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/castnode.hpp"
  32 #include "opto/memnode.hpp"
  33 #include "opto/parse.hpp"
  34 #include "opto/rootnode.hpp"
  35 #include "opto/runtime.hpp"
  36 #include "opto/subnode.hpp"
  37 #include "runtime/deoptimization.hpp"
  38 #include "runtime/handles.inline.hpp"
  39 
  40 //=============================================================================
  41 // Helper methods for _get* and _put* bytecodes
  42 //=============================================================================
  43 bool Parse::static_field_ok_in_clinit(ciField *field, ciMethod *method) {
  44   // Could be the field_holder's <clinit> method, or <clinit> for a subklass.
  45   // Better to check now than to Deoptimize as soon as we execute
  46   assert( field->is_static(), "Only check if field is static");
  47   // is_being_initialized() is too generous.  It allows access to statics
  48   // by threads that are not running the <clinit> before the <clinit> finishes.
  49   // return field->holder()->is_being_initialized();
  50 
  51   // The following restriction is correct but conservative.
  52   // It is also desirable to allow compilation of methods called from <clinit>
  53   // but this generated code will need to be made safe for execution by
  54   // other threads, or the transition from interpreted to compiled code would
  55   // need to be guarded.
  56   ciInstanceKlass *field_holder = field->holder();
  57 
  58   bool access_OK = false;
  59   if (method->holder()->is_subclass_of(field_holder)) {
  60     if (method->is_static()) {
  61       if (method->name() == ciSymbol::class_initializer_name()) {
  62         // OK to access static fields inside initializer
  63         access_OK = true;
  64       }
  65     } else {
  66       if (method->name() == ciSymbol::object_initializer_name()) {
  67         // It's also OK to access static fields inside a constructor,
  68         // because any thread calling the constructor must first have
  69         // synchronized on the class by executing a '_new' bytecode.
  70         access_OK = true;
  71       }
  72     }
  73   }
  74 
  75   return access_OK;
  76 
  77 }
  78 
  79 
  80 void Parse::do_field_access(bool is_get, bool is_field) {
  81   bool will_link;
  82   ciField* field = iter().get_field(will_link);
  83   assert(will_link, "getfield: typeflow responsibility");
  84 
  85   ciInstanceKlass* field_holder = field->holder();
  86 
  87   if (is_field == field->is_static()) {
  88     // Interpreter will throw java_lang_IncompatibleClassChangeError
  89     // Check this before allowing <clinit> methods to access static fields
  90     uncommon_trap(Deoptimization::Reason_unhandled,
  91                   Deoptimization::Action_none);
  92     return;
  93   }
  94 
  95   if (!is_field && !field_holder->is_initialized()) {
  96     if (!static_field_ok_in_clinit(field, method())) {
  97       uncommon_trap(Deoptimization::Reason_uninitialized,
  98                     Deoptimization::Action_reinterpret,
  99                     NULL, "!static_field_ok_in_clinit");
 100       return;
 101     }
 102   }
 103 
 104   // Deoptimize on putfield writes to call site target field.
 105   if (!is_get && field->is_call_site_target()) {
 106     uncommon_trap(Deoptimization::Reason_unhandled,
 107                   Deoptimization::Action_reinterpret,
 108                   NULL, "put to call site target field");
 109     return;
 110   }
 111 
 112   assert(field->will_link(method()->holder(), bc()), "getfield: typeflow responsibility");
 113 
 114   // Note:  We do not check for an unloaded field type here any more.
 115 
 116   // Generate code for the object pointer.
 117   Node* obj;
 118   if (is_field) {
 119     int obj_depth = is_get ? 0 : field->type()->size();
 120     obj = null_check(peek(obj_depth));
 121     // Compile-time detect of null-exception?
 122     if (stopped())  return;
 123 
 124 #ifdef ASSERT
 125     const TypeInstPtr *tjp = TypeInstPtr::make(TypePtr::NotNull, iter().get_declared_field_holder());
 126     assert(_gvn.type(obj)->higher_equal(tjp), "cast_up is no longer needed");
 127 #endif
 128 
 129     if (is_get) {
 130       (void) pop();  // pop receiver before getting
 131       do_get_xxx(obj, field, is_field);
 132     } else {
 133       do_put_xxx(obj, field, is_field);
 134       (void) pop();  // pop receiver after putting
 135     }
 136   } else {
 137     const TypeInstPtr* tip = TypeInstPtr::make(field_holder->java_mirror());
 138     obj = _gvn.makecon(tip);
 139     if (is_get) {
 140       do_get_xxx(obj, field, is_field);
 141     } else {
 142       do_put_xxx(obj, field, is_field);
 143     }
 144   }
 145 }
 146 
 147 
 148 void Parse::do_get_xxx(Node* obj, ciField* field, bool is_field) {
 149   // Does this field have a constant value?  If so, just push the value.
 150   if (field->is_constant()) {
 151     // final or stable field
 152     const Type* con_type = Type::make_constant(field, obj);
 153     if (con_type != NULL) {
 154       push_node(con_type->basic_type(), makecon(con_type));
 155       return;
 156     }
 157   }
 158 
 159   ciType* field_klass = field->type();
 160   bool is_vol = field->is_volatile();
 161 
 162   // Compute address and memory type.
 163   int offset = field->offset_in_bytes();
 164   const TypePtr* adr_type = C->alias_type(field)->adr_type();
 165 
 166   // Insert read barrier for Shenandoah.
 167   obj = shenandoah_read_barrier(obj);
 168 
 169   Node *adr = basic_plus_adr(obj, obj, offset);
 170   BasicType bt = field->layout_type();
 171 
 172   // Build the resultant type of the load
 173   const Type *type;
 174 
 175   bool must_assert_null = false;
 176 
 177   if( bt == T_OBJECT ) {
 178     if (!field->type()->is_loaded()) {
 179       type = TypeInstPtr::BOTTOM;
 180       must_assert_null = true;
 181     } else if (field->is_constant() && field->is_static()) {
 182       // This can happen if the constant oop is non-perm.
 183       ciObject* con = field->constant_value().as_object();
 184       // Do not "join" in the previous type; it doesn't add value,
 185       // and may yield a vacuous result if the field is of interface type.
 186       type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
 187       assert(type != NULL, "field singleton type must be consistent");
 188     } else {
 189       type = TypeOopPtr::make_from_klass(field_klass->as_klass());
 190     }
 191   } else {
 192     type = Type::get_const_basic_type(bt);
 193   }
 194   if (support_IRIW_for_not_multiple_copy_atomic_cpu && field->is_volatile()) {
 195     insert_mem_bar(Op_MemBarVolatile);   // StoreLoad barrier
 196   }
 197   // Build the load.
 198   //
 199   MemNode::MemOrd mo = is_vol ? MemNode::acquire : MemNode::unordered;
 200   bool needs_atomic_access = is_vol || AlwaysAtomicAccesses;
 201   Node* ld = make_load(NULL, adr, type, bt, adr_type, mo, LoadNode::DependsOnlyOnTest, needs_atomic_access);
 202 
 203   // Adjust Java stack
 204   if (type2size[bt] == 1)
 205     push(ld);
 206   else
 207     push_pair(ld);
 208 
 209   if (must_assert_null) {
 210     // Do not take a trap here.  It's possible that the program
 211     // will never load the field's class, and will happily see
 212     // null values in this field forever.  Don't stumble into a
 213     // trap for such a program, or we might get a long series
 214     // of useless recompilations.  (Or, we might load a class
 215     // which should not be loaded.)  If we ever see a non-null
 216     // value, we will then trap and recompile.  (The trap will
 217     // not need to mention the class index, since the class will
 218     // already have been loaded if we ever see a non-null value.)
 219     // uncommon_trap(iter().get_field_signature_index());
 220 #ifndef PRODUCT
 221     if (PrintOpto && (Verbose || WizardMode)) {
 222       method()->print_name(); tty->print_cr(" asserting nullness of field at bci: %d", bci());
 223     }
 224 #endif
 225     if (C->log() != NULL) {
 226       C->log()->elem("assert_null reason='field' klass='%d'",
 227                      C->log()->identify(field->type()));
 228     }
 229     // If there is going to be a trap, put it at the next bytecode:
 230     set_bci(iter().next_bci());
 231     null_assert(peek());
 232     set_bci(iter().cur_bci()); // put it back
 233   }
 234 
 235   // If reference is volatile, prevent following memory ops from
 236   // floating up past the volatile read.  Also prevents commoning
 237   // another volatile read.
 238   if (field->is_volatile()) {
 239     // Memory barrier includes bogus read of value to force load BEFORE membar
 240     insert_mem_bar(Op_MemBarAcquire, ld);
 241   }
 242 }
 243 
 244 void Parse::do_put_xxx(Node* obj, ciField* field, bool is_field) {
 245   bool is_vol = field->is_volatile();
 246   // If reference is volatile, prevent following memory ops from
 247   // floating down past the volatile write.  Also prevents commoning
 248   // another volatile read.
 249   if (is_vol)  insert_mem_bar(Op_MemBarRelease);
 250 
 251   // Insert write barrier for Shenandoah.
 252   obj = shenandoah_write_barrier(obj);
 253 
 254   // Compute address and memory type.
 255   int offset = field->offset_in_bytes();
 256   const TypePtr* adr_type = C->alias_type(field)->adr_type();
 257   Node* adr = basic_plus_adr(obj, obj, offset);
 258   BasicType bt = field->layout_type();
 259   // Value to be stored
 260   Node* val = type2size[bt] == 1 ? pop() : pop_pair();
 261   // Round doubles before storing
 262   if (bt == T_DOUBLE)  val = dstore_rounding(val);
 263 
 264   // Conservatively release stores of object references.
 265   const MemNode::MemOrd mo =
 266     is_vol ?
 267     // Volatile fields need releasing stores.
 268     MemNode::release :
 269     // Non-volatile fields also need releasing stores if they hold an
 270     // object reference, because the object reference might point to
 271     // a freshly created object.
 272     StoreNode::release_if_reference(bt);
 273 
 274   // Store the value.
 275   Node* store;
 276   if (bt == T_OBJECT) {
 277     const TypeOopPtr* field_type;
 278     if (!field->type()->is_loaded()) {
 279       field_type = TypeInstPtr::BOTTOM;
 280     } else {
 281       field_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
 282     }
 283 
 284     val = shenandoah_read_barrier_nomem(val);
 285 
 286     store = store_oop_to_object(control(), obj, adr, adr_type, val, field_type, bt, mo);
 287   } else {
 288     bool needs_atomic_access = is_vol || AlwaysAtomicAccesses;
 289     store = store_to_memory(control(), adr, val, bt, adr_type, mo, needs_atomic_access);
 290   }
 291 
 292   // If reference is volatile, prevent following volatiles ops from
 293   // floating up before the volatile write.
 294   if (is_vol) {
 295     // If not multiple copy atomic, we do the MemBarVolatile before the load.
 296     if (!support_IRIW_for_not_multiple_copy_atomic_cpu) {
 297       insert_mem_bar(Op_MemBarVolatile); // Use fat membar
 298     }
 299     // Remember we wrote a volatile field.
 300     // For not multiple copy atomic cpu (ppc64) a barrier should be issued
 301     // in constructors which have such stores. See do_exits() in parse1.cpp.
 302     if (is_field) {
 303       set_wrote_volatile(true);
 304     }
 305   }
 306 
 307   if (is_field) {
 308     set_wrote_fields(true);
 309   }
 310 
 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     if (field->is_final()) {
 318         set_wrote_final(true);
 319     }
 320     if (field->is_stable()) {
 321         set_wrote_stable(true);
 322     }
 323 
 324     // Preserve allocation ptr to create precedent edge to it in membar
 325     // generated on exit from constructor.
 326     if (C->eliminate_boxing() &&
 327         adr_type->isa_oopptr() && adr_type->is_oopptr()->is_ptr_to_boxed_value() &&
 328         AllocateNode::Ideal_allocation(obj, &_gvn) != NULL) {
 329       set_alloc_with_final(obj);
 330     }
 331   }
 332 }
 333 
 334 //=============================================================================
 335 void Parse::do_anewarray() {
 336   bool will_link;
 337   ciKlass* klass = iter().get_klass(will_link);
 338 
 339   // Uncommon Trap when class that array contains is not loaded
 340   // we need the loaded class for the rest of graph; do not
 341   // initialize the container class (see Java spec)!!!
 342   assert(will_link, "anewarray: typeflow responsibility");
 343 
 344   ciObjArrayKlass* array_klass = ciObjArrayKlass::make(klass);
 345   // Check that array_klass object is loaded
 346   if (!array_klass->is_loaded()) {
 347     // Generate uncommon_trap for unloaded array_class
 348     uncommon_trap(Deoptimization::Reason_unloaded,
 349                   Deoptimization::Action_reinterpret,
 350                   array_klass);
 351     return;
 352   }
 353 
 354   kill_dead_locals();
 355 
 356   const TypeKlassPtr* array_klass_type = TypeKlassPtr::make(array_klass);
 357   Node* count_val = pop();
 358   Node* obj = new_array(makecon(array_klass_type), count_val, 1);
 359   push(obj);
 360 }
 361 
 362 
 363 void Parse::do_newarray(BasicType elem_type) {
 364   kill_dead_locals();
 365 
 366   Node*   count_val = pop();
 367   const TypeKlassPtr* array_klass = TypeKlassPtr::make(ciTypeArrayKlass::make(elem_type));
 368   Node*   obj = new_array(makecon(array_klass), count_val, 1);
 369   // Push resultant oop onto stack
 370   push(obj);
 371 }
 372 
 373 // Expand simple expressions like new int[3][5] and new Object[2][nonConLen].
 374 // Also handle the degenerate 1-dimensional case of anewarray.
 375 Node* Parse::expand_multianewarray(ciArrayKlass* array_klass, Node* *lengths, int ndimensions, int nargs) {
 376   Node* length = lengths[0];
 377   assert(length != NULL, "");
 378   Node* array = new_array(makecon(TypeKlassPtr::make(array_klass)), length, nargs);
 379   if (ndimensions > 1) {
 380     jint length_con = find_int_con(length, -1);
 381     guarantee(length_con >= 0, "non-constant multianewarray");
 382     ciArrayKlass* array_klass_1 = array_klass->as_obj_array_klass()->element_klass()->as_array_klass();
 383     const TypePtr* adr_type = TypeAryPtr::OOPS;
 384     const TypeOopPtr*    elemtype = _gvn.type(array)->is_aryptr()->elem()->make_oopptr();
 385     const intptr_t header   = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
 386     for (jint i = 0; i < length_con; i++) {
 387       Node*    elem   = expand_multianewarray(array_klass_1, &lengths[1], ndimensions-1, nargs);
 388       intptr_t offset = header + ((intptr_t)i << LogBytesPerHeapOop);
 389       Node*    eaddr  = basic_plus_adr(array, offset);
 390       store_oop_to_array(control(), array, eaddr, adr_type, elem, elemtype, T_OBJECT, MemNode::unordered);
 391     }
 392   }
 393   return array;
 394 }
 395 
 396 void Parse::do_multianewarray() {
 397   int ndimensions = iter().get_dimensions();
 398 
 399   // the m-dimensional array
 400   bool will_link;
 401   ciArrayKlass* array_klass = iter().get_klass(will_link)->as_array_klass();
 402   assert(will_link, "multianewarray: typeflow responsibility");
 403 
 404   // Note:  Array classes are always initialized; no is_initialized check.
 405 
 406   kill_dead_locals();
 407 
 408   // get the lengths from the stack (first dimension is on top)
 409   Node** length = NEW_RESOURCE_ARRAY(Node*, ndimensions + 1);
 410   length[ndimensions] = NULL;  // terminating null for make_runtime_call
 411   int j;
 412   for (j = ndimensions-1; j >= 0 ; j--) length[j] = pop();
 413 
 414   // The original expression was of this form: new T[length0][length1]...
 415   // It is often the case that the lengths are small (except the last).
 416   // If that happens, use the fast 1-d creator a constant number of times.
 417   const jint expand_limit = MIN2((juint)MultiArrayExpandLimit, (juint)100);
 418   jint expand_count = 1;        // count of allocations in the expansion
 419   jint expand_fanout = 1;       // running total fanout
 420   for (j = 0; j < ndimensions-1; j++) {
 421     jint dim_con = find_int_con(length[j], -1);
 422     expand_fanout *= dim_con;
 423     expand_count  += expand_fanout; // count the level-J sub-arrays
 424     if (dim_con <= 0
 425         || dim_con > expand_limit
 426         || expand_count > expand_limit) {
 427       expand_count = 0;
 428       break;
 429     }
 430   }
 431 
 432   // Can use multianewarray instead of [a]newarray if only one dimension,
 433   // or if all non-final dimensions are small constants.
 434   if (ndimensions == 1 || (1 <= expand_count && expand_count <= expand_limit)) {
 435     Node* obj = NULL;
 436     // Set the original stack and the reexecute bit for the interpreter
 437     // to reexecute the multianewarray bytecode if deoptimization happens.
 438     // Do it unconditionally even for one dimension multianewarray.
 439     // Note: the reexecute bit will be set in GraphKit::add_safepoint_edges()
 440     // when AllocateArray node for newarray is created.
 441     { PreserveReexecuteState preexecs(this);
 442       inc_sp(ndimensions);
 443       // Pass 0 as nargs since uncommon trap code does not need to restore stack.
 444       obj = expand_multianewarray(array_klass, &length[0], ndimensions, 0);
 445     } //original reexecute and sp are set back here
 446     push(obj);
 447     return;
 448   }
 449 
 450   address fun = NULL;
 451   switch (ndimensions) {
 452   case 1: ShouldNotReachHere(); break;
 453   case 2: fun = OptoRuntime::multianewarray2_Java(); break;
 454   case 3: fun = OptoRuntime::multianewarray3_Java(); break;
 455   case 4: fun = OptoRuntime::multianewarray4_Java(); break;
 456   case 5: fun = OptoRuntime::multianewarray5_Java(); break;
 457   };
 458   Node* c = NULL;
 459 
 460   if (fun != NULL) {
 461     c = make_runtime_call(RC_NO_LEAF | RC_NO_IO,
 462                           OptoRuntime::multianewarray_Type(ndimensions),
 463                           fun, NULL, TypeRawPtr::BOTTOM,
 464                           makecon(TypeKlassPtr::make(array_klass)),
 465                           length[0], length[1], length[2],
 466                           (ndimensions > 2) ? length[3] : NULL,
 467                           (ndimensions > 3) ? length[4] : NULL);
 468   } else {
 469     // Create a java array for dimension sizes
 470     Node* dims = NULL;
 471     { PreserveReexecuteState preexecs(this);
 472       inc_sp(ndimensions);
 473       Node* dims_array_klass = makecon(TypeKlassPtr::make(ciArrayKlass::make(ciType::make(T_INT))));
 474       dims = new_array(dims_array_klass, intcon(ndimensions), 0);
 475 
 476       // Fill-in it with values
 477       for (j = 0; j < ndimensions; j++) {
 478         Node *dims_elem = array_element_address(dims, intcon(j), T_INT);
 479         store_to_memory(control(), dims_elem, length[j], T_INT, TypeAryPtr::INTS, MemNode::unordered);
 480       }
 481     }
 482 
 483     c = make_runtime_call(RC_NO_LEAF | RC_NO_IO,
 484                           OptoRuntime::multianewarrayN_Type(),
 485                           OptoRuntime::multianewarrayN_Java(), NULL, TypeRawPtr::BOTTOM,
 486                           makecon(TypeKlassPtr::make(array_klass)),
 487                           dims);
 488   }
 489   make_slow_call_ex(c, env()->Throwable_klass(), false);
 490 
 491   Node* res = _gvn.transform(new ProjNode(c, TypeFunc::Parms));
 492 
 493   const Type* type = TypeOopPtr::make_from_klass_raw(array_klass);
 494 
 495   // Improve the type:  We know it's not null, exact, and of a given length.
 496   type = type->is_ptr()->cast_to_ptr_type(TypePtr::NotNull);
 497   type = type->is_aryptr()->cast_to_exactness(true);
 498 
 499   const TypeInt* ltype = _gvn.find_int_type(length[0]);
 500   if (ltype != NULL)
 501     type = type->is_aryptr()->cast_to_size(ltype);
 502 
 503     // We cannot sharpen the nested sub-arrays, since the top level is mutable.
 504 
 505   Node* cast = _gvn.transform( new CheckCastPPNode(control(), res, type) );
 506   push(cast);
 507 
 508   // Possible improvements:
 509   // - Make a fast path for small multi-arrays.  (W/ implicit init. loops.)
 510   // - Issue CastII against length[*] values, to TypeInt::POS.
 511 }