22 *
23 */
24
25 #ifndef SHARE_VM_OPTO_MEMNODE_HPP
26 #define SHARE_VM_OPTO_MEMNODE_HPP
27
28 #include "opto/multnode.hpp"
29 #include "opto/node.hpp"
30 #include "opto/opcodes.hpp"
31 #include "opto/type.hpp"
32
33 // Portions of code courtesy of Clifford Click
34
35 class MultiNode;
36 class PhaseCCP;
37 class PhaseTransform;
38
39 //------------------------------MemNode----------------------------------------
40 // Load or Store, possibly throwing a NULL pointer exception
41 class MemNode : public Node {
42 protected:
43 #ifdef ASSERT
44 const TypePtr* _adr_type; // What kind of memory is being addressed?
45 #endif
46 virtual uint size_of() const; // Size is bigger (ASSERT only)
47 public:
48 enum { Control, // When is it safe to do this load?
49 Memory, // Chunk of memory is being loaded from
50 Address, // Actually address, derived from base
51 ValueIn, // Value to store
52 OopStore // Preceeding oop store, only in StoreCM
53 };
54 typedef enum { unordered = 0,
55 acquire, // Load has to acquire or be succeeded by MemBarAcquire.
56 release // Store has to release or be preceded by MemBarRelease.
57 } MemOrd;
58 protected:
59 MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at )
60 : Node(c0,c1,c2 ) {
61 init_class_id(Class_Mem);
62 debug_only(_adr_type=at; adr_type();)
63 }
64 MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at, Node *c3 )
65 : Node(c0,c1,c2,c3) {
66 init_class_id(Class_Mem);
67 debug_only(_adr_type=at; adr_type();)
68 }
69 MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at, Node *c3, Node *c4)
70 : Node(c0,c1,c2,c3,c4) {
71 init_class_id(Class_Mem);
72 debug_only(_adr_type=at; adr_type();)
73 }
74
75 public:
76 // Helpers for the optimizer. Documented in memnode.cpp.
77 static bool detect_ptr_independence(Node* p1, AllocateNode* a1,
78 Node* p2, AllocateNode* a2,
79 PhaseTransform* phase);
80 static bool adr_phi_is_loop_invariant(Node* adr_phi, Node* cast);
81
82 static Node *optimize_simple_memory_chain(Node *mchain, const TypeOopPtr *t_oop, Node *load, PhaseGVN *phase);
83 static Node *optimize_memory_chain(Node *mchain, const TypePtr *t_adr, Node *load, PhaseGVN *phase);
84 // This one should probably be a phase-specific function:
85 static bool all_controls_dominate(Node* dom, Node* sub);
86
87 // Find any cast-away of null-ness and keep its control.
88 static Node *Ideal_common_DU_postCCP( PhaseCCP *ccp, Node* n, Node* adr );
89 virtual Node *Ideal_DU_postCCP( PhaseCCP *ccp );
90
111 virtual int store_Opcode() const { return -1; }
112
113 // What is the type of the value in memory? (T_VOID mean "unspecified".)
114 virtual BasicType memory_type() const = 0;
115 virtual int memory_size() const {
116 #ifdef ASSERT
117 return type2aelembytes(memory_type(), true);
118 #else
119 return type2aelembytes(memory_type());
120 #endif
121 }
122
123 // Search through memory states which precede this node (load or store).
124 // Look for an exact match for the address, with no intervening
125 // aliased stores.
126 Node* find_previous_store(PhaseTransform* phase);
127
128 // Can this node (load or store) accurately see a stored value in
129 // the given memory state? (The state may or may not be in(Memory).)
130 Node* can_see_stored_value(Node* st, PhaseTransform* phase) const;
131
132 #ifndef PRODUCT
133 static void dump_adr_type(const Node* mem, const TypePtr* adr_type, outputStream *st);
134 virtual void dump_spec(outputStream *st) const;
135 #endif
136 };
137
138 //------------------------------LoadNode---------------------------------------
139 // Load value; requires Memory and Address
140 class LoadNode : public MemNode {
141 public:
142 // Some loads (from unsafe) should be pinned: they don't depend only
143 // on the dominating test. The boolean field _depends_only_on_test
144 // below records whether that node depends only on the dominating
145 // test.
146 // Methods used to build LoadNodes pass an argument of type enum
147 // ControlDependency instead of a boolean because those methods
148 // typically have multiple boolean parameters with default values:
149 // passing the wrong boolean to one of these parameters by mistake
150 // goes easily unnoticed. Using an enum, the compiler can check that
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22 *
23 */
24
25 #ifndef SHARE_VM_OPTO_MEMNODE_HPP
26 #define SHARE_VM_OPTO_MEMNODE_HPP
27
28 #include "opto/multnode.hpp"
29 #include "opto/node.hpp"
30 #include "opto/opcodes.hpp"
31 #include "opto/type.hpp"
32
33 // Portions of code courtesy of Clifford Click
34
35 class MultiNode;
36 class PhaseCCP;
37 class PhaseTransform;
38
39 //------------------------------MemNode----------------------------------------
40 // Load or Store, possibly throwing a NULL pointer exception
41 class MemNode : public Node {
42 private:
43 bool _unaligned_access; // Unaligned access from unsafe
44 bool _mismatched_access; // Mismatched access from unsafe: byte read in integer array for instance
45 protected:
46 #ifdef ASSERT
47 const TypePtr* _adr_type; // What kind of memory is being addressed?
48 #endif
49 virtual uint size_of() const;
50 public:
51 enum { Control, // When is it safe to do this load?
52 Memory, // Chunk of memory is being loaded from
53 Address, // Actually address, derived from base
54 ValueIn, // Value to store
55 OopStore // Preceeding oop store, only in StoreCM
56 };
57 typedef enum { unordered = 0,
58 acquire, // Load has to acquire or be succeeded by MemBarAcquire.
59 release // Store has to release or be preceded by MemBarRelease.
60 } MemOrd;
61 protected:
62 MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at )
63 : Node(c0,c1,c2 ), _unaligned_access(false), _mismatched_access(false) {
64 init_class_id(Class_Mem);
65 debug_only(_adr_type=at; adr_type();)
66 }
67 MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at, Node *c3 )
68 : Node(c0,c1,c2,c3), _unaligned_access(false), _mismatched_access(false) {
69 init_class_id(Class_Mem);
70 debug_only(_adr_type=at; adr_type();)
71 }
72 MemNode( Node *c0, Node *c1, Node *c2, const TypePtr* at, Node *c3, Node *c4)
73 : Node(c0,c1,c2,c3,c4), _unaligned_access(false), _mismatched_access(false) {
74 init_class_id(Class_Mem);
75 debug_only(_adr_type=at; adr_type();)
76 }
77
78 public:
79 // Helpers for the optimizer. Documented in memnode.cpp.
80 static bool detect_ptr_independence(Node* p1, AllocateNode* a1,
81 Node* p2, AllocateNode* a2,
82 PhaseTransform* phase);
83 static bool adr_phi_is_loop_invariant(Node* adr_phi, Node* cast);
84
85 static Node *optimize_simple_memory_chain(Node *mchain, const TypeOopPtr *t_oop, Node *load, PhaseGVN *phase);
86 static Node *optimize_memory_chain(Node *mchain, const TypePtr *t_adr, Node *load, PhaseGVN *phase);
87 // This one should probably be a phase-specific function:
88 static bool all_controls_dominate(Node* dom, Node* sub);
89
90 // Find any cast-away of null-ness and keep its control.
91 static Node *Ideal_common_DU_postCCP( PhaseCCP *ccp, Node* n, Node* adr );
92 virtual Node *Ideal_DU_postCCP( PhaseCCP *ccp );
93
114 virtual int store_Opcode() const { return -1; }
115
116 // What is the type of the value in memory? (T_VOID mean "unspecified".)
117 virtual BasicType memory_type() const = 0;
118 virtual int memory_size() const {
119 #ifdef ASSERT
120 return type2aelembytes(memory_type(), true);
121 #else
122 return type2aelembytes(memory_type());
123 #endif
124 }
125
126 // Search through memory states which precede this node (load or store).
127 // Look for an exact match for the address, with no intervening
128 // aliased stores.
129 Node* find_previous_store(PhaseTransform* phase);
130
131 // Can this node (load or store) accurately see a stored value in
132 // the given memory state? (The state may or may not be in(Memory).)
133 Node* can_see_stored_value(Node* st, PhaseTransform* phase) const;
134
135 void set_unaligned_access() { _unaligned_access = true; }
136 bool is_unaligned_access() const { return _unaligned_access; }
137 void set_mismatched_access() { _mismatched_access = true; }
138 bool is_mismatched_access() const { return _mismatched_access; }
139
140 #ifndef PRODUCT
141 static void dump_adr_type(const Node* mem, const TypePtr* adr_type, outputStream *st);
142 virtual void dump_spec(outputStream *st) const;
143 #endif
144 };
145
146 //------------------------------LoadNode---------------------------------------
147 // Load value; requires Memory and Address
148 class LoadNode : public MemNode {
149 public:
150 // Some loads (from unsafe) should be pinned: they don't depend only
151 // on the dominating test. The boolean field _depends_only_on_test
152 // below records whether that node depends only on the dominating
153 // test.
154 // Methods used to build LoadNodes pass an argument of type enum
155 // ControlDependency instead of a boolean because those methods
156 // typically have multiple boolean parameters with default values:
157 // passing the wrong boolean to one of these parameters by mistake
158 // goes easily unnoticed. Using an enum, the compiler can check that
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