/* Loop manipulation code for GNU compiler.
- Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008, 2009 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, 59 Temple Place - Suite 330, Boston, MA
-02111-1307, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "tm.h"
#include "rtl.h"
#include "hard-reg-set.h"
+#include "obstack.h"
#include "basic-block.h"
#include "cfgloop.h"
#include "cfglayout.h"
+#include "cfghooks.h"
#include "output.h"
+#include "tree-flow.h"
-static struct loop * duplicate_loop (struct loops *, struct loop *,
- struct loop *);
-static void duplicate_subloops (struct loops *, struct loop *, struct loop *);
-static void copy_loops_to (struct loops *, struct loop **, int,
+static void duplicate_subloops (struct loop *, struct loop *);
+static void copy_loops_to (struct loop **, int,
struct loop *);
static void loop_redirect_edge (edge, basic_block);
-static bool loop_delete_branch_edge (edge, int);
static void remove_bbs (basic_block *, int);
-static bool rpe_enum_p (basic_block, void *);
+static bool rpe_enum_p (const_basic_block, const void *);
static int find_path (edge, basic_block **);
-static bool alp_enum_p (basic_block, void *);
-static void add_loop (struct loops *, struct loop *);
-static void fix_loop_placements (struct loops *, struct loop *);
-static bool fix_bb_placement (struct loops *, basic_block);
-static void fix_bb_placements (struct loops *, basic_block);
-static void place_new_loop (struct loops *, struct loop *);
-static void scale_loop_frequencies (struct loop *, int, int);
-static void scale_bbs_frequencies (basic_block *, int, int, int);
-static basic_block create_preheader (struct loop *, int);
-static void fix_irreducible_loops (basic_block);
+static void fix_loop_placements (struct loop *, bool *);
+static bool fix_bb_placement (basic_block);
+static void fix_bb_placements (basic_block, bool *);
+static void unloop (struct loop *, bool *);
#define RDIV(X,Y) (((X) + (Y) / 2) / (Y))
-/* Splits basic block BB after INSN, returns created edge. Updates loops
- and dominators. */
-edge
-split_loop_bb (basic_block bb, rtx insn)
-{
- edge e;
-
- /* Split the block. */
- e = split_block (bb, insn);
-
- /* Add dest to loop. */
- add_bb_to_loop (e->dest, e->src->loop_father);
-
- return e;
-}
-
/* Checks whether basic block BB is dominated by DATA. */
static bool
-rpe_enum_p (basic_block bb, void *data)
+rpe_enum_p (const_basic_block bb, const void *data)
{
- return dominated_by_p (CDI_DOMINATORS, bb, data);
+ return dominated_by_p (CDI_DOMINATORS, bb, (const_basic_block) data);
}
-/* Remove basic blocks BBS from loop structure and dominance info,
- and delete them afterwards. */
+/* Remove basic blocks BBS. NBBS is the number of the basic blocks. */
+
static void
remove_bbs (basic_block *bbs, int nbbs)
{
int i;
for (i = 0; i < nbbs; i++)
- {
- remove_bb_from_loops (bbs[i]);
- delete_basic_block (bbs[i]);
- }
+ delete_basic_block (bbs[i]);
}
/* Find path -- i.e. the basic blocks dominated by edge E and put them
static int
find_path (edge e, basic_block **bbs)
{
- gcc_assert (!e->dest->pred->pred_next);
+ gcc_assert (EDGE_COUNT (e->dest->preds) <= 1);
/* Find bbs in the path. */
- *bbs = xcalloc (n_basic_blocks, sizeof (basic_block));
+ *bbs = XCNEWVEC (basic_block, n_basic_blocks);
return dfs_enumerate_from (e->dest, 0, rpe_enum_p, *bbs,
n_basic_blocks, e->dest);
}
-/* Fix placement of basic block BB inside loop hierarchy stored in LOOPS --
+/* Fix placement of basic block BB inside loop hierarchy --
Let L be a loop to that BB belongs. Then every successor of BB must either
1) belong to some superloop of loop L, or
2) be a header of loop K such that K->outer is superloop of L
false if the placement of BB was already correct (provided that placements
of its successors are correct). */
static bool
-fix_bb_placement (struct loops *loops, basic_block bb)
+fix_bb_placement (basic_block bb)
{
edge e;
- struct loop *loop = loops->tree_root, *act;
+ edge_iterator ei;
+ struct loop *loop = current_loops->tree_root, *act;
- for (e = bb->succ; e; e = e->succ_next)
+ FOR_EACH_EDGE (e, ei, bb->succs)
{
if (e->dest == EXIT_BLOCK_PTR)
continue;
act = e->dest->loop_father;
if (act->header == e->dest)
- act = act->outer;
+ act = loop_outer (act);
if (flow_loop_nested_p (loop, act))
loop = act;
return true;
}
+/* Fix placement of LOOP inside loop tree, i.e. find the innermost superloop
+ of LOOP to that leads at least one exit edge of LOOP, and set it
+ as the immediate superloop of LOOP. Return true if the immediate superloop
+ of LOOP changed. */
+
+static bool
+fix_loop_placement (struct loop *loop)
+{
+ unsigned i;
+ edge e;
+ VEC (edge, heap) *exits = get_loop_exit_edges (loop);
+ struct loop *father = current_loops->tree_root, *act;
+ bool ret = false;
+
+ for (i = 0; VEC_iterate (edge, exits, i, e); i++)
+ {
+ act = find_common_loop (loop, e->dest->loop_father);
+ if (flow_loop_nested_p (father, act))
+ father = act;
+ }
+
+ if (father != loop_outer (loop))
+ {
+ for (act = loop_outer (loop); act != father; act = loop_outer (act))
+ act->num_nodes -= loop->num_nodes;
+ flow_loop_tree_node_remove (loop);
+ flow_loop_tree_node_add (father, loop);
+
+ /* The exit edges of LOOP no longer exits its original immediate
+ superloops; remove them from the appropriate exit lists. */
+ for (i = 0; VEC_iterate (edge, exits, i, e); i++)
+ rescan_loop_exit (e, false, false);
+
+ ret = true;
+ }
+
+ VEC_free (edge, heap, exits);
+ return ret;
+}
+
/* Fix placements of basic blocks inside loop hierarchy stored in loops; i.e.
enforce condition condition stated in description of fix_bb_placement. We
start from basic block FROM that had some of its successors removed, so that
its predecessors that may change if placement of FROM changed. Also fix
placement of subloops of FROM->loop_father, that might also be altered due
to this change; the condition for them is similar, except that instead of
- successors we consider edges coming out of the loops. */
+ successors we consider edges coming out of the loops.
+
+ If the changes may invalidate the information about irreducible regions,
+ IRRED_INVALIDATED is set to true. */
+
static void
-fix_bb_placements (struct loops *loops, basic_block from)
+fix_bb_placements (basic_block from,
+ bool *irred_invalidated)
{
sbitmap in_queue;
basic_block *queue, *qtop, *qbeg, *qend;
fix_loop_placement. */
base_loop = from->loop_father;
- if (base_loop == loops->tree_root)
+ if (base_loop == current_loops->tree_root)
return;
in_queue = sbitmap_alloc (last_basic_block);
/* Prevent us from going out of the base_loop. */
SET_BIT (in_queue, base_loop->header->index);
- queue = xmalloc ((base_loop->num_nodes + 1) * sizeof (basic_block));
+ queue = XNEWVEC (basic_block, base_loop->num_nodes + 1);
qtop = queue + base_loop->num_nodes + 1;
qbeg = queue;
qend = queue + 1;
while (qbeg != qend)
{
+ edge_iterator ei;
from = *qbeg;
qbeg++;
if (qbeg == qtop)
else
{
/* Ordinary basic block. */
- if (!fix_bb_placement (loops, from))
+ if (!fix_bb_placement (from))
continue;
}
+ FOR_EACH_EDGE (e, ei, from->succs)
+ {
+ if (e->flags & EDGE_IRREDUCIBLE_LOOP)
+ *irred_invalidated = true;
+ }
+
/* Something has changed, insert predecessors into queue. */
- for (e = from->pred; e; e = e->pred_next)
+ FOR_EACH_EDGE (e, ei, from->preds)
{
basic_block pred = e->src;
struct loop *nca;
+ if (e->flags & EDGE_IRREDUCIBLE_LOOP)
+ *irred_invalidated = true;
+
if (TEST_BIT (in_queue, pred->index))
continue;
free (queue);
}
-/* Basic block from has lost one or more of its predecessors, so it might
- mo longer be part irreducible loop. Fix it and proceed recursively
- for its successors if needed. */
-static void
-fix_irreducible_loops (basic_block from)
-{
- basic_block bb;
- basic_block *stack;
- int stack_top;
- sbitmap on_stack;
- edge *edges, e;
- unsigned n_edges, i;
-
- if (!(from->flags & BB_IRREDUCIBLE_LOOP))
- return;
-
- on_stack = sbitmap_alloc (last_basic_block);
- sbitmap_zero (on_stack);
- SET_BIT (on_stack, from->index);
- stack = xmalloc (from->loop_father->num_nodes * sizeof (basic_block));
- stack[0] = from;
- stack_top = 1;
-
- while (stack_top)
- {
- bb = stack[--stack_top];
- RESET_BIT (on_stack, bb->index);
-
- for (e = bb->pred; e; e = e->pred_next)
- if (e->flags & EDGE_IRREDUCIBLE_LOOP)
- break;
- if (e)
- continue;
-
- bb->flags &= ~BB_IRREDUCIBLE_LOOP;
- if (bb->loop_father->header == bb)
- edges = get_loop_exit_edges (bb->loop_father, &n_edges);
- else
- {
- n_edges = 0;
- for (e = bb->succ; e; e = e->succ_next)
- n_edges++;
- edges = xmalloc (n_edges * sizeof (edge));
- n_edges = 0;
- for (e = bb->succ; e; e = e->succ_next)
- edges[n_edges++] = e;
- }
-
- for (i = 0; i < n_edges; i++)
- {
- e = edges[i];
-
- if (e->flags & EDGE_IRREDUCIBLE_LOOP)
- {
- if (!flow_bb_inside_loop_p (from->loop_father, e->dest))
- continue;
-
- e->flags &= ~EDGE_IRREDUCIBLE_LOOP;
- if (TEST_BIT (on_stack, e->dest->index))
- continue;
-
- SET_BIT (on_stack, e->dest->index);
- stack[stack_top++] = e->dest;
- }
- }
- free (edges);
- }
-
- free (on_stack);
- free (stack);
-}
-
/* Removes path beginning at edge E, i.e. remove basic blocks dominated by E
- and update loop structure stored in LOOPS and dominators. Return true if
- we were able to remove the path, false otherwise (and nothing is affected
- then). */
+ and update loop structures and dominators. Return true if we were able
+ to remove the path, false otherwise (and nothing is affected then). */
bool
-remove_path (struct loops *loops, edge e)
+remove_path (edge e)
{
edge ae;
- basic_block *rem_bbs, *bord_bbs, *dom_bbs, from, bb;
- int i, nrem, n_bord_bbs, n_dom_bbs;
+ basic_block *rem_bbs, *bord_bbs, from, bb;
+ VEC (basic_block, heap) *dom_bbs;
+ int i, nrem, n_bord_bbs, nreml;
sbitmap seen;
- bool deleted;
+ bool irred_invalidated = false;
+ struct loop **deleted_loop;
- if (!loop_delete_branch_edge (e, 0))
+ if (!can_remove_branch_p (e))
return false;
+ /* Keep track of whether we need to update information about irreducible
+ regions. This is the case if the removed area is a part of the
+ irreducible region, or if the set of basic blocks that belong to a loop
+ that is inside an irreducible region is changed, or if such a loop is
+ removed. */
+ if (e->flags & EDGE_IRREDUCIBLE_LOOP)
+ irred_invalidated = true;
+
/* We need to check whether basic blocks are dominated by the edge
e, but we only have basic block dominators. This is easy to
fix -- when e->dest has exactly one predecessor, this corresponds
to blocks dominated by e->dest, if not, split the edge. */
- if (e->dest->pred->pred_next)
- e = loop_split_edge_with (e, NULL_RTX)->pred;
+ if (!single_pred_p (e->dest))
+ e = single_pred_edge (split_edge (e));
/* It may happen that by removing path we remove one or more loops
we belong to. In this case first unloop the loops, then proceed
normally. We may assume that e->dest is not a header of any loop,
as it now has exactly one predecessor. */
- while (e->src->loop_father->outer
+ while (loop_outer (e->src->loop_father)
&& dominated_by_p (CDI_DOMINATORS,
e->src->loop_father->latch, e->dest))
- unloop (loops, e->src->loop_father);
+ unloop (e->src->loop_father, &irred_invalidated);
/* Identify the path. */
nrem = find_path (e, &rem_bbs);
n_bord_bbs = 0;
- bord_bbs = xcalloc (n_basic_blocks, sizeof (basic_block));
+ bord_bbs = XCNEWVEC (basic_block, n_basic_blocks);
seen = sbitmap_alloc (last_basic_block);
sbitmap_zero (seen);
SET_BIT (seen, rem_bbs[i]->index);
for (i = 0; i < nrem; i++)
{
+ edge_iterator ei;
bb = rem_bbs[i];
- for (ae = rem_bbs[i]->succ; ae; ae = ae->succ_next)
+ FOR_EACH_EDGE (ae, ei, rem_bbs[i]->succs)
if (ae->dest != EXIT_BLOCK_PTR && !TEST_BIT (seen, ae->dest->index))
{
SET_BIT (seen, ae->dest->index);
bord_bbs[n_bord_bbs++] = ae->dest;
+
+ if (ae->flags & EDGE_IRREDUCIBLE_LOOP)
+ irred_invalidated = true;
}
}
/* Remove the path. */
from = e->src;
- deleted = loop_delete_branch_edge (e, 1);
- gcc_assert (deleted);
- dom_bbs = xcalloc (n_basic_blocks, sizeof (basic_block));
+ remove_branch (e);
+ dom_bbs = NULL;
/* Cancel loops contained in the path. */
+ deleted_loop = XNEWVEC (struct loop *, nrem);
+ nreml = 0;
for (i = 0; i < nrem; i++)
if (rem_bbs[i]->loop_father->header == rem_bbs[i])
- cancel_loop_tree (loops, rem_bbs[i]->loop_father);
+ deleted_loop[nreml++] = rem_bbs[i]->loop_father;
+
+ for (i = 0; i < nreml; i++)
+ cancel_loop_tree (deleted_loop[i]);
+ free (deleted_loop);
remove_bbs (rem_bbs, nrem);
free (rem_bbs);
/* Find blocks whose dominators may be affected. */
- n_dom_bbs = 0;
sbitmap_zero (seen);
for (i = 0; i < n_bord_bbs; i++)
{
ldom;
ldom = next_dom_son (CDI_DOMINATORS, ldom))
if (!dominated_by_p (CDI_DOMINATORS, from, ldom))
- dom_bbs[n_dom_bbs++] = ldom;
+ VEC_safe_push (basic_block, heap, dom_bbs, ldom);
}
free (seen);
/* Recount dominators. */
- iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, n_dom_bbs);
- free (dom_bbs);
-
- /* These blocks have lost some predecessor(s), thus their irreducible
- status could be changed. */
- for (i = 0; i < n_bord_bbs; i++)
- fix_irreducible_loops (bord_bbs[i]);
+ iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, true);
+ VEC_free (basic_block, heap, dom_bbs);
free (bord_bbs);
/* Fix placements of basic blocks inside loops and the placement of
loops in the loop tree. */
- fix_bb_placements (loops, from);
- fix_loop_placements (loops, from->loop_father);
+ fix_bb_placements (from, &irred_invalidated);
+ fix_loop_placements (from->loop_father, &irred_invalidated);
+
+ if (irred_invalidated
+ && loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS))
+ mark_irreducible_loops ();
return true;
}
-/* Predicate for enumeration in add_loop. */
-static bool
-alp_enum_p (basic_block bb, void *alp_header)
+/* Creates place for a new LOOP in loops structure. */
+
+static void
+place_new_loop (struct loop *loop)
{
- return bb != (basic_block) alp_header;
+ loop->num = number_of_loops ();
+ VEC_safe_push (loop_p, gc, current_loops->larray, loop);
}
/* Given LOOP structure with filled header and latch, find the body of the
- corresponding loop and add it to LOOPS tree. */
-static void
-add_loop (struct loops *loops, struct loop *loop)
+ corresponding loop and add it to loops tree. Insert the LOOP as a son of
+ outer. */
+
+void
+add_loop (struct loop *loop, struct loop *outer)
{
basic_block *bbs;
int i, n;
+ struct loop *subloop;
+ edge e;
+ edge_iterator ei;
/* Add it to loop structure. */
- place_new_loop (loops, loop);
- loop->level = 1;
+ place_new_loop (loop);
+ flow_loop_tree_node_add (outer, loop);
/* Find its nodes. */
- bbs = xcalloc (n_basic_blocks, sizeof (basic_block));
- n = dfs_enumerate_from (loop->latch, 1, alp_enum_p,
- bbs, n_basic_blocks, loop->header);
+ bbs = XNEWVEC (basic_block, n_basic_blocks);
+ n = get_loop_body_with_size (loop, bbs, n_basic_blocks);
for (i = 0; i < n; i++)
- add_bb_to_loop (bbs[i], loop);
- add_bb_to_loop (loop->header, loop);
+ {
+ if (bbs[i]->loop_father == outer)
+ {
+ remove_bb_from_loops (bbs[i]);
+ add_bb_to_loop (bbs[i], loop);
+ continue;
+ }
- free (bbs);
-}
+ loop->num_nodes++;
-/* Multiply all frequencies of basic blocks in array BBS of length NBBS
- by NUM/DEN. */
-static void
-scale_bbs_frequencies (basic_block *bbs, int nbbs, int num, int den)
-{
- int i;
- edge e;
+ /* If we find a direct subloop of OUTER, move it to LOOP. */
+ subloop = bbs[i]->loop_father;
+ if (loop_outer (subloop) == outer
+ && subloop->header == bbs[i])
+ {
+ flow_loop_tree_node_remove (subloop);
+ flow_loop_tree_node_add (loop, subloop);
+ }
+ }
- for (i = 0; i < nbbs; i++)
+ /* Update the information about loop exit edges. */
+ for (i = 0; i < n; i++)
{
- bbs[i]->frequency = (bbs[i]->frequency * num) / den;
- bbs[i]->count = RDIV (bbs[i]->count * num, den);
- for (e = bbs[i]->succ; e; e = e->succ_next)
- e->count = (e->count * num) /den;
+ FOR_EACH_EDGE (e, ei, bbs[i]->succs)
+ {
+ rescan_loop_exit (e, false, false);
+ }
}
+
+ free (bbs);
}
/* Multiply all frequencies in LOOP by NUM/DEN. */
-static void
+void
scale_loop_frequencies (struct loop *loop, int num, int den)
{
basic_block *bbs;
bbs = get_loop_body (loop);
- scale_bbs_frequencies (bbs, loop->num_nodes, num, den);
+ scale_bbs_frequencies_int (bbs, loop->num_nodes, num, den);
free (bbs);
}
+/* Recompute dominance information for basic blocks outside LOOP. */
+
+static void
+update_dominators_in_loop (struct loop *loop)
+{
+ VEC (basic_block, heap) *dom_bbs = NULL;
+ sbitmap seen;
+ basic_block *body;
+ unsigned i;
+
+ seen = sbitmap_alloc (last_basic_block);
+ sbitmap_zero (seen);
+ body = get_loop_body (loop);
+
+ for (i = 0; i < loop->num_nodes; i++)
+ SET_BIT (seen, body[i]->index);
+
+ for (i = 0; i < loop->num_nodes; i++)
+ {
+ basic_block ldom;
+
+ for (ldom = first_dom_son (CDI_DOMINATORS, body[i]);
+ ldom;
+ ldom = next_dom_son (CDI_DOMINATORS, ldom))
+ if (!TEST_BIT (seen, ldom->index))
+ {
+ SET_BIT (seen, ldom->index);
+ VEC_safe_push (basic_block, heap, dom_bbs, ldom);
+ }
+ }
+
+ iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, false);
+ free (body);
+ free (seen);
+ VEC_free (basic_block, heap, dom_bbs);
+}
+
+/* Creates an if region as shown above. CONDITION is used to create
+ the test for the if.
+
+ |
+ | ------------- -------------
+ | | pred_bb | | pred_bb |
+ | ------------- -------------
+ | | |
+ | | | ENTRY_EDGE
+ | | ENTRY_EDGE V
+ | | ====> -------------
+ | | | cond_bb |
+ | | | CONDITION |
+ | | -------------
+ | V / \
+ | ------------- e_false / \ e_true
+ | | succ_bb | V V
+ | ------------- ----------- -----------
+ | | false_bb | | true_bb |
+ | ----------- -----------
+ | \ /
+ | \ /
+ | V V
+ | -------------
+ | | join_bb |
+ | -------------
+ | | exit_edge (result)
+ | V
+ | -----------
+ | | succ_bb |
+ | -----------
+ |
+ */
+
+edge
+create_empty_if_region_on_edge (edge entry_edge, tree condition)
+{
+
+ basic_block succ_bb, cond_bb, true_bb, false_bb, join_bb;
+ edge e_true, e_false, exit_edge;
+ gimple cond_stmt;
+ tree simple_cond;
+ gimple_stmt_iterator gsi;
+
+ succ_bb = entry_edge->dest;
+ cond_bb = split_edge (entry_edge);
+
+ /* Insert condition in cond_bb. */
+ gsi = gsi_last_bb (cond_bb);
+ simple_cond =
+ force_gimple_operand_gsi (&gsi, condition, true, NULL,
+ false, GSI_NEW_STMT);
+ cond_stmt = gimple_build_cond_from_tree (simple_cond, NULL_TREE, NULL_TREE);
+ gsi = gsi_last_bb (cond_bb);
+ gsi_insert_after (&gsi, cond_stmt, GSI_NEW_STMT);
+
+ join_bb = split_edge (single_succ_edge (cond_bb));
+
+ e_true = single_succ_edge (cond_bb);
+ true_bb = split_edge (e_true);
+
+ e_false = make_edge (cond_bb, join_bb, 0);
+ false_bb = split_edge (e_false);
+
+ e_true->flags &= ~EDGE_FALLTHRU;
+ e_true->flags |= EDGE_TRUE_VALUE;
+ e_false->flags &= ~EDGE_FALLTHRU;
+ e_false->flags |= EDGE_FALSE_VALUE;
+
+ set_immediate_dominator (CDI_DOMINATORS, cond_bb, entry_edge->src);
+ set_immediate_dominator (CDI_DOMINATORS, true_bb, cond_bb);
+ set_immediate_dominator (CDI_DOMINATORS, false_bb, cond_bb);
+ set_immediate_dominator (CDI_DOMINATORS, join_bb, cond_bb);
+
+ exit_edge = single_succ_edge (join_bb);
+
+ if (single_pred_p (exit_edge->dest))
+ set_immediate_dominator (CDI_DOMINATORS, exit_edge->dest, join_bb);
+
+ return exit_edge;
+}
+
+/* create_empty_loop_on_edge
+ |
+ | ------------- ------------------------
+ | | pred_bb | | pred_bb |
+ | ------------- | IV_0 = INITIAL_VALUE |
+ | | ------------------------
+ | | ______ | ENTRY_EDGE
+ | | ENTRY_EDGE / V V
+ | | ====> | -----------------------------
+ | | | | IV_BEFORE = phi (IV_0, IV) |
+ | | | | loop_header |
+ | V | | IV_BEFORE <= UPPER_BOUND |
+ | ------------- | -----------------------\-----
+ | | succ_bb | | | \
+ | ------------- | | \ exit_e
+ | | V V---------
+ | | -------------- | succ_bb |
+ | | | loop_latch | ----------
+ | | |IV = IV_BEFORE + STRIDE
+ | | --------------
+ | \ /
+ | \ ___ /
+
+ Creates an empty loop as shown above, the IV_BEFORE is the SSA_NAME
+ that is used before the increment of IV. IV_BEFORE should be used for
+ adding code to the body that uses the IV. OUTER is the outer loop in
+ which the new loop should be inserted. */
+
+struct loop *
+create_empty_loop_on_edge (edge entry_edge,
+ tree initial_value,
+ tree stride, tree upper_bound,
+ tree iv,
+ tree *iv_before,
+ struct loop *outer)
+{
+ basic_block loop_header, loop_latch, succ_bb, pred_bb;
+ struct loop *loop;
+ int freq;
+ gcov_type cnt;
+ gimple_stmt_iterator gsi;
+ bool insert_after;
+ gimple_seq stmts;
+ gimple cond_expr;
+ tree exit_test;
+ edge exit_e;
+ int prob;
+ tree upper_bound_gimplified;
+
+ gcc_assert (entry_edge && initial_value && stride && upper_bound && iv);
+
+ /* Create header, latch and wire up the loop. */
+ pred_bb = entry_edge->src;
+ loop_header = split_edge (entry_edge);
+ loop_latch = split_edge (single_succ_edge (loop_header));
+ succ_bb = single_succ (loop_latch);
+ make_edge (loop_header, succ_bb, 0);
+ redirect_edge_succ_nodup (single_succ_edge (loop_latch), loop_header);
+
+ /* Set immediate dominator information. */
+ set_immediate_dominator (CDI_DOMINATORS, loop_header, pred_bb);
+ set_immediate_dominator (CDI_DOMINATORS, loop_latch, loop_header);
+ set_immediate_dominator (CDI_DOMINATORS, succ_bb, loop_header);
+
+ /* Initialize a loop structure and put it in a loop hierarchy. */
+ loop = alloc_loop ();
+ loop->header = loop_header;
+ loop->latch = loop_latch;
+ add_loop (loop, outer);
+
+ /* TODO: Fix frequencies and counts. */
+ freq = EDGE_FREQUENCY (entry_edge);
+ cnt = entry_edge->count;
+
+ prob = REG_BR_PROB_BASE / 2;
+
+ scale_loop_frequencies (loop, REG_BR_PROB_BASE - prob, REG_BR_PROB_BASE);
+
+ /* Update dominators. */
+ update_dominators_in_loop (loop);
+
+ /* Construct IV code in loop. */
+ initial_value = force_gimple_operand (initial_value, &stmts, true, iv);
+ if (stmts)
+ {
+ gsi_insert_seq_on_edge (loop_preheader_edge (loop), stmts);
+ gsi_commit_edge_inserts ();
+ }
+
+ standard_iv_increment_position (loop, &gsi, &insert_after);
+ create_iv (initial_value, stride, iv, loop, &gsi, insert_after,
+ iv_before, NULL);
+
+ /* Modify edge flags. */
+ exit_e = single_exit (loop);
+ exit_e->flags = EDGE_LOOP_EXIT | EDGE_FALSE_VALUE;
+ single_pred_edge (loop_latch)->flags = EDGE_TRUE_VALUE;
+
+ gsi = gsi_last_bb (exit_e->src);
+
+ upper_bound_gimplified =
+ force_gimple_operand_gsi (&gsi, upper_bound, true, NULL,
+ false, GSI_NEW_STMT);
+ gsi = gsi_last_bb (exit_e->src);
+
+ cond_expr = gimple_build_cond
+ (LE_EXPR, *iv_before, upper_bound_gimplified, NULL_TREE, NULL_TREE);
+
+ exit_test = gimple_cond_lhs (cond_expr);
+ exit_test = force_gimple_operand_gsi (&gsi, exit_test, true, NULL,
+ false, GSI_NEW_STMT);
+ gimple_cond_set_lhs (cond_expr, exit_test);
+ gsi = gsi_last_bb (exit_e->src);
+ gsi_insert_after (&gsi, cond_expr, GSI_NEW_STMT);
+
+ return loop;
+}
+
/* Make area between HEADER_EDGE and LATCH_EDGE a loop by connecting
- latch to header and update loop tree stored in LOOPS and dominators
+ latch to header and update loop tree and dominators
accordingly. Everything between them plus LATCH_EDGE destination must
be dominated by HEADER_EDGE destination, and back-reachable from
LATCH_EDGE source. HEADER_EDGE is redirected to basic block SWITCH_BB,
- FALLTHRU_EDGE (SWITCH_BB) to original destination of HEADER_EDGE and
- BRANCH_EDGE (SWITCH_BB) to original destination of LATCH_EDGE.
- Returns newly created loop. */
+ FALSE_EDGE of SWITCH_BB to original destination of HEADER_EDGE and
+ TRUE_EDGE of SWITCH_BB to original destination of LATCH_EDGE.
+ Returns the newly created loop. Frequencies and counts in the new loop
+ are scaled by FALSE_SCALE and in the old one by TRUE_SCALE. */
struct loop *
-loopify (struct loops *loops, edge latch_edge, edge header_edge,
- basic_block switch_bb)
+loopify (edge latch_edge, edge header_edge,
+ basic_block switch_bb, edge true_edge, edge false_edge,
+ bool redirect_all_edges, unsigned true_scale, unsigned false_scale)
{
basic_block succ_bb = latch_edge->dest;
basic_block pred_bb = header_edge->src;
- basic_block *dom_bbs, *body;
- unsigned n_dom_bbs, i;
- sbitmap seen;
- struct loop *loop = xcalloc (1, sizeof (struct loop));
- struct loop *outer = succ_bb->loop_father->outer;
- int freq, prob, tot_prob;
+ struct loop *loop = alloc_loop ();
+ struct loop *outer = loop_outer (succ_bb->loop_father);
+ int freq;
gcov_type cnt;
edge e;
+ edge_iterator ei;
loop->header = header_edge->dest;
loop->latch = latch_edge->src;
freq = EDGE_FREQUENCY (header_edge);
cnt = header_edge->count;
- prob = switch_bb->succ->probability;
- tot_prob = prob + switch_bb->succ->succ_next->probability;
- if (tot_prob == 0)
- tot_prob = 1;
/* Redirect edges. */
loop_redirect_edge (latch_edge, loop->header);
- loop_redirect_edge (BRANCH_EDGE (switch_bb), succ_bb);
+ loop_redirect_edge (true_edge, succ_bb);
- loop_redirect_edge (header_edge, switch_bb);
- loop_redirect_edge (FALLTHRU_EDGE (switch_bb), loop->header);
+ /* During loop versioning, one of the switch_bb edge is already properly
+ set. Do not redirect it again unless redirect_all_edges is true. */
+ if (redirect_all_edges)
+ {
+ loop_redirect_edge (header_edge, switch_bb);
+ loop_redirect_edge (false_edge, loop->header);
- /* Update dominators. */
- set_immediate_dominator (CDI_DOMINATORS, switch_bb, pred_bb);
- set_immediate_dominator (CDI_DOMINATORS, loop->header, switch_bb);
+ /* Update dominators. */
+ set_immediate_dominator (CDI_DOMINATORS, switch_bb, pred_bb);
+ set_immediate_dominator (CDI_DOMINATORS, loop->header, switch_bb);
+ }
set_immediate_dominator (CDI_DOMINATORS, succ_bb, switch_bb);
/* Compute new loop. */
- add_loop (loops, loop);
- flow_loop_tree_node_add (outer, loop);
+ add_loop (loop, outer);
/* Add switch_bb to appropriate loop. */
+ if (switch_bb->loop_father)
+ remove_bb_from_loops (switch_bb);
add_bb_to_loop (switch_bb, outer);
/* Fix frequencies. */
- switch_bb->frequency = freq;
- switch_bb->count = cnt;
- for (e = switch_bb->succ; e; e = e->succ_next)
- e->count = (switch_bb->count * e->probability) / REG_BR_PROB_BASE;
- scale_loop_frequencies (loop, prob, tot_prob);
- scale_loop_frequencies (succ_bb->loop_father, tot_prob - prob, tot_prob);
-
- /* Update dominators of blocks outside of LOOP. */
- dom_bbs = xcalloc (n_basic_blocks, sizeof (basic_block));
- n_dom_bbs = 0;
- seen = sbitmap_alloc (last_basic_block);
- sbitmap_zero (seen);
- body = get_loop_body (loop);
-
- for (i = 0; i < loop->num_nodes; i++)
- SET_BIT (seen, body[i]->index);
-
- for (i = 0; i < loop->num_nodes; i++)
+ if (redirect_all_edges)
{
- basic_block ldom;
-
- for (ldom = first_dom_son (CDI_DOMINATORS, body[i]);
- ldom;
- ldom = next_dom_son (CDI_DOMINATORS, ldom))
- if (!TEST_BIT (seen, ldom->index))
- {
- SET_BIT (seen, ldom->index);
- dom_bbs[n_dom_bbs++] = ldom;
- }
+ switch_bb->frequency = freq;
+ switch_bb->count = cnt;
+ FOR_EACH_EDGE (e, ei, switch_bb->succs)
+ {
+ e->count = (switch_bb->count * e->probability) / REG_BR_PROB_BASE;
+ }
}
-
- iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, n_dom_bbs);
-
- free (body);
- free (seen);
- free (dom_bbs);
+ scale_loop_frequencies (loop, false_scale, REG_BR_PROB_BASE);
+ scale_loop_frequencies (succ_bb->loop_father, true_scale, REG_BR_PROB_BASE);
+ update_dominators_in_loop (loop);
return loop;
}
-/* Remove the latch edge of a LOOP and update LOOPS tree to indicate that
+/* Remove the latch edge of a LOOP and update loops to indicate that
the LOOP was removed. After this function, original loop latch will
- have no successor, which caller is expected to fix somehow. */
-void
-unloop (struct loops *loops, struct loop *loop)
+ have no successor, which caller is expected to fix somehow.
+
+ If this may cause the information about irreducible regions to become
+ invalid, IRRED_INVALIDATED is set to true. */
+
+static void
+unloop (struct loop *loop, bool *irred_invalidated)
{
basic_block *body;
struct loop *ploop;
unsigned i, n;
basic_block latch = loop->latch;
- edge *edges;
- unsigned n_edges;
+ bool dummy = false;
+
+ if (loop_preheader_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP)
+ *irred_invalidated = true;
/* This is relatively straightforward. The dominators are unchanged, as
loop header dominates loop latch, so the only thing we have to care of
its work. */
body = get_loop_body (loop);
- edges = get_loop_exit_edges (loop, &n_edges);
n = loop->num_nodes;
for (i = 0; i < n; i++)
if (body[i]->loop_father == loop)
{
remove_bb_from_loops (body[i]);
- add_bb_to_loop (body[i], loop->outer);
+ add_bb_to_loop (body[i], loop_outer (loop));
}
free(body);
{
ploop = loop->inner;
flow_loop_tree_node_remove (ploop);
- flow_loop_tree_node_add (loop->outer, ploop);
+ flow_loop_tree_node_add (loop_outer (loop), ploop);
}
/* Remove the loop and free its data. */
- flow_loop_tree_node_remove (loop);
- loops->parray[loop->num] = NULL;
- flow_loop_free (loop);
-
- remove_edge (latch->succ);
- fix_bb_placements (loops, latch);
-
- /* If the loop was inside an irreducible region, we would have to somehow
- update the irreducible marks inside its body. While it is certainly
- possible to do, it is a bit complicated and this situation should be
- very rare, so we just remark all loops in this case. */
- for (i = 0; i < n_edges; i++)
- if (edges[i]->flags & EDGE_IRREDUCIBLE_LOOP)
- break;
- if (i != n_edges)
- mark_irreducible_loops (loops);
- free (edges);
-}
+ delete_loop (loop);
-/* Fix placement of LOOP inside loop tree, i.e. find the innermost superloop
- FATHER of LOOP such that all of the edges coming out of LOOP belong to
- FATHER, and set it as outer loop of LOOP. Return 1 if placement of
- LOOP changed. */
-int
-fix_loop_placement (struct loop *loop)
-{
- basic_block *body;
- unsigned i;
- edge e;
- struct loop *father = loop->pred[0], *act;
+ remove_edge (single_succ_edge (latch));
- body = get_loop_body (loop);
- for (i = 0; i < loop->num_nodes; i++)
- for (e = body[i]->succ; e; e = e->succ_next)
- if (!flow_bb_inside_loop_p (loop, e->dest))
- {
- act = find_common_loop (loop, e->dest->loop_father);
- if (flow_loop_nested_p (father, act))
- father = act;
- }
- free (body);
-
- if (father != loop->outer)
- {
- for (act = loop->outer; act != father; act = act->outer)
- act->num_nodes -= loop->num_nodes;
- flow_loop_tree_node_remove (loop);
- flow_loop_tree_node_add (father, loop);
- return 1;
- }
- return 0;
+ /* We do not pass IRRED_INVALIDATED to fix_bb_placements here, as even if
+ there is an irreducible region inside the cancelled loop, the flags will
+ be still correct. */
+ fix_bb_placements (latch, &dummy);
}
/* Fix placement of superloops of LOOP inside loop tree, i.e. ensure that
condition stated in description of fix_loop_placement holds for them.
It is used in case when we removed some edges coming out of LOOP, which
- may cause the right placement of LOOP inside loop tree to change. */
+ may cause the right placement of LOOP inside loop tree to change.
+
+ IRRED_INVALIDATED is set to true if a change in the loop structures might
+ invalidate the information about irreducible regions. */
+
static void
-fix_loop_placements (struct loops *loops, struct loop *loop)
+fix_loop_placements (struct loop *loop, bool *irred_invalidated)
{
struct loop *outer;
- while (loop->outer)
+ while (loop_outer (loop))
{
- outer = loop->outer;
+ outer = loop_outer (loop);
if (!fix_loop_placement (loop))
- break;
+ break;
/* Changing the placement of a loop in the loop tree may alter the
validity of condition 2) of the description of fix_bb_placement
for its preheader, because the successor is the header and belongs
to the loop. So call fix_bb_placements to fix up the placement
of the preheader and (possibly) of its predecessors. */
- fix_bb_placements (loops, loop_preheader_edge (loop)->src);
+ fix_bb_placements (loop_preheader_edge (loop)->src,
+ irred_invalidated);
loop = outer;
}
}
-/* Creates place for a new LOOP in LOOPS structure. */
-static void
-place_new_loop (struct loops *loops, struct loop *loop)
-{
- loops->parray =
- xrealloc (loops->parray, (loops->num + 1) * sizeof (struct loop *));
- loops->parray[loops->num] = loop;
-
- loop->num = loops->num++;
-}
-
/* Copies copy of LOOP as subloop of TARGET loop, placing newly
- created loop into LOOPS structure. */
-static struct loop *
-duplicate_loop (struct loops *loops, struct loop *loop, struct loop *target)
+ created loop into loops structure. */
+struct loop *
+duplicate_loop (struct loop *loop, struct loop *target)
{
struct loop *cloop;
- cloop = xcalloc (1, sizeof (struct loop));
- place_new_loop (loops, cloop);
-
- /* Initialize copied loop. */
- cloop->level = loop->level;
+ cloop = alloc_loop ();
+ place_new_loop (cloop);
- /* Set it as copy of loop. */
- loop->copy = cloop;
+ /* Mark the new loop as copy of LOOP. */
+ set_loop_copy (loop, cloop);
/* Add it to target. */
flow_loop_tree_node_add (target, cloop);
}
/* Copies structure of subloops of LOOP into TARGET loop, placing
- newly created loops into loop tree stored in LOOPS. */
+ newly created loops into loop tree. */
static void
-duplicate_subloops (struct loops *loops, struct loop *loop, struct loop *target)
+duplicate_subloops (struct loop *loop, struct loop *target)
{
struct loop *aloop, *cloop;
for (aloop = loop->inner; aloop; aloop = aloop->next)
{
- cloop = duplicate_loop (loops, aloop, target);
- duplicate_subloops (loops, aloop, cloop);
+ cloop = duplicate_loop (aloop, target);
+ duplicate_subloops (aloop, cloop);
}
}
/* Copies structure of subloops of N loops, stored in array COPIED_LOOPS,
- into TARGET loop, placing newly created loops into loop tree LOOPS. */
+ into TARGET loop, placing newly created loops into loop tree. */
static void
-copy_loops_to (struct loops *loops, struct loop **copied_loops, int n, struct loop *target)
+copy_loops_to (struct loop **copied_loops, int n, struct loop *target)
{
struct loop *aloop;
int i;
for (i = 0; i < n; i++)
{
- aloop = duplicate_loop (loops, copied_loops[i], target);
- duplicate_subloops (loops, copied_loops[i], aloop);
+ aloop = duplicate_loop (copied_loops[i], target);
+ duplicate_subloops (copied_loops[i], aloop);
}
}
redirect_edge_and_branch_force (e, dest);
}
-/* Deletes edge E from a branch if possible. Unless REALLY_DELETE is set,
- just test whether it is possible to remove the edge. */
-static bool
-loop_delete_branch_edge (edge e, int really_delete)
-{
- basic_block src = e->src;
- basic_block newdest;
- int irr;
- edge snd;
-
- gcc_assert (src->succ->succ_next);
-
- /* Cannot handle more than two exit edges. */
- if (src->succ->succ_next->succ_next)
- return false;
- /* And it must be just a simple branch. */
- if (!any_condjump_p (BB_END (src)))
- return false;
-
- snd = e == src->succ ? src->succ->succ_next : src->succ;
- newdest = snd->dest;
- if (newdest == EXIT_BLOCK_PTR)
- return false;
-
- /* Hopefully the above conditions should suffice. */
- if (!really_delete)
- return true;
-
- /* Redirecting behaves wrongly wrto this flag. */
- irr = snd->flags & EDGE_IRREDUCIBLE_LOOP;
-
- if (!redirect_edge_and_branch (e, newdest))
- return false;
- src->succ->flags &= ~EDGE_IRREDUCIBLE_LOOP;
- src->succ->flags |= irr;
-
- return true;
-}
-
/* Check whether LOOP's body can be duplicated. */
bool
-can_duplicate_loop_p (struct loop *loop)
+can_duplicate_loop_p (const struct loop *loop)
{
int ret;
basic_block *bbs = get_loop_body (loop);
ret = can_copy_bbs_p (bbs, loop->num_nodes);
free (bbs);
-
+
return ret;
}
-/* The NBBS blocks in BBS will get duplicated and the copies will be placed
- to LOOP. Update the single_exit information in superloops of LOOP. */
+/* Sets probability and count of edge E to zero. The probability and count
+ is redistributed evenly to the remaining edges coming from E->src. */
static void
-update_single_exits_after_duplication (basic_block *bbs, unsigned nbbs,
- struct loop *loop)
+set_zero_probability (edge e)
{
- unsigned i;
-
- for (i = 0; i < nbbs; i++)
- bbs[i]->rbi->duplicated = 1;
-
- for (; loop->outer; loop = loop->outer)
+ basic_block bb = e->src;
+ edge_iterator ei;
+ edge ae, last = NULL;
+ unsigned n = EDGE_COUNT (bb->succs);
+ gcov_type cnt = e->count, cnt1;
+ unsigned prob = e->probability, prob1;
+
+ gcc_assert (n > 1);
+ cnt1 = cnt / (n - 1);
+ prob1 = prob / (n - 1);
+
+ FOR_EACH_EDGE (ae, ei, bb->succs)
{
- if (!loop->single_exit)
+ if (ae == e)
continue;
- if (loop->single_exit->src->rbi->duplicated)
- loop->single_exit = NULL;
+ ae->probability += prob1;
+ ae->count += cnt1;
+ last = ae;
}
- for (i = 0; i < nbbs; i++)
- bbs[i]->rbi->duplicated = 0;
-}
+ /* Move the rest to one of the edges. */
+ last->probability += prob % (n - 1);
+ last->count += cnt % (n - 1);
+ e->probability = 0;
+ e->count = 0;
+}
/* Duplicates body of LOOP to given edge E NDUPL times. Takes care of updating
- LOOPS structure and dominators. E's destination must be LOOP header for
+ loop structure and dominators. E's destination must be LOOP header for
this to work, i.e. it must be entry or latch edge of this loop; these are
unique, as the loops must have preheaders for this function to work
correctly (in case E is latch, the function unrolls the loop, if E is entry
original LOOP body, the other copies are numbered in order given by control
flow through them) into TO_REMOVE array. Returns false if duplication is
impossible. */
-int
-duplicate_loop_to_header_edge (struct loop *loop, edge e, struct loops *loops,
+
+bool
+duplicate_loop_to_header_edge (struct loop *loop, edge e,
unsigned int ndupl, sbitmap wont_exit,
- edge orig, edge *to_remove,
- unsigned int *n_to_remove, int flags)
+ edge orig, VEC (edge, heap) **to_remove,
+ int flags)
{
struct loop *target, *aloop;
struct loop **orig_loops;
unsigned i, j, n;
int is_latch = (latch == e->src);
int scale_act = 0, *scale_step = NULL, scale_main = 0;
+ int scale_after_exit = 0;
int p, freq_in, freq_le, freq_out_orig;
int prob_pass_thru, prob_pass_wont_exit, prob_pass_main;
int add_irreducible_flag;
+ basic_block place_after;
+ bitmap bbs_to_scale = NULL;
+ bitmap_iterator bi;
gcc_assert (e->dest == loop->header);
gcc_assert (ndupl > 0);
gcc_assert (!flow_bb_inside_loop_p (loop, orig->dest));
}
- bbs = get_loop_body (loop);
+ n = loop->num_nodes;
+ bbs = get_loop_body_in_dom_order (loop);
+ gcc_assert (bbs[0] == loop->header);
+ gcc_assert (bbs[n - 1] == loop->latch);
/* Check whether duplication is possible. */
if (!can_copy_bbs_p (bbs, loop->num_nodes))
free (bbs);
return false;
}
- new_bbs = xmalloc (sizeof (basic_block) * loop->num_nodes);
+ new_bbs = XNEWVEC (basic_block, loop->num_nodes);
/* In case we are doing loop peeling and the loop is in the middle of
irreducible region, the peeled copies will be inside it too. */
prob_pass_wont_exit =
RDIV (REG_BR_PROB_BASE * (freq_le + freq_out_orig), freq_in);
- scale_step = xmalloc (ndupl * sizeof (int));
+ if (orig
+ && REG_BR_PROB_BASE - orig->probability != 0)
+ {
+ /* The blocks that are dominated by a removed exit edge ORIG have
+ frequencies scaled by this. */
+ scale_after_exit = RDIV (REG_BR_PROB_BASE * REG_BR_PROB_BASE,
+ REG_BR_PROB_BASE - orig->probability);
+ bbs_to_scale = BITMAP_ALLOC (NULL);
+ for (i = 0; i < n; i++)
+ {
+ if (bbs[i] != orig->src
+ && dominated_by_p (CDI_DOMINATORS, bbs[i], orig->src))
+ bitmap_set_bit (bbs_to_scale, i);
+ }
+ }
+
+ scale_step = XNEWVEC (int, ndupl);
- for (i = 1; i <= ndupl; i++)
- scale_step[i - 1] = TEST_BIT (wont_exit, i)
+ for (i = 1; i <= ndupl; i++)
+ scale_step[i - 1] = TEST_BIT (wont_exit, i)
? prob_pass_wont_exit
: prob_pass_thru;
- if (is_latch)
+ /* Complete peeling is special as the probability of exit in last
+ copy becomes 1. */
+ if (flags & DLTHE_FLAG_COMPLETTE_PEEL)
+ {
+ int wanted_freq = EDGE_FREQUENCY (e);
+
+ if (wanted_freq > freq_in)
+ wanted_freq = freq_in;
+
+ gcc_assert (!is_latch);
+ /* First copy has frequency of incoming edge. Each subsequent
+ frequency should be reduced by prob_pass_wont_exit. Caller
+ should've managed the flags so all except for original loop
+ has won't exist set. */
+ scale_act = RDIV (wanted_freq * REG_BR_PROB_BASE, freq_in);
+ /* Now simulate the duplication adjustments and compute header
+ frequency of the last copy. */
+ for (i = 0; i < ndupl; i++)
+ wanted_freq = RDIV (wanted_freq * scale_step[i], REG_BR_PROB_BASE);
+ scale_main = RDIV (wanted_freq * REG_BR_PROB_BASE, freq_in);
+ }
+ else if (is_latch)
{
prob_pass_main = TEST_BIT (wont_exit, 0)
? prob_pass_wont_exit
n_orig_loops = 0;
for (aloop = loop->inner; aloop; aloop = aloop->next)
n_orig_loops++;
- orig_loops = xcalloc (n_orig_loops, sizeof (struct loop *));
+ orig_loops = XCNEWVEC (struct loop *, n_orig_loops);
for (aloop = loop->inner, i = 0; aloop; aloop = aloop->next, i++)
orig_loops[i] = aloop;
- loop->copy = target;
-
- n = loop->num_nodes;
+ set_loop_copy (loop, target);
- first_active = xmalloc (n * sizeof (basic_block));
+ first_active = XNEWVEC (basic_block, n);
if (is_latch)
{
memcpy (first_active, bbs, n * sizeof (basic_block));
first_active_latch = latch;
}
- /* Update the information about single exits. */
- if (loops->state & LOOPS_HAVE_MARKED_SINGLE_EXITS)
- update_single_exits_after_duplication (bbs, n, target);
-
- /* Record exit edge in original loop body. */
- if (orig && TEST_BIT (wont_exit, 0))
- to_remove[(*n_to_remove)++] = orig;
-
spec_edges[SE_ORIG] = orig;
spec_edges[SE_LATCH] = latch_edge;
+ place_after = e->src;
for (j = 0; j < ndupl; j++)
{
/* Copy loops. */
- copy_loops_to (loops, orig_loops, n_orig_loops, target);
+ copy_loops_to (orig_loops, n_orig_loops, target);
/* Copy bbs. */
- copy_bbs (bbs, n, new_bbs, spec_edges, 2, new_spec_edges, loop);
+ copy_bbs (bbs, n, new_bbs, spec_edges, 2, new_spec_edges, loop,
+ place_after);
+ place_after = new_spec_edges[SE_LATCH]->src;
+
+ if (flags & DLTHE_RECORD_COPY_NUMBER)
+ for (i = 0; i < n; i++)
+ {
+ gcc_assert (!new_bbs[i]->aux);
+ new_bbs[i]->aux = (void *)(size_t)(j + 1);
+ }
/* Note whether the blocks and edges belong to an irreducible loop. */
if (add_irreducible_flag)
{
for (i = 0; i < n; i++)
- new_bbs[i]->rbi->duplicated = 1;
+ new_bbs[i]->flags |= BB_DUPLICATED;
for (i = 0; i < n; i++)
{
+ edge_iterator ei;
new_bb = new_bbs[i];
if (new_bb->loop_father == target)
new_bb->flags |= BB_IRREDUCIBLE_LOOP;
- for (ae = new_bb->succ; ae; ae = ae->succ_next)
- if (ae->dest->rbi->duplicated
+ FOR_EACH_EDGE (ae, ei, new_bb->succs)
+ if ((ae->dest->flags & BB_DUPLICATED)
&& (ae->src->loop_father == target
|| ae->dest->loop_father == target))
ae->flags |= EDGE_IRREDUCIBLE_LOOP;
}
for (i = 0; i < n; i++)
- new_bbs[i]->rbi->duplicated = 0;
+ new_bbs[i]->flags &= ~BB_DUPLICATED;
}
/* Redirect the special edges. */
redirect_edge_and_branch_force (new_spec_edges[SE_LATCH],
loop->header);
set_immediate_dominator (CDI_DOMINATORS, new_bbs[0], latch);
- latch = loop->latch = new_bbs[1];
+ latch = loop->latch = new_bbs[n - 1];
e = latch_edge = new_spec_edges[SE_LATCH];
}
else
/* Record exit edge in this copy. */
if (orig && TEST_BIT (wont_exit, j + 1))
- to_remove[(*n_to_remove)++] = new_spec_edges[SE_ORIG];
+ {
+ if (to_remove)
+ VEC_safe_push (edge, heap, *to_remove, new_spec_edges[SE_ORIG]);
+ set_zero_probability (new_spec_edges[SE_ORIG]);
+
+ /* Scale the frequencies of the blocks dominated by the exit. */
+ if (bbs_to_scale)
+ {
+ EXECUTE_IF_SET_IN_BITMAP (bbs_to_scale, 0, i, bi)
+ {
+ scale_bbs_frequencies_int (new_bbs + i, 1, scale_after_exit,
+ REG_BR_PROB_BASE);
+ }
+ }
+ }
/* Record the first copy in the control flow order if it is not
the original loop (i.e. in case of peeling). */
if (!first_active_latch)
{
memcpy (first_active, new_bbs, n * sizeof (basic_block));
- first_active_latch = new_bbs[1];
+ first_active_latch = new_bbs[n - 1];
}
/* Set counts and frequencies. */
if (flags & DLTHE_FLAG_UPDATE_FREQ)
{
- scale_bbs_frequencies (new_bbs, n, scale_act, REG_BR_PROB_BASE);
+ scale_bbs_frequencies_int (new_bbs, n, scale_act, REG_BR_PROB_BASE);
scale_act = RDIV (scale_act * scale_step[j], REG_BR_PROB_BASE);
}
}
free (new_bbs);
free (orig_loops);
-
+
+ /* Record the exit edge in the original loop body, and update the frequencies. */
+ if (orig && TEST_BIT (wont_exit, 0))
+ {
+ if (to_remove)
+ VEC_safe_push (edge, heap, *to_remove, orig);
+ set_zero_probability (orig);
+
+ /* Scale the frequencies of the blocks dominated by the exit. */
+ if (bbs_to_scale)
+ {
+ EXECUTE_IF_SET_IN_BITMAP (bbs_to_scale, 0, i, bi)
+ {
+ scale_bbs_frequencies_int (bbs + i, 1, scale_after_exit,
+ REG_BR_PROB_BASE);
+ }
+ }
+ }
+
/* Update the original loop. */
if (!is_latch)
set_immediate_dominator (CDI_DOMINATORS, e->dest, e->src);
if (flags & DLTHE_FLAG_UPDATE_FREQ)
{
- scale_bbs_frequencies (bbs, n, scale_main, REG_BR_PROB_BASE);
+ scale_bbs_frequencies_int (bbs, n, scale_main, REG_BR_PROB_BASE);
free (scale_step);
}
/* Update dominators of outer blocks if affected. */
for (i = 0; i < n; i++)
{
- basic_block dominated, dom_bb, *dom_bbs;
- int n_dom_bbs,j;
+ basic_block dominated, dom_bb;
+ VEC (basic_block, heap) *dom_bbs;
+ unsigned j;
bb = bbs[i];
- n_dom_bbs = get_dominated_by (CDI_DOMINATORS, bb, &dom_bbs);
- for (j = 0; j < n_dom_bbs; j++)
+ bb->aux = 0;
+
+ dom_bbs = get_dominated_by (CDI_DOMINATORS, bb);
+ for (j = 0; VEC_iterate (basic_block, dom_bbs, j, dominated); j++)
{
- dominated = dom_bbs[j];
if (flow_bb_inside_loop_p (loop, dominated))
continue;
dom_bb = nearest_common_dominator (
CDI_DOMINATORS, first_active[i], first_active_latch);
- set_immediate_dominator (CDI_DOMINATORS, dominated, dom_bb);
+ set_immediate_dominator (CDI_DOMINATORS, dominated, dom_bb);
}
- free (dom_bbs);
+ VEC_free (basic_block, heap, dom_bbs);
}
free (first_active);
free (bbs);
+ BITMAP_FREE (bbs_to_scale);
return true;
}
MFB_KJ_EDGE to the entry part. E is the edge for that we should decide
whether to redirect it. */
-static edge mfb_kj_edge;
-static bool
+edge mfb_kj_edge;
+bool
mfb_keep_just (edge e)
{
return e != mfb_kj_edge;
}
-/* A callback for make_forwarder block, to update data structures for a basic
- block JUMP created by redirecting an edge (only the latch edge is being
- redirected). */
+/* True when a candidate preheader BLOCK has predecessors from LOOP. */
-static void
-mfb_update_loops (basic_block jump)
+static bool
+has_preds_from_loop (basic_block block, struct loop *loop)
{
- struct loop *loop = jump->succ->dest->loop_father;
-
- if (dom_computed[CDI_DOMINATORS])
- set_immediate_dominator (CDI_DOMINATORS, jump, jump->pred->src);
- add_bb_to_loop (jump, loop);
- loop->latch = jump;
+ edge e;
+ edge_iterator ei;
+
+ FOR_EACH_EDGE (e, ei, block->preds)
+ if (e->src->loop_father == loop)
+ return true;
+ return false;
}
/* Creates a pre-header for a LOOP. Returns newly created block. Unless
CP_SIMPLE_PREHEADERS is set in FLAGS, we only force LOOP to have single
entry; otherwise we also force preheader block to have only one successor.
+ When CP_FALLTHRU_PREHEADERS is set in FLAGS, we force the preheader block
+ to be a fallthru predecessor to the loop header and to have only
+ predecessors from outside of the loop.
The function also updates dominators. */
-static basic_block
+basic_block
create_preheader (struct loop *loop, int flags)
{
edge e, fallthru;
basic_block dummy;
- struct loop *cloop, *ploop;
int nentry = 0;
bool irred = false;
+ bool latch_edge_was_fallthru;
+ edge one_succ_pred = NULL, single_entry = NULL;
+ edge_iterator ei;
- cloop = loop->outer;
-
- for (e = loop->header->pred; e; e = e->pred_next)
+ FOR_EACH_EDGE (e, ei, loop->header->preds)
{
if (e->src == loop->latch)
continue;
irred |= (e->flags & EDGE_IRREDUCIBLE_LOOP) != 0;
nentry++;
+ single_entry = e;
+ if (single_succ_p (e->src))
+ one_succ_pred = e;
}
gcc_assert (nentry);
if (nentry == 1)
{
- for (e = loop->header->pred; e->src == loop->latch; e = e->pred_next);
- if (!(flags & CP_SIMPLE_PREHEADERS)
- || !e->src->succ->succ_next)
+ bool need_forwarder_block = false;
+
+ /* We do not allow entry block to be the loop preheader, since we
+ cannot emit code there. */
+ if (single_entry->src == ENTRY_BLOCK_PTR)
+ need_forwarder_block = true;
+ else
+ {
+ /* If we want simple preheaders, also force the preheader to have
+ just a single successor. */
+ if ((flags & CP_SIMPLE_PREHEADERS)
+ && !single_succ_p (single_entry->src))
+ need_forwarder_block = true;
+ /* If we want fallthru preheaders, also create forwarder block when
+ preheader ends with a jump or has predecessors from loop. */
+ else if ((flags & CP_FALLTHRU_PREHEADERS)
+ && (JUMP_P (BB_END (single_entry->src))
+ || has_preds_from_loop (single_entry->src, loop)))
+ need_forwarder_block = true;
+ }
+ if (! need_forwarder_block)
return NULL;
}
mfb_kj_edge = loop_latch_edge (loop);
- fallthru = make_forwarder_block (loop->header, mfb_keep_just,
- mfb_update_loops);
+ latch_edge_was_fallthru = (mfb_kj_edge->flags & EDGE_FALLTHRU) != 0;
+ fallthru = make_forwarder_block (loop->header, mfb_keep_just, NULL);
dummy = fallthru->src;
loop->header = fallthru->dest;
- /* The header could be a latch of some superloop(s); due to design of
- split_block, it would now move to fallthru->dest. */
- for (ploop = loop; ploop; ploop = ploop->outer)
- if (ploop->latch == dummy)
- ploop->latch = fallthru->dest;
+ /* Try to be clever in placing the newly created preheader. The idea is to
+ avoid breaking any "fallthruness" relationship between blocks.
- /* Reorganize blocks so that the preheader is not stuck in the middle of the
- loop. */
- for (e = dummy->pred; e; e = e->pred_next)
- if (e->src != loop->latch)
- break;
- move_block_after (dummy, e->src);
+ The preheader was created just before the header and all incoming edges
+ to the header were redirected to the preheader, except the latch edge.
+ So the only problematic case is when this latch edge was a fallthru
+ edge: it is not anymore after the preheader creation so we have broken
+ the fallthruness. We're therefore going to look for a better place. */
+ if (latch_edge_was_fallthru)
+ {
+ if (one_succ_pred)
+ e = one_succ_pred;
+ else
+ e = EDGE_PRED (dummy, 0);
- loop->header->loop_father = loop;
- add_bb_to_loop (dummy, cloop);
+ move_block_after (dummy, e->src);
+ }
if (irred)
{
dummy->flags |= BB_IRREDUCIBLE_LOOP;
- dummy->succ->flags |= EDGE_IRREDUCIBLE_LOOP;
+ single_succ_edge (dummy)->flags |= EDGE_IRREDUCIBLE_LOOP;
}
if (dump_file)
fprintf (dump_file, "Created preheader block for loop %i\n",
loop->num);
+
+ if (flags & CP_FALLTHRU_PREHEADERS)
+ gcc_assert ((single_succ_edge (dummy)->flags & EDGE_FALLTHRU)
+ && !JUMP_P (BB_END (dummy)));
return dummy;
}
-/* Create preheaders for each loop from loop tree stored in LOOPS; for meaning
- of FLAGS see create_preheader. */
+/* Create preheaders for each loop; for meaning of FLAGS see create_preheader. */
+
void
-create_preheaders (struct loops *loops, int flags)
+create_preheaders (int flags)
{
- unsigned i;
- for (i = 1; i < loops->num; i++)
- create_preheader (loops->parray[i], flags);
- loops->state |= LOOPS_HAVE_PREHEADERS;
+ loop_iterator li;
+ struct loop *loop;
+
+ if (!current_loops)
+ return;
+
+ FOR_EACH_LOOP (li, loop, 0)
+ create_preheader (loop, flags);
+ loops_state_set (LOOPS_HAVE_PREHEADERS);
}
-/* Forces all loop latches of loops from loop tree LOOPS to have only single
- successor. */
+/* Forces all loop latches to have only single successor. */
+
void
-force_single_succ_latches (struct loops *loops)
+force_single_succ_latches (void)
{
- unsigned i;
+ loop_iterator li;
struct loop *loop;
edge e;
- for (i = 1; i < loops->num; i++)
+ FOR_EACH_LOOP (li, loop, 0)
{
- loop = loops->parray[i];
- if (loop->latch != loop->header
- && !loop->latch->succ->succ_next)
+ if (loop->latch != loop->header && single_succ_p (loop->latch))
continue;
- for (e = loop->header->pred; e->src != loop->latch; e = e->pred_next)
- continue;
+ e = find_edge (loop->latch, loop->header);
- loop_split_edge_with (e, NULL_RTX);
+ split_edge (e);
}
- loops->state |= LOOPS_HAVE_SIMPLE_LATCHES;
+ loops_state_set (LOOPS_HAVE_SIMPLE_LATCHES);
}
-/* A quite stupid function to put INSNS on edge E. They are supposed to form
- just one basic block. Jumps in INSNS are not handled, so cfg do not have to
- be ok after this function. The created block is placed on correct place
- in LOOPS structure and its dominator is set. */
-basic_block
-loop_split_edge_with (edge e, rtx insns)
+/* This function is called from loop_version. It splits the entry edge
+ of the loop we want to version, adds the versioning condition, and
+ adjust the edges to the two versions of the loop appropriately.
+ e is an incoming edge. Returns the basic block containing the
+ condition.
+
+ --- edge e ---- > [second_head]
+
+ Split it and insert new conditional expression and adjust edges.
+
+ --- edge e ---> [cond expr] ---> [first_head]
+ |
+ +---------> [second_head]
+
+ THEN_PROB is the probability of then branch of the condition. */
+
+static basic_block
+lv_adjust_loop_entry_edge (basic_block first_head, basic_block second_head,
+ edge e, void *cond_expr, unsigned then_prob)
{
- basic_block src, dest, new_bb;
- struct loop *loop_c;
- edge new_e;
+ basic_block new_head = NULL;
+ edge e1;
- src = e->src;
- dest = e->dest;
+ gcc_assert (e->dest == second_head);
- loop_c = find_common_loop (src->loop_father, dest->loop_father);
+ /* Split edge 'e'. This will create a new basic block, where we can
+ insert conditional expr. */
+ new_head = split_edge (e);
- /* Create basic block for it. */
+ lv_add_condition_to_bb (first_head, second_head, new_head,
+ cond_expr);
- new_bb = split_edge (e);
- add_bb_to_loop (new_bb, loop_c);
- new_bb->flags = insns ? BB_SUPERBLOCK : 0;
+ /* Don't set EDGE_TRUE_VALUE in RTL mode, as it's invalid there. */
+ e = single_succ_edge (new_head);
+ e1 = make_edge (new_head, first_head,
+ current_ir_type () == IR_GIMPLE ? EDGE_TRUE_VALUE : 0);
+ e1->probability = then_prob;
+ e->probability = REG_BR_PROB_BASE - then_prob;
+ e1->count = RDIV (e->count * e1->probability, REG_BR_PROB_BASE);
+ e->count = RDIV (e->count * e->probability, REG_BR_PROB_BASE);
- new_e = new_bb->succ;
- if (e->flags & EDGE_IRREDUCIBLE_LOOP)
+ set_immediate_dominator (CDI_DOMINATORS, first_head, new_head);
+ set_immediate_dominator (CDI_DOMINATORS, second_head, new_head);
+
+ /* Adjust loop header phi nodes. */
+ lv_adjust_loop_header_phi (first_head, second_head, new_head, e1);
+
+ return new_head;
+}
+
+/* Main entry point for Loop Versioning transformation.
+
+ This transformation given a condition and a loop, creates
+ -if (condition) { loop_copy1 } else { loop_copy2 },
+ where loop_copy1 is the loop transformed in one way, and loop_copy2
+ is the loop transformed in another way (or unchanged). 'condition'
+ may be a run time test for things that were not resolved by static
+ analysis (overlapping ranges (anti-aliasing), alignment, etc.).
+
+ THEN_PROB is the probability of the then edge of the if. THEN_SCALE
+ is the ratio by that the frequencies in the original loop should
+ be scaled. ELSE_SCALE is the ratio by that the frequencies in the
+ new loop should be scaled.
+
+ If PLACE_AFTER is true, we place the new loop after LOOP in the
+ instruction stream, otherwise it is placed before LOOP. */
+
+struct loop *
+loop_version (struct loop *loop,
+ void *cond_expr, basic_block *condition_bb,
+ unsigned then_prob, unsigned then_scale, unsigned else_scale,
+ bool place_after)
+{
+ basic_block first_head, second_head;
+ edge entry, latch_edge, true_edge, false_edge;
+ int irred_flag;
+ struct loop *nloop;
+ basic_block cond_bb;
+
+ /* Record entry and latch edges for the loop */
+ entry = loop_preheader_edge (loop);
+ irred_flag = entry->flags & EDGE_IRREDUCIBLE_LOOP;
+ entry->flags &= ~EDGE_IRREDUCIBLE_LOOP;
+
+ /* Note down head of loop as first_head. */
+ first_head = entry->dest;
+
+ /* Duplicate loop. */
+ if (!cfg_hook_duplicate_loop_to_header_edge (loop, entry, 1,
+ NULL, NULL, NULL, 0))
+ return NULL;
+
+ /* After duplication entry edge now points to new loop head block.
+ Note down new head as second_head. */
+ second_head = entry->dest;
+
+ /* Split loop entry edge and insert new block with cond expr. */
+ cond_bb = lv_adjust_loop_entry_edge (first_head, second_head,
+ entry, cond_expr, then_prob);
+ if (condition_bb)
+ *condition_bb = cond_bb;
+
+ if (!cond_bb)
{
- new_bb->flags |= BB_IRREDUCIBLE_LOOP;
- new_e->flags |= EDGE_IRREDUCIBLE_LOOP;
+ entry->flags |= irred_flag;
+ return NULL;
}
- if (insns)
- emit_insn_after (insns, BB_END (new_bb));
+ latch_edge = single_succ_edge (get_bb_copy (loop->latch));
+
+ extract_cond_bb_edges (cond_bb, &true_edge, &false_edge);
+ nloop = loopify (latch_edge,
+ single_pred_edge (get_bb_copy (loop->header)),
+ cond_bb, true_edge, false_edge,
+ false /* Do not redirect all edges. */,
+ then_scale, else_scale);
- if (dest->loop_father->latch == src)
- dest->loop_father->latch = new_bb;
+ /* loopify redirected latch_edge. Update its PENDING_STMTS. */
+ lv_flush_pending_stmts (latch_edge);
- return new_bb;
+ /* loopify redirected condition_bb's succ edge. Update its PENDING_STMTS. */
+ extract_cond_bb_edges (cond_bb, &true_edge, &false_edge);
+ lv_flush_pending_stmts (false_edge);
+ /* Adjust irreducible flag. */
+ if (irred_flag)
+ {
+ cond_bb->flags |= BB_IRREDUCIBLE_LOOP;
+ loop_preheader_edge (loop)->flags |= EDGE_IRREDUCIBLE_LOOP;
+ loop_preheader_edge (nloop)->flags |= EDGE_IRREDUCIBLE_LOOP;
+ single_pred_edge (cond_bb)->flags |= EDGE_IRREDUCIBLE_LOOP;
+ }
+
+ if (place_after)
+ {
+ basic_block *bbs = get_loop_body_in_dom_order (nloop), after;
+ unsigned i;
+
+ after = loop->latch;
+
+ for (i = 0; i < nloop->num_nodes; i++)
+ {
+ move_block_after (bbs[i], after);
+ after = bbs[i];
+ }
+ free (bbs);
+ }
+
+ /* At this point condition_bb is loop preheader with two successors,
+ first_head and second_head. Make sure that loop preheader has only
+ one successor. */
+ split_edge (loop_preheader_edge (loop));
+ split_edge (loop_preheader_edge (nloop));
+
+ return nloop;
}
-/* Uses the natural loop discovery to recreate loop notes. */
+/* The structure of loops might have changed. Some loops might get removed
+ (and their headers and latches were set to NULL), loop exists might get
+ removed (thus the loop nesting may be wrong), and some blocks and edges
+ were changed (so the information about bb --> loop mapping does not have
+ to be correct). But still for the remaining loops the header dominates
+ the latch, and loops did not get new subloops (new loops might possibly
+ get created, but we are not interested in them). Fix up the mess.
+
+ If CHANGED_BBS is not NULL, basic blocks whose loop has changed are
+ marked in it. */
+
void
-create_loop_notes (void)
+fix_loop_structure (bitmap changed_bbs)
{
- rtx insn, head, end;
- struct loops loops;
- struct loop *loop;
- basic_block *first, *last, bb, pbb;
- struct loop **stack, **top;
+ basic_block bb;
+ struct loop *loop, *ploop;
+ loop_iterator li;
+ bool record_exits = false;
+ struct loop **superloop = XNEWVEC (struct loop *, number_of_loops ());
+
+ /* Remove the old bb -> loop mapping. Remember the depth of the blocks in
+ the loop hierarchy, so that we can recognize blocks whose loop nesting
+ relationship has changed. */
+ FOR_EACH_BB (bb)
+ {
+ if (changed_bbs)
+ bb->aux = (void *) (size_t) loop_depth (bb->loop_father);
+ bb->loop_father = current_loops->tree_root;
+ }
-#ifdef ENABLE_CHECKING
- /* Verify that there really are no loop notes. */
- for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
- gcc_assert (!NOTE_P (insn) ||
- NOTE_LINE_NUMBER (insn) != NOTE_INSN_LOOP_BEG);
-#endif
+ if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS))
+ {
+ release_recorded_exits ();
+ record_exits = true;
+ }
- flow_loops_find (&loops, LOOP_TREE);
- free_dominance_info (CDI_DOMINATORS);
- if (loops.num > 1)
+ /* Remove the dead loops from structures. We start from the innermost
+ loops, so that when we remove the loops, we know that the loops inside
+ are preserved, and do not waste time relinking loops that will be
+ removed later. */
+ FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST)
{
- last = xcalloc (loops.num, sizeof (basic_block));
+ if (loop->header)
+ continue;
- FOR_EACH_BB (bb)
+ while (loop->inner)
{
- for (loop = bb->loop_father; loop->outer; loop = loop->outer)
- last[loop->num] = bb;
+ ploop = loop->inner;
+ flow_loop_tree_node_remove (ploop);
+ flow_loop_tree_node_add (loop_outer (loop), ploop);
}
- first = xcalloc (loops.num, sizeof (basic_block));
- stack = xcalloc (loops.num, sizeof (struct loop *));
- top = stack;
+ /* Remove the loop and free its data. */
+ delete_loop (loop);
+ }
+
+ /* Rescan the bodies of loops, starting from the outermost ones. We assume
+ that no optimization interchanges the order of the loops, i.e., it cannot
+ happen that L1 was superloop of L2 before and it is subloop of L2 now
+ (without explicitly updating loop information). At the same time, we also
+ determine the new loop structure. */
+ current_loops->tree_root->num_nodes = n_basic_blocks;
+ FOR_EACH_LOOP (li, loop, 0)
+ {
+ superloop[loop->num] = loop->header->loop_father;
+ loop->num_nodes = flow_loop_nodes_find (loop->header, loop);
+ }
+
+ /* Now fix the loop nesting. */
+ FOR_EACH_LOOP (li, loop, 0)
+ {
+ ploop = superloop[loop->num];
+ if (ploop != loop_outer (loop))
+ {
+ flow_loop_tree_node_remove (loop);
+ flow_loop_tree_node_add (ploop, loop);
+ }
+ }
+ free (superloop);
+ /* Mark the blocks whose loop has changed. */
+ if (changed_bbs)
+ {
FOR_EACH_BB (bb)
{
- for (loop = bb->loop_father; loop->outer; loop = loop->outer)
- {
- if (!first[loop->num])
- {
- *top++ = loop;
- first[loop->num] = bb;
- }
+ if ((void *) (size_t) loop_depth (bb->loop_father) != bb->aux)
+ bitmap_set_bit (changed_bbs, bb->index);
- if (bb == last[loop->num])
- {
- /* Prevent loops from overlapping. */
- while (*--top != loop)
- last[(*top)->num] = EXIT_BLOCK_PTR;
-
- /* If loop starts with jump into it, place the note in
- front of the jump. */
- insn = PREV_INSN (BB_HEAD (first[loop->num]));
- if (insn
- && BARRIER_P (insn))
- insn = PREV_INSN (insn);
-
- if (insn
- && JUMP_P (insn)
- && any_uncondjump_p (insn)
- && onlyjump_p (insn))
- {
- pbb = BLOCK_FOR_INSN (insn);
- gcc_assert (pbb && pbb->succ && !pbb->succ->succ_next);
-
- if (!flow_bb_inside_loop_p (loop, pbb->succ->dest))
- insn = BB_HEAD (first[loop->num]);
- }
- else
- insn = BB_HEAD (first[loop->num]);
-
- head = BB_HEAD (first[loop->num]);
- emit_note_before (NOTE_INSN_LOOP_BEG, insn);
- BB_HEAD (first[loop->num]) = head;
-
- /* Position the note correctly wrto barrier. */
- insn = BB_END (last[loop->num]);
- if (NEXT_INSN (insn)
- && BARRIER_P (NEXT_INSN (insn)))
- insn = NEXT_INSN (insn);
-
- end = BB_END (last[loop->num]);
- emit_note_after (NOTE_INSN_LOOP_END, insn);
- BB_END (last[loop->num]) = end;
- }
- }
+ bb->aux = NULL;
}
-
- free (first);
- free (last);
- free (stack);
}
- flow_loops_free (&loops);
+
+ if (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS))
+ create_preheaders (CP_SIMPLE_PREHEADERS);
+
+ if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES))
+ force_single_succ_latches ();
+
+ if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS))
+ mark_irreducible_loops ();
+
+ if (record_exits)
+ record_loop_exits ();
+
+#ifdef ENABLE_CHECKING
+ verify_loop_structure ();
+#endif
}
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