1 /*
   2  * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_OPTO_VALUETYPENODE_HPP
  26 #define SHARE_VM_OPTO_VALUETYPENODE_HPP
  27 
  28 #include "opto/node.hpp"
  29 #include "opto/connode.hpp"
  30 
  31 class GraphKit;
  32 
  33 class ValueTypeBaseNode : public TypeNode {
  34 protected:
  35   ValueTypeBaseNode(const Type* t, int nb_fields)
  36     : TypeNode(t, nb_fields) {
  37     init_class_id(Class_ValueTypeBase);
  38     Compile::current()->add_value_type(this);
  39   }
  40 
  41   enum { Control,   // Control input
  42          Oop,       // Oop of TypeInstPtr
  43          Values     // Nodes corresponding to values of the value type's fields.
  44                     // Nodes are connected in increasing order of the index of the field they correspond to.
  45   };
  46 
  47   virtual const TypeInstPtr* value_ptr() const = 0;
  48   // Get the klass defining the field layout of the value type
  49   ciValueKlass* value_klass() const { return type()->value_klass(); }
  50 
  51   int make_scalar_in_safepoint(PhaseIterGVN* igvn, Unique_Node_List& worklist, SafePointNode* sfpt);
  52 
  53   const TypePtr* field_adr_type(Node* base, int offset, ciInstanceKlass* holder, DecoratorSet decorators, PhaseGVN& gvn) const;
  54 
  55 public:
  56   // Support for control flow merges
  57   bool has_phi_inputs(Node* region);
  58   ValueTypeBaseNode* clone_with_phis(PhaseGVN* gvn, Node* region);
  59   ValueTypeBaseNode* merge_with(PhaseGVN* gvn, const ValueTypeBaseNode* other, int pnum, bool transform);
  60   void add_new_path(Node* region);
  61 
  62   // Get oop for heap allocated value type (may be TypePtr::NULL_PTR)
  63   Node* get_oop() const    { return in(Oop); }
  64   void  set_oop(Node* oop) { set_req(Oop, oop); }
  65 
  66   // Value type fields
  67   uint          field_count() const { return req() - Values; }
  68   Node*         field_value(uint index) const;
  69   Node*         field_value_by_offset(int offset, bool recursive = false) const;
  70   void      set_field_value(uint index, Node* value);
  71   void      set_field_value_by_offset(int offset, Node* value);
  72   int           field_offset(uint index) const;
  73   uint          field_index(int offset) const;
  74   ciType*       field_type(uint index) const;
  75   bool          field_is_flattened(uint index) const;
  76   bool          field_is_flattenable(uint index) const;
  77 
  78   // Replace ValueTypeNodes in debug info at safepoints with SafePointScalarObjectNodes
  79   void make_scalar_in_safepoints(PhaseIterGVN* igvn);
  80 
  81   // Store the value type as a flattened (headerless) representation
  82   void store_flattened(GraphKit* kit, Node* base, Node* ptr, ciInstanceKlass* holder = NULL, int holder_offset = 0, DecoratorSet decorators = IN_HEAP | MO_UNORDERED) const;
  83   // Store the field values to memory
  84   void store(GraphKit* kit, Node* base, Node* ptr, ciInstanceKlass* holder, int holder_offset = 0, DecoratorSet decorators = IN_HEAP | MO_UNORDERED) const;
  85   // Initialize the value type by loading its field values from memory
  86   void load(GraphKit* kit, Node* base, Node* ptr, ciInstanceKlass* holder, int holder_offset = 0, DecoratorSet decorators = IN_HEAP | MO_UNORDERED);
  87 
  88   // Allocates the value type (if not yet allocated)
  89   ValueTypeBaseNode* allocate(GraphKit* kit, bool safe_for_replace = true);
  90   bool is_allocated(PhaseGVN* phase) const;
  91 
  92   // Ensure that writes to base are comitted before a subsequent store.
  93   void ready_to_publish(GraphKit* kit, Node* base) const;
  94 
  95   void replace_call_results(GraphKit* kit, Node* call, Compile* C);
  96 
  97   // Allocate all non-flattened value type fields
  98   Node* allocate_fields(GraphKit* kit);
  99 };
 100 
 101 //------------------------------ValueTypeNode-------------------------------------
 102 // Node representing a value type in C2 IR
 103 class ValueTypeNode : public ValueTypeBaseNode {
 104   friend class ValueTypeBaseNode;
 105   friend class ValueTypePtrNode;
 106 private:
 107   ValueTypeNode(ciValueKlass* vk, Node* oop)
 108     : ValueTypeBaseNode(TypeValueType::make(vk), Values + vk->nof_declared_nonstatic_fields()) {
 109     init_class_id(Class_ValueType);
 110     init_req(Oop, oop);
 111   }
 112 
 113   // Checks if the value type is loaded from memory and if so returns the oop
 114   Node* is_loaded(PhaseGVN* phase, ciValueKlass* vk = NULL, Node* base = NULL, int holder_offset = 0);
 115 
 116   // Checks if the value type fields are all set to default values
 117   bool is_default(PhaseGVN& gvn) const;
 118 
 119   const TypeInstPtr* value_ptr() const { return TypeInstPtr::make(TypePtr::BotPTR, value_klass()); }
 120 
 121 public:
 122   // Create uninitialized
 123   static ValueTypeNode* make_uninitialized(PhaseGVN& gvn, ciValueKlass* vk);
 124   // Create with default field values
 125   static ValueTypeNode* make_default(PhaseGVN& gvn, ciValueKlass* vk);
 126   // Create and initialize by loading the field values from an oop
 127   static ValueTypeNode* make_from_oop(GraphKit* kit, Node* oop, ciValueKlass* vk);
 128   // Create and initialize by loading the field values from a flattened field or array
 129   static ValueTypeNode* make_from_flattened(GraphKit* kit, ciValueKlass* vk, Node* obj, Node* ptr, ciInstanceKlass* holder = NULL, int holder_offset = 0, DecoratorSet decorators = IN_HEAP | MO_UNORDERED);
 130   // Create and initialize with the inputs or outputs of a MultiNode (method entry or call)
 131   static ValueTypeNode* make_from_multi(GraphKit* kit, MultiNode* multi, ExtendedSignature& sig, ciValueKlass* vk, uint& base_input, bool in);
 132 
 133   ValueTypeNode* make_larval(GraphKit* kit, bool allocate) const;
 134   ValueTypeNode* finish_larval(GraphKit* kit) const;
 135 
 136   // Returns the constant oop of the default value type allocation
 137   static Node* default_oop(PhaseGVN& gvn, ciValueKlass* vk);
 138 
 139   Node* tagged_klass(PhaseGVN& gvn) {
 140     return tagged_klass(value_klass(), gvn);
 141   }
 142   static Node* tagged_klass(ciValueKlass* vk, PhaseGVN& gvn);
 143   // Pass value type as fields at a call or return
 144   void pass_fields(GraphKit* kit, Node* n, ExtendedSignature& sig, uint& base_input, int base_offset = 0);
 145   // Initialize the value type fields with the inputs or outputs of a MultiNode
 146   void initialize_fields(GraphKit* kit, MultiNode* multi, ExtendedSignature& sig, uint& base_input, int base_offset, bool in);
 147 
 148   // Allocation optimizations
 149   void remove_redundant_allocations(PhaseIterGVN* igvn, PhaseIdealLoop* phase);
 150 
 151   virtual Node* Ideal(PhaseGVN* phase, bool can_reshape);
 152   virtual int Opcode() const;
 153 };
 154 
 155 //------------------------------ValueTypePtrNode-------------------------------------
 156 // Node representing a value type as a pointer in C2 IR
 157 class ValueTypePtrNode : public ValueTypeBaseNode {
 158 private:
 159   const TypeInstPtr* value_ptr() const { return type()->isa_instptr(); }
 160 
 161   ValueTypePtrNode(ciValueKlass* vk, Node* oop)
 162     : ValueTypeBaseNode(TypeInstPtr::make(TypePtr::NotNull, vk), Values + vk->nof_declared_nonstatic_fields()) {
 163     init_class_id(Class_ValueTypePtr);
 164     init_req(Oop, oop);
 165   }
 166 
 167 public:
 168   // Create and initialize with the values of a ValueTypeNode
 169   static ValueTypePtrNode* make_from_value_type(GraphKit* kit, ValueTypeNode* vt);
 170   // Create and initialize by loading the field values from an oop
 171   static ValueTypePtrNode* make_from_oop(GraphKit* kit, Node* oop);
 172 
 173   virtual int Opcode() const;
 174 };
 175 
 176 #endif // SHARE_VM_OPTO_VALUETYPENODE_HPP