| /* |
| * Copyright (c) 1998, 2010, 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_VM_COMPILER_METHODLIVENESS_HPP |
| #define SHARE_VM_COMPILER_METHODLIVENESS_HPP |
| |
| #include "utilities/bitMap.hpp" |
| #include "utilities/growableArray.hpp" |
| |
| class ciMethod; |
| |
| class MethodLivenessResult : public BitMap { |
| private: |
| bool _is_valid; |
| |
| public: |
| MethodLivenessResult(BitMap::bm_word_t* map, idx_t size_in_bits) |
| : BitMap(map, size_in_bits) |
| , _is_valid(false) |
| {} |
| |
| MethodLivenessResult(idx_t size_in_bits) |
| : BitMap(size_in_bits) |
| , _is_valid(false) |
| {} |
| |
| void set_is_valid() { _is_valid = true; } |
| bool is_valid() { return _is_valid; } |
| }; |
| |
| class MethodLiveness : public ResourceObj { |
| public: |
| // The BasicBlock class is used to represent a basic block in the |
| // liveness analysis. |
| class BasicBlock : public ResourceObj { |
| private: |
| // This class is only used by the MethodLiveness class. |
| friend class MethodLiveness; |
| |
| // The analyzer which created this basic block. |
| MethodLiveness* _analyzer; |
| |
| // The range of this basic block is [start_bci,limit_bci) |
| int _start_bci; |
| int _limit_bci; |
| |
| // The liveness at the start of the block; |
| BitMap _entry; |
| |
| // The summarized liveness effects of our direct successors reached |
| // by normal control flow |
| BitMap _normal_exit; |
| |
| // The summarized liveness effects of our direct successors reached |
| // by exceptional control flow |
| BitMap _exception_exit; |
| |
| // These members hold the results of the last call to |
| // compute_gen_kill_range(). _gen is the set of locals |
| // used before they are defined in the range. _kill is the |
| // set of locals defined before they are used. |
| BitMap _gen; |
| BitMap _kill; |
| int _last_bci; |
| |
| // A list of all blocks which could come directly before this one |
| // in normal (non-exceptional) control flow. We propagate liveness |
| // information to these blocks. |
| GrowableArray<BasicBlock*>* _normal_predecessors; |
| |
| // A list of all blocks which could come directly before this one |
| // in exceptional control flow. |
| GrowableArray<BasicBlock*>* _exception_predecessors; |
| |
| // The following fields are used to manage a work list used in the |
| // dataflow. |
| BasicBlock *_next; |
| bool _on_work_list; |
| |
| // Our successors call this method to merge liveness information into |
| // our _normal_exit member. |
| bool merge_normal(BitMap other); |
| |
| // Our successors call this method to merge liveness information into |
| // our _exception_exit member. |
| bool merge_exception(BitMap other); |
| |
| // This helper routine is used to help compute the gen/kill pair for |
| // the block. It is also used to answer queries. |
| void compute_gen_kill_range(ciBytecodeStream *bytes); |
| |
| // Compute the gen/kill effect of a single instruction. |
| void compute_gen_kill_single(ciBytecodeStream *instruction); |
| |
| // Helpers for compute_gen_kill_single. |
| void load_one(int local); |
| void load_two(int local); |
| void store_one(int local); |
| void store_two(int local); |
| |
| BasicBlock(MethodLiveness *analyzer, int start, int limit); |
| |
| // -- Accessors |
| |
| int start_bci() const { return _start_bci; } |
| |
| int limit_bci() const { return _limit_bci; } |
| void set_limit_bci(int limit) { _limit_bci = limit; } |
| |
| BasicBlock *next() const { return _next; } |
| void set_next(BasicBlock *next) { _next = next; } |
| |
| bool on_work_list() const { return _on_work_list; } |
| void set_on_work_list(bool val) { _on_work_list = val; } |
| |
| // -- Flow graph construction. |
| |
| // Add a basic block to our list of normal predecessors. |
| void add_normal_predecessor(BasicBlock *pred) { |
| _normal_predecessors->append_if_missing(pred); |
| } |
| |
| // Add a basic block to our list of exceptional predecessors |
| void add_exception_predecessor(BasicBlock *pred) { |
| _exception_predecessors->append_if_missing(pred); |
| } |
| |
| // Split the basic block at splitBci. This basic block |
| // becomes the second half. The first half is newly created. |
| BasicBlock *split(int splitBci); |
| |
| // -- Dataflow. |
| |
| void compute_gen_kill(ciMethod* method); |
| |
| // Propagate changes from this basic block |
| void propagate(MethodLiveness *ml); |
| |
| // -- Query. |
| |
| MethodLivenessResult get_liveness_at(ciMethod* method, int bci); |
| |
| // -- Debugging. |
| |
| void print_on(outputStream *os) const PRODUCT_RETURN; |
| |
| }; // End of MethodLiveness::BasicBlock |
| |
| private: |
| // The method we are analyzing. |
| ciMethod* _method; |
| ciMethod* method() const { return _method; } |
| |
| // The arena for storing structures... |
| Arena* _arena; |
| Arena* arena() const { return _arena; } |
| |
| // We cache the length of the method. |
| int _code_size; |
| |
| // The size of a BitMap. |
| int _bit_map_size_bits; |
| int _bit_map_size_words; |
| |
| // A list of all BasicBlocks. |
| BasicBlock **_block_list; |
| |
| // number of blocks |
| int _block_count; |
| |
| // Keeps track of bci->block mapping. One entry for each bci. Only block starts are |
| // recorded. |
| GrowableArray<BasicBlock*>* _block_map; |
| |
| // Our work list. |
| BasicBlock *_work_list; |
| |
| #ifdef COMPILER1 |
| // bcis where blocks start are marked |
| BitMap _bci_block_start; |
| #endif // COMPILER1 |
| |
| // -- Graph construction & Analysis |
| |
| // Compute ranges and predecessors for basic blocks. |
| void init_basic_blocks(); |
| |
| // Compute gen/kill information for all basic blocks. |
| void init_gen_kill(); |
| |
| // Perform the dataflow. |
| void propagate_liveness(); |
| |
| // The class MethodLiveness::BasicBlock needs special access to some |
| // of our members. |
| friend class MethodLiveness::BasicBlock; |
| |
| // And accessors. |
| int bit_map_size_bits() const { return _bit_map_size_bits; } |
| int bit_map_size_words() const { return _bit_map_size_words; } |
| |
| // Work list manipulation routines. Called internally by BasicBlock. |
| BasicBlock *work_list_get(); |
| void work_list_add(BasicBlock *block); |
| |
| // -- Timing and Statistics. |
| |
| |
| // Timers |
| static elapsedTimer _time_build_graph; |
| static elapsedTimer _time_gen_kill; |
| static elapsedTimer _time_flow; |
| static elapsedTimer _time_query; |
| static elapsedTimer _time_total; |
| |
| #ifndef PRODUCT |
| |
| // Counts |
| static long _total_bytes; |
| static int _total_methods; |
| |
| static long _total_blocks; |
| static int _max_method_blocks; |
| |
| static long _total_edges; |
| static int _max_block_edges; |
| |
| static long _total_exc_edges; |
| static int _max_block_exc_edges; |
| |
| static long _total_method_locals; |
| static int _max_method_locals; |
| |
| static long _total_locals_queried; |
| static long _total_live_locals_queried; |
| |
| static long _total_visits; |
| |
| #endif |
| |
| public: |
| // Create a liveness analyzer for a method |
| MethodLiveness(Arena* arena, ciMethod* method); |
| |
| // Compute liveness information for the method |
| void compute_liveness(); |
| |
| // Find out which locals are live at a specific bci. |
| MethodLivenessResult get_liveness_at(int bci); |
| |
| #ifdef COMPILER1 |
| const BitMap get_bci_block_start() const { return _bci_block_start; } |
| #endif // COMPILER1 |
| |
| static void print_times() PRODUCT_RETURN; |
| }; |
| |
| #endif // SHARE_VM_COMPILER_METHODLIVENESS_HPP |