/* Hooks for cfg representation specific functions.
- Copyright (C) 2003 Free Software Foundation, Inc.
+ Copyright (C) 2003, 2004, 2005, 2007, 2008 Free Software Foundation,
+ Inc.
Contributed by Sebastian Pop <s.pop@laposte.net>
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)
+the Free Software Foundation; either version 3, or (at your option)
any later version.
GCC is distributed in the hope that it will be useful,
GNU General Public License 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 "tree.h"
#include "rtl.h"
#include "basic-block.h"
-
-extern struct cfg_hooks rtl_cfg_hooks;
-extern struct cfg_hooks cfg_layout_rtl_cfg_hooks;
+#include "tree-flow.h"
+#include "timevar.h"
+#include "toplev.h"
+#include "cfgloop.h"
/* A pointer to one of the hooks containers. */
-struct cfg_hooks *cfg_hooks;
+static struct cfg_hooks *cfg_hooks;
/* Initialization of functions specific to the rtl IR. */
void
{
cfg_hooks = &cfg_layout_rtl_cfg_hooks;
}
+
+/* Initialization of functions specific to the tree IR. */
+
+void
+gimple_register_cfg_hooks (void)
+{
+ cfg_hooks = &gimple_cfg_hooks;
+}
+
+struct cfg_hooks
+get_cfg_hooks (void)
+{
+ return *cfg_hooks;
+}
+
+void
+set_cfg_hooks (struct cfg_hooks new_cfg_hooks)
+{
+ *cfg_hooks = new_cfg_hooks;
+}
+
+/* Returns current ir type. */
+
+enum ir_type
+current_ir_type (void)
+{
+ if (cfg_hooks == &gimple_cfg_hooks)
+ return IR_GIMPLE;
+ else if (cfg_hooks == &rtl_cfg_hooks)
+ return IR_RTL_CFGRTL;
+ else if (cfg_hooks == &cfg_layout_rtl_cfg_hooks)
+ return IR_RTL_CFGLAYOUT;
+ else
+ gcc_unreachable ();
+}
+
+/* Verify the CFG consistency.
+
+ Currently it does following: checks edge and basic block list correctness
+ and calls into IL dependent checking then. */
+
+void
+verify_flow_info (void)
+{
+ size_t *edge_checksum;
+ int err = 0;
+ basic_block bb, last_bb_seen;
+ basic_block *last_visited;
+
+ timevar_push (TV_CFG_VERIFY);
+ last_visited = XCNEWVEC (basic_block, last_basic_block);
+ edge_checksum = XCNEWVEC (size_t, last_basic_block);
+
+ /* Check bb chain & numbers. */
+ last_bb_seen = ENTRY_BLOCK_PTR;
+ FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR->next_bb, NULL, next_bb)
+ {
+ if (bb != EXIT_BLOCK_PTR
+ && bb != BASIC_BLOCK (bb->index))
+ {
+ error ("bb %d on wrong place", bb->index);
+ err = 1;
+ }
+
+ if (bb->prev_bb != last_bb_seen)
+ {
+ error ("prev_bb of %d should be %d, not %d",
+ bb->index, last_bb_seen->index, bb->prev_bb->index);
+ err = 1;
+ }
+
+ last_bb_seen = bb;
+ }
+
+ /* Now check the basic blocks (boundaries etc.) */
+ FOR_EACH_BB_REVERSE (bb)
+ {
+ int n_fallthru = 0;
+ edge e;
+ edge_iterator ei;
+
+ if (bb->loop_father != NULL && current_loops == NULL)
+ {
+ error ("verify_flow_info: Block %i has loop_father, but there are no loops",
+ bb->index);
+ err = 1;
+ }
+ if (bb->loop_father == NULL && current_loops != NULL)
+ {
+ error ("verify_flow_info: Block %i lacks loop_father", bb->index);
+ err = 1;
+ }
+
+ if (bb->count < 0)
+ {
+ error ("verify_flow_info: Wrong count of block %i %i",
+ bb->index, (int)bb->count);
+ err = 1;
+ }
+ if (bb->frequency < 0)
+ {
+ error ("verify_flow_info: Wrong frequency of block %i %i",
+ bb->index, bb->frequency);
+ err = 1;
+ }
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ {
+ if (last_visited [e->dest->index] == bb)
+ {
+ error ("verify_flow_info: Duplicate edge %i->%i",
+ e->src->index, e->dest->index);
+ err = 1;
+ }
+ if (e->probability < 0 || e->probability > REG_BR_PROB_BASE)
+ {
+ error ("verify_flow_info: Wrong probability of edge %i->%i %i",
+ e->src->index, e->dest->index, e->probability);
+ err = 1;
+ }
+ if (e->count < 0)
+ {
+ error ("verify_flow_info: Wrong count of edge %i->%i %i",
+ e->src->index, e->dest->index, (int)e->count);
+ err = 1;
+ }
+
+ last_visited [e->dest->index] = bb;
+
+ if (e->flags & EDGE_FALLTHRU)
+ n_fallthru++;
+
+ if (e->src != bb)
+ {
+ error ("verify_flow_info: Basic block %d succ edge is corrupted",
+ bb->index);
+ fprintf (stderr, "Predecessor: ");
+ dump_edge_info (stderr, e, 0);
+ fprintf (stderr, "\nSuccessor: ");
+ dump_edge_info (stderr, e, 1);
+ fprintf (stderr, "\n");
+ err = 1;
+ }
+
+ edge_checksum[e->dest->index] += (size_t) e;
+ }
+ if (n_fallthru > 1)
+ {
+ error ("wrong amount of branch edges after unconditional jump %i", bb->index);
+ err = 1;
+ }
+
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ {
+ if (e->dest != bb)
+ {
+ error ("basic block %d pred edge is corrupted", bb->index);
+ fputs ("Predecessor: ", stderr);
+ dump_edge_info (stderr, e, 0);
+ fputs ("\nSuccessor: ", stderr);
+ dump_edge_info (stderr, e, 1);
+ fputc ('\n', stderr);
+ err = 1;
+ }
+
+ if (ei.index != e->dest_idx)
+ {
+ error ("basic block %d pred edge is corrupted", bb->index);
+ error ("its dest_idx should be %d, not %d",
+ ei.index, e->dest_idx);
+ fputs ("Predecessor: ", stderr);
+ dump_edge_info (stderr, e, 0);
+ fputs ("\nSuccessor: ", stderr);
+ dump_edge_info (stderr, e, 1);
+ fputc ('\n', stderr);
+ err = 1;
+ }
+
+ edge_checksum[e->dest->index] -= (size_t) e;
+ }
+ }
+
+ /* Complete edge checksumming for ENTRY and EXIT. */
+ {
+ edge e;
+ edge_iterator ei;
+
+ FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
+ edge_checksum[e->dest->index] += (size_t) e;
+
+ FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
+ edge_checksum[e->dest->index] -= (size_t) e;
+ }
+
+ FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
+ if (edge_checksum[bb->index])
+ {
+ error ("basic block %i edge lists are corrupted", bb->index);
+ err = 1;
+ }
+
+ last_bb_seen = ENTRY_BLOCK_PTR;
+
+ /* Clean up. */
+ free (last_visited);
+ free (edge_checksum);
+
+ if (cfg_hooks->verify_flow_info)
+ err |= cfg_hooks->verify_flow_info ();
+ if (err)
+ internal_error ("verify_flow_info failed");
+ timevar_pop (TV_CFG_VERIFY);
+}
+
+/* Print out one basic block. This function takes care of the purely
+ graph related information. The cfg hook for the active representation
+ should dump representation-specific information. */
+
+void
+dump_bb (basic_block bb, FILE *outf, int indent)
+{
+ edge e;
+ edge_iterator ei;
+ char *s_indent;
+
+ s_indent = (char *) alloca ((size_t) indent + 1);
+ memset (s_indent, ' ', (size_t) indent);
+ s_indent[indent] = '\0';
+
+ fprintf (outf, ";;%s basic block %d, loop depth %d, count ",
+ s_indent, bb->index, bb->loop_depth);
+ fprintf (outf, HOST_WIDEST_INT_PRINT_DEC, (HOST_WIDEST_INT) bb->count);
+ putc ('\n', outf);
+
+ fprintf (outf, ";;%s prev block ", s_indent);
+ if (bb->prev_bb)
+ fprintf (outf, "%d, ", bb->prev_bb->index);
+ else
+ fprintf (outf, "(nil), ");
+ fprintf (outf, "next block ");
+ if (bb->next_bb)
+ fprintf (outf, "%d", bb->next_bb->index);
+ else
+ fprintf (outf, "(nil)");
+ putc ('\n', outf);
+
+ fprintf (outf, ";;%s pred: ", s_indent);
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ dump_edge_info (outf, e, 0);
+ putc ('\n', outf);
+
+ fprintf (outf, ";;%s succ: ", s_indent);
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ dump_edge_info (outf, e, 1);
+ putc ('\n', outf);
+
+ if (cfg_hooks->dump_bb)
+ cfg_hooks->dump_bb (bb, outf, indent, 0);
+}
+
+/* Redirect edge E to the given basic block DEST and update underlying program
+ representation. Returns edge representing redirected branch (that may not
+ be equivalent to E in the case of duplicate edges being removed) or NULL
+ if edge is not easily redirectable for whatever reason. */
+
+edge
+redirect_edge_and_branch (edge e, basic_block dest)
+{
+ edge ret;
+
+ if (!cfg_hooks->redirect_edge_and_branch)
+ internal_error ("%s does not support redirect_edge_and_branch",
+ cfg_hooks->name);
+
+ ret = cfg_hooks->redirect_edge_and_branch (e, dest);
+
+ /* If RET != E, then either the redirection failed, or the edge E
+ was removed since RET already lead to the same destination. */
+ if (current_loops != NULL && ret == e)
+ rescan_loop_exit (e, false, false);
+
+ return ret;
+}
+
+/* Returns true if it is possible to remove the edge E by redirecting it
+ to the destination of the other edge going from its source. */
+
+bool
+can_remove_branch_p (const_edge e)
+{
+ if (!cfg_hooks->can_remove_branch_p)
+ internal_error ("%s does not support can_remove_branch_p",
+ cfg_hooks->name);
+
+ if (EDGE_COUNT (e->src->succs) != 2)
+ return false;
+
+ return cfg_hooks->can_remove_branch_p (e);
+}
+
+/* Removes E, by redirecting it to the destination of the other edge going
+ from its source. Can_remove_branch_p must be true for E, hence this
+ operation cannot fail. */
+
+void
+remove_branch (edge e)
+{
+ edge other;
+ basic_block src = e->src;
+ int irr;
+
+ gcc_assert (EDGE_COUNT (e->src->succs) == 2);
+
+ other = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e);
+ irr = other->flags & EDGE_IRREDUCIBLE_LOOP;
+
+ e = redirect_edge_and_branch (e, other->dest);
+ gcc_assert (e != NULL);
+
+ e->flags &= ~EDGE_IRREDUCIBLE_LOOP;
+ e->flags |= irr;
+}
+
+/* Removes edge E from cfg. Unlike remove_branch, it does not update IL. */
+
+void
+remove_edge (edge e)
+{
+ if (current_loops != NULL)
+ rescan_loop_exit (e, false, true);
+
+ remove_edge_raw (e);
+}
+
+/* Redirect the edge E to basic block DEST even if it requires creating
+ of a new basic block; then it returns the newly created basic block.
+ Aborts when redirection is impossible. */
+
+basic_block
+redirect_edge_and_branch_force (edge e, basic_block dest)
+{
+ basic_block ret, src = e->src;
+ struct loop *loop;
+
+ if (!cfg_hooks->redirect_edge_and_branch_force)
+ internal_error ("%s does not support redirect_edge_and_branch_force",
+ cfg_hooks->name);
+
+ if (current_loops != NULL)
+ rescan_loop_exit (e, false, true);
+
+ ret = cfg_hooks->redirect_edge_and_branch_force (e, dest);
+ if (ret != NULL
+ && dom_info_available_p (CDI_DOMINATORS))
+ set_immediate_dominator (CDI_DOMINATORS, ret, src);
+
+ if (current_loops != NULL)
+ {
+ if (ret != NULL)
+ {
+ loop = find_common_loop (single_pred (ret)->loop_father,
+ single_succ (ret)->loop_father);
+ add_bb_to_loop (ret, loop);
+ }
+ else if (find_edge (src, dest) == e)
+ rescan_loop_exit (e, true, false);
+ }
+
+ return ret;
+}
+
+/* Splits basic block BB after the specified instruction I (but at least after
+ the labels). If I is NULL, splits just after labels. The newly created edge
+ is returned. The new basic block is created just after the old one. */
+
+edge
+split_block (basic_block bb, void *i)
+{
+ basic_block new_bb;
+ edge res;
+
+ if (!cfg_hooks->split_block)
+ internal_error ("%s does not support split_block", cfg_hooks->name);
+
+ new_bb = cfg_hooks->split_block (bb, i);
+ if (!new_bb)
+ return NULL;
+
+ new_bb->count = bb->count;
+ new_bb->frequency = bb->frequency;
+ new_bb->loop_depth = bb->loop_depth;
+ new_bb->discriminator = bb->discriminator;
+
+ if (dom_info_available_p (CDI_DOMINATORS))
+ {
+ redirect_immediate_dominators (CDI_DOMINATORS, bb, new_bb);
+ set_immediate_dominator (CDI_DOMINATORS, new_bb, bb);
+ }
+
+ if (current_loops != NULL)
+ {
+ add_bb_to_loop (new_bb, bb->loop_father);
+ if (bb->loop_father->latch == bb)
+ bb->loop_father->latch = new_bb;
+ }
+
+ res = make_single_succ_edge (bb, new_bb, EDGE_FALLTHRU);
+
+ if (bb->flags & BB_IRREDUCIBLE_LOOP)
+ {
+ new_bb->flags |= BB_IRREDUCIBLE_LOOP;
+ res->flags |= EDGE_IRREDUCIBLE_LOOP;
+ }
+
+ return res;
+}
+
+/* Splits block BB just after labels. The newly created edge is returned. */
+
+edge
+split_block_after_labels (basic_block bb)
+{
+ return split_block (bb, NULL);
+}
+
+/* Moves block BB immediately after block AFTER. Returns false if the
+ movement was impossible. */
+
+bool
+move_block_after (basic_block bb, basic_block after)
+{
+ bool ret;
+
+ if (!cfg_hooks->move_block_after)
+ internal_error ("%s does not support move_block_after", cfg_hooks->name);
+
+ ret = cfg_hooks->move_block_after (bb, after);
+
+ return ret;
+}
+
+/* Deletes the basic block BB. */
+
+void
+delete_basic_block (basic_block bb)
+{
+ if (!cfg_hooks->delete_basic_block)
+ internal_error ("%s does not support delete_basic_block", cfg_hooks->name);
+
+ cfg_hooks->delete_basic_block (bb);
+
+ if (current_loops != NULL)
+ {
+ struct loop *loop = bb->loop_father;
+
+ /* If we remove the header or the latch of a loop, mark the loop for
+ removal by setting its header and latch to NULL. */
+ if (loop->latch == bb
+ || loop->header == bb)
+ {
+ loop->header = NULL;
+ loop->latch = NULL;
+ }
+
+ remove_bb_from_loops (bb);
+ }
+
+ /* Remove the edges into and out of this block. Note that there may
+ indeed be edges in, if we are removing an unreachable loop. */
+ while (EDGE_COUNT (bb->preds) != 0)
+ remove_edge (EDGE_PRED (bb, 0));
+ while (EDGE_COUNT (bb->succs) != 0)
+ remove_edge (EDGE_SUCC (bb, 0));
+
+ if (dom_info_available_p (CDI_DOMINATORS))
+ delete_from_dominance_info (CDI_DOMINATORS, bb);
+ if (dom_info_available_p (CDI_POST_DOMINATORS))
+ delete_from_dominance_info (CDI_POST_DOMINATORS, bb);
+
+ /* Remove the basic block from the array. */
+ expunge_block (bb);
+}
+
+/* Splits edge E and returns the newly created basic block. */
+
+basic_block
+split_edge (edge e)
+{
+ basic_block ret;
+ gcov_type count = e->count;
+ int freq = EDGE_FREQUENCY (e);
+ edge f;
+ bool irr = (e->flags & EDGE_IRREDUCIBLE_LOOP) != 0;
+ struct loop *loop;
+ basic_block src = e->src, dest = e->dest;
+
+ if (!cfg_hooks->split_edge)
+ internal_error ("%s does not support split_edge", cfg_hooks->name);
+
+ if (current_loops != NULL)
+ rescan_loop_exit (e, false, true);
+
+ ret = cfg_hooks->split_edge (e);
+ ret->count = count;
+ ret->frequency = freq;
+ single_succ_edge (ret)->probability = REG_BR_PROB_BASE;
+ single_succ_edge (ret)->count = count;
+
+ if (irr)
+ {
+ ret->flags |= BB_IRREDUCIBLE_LOOP;
+ single_pred_edge (ret)->flags |= EDGE_IRREDUCIBLE_LOOP;
+ single_succ_edge (ret)->flags |= EDGE_IRREDUCIBLE_LOOP;
+ }
+
+ if (dom_info_available_p (CDI_DOMINATORS))
+ set_immediate_dominator (CDI_DOMINATORS, ret, single_pred (ret));
+
+ if (dom_info_state (CDI_DOMINATORS) >= DOM_NO_FAST_QUERY)
+ {
+ /* There are two cases:
+
+ If the immediate dominator of e->dest is not e->src, it
+ remains unchanged.
+
+ If immediate dominator of e->dest is e->src, it may become
+ ret, provided that all other predecessors of e->dest are
+ dominated by e->dest. */
+
+ if (get_immediate_dominator (CDI_DOMINATORS, single_succ (ret))
+ == single_pred (ret))
+ {
+ edge_iterator ei;
+ FOR_EACH_EDGE (f, ei, single_succ (ret)->preds)
+ {
+ if (f == single_succ_edge (ret))
+ continue;
+
+ if (!dominated_by_p (CDI_DOMINATORS, f->src,
+ single_succ (ret)))
+ break;
+ }
+
+ if (!f)
+ set_immediate_dominator (CDI_DOMINATORS, single_succ (ret), ret);
+ }
+ }
+
+ if (current_loops != NULL)
+ {
+ loop = find_common_loop (src->loop_father, dest->loop_father);
+ add_bb_to_loop (ret, loop);
+
+ if (loop->latch == src)
+ loop->latch = ret;
+ }
+
+ return ret;
+}
+
+/* Creates a new basic block just after the basic block AFTER.
+ HEAD and END are the first and the last statement belonging
+ to the block. If both are NULL, an empty block is created. */
+
+basic_block
+create_basic_block (void *head, void *end, basic_block after)
+{
+ basic_block ret;
+
+ if (!cfg_hooks->create_basic_block)
+ internal_error ("%s does not support create_basic_block", cfg_hooks->name);
+
+ ret = cfg_hooks->create_basic_block (head, end, after);
+
+ if (dom_info_available_p (CDI_DOMINATORS))
+ add_to_dominance_info (CDI_DOMINATORS, ret);
+ if (dom_info_available_p (CDI_POST_DOMINATORS))
+ add_to_dominance_info (CDI_POST_DOMINATORS, ret);
+
+ return ret;
+}
+
+/* Creates an empty basic block just after basic block AFTER. */
+
+basic_block
+create_empty_bb (basic_block after)
+{
+ return create_basic_block (NULL, NULL, after);
+}
+
+/* Checks whether we may merge blocks BB1 and BB2. */
+
+bool
+can_merge_blocks_p (basic_block bb1, basic_block bb2)
+{
+ bool ret;
+
+ if (!cfg_hooks->can_merge_blocks_p)
+ internal_error ("%s does not support can_merge_blocks_p", cfg_hooks->name);
+
+ ret = cfg_hooks->can_merge_blocks_p (bb1, bb2);
+
+ return ret;
+}
+
+void
+predict_edge (edge e, enum br_predictor predictor, int probability)
+{
+ if (!cfg_hooks->predict_edge)
+ internal_error ("%s does not support predict_edge", cfg_hooks->name);
+
+ cfg_hooks->predict_edge (e, predictor, probability);
+}
+
+bool
+predicted_by_p (const_basic_block bb, enum br_predictor predictor)
+{
+ if (!cfg_hooks->predict_edge)
+ internal_error ("%s does not support predicted_by_p", cfg_hooks->name);
+
+ return cfg_hooks->predicted_by_p (bb, predictor);
+}
+
+/* Merges basic block B into basic block A. */
+
+void
+merge_blocks (basic_block a, basic_block b)
+{
+ edge e;
+ edge_iterator ei;
+
+ if (!cfg_hooks->merge_blocks)
+ internal_error ("%s does not support merge_blocks", cfg_hooks->name);
+
+ cfg_hooks->merge_blocks (a, b);
+
+ if (current_loops != NULL)
+ remove_bb_from_loops (b);
+
+ /* Normally there should only be one successor of A and that is B, but
+ partway though the merge of blocks for conditional_execution we'll
+ be merging a TEST block with THEN and ELSE successors. Free the
+ whole lot of them and hope the caller knows what they're doing. */
+
+ while (EDGE_COUNT (a->succs) != 0)
+ remove_edge (EDGE_SUCC (a, 0));
+
+ /* Adjust the edges out of B for the new owner. */
+ FOR_EACH_EDGE (e, ei, b->succs)
+ {
+ e->src = a;
+ if (current_loops != NULL)
+ rescan_loop_exit (e, true, false);
+ }
+ a->succs = b->succs;
+ a->flags |= b->flags;
+
+ /* B hasn't quite yet ceased to exist. Attempt to prevent mishap. */
+ b->preds = b->succs = NULL;
+
+ if (dom_info_available_p (CDI_DOMINATORS))
+ redirect_immediate_dominators (CDI_DOMINATORS, b, a);
+
+ if (dom_info_available_p (CDI_DOMINATORS))
+ delete_from_dominance_info (CDI_DOMINATORS, b);
+ if (dom_info_available_p (CDI_POST_DOMINATORS))
+ delete_from_dominance_info (CDI_POST_DOMINATORS, b);
+
+ expunge_block (b);
+}
+
+/* Split BB into entry part and the rest (the rest is the newly created block).
+ Redirect those edges for that REDIRECT_EDGE_P returns true to the entry
+ part. Returns the edge connecting the entry part to the rest. */
+
+edge
+make_forwarder_block (basic_block bb, bool (*redirect_edge_p) (edge),
+ void (*new_bb_cbk) (basic_block))
+{
+ edge e, fallthru;
+ edge_iterator ei;
+ basic_block dummy, jump;
+ struct loop *loop, *ploop, *cloop;
+
+ if (!cfg_hooks->make_forwarder_block)
+ internal_error ("%s does not support make_forwarder_block",
+ cfg_hooks->name);
+
+ fallthru = split_block_after_labels (bb);
+ dummy = fallthru->src;
+ bb = fallthru->dest;
+
+ /* Redirect back edges we want to keep. */
+ for (ei = ei_start (dummy->preds); (e = ei_safe_edge (ei)); )
+ {
+ basic_block e_src;
+
+ if (redirect_edge_p (e))
+ {
+ ei_next (&ei);
+ continue;
+ }
+
+ dummy->frequency -= EDGE_FREQUENCY (e);
+ dummy->count -= e->count;
+ if (dummy->frequency < 0)
+ dummy->frequency = 0;
+ if (dummy->count < 0)
+ dummy->count = 0;
+ fallthru->count -= e->count;
+ if (fallthru->count < 0)
+ fallthru->count = 0;
+
+ e_src = e->src;
+ jump = redirect_edge_and_branch_force (e, bb);
+ if (jump != NULL)
+ {
+ /* If we redirected the loop latch edge, the JUMP block now acts like
+ the new latch of the loop. */
+ if (current_loops != NULL
+ && dummy->loop_father != NULL
+ && dummy->loop_father->header == dummy
+ && dummy->loop_father->latch == e_src)
+ dummy->loop_father->latch = jump;
+
+ if (new_bb_cbk != NULL)
+ new_bb_cbk (jump);
+ }
+ }
+
+ if (dom_info_available_p (CDI_DOMINATORS))
+ {
+ VEC (basic_block, heap) *doms_to_fix = VEC_alloc (basic_block, heap, 2);
+ VEC_quick_push (basic_block, doms_to_fix, dummy);
+ VEC_quick_push (basic_block, doms_to_fix, bb);
+ iterate_fix_dominators (CDI_DOMINATORS, doms_to_fix, false);
+ VEC_free (basic_block, heap, doms_to_fix);
+ }
+
+ if (current_loops != NULL)
+ {
+ /* If we do not split a loop header, then both blocks belong to the
+ same loop. In case we split loop header and do not redirect the
+ latch edge to DUMMY, then DUMMY belongs to the outer loop, and
+ BB becomes the new header. If latch is not recorded for the loop,
+ we leave this updating on the caller (this may only happen during
+ loop analysis). */
+ loop = dummy->loop_father;
+ if (loop->header == dummy
+ && loop->latch != NULL
+ && find_edge (loop->latch, dummy) == NULL)
+ {
+ remove_bb_from_loops (dummy);
+ loop->header = bb;
+
+ cloop = loop;
+ FOR_EACH_EDGE (e, ei, dummy->preds)
+ {
+ cloop = find_common_loop (cloop, e->src->loop_father);
+ }
+ add_bb_to_loop (dummy, cloop);
+ }
+
+ /* In case we split loop latch, update it. */
+ for (ploop = loop; ploop; ploop = loop_outer (ploop))
+ if (ploop->latch == dummy)
+ ploop->latch = bb;
+ }
+
+ cfg_hooks->make_forwarder_block (fallthru);
+
+ return fallthru;
+}
+
+void
+tidy_fallthru_edge (edge e)
+{
+ if (cfg_hooks->tidy_fallthru_edge)
+ cfg_hooks->tidy_fallthru_edge (e);
+}
+
+/* Fix up edges that now fall through, or rather should now fall through
+ but previously required a jump around now deleted blocks. Simplify
+ the search by only examining blocks numerically adjacent, since this
+ is how they were created. */
+
+void
+tidy_fallthru_edges (void)
+{
+ basic_block b, c;
+
+ if (!cfg_hooks->tidy_fallthru_edge)
+ return;
+
+ if (ENTRY_BLOCK_PTR->next_bb == EXIT_BLOCK_PTR)
+ return;
+
+ FOR_BB_BETWEEN (b, ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR->prev_bb, next_bb)
+ {
+ edge s;
+
+ c = b->next_bb;
+
+ /* We care about simple conditional or unconditional jumps with
+ a single successor.
+
+ If we had a conditional branch to the next instruction when
+ CFG was built, then there will only be one out edge for the
+ block which ended with the conditional branch (since we do
+ not create duplicate edges).
+
+ Furthermore, the edge will be marked as a fallthru because we
+ merge the flags for the duplicate edges. So we do not want to
+ check that the edge is not a FALLTHRU edge. */
+
+ if (single_succ_p (b))
+ {
+ s = single_succ_edge (b);
+ if (! (s->flags & EDGE_COMPLEX)
+ && s->dest == c
+ && !find_reg_note (BB_END (b), REG_CROSSING_JUMP, NULL_RTX))
+ tidy_fallthru_edge (s);
+ }
+ }
+}
+
+/* Returns true if we can duplicate basic block BB. */
+
+bool
+can_duplicate_block_p (const_basic_block bb)
+{
+ if (!cfg_hooks->can_duplicate_block_p)
+ internal_error ("%s does not support can_duplicate_block_p",
+ cfg_hooks->name);
+
+ if (bb == EXIT_BLOCK_PTR || bb == ENTRY_BLOCK_PTR)
+ return false;
+
+ return cfg_hooks->can_duplicate_block_p (bb);
+}
+
+/* Duplicates basic block BB and redirects edge E to it. Returns the
+ new basic block. The new basic block is placed after the basic block
+ AFTER. */
+
+basic_block
+duplicate_block (basic_block bb, edge e, basic_block after)
+{
+ edge s, n;
+ basic_block new_bb;
+ gcov_type new_count = e ? e->count : 0;
+ edge_iterator ei;
+
+ if (!cfg_hooks->duplicate_block)
+ internal_error ("%s does not support duplicate_block",
+ cfg_hooks->name);
+
+ if (bb->count < new_count)
+ new_count = bb->count;
+
+#ifdef ENABLE_CHECKING
+ gcc_assert (can_duplicate_block_p (bb));
+#endif
+
+ new_bb = cfg_hooks->duplicate_block (bb);
+ if (after)
+ move_block_after (new_bb, after);
+
+ new_bb->loop_depth = bb->loop_depth;
+ new_bb->flags = bb->flags;
+ FOR_EACH_EDGE (s, ei, bb->succs)
+ {
+ /* Since we are creating edges from a new block to successors
+ of another block (which therefore are known to be disjoint), there
+ is no need to actually check for duplicated edges. */
+ n = unchecked_make_edge (new_bb, s->dest, s->flags);
+ n->probability = s->probability;
+ if (e && bb->count)
+ {
+ /* Take care for overflows! */
+ n->count = s->count * (new_count * 10000 / bb->count) / 10000;
+ s->count -= n->count;
+ }
+ else
+ n->count = s->count;
+ n->aux = s->aux;
+ }
+
+ if (e)
+ {
+ new_bb->count = new_count;
+ bb->count -= new_count;
+
+ new_bb->frequency = EDGE_FREQUENCY (e);
+ bb->frequency -= EDGE_FREQUENCY (e);
+
+ redirect_edge_and_branch_force (e, new_bb);
+
+ if (bb->count < 0)
+ bb->count = 0;
+ if (bb->frequency < 0)
+ bb->frequency = 0;
+ }
+ else
+ {
+ new_bb->count = bb->count;
+ new_bb->frequency = bb->frequency;
+ }
+
+ set_bb_original (new_bb, bb);
+ set_bb_copy (bb, new_bb);
+
+ /* Add the new block to the copy of the loop of BB, or directly to the loop
+ of BB if the loop is not being copied. */
+ if (current_loops != NULL)
+ {
+ struct loop *cloop = bb->loop_father;
+ struct loop *copy = get_loop_copy (cloop);
+ add_bb_to_loop (new_bb, copy ? copy : cloop);
+ }
+
+ return new_bb;
+}
+
+/* Return 1 if BB ends with a call, possibly followed by some
+ instructions that must stay with the call, 0 otherwise. */
+
+bool
+block_ends_with_call_p (basic_block bb)
+{
+ if (!cfg_hooks->block_ends_with_call_p)
+ internal_error ("%s does not support block_ends_with_call_p", cfg_hooks->name);
+
+ return (cfg_hooks->block_ends_with_call_p) (bb);
+}
+
+/* Return 1 if BB ends with a conditional branch, 0 otherwise. */
+
+bool
+block_ends_with_condjump_p (const_basic_block bb)
+{
+ if (!cfg_hooks->block_ends_with_condjump_p)
+ internal_error ("%s does not support block_ends_with_condjump_p",
+ cfg_hooks->name);
+
+ return (cfg_hooks->block_ends_with_condjump_p) (bb);
+}
+
+/* Add fake edges to the function exit for any non constant and non noreturn
+ calls, volatile inline assembly in the bitmap of blocks specified by
+ BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks
+ that were split.
+
+ The goal is to expose cases in which entering a basic block does not imply
+ that all subsequent instructions must be executed. */
+
+int
+flow_call_edges_add (sbitmap blocks)
+{
+ if (!cfg_hooks->flow_call_edges_add)
+ internal_error ("%s does not support flow_call_edges_add",
+ cfg_hooks->name);
+
+ return (cfg_hooks->flow_call_edges_add) (blocks);
+}
+
+/* This function is called immediately after edge E is added to the
+ edge vector E->dest->preds. */
+
+void
+execute_on_growing_pred (edge e)
+{
+ if (cfg_hooks->execute_on_growing_pred)
+ cfg_hooks->execute_on_growing_pred (e);
+}
+
+/* This function is called immediately before edge E is removed from
+ the edge vector E->dest->preds. */
+
+void
+execute_on_shrinking_pred (edge e)
+{
+ if (cfg_hooks->execute_on_shrinking_pred)
+ cfg_hooks->execute_on_shrinking_pred (e);
+}
+
+/* This is used inside loop versioning when we want to insert
+ stmts/insns on the edges, which have a different behavior
+ in tree's and in RTL, so we made a CFG hook. */
+void
+lv_flush_pending_stmts (edge e)
+{
+ if (cfg_hooks->flush_pending_stmts)
+ cfg_hooks->flush_pending_stmts (e);
+}
+
+/* Loop versioning uses the duplicate_loop_to_header_edge to create
+ a new version of the loop basic-blocks, the parameters here are
+ exactly the same as in duplicate_loop_to_header_edge or
+ tree_duplicate_loop_to_header_edge; while in tree-ssa there is
+ additional work to maintain ssa information that's why there is
+ a need to call the tree_duplicate_loop_to_header_edge rather
+ than duplicate_loop_to_header_edge when we are in tree mode. */
+bool
+cfg_hook_duplicate_loop_to_header_edge (struct loop *loop, edge e,
+ unsigned int ndupl,
+ sbitmap wont_exit, edge orig,
+ VEC (edge, heap) **to_remove,
+ int flags)
+{
+ gcc_assert (cfg_hooks->cfg_hook_duplicate_loop_to_header_edge);
+ return cfg_hooks->cfg_hook_duplicate_loop_to_header_edge (loop, e,
+ ndupl, wont_exit,
+ orig, to_remove,
+ flags);
+}
+
+/* Conditional jumps are represented differently in trees and RTL,
+ this hook takes a basic block that is known to have a cond jump
+ at its end and extracts the taken and not taken edges out of it
+ and store it in E1 and E2 respectively. */
+void
+extract_cond_bb_edges (basic_block b, edge *e1, edge *e2)
+{
+ gcc_assert (cfg_hooks->extract_cond_bb_edges);
+ cfg_hooks->extract_cond_bb_edges (b, e1, e2);
+}
+
+/* Responsible for updating the ssa info (PHI nodes) on the
+ new condition basic block that guards the versioned loop. */
+void
+lv_adjust_loop_header_phi (basic_block first, basic_block second,
+ basic_block new_block, edge e)
+{
+ if (cfg_hooks->lv_adjust_loop_header_phi)
+ cfg_hooks->lv_adjust_loop_header_phi (first, second, new_block, e);
+}
+
+/* Conditions in trees and RTL are different so we need
+ a different handling when we add the condition to the
+ versioning code. */
+void
+lv_add_condition_to_bb (basic_block first, basic_block second,
+ basic_block new_block, void *cond)
+{
+ gcc_assert (cfg_hooks->lv_add_condition_to_bb);
+ cfg_hooks->lv_add_condition_to_bb (first, second, new_block, cond);
+}
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