1 /*
  2  * Copyright (c) 2016, 2025, 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_INLINETYPENODE_HPP
 26 #define SHARE_VM_OPTO_INLINETYPENODE_HPP
 27 
 28 #include "ci/ciInlineKlass.hpp"
 29 #include "gc/shared/c2/barrierSetC2.hpp"
 30 #include "oops/accessDecorators.hpp"
 31 #include "opto/callnode.hpp"
 32 #include "opto/compile.hpp"
 33 #include "opto/loopnode.hpp"
 34 #include "opto/multnode.hpp"
 35 #include "opto/node.hpp"
 36 
 37 class GraphKit;
 38 
 39 //------------------------------InlineTypeNode-------------------------------------
 40 // Node representing an inline type in C2 IR
 41 class InlineTypeNode : public TypeNode {
 42 private:
 43   InlineTypeNode(ciInlineKlass* vk, Node* oop, bool null_free)
 44       : TypeNode(TypeInstPtr::make(null_free ? TypePtr::NotNull : TypePtr::BotPTR, vk), Values + vk->nof_declared_nonstatic_fields()) {
 45     init_class_id(Class_InlineType);
 46     init_req(Oop, oop);
 47     Compile::current()->add_inline_type(this);
 48   }
 49 
 50   enum { Control,    // Control input.
 51          Oop,        // Oop to heap allocated buffer.
 52          IsBuffered, // True if inline type is heap allocated (or nullptr), false otherwise.
 53          NullMarker, // Needs to be checked before using the field values.
 54                      // 0 => InlineType is null
 55                      // 1 => InlineType is non-null
 56                      // Can be dynamic value, not necessarily statically known
 57          Values      // Nodes corresponding to values of the inline type's fields.
 58                      // Nodes are connected in increasing order of the index of the field they correspond to.
 59   };
 60 
 61   // Get the klass defining the field layout of the inline type
 62   ciInlineKlass* inline_klass() const { return type()->inline_klass(); }
 63 
 64   void make_scalar_in_safepoint(PhaseIterGVN* igvn, Unique_Node_List& worklist, SafePointNode* sfpt);
 65   uint add_fields_to_safepoint(Unique_Node_List& worklist, SafePointNode* sfpt);
 66 
 67   // Checks if the inline type is loaded from memory and if so returns the oop
 68   Node* is_loaded(PhaseGVN* phase, ciInlineKlass* vk = nullptr, Node* base = nullptr, int holder_offset = 0);
 69 
 70   // Initialize the inline type fields with the inputs or outputs of a MultiNode
 71   void initialize_fields(GraphKit* kit, MultiNode* multi, uint& base_input, bool in, bool null_free, Node* null_check_region, GrowableArray<ciType*>& visited);
 72   // Initialize the inline type by loading its field values from memory
 73   void load(GraphKit* kit, Node* base, Node* ptr, bool immutable_memory, bool trust_null_free_oop, DecoratorSet decorators, GrowableArray<ciType*>& visited);
 74   // Store the field values to memory
 75   void store(GraphKit* kit, Node* base, Node* ptr, bool immutable_memory, DecoratorSet decorators) const;
 76 
 77   InlineTypeNode* adjust_scalarization_depth_impl(GraphKit* kit, GrowableArray<ciType*>& visited);
 78 
 79   static InlineTypeNode* make_all_zero_impl(PhaseGVN& gvn, ciInlineKlass* vk, GrowableArray<ciType*>& visited);
 80   static InlineTypeNode* make_from_oop_impl(GraphKit* kit, Node* oop, ciInlineKlass* vk, GrowableArray<ciType*>& visited);
 81   static InlineTypeNode* make_null_impl(PhaseGVN& gvn, ciInlineKlass* vk, GrowableArray<ciType*>& visited, bool transform = true);
 82   static InlineTypeNode* make_from_flat_impl(GraphKit* kit, ciInlineKlass* vk, Node* base, Node* ptr, bool atomic, bool immutable_memory,
 83                                              bool null_free, bool trust_null_free_oop, DecoratorSet decorators, GrowableArray<ciType*>& visited);
 84 
 85 public:
 86   // Create with all-zero field values
 87   static InlineTypeNode* make_all_zero(PhaseGVN& gvn, ciInlineKlass* vk);
 88   // Create uninitialized
 89   static InlineTypeNode* make_uninitialized(PhaseGVN& gvn, ciInlineKlass* vk, bool null_free = true);
 90   // Create and initialize by loading the field values from an oop
 91   static InlineTypeNode* make_from_oop(GraphKit* kit, Node* oop, ciInlineKlass* vk);
 92   // Create and initialize by loading the field values from a flat field or array
 93   static InlineTypeNode* make_from_flat(GraphKit* kit, ciInlineKlass* vk, Node* base, Node* ptr,
 94                                         bool atomic, bool immutable_memory, bool null_free, DecoratorSet decorators);
 95   static InlineTypeNode* make_from_flat_array(GraphKit* kit, ciInlineKlass* vk, Node* base, Node* idx);
 96   // Create and initialize with the inputs or outputs of a MultiNode (method entry or call)
 97   static InlineTypeNode* make_from_multi(GraphKit* kit, MultiNode* multi, ciInlineKlass* vk, uint& base_input, bool in, bool null_free = true);
 98   // Create with null field values
 99   static InlineTypeNode* make_null(PhaseGVN& gvn, ciInlineKlass* vk, bool transform = true);
100 
101   // Support for control flow merges
102   bool has_phi_inputs(Node* region);
103   InlineTypeNode* clone_with_phis(PhaseGVN* gvn, Node* region, SafePointNode* map = nullptr, bool is_non_null = false, bool init_with_top = false);
104   InlineTypeNode* merge_with(PhaseGVN* gvn, const InlineTypeNode* other, int phi_index, bool transform);
105   void add_new_path(Node* region);
106 
107   // Get oop for heap allocated inline type (may be TypePtr::NULL_PTR)
108   Node* get_oop() const    { return in(Oop); }
109   void  set_oop(PhaseGVN& gvn, Node* oop) { set_req_X(Oop, oop, &gvn); }
110   Node* get_null_marker() const { return in(NullMarker); }
111   void  set_null_marker(PhaseGVN& gvn, Node* init) { set_req_X(NullMarker, init, &gvn); }
112   void  set_null_marker(PhaseGVN& gvn) { set_null_marker(gvn, gvn.intcon(1)); }
113   Node* get_is_buffered() const { return in(IsBuffered); }
114   void  set_is_buffered(PhaseGVN& gvn, bool buffered = true) { set_req_X(IsBuffered, gvn.intcon(buffered ? 1 : 0), &gvn); }
115 
116   // Checks if the inline type fields are all set to zero
117   bool is_all_zero(PhaseGVN* gvn, bool flat = false) const;
118 
119   // Inline type fields
120   uint          field_count() const { return req() - Values; }
121   Node*         field_value(uint index) const;
122   Node*         field_value_by_offset(int offset, bool recursive) const;
123   void      set_field_value(uint index, Node* value);
124   void      set_field_value_by_offset(int offset, Node* value);
125   int           field_offset(uint index) const;
126   uint          field_index(int offset) const;
127   ciType*       field_type(uint index) const;
128   bool          field_is_flat(uint index) const;
129   bool          field_is_null_free(uint index) const;
130   bool          field_is_volatile(uint index) const;
131   int           field_null_marker_offset(uint index) const;
132 
133   // Replace InlineTypeNodes in debug info at safepoints with SafePointScalarObjectNodes
134   void make_scalar_in_safepoints(PhaseIterGVN* igvn, bool allow_oop = true);
135 
136   // Store the inline type as a flat (headerless) representation
137   void store_flat(GraphKit* kit, Node* base, Node* ptr, bool atomic, bool immutable_memory, bool null_free, DecoratorSet decorators);
138   // Store the inline type as a flat (headerless) representation into an array
139   void store_flat_array(GraphKit* kit, Node* base, Node* idx);
140   // Make sure that inline type is fully scalarized
141   InlineTypeNode* adjust_scalarization_depth(GraphKit* kit);
142 
143   // Allocates the inline type (if not yet allocated)
144   InlineTypeNode* buffer(GraphKit* kit, bool safe_for_replace = true);
145   bool is_allocated(PhaseGVN* phase) const;
146 
147   void replace_call_results(GraphKit* kit, CallNode* call, Compile* C);
148   void replace_field_projs(Compile* C, CallNode* call, uint& proj_idx);
149 
150   // Allocate all non-flat inline type fields
151   InlineTypeNode* allocate_fields(GraphKit* kit);
152 
153   Node* tagged_klass(PhaseGVN& gvn) {
154     return tagged_klass(inline_klass(), gvn);
155   }
156   static Node* tagged_klass(ciInlineKlass* vk, PhaseGVN& gvn);
157   // Pass inline type as fields at a call or return
158   void pass_fields(GraphKit* kit, Node* n, uint& base_input, bool in, bool null_free = true);
159 
160   // Allocation optimizations
161   void remove_redundant_allocations(PhaseIdealLoop* phase);
162 
163   InlineTypeNode* clone_if_required(PhaseGVN* gvn, SafePointNode* map, bool safe_for_replace = true);
164 
165   virtual const Type* Value(PhaseGVN* phase) const;
166 
167   virtual Node* Ideal(PhaseGVN* phase, bool can_reshape);
168 
169   virtual int Opcode() const;
170 };
171 
172 // Load from a flat element, the node produces 1 Proj output for each flattened field of the flat
173 // element. The order of the Proj node is the same as that of _vk->_nonstatic_fields, and the null
174 // marker if existing will be the last Proj output. This node acts as if the load happens
175 // atomically and will be expanded to loading the whole payload and extracting the flattened fields
176 // from the loaded payload. In special cases, such as when the object from which this load reads
177 // does not escape, this node can be expanded to multiple loads from each flattened field.
178 // This node allows us to replace its results with the value from a matching store because the
179 // payload value cannot be directly propagated if it contains oops. This effect, in turn, allows
180 // objects with atomic flat fields to be scalar replaced.
181 class LoadFlatNode final : public SafePointNode {
182 private:
183   ciInlineKlass* _vk;
184   const TypeTuple* _type;
185   bool _null_free;
186   DecoratorSet _decorators;
187 
188 public:
189   static InlineTypeNode* load(GraphKit* kit, ciInlineKlass* vk, Node* base, Node* ptr, bool null_free, bool trust_null_free_oop, DecoratorSet decorators);
190   Node* base() const { return in(TypeFunc::Parms); }
191   Node* ptr() const { return in(TypeFunc::Parms + 1); }
192   bool expand_non_atomic(PhaseIterGVN& igvn);
193   void expand_atomic(PhaseIterGVN& igvn);
194 
195 private:
196   LoadFlatNode(ciInlineKlass* vk, const TypeTuple* type, bool null_free, DecoratorSet decorators)
197     : SafePointNode(TypeFunc::Parms + 2, nullptr, TypePtr::BOTTOM), _vk(vk), _type(type), _null_free(null_free), _decorators(decorators) {
198     init_class_id(Class_LoadFlat);
199     Compile::current()->add_flat_access(this);
200   }
201 
202   virtual int Opcode() const override;
203   virtual const Type* bottom_type() const override { return _type; }
204   virtual uint size_of() const override { return sizeof(LoadFlatNode); }
205   virtual Node* Ideal(PhaseGVN* phase, bool can_reshape) override { return nullptr; }
206   virtual Node* Identity(PhaseGVN* phase) override { return this; }
207   virtual const Type* Value(PhaseGVN* phase) const override;
208 
209   static void collect_field_types(ciInlineKlass* vk, const Type** field_types, int idx, int limit, bool null_free, bool trust_null_free_oop);
210   InlineTypeNode* collect_projs(GraphKit* kit, ciInlineKlass* vk, int proj_con, bool null_free);
211   void expand_projs_atomic(PhaseIterGVN& gvn, Node* ctrl, Node* payload);
212   static Node* get_payload_value(PhaseIterGVN& igvn, Node* ctrl, BasicType payload_bt, Node* payload, const Type* value_type, BasicType value_bt, int offset);
213 };
214 
215 // Store an InlineTypeNode to a flat element, the store acts as if it is atomic. Similar to
216 // LoadFlatNode, this node is expanded to storing a payload created from the field values of the
217 // InlineTypeNode, and under special circumstances, when there is no racing access to the field,
218 // this node can be expanded to multiple stores to each flattened field.
219 // The purposes of this node complement those of LoadFlatNode.
220 class StoreFlatNode final : public SafePointNode {
221 private:
222   bool _null_free;
223   DecoratorSet _decorators;
224 
225 public:
226   static void store(GraphKit* kit, Node* base, Node* ptr, InlineTypeNode* value, bool null_free, DecoratorSet decorators);
227   Node* base() const { return in(TypeFunc::Parms); }
228   Node* ptr() const { return in(TypeFunc::Parms + 1); }
229   InlineTypeNode* value() const { return in(TypeFunc::Parms + 2)->as_InlineType(); }
230   bool expand_non_atomic(PhaseIterGVN& igvn);
231   void expand_atomic(PhaseIterGVN& igvn);
232 
233 private:
234   StoreFlatNode(bool null_free, DecoratorSet decorators)
235     : SafePointNode(TypeFunc::Parms + 3, nullptr, TypePtr::BOTTOM), _null_free(null_free), _decorators(decorators) {
236     init_class_id(Class_StoreFlat);
237     Compile::current()->add_flat_access(this);
238   }
239 
240   virtual int Opcode() const override;
241   virtual const Type* bottom_type() const override { return TypeTuple::MEMBAR; }
242   virtual uint size_of() const override { return sizeof(StoreFlatNode); }
243   virtual Node* Ideal(PhaseGVN* phase, bool can_reshape) override { return nullptr; }
244   virtual Node* Identity(PhaseGVN* phase) override { return this; }
245   virtual const Type* Value(PhaseGVN* phase) const override;
246 
247   static Node* convert_to_payload(PhaseIterGVN& igvn, Node* ctrl, InlineTypeNode* value, bool null_free, int& oop_off_1, int& oop_off_2);
248   static Node* set_payload_value(PhaseIterGVN& igvn, BasicType payload_bt, Node* payload, BasicType val_bt, Node* value, int offset);
249 };
250 
251 #endif // SHARE_VM_OPTO_INLINETYPENODE_HPP