Esempio n. 1
0
static fibheapkey_t
bb_to_key (basic_block bb)
{
  edge e;

  int priority = 0;

  /* Do not start in probably never executed blocks.  */
  if (probably_never_executed_bb_p (bb))
    return BB_FREQ_MAX;

  /* Prefer blocks whose predecessor is an end of some trace
     or whose predecessor edge is EDGE_DFS_BACK.  */
  for (e = bb->pred; e; e = e->pred_next)
    {
      if ((e->src != ENTRY_BLOCK_PTR && bbd[e->src->index].end_of_trace >= 0)
	  || (e->flags & EDGE_DFS_BACK))
	{
	  int edge_freq = EDGE_FREQUENCY (e);

	  if (edge_freq > priority)
	    priority = edge_freq;
	}
    }

  if (priority)
    /* The block with priority should have significantly lower key.  */
    return -(100 * BB_FREQ_MAX + 100 * priority + bb->frequency);
  return -bb->frequency;
}
static inline int 
coalesce_cost_edge (edge e)
{
  if (e->flags & EDGE_ABNORMAL)
    return MUST_COALESCE_COST;

  return coalesce_cost (EDGE_FREQUENCY (e), 
			maybe_hot_bb_p (e->src), 
			EDGE_CRITICAL_P (e));
}
Esempio n. 3
0
/* Check the consistency of profile information.  We can't do that
   in verify_flow_info, as the counts may get invalid for incompletely
   solved graphs, later eliminating of conditionals or roundoff errors.
   It is still practical to have them reported for debugging of simple
   testcases.  */
static void
check_bb_profile (basic_block bb, FILE * file, int indent, int flags)
{
  edge e;
  int sum = 0;
  gcov_type lsum;
  edge_iterator ei;
  struct function *fun = DECL_STRUCT_FUNCTION (current_function_decl);
  char *s_indent = (char *) alloca ((size_t) indent + 1);
  memset ((void *) s_indent, ' ', (size_t) indent);
  s_indent[indent] = '\0';

  if (profile_status_for_function (fun) == PROFILE_ABSENT)
    return;

  if (bb != EXIT_BLOCK_PTR_FOR_FUNCTION (fun))
    {
      FOR_EACH_EDGE (e, ei, bb->succs)
	sum += e->probability;
      if (EDGE_COUNT (bb->succs) && abs (sum - REG_BR_PROB_BASE) > 100)
	fprintf (file, "%s%sInvalid sum of outgoing probabilities %.1f%%\n",
		 (flags & TDF_COMMENT) ? ";; " : "", s_indent,
		 sum * 100.0 / REG_BR_PROB_BASE);
      lsum = 0;
      FOR_EACH_EDGE (e, ei, bb->succs)
	lsum += e->count;
      if (EDGE_COUNT (bb->succs)
	  && (lsum - bb->count > 100 || lsum - bb->count < -100))
	fprintf (file, "%s%sInvalid sum of outgoing counts %i, should be %i\n",
		 (flags & TDF_COMMENT) ? ";; " : "", s_indent,
		 (int) lsum, (int) bb->count);
    }
    if (bb != ENTRY_BLOCK_PTR_FOR_FUNCTION (fun))
    {
      sum = 0;
      FOR_EACH_EDGE (e, ei, bb->preds)
	sum += EDGE_FREQUENCY (e);
      if (abs (sum - bb->frequency) > 100)
	fprintf (file,
		 "%s%sInvalid sum of incoming frequencies %i, should be %i\n",
		 (flags & TDF_COMMENT) ? ";; " : "", s_indent,
		 sum, bb->frequency);
      lsum = 0;
      FOR_EACH_EDGE (e, ei, bb->preds)
	lsum += e->count;
      if (lsum - bb->count > 100 || lsum - bb->count < -100)
	fprintf (file, "%s%sInvalid sum of incoming counts %i, should be %i\n",
		 (flags & TDF_COMMENT) ? ";; " : "", s_indent,
		 (int) lsum, (int) bb->count);
    }
}
Esempio n. 4
0
static void
layout_superblocks (void)
{
  basic_block end = single_succ (ENTRY_BLOCK_PTR);
  basic_block bb = end->next_bb;

  while (bb != EXIT_BLOCK_PTR)
    {
      edge_iterator ei;
      edge e, best = NULL;
      while (end->aux)
	end = end->aux;

      FOR_EACH_EDGE (e, ei, end->succs)
	if (e->dest != EXIT_BLOCK_PTR
	    && e->dest != single_succ (ENTRY_BLOCK_PTR)
	    && !e->dest->il.rtl->visited
	    && (!best || EDGE_FREQUENCY (e) > EDGE_FREQUENCY (best)))
	  best = e;

      if (best)
	{
	  end->aux = best->dest;
	  best->dest->il.rtl->visited = 1;
	}
      else
	for (; bb != EXIT_BLOCK_PTR; bb = bb->next_bb)
	  {
	    if (!bb->il.rtl->visited)
	      {
		end->aux = bb;
		bb->il.rtl->visited = 1;
		break;
	      }
	  }
    }
}
Esempio n. 5
0
static void
layout_superblocks (void)
{
  basic_block end = ENTRY_BLOCK_PTR->succ->dest;
  basic_block bb = ENTRY_BLOCK_PTR->succ->dest->next_bb;

  while (bb != EXIT_BLOCK_PTR)
    {
      edge e, best = NULL;
      while (end->rbi->next)
	end = end->rbi->next;

      for (e = end->succ; e; e = e->succ_next)
	if (e->dest != EXIT_BLOCK_PTR
	    && e->dest != ENTRY_BLOCK_PTR->succ->dest
	    && !e->dest->rbi->visited
	    && (!best || EDGE_FREQUENCY (e) > EDGE_FREQUENCY (best)))
	  best = e;

      if (best)
	{
	  end->rbi->next = best->dest;
	  best->dest->rbi->visited = 1;
	}
      else
	for (; bb != EXIT_BLOCK_PTR; bb = bb->next_bb)
	  {
	    if (!bb->rbi->visited)
	      {
		end->rbi->next = bb;
		bb->rbi->visited = 1;
		break;
	      }
	  }
    }
}
Esempio n. 6
0
static edge
find_best_predecessor (basic_block bb)
{
  edge e;
  edge best = NULL;

  for (e = bb->pred; e; e = e->pred_next)
    if (!best || better_p (e, best))
      best = e;
  if (!best || ignore_bb_p (best->src))
    return NULL;
  if (EDGE_FREQUENCY (best) * REG_BR_PROB_BASE
      < bb->frequency * branch_ratio_cutoff)
    return NULL;
  return best;
}
Esempio n. 7
0
static edge
find_best_predecessor (basic_block bb)
{
  edge e;
  edge best = NULL;
  edge_iterator ei;

  FOR_EACH_EDGE (e, ei, bb->preds)
    if (!best || better_p (e, best))
      best = e;
  if (!best || ignore_bb_p (best->src))
    return NULL;
  if (EDGE_FREQUENCY (best) * REG_BR_PROB_BASE
      < bb->frequency * branch_ratio_cutoff)
    return NULL;
  return best;
}
Esempio n. 8
0
static basic_block
make_forwarder_block (basic_block bb, int redirect_latch, int redirect_nonlatch, edge except, int conn_latch)
{
  edge e, next_e, fallthru;
  basic_block dummy;
  rtx insn;

  insn = PREV_INSN (first_insn_after_basic_block_note (bb));

  /* For empty block split_block will return NULL.  */
  if (BB_END (bb) == insn)
    emit_note_after (NOTE_INSN_DELETED, insn);

  fallthru = split_block (bb, insn);
  dummy = fallthru->src;
  bb = fallthru->dest;

  bb->aux = xmalloc (sizeof (int));
  HEADER_BLOCK (dummy) = 0;
  HEADER_BLOCK (bb) = 1;

  /* Redirect back edges we want to keep.  */
  for (e = dummy->pred; e; e = next_e)
    {
      next_e = e->pred_next;
      if (e == except
	  || !((redirect_latch && LATCH_EDGE (e))
	       || (redirect_nonlatch && !LATCH_EDGE (e))))
	{
	  dummy->frequency -= EDGE_FREQUENCY (e);
	  dummy->count -= e->count;
	  if (dummy->frequency < 0)
	    dummy->frequency = 0;
	  if (dummy->count < 0)
	    dummy->count = 0;
	  redirect_edge_with_latch_update (e, bb);
	}
    }

  alloc_aux_for_edge (fallthru, sizeof (int));
  LATCH_EDGE (fallthru) = conn_latch;

  return dummy;
}
Esempio n. 9
0
static basic_block
rotate_loop (edge back_edge, struct trace *trace, int trace_n)
{
  basic_block bb;

  /* Information about the best end (end after rotation) of the loop.  */
  basic_block best_bb = NULL;
  edge best_edge = NULL;
  int best_freq = -1;
  gcov_type best_count = -1;
  /* The best edge is preferred when its destination is not visited yet
     or is a start block of some trace.  */
  bool is_preferred = false;

  /* Find the most frequent edge that goes out from current trace.  */
  bb = back_edge->dest;
  do
    {
      edge e;
      for (e = bb->succ; e; e = e->succ_next)
	if (e->dest != EXIT_BLOCK_PTR
	    && e->dest->rbi->visited != trace_n
	    && (e->flags & EDGE_CAN_FALLTHRU)
	    && !(e->flags & EDGE_COMPLEX))
	{
	  if (is_preferred)
	    {
	      /* The best edge is preferred.  */
	      if (!e->dest->rbi->visited
		  || bbd[e->dest->index].start_of_trace >= 0)
		{
		  /* The current edge E is also preferred.  */
		  int freq = EDGE_FREQUENCY (e);
		  if (freq > best_freq || e->count > best_count)
		    {
		      best_freq = freq;
		      best_count = e->count;
		      best_edge = e;
		      best_bb = bb;
		    }
		}
	    }
	  else
	    {
	      if (!e->dest->rbi->visited
		  || bbd[e->dest->index].start_of_trace >= 0)
		{
		  /* The current edge E is preferred.  */
		  is_preferred = true;
		  best_freq = EDGE_FREQUENCY (e);
		  best_count = e->count;
		  best_edge = e;
		  best_bb = bb;
		}
	      else
		{
		  int freq = EDGE_FREQUENCY (e);
		  if (!best_edge || freq > best_freq || e->count > best_count)
		    {
		      best_freq = freq;
		      best_count = e->count;
		      best_edge = e;
		      best_bb = bb;
		    }
		}
	    }
	}
      bb = bb->rbi->next;
    }
  while (bb != back_edge->dest);

  if (best_bb)
    {
      /* Rotate the loop so that the BEST_EDGE goes out from the last block of
	 the trace.  */
      if (back_edge->dest == trace->first)
	{
	  trace->first = best_bb->rbi->next;
	}
      else
	{
	  basic_block prev_bb;

	  for (prev_bb = trace->first;
	       prev_bb->rbi->next != back_edge->dest;
	       prev_bb = prev_bb->rbi->next)
	    ;
	  prev_bb->rbi->next = best_bb->rbi->next;

	  /* Try to get rid of uncond jump to cond jump.  */
	  if (prev_bb->succ && !prev_bb->succ->succ_next)
	    {
	      basic_block header = prev_bb->succ->dest;

	      /* Duplicate HEADER if it is a small block containing cond jump
		 in the end.  */
	      if (any_condjump_p (BB_END (header)) && copy_bb_p (header, 0))
		{
		  copy_bb (header, prev_bb->succ, prev_bb, trace_n);
		}
	    }
	}
    }
  else
    {
      /* We have not found suitable loop tail so do no rotation.  */
      best_bb = back_edge->src;
    }
  best_bb->rbi->next = NULL;
  return best_bb;
}
Esempio n. 10
0
static void
eliminate_tail_call (struct tailcall *t)
{
  tree param, rslt;
  gimple stmt, call;
  tree arg;
  size_t idx;
  basic_block bb, first;
  edge e;
  gimple phi;
  gimple_stmt_iterator gsi;
  gimple orig_stmt;

  stmt = orig_stmt = gsi_stmt (t->call_gsi);
  bb = gsi_bb (t->call_gsi);

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "Eliminated tail recursion in bb %d : ",
	       bb->index);
      print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
      fprintf (dump_file, "\n");
    }

  gcc_assert (is_gimple_call (stmt));

  first = single_succ (ENTRY_BLOCK_PTR_FOR_FN (cfun));

  /* Remove the code after call_gsi that will become unreachable.  The
     possibly unreachable code in other blocks is removed later in
     cfg cleanup.  */
  gsi = t->call_gsi;
  gsi_next (&gsi);
  while (!gsi_end_p (gsi))
    {
      gimple t = gsi_stmt (gsi);
      /* Do not remove the return statement, so that redirect_edge_and_branch
	 sees how the block ends.  */
      if (gimple_code (t) == GIMPLE_RETURN)
	break;

      gsi_remove (&gsi, true);
      release_defs (t);
    }

  /* Number of executions of function has reduced by the tailcall.  */
  e = single_succ_edge (gsi_bb (t->call_gsi));
  decrease_profile (EXIT_BLOCK_PTR_FOR_FN (cfun), e->count, EDGE_FREQUENCY (e));
  decrease_profile (ENTRY_BLOCK_PTR_FOR_FN (cfun), e->count,
		    EDGE_FREQUENCY (e));
  if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun))
    decrease_profile (e->dest, e->count, EDGE_FREQUENCY (e));

  /* Replace the call by a jump to the start of function.  */
  e = redirect_edge_and_branch (single_succ_edge (gsi_bb (t->call_gsi)),
				first);
  gcc_assert (e);
  PENDING_STMT (e) = NULL;

  /* Add phi node entries for arguments.  The ordering of the phi nodes should
     be the same as the ordering of the arguments.  */
  for (param = DECL_ARGUMENTS (current_function_decl),
	 idx = 0, gsi = gsi_start_phis (first);
       param;
       param = DECL_CHAIN (param), idx++)
    {
      if (!arg_needs_copy_p (param))
	continue;

      arg = gimple_call_arg (stmt, idx);
      phi = gsi_stmt (gsi);
      gcc_assert (param == SSA_NAME_VAR (PHI_RESULT (phi)));

      add_phi_arg (phi, arg, e, gimple_location (stmt));
      gsi_next (&gsi);
    }

  /* Update the values of accumulators.  */
  adjust_accumulator_values (t->call_gsi, t->mult, t->add, e);

  call = gsi_stmt (t->call_gsi);
  rslt = gimple_call_lhs (call);
  if (rslt != NULL_TREE)
    {
      /* Result of the call will no longer be defined.  So adjust the
	 SSA_NAME_DEF_STMT accordingly.  */
      SSA_NAME_DEF_STMT (rslt) = gimple_build_nop ();
    }

  gsi_remove (&t->call_gsi, true);
  release_defs (call);
}
Esempio n. 11
0
/* Takes care of merging natural loops with shared headers.  */
static void
canonicalize_loop_headers (void)
{
  basic_block header;
  edge e;

  /* Compute the dominators.  */
  calculate_dominance_info (CDI_DOMINATORS);

  alloc_aux_for_blocks (sizeof (int));
  alloc_aux_for_edges (sizeof (int));

  /* Split blocks so that each loop has only single latch.  */
  FOR_EACH_BB (header)
    {
      int num_latches = 0;
      int have_abnormal_edge = 0;

      for (e = header->pred; e; e = e->pred_next)
	{
	  basic_block latch = e->src;

	  if (e->flags & EDGE_ABNORMAL)
	    have_abnormal_edge = 1;

	  if (latch != ENTRY_BLOCK_PTR
	      && dominated_by_p (CDI_DOMINATORS, latch, header))
	    {
	      num_latches++;
	      LATCH_EDGE (e) = 1;
	    }
	}
      if (have_abnormal_edge)
	HEADER_BLOCK (header) = 0;
      else
	HEADER_BLOCK (header) = num_latches;
    }

  free_dominance_info (CDI_DOMINATORS);

  if (HEADER_BLOCK (ENTRY_BLOCK_PTR->succ->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);

      alloc_aux_for_edge (bb->succ, sizeof (int));
      LATCH_EDGE (bb->succ) = 0;
      alloc_aux_for_block (bb, sizeof (int));
      HEADER_BLOCK (bb) = 0;
    }

  FOR_EACH_BB (header)
    {
      int num_latch;
      int want_join_latch;
      int max_freq, is_heavy;
      edge heavy;

      if (!HEADER_BLOCK (header))
	continue;

      num_latch = HEADER_BLOCK (header);

      want_join_latch = (num_latch > 1);

      if (!want_join_latch)
	continue;

      /* Find a heavy edge.  */
      is_heavy = 1;
      heavy = NULL;
      max_freq = 0;
      for (e = header->pred; e; e = e->pred_next)
	if (LATCH_EDGE (e) &&
	    EDGE_FREQUENCY (e) > max_freq)
	  max_freq = EDGE_FREQUENCY (e);
      for (e = header->pred; e; e = e->pred_next)
	if (LATCH_EDGE (e) &&
	    EDGE_FREQUENCY (e) >= max_freq / HEAVY_EDGE_RATIO)
	  {
	    if (heavy)
	      {
		is_heavy = 0;
		break;
	      }
	    else
	      heavy = e;
	  }

      if (is_heavy)
	{
	  basic_block new_header =
	    make_forwarder_block (header, true, true, heavy, 0);
	  if (num_latch > 2)
	    make_forwarder_block (new_header, true, false, NULL, 1);
	}
      else
	make_forwarder_block (header, true, false, NULL, 1);
    }

  free_aux_for_blocks ();
  free_aux_for_edges ();
}
Esempio n. 12
0
static void
connect_traces (int n_traces, struct trace *traces)
{
  int i;
  bool *connected;
  int last_trace;
  int freq_threshold;
  gcov_type count_threshold;

  freq_threshold = max_entry_frequency * DUPLICATION_THRESHOLD / 1000;
  if (max_entry_count < INT_MAX / 1000)
    count_threshold = max_entry_count * DUPLICATION_THRESHOLD / 1000;
  else
    count_threshold = max_entry_count / 1000 * DUPLICATION_THRESHOLD;

  connected = xcalloc (n_traces, sizeof (bool));
  last_trace = -1;
  for (i = 0; i < n_traces; i++)
    {
      int t = i;
      int t2;
      edge e, best;
      int best_len;

      if (connected[t])
	continue;

      connected[t] = true;

      /* Find the predecessor traces.  */
      for (t2 = t; t2 > 0;)
	{
	  best = NULL;
	  best_len = 0;
	  for (e = traces[t2].first->pred; e; e = e->pred_next)
	    {
	      int si = e->src->index;

	      if (e->src != ENTRY_BLOCK_PTR
		  && (e->flags & EDGE_CAN_FALLTHRU)
		  && !(e->flags & EDGE_COMPLEX)
		  && bbd[si].end_of_trace >= 0
		  && !connected[bbd[si].end_of_trace]
		  && (!best
		      || e->probability > best->probability
		      || (e->probability == best->probability
			  && traces[bbd[si].end_of_trace].length > best_len)))
		{
		  best = e;
		  best_len = traces[bbd[si].end_of_trace].length;
		}
	    }
	  if (best)
	    {
	      best->src->rbi->next = best->dest;
	      t2 = bbd[best->src->index].end_of_trace;
	      connected[t2] = true;
	      if (rtl_dump_file)
		{
		  fprintf (rtl_dump_file, "Connection: %d %d\n",
			   best->src->index, best->dest->index);
		}
	    }
	  else
	    break;
	}

      if (last_trace >= 0)
	traces[last_trace].last->rbi->next = traces[t2].first;
      last_trace = t;

      /* Find the successor traces.  */
      while (1)
	{
	  /* Find the continuation of the chain.  */
	  best = NULL;
	  best_len = 0;
	  for (e = traces[t].last->succ; e; e = e->succ_next)
	    {
	      int di = e->dest->index;

	      if (e->dest != EXIT_BLOCK_PTR
		  && (e->flags & EDGE_CAN_FALLTHRU)
		  && !(e->flags & EDGE_COMPLEX)
		  && bbd[di].start_of_trace >= 0
		  && !connected[bbd[di].start_of_trace]
		  && (!best
		      || e->probability > best->probability
		      || (e->probability == best->probability
			  && traces[bbd[di].start_of_trace].length > best_len)))
		{
		  best = e;
		  best_len = traces[bbd[di].start_of_trace].length;
		}
	    }

	  if (best)
	    {
	      if (rtl_dump_file)
		{
		  fprintf (rtl_dump_file, "Connection: %d %d\n",
			   best->src->index, best->dest->index);
		}
	      t = bbd[best->dest->index].start_of_trace;
	      traces[last_trace].last->rbi->next = traces[t].first;
	      connected[t] = true;
	      last_trace = t;
	    }
	  else
	    {
	      /* Try to connect the traces by duplication of 1 block.  */
	      edge e2;
	      basic_block next_bb = NULL;
	      bool try_copy = false;

	      for (e = traces[t].last->succ; e; e = e->succ_next)
		if (e->dest != EXIT_BLOCK_PTR
		    && (e->flags & EDGE_CAN_FALLTHRU)
		    && !(e->flags & EDGE_COMPLEX)
		    && (!best || e->probability > best->probability))
		  {
		    edge best2 = NULL;
		    int best2_len = 0;

		    /* If the destination is a start of a trace which is only
		       one block long, then no need to search the successor
		       blocks of the trace.  Accept it.  */
		    if (bbd[e->dest->index].start_of_trace >= 0
			&& traces[bbd[e->dest->index].start_of_trace].length
			   == 1)
		      {
			best = e;
			try_copy = true;
			continue;
		      }

		    for (e2 = e->dest->succ; e2; e2 = e2->succ_next)
		      {
			int di = e2->dest->index;

			if (e2->dest == EXIT_BLOCK_PTR
			    || ((e2->flags & EDGE_CAN_FALLTHRU)
				&& !(e2->flags & EDGE_COMPLEX)
				&& bbd[di].start_of_trace >= 0
				&& !connected[bbd[di].start_of_trace]
				&& (EDGE_FREQUENCY (e2) >= freq_threshold)
				&& (e2->count >= count_threshold)
				&& (!best2
				    || e2->probability > best2->probability
				    || (e2->probability == best2->probability
					&& traces[bbd[di].start_of_trace].length
					   > best2_len))))
			  {
			    best = e;
			    best2 = e2;
			    if (e2->dest != EXIT_BLOCK_PTR)
			      best2_len = traces[bbd[di].start_of_trace].length;
			    else
			      best2_len = INT_MAX;
			    next_bb = e2->dest;
			    try_copy = true;
			  }
		      }
		  }

	      /* Copy tiny blocks always; copy larger blocks only when the
		 edge is traversed frequently enough.  */
	      if (try_copy
		  && copy_bb_p (best->dest,
				!optimize_size
				&& EDGE_FREQUENCY (best) >= freq_threshold
				&& best->count >= count_threshold))
		{
		  basic_block new_bb;

		  if (rtl_dump_file)
		    {
		      fprintf (rtl_dump_file, "Connection: %d %d ",
			       traces[t].last->index, best->dest->index);
		      if (!next_bb)
			fputc ('\n', rtl_dump_file);
		      else if (next_bb == EXIT_BLOCK_PTR)
			fprintf (rtl_dump_file, "exit\n");
		      else
			fprintf (rtl_dump_file, "%d\n", next_bb->index);
		    }

		  new_bb = copy_bb (best->dest, best, traces[t].last, t);
		  traces[t].last = new_bb;
		  if (next_bb && next_bb != EXIT_BLOCK_PTR)
		    {
		      t = bbd[next_bb->index].start_of_trace;
		      traces[last_trace].last->rbi->next = traces[t].first;
		      connected[t] = true;
		      last_trace = t;
		    }
		  else
		    break;	/* Stop finding the successor traces.  */
		}
	      else
		break;	/* Stop finding the successor traces.  */
	    }
	}
    }

  if (rtl_dump_file)
    {
      basic_block bb;

      fprintf (rtl_dump_file, "Final order:\n");
      for (bb = traces[0].first; bb; bb = bb->rbi->next)
	fprintf (rtl_dump_file, "%d ", bb->index);
      fprintf (rtl_dump_file, "\n");
      fflush (rtl_dump_file);
    }

  FREE (connected);
}
Esempio n. 13
0
static void
find_traces_1_round (int branch_th, int exec_th, gcov_type count_th,
		     struct trace *traces, int *n_traces, int round,
		     fibheap_t *heap)
{
  /* Heap for discarded basic blocks which are possible starting points for
     the next round.  */
  fibheap_t new_heap = fibheap_new ();

  while (!fibheap_empty (*heap))
    {
      basic_block bb;
      struct trace *trace;
      edge best_edge, e;
      fibheapkey_t key;

      bb = fibheap_extract_min (*heap);
      bbd[bb->index].heap = NULL;
      bbd[bb->index].node = NULL;

      if (rtl_dump_file)
	fprintf (rtl_dump_file, "Getting bb %d\n", bb->index);

      /* If the BB's frequency is too low send BB to the next round.  */
      if (round < N_ROUNDS - 1
	  && (bb->frequency < exec_th || bb->count < count_th
	      || probably_never_executed_bb_p (bb)))
	{
	  int key = bb_to_key (bb);
	  bbd[bb->index].heap = new_heap;
	  bbd[bb->index].node = fibheap_insert (new_heap, key, bb);

	  if (rtl_dump_file)
	    fprintf (rtl_dump_file,
		     "  Possible start point of next round: %d (key: %d)\n",
		     bb->index, key);
	  continue;
	}

      trace = traces + *n_traces;
      trace->first = bb;
      trace->round = round;
      trace->length = 0;
      (*n_traces)++;

      do
	{
	  int prob, freq;

	  /* The probability and frequency of the best edge.  */
	  int best_prob = INT_MIN / 2;
	  int best_freq = INT_MIN / 2;

	  best_edge = NULL;
	  mark_bb_visited (bb, *n_traces);
	  trace->length++;

	  if (rtl_dump_file)
	    fprintf (rtl_dump_file, "Basic block %d was visited in trace %d\n",
		     bb->index, *n_traces - 1);

	  /* Select the successor that will be placed after BB.  */
	  for (e = bb->succ; e; e = e->succ_next)
	    {
#ifdef ENABLE_CHECKING
	      if (e->flags & EDGE_FAKE)
		abort ();
#endif

	      if (e->dest == EXIT_BLOCK_PTR)
		continue;

	      if (e->dest->rbi->visited
		  && e->dest->rbi->visited != *n_traces)
		continue;

	      prob = e->probability;
	      freq = EDGE_FREQUENCY (e);

	      /* Edge that cannot be fallthru or improbable or infrequent
		 successor (ie. it is unsuitable successor).  */
	      if (!(e->flags & EDGE_CAN_FALLTHRU) || (e->flags & EDGE_COMPLEX)
		  || prob < branch_th || freq < exec_th || e->count < count_th)
		continue;

	      if (better_edge_p (bb, e, prob, freq, best_prob, best_freq))
		{
		  best_edge = e;
		  best_prob = prob;
		  best_freq = freq;
		}
	    }

	  /* If the best destination has multiple predecessors, and can be
	     duplicated cheaper than a jump, don't allow it to be added
	     to a trace.  We'll duplicate it when connecting traces.  */
	  if (best_edge && best_edge->dest->pred->pred_next
	      && copy_bb_p (best_edge->dest, 0))
	    best_edge = NULL;

	  /* Add all non-selected successors to the heaps.  */
	  for (e = bb->succ; e; e = e->succ_next)
	    {
	      if (e == best_edge
		  || e->dest == EXIT_BLOCK_PTR
		  || e->dest->rbi->visited)
		continue;

	      key = bb_to_key (e->dest);

	      if (bbd[e->dest->index].heap)
		{
		  /* E->DEST is already in some heap.  */
		  if (key != bbd[e->dest->index].node->key)
		    {
		      if (rtl_dump_file)
			{
			  fprintf (rtl_dump_file,
				   "Changing key for bb %d from %ld to %ld.\n",
				   e->dest->index,
				   (long) bbd[e->dest->index].node->key,
				   key);
			}
		      fibheap_replace_key (bbd[e->dest->index].heap,
					   bbd[e->dest->index].node, key);
		    }
		}
	      else
		{
		  fibheap_t which_heap = *heap;

		  prob = e->probability;
		  freq = EDGE_FREQUENCY (e);

		  if (!(e->flags & EDGE_CAN_FALLTHRU)
		      || (e->flags & EDGE_COMPLEX)
		      || prob < branch_th || freq < exec_th
		      || e->count < count_th)
		    {
		      if (round < N_ROUNDS - 1)
			which_heap = new_heap;
		    }

		  bbd[e->dest->index].heap = which_heap;
		  bbd[e->dest->index].node = fibheap_insert (which_heap,
								key, e->dest);

		  if (rtl_dump_file)
		    {
		      fprintf (rtl_dump_file,
			       "  Possible start of %s round: %d (key: %ld)\n",
			       (which_heap == new_heap) ? "next" : "this",
			       e->dest->index, (long) key);
		    }

		}
	    }

	  if (best_edge) /* Suitable successor was found.  */
	    {
	      if (best_edge->dest->rbi->visited == *n_traces)
		{
		  /* We do nothing with one basic block loops.  */
		  if (best_edge->dest != bb)
		    {
		      if (EDGE_FREQUENCY (best_edge)
			  > 4 * best_edge->dest->frequency / 5)
			{
			  /* The loop has at least 4 iterations.  If the loop
			     header is not the first block of the function
			     we can rotate the loop.  */

			  if (best_edge->dest != ENTRY_BLOCK_PTR->next_bb)
			    {
			      if (rtl_dump_file)
				{
				  fprintf (rtl_dump_file,
					   "Rotating loop %d - %d\n",
					   best_edge->dest->index, bb->index);
				}
			      bb->rbi->next = best_edge->dest;
			      bb = rotate_loop (best_edge, trace, *n_traces);
			    }
			}
		      else
			{
			  /* The loop has less than 4 iterations.  */

			  /* Check whether there is another edge from BB.  */
			  edge another_edge;
			  for (another_edge = bb->succ;
			       another_edge;
			       another_edge = another_edge->succ_next)
			    if (another_edge != best_edge)
			      break;

			  if (!another_edge && copy_bb_p (best_edge->dest,
							  !optimize_size))
			    {
			      bb = copy_bb (best_edge->dest, best_edge, bb,
					    *n_traces);
			    }
			}
		    }

		  /* Terminate the trace.  */
		  break;
		}
	      else
		{
		  /* Check for a situation

		    A
		   /|
		  B |
		   \|
		    C

		  where
		  EDGE_FREQUENCY (AB) + EDGE_FREQUENCY (BC)
		    >= EDGE_FREQUENCY (AC).
		  (i.e. 2 * B->frequency >= EDGE_FREQUENCY (AC) )
		  Best ordering is then A B C.

		  This situation is created for example by:

		  if (A) B;
		  C;

		  */

		  for (e = bb->succ; e; e = e->succ_next)
		    if (e != best_edge
			&& (e->flags & EDGE_CAN_FALLTHRU)
			&& !(e->flags & EDGE_COMPLEX)
			&& !e->dest->rbi->visited
			&& !e->dest->pred->pred_next
			&& e->dest->succ
			&& (e->dest->succ->flags & EDGE_CAN_FALLTHRU)
			&& !(e->dest->succ->flags & EDGE_COMPLEX)
			&& !e->dest->succ->succ_next
			&& e->dest->succ->dest == best_edge->dest
			&& 2 * e->dest->frequency >= EDGE_FREQUENCY (best_edge))
		      {
			best_edge = e;
			if (rtl_dump_file)
			  fprintf (rtl_dump_file, "Selecting BB %d\n",
				   best_edge->dest->index);
			break;
		      }

		  bb->rbi->next = best_edge->dest;
		  bb = best_edge->dest;
		}
	    }
	}
      while (best_edge);
      trace->last = bb;
      bbd[trace->first->index].start_of_trace = *n_traces - 1;
      bbd[trace->last->index].end_of_trace = *n_traces - 1;

      /* The trace is terminated so we have to recount the keys in heap
	 (some block can have a lower key because now one of its predecessors
	 is an end of the trace).  */
      for (e = bb->succ; e; e = e->succ_next)
	{
	  if (e->dest == EXIT_BLOCK_PTR
	      || e->dest->rbi->visited)
	    continue;

	  if (bbd[e->dest->index].heap)
	    {
	      key = bb_to_key (e->dest);
	      if (key != bbd[e->dest->index].node->key)
		{
		  if (rtl_dump_file)
		    {
		      fprintf (rtl_dump_file,
			       "Changing key for bb %d from %ld to %ld.\n",
			       e->dest->index,
			       (long) bbd[e->dest->index].node->key, key);
		    }
		  fibheap_replace_key (bbd[e->dest->index].heap,
				       bbd[e->dest->index].node,
				       key);
		}
	    }
	}
    }

  fibheap_delete (*heap);

  /* "Return" the new heap.  */
  *heap = new_heap;
}
Esempio n. 14
0
static basic_block
expand_gimple_tailcall (basic_block bb, tree stmt, bool *can_fallthru)
{
  rtx last2, last;
  edge e;
  edge_iterator ei;
  int probability;
  gcov_type count;

  last2 = last = get_last_insn ();

  expand_expr_stmt (stmt);

  for (last = NEXT_INSN (last); last; last = NEXT_INSN (last))
    if (CALL_P (last) && SIBLING_CALL_P (last))
      goto found;

  maybe_dump_rtl_for_tree_stmt (stmt, last2);

  *can_fallthru = true;
  return NULL;

 found:
  /* ??? Wouldn't it be better to just reset any pending stack adjust?
     Any instructions emitted here are about to be deleted.  */
  do_pending_stack_adjust ();

  /* Remove any non-eh, non-abnormal edges that don't go to exit.  */
  /* ??? I.e. the fallthrough edge.  HOWEVER!  If there were to be
     EH or abnormal edges, we shouldn't have created a tail call in
     the first place.  So it seems to me we should just be removing
     all edges here, or redirecting the existing fallthru edge to
     the exit block.  */

  probability = 0;
  count = 0;

  for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
    {
      if (!(e->flags & (EDGE_ABNORMAL | EDGE_EH)))
	{
	  if (e->dest != EXIT_BLOCK_PTR)
	    {
	      e->dest->count -= e->count;
	      e->dest->frequency -= EDGE_FREQUENCY (e);
	      if (e->dest->count < 0)
	        e->dest->count = 0;
	      if (e->dest->frequency < 0)
	        e->dest->frequency = 0;
	    }
	  count += e->count;
	  probability += e->probability;
	  remove_edge (e);
	}
      else
	ei_next (&ei);
    }

  /* This is somewhat ugly: the call_expr expander often emits instructions
     after the sibcall (to perform the function return).  These confuse the
     find_sub_basic_blocks code, so we need to get rid of these.  */
  last = NEXT_INSN (last);
  gcc_assert (BARRIER_P (last));

  *can_fallthru = false;
  while (NEXT_INSN (last))
    {
      /* For instance an sqrt builtin expander expands if with
	 sibcall in the then and label for `else`.  */
      if (LABEL_P (NEXT_INSN (last)))
	{
	  *can_fallthru = true;
	  break;
	}
      delete_insn (NEXT_INSN (last));
    }

  e = make_edge (bb, EXIT_BLOCK_PTR, EDGE_ABNORMAL | EDGE_SIBCALL);
  e->probability += probability;
  e->count += count;
  BB_END (bb) = last;
  update_bb_for_insn (bb);

  if (NEXT_INSN (last))
    {
      bb = create_basic_block (NEXT_INSN (last), get_last_insn (), bb);

      last = BB_END (bb);
      if (BARRIER_P (last))
	BB_END (bb) = PREV_INSN (last);
    }

  maybe_dump_rtl_for_tree_stmt (stmt, last2);

  return bb;
}
Esempio n. 15
0
static basic_block
expand_gimple_cond_expr (basic_block bb, tree stmt)
{
  basic_block new_bb, dest;
  edge new_edge;
  edge true_edge;
  edge false_edge;
  tree pred = COND_EXPR_COND (stmt);
  tree then_exp = COND_EXPR_THEN (stmt);
  tree else_exp = COND_EXPR_ELSE (stmt);
  rtx last2, last;

  last2 = last = get_last_insn ();

  extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
  if (EXPR_LOCUS (stmt))
    {
      emit_line_note (*(EXPR_LOCUS (stmt)));
      record_block_change (TREE_BLOCK (stmt));
    }

  /* These flags have no purpose in RTL land.  */
  true_edge->flags &= ~EDGE_TRUE_VALUE;
  false_edge->flags &= ~EDGE_FALSE_VALUE;

  /* We can either have a pure conditional jump with one fallthru edge or
     two-way jump that needs to be decomposed into two basic blocks.  */
  if (TREE_CODE (then_exp) == GOTO_EXPR && IS_EMPTY_STMT (else_exp))
    {
      jumpif (pred, label_rtx (GOTO_DESTINATION (then_exp)));
      add_reg_br_prob_note (dump_file, last, true_edge->probability);
      maybe_dump_rtl_for_tree_stmt (stmt, last);
      if (EXPR_LOCUS (then_exp))
	emit_line_note (*(EXPR_LOCUS (then_exp)));
      return NULL;
    }
  if (TREE_CODE (else_exp) == GOTO_EXPR && IS_EMPTY_STMT (then_exp))
    {
      jumpifnot (pred, label_rtx (GOTO_DESTINATION (else_exp)));
      add_reg_br_prob_note (dump_file, last, false_edge->probability);
      maybe_dump_rtl_for_tree_stmt (stmt, last);
      if (EXPR_LOCUS (else_exp))
	emit_line_note (*(EXPR_LOCUS (else_exp)));
      return NULL;
    }
  gcc_assert (TREE_CODE (then_exp) == GOTO_EXPR
	      && TREE_CODE (else_exp) == GOTO_EXPR);

  jumpif (pred, label_rtx (GOTO_DESTINATION (then_exp)));
  add_reg_br_prob_note (dump_file, last, true_edge->probability);
  last = get_last_insn ();
  expand_expr (else_exp, const0_rtx, VOIDmode, 0);

  BB_END (bb) = last;
  if (BARRIER_P (BB_END (bb)))
    BB_END (bb) = PREV_INSN (BB_END (bb));
  update_bb_for_insn (bb);

  new_bb = create_basic_block (NEXT_INSN (last), get_last_insn (), bb);
  dest = false_edge->dest;
  redirect_edge_succ (false_edge, new_bb);
  false_edge->flags |= EDGE_FALLTHRU;
  new_bb->count = false_edge->count;
  new_bb->frequency = EDGE_FREQUENCY (false_edge);
  new_edge = make_edge (new_bb, dest, 0);
  new_edge->probability = REG_BR_PROB_BASE;
  new_edge->count = new_bb->count;
  if (BARRIER_P (BB_END (new_bb)))
    BB_END (new_bb) = PREV_INSN (BB_END (new_bb));
  update_bb_for_insn (new_bb);

  maybe_dump_rtl_for_tree_stmt (stmt, last2);
  
  if (EXPR_LOCUS (else_exp))
    emit_line_note (*(EXPR_LOCUS (else_exp)));

  return new_bb;
}
Esempio n. 16
0
static void
construct_exit_block (void)
{
  rtx head = get_last_insn ();
  rtx end;
  basic_block exit_block;
  edge e, e2;
  unsigned ix;
  edge_iterator ei;

  /* Make sure the locus is set to the end of the function, so that
     epilogue line numbers and warnings are set properly.  */
#ifdef USE_MAPPED_LOCATION
  if (cfun->function_end_locus != UNKNOWN_LOCATION)
#else
  if (cfun->function_end_locus.file)
#endif
    input_location = cfun->function_end_locus;

  /* The following insns belong to the top scope.  */
  record_block_change (DECL_INITIAL (current_function_decl));

  /* Generate rtl for function exit.  */
  expand_function_end ();

  end = get_last_insn ();
  if (head == end)
    return;
  while (NEXT_INSN (head) && NOTE_P (NEXT_INSN (head)))
    head = NEXT_INSN (head);
  exit_block = create_basic_block (NEXT_INSN (head), end,
				   EXIT_BLOCK_PTR->prev_bb);
  exit_block->frequency = EXIT_BLOCK_PTR->frequency;
  exit_block->count = EXIT_BLOCK_PTR->count;

  ix = 0;
  while (ix < EDGE_COUNT (EXIT_BLOCK_PTR->preds))
    {
      e = EDGE_I (EXIT_BLOCK_PTR->preds, ix);
      if (!(e->flags & EDGE_ABNORMAL))
	redirect_edge_succ (e, exit_block);
      else
	ix++;
    }

  e = make_edge (exit_block, EXIT_BLOCK_PTR, EDGE_FALLTHRU);
  e->probability = REG_BR_PROB_BASE;
  e->count = EXIT_BLOCK_PTR->count;
  FOR_EACH_EDGE (e2, ei, EXIT_BLOCK_PTR->preds)
    if (e2 != e)
      {
        e->count -= e2->count;
	exit_block->count -= e2->count;
	exit_block->frequency -= EDGE_FREQUENCY (e2);
      }
  if (e->count < 0)
    e->count = 0;
  if (exit_block->count < 0)
    exit_block->count = 0;
  if (exit_block->frequency < 0)
    exit_block->frequency = 0;
  update_bb_for_insn (exit_block);
}
Esempio n. 17
0
basic_block
cfg_layout_duplicate_bb (basic_block bb, edge e)
{
  rtx insn;
  edge s, n;
  basic_block new_bb;
  gcov_type new_count = e ? e->count : 0;

  if (bb->count < new_count)
    new_count = bb->count;
  if (!bb->pred)
    abort ();
#ifdef ENABLE_CHECKING
  if (!cfg_layout_can_duplicate_bb_p (bb))
    abort ();
#endif

  insn = duplicate_insn_chain (BB_HEAD (bb), BB_END (bb));
  new_bb = create_basic_block (insn,
			       insn ? get_last_insn () : NULL,
			       EXIT_BLOCK_PTR->prev_bb);

  if (bb->rbi->header)
    {
      insn = bb->rbi->header;
      while (NEXT_INSN (insn))
	insn = NEXT_INSN (insn);
      insn = duplicate_insn_chain (bb->rbi->header, insn);
      if (insn)
	new_bb->rbi->header = unlink_insn_chain (insn, get_last_insn ());
    }

  if (bb->rbi->footer)
    {
      insn = bb->rbi->footer;
      while (NEXT_INSN (insn))
	insn = NEXT_INSN (insn);
      insn = duplicate_insn_chain (bb->rbi->footer, insn);
      if (insn)
	new_bb->rbi->footer = unlink_insn_chain (insn, get_last_insn ());
    }

  if (bb->global_live_at_start)
    {
      new_bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack);
      new_bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack);
      COPY_REG_SET (new_bb->global_live_at_start, bb->global_live_at_start);
      COPY_REG_SET (new_bb->global_live_at_end, bb->global_live_at_end);
    }

  new_bb->loop_depth = bb->loop_depth;
  new_bb->flags = bb->flags;
  for (s = bb->succ; s; s = s->succ_next)
    {
      /* 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;
    }

  new_bb->rbi->original = bb;
  bb->rbi->copy = new_bb;

  return new_bb;
}