Mercurial > hg > graal-compiler
view src/share/vm/compiler/methodLiveness.cpp @ 2149:7e37af9d69ef
7011379: G1: overly long concurrent marking cycles
Summary: This changeset introduces filtering of SATB buffers at the point when they are about to be enqueued. If this filtering clears enough entries on each buffer, the buffer can then be re-used and not enqueued. This cuts down the number of SATB buffers that need to be processed by the concurrent marking threads.
Reviewed-by: johnc, ysr
author | tonyp |
---|---|
date | Wed, 19 Jan 2011 09:35:17 -0500 |
parents | f95d63e2154a |
children | 8012aa3ccede |
line wrap: on
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/* * 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. * */ #include "precompiled.hpp" #include "ci/ciMethod.hpp" #include "ci/ciMethodBlocks.hpp" #include "ci/ciStreams.hpp" #include "compiler/methodLiveness.hpp" #include "interpreter/bytecode.hpp" #include "interpreter/bytecodes.hpp" #include "memory/allocation.inline.hpp" #include "utilities/bitMap.inline.hpp" // The MethodLiveness class performs a simple liveness analysis on a method // in order to decide which locals are live (that is, will be used again) at // a particular bytecode index (bci). // // The algorithm goes: // // 1. Break the method into a set of basic blocks. For each basic block we // also keep track of its set of predecessors through normal control flow // and predecessors through exceptional control flow. // // 2. For each basic block, compute two sets, gen (the set of values used before // they are defined) and kill (the set of values defined before they are used) // in the basic block. A basic block "needs" the locals in its gen set to // perform its computation. A basic block "provides" values for the locals in // its kill set, allowing a need from a successor to be ignored. // // 3. Liveness information (the set of locals which are needed) is pushed backwards through // the program, from blocks to their predecessors. We compute and store liveness // information for the normal/exceptional exit paths for each basic block. When // this process reaches a fixed point, we are done. // // 4. When we are asked about the liveness at a particular bci with a basic block, we // compute gen/kill sets which represent execution from that bci to the exit of // its blocks. We then compose this range gen/kill information with the normal // and exceptional exit information for the block to produce liveness information // at that bci. // // The algorithm is approximate in many respects. Notably: // // 1. We do not do the analysis necessary to match jsr's with the appropriate ret. // Instead we make the conservative assumption that any ret can return to any // jsr return site. // 2. Instead of computing the effects of exceptions at every instruction, we // summarize the effects of all exceptional continuations from the block as // a single set (_exception_exit), losing some information but simplifying the // analysis. //-------------------------------------------------------------------------- // The BitCounter class is used for counting the number of bits set in // some BitMap. It is only used when collecting liveness statistics. #ifndef PRODUCT class BitCounter: public BitMapClosure { private: int _count; public: BitCounter() : _count(0) {} // Callback when bit in map is set virtual bool do_bit(size_t offset) { _count++; return true; } int count() { return _count; } }; //-------------------------------------------------------------------------- // Counts long MethodLiveness::_total_bytes = 0; int MethodLiveness::_total_methods = 0; long MethodLiveness::_total_blocks = 0; int MethodLiveness::_max_method_blocks = 0; long MethodLiveness::_total_edges = 0; int MethodLiveness::_max_block_edges = 0; long MethodLiveness::_total_exc_edges = 0; int MethodLiveness::_max_block_exc_edges = 0; long MethodLiveness::_total_method_locals = 0; int MethodLiveness::_max_method_locals = 0; long MethodLiveness::_total_locals_queried = 0; long MethodLiveness::_total_live_locals_queried = 0; long MethodLiveness::_total_visits = 0; #endif // Timers elapsedTimer MethodLiveness::_time_build_graph; elapsedTimer MethodLiveness::_time_gen_kill; elapsedTimer MethodLiveness::_time_flow; elapsedTimer MethodLiveness::_time_query; elapsedTimer MethodLiveness::_time_total; MethodLiveness::MethodLiveness(Arena* arena, ciMethod* method) #ifdef COMPILER1 : _bci_block_start((uintptr_t*)arena->Amalloc((method->code_size() >> LogBitsPerByte) + 1), method->code_size()) #endif { _arena = arena; _method = method; _bit_map_size_bits = method->max_locals(); _bit_map_size_words = (_bit_map_size_bits / sizeof(unsigned int)) + 1; #ifdef COMPILER1 _bci_block_start.clear(); #endif } void MethodLiveness::compute_liveness() { #ifndef PRODUCT if (TraceLivenessGen) { tty->print_cr("################################################################"); tty->print("# Computing liveness information for "); method()->print_short_name(); } if (TimeLivenessAnalysis) _time_total.start(); #endif { TraceTime buildGraph(NULL, &_time_build_graph, TimeLivenessAnalysis); init_basic_blocks(); } { TraceTime genKill(NULL, &_time_gen_kill, TimeLivenessAnalysis); init_gen_kill(); } { TraceTime flow(NULL, &_time_flow, TimeLivenessAnalysis); propagate_liveness(); } #ifndef PRODUCT if (TimeLivenessAnalysis) _time_total.stop(); if (TimeLivenessAnalysis) { // Collect statistics _total_bytes += method()->code_size(); _total_methods++; int num_blocks = _block_count; _total_blocks += num_blocks; _max_method_blocks = MAX2(num_blocks,_max_method_blocks); for (int i=0; i<num_blocks; i++) { BasicBlock *block = _block_list[i]; int numEdges = block->_normal_predecessors->length(); int numExcEdges = block->_exception_predecessors->length(); _total_edges += numEdges; _total_exc_edges += numExcEdges; _max_block_edges = MAX2(numEdges,_max_block_edges); _max_block_exc_edges = MAX2(numExcEdges,_max_block_exc_edges); } int numLocals = _bit_map_size_bits; _total_method_locals += numLocals; _max_method_locals = MAX2(numLocals,_max_method_locals); } #endif } void MethodLiveness::init_basic_blocks() { bool bailout = false; int method_len = method()->code_size(); ciMethodBlocks *mblocks = method()->get_method_blocks(); // Create an array to store the bci->BasicBlock mapping. _block_map = new (arena()) GrowableArray<BasicBlock*>(arena(), method_len, method_len, NULL); _block_count = mblocks->num_blocks(); _block_list = (BasicBlock **) arena()->Amalloc(sizeof(BasicBlock *) * _block_count); // Used for patching up jsr/ret control flow. GrowableArray<BasicBlock*>* jsr_exit_list = new GrowableArray<BasicBlock*>(5); GrowableArray<BasicBlock*>* ret_list = new GrowableArray<BasicBlock*>(5); // generate our block list from ciMethodBlocks for (int blk = 0; blk < _block_count; blk++) { ciBlock *cib = mblocks->block(blk); int start_bci = cib->start_bci(); _block_list[blk] = new (arena()) BasicBlock(this, start_bci, cib->limit_bci()); _block_map->at_put(start_bci, _block_list[blk]); #ifdef COMPILER1 // mark all bcis where a new basic block starts _bci_block_start.set_bit(start_bci); #endif // COMPILER1 } // fill in the predecessors of blocks ciBytecodeStream bytes(method()); for (int blk = 0; blk < _block_count; blk++) { BasicBlock *current_block = _block_list[blk]; int bci = mblocks->block(blk)->control_bci(); if (bci == ciBlock::fall_through_bci) { int limit = current_block->limit_bci(); if (limit < method_len) { BasicBlock *next = _block_map->at(limit); assert( next != NULL, "must be a block immediately following this one."); next->add_normal_predecessor(current_block); } continue; } bytes.reset_to_bci(bci); Bytecodes::Code code = bytes.next(); BasicBlock *dest; // Now we need to interpret the instruction's effect // on control flow. assert (current_block != NULL, "we must have a current block"); switch (code) { case Bytecodes::_ifeq: case Bytecodes::_ifne: case Bytecodes::_iflt: case Bytecodes::_ifge: case Bytecodes::_ifgt: case Bytecodes::_ifle: case Bytecodes::_if_icmpeq: case Bytecodes::_if_icmpne: case Bytecodes::_if_icmplt: case Bytecodes::_if_icmpge: case Bytecodes::_if_icmpgt: case Bytecodes::_if_icmple: case Bytecodes::_if_acmpeq: case Bytecodes::_if_acmpne: case Bytecodes::_ifnull: case Bytecodes::_ifnonnull: // Two way branch. Set predecessors at each destination. dest = _block_map->at(bytes.next_bci()); assert(dest != NULL, "must be a block immediately following this one."); dest->add_normal_predecessor(current_block); dest = _block_map->at(bytes.get_dest()); assert(dest != NULL, "branch desination must start a block."); dest->add_normal_predecessor(current_block); break; case Bytecodes::_goto: dest = _block_map->at(bytes.get_dest()); assert(dest != NULL, "branch desination must start a block."); dest->add_normal_predecessor(current_block); break; case Bytecodes::_goto_w: dest = _block_map->at(bytes.get_far_dest()); assert(dest != NULL, "branch desination must start a block."); dest->add_normal_predecessor(current_block); break; case Bytecodes::_tableswitch: { Bytecode_tableswitch *tableswitch = Bytecode_tableswitch_at(bytes.cur_bcp()); int len = tableswitch->length(); dest = _block_map->at(bci + tableswitch->default_offset()); assert(dest != NULL, "branch desination must start a block."); dest->add_normal_predecessor(current_block); while (--len >= 0) { dest = _block_map->at(bci + tableswitch->dest_offset_at(len)); assert(dest != NULL, "branch desination must start a block."); dest->add_normal_predecessor(current_block); } break; } case Bytecodes::_lookupswitch: { Bytecode_lookupswitch *lookupswitch = Bytecode_lookupswitch_at(bytes.cur_bcp()); int npairs = lookupswitch->number_of_pairs(); dest = _block_map->at(bci + lookupswitch->default_offset()); assert(dest != NULL, "branch desination must start a block."); dest->add_normal_predecessor(current_block); while(--npairs >= 0) { LookupswitchPair *pair = lookupswitch->pair_at(npairs); dest = _block_map->at( bci + pair->offset()); assert(dest != NULL, "branch desination must start a block."); dest->add_normal_predecessor(current_block); } break; } case Bytecodes::_jsr: { assert(bytes.is_wide()==false, "sanity check"); dest = _block_map->at(bytes.get_dest()); assert(dest != NULL, "branch desination must start a block."); dest->add_normal_predecessor(current_block); BasicBlock *jsrExit = _block_map->at(current_block->limit_bci()); assert(jsrExit != NULL, "jsr return bci must start a block."); jsr_exit_list->append(jsrExit); break; } case Bytecodes::_jsr_w: { dest = _block_map->at(bytes.get_far_dest()); assert(dest != NULL, "branch desination must start a block."); dest->add_normal_predecessor(current_block); BasicBlock *jsrExit = _block_map->at(current_block->limit_bci()); assert(jsrExit != NULL, "jsr return bci must start a block."); jsr_exit_list->append(jsrExit); break; } case Bytecodes::_wide: assert(false, "wide opcodes should not be seen here"); break; case Bytecodes::_athrow: case Bytecodes::_ireturn: case Bytecodes::_lreturn: case Bytecodes::_freturn: case Bytecodes::_dreturn: case Bytecodes::_areturn: case Bytecodes::_return: // These opcodes are not the normal predecessors of any other opcodes. break; case Bytecodes::_ret: // We will patch up jsr/rets in a subsequent pass. ret_list->append(current_block); break; case Bytecodes::_breakpoint: // Bail out of there are breakpoints in here. bailout = true; break; default: // Do nothing. break; } } // Patch up the jsr/ret's. We conservatively assume that any ret // can return to any jsr site. int ret_list_len = ret_list->length(); int jsr_exit_list_len = jsr_exit_list->length(); if (ret_list_len > 0 && jsr_exit_list_len > 0) { for (int i = jsr_exit_list_len - 1; i >= 0; i--) { BasicBlock *jsrExit = jsr_exit_list->at(i); for (int i = ret_list_len - 1; i >= 0; i--) { jsrExit->add_normal_predecessor(ret_list->at(i)); } } } // Compute exception edges. for (int b=_block_count-1; b >= 0; b--) { BasicBlock *block = _block_list[b]; int block_start = block->start_bci(); int block_limit = block->limit_bci(); ciExceptionHandlerStream handlers(method()); for (; !handlers.is_done(); handlers.next()) { ciExceptionHandler* handler = handlers.handler(); int start = handler->start(); int limit = handler->limit(); int handler_bci = handler->handler_bci(); int intersect_start = MAX2(block_start, start); int intersect_limit = MIN2(block_limit, limit); if (intersect_start < intersect_limit) { // The catch range has a nonempty intersection with this // basic block. That means this basic block can be an // exceptional predecessor. _block_map->at(handler_bci)->add_exception_predecessor(block); if (handler->is_catch_all()) { // This is a catch-all block. if (intersect_start == block_start && intersect_limit == block_limit) { // The basic block is entirely contained in this catch-all block. // Skip the rest of the exception handlers -- they can never be // reached in execution. break; } } } } } } void MethodLiveness::init_gen_kill() { for (int i=_block_count-1; i >= 0; i--) { _block_list[i]->compute_gen_kill(method()); } } void MethodLiveness::propagate_liveness() { int num_blocks = _block_count; BasicBlock *block; // We start our work list off with all blocks in it. // Alternately, we could start off the work list with the list of all // blocks which could exit the method directly, along with one block // from any infinite loop. If this matters, it can be changed. It // may not be clear from looking at the code, but the order of the // workList will be the opposite of the creation order of the basic // blocks, which should be decent for quick convergence (with the // possible exception of exception handlers, which are all created // early). _work_list = NULL; for (int i = 0; i < num_blocks; i++) { block = _block_list[i]; block->set_next(_work_list); block->set_on_work_list(true); _work_list = block; } while ((block = work_list_get()) != NULL) { block->propagate(this); NOT_PRODUCT(_total_visits++;) } } void MethodLiveness::work_list_add(BasicBlock *block) { if (!block->on_work_list()) { block->set_next(_work_list); block->set_on_work_list(true); _work_list = block; } } MethodLiveness::BasicBlock *MethodLiveness::work_list_get() { BasicBlock *block = _work_list; if (block != NULL) { block->set_on_work_list(false); _work_list = block->next(); } return block; } MethodLivenessResult MethodLiveness::get_liveness_at(int entry_bci) { int bci = entry_bci; bool is_entry = false; if (entry_bci == InvocationEntryBci) { is_entry = true; bci = 0; } MethodLivenessResult answer((uintptr_t*)NULL,0); if (_block_count > 0) { if (TimeLivenessAnalysis) _time_total.start(); if (TimeLivenessAnalysis) _time_query.start(); assert( 0 <= bci && bci < method()->code_size(), "bci out of range" ); BasicBlock *block = _block_map->at(bci); // We may not be at the block start, so search backwards to find the block // containing bci. int t = bci; while (block == NULL && t > 0) { block = _block_map->at(--t); } assert( block != NULL, "invalid bytecode index; must be instruction index" ); assert(bci >= block->start_bci() && bci < block->limit_bci(), "block must contain bci."); answer = block->get_liveness_at(method(), bci); if (is_entry && method()->is_synchronized() && !method()->is_static()) { // Synchronized methods use the receiver once on entry. answer.at_put(0, true); } #ifndef PRODUCT if (TraceLivenessQuery) { tty->print("Liveness query of "); method()->print_short_name(); tty->print(" @ %d : result is ", bci); answer.print_on(tty); } if (TimeLivenessAnalysis) _time_query.stop(); if (TimeLivenessAnalysis) _time_total.stop(); #endif } #ifndef PRODUCT if (TimeLivenessAnalysis) { // Collect statistics. _total_locals_queried += _bit_map_size_bits; BitCounter counter; answer.iterate(&counter); _total_live_locals_queried += counter.count(); } #endif return answer; } #ifndef PRODUCT void MethodLiveness::print_times() { tty->print_cr ("Accumulated liveness analysis times/statistics:"); tty->print_cr ("-----------------------------------------------"); tty->print_cr (" Total : %3.3f sec.", _time_total.seconds()); tty->print_cr (" Build graph : %3.3f sec. (%2.2f%%)", _time_build_graph.seconds(), _time_build_graph.seconds() * 100 / _time_total.seconds()); tty->print_cr (" Gen / Kill : %3.3f sec. (%2.2f%%)", _time_gen_kill.seconds(), _time_gen_kill.seconds() * 100 / _time_total.seconds()); tty->print_cr (" Dataflow : %3.3f sec. (%2.2f%%)", _time_flow.seconds(), _time_flow.seconds() * 100 / _time_total.seconds()); tty->print_cr (" Query : %3.3f sec. (%2.2f%%)", _time_query.seconds(), _time_query.seconds() * 100 / _time_total.seconds()); tty->print_cr (" #bytes : %8d (%3.0f bytes per sec)", _total_bytes, _total_bytes / _time_total.seconds()); tty->print_cr (" #methods : %8d (%3.0f methods per sec)", _total_methods, _total_methods / _time_total.seconds()); tty->print_cr (" avg locals : %3.3f max locals : %3d", (float)_total_method_locals / _total_methods, _max_method_locals); tty->print_cr (" avg blocks : %3.3f max blocks : %3d", (float)_total_blocks / _total_methods, _max_method_blocks); tty->print_cr (" avg bytes : %3.3f", (float)_total_bytes / _total_methods); tty->print_cr (" #blocks : %8d", _total_blocks); tty->print_cr (" avg normal predecessors : %3.3f max normal predecessors : %3d", (float)_total_edges / _total_blocks, _max_block_edges); tty->print_cr (" avg exception predecessors : %3.3f max exception predecessors : %3d", (float)_total_exc_edges / _total_blocks, _max_block_exc_edges); tty->print_cr (" avg visits : %3.3f", (float)_total_visits / _total_blocks); tty->print_cr (" #locals queried : %8d #live : %8d %%live : %2.2f%%", _total_locals_queried, _total_live_locals_queried, 100.0 * _total_live_locals_queried / _total_locals_queried); } #endif MethodLiveness::BasicBlock::BasicBlock(MethodLiveness *analyzer, int start, int limit) : _gen((uintptr_t*)analyzer->arena()->Amalloc(BytesPerWord * analyzer->bit_map_size_words()), analyzer->bit_map_size_bits()), _kill((uintptr_t*)analyzer->arena()->Amalloc(BytesPerWord * analyzer->bit_map_size_words()), analyzer->bit_map_size_bits()), _entry((uintptr_t*)analyzer->arena()->Amalloc(BytesPerWord * analyzer->bit_map_size_words()), analyzer->bit_map_size_bits()), _normal_exit((uintptr_t*)analyzer->arena()->Amalloc(BytesPerWord * analyzer->bit_map_size_words()), analyzer->bit_map_size_bits()), _exception_exit((uintptr_t*)analyzer->arena()->Amalloc(BytesPerWord * analyzer->bit_map_size_words()), analyzer->bit_map_size_bits()), _last_bci(-1) { _analyzer = analyzer; _start_bci = start; _limit_bci = limit; _normal_predecessors = new (analyzer->arena()) GrowableArray<MethodLiveness::BasicBlock*>(analyzer->arena(), 5, 0, NULL); _exception_predecessors = new (analyzer->arena()) GrowableArray<MethodLiveness::BasicBlock*>(analyzer->arena(), 5, 0, NULL); _normal_exit.clear(); _exception_exit.clear(); _entry.clear(); // this initialization is not strictly necessary. // _gen and _kill are cleared at the beginning of compute_gen_kill_range() _gen.clear(); _kill.clear(); } MethodLiveness::BasicBlock *MethodLiveness::BasicBlock::split(int split_bci) { int start = _start_bci; int limit = _limit_bci; if (TraceLivenessGen) { tty->print_cr(" ** Splitting block (%d,%d) at %d", start, limit, split_bci); } GrowableArray<BasicBlock*>* save_predecessors = _normal_predecessors; assert (start < split_bci && split_bci < limit, "improper split"); // Make a new block to cover the first half of the range. BasicBlock *first_half = new (_analyzer->arena()) BasicBlock(_analyzer, start, split_bci); // Assign correct values to the second half (this) _normal_predecessors = first_half->_normal_predecessors; _start_bci = split_bci; add_normal_predecessor(first_half); // Assign correct predecessors to the new first half first_half->_normal_predecessors = save_predecessors; return first_half; } void MethodLiveness::BasicBlock::compute_gen_kill(ciMethod* method) { ciBytecodeStream bytes(method); bytes.reset_to_bci(start_bci()); bytes.set_max_bci(limit_bci()); compute_gen_kill_range(&bytes); } void MethodLiveness::BasicBlock::compute_gen_kill_range(ciBytecodeStream *bytes) { _gen.clear(); _kill.clear(); while (bytes->next() != ciBytecodeStream::EOBC()) { compute_gen_kill_single(bytes); } } void MethodLiveness::BasicBlock::compute_gen_kill_single(ciBytecodeStream *instruction) { int localNum; // We prohibit _gen and _kill from having locals in common. If we // know that one is definitely going to be applied before the other, // we could save some computation time by relaxing this prohibition. switch (instruction->cur_bc()) { case Bytecodes::_nop: case Bytecodes::_goto: case Bytecodes::_goto_w: case Bytecodes::_aconst_null: case Bytecodes::_new: case Bytecodes::_iconst_m1: case Bytecodes::_iconst_0: case Bytecodes::_iconst_1: case Bytecodes::_iconst_2: case Bytecodes::_iconst_3: case Bytecodes::_iconst_4: case Bytecodes::_iconst_5: case Bytecodes::_fconst_0: case Bytecodes::_fconst_1: case Bytecodes::_fconst_2: case Bytecodes::_bipush: case Bytecodes::_sipush: case Bytecodes::_lconst_0: case Bytecodes::_lconst_1: case Bytecodes::_dconst_0: case Bytecodes::_dconst_1: case Bytecodes::_ldc2_w: case Bytecodes::_ldc: case Bytecodes::_ldc_w: case Bytecodes::_iaload: case Bytecodes::_faload: case Bytecodes::_baload: case Bytecodes::_caload: case Bytecodes::_saload: case Bytecodes::_laload: case Bytecodes::_daload: case Bytecodes::_aaload: case Bytecodes::_iastore: case Bytecodes::_fastore: case Bytecodes::_bastore: case Bytecodes::_castore: case Bytecodes::_sastore: case Bytecodes::_lastore: case Bytecodes::_dastore: case Bytecodes::_aastore: case Bytecodes::_pop: case Bytecodes::_pop2: case Bytecodes::_dup: case Bytecodes::_dup_x1: case Bytecodes::_dup_x2: case Bytecodes::_dup2: case Bytecodes::_dup2_x1: case Bytecodes::_dup2_x2: case Bytecodes::_swap: case Bytecodes::_iadd: case Bytecodes::_fadd: case Bytecodes::_isub: case Bytecodes::_fsub: case Bytecodes::_imul: case Bytecodes::_fmul: case Bytecodes::_idiv: case Bytecodes::_fdiv: case Bytecodes::_irem: case Bytecodes::_frem: case Bytecodes::_ishl: case Bytecodes::_ishr: case Bytecodes::_iushr: case Bytecodes::_iand: case Bytecodes::_ior: case Bytecodes::_ixor: case Bytecodes::_l2f: case Bytecodes::_l2i: case Bytecodes::_d2f: case Bytecodes::_d2i: case Bytecodes::_fcmpl: case Bytecodes::_fcmpg: case Bytecodes::_ladd: case Bytecodes::_dadd: case Bytecodes::_lsub: case Bytecodes::_dsub: case Bytecodes::_lmul: case Bytecodes::_dmul: case Bytecodes::_ldiv: case Bytecodes::_ddiv: case Bytecodes::_lrem: case Bytecodes::_drem: case Bytecodes::_land: case Bytecodes::_lor: case Bytecodes::_lxor: case Bytecodes::_ineg: case Bytecodes::_fneg: case Bytecodes::_i2f: case Bytecodes::_f2i: case Bytecodes::_i2c: case Bytecodes::_i2s: case Bytecodes::_i2b: case Bytecodes::_lneg: case Bytecodes::_dneg: case Bytecodes::_l2d: case Bytecodes::_d2l: case Bytecodes::_lshl: case Bytecodes::_lshr: case Bytecodes::_lushr: case Bytecodes::_i2l: case Bytecodes::_i2d: case Bytecodes::_f2l: case Bytecodes::_f2d: case Bytecodes::_lcmp: case Bytecodes::_dcmpl: case Bytecodes::_dcmpg: case Bytecodes::_ifeq: case Bytecodes::_ifne: case Bytecodes::_iflt: case Bytecodes::_ifge: case Bytecodes::_ifgt: case Bytecodes::_ifle: case Bytecodes::_tableswitch: case Bytecodes::_ireturn: case Bytecodes::_freturn: case Bytecodes::_if_icmpeq: case Bytecodes::_if_icmpne: case Bytecodes::_if_icmplt: case Bytecodes::_if_icmpge: case Bytecodes::_if_icmpgt: case Bytecodes::_if_icmple: case Bytecodes::_lreturn: case Bytecodes::_dreturn: case Bytecodes::_if_acmpeq: case Bytecodes::_if_acmpne: case Bytecodes::_jsr: case Bytecodes::_jsr_w: case Bytecodes::_getstatic: case Bytecodes::_putstatic: case Bytecodes::_getfield: case Bytecodes::_putfield: case Bytecodes::_invokevirtual: case Bytecodes::_invokespecial: case Bytecodes::_invokestatic: case Bytecodes::_invokeinterface: case Bytecodes::_invokedynamic: case Bytecodes::_newarray: case Bytecodes::_anewarray: case Bytecodes::_checkcast: case Bytecodes::_arraylength: case Bytecodes::_instanceof: case Bytecodes::_athrow: case Bytecodes::_areturn: case Bytecodes::_monitorenter: case Bytecodes::_monitorexit: case Bytecodes::_ifnull: case Bytecodes::_ifnonnull: case Bytecodes::_multianewarray: case Bytecodes::_lookupswitch: // These bytecodes have no effect on the method's locals. break; case Bytecodes::_return: if (instruction->method()->intrinsic_id() == vmIntrinsics::_Object_init) { // return from Object.init implicitly registers a finalizer // for the receiver if needed, so keep it alive. load_one(0); } break; case Bytecodes::_lload: case Bytecodes::_dload: load_two(instruction->get_index()); break; case Bytecodes::_lload_0: case Bytecodes::_dload_0: load_two(0); break; case Bytecodes::_lload_1: case Bytecodes::_dload_1: load_two(1); break; case Bytecodes::_lload_2: case Bytecodes::_dload_2: load_two(2); break; case Bytecodes::_lload_3: case Bytecodes::_dload_3: load_two(3); break; case Bytecodes::_iload: case Bytecodes::_iinc: case Bytecodes::_fload: case Bytecodes::_aload: case Bytecodes::_ret: load_one(instruction->get_index()); break; case Bytecodes::_iload_0: case Bytecodes::_fload_0: case Bytecodes::_aload_0: load_one(0); break; case Bytecodes::_iload_1: case Bytecodes::_fload_1: case Bytecodes::_aload_1: load_one(1); break; case Bytecodes::_iload_2: case Bytecodes::_fload_2: case Bytecodes::_aload_2: load_one(2); break; case Bytecodes::_iload_3: case Bytecodes::_fload_3: case Bytecodes::_aload_3: load_one(3); break; case Bytecodes::_lstore: case Bytecodes::_dstore: store_two(localNum = instruction->get_index()); break; case Bytecodes::_lstore_0: case Bytecodes::_dstore_0: store_two(0); break; case Bytecodes::_lstore_1: case Bytecodes::_dstore_1: store_two(1); break; case Bytecodes::_lstore_2: case Bytecodes::_dstore_2: store_two(2); break; case Bytecodes::_lstore_3: case Bytecodes::_dstore_3: store_two(3); break; case Bytecodes::_istore: case Bytecodes::_fstore: case Bytecodes::_astore: store_one(instruction->get_index()); break; case Bytecodes::_istore_0: case Bytecodes::_fstore_0: case Bytecodes::_astore_0: store_one(0); break; case Bytecodes::_istore_1: case Bytecodes::_fstore_1: case Bytecodes::_astore_1: store_one(1); break; case Bytecodes::_istore_2: case Bytecodes::_fstore_2: case Bytecodes::_astore_2: store_one(2); break; case Bytecodes::_istore_3: case Bytecodes::_fstore_3: case Bytecodes::_astore_3: store_one(3); break; case Bytecodes::_wide: fatal("Iterator should skip this bytecode"); break; default: tty->print("unexpected opcode: %d\n", instruction->cur_bc()); ShouldNotReachHere(); break; } } void MethodLiveness::BasicBlock::load_two(int local) { load_one(local); load_one(local+1); } void MethodLiveness::BasicBlock::load_one(int local) { if (!_kill.at(local)) { _gen.at_put(local, true); } } void MethodLiveness::BasicBlock::store_two(int local) { store_one(local); store_one(local+1); } void MethodLiveness::BasicBlock::store_one(int local) { if (!_gen.at(local)) { _kill.at_put(local, true); } } void MethodLiveness::BasicBlock::propagate(MethodLiveness *ml) { // These set operations could be combined for efficiency if the // performance of this analysis becomes an issue. _entry.set_union(_normal_exit); _entry.set_difference(_kill); _entry.set_union(_gen); // Note that we merge information from our exceptional successors // just once, rather than at individual bytecodes. _entry.set_union(_exception_exit); if (TraceLivenessGen) { tty->print_cr(" ** Visiting block at %d **", start_bci()); print_on(tty); } int i; for (i=_normal_predecessors->length()-1; i>=0; i--) { BasicBlock *block = _normal_predecessors->at(i); if (block->merge_normal(_entry)) { ml->work_list_add(block); } } for (i=_exception_predecessors->length()-1; i>=0; i--) { BasicBlock *block = _exception_predecessors->at(i); if (block->merge_exception(_entry)) { ml->work_list_add(block); } } } bool MethodLiveness::BasicBlock::merge_normal(BitMap other) { return _normal_exit.set_union_with_result(other); } bool MethodLiveness::BasicBlock::merge_exception(BitMap other) { return _exception_exit.set_union_with_result(other); } MethodLivenessResult MethodLiveness::BasicBlock::get_liveness_at(ciMethod* method, int bci) { MethodLivenessResult answer(NEW_RESOURCE_ARRAY(uintptr_t, _analyzer->bit_map_size_words()), _analyzer->bit_map_size_bits()); answer.set_is_valid(); #ifndef ASSERT if (bci == start_bci()) { answer.set_from(_entry); return answer; } #endif #ifdef ASSERT ResourceMark rm; BitMap g(_gen.size()); g.set_from(_gen); BitMap k(_kill.size()); k.set_from(_kill); #endif if (_last_bci != bci || trueInDebug) { ciBytecodeStream bytes(method); bytes.reset_to_bci(bci); bytes.set_max_bci(limit_bci()); compute_gen_kill_range(&bytes); assert(_last_bci != bci || (g.is_same(_gen) && k.is_same(_kill)), "cached computation is incorrect"); _last_bci = bci; } answer.clear(); answer.set_union(_normal_exit); answer.set_difference(_kill); answer.set_union(_gen); answer.set_union(_exception_exit); #ifdef ASSERT if (bci == start_bci()) { assert(answer.is_same(_entry), "optimized answer must be accurate"); } #endif return answer; } #ifndef PRODUCT void MethodLiveness::BasicBlock::print_on(outputStream *os) const { os->print_cr("==================================================================="); os->print_cr(" Block start: %4d, limit: %4d", _start_bci, _limit_bci); os->print (" Normal predecessors (%2d) @", _normal_predecessors->length()); int i; for (i=0; i < _normal_predecessors->length(); i++) { os->print(" %4d", _normal_predecessors->at(i)->start_bci()); } os->cr(); os->print (" Exceptional predecessors (%2d) @", _exception_predecessors->length()); for (i=0; i < _exception_predecessors->length(); i++) { os->print(" %4d", _exception_predecessors->at(i)->start_bci()); } os->cr(); os->print (" Normal Exit : "); _normal_exit.print_on(os); os->print (" Gen : "); _gen.print_on(os); os->print (" Kill : "); _kill.print_on(os); os->print (" Exception Exit: "); _exception_exit.print_on(os); os->print (" Entry : "); _entry.print_on(os); } #endif // PRODUCT