1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/compiler/methodLiveness.hpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,271 @@
1.4 +/*
1.5 + * Copyright 1998-2006 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +class ciMethod;
1.29 +
1.30 +class MethodLivenessResult : public BitMap {
1.31 + private:
1.32 + bool _is_valid;
1.33 +
1.34 + public:
1.35 + MethodLivenessResult(uintptr_t* map, idx_t size_in_bits)
1.36 + : BitMap(map, size_in_bits)
1.37 + , _is_valid(false)
1.38 + {}
1.39 +
1.40 + MethodLivenessResult(idx_t size_in_bits)
1.41 + : BitMap(size_in_bits)
1.42 + , _is_valid(false)
1.43 + {}
1.44 +
1.45 + void set_is_valid() { _is_valid = true; }
1.46 + bool is_valid() { return _is_valid; }
1.47 +};
1.48 +
1.49 +class MethodLiveness : public ResourceObj {
1.50 + public:
1.51 + // The BasicBlock class is used to represent a basic block in the
1.52 + // liveness analysis.
1.53 + class BasicBlock : public ResourceObj {
1.54 + private:
1.55 + // This class is only used by the MethodLiveness class.
1.56 + friend class MethodLiveness;
1.57 +
1.58 + // The analyzer which created this basic block.
1.59 + MethodLiveness* _analyzer;
1.60 +
1.61 + // The range of this basic block is [start_bci,limit_bci)
1.62 + int _start_bci;
1.63 + int _limit_bci;
1.64 +
1.65 + // The liveness at the start of the block;
1.66 + BitMap _entry;
1.67 +
1.68 + // The summarized liveness effects of our direct successors reached
1.69 + // by normal control flow
1.70 + BitMap _normal_exit;
1.71 +
1.72 + // The summarized liveness effects of our direct successors reached
1.73 + // by exceptional control flow
1.74 + BitMap _exception_exit;
1.75 +
1.76 + // These members hold the results of the last call to
1.77 + // compute_gen_kill_range(). _gen is the set of locals
1.78 + // used before they are defined in the range. _kill is the
1.79 + // set of locals defined before they are used.
1.80 + BitMap _gen;
1.81 + BitMap _kill;
1.82 + int _last_bci;
1.83 +
1.84 + // A list of all blocks which could come directly before this one
1.85 + // in normal (non-exceptional) control flow. We propagate liveness
1.86 + // information to these blocks.
1.87 + GrowableArray<BasicBlock*>* _normal_predecessors;
1.88 +
1.89 + // A list of all blocks which could come directly before this one
1.90 + // in exceptional control flow.
1.91 + GrowableArray<BasicBlock*>* _exception_predecessors;
1.92 +
1.93 + // The following fields are used to manage a work list used in the
1.94 + // dataflow.
1.95 + BasicBlock *_next;
1.96 + bool _on_work_list;
1.97 +
1.98 + // Our successors call this method to merge liveness information into
1.99 + // our _normal_exit member.
1.100 + bool merge_normal(BitMap other);
1.101 +
1.102 + // Our successors call this method to merge liveness information into
1.103 + // our _exception_exit member.
1.104 + bool merge_exception(BitMap other);
1.105 +
1.106 + // This helper routine is used to help compute the gen/kill pair for
1.107 + // the block. It is also used to answer queries.
1.108 + void compute_gen_kill_range(ciBytecodeStream *bytes);
1.109 +
1.110 + // Compute the gen/kill effect of a single instruction.
1.111 + void compute_gen_kill_single(ciBytecodeStream *instruction);
1.112 +
1.113 + // Helpers for compute_gen_kill_single.
1.114 + void load_one(int local);
1.115 + void load_two(int local);
1.116 + void store_one(int local);
1.117 + void store_two(int local);
1.118 +
1.119 + BasicBlock(MethodLiveness *analyzer, int start, int limit);
1.120 +
1.121 + // -- Accessors
1.122 +
1.123 + int start_bci() const { return _start_bci; }
1.124 +
1.125 + int limit_bci() const { return _limit_bci; }
1.126 + void set_limit_bci(int limit) { _limit_bci = limit; }
1.127 +
1.128 + BasicBlock *next() const { return _next; }
1.129 + void set_next(BasicBlock *next) { _next = next; }
1.130 +
1.131 + bool on_work_list() const { return _on_work_list; }
1.132 + void set_on_work_list(bool val) { _on_work_list = val; }
1.133 +
1.134 + // -- Flow graph construction.
1.135 +
1.136 + // Add a basic block to our list of normal predecessors.
1.137 + void add_normal_predecessor(BasicBlock *pred) {
1.138 + _normal_predecessors->append_if_missing(pred);
1.139 + }
1.140 +
1.141 + // Add a basic block to our list of exceptional predecessors
1.142 + void add_exception_predecessor(BasicBlock *pred) {
1.143 + _exception_predecessors->append_if_missing(pred);
1.144 + }
1.145 +
1.146 + // Split the basic block at splitBci. This basic block
1.147 + // becomes the second half. The first half is newly created.
1.148 + BasicBlock *split(int splitBci);
1.149 +
1.150 + // -- Dataflow.
1.151 +
1.152 + void compute_gen_kill(ciMethod* method);
1.153 +
1.154 + // Propagate changes from this basic block
1.155 + void propagate(MethodLiveness *ml);
1.156 +
1.157 + // -- Query.
1.158 +
1.159 + MethodLivenessResult get_liveness_at(ciMethod* method, int bci);
1.160 +
1.161 + // -- Debugging.
1.162 +
1.163 + void print_on(outputStream *os) const PRODUCT_RETURN;
1.164 +
1.165 + }; // End of MethodLiveness::BasicBlock
1.166 +
1.167 + private:
1.168 + // The method we are analyzing.
1.169 + ciMethod* _method;
1.170 + ciMethod* method() const { return _method; }
1.171 +
1.172 + // The arena for storing structures...
1.173 + Arena* _arena;
1.174 + Arena* arena() const { return _arena; }
1.175 +
1.176 + // We cache the length of the method.
1.177 + int _code_size;
1.178 +
1.179 + // The size of a BitMap.
1.180 + int _bit_map_size_bits;
1.181 + int _bit_map_size_words;
1.182 +
1.183 + // A list of all BasicBlocks.
1.184 + BasicBlock **_block_list;
1.185 +
1.186 + // number of blocks
1.187 + int _block_count;
1.188 +
1.189 + // Keeps track of bci->block mapping. One entry for each bci. Only block starts are
1.190 + // recorded.
1.191 + GrowableArray<BasicBlock*>* _block_map;
1.192 +
1.193 + // Our work list.
1.194 + BasicBlock *_work_list;
1.195 +
1.196 +#ifdef COMPILER1
1.197 + // bcis where blocks start are marked
1.198 + BitMap _bci_block_start;
1.199 +#endif // COMPILER1
1.200 +
1.201 + // -- Graph construction & Analysis
1.202 +
1.203 + // Compute ranges and predecessors for basic blocks.
1.204 + void init_basic_blocks();
1.205 +
1.206 + // Compute gen/kill information for all basic blocks.
1.207 + void init_gen_kill();
1.208 +
1.209 + // Perform the dataflow.
1.210 + void propagate_liveness();
1.211 +
1.212 + // The class MethodLiveness::BasicBlock needs special access to some
1.213 + // of our members.
1.214 + friend class MethodLiveness::BasicBlock;
1.215 +
1.216 + // And accessors.
1.217 + int bit_map_size_bits() const { return _bit_map_size_bits; }
1.218 + int bit_map_size_words() const { return _bit_map_size_words; }
1.219 +
1.220 + // Work list manipulation routines. Called internally by BasicBlock.
1.221 + BasicBlock *work_list_get();
1.222 + void work_list_add(BasicBlock *block);
1.223 +
1.224 + // -- Timing and Statistics.
1.225 +
1.226 +
1.227 + // Timers
1.228 + static elapsedTimer _time_build_graph;
1.229 + static elapsedTimer _time_gen_kill;
1.230 + static elapsedTimer _time_flow;
1.231 + static elapsedTimer _time_query;
1.232 + static elapsedTimer _time_total;
1.233 +
1.234 +#ifndef PRODUCT
1.235 +
1.236 + // Counts
1.237 + static long _total_bytes;
1.238 + static int _total_methods;
1.239 +
1.240 + static long _total_blocks;
1.241 + static int _max_method_blocks;
1.242 +
1.243 + static long _total_edges;
1.244 + static int _max_block_edges;
1.245 +
1.246 + static long _total_exc_edges;
1.247 + static int _max_block_exc_edges;
1.248 +
1.249 + static long _total_method_locals;
1.250 + static int _max_method_locals;
1.251 +
1.252 + static long _total_locals_queried;
1.253 + static long _total_live_locals_queried;
1.254 +
1.255 + static long _total_visits;
1.256 +
1.257 +#endif
1.258 +
1.259 + public:
1.260 + // Create a liveness analyzer for a method
1.261 + MethodLiveness(Arena* arena, ciMethod* method);
1.262 +
1.263 + // Compute liveness information for the method
1.264 + void compute_liveness();
1.265 +
1.266 + // Find out which locals are live at a specific bci.
1.267 + MethodLivenessResult get_liveness_at(int bci);
1.268 +
1.269 +#ifdef COMPILER1
1.270 + const BitMap get_bci_block_start() const { return _bci_block_start; }
1.271 +#endif // COMPILER1
1.272 +
1.273 + static void print_times() PRODUCT_RETURN;
1.274 +};
