb,
+ block_stmt_iterator *bsi)
{
tree new_stmt;
basic_block bb;
/* 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)
{
unshare_expr (arg_1));
/* Create new MODIFY expression using RHS. */
- new_stmt = build2 (MODIFY_EXPR, TREE_TYPE (PHI_RESULT (phi)),
- unshare_expr (PHI_RESULT (phi)), rhs);
+ new_stmt = build_gimple_modify_stmt (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_after (bsi, new_stmt, BSI_SAME_STMT);
- bsi_next (bsi);
-
+ bsi_insert_before (bsi, new_stmt, BSI_SAME_STMT);
update_stmt (new_stmt);
if (dump_file && (dump_flags & TDF_DETAILS))
while (phi)
{
tree next = PHI_CHAIN (phi);
- replace_phi_with_cond_modify_expr (phi, cond, true_bb, &bsi);
+ replace_phi_with_cond_gimple_modify_stmt (phi, cond, true_bb, &bsi);
release_phi_node (phi);
phi = next;
}
- bb->phi_nodes = NULL;
+ set_phi_nodes (bb, NULL_TREE);
}
return;
}
basic_block bb, exit_bb, merge_target_bb;
unsigned int orig_loop_num_nodes = loop->num_nodes;
unsigned int i;
- unsigned int n_exits;
+ edge e;
+ edge_iterator ei;
- get_loop_exit_edges (loop, &n_exits);
/* 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 (loop, bb))
- exit_bb = bb;
-
- if (bb == exit_bb)
+ for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei));)
{
- 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. */
- 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 (!loop_exit_edge_p (loop, e))
- {
- redirect_edge_and_branch (e, loop->latch);
- set_immediate_dominator (CDI_DOMINATORS, loop->latch, bb);
- }
- }
- }
- continue;
+ make_edge (loop->header, exit_bb, EDGE_FALLTHRU);
+ set_immediate_dominator (CDI_DOMINATORS, exit_bb, loop->header);
}
- if (bb == loop->latch && empty_block_p (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);
+ }
- /* It is time to remove this basic block. First remove edges. */
- while (EDGE_COUNT (bb->preds) > 0)
- remove_edge (EDGE_PRED (bb, 0));
+ merge_target_bb = loop->header;
+ for (i = 1; i < orig_loop_num_nodes; i++)
+ {
+ block_stmt_iterator bsi;
+ tree_stmt_iterator last;
- /* 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;
- }
+ bb = ifc_bbs[i];
- while (EDGE_COUNT (bb->succs) > 0)
- remove_edge (EDGE_SUCC (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); )
}
/* 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 = tsi_last (bb_stmt_list (merge_target_bb));
+ tsi_link_after (&last, bb_stmt_list (bb), TSI_NEW_STMT);
+ set_bb_stmt_list (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 new temp variable of type TYPE. Add GIMPLE_MODIFY_STMT to assign EXP
to the new variable. */
static tree
/* 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 = build2 (MODIFY_EXPR, type, var, exp);
+ stmt = build_gimple_modify_stmt (var, exp);
/* Get SSA name for the new variable and set make new statement
its definition statement. */
new_name = make_ssa_name (var, stmt);
- TREE_OPERAND (stmt, 0) = new_name;
+ GIMPLE_STMT_OPERAND (stmt, 0) = new_name;
SSA_NAME_DEF_STMT (new_name) = stmt;
return stmt;
gcc_assert (loop->num_nodes);
gcc_assert (loop->latch != EXIT_BLOCK_PTR);
- blocks = xcalloc (loop->num_nodes, sizeof (basic_block));
+ blocks = XCNEWVEC (basic_block, loop->num_nodes);
visited = BITMAP_ALLOC (NULL);
blocks_in_bfs_order = get_loop_body_in_bfs_order (loop);
/* 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
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