--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/opto/superword.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,506 @@
+/*
+ * 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.
+ */
+
+//
+//                  S U P E R W O R D   T R A N S F O R M
+//
+// SuperWords are short, fixed length vectors.
+//
+// Algorithm from:
+//
+// Exploiting SuperWord Level Parallelism with
+//   Multimedia Instruction Sets
+// by
+//   Samuel Larsen and Saman Amarasighe
+//   MIT Laboratory for Computer Science
+// date
+//   May 2000
+// published in
+//   ACM SIGPLAN Notices
+//   Proceedings of ACM PLDI '00,  Volume 35 Issue 5
+//
+// Definition 3.1 A Pack is an n-tuple, <s1, ...,sn>, where
+// s1,...,sn are independent isomorphic statements in a basic
+// block.
+//
+// Definition 3.2 A PackSet is a set of Packs.
+//
+// Definition 3.3 A Pair is a Pack of size two, where the
+// first statement is considered the left element, and the
+// second statement is considered the right element.
+
+class SWPointer;
+class OrderedPair;
+
+// ========================= Dependence Graph =====================
+
+class DepMem;
+
+//------------------------------DepEdge---------------------------
+// An edge in the dependence graph.  The edges incident to a dependence
+// node are threaded through _next_in for incoming edges and _next_out
+// for outgoing edges.
+class DepEdge : public ResourceObj {
+ protected:
+  DepMem* _pred;
+  DepMem* _succ;
+  DepEdge* _next_in;   // list of in edges, null terminated
+  DepEdge* _next_out;  // list of out edges, null terminated
+
+ public:
+  DepEdge(DepMem* pred, DepMem* succ, DepEdge* next_in, DepEdge* next_out) :
+    _pred(pred), _succ(succ), _next_in(next_in), _next_out(next_out) {}
+
+  DepEdge* next_in()  { return _next_in; }
+  DepEdge* next_out() { return _next_out; }
+  DepMem*  pred()     { return _pred; }
+  DepMem*  succ()     { return _succ; }
+
+  void print();
+};
+
+//------------------------------DepMem---------------------------
+// A node in the dependence graph.  _in_head starts the threaded list of
+// incoming edges, and _out_head starts the list of outgoing edges.
+class DepMem : public ResourceObj {
+ protected:
+  Node*    _node;     // Corresponding ideal node
+  DepEdge* _in_head;  // Head of list of in edges, null terminated
+  DepEdge* _out_head; // Head of list of out edges, null terminated
+
+ public:
+  DepMem(Node* node) : _node(node), _in_head(NULL), _out_head(NULL) {}
+
+  Node*    node()                { return _node;     }
+  DepEdge* in_head()             { return _in_head;  }
+  DepEdge* out_head()            { return _out_head; }
+  void set_in_head(DepEdge* hd)  { _in_head = hd;    }
+  void set_out_head(DepEdge* hd) { _out_head = hd;   }
+
+  int in_cnt();  // Incoming edge count
+  int out_cnt(); // Outgoing edge count
+
+  void print();
+};
+
+//------------------------------DepGraph---------------------------
+class DepGraph VALUE_OBJ_CLASS_SPEC {
+ protected:
+  Arena* _arena;
+  GrowableArray<DepMem*> _map;
+  DepMem* _root;
+  DepMem* _tail;
+
+ public:
+  DepGraph(Arena* a) : _arena(a), _map(a, 8,  0, NULL) {
+    _root = new (_arena) DepMem(NULL);
+    _tail = new (_arena) DepMem(NULL);
+  }
+
+  DepMem* root() { return _root; }
+  DepMem* tail() { return _tail; }
+
+  // Return dependence node corresponding to an ideal node
+  DepMem* dep(Node* node) { return _map.at(node->_idx); }
+
+  // Make a new dependence graph node for an ideal node.
+  DepMem* make_node(Node* node);
+
+  // Make a new dependence graph edge dprec->dsucc
+  DepEdge* make_edge(DepMem* dpred, DepMem* dsucc);
+
+  DepEdge* make_edge(Node* pred,   Node* succ)   { return make_edge(dep(pred), dep(succ)); }
+  DepEdge* make_edge(DepMem* pred, Node* succ)   { return make_edge(pred,      dep(succ)); }
+  DepEdge* make_edge(Node* pred,   DepMem* succ) { return make_edge(dep(pred), succ);      }
+
+  void init() { _map.clear(); } // initialize
+
+  void print(Node* n)   { dep(n)->print(); }
+  void print(DepMem* d) { d->print(); }
+};
+
+//------------------------------DepPreds---------------------------
+// Iterator over predecessors in the dependence graph and
+// non-memory-graph inputs of ideal nodes.
+class DepPreds : public StackObj {
+private:
+  Node*    _n;
+  int      _next_idx, _end_idx;
+  DepEdge* _dep_next;
+  Node*    _current;
+  bool     _done;
+
+public:
+  DepPreds(Node* n, DepGraph& dg);
+  Node* current() { return _current; }
+  bool  done()    { return _done; }
+  void  next();
+};
+
+//------------------------------DepSuccs---------------------------
+// Iterator over successors in the dependence graph and
+// non-memory-graph outputs of ideal nodes.
+class DepSuccs : public StackObj {
+private:
+  Node*    _n;
+  int      _next_idx, _end_idx;
+  DepEdge* _dep_next;
+  Node*    _current;
+  bool     _done;
+
+public:
+  DepSuccs(Node* n, DepGraph& dg);
+  Node* current() { return _current; }
+  bool  done()    { return _done; }
+  void  next();
+};
+
+
+// ========================= SuperWord =====================
+
+// -----------------------------SWNodeInfo---------------------------------
+// Per node info needed by SuperWord
+class SWNodeInfo VALUE_OBJ_CLASS_SPEC {
+ public:
+  int         _alignment; // memory alignment for a node
+  int         _depth;     // Max expression (DAG) depth from block start
+  const Type* _velt_type; // vector element type
+  Node_List*  _my_pack;   // pack containing this node
+
+  SWNodeInfo() : _alignment(-1), _depth(0), _velt_type(NULL), _my_pack(NULL) {}
+  static const SWNodeInfo initial;
+};
+
+// -----------------------------SuperWord---------------------------------
+// Transforms scalar operations into packed (superword) operations.
+class SuperWord : public ResourceObj {
+ private:
+  PhaseIdealLoop* _phase;
+  Arena*          _arena;
+  PhaseIterGVN   &_igvn;
+
+  enum consts { top_align = -1, bottom_align = -666 };
+
+  GrowableArray<Node_List*> _packset;    // Packs for the current block
+
+  GrowableArray<int> _bb_idx;            // Map from Node _idx to index within block
+
+  GrowableArray<Node*> _block;           // Nodes in current block
+  GrowableArray<Node*> _data_entry;      // Nodes with all inputs from outside
+  GrowableArray<Node*> _mem_slice_head;  // Memory slice head nodes
+  GrowableArray<Node*> _mem_slice_tail;  // Memory slice tail nodes
+
+  GrowableArray<SWNodeInfo> _node_info;  // Info needed per node
+
+  MemNode* _align_to_ref;                // Memory reference that pre-loop will align to
+
+  GrowableArray<OrderedPair> _disjoint_ptrs; // runtime disambiguated pointer pairs
+
+  DepGraph _dg; // Dependence graph
+
+  // Scratch pads
+  VectorSet    _visited;       // Visited set
+  VectorSet    _post_visited;  // Post-visited set
+  Node_Stack   _n_idx_list;    // List of (node,index) pairs
+  GrowableArray<Node*> _nlist; // List of nodes
+  GrowableArray<Node*> _stk;   // Stack of nodes
+
+ public:
+  SuperWord(PhaseIdealLoop* phase);
+
+  void transform_loop(IdealLoopTree* lpt);
+
+  // Accessors for SWPointer
+  PhaseIdealLoop* phase()          { return _phase; }
+  IdealLoopTree* lpt()             { return _lpt; }
+  PhiNode* iv()                    { return _iv; }
+
+ private:
+  IdealLoopTree* _lpt;             // Current loop tree node
+  LoopNode*      _lp;              // Current LoopNode
+  Node*          _bb;              // Current basic block
+  PhiNode*       _iv;              // Induction var
+
+  // Accessors
+  Arena* arena()                   { return _arena; }
+
+  Node* bb()                       { return _bb; }
+  void  set_bb(Node* bb)           { _bb = bb; }
+
+  void set_lpt(IdealLoopTree* lpt) { _lpt = lpt; }
+
+  LoopNode* lp()                   { return _lp; }
+  void      set_lp(LoopNode* lp)   { _lp = lp;
+                                     _iv = lp->as_CountedLoop()->phi()->as_Phi(); }
+  int      iv_stride()             { return lp()->as_CountedLoop()->stride_con(); }
+
+  int vector_width_in_bytes()      { return Matcher::vector_width_in_bytes(); }
+
+  MemNode* align_to_ref()            { return _align_to_ref; }
+  void  set_align_to_ref(MemNode* m) { _align_to_ref = m; }
+
+  Node* ctrl(Node* n) const { return _phase->has_ctrl(n) ? _phase->get_ctrl(n) : n; }
+
+  // block accessors
+  bool in_bb(Node* n)      { return n != NULL && n->outcnt() > 0 && ctrl(n) == _bb; }
+  int  bb_idx(Node* n)     { assert(in_bb(n), "must be"); return _bb_idx.at(n->_idx); }
+  void set_bb_idx(Node* n, int i) { _bb_idx.at_put_grow(n->_idx, i); }
+
+  // visited set accessors
+  void visited_clear()           { _visited.Clear(); }
+  void visited_set(Node* n)      { return _visited.set(bb_idx(n)); }
+  int visited_test(Node* n)      { return _visited.test(bb_idx(n)); }
+  int visited_test_set(Node* n)  { return _visited.test_set(bb_idx(n)); }
+  void post_visited_clear()      { _post_visited.Clear(); }
+  void post_visited_set(Node* n) { return _post_visited.set(bb_idx(n)); }
+  int post_visited_test(Node* n) { return _post_visited.test(bb_idx(n)); }
+
+  // Ensure node_info contains element "i"
+  void grow_node_info(int i) { if (i >= _node_info.length()) _node_info.at_put_grow(i, SWNodeInfo::initial); }
+
+  // memory alignment for a node
+  int alignment(Node* n)                     { return _node_info.adr_at(bb_idx(n))->_alignment; }
+  void set_alignment(Node* n, int a)         { int i = bb_idx(n); grow_node_info(i); _node_info.adr_at(i)->_alignment = a; }
+
+  // Max expression (DAG) depth from beginning of the block for each node
+  int depth(Node* n)                         { return _node_info.adr_at(bb_idx(n))->_depth; }
+  void set_depth(Node* n, int d)             { int i = bb_idx(n); grow_node_info(i); _node_info.adr_at(i)->_depth = d; }
+
+  // vector element type
+  const Type* velt_type(Node* n)             { return _node_info.adr_at(bb_idx(n))->_velt_type; }
+  void set_velt_type(Node* n, const Type* t) { int i = bb_idx(n); grow_node_info(i); _node_info.adr_at(i)->_velt_type = t; }
+
+  // my_pack
+  Node_List* my_pack(Node* n)                { return !in_bb(n) ? NULL : _node_info.adr_at(bb_idx(n))->_my_pack; }
+  void set_my_pack(Node* n, Node_List* p)    { int i = bb_idx(n); grow_node_info(i); _node_info.adr_at(i)->_my_pack = p; }
+
+  // methods
+
+  // Extract the superword level parallelism
+  void SLP_extract();
+  // Find the adjacent memory references and create pack pairs for them.
+  void find_adjacent_refs();
+  // Find a memory reference to align the loop induction variable to.
+  void find_align_to_ref(Node_List &memops);
+  // Can the preloop align the reference to position zero in the vector?
+  bool ref_is_alignable(SWPointer& p);
+  // Construct dependency graph.
+  void dependence_graph();
+  // Return a memory slice (node list) in predecessor order starting at "start"
+  void mem_slice_preds(Node* start, Node* stop, GrowableArray<Node*> &preds);
+  // Can s1 and s2 be in a pack with s1 immediately preceeding s2 and  s1 aligned at "align"
+  bool stmts_can_pack(Node* s1, Node* s2, int align);
+  // Does s exist in a pack at position pos?
+  bool exists_at(Node* s, uint pos);
+  // Is s1 immediately before s2 in memory?
+  bool are_adjacent_refs(Node* s1, Node* s2);
+  // Are s1 and s2 similar?
+  bool isomorphic(Node* s1, Node* s2);
+  // Is there no data path from s1 to s2 or s2 to s1?
+  bool independent(Node* s1, Node* s2);
+  // Helper for independent
+  bool independent_path(Node* shallow, Node* deep, uint dp=0);
+  void set_alignment(Node* s1, Node* s2, int align);
+  int data_size(Node* s);
+  // Extend packset by following use->def and def->use links from pack members.
+  void extend_packlist();
+  // Extend the packset by visiting operand definitions of nodes in pack p
+  bool follow_use_defs(Node_List* p);
+  // Extend the packset by visiting uses of nodes in pack p
+  bool follow_def_uses(Node_List* p);
+  // Estimate the savings from executing s1 and s2 as a pack
+  int est_savings(Node* s1, Node* s2);
+  int adjacent_profit(Node* s1, Node* s2);
+  int pack_cost(int ct);
+  int unpack_cost(int ct);
+  // Combine packs A and B with A.last == B.first into A.first..,A.last,B.second,..B.last
+  void combine_packs();
+  // Construct the map from nodes to packs.
+  void construct_my_pack_map();
+  // Remove packs that are not implemented or not profitable.
+  void filter_packs();
+  // Adjust the memory graph for the packed operations
+  void schedule();
+  // Within a pack, move stores down to the last executed store,
+  // and move loads up to the first executed load.
+  void co_locate_pack(Node_List* p);
+  // Convert packs into vector node operations
+  void output();
+  // Create a vector operand for the nodes in pack p for operand: in(opd_idx)
+  VectorNode* vector_opd(Node_List* p, int opd_idx);
+  // Can code be generated for pack p?
+  bool implemented(Node_List* p);
+  // For pack p, are all operands and all uses (with in the block) vector?
+  bool profitable(Node_List* p);
+  // If a use of pack p is not a vector use, then replace the use with an extract operation.
+  void insert_extracts(Node_List* p);
+  // Is use->in(u_idx) a vector use?
+  bool is_vector_use(Node* use, int u_idx);
+  // Construct reverse postorder list of block members
+  void construct_bb();
+  // Initialize per node info
+  void initialize_bb();
+  // Insert n into block after pos
+  void bb_insert_after(Node* n, int pos);
+  // Compute max depth for expressions from beginning of block
+  void compute_max_depth();
+  // Compute necessary vector element type for expressions
+  void compute_vector_element_type();
+  // Are s1 and s2 in a pack pair and ordered as s1,s2?
+  bool in_packset(Node* s1, Node* s2);
+  // Is s in pack p?
+  Node_List* in_pack(Node* s, Node_List* p);
+  // Remove the pack at position pos in the packset
+  void remove_pack_at(int pos);
+  // Return the node executed first in pack p.
+  Node* executed_first(Node_List* p);
+  // Return the node executed last in pack p.
+  Node* executed_last(Node_List* p);
+  // Alignment within a vector memory reference
+  int memory_alignment(MemNode* s, int iv_adjust_in_bytes);
+  // (Start, end] half-open range defining which operands are vector
+  void vector_opd_range(Node* n, uint* start, uint* end);
+  // Smallest type containing range of values
+  static const Type* container_type(const Type* t);
+  // 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.
+  void align_initial_loop_index(MemNode* align_to_ref);
+  // Find pre loop end from main loop.  Returns null if none.
+  CountedLoopEndNode* get_pre_loop_end(CountedLoopNode *cl);
+  // Is the use of d1 in u1 at the same operand position as d2 in u2?
+  bool opnd_positions_match(Node* d1, Node* u1, Node* d2, Node* u2);
+  void init();
+
+  // print methods
+  void print_packset();
+  void print_pack(Node_List* p);
+  void print_bb();
+  void print_stmt(Node* s);
+  char* blank(uint depth);
+};
+
+
+//------------------------------SWPointer---------------------------
+// Information about an address for dependence checking and vector alignment
+class SWPointer VALUE_OBJ_CLASS_SPEC {
+ protected:
+  MemNode*   _mem;     // My memory reference node
+  SuperWord* _slp;     // SuperWord class
+
+  Node* _base;         // NULL if unsafe nonheap reference
+  Node* _adr;          // address pointer
+  jint  _scale;        // multipler for iv (in bytes), 0 if no loop iv
+  jint  _offset;       // constant offset (in bytes)
+  Node* _invar;        // invariant offset (in bytes), NULL if none
+  bool  _negate_invar; // if true then use: (0 - _invar)
+
+  PhaseIdealLoop* phase() { return _slp->phase(); }
+  IdealLoopTree*  lpt()   { return _slp->lpt(); }
+  PhiNode*        iv()    { return _slp->iv();  } // Induction var
+
+  bool invariant(Node* n) {
+    Node *n_c = phase()->get_ctrl(n);
+    return !lpt()->is_member(phase()->get_loop(n_c));
+  }
+
+  // Match: k*iv + offset
+  bool scaled_iv_plus_offset(Node* n);
+  // Match: k*iv where k is a constant that's not zero
+  bool scaled_iv(Node* n);
+  // Match: offset is (k [+/- invariant])
+  bool offset_plus_k(Node* n, bool negate = false);
+
+ public:
+  enum CMP {
+    Less          = 1,
+    Greater       = 2,
+    Equal         = 4,
+    NotEqual      = (Less | Greater),
+    NotComparable = (Less | Greater | Equal)
+  };
+
+  SWPointer(MemNode* mem, SuperWord* slp);
+  // Following is used to create a temporary object during
+  // the pattern match of an address expression.
+  SWPointer(SWPointer* p);
+
+  bool valid()  { return _adr != NULL; }
+  bool has_iv() { return _scale != 0; }
+
+  Node* base()            { return _base; }
+  Node* adr()             { return _adr; }
+  int   scale_in_bytes()  { return _scale; }
+  Node* invar()           { return _invar; }
+  bool  negate_invar()    { return _negate_invar; }
+  int   offset_in_bytes() { return _offset; }
+  int   memory_size()     { return _mem->memory_size(); }
+
+  // Comparable?
+  int cmp(SWPointer& q) {
+    if (valid() && q.valid() &&
+        (_adr == q._adr || _base == _adr && q._base == q._adr) &&
+        _scale == q._scale   &&
+        _invar == q._invar   &&
+        _negate_invar == q._negate_invar) {
+      bool overlap = q._offset <   _offset +   memory_size() &&
+                       _offset < q._offset + q.memory_size();
+      return overlap ? Equal : (_offset < q._offset ? Less : Greater);
+    } else {
+      return NotComparable;
+    }
+  }
+
+  bool not_equal(SWPointer& q)    { return not_equal(cmp(q)); }
+  bool equal(SWPointer& q)        { return equal(cmp(q)); }
+  bool comparable(SWPointer& q)   { return comparable(cmp(q)); }
+  static bool not_equal(int cmp)  { return cmp <= NotEqual; }
+  static bool equal(int cmp)      { return cmp == Equal; }
+  static bool comparable(int cmp) { return cmp < NotComparable; }
+
+  void print();
+};
+
+
+//------------------------------OrderedPair---------------------------
+// Ordered pair of Node*.
+class OrderedPair VALUE_OBJ_CLASS_SPEC {
+ protected:
+  Node* _p1;
+  Node* _p2;
+ public:
+  OrderedPair() : _p1(NULL), _p2(NULL) {}
+  OrderedPair(Node* p1, Node* p2) {
+    if (p1->_idx < p2->_idx) {
+      _p1 = p1; _p2 = p2;
+    } else {
+      _p1 = p2; _p2 = p1;
+    }
+  }
+
+  bool operator==(const OrderedPair &rhs) {
+    return _p1 == rhs._p1 && _p2 == rhs._p2;
+  }
+  void print() { tty->print("  (%d, %d)", _p1->_idx, _p2->_idx); }
+
+  static const OrderedPair initial;
+};