/*

 * Copyright (c) 2001, 2019, 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

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 */

#ifndef SHARE_OPTO_GRAPHKIT_HPP

#define SHARE_OPTO_GRAPHKIT_HPP

#include "ci/ciEnv.hpp"

#include "ci/ciMethodData.hpp"

#include "gc/shared/c2/barrierSetC2.hpp"

#include "opto/addnode.hpp"

#include "opto/callnode.hpp"

#include "opto/cfgnode.hpp"

#include "opto/compile.hpp"

#include "opto/divnode.hpp"

#include "opto/mulnode.hpp"

#include "opto/phaseX.hpp"

#include "opto/subnode.hpp"

#include "opto/type.hpp"

#include "runtime/deoptimization.hpp"

class BarrierSetC2;

class FastLockNode;

class FastUnlockNode;

class IdealKit;

class LibraryCallKit;

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               _bci;       // JVM Bytecode Pointer

  ciMethod*         _method;    // JVM Current Method

  BarrierSetC2*     _barrier_set;

 private:

  int               _sp;        // JVM Expression Stack Pointer; don't modify directly!

 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; }

  virtual LibraryCallKit* is_LibraryCallKit() const { return NULL; }

  ciEnv*        env()               const { return _env; }

  PhaseGVN&     gvn()               const { return _gvn; }

  void*         barrier_set_state() const { return C->barrier_set_state(); }

  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 sp)                 { assert(sp >= 0, "sp must be non-negative: %d", sp); _sp = sp; }

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

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

  void dec_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;

  JVMState* sync_jvms_for_reexecute();

#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 to check the JavaThread::_should_post_on_exceptions flag

  // and branch to an uncommon_trap if it is true (with the specified reason and must_throw)

  void uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,

                                                  bool must_throw) ;

  // 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);

  // Some convenient shortcuts for common nodes

  Node* IfTrue(IfNode* iff)                   { return _gvn.transform(new IfTrueNode(iff));      }

  Node* IfFalse(IfNode* iff)                  { return _gvn.transform(new IfFalseNode(iff));     }

  Node* AddI(Node* l, Node* r)                { return _gvn.transform(new AddINode(l, r));       }

  Node* SubI(Node* l, Node* r)                { return _gvn.transform(new SubINode(l, r));       }

  Node* MulI(Node* l, Node* r)                { return _gvn.transform(new MulINode(l, r));       }

  Node* DivI(Node* ctl, Node* l, Node* r)     { return _gvn.transform(new DivINode(ctl, l, r));  }

  Node* AndI(Node* l, Node* r)                { return _gvn.transform(new AndINode(l, r));       }

  Node* OrI(Node* l, Node* r)                 { return _gvn.transform(new OrINode(l, r));        }

  Node* XorI(Node* l, Node* r)                { return _gvn.transform(new XorINode(l, r));       }

  Node* MaxI(Node* l, Node* r)                { return _gvn.transform(new MaxINode(l, r));       }

  Node* MinI(Node* l, Node* r)                { return _gvn.transform(new MinINode(l, r));       }

  Node* LShiftI(Node* l, Node* r)             { return _gvn.transform(new LShiftINode(l, r));    }

  Node* RShiftI(Node* l, Node* r)             { return _gvn.transform(new RShiftINode(l, r));    }

  Node* URShiftI(Node* l, Node* r)            { return _gvn.transform(new URShiftINode(l, r));   }

  Node* CmpI(Node* l, Node* r)                { return _gvn.transform(new CmpINode(l, r));       }

  Node* CmpL(Node* l, Node* r)                { return _gvn.transform(new CmpLNode(l, r));       }

  Node* CmpP(Node* l, Node* r)                { return _gvn.transform(new CmpPNode(l, r));       }

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

  Node* AddP(Node* b, Node* a, Node* o)       { return _gvn.transform(new AddPNode(b, a, o));    }

  // Convert between int and long, and size_t.

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

  Node* ConvI2L(Node* offset);

  Node* ConvI2UL(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.

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

  // Return the value cast to not-null.

  // Be clever about equivalent dominating null checks.

  Node* null_check_common(Node* value, BasicType type,

                          bool assert_null = false,

                          Node* *null_control = NULL,

                          bool speculative = false);

  Node* null_check(Node* value, BasicType type = T_OBJECT) {

    return null_check_common(value, type, false, NULL, !_gvn.type(value)->speculative_maybe_null());

  }

  Node* null_check_receiver() {

    assert(argument(0)->bottom_type()->isa_ptr(), "must be");

    return null_check(argument(0));

  }

  Node* zero_check_int(Node* value) {

    assert(value->bottom_type()->basic_type() == T_INT,

           "wrong type: %s", type2name(value->bottom_type()->basic_type()));

    return null_check_common(value, T_INT);

  }

  Node* zero_check_long(Node* value) {

    assert(value->bottom_type()->basic_type() == T_LONG,

           "wrong type: %s", type2name(value->bottom_type()->basic_type()));

    return null_check_common(value, T_LONG);

  }

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

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

  Node* null_assert(Node* value, BasicType type = T_OBJECT) {

    return null_check_common(value, type, true, NULL, _gvn.type(value)->speculative_always_null());

  }

  // Check if value is null and abort if it is

  Node* must_be_not_null(Node* value, bool do_replace_in_map);

  // 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.

  // If safe_for_replace, then we can replace the value with the cast

  // in the parsing map (the cast is guaranteed to dominate the map)

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

                       bool never_see_null = false,

                       bool safe_for_replace = false,

                       bool speculative = false);

  // Check the null_seen bit.

  bool seems_never_null(Node* obj, ciProfileData* data, bool& speculating);

  void guard_klass_being_initialized(Node* klass);

  void guard_init_thread(Node* klass);

  void clinit_barrier(ciInstanceKlass* ik, ciMethod* context);

  // Check for unique class for receiver at call

  ciKlass* profile_has_unique_klass() {

    ciCallProfile profile = method()->call_profile_at_bci(bci());

    if (profile.count() >= 0 &&         // no cast failures here

        profile.has_receiver(0) &&

        profile.morphism() == 1) {

      return profile.receiver(0);

    }

    return NULL;

  }

  // record type from profiling with the type system

  Node* record_profile_for_speculation(Node* n, ciKlass* exact_kls, ProfilePtrKind ptr_kind);

  void record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc);

  void record_profiled_parameters_for_speculation();

  void record_profiled_return_for_speculation();

  Node* record_profiled_receiver_for_speculation(Node* n);

  // Use the type profile to narrow an object type.

  Node* maybe_cast_profiled_receiver(Node* not_null_obj,

                                     ciKlass* require_klass,

                                     ciKlass* spec,

                                     bool safe_for_replace);

  // Cast obj to type and emit guard unless we had too many traps here already

  Node* maybe_cast_profiled_obj(Node* obj,

                                ciKlass* type,

                                bool not_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);