duke@435: /*
duke@435:  * Copyright 1998-2006 Sun Microsystems, Inc.  All Rights Reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
duke@435:  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435:  * CA 95054 USA or visit www.sun.com if you need additional information or
duke@435:  * have any questions.
duke@435:  *
duke@435:  */
duke@435: 
duke@435: // The MethodLiveness class performs a simple liveness analysis on a method
duke@435: // in order to decide which locals are live (that is, will be used again) at
duke@435: // a particular bytecode index (bci).
duke@435: //
duke@435: // The algorithm goes:
duke@435: //
duke@435: // 1. Break the method into a set of basic blocks.  For each basic block we
duke@435: //    also keep track of its set of predecessors through normal control flow
duke@435: //    and predecessors through exceptional control flow.
duke@435: //
duke@435: // 2. For each basic block, compute two sets, gen (the set of values used before
duke@435: //    they are defined) and kill (the set of values defined before they are used)
duke@435: //    in the basic block.  A basic block "needs" the locals in its gen set to
duke@435: //    perform its computation.  A basic block "provides" values for the locals in
duke@435: //    its kill set, allowing a need from a successor to be ignored.
duke@435: //
duke@435: // 3. Liveness information (the set of locals which are needed) is pushed backwards through
duke@435: //    the program, from blocks to their predecessors.  We compute and store liveness
duke@435: //    information for the normal/exceptional exit paths for each basic block.  When
duke@435: //    this process reaches a fixed point, we are done.
duke@435: //
duke@435: // 4. When we are asked about the liveness at a particular bci with a basic block, we
duke@435: //    compute gen/kill sets which represent execution from that bci to the exit of
duke@435: //    its blocks.  We then compose this range gen/kill information with the normal
duke@435: //    and exceptional exit information for the block to produce liveness information
duke@435: //    at that bci.
duke@435: //
duke@435: // The algorithm is approximate in many respects.  Notably:
duke@435: //
duke@435: // 1. We do not do the analysis necessary to match jsr's with the appropriate ret.
duke@435: //    Instead we make the conservative assumption that any ret can return to any
duke@435: //    jsr return site.
duke@435: // 2. Instead of computing the effects of exceptions at every instruction, we
duke@435: //    summarize the effects of all exceptional continuations from the block as
duke@435: //    a single set (_exception_exit), losing some information but simplifying the
duke@435: //    analysis.
duke@435: 
duke@435: 
duke@435: # include "incls/_precompiled.incl"
duke@435: # include "incls/_methodLiveness.cpp.incl"
duke@435: 
duke@435: //--------------------------------------------------------------------------
duke@435: // The BitCounter class is used for counting the number of bits set in
duke@435: // some BitMap.  It is only used when collecting liveness statistics.
duke@435: 
duke@435: #ifndef PRODUCT
duke@435: 
duke@435: class BitCounter: public BitMapClosure {
duke@435:  private:
duke@435:   int _count;
duke@435:  public:
duke@435:   BitCounter() : _count(0) {}
duke@435: 
duke@435:   // Callback when bit in map is set
duke@435:   virtual void do_bit(size_t offset) {
duke@435:     _count++;
duke@435:   }
duke@435: 
duke@435:   int count() {
duke@435:     return _count;
duke@435:   }
duke@435: };
duke@435: 
duke@435: 
duke@435: //--------------------------------------------------------------------------
duke@435: 
duke@435: 
duke@435: // Counts
duke@435: long MethodLiveness::_total_bytes = 0;
duke@435: int  MethodLiveness::_total_methods = 0;
duke@435: 
duke@435: long MethodLiveness::_total_blocks = 0;
duke@435: int  MethodLiveness::_max_method_blocks = 0;
duke@435: 
duke@435: long MethodLiveness::_total_edges = 0;
duke@435: int  MethodLiveness::_max_block_edges = 0;
duke@435: 
duke@435: long MethodLiveness::_total_exc_edges = 0;
duke@435: int  MethodLiveness::_max_block_exc_edges = 0;
duke@435: 
duke@435: long MethodLiveness::_total_method_locals = 0;
duke@435: int  MethodLiveness::_max_method_locals = 0;
duke@435: 
duke@435: long MethodLiveness::_total_locals_queried = 0;
duke@435: long MethodLiveness::_total_live_locals_queried = 0;
duke@435: 
duke@435: long MethodLiveness::_total_visits = 0;
duke@435: 
duke@435: #endif
duke@435: 
duke@435: // Timers
duke@435: elapsedTimer MethodLiveness::_time_build_graph;
duke@435: elapsedTimer MethodLiveness::_time_gen_kill;
duke@435: elapsedTimer MethodLiveness::_time_flow;
duke@435: elapsedTimer MethodLiveness::_time_query;
duke@435: elapsedTimer MethodLiveness::_time_total;
duke@435: 
duke@435: MethodLiveness::MethodLiveness(Arena* arena, ciMethod* method)
duke@435: #ifdef COMPILER1
duke@435:   : _bci_block_start((uintptr_t*)arena->Amalloc((method->code_size() >> LogBitsPerByte) + 1), method->code_size())
duke@435: #endif
duke@435: {
duke@435:   _arena = arena;
duke@435:   _method = method;
duke@435:   _bit_map_size_bits = method->max_locals();
duke@435:   _bit_map_size_words = (_bit_map_size_bits / sizeof(unsigned int)) + 1;
duke@435: 
duke@435: #ifdef COMPILER1
duke@435:   _bci_block_start.clear();
duke@435: #endif
duke@435: }
duke@435: 
duke@435: void MethodLiveness::compute_liveness() {
duke@435: #ifndef PRODUCT
duke@435:   if (TraceLivenessGen) {
duke@435:     tty->print_cr("################################################################");
duke@435:     tty->print("# Computing liveness information for ");
duke@435:     method()->print_short_name();
duke@435:   }
duke@435: 
duke@435:   if (TimeLivenessAnalysis) _time_total.start();
duke@435: #endif
duke@435: 
duke@435:   {
duke@435:     TraceTime buildGraph(NULL, &_time_build_graph, TimeLivenessAnalysis);
duke@435:     init_basic_blocks();
duke@435:   }
duke@435:   {
duke@435:     TraceTime genKill(NULL, &_time_gen_kill, TimeLivenessAnalysis);
duke@435:     init_gen_kill();
duke@435:   }
duke@435:   {
duke@435:     TraceTime flow(NULL, &_time_flow, TimeLivenessAnalysis);
duke@435:     propagate_liveness();
duke@435:   }
duke@435: 
duke@435: #ifndef PRODUCT
duke@435:   if (TimeLivenessAnalysis) _time_total.stop();
duke@435: 
duke@435:   if (TimeLivenessAnalysis) {
duke@435:     // Collect statistics
duke@435:     _total_bytes += method()->code_size();
duke@435:     _total_methods++;
duke@435: 
duke@435:     int num_blocks = _block_count;
duke@435:     _total_blocks += num_blocks;
duke@435:     _max_method_blocks = MAX2(num_blocks,_max_method_blocks);
duke@435: 
duke@435:     for (int i=0; i<num_blocks; i++) {
duke@435:       BasicBlock *block = _block_list[i];
duke@435: 
duke@435:       int numEdges = block->_normal_predecessors->length();
duke@435:       int numExcEdges = block->_exception_predecessors->length();
duke@435: 
duke@435:       _total_edges += numEdges;
duke@435:       _total_exc_edges += numExcEdges;
duke@435:       _max_block_edges = MAX2(numEdges,_max_block_edges);
duke@435:       _max_block_exc_edges = MAX2(numExcEdges,_max_block_exc_edges);
duke@435:     }
duke@435: 
duke@435:     int numLocals = _bit_map_size_bits;
duke@435:     _total_method_locals += numLocals;
duke@435:     _max_method_locals = MAX2(numLocals,_max_method_locals);
duke@435:   }
duke@435: #endif
duke@435: }
duke@435: 
duke@435: 
duke@435: void MethodLiveness::init_basic_blocks() {
duke@435:   bool bailout = false;
duke@435: 
duke@435:   int method_len = method()->code_size();
duke@435:   ciMethodBlocks *mblocks = method()->get_method_blocks();
duke@435: 
duke@435:   // Create an array to store the bci->BasicBlock mapping.
duke@435:   _block_map = new (arena()) GrowableArray<BasicBlock*>(arena(), method_len, method_len, NULL);
duke@435: 
duke@435:   _block_count = mblocks->num_blocks();
duke@435:   _block_list = (BasicBlock **) arena()->Amalloc(sizeof(BasicBlock *) * _block_count);
duke@435: 
duke@435:   // Used for patching up jsr/ret control flow.
duke@435:   GrowableArray<BasicBlock*>* jsr_exit_list = new GrowableArray<BasicBlock*>(5);
duke@435:   GrowableArray<BasicBlock*>* ret_list = new GrowableArray<BasicBlock*>(5);
duke@435: 
duke@435:   // generate our block list from ciMethodBlocks
duke@435:   for (int blk = 0; blk < _block_count; blk++) {
duke@435:     ciBlock *cib = mblocks->block(blk);
duke@435:      int start_bci = cib->start_bci();
duke@435:     _block_list[blk] = new (arena()) BasicBlock(this, start_bci, cib->limit_bci());
duke@435:     _block_map->at_put(start_bci, _block_list[blk]);
duke@435: #ifdef COMPILER1
duke@435:     // mark all bcis where a new basic block starts
duke@435:     _bci_block_start.set_bit(start_bci);
duke@435: #endif // COMPILER1
duke@435:   }
duke@435:   // fill in the predecessors of blocks
duke@435:   ciBytecodeStream bytes(method());
duke@435: 
duke@435:   for (int blk = 0; blk < _block_count; blk++) {
duke@435:     BasicBlock *current_block = _block_list[blk];
duke@435:     int bci =  mblocks->block(blk)->control_bci();
duke@435: 
duke@435:     if (bci == ciBlock::fall_through_bci) {
duke@435:       int limit = current_block->limit_bci();
duke@435:       if (limit < method_len) {
duke@435:         BasicBlock *next = _block_map->at(limit);
duke@435:         assert( next != NULL, "must be a block immediately following this one.");
duke@435:         next->add_normal_predecessor(current_block);
duke@435:       }
duke@435:       continue;
duke@435:     }
duke@435:     bytes.reset_to_bci(bci);
duke@435:     Bytecodes::Code code = bytes.next();
duke@435:     BasicBlock *dest;
duke@435: 
duke@435:     // Now we need to interpret the instruction's effect
duke@435:     // on control flow.
duke@435:     assert (current_block != NULL, "we must have a current block");
duke@435:     switch (code) {
duke@435:       case Bytecodes::_ifeq:
duke@435:       case Bytecodes::_ifne:
duke@435:       case Bytecodes::_iflt:
duke@435:       case Bytecodes::_ifge:
duke@435:       case Bytecodes::_ifgt:
duke@435:       case Bytecodes::_ifle:
duke@435:       case Bytecodes::_if_icmpeq:
duke@435:       case Bytecodes::_if_icmpne:
duke@435:       case Bytecodes::_if_icmplt:
duke@435:       case Bytecodes::_if_icmpge:
duke@435:       case Bytecodes::_if_icmpgt:
duke@435:       case Bytecodes::_if_icmple:
duke@435:       case Bytecodes::_if_acmpeq:
duke@435:       case Bytecodes::_if_acmpne:
duke@435:       case Bytecodes::_ifnull:
duke@435:       case Bytecodes::_ifnonnull:
duke@435:         // Two way branch.  Set predecessors at each destination.
duke@435:         dest = _block_map->at(bytes.next_bci());
duke@435:         assert(dest != NULL, "must be a block immediately following this one.");
duke@435:         dest->add_normal_predecessor(current_block);
duke@435: 
duke@435:         dest = _block_map->at(bytes.get_dest());
duke@435:         assert(dest != NULL, "branch desination must start a block.");
duke@435:         dest->add_normal_predecessor(current_block);
duke@435:         break;
duke@435:       case Bytecodes::_goto:
duke@435:         dest = _block_map->at(bytes.get_dest());
duke@435:         assert(dest != NULL, "branch desination must start a block.");
duke@435:         dest->add_normal_predecessor(current_block);
duke@435:         break;
duke@435:       case Bytecodes::_goto_w:
duke@435:         dest = _block_map->at(bytes.get_far_dest());
duke@435:         assert(dest != NULL, "branch desination must start a block.");
duke@435:         dest->add_normal_predecessor(current_block);
duke@435:         break;
duke@435:       case Bytecodes::_tableswitch:
duke@435:         {
duke@435:           Bytecode_tableswitch *tableswitch =
duke@435:             Bytecode_tableswitch_at(bytes.cur_bcp());
duke@435: 
duke@435:           int len = tableswitch->length();
duke@435: 
duke@435:           dest = _block_map->at(bci + tableswitch->default_offset());
duke@435:           assert(dest != NULL, "branch desination must start a block.");
duke@435:           dest->add_normal_predecessor(current_block);
duke@435:           while (--len >= 0) {
duke@435:             dest = _block_map->at(bci + tableswitch->dest_offset_at(len));
duke@435:             assert(dest != NULL, "branch desination must start a block.");
duke@435:             dest->add_normal_predecessor(current_block);
duke@435:           }
duke@435:           break;
duke@435:         }
duke@435: 
duke@435:       case Bytecodes::_lookupswitch:
duke@435:         {
duke@435:           Bytecode_lookupswitch *lookupswitch =
duke@435:             Bytecode_lookupswitch_at(bytes.cur_bcp());
duke@435: 
duke@435:           int npairs = lookupswitch->number_of_pairs();
duke@435: 
duke@435:           dest = _block_map->at(bci + lookupswitch->default_offset());
duke@435:           assert(dest != NULL, "branch desination must start a block.");
duke@435:           dest->add_normal_predecessor(current_block);
duke@435:           while(--npairs >= 0) {
duke@435:             LookupswitchPair *pair = lookupswitch->pair_at(npairs);
duke@435:             dest = _block_map->at( bci + pair->offset());
duke@435:             assert(dest != NULL, "branch desination must start a block.");
duke@435:             dest->add_normal_predecessor(current_block);
duke@435:           }
duke@435:           break;
duke@435:         }
duke@435: 
duke@435:       case Bytecodes::_jsr:
duke@435:         {
duke@435:           assert(bytes.is_wide()==false, "sanity check");
duke@435:           dest = _block_map->at(bytes.get_dest());
duke@435:           assert(dest != NULL, "branch desination must start a block.");
duke@435:           dest->add_normal_predecessor(current_block);
duke@435:           BasicBlock *jsrExit = _block_map->at(current_block->limit_bci());
duke@435:           assert(jsrExit != NULL, "jsr return bci must start a block.");
duke@435:           jsr_exit_list->append(jsrExit);
duke@435:           break;
duke@435:         }
duke@435:       case Bytecodes::_jsr_w:
duke@435:         {
duke@435:           dest = _block_map->at(bytes.get_far_dest());
duke@435:           assert(dest != NULL, "branch desination must start a block.");
duke@435:           dest->add_normal_predecessor(current_block);
duke@435:           BasicBlock *jsrExit = _block_map->at(current_block->limit_bci());
duke@435:           assert(jsrExit != NULL, "jsr return bci must start a block.");
duke@435:           jsr_exit_list->append(jsrExit);
duke@435:           break;
duke@435:         }
duke@435: 
duke@435:       case Bytecodes::_wide:
duke@435:         assert(false, "wide opcodes should not be seen here");
duke@435:         break;
duke@435:       case Bytecodes::_athrow:
duke@435:       case Bytecodes::_ireturn:
duke@435:       case Bytecodes::_lreturn:
duke@435:       case Bytecodes::_freturn:
duke@435:       case Bytecodes::_dreturn:
duke@435:       case Bytecodes::_areturn:
duke@435:       case Bytecodes::_return:
duke@435:         // These opcodes are  not the normal predecessors of any other opcodes.
duke@435:         break;
duke@435:       case Bytecodes::_ret:
duke@435:         // We will patch up jsr/rets in a subsequent pass.
duke@435:         ret_list->append(current_block);
duke@435:         break;
duke@435:       case Bytecodes::_breakpoint:
duke@435:         // Bail out of there are breakpoints in here.
duke@435:         bailout = true;
duke@435:         break;
duke@435:       default:
duke@435:         // Do nothing.
duke@435:         break;
duke@435:     }
duke@435:   }
duke@435:   // Patch up the jsr/ret's.  We conservatively assume that any ret
duke@435:   // can return to any jsr site.
duke@435:   int ret_list_len = ret_list->length();
duke@435:   int jsr_exit_list_len = jsr_exit_list->length();
duke@435:   if (ret_list_len > 0 && jsr_exit_list_len > 0) {
duke@435:     for (int i = jsr_exit_list_len - 1; i >= 0; i--) {
duke@435:       BasicBlock *jsrExit = jsr_exit_list->at(i);
duke@435:       for (int i = ret_list_len - 1; i >= 0; i--) {
duke@435:         jsrExit->add_normal_predecessor(ret_list->at(i));
duke@435:       }
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   // Compute exception edges.
duke@435:   for (int b=_block_count-1; b >= 0; b--) {
duke@435:     BasicBlock *block = _block_list[b];
duke@435:     int block_start = block->start_bci();
duke@435:     int block_limit = block->limit_bci();
duke@435:     ciExceptionHandlerStream handlers(method());
duke@435:     for (; !handlers.is_done(); handlers.next()) {
duke@435:       ciExceptionHandler* handler = handlers.handler();
duke@435:       int start       = handler->start();
duke@435:       int limit       = handler->limit();
duke@435:       int handler_bci = handler->handler_bci();
duke@435: 
duke@435:       int intersect_start = MAX2(block_start, start);
duke@435:       int intersect_limit = MIN2(block_limit, limit);
duke@435:       if (intersect_start < intersect_limit) {
duke@435:         // The catch range has a nonempty intersection with this
duke@435:         // basic block.  That means this basic block can be an
duke@435:         // exceptional predecessor.
duke@435:         _block_map->at(handler_bci)->add_exception_predecessor(block);
duke@435: 
duke@435:         if (handler->is_catch_all()) {
duke@435:           // This is a catch-all block.
duke@435:           if (intersect_start == block_start && intersect_limit == block_limit) {
duke@435:             // The basic block is entirely contained in this catch-all block.
duke@435:             // Skip the rest of the exception handlers -- they can never be
duke@435:             // reached in execution.
duke@435:             break;
duke@435:           }
duke@435:         }
duke@435:       }
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: void MethodLiveness::init_gen_kill() {
duke@435:   for (int i=_block_count-1; i >= 0; i--) {
duke@435:     _block_list[i]->compute_gen_kill(method());
duke@435:   }
duke@435: }
duke@435: 
duke@435: void MethodLiveness::propagate_liveness() {
duke@435:   int num_blocks = _block_count;
duke@435:   BasicBlock *block;
duke@435: 
duke@435:   // We start our work list off with all blocks in it.
duke@435:   // Alternately, we could start off the work list with the list of all
duke@435:   // blocks which could exit the method directly, along with one block
duke@435:   // from any infinite loop.  If this matters, it can be changed.  It
duke@435:   // may not be clear from looking at the code, but the order of the
duke@435:   // workList will be the opposite of the creation order of the basic
duke@435:   // blocks, which should be decent for quick convergence (with the
duke@435:   // possible exception of exception handlers, which are all created
duke@435:   // early).
duke@435:   _work_list = NULL;
duke@435:   for (int i = 0; i < num_blocks; i++) {
duke@435:     block = _block_list[i];
duke@435:     block->set_next(_work_list);
duke@435:     block->set_on_work_list(true);
duke@435:     _work_list = block;
duke@435:   }
duke@435: 
duke@435: 
duke@435:   while ((block = work_list_get()) != NULL) {
duke@435:     block->propagate(this);
duke@435:     NOT_PRODUCT(_total_visits++;)
duke@435:   }
duke@435: }
duke@435: 
duke@435: void MethodLiveness::work_list_add(BasicBlock *block) {
duke@435:   if (!block->on_work_list()) {
duke@435:     block->set_next(_work_list);
duke@435:     block->set_on_work_list(true);
duke@435:     _work_list = block;
duke@435:   }
duke@435: }
duke@435: 
duke@435: MethodLiveness::BasicBlock *MethodLiveness::work_list_get() {
duke@435:   BasicBlock *block = _work_list;
duke@435:   if (block != NULL) {
duke@435:     block->set_on_work_list(false);
duke@435:     _work_list = block->next();
duke@435:   }
duke@435:   return block;
duke@435: }
duke@435: 
duke@435: 
duke@435: MethodLivenessResult MethodLiveness::get_liveness_at(int entry_bci) {
duke@435:   int bci = entry_bci;
duke@435:   bool is_entry = false;
duke@435:   if (entry_bci == InvocationEntryBci) {
duke@435:     is_entry = true;
duke@435:     bci = 0;
duke@435:   }
duke@435: 
duke@435:   MethodLivenessResult answer(NULL,0);
duke@435: 
duke@435:   if (_block_count > 0) {
duke@435:     if (TimeLivenessAnalysis) _time_total.start();
duke@435:     if (TimeLivenessAnalysis) _time_query.start();
duke@435: 
duke@435:     assert( 0 <= bci && bci < method()->code_size(), "bci out of range" );
duke@435:     BasicBlock *block = _block_map->at(bci);
duke@435:     // We may not be at the block start, so search backwards to find the block
duke@435:     // containing bci.
duke@435:     int t = bci;
duke@435:     while (block == NULL && t > 0) {
duke@435:      block = _block_map->at(--t);
duke@435:     }
duke@435:     assert( block != NULL, "invalid bytecode index; must be instruction index" );
duke@435:     assert(bci >= block->start_bci() && bci < block->limit_bci(), "block must contain bci.");
duke@435: 
duke@435:     answer = block->get_liveness_at(method(), bci);
duke@435: 
duke@435:     if (is_entry && method()->is_synchronized() && !method()->is_static()) {
duke@435:       // Synchronized methods use the receiver once on entry.
duke@435:       answer.at_put(0, true);
duke@435:     }
duke@435: 
duke@435: #ifndef PRODUCT
duke@435:     if (TraceLivenessQuery) {
duke@435:       tty->print("Liveness query of ");
duke@435:       method()->print_short_name();
duke@435:       tty->print(" @ %d : result is ", bci);
duke@435:       answer.print_on(tty);
duke@435:     }
duke@435: 
duke@435:     if (TimeLivenessAnalysis) _time_query.stop();
duke@435:     if (TimeLivenessAnalysis) _time_total.stop();
duke@435: #endif
duke@435:   }
duke@435: 
duke@435: #ifndef PRODUCT
duke@435:   if (TimeLivenessAnalysis) {
duke@435:     // Collect statistics.
duke@435:     _total_locals_queried += _bit_map_size_bits;
duke@435:     BitCounter counter;
duke@435:     answer.iterate(&counter);
duke@435:     _total_live_locals_queried += counter.count();
duke@435:   }
duke@435: #endif
duke@435: 
duke@435:   return answer;
duke@435: }
duke@435: 
duke@435: 
duke@435: #ifndef PRODUCT
duke@435: 
duke@435: void MethodLiveness::print_times() {
duke@435:   tty->print_cr ("Accumulated liveness analysis times/statistics:");
duke@435:   tty->print_cr ("-----------------------------------------------");
duke@435:   tty->print_cr ("  Total         : %3.3f sec.", _time_total.seconds());
duke@435:   tty->print_cr ("    Build graph : %3.3f sec. (%2.2f%%)", _time_build_graph.seconds(),
duke@435:                  _time_build_graph.seconds() * 100 / _time_total.seconds());
duke@435:   tty->print_cr ("    Gen / Kill  : %3.3f sec. (%2.2f%%)", _time_gen_kill.seconds(),
duke@435:                  _time_gen_kill.seconds() * 100 / _time_total.seconds());
duke@435:   tty->print_cr ("    Dataflow    : %3.3f sec. (%2.2f%%)", _time_flow.seconds(),
duke@435:                  _time_flow.seconds() * 100 / _time_total.seconds());
duke@435:   tty->print_cr ("    Query       : %3.3f sec. (%2.2f%%)", _time_query.seconds(),
duke@435:                  _time_query.seconds() * 100 / _time_total.seconds());
duke@435:   tty->print_cr ("  #bytes   : %8d (%3.0f bytes per sec)",
duke@435:                  _total_bytes,
duke@435:                  _total_bytes / _time_total.seconds());
duke@435:   tty->print_cr ("  #methods : %8d (%3.0f methods per sec)",
duke@435:                  _total_methods,
duke@435:                  _total_methods / _time_total.seconds());
duke@435:   tty->print_cr ("    avg locals : %3.3f    max locals : %3d",
duke@435:                  (float)_total_method_locals / _total_methods,
duke@435:                  _max_method_locals);
duke@435:   tty->print_cr ("    avg blocks : %3.3f    max blocks : %3d",
duke@435:                  (float)_total_blocks / _total_methods,
duke@435:                  _max_method_blocks);
duke@435:   tty->print_cr ("    avg bytes  : %3.3f",
duke@435:                  (float)_total_bytes / _total_methods);
duke@435:   tty->print_cr ("  #blocks  : %8d",
duke@435:                  _total_blocks);
duke@435:   tty->print_cr ("    avg normal predecessors    : %3.3f  max normal predecessors    : %3d",
duke@435:                  (float)_total_edges / _total_blocks,
duke@435:                  _max_block_edges);
duke@435:   tty->print_cr ("    avg exception predecessors : %3.3f  max exception predecessors : %3d",
duke@435:                  (float)_total_exc_edges / _total_blocks,
duke@435:                  _max_block_exc_edges);
duke@435:   tty->print_cr ("    avg visits                 : %3.3f",
duke@435:                  (float)_total_visits / _total_blocks);
duke@435:   tty->print_cr ("  #locals queried : %8d    #live : %8d   %%live : %2.2f%%",
duke@435:                  _total_locals_queried,
duke@435:                  _total_live_locals_queried,
duke@435:                  100.0 * _total_live_locals_queried / _total_locals_queried);
duke@435: }
duke@435: 
duke@435: #endif
duke@435: 
duke@435: 
duke@435: MethodLiveness::BasicBlock::BasicBlock(MethodLiveness *analyzer, int start, int limit) :
duke@435:          _gen((uintptr_t*)analyzer->arena()->Amalloc(BytesPerWord * analyzer->bit_map_size_words()),
duke@435:                          analyzer->bit_map_size_bits()),
duke@435:          _kill((uintptr_t*)analyzer->arena()->Amalloc(BytesPerWord * analyzer->bit_map_size_words()),
duke@435:                          analyzer->bit_map_size_bits()),
duke@435:          _entry((uintptr_t*)analyzer->arena()->Amalloc(BytesPerWord * analyzer->bit_map_size_words()),
duke@435:                          analyzer->bit_map_size_bits()),
duke@435:          _normal_exit((uintptr_t*)analyzer->arena()->Amalloc(BytesPerWord * analyzer->bit_map_size_words()),
duke@435:                          analyzer->bit_map_size_bits()),
duke@435:          _exception_exit((uintptr_t*)analyzer->arena()->Amalloc(BytesPerWord * analyzer->bit_map_size_words()),
duke@435:                          analyzer->bit_map_size_bits()),
duke@435:          _last_bci(-1) {
duke@435:   _analyzer = analyzer;
duke@435:   _start_bci = start;
duke@435:   _limit_bci = limit;
duke@435:   _normal_predecessors =
duke@435:     new (analyzer->arena()) GrowableArray<MethodLiveness::BasicBlock*>(analyzer->arena(), 5, 0, NULL);
duke@435:   _exception_predecessors =
duke@435:     new (analyzer->arena()) GrowableArray<MethodLiveness::BasicBlock*>(analyzer->arena(), 5, 0, NULL);
duke@435:   _normal_exit.clear();
duke@435:   _exception_exit.clear();
duke@435:   _entry.clear();
duke@435: 
duke@435:   // this initialization is not strictly necessary.
duke@435:   // _gen and _kill are cleared at the beginning of compute_gen_kill_range()
duke@435:   _gen.clear();
duke@435:   _kill.clear();
duke@435: }
duke@435: 
duke@435: 
duke@435: 
duke@435: MethodLiveness::BasicBlock *MethodLiveness::BasicBlock::split(int split_bci) {
duke@435:   int start = _start_bci;
duke@435:   int limit = _limit_bci;
duke@435: 
duke@435:   if (TraceLivenessGen) {
duke@435:     tty->print_cr(" ** Splitting block (%d,%d) at %d", start, limit, split_bci);
duke@435:   }
duke@435: 
duke@435:   GrowableArray<BasicBlock*>* save_predecessors = _normal_predecessors;
duke@435: 
duke@435:   assert (start < split_bci && split_bci < limit, "improper split");
duke@435: 
duke@435:   // Make a new block to cover the first half of the range.
duke@435:   BasicBlock *first_half = new (_analyzer->arena()) BasicBlock(_analyzer, start, split_bci);
duke@435: 
duke@435:   // Assign correct values to the second half (this)
duke@435:   _normal_predecessors = first_half->_normal_predecessors;
duke@435:   _start_bci = split_bci;
duke@435:   add_normal_predecessor(first_half);
duke@435: 
duke@435:   // Assign correct predecessors to the new first half
duke@435:   first_half->_normal_predecessors = save_predecessors;
duke@435: 
duke@435:   return first_half;
duke@435: }
duke@435: 
duke@435: void MethodLiveness::BasicBlock::compute_gen_kill(ciMethod* method) {
duke@435:   ciBytecodeStream bytes(method);
duke@435:   bytes.reset_to_bci(start_bci());
duke@435:   bytes.set_max_bci(limit_bci());
duke@435:   compute_gen_kill_range(&bytes);
duke@435: 
duke@435: }
duke@435: 
duke@435: void MethodLiveness::BasicBlock::compute_gen_kill_range(ciBytecodeStream *bytes) {
duke@435:   _gen.clear();
duke@435:   _kill.clear();
duke@435: 
duke@435:   while (bytes->next() != ciBytecodeStream::EOBC()) {
duke@435:     compute_gen_kill_single(bytes);
duke@435:   }
duke@435: }
duke@435: 
duke@435: void MethodLiveness::BasicBlock::compute_gen_kill_single(ciBytecodeStream *instruction) {
duke@435:   int localNum;
duke@435: 
duke@435:   // We prohibit _gen and _kill from having locals in common.  If we
duke@435:   // know that one is definitely going to be applied before the other,
duke@435:   // we could save some computation time by relaxing this prohibition.
duke@435: 
duke@435:   switch (instruction->cur_bc()) {
duke@435:     case Bytecodes::_nop:
duke@435:     case Bytecodes::_goto:
duke@435:     case Bytecodes::_goto_w:
duke@435:     case Bytecodes::_aconst_null:
duke@435:     case Bytecodes::_new:
duke@435:     case Bytecodes::_iconst_m1:
duke@435:     case Bytecodes::_iconst_0:
duke@435:     case Bytecodes::_iconst_1:
duke@435:     case Bytecodes::_iconst_2:
duke@435:     case Bytecodes::_iconst_3:
duke@435:     case Bytecodes::_iconst_4:
duke@435:     case Bytecodes::_iconst_5:
duke@435:     case Bytecodes::_fconst_0:
duke@435:     case Bytecodes::_fconst_1:
duke@435:     case Bytecodes::_fconst_2:
duke@435:     case Bytecodes::_bipush:
duke@435:     case Bytecodes::_sipush:
duke@435:     case Bytecodes::_lconst_0:
duke@435:     case Bytecodes::_lconst_1:
duke@435:     case Bytecodes::_dconst_0:
duke@435:     case Bytecodes::_dconst_1:
duke@435:     case Bytecodes::_ldc2_w:
duke@435:     case Bytecodes::_ldc:
duke@435:     case Bytecodes::_ldc_w:
duke@435:     case Bytecodes::_iaload:
duke@435:     case Bytecodes::_faload:
duke@435:     case Bytecodes::_baload:
duke@435:     case Bytecodes::_caload:
duke@435:     case Bytecodes::_saload:
duke@435:     case Bytecodes::_laload:
duke@435:     case Bytecodes::_daload:
duke@435:     case Bytecodes::_aaload:
duke@435:     case Bytecodes::_iastore:
duke@435:     case Bytecodes::_fastore:
duke@435:     case Bytecodes::_bastore:
duke@435:     case Bytecodes::_castore:
duke@435:     case Bytecodes::_sastore:
duke@435:     case Bytecodes::_lastore:
duke@435:     case Bytecodes::_dastore:
duke@435:     case Bytecodes::_aastore:
duke@435:     case Bytecodes::_pop:
duke@435:     case Bytecodes::_pop2:
duke@435:     case Bytecodes::_dup:
duke@435:     case Bytecodes::_dup_x1:
duke@435:     case Bytecodes::_dup_x2:
duke@435:     case Bytecodes::_dup2:
duke@435:     case Bytecodes::_dup2_x1:
duke@435:     case Bytecodes::_dup2_x2:
duke@435:     case Bytecodes::_swap:
duke@435:     case Bytecodes::_iadd:
duke@435:     case Bytecodes::_fadd:
duke@435:     case Bytecodes::_isub:
duke@435:     case Bytecodes::_fsub:
duke@435:     case Bytecodes::_imul:
duke@435:     case Bytecodes::_fmul:
duke@435:     case Bytecodes::_idiv:
duke@435:     case Bytecodes::_fdiv:
duke@435:     case Bytecodes::_irem:
duke@435:     case Bytecodes::_frem:
duke@435:     case Bytecodes::_ishl:
duke@435:     case Bytecodes::_ishr:
duke@435:     case Bytecodes::_iushr:
duke@435:     case Bytecodes::_iand:
duke@435:     case Bytecodes::_ior:
duke@435:     case Bytecodes::_ixor:
duke@435:     case Bytecodes::_l2f:
duke@435:     case Bytecodes::_l2i:
duke@435:     case Bytecodes::_d2f:
duke@435:     case Bytecodes::_d2i:
duke@435:     case Bytecodes::_fcmpl:
duke@435:     case Bytecodes::_fcmpg:
duke@435:     case Bytecodes::_ladd:
duke@435:     case Bytecodes::_dadd:
duke@435:     case Bytecodes::_lsub:
duke@435:     case Bytecodes::_dsub:
duke@435:     case Bytecodes::_lmul:
duke@435:     case Bytecodes::_dmul:
duke@435:     case Bytecodes::_ldiv:
duke@435:     case Bytecodes::_ddiv:
duke@435:     case Bytecodes::_lrem:
duke@435:     case Bytecodes::_drem:
duke@435:     case Bytecodes::_land:
duke@435:     case Bytecodes::_lor:
duke@435:     case Bytecodes::_lxor:
duke@435:     case Bytecodes::_ineg:
duke@435:     case Bytecodes::_fneg:
duke@435:     case Bytecodes::_i2f:
duke@435:     case Bytecodes::_f2i:
duke@435:     case Bytecodes::_i2c:
duke@435:     case Bytecodes::_i2s:
duke@435:     case Bytecodes::_i2b:
duke@435:     case Bytecodes::_lneg:
duke@435:     case Bytecodes::_dneg:
duke@435:     case Bytecodes::_l2d:
duke@435:     case Bytecodes::_d2l:
duke@435:     case Bytecodes::_lshl:
duke@435:     case Bytecodes::_lshr:
duke@435:     case Bytecodes::_lushr:
duke@435:     case Bytecodes::_i2l:
duke@435:     case Bytecodes::_i2d:
duke@435:     case Bytecodes::_f2l:
duke@435:     case Bytecodes::_f2d:
duke@435:     case Bytecodes::_lcmp:
duke@435:     case Bytecodes::_dcmpl:
duke@435:     case Bytecodes::_dcmpg:
duke@435:     case Bytecodes::_ifeq:
duke@435:     case Bytecodes::_ifne:
duke@435:     case Bytecodes::_iflt:
duke@435:     case Bytecodes::_ifge:
duke@435:     case Bytecodes::_ifgt:
duke@435:     case Bytecodes::_ifle:
duke@435:     case Bytecodes::_tableswitch:
duke@435:     case Bytecodes::_ireturn:
duke@435:     case Bytecodes::_freturn:
duke@435:     case Bytecodes::_if_icmpeq:
duke@435:     case Bytecodes::_if_icmpne:
duke@435:     case Bytecodes::_if_icmplt:
duke@435:     case Bytecodes::_if_icmpge:
duke@435:     case Bytecodes::_if_icmpgt:
duke@435:     case Bytecodes::_if_icmple:
duke@435:     case Bytecodes::_lreturn:
duke@435:     case Bytecodes::_dreturn:
duke@435:     case Bytecodes::_if_acmpeq:
duke@435:     case Bytecodes::_if_acmpne:
duke@435:     case Bytecodes::_jsr:
duke@435:     case Bytecodes::_jsr_w:
duke@435:     case Bytecodes::_getstatic:
duke@435:     case Bytecodes::_putstatic:
duke@435:     case Bytecodes::_getfield:
duke@435:     case Bytecodes::_putfield:
duke@435:     case Bytecodes::_invokevirtual:
duke@435:     case Bytecodes::_invokespecial:
duke@435:     case Bytecodes::_invokestatic:
duke@435:     case Bytecodes::_invokeinterface:
duke@435:     case Bytecodes::_newarray:
duke@435:     case Bytecodes::_anewarray:
duke@435:     case Bytecodes::_checkcast:
duke@435:     case Bytecodes::_arraylength:
duke@435:     case Bytecodes::_instanceof:
duke@435:     case Bytecodes::_athrow:
duke@435:     case Bytecodes::_areturn:
duke@435:     case Bytecodes::_monitorenter:
duke@435:     case Bytecodes::_monitorexit:
duke@435:     case Bytecodes::_ifnull:
duke@435:     case Bytecodes::_ifnonnull:
duke@435:     case Bytecodes::_multianewarray:
duke@435:     case Bytecodes::_lookupswitch:
duke@435:       // These bytecodes have no effect on the method's locals.
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_return:
duke@435:       if (instruction->method()->intrinsic_id() == vmIntrinsics::_Object_init) {
duke@435:         // return from Object.init implicitly registers a finalizer
duke@435:         // for the receiver if needed, so keep it alive.
duke@435:         load_one(0);
duke@435:       }
duke@435:       break;
duke@435: 
duke@435: 
duke@435:     case Bytecodes::_lload:
duke@435:     case Bytecodes::_dload:
duke@435:       load_two(instruction->get_index());
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_lload_0:
duke@435:     case Bytecodes::_dload_0:
duke@435:       load_two(0);
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_lload_1:
duke@435:     case Bytecodes::_dload_1:
duke@435:       load_two(1);
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_lload_2:
duke@435:     case Bytecodes::_dload_2:
duke@435:       load_two(2);
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_lload_3:
duke@435:     case Bytecodes::_dload_3:
duke@435:       load_two(3);
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_iload:
duke@435:     case Bytecodes::_iinc:
duke@435:     case Bytecodes::_fload:
duke@435:     case Bytecodes::_aload:
duke@435:     case Bytecodes::_ret:
duke@435:       load_one(instruction->get_index());
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_iload_0:
duke@435:     case Bytecodes::_fload_0:
duke@435:     case Bytecodes::_aload_0:
duke@435:       load_one(0);
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_iload_1:
duke@435:     case Bytecodes::_fload_1:
duke@435:     case Bytecodes::_aload_1:
duke@435:       load_one(1);
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_iload_2:
duke@435:     case Bytecodes::_fload_2:
duke@435:     case Bytecodes::_aload_2:
duke@435:       load_one(2);
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_iload_3:
duke@435:     case Bytecodes::_fload_3:
duke@435:     case Bytecodes::_aload_3:
duke@435:       load_one(3);
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_lstore:
duke@435:     case Bytecodes::_dstore:
duke@435:       store_two(localNum = instruction->get_index());
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_lstore_0:
duke@435:     case Bytecodes::_dstore_0:
duke@435:       store_two(0);
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_lstore_1:
duke@435:     case Bytecodes::_dstore_1:
duke@435:       store_two(1);
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_lstore_2:
duke@435:     case Bytecodes::_dstore_2:
duke@435:       store_two(2);
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_lstore_3:
duke@435:     case Bytecodes::_dstore_3:
duke@435:       store_two(3);
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_istore:
duke@435:     case Bytecodes::_fstore:
duke@435:     case Bytecodes::_astore:
duke@435:       store_one(instruction->get_index());
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_istore_0:
duke@435:     case Bytecodes::_fstore_0:
duke@435:     case Bytecodes::_astore_0:
duke@435:       store_one(0);
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_istore_1:
duke@435:     case Bytecodes::_fstore_1:
duke@435:     case Bytecodes::_astore_1:
duke@435:       store_one(1);
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_istore_2:
duke@435:     case Bytecodes::_fstore_2:
duke@435:     case Bytecodes::_astore_2:
duke@435:       store_one(2);
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_istore_3:
duke@435:     case Bytecodes::_fstore_3:
duke@435:     case Bytecodes::_astore_3:
duke@435:       store_one(3);
duke@435:       break;
duke@435: 
duke@435:     case Bytecodes::_wide:
duke@435:       fatal("Iterator should skip this bytecode");
duke@435:       break;
duke@435: 
duke@435:     default:
duke@435:       tty->print("unexpected opcode: %d\n", instruction->cur_bc());
duke@435:       ShouldNotReachHere();
duke@435:       break;
duke@435:   }
duke@435: }
duke@435: 
duke@435: void MethodLiveness::BasicBlock::load_two(int local) {
duke@435:   load_one(local);
duke@435:   load_one(local+1);
duke@435: }
duke@435: 
duke@435: void MethodLiveness::BasicBlock::load_one(int local) {
duke@435:   if (!_kill.at(local)) {
duke@435:     _gen.at_put(local, true);
duke@435:   }
duke@435: }
duke@435: 
duke@435: void MethodLiveness::BasicBlock::store_two(int local) {
duke@435:   store_one(local);
duke@435:   store_one(local+1);
duke@435: }
duke@435: 
duke@435: void MethodLiveness::BasicBlock::store_one(int local) {
duke@435:   if (!_gen.at(local)) {
duke@435:     _kill.at_put(local, true);
duke@435:   }
duke@435: }
duke@435: 
duke@435: void MethodLiveness::BasicBlock::propagate(MethodLiveness *ml) {
duke@435:   // These set operations could be combined for efficiency if the
duke@435:   // performance of this analysis becomes an issue.
duke@435:   _entry.set_union(_normal_exit);
duke@435:   _entry.set_difference(_kill);
duke@435:   _entry.set_union(_gen);
duke@435: 
duke@435:   // Note that we merge information from our exceptional successors
duke@435:   // just once, rather than at individual bytecodes.
duke@435:   _entry.set_union(_exception_exit);
duke@435: 
duke@435:   if (TraceLivenessGen) {
duke@435:     tty->print_cr(" ** Visiting block at %d **", start_bci());
duke@435:     print_on(tty);
duke@435:   }
duke@435: 
duke@435:   int i;
duke@435:   for (i=_normal_predecessors->length()-1; i>=0; i--) {
duke@435:     BasicBlock *block = _normal_predecessors->at(i);
duke@435:     if (block->merge_normal(_entry)) {
duke@435:       ml->work_list_add(block);
duke@435:     }
duke@435:   }
duke@435:   for (i=_exception_predecessors->length()-1; i>=0; i--) {
duke@435:     BasicBlock *block = _exception_predecessors->at(i);
duke@435:     if (block->merge_exception(_entry)) {
duke@435:       ml->work_list_add(block);
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: bool MethodLiveness::BasicBlock::merge_normal(BitMap other) {
duke@435:   return _normal_exit.set_union_with_result(other);
duke@435: }
duke@435: 
duke@435: bool MethodLiveness::BasicBlock::merge_exception(BitMap other) {
duke@435:   return _exception_exit.set_union_with_result(other);
duke@435: }
duke@435: 
duke@435: MethodLivenessResult MethodLiveness::BasicBlock::get_liveness_at(ciMethod* method, int bci) {
duke@435:   MethodLivenessResult answer(NEW_RESOURCE_ARRAY(uintptr_t, _analyzer->bit_map_size_words()),
duke@435:                 _analyzer->bit_map_size_bits());
duke@435:   answer.set_is_valid();
duke@435: 
duke@435: #ifndef ASSERT
duke@435:   if (bci == start_bci()) {
duke@435:     answer.set_from(_entry);
duke@435:     return answer;
duke@435:   }
duke@435: #endif
duke@435: 
duke@435: #ifdef ASSERT
duke@435:   ResourceMark rm;
duke@435:   BitMap g(_gen.size()); g.set_from(_gen);
duke@435:   BitMap k(_kill.size()); k.set_from(_kill);
duke@435: #endif
duke@435:   if (_last_bci != bci || trueInDebug) {
duke@435:     ciBytecodeStream bytes(method);
duke@435:     bytes.reset_to_bci(bci);
duke@435:     bytes.set_max_bci(limit_bci());
duke@435:     compute_gen_kill_range(&bytes);
duke@435:     assert(_last_bci != bci ||
duke@435:            (g.is_same(_gen) && k.is_same(_kill)), "cached computation is incorrect");
duke@435:     _last_bci = bci;
duke@435:   }
duke@435: 
duke@435:   answer.clear();
duke@435:   answer.set_union(_normal_exit);
duke@435:   answer.set_difference(_kill);
duke@435:   answer.set_union(_gen);
duke@435:   answer.set_union(_exception_exit);
duke@435: 
duke@435: #ifdef ASSERT
duke@435:   if (bci == start_bci()) {
duke@435:     assert(answer.is_same(_entry), "optimized answer must be accurate");
duke@435:   }
duke@435: #endif
duke@435: 
duke@435:   return answer;
duke@435: }
duke@435: 
duke@435: #ifndef PRODUCT
duke@435: 
duke@435: void MethodLiveness::BasicBlock::print_on(outputStream *os) const {
duke@435:   os->print_cr("===================================================================");
duke@435:   os->print_cr("    Block start: %4d, limit: %4d", _start_bci, _limit_bci);
duke@435:   os->print   ("    Normal predecessors (%2d)      @", _normal_predecessors->length());
duke@435:   int i;
duke@435:   for (i=0; i < _normal_predecessors->length(); i++) {
duke@435:     os->print(" %4d", _normal_predecessors->at(i)->start_bci());
duke@435:   }
duke@435:   os->cr();
duke@435:   os->print   ("    Exceptional predecessors (%2d) @", _exception_predecessors->length());
duke@435:   for (i=0; i < _exception_predecessors->length(); i++) {
duke@435:     os->print(" %4d", _exception_predecessors->at(i)->start_bci());
duke@435:   }
duke@435:   os->cr();
duke@435:   os->print ("    Normal Exit   : ");
duke@435:   _normal_exit.print_on(os);
duke@435:   os->print ("    Gen           : ");
duke@435:   _gen.print_on(os);
duke@435:   os->print ("    Kill          : ");
duke@435:   _kill.print_on(os);
duke@435:   os->print ("    Exception Exit: ");
duke@435:   _exception_exit.print_on(os);
duke@435:   os->print ("    Entry         : ");
duke@435:   _entry.print_on(os);
duke@435: }
duke@435: 
duke@435: #endif // PRODUCT