Check in gcc sources for prebuilt toolchains in Eclair.

1 files changed, 1265 insertions, 0 deletions

diff --git a/gcc-4.3.1/gcc/profile.c b/gcc-4.3.1/gcc/profile.c
new file mode 100644
index 000000000..51747cf43
--- /dev/null
+++ b/gcc-4.3.1/gcc/profile.c
@@ -0,0 +1,1265 @@
+/* Calculate branch probabilities, and basic block execution counts.
+   Copyright (C) 1990, 1991, 1992, 1993, 1994, 1996, 1997, 1998, 1999,
+   2000, 2001, 2002, 2003, 2004, 2005, 2007
+   Free Software Foundation, Inc.
+   Contributed by James E. Wilson, UC Berkeley/Cygnus Support;
+   based on some ideas from Dain Samples of UC Berkeley.
+   Further mangling by Bob Manson, Cygnus Support.
+
+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 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the 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 COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+/* Generate basic block profile instrumentation and auxiliary files.
+   Profile generation is optimized, so that not all arcs in the basic
+   block graph need instrumenting. First, the BB graph is closed with
+   one entry (function start), and one exit (function exit).  Any
+   ABNORMAL_EDGE cannot be instrumented (because there is no control
+   path to place the code). We close the graph by inserting fake
+   EDGE_FAKE edges to the EXIT_BLOCK, from the sources of abnormal
+   edges that do not go to the exit_block. We ignore such abnormal
+   edges.  Naturally these fake edges are never directly traversed,
+   and so *cannot* be directly instrumented.  Some other graph
+   massaging is done. To optimize the instrumentation we generate the
+   BB minimal span tree, only edges that are not on the span tree
+   (plus the entry point) need instrumenting. From that information
+   all other edge counts can be deduced.  By construction all fake
+   edges must be on the spanning tree. We also attempt to place
+   EDGE_CRITICAL edges on the spanning tree.
+
+   The auxiliary files generated are <dumpbase>.gcno (at compile time)
+   and <dumpbase>.gcda (at run time).  The format is
+   described in full in gcov-io.h.  */
+
+/* ??? Register allocation should use basic block execution counts to
+   give preference to the most commonly executed blocks.  */
+
+/* ??? Should calculate branch probabilities before instrumenting code, since
+   then we can use arc counts to help decide which arcs to instrument.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "rtl.h"
+#include "flags.h"
+#include "output.h"
+#include "regs.h"
+#include "expr.h"
+#include "function.h"
+#include "toplev.h"
+#include "coverage.h"
+#include "value-prof.h"
+#include "tree.h"
+#include "cfghooks.h"
+#include "tree-flow.h"
+#include "timevar.h"
+#include "cfgloop.h"
+#include "tree-pass.h"
+
+/* Hooks for profiling.  */
+static struct profile_hooks* profile_hooks;
+
+/* Additional information about the edges we need.  */
+struct edge_info {
+  unsigned int count_valid : 1;
+
+  /* Is on the spanning tree.  */
+  unsigned int on_tree : 1;
+
+  /* Pretend this edge does not exist (it is abnormal and we've
+     inserted a fake to compensate).  */
+  unsigned int ignore : 1;
+};
+
+struct bb_info {
+  unsigned int count_valid : 1;
+
+  /* Number of successor and predecessor edges.  */
+  gcov_type succ_count;
+  gcov_type pred_count;
+};
+
+#define EDGE_INFO(e)  ((struct edge_info *) (e)->aux)
+#define BB_INFO(b)  ((struct bb_info *) (b)->aux)
+
+/* Counter summary from the last set of coverage counts read.  */
+
+const struct gcov_ctr_summary *profile_info;
+
+/* Collect statistics on the performance of this pass for the entire source
+   file.  */
+
+static int total_num_blocks;
+static int total_num_edges;
+static int total_num_edges_ignored;
+static int total_num_edges_instrumented;
+static int total_num_blocks_created;
+static int total_num_passes;
+static int total_num_times_called;
+static int total_hist_br_prob[20];
+static int total_num_never_executed;
+static int total_num_branches;
+
+/* Forward declarations.  */
+static void find_spanning_tree (struct edge_list *);
+static unsigned instrument_edges (struct edge_list *);
+static void instrument_values (histogram_values);
+static void compute_branch_probabilities (void);
+static void compute_value_histograms (histogram_values);
+static gcov_type * get_exec_counts (void);
+static basic_block find_group (basic_block);
+static void union_groups (basic_block, basic_block);
+
+
+/* Add edge instrumentation code to the entire insn chain.
+
+   F is the first insn of the chain.
+   NUM_BLOCKS is the number of basic blocks found in F.  */
+
+static unsigned
+instrument_edges (struct edge_list *el)
+{
+  unsigned num_instr_edges = 0;
+  int num_edges = NUM_EDGES (el);
+  basic_block bb;
+
+  FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
+    {
+      edge e;
+      edge_iterator ei;
+
+      FOR_EACH_EDGE (e, ei, bb->succs)
+	{
+	  struct edge_info *inf = EDGE_INFO (e);
+
+	  if (!inf->ignore && !inf->on_tree)
+	    {
+	      gcc_assert (!(e->flags & EDGE_ABNORMAL));
+	      if (dump_file)
+		fprintf (dump_file, "Edge %d to %d instrumented%s\n",
+			 e->src->index, e->dest->index,
+			 EDGE_CRITICAL_P (e) ? " (and split)" : "");
+	      (profile_hooks->gen_edge_profiler) (num_instr_edges++, e);
+	    }
+	}
+    }
+
+  total_num_blocks_created += num_edges;
+  if (dump_file)
+    fprintf (dump_file, "%d edges instrumented\n", num_instr_edges);
+  return num_instr_edges;
+}
+
+/* Add code to measure histograms for values in list VALUES.  */
+static void
+instrument_values (histogram_values values)
+{
+  unsigned i, t;
+
+  /* Emit code to generate the histograms before the insns.  */
+
+  for (i = 0; i < VEC_length (histogram_value, values); i++)
+    {
+      histogram_value hist = VEC_index (histogram_value, values, i);
+      switch (hist->type)
+	{
+	case HIST_TYPE_INTERVAL:
+	  t = GCOV_COUNTER_V_INTERVAL;
+	  break;
+
+	case HIST_TYPE_POW2:
+	  t = GCOV_COUNTER_V_POW2;
+	  break;
+
+	case HIST_TYPE_SINGLE_VALUE:
+	  t = GCOV_COUNTER_V_SINGLE;
+	  break;
+
+	case HIST_TYPE_CONST_DELTA:
+	  t = GCOV_COUNTER_V_DELTA;
+	  break;
+
+ 	case HIST_TYPE_INDIR_CALL:
+ 	  t = GCOV_COUNTER_V_INDIR;
+ 	  break;
+
+ 	case HIST_TYPE_AVERAGE:
+ 	  t = GCOV_COUNTER_AVERAGE;
+ 	  break;
+
+ 	case HIST_TYPE_IOR:
+ 	  t = GCOV_COUNTER_IOR;
+ 	  break;
+
+	default:
+	  gcc_unreachable ();
+	}
+      if (!coverage_counter_alloc (t, hist->n_counters))
+	continue;
+
+      switch (hist->type)
+	{
+	case HIST_TYPE_INTERVAL:
+	  (profile_hooks->gen_interval_profiler) (hist, t, 0);
+	  break;
+
+	case HIST_TYPE_POW2:
+	  (profile_hooks->gen_pow2_profiler) (hist, t, 0);
+	  break;
+
+	case HIST_TYPE_SINGLE_VALUE:
+	  (profile_hooks->gen_one_value_profiler) (hist, t, 0);
+	  break;
+
+	case HIST_TYPE_CONST_DELTA:
+	  (profile_hooks->gen_const_delta_profiler) (hist, t, 0);
+	  break;
+
+ 	case HIST_TYPE_INDIR_CALL:
+ 	  (profile_hooks->gen_ic_profiler) (hist, t, 0);
+  	  break;
+
+	case HIST_TYPE_AVERAGE:
+	  (profile_hooks->gen_average_profiler) (hist, t, 0);
+	  break;
+
+	case HIST_TYPE_IOR:
+	  (profile_hooks->gen_ior_profiler) (hist, t, 0);
+	  break;
+
+	default:
+	  gcc_unreachable ();
+	}
+    }
+}
+
+
+/* Computes hybrid profile for all matching entries in da_file.  */
+
+static gcov_type *
+get_exec_counts (void)
+{
+  unsigned num_edges = 0;
+  basic_block bb;
+  gcov_type *counts;
+
+  /* Count the edges to be (possibly) instrumented.  */
+  FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
+    {
+      edge e;
+      edge_iterator ei;
+
+      FOR_EACH_EDGE (e, ei, bb->succs)
+	if (!EDGE_INFO (e)->ignore && !EDGE_INFO (e)->on_tree)
+	  num_edges++;
+    }
+
+  counts = get_coverage_counts (GCOV_COUNTER_ARCS, num_edges, &profile_info);
+  if (!counts)
+    return NULL;
+
+  if (dump_file && profile_info)
+    fprintf(dump_file, "Merged %u profiles with maximal count %u.\n",
+	    profile_info->runs, (unsigned) profile_info->sum_max);
+
+  return counts;
+}
+
+
+/* Compute the branch probabilities for the various branches.
+   Annotate them accordingly.  */
+
+static void
+compute_branch_probabilities (void)
+{
+  basic_block bb;
+  int i;
+  int num_edges = 0;
+  int changes;
+  int passes;
+  int hist_br_prob[20];
+  int num_never_executed;
+  int num_branches;
+  gcov_type *exec_counts = get_exec_counts ();
+  int exec_counts_pos = 0;
+
+  /* Very simple sanity checks so we catch bugs in our profiling code.  */
+  if (profile_info)
+    {
+      if (profile_info->run_max * profile_info->runs < profile_info->sum_max)
+	{
+	  error ("corrupted profile info: run_max * runs < sum_max");
+	  exec_counts = NULL;
+	}
+
+      if (profile_info->sum_all < profile_info->sum_max)
+	{
+	  error ("corrupted profile info: sum_all is smaller than sum_max");
+	  exec_counts = NULL;
+	}
+    }
+
+  /* Attach extra info block to each bb.  */
+
+  alloc_aux_for_blocks (sizeof (struct bb_info));
+  FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
+    {
+      edge e;
+      edge_iterator ei;
+
+      FOR_EACH_EDGE (e, ei, bb->succs)
+	if (!EDGE_INFO (e)->ignore)
+	  BB_INFO (bb)->succ_count++;
+      FOR_EACH_EDGE (e, ei, bb->preds)
+	if (!EDGE_INFO (e)->ignore)
+	  BB_INFO (bb)->pred_count++;
+    }
+
+  /* Avoid predicting entry on exit nodes.  */
+  BB_INFO (EXIT_BLOCK_PTR)->succ_count = 2;
+  BB_INFO (ENTRY_BLOCK_PTR)->pred_count = 2;
+
+  /* For each edge not on the spanning tree, set its execution count from
+     the .da file.  */
+
+  /* The first count in the .da file is the number of times that the function
+     was entered.  This is the exec_count for block zero.  */
+
+  FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
+    {
+      edge e;
+      edge_iterator ei;
+
+      FOR_EACH_EDGE (e, ei, bb->succs)
+	if (!EDGE_INFO (e)->ignore && !EDGE_INFO (e)->on_tree)
+	  {
+	    num_edges++;
+	    if (exec_counts)
+	      {
+		e->count = exec_counts[exec_counts_pos++];
+		if (e->count > profile_info->sum_max)
+		  {
+		    error ("corrupted profile info: edge from %i to %i exceeds maximal count",
+			   bb->index, e->dest->index);
+		  }
+	      }
+	    else
+	      e->count = 0;
+
+	    EDGE_INFO (e)->count_valid = 1;
+	    BB_INFO (bb)->succ_count--;
+	    BB_INFO (e->dest)->pred_count--;
+	    if (dump_file)
+	      {
+		fprintf (dump_file, "\nRead edge from %i to %i, count:",
+			 bb->index, e->dest->index);
+		fprintf (dump_file, HOST_WIDEST_INT_PRINT_DEC,
+			 (HOST_WIDEST_INT) e->count);
+	      }
+	  }
+    }
+
+  if (dump_file)
+    fprintf (dump_file, "\n%d edge counts read\n", num_edges);
+
+  /* For every block in the file,
+     - if every exit/entrance edge has a known count, then set the block count
+     - if the block count is known, and every exit/entrance edge but one has
+     a known execution count, then set the count of the remaining edge
+
+     As edge counts are set, decrement the succ/pred count, but don't delete
+     the edge, that way we can easily tell when all edges are known, or only
+     one edge is unknown.  */
+
+  /* The order that the basic blocks are iterated through is important.
+     Since the code that finds spanning trees starts with block 0, low numbered
+     edges are put on the spanning tree in preference to high numbered edges.
+     Hence, most instrumented edges are at the end.  Graph solving works much
+     faster if we propagate numbers from the end to the start.
+
+     This takes an average of slightly more than 3 passes.  */
+
+  changes = 1;
+  passes = 0;
+  while (changes)
+    {
+      passes++;
+      changes = 0;
+      FOR_BB_BETWEEN (bb, EXIT_BLOCK_PTR, NULL, prev_bb)
+	{
+	  struct bb_info *bi = BB_INFO (bb);
+	  if (! bi->count_valid)
+	    {
+	      if (bi->succ_count == 0)
+		{
+		  edge e;
+		  edge_iterator ei;
+		  gcov_type total = 0;
+
+		  FOR_EACH_EDGE (e, ei, bb->succs)
+		    total += e->count;
+		  bb->count = total;
+		  bi->count_valid = 1;
+		  changes = 1;
+		}
+	      else if (bi->pred_count == 0)
+		{
+		  edge e;
+		  edge_iterator ei;
+		  gcov_type total = 0;
+
+		  FOR_EACH_EDGE (e, ei, bb->preds)
+		    total += e->count;
+		  bb->count = total;
+		  bi->count_valid = 1;
+		  changes = 1;
+		}
+	    }
+	  if (bi->count_valid)
+	    {
+	      if (bi->succ_count == 1)
+		{
+		  edge e;
+		  edge_iterator ei;
+		  gcov_type total = 0;
+
+		  /* One of the counts will be invalid, but it is zero,
+		     so adding it in also doesn't hurt.  */
+		  FOR_EACH_EDGE (e, ei, bb->succs)
+		    total += e->count;
+
+		  /* Seedgeh for the invalid edge, and set its count.  */
+		  FOR_EACH_EDGE (e, ei, bb->succs)
+		    if (! EDGE_INFO (e)->count_valid && ! EDGE_INFO (e)->ignore)
+		      break;
+
+		  /* Calculate count for remaining edge by conservation.  */
+		  total = bb->count - total;
+
+		  gcc_assert (e);
+		  EDGE_INFO (e)->count_valid = 1;
+		  e->count = total;
+		  bi->succ_count--;
+
+		  BB_INFO (e->dest)->pred_count--;
+		  changes = 1;
+		}
+	      if (bi->pred_count == 1)
+		{
+		  edge e;
+		  edge_iterator ei;
+		  gcov_type total = 0;
+
+		  /* One of the counts will be invalid, but it is zero,
+		     so adding it in also doesn't hurt.  */
+		  FOR_EACH_EDGE (e, ei, bb->preds)
+		    total += e->count;
+
+		  /* Search for the invalid edge, and set its count.  */
+		  FOR_EACH_EDGE (e, ei, bb->preds)
+		    if (!EDGE_INFO (e)->count_valid && !EDGE_INFO (e)->ignore)
+		      break;
+
+		  /* Calculate count for remaining edge by conservation.  */
+		  total = bb->count - total + e->count;
+
+		  gcc_assert (e);
+		  EDGE_INFO (e)->count_valid = 1;
+		  e->count = total;
+		  bi->pred_count--;
+
+		  BB_INFO (e->src)->succ_count--;
+		  changes = 1;
+		}
+	    }
+	}
+    }
+  if (dump_file)
+    dump_flow_info (dump_file, dump_flags);
+
+  total_num_passes += passes;
+  if (dump_file)
+    fprintf (dump_file, "Graph solving took %d passes.\n\n", passes);
+
+  /* If the graph has been correctly solved, every block will have a
+     succ and pred count of zero.  */
+  FOR_EACH_BB (bb)
+    {
+      gcc_assert (!BB_INFO (bb)->succ_count && !BB_INFO (bb)->pred_count);
+    }
+
+  /* For every edge, calculate its branch probability and add a reg_note
+     to the branch insn to indicate this.  */
+
+  for (i = 0; i < 20; i++)
+    hist_br_prob[i] = 0;
+  num_never_executed = 0;
+  num_branches = 0;
+
+  FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
+    {
+      edge e;
+      edge_iterator ei;
+
+      if (bb->count < 0)
+	{
+	  error ("corrupted profile info: number of iterations for basic block %d thought to be %i",
+		 bb->index, (int)bb->count);
+	  bb->count = 0;
+	}
+      FOR_EACH_EDGE (e, ei, bb->succs)
+	{
+	  /* Function may return twice in the cased the called function is
+	     setjmp or calls fork, but we can't represent this by extra
+	     edge from the entry, since extra edge from the exit is
+	     already present.  We get negative frequency from the entry
+	     point.  */
+	  if ((e->count < 0
+	       && e->dest == EXIT_BLOCK_PTR)
+	      || (e->count > bb->count
+		  && e->dest != EXIT_BLOCK_PTR))
+	    {
+	      if (block_ends_with_call_p (bb))
+		e->count = e->count < 0 ? 0 : bb->count;
+	    }
+	  if (e->count < 0 || e->count > bb->count)
+	    {
+	      error ("corrupted profile info: number of executions for edge %d-%d thought to be %i",
+		     e->src->index, e->dest->index,
+		     (int)e->count);
+	      e->count = bb->count / 2;
+	    }
+	}
+      if (bb->count)
+	{
+	  FOR_EACH_EDGE (e, ei, bb->succs)
+	    e->probability = (e->count * REG_BR_PROB_BASE + bb->count / 2) / bb->count;
+	  if (bb->index >= NUM_FIXED_BLOCKS
+	      && block_ends_with_condjump_p (bb)
+	      && EDGE_COUNT (bb->succs) >= 2)
+	    {
+	      int prob;
+	      edge e;
+	      int index;
+
+	      /* Find the branch edge.  It is possible that we do have fake
+		 edges here.  */
+	      FOR_EACH_EDGE (e, ei, bb->succs)
+		if (!(e->flags & (EDGE_FAKE | EDGE_FALLTHRU)))
+		  break;
+
+	      prob = e->probability;
+	      index = prob * 20 / REG_BR_PROB_BASE;
+
+	      if (index == 20)
+		index = 19;
+	      hist_br_prob[index]++;
+
+	      num_branches++;
+	    }
+	}
+      /* As a last resort, distribute the probabilities evenly.
+	 Use simple heuristics that if there are normal edges,
+	 give all abnormals frequency of 0, otherwise distribute the
+	 frequency over abnormals (this is the case of noreturn
+	 calls).  */
+      else if (profile_status == PROFILE_ABSENT)
+	{
+	  int total = 0;
+
+	  FOR_EACH_EDGE (e, ei, bb->succs)
+	    if (!(e->flags & (EDGE_COMPLEX | EDGE_FAKE)))
+	      total ++;
+	  if (total)
+	    {
+	      FOR_EACH_EDGE (e, ei, bb->succs)
+		if (!(e->flags & (EDGE_COMPLEX | EDGE_FAKE)))
+		  e->probability = REG_BR_PROB_BASE / total;
+		else
+		  e->probability = 0;
+	    }
+	  else
+	    {
+	      total += EDGE_COUNT (bb->succs);
+	      FOR_EACH_EDGE (e, ei, bb->succs)
+		e->probability = REG_BR_PROB_BASE / total;
+	    }
+	  if (bb->index >= NUM_FIXED_BLOCKS
+	      && block_ends_with_condjump_p (bb)
+	      && EDGE_COUNT (bb->succs) >= 2)
+	    num_branches++, num_never_executed;
+	}
+    }
+  counts_to_freqs ();
+
+  if (dump_file)
+    {
+      fprintf (dump_file, "%d branches\n", num_branches);
+      fprintf (dump_file, "%d branches never executed\n",
+	       num_never_executed);
+      if (num_branches)
+	for (i = 0; i < 10; i++)
+	  fprintf (dump_file, "%d%% branches in range %d-%d%%\n",
+		   (hist_br_prob[i] + hist_br_prob[19-i]) * 100 / num_branches,
+		   5 * i, 5 * i + 5);
+
+      total_num_branches += num_branches;
+      total_num_never_executed += num_never_executed;
+      for (i = 0; i < 20; i++)
+	total_hist_br_prob[i] += hist_br_prob[i];
+
+      fputc ('\n', dump_file);
+      fputc ('\n', dump_file);
+    }
+
+  free_aux_for_blocks ();
+}
+
+/* Load value histograms values whose description is stored in VALUES array
+   from .gcda file.  */
+
+static void
+compute_value_histograms (histogram_values values)
+{
+  unsigned i, j, t, any;
+  unsigned n_histogram_counters[GCOV_N_VALUE_COUNTERS];
+  gcov_type *histogram_counts[GCOV_N_VALUE_COUNTERS];
+  gcov_type *act_count[GCOV_N_VALUE_COUNTERS];
+  gcov_type *aact_count;
+ 
+  for (t = 0; t < GCOV_N_VALUE_COUNTERS; t++)
+    n_histogram_counters[t] = 0;
+
+  for (i = 0; i < VEC_length (histogram_value, values); i++)
+    {
+      histogram_value hist = VEC_index (histogram_value, values, i);
+      n_histogram_counters[(int) hist->type] += hist->n_counters;
+    }
+
+  any = 0;
+  for (t = 0; t < GCOV_N_VALUE_COUNTERS; t++)
+    {
+      if (!n_histogram_counters[t])
+	{
+	  histogram_counts[t] = NULL;
+	  continue;
+	}
+
+      histogram_counts[t] =
+	get_coverage_counts (COUNTER_FOR_HIST_TYPE (t),
+			     n_histogram_counters[t], NULL);
+      if (histogram_counts[t])
+	any = 1;
+      act_count[t] = histogram_counts[t];
+    }
+  if (!any)
+    return;
+
+  for (i = 0; i < VEC_length (histogram_value, values); i++)
+    {
+      histogram_value hist = VEC_index (histogram_value, values, i);
+      tree stmt = hist->hvalue.stmt;
+
+      t = (int) hist->type;
+
+      aact_count = act_count[t];
+      act_count[t] += hist->n_counters;
+
+      gimple_add_histogram_value (cfun, stmt, hist);
+      hist->hvalue.counters =  XNEWVEC (gcov_type, hist->n_counters);
+      for (j = 0; j < hist->n_counters; j++)
+	hist->hvalue.counters[j] = aact_count[j];
+    }
+
+  for (t = 0; t < GCOV_N_VALUE_COUNTERS; t++)
+    if (histogram_counts[t])
+      free (histogram_counts[t]);
+}
+
+/* The entry basic block will be moved around so that it has index=1,
+   there is nothing at index 0 and the exit is at n_basic_block.  */
+#define BB_TO_GCOV_INDEX(bb)  ((bb)->index - 1)
+/* When passed NULL as file_name, initialize.
+   When passed something else, output the necessary commands to change
+   line to LINE and offset to FILE_NAME.  */
+static void
+output_location (char const *file_name, int line,
+		 gcov_position_t *offset, basic_block bb)
+{
+  static char const *prev_file_name;
+  static int prev_line;
+  bool name_differs, line_differs;
+
+  if (!file_name)
+    {
+      prev_file_name = NULL;
+      prev_line = -1;
+      return;
+    }
+
+  name_differs = !prev_file_name || strcmp (file_name, prev_file_name);
+  line_differs = prev_line != line;
+
+  if (name_differs || line_differs)
+    {
+      if (!*offset)
+	{
+	  *offset = gcov_write_tag (GCOV_TAG_LINES);
+	  gcov_write_unsigned (BB_TO_GCOV_INDEX (bb));
+	  name_differs = line_differs=true;
+	}
+
+      /* If this is a new source file, then output the
+	 file's name to the .bb file.  */
+      if (name_differs)
+	{
+	  prev_file_name = file_name;
+	  gcov_write_unsigned (0);
+	  gcov_write_string (prev_file_name);
+	}
+      if (line_differs)
+	{
+	  gcov_write_unsigned (line);
+	  prev_line = line;
+	}
+     }
+}
+
+/* Instrument and/or analyze program behavior based on program flow graph.
+   In either case, this function builds a flow graph for the function being
+   compiled.  The flow graph is stored in BB_GRAPH.
+
+   When FLAG_PROFILE_ARCS is nonzero, this function instruments the edges in
+   the flow graph that are needed to reconstruct the dynamic behavior of the
+   flow graph.
+
+   When FLAG_BRANCH_PROBABILITIES is nonzero, this function reads auxiliary
+   information from a data file containing edge count information from previous
+   executions of the function being compiled.  In this case, the flow graph is
+   annotated with actual execution counts, which are later propagated into the
+   rtl for optimization purposes.
+
+   Main entry point of this file.  */
+
+void
+branch_prob (void)
+{
+  basic_block bb;
+  unsigned i;
+  unsigned num_edges, ignored_edges;
+  unsigned num_instrumented;
+  struct edge_list *el;
+  histogram_values values = NULL;
+
+  total_num_times_called++;
+
+  flow_call_edges_add (NULL);
+  add_noreturn_fake_exit_edges ();
+
+  /* We can't handle cyclic regions constructed using abnormal edges.
+     To avoid these we replace every source of abnormal edge by a fake
+     edge from entry node and every destination by fake edge to exit.
+     This keeps graph acyclic and our calculation exact for all normal
+     edges except for exit and entrance ones.
+
+     We also add fake exit edges for each call and asm statement in the
+     basic, since it may not return.  */
+
+  FOR_EACH_BB (bb)
+    {
+      int need_exit_edge = 0, need_entry_edge = 0;
+      int have_exit_edge = 0, have_entry_edge = 0;
+      edge e;
+      edge_iterator ei;
+
+      /* Functions returning multiple times are not handled by extra edges.
+         Instead we simply allow negative counts on edges from exit to the
+         block past call and corresponding probabilities.  We can't go
+         with the extra edges because that would result in flowgraph that
+	 needs to have fake edges outside the spanning tree.  */
+
+      FOR_EACH_EDGE (e, ei, bb->succs)
+	{
+	  block_stmt_iterator bsi;
+	  tree last = NULL;
+
+	  /* It may happen that there are compiler generated statements
+	     without a locus at all.  Go through the basic block from the
+	     last to the first statement looking for a locus.  */
+	  for (bsi = bsi_last (bb); !bsi_end_p (bsi); bsi_prev (&bsi))
+	    {
+	      last = bsi_stmt (bsi);
+	      if (EXPR_LOCUS (last))
+		break;
+	    }
+
+	  /* Edge with goto locus might get wrong coverage info unless
+	     it is the only edge out of BB.   
+	     Don't do that when the locuses match, so 
+	     if (blah) goto something;
+	     is not computed twice.  */
+	  if (last && EXPR_LOCUS (last)
+	      && e->goto_locus
+	      && !single_succ_p (bb)
+#ifdef USE_MAPPED_LOCATION
+	      && (LOCATION_FILE (e->goto_locus)
+	          != LOCATION_FILE (EXPR_LOCATION  (last))
+		  || (LOCATION_LINE (e->goto_locus)
+		      != LOCATION_LINE (EXPR_LOCATION  (last)))))
+#else
+	      && (e->goto_locus->file != EXPR_LOCUS (last)->file
+		  || (e->goto_locus->line != EXPR_LOCUS (last)->line)))
+#endif
+	    {
+	      basic_block new = split_edge (e);
+	      single_succ_edge (new)->goto_locus = e->goto_locus;
+	    }
+	  if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
+	       && e->dest != EXIT_BLOCK_PTR)
+	    need_exit_edge = 1;
+	  if (e->dest == EXIT_BLOCK_PTR)
+	    have_exit_edge = 1;
+	}
+      FOR_EACH_EDGE (e, ei, bb->preds)
+	{
+	  if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
+	       && e->src != ENTRY_BLOCK_PTR)
+	    need_entry_edge = 1;
+	  if (e->src == ENTRY_BLOCK_PTR)
+	    have_entry_edge = 1;
+	}
+
+      if (need_exit_edge && !have_exit_edge)
+	{
+	  if (dump_file)
+	    fprintf (dump_file, "Adding fake exit edge to bb %i\n",
+		     bb->index);
+	  make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE);
+	}
+      if (need_entry_edge && !have_entry_edge)
+	{
+	  if (dump_file)
+	    fprintf (dump_file, "Adding fake entry edge to bb %i\n",
+		     bb->index);
+	  make_edge (ENTRY_BLOCK_PTR, bb, EDGE_FAKE);
+	}
+    }
+
+  el = create_edge_list ();
+  num_edges = NUM_EDGES (el);
+  alloc_aux_for_edges (sizeof (struct edge_info));
+
+  /* The basic blocks are expected to be numbered sequentially.  */
+  compact_blocks ();
+
+  ignored_edges = 0;
+  for (i = 0 ; i < num_edges ; i++)
+    {
+      edge e = INDEX_EDGE (el, i);
+      e->count = 0;
+
+      /* Mark edges we've replaced by fake edges above as ignored.  */
+      if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
+	  && e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR)
+	{
+	  EDGE_INFO (e)->ignore = 1;
+	  ignored_edges++;
+	}
+    }
+
+  /* Create spanning tree from basic block graph, mark each edge that is
+     on the spanning tree.  We insert as many abnormal and critical edges
+     as possible to minimize number of edge splits necessary.  */
+
+  find_spanning_tree (el);
+
+  /* Fake edges that are not on the tree will not be instrumented, so
+     mark them ignored.  */
+  for (num_instrumented = i = 0; i < num_edges; i++)
+    {
+      edge e = INDEX_EDGE (el, i);
+      struct edge_info *inf = EDGE_INFO (e);
+
+      if (inf->ignore || inf->on_tree)
+	/*NOP*/;
+      else if (e->flags & EDGE_FAKE)
+	{
+	  inf->ignore = 1;
+	  ignored_edges++;
+	}
+      else
+	num_instrumented++;
+    }
+
+  total_num_blocks += n_basic_blocks;
+  if (dump_file)
+    fprintf (dump_file, "%d basic blocks\n", n_basic_blocks);
+
+  total_num_edges += num_edges;
+  if (dump_file)
+    fprintf (dump_file, "%d edges\n", num_edges);
+
+  total_num_edges_ignored += ignored_edges;
+  if (dump_file)
+    fprintf (dump_file, "%d ignored edges\n", ignored_edges);
+
+  /* Write the data from which gcov can reconstruct the basic block
+     graph.  */
+
+  /* Basic block flags */
+  if (coverage_begin_output ())
+    {
+      gcov_position_t offset;
+
+      offset = gcov_write_tag (GCOV_TAG_BLOCKS);
+      for (i = 0; i != (unsigned) (n_basic_blocks); i++)
+	gcov_write_unsigned (0);
+      gcov_write_length (offset);
+    }
+
+   /* Keep all basic block indexes nonnegative in the gcov output.
+      Index 0 is used for entry block, last index is for exit block.
+      */
+  ENTRY_BLOCK_PTR->index = 1;
+  EXIT_BLOCK_PTR->index = last_basic_block;
+
+  /* Arcs */
+  if (coverage_begin_output ())
+    {
+      gcov_position_t offset;
+
+      FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb)
+	{
+	  edge e;
+	  edge_iterator ei;
+
+	  offset = gcov_write_tag (GCOV_TAG_ARCS);
+	  gcov_write_unsigned (BB_TO_GCOV_INDEX (bb));
+
+	  FOR_EACH_EDGE (e, ei, bb->succs)
+	    {
+	      struct edge_info *i = EDGE_INFO (e);
+	      if (!i->ignore)
+		{
+		  unsigned flag_bits = 0;
+
+		  if (i->on_tree)
+		    flag_bits |= GCOV_ARC_ON_TREE;
+		  if (e->flags & EDGE_FAKE)
+		    flag_bits |= GCOV_ARC_FAKE;
+		  if (e->flags & EDGE_FALLTHRU)
+		    flag_bits |= GCOV_ARC_FALLTHROUGH;
+		  /* On trees we don't have fallthru flags, but we can
+		     recompute them from CFG shape.  */
+		  if (e->flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)
+		      && e->src->next_bb == e->dest)
+		    flag_bits |= GCOV_ARC_FALLTHROUGH;
+
+		  gcov_write_unsigned (BB_TO_GCOV_INDEX (e->dest));
+		  gcov_write_unsigned (flag_bits);
+	        }
+	    }
+
+	  gcov_write_length (offset);
+	}
+    }
+
+  /* Line numbers.  */
+  if (coverage_begin_output ())
+    {
+      gcov_position_t offset;
+
+      /* Initialize the output.  */
+      output_location (NULL, 0, NULL, NULL);
+
+      FOR_EACH_BB (bb)
+	{
+	  block_stmt_iterator bsi;
+
+	  offset = 0;
+
+	  if (bb == ENTRY_BLOCK_PTR->next_bb)
+	    {
+	      expanded_location curr_location = 
+		expand_location (DECL_SOURCE_LOCATION (current_function_decl));
+	      output_location (curr_location.file, curr_location.line,
+			       &offset, bb);
+	    }
+
+	  for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
+	    {
+	      tree stmt = bsi_stmt (bsi);
+	      if (EXPR_HAS_LOCATION (stmt))
+		output_location (EXPR_FILENAME (stmt), EXPR_LINENO (stmt),
+				 &offset, bb);
+	      /* Take into account modify statements nested in return
+		 produced by C++ NRV transformation.  */
+	      if (TREE_CODE (stmt) == RETURN_EXPR
+		  && TREE_OPERAND (stmt, 0)
+		  && TREE_CODE (TREE_OPERAND (stmt, 0)) == MODIFY_EXPR
+		  && EXPR_HAS_LOCATION (TREE_OPERAND (stmt, 0)))
+		output_location (EXPR_FILENAME (TREE_OPERAND (stmt, 0)),
+				 EXPR_LINENO (TREE_OPERAND (stmt, 0)),
+				 &offset, bb);
+	    }
+
+	  /* Notice GOTO expressions we eliminated while constructing the
+	     CFG.  */
+	  if (single_succ_p (bb) && single_succ_edge (bb)->goto_locus)
+	    {
+	      /* ??? source_locus type is marked deprecated in input.h.  */
+	      source_locus curr_location = single_succ_edge (bb)->goto_locus;
+	      /* ??? The FILE/LINE API is inconsistent for these cases.  */
+#ifdef USE_MAPPED_LOCATION 
+	      output_location (LOCATION_FILE (curr_location),
+			       LOCATION_LINE (curr_location), &offset, bb);
+#else
+	      output_location (curr_location->file, curr_location->line,
+			       &offset, bb);
+#endif
+	    }
+
+	  if (offset)
+	    {
+	      /* A file of NULL indicates the end of run.  */
+	      gcov_write_unsigned (0);
+	      gcov_write_string (NULL);
+	      gcov_write_length (offset);
+	    }
+	}
+    }
+
+  ENTRY_BLOCK_PTR->index = ENTRY_BLOCK;
+  EXIT_BLOCK_PTR->index = EXIT_BLOCK;
+#undef BB_TO_GCOV_INDEX
+
+  if (flag_profile_values)
+    find_values_to_profile (&values);
+
+  if (flag_branch_probabilities)
+    {
+      compute_branch_probabilities ();
+      if (flag_profile_values)
+	compute_value_histograms (values);
+    }
+
+  remove_fake_edges ();
+
+  /* For each edge not on the spanning tree, add counting code.  */
+  if (profile_arc_flag
+      && coverage_counter_alloc (GCOV_COUNTER_ARCS, num_instrumented))
+    {
+      unsigned n_instrumented;
+
+      profile_hooks->init_edge_profiler ();
+
+      n_instrumented = instrument_edges (el);
+
+      gcc_assert (n_instrumented == num_instrumented);
+
+      if (flag_profile_values)
+	instrument_values (values);
+
+      /* Commit changes done by instrumentation.  */
+      bsi_commit_edge_inserts ();
+    }
+
+  free_aux_for_edges ();
+
+  VEC_free (histogram_value, heap, values);
+  free_edge_list (el);
+  if (flag_branch_probabilities)
+    profile_status = PROFILE_READ;
+  coverage_end_function ();
+}
+
+/* Union find algorithm implementation for the basic blocks using
+   aux fields.  */
+
+static basic_block
+find_group (basic_block bb)
+{
+  basic_block group = bb, bb1;
+
+  while ((basic_block) group->aux != group)
+    group = (basic_block) group->aux;
+
+  /* Compress path.  */
+  while ((basic_block) bb->aux != group)
+    {
+      bb1 = (basic_block) bb->aux;
+      bb->aux = (void *) group;
+      bb = bb1;
+    }
+  return group;
+}
+
+static void
+union_groups (basic_block bb1, basic_block bb2)
+{
+  basic_block bb1g = find_group (bb1);
+  basic_block bb2g = find_group (bb2);
+
+  /* ??? I don't have a place for the rank field.  OK.  Lets go w/o it,
+     this code is unlikely going to be performance problem anyway.  */
+  gcc_assert (bb1g != bb2g);
+
+  bb1g->aux = bb2g;
+}
+
+/* This function searches all of the edges in the program flow graph, and puts
+   as many bad edges as possible onto the spanning tree.  Bad edges include
+   abnormals edges, which can't be instrumented at the moment.  Since it is
+   possible for fake edges to form a cycle, we will have to develop some
+   better way in the future.  Also put critical edges to the tree, since they
+   are more expensive to instrument.  */
+
+static void
+find_spanning_tree (struct edge_list *el)
+{
+  int i;
+  int num_edges = NUM_EDGES (el);
+  basic_block bb;
+
+  /* We use aux field for standard union-find algorithm.  */
+  FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
+    bb->aux = bb;
+
+  /* Add fake edge exit to entry we can't instrument.  */
+  union_groups (EXIT_BLOCK_PTR, ENTRY_BLOCK_PTR);
+
+  /* First add all abnormal edges to the tree unless they form a cycle. Also
+     add all edges to EXIT_BLOCK_PTR to avoid inserting profiling code behind
+     setting return value from function.  */
+  for (i = 0; i < num_edges; i++)
+    {
+      edge e = INDEX_EDGE (el, i);
+      if (((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_FAKE))
+	   || e->dest == EXIT_BLOCK_PTR)
+	  && !EDGE_INFO (e)->ignore
+	  && (find_group (e->src) != find_group (e->dest)))
+	{
+	  if (dump_file)
+	    fprintf (dump_file, "Abnormal edge %d to %d put to tree\n",
+		     e->src->index, e->dest->index);
+	  EDGE_INFO (e)->on_tree = 1;
+	  union_groups (e->src, e->dest);
+	}
+    }
+
+  /* Now insert all critical edges to the tree unless they form a cycle.  */
+  for (i = 0; i < num_edges; i++)
+    {
+      edge e = INDEX_EDGE (el, i);
+      if (EDGE_CRITICAL_P (e) && !EDGE_INFO (e)->ignore
+	  && find_group (e->src) != find_group (e->dest))
+	{
+	  if (dump_file)
+	    fprintf (dump_file, "Critical edge %d to %d put to tree\n",
+		     e->src->index, e->dest->index);
+	  EDGE_INFO (e)->on_tree = 1;
+	  union_groups (e->src, e->dest);
+	}
+    }
+
+  /* And now the rest.  */
+  for (i = 0; i < num_edges; i++)
+    {
+      edge e = INDEX_EDGE (el, i);
+      if (!EDGE_INFO (e)->ignore
+	  && find_group (e->src) != find_group (e->dest))
+	{
+	  if (dump_file)
+	    fprintf (dump_file, "Normal edge %d to %d put to tree\n",
+		     e->src->index, e->dest->index);
+	  EDGE_INFO (e)->on_tree = 1;
+	  union_groups (e->src, e->dest);
+	}
+    }
+
+  FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
+    bb->aux = NULL;
+}
+
+/* Perform file-level initialization for branch-prob processing.  */
+
+void
+init_branch_prob (void)
+{
+  int i;
+
+  total_num_blocks = 0;
+  total_num_edges = 0;
+  total_num_edges_ignored = 0;
+  total_num_edges_instrumented = 0;
+  total_num_blocks_created = 0;
+  total_num_passes = 0;
+  total_num_times_called = 0;
+  total_num_branches = 0;
+  total_num_never_executed = 0;
+  for (i = 0; i < 20; i++)
+    total_hist_br_prob[i] = 0;
+}
+
+/* Performs file-level cleanup after branch-prob processing
+   is completed.  */
+
+void
+end_branch_prob (void)
+{
+  if (dump_file)
+    {
+      fprintf (dump_file, "\n");
+      fprintf (dump_file, "Total number of blocks: %d\n",
+	       total_num_blocks);
+      fprintf (dump_file, "Total number of edges: %d\n", total_num_edges);
+      fprintf (dump_file, "Total number of ignored edges: %d\n",
+	       total_num_edges_ignored);
+      fprintf (dump_file, "Total number of instrumented edges: %d\n",
+	       total_num_edges_instrumented);
+      fprintf (dump_file, "Total number of blocks created: %d\n",
+	       total_num_blocks_created);
+      fprintf (dump_file, "Total number of graph solution passes: %d\n",
+	       total_num_passes);
+      if (total_num_times_called != 0)
+	fprintf (dump_file, "Average number of graph solution passes: %d\n",
+		 (total_num_passes + (total_num_times_called  >> 1))
+		 / total_num_times_called);
+      fprintf (dump_file, "Total number of branches: %d\n",
+	       total_num_branches);
+      fprintf (dump_file, "Total number of branches never executed: %d\n",
+	       total_num_never_executed);
+      if (total_num_branches)
+	{
+	  int i;
+
+	  for (i = 0; i < 10; i++)
+	    fprintf (dump_file, "%d%% branches in range %d-%d%%\n",
+		     (total_hist_br_prob[i] + total_hist_br_prob[19-i]) * 100
+		     / total_num_branches, 5*i, 5*i+5);
+	}
+    }
+}
+
+/* Set up hooks to enable tree-based profiling.  */
+
+void
+tree_register_profile_hooks (void)
+{
+  gcc_assert (current_ir_type () == IR_GIMPLE);
+  profile_hooks = &tree_profile_hooks;
+}
+