/*

 * Copyright 2005-2006 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.

 *

 */

//-----------------------------------------------------------------------------

//----------------------------IdealKit-----------------------------------------

// Set of utilities for creating control flow and scalar SSA data flow.

// Control:

//    if_then(left, relop, right)

//    else_ (optional)

//    end_if

//    loop(iv variable, initial, relop, limit)

//       - sets iv to initial for first trip

//       - exits when relation on limit is true

//       - the values of initial and limit should be loop invariant

//       - no increment, must be explicitly coded

//       - final value of iv is available after end_loop (until dead())

//    end_loop

//    make_label(number of gotos)

//    goto_(label)

//    bind(label)

// Data:

//    ConI(integer constant)     - create an integer constant

//    set(variable, value)       - assignment

//    value(variable)            - reference value

//    dead(variable)             - variable's value is no longer live

//    increment(variable, value) - increment variable by value

//    simple operations: AddI, SubI, AndI, LShiftI, etc.

// Example:

//    Node* limit = ??

//    IdealVariable i(kit), j(kit);

//    declares_done();

//    Node* exit = make_label(1); // 1 goto

//    set(j, ConI(0));

//    loop(i, ConI(0), BoolTest::lt, limit); {

//       if_then(value(i), BoolTest::gt, ConI(5)) {

//         set(j, ConI(1));

//         goto_(exit); dead(i);

//       } end_if();

//       increment(i, ConI(1));

//    } end_loop(); dead(i);

//    bind(exit);

//

// See string_indexOf for a more complete example.

class IdealKit;

// Variable definition for IdealKit

class IdealVariable: public StackObj {

 friend class IdealKit;

 private:

  int _id;

  void set_id(int id) { _id = id; }

 public:

  IdealVariable(IdealKit &k);

  int id() { assert(has_id(),"uninitialized id"); return _id; }

  bool has_id() { return _id >= 0; }

};

class IdealKit: public StackObj {

 friend class IdealVariable;

  // The main state (called a cvstate for Control and Variables)

  // contains both the current values of the variables and the

  // current set of predecessor control edges.  The variable values

  // are managed via a Node [in(1)..in(_var_ct)], and the predecessor

  // control edges managed via a RegionNode. The in(0) of the Node

  // for variables points to the RegionNode for the control edges.

 protected:

  Compile * const C;

  PhaseGVN &_gvn;

  GrowableArray<Node*>* _pending_cvstates; // stack of cvstates

  GrowableArray<Node*>* _delay_transform;  // delay invoking gvn.transform until drain

  Node* _cvstate;                          // current cvstate (control, memory and variables)

  uint _var_ct;                            // number of variables

  bool _delay_all_transforms;              // flag forcing all transforms to be delayed

  Node* _initial_ctrl;                     // saves initial control until variables declared

  Node* _initial_memory;                   // saves initial memory  until variables declared

  PhaseGVN& gvn() const { return _gvn; }

  // Create a new cvstate filled with nulls

  Node* new_cvstate();                     // Create a new cvstate

  Node* cvstate() { return _cvstate; }     // current cvstate

  Node* copy_cvstate();                    // copy current cvstate

  void set_ctrl(Node* ctrl) { _cvstate->set_req(TypeFunc::Control, ctrl); }

  // Should this assert this is a MergeMem???

  void set_all_memory(Node* mem){ _cvstate->set_req(TypeFunc::Memory, mem); }

  void set_memory(Node* mem, uint alias_idx );

  void do_memory_merge(Node* merging, Node* join);

  void clear(Node* m);                     // clear a cvstate

  void stop() { clear(_cvstate); }         // clear current cvstate

  Node* delay_transform(Node* n);

  Node* transform(Node* n);                // gvn.transform or push node on delay list

  Node* promote_to_phi(Node* n, Node* reg);// Promote "n" to a phi on region "reg"

  bool was_promoted_to_phi(Node* n, Node* reg) {

    return (n->is_Phi() && n->in(0) == reg);

  }

  void declare(IdealVariable* v) { v->set_id(_var_ct++); }

  // This declares the position where vars are kept in the cvstate

  // For some degree of consistency we use the TypeFunc enum to

  // soak up spots in the inputs even though we only use early Control

  // and Memory slots. (So far.)

  static const uint first_var; // = TypeFunc::Parms + 1;

#ifdef ASSERT

  enum State { NullS=0, BlockS=1, LoopS=2, IfThenS=4, ElseS=8, EndifS= 16 };

  GrowableArray<int>* _state;

  State state() { return (State)(_state->top()); }

#endif

  // Users should not care about slices only MergedMem so no access for them.

  Node* memory(uint alias_idx);

 public:

  IdealKit(PhaseGVN &gvn, Node* control, Node* memory, bool delay_all_transforms = false);

  ~IdealKit() {

    stop();

    drain_delay_transform();

  }

  // Control

  Node* ctrl()                          { return _cvstate->in(TypeFunc::Control); }

  Node* top()                           { return C->top(); }

  MergeMemNode* merged_memory()         { return _cvstate->in(TypeFunc::Memory)->as_MergeMem(); }

  void set(IdealVariable& v, Node* rhs) { _cvstate->set_req(first_var + v.id(), rhs); }

  Node* value(IdealVariable& v)         { return _cvstate->in(first_var + v.id()); }

  void dead(IdealVariable& v)           { set(v, (Node*)NULL); }

  void if_then(Node* left, BoolTest::mask relop, Node* right,

               float prob = PROB_FAIR, float cnt = COUNT_UNKNOWN,

               bool push_new_state = true);

  void else_();

  void end_if();

  void loop(IdealVariable& iv, Node* init, BoolTest::mask cmp, Node* limit,

            float prob = PROB_LIKELY(0.9), float cnt = COUNT_UNKNOWN);

  void end_loop();

  Node* make_label(int goto_ct);

  void bind(Node* lab);

  void goto_(Node* lab, bool bind = false);

  void declares_done();

  void drain_delay_transform();

  Node* IfTrue(IfNode* iff)  { return transform(new (C,1) IfTrueNode(iff)); }

  Node* IfFalse(IfNode* iff) { return transform(new (C,1) IfFalseNode(iff)); }

  // Data

  Node* ConI(jint k) { return (Node*)gvn().intcon(k); }

  Node* makecon(const Type *t)  const { return _gvn.makecon(t); }

  Node* AddI(Node* l, Node* r) { return transform(new (C,3) AddINode(l, r)); }

  Node* SubI(Node* l, Node* r) { return transform(new (C,3) SubINode(l, r)); }

  Node* AndI(Node* l, Node* r) { return transform(new (C,3) AndINode(l, r)); }

  Node* MaxI(Node* l, Node* r) { return transform(new (C,3) MaxINode(l, r)); }

  Node* LShiftI(Node* l, Node* r) { return transform(new (C,3) LShiftINode(l, r)); }

  Node* CmpI(Node* l, Node* r) { return transform(new (C,3) CmpINode(l, r)); }

  Node* Bool(Node* cmp, BoolTest::mask relop) { return transform(new (C,2) BoolNode(cmp, relop)); }

  void  increment(IdealVariable& v, Node* j)  { set(v, AddI(value(v), j)); }

  void  decrement(IdealVariable& v, Node* j)  { set(v, SubI(value(v), j)); }

  Node* CmpL(Node* l, Node* r) { return transform(new (C,3) CmpLNode(l, r)); }

  // TLS

  Node* thread()  {  return gvn().transform(new (C, 1) ThreadLocalNode()); }

  // Pointers

  Node* AddP(Node *base, Node *ptr, Node *off) { return transform(new (C,4) AddPNode(base, ptr, off)); }

  Node* CmpP(Node* l, Node* r) { return transform(new (C,3) CmpPNode(l, r)); }

#ifdef _LP64

  Node* XorX(Node* l, Node* r) { return transform(new (C,3) XorLNode(l, r)); }

#else // _LP64

  Node* XorX(Node* l, Node* r) { return transform(new (C,3) XorINode(l, r)); }

#endif // _LP64

  Node* URShiftX(Node* l, Node* r) { return transform(new (C,3) URShiftXNode(l, r)); }

  Node* ConX(jint k) { return (Node*)gvn().MakeConX(k); }

  Node* CastPX(Node* ctl, Node* p) { return transform(new (C,2) CastP2XNode(ctl, p)); }

  // Add a fixed offset to a pointer

  Node* basic_plus_adr(Node* base, Node* ptr, intptr_t offset);

  // Memory operations

  // This is the base version which is given an alias index.

  Node* load(Node* ctl,

             Node* adr,

             const Type* t,

             BasicType bt,

             int adr_idx,

             bool require_atomic_access = false);

  // Return the new StoreXNode

  Node* store(Node* ctl,

              Node* adr,

              Node* val,

              BasicType bt,

              int adr_idx,

              bool require_atomic_access = false);

  // Store a card mark ordered after store_oop

  Node* storeCM(Node* ctl,

                Node* adr,

                Node* val,

                Node* oop_store,

                BasicType bt,

                int adr_idx);

  // Trivial call

  void make_leaf_call(const TypeFunc *slow_call_type,

                      address slow_call,

                      const char *leaf_name,

                      Node* parm0,

                      Node* parm1 = NULL,

                      Node* parm2 = NULL);

};