1/*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
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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).
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24
25#ifndef SHARE_C1_C1_RANGECHECKELIMINATION_HPP
26#define SHARE_C1_C1_RANGECHECKELIMINATION_HPP
27
28#include "c1/c1_Instruction.hpp"
29
30// Base class for range check elimination
31class RangeCheckElimination : AllStatic {
32public:
33 static void eliminate(IR *ir);
34};
35
36// Implementation
37class RangeCheckEliminator {
38private:
39 int _number_of_instructions;
40 bool _optimistic; // Insert predicates and deoptimize when they fail
41 IR *_ir;
42
43 typedef GrowableArray<BlockBegin*> BlockBeginList;
44 typedef GrowableArray<int> IntegerStack;
45
46 class Verification : public BlockClosure {
47 // RangeCheckEliminator::Verification should never get instatiated on the heap.
48 private:
49 void* operator new(size_t size) throw();
50 void* operator new[](size_t size) throw();
51 void operator delete(void* p) { ShouldNotReachHere(); }
52 void operator delete[](void* p) { ShouldNotReachHere(); }
53
54 IR *_ir;
55 boolArray _used;
56 BlockBeginList _current;
57 BlockBeginList _successors;
58
59 public:
60 Verification(IR *ir);
61 virtual void block_do(BlockBegin *block);
62 bool can_reach(BlockBegin *start, BlockBegin *end, BlockBegin *dont_use = NULL);
63 bool dominates(BlockBegin *dominator, BlockBegin *block);
64 };
65
66public:
67 // Bounds for an instruction in the form x + c which c integer
68 // constant and x another instruction
69 class Bound : public CompilationResourceObj {
70 private:
71 int _upper;
72 Value _upper_instr;
73 int _lower;
74 Value _lower_instr;
75
76 public:
77 Bound();
78 Bound(Value v);
79 Bound(Instruction::Condition cond, Value v, int constant = 0);
80 Bound(int lower, Value lower_instr, int upper, Value upper_instr);
81 ~Bound();
82
83#ifdef ASSERT
84 void add_assertion(Instruction *instruction, Instruction *position, int i, Value instr, Instruction::Condition cond);
85#endif
86 int upper();
87 Value upper_instr();
88 int lower();
89 Value lower_instr();
90 void print();
91 bool check_no_overflow(int const_value);
92 void or_op(Bound *b);
93 void and_op(Bound *b);
94 bool has_upper();
95 bool has_lower();
96 void set_upper(int upper, Value upper_instr);
97 void set_lower(int lower, Value lower_instr);
98 bool is_smaller(Bound *b);
99 void remove_upper();
100 void remove_lower();
101 void add_constant(int value);
102 Bound *copy();
103
104 private:
105 void init();
106 };
107
108
109 class Visitor : public InstructionVisitor {
110 private:
111 Bound *_bound;
112 RangeCheckEliminator *_rce;
113
114 public:
115 void set_range_check_eliminator(RangeCheckEliminator *rce) { _rce = rce; }
116 Bound *bound() const { return _bound; }
117 void clear_bound() { _bound = NULL; }
118
119 protected:
120 // visitor functions
121 void do_Constant (Constant* x);
122 void do_IfOp (IfOp* x);
123 void do_LogicOp (LogicOp* x);
124 void do_ArithmeticOp (ArithmeticOp* x);
125 void do_Phi (Phi* x);
126
127 void do_StoreField (StoreField* x) { /* nothing to do */ };
128 void do_StoreIndexed (StoreIndexed* x) { /* nothing to do */ };
129 void do_MonitorEnter (MonitorEnter* x) { /* nothing to do */ };
130 void do_MonitorExit (MonitorExit* x) { /* nothing to do */ };
131 void do_Invoke (Invoke* x) { /* nothing to do */ };
132 void do_UnsafePutRaw (UnsafePutRaw* x) { /* nothing to do */ };
133 void do_UnsafePutObject(UnsafePutObject* x) { /* nothing to do */ };
134 void do_Intrinsic (Intrinsic* x) { /* nothing to do */ };
135 void do_Local (Local* x) { /* nothing to do */ };
136 void do_LoadField (LoadField* x) { /* nothing to do */ };
137 void do_ArrayLength (ArrayLength* x) { /* nothing to do */ };
138 void do_LoadIndexed (LoadIndexed* x) { /* nothing to do */ };
139 void do_NegateOp (NegateOp* x) { /* nothing to do */ };
140 void do_ShiftOp (ShiftOp* x) { /* nothing to do */ };
141 void do_CompareOp (CompareOp* x) { /* nothing to do */ };
142 void do_Convert (Convert* x) { /* nothing to do */ };
143 void do_NullCheck (NullCheck* x) { /* nothing to do */ };
144 void do_TypeCast (TypeCast* x) { /* nothing to do */ };
145 void do_NewInstance (NewInstance* x) { /* nothing to do */ };
146 void do_NewTypeArray (NewTypeArray* x) { /* nothing to do */ };
147 void do_NewObjectArray (NewObjectArray* x) { /* nothing to do */ };
148 void do_NewMultiArray (NewMultiArray* x) { /* nothing to do */ };
149 void do_CheckCast (CheckCast* x) { /* nothing to do */ };
150 void do_InstanceOf (InstanceOf* x) { /* nothing to do */ };
151 void do_BlockBegin (BlockBegin* x) { /* nothing to do */ };
152 void do_Goto (Goto* x) { /* nothing to do */ };
153 void do_If (If* x) { /* nothing to do */ };
154 void do_IfInstanceOf (IfInstanceOf* x) { /* nothing to do */ };
155 void do_TableSwitch (TableSwitch* x) { /* nothing to do */ };
156 void do_LookupSwitch (LookupSwitch* x) { /* nothing to do */ };
157 void do_Return (Return* x) { /* nothing to do */ };
158 void do_Throw (Throw* x) { /* nothing to do */ };
159 void do_Base (Base* x) { /* nothing to do */ };
160 void do_OsrEntry (OsrEntry* x) { /* nothing to do */ };
161 void do_ExceptionObject(ExceptionObject* x) { /* nothing to do */ };
162 void do_RoundFP (RoundFP* x) { /* nothing to do */ };
163 void do_UnsafeGetRaw (UnsafeGetRaw* x) { /* nothing to do */ };
164 void do_UnsafeGetObject(UnsafeGetObject* x) { /* nothing to do */ };
165 void do_UnsafeGetAndSetObject(UnsafeGetAndSetObject* x) { /* nothing to do */ };
166 void do_ProfileCall (ProfileCall* x) { /* nothing to do */ };
167 void do_ProfileReturnType (ProfileReturnType* x) { /* nothing to do */ };
168 void do_ProfileInvoke (ProfileInvoke* x) { /* nothing to do */ };
169 void do_RuntimeCall (RuntimeCall* x) { /* nothing to do */ };
170 void do_MemBar (MemBar* x) { /* nothing to do */ };
171 void do_RangeCheckPredicate(RangeCheckPredicate* x) { /* nothing to do */ };
172#ifdef ASSERT
173 void do_Assert (Assert* x) { /* nothing to do */ };
174#endif
175 };
176
177#ifdef ASSERT
178 void add_assertions(Bound *bound, Instruction *instruction, Instruction *position);
179#endif
180
181 typedef GrowableArray<Bound*> BoundStack;
182 typedef GrowableArray<BoundStack*> BoundMap;
183 typedef GrowableArray<AccessIndexed*> AccessIndexedList;
184 typedef GrowableArray<Instruction*> InstructionList;
185
186 class AccessIndexedInfo : public CompilationResourceObj {
187 public:
188 AccessIndexedList *_list;
189 int _min;
190 int _max;
191 };
192
193 typedef GrowableArray<AccessIndexedInfo*> AccessIndexedInfoArray;
194 BoundMap _bounds; // Mapping from Instruction's id to current bound
195 AccessIndexedInfoArray _access_indexed_info; // Mapping from Instruction's id to AccessIndexedInfo for in block motion
196 Visitor _visitor;
197
198public:
199 RangeCheckEliminator(IR *ir);
200
201 IR *ir() const { return _ir; }
202
203 // Pass over the dominator tree to identify blocks where there's an oppportunity for optimization
204 bool set_process_block_flags(BlockBegin *block);
205 // The core of the optimization work: pass over the dominator tree
206 // to propagate bound information, insert predicate out of loops,
207 // eliminate bound checks when possible and perform in block motion
208 void calc_bounds(BlockBegin *block, BlockBegin *loop_header);
209 // reorder bound checks within a block in order to eliminate some of them
210 void in_block_motion(BlockBegin *block, AccessIndexedList &accessIndexed, InstructionList &arrays);
211
212 // update/access current bound
213 void update_bound(IntegerStack &pushed, Value v, Instruction::Condition cond, Value value, int constant);
214 void update_bound(IntegerStack &pushed, Value v, Bound *bound);
215 Bound *get_bound(Value v);
216
217 bool loop_invariant(BlockBegin *loop_header, Instruction *instruction); // check for loop invariance
218 void add_access_indexed_info(InstructionList &indices, int i, Value instruction, AccessIndexed *ai); // record indexed access for in block motion
219 void remove_range_check(AccessIndexed *ai); // Mark this instructions as not needing a range check
220 void add_if_condition(IntegerStack &pushed, Value x, Value y, Instruction::Condition condition); // Update bound for an If
221 bool in_array_bound(Bound *bound, Value array); // Check whether bound is known to fall within array
222
223 // helper functions to work with predicates
224 Instruction* insert_after(Instruction* insert_position, Instruction* instr, int bci);
225 Instruction* predicate(Instruction* left, Instruction::Condition cond, Instruction* right, ValueStack* state, Instruction *insert_position, int bci=-1);
226 Instruction* predicate_cmp_with_const(Instruction* instr, Instruction::Condition cond, int constant, ValueStack* state, Instruction *insert_position, int bci=1);
227 Instruction* predicate_add(Instruction* left, int left_const, Instruction::Condition cond, Instruction* right, ValueStack* state, Instruction *insert_position, int bci=-1);
228 Instruction* predicate_add_cmp_with_const(Instruction* left, int left_const, Instruction::Condition cond, int constant, ValueStack* state, Instruction *insert_position, int bci=-1);
229
230 void insert_deoptimization(ValueStack *state, Instruction *insert_position, Instruction *array_instr, // Add predicate
231 Instruction *length_instruction, Instruction *lower_instr, int lower,
232 Instruction *upper_instr, int upper, AccessIndexed *ai);
233 bool is_ok_for_deoptimization(Instruction *insert_position, Instruction *array_instr, // Can we safely add a predicate?
234 Instruction *length_instr, Instruction *lower_instr,
235 int lower, Instruction *upper_instr, int upper);
236 void process_if(IntegerStack &pushed, BlockBegin *block, If *cond); // process If Instruction
237 void process_access_indexed(BlockBegin *loop_header, BlockBegin *block, AccessIndexed *ai); // process indexed access
238
239 void dump_condition_stack(BlockBegin *cur_block);
240 static void print_statistics();
241};
242
243#endif // SHARE_C1_C1_RANGECHECKELIMINATION_HPP
244