/*

 * Copyright 2001-2007 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.

 *

 */

class FastLockNode;

class FastUnlockNode;

class Parse;

class RootNode;

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

//----------------------------GraphKit-----------------------------------------

// Toolkit for building the common sorts of subgraphs.

// Does not know about bytecode parsing or type-flow results.

// It is able to create graphs implementing the semantics of most

// or all bytecodes, so that it can expand intrinsics and calls.

// It may depend on JVMState structure, but it must not depend

// on specific bytecode streams.

class GraphKit : public Phase {

  friend class PreserveJVMState;

 protected:

  ciEnv*            _env;       // Compilation environment

  PhaseGVN         &_gvn;       // Some optimizations while parsing

  SafePointNode*    _map;       // Parser map from JVM to Nodes

  SafePointNode*    _exceptions;// Parser map(s) for exception state(s)

  int               _sp;        // JVM Expression Stack Pointer

  int               _bci;       // JVM Bytecode Pointer

  ciMethod*         _method;    // JVM Current Method

 private:

  SafePointNode*     map_not_null() const {

    assert(_map != NULL, "must call stopped() to test for reset compiler map");

    return _map;

  }

 public:

  GraphKit();                   // empty constructor

  GraphKit(JVMState* jvms);     // the JVM state on which to operate

#ifdef ASSERT

  ~GraphKit() {

    assert(!has_exceptions(), "user must call transfer_exceptions_into_jvms");

  }

#endif

  virtual Parse* is_Parse() const { return NULL; }

  ciEnv*        env()           const { return _env; }

  PhaseGVN&     gvn()           const { return _gvn; }

  void record_for_igvn(Node* n) const { C->record_for_igvn(n); }  // delegate to Compile

  // Handy well-known nodes:

  Node*         null()          const { return zerocon(T_OBJECT); }

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

  RootNode*     root()          const { return C->root(); }

  // Create or find a constant node

  Node* intcon(jint con)        const { return _gvn.intcon(con); }

  Node* longcon(jlong con)      const { return _gvn.longcon(con); }

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

  Node* zerocon(BasicType bt)   const { return _gvn.zerocon(bt); }

  // (See also macro MakeConX in type.hpp, which uses intcon or longcon.)

  jint  find_int_con(Node* n, jint value_if_unknown) {

    return _gvn.find_int_con(n, value_if_unknown);

  }

  jlong find_long_con(Node* n, jlong value_if_unknown) {

    return _gvn.find_long_con(n, value_if_unknown);

  }

  // (See also macro find_intptr_t_con in type.hpp, which uses one of these.)

  // JVM State accessors:

  // Parser mapping from JVM indices into Nodes.

  // Low slots are accessed by the StartNode::enum.

  // Then come the locals at StartNode::Parms to StartNode::Parms+max_locals();

  // Then come JVM stack slots.

  // Finally come the monitors, if any.

  // See layout accessors in class JVMState.

  SafePointNode*     map()      const { return _map; }

  bool               has_exceptions() const { return _exceptions != NULL; }

  JVMState*          jvms()     const { return map_not_null()->_jvms; }

  int                sp()       const { return _sp; }

  int                bci()      const { return _bci; }

  Bytecodes::Code    java_bc()  const;

  ciMethod*          method()   const { return _method; }

  void set_jvms(JVMState* jvms)       { set_map(jvms->map());

                                        assert(jvms == this->jvms(), "sanity");

                                        _sp = jvms->sp();

                                        _bci = jvms->bci();

                                        _method = jvms->has_method() ? jvms->method() : NULL; }

  void set_map(SafePointNode* m)      { _map = m; debug_only(verify_map()); }

  void set_sp(int i)                  { assert(i >= 0, "must be non-negative"); _sp = i; }

  void clean_stack(int from_sp); // clear garbage beyond from_sp to top

  void inc_sp(int i)                  { set_sp(sp() + i); }

  void set_bci(int bci)               { _bci = bci; }

  // Make sure jvms has current bci & sp.

  JVMState* sync_jvms()     const;

#ifdef ASSERT

  // Make sure JVMS has an updated copy of bci and sp.

  // Also sanity-check method, depth, and monitor depth.

  bool jvms_in_sync() const;

  // Make sure the map looks OK.

  void verify_map() const;

  // Make sure a proposed exception state looks OK.

  static void verify_exception_state(SafePointNode* ex_map);

#endif

  // Clone the existing map state.  (Implements PreserveJVMState.)

  SafePointNode* clone_map();

  // Set the map to a clone of the given one.

  void set_map_clone(SafePointNode* m);

  // Tell if the compilation is failing.

  bool failing() const { return C->failing(); }

  // Set _map to NULL, signalling a stop to further bytecode execution.

  // Preserve the map intact for future use, and return it back to the caller.

  SafePointNode* stop() { SafePointNode* m = map(); set_map(NULL); return m; }

  // Stop, but first smash the map's inputs to NULL, to mark it dead.

  void stop_and_kill_map();

  // Tell if _map is NULL, or control is top.

  bool stopped();

  // Tell if this method or any caller method has exception handlers.

  bool has_ex_handler();

  // Save an exception without blowing stack contents or other JVM state.

  // (The extra pointer is stuck with add_req on the map, beyond the JVMS.)

  static void set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop);

  // Recover a saved exception from its map.

  static Node* saved_ex_oop(SafePointNode* ex_map);

  // Recover a saved exception from its map, and remove it from the map.

  static Node* clear_saved_ex_oop(SafePointNode* ex_map);

#ifdef ASSERT

  // Recover a saved exception from its map, and remove it from the map.

  static bool has_saved_ex_oop(SafePointNode* ex_map);

#endif

  // Push an exception in the canonical position for handlers (stack(0)).

  void push_ex_oop(Node* ex_oop) {

    ensure_stack(1);  // ensure room to push the exception

    set_stack(0, ex_oop);

    set_sp(1);

    clean_stack(1);

  }

  // Detach and return an exception state.

  SafePointNode* pop_exception_state() {

    SafePointNode* ex_map = _exceptions;

    if (ex_map != NULL) {

      _exceptions = ex_map->next_exception();

      ex_map->set_next_exception(NULL);

      debug_only(verify_exception_state(ex_map));

    }

    return ex_map;

  }

  // Add an exception, using the given JVM state, without commoning.

  void push_exception_state(SafePointNode* ex_map) {

    debug_only(verify_exception_state(ex_map));

    ex_map->set_next_exception(_exceptions);

    _exceptions = ex_map;

  }

  // Turn the current JVM state into an exception state, appending the ex_oop.

  SafePointNode* make_exception_state(Node* ex_oop);

  // Add an exception, using the given JVM state.

  // Combine all exceptions with a common exception type into a single state.

  // (This is done via combine_exception_states.)

  void add_exception_state(SafePointNode* ex_map);

  // Combine all exceptions of any sort whatever into a single master state.

  SafePointNode* combine_and_pop_all_exception_states() {

    if (_exceptions == NULL)  return NULL;

    SafePointNode* phi_map = pop_exception_state();

    SafePointNode* ex_map;

    while ((ex_map = pop_exception_state()) != NULL) {

      combine_exception_states(ex_map, phi_map);

    }

    return phi_map;

  }

  // Combine the two exception states, building phis as necessary.

  // The second argument is updated to include contributions from the first.

  void combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map);

  // Reset the map to the given state.  If there are any half-finished phis

  // in it (created by combine_exception_states), transform them now.

  // Returns the exception oop.  (Caller must call push_ex_oop if required.)

  Node* use_exception_state(SafePointNode* ex_map);

  // Collect exceptions from a given JVM state into my exception list.

  void add_exception_states_from(JVMState* jvms);

  // Collect all raised exceptions into the current JVM state.

  // Clear the current exception list and map, returns the combined states.

  JVMState* transfer_exceptions_into_jvms();

  // Helper to throw a built-in exception.

  // Range checks take the offending index.

  // Cast and array store checks take the offending class.

  // Others do not take the optional argument.

  // The JVMS must allow the bytecode to be re-executed

  // via an uncommon trap.

  void builtin_throw(Deoptimization::DeoptReason reason, Node* arg = NULL);

  // Helper Functions for adding debug information

  void kill_dead_locals();

#ifdef ASSERT

  bool dead_locals_are_killed();

#endif

  // The call may deoptimize.  Supply required JVM state as debug info.

  // If must_throw is true, the call is guaranteed not to return normally.

  void add_safepoint_edges(SafePointNode* call,

                           bool must_throw = false);

  // How many stack inputs does the current BC consume?

  // And, how does the stack change after the bytecode?

  // Returns false if unknown.

  bool compute_stack_effects(int& inputs, int& depth);

  // Add a fixed offset to a pointer

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

    return basic_plus_adr(base, ptr, MakeConX(offset));

  }

  Node* basic_plus_adr(Node* base, intptr_t offset) {

    return basic_plus_adr(base, base, MakeConX(offset));

  }

  // Add a variable offset to a pointer

  Node* basic_plus_adr(Node* base, Node* offset) {

    return basic_plus_adr(base, base, offset);

  }

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

  // Convert between int and long, and size_t.

  // (See macros ConvI2X, etc., in type.hpp for ConvI2X, etc.)

  Node* ConvI2L(Node* offset);

  Node* ConvL2I(Node* offset);

  // Find out the klass of an object.

  Node* load_object_klass(Node* object);

  // Find out the length of an array.

  Node* load_array_length(Node* array);

  // Helper function to do a NULL pointer check or ZERO check based on type.

  Node* null_check_common(Node* value, BasicType type,

                          bool assert_null, Node* *null_control);

  // Throw an exception if a given value is null.

  // Return the value cast to not-null.

  // Be clever about equivalent dominating null checks.

  Node* do_null_check(Node* value, BasicType type) {

    return null_check_common(value, type, false, NULL);

  }

  // Throw an uncommon trap if a given value is __not__ null.

  // Return the value cast to null, and be clever about dominating checks.

  Node* do_null_assert(Node* value, BasicType type) {

    return null_check_common(value, type, true, NULL);

  }

  // Null check oop.  Return null-path control into (*null_control).

  // Return a cast-not-null node which depends on the not-null control.

  // If never_see_null, use an uncommon trap (*null_control sees a top).

  // The cast is not valid along the null path; keep a copy of the original.

  Node* null_check_oop(Node* value, Node* *null_control,

                       bool never_see_null = false);

  // Cast obj to not-null on this path

  Node* cast_not_null(Node* obj, bool do_replace_in_map = true);

  // Replace all occurrences of one node by another.

  void replace_in_map(Node* old, Node* neww);

  void push(Node* n)    { map_not_null(); _map->set_stack(_map->_jvms,_sp++,n); }

  Node* pop()           { map_not_null(); return _map->stack(_map->_jvms,--_sp); }

  Node* peek(int off=0) { map_not_null(); return _map->stack(_map->_jvms, _sp - off - 1); }

  void push_pair(Node* ldval) {

    push(ldval);

    push(top());  // the halfword is merely a placeholder

  }

  void push_pair_local(int i) {

    // longs are stored in locals in "push" order

    push(  local(i+0) );  // the real value

    assert(local(i+1) == top(), "");

    push(top());  // halfword placeholder

  }

  Node* pop_pair() {

    // the second half is pushed last & popped first; it contains exactly nothing

    Node* halfword = pop();

    assert(halfword == top(), "");

    // the long bits are pushed first & popped last:

    return pop();

  }

  void set_pair_local(int i, Node* lval) {

    // longs are stored in locals as a value/half pair (like doubles)

    set_local(i+0, lval);

    set_local(i+1, top());

  }

  // Push the node, which may be zero, one, or two words.

  void push_node(BasicType n_type, Node* n) {

    int n_size = type2size[n_type];

    if      (n_size == 1)  push(      n );  // T_INT, ...

    else if (n_size == 2)  push_pair( n );  // T_DOUBLE, T_LONG

    else                   { assert(n_size == 0, "must be T_VOID"); }

  }

  Node* pop_node(BasicType n_type) {

    int n_size = type2size[n_type];

    if      (n_size == 1)  return pop();

    else if (n_size == 2)  return pop_pair();

    else                   return NULL;

  }

  Node* control()               const { return map_not_null()->control(); }

  Node* i_o()                   const { return map_not_null()->i_o(); }

  Node* returnadr()             const { return map_not_null()->returnadr(); }

  Node* frameptr()              const { return map_not_null()->frameptr(); }

  Node* local(uint idx)         const { map_not_null(); return _map->local(      _map->_jvms, idx); }

  Node* stack(uint idx)         const { map_not_null(); return _map->stack(      _map->_jvms, idx); }

  Node* argument(uint idx)      const { map_not_null(); return _map->argument(   _map->_jvms, idx); }

  Node* monitor_box(uint idx)   const { map_not_null(); return _map->monitor_box(_map->_jvms, idx); }

  Node* monitor_obj(uint idx)   const { map_not_null(); return _map->monitor_obj(_map->_jvms, idx); }

  void set_control  (Node* c)         { map_not_null()->set_control(c); }

  void set_i_o      (Node* c)         { map_not_null()->set_i_o(c); }

  void set_local(uint idx, Node* c)   { map_not_null(); _map->set_local(   _map->_jvms, idx, c); }

  void set_stack(uint idx, Node* c)   { map_not_null(); _map->set_stack(   _map->_jvms, idx, c); }

  void set_argument(uint idx, Node* c){ map_not_null(); _map->set_argument(_map->_jvms, idx, c); }

  void ensure_stack(uint stk_size)    { map_not_null(); _map->ensure_stack(_map->_jvms, stk_size); }

  // Access unaliased memory

  Node* memory(uint alias_idx);

  Node* memory(const TypePtr *tp) { return memory(C->get_alias_index(tp)); }

  Node* memory(Node* adr) { return memory(_gvn.type(adr)->is_ptr()); }

  // Access immutable memory

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

  // Set unaliased memory

  void set_memory(Node* c, uint alias_idx) { merged_memory()->set_memory_at(alias_idx, c); }

  void set_memory(Node* c, const TypePtr *tp) { set_memory(c,C->get_alias_index(tp)); }

  void set_memory(Node* c, Node* adr) { set_memory(c,_gvn.type(adr)->is_ptr()); }

  // Get the entire memory state (probably a MergeMemNode), and reset it

  // (The resetting prevents somebody from using the dangling Node pointer.)

  Node* reset_memory();

  // Get the entire memory state, asserted to be a MergeMemNode.

  MergeMemNode* merged_memory() {

    Node* mem = map_not_null()->memory();

    assert(mem->is_MergeMem(), "parse memory is always pre-split");

    return mem->as_MergeMem();

  }

  // Set the entire memory state; produce a new MergeMemNode.

  void set_all_memory(Node* newmem);

  // Create a memory projection from the call, then set_all_memory.

  void set_all_memory_call(Node* call);

  // Create a LoadNode, reading from the parser's memory state.

  // (Note:  require_atomic_access is useful only with T_LONG.)

  Node* make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,

                  bool require_atomic_access = false) {

    // This version computes alias_index from bottom_type

    return make_load(ctl, adr, t, bt, adr->bottom_type()->is_ptr(),

                     require_atomic_access);

  }

  Node* make_load(Node* ctl, Node* adr, const Type* t, BasicType bt, const TypePtr* adr_type, bool require_atomic_access = false) {

    // This version computes alias_index from an address type

    assert(adr_type != NULL, "use other make_load factory");

    return make_load(ctl, adr, t, bt, C->get_alias_index(adr_type),

                     require_atomic_access);

  }

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

  Node* make_load(Node* ctl, Node* adr, const Type* t, BasicType bt, int adr_idx, bool require_atomic_access = false);

  // Create & transform a StoreNode and store the effect into the

  // parser's memory state.

  Node* store_to_memory(Node* ctl, Node* adr, Node* val, BasicType bt,

                        const TypePtr* adr_type,

                        bool require_atomic_access = false) {

    // This version computes alias_index from an address type

    assert(adr_type != NULL, "use other store_to_memory factory");

    return store_to_memory(ctl, adr, val, bt,

                           C->get_alias_index(adr_type),

                           require_atomic_access);

  }

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

  // Return the new StoreXNode

  Node* store_to_memory(Node* ctl, Node* adr, Node* val, BasicType bt,

                        int adr_idx,

                        bool require_atomic_access = false);

  // All in one pre-barrier, store, post_barrier

  // Insert a write-barrier'd store.  This is to let generational GC

  // work; we have to flag all oop-stores before the next GC point.

  //

  // It comes in 3 flavors of store to an object, array, or unknown.

  // We use precise card marks for arrays to avoid scanning the entire

  // array. We use imprecise for object. We use precise for unknown

  // since we don't know if we have an array or and object or even

  // where the object starts.

  //

  // If val==NULL, it is taken to be a completely unknown value. QQQ

  Node* store_oop_to_object(Node* ctl,

                            Node* obj,   // containing obj

                            Node* adr,  // actual adress to store val at

                            const TypePtr* adr_type,

                            Node* val,

                            const Type* val_type,

                            BasicType bt);

  Node* store_oop_to_array(Node* ctl,

                           Node* obj,   // containing obj

                           Node* adr,  // actual adress to store val at

                           const TypePtr* adr_type,

                           Node* val,

                           const Type* val_type,

                           BasicType bt);

  // Could be an array or object we don't know at compile time (unsafe ref.)

  Node* store_oop_to_unknown(Node* ctl,

                             Node* obj,   // containing obj

                             Node* adr,  // actual adress to store val at

                             const TypePtr* adr_type,

                             Node* val,

                             const Type* val_type,

                             BasicType bt);

  // For the few case where the barriers need special help

  void pre_barrier(Node* ctl, Node* obj, Node* adr, uint adr_idx,

                   Node* val, const Type* val_type, BasicType bt);

  void post_barrier(Node* ctl, Node* store, Node* obj, Node* adr, uint adr_idx,

                    Node* val, BasicType bt, bool use_precise);

  // Return addressing for an array element.

  Node* array_element_address(Node* ary, Node* idx, BasicType elembt,

                              // Optional constraint on the array size:

                              const TypeInt* sizetype = NULL);

  // Return a load of array element at idx.

  Node* load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype);

  // CMS card-marks have an input from the corresponding oop_store

  void  cms_card_mark(Node* ctl, Node* adr, Node* val, Node* oop_store);

  //---------------- Dtrace support --------------------

  void make_dtrace_method_entry_exit(ciMethod* method, bool is_entry);

  void make_dtrace_method_entry(ciMethod* method) {

    make_dtrace_method_entry_exit(method, true);

  }

  void make_dtrace_method_exit(ciMethod* method) {

    make_dtrace_method_entry_exit(method, false);

  }

  //--------------- stub generation -------------------

 public:

  void gen_stub(address C_function,

                const char *name,

                int is_fancy_jump,

                bool pass_tls,

                bool return_pc);

  //---------- help for generating calls --------------

  // Do a null check on the receiver, which is in argument(0).

  Node* null_check_receiver(ciMethod* callee) {

    assert(!callee->is_static(), "must be a virtual method");

    int nargs = 1 + callee->signature()->size();

    // Null check on self without removing any arguments.  The argument

    // null check technically happens in the wrong place, which can lead to

    // invalid stack traces when the primitive is inlined into a method

    // which handles NullPointerExceptions.

    Node* receiver = argument(0);

    _sp += nargs;

    receiver = do_null_check(receiver, T_OBJECT);

    _sp -= nargs;

    return receiver;

  }

  // Fill in argument edges for the call from argument(0), argument(1), ...

  // (The next step is to call set_edges_for_java_call.)

  void  set_arguments_for_java_call(CallJavaNode* call);

  // Fill in non-argument edges for the call.

  // Transform the call, and update the basics: control, i_o, memory.

  // (The next step is usually to call set_results_for_java_call.)

  void set_edges_for_java_call(CallJavaNode* call,

                               bool must_throw = false);

  // Finish up a java call that was started by set_edges_for_java_call.

  // Call add_exception on any throw arising from the call.