Пример #1
0
int main()
{
	uv_idle_t idler;

    uv_idle_init(get_loop(), &idler);
    uv_idle_start(&idler, wait_for_a_while);


    printf("Now quitting.\n");
    uv_run(get_loop(), UV_RUN_DEFAULT);

    return 0;
}
Пример #2
0
//------------------------------register_new_node------------------------------
void PhaseIdealLoop::register_new_node( Node *n, Node *blk ) {
  _igvn.register_new_node_with_optimizer(n);
  set_ctrl(n, blk);
  IdealLoopTree *loop = get_loop(blk);
  if( !loop->_child )
    loop->_body.push(n);
}
Пример #3
0
//------------------------------split_thru_region------------------------------
// Split Node 'n' through merge point.
Node *PhaseIdealLoop::split_thru_region( Node *n, Node *region ) {
  uint wins = 0;
  assert( n->is_CFG(), "" );
  assert( region->is_Region(), "" );
  Node *r = new (C, region->req()) RegionNode( region->req() );
  IdealLoopTree *loop = get_loop( n );
  for( uint i = 1; i < region->req(); i++ ) {
    Node *x = n->clone();
    Node *in0 = n->in(0);
    if( in0->in(0) == region ) x->set_req( 0, in0->in(i) );
    for( uint j = 1; j < n->req(); j++ ) {
      Node *in = n->in(j);
      if( get_ctrl(in) == region )
        x->set_req( j, in->in(i) );
    }
    _igvn.register_new_node_with_optimizer(x);
    set_loop(x, loop);
    set_idom(x, x->in(0), dom_depth(x->in(0))+1);
    r->init_req(i, x);
  }

  // Record region
  r->set_req(0,region);         // Not a TRUE RegionNode
  _igvn.register_new_node_with_optimizer(r);
  set_loop(r, loop);
  if( !loop->_child )
    loop->_body.push(r);
  return r;
}
Пример #4
0
tree
reset_evolution_in_loop (unsigned loop_num,
			 tree chrec,
			 tree new_evol)
{
  struct loop *loop = get_loop (cfun, loop_num);

  if (POINTER_TYPE_P (chrec_type (chrec)))
    gcc_assert (ptrofftype_p (chrec_type (new_evol)));
  else
    gcc_assert (chrec_type (chrec) == chrec_type (new_evol));

  if (TREE_CODE (chrec) == POLYNOMIAL_CHREC
      && flow_loop_nested_p (loop, get_chrec_loop (chrec)))
    {
      tree left = reset_evolution_in_loop (loop_num, CHREC_LEFT (chrec),
					   new_evol);
      tree right = reset_evolution_in_loop (loop_num, CHREC_RIGHT (chrec),
					    new_evol);
      return build3 (POLYNOMIAL_CHREC, TREE_TYPE (left),
		     CHREC_VAR (chrec), left, right);
    }

  while (TREE_CODE (chrec) == POLYNOMIAL_CHREC
	 && CHREC_VARIABLE (chrec) == loop_num)
    chrec = CHREC_LEFT (chrec);

  return build_polynomial_chrec (loop_num, chrec, new_evol);
}
Пример #5
0
tree
hide_evolution_in_other_loops_than_loop (tree chrec,
					 unsigned loop_num)
{
  struct loop *loop = get_loop (cfun, loop_num), *chloop;
  if (automatically_generated_chrec_p (chrec))
    return chrec;

  switch (TREE_CODE (chrec))
    {
    case POLYNOMIAL_CHREC:
      chloop = get_chrec_loop (chrec);

      if (chloop == loop)
	return build_polynomial_chrec
	  (loop_num,
	   hide_evolution_in_other_loops_than_loop (CHREC_LEFT (chrec),
						    loop_num),
	   CHREC_RIGHT (chrec));

      else if (flow_loop_nested_p (chloop, loop))
	/* There is no evolution in this loop.  */
	return initial_condition (chrec);

      else
	{
	  gcc_assert (flow_loop_nested_p (loop, chloop));
	  return hide_evolution_in_other_loops_than_loop (CHREC_LEFT (chrec),
							  loop_num);
	}

    default:
      return chrec;
    }
}
Пример #6
0
static tree
chrec_evaluate (unsigned var, tree chrec, tree n, unsigned int k)
{
  tree arg0, arg1, binomial_n_k;
  tree type = TREE_TYPE (chrec);
  struct loop *var_loop = get_loop (cfun, var);

  while (TREE_CODE (chrec) == POLYNOMIAL_CHREC
	 && flow_loop_nested_p (var_loop, get_chrec_loop (chrec)))
    chrec = CHREC_LEFT (chrec);

  if (TREE_CODE (chrec) == POLYNOMIAL_CHREC
      && CHREC_VARIABLE (chrec) == var)
    {
      arg1 = chrec_evaluate (var, CHREC_RIGHT (chrec), n, k + 1);
      if (arg1 == chrec_dont_know)
	return chrec_dont_know;
      binomial_n_k = tree_fold_binomial (type, n, k);
      if (!binomial_n_k)
	return chrec_dont_know;
      arg0 = fold_build2 (MULT_EXPR, type,
			  CHREC_LEFT (chrec), binomial_n_k);
      return chrec_fold_plus (type, arg0, arg1);
    }

  binomial_n_k = tree_fold_binomial (type, n, k);
  if (!binomial_n_k)
    return chrec_dont_know;

  return fold_build2 (MULT_EXPR, type, chrec, binomial_n_k);
}
Пример #7
0
static int loop_destroy(lua_State *L) {
    loop_t *lo = get_loop(L, 1);
    struct ev_loop* loop = lo->loop;
    if(loop) {
        lo->loop = 0;
        ev_loop_destroy(loop);
    }
    return 0;
}
Пример #8
0
static bool
evolution_function_is_invariant_rec_p (tree chrec, int loopnum)
{
  if (evolution_function_is_constant_p (chrec))
    return true;

  if (TREE_CODE (chrec) == SSA_NAME
      && (loopnum == 0
	  || expr_invariant_in_loop_p (get_loop (cfun, loopnum), chrec)))
    return true;

  if (TREE_CODE (chrec) == POLYNOMIAL_CHREC)
    {
      if (CHREC_VARIABLE (chrec) == (unsigned) loopnum
	  || flow_loop_nested_p (get_loop (cfun, loopnum),
				 get_chrec_loop (chrec))
	  || !evolution_function_is_invariant_rec_p (CHREC_RIGHT (chrec),
						     loopnum)
	  || !evolution_function_is_invariant_rec_p (CHREC_LEFT (chrec),
						     loopnum))
	return false;
      return true;
    }

  switch (TREE_OPERAND_LENGTH (chrec))
    {
    case 2:
      if (!evolution_function_is_invariant_rec_p (TREE_OPERAND (chrec, 1),
						  loopnum))
	return false;

    case 1:
      if (!evolution_function_is_invariant_rec_p (TREE_OPERAND (chrec, 0),
						  loopnum))
	return false;
      return true;

    default:
      return false;
    }

  return false;
}
Пример #9
0
static tree
chrec_component_in_loop_num (tree chrec,
			     unsigned loop_num,
			     bool right)
{
  tree component;
  struct loop *loop = get_loop (cfun, loop_num), *chloop;

  if (automatically_generated_chrec_p (chrec))
    return chrec;

  switch (TREE_CODE (chrec))
    {
    case POLYNOMIAL_CHREC:
      chloop = get_chrec_loop (chrec);

      if (chloop == loop)
	{
	  if (right)
	    component = CHREC_RIGHT (chrec);
	  else
	    component = CHREC_LEFT (chrec);

	  if (TREE_CODE (CHREC_LEFT (chrec)) != POLYNOMIAL_CHREC
	      || CHREC_VARIABLE (CHREC_LEFT (chrec)) != CHREC_VARIABLE (chrec))
	    return component;

	  else
	    return build_polynomial_chrec
	      (loop_num,
	       chrec_component_in_loop_num (CHREC_LEFT (chrec),
					    loop_num,
					    right),
	       component);
	}

      else if (flow_loop_nested_p (chloop, loop))
	/* There is no evolution part in this loop.  */
	return NULL_TREE;

      else
	{
	  gcc_assert (flow_loop_nested_p (loop, chloop));
	  return chrec_component_in_loop_num (CHREC_LEFT (chrec),
					      loop_num,
					      right);
	}

     default:
      if (right)
	return NULL_TREE;
      else
	return chrec;
    }
}
Пример #10
0
// L statck:
//  4: ud
//  3: cb
//  2: flags
//  1: loop
static int loop_run(lua_State *L) {
    struct ev_loop *loop;
    loop_t *lo = get_loop(L, 1);
    int flags = luaL_checkinteger(L, 2);
    luaL_checktype(L, 3, LUA_TFUNCTION);
    luaL_checkany(L, 4);
    lua_pushcfunction(L, traceback);

    loop = lo->loop;
    ev_set_userdata(loop, L);
    lua_pushboolean(L, ev_run(loop, flags));
    ev_set_userdata(loop, NULL);
    return 1;
}
Пример #11
0
int main(int argc, char **argv)
{
	int ret;
	if(sigaction(SIGINT, &sigact, NULL) < 0 ||
		sigaction(SIGTERM, &sigact, NULL) < 0) {
		perror("Error installing signal handler");
		return 1;
	}

	if(initialise_options(&opt, argc, argv) < 0)
		return 1;

	ret = get_loop(&opt);

	destroy_options(&opt);
	return ret;

}
Пример #12
0
static int timer_again(lua_State *L) {
    ev_timer *w = get_timer(L, 1);
    loop_t *lo = get_loop(L, 2);
    ev_timer_again(lo->loop, w);
    return 0;
}
Пример #13
0
//------------------------------create_new_if_for_predicate------------------------
// create a new if above the uct_if_pattern for the predicate to be promoted.
//
//          before                                after
//        ----------                           ----------
//           ctrl                                 ctrl
//            |                                     |
//            |                                     |
//            v                                     v
//           iff                                 new_iff
//          /    \                                /      \
//         /      \                              /        \
//        v        v                            v          v
//  uncommon_proj cont_proj                   if_uct     if_cont
// \      |        |                           |          |
//  \     |        |                           |          |
//   v    v        v                           |          v
//     rgn       loop                          |         iff
//      |                                      |        /     \
//      |                                      |       /       \
//      v                                      |      v         v
// uncommon_trap                               | uncommon_proj cont_proj
//                                           \  \    |           |
//                                            \  \   |           |
//                                             v  v  v           v
//                                               rgn           loop
//                                                |
//                                                |
//                                                v
//                                           uncommon_trap
//
//
// We will create a region to guard the uct call if there is no one there.
// The true projecttion (if_cont) of the new_iff is returned.
// This code is also used to clone predicates to clonned loops.
ProjNode* PhaseIdealLoop::create_new_if_for_predicate(ProjNode* cont_proj, Node* new_entry,
                                                      Deoptimization::DeoptReason reason) {
  assert(is_uncommon_trap_if_pattern(cont_proj, reason), "must be a uct if pattern!");
  IfNode* iff = cont_proj->in(0)->as_If();

  ProjNode *uncommon_proj = iff->proj_out(1 - cont_proj->_con);
  Node     *rgn   = uncommon_proj->unique_ctrl_out();
  assert(rgn->is_Region() || rgn->is_Call(), "must be a region or call uct");

  uint proj_index = 1; // region's edge corresponding to uncommon_proj
  if (!rgn->is_Region()) { // create a region to guard the call
    assert(rgn->is_Call(), "must be call uct");
    CallNode* call = rgn->as_Call();
    IdealLoopTree* loop = get_loop(call);
    rgn = new (C) RegionNode(1);
    rgn->add_req(uncommon_proj);
    register_control(rgn, loop, uncommon_proj);
    _igvn.hash_delete(call);
    call->set_req(0, rgn);
    // When called from beautify_loops() idom is not constructed yet.
    if (_idom != NULL) {
      set_idom(call, rgn, dom_depth(rgn));
    }
  } else {
    // Find region's edge corresponding to uncommon_proj
    for (; proj_index < rgn->req(); proj_index++)
      if (rgn->in(proj_index) == uncommon_proj) break;
    assert(proj_index < rgn->req(), "sanity");
  }

  Node* entry = iff->in(0);
  if (new_entry != NULL) {
    // Clonning the predicate to new location.
    entry = new_entry;
  }
  // Create new_iff
  IdealLoopTree* lp = get_loop(entry);
  IfNode *new_iff = iff->clone()->as_If();
  new_iff->set_req(0, entry);
  register_control(new_iff, lp, entry);
  Node *if_cont = new (C) IfTrueNode(new_iff);
  Node *if_uct  = new (C) IfFalseNode(new_iff);
  if (cont_proj->is_IfFalse()) {
    // Swap
    Node* tmp = if_uct; if_uct = if_cont; if_cont = tmp;
  }
  register_control(if_cont, lp, new_iff);
  register_control(if_uct, get_loop(rgn), new_iff);

  // if_uct to rgn
  _igvn.hash_delete(rgn);
  rgn->add_req(if_uct);
  // When called from beautify_loops() idom is not constructed yet.
  if (_idom != NULL) {
    Node* ridom = idom(rgn);
    Node* nrdom = dom_lca(ridom, new_iff);
    set_idom(rgn, nrdom, dom_depth(rgn));
  }

  // If rgn has phis add new edges which has the same
  // value as on original uncommon_proj pass.
  assert(rgn->in(rgn->req() -1) == if_uct, "new edge should be last");
  bool has_phi = false;
  for (DUIterator_Fast imax, i = rgn->fast_outs(imax); i < imax; i++) {
    Node* use = rgn->fast_out(i);
    if (use->is_Phi() && use->outcnt() > 0) {
      assert(use->in(0) == rgn, "");
      _igvn.rehash_node_delayed(use);
      use->add_req(use->in(proj_index));
      has_phi = true;
    }
  }
  assert(!has_phi || rgn->req() > 3, "no phis when region is created");

  if (new_entry == NULL) {
    // Attach if_cont to iff
    _igvn.hash_delete(iff);
    iff->set_req(0, if_cont);
    if (_idom != NULL) {
      set_idom(iff, if_cont, dom_depth(iff));
    }
  }
  return if_cont->as_Proj();
}
Пример #14
0
unsigned
vectorize_loops (void)
{
  unsigned int i;
  unsigned int num_vectorized_loops = 0;
  unsigned int vect_loops_num;
  loop_iterator li;
  struct loop *loop;

  vect_loops_num = number_of_loops ();

  /* Bail out if there are no loops.  */
  if (vect_loops_num <= 1)
    return 0;

  /* Fix the verbosity level if not defined explicitly by the user.  */
  vect_set_dump_settings (false);

  init_stmt_vec_info_vec ();

  /*  ----------- Analyze loops. -----------  */

  /* If some loop was duplicated, it gets bigger number
     than all previously defined loops.  This fact allows us to run
     only over initial loops skipping newly generated ones.  */
  FOR_EACH_LOOP (li, loop, 0)
    if (optimize_loop_nest_for_speed_p (loop))
      {
	loop_vec_info loop_vinfo;

	vect_location = find_loop_location (loop);
        if (vect_location != UNKNOWN_LOC
            && vect_verbosity_level > REPORT_NONE)
	  fprintf (vect_dump, "\nAnalyzing loop at %s:%d\n",
            LOC_FILE (vect_location), LOC_LINE (vect_location));

	loop_vinfo = vect_analyze_loop (loop);
	loop->aux = loop_vinfo;

	if (!loop_vinfo || !LOOP_VINFO_VECTORIZABLE_P (loop_vinfo))
	  continue;

        if (vect_location != UNKNOWN_LOC
            && vect_verbosity_level > REPORT_NONE)
          fprintf (vect_dump, "\n\nVectorizing loop at %s:%d\n",
            LOC_FILE (vect_location), LOC_LINE (vect_location));

	vect_transform_loop (loop_vinfo);
	num_vectorized_loops++;
      }

  vect_location = UNKNOWN_LOC;

  statistics_counter_event (cfun, "Vectorized loops", num_vectorized_loops);
  if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS)
      || (num_vectorized_loops > 0
	  && vect_print_dump_info (REPORT_VECTORIZED_LOCATIONS)))
    fprintf (vect_dump, "vectorized %u loops in function.\n",
	     num_vectorized_loops);

  /*  ----------- Finalize. -----------  */

  mark_sym_for_renaming (gimple_vop (cfun));

  for (i = 1; i < vect_loops_num; i++)
    {
      loop_vec_info loop_vinfo;

      loop = get_loop (i);
      if (!loop)
	continue;
      loop_vinfo = (loop_vec_info) loop->aux;
      destroy_loop_vec_info (loop_vinfo, true);
      loop->aux = NULL;
    }

  free_stmt_vec_info_vec ();

  return num_vectorized_loops > 0 ? TODO_cleanup_cfg : 0;
}
Пример #15
0
unsigned
vectorize_loops (void)
{
    unsigned int i;
    unsigned int num_vectorized_loops = 0;
    unsigned int vect_loops_num;
    loop_iterator li;
    struct loop *loop;

    vect_loops_num = number_of_loops (cfun);

    /* Bail out if there are no loops.  */
    if (vect_loops_num <= 1)
        return 0;

    init_stmt_vec_info_vec ();

    /*  ----------- Analyze loops. -----------  */

    /* If some loop was duplicated, it gets bigger number
       than all previously defined loops.  This fact allows us to run
       only over initial loops skipping newly generated ones.  */
    FOR_EACH_LOOP (li, loop, 0)
    if (optimize_loop_nest_for_speed_p (loop))
    {
        loop_vec_info loop_vinfo;
        vect_location = find_loop_location (loop);
        if (LOCATION_LOCUS (vect_location) != UNKNOWN_LOC
                && dump_enabled_p ())
            dump_printf (MSG_NOTE, "\nAnalyzing loop at %s:%d\n",
                         LOC_FILE (vect_location), LOC_LINE (vect_location));

        loop_vinfo = vect_analyze_loop (loop);
        loop->aux = loop_vinfo;

        if (!loop_vinfo || !LOOP_VINFO_VECTORIZABLE_P (loop_vinfo))
            continue;

        if (LOCATION_LOCUS (vect_location) != UNKNOWN_LOC
                && dump_enabled_p ())
            dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, vect_location,
                             "Vectorized loop\n");
        vect_transform_loop (loop_vinfo);
        num_vectorized_loops++;
    }

    vect_location = UNKNOWN_LOC;

    statistics_counter_event (cfun, "Vectorized loops", num_vectorized_loops);
    if (dump_enabled_p ()
            || (num_vectorized_loops > 0 && dump_enabled_p ()))
        dump_printf_loc (MSG_NOTE, vect_location,
                         "vectorized %u loops in function.\n",
                         num_vectorized_loops);

    /*  ----------- Finalize. -----------  */

    for (i = 1; i < vect_loops_num; i++)
    {
        loop_vec_info loop_vinfo;

        loop = get_loop (cfun, i);
        if (!loop)
            continue;
        loop_vinfo = (loop_vec_info) loop->aux;
        destroy_loop_vec_info (loop_vinfo, true);
        loop->aux = NULL;
    }

    free_stmt_vec_info_vec ();

    if (num_vectorized_loops > 0)
    {
        /* If we vectorized any loop only virtual SSA form needs to be updated.
        ???  Also while we try hard to update loop-closed SSA form we fail
         to properly do this in some corner-cases (see PR56286).  */
        rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa_only_virtuals);
        return TODO_cleanup_cfg;
    }

    return 0;
}
Пример #16
0
static int loop_tostring(lua_State *L) {
    loop_t *lo = get_loop(L, 1);
    lua_pushfstring(L, "loop: %p", lo);
    return 1;
}
Пример #17
0
unsigned
vectorize_loops (void)
{
  unsigned int i;
  unsigned int num_vectorized_loops = 0;
  unsigned int vect_loops_num;
  loop_iterator li;
  struct loop *loop;

  vect_loops_num = number_of_loops ();

  /* Bail out if there are no loops.  */
  if (vect_loops_num <= 1)
    return 0;

  init_stmt_vec_info_vec ();

  /*  ----------- Analyze loops. -----------  */

  /* If some loop was duplicated, it gets bigger number
     than all previously defined loops.  This fact allows us to run
     only over initial loops skipping newly generated ones.  */
  FOR_EACH_LOOP (li, loop, 0)
    if (optimize_loop_nest_for_speed_p (loop))
      {
	loop_vec_info loop_vinfo;
	vect_location = find_loop_location (loop);
        if (LOCATION_LOCUS (vect_location) != UNKNOWN_LOC
	    && dump_enabled_p ())
	  dump_printf (MSG_ALL, "\nAnalyzing loop at %s:%d\n",
                       LOC_FILE (vect_location), LOC_LINE (vect_location));

	loop_vinfo = vect_analyze_loop (loop);
	loop->aux = loop_vinfo;

	if (!loop_vinfo || !LOOP_VINFO_VECTORIZABLE_P (loop_vinfo))
	  continue;

        if (LOCATION_LOCUS (vect_location) != UNKNOWN_LOC
	    && dump_enabled_p ())
          dump_printf (MSG_ALL, "\n\nVectorizing loop at %s:%d\n",
                       LOC_FILE (vect_location), LOC_LINE (vect_location));
	vect_transform_loop (loop_vinfo);
	num_vectorized_loops++;
      }

  vect_location = UNKNOWN_LOC;

  statistics_counter_event (cfun, "Vectorized loops", num_vectorized_loops);
  if (dump_enabled_p ()
      || (num_vectorized_loops > 0 && dump_enabled_p ()))
    dump_printf_loc (MSG_ALL, vect_location,
                     "vectorized %u loops in function.\n",
                     num_vectorized_loops);

  /*  ----------- Finalize. -----------  */

  for (i = 1; i < vect_loops_num; i++)
    {
      loop_vec_info loop_vinfo;

      loop = get_loop (i);
      if (!loop)
	continue;
      loop_vinfo = (loop_vec_info) loop->aux;
      destroy_loop_vec_info (loop_vinfo, true);
      loop->aux = NULL;
    }

  free_stmt_vec_info_vec ();

  return num_vectorized_loops > 0 ? TODO_cleanup_cfg : 0;
}
Пример #18
0
//------------------------------do_split_if------------------------------------
// Found an If getting its condition-code input from a Phi in the same block.
// Split thru the Region.
void PhaseIdealLoop::do_split_if( Node *iff ) {
#ifndef PRODUCT
  if( PrintOpto && VerifyLoopOptimizations )
    tty->print_cr("Split-if");
#endif
  C->set_major_progress();
  Node *region = iff->in(0);
  Node *region_dom = idom(region);

  // We are going to clone this test (and the control flow with it) up through
  // the incoming merge point.  We need to empty the current basic block.
  // Clone any instructions which must be in this block up through the merge
  // point.
  DUIterator i, j;
  bool progress = true;
  while (progress) {
    progress = false;
    for (i = region->outs(); region->has_out(i); i++) {
      Node* n = region->out(i);
      if( n == region ) continue;
      // The IF to be split is OK.
      if( n == iff ) continue;
      if( !n->is_Phi() ) {      // Found pinned memory op or such
        if (split_up(n, region, iff)) {
          i = region->refresh_out_pos(i);
          progress = true;
        }
        continue;
      }
      assert( n->in(0) == region, "" );

      // Recursively split up all users of a Phi
      for (j = n->outs(); n->has_out(j); j++) {
        Node* m = n->out(j);
        // If m is dead, throw it away, and declare progress
        if (_nodes[m->_idx] == NULL) {
          _igvn.remove_dead_node(m);
          // fall through
        }
        else if (m != iff && split_up(m, region, iff)) {
          // fall through
        } else {
          continue;
        }
        // Something unpredictable changed.
        // Tell the iterators to refresh themselves, and rerun the loop.
        i = region->refresh_out_pos(i);
        j = region->refresh_out_pos(j);
        progress = true;
      }
    }
  }

  // Now we have no instructions in the block containing the IF.
  // Split the IF.
  Node *new_iff = split_thru_region( iff, region );

  // Replace both uses of 'new_iff' with Regions merging True/False
  // paths.  This makes 'new_iff' go dead.
  Node *old_false, *old_true;
  Node *new_false, *new_true;
  for (DUIterator_Last j2min, j2 = iff->last_outs(j2min); j2 >= j2min; --j2) {
    Node *ifp = iff->last_out(j2);
    assert( ifp->Opcode() == Op_IfFalse || ifp->Opcode() == Op_IfTrue, "" );
    ifp->set_req(0, new_iff);
    Node *ifpx = split_thru_region( ifp, region );

    // Replace 'If' projection of a Region with a Region of
    // 'If' projections.
    ifpx->set_req(0, ifpx);       // A TRUE RegionNode

    // Setup dominator info
    set_idom(ifpx, region_dom, dom_depth(region_dom) + 1);

    // Check for splitting loop tails
    if( get_loop(iff)->tail() == ifp )
      get_loop(iff)->_tail = ifpx;

    // Replace in the graph with lazy-update mechanism
    new_iff->set_req(0, new_iff); // hook self so it does not go dead
    lazy_replace_proj( ifp, ifpx );
    new_iff->set_req(0, region);

    // Record bits for later xforms
    if( ifp->Opcode() == Op_IfFalse ) {
      old_false = ifp;
      new_false = ifpx;
    } else {
      old_true = ifp;
      new_true = ifpx;
    }
  }
  _igvn.remove_dead_node(new_iff);
  // Lazy replace IDOM info with the region's dominator
  lazy_replace( iff, region_dom );

  // Now make the original merge point go dead, by handling all its uses.
  small_cache region_cache;
  // Preload some control flow in region-cache
  region_cache.lru_insert( new_false, new_false );
  region_cache.lru_insert( new_true , new_true  );
  // Now handle all uses of the splitting block
  for (DUIterator_Last kmin, k = region->last_outs(kmin); k >= kmin; --k) {
    Node* phi = region->last_out(k);
    if( !phi->in(0) ) {         // Dead phi?  Remove it
      _igvn.remove_dead_node(phi);
      continue;
    }
    assert( phi->in(0) == region, "" );
    if( phi == region ) {       // Found the self-reference
      phi->set_req(0, NULL);
      continue;                 // Break the self-cycle
    }
    // Expected common case: Phi hanging off of Region
    if( phi->is_Phi() ) {
      // Need a per-def cache.  Phi represents a def, so make a cache
      small_cache phi_cache;

      // Inspect all Phi uses to make the Phi go dead
      for (DUIterator_Last lmin, l = phi->last_outs(lmin); l >= lmin; --l) {
        Node* use = phi->last_out(l);
        // Compute the new DEF for this USE.  New DEF depends on the path
        // taken from the original DEF to the USE.  The new DEF may be some
        // collection of PHI's merging values from different paths.  The Phis
        // inserted depend only on the location of the USE.  We use a
        // 2-element cache to handle multiple uses from the same block.
        handle_use( use, phi, &phi_cache, region_dom, new_false, new_true, old_false, old_true );
      } // End of while phi has uses

      // Because handle_use might relocate region->_out,
      // we must refresh the iterator.
      k = region->last_outs(kmin);

      // Remove the dead Phi
      _igvn.remove_dead_node( phi );

    } else {
      // Random memory op guarded by Region.  Compute new DEF for USE.
      handle_use( phi, region, &region_cache, region_dom, new_false, new_true, old_false, old_true );
    }

  } // End of while merge point has phis

  // Any leftover bits in the splitting block must not have depended on local
  // Phi inputs (these have already been split-up).  Hence it's safe to hoist
  // these guys to the dominating point.
  lazy_replace( region, region_dom );
#ifndef PRODUCT
  if( VerifyLoopOptimizations ) verify();
#endif
}