Ejemplo n.º 1
0
LoopNode* PhaseIdealLoop::create_reserve_version_of_loop(IdealLoopTree *loop, CountedLoopReserveKit* lk) {
  Node_List old_new;
  LoopNode* head  = loop->_head->as_Loop();
  bool counted_loop = head->is_CountedLoop();
  Node*     entry = head->in(LoopNode::EntryControl);
  _igvn.rehash_node_delayed(entry);
  IdealLoopTree* outer_loop = loop->_parent;

  ConINode* const_1 = _igvn.intcon(1);
  set_ctrl(const_1, C->root());
  IfNode* iff = new IfNode(entry, const_1, PROB_MAX, COUNT_UNKNOWN);
  register_node(iff, outer_loop, entry, dom_depth(entry));
  ProjNode* iffast = new IfTrueNode(iff);
  register_node(iffast, outer_loop, iff, dom_depth(iff));
  ProjNode* ifslow = new IfFalseNode(iff);
  register_node(ifslow, outer_loop, iff, dom_depth(iff));

  // Clone the loop body.  The clone becomes the fast loop.  The
  // original pre-header will (illegally) have 3 control users
  // (old & new loops & new if).
  clone_loop(loop, old_new, dom_depth(head), iff);
  assert(old_new[head->_idx]->is_Loop(), "" );

  LoopNode* slow_head = old_new[head->_idx]->as_Loop();

#ifndef PRODUCT
  if (TraceLoopOpts) {
    tty->print_cr("PhaseIdealLoop::create_reserve_version_of_loop:");
    tty->print("\t iff = %d, ", iff->_idx); iff->dump();
    tty->print("\t iffast = %d, ", iffast->_idx); iffast->dump();
    tty->print("\t ifslow = %d, ", ifslow->_idx); ifslow->dump();
    tty->print("\t before replace_input_of: head = %d, ", head->_idx); head->dump();
    tty->print("\t before replace_input_of: slow_head = %d, ", slow_head->_idx); slow_head->dump();
  }
#endif

  // Fast (true) control
  _igvn.replace_input_of(head, LoopNode::EntryControl, iffast);
  // Slow (false) control
  _igvn.replace_input_of(slow_head, LoopNode::EntryControl, ifslow);

  recompute_dom_depth();

  lk->set_iff(iff);

#ifndef PRODUCT
  if (TraceLoopOpts ) {
    tty->print("\t after  replace_input_of: head = %d, ", head->_idx); head->dump();
    tty->print("\t after  replace_input_of: slow_head = %d, ", slow_head->_idx); slow_head->dump();
  }
#endif

  return slow_head->as_Loop();
}
Ejemplo n.º 2
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;
}
Ejemplo n.º 3
0
//-------------------------------register_control-------------------------
void PhaseIdealLoop::register_control(Node* n, IdealLoopTree *loop, Node* pred) {
  assert(n->is_CFG(), "must be control node");
  _igvn.register_new_node_with_optimizer(n);
  loop->_body.push(n);
  set_loop(n, loop);
  // When called from beautify_loops() idom is not constructed yet.
  if (_idom != NULL) {
    set_idom(n, pred, dom_depth(pred));
  }
}
Ejemplo n.º 4
0
//-------------------------create_slow_version_of_loop------------------------
// Create a slow version of the loop by cloning the loop
// and inserting an if to select fast-slow versions.
// Return control projection of the entry to the fast version.
ProjNode* PhaseIdealLoop::create_slow_version_of_loop(IdealLoopTree *loop,
                                                      Node_List &old_new,
                                                      int opcode) {
  LoopNode* head  = loop->_head->as_Loop();
  bool counted_loop = head->is_CountedLoop();
  Node*     entry = head->in(LoopNode::EntryControl);
  _igvn.rehash_node_delayed(entry);
  IdealLoopTree* outer_loop = loop->_parent;

  Node *cont      = _igvn.intcon(1);
  set_ctrl(cont, C->root());
  Node* opq       = new Opaque1Node(C, cont);
  register_node(opq, outer_loop, entry, dom_depth(entry));
  Node *bol       = new Conv2BNode(opq);
  register_node(bol, outer_loop, entry, dom_depth(entry));
  IfNode* iff = (opcode == Op_RangeCheck) ? new RangeCheckNode(entry, bol, PROB_MAX, COUNT_UNKNOWN) :
    new IfNode(entry, bol, PROB_MAX, COUNT_UNKNOWN);
  register_node(iff, outer_loop, entry, dom_depth(entry));
  ProjNode* iffast = new IfTrueNode(iff);
  register_node(iffast, outer_loop, iff, dom_depth(iff));
  ProjNode* ifslow = new IfFalseNode(iff);
  register_node(ifslow, outer_loop, iff, dom_depth(iff));

  // Clone the loop body.  The clone becomes the fast loop.  The
  // original pre-header will (illegally) have 3 control users
  // (old & new loops & new if).
  clone_loop(loop, old_new, dom_depth(head), iff);
  assert(old_new[head->_idx]->is_Loop(), "" );

  // Fast (true) control
  Node* iffast_pred = clone_loop_predicates(entry, iffast, !counted_loop);
  _igvn.replace_input_of(head, LoopNode::EntryControl, iffast_pred);
  set_idom(head, iffast_pred, dom_depth(head));

  // Slow (false) control
  Node* ifslow_pred = clone_loop_predicates(entry, ifslow, !counted_loop);
  LoopNode* slow_head = old_new[head->_idx]->as_Loop();
  _igvn.replace_input_of(slow_head, LoopNode::EntryControl, ifslow_pred);
  set_idom(slow_head, ifslow_pred, dom_depth(slow_head));

  recompute_dom_depth();

  return iffast;
}
Ejemplo n.º 5
0
//-------------------------create_slow_version_of_loop------------------------
// Create a slow version of the loop by cloning the loop
// and inserting an if to select fast-slow versions.
// Return control projection of the entry to the fast version.
ProjNode* PhaseIdealLoop::create_slow_version_of_loop(IdealLoopTree *loop,
                                                      Node_List &old_new) {
  LoopNode* head  = loop->_head->as_Loop();
  Node*     entry = head->in(LoopNode::EntryControl);
  _igvn.hash_delete(entry);
  _igvn._worklist.push(entry);
  IdealLoopTree* outer_loop = loop->_parent;

  Node *cont      = _igvn.intcon(1);
  set_ctrl(cont, C->root());
  Node* opq       = new (C, 2) Opaque1Node(C, cont);
  register_node(opq, outer_loop, entry, dom_depth(entry));
  Node *bol       = new (C, 2) Conv2BNode(opq);
  register_node(bol, outer_loop, entry, dom_depth(entry));
  IfNode* iff = new (C, 2) IfNode(entry, bol, PROB_MAX, COUNT_UNKNOWN);
  register_node(iff, outer_loop, entry, dom_depth(entry));
  ProjNode* iffast = new (C, 1) IfTrueNode(iff);
  register_node(iffast, outer_loop, iff, dom_depth(iff));
  ProjNode* ifslow = new (C, 1) IfFalseNode(iff);
  register_node(ifslow, outer_loop, iff, dom_depth(iff));

  // Clone the loop body.  The clone becomes the fast loop.  The
  // original pre-header will (illegally) have 2 control users (old & new loops).
  clone_loop(loop, old_new, dom_depth(head), iff);
  assert(old_new[head->_idx]->is_Loop(), "" );

  // Fast (true) control
  _igvn.hash_delete(head);
  head->set_req(LoopNode::EntryControl, iffast);
  set_idom(head, iffast, dom_depth(head));
  _igvn._worklist.push(head);

  // Slow (false) control
  LoopNode* slow_head = old_new[head->_idx]->as_Loop();
  _igvn.hash_delete(slow_head);
  slow_head->set_req(LoopNode::EntryControl, ifslow);
  set_idom(slow_head, ifslow, dom_depth(slow_head));
  _igvn._worklist.push(slow_head);

  recompute_dom_depth();

  return iffast;
}
Ejemplo n.º 6
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();
}
Ejemplo n.º 7
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
}