/* Natural loop discovery code for GNU compiler.
- Copyright (C) 2000, 2001, 2003, 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2010
+ 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 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/>. */
#include "config.h"
#include "system.h"
#include "obstack.h"
#include "function.h"
#include "basic-block.h"
-#include "toplev.h"
#include "cfgloop.h"
+#include "diagnostic-core.h"
#include "flags.h"
#include "tree.h"
#include "tree-flow.h"
#include "pointer-set.h"
#include "output.h"
+#include "ggc.h"
static void flow_loops_cfg_dump (FILE *);
\f
{
fprintf (file, "multiple latches:");
latches = get_loop_latch_edges (loop);
- for (i = 0; VEC_iterate (edge, latches, i, e); i++)
+ FOR_EACH_VEC_ELT (edge, latches, i, e)
fprintf (file, " %d", e->src->index);
VEC_free (edge, heap, latches);
fprintf (file, "\n");
}
/* Free data allocated for LOOP. */
+
void
flow_loop_free (struct loop *loop)
{
struct loop_exit *exit, *next;
- VEC_free (loop_p, heap, loop->superloops);
+ VEC_free (loop_p, gc, loop->superloops);
/* Break the list of the loop exit records. They will be freed when the
corresponding edge is rescanned or removed, and this avoids
accessing the (already released) head of the list stored in the
loop structure. */
- for (exit = loop->exits.next; exit != &loop->exits; exit = next)
+ for (exit = loop->exits->next; exit != loop->exits; exit = next)
{
next = exit->next;
exit->next = exit;
exit->prev = exit;
}
-
- free (loop);
+
+ ggc_free (loop->exits);
+ ggc_free (loop);
}
/* Free all the memory allocated for LOOPS. */
loop_p loop;
/* Free the loop descriptors. */
- for (i = 0; VEC_iterate (loop_p, loops->larray, i, loop); i++)
+ FOR_EACH_VEC_ELT (loop_p, loops->larray, i, loop)
{
if (!loop)
continue;
flow_loop_free (loop);
}
- VEC_free (loop_p, heap, loops->larray);
- loops->larray = NULL;
+ VEC_free (loop_p, gc, loops->larray);
}
}
unsigned depth = loop_depth (father) + 1;
unsigned i;
- /* Remember the current loop depth if it is the largest seen so far. */
- cfun->max_loop_depth = MAX (cfun->max_loop_depth, (int) depth);
-
VEC_truncate (loop_p, loop->superloops, 0);
- VEC_reserve (loop_p, heap, loop->superloops, depth);
- for (i = 0; VEC_iterate (loop_p, father->superloops, i, ploop); i++)
+ VEC_reserve (loop_p, gc, loop->superloops, depth);
+ FOR_EACH_VEC_ELT (loop_p, father->superloops, i, ploop)
VEC_quick_push (loop_p, loop->superloops, ploop);
VEC_quick_push (loop_p, loop->superloops, father);
struct loop *
alloc_loop (void)
{
- struct loop *loop = XCNEW (struct loop);
+ struct loop *loop = ggc_alloc_cleared_loop ();
+
+ loop->exits = ggc_alloc_cleared_loop_exit ();
+ loop->exits->next = loop->exits->prev = loop->exits;
+ loop->can_be_parallel = false;
- loop->exits.next = loop->exits.prev = &loop->exits;
return loop;
}
+/* Initializes loops structure LOOPS, reserving place for NUM_LOOPS loops
+ (including the root of the loop tree). */
+
+static void
+init_loops_structure (struct loops *loops, unsigned num_loops)
+{
+ struct loop *root;
+
+ memset (loops, 0, sizeof *loops);
+ loops->larray = VEC_alloc (loop_p, gc, num_loops);
+
+ /* Dummy loop containing whole function. */
+ root = alloc_loop ();
+ root->num_nodes = n_basic_blocks;
+ root->latch = EXIT_BLOCK_PTR;
+ root->header = ENTRY_BLOCK_PTR;
+ ENTRY_BLOCK_PTR->loop_father = root;
+ EXIT_BLOCK_PTR->loop_father = root;
+
+ VEC_quick_push (loop_p, loops->larray, root);
+ loops->tree_root = root;
+}
+
/* Find all the natural loops in the function and save in LOOPS structure and
recalculate loop_depth information in basic block structures.
Return the number of natural loops found. */
int *rc_order;
basic_block header;
basic_block bb;
- struct loop *root;
-
- memset (loops, 0, sizeof *loops);
- /* We are going to recount the maximum loop depth,
- so throw away the last count. */
- cfun->max_loop_depth = 0;
+ /* Ensure that the dominators are computed. */
+ calculate_dominance_info (CDI_DOMINATORS);
/* Taking care of this degenerate case makes the rest of
this code simpler. */
if (n_basic_blocks == NUM_FIXED_BLOCKS)
- return 0;
+ {
+ init_loops_structure (loops, 1);
+ return 1;
+ }
dfs_order = NULL;
rc_order = NULL;
- /* Ensure that the dominators are computed. */
- calculate_dominance_info (CDI_DOMINATORS);
-
/* Count the number of loop headers. This should be the
same as the number of natural loops. */
headers = sbitmap_alloc (last_basic_block);
/* If we have an abnormal predecessor, do not consider the
loop (not worth the problems). */
- FOR_EACH_EDGE (e, ei, header->preds)
- if (e->flags & EDGE_ABNORMAL)
- break;
- if (e)
+ if (bb_has_abnormal_pred (header))
continue;
FOR_EACH_EDGE (e, ei, header->preds)
}
/* Allocate loop structures. */
- loops->larray = VEC_alloc (loop_p, heap, num_loops + 1);
-
- /* Dummy loop containing whole function. */
- root = alloc_loop ();
- root->num_nodes = n_basic_blocks;
- root->latch = EXIT_BLOCK_PTR;
- root->header = ENTRY_BLOCK_PTR;
- ENTRY_BLOCK_PTR->loop_father = root;
- EXIT_BLOCK_PTR->loop_father = root;
-
- VEC_quick_push (loop_p, loops->larray, root);
- loops->tree_root = root;
+ init_loops_structure (loops, num_loops + 1);
/* Find and record information about all the natural loops
in the CFG. */
sbitmap_free (headers);
loops->exits = NULL;
- loops->state = 0;
return VEC_length (loop_p, loops->larray);
}
profile is usually too flat and unreliable for this (and it is mostly based
on the loop structure of the program, so it does not make much sense to
derive the loop structure from it). */
-
+
static edge
find_subloop_latch_edge_by_profile (VEC (edge, heap) *latches)
{
edge e, me = NULL;
gcov_type mcount = 0, tcount = 0;
- for (i = 0; VEC_iterate (edge, latches, i, e); i++)
+ FOR_EACH_VEC_ELT (edge, latches, i, e)
{
if (e->count > mcount)
{
another edge. */
static edge
-find_subloop_latch_edge_by_ivs (struct loop *loop, VEC (edge, heap) *latches)
+find_subloop_latch_edge_by_ivs (struct loop *loop ATTRIBUTE_UNUSED, VEC (edge, heap) *latches)
{
edge e, latch = VEC_index (edge, latches, 0);
unsigned i;
- tree phi, lop;
+ gimple phi;
+ gimple_stmt_iterator psi;
+ tree lop;
basic_block bb;
/* Find the candidate for the latch edge. */
latch = e;
/* Verify that it dominates all the latch edges. */
- for (i = 0; VEC_iterate (edge, latches, i, e); i++)
+ FOR_EACH_VEC_ELT (edge, latches, i, e)
if (!dominated_by_p (CDI_DOMINATORS, e->src, latch->src))
return NULL;
/* Check for a phi node that would deny that this is a latch edge of
a subloop. */
- for (phi = phi_nodes (loop->header); phi; phi = PHI_CHAIN (phi))
+ for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi))
{
+ phi = gsi_stmt (psi);
lop = PHI_ARG_DEF_FROM_EDGE (phi, latch);
/* Ignore the values that are not changed inside the subloop. */
if (TREE_CODE (lop) != SSA_NAME
|| SSA_NAME_DEF_STMT (lop) == phi)
continue;
- bb = bb_for_stmt (SSA_NAME_DEF_STMT (lop));
+ bb = gimple_bb (SSA_NAME_DEF_STMT (lop));
if (!bb || !flow_bb_inside_loop_p (loop, bb))
continue;
- for (i = 0; VEC_iterate (edge, latches, i, e); i++)
+ FOR_EACH_VEC_ELT (edge, latches, i, e)
if (e != latch
&& PHI_ARG_DEF_FROM_EDGE (phi, e) == lop)
return NULL;
edge_iterator ei;
edge e, new_entry;
struct loop *new_loop;
-
+
mfb_reis_set = pointer_set_create ();
FOR_EACH_EDGE (e, ei, loop->header->preds)
{
fprintf (dump_file, "Merged latch edges of loop %d\n", loop->num);
mfb_reis_set = pointer_set_create ();
- for (i = 0; VEC_iterate (edge, latches, i, e); i++)
+ FOR_EACH_VEC_ELT (edge, latches, i, e)
pointer_set_insert (mfb_reis_set, e);
latch = make_forwarder_block (loop->header, mfb_redirect_edges_in_set,
NULL);
/* Return nonzero if basic block BB belongs to LOOP. */
bool
-flow_bb_inside_loop_p (const struct loop *loop, const basic_block bb)
+flow_bb_inside_loop_p (const struct loop *loop, const_basic_block bb)
{
struct loop *source_loop;
/* Enumeration predicate for get_loop_body_with_size. */
static bool
-glb_enum_p (basic_block bb, void *glb_loop)
+glb_enum_p (const_basic_block bb, const void *glb_loop)
{
- struct loop *loop = glb_loop;
+ const struct loop *const loop = (const struct loop *) glb_loop;
return (bb != loop->header
&& dominated_by_p (CDI_DOMINATORS, bb, loop->header));
}
unsigned max_size)
{
return dfs_enumerate_from (loop->header, 1, glb_enum_p,
- body, max_size, (void *) loop);
+ body, max_size, loop);
}
/* Gets basic blocks of a LOOP. Header is the 0-th block, rest is in dfs
return tovisit;
}
+/* Gets body of a LOOP sorted via provided BB_COMPARATOR. */
+
+basic_block *
+get_loop_body_in_custom_order (const struct loop *loop,
+ int (*bb_comparator) (const void *, const void *))
+{
+ basic_block *bbs = get_loop_body (loop);
+
+ qsort (bbs, loop->num_nodes, sizeof (basic_block), bb_comparator);
+
+ return bbs;
+}
+
/* Get body of a LOOP in breadth first sort order. */
basic_block *
edge e;
edge_iterator ei;
- if (!bitmap_bit_p (visited, bb->index))
- {
- /* This basic block is now visited */
- bitmap_set_bit (visited, bb->index);
- blocks[i++] = bb;
- }
+ if (bitmap_set_bit (visited, bb->index))
+ /* This basic block is now visited */
+ blocks[i++] = bb;
FOR_EACH_EDGE (e, ei, bb->succs)
{
if (flow_bb_inside_loop_p (loop, e->dest))
{
- if (!bitmap_bit_p (visited, e->dest->index))
- {
- bitmap_set_bit (visited, e->dest->index);
- blocks[i++] = e->dest;
- }
+ if (bitmap_set_bit (visited, e->dest->index))
+ blocks[i++] = e->dest;
}
}
static hashval_t
loop_exit_hash (const void *ex)
{
- struct loop_exit *exit = (struct loop_exit *) ex;
+ const struct loop_exit *const exit = (const struct loop_exit *) ex;
return htab_hash_pointer (exit->e);
}
static int
loop_exit_eq (const void *ex, const void *e)
{
- struct loop_exit *exit = (struct loop_exit *) ex;
+ const struct loop_exit *const exit = (const struct loop_exit *) ex;
return exit->e == e;
}
for (; exit; exit = next)
{
next = exit->next_e;
-
+
exit->next->prev = exit->prev;
exit->prev->next = exit->next;
- free (exit);
+ ggc_free (exit);
}
}
static struct loop_exit *
get_exit_descriptions (edge e)
{
- return htab_find_with_hash (current_loops->exits, e,
- htab_hash_pointer (e));
+ return (struct loop_exit *) htab_find_with_hash (current_loops->exits, e,
+ htab_hash_pointer (e));
}
/* Updates the lists of loop exits in that E appears.
struct loop_exit *exits = NULL, *exit;
struct loop *aloop, *cloop;
- if ((current_loops->state & LOOPS_HAVE_RECORDED_EXITS) == 0)
+ if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS))
return;
if (!removed
aloop != cloop;
aloop = loop_outer (aloop))
{
- exit = XNEW (struct loop_exit);
+ exit = ggc_alloc_loop_exit ();
exit->e = e;
- exit->next = aloop->exits.next;
- exit->prev = &aloop->exits;
+ exit->next = aloop->exits->next;
+ exit->prev = aloop->exits;
exit->next->prev = exit;
exit->prev->next = exit;
exit->next_e = exits;
exits = exit;
}
- }
+ }
if (!exits && new_edge)
return;
if (!current_loops)
return;
- if (current_loops->state & LOOPS_HAVE_RECORDED_EXITS)
+ if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS))
return;
- current_loops->state |= LOOPS_HAVE_RECORDED_EXITS;
+ loops_state_set (LOOPS_HAVE_RECORDED_EXITS);
gcc_assert (current_loops->exits == NULL);
- current_loops->exits = htab_create (2 * number_of_loops (),
- loop_exit_hash,
- loop_exit_eq,
- loop_exit_free);
+ current_loops->exits = htab_create_ggc (2 * number_of_loops (),
+ loop_exit_hash, loop_exit_eq,
+ loop_exit_free);
FOR_EACH_BB (bb)
{
static int
dump_recorded_exit (void **slot, void *file)
{
- struct loop_exit *exit = *slot;
+ struct loop_exit *exit = (struct loop_exit *) *slot;
unsigned n = 0;
edge e = exit->e;
for (; exit != NULL; exit = exit->next_e)
n++;
- fprintf (file, "Edge %d->%d exits %u loops\n",
+ fprintf ((FILE*) file, "Edge %d->%d exits %u loops\n",
e->src->index, e->dest->index, n);
return 1;
void
release_recorded_exits (void)
{
- gcc_assert (current_loops->state & LOOPS_HAVE_RECORDED_EXITS);
+ gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS));
htab_delete (current_loops->exits);
current_loops->exits = NULL;
- current_loops->state &= ~LOOPS_HAVE_RECORDED_EXITS;
+ loops_state_clear (LOOPS_HAVE_RECORDED_EXITS);
}
/* Returns the list of the exit edges of a LOOP. */
/* If we maintain the lists of exits, use them. Otherwise we must
scan the body of the loop. */
- if (current_loops->state & LOOPS_HAVE_RECORDED_EXITS)
+ if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS))
{
- for (exit = loop->exits.next; exit->e; exit = exit->next)
+ for (exit = loop->exits->next; exit->e; exit = exit->next)
VEC_safe_push (edge, heap, edges, exit->e);
}
else
bb->loop_father = loop;
bb->loop_depth = loop_depth (loop);
loop->num_nodes++;
- for (i = 0; VEC_iterate (loop_p, loop->superloops, i, ploop); i++)
+ FOR_EACH_VEC_ELT (loop_p, loop->superloops, i, ploop)
ploop->num_nodes++;
FOR_EACH_EDGE (e, ei, bb->succs)
gcc_assert (loop != NULL);
loop->num_nodes--;
- for (i = 0; VEC_iterate (loop_p, loop->superloops, i, ploop); i++)
+ FOR_EACH_VEC_ELT (loop_p, loop->superloops, i, ploop)
ploop->num_nodes--;
bb->loop_father = NULL;
bb->loop_depth = 0;
-- loop latches have only single successor that is header of their loop
-- irreducible loops are correctly marked
*/
-void
+DEBUG_FUNCTION void
verify_loop_structure (void)
{
unsigned *sizes, i, j;
{
i = loop->num;
- if ((current_loops->state & LOOPS_HAVE_PREHEADERS)
+ if (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS)
&& EDGE_COUNT (loop->header->preds) != 2)
{
- error ("loop %d's header does not have exactly 2 entries", i);
+ error ("loop %d%'s header does not have exactly 2 entries", i);
err = 1;
}
- if (current_loops->state & LOOPS_HAVE_SIMPLE_LATCHES)
+ if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES))
{
if (!single_succ_p (loop->latch))
{
- error ("loop %d's latch does not have exactly 1 successor", i);
+ error ("loop %d%'s latch does not have exactly 1 successor", i);
err = 1;
}
if (single_succ (loop->latch) != loop->header)
{
- error ("loop %d's latch does not have header as successor", i);
+ error ("loop %d%'s latch does not have header as successor", i);
err = 1;
}
if (loop->latch->loop_father != loop)
{
- error ("loop %d's latch does not belong directly to it", i);
+ error ("loop %d%'s latch does not belong directly to it", i);
err = 1;
}
}
if (loop->header->loop_father != loop)
{
- error ("loop %d's header does not belong directly to it", i);
+ error ("loop %d%'s header does not belong directly to it", i);
err = 1;
}
- if ((current_loops->state & LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)
+ if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)
&& (loop_latch_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP))
{
- error ("loop %d's latch is marked as part of irreducible region", i);
+ error ("loop %d%'s latch is marked as part of irreducible region", i);
err = 1;
}
}
/* Check irreducible loops. */
- if (current_loops->state & LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)
+ if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS))
{
/* Record old info. */
irreds = sbitmap_alloc (last_basic_block);
/* Check the recorded loop exits. */
FOR_EACH_LOOP (li, loop, 0)
{
- if (loop->exits.e != NULL)
+ if (!loop->exits || loop->exits->e != NULL)
{
error ("corrupted head of the exits list of loop %d",
loop->num);
{
/* Check that the list forms a cycle, and all elements except
for the head are nonnull. */
- for (mexit = &loop->exits, exit = mexit->next, i = 0;
+ for (mexit = loop->exits, exit = mexit->next, i = 0;
exit->e && exit != mexit;
exit = exit->next)
{
mexit = mexit->next;
}
- if (exit != &loop->exits)
+ if (exit != loop->exits)
{
error ("corrupted exits list of loop %d", loop->num);
err = 1;
}
}
- if ((current_loops->state & LOOPS_HAVE_RECORDED_EXITS) == 0)
+ if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS))
{
- if (loop->exits.next != &loop->exits)
+ if (loop->exits->next != loop->exits)
{
error ("nonempty exits list of loop %d, but exits are not recorded",
loop->num);
}
}
- if (current_loops->state & LOOPS_HAVE_RECORDED_EXITS)
+ if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS))
{
unsigned n_exits = 0, eloops;
exit = get_exit_descriptions (e);
if (!exit)
{
- error ("Exit %d->%d not recorded",
+ error ("exit %d->%d not recorded",
e->src->index, e->dest->index);
err = 1;
}
if (eloops != 0)
{
- error ("Wrong list of exited loops for edge %d->%d",
+ error ("wrong list of exited loops for edge %d->%d",
e->src->index, e->dest->index);
err = 1;
}
if (n_exits != htab_elements (current_loops->exits))
{
- error ("Too many loop exits recorded");
+ error ("too many loop exits recorded");
err = 1;
}
FOR_EACH_LOOP (li, loop, 0)
{
eloops = 0;
- for (exit = loop->exits.next; exit->e; exit = exit->next)
+ for (exit = loop->exits->next; exit->e; exit = exit->next)
eloops++;
if (eloops != sizes[loop->num])
{
edge e;
edge_iterator ei;
- gcc_assert ((current_loops->state & LOOPS_HAVE_PREHEADERS) != 0);
+ gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS));
FOR_EACH_EDGE (e, ei, loop->header->preds)
if (e->src != loop->latch)
/* Returns true if E is an exit of LOOP. */
bool
-loop_exit_edge_p (const struct loop *loop, edge e)
+loop_exit_edge_p (const struct loop *loop, const_edge e)
{
return (flow_bb_inside_loop_p (loop, e->src)
&& !flow_bb_inside_loop_p (loop, e->dest));
edge
single_exit (const struct loop *loop)
{
- struct loop_exit *exit = loop->exits.next;
+ struct loop_exit *exit = loop->exits->next;
- if ((current_loops->state & LOOPS_HAVE_RECORDED_EXITS) == 0)
+ if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS))
return NULL;
- if (exit->e && exit->next == &loop->exits)
+ if (exit->e && exit->next == loop->exits)
return exit->e;
else
return NULL;
}
+
+/* Returns true when BB has an incoming edge exiting LOOP. */
+
+bool
+loop_exits_to_bb_p (struct loop *loop, basic_block bb)
+{
+ edge e;
+ edge_iterator ei;
+
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ if (loop_exit_edge_p (loop, e))
+ return true;
+
+ return false;
+}
+
+/* Returns true when BB has an outgoing edge exiting LOOP. */
+
+bool
+loop_exits_from_bb_p (struct loop *loop, basic_block bb)
+{
+ edge e;
+ edge_iterator ei;
+
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ if (loop_exit_edge_p (loop, e))
+ return true;
+
+ return false;
+}