--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/opto/superword.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,2025 @@
+/*
+ * Copyright 2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+#include "incls/_precompiled.incl"
+#include "incls/_superword.cpp.incl"
+
+//
+//                  S U P E R W O R D   T R A N S F O R M
+//=============================================================================
+
+//------------------------------SuperWord---------------------------
+SuperWord::SuperWord(PhaseIdealLoop* phase) :
+  _phase(phase),
+  _igvn(phase->_igvn),
+  _arena(phase->C->comp_arena()),
+  _packset(arena(), 8,  0, NULL),         // packs for the current block
+  _bb_idx(arena(), (int)(1.10 * phase->C->unique()), 0, 0), // node idx to index in bb
+  _block(arena(), 8,  0, NULL),           // nodes in current block
+  _data_entry(arena(), 8,  0, NULL),      // nodes with all inputs from outside
+  _mem_slice_head(arena(), 8,  0, NULL),  // memory slice heads
+  _mem_slice_tail(arena(), 8,  0, NULL),  // memory slice tails
+  _node_info(arena(), 8,  0, SWNodeInfo::initial), // info needed per node
+  _align_to_ref(NULL),                    // memory reference to align vectors to
+  _disjoint_ptrs(arena(), 8,  0, OrderedPair::initial), // runtime disambiguated pointer pairs
+  _dg(_arena),                            // dependence graph
+  _visited(arena()),                      // visited node set
+  _post_visited(arena()),                 // post visited node set
+  _n_idx_list(arena(), 8),                // scratch list of (node,index) pairs
+  _stk(arena(), 8, 0, NULL),              // scratch stack of nodes
+  _nlist(arena(), 8, 0, NULL),            // scratch list of nodes
+  _lpt(NULL),                             // loop tree node
+  _lp(NULL),                              // LoopNode
+  _bb(NULL),                              // basic block
+  _iv(NULL)                               // induction var
+{}
+
+//------------------------------transform_loop---------------------------
+void SuperWord::transform_loop(IdealLoopTree* lpt) {
+  assert(lpt->_head->is_CountedLoop(), "must be");
+  CountedLoopNode *cl = lpt->_head->as_CountedLoop();
+
+  if (!cl->is_main_loop() ) return; // skip normal, pre, and post loops
+
+  // Check for no control flow in body (other than exit)
+  Node *cl_exit = cl->loopexit();
+  if (cl_exit->in(0) != lpt->_head) return;
+
+  // Check for pre-loop ending with CountedLoopEnd(Bool(Cmp(x,Opaque1(limit))))
+  CountedLoopEndNode* pre_end = get_pre_loop_end(cl);
+  if (pre_end == NULL) return;
+  Node *pre_opaq1 = pre_end->limit();
+  if (pre_opaq1->Opcode() != Op_Opaque1) return;
+
+  // Do vectors exist on this architecture?
+  if (vector_width_in_bytes() == 0) return;
+
+  init(); // initialize data structures
+
+  set_lpt(lpt);
+  set_lp(cl);
+
+ // For now, define one block which is the entire loop body
+  set_bb(cl);
+
+  assert(_packset.length() == 0, "packset must be empty");
+  SLP_extract();
+}
+
+//------------------------------SLP_extract---------------------------
+// Extract the superword level parallelism
+//
+// 1) A reverse post-order of nodes in the block is constructed.  By scanning
+//    this list from first to last, all definitions are visited before their uses.
+//
+// 2) A point-to-point dependence graph is constructed between memory references.
+//    This simplies the upcoming "independence" checker.
+//
+// 3) The maximum depth in the node graph from the beginning of the block
+//    to each node is computed.  This is used to prune the graph search
+//    in the independence checker.
+//
+// 4) For integer types, the necessary bit width is propagated backwards
+//    from stores to allow packed operations on byte, char, and short
+//    integers.  This reverses the promotion to type "int" that javac
+//    did for operations like: char c1,c2,c3;  c1 = c2 + c3.
+//
+// 5) One of the memory references is picked to be an aligned vector reference.
+//    The pre-loop trip count is adjusted to align this reference in the
+//    unrolled body.
+//
+// 6) The initial set of pack pairs is seeded with memory references.
+//
+// 7) The set of pack pairs is extended by following use->def and def->use links.
+//
+// 8) The pairs are combined into vector sized packs.
+//
+// 9) Reorder the memory slices to co-locate members of the memory packs.
+//
+// 10) Generate ideal vector nodes for the final set of packs and where necessary,
+//    inserting scalar promotion, vector creation from multiple scalars, and
+//    extraction of scalar values from vectors.
+//
+void SuperWord::SLP_extract() {
+
+  // Ready the block
+
+  construct_bb();
+
+  dependence_graph();
+
+  compute_max_depth();
+
+  compute_vector_element_type();
+
+  // Attempt vectorization
+
+  find_adjacent_refs();
+
+  extend_packlist();
+
+  combine_packs();
+
+  construct_my_pack_map();
+
+  filter_packs();
+
+  schedule();
+
+  output();
+}
+
+//------------------------------find_adjacent_refs---------------------------
+// Find the adjacent memory references and create pack pairs for them.
+// This is the initial set of packs that will then be extended by
+// following use->def and def->use links.  The align positions are
+// assigned relative to the reference "align_to_ref"
+void SuperWord::find_adjacent_refs() {
+  // Get list of memory operations
+  Node_List memops;
+  for (int i = 0; i < _block.length(); i++) {
+    Node* n = _block.at(i);
+    if (n->is_Mem() && in_bb(n)) {
+      int align = memory_alignment(n->as_Mem(), 0);
+      if (align != bottom_align) {
+        memops.push(n);
+      }
+    }
+  }
+  if (memops.size() == 0) return;
+
+  // Find a memory reference to align to.  The pre-loop trip count
+  // is modified to align this reference to a vector-aligned address
+  find_align_to_ref(memops);
+  if (align_to_ref() == NULL) return;
+
+  SWPointer align_to_ref_p(align_to_ref(), this);
+  int offset = align_to_ref_p.offset_in_bytes();
+  int scale  = align_to_ref_p.scale_in_bytes();
+  int vw              = vector_width_in_bytes();
+  int stride_sign     = (scale * iv_stride()) > 0 ? 1 : -1;
+  int iv_adjustment   = (stride_sign * vw - (offset % vw)) % vw;
+
+#ifndef PRODUCT
+  if (TraceSuperWord)
+    tty->print_cr("\noffset = %d iv_adjustment = %d  elt_align = %d",
+                  offset, iv_adjustment, align_to_ref_p.memory_size());
+#endif
+
+  // Set alignment relative to "align_to_ref"
+  for (int i = memops.size() - 1; i >= 0; i--) {
+    MemNode* s = memops.at(i)->as_Mem();
+    SWPointer p2(s, this);
+    if (p2.comparable(align_to_ref_p)) {
+      int align = memory_alignment(s, iv_adjustment);
+      set_alignment(s, align);
+    } else {
+      memops.remove(i);
+    }
+  }
+
+  // Create initial pack pairs of memory operations
+  for (uint i = 0; i < memops.size(); i++) {
+    Node* s1 = memops.at(i);
+    for (uint j = 0; j < memops.size(); j++) {
+      Node* s2 = memops.at(j);
+      if (s1 != s2 && are_adjacent_refs(s1, s2)) {
+        int align = alignment(s1);
+        if (stmts_can_pack(s1, s2, align)) {
+          Node_List* pair = new Node_List();
+          pair->push(s1);
+          pair->push(s2);
+          _packset.append(pair);
+        }
+      }
+    }
+  }
+
+#ifndef PRODUCT
+  if (TraceSuperWord) {
+    tty->print_cr("\nAfter find_adjacent_refs");
+    print_packset();
+  }
+#endif
+}
+
+//------------------------------find_align_to_ref---------------------------
+// Find a memory reference to align the loop induction variable to.
+// Looks first at stores then at loads, looking for a memory reference
+// with the largest number of references similar to it.
+void SuperWord::find_align_to_ref(Node_List &memops) {
+  GrowableArray<int> cmp_ct(arena(), memops.size(), memops.size(), 0);
+
+  // Count number of comparable memory ops
+  for (uint i = 0; i < memops.size(); i++) {
+    MemNode* s1 = memops.at(i)->as_Mem();
+    SWPointer p1(s1, this);
+    // Discard if pre loop can't align this reference
+    if (!ref_is_alignable(p1)) {
+      *cmp_ct.adr_at(i) = 0;
+      continue;
+    }
+    for (uint j = i+1; j < memops.size(); j++) {
+      MemNode* s2 = memops.at(j)->as_Mem();
+      if (isomorphic(s1, s2)) {
+        SWPointer p2(s2, this);
+        if (p1.comparable(p2)) {
+          (*cmp_ct.adr_at(i))++;
+          (*cmp_ct.adr_at(j))++;
+        }
+      }
+    }
+  }
+
+  // Find Store (or Load) with the greatest number of "comparable" references
+  int max_ct        = 0;
+  int max_idx       = -1;
+  int min_size      = max_jint;
+  int min_iv_offset = max_jint;
+  for (uint j = 0; j < memops.size(); j++) {
+    MemNode* s = memops.at(j)->as_Mem();
+    if (s->is_Store()) {
+      SWPointer p(s, this);
+      if (cmp_ct.at(j) > max_ct ||
+          cmp_ct.at(j) == max_ct && (data_size(s) < min_size ||
+                                     data_size(s) == min_size &&
+                                        p.offset_in_bytes() < min_iv_offset)) {
+        max_ct = cmp_ct.at(j);
+        max_idx = j;
+        min_size = data_size(s);
+        min_iv_offset = p.offset_in_bytes();
+      }
+    }
+  }
+  // If no stores, look at loads
+  if (max_ct == 0) {
+    for (uint j = 0; j < memops.size(); j++) {
+      MemNode* s = memops.at(j)->as_Mem();
+      if (s->is_Load()) {
+        SWPointer p(s, this);
+        if (cmp_ct.at(j) > max_ct ||
+            cmp_ct.at(j) == max_ct && (data_size(s) < min_size ||
+                                       data_size(s) == min_size &&
+                                          p.offset_in_bytes() < min_iv_offset)) {
+          max_ct = cmp_ct.at(j);
+          max_idx = j;
+          min_size = data_size(s);
+          min_iv_offset = p.offset_in_bytes();
+        }
+      }
+    }
+  }
+
+  if (max_ct > 0)
+    set_align_to_ref(memops.at(max_idx)->as_Mem());
+
+#ifndef PRODUCT
+  if (TraceSuperWord && Verbose) {
+    tty->print_cr("\nVector memops after find_align_to_refs");
+    for (uint i = 0; i < memops.size(); i++) {
+      MemNode* s = memops.at(i)->as_Mem();
+      s->dump();
+    }
+  }
+#endif
+}
+
+//------------------------------ref_is_alignable---------------------------
+// Can the preloop align the reference to position zero in the vector?
+bool SuperWord::ref_is_alignable(SWPointer& p) {
+  if (!p.has_iv()) {
+    return true;   // no induction variable
+  }
+  CountedLoopEndNode* pre_end = get_pre_loop_end(lp()->as_CountedLoop());
+  assert(pre_end->stride_is_con(), "pre loop stride is constant");
+  int preloop_stride = pre_end->stride_con();
+
+  int span = preloop_stride * p.scale_in_bytes();
+
+  // Stride one accesses are alignable.
+  if (ABS(span) == p.memory_size())
+    return true;
+
+  // If initial offset from start of object is computable,
+  // compute alignment within the vector.
+  int vw = vector_width_in_bytes();
+  if (vw % span == 0) {
+    Node* init_nd = pre_end->init_trip();
+    if (init_nd->is_Con() && p.invar() == NULL) {
+      int init = init_nd->bottom_type()->is_int()->get_con();
+
+      int init_offset = init * p.scale_in_bytes() + p.offset_in_bytes();
+      assert(init_offset >= 0, "positive offset from object start");
+
+      if (span > 0) {
+        return (vw - (init_offset % vw)) % span == 0;
+      } else {
+        assert(span < 0, "nonzero stride * scale");
+        return (init_offset % vw) % -span == 0;
+      }
+    }
+  }
+  return false;
+}
+
+//---------------------------dependence_graph---------------------------
+// Construct dependency graph.
+// Add dependence edges to load/store nodes for memory dependence
+//    A.out()->DependNode.in(1) and DependNode.out()->B.prec(x)
+void SuperWord::dependence_graph() {
+  // First, assign a dependence node to each memory node
+  for (int i = 0; i < _block.length(); i++ ) {
+    Node *n = _block.at(i);
+    if (n->is_Mem() || n->is_Phi() && n->bottom_type() == Type::MEMORY) {
+      _dg.make_node(n);
+    }
+  }
+
+  // For each memory slice, create the dependences
+  for (int i = 0; i < _mem_slice_head.length(); i++) {
+    Node* n      = _mem_slice_head.at(i);
+    Node* n_tail = _mem_slice_tail.at(i);
+
+    // Get slice in predecessor order (last is first)
+    mem_slice_preds(n_tail, n, _nlist);
+
+    // Make the slice dependent on the root
+    DepMem* slice = _dg.dep(n);
+    _dg.make_edge(_dg.root(), slice);
+
+    // Create a sink for the slice
+    DepMem* slice_sink = _dg.make_node(NULL);
+    _dg.make_edge(slice_sink, _dg.tail());
+
+    // Now visit each pair of memory ops, creating the edges
+    for (int j = _nlist.length() - 1; j >= 0 ; j--) {
+      Node* s1 = _nlist.at(j);
+
+      // If no dependency yet, use slice
+      if (_dg.dep(s1)->in_cnt() == 0) {
+        _dg.make_edge(slice, s1);
+      }
+      SWPointer p1(s1->as_Mem(), this);
+      bool sink_dependent = true;
+      for (int k = j - 1; k >= 0; k--) {
+        Node* s2 = _nlist.at(k);
+        if (s1->is_Load() && s2->is_Load())
+          continue;
+        SWPointer p2(s2->as_Mem(), this);
+
+        int cmp = p1.cmp(p2);
+        if (SuperWordRTDepCheck &&
+            p1.base() != p2.base() && p1.valid() && p2.valid()) {
+          // Create a runtime check to disambiguate
+          OrderedPair pp(p1.base(), p2.base());
+          _disjoint_ptrs.append_if_missing(pp);
+        } else if (!SWPointer::not_equal(cmp)) {
+          // Possibly same address
+          _dg.make_edge(s1, s2);
+          sink_dependent = false;
+        }
+      }
+      if (sink_dependent) {
+        _dg.make_edge(s1, slice_sink);
+      }
+    }
+#ifndef PRODUCT
+    if (TraceSuperWord) {
+      tty->print_cr("\nDependence graph for slice: %d", n->_idx);
+      for (int q = 0; q < _nlist.length(); q++) {
+        _dg.print(_nlist.at(q));
+      }
+      tty->cr();
+    }
+#endif
+    _nlist.clear();
+  }
+
+#ifndef PRODUCT
+  if (TraceSuperWord) {
+    tty->print_cr("\ndisjoint_ptrs: %s", _disjoint_ptrs.length() > 0 ? "" : "NONE");
+    for (int r = 0; r < _disjoint_ptrs.length(); r++) {
+      _disjoint_ptrs.at(r).print();
+      tty->cr();
+    }
+    tty->cr();
+  }
+#endif
+}
+
+//---------------------------mem_slice_preds---------------------------
+// Return a memory slice (node list) in predecessor order starting at "start"
+void SuperWord::mem_slice_preds(Node* start, Node* stop, GrowableArray<Node*> &preds) {
+  assert(preds.length() == 0, "start empty");
+  Node* n = start;
+  Node* prev = NULL;
+  while (true) {
+    assert(in_bb(n), "must be in block");
+    for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
+      Node* out = n->fast_out(i);
+      if (out->is_Load()) {
+        if (in_bb(out)) {
+          preds.push(out);
+        }
+      } else {
+        // FIXME
+        if (out->is_MergeMem() && !in_bb(out)) {
+          // Either unrolling is causing a memory edge not to disappear,
+          // or need to run igvn.optimize() again before SLP
+        } else if (out->is_Phi() && out->bottom_type() == Type::MEMORY && !in_bb(out)) {
+          // Ditto.  Not sure what else to check further.
+        } else if (out->Opcode() == Op_StoreCM && out->in(4) == n) {
+          // StoreCM has an input edge used as a precedence edge.
+          // Maybe an issue when oop stores are vectorized.
+        } else {
+          assert(out == prev || prev == NULL, "no branches off of store slice");
+        }
+      }
+    }
+    if (n == stop) break;
+    preds.push(n);
+    prev = n;
+    n = n->in(MemNode::Memory);
+  }
+}
+
+//------------------------------stmts_can_pack---------------------------
+// Can s1 and s2 be in a pack with s1 immediately preceeding s2 and
+// s1 aligned at "align"
+bool SuperWord::stmts_can_pack(Node* s1, Node* s2, int align) {
+  if (isomorphic(s1, s2)) {
+    if (independent(s1, s2)) {
+      if (!exists_at(s1, 0) && !exists_at(s2, 1)) {
+        if (!s1->is_Mem() || are_adjacent_refs(s1, s2)) {
+          int s1_align = alignment(s1);
+          int s2_align = alignment(s2);
+          if (s1_align == top_align || s1_align == align) {
+            if (s2_align == top_align || s2_align == align + data_size(s1)) {
+              return true;
+            }
+          }
+        }
+      }
+    }
+  }
+  return false;
+}
+
+//------------------------------exists_at---------------------------
+// Does s exist in a pack at position pos?
+bool SuperWord::exists_at(Node* s, uint pos) {
+  for (int i = 0; i < _packset.length(); i++) {
+    Node_List* p = _packset.at(i);
+    if (p->at(pos) == s) {
+      return true;
+    }
+  }
+  return false;
+}
+
+//------------------------------are_adjacent_refs---------------------------
+// Is s1 immediately before s2 in memory?
+bool SuperWord::are_adjacent_refs(Node* s1, Node* s2) {
+  if (!s1->is_Mem() || !s2->is_Mem()) return false;
+  if (!in_bb(s1)    || !in_bb(s2))    return false;
+  // FIXME - co_locate_pack fails on Stores in different mem-slices, so
+  // only pack memops that are in the same alias set until that's fixed.
+  if (_phase->C->get_alias_index(s1->as_Mem()->adr_type()) !=
+      _phase->C->get_alias_index(s2->as_Mem()->adr_type()))
+    return false;
+  SWPointer p1(s1->as_Mem(), this);
+  SWPointer p2(s2->as_Mem(), this);
+  if (p1.base() != p2.base() || !p1.comparable(p2)) return false;
+  int diff = p2.offset_in_bytes() - p1.offset_in_bytes();
+  return diff == data_size(s1);
+}
+
+//------------------------------isomorphic---------------------------
+// Are s1 and s2 similar?
+bool SuperWord::isomorphic(Node* s1, Node* s2) {
+  if (s1->Opcode() != s2->Opcode()) return false;
+  if (s1->req() != s2->req()) return false;
+  if (s1->in(0) != s2->in(0)) return false;
+  if (velt_type(s1) != velt_type(s2)) return false;
+  return true;
+}
+
+//------------------------------independent---------------------------
+// Is there no data path from s1 to s2 or s2 to s1?
+bool SuperWord::independent(Node* s1, Node* s2) {
+  //  assert(s1->Opcode() == s2->Opcode(), "check isomorphic first");
+  int d1 = depth(s1);
+  int d2 = depth(s2);
+  if (d1 == d2) return s1 != s2;
+  Node* deep    = d1 > d2 ? s1 : s2;
+  Node* shallow = d1 > d2 ? s2 : s1;
+
+  visited_clear();
+
+  return independent_path(shallow, deep);
+}
+
+//------------------------------independent_path------------------------------
+// Helper for independent
+bool SuperWord::independent_path(Node* shallow, Node* deep, uint dp) {
+  if (dp >= 1000) return false; // stop deep recursion
+  visited_set(deep);
+  int shal_depth = depth(shallow);
+  assert(shal_depth <= depth(deep), "must be");
+  for (DepPreds preds(deep, _dg); !preds.done(); preds.next()) {
+    Node* pred = preds.current();
+    if (in_bb(pred) && !visited_test(pred)) {
+      if (shallow == pred) {
+        return false;
+      }
+      if (shal_depth < depth(pred) && !independent_path(shallow, pred, dp+1)) {
+        return false;
+      }
+    }
+  }
+  return true;
+}
+
+//------------------------------set_alignment---------------------------
+void SuperWord::set_alignment(Node* s1, Node* s2, int align) {
+  set_alignment(s1, align);
+  set_alignment(s2, align + data_size(s1));
+}
+
+//------------------------------data_size---------------------------
+int SuperWord::data_size(Node* s) {
+  const Type* t = velt_type(s);
+  BasicType  bt = t->array_element_basic_type();
+  int bsize = type2aelembytes[bt];
+  assert(bsize != 0, "valid size");
+  return bsize;
+}
+
+//------------------------------extend_packlist---------------------------
+// Extend packset by following use->def and def->use links from pack members.
+void SuperWord::extend_packlist() {
+  bool changed;
+  do {
+    changed = false;
+    for (int i = 0; i < _packset.length(); i++) {
+      Node_List* p = _packset.at(i);
+      changed |= follow_use_defs(p);
+      changed |= follow_def_uses(p);
+    }
+  } while (changed);
+
+#ifndef PRODUCT
+  if (TraceSuperWord) {
+    tty->print_cr("\nAfter extend_packlist");
+    print_packset();
+  }
+#endif
+}
+
+//------------------------------follow_use_defs---------------------------
+// Extend the packset by visiting operand definitions of nodes in pack p
+bool SuperWord::follow_use_defs(Node_List* p) {
+  Node* s1 = p->at(0);
+  Node* s2 = p->at(1);
+  assert(p->size() == 2, "just checking");
+  assert(s1->req() == s2->req(), "just checking");
+  assert(alignment(s1) + data_size(s1) == alignment(s2), "just checking");
+
+  if (s1->is_Load()) return false;
+
+  int align = alignment(s1);
+  bool changed = false;
+  int start = s1->is_Store() ? MemNode::ValueIn   : 1;
+  int end   = s1->is_Store() ? MemNode::ValueIn+1 : s1->req();
+  for (int j = start; j < end; j++) {
+    Node* t1 = s1->in(j);
+    Node* t2 = s2->in(j);
+    if (!in_bb(t1) || !in_bb(t2))
+      continue;
+    if (stmts_can_pack(t1, t2, align)) {
+      if (est_savings(t1, t2) >= 0) {
+        Node_List* pair = new Node_List();
+        pair->push(t1);
+        pair->push(t2);
+        _packset.append(pair);
+        set_alignment(t1, t2, align);
+        changed = true;
+      }
+    }
+  }
+  return changed;
+}
+
+//------------------------------follow_def_uses---------------------------
+// Extend the packset by visiting uses of nodes in pack p
+bool SuperWord::follow_def_uses(Node_List* p) {
+  bool changed = false;
+  Node* s1 = p->at(0);
+  Node* s2 = p->at(1);
+  assert(p->size() == 2, "just checking");
+  assert(s1->req() == s2->req(), "just checking");
+  assert(alignment(s1) + data_size(s1) == alignment(s2), "just checking");
+
+  if (s1->is_Store()) return false;
+
+  int align = alignment(s1);
+  int savings = -1;
+  Node* u1 = NULL;
+  Node* u2 = NULL;
+  for (DUIterator_Fast imax, i = s1->fast_outs(imax); i < imax; i++) {
+    Node* t1 = s1->fast_out(i);
+    if (!in_bb(t1)) continue;
+    for (DUIterator_Fast jmax, j = s2->fast_outs(jmax); j < jmax; j++) {
+      Node* t2 = s2->fast_out(j);
+      if (!in_bb(t2)) continue;
+      if (!opnd_positions_match(s1, t1, s2, t2))
+        continue;
+      if (stmts_can_pack(t1, t2, align)) {
+        int my_savings = est_savings(t1, t2);
+        if (my_savings > savings) {
+          savings = my_savings;
+          u1 = t1;
+          u2 = t2;
+        }
+      }
+    }
+  }
+  if (savings >= 0) {
+    Node_List* pair = new Node_List();
+    pair->push(u1);
+    pair->push(u2);
+    _packset.append(pair);
+    set_alignment(u1, u2, align);
+    changed = true;
+  }
+  return changed;
+}
+
+//---------------------------opnd_positions_match-------------------------
+// Is the use of d1 in u1 at the same operand position as d2 in u2?
+bool SuperWord::opnd_positions_match(Node* d1, Node* u1, Node* d2, Node* u2) {
+  uint ct = u1->req();
+  if (ct != u2->req()) return false;
+  uint i1 = 0;
+  uint i2 = 0;
+  do {
+    for (i1++; i1 < ct; i1++) if (u1->in(i1) == d1) break;
+    for (i2++; i2 < ct; i2++) if (u2->in(i2) == d2) break;
+    if (i1 != i2) {
+      return false;
+    }
+  } while (i1 < ct);
+  return true;
+}
+
+//------------------------------est_savings---------------------------
+// Estimate the savings from executing s1 and s2 as a pack
+int SuperWord::est_savings(Node* s1, Node* s2) {
+  int save = 2 - 1; // 2 operations per instruction in packed form
+
+  // inputs
+  for (uint i = 1; i < s1->req(); i++) {
+    Node* x1 = s1->in(i);
+    Node* x2 = s2->in(i);
+    if (x1 != x2) {
+      if (are_adjacent_refs(x1, x2)) {
+        save += adjacent_profit(x1, x2);
+      } else if (!in_packset(x1, x2)) {
+        save -= pack_cost(2);
+      } else {
+        save += unpack_cost(2);
+      }
+    }
+  }
+
+  // uses of result
+  uint ct = 0;
+  for (DUIterator_Fast imax, i = s1->fast_outs(imax); i < imax; i++) {
+    Node* s1_use = s1->fast_out(i);
+    for (int j = 0; j < _packset.length(); j++) {
+      Node_List* p = _packset.at(j);
+      if (p->at(0) == s1_use) {
+        for (DUIterator_Fast kmax, k = s2->fast_outs(kmax); k < kmax; k++) {
+          Node* s2_use = s2->fast_out(k);
+          if (p->at(p->size()-1) == s2_use) {
+            ct++;
+            if (are_adjacent_refs(s1_use, s2_use)) {
+              save += adjacent_profit(s1_use, s2_use);
+            }
+          }
+        }
+      }
+    }
+  }
+
+  if (ct < s1->outcnt()) save += unpack_cost(1);
+  if (ct < s2->outcnt()) save += unpack_cost(1);
+
+  return save;
+}
+
+//------------------------------costs---------------------------
+int SuperWord::adjacent_profit(Node* s1, Node* s2) { return 2; }
+int SuperWord::pack_cost(int ct)   { return ct; }
+int SuperWord::unpack_cost(int ct) { return ct; }
+
+//------------------------------combine_packs---------------------------
+// Combine packs A and B with A.last == B.first into A.first..,A.last,B.second,..B.last
+void SuperWord::combine_packs() {
+  bool changed;
+  do {
+    changed = false;
+    for (int i = 0; i < _packset.length(); i++) {
+      Node_List* p1 = _packset.at(i);
+      if (p1 == NULL) continue;
+      for (int j = 0; j < _packset.length(); j++) {
+        Node_List* p2 = _packset.at(j);
+        if (p2 == NULL) continue;
+        if (p1->at(p1->size()-1) == p2->at(0)) {
+          for (uint k = 1; k < p2->size(); k++) {
+            p1->push(p2->at(k));
+          }
+          _packset.at_put(j, NULL);
+          changed = true;
+        }
+      }
+    }
+  } while (changed);
+
+  for (int i = _packset.length() - 1; i >= 0; i--) {
+    Node_List* p1 = _packset.at(i);
+    if (p1 == NULL) {
+      _packset.remove_at(i);
+    }
+  }
+
+#ifndef PRODUCT
+  if (TraceSuperWord) {
+    tty->print_cr("\nAfter combine_packs");
+    print_packset();
+  }
+#endif
+}
+
+//-----------------------------construct_my_pack_map--------------------------
+// Construct the map from nodes to packs.  Only valid after the
+// point where a node is only in one pack (after combine_packs).
+void SuperWord::construct_my_pack_map() {
+  Node_List* rslt = NULL;
+  for (int i = 0; i < _packset.length(); i++) {
+    Node_List* p = _packset.at(i);
+    for (uint j = 0; j < p->size(); j++) {
+      Node* s = p->at(j);
+      assert(my_pack(s) == NULL, "only in one pack");
+      set_my_pack(s, p);
+    }
+  }
+}
+
+//------------------------------filter_packs---------------------------
+// Remove packs that are not implemented or not profitable.
+void SuperWord::filter_packs() {
+
+  // Remove packs that are not implemented
+  for (int i = _packset.length() - 1; i >= 0; i--) {
+    Node_List* pk = _packset.at(i);
+    bool impl = implemented(pk);
+    if (!impl) {
+#ifndef PRODUCT
+      if (TraceSuperWord && Verbose) {
+        tty->print_cr("Unimplemented");
+        pk->at(0)->dump();
+      }
+#endif
+      remove_pack_at(i);
+    }
+  }
+
+  // Remove packs that are not profitable
+  bool changed;
+  do {
+    changed = false;
+    for (int i = _packset.length() - 1; i >= 0; i--) {
+      Node_List* pk = _packset.at(i);
+      bool prof = profitable(pk);
+      if (!prof) {
+#ifndef PRODUCT
+        if (TraceSuperWord && Verbose) {
+          tty->print_cr("Unprofitable");
+          pk->at(0)->dump();
+        }
+#endif
+        remove_pack_at(i);
+        changed = true;
+      }
+    }
+  } while (changed);
+
+#ifndef PRODUCT
+  if (TraceSuperWord) {
+    tty->print_cr("\nAfter filter_packs");
+    print_packset();
+    tty->cr();
+  }
+#endif
+}
+
+//------------------------------implemented---------------------------
+// Can code be generated for pack p?
+bool SuperWord::implemented(Node_List* p) {
+  Node* p0 = p->at(0);
+  int vopc = VectorNode::opcode(p0->Opcode(), p->size(), velt_type(p0));
+  return vopc > 0 && Matcher::has_match_rule(vopc);
+}
+
+//------------------------------profitable---------------------------
+// For pack p, are all operands and all uses (with in the block) vector?
+bool SuperWord::profitable(Node_List* p) {
+  Node* p0 = p->at(0);
+  uint start, end;
+  vector_opd_range(p0, &start, &end);
+
+  // Return false if some input is not vector and inside block
+  for (uint i = start; i < end; i++) {
+    if (!is_vector_use(p0, i)) {
+      // For now, return false if not scalar promotion case (inputs are the same.)
+      // Later, implement PackNode and allow differring, non-vector inputs
+      // (maybe just the ones from outside the block.)
+      Node* p0_def = p0->in(i);
+      for (uint j = 1; j < p->size(); j++) {
+        Node* use = p->at(j);
+        Node* def = use->in(i);
+        if (p0_def != def)
+          return false;
+      }
+    }
+  }
+  if (!p0->is_Store()) {
+    // For now, return false if not all uses are vector.
+    // Later, implement ExtractNode and allow non-vector uses (maybe
+    // just the ones outside the block.)
+    for (uint i = 0; i < p->size(); i++) {
+      Node* def = p->at(i);
+      for (DUIterator_Fast jmax, j = def->fast_outs(jmax); j < jmax; j++) {
+        Node* use = def->fast_out(j);
+        for (uint k = 0; k < use->req(); k++) {
+          Node* n = use->in(k);
+          if (def == n) {
+            if (!is_vector_use(use, k)) {
+              return false;
+            }
+          }
+        }
+      }
+    }
+  }
+  return true;
+}
+
+//------------------------------schedule---------------------------
+// Adjust the memory graph for the packed operations
+void SuperWord::schedule() {
+
+  // Co-locate in the memory graph the members of each memory pack
+  for (int i = 0; i < _packset.length(); i++) {
+    co_locate_pack(_packset.at(i));
+  }
+}
+
+//------------------------------co_locate_pack---------------------------
+// Within a pack, move stores down to the last executed store,
+// and move loads up to the first executed load.
+void SuperWord::co_locate_pack(Node_List* pk) {
+  if (pk->at(0)->is_Store()) {
+    // Push Stores down towards last executed pack member
+    MemNode* first     = executed_first(pk)->as_Mem();
+    MemNode* last      = executed_last(pk)->as_Mem();
+    MemNode* insert_pt = last;
+    MemNode* current   = last->in(MemNode::Memory)->as_Mem();
+    while (true) {
+      assert(in_bb(current), "stay in block");
+      Node* my_mem = current->in(MemNode::Memory);
+      if (in_pack(current, pk)) {
+        // Forward users of my memory state to my input memory state
+        _igvn.hash_delete(current);
+        _igvn.hash_delete(my_mem);
+        for (DUIterator i = current->outs(); current->has_out(i); i++) {
+          Node* use = current->out(i);
+          if (use->is_Mem()) {
+            assert(use->in(MemNode::Memory) == current, "must be");
+            _igvn.hash_delete(use);
+            use->set_req(MemNode::Memory, my_mem);
+            _igvn._worklist.push(use);
+            --i; // deleted this edge; rescan position
+          }
+        }
+        // put current immediately before insert_pt
+        current->set_req(MemNode::Memory, insert_pt->in(MemNode::Memory));
+        _igvn.hash_delete(insert_pt);
+        insert_pt->set_req(MemNode::Memory, current);
+        _igvn._worklist.push(insert_pt);
+        _igvn._worklist.push(current);
+        insert_pt = current;
+      }
+      if (current == first) break;
+      current = my_mem->as_Mem();
+    }
+  } else if (pk->at(0)->is_Load()) {
+    // Pull Loads up towards first executed pack member
+    LoadNode* first = executed_first(pk)->as_Load();
+    Node* first_mem = first->in(MemNode::Memory);
+    _igvn.hash_delete(first_mem);
+    // Give each load same memory state as first
+    for (uint i = 0; i < pk->size(); i++) {
+      LoadNode* ld = pk->at(i)->as_Load();
+      _igvn.hash_delete(ld);
+      ld->set_req(MemNode::Memory, first_mem);
+      _igvn._worklist.push(ld);
+    }
+  }
+}
+
+//------------------------------output---------------------------
+// Convert packs into vector node operations
+void SuperWord::output() {
+  if (_packset.length() == 0) return;
+
+  // MUST ENSURE main loop's initial value is properly aligned:
+  //  (iv_initial_value + min_iv_offset) % vector_width_in_bytes() == 0
+
+  align_initial_loop_index(align_to_ref());
+
+  // Insert extract (unpack) operations for scalar uses
+  for (int i = 0; i < _packset.length(); i++) {
+    insert_extracts(_packset.at(i));
+  }
+
+  for (int i = 0; i < _block.length(); i++) {
+    Node* n = _block.at(i);
+    Node_List* p = my_pack(n);
+    if (p && n == executed_last(p)) {
+      uint vlen = p->size();
+      Node* vn = NULL;
+      Node* low_adr = p->at(0);
+      Node* first   = executed_first(p);
+      if (n->is_Load()) {
+        int   opc = n->Opcode();
+        Node* ctl = n->in(MemNode::Control);
+        Node* mem = first->in(MemNode::Memory);
+        Node* adr = low_adr->in(MemNode::Address);
+        const TypePtr* atyp = n->adr_type();
+        vn = VectorLoadNode::make(_phase->C, opc, ctl, mem, adr, atyp, vlen);
+
+      } else if (n->is_Store()) {
+        // Promote value to be stored to vector
+        VectorNode* val = vector_opd(p, MemNode::ValueIn);
+
+        int   opc = n->Opcode();
+        Node* ctl = n->in(MemNode::Control);
+        Node* mem = first->in(MemNode::Memory);
+        Node* adr = low_adr->in(MemNode::Address);
+        const TypePtr* atyp = n->adr_type();
+        vn = VectorStoreNode::make(_phase->C, opc, ctl, mem, adr, atyp, val, vlen);
+
+      } else if (n->req() == 3) {
+        // Promote operands to vector
+        Node* in1 = vector_opd(p, 1);
+        Node* in2 = vector_opd(p, 2);
+        vn = VectorNode::make(_phase->C, n->Opcode(), in1, in2, vlen, velt_type(n));
+
+      } else {
+        ShouldNotReachHere();
+      }
+
+      _phase->_igvn.register_new_node_with_optimizer(vn);
+      _phase->set_ctrl(vn, _phase->get_ctrl(p->at(0)));
+      for (uint j = 0; j < p->size(); j++) {
+        Node* pm = p->at(j);
+        _igvn.hash_delete(pm);
+        _igvn.subsume_node(pm, vn);
+      }
+      _igvn._worklist.push(vn);
+    }
+  }
+}
+
+//------------------------------vector_opd---------------------------
+// Create a vector operand for the nodes in pack p for operand: in(opd_idx)
+VectorNode* SuperWord::vector_opd(Node_List* p, int opd_idx) {
+  Node* p0 = p->at(0);
+  uint vlen = p->size();
+  Node* opd = p0->in(opd_idx);
+
+  bool same_opd = true;
+  for (uint i = 1; i < vlen; i++) {
+    Node* pi = p->at(i);
+    Node* in = pi->in(opd_idx);
+    if (opd != in) {
+      same_opd = false;
+      break;
+    }
+  }
+
+  if (same_opd) {
+    if (opd->is_Vector()) {
+      return (VectorNode*)opd; // input is matching vector
+    }
+    // Convert scalar input to vector. Use p0's type because it's container
+    // maybe smaller than the operand's container.
+    const Type* opd_t = velt_type(!in_bb(opd) ? p0 : opd);
+    const Type* p0_t  = velt_type(p0);
+    if (p0_t->higher_equal(opd_t)) opd_t = p0_t;
+    VectorNode* vn    = VectorNode::scalar2vector(_phase->C, opd, vlen, opd_t);
+
+    _phase->_igvn.register_new_node_with_optimizer(vn);
+    _phase->set_ctrl(vn, _phase->get_ctrl(opd));
+    return vn;
+  }
+
+  // Insert pack operation
+  const Type* opd_t = velt_type(!in_bb(opd) ? p0 : opd);
+  PackNode* pk = PackNode::make(_phase->C, opd, opd_t);
+
+  for (uint i = 1; i < vlen; i++) {
+    Node* pi = p->at(i);
+    Node* in = pi->in(opd_idx);
+    assert(my_pack(in) == NULL, "Should already have been unpacked");
+    assert(opd_t == velt_type(!in_bb(in) ? pi : in), "all same type");
+    pk->add_opd(in);
+  }
+  _phase->_igvn.register_new_node_with_optimizer(pk);
+  _phase->set_ctrl(pk, _phase->get_ctrl(opd));
+  return pk;
+}
+
+//------------------------------insert_extracts---------------------------
+// If a use of pack p is not a vector use, then replace the
+// use with an extract operation.
+void SuperWord::insert_extracts(Node_List* p) {
+  if (p->at(0)->is_Store()) return;
+  assert(_n_idx_list.is_empty(), "empty (node,index) list");
+
+  // Inspect each use of each pack member.  For each use that is
+  // not a vector use, replace the use with an extract operation.
+
+  for (uint i = 0; i < p->size(); i++) {
+    Node* def = p->at(i);
+    for (DUIterator_Fast jmax, j = def->fast_outs(jmax); j < jmax; j++) {
+      Node* use = def->fast_out(j);
+      for (uint k = 0; k < use->req(); k++) {
+        Node* n = use->in(k);
+        if (def == n) {
+          if (!is_vector_use(use, k)) {
+            _n_idx_list.push(use, k);
+          }
+        }
+      }
+    }
+  }
+
+  while (_n_idx_list.is_nonempty()) {
+    Node* use = _n_idx_list.node();
+    int   idx = _n_idx_list.index();
+    _n_idx_list.pop();
+    Node* def = use->in(idx);
+
+    // Insert extract operation
+    _igvn.hash_delete(def);
+    _igvn.hash_delete(use);
+    int def_pos = alignment(def) / data_size(def);
+    const Type* def_t = velt_type(def);
+
+    Node* ex = ExtractNode::make(_phase->C, def, def_pos, def_t);
+    _phase->_igvn.register_new_node_with_optimizer(ex);
+    _phase->set_ctrl(ex, _phase->get_ctrl(def));
+    use->set_req(idx, ex);
+    _igvn._worklist.push(def);
+    _igvn._worklist.push(use);
+
+    bb_insert_after(ex, bb_idx(def));
+    set_velt_type(ex, def_t);
+  }
+}
+
+//------------------------------is_vector_use---------------------------
+// Is use->in(u_idx) a vector use?
+bool SuperWord::is_vector_use(Node* use, int u_idx) {
+  Node_List* u_pk = my_pack(use);
+  if (u_pk == NULL) return false;
+  Node* def = use->in(u_idx);
+  Node_List* d_pk = my_pack(def);
+  if (d_pk == NULL) {
+    // check for scalar promotion
+    Node* n = u_pk->at(0)->in(u_idx);
+    for (uint i = 1; i < u_pk->size(); i++) {
+      if (u_pk->at(i)->in(u_idx) != n) return false;
+    }
+    return true;
+  }
+  if (u_pk->size() != d_pk->size())
+    return false;
+  for (uint i = 0; i < u_pk->size(); i++) {
+    Node* ui = u_pk->at(i);
+    Node* di = d_pk->at(i);
+    if (ui->in(u_idx) != di || alignment(ui) != alignment(di))
+      return false;
+  }
+  return true;
+}
+
+//------------------------------construct_bb---------------------------
+// Construct reverse postorder list of block members
+void SuperWord::construct_bb() {
+  Node* entry = bb();
+
+  assert(_stk.length() == 0,            "stk is empty");
+  assert(_block.length() == 0,          "block is empty");
+  assert(_data_entry.length() == 0,     "data_entry is empty");
+  assert(_mem_slice_head.length() == 0, "mem_slice_head is empty");
+  assert(_mem_slice_tail.length() == 0, "mem_slice_tail is empty");
+
+  // Find non-control nodes with no inputs from within block,
+  // create a temporary map from node _idx to bb_idx for use
+  // by the visited and post_visited sets,
+  // and count number of nodes in block.
+  int bb_ct = 0;
+  for (uint i = 0; i < lpt()->_body.size(); i++ ) {
+    Node *n = lpt()->_body.at(i);
+    set_bb_idx(n, i); // Create a temporary map
+    if (in_bb(n)) {
+      bb_ct++;
+      if (!n->is_CFG()) {
+        bool found = false;
+        for (uint j = 0; j < n->req(); j++) {
+          Node* def = n->in(j);
+          if (def && in_bb(def)) {
+            found = true;
+            break;
+          }
+        }
+        if (!found) {
+          assert(n != entry, "can't be entry");
+          _data_entry.push(n);
+        }
+      }
+    }
+  }
+
+  // Find memory slices (head and tail)
+  for (DUIterator_Fast imax, i = lp()->fast_outs(imax); i < imax; i++) {
+    Node *n = lp()->fast_out(i);
+    if (in_bb(n) && (n->is_Phi() && n->bottom_type() == Type::MEMORY)) {
+      Node* n_tail  = n->in(LoopNode::LoopBackControl);
+      _mem_slice_head.push(n);
+      _mem_slice_tail.push(n_tail);
+    }
+  }
+
+  // Create an RPO list of nodes in block
+
+  visited_clear();
+  post_visited_clear();
+
+  // Push all non-control nodes with no inputs from within block, then control entry
+  for (int j = 0; j < _data_entry.length(); j++) {
+    Node* n = _data_entry.at(j);
+    visited_set(n);
+    _stk.push(n);
+  }
+  visited_set(entry);
+  _stk.push(entry);
+
+  // Do a depth first walk over out edges
+  int rpo_idx = bb_ct - 1;
+  int size;
+  while ((size = _stk.length()) > 0) {
+    Node* n = _stk.top(); // Leave node on stack
+    if (!visited_test_set(n)) {
+      // forward arc in graph
+    } else if (!post_visited_test(n)) {
+      // cross or back arc
+      for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
+        Node *use = n->fast_out(i);
+        if (in_bb(use) && !visited_test(use) &&
+            // Don't go around backedge
+            (!use->is_Phi() || n == entry)) {
+          _stk.push(use);
+        }
+      }
+      if (_stk.length() == size) {
+        // There were no additional uses, post visit node now
+        _stk.pop(); // Remove node from stack
+        assert(rpo_idx >= 0, "");
+        _block.at_put_grow(rpo_idx, n);
+        rpo_idx--;
+        post_visited_set(n);
+        assert(rpo_idx >= 0 || _stk.is_empty(), "");
+      }
+    } else {
+      _stk.pop(); // Remove post-visited node from stack
+    }
+  }
+
+  // Create real map of block indices for nodes
+  for (int j = 0; j < _block.length(); j++) {
+    Node* n = _block.at(j);
+    set_bb_idx(n, j);
+  }
+
+  initialize_bb(); // Ensure extra info is allocated.
+
+#ifndef PRODUCT
+  if (TraceSuperWord) {
+    print_bb();
+    tty->print_cr("\ndata entry nodes: %s", _data_entry.length() > 0 ? "" : "NONE");
+    for (int m = 0; m < _data_entry.length(); m++) {
+      tty->print("%3d ", m);
+      _data_entry.at(m)->dump();
+    }
+    tty->print_cr("\nmemory slices: %s", _mem_slice_head.length() > 0 ? "" : "NONE");
+    for (int m = 0; m < _mem_slice_head.length(); m++) {
+      tty->print("%3d ", m); _mem_slice_head.at(m)->dump();
+      tty->print("    ");    _mem_slice_tail.at(m)->dump();
+    }
+  }
+#endif
+  assert(rpo_idx == -1 && bb_ct == _block.length(), "all block members found");
+}
+
+//------------------------------initialize_bb---------------------------
+// Initialize per node info
+void SuperWord::initialize_bb() {
+  Node* last = _block.at(_block.length() - 1);
+  grow_node_info(bb_idx(last));
+}
+
+//------------------------------bb_insert_after---------------------------
+// Insert n into block after pos
+void SuperWord::bb_insert_after(Node* n, int pos) {
+  int n_pos = pos + 1;
+  // Make room
+  for (int i = _block.length() - 1; i >= n_pos; i--) {
+    _block.at_put_grow(i+1, _block.at(i));
+  }
+  for (int j = _node_info.length() - 1; j >= n_pos; j--) {
+    _node_info.at_put_grow(j+1, _node_info.at(j));
+  }
+  // Set value
+  _block.at_put_grow(n_pos, n);
+  _node_info.at_put_grow(n_pos, SWNodeInfo::initial);
+  // Adjust map from node->_idx to _block index
+  for (int i = n_pos; i < _block.length(); i++) {
+    set_bb_idx(_block.at(i), i);
+  }
+}
+
+//------------------------------compute_max_depth---------------------------
+// Compute max depth for expressions from beginning of block
+// Use to prune search paths during test for independence.
+void SuperWord::compute_max_depth() {
+  int ct = 0;
+  bool again;
+  do {
+    again = false;
+    for (int i = 0; i < _block.length(); i++) {
+      Node* n = _block.at(i);
+      if (!n->is_Phi()) {
+        int d_orig = depth(n);
+        int d_in   = 0;
+        for (DepPreds preds(n, _dg); !preds.done(); preds.next()) {
+          Node* pred = preds.current();
+          if (in_bb(pred)) {
+            d_in = MAX2(d_in, depth(pred));
+          }
+        }
+        if (d_in + 1 != d_orig) {
+          set_depth(n, d_in + 1);
+          again = true;
+        }
+      }
+    }
+    ct++;
+  } while (again);
+#ifndef PRODUCT
+  if (TraceSuperWord && Verbose)
+    tty->print_cr("compute_max_depth iterated: %d times", ct);
+#endif
+}
+
+//-------------------------compute_vector_element_type-----------------------
+// Compute necessary vector element type for expressions
+// This propagates backwards a narrower integer type when the
+// upper bits of the value are not needed.
+// Example:  char a,b,c;  a = b + c;
+// Normally the type of the add is integer, but for packed character
+// operations the type of the add needs to be char.
+void SuperWord::compute_vector_element_type() {
+#ifndef PRODUCT
+  if (TraceSuperWord && Verbose)
+    tty->print_cr("\ncompute_velt_type:");
+#endif
+
+  // Initial type
+  for (int i = 0; i < _block.length(); i++) {
+    Node* n = _block.at(i);
+    const Type* t  = n->is_Mem() ? Type::get_const_basic_type(n->as_Mem()->memory_type())
+                                 : _igvn.type(n);
+    const Type* vt = container_type(t);
+    set_velt_type(n, vt);
+  }
+
+  // Propagate narrowed type backwards through operations
+  // that don't depend on higher order bits
+  for (int i = _block.length() - 1; i >= 0; i--) {
+    Node* n = _block.at(i);
+    // Only integer types need be examined
+    if (n->bottom_type()->isa_int()) {
+      uint start, end;
+      vector_opd_range(n, &start, &end);
+      const Type* vt = velt_type(n);
+
+      for (uint j = start; j < end; j++) {
+        Node* in  = n->in(j);
+        // Don't propagate through a type conversion
+        if (n->bottom_type() != in->bottom_type())
+          continue;
+        switch(in->Opcode()) {
+        case Op_AddI:    case Op_AddL:
+        case Op_SubI:    case Op_SubL:
+        case Op_MulI:    case Op_MulL:
+        case Op_AndI:    case Op_AndL:
+        case Op_OrI:     case Op_OrL:
+        case Op_XorI:    case Op_XorL:
+        case Op_LShiftI: case Op_LShiftL:
+        case Op_CMoveI:  case Op_CMoveL:
+          if (in_bb(in)) {
+            bool same_type = true;
+            for (DUIterator_Fast kmax, k = in->fast_outs(kmax); k < kmax; k++) {
+              Node *use = in->fast_out(k);
+              if (!in_bb(use) || velt_type(use) != vt) {
+                same_type = false;
+                break;
+              }
+            }
+            if (same_type) {
+              set_velt_type(in, vt);
+            }
+          }
+        }
+      }
+    }
+  }
+#ifndef PRODUCT
+  if (TraceSuperWord && Verbose) {
+    for (int i = 0; i < _block.length(); i++) {
+      Node* n = _block.at(i);
+      velt_type(n)->dump();
+      tty->print("\t");
+      n->dump();
+    }
+  }
+#endif
+}
+
+//------------------------------memory_alignment---------------------------
+// Alignment within a vector memory reference
+int SuperWord::memory_alignment(MemNode* s, int iv_adjust_in_bytes) {
+  SWPointer p(s, this);
+  if (!p.valid()) {
+    return bottom_align;
+  }
+  int offset  = p.offset_in_bytes();
+  offset     += iv_adjust_in_bytes;
+  int off_rem = offset % vector_width_in_bytes();
+  int off_mod = off_rem >= 0 ? off_rem : off_rem + vector_width_in_bytes();
+  return off_mod;
+}
+
+//---------------------------container_type---------------------------
+// Smallest type containing range of values
+const Type* SuperWord::container_type(const Type* t) {
+  if (t->isa_aryptr()) {
+    t = t->is_aryptr()->elem();
+  }
+  if (t->basic_type() == T_INT) {
+    if (t->higher_equal(TypeInt::BOOL))  return TypeInt::BOOL;
+    if (t->higher_equal(TypeInt::BYTE))  return TypeInt::BYTE;
+    if (t->higher_equal(TypeInt::CHAR))  return TypeInt::CHAR;
+    if (t->higher_equal(TypeInt::SHORT)) return TypeInt::SHORT;
+    return TypeInt::INT;
+  }
+  return t;
+}
+
+//-------------------------vector_opd_range-----------------------
+// (Start, end] half-open range defining which operands are vector
+void SuperWord::vector_opd_range(Node* n, uint* start, uint* end) {
+  switch (n->Opcode()) {
+  case Op_LoadB:   case Op_LoadC:
+  case Op_LoadI:   case Op_LoadL:
+  case Op_LoadF:   case Op_LoadD:
+  case Op_LoadP:
+    *start = 0;
+    *end   = 0;
+    return;
+  case Op_StoreB:  case Op_StoreC:
+  case Op_StoreI:  case Op_StoreL:
+  case Op_StoreF:  case Op_StoreD:
+  case Op_StoreP:
+    *start = MemNode::ValueIn;
+    *end   = *start + 1;
+    return;
+  case Op_LShiftI: case Op_LShiftL:
+    *start = 1;
+    *end   = 2;
+    return;
+  case Op_CMoveI:  case Op_CMoveL:  case Op_CMoveF:  case Op_CMoveD:
+    *start = 2;
+    *end   = n->req();
+    return;
+  }
+  *start = 1;
+  *end   = n->req(); // default is all operands
+}
+
+//------------------------------in_packset---------------------------
+// Are s1 and s2 in a pack pair and ordered as s1,s2?
+bool SuperWord::in_packset(Node* s1, Node* s2) {
+  for (int i = 0; i < _packset.length(); i++) {
+    Node_List* p = _packset.at(i);
+    assert(p->size() == 2, "must be");
+    if (p->at(0) == s1 && p->at(p->size()-1) == s2) {
+      return true;
+    }
+  }
+  return false;
+}
+
+//------------------------------in_pack---------------------------
+// Is s in pack p?
+Node_List* SuperWord::in_pack(Node* s, Node_List* p) {
+  for (uint i = 0; i < p->size(); i++) {
+    if (p->at(i) == s) {
+      return p;
+    }
+  }
+  return NULL;
+}
+
+//------------------------------remove_pack_at---------------------------
+// Remove the pack at position pos in the packset
+void SuperWord::remove_pack_at(int pos) {
+  Node_List* p = _packset.at(pos);
+  for (uint i = 0; i < p->size(); i++) {
+    Node* s = p->at(i);
+    set_my_pack(s, NULL);
+  }
+  _packset.remove_at(pos);
+}
+
+//------------------------------executed_first---------------------------
+// Return the node executed first in pack p.  Uses the RPO block list
+// to determine order.
+Node* SuperWord::executed_first(Node_List* p) {
+  Node* n = p->at(0);
+  int n_rpo = bb_idx(n);
+  for (uint i = 1; i < p->size(); i++) {
+    Node* s = p->at(i);
+    int s_rpo = bb_idx(s);
+    if (s_rpo < n_rpo) {
+      n = s;
+      n_rpo = s_rpo;
+    }
+  }
+  return n;
+}
+
+//------------------------------executed_last---------------------------
+// Return the node executed last in pack p.
+Node* SuperWord::executed_last(Node_List* p) {
+  Node* n = p->at(0);
+  int n_rpo = bb_idx(n);
+  for (uint i = 1; i < p->size(); i++) {
+    Node* s = p->at(i);
+    int s_rpo = bb_idx(s);
+    if (s_rpo > n_rpo) {
+      n = s;
+      n_rpo = s_rpo;
+    }
+  }
+  return n;
+}
+
+//----------------------------align_initial_loop_index---------------------------
+// Adjust pre-loop limit so that in main loop, a load/store reference
+// to align_to_ref will be a position zero in the vector.
+//   (iv + k) mod vector_align == 0
+void SuperWord::align_initial_loop_index(MemNode* align_to_ref) {
+  CountedLoopNode *main_head = lp()->as_CountedLoop();
+  assert(main_head->is_main_loop(), "");
+  CountedLoopEndNode* pre_end = get_pre_loop_end(main_head);
+  assert(pre_end != NULL, "");
+  Node *pre_opaq1 = pre_end->limit();
+  assert(pre_opaq1->Opcode() == Op_Opaque1, "");
+  Opaque1Node *pre_opaq = (Opaque1Node*)pre_opaq1;
+  Node *pre_limit = pre_opaq->in(1);
+
+  // Where we put new limit calculations
+  Node *pre_ctrl = pre_end->loopnode()->in(LoopNode::EntryControl);
+
+  // Ensure the original loop limit is available from the
+  // pre-loop Opaque1 node.
+  Node *orig_limit = pre_opaq->original_loop_limit();
+  assert(orig_limit != NULL && _igvn.type(orig_limit) != Type::TOP, "");
+
+  SWPointer align_to_ref_p(align_to_ref, this);
+
+  // Let l0 == original pre_limit, l == new pre_limit, V == v_align
+  //
+  // For stride > 0
+  //   Need l such that l > l0 && (l+k)%V == 0
+  //   Find n such that l = (l0 + n)
+  //   (l0 + n + k) % V == 0
+  //   n = [V - (l0 + k)%V]%V
+  //   new limit = l0 + [V - (l0 + k)%V]%V
+  // For stride < 0
+  //   Need l such that l < l0 && (l+k)%V == 0
+  //   Find n such that l = (l0 - n)
+  //   (l0 - n + k) % V == 0
+  //   n = (l0 + k)%V
+  //   new limit = l0 - (l0 + k)%V
+
+  int elt_size = align_to_ref_p.memory_size();
+  int v_align  = vector_width_in_bytes() / elt_size;
+  int k        = align_to_ref_p.offset_in_bytes() / elt_size;
+
+  Node *kn   = _igvn.intcon(k);
+  Node *limk = new (_phase->C, 3) AddINode(pre_limit, kn);
+  _phase->_igvn.register_new_node_with_optimizer(limk);
+  _phase->set_ctrl(limk, pre_ctrl);
+  if (align_to_ref_p.invar() != NULL) {
+    Node* log2_elt = _igvn.intcon(exact_log2(elt_size));
+    Node* aref     = new (_phase->C, 3) URShiftINode(align_to_ref_p.invar(), log2_elt);
+    _phase->_igvn.register_new_node_with_optimizer(aref);
+    _phase->set_ctrl(aref, pre_ctrl);
+    if (!align_to_ref_p.negate_invar()) {
+      limk = new (_phase->C, 3) AddINode(limk, aref);
+    } else {
+      limk = new (_phase->C, 3) SubINode(limk, aref);
+    }
+    _phase->_igvn.register_new_node_with_optimizer(limk);
+    _phase->set_ctrl(limk, pre_ctrl);
+  }
+  Node* va_msk = _igvn.intcon(v_align - 1);
+  Node* n      = new (_phase->C, 3) AndINode(limk, va_msk);
+  _phase->_igvn.register_new_node_with_optimizer(n);
+  _phase->set_ctrl(n, pre_ctrl);
+  Node* newlim;
+  if (iv_stride() > 0) {
+    Node* va  = _igvn.intcon(v_align);
+    Node* adj = new (_phase->C, 3) SubINode(va, n);
+    _phase->_igvn.register_new_node_with_optimizer(adj);
+    _phase->set_ctrl(adj, pre_ctrl);
+    Node* adj2 = new (_phase->C, 3) AndINode(adj, va_msk);
+    _phase->_igvn.register_new_node_with_optimizer(adj2);
+    _phase->set_ctrl(adj2, pre_ctrl);
+    newlim = new (_phase->C, 3) AddINode(pre_limit, adj2);
+  } else {
+    newlim = new (_phase->C, 3) SubINode(pre_limit, n);
+  }
+  _phase->_igvn.register_new_node_with_optimizer(newlim);
+  _phase->set_ctrl(newlim, pre_ctrl);
+  Node* constrained =
+    (iv_stride() > 0) ? (Node*) new (_phase->C,3) MinINode(newlim, orig_limit)
+                      : (Node*) new (_phase->C,3) MaxINode(newlim, orig_limit);
+  _phase->_igvn.register_new_node_with_optimizer(constrained);
+  _phase->set_ctrl(constrained, pre_ctrl);
+  _igvn.hash_delete(pre_opaq);
+  pre_opaq->set_req(1, constrained);
+}
+
+//----------------------------get_pre_loop_end---------------------------
+// Find pre loop end from main loop.  Returns null if none.
+CountedLoopEndNode* SuperWord::get_pre_loop_end(CountedLoopNode *cl) {
+  Node *ctrl = cl->in(LoopNode::EntryControl);
+  if (!ctrl->is_IfTrue() && !ctrl->is_IfFalse()) return NULL;
+  Node *iffm = ctrl->in(0);
+  if (!iffm->is_If()) return NULL;
+  Node *p_f = iffm->in(0);
+  if (!p_f->is_IfFalse()) return NULL;
+  if (!p_f->in(0)->is_CountedLoopEnd()) return NULL;
+  CountedLoopEndNode *pre_end = p_f->in(0)->as_CountedLoopEnd();
+  if (!pre_end->loopnode()->is_pre_loop()) return NULL;
+  return pre_end;
+}
+
+
+//------------------------------init---------------------------
+void SuperWord::init() {
+  _dg.init();
+  _packset.clear();
+  _disjoint_ptrs.clear();
+  _block.clear();
+  _data_entry.clear();
+  _mem_slice_head.clear();
+  _mem_slice_tail.clear();
+  _node_info.clear();
+  _align_to_ref = NULL;
+  _lpt = NULL;
+  _lp = NULL;
+  _bb = NULL;
+  _iv = NULL;
+}
+
+//------------------------------print_packset---------------------------
+void SuperWord::print_packset() {
+#ifndef PRODUCT
+  tty->print_cr("packset");
+  for (int i = 0; i < _packset.length(); i++) {
+    tty->print_cr("Pack: %d", i);
+    Node_List* p = _packset.at(i);
+    print_pack(p);
+  }
+#endif
+}
+
+//------------------------------print_pack---------------------------
+void SuperWord::print_pack(Node_List* p) {
+  for (uint i = 0; i < p->size(); i++) {
+    print_stmt(p->at(i));
+  }
+}
+
+//------------------------------print_bb---------------------------
+void SuperWord::print_bb() {
+#ifndef PRODUCT
+  tty->print_cr("\nBlock");
+  for (int i = 0; i < _block.length(); i++) {
+    Node* n = _block.at(i);
+    tty->print("%d ", i);
+    if (n) {
+      n->dump();
+    }
+  }
+#endif
+}
+
+//------------------------------print_stmt---------------------------
+void SuperWord::print_stmt(Node* s) {
+#ifndef PRODUCT
+  tty->print(" align: %d \t", alignment(s));
+  s->dump();
+#endif
+}
+
+//------------------------------blank---------------------------
+char* SuperWord::blank(uint depth) {
+  static char blanks[101];
+  assert(depth < 101, "too deep");
+  for (uint i = 0; i < depth; i++) blanks[i] = ' ';
+  blanks[depth] = '\0';
+  return blanks;
+}
+
+
+//==============================SWPointer===========================
+
+//----------------------------SWPointer------------------------
+SWPointer::SWPointer(MemNode* mem, SuperWord* slp) :
+  _mem(mem), _slp(slp),  _base(NULL),  _adr(NULL),
+  _scale(0), _offset(0), _invar(NULL), _negate_invar(false) {
+
+  Node* adr = mem->in(MemNode::Address);
+  if (!adr->is_AddP()) {
+    assert(!valid(), "too complex");
+    return;
+  }
+  // Match AddP(base, AddP(ptr, k*iv [+ invariant]), constant)
+  Node* base = adr->in(AddPNode::Base);
+  for (int i = 0; i < 3; i++) {
+    if (!scaled_iv_plus_offset(adr->in(AddPNode::Offset))) {
+      assert(!valid(), "too complex");
+      return;
+    }
+    adr = adr->in(AddPNode::Address);
+    if (base == adr || !adr->is_AddP()) {
+      break; // stop looking at addp's
+    }
+  }
+  _base = base;
+  _adr  = adr;
+  assert(valid(), "Usable");
+}
+
+// Following is used to create a temporary object during
+// the pattern match of an address expression.
+SWPointer::SWPointer(SWPointer* p) :
+  _mem(p->_mem), _slp(p->_slp),  _base(NULL),  _adr(NULL),
+  _scale(0), _offset(0), _invar(NULL), _negate_invar(false) {}
+
+//------------------------scaled_iv_plus_offset--------------------
+// Match: k*iv + offset
+// where: k is a constant that maybe zero, and
+//        offset is (k2 [+/- invariant]) where k2 maybe zero and invariant is optional
+bool SWPointer::scaled_iv_plus_offset(Node* n) {
+  if (scaled_iv(n)) {
+    return true;
+  }
+  if (offset_plus_k(n)) {
+    return true;
+  }
+  int opc = n->Opcode();
+  if (opc == Op_AddI) {
+    if (scaled_iv(n->in(1)) && offset_plus_k(n->in(2))) {
+      return true;
+    }
+    if (scaled_iv(n->in(2)) && offset_plus_k(n->in(1))) {
+      return true;
+    }
+  } else if (opc == Op_SubI) {
+    if (scaled_iv(n->in(1)) && offset_plus_k(n->in(2), true)) {
+      return true;
+    }
+    if (scaled_iv(n->in(2)) && offset_plus_k(n->in(1))) {
+      _scale *= -1;
+      return true;
+    }
+  }
+  return false;
+}
+
+//----------------------------scaled_iv------------------------
+// Match: k*iv where k is a constant that's not zero
+bool SWPointer::scaled_iv(Node* n) {
+  if (_scale != 0) {
+    return false;  // already found a scale
+  }
+  if (n == iv()) {
+    _scale = 1;
+    return true;
+  }
+  int opc = n->Opcode();
+  if (opc == Op_MulI) {
+    if (n->in(1) == iv() && n->in(2)->is_Con()) {
+      _scale = n->in(2)->get_int();
+      return true;
+    } else if (n->in(2) == iv() && n->in(1)->is_Con()) {
+      _scale = n->in(1)->get_int();
+      return true;
+    }
+  } else if (opc == Op_LShiftI) {
+    if (n->in(1) == iv() && n->in(2)->is_Con()) {
+      _scale = 1 << n->in(2)->get_int();
+      return true;
+    }
+  } else if (opc == Op_ConvI2L) {
+    if (scaled_iv_plus_offset(n->in(1))) {
+      return true;
+    }
+  } else if (opc == Op_LShiftL) {
+    if (!has_iv() && _invar == NULL) {
+      // Need to preserve the current _offset value, so
+      // create a temporary object for this expression subtree.
+      // Hacky, so should re-engineer the address pattern match.
+      SWPointer tmp(this);
+      if (tmp.scaled_iv_plus_offset(n->in(1))) {
+        if (tmp._invar == NULL) {
+          int mult = 1 << n->in(2)->get_int();
+          _scale   = tmp._scale  * mult;
+          _offset += tmp._offset * mult;
+          return true;
+        }
+      }
+    }
+  }
+  return false;
+}
+
+//----------------------------offset_plus_k------------------------
+// Match: offset is (k [+/- invariant])
+// where k maybe zero and invariant is optional, but not both.
+bool SWPointer::offset_plus_k(Node* n, bool negate) {
+  int opc = n->Opcode();
+  if (opc == Op_ConI) {
+    _offset += negate ? -(n->get_int()) : n->get_int();
+    return true;
+  } else if (opc == Op_ConL) {
+    // Okay if value fits into an int
+    const TypeLong* t = n->find_long_type();
+    if (t->higher_equal(TypeLong::INT)) {
+      jlong loff = n->get_long();
+      jint  off  = (jint)loff;
+      _offset += negate ? -off : loff;
+      return true;
+    }
+    return false;
+  }
+  if (_invar != NULL) return false; // already have an invariant
+  if (opc == Op_AddI) {
+    if (n->in(2)->is_Con() && invariant(n->in(1))) {
+      _negate_invar = negate;
+      _invar = n->in(1);
+      _offset += negate ? -(n->in(2)->get_int()) : n->in(2)->get_int();
+      return true;
+    } else if (n->in(1)->is_Con() && invariant(n->in(2))) {
+      _offset += negate ? -(n->in(1)->get_int()) : n->in(1)->get_int();
+      _negate_invar = negate;
+      _invar = n->in(2);
+      return true;
+    }
+  }
+  if (opc == Op_SubI) {
+    if (n->in(2)->is_Con() && invariant(n->in(1))) {
+      _negate_invar = negate;
+      _invar = n->in(1);
+      _offset += !negate ? -(n->in(2)->get_int()) : n->in(2)->get_int();
+      return true;
+    } else if (n->in(1)->is_Con() && invariant(n->in(2))) {
+      _offset += negate ? -(n->in(1)->get_int()) : n->in(1)->get_int();
+      _negate_invar = !negate;
+      _invar = n->in(2);
+      return true;
+    }
+  }
+  if (invariant(n)) {
+    _negate_invar = negate;
+    _invar = n;
+    return true;
+  }
+  return false;
+}
+
+//----------------------------print------------------------
+void SWPointer::print() {
+#ifndef PRODUCT
+  tty->print("base: %d  adr: %d  scale: %d  offset: %d  invar: %c%d\n",
+             _base != NULL ? _base->_idx : 0,
+             _adr  != NULL ? _adr->_idx  : 0,
+             _scale, _offset,
+             _negate_invar?'-':'+',
+             _invar != NULL ? _invar->_idx : 0);
+#endif
+}
+
+// ========================= OrderedPair =====================
+
+const OrderedPair OrderedPair::initial;
+
+// ========================= SWNodeInfo =====================
+
+const SWNodeInfo SWNodeInfo::initial;
+
+
+// ============================ DepGraph ===========================
+
+//------------------------------make_node---------------------------
+// Make a new dependence graph node for an ideal node.
+DepMem* DepGraph::make_node(Node* node) {
+  DepMem* m = new (_arena) DepMem(node);
+  if (node != NULL) {
+    assert(_map.at_grow(node->_idx) == NULL, "one init only");
+    _map.at_put_grow(node->_idx, m);
+  }
+  return m;
+}
+
+//------------------------------make_edge---------------------------
+// Make a new dependence graph edge from dpred -> dsucc
+DepEdge* DepGraph::make_edge(DepMem* dpred, DepMem* dsucc) {
+  DepEdge* e = new (_arena) DepEdge(dpred, dsucc, dsucc->in_head(), dpred->out_head());
+  dpred->set_out_head(e);
+  dsucc->set_in_head(e);
+  return e;
+}
+
+// ========================== DepMem ========================
+
+//------------------------------in_cnt---------------------------
+int DepMem::in_cnt() {
+  int ct = 0;
+  for (DepEdge* e = _in_head; e != NULL; e = e->next_in()) ct++;
+  return ct;
+}
+
+//------------------------------out_cnt---------------------------
+int DepMem::out_cnt() {
+  int ct = 0;
+  for (DepEdge* e = _out_head; e != NULL; e = e->next_out()) ct++;
+  return ct;
+}
+
+//------------------------------print-----------------------------
+void DepMem::print() {
+#ifndef PRODUCT
+  tty->print("  DepNode %d (", _node->_idx);
+  for (DepEdge* p = _in_head; p != NULL; p = p->next_in()) {
+    Node* pred = p->pred()->node();
+    tty->print(" %d", pred != NULL ? pred->_idx : 0);
+  }
+  tty->print(") [");
+  for (DepEdge* s = _out_head; s != NULL; s = s->next_out()) {
+    Node* succ = s->succ()->node();
+    tty->print(" %d", succ != NULL ? succ->_idx : 0);
+  }
+  tty->print_cr(" ]");
+#endif
+}
+
+// =========================== DepEdge =========================
+
+//------------------------------DepPreds---------------------------
+void DepEdge::print() {
+#ifndef PRODUCT
+  tty->print_cr("DepEdge: %d [ %d ]", _pred->node()->_idx, _succ->node()->_idx);
+#endif
+}
+
+// =========================== DepPreds =========================
+// Iterator over predecessor edges in the dependence graph.
+
+//------------------------------DepPreds---------------------------
+DepPreds::DepPreds(Node* n, DepGraph& dg) {
+  _n = n;
+  _done = false;
+  if (_n->is_Store() || _n->is_Load()) {
+    _next_idx = MemNode::Address;
+    _end_idx  = n->req();
+    _dep_next = dg.dep(_n)->in_head();
+  } else if (_n->is_Mem()) {
+    _next_idx = 0;
+    _end_idx  = 0;
+    _dep_next = dg.dep(_n)->in_head();
+  } else {
+    _next_idx = 1;
+    _end_idx  = _n->req();
+    _dep_next = NULL;
+  }
+  next();
+}
+
+//------------------------------next---------------------------
+void DepPreds::next() {
+  if (_dep_next != NULL) {
+    _current  = _dep_next->pred()->node();
+    _dep_next = _dep_next->next_in();
+  } else if (_next_idx < _end_idx) {
+    _current  = _n->in(_next_idx++);
+  } else {
+    _done = true;
+  }
+}
+
+// =========================== DepSuccs =========================
+// Iterator over successor edges in the dependence graph.
+
+//------------------------------DepSuccs---------------------------
+DepSuccs::DepSuccs(Node* n, DepGraph& dg) {
+  _n = n;
+  _done = false;
+  if (_n->is_Load()) {
+    _next_idx = 0;
+    _end_idx  = _n->outcnt();
+    _dep_next = dg.dep(_n)->out_head();
+  } else if (_n->is_Mem() || _n->is_Phi() && _n->bottom_type() == Type::MEMORY) {
+    _next_idx = 0;
+    _end_idx  = 0;
+    _dep_next = dg.dep(_n)->out_head();
+  } else {
+    _next_idx = 0;
+    _end_idx  = _n->outcnt();
+    _dep_next = NULL;
+  }
+  next();
+}
+
+//-------------------------------next---------------------------
+void DepSuccs::next() {
+  if (_dep_next != NULL) {
+    _current  = _dep_next->succ()->node();
+    _dep_next = _dep_next->next_out();
+  } else if (_next_idx < _end_idx) {
+    _current  = _n->raw_out(_next_idx++);
+  } else {
+    _done = true;
+  }
+}