/* Natural loop discovery code for GNU compiler.
- Copyright (C) 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2010
- Free Software Foundation, Inc.
+ Copyright (C) 2000-2014 Free Software Foundation, Inc.
This file is part of GCC.
#include "coretypes.h"
#include "tm.h"
#include "rtl.h"
+#include "hashtab.h"
+#include "hash-set.h"
+#include "vec.h"
+#include "machmode.h"
#include "hard-reg-set.h"
-#include "obstack.h"
+#include "input.h"
#include "function.h"
+#include "predict.h"
+#include "dominance.h"
+#include "cfg.h"
+#include "cfganal.h"
#include "basic-block.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"
+#include "tree-ssa-alias.h"
+#include "internal-fn.h"
+#include "gimple-expr.h"
+#include "is-a.h"
+#include "gimple.h"
+#include "gimple-iterator.h"
+#include "gimple-ssa.h"
+#include "dumpfile.h"
static void flow_loops_cfg_dump (FILE *);
\f
if (!file)
return;
- FOR_EACH_BB (bb)
+ FOR_EACH_BB_FN (bb, cfun)
{
edge succ;
edge_iterator ei;
unsigned odepth = loop_depth (outer);
return (loop_depth (loop) > odepth
- && VEC_index (loop_p, loop->superloops, odepth) == outer);
+ && (*loop->superloops)[odepth] == outer);
}
/* Returns the loop such that LOOP is nested DEPTH (indexed from zero)
if (depth == ldepth)
return loop;
- return VEC_index (loop_p, loop->superloops, depth);
+ return (*loop->superloops)[depth];
}
/* Returns the list of the latch edges of LOOP. */
-static VEC (edge, heap) *
+static vec<edge>
get_loop_latch_edges (const struct loop *loop)
{
edge_iterator ei;
edge e;
- VEC (edge, heap) *ret = NULL;
+ vec<edge> ret = vNULL;
FOR_EACH_EDGE (e, ei, loop->header->preds)
{
if (dominated_by_p (CDI_DOMINATORS, e->src, loop->header))
- VEC_safe_push (edge, heap, ret, e);
+ ret.safe_push (e);
}
return ret;
{
basic_block *bbs;
unsigned i;
- VEC (edge, heap) *latches;
+ vec<edge> latches;
edge e;
if (! loop || ! loop->header)
{
fprintf (file, "multiple latches:");
latches = get_loop_latch_edges (loop);
- FOR_EACH_VEC_ELT (edge, latches, i, e)
+ FOR_EACH_VEC_ELT (latches, i, e)
fprintf (file, " %d", e->src->index);
- VEC_free (edge, heap, latches);
+ latches.release ();
fprintf (file, "\n");
}
void
flow_loops_dump (FILE *file, void (*loop_dump_aux) (const struct loop *, FILE *, int), int verbose)
{
- loop_iterator li;
struct loop *loop;
if (!current_loops || ! file)
return;
- fprintf (file, ";; %d loops found\n", number_of_loops ());
+ fprintf (file, ";; %d loops found\n", number_of_loops (cfun));
- FOR_EACH_LOOP (li, loop, LI_INCLUDE_ROOT)
+ FOR_EACH_LOOP (loop, LI_INCLUDE_ROOT)
{
flow_loop_dump (loop, file, loop_dump_aux, verbose);
}
{
struct loop_exit *exit, *next;
- VEC_free (loop_p, gc, loop->superloops);
+ vec_free (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
loop_p loop;
/* Free the loop descriptors. */
- FOR_EACH_VEC_ELT (loop_p, loops->larray, i, loop)
+ FOR_EACH_VEC_SAFE_ELT (loops->larray, i, loop)
{
if (!loop)
continue;
flow_loop_free (loop);
}
- VEC_free (loop_p, gc, loops->larray);
+ vec_free (loops->larray);
}
}
int
flow_loop_nodes_find (basic_block header, struct loop *loop)
{
- VEC (basic_block, heap) *stack = NULL;
+ vec<basic_block> stack = vNULL;
int num_nodes = 1;
edge latch;
edge_iterator latch_ei;
- unsigned depth = loop_depth (loop);
header->loop_father = loop;
- header->loop_depth = depth;
FOR_EACH_EDGE (latch, latch_ei, loop->header->preds)
{
continue;
num_nodes++;
- VEC_safe_push (basic_block, heap, stack, latch->src);
+ stack.safe_push (latch->src);
latch->src->loop_father = loop;
- latch->src->loop_depth = depth;
- while (!VEC_empty (basic_block, stack))
+ while (!stack.is_empty ())
{
basic_block node;
edge e;
edge_iterator ei;
- node = VEC_pop (basic_block, stack);
+ node = stack.pop ();
FOR_EACH_EDGE (e, ei, node->preds)
{
if (ancestor->loop_father != loop)
{
ancestor->loop_father = loop;
- ancestor->loop_depth = depth;
num_nodes++;
- VEC_safe_push (basic_block, heap, stack, ancestor);
+ stack.safe_push (ancestor);
}
}
}
}
- VEC_free (basic_block, heap, stack);
+ stack.release ();
return num_nodes;
}
unsigned depth = loop_depth (father) + 1;
unsigned i;
- VEC_truncate (loop_p, loop->superloops, 0);
- 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);
+ loop->superloops = 0;
+ vec_alloc (loop->superloops, depth);
+ FOR_EACH_VEC_SAFE_ELT (father->superloops, i, ploop)
+ loop->superloops->quick_push (ploop);
+ loop->superloops->quick_push (father);
for (ploop = loop->inner; ploop; ploop = ploop->next)
establish_preds (ploop, loop);
prev->next = loop->next;
}
- VEC_truncate (loop_p, loop->superloops, 0);
+ loop->superloops = NULL;
}
/* Allocates and returns new loop structure. */
struct loop *
alloc_loop (void)
{
- struct loop *loop = ggc_alloc_cleared_loop ();
+ struct loop *loop = ggc_cleared_alloc<struct loop> ();
- loop->exits = ggc_alloc_cleared_loop_exit ();
+ loop->exits = ggc_cleared_alloc<loop_exit> ();
loop->exits->next = loop->exits->prev = loop->exits;
loop->can_be_parallel = false;
-
+ loop->nb_iterations_upper_bound = 0;
+ loop->nb_iterations_estimate = 0;
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)
+void
+init_loops_structure (struct function *fn,
+ struct loops *loops, unsigned num_loops)
{
struct loop *root;
memset (loops, 0, sizeof *loops);
- loops->larray = VEC_alloc (loop_p, gc, num_loops);
+ vec_alloc (loops->larray, 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;
+ root->num_nodes = n_basic_blocks_for_fn (fn);
+ root->latch = EXIT_BLOCK_PTR_FOR_FN (fn);
+ root->header = ENTRY_BLOCK_PTR_FOR_FN (fn);
+ ENTRY_BLOCK_PTR_FOR_FN (fn)->loop_father = root;
+ EXIT_BLOCK_PTR_FOR_FN (fn)->loop_father = root;
- VEC_quick_push (loop_p, loops->larray, root);
+ loops->larray->quick_push (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. */
+/* Returns whether HEADER is a loop header. */
-int
-flow_loops_find (struct loops *loops)
+bool
+bb_loop_header_p (basic_block header)
{
- int b;
- int num_loops;
+ edge_iterator ei;
edge e;
- sbitmap headers;
- int *dfs_order;
+
+ /* If we have an abnormal predecessor, do not consider the
+ loop (not worth the problems). */
+ if (bb_has_abnormal_pred (header))
+ return false;
+
+ /* Look for back edges where a predecessor is dominated
+ by this block. A natural loop has a single entry
+ node (header) that dominates all the nodes in the
+ loop. It also has single back edge to the header
+ from a latch node. */
+ FOR_EACH_EDGE (e, ei, header->preds)
+ {
+ basic_block latch = e->src;
+ if (latch != ENTRY_BLOCK_PTR_FOR_FN (cfun)
+ && dominated_by_p (CDI_DOMINATORS, latch, header))
+ return true;
+ }
+
+ return false;
+}
+
+/* Find all the natural loops in the function and save in LOOPS structure and
+ recalculate loop_father information in basic block structures.
+ If LOOPS is non-NULL then the loop structures for already recorded loops
+ will be re-used and their number will not change. We assume that no
+ stale loops exist in LOOPS.
+ When LOOPS is NULL it is allocated and re-built from scratch.
+ Return the built LOOPS structure. */
+
+struct loops *
+flow_loops_find (struct loops *loops)
+{
+ bool from_scratch = (loops == NULL);
int *rc_order;
- basic_block header;
- basic_block bb;
+ int b;
+ unsigned i;
/* 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)
+ if (!loops)
{
- init_loops_structure (loops, 1);
- return 1;
+ loops = ggc_cleared_alloc<struct loops> ();
+ init_loops_structure (cfun, loops, 1);
}
- dfs_order = NULL;
- rc_order = NULL;
+ /* Ensure that loop exits were released. */
+ gcc_assert (loops->exits == NULL);
- /* Count the number of loop headers. This should be the
- same as the number of natural loops. */
- headers = sbitmap_alloc (last_basic_block);
- sbitmap_zero (headers);
+ /* Taking care of this degenerate case makes the rest of
+ this code simpler. */
+ if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS)
+ return loops;
- num_loops = 0;
- FOR_EACH_BB (header)
- {
- edge_iterator ei;
+ /* The root loop node contains all basic-blocks. */
+ loops->tree_root->num_nodes = n_basic_blocks_for_fn (cfun);
- header->loop_depth = 0;
+ /* Compute depth first search order of the CFG so that outer
+ natural loops will be found before inner natural loops. */
+ rc_order = XNEWVEC (int, n_basic_blocks_for_fn (cfun));
+ pre_and_rev_post_order_compute (NULL, rc_order, false);
- /* If we have an abnormal predecessor, do not consider the
- loop (not worth the problems). */
- if (bb_has_abnormal_pred (header))
- continue;
-
- FOR_EACH_EDGE (e, ei, header->preds)
+ /* Gather all loop headers in reverse completion order and allocate
+ loop structures for loops that are not already present. */
+ auto_vec<loop_p> larray (loops->larray->length ());
+ for (b = 0; b < n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS; b++)
+ {
+ basic_block header = BASIC_BLOCK_FOR_FN (cfun, rc_order[b]);
+ if (bb_loop_header_p (header))
{
- basic_block latch = e->src;
-
- gcc_assert (!(e->flags & EDGE_ABNORMAL));
+ struct loop *loop;
- /* Look for back edges where a predecessor is dominated
- by this block. A natural loop has a single entry
- node (header) that dominates all the nodes in the
- loop. It also has single back edge to the header
- from a latch node. */
- if (latch != ENTRY_BLOCK_PTR
- && dominated_by_p (CDI_DOMINATORS, latch, header))
+ /* The current active loop tree has valid loop-fathers for
+ header blocks. */
+ if (!from_scratch
+ && header->loop_father->header == header)
+ {
+ loop = header->loop_father;
+ /* If we found an existing loop remove it from the
+ loop tree. It is going to be inserted again
+ below. */
+ flow_loop_tree_node_remove (loop);
+ }
+ else
{
- /* Shared headers should be eliminated by now. */
- SET_BIT (headers, header->index);
- num_loops++;
+ /* Otherwise allocate a new loop structure for the loop. */
+ loop = alloc_loop ();
+ /* ??? We could re-use unused loop slots here. */
+ loop->num = loops->larray->length ();
+ vec_safe_push (loops->larray, loop);
+ loop->header = header;
+
+ if (!from_scratch
+ && dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "flow_loops_find: discovered new "
+ "loop %d with header %d\n",
+ loop->num, header->index);
}
+ /* Reset latch, we recompute it below. */
+ loop->latch = NULL;
+ larray.safe_push (loop);
}
- }
- /* Allocate loop structures. */
- init_loops_structure (loops, num_loops + 1);
+ /* Make blocks part of the loop root node at start. */
+ header->loop_father = loops->tree_root;
+ }
- /* Find and record information about all the natural loops
- in the CFG. */
- FOR_EACH_BB (bb)
- bb->loop_father = loops->tree_root;
+ free (rc_order);
- if (num_loops)
+ /* Now iterate over the loops found, insert them into the loop tree
+ and assign basic-block ownership. */
+ for (i = 0; i < larray.length (); ++i)
{
- /* Compute depth first search order of the CFG so that outer
- natural loops will be found before inner natural loops. */
- dfs_order = XNEWVEC (int, n_basic_blocks);
- rc_order = XNEWVEC (int, n_basic_blocks);
- pre_and_rev_post_order_compute (dfs_order, rc_order, false);
+ struct loop *loop = larray[i];
+ basic_block header = loop->header;
+ edge_iterator ei;
+ edge e;
- num_loops = 1;
+ flow_loop_tree_node_add (header->loop_father, loop);
+ loop->num_nodes = flow_loop_nodes_find (loop->header, loop);
- for (b = 0; b < n_basic_blocks - NUM_FIXED_BLOCKS; b++)
+ /* Look for the latch for this header block, if it has just a
+ single one. */
+ FOR_EACH_EDGE (e, ei, header->preds)
{
- struct loop *loop;
- edge_iterator ei;
-
- /* Search the nodes of the CFG in reverse completion order
- so that we can find outer loops first. */
- if (!TEST_BIT (headers, rc_order[b]))
- continue;
-
- header = BASIC_BLOCK (rc_order[b]);
-
- loop = alloc_loop ();
- VEC_quick_push (loop_p, loops->larray, loop);
-
- loop->header = header;
- loop->num = num_loops;
- num_loops++;
-
- flow_loop_tree_node_add (header->loop_father, loop);
- loop->num_nodes = flow_loop_nodes_find (loop->header, loop);
+ basic_block latch = e->src;
- /* Look for the latch for this header block, if it has just a
- single one. */
- FOR_EACH_EDGE (e, ei, header->preds)
+ if (flow_bb_inside_loop_p (loop, latch))
{
- basic_block latch = e->src;
-
- if (flow_bb_inside_loop_p (loop, latch))
+ if (loop->latch != NULL)
{
- if (loop->latch != NULL)
- {
- /* More than one latch edge. */
- loop->latch = NULL;
- break;
- }
- loop->latch = latch;
+ /* More than one latch edge. */
+ loop->latch = NULL;
+ break;
}
+ loop->latch = latch;
}
}
-
- free (dfs_order);
- free (rc_order);
}
- sbitmap_free (headers);
-
- loops->exits = NULL;
- return VEC_length (loop_p, loops->larray);
+ return loops;
}
/* Ratio of frequencies of edges so that one of more latch edges is
derive the loop structure from it). */
static edge
-find_subloop_latch_edge_by_profile (VEC (edge, heap) *latches)
+find_subloop_latch_edge_by_profile (vec<edge> latches)
{
unsigned i;
edge e, me = NULL;
gcov_type mcount = 0, tcount = 0;
- FOR_EACH_VEC_ELT (edge, latches, i, e)
+ FOR_EACH_VEC_ELT (latches, i, e)
{
if (e->count > mcount)
{
another edge. */
static edge
-find_subloop_latch_edge_by_ivs (struct loop *loop ATTRIBUTE_UNUSED, VEC (edge, heap) *latches)
+find_subloop_latch_edge_by_ivs (struct loop *loop ATTRIBUTE_UNUSED, vec<edge> latches)
{
- edge e, latch = VEC_index (edge, latches, 0);
+ edge e, latch = latches[0];
unsigned i;
gimple phi;
gimple_stmt_iterator psi;
basic_block bb;
/* Find the candidate for the latch edge. */
- for (i = 1; VEC_iterate (edge, latches, i, e); i++)
+ for (i = 1; latches.iterate (i, &e); i++)
if (dominated_by_p (CDI_DOMINATORS, latch->src, e->src))
latch = e;
/* Verify that it dominates all the latch edges. */
- FOR_EACH_VEC_ELT (edge, latches, i, e)
+ FOR_EACH_VEC_ELT (latches, i, e)
if (!dominated_by_p (CDI_DOMINATORS, e->src, latch->src))
return NULL;
if (!bb || !flow_bb_inside_loop_p (loop, bb))
continue;
- FOR_EACH_VEC_ELT (edge, latches, i, e)
+ FOR_EACH_VEC_ELT (latches, i, e)
if (e != latch
&& PHI_ARG_DEF_FROM_EDGE (phi, e) == lop)
return NULL;
static edge
find_subloop_latch_edge (struct loop *loop)
{
- VEC (edge, heap) *latches = get_loop_latch_edges (loop);
+ vec<edge> latches = get_loop_latch_edges (loop);
edge latch = NULL;
- if (VEC_length (edge, latches) > 1)
+ if (latches.length () > 1)
{
latch = find_subloop_latch_edge_by_profile (latches);
latch = find_subloop_latch_edge_by_ivs (loop, latches);
}
- VEC_free (edge, heap, latches);
+ latches.release ();
return latch;
}
/* Callback for make_forwarder_block. Returns true if the edge E is marked
in the set MFB_REIS_SET. */
-static struct pointer_set_t *mfb_reis_set;
+static hash_set<edge> *mfb_reis_set;
static bool
mfb_redirect_edges_in_set (edge e)
{
- return pointer_set_contains (mfb_reis_set, e);
+ return mfb_reis_set->contains (e);
}
/* Creates a subloop of LOOP with latch edge LATCH. */
edge e, new_entry;
struct loop *new_loop;
- mfb_reis_set = pointer_set_create ();
+ mfb_reis_set = new hash_set<edge>;
FOR_EACH_EDGE (e, ei, loop->header->preds)
{
if (e != latch)
- pointer_set_insert (mfb_reis_set, e);
+ mfb_reis_set->add (e);
}
new_entry = make_forwarder_block (loop->header, mfb_redirect_edges_in_set,
NULL);
- pointer_set_destroy (mfb_reis_set);
+ delete mfb_reis_set;
loop->header = new_entry->src;
static void
merge_latch_edges (struct loop *loop)
{
- VEC (edge, heap) *latches = get_loop_latch_edges (loop);
+ vec<edge> latches = get_loop_latch_edges (loop);
edge latch, e;
unsigned i;
- gcc_assert (VEC_length (edge, latches) > 0);
+ gcc_assert (latches.length () > 0);
- if (VEC_length (edge, latches) == 1)
- loop->latch = VEC_index (edge, latches, 0)->src;
+ if (latches.length () == 1)
+ loop->latch = latches[0]->src;
else
{
if (dump_file)
fprintf (dump_file, "Merged latch edges of loop %d\n", loop->num);
- mfb_reis_set = pointer_set_create ();
- FOR_EACH_VEC_ELT (edge, latches, i, e)
- pointer_set_insert (mfb_reis_set, e);
+ mfb_reis_set = new hash_set<edge>;
+ FOR_EACH_VEC_ELT (latches, i, e)
+ mfb_reis_set->add (e);
latch = make_forwarder_block (loop->header, mfb_redirect_edges_in_set,
NULL);
- pointer_set_destroy (mfb_reis_set);
+ delete mfb_reis_set;
loop->header = latch->dest;
loop->latch = latch->src;
}
- VEC_free (edge, heap, latches);
+ latches.release ();
}
/* LOOP may have several latch edges. Transform it into (possibly several)
block. This would cause problems if the entry edge was the one from the
entry block. To avoid having to handle this case specially, split
such entry edge. */
- e = find_edge (ENTRY_BLOCK_PTR, loop->header);
+ e = find_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun), loop->header);
if (e)
split_edge (e);
void
disambiguate_loops_with_multiple_latches (void)
{
- loop_iterator li;
struct loop *loop;
- FOR_EACH_LOOP (li, loop, 0)
+ FOR_EACH_LOOP (loop, 0)
{
if (!loop->latch)
disambiguate_multiple_latches (loop);
{
struct loop *source_loop;
- if (bb == ENTRY_BLOCK_PTR || bb == EXIT_BLOCK_PTR)
+ if (bb == ENTRY_BLOCK_PTR_FOR_FN (cfun)
+ || bb == EXIT_BLOCK_PTR_FOR_FN (cfun))
return 0;
source_loop = bb->loop_father;
gcc_assert (loop->num_nodes);
- body = XCNEWVEC (basic_block, loop->num_nodes);
+ body = XNEWVEC (basic_block, loop->num_nodes);
- if (loop->latch == EXIT_BLOCK_PTR)
+ if (loop->latch == EXIT_BLOCK_PTR_FOR_FN (cfun))
{
/* There may be blocks unreachable from EXIT_BLOCK, hence we need to
special-case the fake loop that contains the whole function. */
- gcc_assert (loop->num_nodes == (unsigned) n_basic_blocks);
+ gcc_assert (loop->num_nodes == (unsigned) n_basic_blocks_for_fn (cfun));
body[tv++] = loop->header;
- body[tv++] = EXIT_BLOCK_PTR;
- FOR_EACH_BB (bb)
+ body[tv++] = EXIT_BLOCK_PTR_FOR_FN (cfun);
+ FOR_EACH_BB_FN (bb, cfun)
body[tv++] = bb;
}
else
gcc_assert (loop->num_nodes);
- tovisit = XCNEWVEC (basic_block, loop->num_nodes);
+ tovisit = XNEWVEC (basic_block, loop->num_nodes);
- gcc_assert (loop->latch != EXIT_BLOCK_PTR);
+ gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun));
tv = 0;
fill_sons_in_loop (loop, loop->header, tovisit, &tv);
unsigned int vc = 1;
gcc_assert (loop->num_nodes);
- gcc_assert (loop->latch != EXIT_BLOCK_PTR);
+ gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun));
- blocks = XCNEWVEC (basic_block, loop->num_nodes);
+ blocks = XNEWVEC (basic_block, loop->num_nodes);
visited = BITMAP_ALLOC (NULL);
bb = loop->header;
/* Hash function for struct loop_exit. */
-static hashval_t
-loop_exit_hash (const void *ex)
+hashval_t
+loop_exit_hasher::hash (loop_exit *exit)
{
- const struct loop_exit *const exit = (const struct loop_exit *) ex;
-
return htab_hash_pointer (exit->e);
}
/* Equality function for struct loop_exit. Compares with edge. */
-static int
-loop_exit_eq (const void *ex, const void *e)
+bool
+loop_exit_hasher::equal (loop_exit *exit, edge e)
{
- const struct loop_exit *const exit = (const struct loop_exit *) ex;
-
return exit->e == e;
}
/* Frees the list of loop exit descriptions EX. */
-static void
-loop_exit_free (void *ex)
+void
+loop_exit_hasher::remove (loop_exit *exit)
{
- struct loop_exit *exit = (struct loop_exit *) ex, *next;
-
+ loop_exit *next;
for (; exit; exit = next)
{
next = exit->next_e;
static struct loop_exit *
get_exit_descriptions (edge e)
{
- return (struct loop_exit *) htab_find_with_hash (current_loops->exits, e,
- htab_hash_pointer (e));
+ return current_loops->exits->find_with_hash (e, htab_hash_pointer (e));
}
/* Updates the lists of loop exits in that E appears.
void
rescan_loop_exit (edge e, bool new_edge, bool removed)
{
- void **slot;
struct loop_exit *exits = NULL, *exit;
struct loop *aloop, *cloop;
aloop != cloop;
aloop = loop_outer (aloop))
{
- exit = ggc_alloc_loop_exit ();
+ exit = ggc_alloc<loop_exit> ();
exit->e = e;
exit->next = aloop->exits->next;
if (!exits && new_edge)
return;
- slot = htab_find_slot_with_hash (current_loops->exits, e,
- htab_hash_pointer (e),
- exits ? INSERT : NO_INSERT);
+ loop_exit **slot
+ = current_loops->exits->find_slot_with_hash (e, htab_hash_pointer (e),
+ exits ? INSERT : NO_INSERT);
if (!slot)
return;
if (exits)
{
if (*slot)
- loop_exit_free (*slot);
+ loop_exit_hasher::remove (*slot);
*slot = exits;
}
else
- htab_clear_slot (current_loops->exits, slot);
+ current_loops->exits->clear_slot (slot);
}
/* For each loop, record list of exit edges, and start maintaining these
loops_state_set (LOOPS_HAVE_RECORDED_EXITS);
gcc_assert (current_loops->exits == NULL);
- current_loops->exits = htab_create_ggc (2 * number_of_loops (),
- loop_exit_hash, loop_exit_eq,
- loop_exit_free);
+ current_loops->exits
+ = hash_table<loop_exit_hasher>::create_ggc (2 * number_of_loops (cfun));
- FOR_EACH_BB (bb)
+ FOR_EACH_BB_FN (bb, cfun)
{
FOR_EACH_EDGE (e, ei, bb->succs)
{
/* Dumps information about the exit in *SLOT to FILE.
Callback for htab_traverse. */
-static int
-dump_recorded_exit (void **slot, void *file)
+int
+dump_recorded_exit (loop_exit **slot, FILE *file)
{
- struct loop_exit *exit = (struct loop_exit *) *slot;
+ struct loop_exit *exit = *slot;
unsigned n = 0;
edge e = exit->e;
for (; exit != NULL; exit = exit->next_e)
n++;
- fprintf ((FILE*) file, "Edge %d->%d exits %u loops\n",
+ fprintf (file, "Edge %d->%d exits %u loops\n",
e->src->index, e->dest->index, n);
return 1;
{
if (!current_loops->exits)
return;
- htab_traverse (current_loops->exits, dump_recorded_exit, file);
+ current_loops->exits->traverse<FILE *, dump_recorded_exit> (file);
}
/* Releases lists of loop exits. */
release_recorded_exits (void)
{
gcc_assert (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS));
- htab_delete (current_loops->exits);
+ current_loops->exits->empty ();
current_loops->exits = NULL;
loops_state_clear (LOOPS_HAVE_RECORDED_EXITS);
}
/* Returns the list of the exit edges of a LOOP. */
-VEC (edge, heap) *
+vec<edge>
get_loop_exit_edges (const struct loop *loop)
{
- VEC (edge, heap) *edges = NULL;
+ vec<edge> edges = vNULL;
edge e;
unsigned i;
basic_block *body;
edge_iterator ei;
struct loop_exit *exit;
- gcc_assert (loop->latch != EXIT_BLOCK_PTR);
+ gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun));
/* If we maintain the lists of exits, use them. Otherwise we must
scan the body of the loop. */
if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS))
{
for (exit = loop->exits->next; exit->e; exit = exit->next)
- VEC_safe_push (edge, heap, edges, exit->e);
+ edges.safe_push (exit->e);
}
else
{
FOR_EACH_EDGE (e, ei, body[i]->succs)
{
if (!flow_bb_inside_loop_p (loop, e->dest))
- VEC_safe_push (edge, heap, edges, e);
+ edges.safe_push (e);
}
free (body);
}
unsigned i, n;
basic_block * body;
- gcc_assert (loop->latch != EXIT_BLOCK_PTR);
+ gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun));
body = get_loop_body (loop);
n = 0;
gcc_assert (bb->loop_father == NULL);
bb->loop_father = loop;
- bb->loop_depth = loop_depth (loop);
loop->num_nodes++;
- FOR_EACH_VEC_ELT (loop_p, loop->superloops, i, ploop)
+ FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop)
ploop->num_nodes++;
FOR_EACH_EDGE (e, ei, bb->succs)
void
remove_bb_from_loops (basic_block bb)
{
- int i;
+ unsigned i;
struct loop *loop = bb->loop_father;
loop_p ploop;
edge_iterator ei;
gcc_assert (loop != NULL);
loop->num_nodes--;
- FOR_EACH_VEC_ELT (loop_p, loop->superloops, i, ploop)
+ FOR_EACH_VEC_SAFE_ELT (loop->superloops, i, ploop)
ploop->num_nodes--;
bb->loop_father = NULL;
- bb->loop_depth = 0;
FOR_EACH_EDGE (e, ei, bb->succs)
{
ddepth = loop_depth (loop_d);
if (sdepth < ddepth)
- loop_d = VEC_index (loop_p, loop_d->superloops, sdepth);
+ loop_d = (*loop_d->superloops)[sdepth];
else if (sdepth > ddepth)
- loop_s = VEC_index (loop_p, loop_s->superloops, ddepth);
+ loop_s = (*loop_s->superloops)[ddepth];
while (loop_s != loop_d)
{
flow_loop_tree_node_remove (loop);
/* Remove loop from loops array. */
- VEC_replace (loop_p, current_loops->larray, loop->num, NULL);
+ (*current_loops->larray)[loop->num] = NULL;
/* Free loop data. */
flow_loop_free (loop);
-- loop header have just single entry edge and single latch edge
-- loop latches have only single successor that is header of their loop
-- irreducible loops are correctly marked
+ -- the cached loop depth and loop father of each bb is correct
*/
DEBUG_FUNCTION void
verify_loop_structure (void)
{
unsigned *sizes, i, j;
sbitmap irreds;
- basic_block *bbs, bb;
+ basic_block bb, *bbs;
struct loop *loop;
int err = 0;
edge e;
- unsigned num = number_of_loops ();
- loop_iterator li;
+ unsigned num = number_of_loops (cfun);
struct loop_exit *exit, *mexit;
+ bool dom_available = dom_info_available_p (CDI_DOMINATORS);
+ sbitmap visited;
- /* Check sizes. */
- sizes = XCNEWVEC (unsigned, num);
- sizes[0] = 2;
+ if (loops_state_satisfies_p (LOOPS_NEED_FIXUP))
+ {
+ error ("loop verification on loop tree that needs fixup");
+ err = 1;
+ }
- FOR_EACH_BB (bb)
- for (loop = bb->loop_father; loop; loop = loop_outer (loop))
- sizes[loop->num]++;
+ /* We need up-to-date dominators, compute or verify them. */
+ if (!dom_available)
+ calculate_dominance_info (CDI_DOMINATORS);
+ else
+ verify_dominators (CDI_DOMINATORS);
- FOR_EACH_LOOP (li, loop, LI_INCLUDE_ROOT)
+ /* Check the headers. */
+ FOR_EACH_BB_FN (bb, cfun)
+ if (bb_loop_header_p (bb))
+ {
+ if (bb->loop_father->header == NULL)
+ {
+ error ("loop with header %d marked for removal", bb->index);
+ err = 1;
+ }
+ else if (bb->loop_father->header != bb)
+ {
+ error ("loop with header %d not in loop tree", bb->index);
+ err = 1;
+ }
+ }
+ else if (bb->loop_father->header == bb)
+ {
+ error ("non-loop with header %d not marked for removal", bb->index);
+ err = 1;
+ }
+
+ /* Check the recorded loop father and sizes of loops. */
+ visited = sbitmap_alloc (last_basic_block_for_fn (cfun));
+ bitmap_clear (visited);
+ bbs = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun));
+ FOR_EACH_LOOP (loop, LI_FROM_INNERMOST)
{
- i = loop->num;
+ unsigned n;
- if (loop->num_nodes != sizes[i])
+ if (loop->header == NULL)
+ {
+ error ("removed loop %d in loop tree", loop->num);
+ err = 1;
+ continue;
+ }
+
+ n = get_loop_body_with_size (loop, bbs, n_basic_blocks_for_fn (cfun));
+ if (loop->num_nodes != n)
{
error ("size of loop %d should be %d, not %d",
- i, sizes[i], loop->num_nodes);
+ loop->num, n, loop->num_nodes);
err = 1;
}
- }
- /* Check get_loop_body. */
- FOR_EACH_LOOP (li, loop, 0)
- {
- bbs = get_loop_body (loop);
+ for (j = 0; j < n; j++)
+ {
+ bb = bbs[j];
- for (j = 0; j < loop->num_nodes; j++)
- if (!flow_bb_inside_loop_p (loop, bbs[j]))
- {
- error ("bb %d do not belong to loop %d",
- bbs[j]->index, loop->num);
- err = 1;
- }
- free (bbs);
+ if (!flow_bb_inside_loop_p (loop, bb))
+ {
+ error ("bb %d does not belong to loop %d",
+ bb->index, loop->num);
+ err = 1;
+ }
+
+ /* Ignore this block if it is in an inner loop. */
+ if (bitmap_bit_p (visited, bb->index))
+ continue;
+ bitmap_set_bit (visited, bb->index);
+
+ if (bb->loop_father != loop)
+ {
+ error ("bb %d has father loop %d, should be loop %d",
+ bb->index, bb->loop_father->num, loop->num);
+ err = 1;
+ }
+ }
}
+ free (bbs);
+ sbitmap_free (visited);
/* Check headers and latches. */
- FOR_EACH_LOOP (li, loop, 0)
+ FOR_EACH_LOOP (loop, 0)
{
i = loop->num;
-
+ if (loop->header == NULL)
+ continue;
+ if (!bb_loop_header_p (loop->header))
+ {
+ error ("loop %d%'s header is not a loop header", i);
+ err = 1;
+ }
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);
err = 1;
}
+ if (loop->latch)
+ {
+ if (!find_edge (loop->latch, loop->header))
+ {
+ error ("loop %d%'s latch does not have an edge to its header", i);
+ err = 1;
+ }
+ if (!dominated_by_p (CDI_DOMINATORS, loop->latch, loop->header))
+ {
+ error ("loop %d%'s latch is not dominated by its header", i);
+ err = 1;
+ }
+ }
if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES))
{
if (!single_succ_p (loop->latch))
if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS))
{
/* Record old info. */
- irreds = sbitmap_alloc (last_basic_block);
- FOR_EACH_BB (bb)
+ irreds = sbitmap_alloc (last_basic_block_for_fn (cfun));
+ FOR_EACH_BB_FN (bb, cfun)
{
edge_iterator ei;
if (bb->flags & BB_IRREDUCIBLE_LOOP)
- SET_BIT (irreds, bb->index);
+ bitmap_set_bit (irreds, bb->index);
else
- RESET_BIT (irreds, bb->index);
+ bitmap_clear_bit (irreds, bb->index);
FOR_EACH_EDGE (e, ei, bb->succs)
if (e->flags & EDGE_IRREDUCIBLE_LOOP)
e->flags |= EDGE_ALL_FLAGS + 1;
mark_irreducible_loops ();
/* Compare. */
- FOR_EACH_BB (bb)
+ FOR_EACH_BB_FN (bb, cfun)
{
edge_iterator ei;
if ((bb->flags & BB_IRREDUCIBLE_LOOP)
- && !TEST_BIT (irreds, bb->index))
+ && !bitmap_bit_p (irreds, bb->index))
{
error ("basic block %d should be marked irreducible", bb->index);
err = 1;
}
else if (!(bb->flags & BB_IRREDUCIBLE_LOOP)
- && TEST_BIT (irreds, bb->index))
+ && bitmap_bit_p (irreds, bb->index))
{
error ("basic block %d should not be marked irreducible", bb->index);
err = 1;
}
/* Check the recorded loop exits. */
- FOR_EACH_LOOP (li, loop, 0)
+ FOR_EACH_LOOP (loop, 0)
{
if (!loop->exits || loop->exits->e != NULL)
{
{
unsigned n_exits = 0, eloops;
+ sizes = XCNEWVEC (unsigned, num);
memset (sizes, 0, sizeof (unsigned) * num);
- FOR_EACH_BB (bb)
+ FOR_EACH_BB_FN (bb, cfun)
{
edge_iterator ei;
if (bb->loop_father == current_loops->tree_root)
eloops++;
for (loop = bb->loop_father;
- loop != e->dest->loop_father;
+ loop != e->dest->loop_father
+ /* When a loop exit is also an entry edge which
+ can happen when avoiding CFG manipulations
+ then the last loop exited is the outer loop
+ of the loop entered. */
+ && loop != loop_outer (e->dest->loop_father);
loop = loop_outer (loop))
{
eloops--;
}
}
- if (n_exits != htab_elements (current_loops->exits))
+ if (n_exits != current_loops->exits->elements ())
{
error ("too many loop exits recorded");
err = 1;
}
- FOR_EACH_LOOP (li, loop, 0)
+ FOR_EACH_LOOP (loop, 0)
{
eloops = 0;
for (exit = loop->exits->next; exit->e; exit = exit->next)
err = 1;
}
}
+
+ free (sizes);
}
gcc_assert (!err);
- free (sizes);
+ if (!dom_available)
+ free_dominance_info (CDI_DOMINATORS);
}
/* Returns latch edge of LOOP. */
return false;
}
+
+/* Return location corresponding to the loop control condition if possible. */
+
+location_t
+get_loop_location (struct loop *loop)
+{
+ rtx_insn *insn = NULL;
+ struct niter_desc *desc = NULL;
+ edge exit;
+
+ /* For a for or while loop, we would like to return the location
+ of the for or while statement, if possible. To do this, look
+ for the branch guarding the loop back-edge. */
+
+ /* If this is a simple loop with an in_edge, then the loop control
+ branch is typically at the end of its source. */
+ desc = get_simple_loop_desc (loop);
+ if (desc->in_edge)
+ {
+ FOR_BB_INSNS_REVERSE (desc->in_edge->src, insn)
+ {
+ if (INSN_P (insn) && INSN_HAS_LOCATION (insn))
+ return INSN_LOCATION (insn);
+ }
+ }
+ /* If loop has a single exit, then the loop control branch
+ must be at the end of its source. */
+ if ((exit = single_exit (loop)))
+ {
+ FOR_BB_INSNS_REVERSE (exit->src, insn)
+ {
+ if (INSN_P (insn) && INSN_HAS_LOCATION (insn))
+ return INSN_LOCATION (insn);
+ }
+ }
+ /* Next check the latch, to see if it is non-empty. */
+ FOR_BB_INSNS_REVERSE (loop->latch, insn)
+ {
+ if (INSN_P (insn) && INSN_HAS_LOCATION (insn))
+ return INSN_LOCATION (insn);
+ }
+ /* Finally, if none of the above identifies the loop control branch,
+ return the first location in the loop header. */
+ FOR_BB_INSNS (loop->header, insn)
+ {
+ if (INSN_P (insn) && INSN_HAS_LOCATION (insn))
+ return INSN_LOCATION (insn);
+ }
+ /* If all else fails, simply return the current function location. */
+ return DECL_SOURCE_LOCATION (current_function_decl);
+}
+
+/* Records that every statement in LOOP is executed I_BOUND times.
+ REALISTIC is true if I_BOUND is expected to be close to the real number
+ of iterations. UPPER is true if we are sure the loop iterates at most
+ I_BOUND times. */
+
+void
+record_niter_bound (struct loop *loop, const widest_int &i_bound,
+ bool realistic, bool upper)
+{
+ /* Update the bounds only when there is no previous estimation, or when the
+ current estimation is smaller. */
+ if (upper
+ && (!loop->any_upper_bound
+ || wi::ltu_p (i_bound, loop->nb_iterations_upper_bound)))
+ {
+ loop->any_upper_bound = true;
+ loop->nb_iterations_upper_bound = i_bound;
+ }
+ if (realistic
+ && (!loop->any_estimate
+ || wi::ltu_p (i_bound, loop->nb_iterations_estimate)))
+ {
+ loop->any_estimate = true;
+ loop->nb_iterations_estimate = i_bound;
+ }
+
+ /* If an upper bound is smaller than the realistic estimate of the
+ number of iterations, use the upper bound instead. */
+ if (loop->any_upper_bound
+ && loop->any_estimate
+ && wi::ltu_p (loop->nb_iterations_upper_bound,
+ loop->nb_iterations_estimate))
+ loop->nb_iterations_estimate = loop->nb_iterations_upper_bound;
+}
+
+/* Similar to get_estimated_loop_iterations, but returns the estimate only
+ if it fits to HOST_WIDE_INT. If this is not the case, or the estimate
+ on the number of iterations of LOOP could not be derived, returns -1. */
+
+HOST_WIDE_INT
+get_estimated_loop_iterations_int (struct loop *loop)
+{
+ widest_int nit;
+ HOST_WIDE_INT hwi_nit;
+
+ if (!get_estimated_loop_iterations (loop, &nit))
+ return -1;
+
+ if (!wi::fits_shwi_p (nit))
+ return -1;
+ hwi_nit = nit.to_shwi ();
+
+ return hwi_nit < 0 ? -1 : hwi_nit;
+}
+
+/* Returns an upper bound on the number of executions of statements
+ in the LOOP. For statements before the loop exit, this exceeds
+ the number of execution of the latch by one. */
+
+HOST_WIDE_INT
+max_stmt_executions_int (struct loop *loop)
+{
+ HOST_WIDE_INT nit = get_max_loop_iterations_int (loop);
+ HOST_WIDE_INT snit;
+
+ if (nit == -1)
+ return -1;
+
+ snit = (HOST_WIDE_INT) ((unsigned HOST_WIDE_INT) nit + 1);
+
+ /* If the computation overflows, return -1. */
+ return snit < 0 ? -1 : snit;
+}
+
+/* Sets NIT to the estimated number of executions of the latch of the
+ LOOP. If we have no reliable estimate, the function returns false, otherwise
+ returns true. */
+
+bool
+get_estimated_loop_iterations (struct loop *loop, widest_int *nit)
+{
+ /* Even if the bound is not recorded, possibly we can derrive one from
+ profile. */
+ if (!loop->any_estimate)
+ {
+ if (loop->header->count)
+ {
+ *nit = gcov_type_to_wide_int
+ (expected_loop_iterations_unbounded (loop) + 1);
+ return true;
+ }
+ return false;
+ }
+
+ *nit = loop->nb_iterations_estimate;
+ return true;
+}
+
+/* Sets NIT to an upper bound for the maximum number of executions of the
+ latch of the LOOP. If we have no reliable estimate, the function returns
+ false, otherwise returns true. */
+
+bool
+get_max_loop_iterations (struct loop *loop, widest_int *nit)
+{
+ if (!loop->any_upper_bound)
+ return false;
+
+ *nit = loop->nb_iterations_upper_bound;
+ return true;
+}
+
+/* Similar to get_max_loop_iterations, but returns the estimate only
+ if it fits to HOST_WIDE_INT. If this is not the case, or the estimate
+ on the number of iterations of LOOP could not be derived, returns -1. */
+
+HOST_WIDE_INT
+get_max_loop_iterations_int (struct loop *loop)
+{
+ widest_int nit;
+ HOST_WIDE_INT hwi_nit;
+
+ if (!get_max_loop_iterations (loop, &nit))
+ return -1;
+
+ if (!wi::fits_shwi_p (nit))
+ return -1;
+ hwi_nit = nit.to_shwi ();
+
+ return hwi_nit < 0 ? -1 : hwi_nit;
+}
+
+/* Returns the loop depth of the loop BB belongs to. */
+
+int
+bb_loop_depth (const_basic_block bb)
+{
+ return bb->loop_father ? loop_depth (bb->loop_father) : 0;
+}
+
+/* Marks LOOP for removal and sets LOOPS_NEED_FIXUP. */
+
+void
+mark_loop_for_removal (loop_p loop)
+{
+ loop->former_header = loop->header;
+ loop->header = NULL;
+ loop->latch = NULL;
+ loops_state_set (LOOPS_NEED_FIXUP);
+}
+
projects / gcc.git / blobdiff