1 /*
   2  * Copyright (c) 2017, 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 "ci/ciValueKlass.hpp"
  27 #include "opto/addnode.hpp"
  28 #include "opto/castnode.hpp"
  29 #include "opto/graphKit.hpp"
  30 #include "opto/rootnode.hpp"
  31 #include "opto/valuetypenode.hpp"
  32 #include "opto/phaseX.hpp"
  33 
  34 // Clones the values type to handle control flow merges involving multiple value types.
  35 // The inputs are replaced by PhiNodes to represent the merged values for the given region.
  36 ValueTypeBaseNode* ValueTypeBaseNode::clone_with_phis(PhaseGVN* gvn, Node* region) {
  37   assert(!has_phi_inputs(region), "already cloned with phis");
  38   ValueTypeBaseNode* vt = clone()->as_ValueTypeBase();
  39 
  40   // Create a PhiNode for merging the oop values
  41   const Type* phi_type = Type::get_const_type(value_klass());
  42   PhiNode* oop = PhiNode::make(region, vt->get_oop(), phi_type);
  43   gvn->set_type(oop, phi_type);
  44   vt->set_oop(oop);
  45 
  46   // Create a PhiNode each for merging the field values
  47   for (uint i = 0; i < vt->field_count(); ++i) {
  48     ciType* type = vt->field_type(i);
  49     Node*  value = vt->field_value(i);
  50     if (type->is_valuetype() && value->isa_ValueType()) {
  51       // Handle flattened value type fields recursively
  52       value = value->as_ValueType()->clone_with_phis(gvn, region);
  53     } else {
  54       phi_type = Type::get_const_type(type);
  55       value = PhiNode::make(region, value, phi_type);
  56       gvn->set_type(value, phi_type);
  57     }
  58     vt->set_field_value(i, value);
  59   }
  60   gvn->set_type(vt, vt->bottom_type());
  61   return vt;
  62 }
  63 
  64 // Checks if the inputs of the ValueBaseTypeNode were replaced by PhiNodes
  65 // for the given region (see ValueBaseTypeNode::clone_with_phis).
  66 bool ValueTypeBaseNode::has_phi_inputs(Node* region) {
  67   // Check oop input
  68   bool result = get_oop()->is_Phi() && get_oop()->as_Phi()->region() == region;
  69 #ifdef ASSERT
  70   if (result) {
  71     // Check all field value inputs for consistency
  72     for (uint i = Oop; i < field_count(); ++i) {
  73       Node* n = in(i);
  74       if (n->is_ValueTypeBase()) {
  75         assert(n->as_ValueTypeBase()->has_phi_inputs(region), "inconsistent phi inputs");
  76       } else {
  77         assert(n->is_Phi() && n->as_Phi()->region() == region, "inconsistent phi inputs");
  78       }
  79     }
  80   }
  81 #endif
  82   return result;
  83 }
  84 
  85 // Merges 'this' with 'other' by updating the input PhiNodes added by 'clone_with_phis'
  86 ValueTypeBaseNode* ValueTypeBaseNode::merge_with(PhaseGVN* gvn, const ValueTypeBaseNode* other, int pnum, bool transform) {
  87   // Merge oop inputs
  88   PhiNode* phi = get_oop()->as_Phi();
  89   phi->set_req(pnum, other->get_oop());
  90   if (transform) {
  91     set_oop(gvn->transform(phi));
  92     gvn->record_for_igvn(phi);
  93   }
  94   // Merge field values
  95   for (uint i = 0; i < field_count(); ++i) {
  96     Node* val1 =        field_value(i);
  97     Node* val2 = other->field_value(i);
  98     if (val1->is_ValueType()) {
  99       val1->as_ValueType()->merge_with(gvn, val2->as_ValueType(), pnum, transform);
 100     } else {
 101       assert(val1->is_Phi(), "must be a phi node");
 102       assert(!val2->is_ValueType(), "inconsistent merge values");
 103       val1->set_req(pnum, val2);
 104     }
 105     if (transform) {
 106       set_field_value(i, gvn->transform(val1));
 107       gvn->record_for_igvn(val1);
 108     }
 109   }
 110   return this;
 111 }
 112 
 113 // Adds a new merge path to a valuetype node with phi inputs
 114 void ValueTypeBaseNode::add_new_path(Node* region) {
 115   assert(has_phi_inputs(region), "must have phi inputs");
 116 
 117   PhiNode* phi = get_oop()->as_Phi();
 118   phi->add_req(NULL);
 119   assert(phi->req() == region->req(), "must be same size as region");
 120 
 121   for (uint i = 0; i < field_count(); ++i) {
 122     Node* val = field_value(i);
 123     if (val->is_ValueType()) {
 124       val->as_ValueType()->add_new_path(region);
 125     } else {
 126       val->as_Phi()->add_req(NULL);
 127       assert(val->req() == region->req(), "must be same size as region");
 128     }
 129   }
 130 }
 131 
 132 Node* ValueTypeBaseNode::field_value(uint index) const {
 133   assert(index < field_count(), "index out of bounds");
 134   return in(Values + index);
 135 }
 136 
 137 // Get the value of the field at the given offset.
 138 // If 'recursive' is true, flattened value type fields will be resolved recursively.
 139 Node* ValueTypeBaseNode::field_value_by_offset(int offset, bool recursive) const {
 140   // If the field at 'offset' belongs to a flattened value type field, 'index' refers to the
 141   // corresponding ValueTypeNode input and 'sub_offset' is the offset in flattened value type.
 142   int index = value_klass()->field_index_by_offset(offset);
 143   int sub_offset = offset - field_offset(index);
 144   Node* value = field_value(index);
 145   assert(value != NULL, "field value not found");
 146   if (recursive && value->is_ValueType()) {
 147     ValueTypeNode* vt = value->as_ValueType();
 148     if (field_is_flattened(index)) {
 149       // Flattened value type field
 150       sub_offset += vt->value_klass()->first_field_offset(); // Add header size
 151       return vt->field_value_by_offset(sub_offset, recursive);
 152     } else {
 153       assert(sub_offset == 0, "should not have a sub offset");
 154       return vt;
 155     }
 156   }
 157   assert(!(recursive && value->is_ValueType()), "should not be a value type");
 158   assert(sub_offset == 0, "offset mismatch");
 159   return value;
 160 }
 161 
 162 void ValueTypeBaseNode::set_field_value(uint index, Node* value) {
 163   assert(index < field_count(), "index out of bounds");
 164   set_req(Values + index, value);
 165 }
 166 
 167 void ValueTypeBaseNode::set_field_value_by_offset(int offset, Node* value) {
 168   uint i = 0;
 169   for (; i < field_count() && field_offset(i) != offset; i++) { }
 170   assert(i < field_count(), "field not found");
 171   set_field_value(i, value);
 172 }
 173 
 174 int ValueTypeBaseNode::field_offset(uint index) const {
 175   assert(index < field_count(), "index out of bounds");
 176   return value_klass()->declared_nonstatic_field_at(index)->offset();
 177 }
 178 
 179 ciType* ValueTypeBaseNode::field_type(uint index) const {
 180   assert(index < field_count(), "index out of bounds");
 181   return value_klass()->declared_nonstatic_field_at(index)->type();
 182 }
 183 
 184 bool ValueTypeBaseNode::field_is_flattened(uint index) const {
 185   assert(index < field_count(), "index out of bounds");
 186   ciField* field = value_klass()->declared_nonstatic_field_at(index);
 187   assert(!field->is_flattened() || field->type()->is_valuetype(), "must be a value type");
 188   return field->is_flattened();
 189 }
 190 
 191 bool ValueTypeBaseNode::field_is_flattenable(uint index) const {
 192   assert(index < field_count(), "index out of bounds");
 193   ciField* field = value_klass()->declared_nonstatic_field_at(index);
 194   assert(!field->is_flattenable() || field->type()->is_valuetype(), "must be a value type");
 195   return field->is_flattenable();
 196 }
 197 
 198 int ValueTypeBaseNode::make_scalar_in_safepoint(PhaseIterGVN* igvn, Unique_Node_List& worklist, SafePointNode* sfpt) {
 199   ciValueKlass* vk = value_klass();
 200   uint nfields = vk->nof_nonstatic_fields();
 201   JVMState* jvms = sfpt->jvms();
 202   int start = jvms->debug_start();
 203   int end   = jvms->debug_end();
 204   // Replace safepoint edge by SafePointScalarObjectNode and add field values
 205   assert(jvms != NULL, "missing JVMS");
 206   uint first_ind = (sfpt->req() - jvms->scloff());
 207   SafePointScalarObjectNode* sobj = new SafePointScalarObjectNode(value_ptr(),
 208 #ifdef ASSERT
 209                                                                   NULL,
 210 #endif
 211                                                                   first_ind, nfields);
 212   sobj->init_req(0, igvn->C->root());
 213   // Iterate over the value type fields in order of increasing
 214   // offset and add the field values to the safepoint.
 215   for (uint j = 0; j < nfields; ++j) {
 216     int offset = vk->nonstatic_field_at(j)->offset();
 217     Node* value = field_value_by_offset(offset, true /* include flattened value type fields */);
 218     if (value->is_ValueType()) {
 219       // Add value type field to the worklist to process later
 220       worklist.push(value);
 221     }
 222     sfpt->add_req(value);
 223   }
 224   jvms->set_endoff(sfpt->req());
 225   sobj = igvn->transform(sobj)->as_SafePointScalarObject();
 226   igvn->rehash_node_delayed(sfpt);
 227   return sfpt->replace_edges_in_range(this, sobj, start, end);
 228 }
 229 
 230 void ValueTypeBaseNode::make_scalar_in_safepoints(PhaseIterGVN* igvn) {
 231   // Process all safepoint uses and scalarize value type
 232   Unique_Node_List worklist;
 233   for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
 234     SafePointNode* sfpt = fast_out(i)->isa_SafePoint();
 235     if (sfpt != NULL && !sfpt->is_CallLeaf() && (!sfpt->is_Call() || sfpt->as_Call()->has_debug_use(this))) {
 236       int nb = 0;
 237       if (is_allocated(igvn) && get_oop()->is_Con()) {
 238         // Value type is allocated with a constant oop, link it directly
 239         nb = sfpt->replace_edges_in_range(this, get_oop(), sfpt->jvms()->debug_start(), sfpt->jvms()->debug_end());
 240         igvn->rehash_node_delayed(sfpt);
 241       } else {
 242         nb = make_scalar_in_safepoint(igvn, worklist, sfpt);
 243       }
 244       --i; imax -= nb;
 245     }
 246   }
 247   // Now scalarize non-flattened fields
 248   for (uint i = 0; i < worklist.size(); ++i) {
 249     Node* vt = worklist.at(i);
 250     vt->as_ValueType()->make_scalar_in_safepoints(igvn);
 251   }
 252 }
 253 
 254 void ValueTypeBaseNode::initialize(GraphKit* kit, MultiNode* multi, ciValueKlass* vk, int base_offset, uint& base_input, bool in) {
 255   assert(base_offset >= 0, "offset in value type must be positive");
 256   assert(base_input >= TypeFunc::Parms, "invalid base input");
 257   PhaseGVN& gvn = kit->gvn();
 258   for (uint i = 0; i < field_count(); i++) {
 259     ciType* ft = field_type(i);
 260     int offset = base_offset + field_offset(i);
 261     if (field_is_flattened(i)) {
 262       // Flattened value type field
 263       ValueTypeNode* vt = ValueTypeNode::make_uninitialized(gvn, ft->as_value_klass());
 264       uint base = base_input;
 265       vt->initialize(kit, multi, vk, offset - value_klass()->first_field_offset(), base, in);
 266       set_field_value(i, gvn.transform(vt));
 267     } else {
 268       int j = 0; int extra = 0;
 269       for (; j < vk->nof_nonstatic_fields(); j++) {
 270         ciField* f = vk->nonstatic_field_at(j);
 271         if (offset == f->offset()) {
 272           assert(f->type() == ft, "inconsistent field type");
 273           break;
 274         }
 275         BasicType bt = f->type()->basic_type();
 276         if (bt == T_LONG || bt == T_DOUBLE) {
 277           extra++;
 278         }
 279       }
 280       assert(j != vk->nof_nonstatic_fields(), "must find");
 281       Node* parm = NULL;
 282       int index = base_input + j + extra;
 283 
 284       ciMethod* method = multi->is_Start()? kit->C->method() : multi->as_CallStaticJava()->method();
 285       SigEntry res_entry = method->get_Method()->get_res_entry();
 286       if (res_entry._offset != -1 && (index - TypeFunc::Parms) >= res_entry._offset) {
 287         // Skip reserved entry
 288         index += type2size[res_entry._bt];
 289       }
 290       if (multi->is_Start()) {
 291         assert(in, "return from start?");
 292         parm = gvn.transform(new ParmNode(multi->as_Start(), index));
 293       } else {
 294         if (in) {
 295           parm = multi->as_Call()->in(index);
 296         } else {
 297           parm = gvn.transform(new ProjNode(multi->as_Call(), index));
 298         }
 299       }
 300 
 301       if (field_is_flattenable(i)) {
 302         // Non-flattened but flattenable value type
 303         if (ft->as_value_klass()->is_scalarizable()) {
 304           parm = ValueTypeNode::make_from_oop(kit, parm, ft->as_value_klass());
 305         } else {
 306           parm = kit->null2default(parm, ft->as_value_klass());
 307         }
 308       }
 309 
 310       set_field_value(i, parm);
 311       // Record all these guys for later GVN.
 312       gvn.record_for_igvn(parm);
 313     }
 314   }
 315   base_input += vk->value_arg_slots();
 316 }
 317 
 318 const TypePtr* ValueTypeBaseNode::field_adr_type(Node* base, int offset, ciInstanceKlass* holder, DecoratorSet decorators, PhaseGVN& gvn) const {
 319   const TypeAryPtr* ary_type = gvn.type(base)->isa_aryptr();
 320   const TypePtr* adr_type = NULL;
 321   bool is_array = ary_type != NULL;
 322   if ((decorators & C2_MISMATCHED) != 0) {
 323     adr_type = TypeRawPtr::BOTTOM;
 324   } else if (is_array) {
 325     // In the case of a flattened value type array, each field has its own slice
 326     adr_type = ary_type->with_field_offset(offset)->add_offset(Type::OffsetBot);
 327   } else {
 328     ciField* field = holder->get_field_by_offset(offset, false);
 329     assert(field != NULL, "field not found");
 330     adr_type = gvn.C->alias_type(field)->adr_type();
 331   }
 332   return adr_type;
 333 }
 334 
 335 void ValueTypeBaseNode::load(GraphKit* kit, Node* base, Node* ptr, ciInstanceKlass* holder, int holder_offset, DecoratorSet decorators) {
 336   // Initialize the value type by loading its field values from
 337   // memory and adding the values as input edges to the node.
 338   for (uint i = 0; i < field_count(); ++i) {
 339     int offset = holder_offset + field_offset(i);
 340     Node* value = NULL;
 341     ciType* ft = field_type(i);
 342     if (field_is_flattened(i)) {
 343       // Recursively load the flattened value type field
 344       value = ValueTypeNode::make_from_flattened(kit, ft->as_value_klass(), base, ptr, holder, offset, decorators);
 345     } else {
 346       const TypeOopPtr* oop_ptr = kit->gvn().type(base)->isa_oopptr();
 347       bool is_array = (oop_ptr->isa_aryptr() != NULL);
 348       if (base->is_Con() && !is_array) {
 349         // If the oop to the value type is constant (static final field), we can
 350         // also treat the fields as constants because the value type is immutable.
 351         ciObject* constant_oop = oop_ptr->const_oop();
 352         ciField* field = holder->get_field_by_offset(offset, false);
 353         assert(field != NULL, "field not found");
 354         ciConstant constant = constant_oop->as_instance()->field_value(field);
 355         const Type* con_type = Type::make_from_constant(constant, /*require_const=*/ true);
 356         assert(con_type != NULL, "type not found");
 357         value = kit->gvn().transform(kit->makecon(con_type));
 358       } else {
 359         // Load field value from memory
 360         const TypePtr* adr_type = field_adr_type(base, offset, holder, decorators, kit->gvn());
 361         Node* adr = kit->basic_plus_adr(base, ptr, offset);
 362         BasicType bt = type2field[ft->basic_type()];
 363         assert(is_java_primitive(bt) || adr->bottom_type()->is_ptr_to_narrowoop() == UseCompressedOops, "inconsistent");
 364         const Type* val_type = Type::get_const_type(ft);
 365         if (is_array) {
 366           decorators |= IS_ARRAY;
 367         }
 368         value = kit->access_load_at(base, adr, adr_type, val_type, bt, decorators);
 369       }
 370       if (field_is_flattenable(i)) {
 371         // Loading a non-flattened but flattenable value type from memory
 372         if (ft->as_value_klass()->is_scalarizable()) {
 373           value = ValueTypeNode::make_from_oop(kit, value, ft->as_value_klass());
 374         } else {
 375           value = kit->null2default(value, ft->as_value_klass());
 376         }
 377       }
 378     }
 379     set_field_value(i, value);
 380   }
 381 }
 382 
 383 void ValueTypeBaseNode::store_flattened(GraphKit* kit, Node* base, Node* ptr, ciInstanceKlass* holder, int holder_offset, DecoratorSet decorators) const {
 384   // The value type is embedded into the object without an oop header. Subtract the
 385   // offset of the first field to account for the missing header when storing the values.
 386   if (holder == NULL) {
 387     holder = value_klass();
 388   }
 389   holder_offset -= value_klass()->first_field_offset();
 390   store(kit, base, ptr, holder, holder_offset, false, decorators);
 391 }
 392 
 393 void ValueTypeBaseNode::store(GraphKit* kit, Node* base, Node* ptr, ciInstanceKlass* holder, int holder_offset, bool deoptimize_on_exception, DecoratorSet decorators) const {
 394   // Write field values to memory
 395   for (uint i = 0; i < field_count(); ++i) {
 396     int offset = holder_offset + field_offset(i);
 397     Node* value = field_value(i);
 398     ciType* ft = field_type(i);
 399     if (field_is_flattened(i)) {
 400       // Recursively store the flattened value type field
 401       if (!value->is_ValueType()) {
 402         assert(!kit->gvn().type(value)->maybe_null(), "should never be null");
 403         value = ValueTypeNode::make_from_oop(kit, value, ft->as_value_klass());
 404       }
 405       value->as_ValueType()->store_flattened(kit, base, ptr, holder, offset, decorators);
 406     } else {
 407       // Store field value to memory
 408       const TypePtr* adr_type = field_adr_type(base, offset, holder, decorators, kit->gvn());
 409       Node* adr = kit->basic_plus_adr(base, ptr, offset);
 410       BasicType bt = type2field[ft->basic_type()];
 411       assert(is_java_primitive(bt) || adr->bottom_type()->is_ptr_to_narrowoop() == UseCompressedOops, "inconsistent");
 412       const Type* val_type = Type::get_const_type(ft);
 413       const TypeAryPtr* ary_type = kit->gvn().type(base)->isa_aryptr();
 414       if (ary_type != NULL) {
 415         decorators |= IS_ARRAY;
 416       }
 417       kit->access_store_at(base, adr, adr_type, value, val_type, bt, decorators, deoptimize_on_exception);
 418     }
 419   }
 420 }
 421 
 422 ValueTypeBaseNode* ValueTypeBaseNode::allocate(GraphKit* kit, bool deoptimize_on_exception) {
 423   // Check if value type is already allocated
 424   Node* null_ctl = kit->top();
 425   Node* not_null_oop = kit->null_check_oop(get_oop(), &null_ctl);
 426   if (null_ctl->is_top()) {
 427     // Value type is allocated
 428     return this;
 429   }
 430   assert(!is_allocated(&kit->gvn()), "should not be allocated");
 431   RegionNode* region = new RegionNode(3);
 432 
 433   // Oop is non-NULL, use it
 434   region->init_req(1, kit->control());
 435   PhiNode* oop = PhiNode::make(region, not_null_oop, value_ptr());
 436   PhiNode* io  = PhiNode::make(region, kit->i_o(), Type::ABIO);
 437   PhiNode* mem = PhiNode::make(region, kit->merged_memory(), Type::MEMORY, TypePtr::BOTTOM);
 438 
 439   {
 440     // Oop is NULL, allocate and initialize buffer
 441     PreserveJVMState pjvms(kit);
 442     kit->set_control(null_ctl);
 443     kit->kill_dead_locals();
 444     ciValueKlass* vk = value_klass();
 445     Node* klass_node = kit->makecon(TypeKlassPtr::make(vk));
 446     Node* alloc_oop  = kit->new_instance(klass_node, NULL, NULL, deoptimize_on_exception, this);
 447     store(kit, alloc_oop, alloc_oop, vk, 0, deoptimize_on_exception);
 448     region->init_req(2, kit->control());
 449     oop   ->init_req(2, alloc_oop);
 450     io    ->init_req(2, kit->i_o());
 451     mem   ->init_req(2, kit->merged_memory());
 452   }
 453 
 454   // Update GraphKit
 455   kit->set_control(kit->gvn().transform(region));
 456   kit->set_i_o(kit->gvn().transform(io));
 457   kit->set_all_memory(kit->gvn().transform(mem));
 458   kit->record_for_igvn(region);
 459   kit->record_for_igvn(oop);
 460   kit->record_for_igvn(io);
 461   kit->record_for_igvn(mem);
 462 
 463   // Use cloned ValueTypeNode to propagate oop from now on
 464   Node* res_oop = kit->gvn().transform(oop);
 465   ValueTypeBaseNode* vt = clone()->as_ValueTypeBase();
 466   vt->set_oop(res_oop);
 467   vt = kit->gvn().transform(vt)->as_ValueTypeBase();
 468   kit->replace_in_map(this, vt);
 469   return vt;
 470 }
 471 
 472 bool ValueTypeBaseNode::is_allocated(PhaseGVN* phase) const {
 473   Node* oop = get_oop();
 474   const Type* oop_type = (phase != NULL) ? phase->type(oop) : oop->bottom_type();
 475   return !oop_type->maybe_null();
 476 }
 477 
 478 // When a call returns multiple values, it has several result
 479 // projections, one per field. Replacing the result of the call by a
 480 // value type node (after late inlining) requires that for each result
 481 // projection, we find the corresponding value type field.
 482 void ValueTypeBaseNode::replace_call_results(GraphKit* kit, Node* call, Compile* C) {
 483   ciValueKlass* vk = value_klass();
 484   for (DUIterator_Fast imax, i = call->fast_outs(imax); i < imax; i++) {
 485     ProjNode* pn = call->fast_out(i)->as_Proj();
 486     uint con = pn->_con;
 487     if (con >= TypeFunc::Parms+1) {
 488       uint field_nb = con - (TypeFunc::Parms+1);
 489       int extra = 0;
 490       for (uint j = 0; j < field_nb - extra; j++) {
 491         ciField* f = vk->nonstatic_field_at(j);
 492         BasicType bt = f->type()->basic_type();
 493         if (bt == T_LONG || bt == T_DOUBLE) {
 494           extra++;
 495         }
 496       }
 497       ciField* f = vk->nonstatic_field_at(field_nb - extra);
 498       Node* field = field_value_by_offset(f->offset(), true);
 499       if (field->is_ValueType()) {
 500         assert(f->is_flattened(), "should be flattened");
 501         field = field->as_ValueType()->allocate(kit)->get_oop();
 502       }
 503       C->gvn_replace_by(pn, field);
 504       C->initial_gvn()->hash_delete(pn);
 505       pn->set_req(0, C->top());
 506       --i; --imax;
 507     }
 508   }
 509 }
 510 
 511 ValueTypeNode* ValueTypeNode::make_uninitialized(PhaseGVN& gvn, ciValueKlass* vk) {
 512   // Create a new ValueTypeNode with uninitialized values and NULL oop
 513   return new ValueTypeNode(vk, gvn.zerocon(T_VALUETYPE));
 514 }
 515 
 516 Node* ValueTypeNode::default_oop(PhaseGVN& gvn, ciValueKlass* vk) {
 517   // Returns the constant oop of the default value type allocation
 518   return gvn.makecon(TypeInstPtr::make(vk->default_value_instance()));
 519 }
 520 
 521 ValueTypeNode* ValueTypeNode::make_default(PhaseGVN& gvn, ciValueKlass* vk) {
 522   // Create a new ValueTypeNode with default values
 523   ValueTypeNode* vt = new ValueTypeNode(vk, default_oop(gvn, vk));
 524   for (uint i = 0; i < vt->field_count(); ++i) {
 525     ciType* field_type = vt->field_type(i);
 526     Node* value = NULL;
 527     if (field_type->is_valuetype() && vt->field_is_flattenable(i)) {
 528       ciValueKlass* field_klass = field_type->as_value_klass();
 529       if (field_klass->is_scalarizable() || vt->field_is_flattened(i)) {
 530         value = ValueTypeNode::make_default(gvn, field_klass);
 531       } else {
 532         value = default_oop(gvn, field_klass);
 533       }
 534     } else {
 535       value = gvn.zerocon(field_type->basic_type());
 536     }
 537     vt->set_field_value(i, value);
 538   }
 539   vt = gvn.transform(vt)->as_ValueType();
 540   assert(vt->is_default(gvn), "must be the default value type");
 541   return vt;
 542 }
 543 
 544 bool ValueTypeNode::is_default(PhaseGVN& gvn) const {
 545   for (uint i = 0; i < field_count(); ++i) {
 546     Node* value = field_value(i);
 547     if (!gvn.type(value)->is_zero_type() &&
 548         !(value->is_ValueType() && value->as_ValueType()->is_default(gvn)) &&
 549         !(field_type(i)->is_valuetype() && value == default_oop(gvn, field_type(i)->as_value_klass()))) {
 550       return false;
 551     }
 552   }
 553   return true;
 554 }
 555 
 556 ValueTypeNode* ValueTypeNode::make_from_oop(GraphKit* kit, Node* oop, ciValueKlass* vk) {
 557   PhaseGVN& gvn = kit->gvn();
 558 
 559   // Create and initialize a ValueTypeNode by loading all field
 560   // values from a heap-allocated version and also save the oop.
 561   ValueTypeNode* vt = new ValueTypeNode(vk, oop);
 562 
 563   if (oop->isa_ValueTypePtr()) {
 564     // Can happen with late inlining
 565     ValueTypePtrNode* vtptr = oop->as_ValueTypePtr();
 566     vt->set_oop(vtptr->get_oop());
 567     for (uint i = Oop+1; i < vtptr->req(); ++i) {
 568       vt->init_req(i, vtptr->in(i));
 569     }
 570   } else if (gvn.type(oop)->maybe_null()) {
 571     // Add a null check because the oop may be null
 572     Node* null_ctl = kit->top();
 573     Node* not_null_oop = kit->null_check_oop(oop, &null_ctl);
 574     if (kit->stopped()) {
 575       // Constant null
 576       kit->set_control(null_ctl);
 577       return make_default(gvn, vk);
 578     }
 579     vt->set_oop(not_null_oop);
 580     vt->load(kit, not_null_oop, not_null_oop, vk, /* holder_offset */ 0);
 581 
 582     if (null_ctl != kit->top()) {
 583       // Return default value type if oop is null
 584       ValueTypeNode* def = make_default(gvn, vk);
 585       Node* region = new RegionNode(3);
 586       region->init_req(1, kit->control());
 587       region->init_req(2, null_ctl);
 588 
 589       vt = vt->clone_with_phis(&gvn, region)->as_ValueType();
 590       vt->merge_with(&gvn, def, 2, true);
 591       kit->set_control(gvn.transform(region));
 592     }
 593   } else {
 594     // Oop can never be null
 595     Node* init_ctl = kit->control();
 596     vt->load(kit, oop, oop, vk, /* holder_offset */ 0);
 597     assert(init_ctl != kit->control() || oop->is_Con() || oop->is_CheckCastPP() || oop->Opcode() == Op_ValueTypePtr ||
 598            vt->is_loaded(&gvn) == oop, "value type should be loaded");
 599   }
 600 
 601   assert(vt->is_allocated(&gvn), "value type should be allocated");
 602   return gvn.transform(vt)->as_ValueType();
 603 }
 604 
 605 // GraphKit wrapper for the 'make_from_flattened' method
 606 ValueTypeNode* ValueTypeNode::make_from_flattened(GraphKit* kit, ciValueKlass* vk, Node* obj, Node* ptr, ciInstanceKlass* holder, int holder_offset, DecoratorSet decorators) {
 607   // Create and initialize a ValueTypeNode by loading all field values from
 608   // a flattened value type field at 'holder_offset' or from a value type array.
 609   ValueTypeNode* vt = make_uninitialized(kit->gvn(), vk);
 610   // The value type is flattened into the object without an oop header. Subtract the
 611   // offset of the first field to account for the missing header when loading the values.
 612   holder_offset -= vk->first_field_offset();
 613   vt->load(kit, obj, ptr, holder, holder_offset, decorators);
 614   assert(vt->is_loaded(&kit->gvn()) != obj, "holder oop should not be used as flattened value type oop");
 615   return kit->gvn().transform(vt)->as_ValueType();
 616 }
 617 
 618 ValueTypeNode* ValueTypeNode::make_from_multi(GraphKit* kit, MultiNode* multi, ciValueKlass* vk, uint& base_input, bool in) {
 619   ValueTypeNode* vt = ValueTypeNode::make_uninitialized(kit->gvn(), vk);
 620   vt->initialize(kit, multi, vk, 0, base_input, in);
 621   return kit->gvn().transform(vt)->as_ValueType();
 622 }
 623 
 624 ValueTypeNode* ValueTypeNode::make_larval(GraphKit* kit, bool allocate) const {
 625   ciValueKlass* vk = value_klass();
 626   ValueTypeNode* res = clone()->as_ValueType();
 627   if (allocate) {
 628     Node* klass_node = kit->makecon(TypeKlassPtr::make(vk));
 629     Node* alloc_oop  = kit->new_instance(klass_node, NULL, NULL, false);
 630     AllocateNode* alloc = AllocateNode::Ideal_allocation(alloc_oop, &kit->gvn());
 631     alloc->_larval = true;
 632 
 633     store(kit, alloc_oop, alloc_oop, vk, 0, false);
 634     res->set_oop(alloc_oop);
 635   }
 636   res->set_type(TypeValueType::make(vk, true));
 637   res = kit->gvn().transform(res)->as_ValueType();
 638   return res;
 639 }
 640 
 641 ValueTypeNode* ValueTypeNode::finish_larval(GraphKit* kit) const {
 642   Node* obj = get_oop();
 643   Node* mark_addr = kit->basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
 644   Node* mark = kit->make_load(NULL, mark_addr, TypeX_X, TypeX_X->basic_type(), MemNode::unordered);
 645   mark = kit->gvn().transform(new AndXNode(mark, kit->MakeConX(~markOopDesc::larval_mask_in_place)));
 646   kit->store_to_memory(kit->control(), mark_addr, mark, TypeX_X->basic_type(), kit->gvn().type(mark_addr)->is_ptr(), MemNode::unordered);
 647 
 648   ciValueKlass* vk = value_klass();
 649   ValueTypeNode* res = clone()->as_ValueType();
 650   res->set_type(TypeValueType::make(vk, false));
 651   res = kit->gvn().transform(res)->as_ValueType();
 652   return res;
 653 }
 654 
 655 Node* ValueTypeNode::is_loaded(PhaseGVN* phase, ciValueKlass* vk, Node* base, int holder_offset) {
 656   if (vk == NULL) {
 657     vk = value_klass();
 658   }
 659   if (field_count() == 0) {
 660     assert(is_allocated(phase), "must be allocated");
 661     return get_oop();
 662   }
 663   for (uint i = 0; i < field_count(); ++i) {
 664     int offset = holder_offset + field_offset(i);
 665     Node* value = field_value(i);
 666     if (value->is_ValueType()) {
 667       ValueTypeNode* vt = value->as_ValueType();
 668       if (field_is_flattened(i)) {
 669         // Check value type field load recursively
 670         base = vt->is_loaded(phase, vk, base, offset - vt->value_klass()->first_field_offset());
 671         if (base == NULL) {
 672           return NULL;
 673         }
 674         continue;
 675       } else {
 676         value = vt->get_oop();
 677         if (value->Opcode() == Op_CastPP) {
 678           // Skip CastPP
 679           value = value->in(1);
 680         }
 681       }
 682     }
 683     if (value->isa_DecodeN()) {
 684       // Skip DecodeN
 685       value = value->in(1);
 686     }
 687     if (value->isa_Load()) {
 688       // Check if base and offset of field load matches value type layout
 689       intptr_t loffset = 0;
 690       Node* lbase = AddPNode::Ideal_base_and_offset(value->in(MemNode::Address), phase, loffset);
 691       if (lbase == NULL || (lbase != base && base != NULL) || loffset != offset) {
 692         return NULL;
 693       } else if (base == NULL) {
 694         // Set base and check if pointer type matches
 695         base = lbase;
 696         const TypeInstPtr* vtptr = phase->type(base)->isa_instptr();
 697         if (vtptr == NULL || !vtptr->klass()->equals(vk)) {
 698           return NULL;
 699         }
 700       }
 701     } else {
 702       return NULL;
 703     }
 704   }
 705   return base;
 706 }
 707 
 708 Node* ValueTypeNode::allocate_fields(GraphKit* kit) {
 709   ValueTypeNode* vt = clone()->as_ValueType();
 710   for (uint i = 0; i < field_count(); i++) {
 711      ValueTypeNode* value = field_value(i)->isa_ValueType();
 712      if (field_is_flattened(i)) {
 713        // Flattened value type field
 714        vt->set_field_value(i, value->allocate_fields(kit));
 715      } else if (value != NULL){
 716        // Non-flattened value type field
 717        vt->set_field_value(i, value->allocate(kit));
 718      }
 719   }
 720   vt = kit->gvn().transform(vt)->as_ValueType();
 721   kit->replace_in_map(this, vt);
 722   return vt;
 723 }
 724 
 725 Node* ValueTypeNode::tagged_klass(PhaseGVN& gvn) {
 726   ciValueKlass* vk = value_klass();
 727   const TypeKlassPtr* tk = TypeKlassPtr::make(vk);
 728   intptr_t bits = tk->get_con();
 729   set_nth_bit(bits, 0);
 730   return gvn.makecon(TypeRawPtr::make((address)bits));
 731 }
 732 
 733 uint ValueTypeNode::pass_fields(Node* n, int base_input, GraphKit& kit, bool assert_allocated, ciValueKlass* base_vk, int base_offset) {
 734   assert(base_input >= TypeFunc::Parms, "invalid base input");
 735   ciValueKlass* vk = value_klass();
 736   if (base_vk == NULL) {
 737     base_vk = vk;
 738   }
 739   uint edges = 0;
 740   for (uint i = 0; i < field_count(); i++) {
 741     int offset = base_offset + field_offset(i) - (base_offset > 0 ? vk->first_field_offset() : 0);
 742     Node* arg = field_value(i);
 743     if (field_is_flattened(i)) {
 744        // Flattened value type field
 745        edges += arg->as_ValueType()->pass_fields(n, base_input, kit, assert_allocated, base_vk, offset);
 746     } else {
 747       int j = 0; int extra = 0;
 748       for (; j < base_vk->nof_nonstatic_fields(); j++) {
 749         ciField* field = base_vk->nonstatic_field_at(j);
 750         if (offset == field->offset()) {
 751           assert(field->type() == field_type(i), "inconsistent field type");
 752           break;
 753         }
 754         BasicType bt = field->type()->basic_type();
 755         if (bt == T_LONG || bt == T_DOUBLE) {
 756           extra++;
 757         }
 758       }
 759       if (arg->is_ValueType()) {
 760         // non-flattened value type field
 761         ValueTypeNode* vt = arg->as_ValueType();
 762         assert(!assert_allocated || vt->is_allocated(&kit.gvn()), "value type field should be allocated");
 763         arg = vt->allocate(&kit)->get_oop();
 764       }
 765 
 766       int index = base_input + j + extra;
 767       n->init_req(index++, arg);
 768       edges++;
 769       BasicType bt = field_type(i)->basic_type();
 770       if (bt == T_LONG || bt == T_DOUBLE) {
 771         n->init_req(index++, kit.top());
 772         edges++;
 773       }
 774       if (n->isa_CallJava()) {
 775         Method* m = n->as_CallJava()->method()->get_Method();
 776         SigEntry res_entry = m->get_res_entry();
 777         if ((index - TypeFunc::Parms) == res_entry._offset) {
 778           // Skip reserved entry
 779           int size = type2size[res_entry._bt];
 780           n->init_req(index++, kit.top());
 781           if (size == 2) {
 782             n->init_req(index++, kit.top());
 783           }
 784           base_input += size;
 785           edges += size;
 786         }
 787       }
 788     }
 789   }
 790   return edges;
 791 }
 792 
 793 Node* ValueTypeNode::Ideal(PhaseGVN* phase, bool can_reshape) {
 794   Node* oop = get_oop();
 795   if (is_default(*phase) && (!oop->is_Con() || phase->type(oop)->is_zero_type())) {
 796     // Use the pre-allocated oop for default value types
 797     set_oop(default_oop(*phase, value_klass()));
 798     return this;
 799   } else if (oop->isa_ValueTypePtr()) {
 800     // Can happen with late inlining
 801     ValueTypePtrNode* vtptr = oop->as_ValueTypePtr();
 802     set_oop(vtptr->get_oop());
 803     for (uint i = Oop+1; i < vtptr->req(); ++i) {
 804       set_req(i, vtptr->in(i));
 805     }
 806     return this;
 807   }
 808 
 809   if (!is_allocated(phase)) {
 810     // Save base oop if fields are loaded from memory and the value
 811     // type is not buffered (in this case we should not use the oop).
 812     Node* base = is_loaded(phase);
 813     if (base != NULL) {
 814       set_oop(base);
 815       assert(is_allocated(phase), "should now be allocated");
 816       return this;
 817     }
 818   }
 819 
 820   if (can_reshape) {
 821     PhaseIterGVN* igvn = phase->is_IterGVN();
 822 
 823     if (is_default(*phase)) {
 824       // Search for users of the default value type
 825       for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
 826         Node* user = fast_out(i);
 827         AllocateNode* alloc = user->isa_Allocate();
 828         if (alloc != NULL && alloc->result_cast() != NULL && alloc->in(AllocateNode::ValueNode) == this) {
 829           // Found an allocation of the default value type.
 830           // If the code in StoreNode::Identity() that removes useless stores was not yet
 831           // executed or ReduceFieldZeroing is disabled, there can still be initializing
 832           // stores (only zero-type or default value stores, because value types are immutable).
 833           Node* res = alloc->result_cast();
 834           for (DUIterator_Fast jmax, j = res->fast_outs(jmax); j < jmax; j++) {
 835             AddPNode* addp = res->fast_out(j)->isa_AddP();
 836             if (addp != NULL) {
 837               for (DUIterator_Fast kmax, k = addp->fast_outs(kmax); k < kmax; k++) {
 838                 StoreNode* store = addp->fast_out(k)->isa_Store();
 839                 if (store != NULL && store->outcnt() != 0) {
 840                   // Remove the useless store
 841                   igvn->replace_in_uses(store, store->in(MemNode::Memory));
 842                 }
 843               }
 844             }
 845           }
 846           // Replace allocation by pre-allocated oop
 847           igvn->replace_node(res, default_oop(*phase, value_klass()));
 848         } else if (user->is_ValueType()) {
 849           // Add value type user to worklist to give it a chance to get optimized as well
 850           igvn->_worklist.push(user);
 851         }
 852       }
 853     }
 854 
 855     if (is_allocated(igvn)) {
 856       // Value type is heap allocated, search for safepoint uses
 857       for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
 858         Node* out = fast_out(i);
 859         if (out->is_SafePoint()) {
 860           // Let SafePointNode::Ideal() take care of re-wiring the
 861           // safepoint to the oop input instead of the value type node.
 862           igvn->rehash_node_delayed(out);
 863         }
 864       }
 865     }
 866   }
 867   return NULL;
 868 }
 869 
 870 // Search for multiple allocations of this value type
 871 // and try to replace them by dominating allocations.
 872 void ValueTypeNode::remove_redundant_allocations(PhaseIterGVN* igvn, PhaseIdealLoop* phase) {
 873   assert(EliminateAllocations, "allocation elimination should be enabled");
 874   // Search for allocations of this value type
 875   for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
 876     AllocateNode* alloc = fast_out(i)->isa_Allocate();
 877     if (alloc != NULL && alloc->result_cast() != NULL && alloc->in(AllocateNode::ValueNode) == this) {
 878       assert(!is_default(*igvn), "default value type allocation");
 879       Node* res_dom = NULL;
 880       if (is_allocated(igvn)) {
 881         // The value type is already allocated but still connected to an AllocateNode.
 882         // This can happen with late inlining when we first allocate a value type argument
 883         // but later decide to inline the call with the callee code also allocating.
 884         res_dom = get_oop();
 885       } else {
 886         // Search for a dominating allocation of the same value type
 887         for (DUIterator_Fast jmax, j = fast_outs(jmax); j < jmax; j++) {
 888           Node* out2 = fast_out(j);
 889           if (alloc != out2 && out2->is_Allocate() && out2->in(AllocateNode::ValueNode) == this &&
 890               phase->is_dominator(out2, alloc)) {
 891             AllocateNode* alloc_dom =  out2->as_Allocate();
 892             assert(alloc->in(AllocateNode::KlassNode) == alloc_dom->in(AllocateNode::KlassNode), "klasses should match");
 893             res_dom = alloc_dom->result_cast();
 894             break;
 895           }
 896         }
 897       }
 898       if (res_dom != NULL) {
 899         // Move users to dominating allocation
 900         Node* res = alloc->result_cast();
 901         igvn->replace_node(res, res_dom);
 902         // The result of the dominated allocation is now unused and will be
 903         // removed later in AllocateNode::Ideal() to not confuse loop opts.
 904         igvn->record_for_igvn(alloc);
 905 #ifdef ASSERT
 906         if (PrintEliminateAllocations) {
 907           tty->print("++++ Eliminated: %d Allocate ", alloc->_idx);
 908           dump_spec(tty);
 909           tty->cr();
 910         }
 911 #endif
 912       }
 913     }
 914   }
 915 
 916   // Process users
 917   for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
 918     Node* out = fast_out(i);
 919     if (out->is_ValueType()) {
 920       // Recursively process value type users
 921       out->as_ValueType()->remove_redundant_allocations(igvn, phase);
 922     } else if (out->isa_Allocate() != NULL) {
 923       // Allocate users should be linked
 924       assert(out->in(AllocateNode::ValueNode) == this, "should be linked");
 925     } else {
 926 #ifdef ASSERT
 927       // The value type should not have any other users at this time
 928       out->dump();
 929       assert(false, "unexpected user of value type");
 930 #endif
 931     }
 932   }
 933 }
 934 
 935 ValueTypePtrNode* ValueTypePtrNode::make_from_value_type(GraphKit* kit, ValueTypeNode* vt, bool deoptimize_on_exception) {
 936   Node* oop = vt->allocate(kit, deoptimize_on_exception)->get_oop();
 937   ValueTypePtrNode* vtptr = new ValueTypePtrNode(vt->value_klass(), oop);
 938   for (uint i = Oop+1; i < vt->req(); i++) {
 939     vtptr->init_req(i, vt->in(i));
 940   }
 941   return kit->gvn().transform(vtptr)->as_ValueTypePtr();
 942 }
 943 
 944 ValueTypePtrNode* ValueTypePtrNode::make_from_oop(GraphKit* kit, Node* oop) {
 945   // Create and initialize a ValueTypePtrNode by loading all field
 946   // values from a heap-allocated version and also save the oop.
 947   ciValueKlass* vk = kit->gvn().type(oop)->value_klass();
 948   ValueTypePtrNode* vtptr = new ValueTypePtrNode(vk, oop);
 949   vtptr->load(kit, oop, oop, vk);
 950   return kit->gvn().transform(vtptr)->as_ValueTypePtr();
 951 }