1 /*
2 * Copyright (c) 2012, 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_C1_C1_RANGECHECKELIMINATION_HPP
26 #define SHARE_VM_C1_C1_RANGECHECKELIMINATION_HPP
27
28 #include "c1/c1_Instruction.hpp"
29
30 // Base class for range check elimination
31 class RangeCheckElimination : AllStatic {
32 public:
33 static void eliminate(IR *ir);
34 };
35
36 // Implementation
37 class RangeCheckEliminator VALUE_OBJ_CLASS_SPEC {
38 private:
39 int _number_of_instructions;
40 bool _optimistic; // Insert predicates and deoptimize when they fail
41 IR *_ir;
42
43 define_array(BlockBeginArray, BlockBegin*)
44 define_stack(BlockBeginList, BlockBeginArray)
45 define_stack(IntegerStack, intArray)
46 define_array(IntegerMap, IntegerStack*)
47
48 class Verification : public _ValueObj /*VALUE_OBJ_CLASS_SPEC*/, public BlockClosure {
49 private:
50 IR *_ir;
51 boolArray _used;
52 BlockBeginList _current;
53 BlockBeginList _successors;
54
55 public:
56 Verification(IR *ir);
57 virtual void block_do(BlockBegin *block);
58 bool can_reach(BlockBegin *start, BlockBegin *end, BlockBegin *dont_use = NULL);
59 bool dominates(BlockBegin *dominator, BlockBegin *block);
60 };
61
62 public:
63 // Bounds for an instruction in the form x + c which c integer
64 // constant and x another instruction
65 class Bound : public CompilationResourceObj {
66 private:
67 int _upper;
68 Value _upper_instr;
69 int _lower;
70 Value _lower_instr;
71
72 public:
73 Bound();
74 Bound(Value v);
75 Bound(Instruction::Condition cond, Value v, int constant = 0);
76 Bound(int lower, Value lower_instr, int upper, Value upper_instr);
77 ~Bound();
78
79 #ifdef ASSERT
80 void add_assertion(Instruction *instruction, Instruction *position, int i, Value instr, Instruction::Condition cond);
81 #endif
82 int upper();
83 Value upper_instr();
84 int lower();
85 Value lower_instr();
86 void print();
87 bool check_no_overflow(int const_value);
88 void or_op(Bound *b);
89 void and_op(Bound *b);
90 bool has_upper();
91 bool has_lower();
92 void set_upper(int upper, Value upper_instr);
93 void set_lower(int lower, Value lower_instr);
94 bool is_smaller(Bound *b);
95 void remove_upper();
96 void remove_lower();
97 void add_constant(int value);
98 Bound *copy();
99
100 private:
101 void init();
102 };
103
104
105 class Visitor : public InstructionVisitor {
106 private:
107 Bound *_bound;
108 RangeCheckEliminator *_rce;
109
110 public:
111 void set_range_check_eliminator(RangeCheckEliminator *rce) { _rce = rce; }
112 Bound *bound() const { return _bound; }
113 void clear_bound() { _bound = NULL; }
114
115 protected:
116 // visitor functions
117 void do_Constant (Constant* x);
118 void do_IfOp (IfOp* x);
119 void do_LogicOp (LogicOp* x);
120 void do_ArithmeticOp (ArithmeticOp* x);
121 void do_Phi (Phi* x);
122
123 void do_StoreField (StoreField* x) { /* nothing to do */ };
124 void do_StoreIndexed (StoreIndexed* x) { /* nothing to do */ };
125 void do_MonitorEnter (MonitorEnter* x) { /* nothing to do */ };
126 void do_MonitorExit (MonitorExit* x) { /* nothing to do */ };
127 void do_Invoke (Invoke* x) { /* nothing to do */ };
128 void do_UnsafePutRaw (UnsafePutRaw* x) { /* nothing to do */ };
129 void do_UnsafePutObject(UnsafePutObject* x) { /* nothing to do */ };
130 void do_Intrinsic (Intrinsic* x) { /* nothing to do */ };
131 void do_Local (Local* x) { /* nothing to do */ };
132 void do_LoadField (LoadField* x) { /* nothing to do */ };
133 void do_ArrayLength (ArrayLength* x) { /* nothing to do */ };
134 void do_LoadIndexed (LoadIndexed* x) { /* nothing to do */ };
135 void do_NegateOp (NegateOp* x) { /* nothing to do */ };
136 void do_ShiftOp (ShiftOp* x) { /* nothing to do */ };
137 void do_CompareOp (CompareOp* x) { /* nothing to do */ };
138 void do_Convert (Convert* x) { /* nothing to do */ };
139 void do_NullCheck (NullCheck* x) { /* nothing to do */ };
140 void do_TypeCast (TypeCast* x) { /* nothing to do */ };
141 void do_NewInstance (NewInstance* x) { /* nothing to do */ };
142 void do_NewTypeArray (NewTypeArray* x) { /* nothing to do */ };
143 void do_NewObjectArray (NewObjectArray* x) { /* nothing to do */ };
144 void do_NewMultiArray (NewMultiArray* x) { /* nothing to do */ };
145 void do_CheckCast (CheckCast* x) { /* nothing to do */ };
146 void do_InstanceOf (InstanceOf* x) { /* nothing to do */ };
147 void do_BlockBegin (BlockBegin* x) { /* nothing to do */ };
148 void do_Goto (Goto* x) { /* nothing to do */ };
149 void do_If (If* x) { /* nothing to do */ };
150 void do_IfInstanceOf (IfInstanceOf* x) { /* nothing to do */ };
151 void do_TableSwitch (TableSwitch* x) { /* nothing to do */ };
152 void do_LookupSwitch (LookupSwitch* x) { /* nothing to do */ };
153 void do_Return (Return* x) { /* nothing to do */ };
154 void do_Throw (Throw* x) { /* nothing to do */ };
155 void do_Base (Base* x) { /* nothing to do */ };
156 void do_OsrEntry (OsrEntry* x) { /* nothing to do */ };
157 void do_ExceptionObject(ExceptionObject* x) { /* nothing to do */ };
158 void do_RoundFP (RoundFP* x) { /* nothing to do */ };
159 void do_UnsafeGetRaw (UnsafeGetRaw* x) { /* nothing to do */ };
160 void do_UnsafeGetObject(UnsafeGetObject* x) { /* nothing to do */ };
161 void do_UnsafeGetAndSetObject(UnsafeGetAndSetObject* x) { /* nothing to do */ };
162 void do_UnsafePrefetchRead (UnsafePrefetchRead* x) { /* nothing to do */ };
163 void do_UnsafePrefetchWrite(UnsafePrefetchWrite* x) { /* nothing to do */ };
164 void do_ProfileCall (ProfileCall* x) { /* nothing to do */ };
165 void do_ProfileInvoke (ProfileInvoke* x) { /* nothing to do */ };
166 void do_RuntimeCall (RuntimeCall* x) { /* nothing to do */ };
167 void do_MemBar (MemBar* x) { /* nothing to do */ };
168 void do_RangeCheckPredicate(RangeCheckPredicate* x) { /* nothing to do */ };
169 #ifdef ASSERT
170 void do_Assert (Assert* x) { /* nothing to do */ };
171 #endif
172 };
173
174 #ifdef ASSERT
175 void add_assertions(Bound *bound, Instruction *instruction, Instruction *position);
176 #endif
177
178 define_array(BoundArray, Bound *)
179 define_stack(BoundStack, BoundArray)
180 define_array(BoundMap, BoundStack *)
181 define_array(AccessIndexedArray, AccessIndexed *)
182 define_stack(AccessIndexedList, AccessIndexedArray)
183 define_array(InstructionArray, Instruction *)
184 define_stack(InstructionList, InstructionArray)
185
186 class AccessIndexedInfo : public CompilationResourceObj {
187 public:
188 AccessIndexedList *_list;
189 int _min;
190 int _max;
191 };
192
193 define_array(AccessIndexedInfoArray, AccessIndexedInfo *)
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
198 public:
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_VM_C1_C1_RANGECHECKELIMINATION_HPP