/* Induction variable canonicalization.
- Copyright (C) 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2004, 2005, 2007 Free Software Foundation, Inc.
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
+Free 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
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 detects the loops that iterate a constant number of times,
adds a canonical induction variable (step -1, tested against 0)
update_stmt (cond);
}
-/* Computes an estimated number of insns in LOOP. */
+/* Computes an estimated number of insns in LOOP, weighted by WEIGHTS. */
unsigned
-tree_num_loop_insns (struct loop *loop)
+tree_num_loop_insns (struct loop *loop, eni_weights *weights)
{
basic_block *body = get_loop_body (loop);
block_stmt_iterator bsi;
for (i = 0; i < loop->num_nodes; i++)
for (bsi = bsi_start (body[i]); !bsi_end_p (bsi); bsi_next (&bsi))
- size += estimate_num_insns (bsi_stmt (bsi));
+ size += estimate_num_insns (bsi_stmt (bsi), weights);
free (body);
return size;
enum unroll_level ul)
{
unsigned HOST_WIDE_INT n_unroll, ninsns, max_unroll, unr_insns;
- tree old_cond, cond, dont_exit, do_exit;
+ tree cond;
if (loop->inner)
return false;
if (ul == UL_SINGLE_ITER)
return false;
- ninsns = tree_num_loop_insns (loop);
+ ninsns = tree_num_loop_insns (loop, &eni_size_weights);
if (n_unroll * ninsns
> (unsigned) PARAM_VALUE (PARAM_MAX_COMPLETELY_PEELED_INSNS))
return false;
- if (ul == UL_NO_GROWTH)
+ unr_insns = estimated_unrolled_size (ninsns, n_unroll);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, " Loop size: %d\n", (int) ninsns);
+ fprintf (dump_file, " Estimated size after unrolling: %d\n",
+ (int) unr_insns);
+ }
+
+ if (ul == UL_NO_GROWTH
+ && unr_insns > ninsns)
{
- unr_insns = estimated_unrolled_size (ninsns, n_unroll);
-
if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, " Loop size: %d\n", (int) ninsns);
- fprintf (dump_file, " Estimated size after unrolling: %d\n",
- (int) unr_insns);
- }
-
- if (unr_insns > ninsns)
- {
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "Not unrolling loop %d:\n", loop->num);
- return false;
- }
+ fprintf (dump_file, "Not unrolling loop %d.\n", loop->num);
+ return false;
}
}
- if (exit->flags & EDGE_TRUE_VALUE)
- {
- dont_exit = boolean_false_node;
- do_exit = boolean_true_node;
- }
- else
- {
- dont_exit = boolean_true_node;
- do_exit = boolean_false_node;
- }
- cond = last_stmt (exit->src);
-
if (n_unroll)
{
sbitmap wont_exit;
- edge *edges_to_remove = XNEWVEC (edge, n_unroll);
- unsigned int n_to_remove = 0;
+ edge e;
+ unsigned i;
+ VEC (edge, heap) *to_remove = NULL;
- old_cond = COND_EXPR_COND (cond);
- COND_EXPR_COND (cond) = dont_exit;
- update_stmt (cond);
initialize_original_copy_tables ();
-
wont_exit = sbitmap_alloc (n_unroll + 1);
sbitmap_ones (wont_exit);
RESET_BIT (wont_exit, 0);
if (!tree_duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
n_unroll, wont_exit,
- exit, edges_to_remove,
- &n_to_remove,
+ exit, &to_remove,
DLTHE_FLAG_UPDATE_FREQ
| DLTHE_FLAG_COMPLETTE_PEEL))
{
- COND_EXPR_COND (cond) = old_cond;
- update_stmt (cond);
free_original_copy_tables ();
free (wont_exit);
- free (edges_to_remove);
return false;
}
+
+ for (i = 0; VEC_iterate (edge, to_remove, i, e); i++)
+ {
+ bool ok = remove_path (e);
+ gcc_assert (ok);
+ }
+
+ VEC_free (edge, heap, to_remove);
free (wont_exit);
- free (edges_to_remove);
free_original_copy_tables ();
}
-
- COND_EXPR_COND (cond) = do_exit;
- update_stmt (cond);
+ cond = last_stmt (exit->src);
+ COND_EXPR_COND (cond) = (exit->flags & EDGE_TRUE_VALUE) ? boolean_true_node
+ : boolean_false_node;
+ update_stmt (cond);
update_ssa (TODO_update_ssa);
if (dump_file && (dump_flags & TDF_DETAILS))
edge exit = NULL;
tree niter;
- niter = number_of_iterations_in_loop (loop);
+ niter = number_of_latch_executions (loop);
if (TREE_CODE (niter) == INTEGER_CST)
{
exit = single_exit (loop);
if (!just_once_each_iteration_p (loop, exit->src))
return false;
-
- /* The result of number_of_iterations_in_loop is by one higher than
- we expect (i.e. it returns number of executions of the exit
- condition, not of the loop latch edge). */
- niter = fold_build2 (MINUS_EXPR, TREE_TYPE (niter), niter,
- build_int_cst (TREE_TYPE (niter), 1));
}
else
{
size of the code does not increase. */
unsigned int
-tree_unroll_loops_completely (bool may_increase_size)
+tree_unroll_loops_completely (bool may_increase_size, bool unroll_outer)
{
loop_iterator li;
struct loop *loop;
- bool changed = false;
+ bool changed;
enum unroll_level ul;
- FOR_EACH_LOOP (li, loop, 0)
+ do
{
- if (may_increase_size && maybe_hot_bb_p (loop->header))
- ul = UL_ALL;
- else
- ul = UL_NO_GROWTH;
- changed |= canonicalize_loop_induction_variables (loop,
- false, ul,
- !flag_tree_loop_ivcanon);
- }
+ changed = false;
- /* Clean up the information about numbers of iterations, since complete
- unrolling might have invalidated it. */
- scev_reset ();
+ FOR_EACH_LOOP (li, loop, LI_ONLY_INNERMOST)
+ {
+ if (may_increase_size && maybe_hot_bb_p (loop->header)
+ /* Unroll outermost loops only if asked to do so or they do
+ not cause code growth. */
+ && (unroll_outer
+ || loop_outer (loop_outer (loop))))
+ ul = UL_ALL;
+ else
+ ul = UL_NO_GROWTH;
+ changed |= canonicalize_loop_induction_variables
+ (loop, false, ul, !flag_tree_loop_ivcanon);
+ }
+
+ if (changed)
+ {
+ /* This will take care of removing completely unrolled loops
+ from the loop structures so we can continue unrolling now
+ innermost loops. */
+ if (cleanup_tree_cfg ())
+ update_ssa (TODO_update_ssa_only_virtuals);
+
+ /* Clean up the information about numbers of iterations, since
+ complete unrolling might have invalidated it. */
+ scev_reset ();
+ }
+ }
+ while (changed);
- if (changed)
- return TODO_cleanup_cfg;
return 0;
}
unsigned n_before, freq_in, freq_h;
gcov_type exit_count = exit->count;
+ if (dump_file)
+ fprintf (dump_file, "Removing empty loop %d\n", loop->num);
+
non_exit = EDGE_SUCC (exit->src, 0);
if (non_exit == exit)
non_exit = EDGE_SUCC (exit->src, 1);
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