src/share/vm/ci/ciTypeFlow.cpp

Wed, 06 Jan 2010 14:22:39 -0800

author
never
date
Wed, 06 Jan 2010 14:22:39 -0800
changeset 1577
4ce7240d622c
parent 1572
97125851f396
child 1907
c18cbe5936b8
child 1920
ab102d5d923e
permissions
-rw-r--r--

6914300: ciEnv should export all well known classes
Reviewed-by: kvn, twisti

     1 /*
     2  * Copyright 2000-2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 #include "incls/_precompiled.incl"
    26 #include "incls/_ciTypeFlow.cpp.incl"
    28 // ciTypeFlow::JsrSet
    29 //
    30 // A JsrSet represents some set of JsrRecords.  This class
    31 // is used to record a set of all jsr routines which we permit
    32 // execution to return (ret) from.
    33 //
    34 // During abstract interpretation, JsrSets are used to determine
    35 // whether two paths which reach a given block are unique, and
    36 // should be cloned apart, or are compatible, and should merge
    37 // together.
    39 // ------------------------------------------------------------------
    40 // ciTypeFlow::JsrSet::JsrSet
    41 ciTypeFlow::JsrSet::JsrSet(Arena* arena, int default_len) {
    42   if (arena != NULL) {
    43     // Allocate growable array in Arena.
    44     _set = new (arena) GrowableArray<JsrRecord*>(arena, default_len, 0, NULL);
    45   } else {
    46     // Allocate growable array in current ResourceArea.
    47     _set = new GrowableArray<JsrRecord*>(4, 0, NULL, false);
    48   }
    49 }
    51 // ------------------------------------------------------------------
    52 // ciTypeFlow::JsrSet::copy_into
    53 void ciTypeFlow::JsrSet::copy_into(JsrSet* jsrs) {
    54   int len = size();
    55   jsrs->_set->clear();
    56   for (int i = 0; i < len; i++) {
    57     jsrs->_set->append(_set->at(i));
    58   }
    59 }
    61 // ------------------------------------------------------------------
    62 // ciTypeFlow::JsrSet::is_compatible_with
    63 //
    64 // !!!! MISGIVINGS ABOUT THIS... disregard
    65 //
    66 // Is this JsrSet compatible with some other JsrSet?
    67 //
    68 // In set-theoretic terms, a JsrSet can be viewed as a partial function
    69 // from entry addresses to return addresses.  Two JsrSets A and B are
    70 // compatible iff
    71 //
    72 //   For any x,
    73 //   A(x) defined and B(x) defined implies A(x) == B(x)
    74 //
    75 // Less formally, two JsrSets are compatible when they have identical
    76 // return addresses for any entry addresses they share in common.
    77 bool ciTypeFlow::JsrSet::is_compatible_with(JsrSet* other) {
    78   // Walk through both sets in parallel.  If the same entry address
    79   // appears in both sets, then the return address must match for
    80   // the sets to be compatible.
    81   int size1 = size();
    82   int size2 = other->size();
    84   // Special case.  If nothing is on the jsr stack, then there can
    85   // be no ret.
    86   if (size2 == 0) {
    87     return true;
    88   } else if (size1 != size2) {
    89     return false;
    90   } else {
    91     for (int i = 0; i < size1; i++) {
    92       JsrRecord* record1 = record_at(i);
    93       JsrRecord* record2 = other->record_at(i);
    94       if (record1->entry_address() != record2->entry_address() ||
    95           record1->return_address() != record2->return_address()) {
    96         return false;
    97       }
    98     }
    99     return true;
   100   }
   102 #if 0
   103   int pos1 = 0;
   104   int pos2 = 0;
   105   int size1 = size();
   106   int size2 = other->size();
   107   while (pos1 < size1 && pos2 < size2) {
   108     JsrRecord* record1 = record_at(pos1);
   109     JsrRecord* record2 = other->record_at(pos2);
   110     int entry1 = record1->entry_address();
   111     int entry2 = record2->entry_address();
   112     if (entry1 < entry2) {
   113       pos1++;
   114     } else if (entry1 > entry2) {
   115       pos2++;
   116     } else {
   117       if (record1->return_address() == record2->return_address()) {
   118         pos1++;
   119         pos2++;
   120       } else {
   121         // These two JsrSets are incompatible.
   122         return false;
   123       }
   124     }
   125   }
   126   // The two JsrSets agree.
   127   return true;
   128 #endif
   129 }
   131 // ------------------------------------------------------------------
   132 // ciTypeFlow::JsrSet::insert_jsr_record
   133 //
   134 // Insert the given JsrRecord into the JsrSet, maintaining the order
   135 // of the set and replacing any element with the same entry address.
   136 void ciTypeFlow::JsrSet::insert_jsr_record(JsrRecord* record) {
   137   int len = size();
   138   int entry = record->entry_address();
   139   int pos = 0;
   140   for ( ; pos < len; pos++) {
   141     JsrRecord* current = record_at(pos);
   142     if (entry == current->entry_address()) {
   143       // Stomp over this entry.
   144       _set->at_put(pos, record);
   145       assert(size() == len, "must be same size");
   146       return;
   147     } else if (entry < current->entry_address()) {
   148       break;
   149     }
   150   }
   152   // Insert the record into the list.
   153   JsrRecord* swap = record;
   154   JsrRecord* temp = NULL;
   155   for ( ; pos < len; pos++) {
   156     temp = _set->at(pos);
   157     _set->at_put(pos, swap);
   158     swap = temp;
   159   }
   160   _set->append(swap);
   161   assert(size() == len+1, "must be larger");
   162 }
   164 // ------------------------------------------------------------------
   165 // ciTypeFlow::JsrSet::remove_jsr_record
   166 //
   167 // Remove the JsrRecord with the given return address from the JsrSet.
   168 void ciTypeFlow::JsrSet::remove_jsr_record(int return_address) {
   169   int len = size();
   170   for (int i = 0; i < len; i++) {
   171     if (record_at(i)->return_address() == return_address) {
   172       // We have found the proper entry.  Remove it from the
   173       // JsrSet and exit.
   174       for (int j = i+1; j < len ; j++) {
   175         _set->at_put(j-1, _set->at(j));
   176       }
   177       _set->trunc_to(len-1);
   178       assert(size() == len-1, "must be smaller");
   179       return;
   180     }
   181   }
   182   assert(false, "verify: returning from invalid subroutine");
   183 }
   185 // ------------------------------------------------------------------
   186 // ciTypeFlow::JsrSet::apply_control
   187 //
   188 // Apply the effect of a control-flow bytecode on the JsrSet.  The
   189 // only bytecodes that modify the JsrSet are jsr and ret.
   190 void ciTypeFlow::JsrSet::apply_control(ciTypeFlow* analyzer,
   191                                        ciBytecodeStream* str,
   192                                        ciTypeFlow::StateVector* state) {
   193   Bytecodes::Code code = str->cur_bc();
   194   if (code == Bytecodes::_jsr) {
   195     JsrRecord* record =
   196       analyzer->make_jsr_record(str->get_dest(), str->next_bci());
   197     insert_jsr_record(record);
   198   } else if (code == Bytecodes::_jsr_w) {
   199     JsrRecord* record =
   200       analyzer->make_jsr_record(str->get_far_dest(), str->next_bci());
   201     insert_jsr_record(record);
   202   } else if (code == Bytecodes::_ret) {
   203     Cell local = state->local(str->get_index());
   204     ciType* return_address = state->type_at(local);
   205     assert(return_address->is_return_address(), "verify: wrong type");
   206     if (size() == 0) {
   207       // Ret-state underflow:  Hit a ret w/o any previous jsrs.  Bail out.
   208       // This can happen when a loop is inside a finally clause (4614060).
   209       analyzer->record_failure("OSR in finally clause");
   210       return;
   211     }
   212     remove_jsr_record(return_address->as_return_address()->bci());
   213   }
   214 }
   216 #ifndef PRODUCT
   217 // ------------------------------------------------------------------
   218 // ciTypeFlow::JsrSet::print_on
   219 void ciTypeFlow::JsrSet::print_on(outputStream* st) const {
   220   st->print("{ ");
   221   int num_elements = size();
   222   if (num_elements > 0) {
   223     int i = 0;
   224     for( ; i < num_elements - 1; i++) {
   225       _set->at(i)->print_on(st);
   226       st->print(", ");
   227     }
   228     _set->at(i)->print_on(st);
   229     st->print(" ");
   230   }
   231   st->print("}");
   232 }
   233 #endif
   235 // ciTypeFlow::StateVector
   236 //
   237 // A StateVector summarizes the type information at some point in
   238 // the program.
   240 // ------------------------------------------------------------------
   241 // ciTypeFlow::StateVector::type_meet
   242 //
   243 // Meet two types.
   244 //
   245 // The semi-lattice of types use by this analysis are modeled on those
   246 // of the verifier.  The lattice is as follows:
   247 //
   248 //        top_type() >= all non-extremal types >= bottom_type
   249 //                             and
   250 //   Every primitive type is comparable only with itself.  The meet of
   251 //   reference types is determined by their kind: instance class,
   252 //   interface, or array class.  The meet of two types of the same
   253 //   kind is their least common ancestor.  The meet of two types of
   254 //   different kinds is always java.lang.Object.
   255 ciType* ciTypeFlow::StateVector::type_meet_internal(ciType* t1, ciType* t2, ciTypeFlow* analyzer) {
   256   assert(t1 != t2, "checked in caller");
   257   if (t1->equals(top_type())) {
   258     return t2;
   259   } else if (t2->equals(top_type())) {
   260     return t1;
   261   } else if (t1->is_primitive_type() || t2->is_primitive_type()) {
   262     // Special case null_type.  null_type meet any reference type T
   263     // is T.  null_type meet null_type is null_type.
   264     if (t1->equals(null_type())) {
   265       if (!t2->is_primitive_type() || t2->equals(null_type())) {
   266         return t2;
   267       }
   268     } else if (t2->equals(null_type())) {
   269       if (!t1->is_primitive_type()) {
   270         return t1;
   271       }
   272     }
   274     // At least one of the two types is a non-top primitive type.
   275     // The other type is not equal to it.  Fall to bottom.
   276     return bottom_type();
   277   } else {
   278     // Both types are non-top non-primitive types.  That is,
   279     // both types are either instanceKlasses or arrayKlasses.
   280     ciKlass* object_klass = analyzer->env()->Object_klass();
   281     ciKlass* k1 = t1->as_klass();
   282     ciKlass* k2 = t2->as_klass();
   283     if (k1->equals(object_klass) || k2->equals(object_klass)) {
   284       return object_klass;
   285     } else if (!k1->is_loaded() || !k2->is_loaded()) {
   286       // Unloaded classes fall to java.lang.Object at a merge.
   287       return object_klass;
   288     } else if (k1->is_interface() != k2->is_interface()) {
   289       // When an interface meets a non-interface, we get Object;
   290       // This is what the verifier does.
   291       return object_klass;
   292     } else if (k1->is_array_klass() || k2->is_array_klass()) {
   293       // When an array meets a non-array, we get Object.
   294       // When objArray meets typeArray, we also get Object.
   295       // And when typeArray meets different typeArray, we again get Object.
   296       // But when objArray meets objArray, we look carefully at element types.
   297       if (k1->is_obj_array_klass() && k2->is_obj_array_klass()) {
   298         // Meet the element types, then construct the corresponding array type.
   299         ciKlass* elem1 = k1->as_obj_array_klass()->element_klass();
   300         ciKlass* elem2 = k2->as_obj_array_klass()->element_klass();
   301         ciKlass* elem  = type_meet_internal(elem1, elem2, analyzer)->as_klass();
   302         // Do an easy shortcut if one type is a super of the other.
   303         if (elem == elem1) {
   304           assert(k1 == ciObjArrayKlass::make(elem), "shortcut is OK");
   305           return k1;
   306         } else if (elem == elem2) {
   307           assert(k2 == ciObjArrayKlass::make(elem), "shortcut is OK");
   308           return k2;
   309         } else {
   310           return ciObjArrayKlass::make(elem);
   311         }
   312       } else {
   313         return object_klass;
   314       }
   315     } else {
   316       // Must be two plain old instance klasses.
   317       assert(k1->is_instance_klass(), "previous cases handle non-instances");
   318       assert(k2->is_instance_klass(), "previous cases handle non-instances");
   319       return k1->least_common_ancestor(k2);
   320     }
   321   }
   322 }
   325 // ------------------------------------------------------------------
   326 // ciTypeFlow::StateVector::StateVector
   327 //
   328 // Build a new state vector
   329 ciTypeFlow::StateVector::StateVector(ciTypeFlow* analyzer) {
   330   _outer = analyzer;
   331   _stack_size = -1;
   332   _monitor_count = -1;
   333   // Allocate the _types array
   334   int max_cells = analyzer->max_cells();
   335   _types = (ciType**)analyzer->arena()->Amalloc(sizeof(ciType*) * max_cells);
   336   for (int i=0; i<max_cells; i++) {
   337     _types[i] = top_type();
   338   }
   339   _trap_bci = -1;
   340   _trap_index = 0;
   341   _def_locals.clear();
   342 }
   345 // ------------------------------------------------------------------
   346 // ciTypeFlow::get_start_state
   347 //
   348 // Set this vector to the method entry state.
   349 const ciTypeFlow::StateVector* ciTypeFlow::get_start_state() {
   350   StateVector* state = new StateVector(this);
   351   if (is_osr_flow()) {
   352     ciTypeFlow* non_osr_flow = method()->get_flow_analysis();
   353     if (non_osr_flow->failing()) {
   354       record_failure(non_osr_flow->failure_reason());
   355       return NULL;
   356     }
   357     JsrSet* jsrs = new JsrSet(NULL, 16);
   358     Block* non_osr_block = non_osr_flow->existing_block_at(start_bci(), jsrs);
   359     if (non_osr_block == NULL) {
   360       record_failure("cannot reach OSR point");
   361       return NULL;
   362     }
   363     // load up the non-OSR state at this point
   364     non_osr_block->copy_state_into(state);
   365     int non_osr_start = non_osr_block->start();
   366     if (non_osr_start != start_bci()) {
   367       // must flow forward from it
   368       if (CITraceTypeFlow) {
   369         tty->print_cr(">> Interpreting pre-OSR block %d:", non_osr_start);
   370       }
   371       Block* block = block_at(non_osr_start, jsrs);
   372       assert(block->limit() == start_bci(), "must flow forward to start");
   373       flow_block(block, state, jsrs);
   374     }
   375     return state;
   376     // Note:  The code below would be an incorrect for an OSR flow,
   377     // even if it were possible for an OSR entry point to be at bci zero.
   378   }
   379   // "Push" the method signature into the first few locals.
   380   state->set_stack_size(-max_locals());
   381   if (!method()->is_static()) {
   382     state->push(method()->holder());
   383     assert(state->tos() == state->local(0), "");
   384   }
   385   for (ciSignatureStream str(method()->signature());
   386        !str.at_return_type();
   387        str.next()) {
   388     state->push_translate(str.type());
   389   }
   390   // Set the rest of the locals to bottom.
   391   Cell cell = state->next_cell(state->tos());
   392   state->set_stack_size(0);
   393   int limit = state->limit_cell();
   394   for (; cell < limit; cell = state->next_cell(cell)) {
   395     state->set_type_at(cell, state->bottom_type());
   396   }
   397   // Lock an object, if necessary.
   398   state->set_monitor_count(method()->is_synchronized() ? 1 : 0);
   399   return state;
   400 }
   402 // ------------------------------------------------------------------
   403 // ciTypeFlow::StateVector::copy_into
   404 //
   405 // Copy our value into some other StateVector
   406 void ciTypeFlow::StateVector::copy_into(ciTypeFlow::StateVector* copy)
   407 const {
   408   copy->set_stack_size(stack_size());
   409   copy->set_monitor_count(monitor_count());
   410   Cell limit = limit_cell();
   411   for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
   412     copy->set_type_at(c, type_at(c));
   413   }
   414 }
   416 // ------------------------------------------------------------------
   417 // ciTypeFlow::StateVector::meet
   418 //
   419 // Meets this StateVector with another, destructively modifying this
   420 // one.  Returns true if any modification takes place.
   421 bool ciTypeFlow::StateVector::meet(const ciTypeFlow::StateVector* incoming) {
   422   if (monitor_count() == -1) {
   423     set_monitor_count(incoming->monitor_count());
   424   }
   425   assert(monitor_count() == incoming->monitor_count(), "monitors must match");
   427   if (stack_size() == -1) {
   428     set_stack_size(incoming->stack_size());
   429     Cell limit = limit_cell();
   430     #ifdef ASSERT
   431     { for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
   432         assert(type_at(c) == top_type(), "");
   433     } }
   434     #endif
   435     // Make a simple copy of the incoming state.
   436     for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
   437       set_type_at(c, incoming->type_at(c));
   438     }
   439     return true;  // it is always different the first time
   440   }
   441 #ifdef ASSERT
   442   if (stack_size() != incoming->stack_size()) {
   443     _outer->method()->print_codes();
   444     tty->print_cr("!!!! Stack size conflict");
   445     tty->print_cr("Current state:");
   446     print_on(tty);
   447     tty->print_cr("Incoming state:");
   448     ((StateVector*)incoming)->print_on(tty);
   449   }
   450 #endif
   451   assert(stack_size() == incoming->stack_size(), "sanity");
   453   bool different = false;
   454   Cell limit = limit_cell();
   455   for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
   456     ciType* t1 = type_at(c);
   457     ciType* t2 = incoming->type_at(c);
   458     if (!t1->equals(t2)) {
   459       ciType* new_type = type_meet(t1, t2);
   460       if (!t1->equals(new_type)) {
   461         set_type_at(c, new_type);
   462         different = true;
   463       }
   464     }
   465   }
   466   return different;
   467 }
   469 // ------------------------------------------------------------------
   470 // ciTypeFlow::StateVector::meet_exception
   471 //
   472 // Meets this StateVector with another, destructively modifying this
   473 // one.  The incoming state is coming via an exception.  Returns true
   474 // if any modification takes place.
   475 bool ciTypeFlow::StateVector::meet_exception(ciInstanceKlass* exc,
   476                                      const ciTypeFlow::StateVector* incoming) {
   477   if (monitor_count() == -1) {
   478     set_monitor_count(incoming->monitor_count());
   479   }
   480   assert(monitor_count() == incoming->monitor_count(), "monitors must match");
   482   if (stack_size() == -1) {
   483     set_stack_size(1);
   484   }
   486   assert(stack_size() ==  1, "must have one-element stack");
   488   bool different = false;
   490   // Meet locals from incoming array.
   491   Cell limit = local(_outer->max_locals()-1);
   492   for (Cell c = start_cell(); c <= limit; c = next_cell(c)) {
   493     ciType* t1 = type_at(c);
   494     ciType* t2 = incoming->type_at(c);
   495     if (!t1->equals(t2)) {
   496       ciType* new_type = type_meet(t1, t2);
   497       if (!t1->equals(new_type)) {
   498         set_type_at(c, new_type);
   499         different = true;
   500       }
   501     }
   502   }
   504   // Handle stack separately.  When an exception occurs, the
   505   // only stack entry is the exception instance.
   506   ciType* tos_type = type_at_tos();
   507   if (!tos_type->equals(exc)) {
   508     ciType* new_type = type_meet(tos_type, exc);
   509     if (!tos_type->equals(new_type)) {
   510       set_type_at_tos(new_type);
   511       different = true;
   512     }
   513   }
   515   return different;
   516 }
   518 // ------------------------------------------------------------------
   519 // ciTypeFlow::StateVector::push_translate
   520 void ciTypeFlow::StateVector::push_translate(ciType* type) {
   521   BasicType basic_type = type->basic_type();
   522   if (basic_type == T_BOOLEAN || basic_type == T_CHAR ||
   523       basic_type == T_BYTE    || basic_type == T_SHORT) {
   524     push_int();
   525   } else {
   526     push(type);
   527     if (type->is_two_word()) {
   528       push(half_type(type));
   529     }
   530   }
   531 }
   533 // ------------------------------------------------------------------
   534 // ciTypeFlow::StateVector::do_aaload
   535 void ciTypeFlow::StateVector::do_aaload(ciBytecodeStream* str) {
   536   pop_int();
   537   ciObjArrayKlass* array_klass = pop_objArray();
   538   if (array_klass == NULL) {
   539     // Did aaload on a null reference; push a null and ignore the exception.
   540     // This instruction will never continue normally.  All we have to do
   541     // is report a value that will meet correctly with any downstream
   542     // reference types on paths that will truly be executed.  This null type
   543     // meets with any reference type to yield that same reference type.
   544     // (The compiler will generate an unconditional exception here.)
   545     push(null_type());
   546     return;
   547   }
   548   if (!array_klass->is_loaded()) {
   549     // Only fails for some -Xcomp runs
   550     trap(str, array_klass,
   551          Deoptimization::make_trap_request
   552          (Deoptimization::Reason_unloaded,
   553           Deoptimization::Action_reinterpret));
   554     return;
   555   }
   556   ciKlass* element_klass = array_klass->element_klass();
   557   if (!element_klass->is_loaded() && element_klass->is_instance_klass()) {
   558     Untested("unloaded array element class in ciTypeFlow");
   559     trap(str, element_klass,
   560          Deoptimization::make_trap_request
   561          (Deoptimization::Reason_unloaded,
   562           Deoptimization::Action_reinterpret));
   563   } else {
   564     push_object(element_klass);
   565   }
   566 }
   569 // ------------------------------------------------------------------
   570 // ciTypeFlow::StateVector::do_checkcast
   571 void ciTypeFlow::StateVector::do_checkcast(ciBytecodeStream* str) {
   572   bool will_link;
   573   ciKlass* klass = str->get_klass(will_link);
   574   if (!will_link) {
   575     // VM's interpreter will not load 'klass' if object is NULL.
   576     // Type flow after this block may still be needed in two situations:
   577     // 1) C2 uses do_null_assert() and continues compilation for later blocks
   578     // 2) C2 does an OSR compile in a later block (see bug 4778368).
   579     pop_object();
   580     do_null_assert(klass);
   581   } else {
   582     pop_object();
   583     push_object(klass);
   584   }
   585 }
   587 // ------------------------------------------------------------------
   588 // ciTypeFlow::StateVector::do_getfield
   589 void ciTypeFlow::StateVector::do_getfield(ciBytecodeStream* str) {
   590   // could add assert here for type of object.
   591   pop_object();
   592   do_getstatic(str);
   593 }
   595 // ------------------------------------------------------------------
   596 // ciTypeFlow::StateVector::do_getstatic
   597 void ciTypeFlow::StateVector::do_getstatic(ciBytecodeStream* str) {
   598   bool will_link;
   599   ciField* field = str->get_field(will_link);
   600   if (!will_link) {
   601     trap(str, field->holder(), str->get_field_holder_index());
   602   } else {
   603     ciType* field_type = field->type();
   604     if (!field_type->is_loaded()) {
   605       // Normally, we need the field's type to be loaded if we are to
   606       // do anything interesting with its value.
   607       // We used to do this:  trap(str, str->get_field_signature_index());
   608       //
   609       // There is one good reason not to trap here.  Execution can
   610       // get past this "getfield" or "getstatic" if the value of
   611       // the field is null.  As long as the value is null, the class
   612       // does not need to be loaded!  The compiler must assume that
   613       // the value of the unloaded class reference is null; if the code
   614       // ever sees a non-null value, loading has occurred.
   615       //
   616       // This actually happens often enough to be annoying.  If the
   617       // compiler throws an uncommon trap at this bytecode, you can
   618       // get an endless loop of recompilations, when all the code
   619       // needs to do is load a series of null values.  Also, a trap
   620       // here can make an OSR entry point unreachable, triggering the
   621       // assert on non_osr_block in ciTypeFlow::get_start_state.
   622       // (See bug 4379915.)
   623       do_null_assert(field_type->as_klass());
   624     } else {
   625       push_translate(field_type);
   626     }
   627   }
   628 }
   630 // ------------------------------------------------------------------
   631 // ciTypeFlow::StateVector::do_invoke
   632 void ciTypeFlow::StateVector::do_invoke(ciBytecodeStream* str,
   633                                         bool has_receiver) {
   634   bool will_link;
   635   ciMethod* method = str->get_method(will_link);
   636   if (!will_link) {
   637     // We weren't able to find the method.
   638     if (str->cur_bc() == Bytecodes::_invokedynamic) {
   639       trap(str, NULL,
   640            Deoptimization::make_trap_request
   641            (Deoptimization::Reason_uninitialized,
   642             Deoptimization::Action_reinterpret));
   643     } else {
   644       ciKlass* unloaded_holder = method->holder();
   645       trap(str, unloaded_holder, str->get_method_holder_index());
   646     }
   647   } else {
   648     ciSignature* signature = method->signature();
   649     ciSignatureStream sigstr(signature);
   650     int arg_size = signature->size();
   651     int stack_base = stack_size() - arg_size;
   652     int i = 0;
   653     for( ; !sigstr.at_return_type(); sigstr.next()) {
   654       ciType* type = sigstr.type();
   655       ciType* stack_type = type_at(stack(stack_base + i++));
   656       // Do I want to check this type?
   657       // assert(stack_type->is_subtype_of(type), "bad type for field value");
   658       if (type->is_two_word()) {
   659         ciType* stack_type2 = type_at(stack(stack_base + i++));
   660         assert(stack_type2->equals(half_type(type)), "must be 2nd half");
   661       }
   662     }
   663     assert(arg_size == i, "must match");
   664     for (int j = 0; j < arg_size; j++) {
   665       pop();
   666     }
   667     if (has_receiver) {
   668       // Check this?
   669       pop_object();
   670     }
   671     assert(!sigstr.is_done(), "must have return type");
   672     ciType* return_type = sigstr.type();
   673     if (!return_type->is_void()) {
   674       if (!return_type->is_loaded()) {
   675         // As in do_getstatic(), generally speaking, we need the return type to
   676         // be loaded if we are to do anything interesting with its value.
   677         // We used to do this:  trap(str, str->get_method_signature_index());
   678         //
   679         // We do not trap here since execution can get past this invoke if
   680         // the return value is null.  As long as the value is null, the class
   681         // does not need to be loaded!  The compiler must assume that
   682         // the value of the unloaded class reference is null; if the code
   683         // ever sees a non-null value, loading has occurred.
   684         //
   685         // See do_getstatic() for similar explanation, as well as bug 4684993.
   686         do_null_assert(return_type->as_klass());
   687       } else {
   688         push_translate(return_type);
   689       }
   690     }
   691   }
   692 }
   694 // ------------------------------------------------------------------
   695 // ciTypeFlow::StateVector::do_jsr
   696 void ciTypeFlow::StateVector::do_jsr(ciBytecodeStream* str) {
   697   push(ciReturnAddress::make(str->next_bci()));
   698 }
   700 // ------------------------------------------------------------------
   701 // ciTypeFlow::StateVector::do_ldc
   702 void ciTypeFlow::StateVector::do_ldc(ciBytecodeStream* str) {
   703   ciConstant con = str->get_constant();
   704   BasicType basic_type = con.basic_type();
   705   if (basic_type == T_ILLEGAL) {
   706     // OutOfMemoryError in the CI while loading constant
   707     push_null();
   708     outer()->record_failure("ldc did not link");
   709     return;
   710   }
   711   if (basic_type == T_OBJECT || basic_type == T_ARRAY) {
   712     ciObject* obj = con.as_object();
   713     if (obj->is_null_object()) {
   714       push_null();
   715     } else if (obj->is_klass()) {
   716       // The type of ldc <class> is java.lang.Class
   717       push_object(outer()->env()->Class_klass());
   718     } else {
   719       push_object(obj->klass());
   720     }
   721   } else {
   722     push_translate(ciType::make(basic_type));
   723   }
   724 }
   726 // ------------------------------------------------------------------
   727 // ciTypeFlow::StateVector::do_multianewarray
   728 void ciTypeFlow::StateVector::do_multianewarray(ciBytecodeStream* str) {
   729   int dimensions = str->get_dimensions();
   730   bool will_link;
   731   ciArrayKlass* array_klass = str->get_klass(will_link)->as_array_klass();
   732   if (!will_link) {
   733     trap(str, array_klass, str->get_klass_index());
   734   } else {
   735     for (int i = 0; i < dimensions; i++) {
   736       pop_int();
   737     }
   738     push_object(array_klass);
   739   }
   740 }
   742 // ------------------------------------------------------------------
   743 // ciTypeFlow::StateVector::do_new
   744 void ciTypeFlow::StateVector::do_new(ciBytecodeStream* str) {
   745   bool will_link;
   746   ciKlass* klass = str->get_klass(will_link);
   747   if (!will_link || str->is_unresolved_klass()) {
   748     trap(str, klass, str->get_klass_index());
   749   } else {
   750     push_object(klass);
   751   }
   752 }
   754 // ------------------------------------------------------------------
   755 // ciTypeFlow::StateVector::do_newarray
   756 void ciTypeFlow::StateVector::do_newarray(ciBytecodeStream* str) {
   757   pop_int();
   758   ciKlass* klass = ciTypeArrayKlass::make((BasicType)str->get_index());
   759   push_object(klass);
   760 }
   762 // ------------------------------------------------------------------
   763 // ciTypeFlow::StateVector::do_putfield
   764 void ciTypeFlow::StateVector::do_putfield(ciBytecodeStream* str) {
   765   do_putstatic(str);
   766   if (_trap_bci != -1)  return;  // unloaded field holder, etc.
   767   // could add assert here for type of object.
   768   pop_object();
   769 }
   771 // ------------------------------------------------------------------
   772 // ciTypeFlow::StateVector::do_putstatic
   773 void ciTypeFlow::StateVector::do_putstatic(ciBytecodeStream* str) {
   774   bool will_link;
   775   ciField* field = str->get_field(will_link);
   776   if (!will_link) {
   777     trap(str, field->holder(), str->get_field_holder_index());
   778   } else {
   779     ciType* field_type = field->type();
   780     ciType* type = pop_value();
   781     // Do I want to check this type?
   782     //      assert(type->is_subtype_of(field_type), "bad type for field value");
   783     if (field_type->is_two_word()) {
   784       ciType* type2 = pop_value();
   785       assert(type2->is_two_word(), "must be 2nd half");
   786       assert(type == half_type(type2), "must be 2nd half");
   787     }
   788   }
   789 }
   791 // ------------------------------------------------------------------
   792 // ciTypeFlow::StateVector::do_ret
   793 void ciTypeFlow::StateVector::do_ret(ciBytecodeStream* str) {
   794   Cell index = local(str->get_index());
   796   ciType* address = type_at(index);
   797   assert(address->is_return_address(), "bad return address");
   798   set_type_at(index, bottom_type());
   799 }
   801 // ------------------------------------------------------------------
   802 // ciTypeFlow::StateVector::trap
   803 //
   804 // Stop interpretation of this path with a trap.
   805 void ciTypeFlow::StateVector::trap(ciBytecodeStream* str, ciKlass* klass, int index) {
   806   _trap_bci = str->cur_bci();
   807   _trap_index = index;
   809   // Log information about this trap:
   810   CompileLog* log = outer()->env()->log();
   811   if (log != NULL) {
   812     int mid = log->identify(outer()->method());
   813     int kid = (klass == NULL)? -1: log->identify(klass);
   814     log->begin_elem("uncommon_trap method='%d' bci='%d'", mid, str->cur_bci());
   815     char buf[100];
   816     log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
   817                                                           index));
   818     if (kid >= 0)
   819       log->print(" klass='%d'", kid);
   820     log->end_elem();
   821   }
   822 }
   824 // ------------------------------------------------------------------
   825 // ciTypeFlow::StateVector::do_null_assert
   826 // Corresponds to graphKit::do_null_assert.
   827 void ciTypeFlow::StateVector::do_null_assert(ciKlass* unloaded_klass) {
   828   if (unloaded_klass->is_loaded()) {
   829     // We failed to link, but we can still compute with this class,
   830     // since it is loaded somewhere.  The compiler will uncommon_trap
   831     // if the object is not null, but the typeflow pass can not assume
   832     // that the object will be null, otherwise it may incorrectly tell
   833     // the parser that an object is known to be null. 4761344, 4807707
   834     push_object(unloaded_klass);
   835   } else {
   836     // The class is not loaded anywhere.  It is safe to model the
   837     // null in the typestates, because we can compile in a null check
   838     // which will deoptimize us if someone manages to load the
   839     // class later.
   840     push_null();
   841   }
   842 }
   845 // ------------------------------------------------------------------
   846 // ciTypeFlow::StateVector::apply_one_bytecode
   847 //
   848 // Apply the effect of one bytecode to this StateVector
   849 bool ciTypeFlow::StateVector::apply_one_bytecode(ciBytecodeStream* str) {
   850   _trap_bci = -1;
   851   _trap_index = 0;
   853   if (CITraceTypeFlow) {
   854     tty->print_cr(">> Interpreting bytecode %d:%s", str->cur_bci(),
   855                   Bytecodes::name(str->cur_bc()));
   856   }
   858   switch(str->cur_bc()) {
   859   case Bytecodes::_aaload: do_aaload(str);                       break;
   861   case Bytecodes::_aastore:
   862     {
   863       pop_object();
   864       pop_int();
   865       pop_objArray();
   866       break;
   867     }
   868   case Bytecodes::_aconst_null:
   869     {
   870       push_null();
   871       break;
   872     }
   873   case Bytecodes::_aload:   load_local_object(str->get_index());    break;
   874   case Bytecodes::_aload_0: load_local_object(0);                   break;
   875   case Bytecodes::_aload_1: load_local_object(1);                   break;
   876   case Bytecodes::_aload_2: load_local_object(2);                   break;
   877   case Bytecodes::_aload_3: load_local_object(3);                   break;
   879   case Bytecodes::_anewarray:
   880     {
   881       pop_int();
   882       bool will_link;
   883       ciKlass* element_klass = str->get_klass(will_link);
   884       if (!will_link) {
   885         trap(str, element_klass, str->get_klass_index());
   886       } else {
   887         push_object(ciObjArrayKlass::make(element_klass));
   888       }
   889       break;
   890     }
   891   case Bytecodes::_areturn:
   892   case Bytecodes::_ifnonnull:
   893   case Bytecodes::_ifnull:
   894     {
   895       pop_object();
   896       break;
   897     }
   898   case Bytecodes::_monitorenter:
   899     {
   900       pop_object();
   901       set_monitor_count(monitor_count() + 1);
   902       break;
   903     }
   904   case Bytecodes::_monitorexit:
   905     {
   906       pop_object();
   907       assert(monitor_count() > 0, "must be a monitor to exit from");
   908       set_monitor_count(monitor_count() - 1);
   909       break;
   910     }
   911   case Bytecodes::_arraylength:
   912     {
   913       pop_array();
   914       push_int();
   915       break;
   916     }
   917   case Bytecodes::_astore:   store_local_object(str->get_index());  break;
   918   case Bytecodes::_astore_0: store_local_object(0);                 break;
   919   case Bytecodes::_astore_1: store_local_object(1);                 break;
   920   case Bytecodes::_astore_2: store_local_object(2);                 break;
   921   case Bytecodes::_astore_3: store_local_object(3);                 break;
   923   case Bytecodes::_athrow:
   924     {
   925       NEEDS_CLEANUP;
   926       pop_object();
   927       break;
   928     }
   929   case Bytecodes::_baload:
   930   case Bytecodes::_caload:
   931   case Bytecodes::_iaload:
   932   case Bytecodes::_saload:
   933     {
   934       pop_int();
   935       ciTypeArrayKlass* array_klass = pop_typeArray();
   936       // Put assert here for right type?
   937       push_int();
   938       break;
   939     }
   940   case Bytecodes::_bastore:
   941   case Bytecodes::_castore:
   942   case Bytecodes::_iastore:
   943   case Bytecodes::_sastore:
   944     {
   945       pop_int();
   946       pop_int();
   947       pop_typeArray();
   948       // assert here?
   949       break;
   950     }
   951   case Bytecodes::_bipush:
   952   case Bytecodes::_iconst_m1:
   953   case Bytecodes::_iconst_0:
   954   case Bytecodes::_iconst_1:
   955   case Bytecodes::_iconst_2:
   956   case Bytecodes::_iconst_3:
   957   case Bytecodes::_iconst_4:
   958   case Bytecodes::_iconst_5:
   959   case Bytecodes::_sipush:
   960     {
   961       push_int();
   962       break;
   963     }
   964   case Bytecodes::_checkcast: do_checkcast(str);                  break;
   966   case Bytecodes::_d2f:
   967     {
   968       pop_double();
   969       push_float();
   970       break;
   971     }
   972   case Bytecodes::_d2i:
   973     {
   974       pop_double();
   975       push_int();
   976       break;
   977     }
   978   case Bytecodes::_d2l:
   979     {
   980       pop_double();
   981       push_long();
   982       break;
   983     }
   984   case Bytecodes::_dadd:
   985   case Bytecodes::_ddiv:
   986   case Bytecodes::_dmul:
   987   case Bytecodes::_drem:
   988   case Bytecodes::_dsub:
   989     {
   990       pop_double();
   991       pop_double();
   992       push_double();
   993       break;
   994     }
   995   case Bytecodes::_daload:
   996     {
   997       pop_int();
   998       ciTypeArrayKlass* array_klass = pop_typeArray();
   999       // Put assert here for right type?
  1000       push_double();
  1001       break;
  1003   case Bytecodes::_dastore:
  1005       pop_double();
  1006       pop_int();
  1007       pop_typeArray();
  1008       // assert here?
  1009       break;
  1011   case Bytecodes::_dcmpg:
  1012   case Bytecodes::_dcmpl:
  1014       pop_double();
  1015       pop_double();
  1016       push_int();
  1017       break;
  1019   case Bytecodes::_dconst_0:
  1020   case Bytecodes::_dconst_1:
  1022       push_double();
  1023       break;
  1025   case Bytecodes::_dload:   load_local_double(str->get_index());    break;
  1026   case Bytecodes::_dload_0: load_local_double(0);                   break;
  1027   case Bytecodes::_dload_1: load_local_double(1);                   break;
  1028   case Bytecodes::_dload_2: load_local_double(2);                   break;
  1029   case Bytecodes::_dload_3: load_local_double(3);                   break;
  1031   case Bytecodes::_dneg:
  1033       pop_double();
  1034       push_double();
  1035       break;
  1037   case Bytecodes::_dreturn:
  1039       pop_double();
  1040       break;
  1042   case Bytecodes::_dstore:   store_local_double(str->get_index());  break;
  1043   case Bytecodes::_dstore_0: store_local_double(0);                 break;
  1044   case Bytecodes::_dstore_1: store_local_double(1);                 break;
  1045   case Bytecodes::_dstore_2: store_local_double(2);                 break;
  1046   case Bytecodes::_dstore_3: store_local_double(3);                 break;
  1048   case Bytecodes::_dup:
  1050       push(type_at_tos());
  1051       break;
  1053   case Bytecodes::_dup_x1:
  1055       ciType* value1 = pop_value();
  1056       ciType* value2 = pop_value();
  1057       push(value1);
  1058       push(value2);
  1059       push(value1);
  1060       break;
  1062   case Bytecodes::_dup_x2:
  1064       ciType* value1 = pop_value();
  1065       ciType* value2 = pop_value();
  1066       ciType* value3 = pop_value();
  1067       push(value1);
  1068       push(value3);
  1069       push(value2);
  1070       push(value1);
  1071       break;
  1073   case Bytecodes::_dup2:
  1075       ciType* value1 = pop_value();
  1076       ciType* value2 = pop_value();
  1077       push(value2);
  1078       push(value1);
  1079       push(value2);
  1080       push(value1);
  1081       break;
  1083   case Bytecodes::_dup2_x1:
  1085       ciType* value1 = pop_value();
  1086       ciType* value2 = pop_value();
  1087       ciType* value3 = pop_value();
  1088       push(value2);
  1089       push(value1);
  1090       push(value3);
  1091       push(value2);
  1092       push(value1);
  1093       break;
  1095   case Bytecodes::_dup2_x2:
  1097       ciType* value1 = pop_value();
  1098       ciType* value2 = pop_value();
  1099       ciType* value3 = pop_value();
  1100       ciType* value4 = pop_value();
  1101       push(value2);
  1102       push(value1);
  1103       push(value4);
  1104       push(value3);
  1105       push(value2);
  1106       push(value1);
  1107       break;
  1109   case Bytecodes::_f2d:
  1111       pop_float();
  1112       push_double();
  1113       break;
  1115   case Bytecodes::_f2i:
  1117       pop_float();
  1118       push_int();
  1119       break;
  1121   case Bytecodes::_f2l:
  1123       pop_float();
  1124       push_long();
  1125       break;
  1127   case Bytecodes::_fadd:
  1128   case Bytecodes::_fdiv:
  1129   case Bytecodes::_fmul:
  1130   case Bytecodes::_frem:
  1131   case Bytecodes::_fsub:
  1133       pop_float();
  1134       pop_float();
  1135       push_float();
  1136       break;
  1138   case Bytecodes::_faload:
  1140       pop_int();
  1141       ciTypeArrayKlass* array_klass = pop_typeArray();
  1142       // Put assert here.
  1143       push_float();
  1144       break;
  1146   case Bytecodes::_fastore:
  1148       pop_float();
  1149       pop_int();
  1150       ciTypeArrayKlass* array_klass = pop_typeArray();
  1151       // Put assert here.
  1152       break;
  1154   case Bytecodes::_fcmpg:
  1155   case Bytecodes::_fcmpl:
  1157       pop_float();
  1158       pop_float();
  1159       push_int();
  1160       break;
  1162   case Bytecodes::_fconst_0:
  1163   case Bytecodes::_fconst_1:
  1164   case Bytecodes::_fconst_2:
  1166       push_float();
  1167       break;
  1169   case Bytecodes::_fload:   load_local_float(str->get_index());     break;
  1170   case Bytecodes::_fload_0: load_local_float(0);                    break;
  1171   case Bytecodes::_fload_1: load_local_float(1);                    break;
  1172   case Bytecodes::_fload_2: load_local_float(2);                    break;
  1173   case Bytecodes::_fload_3: load_local_float(3);                    break;
  1175   case Bytecodes::_fneg:
  1177       pop_float();
  1178       push_float();
  1179       break;
  1181   case Bytecodes::_freturn:
  1183       pop_float();
  1184       break;
  1186   case Bytecodes::_fstore:    store_local_float(str->get_index());   break;
  1187   case Bytecodes::_fstore_0:  store_local_float(0);                  break;
  1188   case Bytecodes::_fstore_1:  store_local_float(1);                  break;
  1189   case Bytecodes::_fstore_2:  store_local_float(2);                  break;
  1190   case Bytecodes::_fstore_3:  store_local_float(3);                  break;
  1192   case Bytecodes::_getfield:  do_getfield(str);                      break;
  1193   case Bytecodes::_getstatic: do_getstatic(str);                     break;
  1195   case Bytecodes::_goto:
  1196   case Bytecodes::_goto_w:
  1197   case Bytecodes::_nop:
  1198   case Bytecodes::_return:
  1200       // do nothing.
  1201       break;
  1203   case Bytecodes::_i2b:
  1204   case Bytecodes::_i2c:
  1205   case Bytecodes::_i2s:
  1206   case Bytecodes::_ineg:
  1208       pop_int();
  1209       push_int();
  1210       break;
  1212   case Bytecodes::_i2d:
  1214       pop_int();
  1215       push_double();
  1216       break;
  1218   case Bytecodes::_i2f:
  1220       pop_int();
  1221       push_float();
  1222       break;
  1224   case Bytecodes::_i2l:
  1226       pop_int();
  1227       push_long();
  1228       break;
  1230   case Bytecodes::_iadd:
  1231   case Bytecodes::_iand:
  1232   case Bytecodes::_idiv:
  1233   case Bytecodes::_imul:
  1234   case Bytecodes::_ior:
  1235   case Bytecodes::_irem:
  1236   case Bytecodes::_ishl:
  1237   case Bytecodes::_ishr:
  1238   case Bytecodes::_isub:
  1239   case Bytecodes::_iushr:
  1240   case Bytecodes::_ixor:
  1242       pop_int();
  1243       pop_int();
  1244       push_int();
  1245       break;
  1247   case Bytecodes::_if_acmpeq:
  1248   case Bytecodes::_if_acmpne:
  1250       pop_object();
  1251       pop_object();
  1252       break;
  1254   case Bytecodes::_if_icmpeq:
  1255   case Bytecodes::_if_icmpge:
  1256   case Bytecodes::_if_icmpgt:
  1257   case Bytecodes::_if_icmple:
  1258   case Bytecodes::_if_icmplt:
  1259   case Bytecodes::_if_icmpne:
  1261       pop_int();
  1262       pop_int();
  1263       break;
  1265   case Bytecodes::_ifeq:
  1266   case Bytecodes::_ifle:
  1267   case Bytecodes::_iflt:
  1268   case Bytecodes::_ifge:
  1269   case Bytecodes::_ifgt:
  1270   case Bytecodes::_ifne:
  1271   case Bytecodes::_ireturn:
  1272   case Bytecodes::_lookupswitch:
  1273   case Bytecodes::_tableswitch:
  1275       pop_int();
  1276       break;
  1278   case Bytecodes::_iinc:
  1280       int lnum = str->get_index();
  1281       check_int(local(lnum));
  1282       store_to_local(lnum);
  1283       break;
  1285   case Bytecodes::_iload:   load_local_int(str->get_index()); break;
  1286   case Bytecodes::_iload_0: load_local_int(0);                      break;
  1287   case Bytecodes::_iload_1: load_local_int(1);                      break;
  1288   case Bytecodes::_iload_2: load_local_int(2);                      break;
  1289   case Bytecodes::_iload_3: load_local_int(3);                      break;
  1291   case Bytecodes::_instanceof:
  1293       // Check for uncommon trap:
  1294       do_checkcast(str);
  1295       pop_object();
  1296       push_int();
  1297       break;
  1299   case Bytecodes::_invokeinterface: do_invoke(str, true);           break;
  1300   case Bytecodes::_invokespecial:   do_invoke(str, true);           break;
  1301   case Bytecodes::_invokestatic:    do_invoke(str, false);          break;
  1302   case Bytecodes::_invokevirtual:   do_invoke(str, true);           break;
  1303   case Bytecodes::_invokedynamic:   do_invoke(str, false);          break;
  1305   case Bytecodes::_istore:   store_local_int(str->get_index());     break;
  1306   case Bytecodes::_istore_0: store_local_int(0);                    break;
  1307   case Bytecodes::_istore_1: store_local_int(1);                    break;
  1308   case Bytecodes::_istore_2: store_local_int(2);                    break;
  1309   case Bytecodes::_istore_3: store_local_int(3);                    break;
  1311   case Bytecodes::_jsr:
  1312   case Bytecodes::_jsr_w: do_jsr(str);                              break;
  1314   case Bytecodes::_l2d:
  1316       pop_long();
  1317       push_double();
  1318       break;
  1320   case Bytecodes::_l2f:
  1322       pop_long();
  1323       push_float();
  1324       break;
  1326   case Bytecodes::_l2i:
  1328       pop_long();
  1329       push_int();
  1330       break;
  1332   case Bytecodes::_ladd:
  1333   case Bytecodes::_land:
  1334   case Bytecodes::_ldiv:
  1335   case Bytecodes::_lmul:
  1336   case Bytecodes::_lor:
  1337   case Bytecodes::_lrem:
  1338   case Bytecodes::_lsub:
  1339   case Bytecodes::_lxor:
  1341       pop_long();
  1342       pop_long();
  1343       push_long();
  1344       break;
  1346   case Bytecodes::_laload:
  1348       pop_int();
  1349       ciTypeArrayKlass* array_klass = pop_typeArray();
  1350       // Put assert here for right type?
  1351       push_long();
  1352       break;
  1354   case Bytecodes::_lastore:
  1356       pop_long();
  1357       pop_int();
  1358       pop_typeArray();
  1359       // assert here?
  1360       break;
  1362   case Bytecodes::_lcmp:
  1364       pop_long();
  1365       pop_long();
  1366       push_int();
  1367       break;
  1369   case Bytecodes::_lconst_0:
  1370   case Bytecodes::_lconst_1:
  1372       push_long();
  1373       break;
  1375   case Bytecodes::_ldc:
  1376   case Bytecodes::_ldc_w:
  1377   case Bytecodes::_ldc2_w:
  1379       do_ldc(str);
  1380       break;
  1383   case Bytecodes::_lload:   load_local_long(str->get_index());      break;
  1384   case Bytecodes::_lload_0: load_local_long(0);                     break;
  1385   case Bytecodes::_lload_1: load_local_long(1);                     break;
  1386   case Bytecodes::_lload_2: load_local_long(2);                     break;
  1387   case Bytecodes::_lload_3: load_local_long(3);                     break;
  1389   case Bytecodes::_lneg:
  1391       pop_long();
  1392       push_long();
  1393       break;
  1395   case Bytecodes::_lreturn:
  1397       pop_long();
  1398       break;
  1400   case Bytecodes::_lshl:
  1401   case Bytecodes::_lshr:
  1402   case Bytecodes::_lushr:
  1404       pop_int();
  1405       pop_long();
  1406       push_long();
  1407       break;
  1409   case Bytecodes::_lstore:   store_local_long(str->get_index());    break;
  1410   case Bytecodes::_lstore_0: store_local_long(0);                   break;
  1411   case Bytecodes::_lstore_1: store_local_long(1);                   break;
  1412   case Bytecodes::_lstore_2: store_local_long(2);                   break;
  1413   case Bytecodes::_lstore_3: store_local_long(3);                   break;
  1415   case Bytecodes::_multianewarray: do_multianewarray(str);          break;
  1417   case Bytecodes::_new:      do_new(str);                           break;
  1419   case Bytecodes::_newarray: do_newarray(str);                      break;
  1421   case Bytecodes::_pop:
  1423       pop();
  1424       break;
  1426   case Bytecodes::_pop2:
  1428       pop();
  1429       pop();
  1430       break;
  1433   case Bytecodes::_putfield:       do_putfield(str);                 break;
  1434   case Bytecodes::_putstatic:      do_putstatic(str);                break;
  1436   case Bytecodes::_ret: do_ret(str);                                 break;
  1438   case Bytecodes::_swap:
  1440       ciType* value1 = pop_value();
  1441       ciType* value2 = pop_value();
  1442       push(value1);
  1443       push(value2);
  1444       break;
  1446   case Bytecodes::_wide:
  1447   default:
  1449       // The iterator should skip this.
  1450       ShouldNotReachHere();
  1451       break;
  1455   if (CITraceTypeFlow) {
  1456     print_on(tty);
  1459   return (_trap_bci != -1);
  1462 #ifndef PRODUCT
  1463 // ------------------------------------------------------------------
  1464 // ciTypeFlow::StateVector::print_cell_on
  1465 void ciTypeFlow::StateVector::print_cell_on(outputStream* st, Cell c) const {
  1466   ciType* type = type_at(c);
  1467   if (type == top_type()) {
  1468     st->print("top");
  1469   } else if (type == bottom_type()) {
  1470     st->print("bottom");
  1471   } else if (type == null_type()) {
  1472     st->print("null");
  1473   } else if (type == long2_type()) {
  1474     st->print("long2");
  1475   } else if (type == double2_type()) {
  1476     st->print("double2");
  1477   } else if (is_int(type)) {
  1478     st->print("int");
  1479   } else if (is_long(type)) {
  1480     st->print("long");
  1481   } else if (is_float(type)) {
  1482     st->print("float");
  1483   } else if (is_double(type)) {
  1484     st->print("double");
  1485   } else if (type->is_return_address()) {
  1486     st->print("address(%d)", type->as_return_address()->bci());
  1487   } else {
  1488     if (type->is_klass()) {
  1489       type->as_klass()->name()->print_symbol_on(st);
  1490     } else {
  1491       st->print("UNEXPECTED TYPE");
  1492       type->print();
  1497 // ------------------------------------------------------------------
  1498 // ciTypeFlow::StateVector::print_on
  1499 void ciTypeFlow::StateVector::print_on(outputStream* st) const {
  1500   int num_locals   = _outer->max_locals();
  1501   int num_stack    = stack_size();
  1502   int num_monitors = monitor_count();
  1503   st->print_cr("  State : locals %d, stack %d, monitors %d", num_locals, num_stack, num_monitors);
  1504   if (num_stack >= 0) {
  1505     int i;
  1506     for (i = 0; i < num_locals; i++) {
  1507       st->print("    local %2d : ", i);
  1508       print_cell_on(st, local(i));
  1509       st->cr();
  1511     for (i = 0; i < num_stack; i++) {
  1512       st->print("    stack %2d : ", i);
  1513       print_cell_on(st, stack(i));
  1514       st->cr();
  1518 #endif
  1521 // ------------------------------------------------------------------
  1522 // ciTypeFlow::SuccIter::next
  1523 //
  1524 void ciTypeFlow::SuccIter::next() {
  1525   int succ_ct = _pred->successors()->length();
  1526   int next = _index + 1;
  1527   if (next < succ_ct) {
  1528     _index = next;
  1529     _succ = _pred->successors()->at(next);
  1530     return;
  1532   for (int i = next - succ_ct; i < _pred->exceptions()->length(); i++) {
  1533     // Do not compile any code for unloaded exception types.
  1534     // Following compiler passes are responsible for doing this also.
  1535     ciInstanceKlass* exception_klass = _pred->exc_klasses()->at(i);
  1536     if (exception_klass->is_loaded()) {
  1537       _index = next;
  1538       _succ = _pred->exceptions()->at(i);
  1539       return;
  1541     next++;
  1543   _index = -1;
  1544   _succ = NULL;
  1547 // ------------------------------------------------------------------
  1548 // ciTypeFlow::SuccIter::set_succ
  1549 //
  1550 void ciTypeFlow::SuccIter::set_succ(Block* succ) {
  1551   int succ_ct = _pred->successors()->length();
  1552   if (_index < succ_ct) {
  1553     _pred->successors()->at_put(_index, succ);
  1554   } else {
  1555     int idx = _index - succ_ct;
  1556     _pred->exceptions()->at_put(idx, succ);
  1560 // ciTypeFlow::Block
  1561 //
  1562 // A basic block.
  1564 // ------------------------------------------------------------------
  1565 // ciTypeFlow::Block::Block
  1566 ciTypeFlow::Block::Block(ciTypeFlow* outer,
  1567                          ciBlock *ciblk,
  1568                          ciTypeFlow::JsrSet* jsrs) {
  1569   _ciblock = ciblk;
  1570   _exceptions = NULL;
  1571   _exc_klasses = NULL;
  1572   _successors = NULL;
  1573   _state = new (outer->arena()) StateVector(outer);
  1574   JsrSet* new_jsrs =
  1575     new (outer->arena()) JsrSet(outer->arena(), jsrs->size());
  1576   jsrs->copy_into(new_jsrs);
  1577   _jsrs = new_jsrs;
  1578   _next = NULL;
  1579   _on_work_list = false;
  1580   _backedge_copy = false;
  1581   _exception_entry = false;
  1582   _trap_bci = -1;
  1583   _trap_index = 0;
  1584   df_init();
  1586   if (CITraceTypeFlow) {
  1587     tty->print_cr(">> Created new block");
  1588     print_on(tty);
  1591   assert(this->outer() == outer, "outer link set up");
  1592   assert(!outer->have_block_count(), "must not have mapped blocks yet");
  1595 // ------------------------------------------------------------------
  1596 // ciTypeFlow::Block::df_init
  1597 void ciTypeFlow::Block::df_init() {
  1598   _pre_order = -1; assert(!has_pre_order(), "");
  1599   _post_order = -1; assert(!has_post_order(), "");
  1600   _loop = NULL;
  1601   _irreducible_entry = false;
  1602   _rpo_next = NULL;
  1605 // ------------------------------------------------------------------
  1606 // ciTypeFlow::Block::successors
  1607 //
  1608 // Get the successors for this Block.
  1609 GrowableArray<ciTypeFlow::Block*>*
  1610 ciTypeFlow::Block::successors(ciBytecodeStream* str,
  1611                               ciTypeFlow::StateVector* state,
  1612                               ciTypeFlow::JsrSet* jsrs) {
  1613   if (_successors == NULL) {
  1614     if (CITraceTypeFlow) {
  1615       tty->print(">> Computing successors for block ");
  1616       print_value_on(tty);
  1617       tty->cr();
  1620     ciTypeFlow* analyzer = outer();
  1621     Arena* arena = analyzer->arena();
  1622     Block* block = NULL;
  1623     bool has_successor = !has_trap() &&
  1624                          (control() != ciBlock::fall_through_bci || limit() < analyzer->code_size());
  1625     if (!has_successor) {
  1626       _successors =
  1627         new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
  1628       // No successors
  1629     } else if (control() == ciBlock::fall_through_bci) {
  1630       assert(str->cur_bci() == limit(), "bad block end");
  1631       // This block simply falls through to the next.
  1632       _successors =
  1633         new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
  1635       Block* block = analyzer->block_at(limit(), _jsrs);
  1636       assert(_successors->length() == FALL_THROUGH, "");
  1637       _successors->append(block);
  1638     } else {
  1639       int current_bci = str->cur_bci();
  1640       int next_bci = str->next_bci();
  1641       int branch_bci = -1;
  1642       Block* target = NULL;
  1643       assert(str->next_bci() == limit(), "bad block end");
  1644       // This block is not a simple fall-though.  Interpret
  1645       // the current bytecode to find our successors.
  1646       switch (str->cur_bc()) {
  1647       case Bytecodes::_ifeq:         case Bytecodes::_ifne:
  1648       case Bytecodes::_iflt:         case Bytecodes::_ifge:
  1649       case Bytecodes::_ifgt:         case Bytecodes::_ifle:
  1650       case Bytecodes::_if_icmpeq:    case Bytecodes::_if_icmpne:
  1651       case Bytecodes::_if_icmplt:    case Bytecodes::_if_icmpge:
  1652       case Bytecodes::_if_icmpgt:    case Bytecodes::_if_icmple:
  1653       case Bytecodes::_if_acmpeq:    case Bytecodes::_if_acmpne:
  1654       case Bytecodes::_ifnull:       case Bytecodes::_ifnonnull:
  1655         // Our successors are the branch target and the next bci.
  1656         branch_bci = str->get_dest();
  1657         _successors =
  1658           new (arena) GrowableArray<Block*>(arena, 2, 0, NULL);
  1659         assert(_successors->length() == IF_NOT_TAKEN, "");
  1660         _successors->append(analyzer->block_at(next_bci, jsrs));
  1661         assert(_successors->length() == IF_TAKEN, "");
  1662         _successors->append(analyzer->block_at(branch_bci, jsrs));
  1663         break;
  1665       case Bytecodes::_goto:
  1666         branch_bci = str->get_dest();
  1667         _successors =
  1668           new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
  1669         assert(_successors->length() == GOTO_TARGET, "");
  1670         _successors->append(analyzer->block_at(branch_bci, jsrs));
  1671         break;
  1673       case Bytecodes::_jsr:
  1674         branch_bci = str->get_dest();
  1675         _successors =
  1676           new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
  1677         assert(_successors->length() == GOTO_TARGET, "");
  1678         _successors->append(analyzer->block_at(branch_bci, jsrs));
  1679         break;
  1681       case Bytecodes::_goto_w:
  1682       case Bytecodes::_jsr_w:
  1683         _successors =
  1684           new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
  1685         assert(_successors->length() == GOTO_TARGET, "");
  1686         _successors->append(analyzer->block_at(str->get_far_dest(), jsrs));
  1687         break;
  1689       case Bytecodes::_tableswitch:  {
  1690         Bytecode_tableswitch *tableswitch =
  1691           Bytecode_tableswitch_at(str->cur_bcp());
  1693         int len = tableswitch->length();
  1694         _successors =
  1695           new (arena) GrowableArray<Block*>(arena, len+1, 0, NULL);
  1696         int bci = current_bci + tableswitch->default_offset();
  1697         Block* block = analyzer->block_at(bci, jsrs);
  1698         assert(_successors->length() == SWITCH_DEFAULT, "");
  1699         _successors->append(block);
  1700         while (--len >= 0) {
  1701           int bci = current_bci + tableswitch->dest_offset_at(len);
  1702           block = analyzer->block_at(bci, jsrs);
  1703           assert(_successors->length() >= SWITCH_CASES, "");
  1704           _successors->append_if_missing(block);
  1706         break;
  1709       case Bytecodes::_lookupswitch: {
  1710         Bytecode_lookupswitch *lookupswitch =
  1711           Bytecode_lookupswitch_at(str->cur_bcp());
  1713         int npairs = lookupswitch->number_of_pairs();
  1714         _successors =
  1715           new (arena) GrowableArray<Block*>(arena, npairs+1, 0, NULL);
  1716         int bci = current_bci + lookupswitch->default_offset();
  1717         Block* block = analyzer->block_at(bci, jsrs);
  1718         assert(_successors->length() == SWITCH_DEFAULT, "");
  1719         _successors->append(block);
  1720         while(--npairs >= 0) {
  1721           LookupswitchPair *pair = lookupswitch->pair_at(npairs);
  1722           int bci = current_bci + pair->offset();
  1723           Block* block = analyzer->block_at(bci, jsrs);
  1724           assert(_successors->length() >= SWITCH_CASES, "");
  1725           _successors->append_if_missing(block);
  1727         break;
  1730       case Bytecodes::_athrow:     case Bytecodes::_ireturn:
  1731       case Bytecodes::_lreturn:    case Bytecodes::_freturn:
  1732       case Bytecodes::_dreturn:    case Bytecodes::_areturn:
  1733       case Bytecodes::_return:
  1734         _successors =
  1735           new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
  1736         // No successors
  1737         break;
  1739       case Bytecodes::_ret: {
  1740         _successors =
  1741           new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
  1743         Cell local = state->local(str->get_index());
  1744         ciType* return_address = state->type_at(local);
  1745         assert(return_address->is_return_address(), "verify: wrong type");
  1746         int bci = return_address->as_return_address()->bci();
  1747         assert(_successors->length() == GOTO_TARGET, "");
  1748         _successors->append(analyzer->block_at(bci, jsrs));
  1749         break;
  1752       case Bytecodes::_wide:
  1753       default:
  1754         ShouldNotReachHere();
  1755         break;
  1759   return _successors;
  1762 // ------------------------------------------------------------------
  1763 // ciTypeFlow::Block:compute_exceptions
  1764 //
  1765 // Compute the exceptional successors and types for this Block.
  1766 void ciTypeFlow::Block::compute_exceptions() {
  1767   assert(_exceptions == NULL && _exc_klasses == NULL, "repeat");
  1769   if (CITraceTypeFlow) {
  1770     tty->print(">> Computing exceptions for block ");
  1771     print_value_on(tty);
  1772     tty->cr();
  1775   ciTypeFlow* analyzer = outer();
  1776   Arena* arena = analyzer->arena();
  1778   // Any bci in the block will do.
  1779   ciExceptionHandlerStream str(analyzer->method(), start());
  1781   // Allocate our growable arrays.
  1782   int exc_count = str.count();
  1783   _exceptions = new (arena) GrowableArray<Block*>(arena, exc_count, 0, NULL);
  1784   _exc_klasses = new (arena) GrowableArray<ciInstanceKlass*>(arena, exc_count,
  1785                                                              0, NULL);
  1787   for ( ; !str.is_done(); str.next()) {
  1788     ciExceptionHandler* handler = str.handler();
  1789     int bci = handler->handler_bci();
  1790     ciInstanceKlass* klass = NULL;
  1791     if (bci == -1) {
  1792       // There is no catch all.  It is possible to exit the method.
  1793       break;
  1795     if (handler->is_catch_all()) {
  1796       klass = analyzer->env()->Throwable_klass();
  1797     } else {
  1798       klass = handler->catch_klass();
  1800     _exceptions->append(analyzer->block_at(bci, _jsrs));
  1801     _exc_klasses->append(klass);
  1805 // ------------------------------------------------------------------
  1806 // ciTypeFlow::Block::set_backedge_copy
  1807 // Use this only to make a pre-existing public block into a backedge copy.
  1808 void ciTypeFlow::Block::set_backedge_copy(bool z) {
  1809   assert(z || (z == is_backedge_copy()), "cannot make a backedge copy public");
  1810   _backedge_copy = z;
  1813 // ------------------------------------------------------------------
  1814 // ciTypeFlow::Block::is_clonable_exit
  1815 //
  1816 // At most 2 normal successors, one of which continues looping,
  1817 // and all exceptional successors must exit.
  1818 bool ciTypeFlow::Block::is_clonable_exit(ciTypeFlow::Loop* lp) {
  1819   int normal_cnt  = 0;
  1820   int in_loop_cnt = 0;
  1821   for (SuccIter iter(this); !iter.done(); iter.next()) {
  1822     Block* succ = iter.succ();
  1823     if (iter.is_normal_ctrl()) {
  1824       if (++normal_cnt > 2) return false;
  1825       if (lp->contains(succ->loop())) {
  1826         if (++in_loop_cnt > 1) return false;
  1828     } else {
  1829       if (lp->contains(succ->loop())) return false;
  1832   return in_loop_cnt == 1;
  1835 // ------------------------------------------------------------------
  1836 // ciTypeFlow::Block::looping_succ
  1837 //
  1838 ciTypeFlow::Block* ciTypeFlow::Block::looping_succ(ciTypeFlow::Loop* lp) {
  1839   assert(successors()->length() <= 2, "at most 2 normal successors");
  1840   for (SuccIter iter(this); !iter.done(); iter.next()) {
  1841     Block* succ = iter.succ();
  1842     if (lp->contains(succ->loop())) {
  1843       return succ;
  1846   return NULL;
  1849 #ifndef PRODUCT
  1850 // ------------------------------------------------------------------
  1851 // ciTypeFlow::Block::print_value_on
  1852 void ciTypeFlow::Block::print_value_on(outputStream* st) const {
  1853   if (has_pre_order()) st->print("#%-2d ", pre_order());
  1854   if (has_rpo())       st->print("rpo#%-2d ", rpo());
  1855   st->print("[%d - %d)", start(), limit());
  1856   if (is_loop_head()) st->print(" lphd");
  1857   if (is_irreducible_entry()) st->print(" irred");
  1858   if (_jsrs->size() > 0) { st->print("/");  _jsrs->print_on(st); }
  1859   if (is_backedge_copy())  st->print("/backedge_copy");
  1862 // ------------------------------------------------------------------
  1863 // ciTypeFlow::Block::print_on
  1864 void ciTypeFlow::Block::print_on(outputStream* st) const {
  1865   if ((Verbose || WizardMode)) {
  1866     outer()->method()->print_codes_on(start(), limit(), st);
  1868   st->print_cr("  ====================================================  ");
  1869   st->print ("  ");
  1870   print_value_on(st);
  1871   st->print(" Stored locals: "); def_locals()->print_on(st, outer()->method()->max_locals()); tty->cr();
  1872   if (loop() && loop()->parent() != NULL) {
  1873     st->print(" loops:");
  1874     Loop* lp = loop();
  1875     do {
  1876       st->print(" %d<-%d", lp->head()->pre_order(),lp->tail()->pre_order());
  1877       if (lp->is_irreducible()) st->print("(ir)");
  1878       lp = lp->parent();
  1879     } while (lp->parent() != NULL);
  1881   st->cr();
  1882   _state->print_on(st);
  1883   if (_successors == NULL) {
  1884     st->print_cr("  No successor information");
  1885   } else {
  1886     int num_successors = _successors->length();
  1887     st->print_cr("  Successors : %d", num_successors);
  1888     for (int i = 0; i < num_successors; i++) {
  1889       Block* successor = _successors->at(i);
  1890       st->print("    ");
  1891       successor->print_value_on(st);
  1892       st->cr();
  1895   if (_exceptions == NULL) {
  1896     st->print_cr("  No exception information");
  1897   } else {
  1898     int num_exceptions = _exceptions->length();
  1899     st->print_cr("  Exceptions : %d", num_exceptions);
  1900     for (int i = 0; i < num_exceptions; i++) {
  1901       Block* exc_succ = _exceptions->at(i);
  1902       ciInstanceKlass* exc_klass = _exc_klasses->at(i);
  1903       st->print("    ");
  1904       exc_succ->print_value_on(st);
  1905       st->print(" -- ");
  1906       exc_klass->name()->print_symbol_on(st);
  1907       st->cr();
  1910   if (has_trap()) {
  1911     st->print_cr("  Traps on %d with trap index %d", trap_bci(), trap_index());
  1913   st->print_cr("  ====================================================  ");
  1915 #endif
  1917 #ifndef PRODUCT
  1918 // ------------------------------------------------------------------
  1919 // ciTypeFlow::LocalSet::print_on
  1920 void ciTypeFlow::LocalSet::print_on(outputStream* st, int limit) const {
  1921   st->print("{");
  1922   for (int i = 0; i < max; i++) {
  1923     if (test(i)) st->print(" %d", i);
  1925   if (limit > max) {
  1926     st->print(" %d..%d ", max, limit);
  1928   st->print(" }");
  1930 #endif
  1932 // ciTypeFlow
  1933 //
  1934 // This is a pass over the bytecodes which computes the following:
  1935 //   basic block structure
  1936 //   interpreter type-states (a la the verifier)
  1938 // ------------------------------------------------------------------
  1939 // ciTypeFlow::ciTypeFlow
  1940 ciTypeFlow::ciTypeFlow(ciEnv* env, ciMethod* method, int osr_bci) {
  1941   _env = env;
  1942   _method = method;
  1943   _methodBlocks = method->get_method_blocks();
  1944   _max_locals = method->max_locals();
  1945   _max_stack = method->max_stack();
  1946   _code_size = method->code_size();
  1947   _has_irreducible_entry = false;
  1948   _osr_bci = osr_bci;
  1949   _failure_reason = NULL;
  1950   assert(start_bci() >= 0 && start_bci() < code_size() , "correct osr_bci argument");
  1951   _work_list = NULL;
  1953   _ciblock_count = _methodBlocks->num_blocks();
  1954   _idx_to_blocklist = NEW_ARENA_ARRAY(arena(), GrowableArray<Block*>*, _ciblock_count);
  1955   for (int i = 0; i < _ciblock_count; i++) {
  1956     _idx_to_blocklist[i] = NULL;
  1958   _block_map = NULL;  // until all blocks are seen
  1959   _jsr_count = 0;
  1960   _jsr_records = NULL;
  1963 // ------------------------------------------------------------------
  1964 // ciTypeFlow::work_list_next
  1965 //
  1966 // Get the next basic block from our work list.
  1967 ciTypeFlow::Block* ciTypeFlow::work_list_next() {
  1968   assert(!work_list_empty(), "work list must not be empty");
  1969   Block* next_block = _work_list;
  1970   _work_list = next_block->next();
  1971   next_block->set_next(NULL);
  1972   next_block->set_on_work_list(false);
  1973   return next_block;
  1976 // ------------------------------------------------------------------
  1977 // ciTypeFlow::add_to_work_list
  1978 //
  1979 // Add a basic block to our work list.
  1980 // List is sorted by decreasing postorder sort (same as increasing RPO)
  1981 void ciTypeFlow::add_to_work_list(ciTypeFlow::Block* block) {
  1982   assert(!block->is_on_work_list(), "must not already be on work list");
  1984   if (CITraceTypeFlow) {
  1985     tty->print(">> Adding block ");
  1986     block->print_value_on(tty);
  1987     tty->print_cr(" to the work list : ");
  1990   block->set_on_work_list(true);
  1992   // decreasing post order sort
  1994   Block* prev = NULL;
  1995   Block* current = _work_list;
  1996   int po = block->post_order();
  1997   while (current != NULL) {
  1998     if (!current->has_post_order() || po > current->post_order())
  1999       break;
  2000     prev = current;
  2001     current = current->next();
  2003   if (prev == NULL) {
  2004     block->set_next(_work_list);
  2005     _work_list = block;
  2006   } else {
  2007     block->set_next(current);
  2008     prev->set_next(block);
  2011   if (CITraceTypeFlow) {
  2012     tty->cr();
  2016 // ------------------------------------------------------------------
  2017 // ciTypeFlow::block_at
  2018 //
  2019 // Return the block beginning at bci which has a JsrSet compatible
  2020 // with jsrs.
  2021 ciTypeFlow::Block* ciTypeFlow::block_at(int bci, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
  2022   // First find the right ciBlock.
  2023   if (CITraceTypeFlow) {
  2024     tty->print(">> Requesting block for %d/", bci);
  2025     jsrs->print_on(tty);
  2026     tty->cr();
  2029   ciBlock* ciblk = _methodBlocks->block_containing(bci);
  2030   assert(ciblk->start_bci() == bci, "bad ciBlock boundaries");
  2031   Block* block = get_block_for(ciblk->index(), jsrs, option);
  2033   assert(block == NULL? (option == no_create): block->is_backedge_copy() == (option == create_backedge_copy), "create option consistent with result");
  2035   if (CITraceTypeFlow) {
  2036     if (block != NULL) {
  2037       tty->print(">> Found block ");
  2038       block->print_value_on(tty);
  2039       tty->cr();
  2040     } else {
  2041       tty->print_cr(">> No such block.");
  2045   return block;
  2048 // ------------------------------------------------------------------
  2049 // ciTypeFlow::make_jsr_record
  2050 //
  2051 // Make a JsrRecord for a given (entry, return) pair, if such a record
  2052 // does not already exist.
  2053 ciTypeFlow::JsrRecord* ciTypeFlow::make_jsr_record(int entry_address,
  2054                                                    int return_address) {
  2055   if (_jsr_records == NULL) {
  2056     _jsr_records = new (arena()) GrowableArray<JsrRecord*>(arena(),
  2057                                                            _jsr_count,
  2058                                                            0,
  2059                                                            NULL);
  2061   JsrRecord* record = NULL;
  2062   int len = _jsr_records->length();
  2063   for (int i = 0; i < len; i++) {
  2064     JsrRecord* record = _jsr_records->at(i);
  2065     if (record->entry_address() == entry_address &&
  2066         record->return_address() == return_address) {
  2067       return record;
  2071   record = new (arena()) JsrRecord(entry_address, return_address);
  2072   _jsr_records->append(record);
  2073   return record;
  2076 // ------------------------------------------------------------------
  2077 // ciTypeFlow::flow_exceptions
  2078 //
  2079 // Merge the current state into all exceptional successors at the
  2080 // current point in the code.
  2081 void ciTypeFlow::flow_exceptions(GrowableArray<ciTypeFlow::Block*>* exceptions,
  2082                                  GrowableArray<ciInstanceKlass*>* exc_klasses,
  2083                                  ciTypeFlow::StateVector* state) {
  2084   int len = exceptions->length();
  2085   assert(exc_klasses->length() == len, "must have same length");
  2086   for (int i = 0; i < len; i++) {
  2087     Block* block = exceptions->at(i);
  2088     ciInstanceKlass* exception_klass = exc_klasses->at(i);
  2090     if (!exception_klass->is_loaded()) {
  2091       // Do not compile any code for unloaded exception types.
  2092       // Following compiler passes are responsible for doing this also.
  2093       continue;
  2096     if (block->meet_exception(exception_klass, state)) {
  2097       // Block was modified and has PO.  Add it to the work list.
  2098       if (block->has_post_order() &&
  2099           !block->is_on_work_list()) {
  2100         add_to_work_list(block);
  2106 // ------------------------------------------------------------------
  2107 // ciTypeFlow::flow_successors
  2108 //
  2109 // Merge the current state into all successors at the current point
  2110 // in the code.
  2111 void ciTypeFlow::flow_successors(GrowableArray<ciTypeFlow::Block*>* successors,
  2112                                  ciTypeFlow::StateVector* state) {
  2113   int len = successors->length();
  2114   for (int i = 0; i < len; i++) {
  2115     Block* block = successors->at(i);
  2116     if (block->meet(state)) {
  2117       // Block was modified and has PO.  Add it to the work list.
  2118       if (block->has_post_order() &&
  2119           !block->is_on_work_list()) {
  2120         add_to_work_list(block);
  2126 // ------------------------------------------------------------------
  2127 // ciTypeFlow::can_trap
  2128 //
  2129 // Tells if a given instruction is able to generate an exception edge.
  2130 bool ciTypeFlow::can_trap(ciBytecodeStream& str) {
  2131   // Cf. GenerateOopMap::do_exception_edge.
  2132   if (!Bytecodes::can_trap(str.cur_bc()))  return false;
  2134   switch (str.cur_bc()) {
  2135     case Bytecodes::_ldc:
  2136     case Bytecodes::_ldc_w:
  2137     case Bytecodes::_ldc2_w:
  2138     case Bytecodes::_aload_0:
  2139       // These bytecodes can trap for rewriting.  We need to assume that
  2140       // they do not throw exceptions to make the monitor analysis work.
  2141       return false;
  2143     case Bytecodes::_ireturn:
  2144     case Bytecodes::_lreturn:
  2145     case Bytecodes::_freturn:
  2146     case Bytecodes::_dreturn:
  2147     case Bytecodes::_areturn:
  2148     case Bytecodes::_return:
  2149       // We can assume the monitor stack is empty in this analysis.
  2150       return false;
  2152     case Bytecodes::_monitorexit:
  2153       // We can assume monitors are matched in this analysis.
  2154       return false;
  2157   return true;
  2160 // ------------------------------------------------------------------
  2161 // ciTypeFlow::clone_loop_heads
  2162 //
  2163 // Clone the loop heads
  2164 bool ciTypeFlow::clone_loop_heads(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
  2165   bool rslt = false;
  2166   for (PreorderLoops iter(loop_tree_root()); !iter.done(); iter.next()) {
  2167     lp = iter.current();
  2168     Block* head = lp->head();
  2169     if (lp == loop_tree_root() ||
  2170         lp->is_irreducible() ||
  2171         !head->is_clonable_exit(lp))
  2172       continue;
  2174     // check not already cloned
  2175     if (head->backedge_copy_count() != 0)
  2176       continue;
  2178     // check _no_ shared head below us
  2179     Loop* ch;
  2180     for (ch = lp->child(); ch != NULL && ch->head() != head; ch = ch->sibling());
  2181     if (ch != NULL)
  2182       continue;
  2184     // Clone head
  2185     Block* new_head = head->looping_succ(lp);
  2186     Block* clone = clone_loop_head(lp, temp_vector, temp_set);
  2187     // Update lp's info
  2188     clone->set_loop(lp);
  2189     lp->set_head(new_head);
  2190     lp->set_tail(clone);
  2191     // And move original head into outer loop
  2192     head->set_loop(lp->parent());
  2194     rslt = true;
  2196   return rslt;
  2199 // ------------------------------------------------------------------
  2200 // ciTypeFlow::clone_loop_head
  2201 //
  2202 // Clone lp's head and replace tail's successors with clone.
  2203 //
  2204 //  |
  2205 //  v
  2206 // head <-> body
  2207 //  |
  2208 //  v
  2209 // exit
  2210 //
  2211 // new_head
  2212 //
  2213 //  |
  2214 //  v
  2215 // head ----------\
  2216 //  |             |
  2217 //  |             v
  2218 //  |  clone <-> body
  2219 //  |    |
  2220 //  | /--/
  2221 //  | |
  2222 //  v v
  2223 // exit
  2224 //
  2225 ciTypeFlow::Block* ciTypeFlow::clone_loop_head(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
  2226   Block* head = lp->head();
  2227   Block* tail = lp->tail();
  2228   if (CITraceTypeFlow) {
  2229     tty->print(">> Requesting clone of loop head "); head->print_value_on(tty);
  2230     tty->print("  for predecessor ");                tail->print_value_on(tty);
  2231     tty->cr();
  2233   Block* clone = block_at(head->start(), head->jsrs(), create_backedge_copy);
  2234   assert(clone->backedge_copy_count() == 1, "one backedge copy for all back edges");
  2236   assert(!clone->has_pre_order(), "just created");
  2237   clone->set_next_pre_order();
  2239   // Insert clone after (orig) tail in reverse post order
  2240   clone->set_rpo_next(tail->rpo_next());
  2241   tail->set_rpo_next(clone);
  2243   // tail->head becomes tail->clone
  2244   for (SuccIter iter(tail); !iter.done(); iter.next()) {
  2245     if (iter.succ() == head) {
  2246       iter.set_succ(clone);
  2249   flow_block(tail, temp_vector, temp_set);
  2250   if (head == tail) {
  2251     // For self-loops, clone->head becomes clone->clone
  2252     flow_block(clone, temp_vector, temp_set);
  2253     for (SuccIter iter(clone); !iter.done(); iter.next()) {
  2254       if (iter.succ() == head) {
  2255         iter.set_succ(clone);
  2256         break;
  2260   flow_block(clone, temp_vector, temp_set);
  2262   return clone;
  2265 // ------------------------------------------------------------------
  2266 // ciTypeFlow::flow_block
  2267 //
  2268 // Interpret the effects of the bytecodes on the incoming state
  2269 // vector of a basic block.  Push the changed state to succeeding
  2270 // basic blocks.
  2271 void ciTypeFlow::flow_block(ciTypeFlow::Block* block,
  2272                             ciTypeFlow::StateVector* state,
  2273                             ciTypeFlow::JsrSet* jsrs) {
  2274   if (CITraceTypeFlow) {
  2275     tty->print("\n>> ANALYZING BLOCK : ");
  2276     tty->cr();
  2277     block->print_on(tty);
  2279   assert(block->has_pre_order(), "pre-order is assigned before 1st flow");
  2281   int start = block->start();
  2282   int limit = block->limit();
  2283   int control = block->control();
  2284   if (control != ciBlock::fall_through_bci) {
  2285     limit = control;
  2288   // Grab the state from the current block.
  2289   block->copy_state_into(state);
  2290   state->def_locals()->clear();
  2292   GrowableArray<Block*>*           exceptions = block->exceptions();
  2293   GrowableArray<ciInstanceKlass*>* exc_klasses = block->exc_klasses();
  2294   bool has_exceptions = exceptions->length() > 0;
  2296   bool exceptions_used = false;
  2298   ciBytecodeStream str(method());
  2299   str.reset_to_bci(start);
  2300   Bytecodes::Code code;
  2301   while ((code = str.next()) != ciBytecodeStream::EOBC() &&
  2302          str.cur_bci() < limit) {
  2303     // Check for exceptional control flow from this point.
  2304     if (has_exceptions && can_trap(str)) {
  2305       flow_exceptions(exceptions, exc_klasses, state);
  2306       exceptions_used = true;
  2308     // Apply the effects of the current bytecode to our state.
  2309     bool res = state->apply_one_bytecode(&str);
  2311     // Watch for bailouts.
  2312     if (failing())  return;
  2314     if (res) {
  2316       // We have encountered a trap.  Record it in this block.
  2317       block->set_trap(state->trap_bci(), state->trap_index());
  2319       if (CITraceTypeFlow) {
  2320         tty->print_cr(">> Found trap");
  2321         block->print_on(tty);
  2324       // Save set of locals defined in this block
  2325       block->def_locals()->add(state->def_locals());
  2327       // Record (no) successors.
  2328       block->successors(&str, state, jsrs);
  2330       assert(!has_exceptions || exceptions_used, "Not removing exceptions");
  2332       // Discontinue interpretation of this Block.
  2333       return;
  2337   GrowableArray<Block*>* successors = NULL;
  2338   if (control != ciBlock::fall_through_bci) {
  2339     // Check for exceptional control flow from this point.
  2340     if (has_exceptions && can_trap(str)) {
  2341       flow_exceptions(exceptions, exc_klasses, state);
  2342       exceptions_used = true;
  2345     // Fix the JsrSet to reflect effect of the bytecode.
  2346     block->copy_jsrs_into(jsrs);
  2347     jsrs->apply_control(this, &str, state);
  2349     // Find successor edges based on old state and new JsrSet.
  2350     successors = block->successors(&str, state, jsrs);
  2352     // Apply the control changes to the state.
  2353     state->apply_one_bytecode(&str);
  2354   } else {
  2355     // Fall through control
  2356     successors = block->successors(&str, NULL, NULL);
  2359   // Save set of locals defined in this block
  2360   block->def_locals()->add(state->def_locals());
  2362   // Remove untaken exception paths
  2363   if (!exceptions_used)
  2364     exceptions->clear();
  2366   // Pass our state to successors.
  2367   flow_successors(successors, state);
  2370 // ------------------------------------------------------------------
  2371 // ciTypeFlow::PostOrderLoops::next
  2372 //
  2373 // Advance to next loop tree using a postorder, left-to-right traversal.
  2374 void ciTypeFlow::PostorderLoops::next() {
  2375   assert(!done(), "must not be done.");
  2376   if (_current->sibling() != NULL) {
  2377     _current = _current->sibling();
  2378     while (_current->child() != NULL) {
  2379       _current = _current->child();
  2381   } else {
  2382     _current = _current->parent();
  2386 // ------------------------------------------------------------------
  2387 // ciTypeFlow::PreOrderLoops::next
  2388 //
  2389 // Advance to next loop tree using a preorder, left-to-right traversal.
  2390 void ciTypeFlow::PreorderLoops::next() {
  2391   assert(!done(), "must not be done.");
  2392   if (_current->child() != NULL) {
  2393     _current = _current->child();
  2394   } else if (_current->sibling() != NULL) {
  2395     _current = _current->sibling();
  2396   } else {
  2397     while (_current != _root && _current->sibling() == NULL) {
  2398       _current = _current->parent();
  2400     if (_current == _root) {
  2401       _current = NULL;
  2402       assert(done(), "must be done.");
  2403     } else {
  2404       assert(_current->sibling() != NULL, "must be more to do");
  2405       _current = _current->sibling();
  2410 // ------------------------------------------------------------------
  2411 // ciTypeFlow::Loop::sorted_merge
  2412 //
  2413 // Merge the branch lp into this branch, sorting on the loop head
  2414 // pre_orders. Returns the leaf of the merged branch.
  2415 // Child and sibling pointers will be setup later.
  2416 // Sort is (looking from leaf towards the root)
  2417 //  descending on primary key: loop head's pre_order, and
  2418 //  ascending  on secondary key: loop tail's pre_order.
  2419 ciTypeFlow::Loop* ciTypeFlow::Loop::sorted_merge(Loop* lp) {
  2420   Loop* leaf = this;
  2421   Loop* prev = NULL;
  2422   Loop* current = leaf;
  2423   while (lp != NULL) {
  2424     int lp_pre_order = lp->head()->pre_order();
  2425     // Find insertion point for "lp"
  2426     while (current != NULL) {
  2427       if (current == lp)
  2428         return leaf; // Already in list
  2429       if (current->head()->pre_order() < lp_pre_order)
  2430         break;
  2431       if (current->head()->pre_order() == lp_pre_order &&
  2432           current->tail()->pre_order() > lp->tail()->pre_order()) {
  2433         break;
  2435       prev = current;
  2436       current = current->parent();
  2438     Loop* next_lp = lp->parent(); // Save future list of items to insert
  2439     // Insert lp before current
  2440     lp->set_parent(current);
  2441     if (prev != NULL) {
  2442       prev->set_parent(lp);
  2443     } else {
  2444       leaf = lp;
  2446     prev = lp;     // Inserted item is new prev[ious]
  2447     lp = next_lp;  // Next item to insert
  2449   return leaf;
  2452 // ------------------------------------------------------------------
  2453 // ciTypeFlow::build_loop_tree
  2454 //
  2455 // Incrementally build loop tree.
  2456 void ciTypeFlow::build_loop_tree(Block* blk) {
  2457   assert(!blk->is_post_visited(), "precondition");
  2458   Loop* innermost = NULL; // merge of loop tree branches over all successors
  2460   for (SuccIter iter(blk); !iter.done(); iter.next()) {
  2461     Loop*  lp   = NULL;
  2462     Block* succ = iter.succ();
  2463     if (!succ->is_post_visited()) {
  2464       // Found backedge since predecessor post visited, but successor is not
  2465       assert(succ->pre_order() <= blk->pre_order(), "should be backedge");
  2467       // Create a LoopNode to mark this loop.
  2468       lp = new (arena()) Loop(succ, blk);
  2469       if (succ->loop() == NULL)
  2470         succ->set_loop(lp);
  2471       // succ->loop will be updated to innermost loop on a later call, when blk==succ
  2473     } else {  // Nested loop
  2474       lp = succ->loop();
  2476       // If succ is loop head, find outer loop.
  2477       while (lp != NULL && lp->head() == succ) {
  2478         lp = lp->parent();
  2480       if (lp == NULL) {
  2481         // Infinite loop, it's parent is the root
  2482         lp = loop_tree_root();
  2486     // Check for irreducible loop.
  2487     // Successor has already been visited. If the successor's loop head
  2488     // has already been post-visited, then this is another entry into the loop.
  2489     while (lp->head()->is_post_visited() && lp != loop_tree_root()) {
  2490       _has_irreducible_entry = true;
  2491       lp->set_irreducible(succ);
  2492       if (!succ->is_on_work_list()) {
  2493         // Assume irreducible entries need more data flow
  2494         add_to_work_list(succ);
  2496       Loop* plp = lp->parent();
  2497       if (plp == NULL) {
  2498         // This only happens for some irreducible cases.  The parent
  2499         // will be updated during a later pass.
  2500         break;
  2502       lp = plp;
  2505     // Merge loop tree branch for all successors.
  2506     innermost = innermost == NULL ? lp : innermost->sorted_merge(lp);
  2508   } // end loop
  2510   if (innermost == NULL) {
  2511     assert(blk->successors()->length() == 0, "CFG exit");
  2512     blk->set_loop(loop_tree_root());
  2513   } else if (innermost->head() == blk) {
  2514     // If loop header, complete the tree pointers
  2515     if (blk->loop() != innermost) {
  2516 #if ASSERT
  2517       assert(blk->loop()->head() == innermost->head(), "same head");
  2518       Loop* dl;
  2519       for (dl = innermost; dl != NULL && dl != blk->loop(); dl = dl->parent());
  2520       assert(dl == blk->loop(), "blk->loop() already in innermost list");
  2521 #endif
  2522       blk->set_loop(innermost);
  2524     innermost->def_locals()->add(blk->def_locals());
  2525     Loop* l = innermost;
  2526     Loop* p = l->parent();
  2527     while (p && l->head() == blk) {
  2528       l->set_sibling(p->child());  // Put self on parents 'next child'
  2529       p->set_child(l);             // Make self the first child of parent
  2530       p->def_locals()->add(l->def_locals());
  2531       l = p;                       // Walk up the parent chain
  2532       p = l->parent();
  2534   } else {
  2535     blk->set_loop(innermost);
  2536     innermost->def_locals()->add(blk->def_locals());
  2540 // ------------------------------------------------------------------
  2541 // ciTypeFlow::Loop::contains
  2542 //
  2543 // Returns true if lp is nested loop.
  2544 bool ciTypeFlow::Loop::contains(ciTypeFlow::Loop* lp) const {
  2545   assert(lp != NULL, "");
  2546   if (this == lp || head() == lp->head()) return true;
  2547   int depth1 = depth();
  2548   int depth2 = lp->depth();
  2549   if (depth1 > depth2)
  2550     return false;
  2551   while (depth1 < depth2) {
  2552     depth2--;
  2553     lp = lp->parent();
  2555   return this == lp;
  2558 // ------------------------------------------------------------------
  2559 // ciTypeFlow::Loop::depth
  2560 //
  2561 // Loop depth
  2562 int ciTypeFlow::Loop::depth() const {
  2563   int dp = 0;
  2564   for (Loop* lp = this->parent(); lp != NULL; lp = lp->parent())
  2565     dp++;
  2566   return dp;
  2569 #ifndef PRODUCT
  2570 // ------------------------------------------------------------------
  2571 // ciTypeFlow::Loop::print
  2572 void ciTypeFlow::Loop::print(outputStream* st, int indent) const {
  2573   for (int i = 0; i < indent; i++) st->print(" ");
  2574   st->print("%d<-%d %s",
  2575             is_root() ? 0 : this->head()->pre_order(),
  2576             is_root() ? 0 : this->tail()->pre_order(),
  2577             is_irreducible()?" irr":"");
  2578   st->print(" defs: ");
  2579   def_locals()->print_on(st, _head->outer()->method()->max_locals());
  2580   st->cr();
  2581   for (Loop* ch = child(); ch != NULL; ch = ch->sibling())
  2582     ch->print(st, indent+2);
  2584 #endif
  2586 // ------------------------------------------------------------------
  2587 // ciTypeFlow::df_flow_types
  2588 //
  2589 // Perform the depth first type flow analysis. Helper for flow_types.
  2590 void ciTypeFlow::df_flow_types(Block* start,
  2591                                bool do_flow,
  2592                                StateVector* temp_vector,
  2593                                JsrSet* temp_set) {
  2594   int dft_len = 100;
  2595   GrowableArray<Block*> stk(arena(), dft_len, 0, NULL);
  2597   ciBlock* dummy = _methodBlocks->make_dummy_block();
  2598   JsrSet* root_set = new JsrSet(NULL, 0);
  2599   Block* root_head = new (arena()) Block(this, dummy, root_set);
  2600   Block* root_tail = new (arena()) Block(this, dummy, root_set);
  2601   root_head->set_pre_order(0);
  2602   root_head->set_post_order(0);
  2603   root_tail->set_pre_order(max_jint);
  2604   root_tail->set_post_order(max_jint);
  2605   set_loop_tree_root(new (arena()) Loop(root_head, root_tail));
  2607   stk.push(start);
  2609   _next_pre_order = 0;  // initialize pre_order counter
  2610   _rpo_list = NULL;
  2611   int next_po = 0;      // initialize post_order counter
  2613   // Compute RPO and the control flow graph
  2614   int size;
  2615   while ((size = stk.length()) > 0) {
  2616     Block* blk = stk.top(); // Leave node on stack
  2617     if (!blk->is_visited()) {
  2618       // forward arc in graph
  2619       assert (!blk->has_pre_order(), "");
  2620       blk->set_next_pre_order();
  2622       if (_next_pre_order >= MaxNodeLimit / 2) {
  2623         // Too many basic blocks.  Bail out.
  2624         // This can happen when try/finally constructs are nested to depth N,
  2625         // and there is O(2**N) cloning of jsr bodies.  See bug 4697245!
  2626         // "MaxNodeLimit / 2" is used because probably the parser will
  2627         // generate at least twice that many nodes and bail out.
  2628         record_failure("too many basic blocks");
  2629         return;
  2631       if (do_flow) {
  2632         flow_block(blk, temp_vector, temp_set);
  2633         if (failing()) return; // Watch for bailouts.
  2635     } else if (!blk->is_post_visited()) {
  2636       // cross or back arc
  2637       for (SuccIter iter(blk); !iter.done(); iter.next()) {
  2638         Block* succ = iter.succ();
  2639         if (!succ->is_visited()) {
  2640           stk.push(succ);
  2643       if (stk.length() == size) {
  2644         // There were no additional children, post visit node now
  2645         stk.pop(); // Remove node from stack
  2647         build_loop_tree(blk);
  2648         blk->set_post_order(next_po++);   // Assign post order
  2649         prepend_to_rpo_list(blk);
  2650         assert(blk->is_post_visited(), "");
  2652         if (blk->is_loop_head() && !blk->is_on_work_list()) {
  2653           // Assume loop heads need more data flow
  2654           add_to_work_list(blk);
  2657     } else {
  2658       stk.pop(); // Remove post-visited node from stack
  2663 // ------------------------------------------------------------------
  2664 // ciTypeFlow::flow_types
  2665 //
  2666 // Perform the type flow analysis, creating and cloning Blocks as
  2667 // necessary.
  2668 void ciTypeFlow::flow_types() {
  2669   ResourceMark rm;
  2670   StateVector* temp_vector = new StateVector(this);
  2671   JsrSet* temp_set = new JsrSet(NULL, 16);
  2673   // Create the method entry block.
  2674   Block* start = block_at(start_bci(), temp_set);
  2676   // Load the initial state into it.
  2677   const StateVector* start_state = get_start_state();
  2678   if (failing())  return;
  2679   start->meet(start_state);
  2681   // Depth first visit
  2682   df_flow_types(start, true /*do flow*/, temp_vector, temp_set);
  2684   if (failing())  return;
  2685   assert(_rpo_list == start, "must be start");
  2687   // Any loops found?
  2688   if (loop_tree_root()->child() != NULL &&
  2689       env()->comp_level() >= CompLevel_full_optimization) {
  2690       // Loop optimizations are not performed on Tier1 compiles.
  2692     bool changed = clone_loop_heads(loop_tree_root(), temp_vector, temp_set);
  2694     // If some loop heads were cloned, recompute postorder and loop tree
  2695     if (changed) {
  2696       loop_tree_root()->set_child(NULL);
  2697       for (Block* blk = _rpo_list; blk != NULL;) {
  2698         Block* next = blk->rpo_next();
  2699         blk->df_init();
  2700         blk = next;
  2702       df_flow_types(start, false /*no flow*/, temp_vector, temp_set);
  2706   if (CITraceTypeFlow) {
  2707     tty->print_cr("\nLoop tree");
  2708     loop_tree_root()->print();
  2711   // Continue flow analysis until fixed point reached
  2713   debug_only(int max_block = _next_pre_order;)
  2715   while (!work_list_empty()) {
  2716     Block* blk = work_list_next();
  2717     assert (blk->has_post_order(), "post order assigned above");
  2719     flow_block(blk, temp_vector, temp_set);
  2721     assert (max_block == _next_pre_order, "no new blocks");
  2722     assert (!failing(), "no more bailouts");
  2726 // ------------------------------------------------------------------
  2727 // ciTypeFlow::map_blocks
  2728 //
  2729 // Create the block map, which indexes blocks in reverse post-order.
  2730 void ciTypeFlow::map_blocks() {
  2731   assert(_block_map == NULL, "single initialization");
  2732   int block_ct = _next_pre_order;
  2733   _block_map = NEW_ARENA_ARRAY(arena(), Block*, block_ct);
  2734   assert(block_ct == block_count(), "");
  2736   Block* blk = _rpo_list;
  2737   for (int m = 0; m < block_ct; m++) {
  2738     int rpo = blk->rpo();
  2739     assert(rpo == m, "should be sequential");
  2740     _block_map[rpo] = blk;
  2741     blk = blk->rpo_next();
  2743   assert(blk == NULL, "should be done");
  2745   for (int j = 0; j < block_ct; j++) {
  2746     assert(_block_map[j] != NULL, "must not drop any blocks");
  2747     Block* block = _block_map[j];
  2748     // Remove dead blocks from successor lists:
  2749     for (int e = 0; e <= 1; e++) {
  2750       GrowableArray<Block*>* l = e? block->exceptions(): block->successors();
  2751       for (int k = 0; k < l->length(); k++) {
  2752         Block* s = l->at(k);
  2753         if (!s->has_post_order()) {
  2754           if (CITraceTypeFlow) {
  2755             tty->print("Removing dead %s successor of #%d: ", (e? "exceptional":  "normal"), block->pre_order());
  2756             s->print_value_on(tty);
  2757             tty->cr();
  2759           l->remove(s);
  2760           --k;
  2767 // ------------------------------------------------------------------
  2768 // ciTypeFlow::get_block_for
  2769 //
  2770 // Find a block with this ciBlock which has a compatible JsrSet.
  2771 // If no such block exists, create it, unless the option is no_create.
  2772 // If the option is create_backedge_copy, always create a fresh backedge copy.
  2773 ciTypeFlow::Block* ciTypeFlow::get_block_for(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
  2774   Arena* a = arena();
  2775   GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
  2776   if (blocks == NULL) {
  2777     // Query only?
  2778     if (option == no_create)  return NULL;
  2780     // Allocate the growable array.
  2781     blocks = new (a) GrowableArray<Block*>(a, 4, 0, NULL);
  2782     _idx_to_blocklist[ciBlockIndex] = blocks;
  2785   if (option != create_backedge_copy) {
  2786     int len = blocks->length();
  2787     for (int i = 0; i < len; i++) {
  2788       Block* block = blocks->at(i);
  2789       if (!block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
  2790         return block;
  2795   // Query only?
  2796   if (option == no_create)  return NULL;
  2798   // We did not find a compatible block.  Create one.
  2799   Block* new_block = new (a) Block(this, _methodBlocks->block(ciBlockIndex), jsrs);
  2800   if (option == create_backedge_copy)  new_block->set_backedge_copy(true);
  2801   blocks->append(new_block);
  2802   return new_block;
  2805 // ------------------------------------------------------------------
  2806 // ciTypeFlow::backedge_copy_count
  2807 //
  2808 int ciTypeFlow::backedge_copy_count(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs) const {
  2809   GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
  2811   if (blocks == NULL) {
  2812     return 0;
  2815   int count = 0;
  2816   int len = blocks->length();
  2817   for (int i = 0; i < len; i++) {
  2818     Block* block = blocks->at(i);
  2819     if (block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
  2820       count++;
  2824   return count;
  2827 // ------------------------------------------------------------------
  2828 // ciTypeFlow::do_flow
  2829 //
  2830 // Perform type inference flow analysis.
  2831 void ciTypeFlow::do_flow() {
  2832   if (CITraceTypeFlow) {
  2833     tty->print_cr("\nPerforming flow analysis on method");
  2834     method()->print();
  2835     if (is_osr_flow())  tty->print(" at OSR bci %d", start_bci());
  2836     tty->cr();
  2837     method()->print_codes();
  2839   if (CITraceTypeFlow) {
  2840     tty->print_cr("Initial CI Blocks");
  2841     print_on(tty);
  2843   flow_types();
  2844   // Watch for bailouts.
  2845   if (failing()) {
  2846     return;
  2849   map_blocks();
  2851   if (CIPrintTypeFlow || CITraceTypeFlow) {
  2852     rpo_print_on(tty);
  2856 // ------------------------------------------------------------------
  2857 // ciTypeFlow::record_failure()
  2858 // The ciTypeFlow object keeps track of failure reasons separately from the ciEnv.
  2859 // This is required because there is not a 1-1 relation between the ciEnv and
  2860 // the TypeFlow passes within a compilation task.  For example, if the compiler
  2861 // is considering inlining a method, it will request a TypeFlow.  If that fails,
  2862 // the compilation as a whole may continue without the inlining.  Some TypeFlow
  2863 // requests are not optional; if they fail the requestor is responsible for
  2864 // copying the failure reason up to the ciEnv.  (See Parse::Parse.)
  2865 void ciTypeFlow::record_failure(const char* reason) {
  2866   if (env()->log() != NULL) {
  2867     env()->log()->elem("failure reason='%s' phase='typeflow'", reason);
  2869   if (_failure_reason == NULL) {
  2870     // Record the first failure reason.
  2871     _failure_reason = reason;
  2875 #ifndef PRODUCT
  2876 // ------------------------------------------------------------------
  2877 // ciTypeFlow::print_on
  2878 void ciTypeFlow::print_on(outputStream* st) const {
  2879   // Walk through CI blocks
  2880   st->print_cr("********************************************************");
  2881   st->print   ("TypeFlow for ");
  2882   method()->name()->print_symbol_on(st);
  2883   int limit_bci = code_size();
  2884   st->print_cr("  %d bytes", limit_bci);
  2885   ciMethodBlocks  *mblks = _methodBlocks;
  2886   ciBlock* current = NULL;
  2887   for (int bci = 0; bci < limit_bci; bci++) {
  2888     ciBlock* blk = mblks->block_containing(bci);
  2889     if (blk != NULL && blk != current) {
  2890       current = blk;
  2891       current->print_on(st);
  2893       GrowableArray<Block*>* blocks = _idx_to_blocklist[blk->index()];
  2894       int num_blocks = (blocks == NULL) ? 0 : blocks->length();
  2896       if (num_blocks == 0) {
  2897         st->print_cr("  No Blocks");
  2898       } else {
  2899         for (int i = 0; i < num_blocks; i++) {
  2900           Block* block = blocks->at(i);
  2901           block->print_on(st);
  2904       st->print_cr("--------------------------------------------------------");
  2905       st->cr();
  2908   st->print_cr("********************************************************");
  2909   st->cr();
  2912 void ciTypeFlow::rpo_print_on(outputStream* st) const {
  2913   st->print_cr("********************************************************");
  2914   st->print   ("TypeFlow for ");
  2915   method()->name()->print_symbol_on(st);
  2916   int limit_bci = code_size();
  2917   st->print_cr("  %d bytes", limit_bci);
  2918   for (Block* blk = _rpo_list; blk != NULL; blk = blk->rpo_next()) {
  2919     blk->print_on(st);
  2920     st->print_cr("--------------------------------------------------------");
  2921     st->cr();
  2923   st->print_cr("********************************************************");
  2924   st->cr();
  2926 #endif

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