/* * Copyright (c) 2000, 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_CI_CITYPEFLOW_HPP #define SHARE_CI_CITYPEFLOW_HPP #ifdef COMPILER2 #include "ci/ciEnv.hpp" #include "ci/ciKlass.hpp" #include "ci/ciMethodBlocks.hpp" #endif class ciTypeFlow : public ResourceObj { private: ciEnv* _env; ciMethod* _method; ciMethodBlocks* _methodBlocks; int _osr_bci; // information cached from the method: int _max_locals; int _max_stack; int _code_size; bool _has_irreducible_entry; const char* _failure_reason; public: class StateVector; class Loop; class Block; // Build a type flow analyzer // Do an OSR analysis if osr_bci >= 0. ciTypeFlow(ciEnv* env, ciMethod* method, int osr_bci = InvocationEntryBci); // Accessors ciMethod* method() const { return _method; } ciEnv* env() { return _env; } Arena* arena() { return _env->arena(); } bool is_osr_flow() const{ return _osr_bci != InvocationEntryBci; } int start_bci() const { return is_osr_flow()? _osr_bci: 0; } int max_locals() const { return _max_locals; } int max_stack() const { return _max_stack; } int max_cells() const { return _max_locals + _max_stack; } int code_size() const { return _code_size; } bool has_irreducible_entry() const { return _has_irreducible_entry; } // Represents information about an "active" jsr call. This // class represents a call to the routine at some entry address // with some distinct return address. class JsrRecord : public ResourceObj { private: int _entry_address; int _return_address; public: JsrRecord(int entry_address, int return_address) { _entry_address = entry_address; _return_address = return_address; } int entry_address() const { return _entry_address; } int return_address() const { return _return_address; } void print_on(outputStream* st) const { #ifndef PRODUCT st->print("%d->%d", entry_address(), return_address()); #endif } }; // A JsrSet represents some set of JsrRecords. This class // is used to record a set of all jsr routines which we permit // execution to return (ret) from. // // During abstract interpretation, JsrSets are used to determine // whether two paths which reach a given block are unique, and // should be cloned apart, or are compatible, and should merge // together. // // Note that different amounts of effort can be expended determining // if paths are compatible. class JsrSet : public ResourceObj { private: GrowableArray* _set; JsrRecord* record_at(int i) { return _set->at(i); } // Insert the given JsrRecord into the JsrSet, maintaining the order // of the set and replacing any element with the same entry address. void insert_jsr_record(JsrRecord* record); // Remove the JsrRecord with the given return address from the JsrSet. void remove_jsr_record(int return_address); public: JsrSet(Arena* arena, int default_len = 4); // Copy this JsrSet. void copy_into(JsrSet* jsrs); // Is this JsrSet compatible with some other JsrSet? bool is_compatible_with(JsrSet* other); // Apply the effect of a single bytecode to the JsrSet. void apply_control(ciTypeFlow* analyzer, ciBytecodeStream* str, StateVector* state); // What is the cardinality of this set? int size() const { return _set->length(); } void print_on(outputStream* st) const PRODUCT_RETURN; }; class LocalSet { private: enum Constants { max = 63 }; uint64_t _bits; public: LocalSet() : _bits(0) {} void add(uint32_t i) { if (i < (uint32_t)max) _bits |= (1LL << i); } void add(LocalSet* ls) { _bits |= ls->_bits; } bool test(uint32_t i) const { return i < (uint32_t)max ? (_bits>>i)&1U : true; } void clear() { _bits = 0; } void print_on(outputStream* st, int limit) const PRODUCT_RETURN; }; // Used as a combined index for locals and temps enum Cell { Cell_0, Cell_max = INT_MAX }; // A StateVector summarizes the type information at some // point in the program class StateVector : public ResourceObj { private: ciType** _types; int _stack_size; int _monitor_count; ciTypeFlow* _outer; int _trap_bci; int _trap_index; LocalSet _def_locals; // For entire block static ciType* type_meet_internal(ciType* t1, ciType* t2, ciTypeFlow* analyzer); public: // Special elements in our type lattice. enum { T_TOP = T_VOID, // why not? T_BOTTOM = T_CONFLICT, T_LONG2 = T_SHORT, // 2nd word of T_LONG T_DOUBLE2 = T_CHAR, // 2nd word of T_DOUBLE T_NULL = T_BYTE // for now. }; static ciType* top_type() { return ciType::make((BasicType)T_TOP); } static ciType* bottom_type() { return ciType::make((BasicType)T_BOTTOM); } static ciType* long2_type() { return ciType::make((BasicType)T_LONG2); } static ciType* double2_type(){ return ciType::make((BasicType)T_DOUBLE2); } static ciType* null_type() { return ciType::make((BasicType)T_NULL); } static ciType* half_type(ciType* t) { switch (t->basic_type()) { case T_LONG: return long2_type(); case T_DOUBLE: return double2_type(); default: ShouldNotReachHere(); return NULL; } } // The meet operation for our type lattice. ciType* type_meet(ciType* t1, ciType* t2) { return type_meet_internal(t1, t2, outer()); } // Accessors ciTypeFlow* outer() const { return _outer; } int stack_size() const { return _stack_size; } void set_stack_size(int ss) { _stack_size = ss; } int monitor_count() const { return _monitor_count; } void set_monitor_count(int mc) { _monitor_count = mc; } LocalSet* def_locals() { return &_def_locals; } const LocalSet* def_locals() const { return &_def_locals; } static Cell start_cell() { return (Cell)0; } static Cell next_cell(Cell c) { return (Cell)(((int)c) + 1); } Cell limit_cell() const { return (Cell)(outer()->max_locals() + stack_size()); } // Cell creation Cell local(int lnum) const { assert(lnum < outer()->max_locals(), "index check"); return (Cell)(lnum); } Cell stack(int snum) const { assert(snum < stack_size(), "index check"); return (Cell)(outer()->max_locals() + snum); } Cell tos() const { return stack(stack_size()-1); } // For external use only: ciType* local_type_at(int i) const { return type_at(local(i)); } ciType* stack_type_at(int i) const { return type_at(stack(i)); } // Accessors for the type of some Cell c ciType* type_at(Cell c) const { assert(start_cell() <= c && c < limit_cell(), "out of bounds"); return _types[c]; } void set_type_at(Cell c, ciType* type) { assert(start_cell() <= c && c < limit_cell(), "out of bounds"); _types[c] = type; } // Top-of-stack operations. void set_type_at_tos(ciType* type) { set_type_at(tos(), type); } ciType* type_at_tos() const { return type_at(tos()); } void push(ciType* type) { _stack_size++; set_type_at_tos(type); } void pop() { debug_only(set_type_at_tos(bottom_type())); _stack_size--; } ciType* pop_value() { ciType* t = type_at_tos(); pop(); return t; } // Convenience operations. bool is_reference(ciType* type) const { return type == null_type() || !type->is_primitive_type(); } bool is_int(ciType* type) const { return type->basic_type() == T_INT; } bool is_long(ciType* type) const { return type->basic_type() == T_LONG; } bool is_float(ciType* type) const { return type->basic_type() == T_FLOAT; } bool is_double(ciType* type) const { return type->basic_type() == T_DOUBLE; } void store_to_local(int lnum) { _def_locals.add((uint) lnum); } void push_translate(ciType* type); void push_int() { push(ciType::make(T_INT)); } void pop_int() { assert(is_int(type_at_tos()), "must be integer"); pop(); } void check_int(Cell c) { assert(is_int(type_at(c)), "must be integer"); } void push_double() { push(ciType::make(T_DOUBLE)); push(double2_type()); } void pop_double() { assert(type_at_tos() == double2_type(), "must be 2nd half"); pop(); assert(is_double(type_at_tos()), "must be double"); pop(); } void push_float() { push(ciType::make(T_FLOAT)); } void pop_float() { assert(is_float(type_at_tos()), "must be float"); pop(); } void push_long() { push(ciType::make(T_LONG)); push(long2_type()); } void pop_long() { assert(type_at_tos() == long2_type(), "must be 2nd half"); pop(); assert(is_long(type_at_tos()), "must be long"); pop(); } void push_object(ciKlass* klass) { push(klass); } void pop_object() { assert(is_reference(type_at_tos()), "must be reference type"); pop(); } void pop_array() { assert(type_at_tos() == null_type() || type_at_tos()->is_array_klass(), "must be array type"); pop(); } // pop_valueOrobjArray and pop_typeArray narrow the tos to ciObjArrayKlass, // ciValueArrayKlass or ciTypeArrayKlass (resp.). In the rare case that an explicit // null is popped from the stack, we return NULL. Caller beware. ciArrayKlass* pop_objOrValueArray() { ciType* array = pop_value(); if (array == null_type()) return NULL; // Value type arrays may contain oop or flattened representation assert(array->is_obj_array_klass() || (ValueArrayFlatten && array->is_value_array_klass()), "must be value or object array type"); return array->as_array_klass(); } ciTypeArrayKlass* pop_typeArray() { ciType* array = pop_value(); if (array == null_type()) return NULL; assert(array->is_type_array_klass(), "must be prim array type"); return array->as_type_array_klass(); } void push_null() { push(null_type()); } void do_null_assert(ciKlass* unloaded_klass); // Helper convenience routines. void do_aload(ciBytecodeStream* str); void do_checkcast(ciBytecodeStream* str); void do_getfield(ciBytecodeStream* str); void do_getstatic(ciBytecodeStream* str); void do_invoke(ciBytecodeStream* str, bool has_receiver); void do_jsr(ciBytecodeStream* str); void do_ldc(ciBytecodeStream* str); void do_multianewarray(ciBytecodeStream* str); void do_new(ciBytecodeStream* str); void do_defaultvalue(ciBytecodeStream* str); void do_withfield(ciBytecodeStream* str); void do_newarray(ciBytecodeStream* str); void do_putfield(ciBytecodeStream* str); void do_putstatic(ciBytecodeStream* str); void do_ret(ciBytecodeStream* str); void overwrite_local_double_long(int index) { // Invalidate the previous local if it contains first half of // a double or long value since it's seconf half is being overwritten. int prev_index = index - 1; if (prev_index >= 0 && (is_double(type_at(local(prev_index))) || is_long(type_at(local(prev_index))))) { set_type_at(local(prev_index), bottom_type()); } } void load_local_object(int index) { ciType* type = type_at(local(index)); assert(is_reference(type), "must be reference type"); push(type); } void store_local_object(int index) { ciType* type = pop_value(); assert(is_reference(type) || type->is_return_address(), "must be reference type or return address"); overwrite_local_double_long(index); set_type_at(local(index), type); store_to_local(index); } void load_local_double(int index) { ciType* type = type_at(local(index)); ciType* type2 = type_at(local(index+1)); assert(is_double(type), "must be double type"); assert(type2 == double2_type(), "must be 2nd half"); push(type); push(double2_type()); } void store_local_double(int index) { ciType* type2 = pop_value(); ciType* type = pop_value(); assert(is_double(type), "must be double"); assert(type2 == double2_type(), "must be 2nd half"); overwrite_local_double_long(index); set_type_at(local(index), type); set_type_at(local(index+1), type2); store_to_local(index); store_to_local(index+1); } void load_local_float(int index) { ciType* type = type_at(local(index)); assert(is_float(type), "must be float type"); push(type); } void store_local_float(int index) { ciType* type = pop_value(); assert(is_float(type), "must be float type"); overwrite_local_double_long(index); set_type_at(local(index), type); store_to_local(index); } void load_local_int(int index) { ciType* type = type_at(local(index)); assert(is_int(type), "must be int type"); push(type); } void store_local_int(int index) { ciType* type = pop_value(); assert(is_int(type), "must be int type"); overwrite_local_double_long(index); set_type_at(local(index), type); store_to_local(index); } void load_local_long(int index) { ciType* type = type_at(local(index)); ciType* type2 = type_at(local(index+1)); assert(is_long(type), "must be long type"); assert(type2 == long2_type(), "must be 2nd half"); push(type); push(long2_type()); } void store_local_long(int index) { ciType* type2 = pop_value(); ciType* type = pop_value(); assert(is_long(type), "must be long"); assert(type2 == long2_type(), "must be 2nd half"); overwrite_local_double_long(index); set_type_at(local(index), type); set_type_at(local(index+1), type2); store_to_local(index); store_to_local(index+1); } // Stop interpretation of this path with a trap. void trap(ciBytecodeStream* str, ciKlass* klass, int index); public: StateVector(ciTypeFlow* outer); // Copy our value into some other StateVector void copy_into(StateVector* copy) const; // Meets this StateVector with another, destructively modifying this // one. Returns true if any modification takes place. bool meet(const StateVector* incoming); // Ditto, except that the incoming state is coming from an exception. bool meet_exception(ciInstanceKlass* exc, const StateVector* incoming); // Apply the effect of one bytecode to this StateVector bool apply_one_bytecode(ciBytecodeStream* stream); // What is the bci of the trap? int trap_bci() { return _trap_bci; } // What is the index associated with the trap? int trap_index() { return _trap_index; } void print_cell_on(outputStream* st, Cell c) const PRODUCT_RETURN; void print_on(outputStream* st) const PRODUCT_RETURN; }; // Parameter for "find_block" calls: // Describes the difference between a public and backedge copy. enum CreateOption { create_public_copy, create_backedge_copy, no_create }; // Successor iterator class SuccIter : public StackObj { private: Block* _pred; int _index; Block* _succ; public: SuccIter() : _pred(NULL), _index(-1), _succ(NULL) {} SuccIter(Block* pred) : _pred(pred), _index(-1), _succ(NULL) { next(); } int index() { return _index; } Block* pred() { return _pred; } // Return predecessor bool done() { return _index < 0; } // Finished? Block* succ() { return _succ; } // Return current successor void next(); // Advance void set_succ(Block* succ); // Update current successor bool is_normal_ctrl() { return index() < _pred->successors()->length(); } }; // A basic block class Block : public ResourceObj { private: ciBlock* _ciblock; GrowableArray* _exceptions; GrowableArray* _exc_klasses; GrowableArray* _successors; GrowableArray* _predecessors; StateVector* _state; JsrSet* _jsrs; int _trap_bci; int _trap_index; // pre_order, assigned at first visit. Used as block ID and "visited" tag int _pre_order; // A post-order, used to compute the reverse post order (RPO) provided to the client int _post_order; // used to compute rpo // Has this block been cloned for a loop backedge? bool _backedge_copy; // This block is entry to irreducible loop. bool _irreducible_entry; // This block has monitor entry point. bool _has_monitorenter; // A pointer used for our internal work list bool _on_work_list; // on the work list Block* _next; Block* _rpo_next; // Reverse post order list // Loop info Loop* _loop; // nearest loop ciBlock* ciblock() const { return _ciblock; } StateVector* state() const { return _state; } // Compute the exceptional successors and types for this Block. void compute_exceptions(); public: // constructors Block(ciTypeFlow* outer, ciBlock* ciblk, JsrSet* jsrs); void set_trap(int trap_bci, int trap_index) { _trap_bci = trap_bci; _trap_index = trap_index; assert(has_trap(), ""); } bool has_trap() const { return _trap_bci != -1; } int trap_bci() const { assert(has_trap(), ""); return _trap_bci; } int trap_index() const { assert(has_trap(), ""); return _trap_index; } // accessors ciTypeFlow* outer() const { return state()->outer(); } int start() const { return _ciblock->start_bci(); } int limit() const { return _ciblock->limit_bci(); } int control() const { return _ciblock->control_bci(); } JsrSet* jsrs() const { return _jsrs; } bool is_backedge_copy() const { return _backedge_copy; } void set_backedge_copy(bool z); int backedge_copy_count() const { return outer()->backedge_copy_count(ciblock()->index(), _jsrs); } // access to entry state int stack_size() const { return _state->stack_size(); } int monitor_count() const { return _state->monitor_count(); } ciType* local_type_at(int i) const { return _state->local_type_at(i); } ciType* stack_type_at(int i) const { return _state->stack_type_at(i); } // Data flow on locals bool is_invariant_local(uint v) const { assert(is_loop_head(), "only loop heads"); // Find outermost loop with same loop head Loop* lp = loop(); while (lp->parent() != NULL) { if (lp->parent()->head() != lp->head()) break; lp = lp->parent(); } return !lp->def_locals()->test(v); } LocalSet* def_locals() { return _state->def_locals(); } const LocalSet* def_locals() const { return _state->def_locals(); } // Get the successors for this Block. GrowableArray* successors(ciBytecodeStream* str, StateVector* state, JsrSet* jsrs); GrowableArray* successors() { assert(_successors != NULL, "must be filled in"); return _successors; } // Predecessors of this block (including exception edges) GrowableArray* predecessors() { assert(_predecessors != NULL, "must be filled in"); return _predecessors; } // Get the exceptional successors for this Block. GrowableArray* exceptions() { if (_exceptions == NULL) { compute_exceptions(); } return _exceptions; } // Get the exception klasses corresponding to the // exceptional successors for this Block. GrowableArray* exc_klasses() { if (_exc_klasses == NULL) { compute_exceptions(); } return _exc_klasses; } // Is this Block compatible with a given JsrSet? bool is_compatible_with(JsrSet* other) { return _jsrs->is_compatible_with(other); } // Copy the value of our state vector into another. void copy_state_into(StateVector* copy) const { _state->copy_into(copy); } // Copy the value of our JsrSet into another void copy_jsrs_into(JsrSet* copy) const { _jsrs->copy_into(copy); } // Meets the start state of this block with another state, destructively // modifying this one. Returns true if any modification takes place. bool meet(const StateVector* incoming) { return state()->meet(incoming); } // Ditto, except that the incoming state is coming from an // exception path. This means the stack is replaced by the // appropriate exception type. bool meet_exception(ciInstanceKlass* exc, const StateVector* incoming) { return state()->meet_exception(exc, incoming); } // Work list manipulation void set_next(Block* block) { _next = block; } Block* next() const { return _next; } void set_on_work_list(bool c) { _on_work_list = c; } bool is_on_work_list() const { return _on_work_list; } bool has_pre_order() const { return _pre_order >= 0; } void set_pre_order(int po) { assert(!has_pre_order(), ""); _pre_order = po; } int pre_order() const { assert(has_pre_order(), ""); return _pre_order; } void set_next_pre_order() { set_pre_order(outer()->inc_next_pre_order()); } bool is_start() const { return _pre_order == outer()->start_block_num(); } // Reverse post order void df_init(); bool has_post_order() const { return _post_order >= 0; } void set_post_order(int po) { assert(!has_post_order() && po >= 0, ""); _post_order = po; } void reset_post_order(int o){ _post_order = o; } int post_order() const { assert(has_post_order(), ""); return _post_order; } bool has_rpo() const { return has_post_order() && outer()->have_block_count(); } int rpo() const { assert(has_rpo(), ""); return outer()->block_count() - post_order() - 1; } void set_rpo_next(Block* b) { _rpo_next = b; } Block* rpo_next() { return _rpo_next; } // Loops Loop* loop() const { return _loop; } void set_loop(Loop* lp) { _loop = lp; } bool is_loop_head() const { return _loop && _loop->head() == this; } void set_irreducible_entry(bool c) { _irreducible_entry = c; } bool is_irreducible_entry() const { return _irreducible_entry; } void set_has_monitorenter() { _has_monitorenter = true; } bool has_monitorenter() const { return _has_monitorenter; } bool is_visited() const { return has_pre_order(); } bool is_post_visited() const { return has_post_order(); } bool is_clonable_exit(Loop* lp); Block* looping_succ(Loop* lp); // Successor inside of loop bool is_single_entry_loop_head() const { if (!is_loop_head()) return false; for (Loop* lp = loop(); lp != NULL && lp->head() == this; lp = lp->parent()) if (lp->is_irreducible()) return false; return true; } void print_value_on(outputStream* st) const PRODUCT_RETURN; void print_on(outputStream* st) const PRODUCT_RETURN; }; // Loop class Loop : public ResourceObj { private: Loop* _parent; Loop* _sibling; // List of siblings, null terminated Loop* _child; // Head of child list threaded thru sibling pointer Block* _head; // Head of loop Block* _tail; // Tail of loop bool _irreducible; LocalSet _def_locals; public: Loop(Block* head, Block* tail) : _parent(NULL), _sibling(NULL), _child(NULL), _head(head), _tail(tail), _irreducible(false), _def_locals() {} Loop* parent() const { return _parent; } Loop* sibling() const { return _sibling; } Loop* child() const { return _child; } Block* head() const { return _head; } Block* tail() const { return _tail; } void set_parent(Loop* p) { _parent = p; } void set_sibling(Loop* s) { _sibling = s; } void set_child(Loop* c) { _child = c; } void set_head(Block* hd) { _head = hd; } void set_tail(Block* tl) { _tail = tl; } int depth() const; // nesting depth // Returns true if lp is a nested loop or us. bool contains(Loop* lp) const; bool contains(Block* blk) const { return contains(blk->loop()); } // Data flow on locals LocalSet* def_locals() { return &_def_locals; } const LocalSet* def_locals() const { return &_def_locals; } // Merge the branch lp into this branch, sorting on the loop head // pre_orders. Returns the new branch. Loop* sorted_merge(Loop* lp); // Mark non-single entry to loop void set_irreducible(Block* entry) { _irreducible = true; entry->set_irreducible_entry(true); } bool is_irreducible() const { return _irreducible; } bool is_root() const { return _tail->pre_order() == max_jint; } void print(outputStream* st = tty, int indent = 0) const PRODUCT_RETURN; }; // Preorder iteration over the loop tree. class PreorderLoops : public StackObj { private: Loop* _root; Loop* _current; public: PreorderLoops(Loop* root) : _root(root), _current(root) {} bool done() { return _current == NULL; } // Finished iterating? void next(); // Advance to next loop Loop* current() { return _current; } // Return current loop. }; // Standard indexes of successors, for various bytecodes. enum { FALL_THROUGH = 0, // normal control IF_NOT_TAKEN = 0, // the not-taken branch of an if (i.e., fall-through) IF_TAKEN = 1, // the taken branch of an if GOTO_TARGET = 0, // unique successor for goto, jsr, or ret SWITCH_DEFAULT = 0, // default branch of a switch SWITCH_CASES = 1 // first index for any non-default switch branches // Unlike in other blocks, the successors of a switch are listed uniquely. }; private: // A mapping from pre_order to Blocks. This array is created // only at the end of the flow. Block** _block_map; // For each ciBlock index, a list of Blocks which share this ciBlock. GrowableArray** _idx_to_blocklist; // count of ciBlocks int _ciblock_count; // Tells if a given instruction is able to generate an exception edge. bool can_trap(ciBytecodeStream& str); // Clone the loop heads. Returns true if any cloning occurred. bool clone_loop_heads(Loop* lp, StateVector* temp_vector, JsrSet* temp_set); // Clone lp's head and replace tail's successors with clone. Block* clone_loop_head(Loop* lp, StateVector* temp_vector, JsrSet* temp_set); public: // Return the block beginning at bci which has a JsrSet compatible // with jsrs. Block* block_at(int bci, JsrSet* set, CreateOption option = create_public_copy); // block factory Block* get_block_for(int ciBlockIndex, JsrSet* jsrs, CreateOption option = create_public_copy); // How many of the blocks have the backedge_copy bit set? int backedge_copy_count(int ciBlockIndex, JsrSet* jsrs) const; // Return an existing block containing bci which has a JsrSet compatible // with jsrs, or NULL if there is none. Block* existing_block_at(int bci, JsrSet* set) { return block_at(bci, set, no_create); } // Tell whether the flow analysis has encountered an error of some sort. bool failing() { return env()->failing() || _failure_reason != NULL; } // Reason this compilation is failing, such as "too many basic blocks". const char* failure_reason() { return _failure_reason; } // Note a failure. void record_failure(const char* reason); // Return the block of a given pre-order number. int have_block_count() const { return _block_map != NULL; } int block_count() const { assert(have_block_count(), ""); return _next_pre_order; } Block* pre_order_at(int po) const { assert(0 <= po && po < block_count(), "out of bounds"); return _block_map[po]; } Block* start_block() const { return pre_order_at(start_block_num()); } int start_block_num() const { return 0; } Block* rpo_at(int rpo) const { assert(0 <= rpo && rpo < block_count(), "out of bounds"); return _block_map[rpo]; } int inc_next_pre_order() { return _next_pre_order++; } ciType* mark_as_never_null(ciType* type); private: // A work list used during flow analysis. Block* _work_list; // List of blocks in reverse post order Block* _rpo_list; // Next Block::_pre_order. After mapping, doubles as block_count. int _next_pre_order; // Are there more blocks on the work list? bool work_list_empty() { return _work_list == NULL; } // Get the next basic block from our work list. Block* work_list_next(); // Add a basic block to our work list. void add_to_work_list(Block* block); // Prepend a basic block to rpo list. void prepend_to_rpo_list(Block* blk) { blk->set_rpo_next(_rpo_list); _rpo_list = blk; } // Root of the loop tree Loop* _loop_tree_root; // State used for make_jsr_record int _jsr_count; GrowableArray* _jsr_records; public: // Make a JsrRecord for a given (entry, return) pair, if such a record // does not already exist. JsrRecord* make_jsr_record(int entry_address, int return_address); void set_loop_tree_root(Loop* ltr) { _loop_tree_root = ltr; } Loop* loop_tree_root() { return _loop_tree_root; } private: // Get the initial state for start_bci: const StateVector* get_start_state(); // Merge the current state into all exceptional successors at the // current point in the code. void flow_exceptions(GrowableArray* exceptions, GrowableArray* exc_klasses, StateVector* state); // Merge the current state into all successors at the current point // in the code. void flow_successors(GrowableArray* successors, StateVector* state); // Interpret the effects of the bytecodes on the incoming state // vector of a basic block. Push the changed state to succeeding // basic blocks. void flow_block(Block* block, StateVector* scratch_state, JsrSet* scratch_jsrs); // Perform the type flow analysis, creating and cloning Blocks as // necessary. void flow_types(); // Perform the depth first type flow analysis. Helper for flow_types. void df_flow_types(Block* start, bool do_flow, StateVector* temp_vector, JsrSet* temp_set); // Incrementally build loop tree. void build_loop_tree(Block* blk); // Create the block map, which indexes blocks in pre_order. void map_blocks(); public: // Perform type inference flow analysis. void do_flow(); // Determine if bci is dominated by dom_bci bool is_dominated_by(int bci, int dom_bci); void print_on(outputStream* st) const PRODUCT_RETURN; void rpo_print_on(outputStream* st) const PRODUCT_RETURN; }; #endif // SHARE_CI_CITYPEFLOW_HPP