2004-09-24 Ben Elliston <bje@au.ibm.com>

	    Steven Bosscher  <stevenb@suse.de>
	    Andrew Pinski  <pinskia@physics.uc.edu>

	Merge from edge-vector-branch:
	* basic-block.h: Include vec.h, errors.h. Instantiate a VEC(edge).
	(struct edge_def): Remove pred_next, succ_next members.
	(struct basic_block_def): Remove pred, succ members.  Add preds
	and succs members of type VEC(edge).
	(FALLTHRU_EDGE): Redefine using EDGE_SUCC.
	(BRANCH_EDGE): Likewise.
	(EDGE_CRITICAL_P): Redefine using EDGE_COUNT.
	(EDGE_COUNT, EDGE_I, EDGE_PRED, EDGE_SUCC): New.
	(edge_iterator): New.
	(ei_start, ei_last, ei_end_p, ei_one_before_end_p): New.
	(ei_next, ei_prev, ei_edge, ei_safe_edge): Likewise.
	(FOR_EACH_EDGE): New.
	* bb-reorder.c (find_traces): Use FOR_EACH_EDGE and EDGE_* macros
	where applicable.
	(rotate_loop): Likewise.
	(find_traces_1_route): Likewise.
	(bb_to_key): Likewise.
	(connect_traces): Likewise.
	(copy_bb_p): Likewise.
	(find_rarely_executed_basic_blocks_and_crossing_edges): Likewise.
	(add_labels_and_missing_jumps): Likewise.
	(fix_up_fall_thru_edges): Likewise.
	(find_jump_block): Likewise.
	(fix_crossing_conditional_branches): Likewise.
	(fix_crossing_unconditional_branches): Likewise.
	(add_reg_crossing_jump_notes): Likewise.
	* bt-load.c (augment_live_range): Likewise.
	* cfg.c (clear_edges): Likewise.
	(unchecked_make_edge): Likewise.
	(cached_make_edge): Likewise.
	(make_single_succ_edge): Likewise.
	(remove_edge): Likewise.
	(redirect_edge_succ_nodup): Likewise.
	(check_bb_profile): Likewise.
	(dump_flow_info): Likewise.
	(alloc_aux_for_edges): Likewise.
	(clear_aux_for_edges): Likewise.
	(dump_cfg_bb_info): Likewise.
	* cfganal.c (forwarder_block_p): Likewise.
	(can_fallthru): Likewise.
	(could_fall_through): Likewise.
	(mark_dfs_back_edges): Likewise.
	(set_edge_can_fallthru_flag): Likewise.
	(find_unreachable_blocks): Likewise.
	(create_edge_list): Likewise.
	(verify_edge_list): Likewise.
	(add_noreturn_fake_exit_edges): Likewise.
	(connect_infinite_loops_to_exit): Likewise.
	(flow_reverse_top_sort_order_compute): Likewise.
	(flow_depth_first_order_compute): Likewise.
	(flow_preorder_transversal_compute): Likewise.
	(flow_dfs_compute_reverse_execute): Likewise.
	(dfs_enumerate_from): Likewise.
	(compute_dominance_frontiers_1): Likewise.
	* cfgbuild.c (make_edges): Likewise.
	(compute_outgoing_frequencies): Likewise.
	(find_many_sub_basic_blocks): Likewise.
	(find_sub_basic_blocks): Likewise.
	* cfgcleanup.c (try_simplify_condjump): Likewise.
	(thread_jump): Likewise.
	(try_forward_edges): Likewise.
	(merge_blocks_move): Likewise.
	(outgoing_edges_match): Likewise.
	(try_crossjump_to_edge): Likewise.
	(try_crossjump_bb): Likewise.
	(try_optimize_cfg): Likewise.
	(merge_seq_blocks): Likewise.
	* cfgexpand.c (expand_gimple_tailcall): Likewise.
	(expand_gimple_basic_block): Likewise.
	(construct_init_block): Likewise.
	(construct_exit_block): Likewise.
	* cfghooks.c (verify_flow_info): Likewise.
	(dump_bb): Likewise.
	(delete_basic_block): Likewise.
	(split_edge): Likewise.
	(merge_blocks): Likewise.
	(make_forwarder_block): Likewise.
	(tidy_fallthru_edges): Likewise.
	(can_duplicate_block_p): Likewise.
	(duplicate_block): Likewise.
	* cfglayout.c (fixup_reorder_chain): Likewise.
	(fixup_fallthru_exit_predecessor): Likewise.
	(can_copy_bbs_p): Likewise.
	(copy_bbs): Likewise.
	* cfgloop.c (flow_loops_cfg_dump): Likewise.
	(flow_loop_entry_edges_find): Likewise.
	(flow_loop_exit_edges_find): Likewise.
	(flow_loop_nodes_find): Likewise.
	(mark_single_exit_loops): Likewise.
	(flow_loop_pre_header_scan): Likewise.
	(flow_loop_pre_header_find): Likewise.
	(update_latch_info): Likewise.
	(canonicalize_loop_headers): Likewise.
	(flow_loops_find): Likewise.
	(get_loop_body_in_bfs_order): Likewise.
	(get_loop_exit_edges): Likewise.
	(num_loop_branches): Likewise.
	(verify_loop_structure): Likewise.
	(loop_latch_edge): Likewise.
	(loop_preheader_edge): Likewise.
	* cfgloopanal.c (mark_irreducible_loops): Likewise.
	(expected_loop_iterations): Likewise.
	* cfgloopmanip.c (remove_bbs): Likewise.
	(fix_bb_placement): Likewise.
	(fix_irreducible_loops): Likewise.
	(remove_path): Likewise.
	(scale_bbs_frequencies): Likewise.
	(loopify): Likewise.
	(unloop): Likewise.
	(fix_loop_placement): Likewise.
	(loop_delete_branch_edge): Likewise.
	(duplicate_loop_to_header_edge): Likewise.
	(mfb_keep_just): Likewise.
	(create_preheader): Likewise.
	(force_single_succ_latches): Likewise.
	(loop_split_edge_with): Likewise.
	(create_loop_notes): Likewise.
	* cfgrtl.c (rtl_split_block): Likewise.
	(rtl_merge_blocks): Likewise.
	(rtl_can_merge_blocks): Likewise.
	(try_redirect_by_replacing_jump): Likewise.
	(force_nonfallthru_and_redirect): Likewise.
	(rtl_tidy_fallthru_edge): Likewise.
	(commit_one_edge_insertion): Likewise.
	(commit_edge_insertions): Likewise.
	(commit_edge_insertions_watch_calls): Likewise.
	(rtl_verify_flow_info_1): Likewise.
	(rtl_verify_flow_info): Likewise.
	(purge_dead_edges): Likewise.
	(cfg_layout_redirect_edge_and_branch): Likewise.
	(cfg_layout_can_merge_blocks_p): Likewise.
	(rtl_flow_call_edges_add): Likewise.
	* cse.c (cse_cc_succs): Likewise.
	* df.c (hybrid_search): Likewise.
	* dominance.c (calc_dfs_tree_nonrec): Likewise.
	(calc_dfs_tree): Likewise.
	(calc_idoms): Likewise.
	(recount_dominator): Likewise.
	* domwalk.c (walk_dominator_tree): Likewise.
	* except.c (emit_to_new_bb_before): Likewise.
	(connect_post_landing_pads): Likewise.
	(sjlj_emit_function_enter): Likewise.
	(sjlj_emit_function_exit): Likewise.
	(finish_eh_generation): Likewise.
	* final.c (compute_alignments): Likewise.
	* flow.c (calculate_global_regs_live): Likewise.
	(initialize_uninitialized_subregs): Likewise.
	(init_propagate_block_info): Likewise.
	* function.c (thread_prologue_and_epilogue_insns): Likewise.
	* gcse.c (find_implicit_sets): Likewise.
	(bypass_block): Likewise.
	(bypass_conditional_jumps): Likewise.
	(compute_pre_data): Likewise.
	(insert_insn_end_bb): Likewise.
	(insert_store): Likewise.
	(remove_reachable_equiv_notes): Likewise.
	* global.c (global_conflicts): Likewise.
	(calculate_reg_pav): Likewise.
	* graph.c (print_rtl_graph_with_bb): Likewise.
	* ifcvt.c (mark_loop_exit_edges): Likewise.
	(merge_if_block): Likewise.
	(find_if_header): Likewise.
	(block_jumps_and_fallthru_p): Likewise.
	(find_if_block): Likewise.
	(find_cond_trap): Likewise.
	(block_has_only_trap): Likewise.
	(find_if_case1): Likewise.
	(find_if_case_2): Likewise.
	* lambda-code.c (lambda_loopnest_to_gcc_loopnest): Likewise.
	(perfect_nestify): Likewise.
	* lcm.c (compute_antinout_edge): Likewise.
	(compute_laterin): Likewise.
	(compute_available): Likewise.
	(compute_nearerout): Likewise.
	* loop-doloop.c (doloop_modify): Likewise.
	* loop-init.c (loop_optimizer_init): Likewise.
	* loop-invariant.c (find_exits): Likewise.
	* loop-iv.c (simplify_using_initial_values): Likewise.
	(check_simple_exit): Likewise.
	(find_simple_exit): Likewise.
	* loop-unroll.c (peel_loop_completely): Likewise.
	(unroll_loop_constant_iterations): Likewise.
	(unroll_loop_runtime_iterations): Likewise.
	* loop-unswitch.c (may_unswitch_on): Likewise.
	(unswitch_loop): Likewise.
	* modulo-sched.c (generate_prolog_epilog): Likewise.
	(sms_schedule): Likewise.
	* postreload-gcse.c (eliminate_partially_redundant_load):
	Likewise.
	* predict.c (can_predict_insn_p): Likewise.
	(set_even_probabilities): Likewise.
	(combine_predictions_for_bb): Likewise.
	(predict_loops): Likewise.
	(estimate_probability): Likewise.
	(tree_predict_by_opcode): Likewise.
	(tree_estimate_probability): Likewise.
	(last_basic_block_p): Likewise.
	(propagate_freq): Likewise.
	(estimate_loops_at_level): Likewise.
	(estimate_bb_frequencies): Likewise.
	* profile.c (instrument_edges): Likewise.
	(get_exec_counts): Likewise.
	(compute_branch_probabilities): Likewise.
	(branch_prob): Likewise.
	* ra-build.c (live_in): Likewise.
	* ra-rewrite.c (rewrite_program2): Likewise.
	* ra.c (reg_alloc): Likewise.
	* reg-stack.c (reg_to_stack): Likewise.
	(convert_regs_entry): Likewise.
	(compensate_edge): Likewise.
	(convert_regs_1): Likewise,
	(convert_regs_2): Likewise.
	(convert_regs): Likewise.
	* regrename.c (copyprop_hardreg_forward): Likewise.
	* reload1.c (fixup_abnormal_edges): Likewise.
	* sbitmap.c (sbitmap_intersection_of_succs): Likewise.
	(sbitmap_insersection_of_preds): Likewise.
	(sbitmap_union_of_succs): Likewise.
	(sbitmap_union_of_preds): Likewise.
	* sched-ebb.c (compute_jump_reg_dependencies): Likewise.
	(fix_basic_block_boundaries): Likewise.
	(sched_ebbs): Likewise.
	* sched-rgn.c (build_control_flow): Likewise.
	(find_rgns): Likewise.
	* tracer.c (find_best_successor): Likewise.
	(find_best_predecessor): Likewise.
	(tail_duplicate): Likewise.
	* tree-cfg.c (make_edges): Likewise.
	(make_ctrl_stmt_edges): Likewise.
	(make_goto_expr_edges): Likewise.
	(tree_can_merge_blocks_p): Likewise.
	(tree_merge_blocks): Likewise.
	(cfg_remove_useless_stmts_bb): Likewise.
	(remove_phi_nodes_and_edges_for_unreachable_block): Likewise.
	(tree_block_forwards_to): Likewise.
	(cleanup_control_expr_graph): Likewise.
	(find_taken_edge): Likewise.
	(dump_cfg_stats): Likewise.
	(tree_cfg2vcg): Likewise.
	(disband_implicit_edges): Likewise.
	(tree_find_edge_insert_loc): Likewise.
	(bsi_commit_edge_inserts): Likewise.
	(tree_split_edge): Likewise.
	(tree_verify_flow_info): Likewise.
	(tree_make_forwarder_block): Likewise.
	(tree_forwarder_block_p): Likewise.
	(thread_jumps): Likewise.
	(tree_try_redirect_by_replacing_jump): Likewise.
	(tree_split_block): Likewise.
	(add_phi_args_after_copy_bb): Likewise.
	(rewrite_to_new_ssa_names_bb): Likewise.
	(dump_function_to_file): Likewise.
	(print_pred_bbs): Likewise.
	(print_loop): Likewise.
	(tree_flow_call_edges_add): Likewise.
	(split_critical_edges): Likewise.
	(execute_warn_function_return): Likewise.
	(extract_true_false_edges_from_block): Likewise.
	* tree-if-conv.c (tree_if_conversion): Likewise.
	(if_convertable_bb_p): Likewise.
	(find_phi_replacement_condition): Likewise.
	(combine_blocks): Likewise.
	* tree-into-ssa.c (compute_global_livein): Likewise.
	(ssa_mark_phi_uses): Likewise.
	(ssa_rewrite_initialize_block): Likewise.
	(rewrite_add_phi_arguments): Likewise.
	(ssa_rewrite_phi_arguments): Likewise.
	(insert_phi_nodes_for): Likewise.
	(rewrite_into_ssa): Likewise.
	(rewrite_ssa_into_ssa): Likewise.
	* tree-mudflap.c (mf_build_check_statement_for): Likewise.
	* tree-outof-ssa.c (coalesce_abnormal_edges): Likewise.
	(rewrite_trees): Likewise.
	* tree-pretty-print.c (dump_bb_header): Likewise.
	(dump_implicit_edges): Likewise.
	* tree-sra.c (insert_edge_copies): Likewise.
	(find_obviously_necessary_stmts): Likewise.
	(remove_data_stmt): Likewise.
	* tree-ssa-dom.c (thread_across_edge): Likewise.
	(dom_opt_finalize_block): Likewise.
	(single_incoming_edge_ignoring_loop_edges): Likewise.
	(record_equivalences_from_incoming_edges): Likewise.
	(cprop_into_successor_phis): Likewise.
	* tree-ssa-live.c (live_worklist): Likewise.
	(calculate_live_on_entry): Likewise.
	(calculate_live_on_exit): Likewise.
	* tree-ssa-loop-ch.c (should_duplicate_loop_header_p): Likewise.
	(copy_loop_headers): Likewise.
	* tree-ssa-loop-im.c (loop_commit_inserts): Likewise.
	(fill_always_executed_in): Likewise.
	* tree-ssa-loop-ivcanon.c (create_canonical_iv): Likewise.
	* tree-ssa-loop-ivopts.c (find_interesting_uses): Likewise.
	(compute_phi_arg_on_exit): Likewise.
	* tree-ssa-loop-manip.c (add_exit_phis_edge): Likewise.
	(get_loops_exit): Likewise.
	(split_loop_exit_edge): Likewise.
	(ip_normal_pos): Likewise.
	* tree-ssa-loop-niter.c (simplify_using_initial_conditions):
	Likewise.
	* tree-ssa-phiopt.c (candidate_bb_for_phi_optimization): Likewise.
	(replace_phi_with_stmt): Likewise.
	(value_replacement): Likewise.
	* tree-ssa-pre.c (compute_antic_aux): Likewise.
	(insert_aux): Likewise.
	(init_pre): Likewise.
	* tree-ssa-propagate.c (simulate_stmt): Likewise.
	(simulate_block): Likewise.
	(ssa_prop_init): Likewise.
	* tree-ssa-threadupdate.c (thread_block): Likewise.
	(create_block_for_threading): Likewise.
	(remove_last_stmt_and_useless_edges): Likewise.
	* tree-ssa.c (verify_phi_args): Likewise.
	(verify_ssa): Likewise.
	* tree_tailcall.c (independent_of_stmt_p): Likewise.
	(find_tail_calls): Likewise.
	(eliminate_tail_call): Likewise.
	(tree_optimize_tail_calls_1): Likewise.
	* tree-vectorizer.c (vect_transform_loop): Likewise.
	* var-tracking.c (prologue_stack_adjust): Likewise.
	(vt_stack_adjustments): Likewise.
	(vt_find_locations): Likewise.
	* config/frv/frv.c (frv_ifcvt_modify_tests): Likewise.
	* config/i386/i386.c (ix86_pad_returns): Likewise.
	* config/ia64/ia64.c (ia64_expand_prologue): Likewise.
	* config/rs6000/rs6000.c (rs6000_emit_prologue): Likewise.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@88222 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 62 insertions, 42 deletions

diff --git a/gcc/cfgloop.c b/gcc/cfgloop.c
index 01b9a4612de..a38af1643ae 100644
--- a/gcc/cfgloop.c
+++ b/gcc/cfgloop.c
@@ -64,9 +64,10 @@ flow_loops_cfg_dump (const struct loops *loops, FILE *file)
   FOR_EACH_BB (bb)
     {
       edge succ;
+      edge_iterator ei;
 
       fprintf (file, ";; %d succs { ", bb->index);
-      for (succ = bb->succ; succ; succ = succ->succ_next)
+      FOR_EACH_EDGE (succ, ei, bb->succs)
 	fprintf (file, "%d ", succ->dest->index);
       fprintf (file, "}\n");
     }
@@ -242,10 +243,11 @@ static void
 flow_loop_entry_edges_find (struct loop *loop)
 {
   edge e;
+  edge_iterator ei;
   int num_entries;
 
   num_entries = 0;
-  for (e = loop->header->pred; e; e = e->pred_next)
+  FOR_EACH_EDGE (e, ei, loop->header->preds)
     {
       if (flow_loop_outside_edge_p (loop, e))
 	num_entries++;
@@ -256,7 +258,7 @@ flow_loop_entry_edges_find (struct loop *loop)
   loop->entry_edges = xmalloc (num_entries * sizeof (edge *));
 
   num_entries = 0;
-  for (e = loop->header->pred; e; e = e->pred_next)
+  FOR_EACH_EDGE (e, ei, loop->header->preds)
     {
       if (flow_loop_outside_edge_p (loop, e))
 	loop->entry_edges[num_entries++] = e;
@@ -284,8 +286,9 @@ flow_loop_exit_edges_find (struct loop *loop)
   bbs = get_loop_body (loop);
   for (i = 0; i < loop->num_nodes; i++)
     {
+      edge_iterator ei;
       node = bbs[i];
-      for (e = node->succ; e; e = e->succ_next)
+      FOR_EACH_EDGE (e, ei, node->succs)
 	{
 	  basic_block dest = e->dest;
 
@@ -306,8 +309,9 @@ flow_loop_exit_edges_find (struct loop *loop)
   num_exits = 0;
   for (i = 0; i < loop->num_nodes; i++)
     {
+      edge_iterator ei;
       node = bbs[i];
-      for (e = node->succ; e; e = e->succ_next)
+      FOR_EACH_EDGE (e, ei, node->succs)
 	{
 	  basic_block dest = e->dest;
 
@@ -348,10 +352,11 @@ flow_loop_nodes_find (basic_block header, struct loop *loop)
 	{
 	  basic_block node;
 	  edge e;
+	  edge_iterator ei;
 
 	  node = stack[--sp];
 
-	  for (e = node->pred; e; e = e->pred_next)
+	  FOR_EACH_EDGE (e, ei, node->preds)
 	    {
 	      basic_block ancestor = e->src;
 
@@ -390,9 +395,10 @@ mark_single_exit_loops (struct loops *loops)
 
   FOR_EACH_BB (bb)
     {
+      edge_iterator ei;
       if (bb->loop_father == loops->tree_root)
 	continue;
-      for (e = bb->succ; e; e = e->succ_next)
+      FOR_EACH_EDGE (e, ei, bb->succs)
 	{
 	  if (e->dest == EXIT_BLOCK_PTR)
 	    continue;
@@ -407,7 +413,7 @@ mark_single_exit_loops (struct loops *loops)
 	      /* If we have already seen an exit, mark this by the edge that
 		 surely does not occur as any exit.  */
 	      if (loop->single_exit)
-		loop->single_exit = ENTRY_BLOCK_PTR->succ;
+		loop->single_exit = EDGE_SUCC (ENTRY_BLOCK_PTR, 0);
 	      else
 		loop->single_exit = e;
 	    }
@@ -420,7 +426,7 @@ mark_single_exit_loops (struct loops *loops)
       if (!loop)
 	continue;
 
-      if (loop->single_exit == ENTRY_BLOCK_PTR->succ)
+      if (loop->single_exit == EDGE_SUCC (ENTRY_BLOCK_PTR, 0))
 	loop->single_exit = NULL;
     }
 
@@ -448,9 +454,10 @@ flow_loop_pre_header_scan (struct loop *loop)
   /* Count number of edges along trace from loop header to
      root of pre-header extended basic block.  Usually this is
      only one or two edges.  */
-  for (num = 1; ebb->pred->src != ENTRY_BLOCK_PTR && ! ebb->pred->pred_next;
+  for (num = 1;
+       EDGE_PRED (ebb, 0)->src != ENTRY_BLOCK_PTR && EDGE_COUNT (ebb->preds) == 1;
        num++)
-    ebb = ebb->pred->src;
+    ebb = EDGE_PRED (ebb, 0)->src;
 
   loop->pre_header_edges = xmalloc (num * sizeof (edge));
   loop->num_pre_header_edges = num;
@@ -458,7 +465,7 @@ flow_loop_pre_header_scan (struct loop *loop)
   /* Store edges in order that they are followed.  The source of the first edge
      is the root node of the pre-header extended basic block and the
      destination of the last last edge is the loop header.  */
-  for (e = loop->entry_edges[0]; num; e = e->src->pred)
+  for (e = loop->entry_edges[0]; num; e = EDGE_PRED (e->src, 0))
     loop->pre_header_edges[--num] = e;
 }
 
@@ -470,11 +477,12 @@ flow_loop_pre_header_find (basic_block header)
 {
   basic_block pre_header;
   edge e;
+  edge_iterator ei;
 
   /* If block p is a predecessor of the header and is the only block
      that the header does not dominate, then it is the pre-header.  */
   pre_header = NULL;
-  for (e = header->pred; e; e = e->pred_next)
+  FOR_EACH_EDGE (e, ei, header->preds)
     {
       basic_block node = e->src;
 
@@ -630,9 +638,9 @@ update_latch_info (basic_block jump)
 {
   alloc_aux_for_block (jump, sizeof (int));
   HEADER_BLOCK (jump) = 0;
-  alloc_aux_for_edge (jump->pred, sizeof (int));
-  LATCH_EDGE (jump->pred) = 0;
-  set_immediate_dominator (CDI_DOMINATORS, jump, jump->pred->src);
+  alloc_aux_for_edge (EDGE_PRED (jump, 0), sizeof (int));
+  LATCH_EDGE (EDGE_PRED (jump, 0)) = 0;
+  set_immediate_dominator (CDI_DOMINATORS, jump, EDGE_PRED (jump, 0)->src);
 }
 
 /* A callback for make_forwarder block, to redirect all edges except for
@@ -670,10 +678,11 @@ canonicalize_loop_headers (void)
   /* Split blocks so that each loop has only single latch.  */
   FOR_EACH_BB (header)
     {
+      edge_iterator ei;
       int num_latches = 0;
       int have_abnormal_edge = 0;
 
-      for (e = header->pred; e; e = e->pred_next)
+      FOR_EACH_EDGE (e, ei, header->preds)
 	{
 	  basic_block latch = e->src;
 
@@ -693,16 +702,16 @@ canonicalize_loop_headers (void)
 	HEADER_BLOCK (header) = num_latches;
     }
 
-  if (HEADER_BLOCK (ENTRY_BLOCK_PTR->succ->dest))
+  if (HEADER_BLOCK (EDGE_SUCC (ENTRY_BLOCK_PTR, 0)->dest))
     {
       basic_block bb;
 
       /* We could not redirect edges freely here. On the other hand,
 	 we can simply split the edge from entry block.  */
-      bb = split_edge (ENTRY_BLOCK_PTR->succ);
+      bb = split_edge (EDGE_SUCC (ENTRY_BLOCK_PTR, 0));
 
-      alloc_aux_for_edge (bb->succ, sizeof (int));
-      LATCH_EDGE (bb->succ) = 0;
+      alloc_aux_for_edge (EDGE_SUCC (bb, 0), sizeof (int));
+      LATCH_EDGE (EDGE_SUCC (bb, 0)) = 0;
       alloc_aux_for_block (bb, sizeof (int));
       HEADER_BLOCK (bb) = 0;
     }
@@ -711,6 +720,7 @@ canonicalize_loop_headers (void)
     {
       int max_freq, is_heavy;
       edge heavy, tmp_edge;
+      edge_iterator ei;
 
       if (HEADER_BLOCK (header) <= 1)
 	continue;
@@ -719,11 +729,11 @@ canonicalize_loop_headers (void)
       is_heavy = 1;
       heavy = NULL;
       max_freq = 0;
-      for (e = header->pred; e; e = e->pred_next)
+      FOR_EACH_EDGE (e, ei, header->preds)
 	if (LATCH_EDGE (e) &&
 	    EDGE_FREQUENCY (e) > max_freq)
 	  max_freq = EDGE_FREQUENCY (e);
-      for (e = header->pred; e; e = e->pred_next)
+      FOR_EACH_EDGE (e, ei, header->preds)
 	if (LATCH_EDGE (e) &&
 	    EDGE_FREQUENCY (e) >= max_freq / HEAVY_EDGE_RATIO)
 	  {
@@ -817,19 +827,20 @@ flow_loops_find (struct loops *loops, int flags)
   num_loops = 0;
   FOR_EACH_BB (header)
     {
+      edge_iterator ei;
       int more_latches = 0;
 
       header->loop_depth = 0;
 
       /* If we have an abnormal predecessor, do not consider the
 	 loop (not worth the problems).  */
-      for (e = header->pred; e; e = e->pred_next)
+      FOR_EACH_EDGE (e, ei, header->preds)
 	if (e->flags & EDGE_ABNORMAL)
 	  break;
       if (e)
 	continue;
 
-      for (e = header->pred; e; e = e->pred_next)
+      FOR_EACH_EDGE (e, ei, header->preds)
 	{
 	  basic_block latch = e->src;
 
@@ -893,6 +904,7 @@ flow_loops_find (struct loops *loops, int flags)
       for (b = 0; b < n_basic_blocks; b++)
 	{
 	  struct loop *loop;
+	  edge_iterator ei;
 
 	  /* Search the nodes of the CFG in reverse completion order
 	     so that we can find outer loops first.  */
@@ -908,7 +920,7 @@ flow_loops_find (struct loops *loops, int flags)
 	  num_loops++;
 
 	  /* Look for the latch for this header block.  */
-	  for (e = header->pred; e; e = e->pred_next)
+	  FOR_EACH_EDGE (e, ei, header->preds)
 	    {
 	      basic_block latch = e->src;
 
@@ -1096,6 +1108,7 @@ get_loop_body_in_bfs_order (const struct loop *loop)
   while (i < loop->num_nodes)
     {
       edge e;
+      edge_iterator ei;
       
       if (!bitmap_bit_p (visited, bb->index))
         { 
@@ -1104,7 +1117,7 @@ get_loop_body_in_bfs_order (const struct loop *loop)
           blocks[i++] = bb;
         }
       
-      for (e = bb->succ; e; e = e->succ_next)
+      FOR_EACH_EDGE (e, ei, bb->succs)
         { 
           if (flow_bb_inside_loop_p (loop, e->dest))
             { 
@@ -1132,20 +1145,21 @@ get_loop_exit_edges (const struct loop *loop, unsigned int *n_edges)
   edge *edges, e;
   unsigned i, n;
   basic_block * body;
+  edge_iterator ei;
 
   gcc_assert (loop->latch != EXIT_BLOCK_PTR);
 
   body = get_loop_body (loop);
   n = 0;
   for (i = 0; i < loop->num_nodes; i++)
-    for (e = body[i]->succ; e; e = e->succ_next)
+    FOR_EACH_EDGE (e, ei, body[i]->succs)
       if (!flow_bb_inside_loop_p (loop, e->dest))
 	n++;
   edges = xmalloc (n * sizeof (edge));
   *n_edges = n;
   n = 0;
   for (i = 0; i < loop->num_nodes; i++)
-    for (e = body[i]->succ; e; e = e->succ_next)
+    FOR_EACH_EDGE (e, ei, body[i]->succs)
       if (!flow_bb_inside_loop_p (loop, e->dest))
 	edges[n++] = e;
   free (body);
@@ -1166,7 +1180,7 @@ num_loop_branches (const struct loop *loop)
   body = get_loop_body (loop);
   n = 0;
   for (i = 0; i < loop->num_nodes; i++)
-    if (body[i]->succ && body[i]->succ->succ_next)
+    if (EDGE_COUNT (body[i]->succs) >= 2)
       n++;
   free (body);
 
@@ -1317,21 +1331,19 @@ verify_loop_structure (struct loops *loops)
 	continue;
 
       if ((loops->state & LOOPS_HAVE_PREHEADERS)
-	  && (!loop->header->pred->pred_next
-	      || loop->header->pred->pred_next->pred_next))
+	  && EDGE_COUNT (loop->header->preds) != 2)
 	{
 	  error ("Loop %d's header does not have exactly 2 entries.", i);
 	  err = 1;
 	}
       if (loops->state & LOOPS_HAVE_SIMPLE_LATCHES)
 	{
-	  if (!loop->latch->succ
-	      || loop->latch->succ->succ_next)
+	  if (EDGE_COUNT (loop->latch->succs) != 1)
 	    {
 	      error ("Loop %d's latch does not have exactly 1 successor.", i);
 	      err = 1;
 	    }
-	  if (loop->latch->succ->dest != loop->header)
+	  if (EDGE_SUCC (loop->latch, 0)->dest != loop->header)
 	    {
 	      error ("Loop %d's latch does not have header as successor.", i);
 	      err = 1;
@@ -1362,11 +1374,12 @@ verify_loop_structure (struct loops *loops)
       irreds = sbitmap_alloc (last_basic_block);
       FOR_EACH_BB (bb)
 	{
+	  edge_iterator ei;
 	  if (bb->flags & BB_IRREDUCIBLE_LOOP)
 	    SET_BIT (irreds, bb->index);
 	  else
 	    RESET_BIT (irreds, bb->index);
-	  for (e = bb->succ; e; e = e->succ_next)
+	  FOR_EACH_EDGE (e, ei, bb->succs)
 	    if (e->flags & EDGE_IRREDUCIBLE_LOOP)
 	      e->flags |= EDGE_ALL_FLAGS + 1;
 	}
@@ -1377,6 +1390,8 @@ verify_loop_structure (struct loops *loops)
       /* Compare.  */
       FOR_EACH_BB (bb)
 	{
+	  edge_iterator ei;
+
 	  if ((bb->flags & BB_IRREDUCIBLE_LOOP)
 	      && !TEST_BIT (irreds, bb->index))
 	    {
@@ -1389,7 +1404,7 @@ verify_loop_structure (struct loops *loops)
 	      error ("Basic block %d should not be marked irreducible.", bb->index);
 	      err = 1;
 	    }
-	  for (e = bb->succ; e; e = e->succ_next)
+	  FOR_EACH_EDGE (e, ei, bb->succs)
 	    {
 	      if ((e->flags & EDGE_IRREDUCIBLE_LOOP)
 		  && !(e->flags & (EDGE_ALL_FLAGS + 1)))
@@ -1417,9 +1432,10 @@ verify_loop_structure (struct loops *loops)
       memset (sizes, 0, sizeof (unsigned) * loops->num);
       FOR_EACH_BB (bb)
 	{
+	  edge_iterator ei;
 	  if (bb->loop_father == loops->tree_root)
 	    continue;
-	  for (e = bb->succ; e; e = e->succ_next)
+	  FOR_EACH_EDGE (e, ei, bb->succs)
 	    {
 	      if (e->dest == EXIT_BLOCK_PTR)
 		continue;
@@ -1482,9 +1498,11 @@ edge
 loop_latch_edge (const struct loop *loop)
 {
   edge e;
+  edge_iterator ei;
 
-  for (e = loop->header->pred; e->src != loop->latch; e = e->pred_next)
-    continue;
+  FOR_EACH_EDGE (e, ei, loop->header->preds)
+    if (e->src == loop->latch)
+      break;
 
   return e;
 }
@@ -1494,9 +1512,11 @@ edge
 loop_preheader_edge (const struct loop *loop)
 {
   edge e;
+  edge_iterator ei;
 
-  for (e = loop->header->pred; e->src == loop->latch; e = e->pred_next)
-    continue;
+  FOR_EACH_EDGE (e, ei, loop->header->preds)
+    if (e->src != loop->latch)
+      break;
 
   return e;
 }