src/share/vm/opto/parse3.cpp

Tue, 10 Sep 2013 14:51:48 -0700

author
vlivanov
date
Tue, 10 Sep 2013 14:51:48 -0700
changeset 5658
edb5ab0f3fe5
parent 5437
fcf521c3fbc6
child 6313
de95063c0e34
child 6479
2113136690bc
permissions
-rw-r--r--

8001107: @Stable annotation for constant folding of lazily evaluated variables
Reviewed-by: rbackman, twisti, kvn
Contributed-by: john.r.rose@oracle.com, vladimir.x.ivanov@oracle.com

     1 /*
     2  * Copyright (c) 1998, 2013, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 #include "precompiled.hpp"
    26 #include "compiler/compileLog.hpp"
    27 #include "interpreter/linkResolver.hpp"
    28 #include "memory/universe.inline.hpp"
    29 #include "oops/objArrayKlass.hpp"
    30 #include "opto/addnode.hpp"
    31 #include "opto/memnode.hpp"
    32 #include "opto/parse.hpp"
    33 #include "opto/rootnode.hpp"
    34 #include "opto/runtime.hpp"
    35 #include "opto/subnode.hpp"
    36 #include "runtime/deoptimization.hpp"
    37 #include "runtime/handles.inline.hpp"
    39 //=============================================================================
    40 // Helper methods for _get* and _put* bytecodes
    41 //=============================================================================
    42 bool Parse::static_field_ok_in_clinit(ciField *field, ciMethod *method) {
    43   // Could be the field_holder's <clinit> method, or <clinit> for a subklass.
    44   // Better to check now than to Deoptimize as soon as we execute
    45   assert( field->is_static(), "Only check if field is static");
    46   // is_being_initialized() is too generous.  It allows access to statics
    47   // by threads that are not running the <clinit> before the <clinit> finishes.
    48   // return field->holder()->is_being_initialized();
    50   // The following restriction is correct but conservative.
    51   // It is also desirable to allow compilation of methods called from <clinit>
    52   // but this generated code will need to be made safe for execution by
    53   // other threads, or the transition from interpreted to compiled code would
    54   // need to be guarded.
    55   ciInstanceKlass *field_holder = field->holder();
    57   bool access_OK = false;
    58   if (method->holder()->is_subclass_of(field_holder)) {
    59     if (method->is_static()) {
    60       if (method->name() == ciSymbol::class_initializer_name()) {
    61         // OK to access static fields inside initializer
    62         access_OK = true;
    63       }
    64     } else {
    65       if (method->name() == ciSymbol::object_initializer_name()) {
    66         // It's also OK to access static fields inside a constructor,
    67         // because any thread calling the constructor must first have
    68         // synchronized on the class by executing a '_new' bytecode.
    69         access_OK = true;
    70       }
    71     }
    72   }
    74   return access_OK;
    76 }
    79 void Parse::do_field_access(bool is_get, bool is_field) {
    80   bool will_link;
    81   ciField* field = iter().get_field(will_link);
    82   assert(will_link, "getfield: typeflow responsibility");
    84   ciInstanceKlass* field_holder = field->holder();
    86   if (is_field == field->is_static()) {
    87     // Interpreter will throw java_lang_IncompatibleClassChangeError
    88     // Check this before allowing <clinit> methods to access static fields
    89     uncommon_trap(Deoptimization::Reason_unhandled,
    90                   Deoptimization::Action_none);
    91     return;
    92   }
    94   if (!is_field && !field_holder->is_initialized()) {
    95     if (!static_field_ok_in_clinit(field, method())) {
    96       uncommon_trap(Deoptimization::Reason_uninitialized,
    97                     Deoptimization::Action_reinterpret,
    98                     NULL, "!static_field_ok_in_clinit");
    99       return;
   100     }
   101   }
   103   // Deoptimize on putfield writes to call site target field.
   104   if (!is_get && field->is_call_site_target()) {
   105     uncommon_trap(Deoptimization::Reason_unhandled,
   106                   Deoptimization::Action_reinterpret,
   107                   NULL, "put to call site target field");
   108     return;
   109   }
   111   assert(field->will_link(method()->holder(), bc()), "getfield: typeflow responsibility");
   113   // Note:  We do not check for an unloaded field type here any more.
   115   // Generate code for the object pointer.
   116   Node* obj;
   117   if (is_field) {
   118     int obj_depth = is_get ? 0 : field->type()->size();
   119     obj = null_check(peek(obj_depth));
   120     // Compile-time detect of null-exception?
   121     if (stopped())  return;
   123 #ifdef ASSERT
   124     const TypeInstPtr *tjp = TypeInstPtr::make(TypePtr::NotNull, iter().get_declared_field_holder());
   125     assert(_gvn.type(obj)->higher_equal(tjp), "cast_up is no longer needed");
   126 #endif
   128     if (is_get) {
   129       (void) pop();  // pop receiver before getting
   130       do_get_xxx(obj, field, is_field);
   131     } else {
   132       do_put_xxx(obj, field, is_field);
   133       (void) pop();  // pop receiver after putting
   134     }
   135   } else {
   136     const TypeInstPtr* tip = TypeInstPtr::make(field_holder->java_mirror());
   137     obj = _gvn.makecon(tip);
   138     if (is_get) {
   139       do_get_xxx(obj, field, is_field);
   140     } else {
   141       do_put_xxx(obj, field, is_field);
   142     }
   143   }
   144 }
   147 void Parse::do_get_xxx(Node* obj, ciField* field, bool is_field) {
   148   // Does this field have a constant value?  If so, just push the value.
   149   if (field->is_constant()) {
   150     // final or stable field
   151     const Type* stable_type = NULL;
   152     if (FoldStableValues && field->is_stable()) {
   153       stable_type = Type::get_const_type(field->type());
   154       if (field->type()->is_array_klass()) {
   155         int stable_dimension = field->type()->as_array_klass()->dimension();
   156         stable_type = stable_type->is_aryptr()->cast_to_stable(true, stable_dimension);
   157       }
   158     }
   159     if (field->is_static()) {
   160       // final static field
   161       if (C->eliminate_boxing()) {
   162         // The pointers in the autobox arrays are always non-null.
   163         ciSymbol* klass_name = field->holder()->name();
   164         if (field->name() == ciSymbol::cache_field_name() &&
   165             field->holder()->uses_default_loader() &&
   166             (klass_name == ciSymbol::java_lang_Character_CharacterCache() ||
   167              klass_name == ciSymbol::java_lang_Byte_ByteCache() ||
   168              klass_name == ciSymbol::java_lang_Short_ShortCache() ||
   169              klass_name == ciSymbol::java_lang_Integer_IntegerCache() ||
   170              klass_name == ciSymbol::java_lang_Long_LongCache())) {
   171           bool require_const = true;
   172           bool autobox_cache = true;
   173           if (push_constant(field->constant_value(), require_const, autobox_cache)) {
   174             return;
   175           }
   176         }
   177       }
   178       if (push_constant(field->constant_value(), false, false, stable_type))
   179         return;
   180     } else {
   181       // final or stable non-static field
   182       // Treat final non-static fields of trusted classes (classes in
   183       // java.lang.invoke and sun.invoke packages and subpackages) as
   184       // compile time constants.
   185       if (obj->is_Con()) {
   186         const TypeOopPtr* oop_ptr = obj->bottom_type()->isa_oopptr();
   187         ciObject* constant_oop = oop_ptr->const_oop();
   188         ciConstant constant = field->constant_value_of(constant_oop);
   189         if (FoldStableValues && field->is_stable() && constant.is_null_or_zero()) {
   190           // fall through to field load; the field is not yet initialized
   191         } else {
   192           if (push_constant(constant, true, false, stable_type))
   193             return;
   194         }
   195       }
   196     }
   197   }
   199   ciType* field_klass = field->type();
   200   bool is_vol = field->is_volatile();
   202   // Compute address and memory type.
   203   int offset = field->offset_in_bytes();
   204   const TypePtr* adr_type = C->alias_type(field)->adr_type();
   205   Node *adr = basic_plus_adr(obj, obj, offset);
   206   BasicType bt = field->layout_type();
   208   // Build the resultant type of the load
   209   const Type *type;
   211   bool must_assert_null = false;
   213   if( bt == T_OBJECT ) {
   214     if (!field->type()->is_loaded()) {
   215       type = TypeInstPtr::BOTTOM;
   216       must_assert_null = true;
   217     } else if (field->is_constant() && field->is_static()) {
   218       // This can happen if the constant oop is non-perm.
   219       ciObject* con = field->constant_value().as_object();
   220       // Do not "join" in the previous type; it doesn't add value,
   221       // and may yield a vacuous result if the field is of interface type.
   222       type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
   223       assert(type != NULL, "field singleton type must be consistent");
   224     } else {
   225       type = TypeOopPtr::make_from_klass(field_klass->as_klass());
   226     }
   227   } else {
   228     type = Type::get_const_basic_type(bt);
   229   }
   230   // Build the load.
   231   Node* ld = make_load(NULL, adr, type, bt, adr_type, is_vol);
   233   // Adjust Java stack
   234   if (type2size[bt] == 1)
   235     push(ld);
   236   else
   237     push_pair(ld);
   239   if (must_assert_null) {
   240     // Do not take a trap here.  It's possible that the program
   241     // will never load the field's class, and will happily see
   242     // null values in this field forever.  Don't stumble into a
   243     // trap for such a program, or we might get a long series
   244     // of useless recompilations.  (Or, we might load a class
   245     // which should not be loaded.)  If we ever see a non-null
   246     // value, we will then trap and recompile.  (The trap will
   247     // not need to mention the class index, since the class will
   248     // already have been loaded if we ever see a non-null value.)
   249     // uncommon_trap(iter().get_field_signature_index());
   250 #ifndef PRODUCT
   251     if (PrintOpto && (Verbose || WizardMode)) {
   252       method()->print_name(); tty->print_cr(" asserting nullness of field at bci: %d", bci());
   253     }
   254 #endif
   255     if (C->log() != NULL) {
   256       C->log()->elem("assert_null reason='field' klass='%d'",
   257                      C->log()->identify(field->type()));
   258     }
   259     // If there is going to be a trap, put it at the next bytecode:
   260     set_bci(iter().next_bci());
   261     null_assert(peek());
   262     set_bci(iter().cur_bci()); // put it back
   263   }
   265   // If reference is volatile, prevent following memory ops from
   266   // floating up past the volatile read.  Also prevents commoning
   267   // another volatile read.
   268   if (field->is_volatile()) {
   269     // Memory barrier includes bogus read of value to force load BEFORE membar
   270     insert_mem_bar(Op_MemBarAcquire, ld);
   271   }
   272 }
   274 void Parse::do_put_xxx(Node* obj, ciField* field, bool is_field) {
   275   bool is_vol = field->is_volatile();
   276   // If reference is volatile, prevent following memory ops from
   277   // floating down past the volatile write.  Also prevents commoning
   278   // another volatile read.
   279   if (is_vol)  insert_mem_bar(Op_MemBarRelease);
   281   // Compute address and memory type.
   282   int offset = field->offset_in_bytes();
   283   const TypePtr* adr_type = C->alias_type(field)->adr_type();
   284   Node* adr = basic_plus_adr(obj, obj, offset);
   285   BasicType bt = field->layout_type();
   286   // Value to be stored
   287   Node* val = type2size[bt] == 1 ? pop() : pop_pair();
   288   // Round doubles before storing
   289   if (bt == T_DOUBLE)  val = dstore_rounding(val);
   291   // Store the value.
   292   Node* store;
   293   if (bt == T_OBJECT) {
   294     const TypeOopPtr* field_type;
   295     if (!field->type()->is_loaded()) {
   296       field_type = TypeInstPtr::BOTTOM;
   297     } else {
   298       field_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
   299     }
   300     store = store_oop_to_object( control(), obj, adr, adr_type, val, field_type, bt);
   301   } else {
   302     store = store_to_memory( control(), adr, val, bt, adr_type, is_vol );
   303   }
   305   // If reference is volatile, prevent following volatiles ops from
   306   // floating up before the volatile write.
   307   if (is_vol) {
   308     insert_mem_bar(Op_MemBarVolatile); // Use fat membar
   309   }
   311   // If the field is final, the rules of Java say we are in <init> or <clinit>.
   312   // Note the presence of writes to final non-static fields, so that we
   313   // can insert a memory barrier later on to keep the writes from floating
   314   // out of the constructor.
   315   // Any method can write a @Stable field; insert memory barriers after those also.
   316   if (is_field && (field->is_final() || field->is_stable())) {
   317     set_wrote_final(true);
   318     // Preserve allocation ptr to create precedent edge to it in membar
   319     // generated on exit from constructor.
   320     if (C->eliminate_boxing() &&
   321         adr_type->isa_oopptr() && adr_type->is_oopptr()->is_ptr_to_boxed_value() &&
   322         AllocateNode::Ideal_allocation(obj, &_gvn) != NULL) {
   323       set_alloc_with_final(obj);
   324     }
   325   }
   326 }
   330 bool Parse::push_constant(ciConstant constant, bool require_constant, bool is_autobox_cache, const Type* stable_type) {
   331   const Type* con_type = Type::make_from_constant(constant, require_constant, is_autobox_cache);
   332   switch (constant.basic_type()) {
   333   case T_ARRAY:
   334   case T_OBJECT:
   335     // cases:
   336     //   can_be_constant    = (oop not scavengable || ScavengeRootsInCode != 0)
   337     //   should_be_constant = (oop not scavengable || ScavengeRootsInCode >= 2)
   338     // An oop is not scavengable if it is in the perm gen.
   339     if (stable_type != NULL && con_type != NULL && con_type->isa_oopptr())
   340       con_type = con_type->join(stable_type);
   341     break;
   343   case T_ILLEGAL:
   344     // Invalid ciConstant returned due to OutOfMemoryError in the CI
   345     assert(C->env()->failing(), "otherwise should not see this");
   346     // These always occur because of object types; we are going to
   347     // bail out anyway, so make the stack depths match up
   348     push( zerocon(T_OBJECT) );
   349     return false;
   350   }
   352   if (con_type == NULL)
   353     // we cannot inline the oop, but we can use it later to narrow a type
   354     return false;
   356   push_node(constant.basic_type(), makecon(con_type));
   357   return true;
   358 }
   361 //=============================================================================
   362 void Parse::do_anewarray() {
   363   bool will_link;
   364   ciKlass* klass = iter().get_klass(will_link);
   366   // Uncommon Trap when class that array contains is not loaded
   367   // we need the loaded class for the rest of graph; do not
   368   // initialize the container class (see Java spec)!!!
   369   assert(will_link, "anewarray: typeflow responsibility");
   371   ciObjArrayKlass* array_klass = ciObjArrayKlass::make(klass);
   372   // Check that array_klass object is loaded
   373   if (!array_klass->is_loaded()) {
   374     // Generate uncommon_trap for unloaded array_class
   375     uncommon_trap(Deoptimization::Reason_unloaded,
   376                   Deoptimization::Action_reinterpret,
   377                   array_klass);
   378     return;
   379   }
   381   kill_dead_locals();
   383   const TypeKlassPtr* array_klass_type = TypeKlassPtr::make(array_klass);
   384   Node* count_val = pop();
   385   Node* obj = new_array(makecon(array_klass_type), count_val, 1);
   386   push(obj);
   387 }
   390 void Parse::do_newarray(BasicType elem_type) {
   391   kill_dead_locals();
   393   Node*   count_val = pop();
   394   const TypeKlassPtr* array_klass = TypeKlassPtr::make(ciTypeArrayKlass::make(elem_type));
   395   Node*   obj = new_array(makecon(array_klass), count_val, 1);
   396   // Push resultant oop onto stack
   397   push(obj);
   398 }
   400 // Expand simple expressions like new int[3][5] and new Object[2][nonConLen].
   401 // Also handle the degenerate 1-dimensional case of anewarray.
   402 Node* Parse::expand_multianewarray(ciArrayKlass* array_klass, Node* *lengths, int ndimensions, int nargs) {
   403   Node* length = lengths[0];
   404   assert(length != NULL, "");
   405   Node* array = new_array(makecon(TypeKlassPtr::make(array_klass)), length, nargs);
   406   if (ndimensions > 1) {
   407     jint length_con = find_int_con(length, -1);
   408     guarantee(length_con >= 0, "non-constant multianewarray");
   409     ciArrayKlass* array_klass_1 = array_klass->as_obj_array_klass()->element_klass()->as_array_klass();
   410     const TypePtr* adr_type = TypeAryPtr::OOPS;
   411     const TypeOopPtr*    elemtype = _gvn.type(array)->is_aryptr()->elem()->make_oopptr();
   412     const intptr_t header   = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
   413     for (jint i = 0; i < length_con; i++) {
   414       Node*    elem   = expand_multianewarray(array_klass_1, &lengths[1], ndimensions-1, nargs);
   415       intptr_t offset = header + ((intptr_t)i << LogBytesPerHeapOop);
   416       Node*    eaddr  = basic_plus_adr(array, offset);
   417       store_oop_to_array(control(), array, eaddr, adr_type, elem, elemtype, T_OBJECT);
   418     }
   419   }
   420   return array;
   421 }
   423 void Parse::do_multianewarray() {
   424   int ndimensions = iter().get_dimensions();
   426   // the m-dimensional array
   427   bool will_link;
   428   ciArrayKlass* array_klass = iter().get_klass(will_link)->as_array_klass();
   429   assert(will_link, "multianewarray: typeflow responsibility");
   431   // Note:  Array classes are always initialized; no is_initialized check.
   433   kill_dead_locals();
   435   // get the lengths from the stack (first dimension is on top)
   436   Node** length = NEW_RESOURCE_ARRAY(Node*, ndimensions + 1);
   437   length[ndimensions] = NULL;  // terminating null for make_runtime_call
   438   int j;
   439   for (j = ndimensions-1; j >= 0 ; j--) length[j] = pop();
   441   // The original expression was of this form: new T[length0][length1]...
   442   // It is often the case that the lengths are small (except the last).
   443   // If that happens, use the fast 1-d creator a constant number of times.
   444   const jint expand_limit = MIN2((juint)MultiArrayExpandLimit, (juint)100);
   445   jint expand_count = 1;        // count of allocations in the expansion
   446   jint expand_fanout = 1;       // running total fanout
   447   for (j = 0; j < ndimensions-1; j++) {
   448     jint dim_con = find_int_con(length[j], -1);
   449     expand_fanout *= dim_con;
   450     expand_count  += expand_fanout; // count the level-J sub-arrays
   451     if (dim_con <= 0
   452         || dim_con > expand_limit
   453         || expand_count > expand_limit) {
   454       expand_count = 0;
   455       break;
   456     }
   457   }
   459   // Can use multianewarray instead of [a]newarray if only one dimension,
   460   // or if all non-final dimensions are small constants.
   461   if (ndimensions == 1 || (1 <= expand_count && expand_count <= expand_limit)) {
   462     Node* obj = NULL;
   463     // Set the original stack and the reexecute bit for the interpreter
   464     // to reexecute the multianewarray bytecode if deoptimization happens.
   465     // Do it unconditionally even for one dimension multianewarray.
   466     // Note: the reexecute bit will be set in GraphKit::add_safepoint_edges()
   467     // when AllocateArray node for newarray is created.
   468     { PreserveReexecuteState preexecs(this);
   469       inc_sp(ndimensions);
   470       // Pass 0 as nargs since uncommon trap code does not need to restore stack.
   471       obj = expand_multianewarray(array_klass, &length[0], ndimensions, 0);
   472     } //original reexecute and sp are set back here
   473     push(obj);
   474     return;
   475   }
   477   address fun = NULL;
   478   switch (ndimensions) {
   479   case 1: ShouldNotReachHere(); break;
   480   case 2: fun = OptoRuntime::multianewarray2_Java(); break;
   481   case 3: fun = OptoRuntime::multianewarray3_Java(); break;
   482   case 4: fun = OptoRuntime::multianewarray4_Java(); break;
   483   case 5: fun = OptoRuntime::multianewarray5_Java(); break;
   484   };
   485   Node* c = NULL;
   487   if (fun != NULL) {
   488     c = make_runtime_call(RC_NO_LEAF | RC_NO_IO,
   489                           OptoRuntime::multianewarray_Type(ndimensions),
   490                           fun, NULL, TypeRawPtr::BOTTOM,
   491                           makecon(TypeKlassPtr::make(array_klass)),
   492                           length[0], length[1], length[2],
   493                           (ndimensions > 2) ? length[3] : NULL,
   494                           (ndimensions > 3) ? length[4] : NULL);
   495   } else {
   496     // Create a java array for dimension sizes
   497     Node* dims = NULL;
   498     { PreserveReexecuteState preexecs(this);
   499       inc_sp(ndimensions);
   500       Node* dims_array_klass = makecon(TypeKlassPtr::make(ciArrayKlass::make(ciType::make(T_INT))));
   501       dims = new_array(dims_array_klass, intcon(ndimensions), 0);
   503       // Fill-in it with values
   504       for (j = 0; j < ndimensions; j++) {
   505         Node *dims_elem = array_element_address(dims, intcon(j), T_INT);
   506         store_to_memory(control(), dims_elem, length[j], T_INT, TypeAryPtr::INTS);
   507       }
   508     }
   510     c = make_runtime_call(RC_NO_LEAF | RC_NO_IO,
   511                           OptoRuntime::multianewarrayN_Type(),
   512                           OptoRuntime::multianewarrayN_Java(), NULL, TypeRawPtr::BOTTOM,
   513                           makecon(TypeKlassPtr::make(array_klass)),
   514                           dims);
   515   }
   516   make_slow_call_ex(c, env()->Throwable_klass(), false);
   518   Node* res = _gvn.transform(new (C) ProjNode(c, TypeFunc::Parms));
   520   const Type* type = TypeOopPtr::make_from_klass_raw(array_klass);
   522   // Improve the type:  We know it's not null, exact, and of a given length.
   523   type = type->is_ptr()->cast_to_ptr_type(TypePtr::NotNull);
   524   type = type->is_aryptr()->cast_to_exactness(true);
   526   const TypeInt* ltype = _gvn.find_int_type(length[0]);
   527   if (ltype != NULL)
   528     type = type->is_aryptr()->cast_to_size(ltype);
   530     // We cannot sharpen the nested sub-arrays, since the top level is mutable.
   532   Node* cast = _gvn.transform( new (C) CheckCastPPNode(control(), res, type) );
   533   push(cast);
   535   // Possible improvements:
   536   // - Make a fast path for small multi-arrays.  (W/ implicit init. loops.)
   537   // - Issue CastII against length[*] values, to TypeInt::POS.
   538 }

mercurial