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  */
  24 
  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"
  38 
  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();
  49 
  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();
  56 
  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   }
  73 
  74   return access_OK;
  75 
  76 }
  77 
  78 
  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");
  83 
  84   ciInstanceKlass* field_holder = field->holder();
  85 
  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   }
  93 
  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   }
 102 
 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   }
 110 
 111   assert(field->will_link(method()->holder(), bc()), "getfield: typeflow responsibility");
 112 
 113   // Note:  We do not check for an unloaded field type here any more.
 114 
 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;
 122 
 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
 127 
 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 }
 145 
 146 
 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   }
 198 
 199   ciType* field_klass = field->type();
 200   bool is_vol = field->is_volatile();
 201 
 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();
 207 
 208   // Build the resultant type of the load
 209   const Type *type;
 210 
 211   bool must_assert_null = false;
 212 
 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   //
 232   LoadNode::Sem sem = is_vol ? LoadNode::acquire : LoadNode::unordered;
 233   Node* ld = make_load(NULL, adr, type, bt, adr_type, is_vol, sem);
 234 
 235   // Adjust Java stack
 236   if (type2size[bt] == 1)
 237     push(ld);
 238   else
 239     push_pair(ld);
 240 
 241   if (must_assert_null) {
 242     // Do not take a trap here.  It's possible that the program
 243     // will never load the field's class, and will happily see
 244     // null values in this field forever.  Don't stumble into a
 245     // trap for such a program, or we might get a long series
 246     // of useless recompilations.  (Or, we might load a class
 247     // which should not be loaded.)  If we ever see a non-null
 248     // value, we will then trap and recompile.  (The trap will
 249     // not need to mention the class index, since the class will
 250     // already have been loaded if we ever see a non-null value.)
 251     // uncommon_trap(iter().get_field_signature_index());
 252 #ifndef PRODUCT
 253     if (PrintOpto && (Verbose || WizardMode)) {
 254       method()->print_name(); tty->print_cr(" asserting nullness of field at bci: %d", bci());
 255     }
 256 #endif
 257     if (C->log() != NULL) {
 258       C->log()->elem("assert_null reason='field' klass='%d'",
 259                      C->log()->identify(field->type()));
 260     }
 261     // If there is going to be a trap, put it at the next bytecode:
 262     set_bci(iter().next_bci());
 263     null_assert(peek());
 264     set_bci(iter().cur_bci()); // put it back
 265   }
 266 
 267   // If reference is volatile, prevent following memory ops from
 268   // floating up past the volatile read.  Also prevents commoning
 269   // another volatile read.
 270   if (field->is_volatile()) {
 271     // Memory barrier includes bogus read of value to force load BEFORE membar
 272     insert_mem_bar(Op_MemBarAcquire, ld);
 273   }
 274 }
 275 
 276 void Parse::do_put_xxx(Node* obj, ciField* field, bool is_field) {
 277   bool is_vol = field->is_volatile();
 278   // If reference is volatile, prevent following memory ops from
 279   // floating down past the volatile write.  Also prevents commoning
 280   // another volatile read.
 281   if (is_vol)  insert_mem_bar(Op_MemBarRelease);
 282 
 283   // Compute address and memory type.
 284   int offset = field->offset_in_bytes();
 285   const TypePtr* adr_type = C->alias_type(field)->adr_type();
 286   Node* adr = basic_plus_adr(obj, obj, offset);
 287   BasicType bt = field->layout_type();
 288   // Value to be stored
 289   Node* val = type2size[bt] == 1 ? pop() : pop_pair();
 290   // Round doubles before storing
 291   if (bt == T_DOUBLE)  val = dstore_rounding(val);
 292 
 293   // Conservatively release stores of object references.
 294   const StoreNode::Sem sem =
 295     is_vol ?
 296     // Volatile fields need releasing stores.
 297     StoreNode::release :
 298     // Non-volatile fields also need releasing stores if they hold an
 299     // object reference, because the object reference might point to
 300     // a freshly created object.
 301     StoreNode::release_if_reference(bt);
 302 
 303   // Store the value.
 304   Node* store;
 305   if (bt == T_OBJECT) {
 306     const TypeOopPtr* field_type;
 307     if (!field->type()->is_loaded()) {
 308       field_type = TypeInstPtr::BOTTOM;
 309     } else {
 310       field_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
 311     }
 312     store = store_oop_to_object(control(), obj, adr, adr_type, val, field_type, bt, sem);
 313   } else {
 314     store = store_to_memory(control(), adr, val, bt, adr_type, is_vol, sem);
 315   }
 316 
 317   // If reference is volatile, prevent following volatiles ops from
 318   // floating up before the volatile write.
 319   if (is_vol) {
 320     insert_mem_bar(Op_MemBarVolatile); // Use fat membar
 321   }
 322 
 323   // If the field is final, the rules of Java say we are in <init> or <clinit>.
 324   // Note the presence of writes to final non-static fields, so that we
 325   // can insert a memory barrier later on to keep the writes from floating
 326   // out of the constructor.
 327   // Any method can write a @Stable field; insert memory barriers after those also.
 328   if (is_field && (field->is_final() || field->is_stable())) {
 329     set_wrote_final(true);
 330     // Preserve allocation ptr to create precedent edge to it in membar
 331     // generated on exit from constructor.
 332     if (C->eliminate_boxing() &&
 333         adr_type->isa_oopptr() && adr_type->is_oopptr()->is_ptr_to_boxed_value() &&
 334         AllocateNode::Ideal_allocation(obj, &_gvn) != NULL) {
 335       set_alloc_with_final(obj);
 336     }
 337   }
 338 }
 339 
 340 
 341 
 342 bool Parse::push_constant(ciConstant constant, bool require_constant, bool is_autobox_cache, const Type* stable_type) {
 343   const Type* con_type = Type::make_from_constant(constant, require_constant, is_autobox_cache);
 344   switch (constant.basic_type()) {
 345   case T_ARRAY:
 346   case T_OBJECT:
 347     // cases:
 348     //   can_be_constant    = (oop not scavengable || ScavengeRootsInCode != 0)
 349     //   should_be_constant = (oop not scavengable || ScavengeRootsInCode >= 2)
 350     // An oop is not scavengable if it is in the perm gen.
 351     if (stable_type != NULL && con_type != NULL && con_type->isa_oopptr())
 352       con_type = con_type->join(stable_type);
 353     break;
 354 
 355   case T_ILLEGAL:
 356     // Invalid ciConstant returned due to OutOfMemoryError in the CI
 357     assert(C->env()->failing(), "otherwise should not see this");
 358     // These always occur because of object types; we are going to
 359     // bail out anyway, so make the stack depths match up
 360     push( zerocon(T_OBJECT) );
 361     return false;
 362   }
 363 
 364   if (con_type == NULL)
 365     // we cannot inline the oop, but we can use it later to narrow a type
 366     return false;
 367 
 368   push_node(constant.basic_type(), makecon(con_type));
 369   return true;
 370 }
 371 
 372 
 373 //=============================================================================
 374 void Parse::do_anewarray() {
 375   bool will_link;
 376   ciKlass* klass = iter().get_klass(will_link);
 377 
 378   // Uncommon Trap when class that array contains is not loaded
 379   // we need the loaded class for the rest of graph; do not
 380   // initialize the container class (see Java spec)!!!
 381   assert(will_link, "anewarray: typeflow responsibility");
 382 
 383   ciObjArrayKlass* array_klass = ciObjArrayKlass::make(klass);
 384   // Check that array_klass object is loaded
 385   if (!array_klass->is_loaded()) {
 386     // Generate uncommon_trap for unloaded array_class
 387     uncommon_trap(Deoptimization::Reason_unloaded,
 388                   Deoptimization::Action_reinterpret,
 389                   array_klass);
 390     return;
 391   }
 392 
 393   kill_dead_locals();
 394 
 395   const TypeKlassPtr* array_klass_type = TypeKlassPtr::make(array_klass);
 396   Node* count_val = pop();
 397   Node* obj = new_array(makecon(array_klass_type), count_val, 1);
 398   push(obj);
 399 }
 400 
 401 
 402 void Parse::do_newarray(BasicType elem_type) {
 403   kill_dead_locals();
 404 
 405   Node*   count_val = pop();
 406   const TypeKlassPtr* array_klass = TypeKlassPtr::make(ciTypeArrayKlass::make(elem_type));
 407   Node*   obj = new_array(makecon(array_klass), count_val, 1);
 408   // Push resultant oop onto stack
 409   push(obj);
 410 }
 411 
 412 // Expand simple expressions like new int[3][5] and new Object[2][nonConLen].
 413 // Also handle the degenerate 1-dimensional case of anewarray.
 414 Node* Parse::expand_multianewarray(ciArrayKlass* array_klass, Node* *lengths, int ndimensions, int nargs) {
 415   Node* length = lengths[0];
 416   assert(length != NULL, "");
 417   Node* array = new_array(makecon(TypeKlassPtr::make(array_klass)), length, nargs);
 418   if (ndimensions > 1) {
 419     jint length_con = find_int_con(length, -1);
 420     guarantee(length_con >= 0, "non-constant multianewarray");
 421     ciArrayKlass* array_klass_1 = array_klass->as_obj_array_klass()->element_klass()->as_array_klass();
 422     const TypePtr* adr_type = TypeAryPtr::OOPS;
 423     const TypeOopPtr*    elemtype = _gvn.type(array)->is_aryptr()->elem()->make_oopptr();
 424     const intptr_t header   = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
 425     for (jint i = 0; i < length_con; i++) {
 426       Node*    elem   = expand_multianewarray(array_klass_1, &lengths[1], ndimensions-1, nargs);
 427       intptr_t offset = header + ((intptr_t)i << LogBytesPerHeapOop);
 428       Node*    eaddr  = basic_plus_adr(array, offset);
 429       store_oop_to_array(control(), array, eaddr, adr_type, elem, elemtype, T_OBJECT, StoreNode::unordered);
 430     }
 431   }
 432   return array;
 433 }
 434 
 435 void Parse::do_multianewarray() {
 436   int ndimensions = iter().get_dimensions();
 437 
 438   // the m-dimensional array
 439   bool will_link;
 440   ciArrayKlass* array_klass = iter().get_klass(will_link)->as_array_klass();
 441   assert(will_link, "multianewarray: typeflow responsibility");
 442 
 443   // Note:  Array classes are always initialized; no is_initialized check.
 444 
 445   kill_dead_locals();
 446 
 447   // get the lengths from the stack (first dimension is on top)
 448   Node** length = NEW_RESOURCE_ARRAY(Node*, ndimensions + 1);
 449   length[ndimensions] = NULL;  // terminating null for make_runtime_call
 450   int j;
 451   for (j = ndimensions-1; j >= 0 ; j--) length[j] = pop();
 452 
 453   // The original expression was of this form: new T[length0][length1]...
 454   // It is often the case that the lengths are small (except the last).
 455   // If that happens, use the fast 1-d creator a constant number of times.
 456   const jint expand_limit = MIN2((juint)MultiArrayExpandLimit, (juint)100);
 457   jint expand_count = 1;        // count of allocations in the expansion
 458   jint expand_fanout = 1;       // running total fanout
 459   for (j = 0; j < ndimensions-1; j++) {
 460     jint dim_con = find_int_con(length[j], -1);
 461     expand_fanout *= dim_con;
 462     expand_count  += expand_fanout; // count the level-J sub-arrays
 463     if (dim_con <= 0
 464         || dim_con > expand_limit
 465         || expand_count > expand_limit) {
 466       expand_count = 0;
 467       break;
 468     }
 469   }
 470 
 471   // Can use multianewarray instead of [a]newarray if only one dimension,
 472   // or if all non-final dimensions are small constants.
 473   if (ndimensions == 1 || (1 <= expand_count && expand_count <= expand_limit)) {
 474     Node* obj = NULL;
 475     // Set the original stack and the reexecute bit for the interpreter
 476     // to reexecute the multianewarray bytecode if deoptimization happens.
 477     // Do it unconditionally even for one dimension multianewarray.
 478     // Note: the reexecute bit will be set in GraphKit::add_safepoint_edges()
 479     // when AllocateArray node for newarray is created.
 480     { PreserveReexecuteState preexecs(this);
 481       inc_sp(ndimensions);
 482       // Pass 0 as nargs since uncommon trap code does not need to restore stack.
 483       obj = expand_multianewarray(array_klass, &length[0], ndimensions, 0);
 484     } //original reexecute and sp are set back here
 485     push(obj);
 486     return;
 487   }
 488 
 489   address fun = NULL;
 490   switch (ndimensions) {
 491   case 1: ShouldNotReachHere(); break;
 492   case 2: fun = OptoRuntime::multianewarray2_Java(); break;
 493   case 3: fun = OptoRuntime::multianewarray3_Java(); break;
 494   case 4: fun = OptoRuntime::multianewarray4_Java(); break;
 495   case 5: fun = OptoRuntime::multianewarray5_Java(); break;
 496   };
 497   Node* c = NULL;
 498 
 499   if (fun != NULL) {
 500     c = make_runtime_call(RC_NO_LEAF | RC_NO_IO,
 501                           OptoRuntime::multianewarray_Type(ndimensions),
 502                           fun, NULL, TypeRawPtr::BOTTOM,
 503                           makecon(TypeKlassPtr::make(array_klass)),
 504                           length[0], length[1], length[2],
 505                           (ndimensions > 2) ? length[3] : NULL,
 506                           (ndimensions > 3) ? length[4] : NULL);
 507   } else {
 508     // Create a java array for dimension sizes
 509     Node* dims = NULL;
 510     { PreserveReexecuteState preexecs(this);
 511       inc_sp(ndimensions);
 512       Node* dims_array_klass = makecon(TypeKlassPtr::make(ciArrayKlass::make(ciType::make(T_INT))));
 513       dims = new_array(dims_array_klass, intcon(ndimensions), 0);
 514 
 515       // Fill-in it with values
 516       for (j = 0; j < ndimensions; j++) {
 517         Node *dims_elem = array_element_address(dims, intcon(j), T_INT);
 518         store_to_memory(control(), dims_elem, length[j], T_INT, TypeAryPtr::INTS, false, StoreNode::unordered);
 519       }
 520     }
 521 
 522     c = make_runtime_call(RC_NO_LEAF | RC_NO_IO,
 523                           OptoRuntime::multianewarrayN_Type(),
 524                           OptoRuntime::multianewarrayN_Java(), NULL, TypeRawPtr::BOTTOM,
 525                           makecon(TypeKlassPtr::make(array_klass)),
 526                           dims);
 527   }
 528   make_slow_call_ex(c, env()->Throwable_klass(), false);
 529 
 530   Node* res = _gvn.transform(new (C) ProjNode(c, TypeFunc::Parms));
 531 
 532   const Type* type = TypeOopPtr::make_from_klass_raw(array_klass);
 533 
 534   // Improve the type:  We know it's not null, exact, and of a given length.
 535   type = type->is_ptr()->cast_to_ptr_type(TypePtr::NotNull);
 536   type = type->is_aryptr()->cast_to_exactness(true);
 537 
 538   const TypeInt* ltype = _gvn.find_int_type(length[0]);
 539   if (ltype != NULL)
 540     type = type->is_aryptr()->cast_to_size(ltype);
 541 
 542     // We cannot sharpen the nested sub-arrays, since the top level is mutable.
 543 
 544   Node* cast = _gvn.transform( new (C) CheckCastPPNode(control(), res, type) );
 545   push(cast);
 546 
 547   // Possible improvements:
 548   // - Make a fast path for small multi-arrays.  (W/ implicit init. loops.)
 549   // - Issue CastII against length[*] values, to TypeInt::POS.
 550 }