/* * Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #ifndef SHARE_C1_C1_RANGECHECKELIMINATION_HPP #define SHARE_C1_C1_RANGECHECKELIMINATION_HPP #include "c1/c1_Instruction.hpp" // Base class for range check elimination class RangeCheckElimination : AllStatic { public: static void eliminate(IR *ir); }; // Implementation class RangeCheckEliminator { private: int _number_of_instructions; bool _optimistic; // Insert predicates and deoptimize when they fail IR *_ir; typedef GrowableArray BlockBeginList; typedef GrowableArray IntegerStack; class Verification : public BlockClosure { // RangeCheckEliminator::Verification should never get instatiated on the heap. private: void* operator new(size_t size) throw(); void* operator new[](size_t size) throw(); void operator delete(void* p) { ShouldNotReachHere(); } void operator delete[](void* p) { ShouldNotReachHere(); } IR *_ir; boolArray _used; BlockBeginList _current; BlockBeginList _successors; public: Verification(IR *ir); virtual void block_do(BlockBegin *block); bool can_reach(BlockBegin *start, BlockBegin *end, BlockBegin *dont_use = NULL); bool dominates(BlockBegin *dominator, BlockBegin *block); }; public: // Bounds for an instruction in the form x + c which c integer // constant and x another instruction class Bound : public CompilationResourceObj { private: int _upper; Value _upper_instr; int _lower; Value _lower_instr; public: Bound(); Bound(Value v); Bound(Instruction::Condition cond, Value v, int constant = 0); Bound(int lower, Value lower_instr, int upper, Value upper_instr); ~Bound(); #ifdef ASSERT void add_assertion(Instruction *instruction, Instruction *position, int i, Value instr, Instruction::Condition cond); #endif int upper(); Value upper_instr(); int lower(); Value lower_instr(); void print(); bool check_no_overflow(int const_value); void or_op(Bound *b); void and_op(Bound *b); bool has_upper(); bool has_lower(); void set_upper(int upper, Value upper_instr); void set_lower(int lower, Value lower_instr); bool is_smaller(Bound *b); void remove_upper(); void remove_lower(); void add_constant(int value); Bound *copy(); private: void init(); }; class Visitor : public InstructionVisitor { private: Bound *_bound; RangeCheckEliminator *_rce; public: void set_range_check_eliminator(RangeCheckEliminator *rce) { _rce = rce; } Bound *bound() const { return _bound; } void clear_bound() { _bound = NULL; } protected: // visitor functions void do_Constant (Constant* x); void do_IfOp (IfOp* x); void do_LogicOp (LogicOp* x); void do_ArithmeticOp (ArithmeticOp* x); void do_Phi (Phi* x); void do_StoreField (StoreField* x) { /* nothing to do */ }; void do_StoreIndexed (StoreIndexed* x) { /* nothing to do */ }; void do_MonitorEnter (MonitorEnter* x) { /* nothing to do */ }; void do_MonitorExit (MonitorExit* x) { /* nothing to do */ }; void do_Invoke (Invoke* x) { /* nothing to do */ }; void do_UnsafePutRaw (UnsafePutRaw* x) { /* nothing to do */ }; void do_UnsafePutObject(UnsafePutObject* x) { /* nothing to do */ }; void do_Intrinsic (Intrinsic* x) { /* nothing to do */ }; void do_Local (Local* x) { /* nothing to do */ }; void do_LoadField (LoadField* x) { /* nothing to do */ }; void do_ArrayLength (ArrayLength* x) { /* nothing to do */ }; void do_LoadIndexed (LoadIndexed* x) { /* nothing to do */ }; void do_NegateOp (NegateOp* x) { /* nothing to do */ }; void do_ShiftOp (ShiftOp* x) { /* nothing to do */ }; void do_CompareOp (CompareOp* x) { /* nothing to do */ }; void do_Convert (Convert* x) { /* nothing to do */ }; void do_NullCheck (NullCheck* x) { /* nothing to do */ }; void do_TypeCast (TypeCast* x) { /* nothing to do */ }; void do_NewInstance (NewInstance* x) { /* nothing to do */ }; void do_NewValueTypeInstance (NewValueTypeInstance* x) { /* nothing to do */ }; void do_NewTypeArray (NewTypeArray* x) { /* nothing to do */ }; void do_NewObjectArray (NewObjectArray* x) { /* nothing to do */ }; void do_NewMultiArray (NewMultiArray* x) { /* nothing to do */ }; void do_WithField (WithField* x) { /* nothing to do */ }; void do_DefaultValue (DefaultValue* x) { /* nothing to do */ }; void do_CheckCast (CheckCast* x) { /* nothing to do */ }; void do_InstanceOf (InstanceOf* x) { /* nothing to do */ }; void do_BlockBegin (BlockBegin* x) { /* nothing to do */ }; void do_Goto (Goto* x) { /* nothing to do */ }; void do_If (If* x) { /* nothing to do */ }; void do_IfInstanceOf (IfInstanceOf* x) { /* nothing to do */ }; void do_TableSwitch (TableSwitch* x) { /* nothing to do */ }; void do_LookupSwitch (LookupSwitch* x) { /* nothing to do */ }; void do_Return (Return* x) { /* nothing to do */ }; void do_Throw (Throw* x) { /* nothing to do */ }; void do_Base (Base* x) { /* nothing to do */ }; void do_OsrEntry (OsrEntry* x) { /* nothing to do */ }; void do_ExceptionObject(ExceptionObject* x) { /* nothing to do */ }; void do_RoundFP (RoundFP* x) { /* nothing to do */ }; void do_UnsafeGetRaw (UnsafeGetRaw* x) { /* nothing to do */ }; void do_UnsafeGetObject(UnsafeGetObject* x) { /* nothing to do */ }; void do_UnsafeGetAndSetObject(UnsafeGetAndSetObject* x) { /* nothing to do */ }; void do_ProfileCall (ProfileCall* x) { /* nothing to do */ }; void do_ProfileReturnType (ProfileReturnType* x) { /* nothing to do */ }; void do_ProfileInvoke (ProfileInvoke* x) { /* nothing to do */ }; void do_RuntimeCall (RuntimeCall* x) { /* nothing to do */ }; void do_MemBar (MemBar* x) { /* nothing to do */ }; void do_RangeCheckPredicate(RangeCheckPredicate* x) { /* nothing to do */ }; #ifdef ASSERT void do_Assert (Assert* x) { /* nothing to do */ }; #endif }; #ifdef ASSERT void add_assertions(Bound *bound, Instruction *instruction, Instruction *position); #endif typedef GrowableArray BoundStack; typedef GrowableArray BoundMap; typedef GrowableArray AccessIndexedList; typedef GrowableArray InstructionList; class AccessIndexedInfo : public CompilationResourceObj { public: AccessIndexedList *_list; int _min; int _max; }; typedef GrowableArray AccessIndexedInfoArray; BoundMap _bounds; // Mapping from Instruction's id to current bound AccessIndexedInfoArray _access_indexed_info; // Mapping from Instruction's id to AccessIndexedInfo for in block motion Visitor _visitor; public: RangeCheckEliminator(IR *ir); IR *ir() const { return _ir; } // Pass over the dominator tree to identify blocks where there's an oppportunity for optimization bool set_process_block_flags(BlockBegin *block); // The core of the optimization work: pass over the dominator tree // to propagate bound information, insert predicate out of loops, // eliminate bound checks when possible and perform in block motion void calc_bounds(BlockBegin *block, BlockBegin *loop_header); // reorder bound checks within a block in order to eliminate some of them void in_block_motion(BlockBegin *block, AccessIndexedList &accessIndexed, InstructionList &arrays); // update/access current bound void update_bound(IntegerStack &pushed, Value v, Instruction::Condition cond, Value value, int constant); void update_bound(IntegerStack &pushed, Value v, Bound *bound); Bound *get_bound(Value v); bool loop_invariant(BlockBegin *loop_header, Instruction *instruction); // check for loop invariance void add_access_indexed_info(InstructionList &indices, int i, Value instruction, AccessIndexed *ai); // record indexed access for in block motion void remove_range_check(AccessIndexed *ai); // Mark this instructions as not needing a range check void add_if_condition(IntegerStack &pushed, Value x, Value y, Instruction::Condition condition); // Update bound for an If bool in_array_bound(Bound *bound, Value array); // Check whether bound is known to fall within array // helper functions to work with predicates Instruction* insert_after(Instruction* insert_position, Instruction* instr, int bci); Instruction* predicate(Instruction* left, Instruction::Condition cond, Instruction* right, ValueStack* state, Instruction *insert_position, int bci=-1); Instruction* predicate_cmp_with_const(Instruction* instr, Instruction::Condition cond, int constant, ValueStack* state, Instruction *insert_position, int bci=1); Instruction* predicate_add(Instruction* left, int left_const, Instruction::Condition cond, Instruction* right, ValueStack* state, Instruction *insert_position, int bci=-1); Instruction* predicate_add_cmp_with_const(Instruction* left, int left_const, Instruction::Condition cond, int constant, ValueStack* state, Instruction *insert_position, int bci=-1); void insert_deoptimization(ValueStack *state, Instruction *insert_position, Instruction *array_instr, // Add predicate Instruction *length_instruction, Instruction *lower_instr, int lower, Instruction *upper_instr, int upper, AccessIndexed *ai); bool is_ok_for_deoptimization(Instruction *insert_position, Instruction *array_instr, // Can we safely add a predicate? Instruction *length_instr, Instruction *lower_instr, int lower, Instruction *upper_instr, int upper); void process_if(IntegerStack &pushed, BlockBegin *block, If *cond); // process If Instruction void process_access_indexed(BlockBegin *loop_header, BlockBegin *block, AccessIndexed *ai); // process indexed access void dump_condition_stack(BlockBegin *cur_block); static void print_statistics(); }; #endif // SHARE_C1_C1_RANGECHECKELIMINATION_HPP