jdk8-mips64-public/hotspot: src/share/vm/compiler/methodLiveness.cpp@f90c822e73f8 (annotated)

src/share/vm/compiler/methodLiveness.cpp@f90c822e73f8 (annotated)

src/share/vm/compiler/methodLiveness.cpp

Wed, 27 Apr 2016 01:25:04 +0800

author: aoqi
date: Wed, 27 Apr 2016 01:25:04 +0800
changeset 0: f90c822e73f8
child 6876: 710a3c8b516e
permissions: -rw-r--r--

Initial load
http://hg.openjdk.java.net/jdk8u/jdk8u/hotspot/
changeset: 6782:28b50d07f6f8
tag: jdk8u25-b17

 /*
  * Copyright (c) 1998, 2014, 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"
 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
 // 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(&bytes);
           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(&bytes);
           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,
 .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

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/compiler/methodLiveness.cpp@f90c822e73f8 (annotated)

src/share/vm/compiler/methodLiveness.cpp