src/share/vm/ci/bcEscapeAnalyzer.cpp

Tue, 08 Aug 2017 15:57:29 +0800

author
aoqi
date
Tue, 08 Aug 2017 15:57:29 +0800
changeset 6876
710a3c8b516e
parent 6702
42d9a5f06728
parent 0
f90c822e73f8
child 7535
7ae4e26cb1e0
permissions
-rw-r--r--

merge

     1 /*
     2  * Copyright (c) 2005, 2014, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 #include "precompiled.hpp"
    26 #include "ci/bcEscapeAnalyzer.hpp"
    27 #include "ci/ciConstant.hpp"
    28 #include "ci/ciField.hpp"
    29 #include "ci/ciMethodBlocks.hpp"
    30 #include "ci/ciStreams.hpp"
    31 #include "interpreter/bytecode.hpp"
    32 #include "utilities/bitMap.inline.hpp"
    36 #ifndef PRODUCT
    37   #define TRACE_BCEA(level, code)                                            \
    38     if (EstimateArgEscape && BCEATraceLevel >= level) {                        \
    39       code;                                                                  \
    40     }
    41 #else
    42   #define TRACE_BCEA(level, code)
    43 #endif
    45 // Maintain a map of which aguments a local variable or
    46 // stack slot may contain.  In addition to tracking
    47 // arguments, it tracks two special values, "allocated"
    48 // which represents any object allocated in the current
    49 // method, and "unknown" which is any other object.
    50 // Up to 30 arguments are handled, with the last one
    51 // representing summary information for any extra arguments
    52 class BCEscapeAnalyzer::ArgumentMap {
    53   uint  _bits;
    54   enum {MAXBIT = 29,
    55         ALLOCATED = 1,
    56         UNKNOWN = 2};
    58   uint int_to_bit(uint e) const {
    59     if (e > MAXBIT)
    60       e = MAXBIT;
    61     return (1 << (e + 2));
    62   }
    64 public:
    65   ArgumentMap()                         { _bits = 0;}
    66   void set_bits(uint bits)              { _bits = bits;}
    67   uint get_bits() const                 { return _bits;}
    68   void clear()                          { _bits = 0;}
    69   void set_all()                        { _bits = ~0u; }
    70   bool is_empty() const                 { return _bits == 0; }
    71   bool contains(uint var) const         { return (_bits & int_to_bit(var)) != 0; }
    72   bool is_singleton(uint var) const     { return (_bits == int_to_bit(var)); }
    73   bool contains_unknown() const         { return (_bits & UNKNOWN) != 0; }
    74   bool contains_allocated() const       { return (_bits & ALLOCATED) != 0; }
    75   bool contains_vars() const            { return (_bits & (((1 << MAXBIT) -1) << 2)) != 0; }
    76   void set(uint var)                    { _bits = int_to_bit(var); }
    77   void add(uint var)                    { _bits |= int_to_bit(var); }
    78   void add_unknown()                    { _bits = UNKNOWN; }
    79   void add_allocated()                  { _bits = ALLOCATED; }
    80   void set_union(const ArgumentMap &am)     { _bits |= am._bits; }
    81   void set_intersect(const ArgumentMap &am) { _bits |= am._bits; }
    82   void set_difference(const ArgumentMap &am) { _bits &=  ~am._bits; }
    83   void operator=(const ArgumentMap &am) { _bits = am._bits; }
    84   bool operator==(const ArgumentMap &am) { return _bits == am._bits; }
    85   bool operator!=(const ArgumentMap &am) { return _bits != am._bits; }
    86 };
    88 class BCEscapeAnalyzer::StateInfo {
    89 public:
    90   ArgumentMap *_vars;
    91   ArgumentMap *_stack;
    92   short _stack_height;
    93   short _max_stack;
    94   bool _initialized;
    95   ArgumentMap empty_map;
    97   StateInfo() {
    98     empty_map.clear();
    99   }
   101   ArgumentMap raw_pop()  { guarantee(_stack_height > 0, "stack underflow"); return _stack[--_stack_height]; }
   102   ArgumentMap  apop()    { return raw_pop(); }
   103   void spop()            { raw_pop(); }
   104   void lpop()            { spop(); spop(); }
   105   void raw_push(ArgumentMap i)   { guarantee(_stack_height < _max_stack, "stack overflow"); _stack[_stack_height++] = i; }
   106   void apush(ArgumentMap i)      { raw_push(i); }
   107   void spush()           { raw_push(empty_map); }
   108   void lpush()           { spush(); spush(); }
   110 };
   112 void BCEscapeAnalyzer::set_returned(ArgumentMap vars) {
   113   for (int i = 0; i < _arg_size; i++) {
   114     if (vars.contains(i))
   115       _arg_returned.set(i);
   116   }
   117   _return_local = _return_local && !(vars.contains_unknown() || vars.contains_allocated());
   118   _return_allocated = _return_allocated && vars.contains_allocated() && !(vars.contains_unknown() || vars.contains_vars());
   119 }
   121 // return true if any element of vars is an argument
   122 bool BCEscapeAnalyzer::is_argument(ArgumentMap vars) {
   123   for (int i = 0; i < _arg_size; i++) {
   124     if (vars.contains(i))
   125       return true;
   126   }
   127   return false;
   128 }
   130 // return true if any element of vars is an arg_stack argument
   131 bool BCEscapeAnalyzer::is_arg_stack(ArgumentMap vars){
   132   if (_conservative)
   133     return true;
   134   for (int i = 0; i < _arg_size; i++) {
   135     if (vars.contains(i) && _arg_stack.test(i))
   136       return true;
   137   }
   138   return false;
   139 }
   141 // return true if all argument elements of vars are returned
   142 bool BCEscapeAnalyzer::returns_all(ArgumentMap vars) {
   143   for (int i = 0; i < _arg_size; i++) {
   144     if (vars.contains(i) && !_arg_returned.test(i)) {
   145       return false;
   146     }
   147   }
   148   return true;
   149 }
   151 void BCEscapeAnalyzer::clear_bits(ArgumentMap vars, VectorSet &bm) {
   152   for (int i = 0; i < _arg_size; i++) {
   153     if (vars.contains(i)) {
   154       bm >>= i;
   155     }
   156   }
   157 }
   159 void BCEscapeAnalyzer::set_method_escape(ArgumentMap vars) {
   160   clear_bits(vars, _arg_local);
   161   if (vars.contains_allocated()) {
   162     _allocated_escapes = true;
   163   }
   164 }
   166 void BCEscapeAnalyzer::set_global_escape(ArgumentMap vars, bool merge) {
   167   clear_bits(vars, _arg_local);
   168   clear_bits(vars, _arg_stack);
   169   if (vars.contains_allocated())
   170     _allocated_escapes = true;
   172   if (merge && !vars.is_empty()) {
   173     // Merge new state into already processed block.
   174     // New state is not taken into account and
   175     // it may invalidate set_returned() result.
   176     if (vars.contains_unknown() || vars.contains_allocated()) {
   177       _return_local = false;
   178     }
   179     if (vars.contains_unknown() || vars.contains_vars()) {
   180       _return_allocated = false;
   181     }
   182     if (_return_local && vars.contains_vars() && !returns_all(vars)) {
   183       // Return result should be invalidated if args in new
   184       // state are not recorded in return state.
   185       _return_local = false;
   186     }
   187   }
   188 }
   190 void BCEscapeAnalyzer::set_dirty(ArgumentMap vars) {
   191   clear_bits(vars, _dirty);
   192 }
   194 void BCEscapeAnalyzer::set_modified(ArgumentMap vars, int offs, int size) {
   196   for (int i = 0; i < _arg_size; i++) {
   197     if (vars.contains(i)) {
   198       set_arg_modified(i, offs, size);
   199     }
   200   }
   201   if (vars.contains_unknown())
   202     _unknown_modified = true;
   203 }
   205 bool BCEscapeAnalyzer::is_recursive_call(ciMethod* callee) {
   206   for (BCEscapeAnalyzer* scope = this; scope != NULL; scope = scope->_parent) {
   207     if (scope->method() == callee) {
   208       return true;
   209     }
   210   }
   211   return false;
   212 }
   214 bool BCEscapeAnalyzer::is_arg_modified(int arg, int offset, int size_in_bytes) {
   215   if (offset == OFFSET_ANY)
   216     return _arg_modified[arg] != 0;
   217   assert(arg >= 0 && arg < _arg_size, "must be an argument.");
   218   bool modified = false;
   219   int l = offset / HeapWordSize;
   220   int h = round_to(offset + size_in_bytes, HeapWordSize) / HeapWordSize;
   221   if (l > ARG_OFFSET_MAX)
   222     l = ARG_OFFSET_MAX;
   223   if (h > ARG_OFFSET_MAX+1)
   224     h = ARG_OFFSET_MAX + 1;
   225   for (int i = l; i < h; i++) {
   226     modified = modified || (_arg_modified[arg] & (1 << i)) != 0;
   227   }
   228   return modified;
   229 }
   231 void BCEscapeAnalyzer::set_arg_modified(int arg, int offset, int size_in_bytes) {
   232   if (offset == OFFSET_ANY) {
   233     _arg_modified[arg] =  (uint) -1;
   234     return;
   235   }
   236   assert(arg >= 0 && arg < _arg_size, "must be an argument.");
   237   int l = offset / HeapWordSize;
   238   int h = round_to(offset + size_in_bytes, HeapWordSize) / HeapWordSize;
   239   if (l > ARG_OFFSET_MAX)
   240     l = ARG_OFFSET_MAX;
   241   if (h > ARG_OFFSET_MAX+1)
   242     h = ARG_OFFSET_MAX + 1;
   243   for (int i = l; i < h; i++) {
   244     _arg_modified[arg] |= (1 << i);
   245   }
   246 }
   248 void BCEscapeAnalyzer::invoke(StateInfo &state, Bytecodes::Code code, ciMethod* target, ciKlass* holder) {
   249   int i;
   251   // retrieve information about the callee
   252   ciInstanceKlass* klass = target->holder();
   253   ciInstanceKlass* calling_klass = method()->holder();
   254   ciInstanceKlass* callee_holder = ciEnv::get_instance_klass_for_declared_method_holder(holder);
   255   ciInstanceKlass* actual_recv = callee_holder;
   257   // Some methods are obviously bindable without any type checks so
   258   // convert them directly to an invokespecial or invokestatic.
   259   if (target->is_loaded() && !target->is_abstract() && target->can_be_statically_bound()) {
   260     switch (code) {
   261     case Bytecodes::_invokevirtual:
   262       code = Bytecodes::_invokespecial;
   263       break;
   264     case Bytecodes::_invokehandle:
   265       code = target->is_static() ? Bytecodes::_invokestatic : Bytecodes::_invokespecial;
   266       break;
   267     }
   268   }
   270   // compute size of arguments
   271   int arg_size = target->invoke_arg_size(code);
   272   int arg_base = MAX2(state._stack_height - arg_size, 0);
   274   // direct recursive calls are skipped if they can be bound statically without introducing
   275   // dependencies and if parameters are passed at the same position as in the current method
   276   // other calls are skipped if there are no unescaped arguments passed to them
   277   bool directly_recursive = (method() == target) &&
   278                (code != Bytecodes::_invokevirtual || target->is_final_method() || state._stack[arg_base] .is_empty());
   280   // check if analysis of callee can safely be skipped
   281   bool skip_callee = true;
   282   for (i = state._stack_height - 1; i >= arg_base && skip_callee; i--) {
   283     ArgumentMap arg = state._stack[i];
   284     skip_callee = !is_argument(arg) || !is_arg_stack(arg) || (directly_recursive && arg.is_singleton(i - arg_base));
   285   }
   286   // For now we conservatively skip invokedynamic.
   287   if (code == Bytecodes::_invokedynamic) {
   288     skip_callee = true;
   289   }
   290   if (skip_callee) {
   291     TRACE_BCEA(3, tty->print_cr("[EA] skipping method %s::%s", holder->name()->as_utf8(), target->name()->as_utf8()));
   292     for (i = 0; i < arg_size; i++) {
   293       set_method_escape(state.raw_pop());
   294     }
   295     _unknown_modified = true;  // assume the worst since we don't analyze the called method
   296     return;
   297   }
   299   // determine actual method (use CHA if necessary)
   300   ciMethod* inline_target = NULL;
   301   if (target->is_loaded() && klass->is_loaded()
   302       && (klass->is_initialized() || klass->is_interface() && target->holder()->is_initialized())
   303       && target->is_loaded()) {
   304     if (code == Bytecodes::_invokestatic
   305         || code == Bytecodes::_invokespecial
   306         || code == Bytecodes::_invokevirtual && target->is_final_method()) {
   307       inline_target = target;
   308     } else {
   309       inline_target = target->find_monomorphic_target(calling_klass, callee_holder, actual_recv);
   310     }
   311   }
   313   if (inline_target != NULL && !is_recursive_call(inline_target)) {
   314     // analyze callee
   315     BCEscapeAnalyzer analyzer(inline_target, this);
   317     // adjust escape state of actual parameters
   318     bool must_record_dependencies = false;
   319     for (i = arg_size - 1; i >= 0; i--) {
   320       ArgumentMap arg = state.raw_pop();
   321       if (!is_argument(arg))
   322         continue;
   323       for (int j = 0; j < _arg_size; j++) {
   324         if (arg.contains(j)) {
   325           _arg_modified[j] |= analyzer._arg_modified[i];
   326         }
   327       }
   328       if (!is_arg_stack(arg)) {
   329         // arguments have already been recognized as escaping
   330       } else if (analyzer.is_arg_stack(i) && !analyzer.is_arg_returned(i)) {
   331         set_method_escape(arg);
   332         must_record_dependencies = true;
   333       } else {
   334         set_global_escape(arg);
   335       }
   336     }
   337     _unknown_modified = _unknown_modified || analyzer.has_non_arg_side_affects();
   339     // record dependencies if at least one parameter retained stack-allocatable
   340     if (must_record_dependencies) {
   341       if (code == Bytecodes::_invokeinterface || code == Bytecodes::_invokevirtual && !target->is_final_method()) {
   342         _dependencies.append(actual_recv);
   343         _dependencies.append(inline_target);
   344       }
   345       _dependencies.appendAll(analyzer.dependencies());
   346     }
   347   } else {
   348     TRACE_BCEA(1, tty->print_cr("[EA] virtual method %s is not monomorphic.",
   349                                 target->name()->as_utf8()));
   350     // conservatively mark all actual parameters as escaping globally
   351     for (i = 0; i < arg_size; i++) {
   352       ArgumentMap arg = state.raw_pop();
   353       if (!is_argument(arg))
   354         continue;
   355       set_modified(arg, OFFSET_ANY, type2size[T_INT]*HeapWordSize);
   356       set_global_escape(arg);
   357     }
   358     _unknown_modified = true;  // assume the worst since we don't know the called method
   359   }
   360 }
   362 bool BCEscapeAnalyzer::contains(uint arg_set1, uint arg_set2) {
   363   return ((~arg_set1) | arg_set2) == 0;
   364 }
   367 void BCEscapeAnalyzer::iterate_one_block(ciBlock *blk, StateInfo &state, GrowableArray<ciBlock *> &successors) {
   369   blk->set_processed();
   370   ciBytecodeStream s(method());
   371   int limit_bci = blk->limit_bci();
   372   bool fall_through = false;
   373   ArgumentMap allocated_obj;
   374   allocated_obj.add_allocated();
   375   ArgumentMap unknown_obj;
   376   unknown_obj.add_unknown();
   377   ArgumentMap empty_map;
   379   s.reset_to_bci(blk->start_bci());
   380   while (s.next() != ciBytecodeStream::EOBC() && s.cur_bci() < limit_bci) {
   381     fall_through = true;
   382     switch (s.cur_bc()) {
   383       case Bytecodes::_nop:
   384         break;
   385       case Bytecodes::_aconst_null:
   386         state.apush(unknown_obj);
   387         break;
   388       case Bytecodes::_iconst_m1:
   389       case Bytecodes::_iconst_0:
   390       case Bytecodes::_iconst_1:
   391       case Bytecodes::_iconst_2:
   392       case Bytecodes::_iconst_3:
   393       case Bytecodes::_iconst_4:
   394       case Bytecodes::_iconst_5:
   395       case Bytecodes::_fconst_0:
   396       case Bytecodes::_fconst_1:
   397       case Bytecodes::_fconst_2:
   398       case Bytecodes::_bipush:
   399       case Bytecodes::_sipush:
   400         state.spush();
   401         break;
   402       case Bytecodes::_lconst_0:
   403       case Bytecodes::_lconst_1:
   404       case Bytecodes::_dconst_0:
   405       case Bytecodes::_dconst_1:
   406         state.lpush();
   407         break;
   408       case Bytecodes::_ldc:
   409       case Bytecodes::_ldc_w:
   410       case Bytecodes::_ldc2_w:
   411       {
   412         // Avoid calling get_constant() which will try to allocate
   413         // unloaded constant. We need only constant's type.
   414         int index = s.get_constant_pool_index();
   415         constantTag tag = s.get_constant_pool_tag(index);
   416         if (tag.is_long() || tag.is_double()) {
   417           // Only longs and doubles use 2 stack slots.
   418           state.lpush();
   419         } else if (tag.basic_type() == T_OBJECT) {
   420           state.apush(unknown_obj);
   421         } else {
   422           state.spush();
   423         }
   424         break;
   425       }
   426       case Bytecodes::_aload:
   427         state.apush(state._vars[s.get_index()]);
   428         break;
   429       case Bytecodes::_iload:
   430       case Bytecodes::_fload:
   431       case Bytecodes::_iload_0:
   432       case Bytecodes::_iload_1:
   433       case Bytecodes::_iload_2:
   434       case Bytecodes::_iload_3:
   435       case Bytecodes::_fload_0:
   436       case Bytecodes::_fload_1:
   437       case Bytecodes::_fload_2:
   438       case Bytecodes::_fload_3:
   439         state.spush();
   440         break;
   441       case Bytecodes::_lload:
   442       case Bytecodes::_dload:
   443       case Bytecodes::_lload_0:
   444       case Bytecodes::_lload_1:
   445       case Bytecodes::_lload_2:
   446       case Bytecodes::_lload_3:
   447       case Bytecodes::_dload_0:
   448       case Bytecodes::_dload_1:
   449       case Bytecodes::_dload_2:
   450       case Bytecodes::_dload_3:
   451         state.lpush();
   452         break;
   453       case Bytecodes::_aload_0:
   454         state.apush(state._vars[0]);
   455         break;
   456       case Bytecodes::_aload_1:
   457         state.apush(state._vars[1]);
   458         break;
   459       case Bytecodes::_aload_2:
   460         state.apush(state._vars[2]);
   461         break;
   462       case Bytecodes::_aload_3:
   463         state.apush(state._vars[3]);
   464         break;
   465       case Bytecodes::_iaload:
   466       case Bytecodes::_faload:
   467       case Bytecodes::_baload:
   468       case Bytecodes::_caload:
   469       case Bytecodes::_saload:
   470         state.spop();
   471         set_method_escape(state.apop());
   472         state.spush();
   473         break;
   474       case Bytecodes::_laload:
   475       case Bytecodes::_daload:
   476         state.spop();
   477         set_method_escape(state.apop());
   478         state.lpush();
   479         break;
   480       case Bytecodes::_aaload:
   481         { state.spop();
   482           ArgumentMap array = state.apop();
   483           set_method_escape(array);
   484           state.apush(unknown_obj);
   485           set_dirty(array);
   486         }
   487         break;
   488       case Bytecodes::_istore:
   489       case Bytecodes::_fstore:
   490       case Bytecodes::_istore_0:
   491       case Bytecodes::_istore_1:
   492       case Bytecodes::_istore_2:
   493       case Bytecodes::_istore_3:
   494       case Bytecodes::_fstore_0:
   495       case Bytecodes::_fstore_1:
   496       case Bytecodes::_fstore_2:
   497       case Bytecodes::_fstore_3:
   498         state.spop();
   499         break;
   500       case Bytecodes::_lstore:
   501       case Bytecodes::_dstore:
   502       case Bytecodes::_lstore_0:
   503       case Bytecodes::_lstore_1:
   504       case Bytecodes::_lstore_2:
   505       case Bytecodes::_lstore_3:
   506       case Bytecodes::_dstore_0:
   507       case Bytecodes::_dstore_1:
   508       case Bytecodes::_dstore_2:
   509       case Bytecodes::_dstore_3:
   510         state.lpop();
   511         break;
   512       case Bytecodes::_astore:
   513         state._vars[s.get_index()] = state.apop();
   514         break;
   515       case Bytecodes::_astore_0:
   516         state._vars[0] = state.apop();
   517         break;
   518       case Bytecodes::_astore_1:
   519         state._vars[1] = state.apop();
   520         break;
   521       case Bytecodes::_astore_2:
   522         state._vars[2] = state.apop();
   523         break;
   524       case Bytecodes::_astore_3:
   525         state._vars[3] = state.apop();
   526         break;
   527       case Bytecodes::_iastore:
   528       case Bytecodes::_fastore:
   529       case Bytecodes::_bastore:
   530       case Bytecodes::_castore:
   531       case Bytecodes::_sastore:
   532       {
   533         state.spop();
   534         state.spop();
   535         ArgumentMap arr = state.apop();
   536         set_method_escape(arr);
   537         set_modified(arr, OFFSET_ANY, type2size[T_INT]*HeapWordSize);
   538         break;
   539       }
   540       case Bytecodes::_lastore:
   541       case Bytecodes::_dastore:
   542       {
   543         state.lpop();
   544         state.spop();
   545         ArgumentMap arr = state.apop();
   546         set_method_escape(arr);
   547         set_modified(arr, OFFSET_ANY, type2size[T_LONG]*HeapWordSize);
   548         break;
   549       }
   550       case Bytecodes::_aastore:
   551       {
   552         set_global_escape(state.apop());
   553         state.spop();
   554         ArgumentMap arr = state.apop();
   555         set_modified(arr, OFFSET_ANY, type2size[T_OBJECT]*HeapWordSize);
   556         break;
   557       }
   558       case Bytecodes::_pop:
   559         state.raw_pop();
   560         break;
   561       case Bytecodes::_pop2:
   562         state.raw_pop();
   563         state.raw_pop();
   564         break;
   565       case Bytecodes::_dup:
   566         { ArgumentMap w1 = state.raw_pop();
   567           state.raw_push(w1);
   568           state.raw_push(w1);
   569         }
   570         break;
   571       case Bytecodes::_dup_x1:
   572         { ArgumentMap w1 = state.raw_pop();
   573           ArgumentMap w2 = state.raw_pop();
   574           state.raw_push(w1);
   575           state.raw_push(w2);
   576           state.raw_push(w1);
   577         }
   578         break;
   579       case Bytecodes::_dup_x2:
   580         { ArgumentMap w1 = state.raw_pop();
   581           ArgumentMap w2 = state.raw_pop();
   582           ArgumentMap w3 = state.raw_pop();
   583           state.raw_push(w1);
   584           state.raw_push(w3);
   585           state.raw_push(w2);
   586           state.raw_push(w1);
   587         }
   588         break;
   589       case Bytecodes::_dup2:
   590         { ArgumentMap w1 = state.raw_pop();
   591           ArgumentMap w2 = state.raw_pop();
   592           state.raw_push(w2);
   593           state.raw_push(w1);
   594           state.raw_push(w2);
   595           state.raw_push(w1);
   596         }
   597         break;
   598       case Bytecodes::_dup2_x1:
   599         { ArgumentMap w1 = state.raw_pop();
   600           ArgumentMap w2 = state.raw_pop();
   601           ArgumentMap w3 = state.raw_pop();
   602           state.raw_push(w2);
   603           state.raw_push(w1);
   604           state.raw_push(w3);
   605           state.raw_push(w2);
   606           state.raw_push(w1);
   607         }
   608         break;
   609       case Bytecodes::_dup2_x2:
   610         { ArgumentMap w1 = state.raw_pop();
   611           ArgumentMap w2 = state.raw_pop();
   612           ArgumentMap w3 = state.raw_pop();
   613           ArgumentMap w4 = state.raw_pop();
   614           state.raw_push(w2);
   615           state.raw_push(w1);
   616           state.raw_push(w4);
   617           state.raw_push(w3);
   618           state.raw_push(w2);
   619           state.raw_push(w1);
   620         }
   621         break;
   622       case Bytecodes::_swap:
   623         { ArgumentMap w1 = state.raw_pop();
   624           ArgumentMap w2 = state.raw_pop();
   625           state.raw_push(w1);
   626           state.raw_push(w2);
   627         }
   628         break;
   629       case Bytecodes::_iadd:
   630       case Bytecodes::_fadd:
   631       case Bytecodes::_isub:
   632       case Bytecodes::_fsub:
   633       case Bytecodes::_imul:
   634       case Bytecodes::_fmul:
   635       case Bytecodes::_idiv:
   636       case Bytecodes::_fdiv:
   637       case Bytecodes::_irem:
   638       case Bytecodes::_frem:
   639       case Bytecodes::_iand:
   640       case Bytecodes::_ior:
   641       case Bytecodes::_ixor:
   642         state.spop();
   643         state.spop();
   644         state.spush();
   645         break;
   646       case Bytecodes::_ladd:
   647       case Bytecodes::_dadd:
   648       case Bytecodes::_lsub:
   649       case Bytecodes::_dsub:
   650       case Bytecodes::_lmul:
   651       case Bytecodes::_dmul:
   652       case Bytecodes::_ldiv:
   653       case Bytecodes::_ddiv:
   654       case Bytecodes::_lrem:
   655       case Bytecodes::_drem:
   656       case Bytecodes::_land:
   657       case Bytecodes::_lor:
   658       case Bytecodes::_lxor:
   659         state.lpop();
   660         state.lpop();
   661         state.lpush();
   662         break;
   663       case Bytecodes::_ishl:
   664       case Bytecodes::_ishr:
   665       case Bytecodes::_iushr:
   666         state.spop();
   667         state.spop();
   668         state.spush();
   669         break;
   670       case Bytecodes::_lshl:
   671       case Bytecodes::_lshr:
   672       case Bytecodes::_lushr:
   673         state.spop();
   674         state.lpop();
   675         state.lpush();
   676         break;
   677       case Bytecodes::_ineg:
   678       case Bytecodes::_fneg:
   679         state.spop();
   680         state.spush();
   681         break;
   682       case Bytecodes::_lneg:
   683       case Bytecodes::_dneg:
   684         state.lpop();
   685         state.lpush();
   686         break;
   687       case Bytecodes::_iinc:
   688         break;
   689       case Bytecodes::_i2l:
   690       case Bytecodes::_i2d:
   691       case Bytecodes::_f2l:
   692       case Bytecodes::_f2d:
   693         state.spop();
   694         state.lpush();
   695         break;
   696       case Bytecodes::_i2f:
   697       case Bytecodes::_f2i:
   698         state.spop();
   699         state.spush();
   700         break;
   701       case Bytecodes::_l2i:
   702       case Bytecodes::_l2f:
   703       case Bytecodes::_d2i:
   704       case Bytecodes::_d2f:
   705         state.lpop();
   706         state.spush();
   707         break;
   708       case Bytecodes::_l2d:
   709       case Bytecodes::_d2l:
   710         state.lpop();
   711         state.lpush();
   712         break;
   713       case Bytecodes::_i2b:
   714       case Bytecodes::_i2c:
   715       case Bytecodes::_i2s:
   716         state.spop();
   717         state.spush();
   718         break;
   719       case Bytecodes::_lcmp:
   720       case Bytecodes::_dcmpl:
   721       case Bytecodes::_dcmpg:
   722         state.lpop();
   723         state.lpop();
   724         state.spush();
   725         break;
   726       case Bytecodes::_fcmpl:
   727       case Bytecodes::_fcmpg:
   728         state.spop();
   729         state.spop();
   730         state.spush();
   731         break;
   732       case Bytecodes::_ifeq:
   733       case Bytecodes::_ifne:
   734       case Bytecodes::_iflt:
   735       case Bytecodes::_ifge:
   736       case Bytecodes::_ifgt:
   737       case Bytecodes::_ifle:
   738       {
   739         state.spop();
   740         int dest_bci = s.get_dest();
   741         assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
   742         assert(s.next_bci() == limit_bci, "branch must end block");
   743         successors.push(_methodBlocks->block_containing(dest_bci));
   744         break;
   745       }
   746       case Bytecodes::_if_icmpeq:
   747       case Bytecodes::_if_icmpne:
   748       case Bytecodes::_if_icmplt:
   749       case Bytecodes::_if_icmpge:
   750       case Bytecodes::_if_icmpgt:
   751       case Bytecodes::_if_icmple:
   752       {
   753         state.spop();
   754         state.spop();
   755         int dest_bci = s.get_dest();
   756         assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
   757         assert(s.next_bci() == limit_bci, "branch must end block");
   758         successors.push(_methodBlocks->block_containing(dest_bci));
   759         break;
   760       }
   761       case Bytecodes::_if_acmpeq:
   762       case Bytecodes::_if_acmpne:
   763       {
   764         set_method_escape(state.apop());
   765         set_method_escape(state.apop());
   766         int dest_bci = s.get_dest();
   767         assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
   768         assert(s.next_bci() == limit_bci, "branch must end block");
   769         successors.push(_methodBlocks->block_containing(dest_bci));
   770         break;
   771       }
   772       case Bytecodes::_goto:
   773       {
   774         int dest_bci = s.get_dest();
   775         assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
   776         assert(s.next_bci() == limit_bci, "branch must end block");
   777         successors.push(_methodBlocks->block_containing(dest_bci));
   778         fall_through = false;
   779         break;
   780       }
   781       case Bytecodes::_jsr:
   782       {
   783         int dest_bci = s.get_dest();
   784         assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
   785         assert(s.next_bci() == limit_bci, "branch must end block");
   786         state.apush(empty_map);
   787         successors.push(_methodBlocks->block_containing(dest_bci));
   788         fall_through = false;
   789         break;
   790       }
   791       case Bytecodes::_ret:
   792         // we don't track  the destination of a "ret" instruction
   793         assert(s.next_bci() == limit_bci, "branch must end block");
   794         fall_through = false;
   795         break;
   796       case Bytecodes::_return:
   797         assert(s.next_bci() == limit_bci, "return must end block");
   798         fall_through = false;
   799         break;
   800       case Bytecodes::_tableswitch:
   801         {
   802           state.spop();
   803           Bytecode_tableswitch sw(&s);
   804           int len = sw.length();
   805           int dest_bci;
   806           for (int i = 0; i < len; i++) {
   807             dest_bci = s.cur_bci() + sw.dest_offset_at(i);
   808             assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
   809             successors.push(_methodBlocks->block_containing(dest_bci));
   810           }
   811           dest_bci = s.cur_bci() + sw.default_offset();
   812           assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
   813           successors.push(_methodBlocks->block_containing(dest_bci));
   814           assert(s.next_bci() == limit_bci, "branch must end block");
   815           fall_through = false;
   816           break;
   817         }
   818       case Bytecodes::_lookupswitch:
   819         {
   820           state.spop();
   821           Bytecode_lookupswitch sw(&s);
   822           int len = sw.number_of_pairs();
   823           int dest_bci;
   824           for (int i = 0; i < len; i++) {
   825             dest_bci = s.cur_bci() + sw.pair_at(i).offset();
   826             assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
   827             successors.push(_methodBlocks->block_containing(dest_bci));
   828           }
   829           dest_bci = s.cur_bci() + sw.default_offset();
   830           assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
   831           successors.push(_methodBlocks->block_containing(dest_bci));
   832           fall_through = false;
   833           break;
   834         }
   835       case Bytecodes::_ireturn:
   836       case Bytecodes::_freturn:
   837         state.spop();
   838         fall_through = false;
   839         break;
   840       case Bytecodes::_lreturn:
   841       case Bytecodes::_dreturn:
   842         state.lpop();
   843         fall_through = false;
   844         break;
   845       case Bytecodes::_areturn:
   846         set_returned(state.apop());
   847         fall_through = false;
   848         break;
   849       case Bytecodes::_getstatic:
   850       case Bytecodes::_getfield:
   851         { bool ignored_will_link;
   852           ciField* field = s.get_field(ignored_will_link);
   853           BasicType field_type = field->type()->basic_type();
   854           if (s.cur_bc() != Bytecodes::_getstatic) {
   855             set_method_escape(state.apop());
   856           }
   857           if (field_type == T_OBJECT || field_type == T_ARRAY) {
   858             state.apush(unknown_obj);
   859           } else if (type2size[field_type] == 1) {
   860             state.spush();
   861           } else {
   862             state.lpush();
   863           }
   864         }
   865         break;
   866       case Bytecodes::_putstatic:
   867       case Bytecodes::_putfield:
   868         { bool will_link;
   869           ciField* field = s.get_field(will_link);
   870           BasicType field_type = field->type()->basic_type();
   871           if (field_type == T_OBJECT || field_type == T_ARRAY) {
   872             set_global_escape(state.apop());
   873           } else if (type2size[field_type] == 1) {
   874             state.spop();
   875           } else {
   876             state.lpop();
   877           }
   878           if (s.cur_bc() != Bytecodes::_putstatic) {
   879             ArgumentMap p = state.apop();
   880             set_method_escape(p);
   881             set_modified(p, will_link ? field->offset() : OFFSET_ANY, type2size[field_type]*HeapWordSize);
   882           }
   883         }
   884         break;
   885       case Bytecodes::_invokevirtual:
   886       case Bytecodes::_invokespecial:
   887       case Bytecodes::_invokestatic:
   888       case Bytecodes::_invokedynamic:
   889       case Bytecodes::_invokeinterface:
   890         { bool ignored_will_link;
   891           ciSignature* declared_signature = NULL;
   892           ciMethod* target = s.get_method(ignored_will_link, &declared_signature);
   893           ciKlass*  holder = s.get_declared_method_holder();
   894           assert(declared_signature != NULL, "cannot be null");
   895           // Push appendix argument, if one.
   896           if (s.has_appendix()) {
   897             state.apush(unknown_obj);
   898           }
   899           // Pass in raw bytecode because we need to see invokehandle instructions.
   900           invoke(state, s.cur_bc_raw(), target, holder);
   901           // We are using the return type of the declared signature here because
   902           // it might be a more concrete type than the one from the target (for
   903           // e.g. invokedynamic and invokehandle).
   904           ciType* return_type = declared_signature->return_type();
   905           if (!return_type->is_primitive_type()) {
   906             state.apush(unknown_obj);
   907           } else if (return_type->is_one_word()) {
   908             state.spush();
   909           } else if (return_type->is_two_word()) {
   910             state.lpush();
   911           }
   912         }
   913         break;
   914       case Bytecodes::_new:
   915         state.apush(allocated_obj);
   916         break;
   917       case Bytecodes::_newarray:
   918       case Bytecodes::_anewarray:
   919         state.spop();
   920         state.apush(allocated_obj);
   921         break;
   922       case Bytecodes::_multianewarray:
   923         { int i = s.cur_bcp()[3];
   924           while (i-- > 0) state.spop();
   925           state.apush(allocated_obj);
   926         }
   927         break;
   928       case Bytecodes::_arraylength:
   929         set_method_escape(state.apop());
   930         state.spush();
   931         break;
   932       case Bytecodes::_athrow:
   933         set_global_escape(state.apop());
   934         fall_through = false;
   935         break;
   936       case Bytecodes::_checkcast:
   937         { ArgumentMap obj = state.apop();
   938           set_method_escape(obj);
   939           state.apush(obj);
   940         }
   941         break;
   942       case Bytecodes::_instanceof:
   943         set_method_escape(state.apop());
   944         state.spush();
   945         break;
   946       case Bytecodes::_monitorenter:
   947       case Bytecodes::_monitorexit:
   948         state.apop();
   949         break;
   950       case Bytecodes::_wide:
   951         ShouldNotReachHere();
   952         break;
   953       case Bytecodes::_ifnull:
   954       case Bytecodes::_ifnonnull:
   955       {
   956         set_method_escape(state.apop());
   957         int dest_bci = s.get_dest();
   958         assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
   959         assert(s.next_bci() == limit_bci, "branch must end block");
   960         successors.push(_methodBlocks->block_containing(dest_bci));
   961         break;
   962       }
   963       case Bytecodes::_goto_w:
   964       {
   965         int dest_bci = s.get_far_dest();
   966         assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
   967         assert(s.next_bci() == limit_bci, "branch must end block");
   968         successors.push(_methodBlocks->block_containing(dest_bci));
   969         fall_through = false;
   970         break;
   971       }
   972       case Bytecodes::_jsr_w:
   973       {
   974         int dest_bci = s.get_far_dest();
   975         assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
   976         assert(s.next_bci() == limit_bci, "branch must end block");
   977         state.apush(empty_map);
   978         successors.push(_methodBlocks->block_containing(dest_bci));
   979         fall_through = false;
   980         break;
   981       }
   982       case Bytecodes::_breakpoint:
   983         break;
   984       default:
   985         ShouldNotReachHere();
   986         break;
   987     }
   989   }
   990   if (fall_through) {
   991     int fall_through_bci = s.cur_bci();
   992     if (fall_through_bci < _method->code_size()) {
   993       assert(_methodBlocks->is_block_start(fall_through_bci), "must fall through to block start.");
   994       successors.push(_methodBlocks->block_containing(fall_through_bci));
   995     }
   996   }
   997 }
   999 void BCEscapeAnalyzer::merge_block_states(StateInfo *blockstates, ciBlock *dest, StateInfo *s_state) {
  1000   StateInfo *d_state = blockstates + dest->index();
  1001   int nlocals = _method->max_locals();
  1003   // exceptions may cause transfer of control to handlers in the middle of a
  1004   // block, so we don't merge the incoming state of exception handlers
  1005   if (dest->is_handler())
  1006     return;
  1007   if (!d_state->_initialized ) {
  1008     // destination not initialized, just copy
  1009     for (int i = 0; i < nlocals; i++) {
  1010       d_state->_vars[i] = s_state->_vars[i];
  1012     for (int i = 0; i < s_state->_stack_height; i++) {
  1013       d_state->_stack[i] = s_state->_stack[i];
  1015     d_state->_stack_height = s_state->_stack_height;
  1016     d_state->_max_stack = s_state->_max_stack;
  1017     d_state->_initialized = true;
  1018   } else if (!dest->processed()) {
  1019     // we have not yet walked the bytecodes of dest, we can merge
  1020     // the states
  1021     assert(d_state->_stack_height == s_state->_stack_height, "computed stack heights must match");
  1022     for (int i = 0; i < nlocals; i++) {
  1023       d_state->_vars[i].set_union(s_state->_vars[i]);
  1025     for (int i = 0; i < s_state->_stack_height; i++) {
  1026       d_state->_stack[i].set_union(s_state->_stack[i]);
  1028   } else {
  1029     // the bytecodes of dest have already been processed, mark any
  1030     // arguments in the source state which are not in the dest state
  1031     // as global escape.
  1032     // Future refinement:  we only need to mark these variable to the
  1033     // maximum escape of any variables in dest state
  1034     assert(d_state->_stack_height == s_state->_stack_height, "computed stack heights must match");
  1035     ArgumentMap extra_vars;
  1036     for (int i = 0; i < nlocals; i++) {
  1037       ArgumentMap t;
  1038       t = s_state->_vars[i];
  1039       t.set_difference(d_state->_vars[i]);
  1040       extra_vars.set_union(t);
  1042     for (int i = 0; i < s_state->_stack_height; i++) {
  1043       ArgumentMap t;
  1044       //extra_vars |= !d_state->_vars[i] & s_state->_vars[i];
  1045       t.clear();
  1046       t = s_state->_stack[i];
  1047       t.set_difference(d_state->_stack[i]);
  1048       extra_vars.set_union(t);
  1050     set_global_escape(extra_vars, true);
  1054 void BCEscapeAnalyzer::iterate_blocks(Arena *arena) {
  1055   int numblocks = _methodBlocks->num_blocks();
  1056   int stkSize   = _method->max_stack();
  1057   int numLocals = _method->max_locals();
  1058   StateInfo state;
  1060   int datacount = (numblocks + 1) * (stkSize + numLocals);
  1061   int datasize = datacount * sizeof(ArgumentMap);
  1062   StateInfo *blockstates = (StateInfo *) arena->Amalloc(numblocks * sizeof(StateInfo));
  1063   ArgumentMap *statedata  = (ArgumentMap *) arena->Amalloc(datasize);
  1064   for (int i = 0; i < datacount; i++) ::new ((void*)&statedata[i]) ArgumentMap();
  1065   ArgumentMap *dp = statedata;
  1066   state._vars = dp;
  1067   dp += numLocals;
  1068   state._stack = dp;
  1069   dp += stkSize;
  1070   state._initialized = false;
  1071   state._max_stack = stkSize;
  1072   for (int i = 0; i < numblocks; i++) {
  1073     blockstates[i]._vars = dp;
  1074     dp += numLocals;
  1075     blockstates[i]._stack = dp;
  1076     dp += stkSize;
  1077     blockstates[i]._initialized = false;
  1078     blockstates[i]._stack_height = 0;
  1079     blockstates[i]._max_stack  = stkSize;
  1081   GrowableArray<ciBlock *> worklist(arena, numblocks / 4, 0, NULL);
  1082   GrowableArray<ciBlock *> successors(arena, 4, 0, NULL);
  1084   _methodBlocks->clear_processed();
  1086   // initialize block 0 state from method signature
  1087   ArgumentMap allVars;   // all oop arguments to method
  1088   ciSignature* sig = method()->signature();
  1089   int j = 0;
  1090   ciBlock* first_blk = _methodBlocks->block_containing(0);
  1091   int fb_i = first_blk->index();
  1092   if (!method()->is_static()) {
  1093     // record information for "this"
  1094     blockstates[fb_i]._vars[j].set(j);
  1095     allVars.add(j);
  1096     j++;
  1098   for (int i = 0; i < sig->count(); i++) {
  1099     ciType* t = sig->type_at(i);
  1100     if (!t->is_primitive_type()) {
  1101       blockstates[fb_i]._vars[j].set(j);
  1102       allVars.add(j);
  1104     j += t->size();
  1106   blockstates[fb_i]._initialized = true;
  1107   assert(j == _arg_size, "just checking");
  1109   ArgumentMap unknown_map;
  1110   unknown_map.add_unknown();
  1112   worklist.push(first_blk);
  1113   while(worklist.length() > 0) {
  1114     ciBlock *blk = worklist.pop();
  1115     StateInfo *blkState = blockstates + blk->index();
  1116     if (blk->is_handler() || blk->is_ret_target()) {
  1117       // for an exception handler or a target of a ret instruction, we assume the worst case,
  1118       // that any variable could contain any argument
  1119       for (int i = 0; i < numLocals; i++) {
  1120         state._vars[i] = allVars;
  1122       if (blk->is_handler()) {
  1123         state._stack_height = 1;
  1124       } else {
  1125         state._stack_height = blkState->_stack_height;
  1127       for (int i = 0; i < state._stack_height; i++) {
  1128 // ??? should this be unknown_map ???
  1129         state._stack[i] = allVars;
  1131     } else {
  1132       for (int i = 0; i < numLocals; i++) {
  1133         state._vars[i] = blkState->_vars[i];
  1135       for (int i = 0; i < blkState->_stack_height; i++) {
  1136         state._stack[i] = blkState->_stack[i];
  1138       state._stack_height = blkState->_stack_height;
  1140     iterate_one_block(blk, state, successors);
  1141     // if this block has any exception handlers, push them
  1142     // onto successor list
  1143     if (blk->has_handler()) {
  1144       DEBUG_ONLY(int handler_count = 0;)
  1145       int blk_start = blk->start_bci();
  1146       int blk_end = blk->limit_bci();
  1147       for (int i = 0; i < numblocks; i++) {
  1148         ciBlock *b = _methodBlocks->block(i);
  1149         if (b->is_handler()) {
  1150           int ex_start = b->ex_start_bci();
  1151           int ex_end = b->ex_limit_bci();
  1152           if ((ex_start >= blk_start && ex_start < blk_end) ||
  1153               (ex_end > blk_start && ex_end <= blk_end)) {
  1154             successors.push(b);
  1156           DEBUG_ONLY(handler_count++;)
  1159       assert(handler_count > 0, "must find at least one handler");
  1161     // merge computed variable state with successors
  1162     while(successors.length() > 0) {
  1163       ciBlock *succ = successors.pop();
  1164       merge_block_states(blockstates, succ, &state);
  1165       if (!succ->processed())
  1166         worklist.push(succ);
  1171 bool BCEscapeAnalyzer::do_analysis() {
  1172   Arena* arena = CURRENT_ENV->arena();
  1173   // identify basic blocks
  1174   _methodBlocks = _method->get_method_blocks();
  1176   iterate_blocks(arena);
  1177   // TEMPORARY
  1178   return true;
  1181 vmIntrinsics::ID BCEscapeAnalyzer::known_intrinsic() {
  1182   vmIntrinsics::ID iid = method()->intrinsic_id();
  1184   if (iid == vmIntrinsics::_getClass ||
  1185       iid ==  vmIntrinsics::_fillInStackTrace ||
  1186       iid == vmIntrinsics::_hashCode)
  1187     return iid;
  1188   else
  1189     return vmIntrinsics::_none;
  1192 bool BCEscapeAnalyzer::compute_escape_for_intrinsic(vmIntrinsics::ID iid) {
  1193   ArgumentMap arg;
  1194   arg.clear();
  1195   switch (iid) {
  1196   case vmIntrinsics::_getClass:
  1197     _return_local = false;
  1198     break;
  1199   case vmIntrinsics::_fillInStackTrace:
  1200     arg.set(0); // 'this'
  1201     set_returned(arg);
  1202     break;
  1203   case vmIntrinsics::_hashCode:
  1204     // initialized state is correct
  1205     break;
  1206   default:
  1207     assert(false, "unexpected intrinsic");
  1209   return true;
  1212 void BCEscapeAnalyzer::initialize() {
  1213   int i;
  1215   // clear escape information (method may have been deoptimized)
  1216   methodData()->clear_escape_info();
  1218   // initialize escape state of object parameters
  1219   ciSignature* sig = method()->signature();
  1220   int j = 0;
  1221   if (!method()->is_static()) {
  1222     _arg_local.set(0);
  1223     _arg_stack.set(0);
  1224     j++;
  1226   for (i = 0; i < sig->count(); i++) {
  1227     ciType* t = sig->type_at(i);
  1228     if (!t->is_primitive_type()) {
  1229       _arg_local.set(j);
  1230       _arg_stack.set(j);
  1232     j += t->size();
  1234   assert(j == _arg_size, "just checking");
  1236   // start with optimistic assumption
  1237   ciType *rt = _method->return_type();
  1238   if (rt->is_primitive_type()) {
  1239     _return_local = false;
  1240     _return_allocated = false;
  1241   } else {
  1242     _return_local = true;
  1243     _return_allocated = true;
  1245   _allocated_escapes = false;
  1246   _unknown_modified = false;
  1249 void BCEscapeAnalyzer::clear_escape_info() {
  1250   ciSignature* sig = method()->signature();
  1251   int arg_count = sig->count();
  1252   ArgumentMap var;
  1253   if (!method()->is_static()) {
  1254     arg_count++;  // allow for "this"
  1256   for (int i = 0; i < arg_count; i++) {
  1257     set_arg_modified(i, OFFSET_ANY, 4);
  1258     var.clear();
  1259     var.set(i);
  1260     set_modified(var, OFFSET_ANY, 4);
  1261     set_global_escape(var);
  1263   _arg_local.Clear();
  1264   _arg_stack.Clear();
  1265   _arg_returned.Clear();
  1266   _return_local = false;
  1267   _return_allocated = false;
  1268   _allocated_escapes = true;
  1269   _unknown_modified = true;
  1273 void BCEscapeAnalyzer::compute_escape_info() {
  1274   int i;
  1275   assert(!methodData()->has_escape_info(), "do not overwrite escape info");
  1277   vmIntrinsics::ID iid = known_intrinsic();
  1279   // check if method can be analyzed
  1280   if (iid ==  vmIntrinsics::_none && (method()->is_abstract() || method()->is_native() || !method()->holder()->is_initialized()
  1281       || _level > MaxBCEAEstimateLevel
  1282       || method()->code_size() > MaxBCEAEstimateSize)) {
  1283     if (BCEATraceLevel >= 1) {
  1284       tty->print("Skipping method because: ");
  1285       if (method()->is_abstract())
  1286         tty->print_cr("method is abstract.");
  1287       else if (method()->is_native())
  1288         tty->print_cr("method is native.");
  1289       else if (!method()->holder()->is_initialized())
  1290         tty->print_cr("class of method is not initialized.");
  1291       else if (_level > MaxBCEAEstimateLevel)
  1292         tty->print_cr("level (%d) exceeds MaxBCEAEstimateLevel (%d).",
  1293                       _level, (int) MaxBCEAEstimateLevel);
  1294       else if (method()->code_size() > MaxBCEAEstimateSize)
  1295         tty->print_cr("code size (%d) exceeds MaxBCEAEstimateSize (%d).",
  1296                       method()->code_size(), (int) MaxBCEAEstimateSize);
  1297       else
  1298         ShouldNotReachHere();
  1300     clear_escape_info();
  1302     return;
  1305   if (BCEATraceLevel >= 1) {
  1306     tty->print("[EA] estimating escape information for");
  1307     if (iid != vmIntrinsics::_none)
  1308       tty->print(" intrinsic");
  1309     method()->print_short_name();
  1310     tty->print_cr(" (%d bytes)", method()->code_size());
  1313   bool success;
  1315   initialize();
  1317   // Do not scan method if it has no object parameters and
  1318   // does not returns an object (_return_allocated is set in initialize()).
  1319   if (_arg_local.Size() == 0 && !_return_allocated) {
  1320     // Clear all info since method's bytecode was not analysed and
  1321     // set pessimistic escape information.
  1322     clear_escape_info();
  1323     methodData()->set_eflag(MethodData::allocated_escapes);
  1324     methodData()->set_eflag(MethodData::unknown_modified);
  1325     methodData()->set_eflag(MethodData::estimated);
  1326     return;
  1329   if (iid != vmIntrinsics::_none)
  1330     success = compute_escape_for_intrinsic(iid);
  1331   else {
  1332     success = do_analysis();
  1335   // don't store interprocedural escape information if it introduces
  1336   // dependencies or if method data is empty
  1337   //
  1338   if (!has_dependencies() && !methodData()->is_empty()) {
  1339     for (i = 0; i < _arg_size; i++) {
  1340       if (_arg_local.test(i)) {
  1341         assert(_arg_stack.test(i), "inconsistent escape info");
  1342         methodData()->set_arg_local(i);
  1343         methodData()->set_arg_stack(i);
  1344       } else if (_arg_stack.test(i)) {
  1345         methodData()->set_arg_stack(i);
  1347       if (_arg_returned.test(i)) {
  1348         methodData()->set_arg_returned(i);
  1350       methodData()->set_arg_modified(i, _arg_modified[i]);
  1352     if (_return_local) {
  1353       methodData()->set_eflag(MethodData::return_local);
  1355     if (_return_allocated) {
  1356       methodData()->set_eflag(MethodData::return_allocated);
  1358     if (_allocated_escapes) {
  1359       methodData()->set_eflag(MethodData::allocated_escapes);
  1361     if (_unknown_modified) {
  1362       methodData()->set_eflag(MethodData::unknown_modified);
  1364     methodData()->set_eflag(MethodData::estimated);
  1368 void BCEscapeAnalyzer::read_escape_info() {
  1369   assert(methodData()->has_escape_info(), "no escape info available");
  1371   // read escape information from method descriptor
  1372   for (int i = 0; i < _arg_size; i++) {
  1373     if (methodData()->is_arg_local(i))
  1374       _arg_local.set(i);
  1375     if (methodData()->is_arg_stack(i))
  1376       _arg_stack.set(i);
  1377     if (methodData()->is_arg_returned(i))
  1378       _arg_returned.set(i);
  1379     _arg_modified[i] = methodData()->arg_modified(i);
  1381   _return_local = methodData()->eflag_set(MethodData::return_local);
  1382   _return_allocated = methodData()->eflag_set(MethodData::return_allocated);
  1383   _allocated_escapes = methodData()->eflag_set(MethodData::allocated_escapes);
  1384   _unknown_modified = methodData()->eflag_set(MethodData::unknown_modified);
  1388 #ifndef PRODUCT
  1389 void BCEscapeAnalyzer::dump() {
  1390   tty->print("[EA] estimated escape information for");
  1391   method()->print_short_name();
  1392   tty->print_cr(has_dependencies() ? " (not stored)" : "");
  1393   tty->print("     non-escaping args:      ");
  1394   _arg_local.print_on(tty);
  1395   tty->print("     stack-allocatable args: ");
  1396   _arg_stack.print_on(tty);
  1397   if (_return_local) {
  1398     tty->print("     returned args:          ");
  1399     _arg_returned.print_on(tty);
  1400   } else if (is_return_allocated()) {
  1401     tty->print_cr("     return allocated value");
  1402   } else {
  1403     tty->print_cr("     return non-local value");
  1405   tty->print("     modified args: ");
  1406   for (int i = 0; i < _arg_size; i++) {
  1407     if (_arg_modified[i] == 0)
  1408       tty->print("    0");
  1409     else
  1410       tty->print("    0x%x", _arg_modified[i]);
  1412   tty->cr();
  1413   tty->print("     flags: ");
  1414   if (_return_allocated)
  1415     tty->print(" return_allocated");
  1416   if (_allocated_escapes)
  1417     tty->print(" allocated_escapes");
  1418   if (_unknown_modified)
  1419     tty->print(" unknown_modified");
  1420   tty->cr();
  1422 #endif
  1424 BCEscapeAnalyzer::BCEscapeAnalyzer(ciMethod* method, BCEscapeAnalyzer* parent)
  1425     : _conservative(method == NULL || !EstimateArgEscape)
  1426     , _arena(CURRENT_ENV->arena())
  1427     , _method(method)
  1428     , _methodData(method ? method->method_data() : NULL)
  1429     , _arg_size(method ? method->arg_size() : 0)
  1430     , _arg_local(_arena)
  1431     , _arg_stack(_arena)
  1432     , _arg_returned(_arena)
  1433     , _dirty(_arena)
  1434     , _return_local(false)
  1435     , _return_allocated(false)
  1436     , _allocated_escapes(false)
  1437     , _unknown_modified(false)
  1438     , _dependencies(_arena, 4, 0, NULL)
  1439     , _parent(parent)
  1440     , _level(parent == NULL ? 0 : parent->level() + 1) {
  1441   if (!_conservative) {
  1442     _arg_local.Clear();
  1443     _arg_stack.Clear();
  1444     _arg_returned.Clear();
  1445     _dirty.Clear();
  1446     Arena* arena = CURRENT_ENV->arena();
  1447     _arg_modified = (uint *) arena->Amalloc(_arg_size * sizeof(uint));
  1448     Copy::zero_to_bytes(_arg_modified, _arg_size * sizeof(uint));
  1450     if (methodData() == NULL)
  1451       return;
  1452     bool printit = _method->should_print_assembly();
  1453     if (methodData()->has_escape_info()) {
  1454       TRACE_BCEA(2, tty->print_cr("[EA] Reading previous results for %s.%s",
  1455                                   method->holder()->name()->as_utf8(),
  1456                                   method->name()->as_utf8()));
  1457       read_escape_info();
  1458     } else {
  1459       TRACE_BCEA(2, tty->print_cr("[EA] computing results for %s.%s",
  1460                                   method->holder()->name()->as_utf8(),
  1461                                   method->name()->as_utf8()));
  1463       compute_escape_info();
  1464       methodData()->update_escape_info();
  1466 #ifndef PRODUCT
  1467     if (BCEATraceLevel >= 3) {
  1468       // dump escape information
  1469       dump();
  1471 #endif
  1475 void BCEscapeAnalyzer::copy_dependencies(Dependencies *deps) {
  1476   if (ciEnv::current()->jvmti_can_hotswap_or_post_breakpoint()) {
  1477     // Also record evol dependencies so redefinition of the
  1478     // callee will trigger recompilation.
  1479     deps->assert_evol_method(method());
  1481   for (int i = 0; i < _dependencies.length(); i+=2) {
  1482     ciKlass *k = _dependencies.at(i)->as_klass();
  1483     ciMethod *m = _dependencies.at(i+1)->as_method();
  1484     deps->assert_unique_concrete_method(k, m);

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