alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (superword.cpp)

This example Java source code file (superword.cpp) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

basictype, depedge, depmem, duiterator_fast, memnode, memnode\:\:memory, node, node_list, null, product, swpointer, t_int, tracesuperword, type

The superword.cpp Java example source code

/*
 * Copyright (c) 2007, 2013, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

#include "precompiled.hpp"
#include "compiler/compileLog.hpp"
#include "libadt/vectset.hpp"
#include "memory/allocation.inline.hpp"
#include "opto/addnode.hpp"
#include "opto/callnode.hpp"
#include "opto/divnode.hpp"
#include "opto/matcher.hpp"
#include "opto/memnode.hpp"
#include "opto/mulnode.hpp"
#include "opto/opcodes.hpp"
#include "opto/superword.hpp"
#include "opto/vectornode.hpp"

//
//                  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(UseSuperWord, "should be");
  // Do vectors exist on this architecture?
  if (Matcher::vector_width_in_bytes(T_BYTE) < 2) return;

  assert(lpt->_head->is_CountedLoop(), "must be");
  CountedLoopNode *cl = lpt->_head->as_CountedLoop();

  if (!cl->is_valid_counted_loop()) return; // skip malformed counted loop

  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;

  // Make sure the are no extra control users of the loop backedge
  if (cl->back_control()->outcnt() != 1) {
    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;

  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

  if (!construct_bb())
    return; // Exit if no interesting nodes or complex graph.

  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() && !n->is_LoadStore() && in_bb(n) &&
        is_java_primitive(n->as_Mem()->memory_type())) {
      int align = memory_alignment(n->as_Mem(), 0);
      if (align != bottom_align) {
        memops.push(n);
      }
    }
  }

  Node_List align_to_refs;
  int best_iv_adjustment = 0;
  MemNode* best_align_to_mem_ref = NULL;

  while (memops.size() != 0) {
    // Find a memory reference to align to.
    MemNode* mem_ref = find_align_to_ref(memops);
    if (mem_ref == NULL) break;
    align_to_refs.push(mem_ref);
    int iv_adjustment = get_iv_adjustment(mem_ref);

    if (best_align_to_mem_ref == NULL) {
      // Set memory reference which is the best from all memory operations
      // to be used for alignment. The pre-loop trip count is modified to align
      // this reference to a vector-aligned address.
      best_align_to_mem_ref = mem_ref;
      best_iv_adjustment = iv_adjustment;
    }

    SWPointer align_to_ref_p(mem_ref, this);
    // Set alignment relative to "align_to_ref" for all related memory operations.
    for (int i = memops.size() - 1; i >= 0; i--) {
      MemNode* s = memops.at(i)->as_Mem();
      if (isomorphic(s, mem_ref)) {
        SWPointer p2(s, this);
        if (p2.comparable(align_to_ref_p)) {
          int align = memory_alignment(s, iv_adjustment);
          set_alignment(s, align);
        }
      }
    }

    // Create initial pack pairs of memory operations for which
    // alignment is set and vectors will be aligned.
    bool create_pack = true;
    if (memory_alignment(mem_ref, best_iv_adjustment) == 0) {
      if (!Matcher::misaligned_vectors_ok()) {
        int vw = vector_width(mem_ref);
        int vw_best = vector_width(best_align_to_mem_ref);
        if (vw > vw_best) {
          // Do not vectorize a memory access with more elements per vector
          // if unaligned memory access is not allowed because number of
          // iterations in pre-loop will be not enough to align it.
          create_pack = false;
        }
      }
    } else {
      if (same_velt_type(mem_ref, best_align_to_mem_ref)) {
        // Can't allow vectorization of unaligned memory accesses with the
        // same type since it could be overlapped accesses to the same array.
        create_pack = false;
      } else {
        // Allow independent (different type) unaligned memory operations
        // if HW supports them.
        if (!Matcher::misaligned_vectors_ok()) {
          create_pack = false;
        } else {
          // Check if packs of the same memory type but
          // with a different alignment were created before.
          for (uint i = 0; i < align_to_refs.size(); i++) {
            MemNode* mr = align_to_refs.at(i)->as_Mem();
            if (same_velt_type(mr, mem_ref) &&
                memory_alignment(mr, iv_adjustment) != 0)
              create_pack = false;
          }
        }
      }
    }
    if (create_pack) {
      for (uint i = 0; i < memops.size(); i++) {
        Node* s1 = memops.at(i);
        int align = alignment(s1);
        if (align == top_align) continue;
        for (uint j = 0; j < memops.size(); j++) {
          Node* s2 = memops.at(j);
          if (alignment(s2) == top_align) continue;
          if (s1 != s2 && are_adjacent_refs(s1, s2)) {
            if (stmts_can_pack(s1, s2, align)) {
              Node_List* pair = new Node_List();
              pair->push(s1);
              pair->push(s2);
              _packset.append(pair);
            }
          }
        }
      }
    } else { // Don't create unaligned pack
      // First, remove remaining memory ops of the same type from the list.
      for (int i = memops.size() - 1; i >= 0; i--) {
        MemNode* s = memops.at(i)->as_Mem();
        if (same_velt_type(s, mem_ref)) {
          memops.remove(i);
        }
      }

      // Second, remove already constructed packs of the same type.
      for (int i = _packset.length() - 1; i >= 0; i--) {
        Node_List* p = _packset.at(i);
        MemNode* s = p->at(0)->as_Mem();
        if (same_velt_type(s, mem_ref)) {
          remove_pack_at(i);
        }
      }

      // If needed find the best memory reference for loop alignment again.
      if (same_velt_type(mem_ref, best_align_to_mem_ref)) {
        // Put memory ops from remaining packs back on memops list for
        // the best alignment search.
        uint orig_msize = memops.size();
        for (int i = 0; i < _packset.length(); i++) {
          Node_List* p = _packset.at(i);
          MemNode* s = p->at(0)->as_Mem();
          assert(!same_velt_type(s, mem_ref), "sanity");
          memops.push(s);
        }
        MemNode* best_align_to_mem_ref = find_align_to_ref(memops);
        if (best_align_to_mem_ref == NULL) break;
        best_iv_adjustment = get_iv_adjustment(best_align_to_mem_ref);
        // Restore list.
        while (memops.size() > orig_msize)
          (void)memops.pop();
      }
    } // unaligned memory accesses

    // Remove used mem nodes.
    for (int i = memops.size() - 1; i >= 0; i--) {
      MemNode* m = memops.at(i)->as_Mem();
      if (alignment(m) != top_align) {
        memops.remove(i);
      }
    }

  } // while (memops.size() != 0
  set_align_to_ref(best_align_to_mem_ref);

#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.
MemNode* 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,
  // biggest vector size, smallest data size and smallest iv offset.
  int max_ct        = 0;
  int max_vw        = 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()) {
      int vw = vector_width_in_bytes(s);
      assert(vw > 1, "sanity");
      SWPointer p(s, this);
      if (cmp_ct.at(j) >  max_ct ||
          cmp_ct.at(j) == max_ct &&
            (vw >  max_vw ||
             vw == max_vw &&
              (data_size(s) <  min_size ||
               data_size(s) == min_size &&
                 (p.offset_in_bytes() < min_iv_offset)))) {
        max_ct = cmp_ct.at(j);
        max_vw = vw;
        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()) {
        int vw = vector_width_in_bytes(s);
        assert(vw > 1, "sanity");
        SWPointer p(s, this);
        if (cmp_ct.at(j) >  max_ct ||
            cmp_ct.at(j) == max_ct &&
              (vw >  max_vw ||
               vw == max_vw &&
                (data_size(s) <  min_size ||
                 data_size(s) == min_size &&
                   (p.offset_in_bytes() < min_iv_offset)))) {
          max_ct = cmp_ct.at(j);
          max_vw = vw;
          max_idx = j;
          min_size = data_size(s);
          min_iv_offset = p.offset_in_bytes();
        }
      }
    }
  }

#ifdef ASSERT
  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

  if (max_ct > 0) {
#ifdef ASSERT
    if (TraceSuperWord) {
      tty->print("\nVector align to node: ");
      memops.at(max_idx)->as_Mem()->dump();
    }
#endif
    return memops.at(max_idx)->as_Mem();
  }
  return NULL;
}

//------------------------------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(p.mem());
  assert(vw > 1, "sanity");
  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;
}

//---------------------------get_iv_adjustment---------------------------
// Calculate loop's iv adjustment for this memory ops.
int SuperWord::get_iv_adjustment(MemNode* mem_ref) {
  SWPointer align_to_ref_p(mem_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(mem_ref);
  assert(vw > 1, "sanity");
  int stride_sign   = (scale * iv_stride()) > 0 ? 1 : -1;
  // At least one iteration is executed in pre-loop by default. As result
  // several iterations are needed to align memory operations in main-loop even
  // if offset is 0.
  int iv_adjustment_in_bytes = (stride_sign * vw - (offset % vw));
  int elt_size = align_to_ref_p.memory_size();
  assert(((ABS(iv_adjustment_in_bytes) % elt_size) == 0),
         err_msg_res("(%d) should be divisible by (%d)", iv_adjustment_in_bytes, elt_size));
  int iv_adjustment = iv_adjustment_in_bytes/elt_size;

#ifndef PRODUCT
  if (TraceSuperWord)
    tty->print_cr("\noffset = %d iv_adjust = %d elt_size = %d scale = %d iv_stride = %d vect_size %d",
                  offset, iv_adjustment, elt_size, scale, iv_stride(), vw);
#endif
  return iv_adjustment;
}

//---------------------------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(MemNode::OopStore) == 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;
    assert(n->is_Mem(), err_msg_res("unexpected node %s", n->Name()));
    n = n->in(MemNode::Memory);
  }
}

//------------------------------stmts_can_pack---------------------------
// Can s1 and s2 be in a pack with s1 immediately preceding s2 and
// s1 aligned at "align"
bool SuperWord::stmts_can_pack(Node* s1, Node* s2, int align) {

  // Do not use superword for non-primitives
  BasicType bt1 = velt_basic_type(s1);
  BasicType bt2 = velt_basic_type(s2);
  if(!is_java_primitive(bt1) || !is_java_primitive(bt2))
    return false;
  if (Matcher::max_vector_size(bt1) < 2) {
    return false; // No vectors for this type
  }

  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;

  // Do not use superword for non-primitives
  if (!is_java_primitive(s1->as_Mem()->memory_type()) ||
      !is_java_primitive(s2->as_Mem()->memory_type())) {
    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 (!same_velt_type(s1, 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);
  if (align == top_align || align == bottom_align) {
    set_alignment(s2, align);
  } else {
    set_alignment(s2, align + data_size(s1));
  }
}

//------------------------------data_size---------------------------
int SuperWord::data_size(Node* s) {
  int bsize = type2aelembytes(velt_basic_type(s));
  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) {
  assert(p->size() == 2, "just checking");
  Node* s1 = p->at(0);
  Node* s2 = p->at(1);
  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) {
      if ((i1 == (3-i2)) && (u2->is_Add() || u2->is_Mul())) {
        // Further analysis relies on operands position matching.
        u2->swap_edges(i1, i2);
      } else {
        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_in = 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_in += adjacent_profit(x1, x2);
      } else if (!in_packset(x1, x2)) {
        save_in -= pack_cost(2);
      } else {
        save_in += unpack_cost(2);
      }
    }
  }

  // uses of result
  uint ct = 0;
  int save_use = 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_use += adjacent_profit(s1_use, s2_use);
            }
          }
        }
      }
    }
  }

  if (ct < s1->outcnt()) save_use += unpack_cost(1);
  if (ct < s2->outcnt()) save_use += unpack_cost(1);

  return MAX2(save_in, save_use);
}

//------------------------------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 = true;
  // Combine packs regardless max vector size.
  while (changed) {
    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 (i == j) 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;
        }
      }
    }
  }

  // Split packs which have size greater then max vector size.
  for (int i = 0; i < _packset.length(); i++) {
    Node_List* p1 = _packset.at(i);
    if (p1 != NULL) {
      BasicType bt = velt_basic_type(p1->at(0));
      uint max_vlen = Matcher::max_vector_size(bt); // Max elements in vector
      assert(is_power_of_2(max_vlen), "sanity");
      uint psize = p1->size();
      if (!is_power_of_2(psize)) {
        // Skip pack which can't be vector.
        // case1: for(...) { a[i] = i; }    elements values are different (i+x)
        // case2: for(...) { a[i] = b[i+1]; }  can't align both, load and store
        _packset.at_put(i, NULL);
        continue;
      }
      if (psize > max_vlen) {
        Node_List* pack = new Node_List();
        for (uint j = 0; j < psize; j++) {
          pack->push(p1->at(j));
          if (pack->size() >= max_vlen) {
            assert(is_power_of_2(pack->size()), "sanity");
            _packset.append(pack);
            pack = new Node_List();
          }
        }
        _packset.at_put(i, NULL);
      }
    }
  }

  // Compress list.
  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);
  return VectorNode::implemented(p0->Opcode(), p->size(), velt_basic_type(p0));
}

//------------------------------same_inputs--------------------------
// For pack p, are all idx operands the same?
static bool same_inputs(Node_List* p, int idx) {
  Node* p0 = p->at(0);
  uint vlen = p->size();
  Node* p0_def = p0->in(idx);
  for (uint i = 1; i < vlen; i++) {
    Node* pi = p->at(i);
    Node* pi_def = pi->in(idx);
    if (p0_def != pi_def)
      return false;
  }
  return true;
}

//------------------------------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;
  VectorNode::vector_operands(p0, &start, &end);

  // Return false if some inputs are not vectors or vectors with different
  // size or alignment.
  // Also, for now, return false if not scalar promotion case when inputs are
  // the same. Later, implement PackNode and allow differing, non-vector inputs
  // (maybe just the ones from outside the block.)
  for (uint i = start; i < end; i++) {
    if (!is_vector_use(p0, i))
      return false;
  }
  if (VectorNode::is_shift(p0)) {
    // For now, return false if shift count is vector or not scalar promotion
    // case (different shift counts) because it is not supported yet.
    Node* cnt = p0->in(2);
    Node_List* cnt_pk = my_pack(cnt);
    if (cnt_pk != NULL)
      return false;
    if (!same_inputs(p, 2))
      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));
  }
}

//-------------------------------remove_and_insert-------------------
// Remove "current" from its current position in the memory graph and insert
// it after the appropriate insertion point (lip or uip).
void SuperWord::remove_and_insert(MemNode *current, MemNode *prev, MemNode *lip,
                                  Node *uip, Unique_Node_List &sched_before) {
  Node* my_mem = current->in(MemNode::Memory);
  bool sched_up = sched_before.member(current);

  // remove current_store from its current position in the memmory graph
  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");
      if (use == prev) { // connect prev to my_mem
          _igvn.replace_input_of(use, MemNode::Memory, my_mem);
          --i; //deleted this edge; rescan position
      } else if (sched_before.member(use)) {
        if (!sched_up) { // Will be moved together with current
          _igvn.replace_input_of(use, MemNode::Memory, uip);
          --i; //deleted this edge; rescan position
        }
      } else {
        if (sched_up) { // Will be moved together with current
          _igvn.replace_input_of(use, MemNode::Memory, lip);
          --i; //deleted this edge; rescan position
        }
      }
    }
  }

  Node *insert_pt =  sched_up ?  uip : lip;

  // all uses of insert_pt's memory state should use current's instead
  for (DUIterator i = insert_pt->outs(); insert_pt->has_out(i); i++) {
    Node* use = insert_pt->out(i);
    if (use->is_Mem()) {
      assert(use->in(MemNode::Memory) == insert_pt, "must be");
      _igvn.replace_input_of(use, MemNode::Memory, current);
      --i; //deleted this edge; rescan position
    } else if (!sched_up && use->is_Phi() && use->bottom_type() == Type::MEMORY) {
      uint pos; //lip (lower insert point) must be the last one in the memory slice
      for (pos=1; pos < use->req(); pos++) {
        if (use->in(pos) == insert_pt) break;
      }
      _igvn.replace_input_of(use, pos, current);
      --i;
    }
  }

  //connect current to insert_pt
  _igvn.replace_input_of(current, MemNode::Memory, insert_pt);
}

//------------------------------co_locate_pack----------------------------------
// To schedule a store pack, we need to move any sandwiched memory ops either before
// or after the pack, based upon dependence information:
// (1) If any store in the pack depends on the sandwiched memory op, the
//     sandwiched memory op must be scheduled BEFORE the pack;
// (2) If a sandwiched memory op depends on any store in the pack, the
//     sandwiched memory op must be scheduled AFTER the pack;
// (3) If a sandwiched memory op (say, memA) depends on another sandwiched
//     memory op (say memB), memB must be scheduled before memA. So, if memA is
//     scheduled before the pack, memB must also be scheduled before the pack;
// (4) If there is no dependence restriction for a sandwiched memory op, we simply
//     schedule this store AFTER the pack
// (5) We know there is no dependence cycle, so there in no other case;
// (6) Finally, all memory ops in another single pack should be moved in the same direction.
//
// To schedule a load pack, we use the memory state of either the first or the last load in
// the pack, based on the dependence constraint.
void SuperWord::co_locate_pack(Node_List* pk) {
  if (pk->at(0)->is_Store()) {
    MemNode* first     = executed_first(pk)->as_Mem();
    MemNode* last      = executed_last(pk)->as_Mem();
    Unique_Node_List schedule_before_pack;
    Unique_Node_List memops;

    MemNode* current   = last->in(MemNode::Memory)->as_Mem();
    MemNode* previous  = last;
    while (true) {
      assert(in_bb(current), "stay in block");
      memops.push(previous);
      for (DUIterator i = current->outs(); current->has_out(i); i++) {
        Node* use = current->out(i);
        if (use->is_Mem() && use != previous)
          memops.push(use);
      }
      if (current == first) break;
      previous = current;
      current  = current->in(MemNode::Memory)->as_Mem();
    }

    // determine which memory operations should be scheduled before the pack
    for (uint i = 1; i < memops.size(); i++) {
      Node *s1 = memops.at(i);
      if (!in_pack(s1, pk) && !schedule_before_pack.member(s1)) {
        for (uint j = 0; j< i; j++) {
          Node *s2 = memops.at(j);
          if (!independent(s1, s2)) {
            if (in_pack(s2, pk) || schedule_before_pack.member(s2)) {
              schedule_before_pack.push(s1); // s1 must be scheduled before
              Node_List* mem_pk = my_pack(s1);
              if (mem_pk != NULL) {
                for (uint ii = 0; ii < mem_pk->size(); ii++) {
                  Node* s = mem_pk->at(ii);  // follow partner
                  if (memops.member(s) && !schedule_before_pack.member(s))
                    schedule_before_pack.push(s);
                }
              }
              break;
            }
          }
        }
      }
    }

    Node*    upper_insert_pt = first->in(MemNode::Memory);
    // Following code moves loads connected to upper_insert_pt below aliased stores.
    // Collect such loads here and reconnect them back to upper_insert_pt later.
    memops.clear();
    for (DUIterator i = upper_insert_pt->outs(); upper_insert_pt->has_out(i); i++) {
      Node* use = upper_insert_pt->out(i);
      if (!use->is_Store())
        memops.push(use);
    }

    MemNode* lower_insert_pt = last;
    previous                 = last; //previous store in pk
    current                  = last->in(MemNode::Memory)->as_Mem();

    // start scheduling from "last" to "first"
    while (true) {
      assert(in_bb(current), "stay in block");
      assert(in_pack(previous, pk), "previous stays in pack");
      Node* my_mem = current->in(MemNode::Memory);

      if (in_pack(current, pk)) {
        // Forward users of my memory state (except "previous) to my input memory state
        for (DUIterator i = current->outs(); current->has_out(i); i++) {
          Node* use = current->out(i);
          if (use->is_Mem() && use != previous) {
            assert(use->in(MemNode::Memory) == current, "must be");
            if (schedule_before_pack.member(use)) {
              _igvn.replace_input_of(use, MemNode::Memory, upper_insert_pt);
            } else {
              _igvn.replace_input_of(use, MemNode::Memory, lower_insert_pt);
            }
            --i; // deleted this edge; rescan position
          }
        }
        previous = current;
      } else { // !in_pack(current, pk) ==> a sandwiched store
        remove_and_insert(current, previous, lower_insert_pt, upper_insert_pt, schedule_before_pack);
      }

      if (current == first) break;
      current = my_mem->as_Mem();
    } // end while

    // Reconnect loads back to upper_insert_pt.
    for (uint i = 0; i < memops.size(); i++) {
      Node *ld = memops.at(i);
      if (ld->in(MemNode::Memory) != upper_insert_pt) {
        _igvn.replace_input_of(ld, MemNode::Memory, upper_insert_pt);
      }
    }
  } else if (pk->at(0)->is_Load()) { //load
    // all loads in the pack should have the same memory state. By default,
    // we use the memory state of the last load. However, if any load could
    // not be moved down due to the dependence constraint, we use the memory
    // state of the first load.
    Node* last_mem  = executed_last(pk)->in(MemNode::Memory);
    Node* first_mem = executed_first(pk)->in(MemNode::Memory);
    bool schedule_last = true;
    for (uint i = 0; i < pk->size(); i++) {
      Node* ld = pk->at(i);
      for (Node* current = last_mem; current != ld->in(MemNode::Memory);
           current=current->in(MemNode::Memory)) {
        assert(current != first_mem, "corrupted memory graph");
        if(current->is_Mem() && !independent(current, ld)){
          schedule_last = false; // a later store depends on this load
          break;
        }
      }
    }

    Node* mem_input = schedule_last ? last_mem : first_mem;
    _igvn.hash_delete(mem_input);
    // Give each load the same memory state
    for (uint i = 0; i < pk->size(); i++) {
      LoadNode* ld = pk->at(i)->as_Load();
      _igvn.replace_input_of(ld, MemNode::Memory, mem_input);
    }
  }
}

//------------------------------output---------------------------
// Convert packs into vector node operations
void SuperWord::output() {
  if (_packset.length() == 0) return;

#ifndef PRODUCT
  if (TraceLoopOpts) {
    tty->print("SuperWord    ");
    lpt()->dump_head();
  }
#endif

  // 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));
  }

  Compile* C = _phase->C;
  uint max_vlen_in_bytes = 0;
  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();
      uint vlen_in_bytes = 0;
      Node* vn = NULL;
      Node* low_adr = p->at(0);
      Node* first   = executed_first(p);
      int   opc = n->Opcode();
      if (n->is_Load()) {
        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 = LoadVectorNode::make(C, opc, ctl, mem, adr, atyp, vlen, velt_basic_type(n));
        vlen_in_bytes = vn->as_LoadVector()->memory_size();
      } else if (n->is_Store()) {
        // Promote value to be stored to vector
        Node* val = vector_opd(p, MemNode::ValueIn);
        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 = StoreVectorNode::make(C, opc, ctl, mem, adr, atyp, val, vlen);
        vlen_in_bytes = vn->as_StoreVector()->memory_size();
      } else if (n->req() == 3) {
        // Promote operands to vector
        Node* in1 = vector_opd(p, 1);
        Node* in2 = vector_opd(p, 2);
        if (VectorNode::is_invariant_vector(in1) && (n->is_Add() || n->is_Mul())) {
          // Move invariant vector input into second position to avoid register spilling.
          Node* tmp = in1;
          in1 = in2;
          in2 = tmp;
        }
        vn = VectorNode::make(C, opc, in1, in2, vlen, velt_basic_type(n));
        vlen_in_bytes = vn->as_Vector()->length_in_bytes();
      } else {
        ShouldNotReachHere();
      }
      assert(vn != NULL, "sanity");
      _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.replace_node(pm, vn);
      }
      _igvn._worklist.push(vn);

      if (vlen_in_bytes > max_vlen_in_bytes) {
        max_vlen_in_bytes = vlen_in_bytes;
      }
#ifdef ASSERT
      if (TraceNewVectors) {
        tty->print("new Vector node: ");
        vn->dump();
      }
#endif
    }
  }
  C->set_max_vector_size(max_vlen_in_bytes);
}

//------------------------------vector_opd---------------------------
// Create a vector operand for the nodes in pack p for operand: in(opd_idx)
Node* SuperWord::vector_opd(Node_List* p, int opd_idx) {
  Node* p0 = p->at(0);
  uint vlen = p->size();
  Node* opd = p0->in(opd_idx);

  if (same_inputs(p, opd_idx)) {
    if (opd->is_Vector() || opd->is_LoadVector()) {
      assert(((opd_idx != 2) || !VectorNode::is_shift(p0)), "shift's count can't be vector");
      return opd; // input is matching vector
    }
    if ((opd_idx == 2) && VectorNode::is_shift(p0)) {
      Compile* C = _phase->C;
      Node* cnt = opd;
      // Vector instructions do not mask shift count, do it here.
      juint mask = (p0->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
      const TypeInt* t = opd->find_int_type();
      if (t != NULL && t->is_con()) {
        juint shift = t->get_con();
        if (shift > mask) { // Unsigned cmp
          cnt = ConNode::make(C, TypeInt::make(shift & mask));
        }
      } else {
        if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
          cnt = ConNode::make(C, TypeInt::make(mask));
          _igvn.register_new_node_with_optimizer(cnt);
          cnt = new (C) AndINode(opd, cnt);
          _igvn.register_new_node_with_optimizer(cnt);
          _phase->set_ctrl(cnt, _phase->get_ctrl(opd));
        }
        assert(opd->bottom_type()->isa_int(), "int type only");
        // Move non constant shift count into vector register.
        cnt = VectorNode::shift_count(C, p0, cnt, vlen, velt_basic_type(p0));
      }
      if (cnt != opd) {
        _igvn.register_new_node_with_optimizer(cnt);
        _phase->set_ctrl(cnt, _phase->get_ctrl(opd));
      }
      return cnt;
    }
    assert(!opd->is_StoreVector(), "such vector is not expected here");
    // Convert scalar input to vector with the same number of elements as
    // p0's vector. Use p0's type because size of operand's container in
    // vector should match p0's size regardless operand's size.
    const Type* p0_t = velt_type(p0);
    VectorNode* vn = VectorNode::scalar2vector(_phase->C, opd, vlen, p0_t);

    _igvn.register_new_node_with_optimizer(vn);
    _phase->set_ctrl(vn, _phase->get_ctrl(opd));
#ifdef ASSERT
    if (TraceNewVectors) {
      tty->print("new Vector node: ");
      vn->dump();
    }
#endif
    return vn;
  }

  // Insert pack operation
  BasicType bt = velt_basic_type(p0);
  PackNode* pk = PackNode::make(_phase->C, opd, vlen, bt);
  DEBUG_ONLY( const BasicType opd_bt = opd->bottom_type()->basic_type(); )

  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_bt == in->bottom_type()->basic_type(), "all same type");
    pk->add_opd(in);
  }
  _igvn.register_new_node_with_optimizer(pk);
  _phase->set_ctrl(pk, _phase->get_ctrl(opd));
#ifdef ASSERT
  if (TraceNewVectors) {
    tty->print("new Vector node: ");
    pk->dump();
  }
#endif
  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);
    int def_pos = alignment(def) / data_size(def);

    Node* ex = ExtractNode::make(_phase->C, def, def_pos, velt_basic_type(def));
    _igvn.register_new_node_with_optimizer(ex);
    _phase->set_ctrl(ex, _phase->get_ctrl(def));
    _igvn.replace_input_of(use, idx, ex);
    _igvn._worklist.push(def);

    bb_insert_after(ex, bb_idx(def));
    set_velt_type(ex, velt_type(def));
  }
}

//------------------------------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
bool 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)) {
      if (n->is_LoadStore() || n->is_MergeMem() ||
          (n->is_Proj() && !n->as_Proj()->is_CFG())) {
        // Bailout if the loop has LoadStore, MergeMem or data Proj
        // nodes. Superword optimization does not work with them.
        return false;
      }
      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);
      if (n_tail != n->in(LoopNode::EntryControl)) {
        if (!n_tail->is_Mem()) {
          assert(n_tail->is_Mem(), err_msg_res("unexpected node for memory slice: %s", n_tail->Name()));
          return false; // Bailout
        }
        _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");
  return (_mem_slice_head.length() > 0) || (_data_entry.length() > 0);
}

//------------------------------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);
    set_velt_type(n, container_type(n));
  }

  // Propagate integer 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
    const Type* vtn = velt_type(n);
    if (vtn->basic_type() == T_INT) {
      uint start, end;
      VectorNode::vector_operands(n, &start, &end);

      for (uint j = start; j < end; j++) {
        Node* in  = n->in(j);
        // Don't propagate through a memory
        if (!in->is_Mem() && in_bb(in) && velt_type(in)->basic_type() == T_INT &&
            data_size(n) < data_size(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) || !same_velt_type(use, n)) {
              same_type = false;
              break;
            }
          }
          if (same_type) {
            // For right shifts of small integer types (bool, byte, char, short)
            // we need precise information about sign-ness. Only Load nodes have
            // this information because Store nodes are the same for signed and
            // unsigned values. And any arithmetic operation after a load may
            // expand a value to signed Int so such right shifts can't be used
            // because vector elements do not have upper bits of Int.
            const Type* vt = vtn;
            if (VectorNode::is_shift(in)) {
              Node* load = in->in(1);
              if (load->is_Load() && in_bb(load) && (velt_type(load)->basic_type() == T_INT)) {
                vt = velt_type(load);
              } else if (in->Opcode() != Op_LShiftI) {
                // Widen type to Int to avoid creation of right shift vector
                // (align + data_size(s1) check in stmts_can_pack() will fail).
                // Note, left shifts work regardless type.
                vt = TypeInt::INT;
              }
            }
            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) {
  SWPointer p(s, this);
  if (!p.valid()) {
    return bottom_align;
  }
  int vw = vector_width_in_bytes(s);
  if (vw < 2) {
    return bottom_align; // No vectors for this type
  }
  int offset  = p.offset_in_bytes();
  offset     += iv_adjust*p.memory_size();
  int off_rem = offset % vw;
  int off_mod = off_rem >= 0 ? off_rem : off_rem + vw;
  return off_mod;
}

//---------------------------container_type---------------------------
// Smallest type containing range of values
const Type* SuperWord::container_type(Node* n) {
  if (n->is_Mem()) {
    BasicType bt = n->as_Mem()->memory_type();
    if (n->is_Store() && (bt == T_CHAR)) {
      // Use T_SHORT type instead of T_CHAR for stored values because any
      // preceding arithmetic operation extends values to signed Int.
      bt = T_SHORT;
    }
    if (n->Opcode() == Op_LoadUB) {
      // Adjust type for unsigned byte loads, it is important for right shifts.
      // T_BOOLEAN is used because there is no basic type representing type
      // TypeInt::UBYTE. Use of T_BOOLEAN for vectors is fine because only
      // size (one byte) and sign is important.
      bt = T_BOOLEAN;
    }
    return Type::get_const_basic_type(bt);
  }
  const Type* t = _igvn.type(n);
  if (t->basic_type() == T_INT) {
    // A narrow type of arithmetic operations will be determined by
    // propagating the type of memory operations.
    return TypeInt::INT;
  }
  return t;
}

bool SuperWord::same_velt_type(Node* n1, Node* n2) {
  const Type* vt1 = velt_type(n1);
  const Type* vt2 = velt_type(n2);
  if (vt1->basic_type() == T_INT && vt2->basic_type() == T_INT) {
    // Compare vectors element sizes for integer types.
    return data_size(n1) == data_size(n2);
  }
  return vt1 == vt2;
}

//------------------------------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 *lim0 = 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);
  assert(align_to_ref_p.valid(), "sanity");

  // Given:
  //     lim0 == original pre loop limit
  //     V == v_align (power of 2)
  //     invar == extra invariant piece of the address expression
  //     e == offset [ +/- invar ]
  //
  // When reassociating expressions involving '%' the basic rules are:
  //     (a - b) % k == 0   =>  a % k == b % k
  // and:
  //     (a + b) % k == 0   =>  a % k == (k - b) % k
  //
  // For stride > 0 && scale > 0,
  //   Derive the new pre-loop limit "lim" such that the two constraints:
  //     (1) lim = lim0 + N           (where N is some positive integer < V)
  //     (2) (e + lim) % V == 0
  //   are true.
  //
  //   Substituting (1) into (2),
  //     (e + lim0 + N) % V == 0
  //   solve for N:
  //     N = (V - (e + lim0)) % V
  //   substitute back into (1), so that new limit
  //     lim = lim0 + (V - (e + lim0)) % V
  //
  // For stride > 0 && scale < 0
  //   Constraints:
  //     lim = lim0 + N
  //     (e - lim) % V == 0
  //   Solving for lim:
  //     (e - lim0 - N) % V == 0
  //     N = (e - lim0) % V
  //     lim = lim0 + (e - lim0) % V
  //
  // For stride < 0 && scale > 0
  //   Constraints:
  //     lim = lim0 - N
  //     (e + lim) % V == 0
  //   Solving for lim:
  //     (e + lim0 - N) % V == 0
  //     N = (e + lim0) % V
  //     lim = lim0 - (e + lim0) % V
  //
  // For stride < 0 && scale < 0
  //   Constraints:
  //     lim = lim0 - N
  //     (e - lim) % V == 0
  //   Solving for lim:
  //     (e - lim0 + N) % V == 0
  //     N = (V - (e - lim0)) % V
  //     lim = lim0 - (V - (e - lim0)) % V

  int vw = vector_width_in_bytes(align_to_ref);
  int stride   = iv_stride();
  int scale    = align_to_ref_p.scale_in_bytes();
  int elt_size = align_to_ref_p.memory_size();
  int v_align  = vw / elt_size;
  assert(v_align > 1, "sanity");
  int offset   = align_to_ref_p.offset_in_bytes() / elt_size;
  Node *offsn  = _igvn.intcon(offset);

  Node *e = offsn;
  if (align_to_ref_p.invar() != NULL) {
    // incorporate any extra invariant piece producing (offset +/- invar) >>> log2(elt)
    Node* log2_elt = _igvn.intcon(exact_log2(elt_size));
    Node* aref     = new (_phase->C) URShiftINode(align_to_ref_p.invar(), log2_elt);
    _igvn.register_new_node_with_optimizer(aref);
    _phase->set_ctrl(aref, pre_ctrl);
    if (align_to_ref_p.negate_invar()) {
      e = new (_phase->C) SubINode(e, aref);
    } else {
      e = new (_phase->C) AddINode(e, aref);
    }
    _igvn.register_new_node_with_optimizer(e);
    _phase->set_ctrl(e, pre_ctrl);
  }
  if (vw > ObjectAlignmentInBytes) {
    // incorporate base e +/- base && Mask >>> log2(elt)
    Node* xbase = new(_phase->C) CastP2XNode(NULL, align_to_ref_p.base());
    _igvn.register_new_node_with_optimizer(xbase);
#ifdef _LP64
    xbase  = new (_phase->C) ConvL2INode(xbase);
    _igvn.register_new_node_with_optimizer(xbase);
#endif
    Node* mask = _igvn.intcon(vw-1);
    Node* masked_xbase  = new (_phase->C) AndINode(xbase, mask);
    _igvn.register_new_node_with_optimizer(masked_xbase);
    Node* log2_elt = _igvn.intcon(exact_log2(elt_size));
    Node* bref     = new (_phase->C) URShiftINode(masked_xbase, log2_elt);
    _igvn.register_new_node_with_optimizer(bref);
    _phase->set_ctrl(bref, pre_ctrl);
    e = new (_phase->C) AddINode(e, bref);
    _igvn.register_new_node_with_optimizer(e);
    _phase->set_ctrl(e, pre_ctrl);
  }

  // compute e +/- lim0
  if (scale < 0) {
    e = new (_phase->C) SubINode(e, lim0);
  } else {
    e = new (_phase->C) AddINode(e, lim0);
  }
  _igvn.register_new_node_with_optimizer(e);
  _phase->set_ctrl(e, pre_ctrl);

  if (stride * scale > 0) {
    // compute V - (e +/- lim0)
    Node* va  = _igvn.intcon(v_align);
    e = new (_phase->C) SubINode(va, e);
    _igvn.register_new_node_with_optimizer(e);
    _phase->set_ctrl(e, pre_ctrl);
  }
  // compute N = (exp) % V
  Node* va_msk = _igvn.intcon(v_align - 1);
  Node* N = new (_phase->C) AndINode(e, va_msk);
  _igvn.register_new_node_with_optimizer(N);
  _phase->set_ctrl(N, pre_ctrl);

  //   substitute back into (1), so that new limit
  //     lim = lim0 + N
  Node* lim;
  if (stride < 0) {
    lim = new (_phase->C) SubINode(lim0, N);
  } else {
    lim = new (_phase->C) AddINode(lim0, N);
  }
  _igvn.register_new_node_with_optimizer(lim);
  _phase->set_ctrl(lim, pre_ctrl);
  Node* constrained =
    (stride > 0) ? (Node*) new (_phase->C) MinINode(lim, orig_limit)
                 : (Node*) new (_phase->C) MaxINode(lim, orig_limit);
  _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);
  //unsafe reference could not be aligned appropriately without runtime checking
  if (base == NULL || base->bottom_type() == Type::TOP) {
    assert(!valid(), "unsafe access");
    return;
  }
  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;
  }
}

Other Java examples (source code examples)

Here is a short list of links related to this Java superword.cpp source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2024 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.