1 /*
   2  * Copyright (c) 2005, 2025, 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 "ci/ciFlatArrayKlass.hpp"
  26 #include "ci/ciInstanceKlass.hpp"
  27 #include "compiler/compileLog.hpp"
  28 #include "gc/shared/collectedHeap.inline.hpp"
  29 #include "gc/shared/tlab_globals.hpp"
  30 #include "libadt/vectset.hpp"
  31 #include "memory/universe.hpp"
  32 #include "opto/addnode.hpp"
  33 #include "opto/arraycopynode.hpp"
  34 #include "opto/callnode.hpp"
  35 #include "opto/castnode.hpp"
  36 #include "opto/cfgnode.hpp"
  37 #include "opto/compile.hpp"
  38 #include "opto/convertnode.hpp"
  39 #include "opto/graphKit.hpp"
  40 #include "opto/inlinetypenode.hpp"
  41 #include "opto/intrinsicnode.hpp"
  42 #include "opto/locknode.hpp"
  43 #include "opto/loopnode.hpp"
  44 #include "opto/macro.hpp"
  45 #include "opto/memnode.hpp"
  46 #include "opto/narrowptrnode.hpp"
  47 #include "opto/node.hpp"
  48 #include "opto/opaquenode.hpp"
  49 #include "opto/phaseX.hpp"
  50 #include "opto/rootnode.hpp"
  51 #include "opto/runtime.hpp"
  52 #include "opto/subnode.hpp"
  53 #include "opto/subtypenode.hpp"
  54 #include "opto/type.hpp"
  55 #include "prims/jvmtiExport.hpp"
  56 #include "runtime/continuation.hpp"
  57 #include "runtime/sharedRuntime.hpp"
  58 #include "runtime/stubRoutines.hpp"
  59 #include "utilities/globalDefinitions.hpp"
  60 #include "utilities/macros.hpp"
  61 #include "utilities/powerOfTwo.hpp"
  62 #if INCLUDE_G1GC
  63 #include "gc/g1/g1ThreadLocalData.hpp"
  64 #endif // INCLUDE_G1GC
  65 
  66 
  67 //
  68 // Replace any references to "oldref" in inputs to "use" with "newref".
  69 // Returns the number of replacements made.
  70 //
  71 int PhaseMacroExpand::replace_input(Node *use, Node *oldref, Node *newref) {
  72   int nreplacements = 0;
  73   uint req = use->req();
  74   for (uint j = 0; j < use->len(); j++) {
  75     Node *uin = use->in(j);
  76     if (uin == oldref) {
  77       if (j < req)
  78         use->set_req(j, newref);
  79       else
  80         use->set_prec(j, newref);
  81       nreplacements++;
  82     } else if (j >= req && uin == nullptr) {
  83       break;
  84     }
  85   }
  86   return nreplacements;
  87 }
  88 
  89 
  90 Node* PhaseMacroExpand::opt_bits_test(Node* ctrl, Node* region, int edge, Node* word) {
  91   Node* cmp = word;
  92   Node* bol = transform_later(new BoolNode(cmp, BoolTest::ne));
  93   IfNode* iff = new IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );
  94   transform_later(iff);
  95 
  96   // Fast path taken.
  97   Node *fast_taken = transform_later(new IfFalseNode(iff));
  98 
  99   // Fast path not-taken, i.e. slow path
 100   Node *slow_taken = transform_later(new IfTrueNode(iff));
 101 
 102     region->init_req(edge, fast_taken); // Capture fast-control
 103     return slow_taken;
 104 }
 105 
 106 //--------------------copy_predefined_input_for_runtime_call--------------------
 107 void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) {
 108   // Set fixed predefined input arguments
 109   call->init_req( TypeFunc::Control, ctrl );
 110   call->init_req( TypeFunc::I_O    , oldcall->in( TypeFunc::I_O) );
 111   call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ?????
 112   call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) );
 113   call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) );
 114 }
 115 
 116 //------------------------------make_slow_call---------------------------------
 117 CallNode* PhaseMacroExpand::make_slow_call(CallNode *oldcall, const TypeFunc* slow_call_type,
 118                                            address slow_call, const char* leaf_name, Node* slow_path,
 119                                            Node* parm0, Node* parm1, Node* parm2) {
 120 
 121   // Slow-path call
 122  CallNode *call = leaf_name
 123    ? (CallNode*)new CallLeafNode      ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM )
 124    : (CallNode*)new CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), TypeRawPtr::BOTTOM );
 125 
 126   // Slow path call has no side-effects, uses few values
 127   copy_predefined_input_for_runtime_call(slow_path, oldcall, call );
 128   if (parm0 != nullptr)  call->init_req(TypeFunc::Parms+0, parm0);
 129   if (parm1 != nullptr)  call->init_req(TypeFunc::Parms+1, parm1);
 130   if (parm2 != nullptr)  call->init_req(TypeFunc::Parms+2, parm2);
 131   call->copy_call_debug_info(&_igvn, oldcall);
 132   call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
 133   _igvn.replace_node(oldcall, call);
 134   transform_later(call);
 135 
 136   return call;
 137 }
 138 
 139 void PhaseMacroExpand::eliminate_gc_barrier(Node* p2x) {
 140   BarrierSetC2 *bs = BarrierSet::barrier_set()->barrier_set_c2();
 141   bs->eliminate_gc_barrier(&_igvn, p2x);
 142 #ifndef PRODUCT
 143   if (PrintOptoStatistics) {
 144     Atomic::inc(&PhaseMacroExpand::_GC_barriers_removed_counter);
 145   }
 146 #endif
 147 }
 148 
 149 // Search for a memory operation for the specified memory slice.
 150 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc, PhaseGVN *phase) {
 151   Node *orig_mem = mem;
 152   Node *alloc_mem = alloc->as_Allocate()->proj_out_or_null(TypeFunc::Memory, /*io_use:*/false);
 153   assert(alloc_mem != nullptr, "Allocation without a memory projection.");
 154   const TypeOopPtr *tinst = phase->C->get_adr_type(alias_idx)->isa_oopptr();
 155   while (true) {
 156     if (mem == alloc_mem || mem == start_mem ) {
 157       return mem;  // hit one of our sentinels
 158     } else if (mem->is_MergeMem()) {
 159       mem = mem->as_MergeMem()->memory_at(alias_idx);
 160     } else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) {
 161       Node *in = mem->in(0);
 162       // we can safely skip over safepoints, calls, locks and membars because we
 163       // already know that the object is safe to eliminate.
 164       if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) {
 165         return in;
 166       } else if (in->is_Call()) {
 167         CallNode *call = in->as_Call();
 168         if (call->may_modify(tinst, phase)) {
 169           assert(call->is_ArrayCopy(), "ArrayCopy is the only call node that doesn't make allocation escape");
 170           if (call->as_ArrayCopy()->modifies(offset, offset, phase, false)) {
 171             return in;
 172           }
 173         }
 174         mem = in->in(TypeFunc::Memory);
 175       } else if (in->is_MemBar()) {
 176         ArrayCopyNode* ac = nullptr;
 177         if (ArrayCopyNode::may_modify(tinst, in->as_MemBar(), phase, ac)) {
 178           if (ac != nullptr) {
 179             assert(ac->is_clonebasic(), "Only basic clone is a non escaping clone");
 180             return ac;
 181           }
 182         }
 183         mem = in->in(TypeFunc::Memory);
 184       } else {
 185 #ifdef ASSERT
 186         in->dump();
 187         mem->dump();
 188         assert(false, "unexpected projection");
 189 #endif
 190       }
 191     } else if (mem->is_Store()) {
 192       const TypePtr* atype = mem->as_Store()->adr_type();
 193       int adr_idx = phase->C->get_alias_index(atype);
 194       if (adr_idx == alias_idx) {
 195         assert(atype->isa_oopptr(), "address type must be oopptr");
 196         int adr_offset = atype->flat_offset();
 197         uint adr_iid = atype->is_oopptr()->instance_id();
 198         // Array elements references have the same alias_idx
 199         // but different offset and different instance_id.
 200         if (adr_offset == offset && adr_iid == alloc->_idx) {
 201           return mem;
 202         }
 203       } else {
 204         assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw");
 205       }
 206       mem = mem->in(MemNode::Memory);
 207     } else if (mem->is_ClearArray()) {
 208       if (!ClearArrayNode::step_through(&mem, alloc->_idx, phase)) {
 209         // Can not bypass initialization of the instance
 210         // we are looking.
 211         DEBUG_ONLY(intptr_t offset;)
 212         assert(alloc == AllocateNode::Ideal_allocation(mem->in(3), phase, offset), "sanity");
 213         InitializeNode* init = alloc->as_Allocate()->initialization();
 214         // We are looking for stored value, return Initialize node
 215         // or memory edge from Allocate node.
 216         if (init != nullptr) {
 217           return init;
 218         } else {
 219           return alloc->in(TypeFunc::Memory); // It will produce zero value (see callers).
 220         }
 221       }
 222       // Otherwise skip it (the call updated 'mem' value).
 223     } else if (mem->Opcode() == Op_SCMemProj) {
 224       mem = mem->in(0);
 225       Node* adr = nullptr;
 226       if (mem->is_LoadStore()) {
 227         adr = mem->in(MemNode::Address);
 228       } else {
 229         assert(mem->Opcode() == Op_EncodeISOArray ||
 230                mem->Opcode() == Op_StrCompressedCopy, "sanity");
 231         adr = mem->in(3); // Destination array
 232       }
 233       const TypePtr* atype = adr->bottom_type()->is_ptr();
 234       int adr_idx = phase->C->get_alias_index(atype);
 235       if (adr_idx == alias_idx) {
 236         DEBUG_ONLY(mem->dump();)
 237         assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
 238         return nullptr;
 239       }
 240       mem = mem->in(MemNode::Memory);
 241     } else if (mem->Opcode() == Op_StrInflatedCopy) {
 242       Node* adr = mem->in(3); // Destination array
 243       const TypePtr* atype = adr->bottom_type()->is_ptr();
 244       int adr_idx = phase->C->get_alias_index(atype);
 245       if (adr_idx == alias_idx) {
 246         DEBUG_ONLY(mem->dump();)
 247         assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
 248         return nullptr;
 249       }
 250       mem = mem->in(MemNode::Memory);
 251     } else {
 252       return mem;
 253     }
 254     assert(mem != orig_mem, "dead memory loop");
 255   }
 256 }
 257 
 258 // Generate loads from source of the arraycopy for fields of
 259 // destination needed at a deoptimization point
 260 Node* PhaseMacroExpand::make_arraycopy_load(ArrayCopyNode* ac, intptr_t offset, Node* ctl, Node* mem, BasicType ft, const Type *ftype, AllocateNode *alloc) {
 261   BasicType bt = ft;
 262   const Type *type = ftype;
 263   if (ft == T_NARROWOOP) {
 264     bt = T_OBJECT;
 265     type = ftype->make_oopptr();
 266   }
 267   Node* res = nullptr;
 268   if (ac->is_clonebasic()) {
 269     assert(ac->in(ArrayCopyNode::Src) != ac->in(ArrayCopyNode::Dest), "clone source equals destination");
 270     Node* base = ac->in(ArrayCopyNode::Src);
 271     Node* adr = _igvn.transform(new AddPNode(base, base, _igvn.MakeConX(offset)));
 272     const TypePtr* adr_type = _igvn.type(base)->is_ptr()->add_offset(offset);
 273     MergeMemNode* mergemen = _igvn.transform(MergeMemNode::make(mem))->as_MergeMem();
 274     BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 275     res = ArrayCopyNode::load(bs, &_igvn, ctl, mergemen, adr, adr_type, type, bt);
 276   } else {
 277     if (ac->modifies(offset, offset, &_igvn, true)) {
 278       assert(ac->in(ArrayCopyNode::Dest) == alloc->result_cast(), "arraycopy destination should be allocation's result");
 279       uint shift = exact_log2(type2aelembytes(bt));
 280       Node* src_pos = ac->in(ArrayCopyNode::SrcPos);
 281       Node* dest_pos = ac->in(ArrayCopyNode::DestPos);
 282       const TypeInt* src_pos_t = _igvn.type(src_pos)->is_int();
 283       const TypeInt* dest_pos_t = _igvn.type(dest_pos)->is_int();
 284 
 285       Node* adr = nullptr;
 286       Node* base = ac->in(ArrayCopyNode::Src);
 287       const TypeAryPtr* adr_type = _igvn.type(base)->is_aryptr();
 288       if (adr_type->is_flat()) {
 289         shift = adr_type->flat_log_elem_size();
 290       }
 291       if (src_pos_t->is_con() && dest_pos_t->is_con()) {
 292         intptr_t off = ((src_pos_t->get_con() - dest_pos_t->get_con()) << shift) + offset;
 293         adr = _igvn.transform(new AddPNode(base, base, _igvn.MakeConX(off)));
 294         adr_type = _igvn.type(adr)->is_aryptr();
 295         assert(adr_type == _igvn.type(base)->is_aryptr()->add_field_offset_and_offset(off), "incorrect address type");
 296         if (ac->in(ArrayCopyNode::Src) == ac->in(ArrayCopyNode::Dest)) {
 297           // Don't emit a new load from src if src == dst but try to get the value from memory instead
 298           return value_from_mem(ac->in(TypeFunc::Memory), ctl, ft, ftype, adr_type, alloc);
 299         }
 300       } else {
 301         if (ac->in(ArrayCopyNode::Src) == ac->in(ArrayCopyNode::Dest)) {
 302           // Non constant offset in the array: we can't statically
 303           // determine the value
 304           return nullptr;
 305         }
 306         Node* diff = _igvn.transform(new SubINode(ac->in(ArrayCopyNode::SrcPos), ac->in(ArrayCopyNode::DestPos)));
 307 #ifdef _LP64
 308         diff = _igvn.transform(new ConvI2LNode(diff));
 309 #endif
 310         diff = _igvn.transform(new LShiftXNode(diff, _igvn.intcon(shift)));
 311 
 312         Node* off = _igvn.transform(new AddXNode(_igvn.MakeConX(offset), diff));
 313         adr = _igvn.transform(new AddPNode(base, base, off));
 314         // In the case of a flat inline type array, each field has its
 315         // own slice so we need to extract the field being accessed from
 316         // the address computation
 317         adr_type = adr_type->add_field_offset_and_offset(offset)->add_offset(Type::OffsetBot)->is_aryptr();
 318         adr = _igvn.transform(new CastPPNode(ctl, adr, adr_type));
 319       }
 320       MergeMemNode* mergemen = _igvn.transform(MergeMemNode::make(mem))->as_MergeMem();
 321       BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 322       res = ArrayCopyNode::load(bs, &_igvn, ctl, mergemen, adr, adr_type, type, bt);
 323     }
 324   }
 325   if (res != nullptr) {
 326     if (ftype->isa_narrowoop()) {
 327       // PhaseMacroExpand::scalar_replacement adds DecodeN nodes
 328       assert(res->isa_DecodeN(), "should be narrow oop");
 329       res = _igvn.transform(new EncodePNode(res, ftype));
 330     }
 331     return res;
 332   }
 333   return nullptr;
 334 }
 335 
 336 //
 337 // Given a Memory Phi, compute a value Phi containing the values from stores
 338 // on the input paths.
 339 // Note: this function is recursive, its depth is limited by the "level" argument
 340 // Returns the computed Phi, or null if it cannot compute it.
 341 Node *PhaseMacroExpand::value_from_mem_phi(Node *mem, BasicType ft, const Type *phi_type, const TypeOopPtr *adr_t, AllocateNode *alloc, Node_Stack *value_phis, int level) {
 342   assert(mem->is_Phi(), "sanity");
 343   int alias_idx = C->get_alias_index(adr_t);
 344   int offset = adr_t->flat_offset();
 345   int instance_id = adr_t->instance_id();
 346 
 347   // Check if an appropriate value phi already exists.
 348   Node* region = mem->in(0);
 349   for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) {
 350     Node* phi = region->fast_out(k);
 351     if (phi->is_Phi() && phi != mem &&
 352         phi->as_Phi()->is_same_inst_field(phi_type, (int)mem->_idx, instance_id, alias_idx, offset)) {
 353       return phi;
 354     }
 355   }
 356   // Check if an appropriate new value phi already exists.
 357   Node* new_phi = value_phis->find(mem->_idx);
 358   if (new_phi != nullptr)
 359     return new_phi;
 360 
 361   if (level <= 0) {
 362     return nullptr; // Give up: phi tree too deep
 363   }
 364   Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
 365   Node *alloc_mem = alloc->proj_out_or_null(TypeFunc::Memory, /*io_use:*/false);
 366   assert(alloc_mem != nullptr, "Allocation without a memory projection.");
 367 
 368   uint length = mem->req();
 369   GrowableArray <Node *> values(length, length, nullptr);
 370 
 371   // create a new Phi for the value
 372   PhiNode *phi = new PhiNode(mem->in(0), phi_type, nullptr, mem->_idx, instance_id, alias_idx, offset);
 373   transform_later(phi);
 374   value_phis->push(phi, mem->_idx);
 375 
 376   for (uint j = 1; j < length; j++) {
 377     Node *in = mem->in(j);
 378     if (in == nullptr || in->is_top()) {
 379       values.at_put(j, in);
 380     } else {
 381       Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn);
 382       if (val == start_mem || val == alloc_mem) {
 383         // hit a sentinel, return appropriate value
 384         Node* init_value = alloc->in(AllocateNode::InitValue);
 385         if (init_value != nullptr) {
 386           if (val == start_mem) {
 387             // TODO 8350865 Scalar replacement does not work well for flat arrays.
 388             // Somehow we ended up with root mem and therefore walked past the alloc. Fix this. Triggered by TestGenerated::test15
 389             // Don't we need field_value_by_offset?
 390             return nullptr;
 391           }
 392           values.at_put(j, init_value);
 393         } else {
 394           assert(alloc->in(AllocateNode::RawInitValue) == nullptr, "init value may not be null");
 395           values.at_put(j, _igvn.zerocon(ft));
 396         }
 397         continue;
 398       }
 399       if (val->is_Initialize()) {
 400         val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
 401       }
 402       if (val == nullptr) {
 403         return nullptr;  // can't find a value on this path
 404       }
 405       if (val == mem) {
 406         values.at_put(j, mem);
 407       } else if (val->is_Store()) {
 408         Node* n = val->in(MemNode::ValueIn);
 409         BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 410         n = bs->step_over_gc_barrier(n);
 411         if (is_subword_type(ft)) {
 412           n = Compile::narrow_value(ft, n, phi_type, &_igvn, true);
 413         }
 414         values.at_put(j, n);
 415       } else if (val->is_Proj() && val->in(0) == alloc) {
 416         Node* init_value = alloc->in(AllocateNode::InitValue);
 417         if (init_value != nullptr) {
 418           // TODO 8350865 Scalar replacement does not work well for flat arrays.
 419           // Is this correct for non-all-zero init values? Don't we need field_value_by_offset?
 420           values.at_put(j, init_value);
 421         } else {
 422           assert(alloc->in(AllocateNode::RawInitValue) == nullptr, "init value may not be null");
 423           values.at_put(j, _igvn.zerocon(ft));
 424         }
 425       } else if (val->is_Phi()) {
 426         val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1);
 427         if (val == nullptr) {
 428           return nullptr;
 429         }
 430         values.at_put(j, val);
 431       } else if (val->Opcode() == Op_SCMemProj) {
 432         assert(val->in(0)->is_LoadStore() ||
 433                val->in(0)->Opcode() == Op_EncodeISOArray ||
 434                val->in(0)->Opcode() == Op_StrCompressedCopy, "sanity");
 435         assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
 436         return nullptr;
 437       } else if (val->is_ArrayCopy()) {
 438         Node* res = make_arraycopy_load(val->as_ArrayCopy(), offset, val->in(0), val->in(TypeFunc::Memory), ft, phi_type, alloc);
 439         if (res == nullptr) {
 440           return nullptr;
 441         }
 442         values.at_put(j, res);
 443       } else if (val->is_top()) {
 444         // This indicates that this path into the phi is dead. Top will eventually also propagate into the Region.
 445         // IGVN will clean this up later.
 446         values.at_put(j, val);
 447       } else {
 448         DEBUG_ONLY( val->dump(); )
 449         assert(false, "unknown node on this path");
 450         return nullptr;  // unknown node on this path
 451       }
 452     }
 453   }
 454   // Set Phi's inputs
 455   for (uint j = 1; j < length; j++) {
 456     if (values.at(j) == mem) {
 457       phi->init_req(j, phi);
 458     } else {
 459       phi->init_req(j, values.at(j));
 460     }
 461   }
 462   return phi;
 463 }
 464 
 465 // Search the last value stored into the object's field.
 466 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, Node *sfpt_ctl, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, AllocateNode *alloc) {
 467   assert(adr_t->is_known_instance_field(), "instance required");
 468   int instance_id = adr_t->instance_id();
 469   assert((uint)instance_id == alloc->_idx, "wrong allocation");
 470 
 471   int alias_idx = C->get_alias_index(adr_t);
 472   int offset = adr_t->flat_offset();
 473   Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
 474   Node *alloc_mem = alloc->proj_out_or_null(TypeFunc::Memory, /*io_use:*/false);
 475   assert(alloc_mem != nullptr, "Allocation without a memory projection.");
 476   VectorSet visited;
 477 
 478   bool done = sfpt_mem == alloc_mem;
 479   Node *mem = sfpt_mem;
 480   while (!done) {
 481     if (visited.test_set(mem->_idx)) {
 482       return nullptr;  // found a loop, give up
 483     }
 484     mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn);
 485     if (mem == start_mem || mem == alloc_mem) {
 486       done = true;  // hit a sentinel, return appropriate 0 value
 487     } else if (mem->is_Initialize()) {
 488       mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
 489       if (mem == nullptr) {
 490         done = true; // Something went wrong.
 491       } else if (mem->is_Store()) {
 492         const TypePtr* atype = mem->as_Store()->adr_type();
 493         assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");
 494         done = true;
 495       }
 496     } else if (mem->is_Store()) {
 497       const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();
 498       assert(atype != nullptr, "address type must be oopptr");
 499       assert(C->get_alias_index(atype) == alias_idx &&
 500              atype->is_known_instance_field() && atype->flat_offset() == offset &&
 501              atype->instance_id() == instance_id, "store is correct memory slice");
 502       done = true;
 503     } else if (mem->is_Phi()) {
 504       // try to find a phi's unique input
 505       Node *unique_input = nullptr;
 506       Node *top = C->top();
 507       for (uint i = 1; i < mem->req(); i++) {
 508         Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn);
 509         if (n == nullptr || n == top || n == mem) {
 510           continue;
 511         } else if (unique_input == nullptr) {
 512           unique_input = n;
 513         } else if (unique_input != n) {
 514           unique_input = top;
 515           break;
 516         }
 517       }
 518       if (unique_input != nullptr && unique_input != top) {
 519         mem = unique_input;
 520       } else {
 521         done = true;
 522       }
 523     } else if (mem->is_ArrayCopy()) {
 524       done = true;
 525     } else {
 526       DEBUG_ONLY( mem->dump(); )
 527       assert(false, "unexpected node");
 528     }
 529   }
 530   if (mem != nullptr) {
 531     if (mem == start_mem || mem == alloc_mem) {
 532       // hit a sentinel, return appropriate value
 533       Node* init_value = alloc->in(AllocateNode::InitValue);
 534       if (init_value != nullptr) {
 535         if (adr_t->is_flat()) {
 536           if (init_value->is_EncodeP()) {
 537             init_value = init_value->in(1);
 538           }
 539           assert(adr_t->is_aryptr()->field_offset().get() != Type::OffsetBot, "Unknown offset");
 540           offset = adr_t->is_aryptr()->field_offset().get() + init_value->bottom_type()->inline_klass()->payload_offset();
 541           init_value = init_value->as_InlineType()->field_value_by_offset(offset, true);
 542           if (ft == T_NARROWOOP) {
 543             init_value = transform_later(new EncodePNode(init_value, init_value->bottom_type()->make_ptr()));
 544           }
 545         }
 546         return init_value;
 547       }
 548       assert(alloc->in(AllocateNode::RawInitValue) == nullptr, "init value may not be null");
 549       return _igvn.zerocon(ft);
 550     } else if (mem->is_Store()) {
 551       Node* n = mem->in(MemNode::ValueIn);
 552       BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 553       n = bs->step_over_gc_barrier(n);
 554       return n;
 555     } else if (mem->is_Phi()) {
 556       // attempt to produce a Phi reflecting the values on the input paths of the Phi
 557       Node_Stack value_phis(8);
 558       Node* phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit);
 559       if (phi != nullptr) {
 560         return phi;
 561       } else {
 562         // Kill all new Phis
 563         while(value_phis.is_nonempty()) {
 564           Node* n = value_phis.node();
 565           _igvn.replace_node(n, C->top());
 566           value_phis.pop();
 567         }
 568       }
 569     } else if (mem->is_ArrayCopy()) {
 570       Node* ctl = mem->in(0);
 571       Node* m = mem->in(TypeFunc::Memory);
 572       if (sfpt_ctl->is_Proj() && sfpt_ctl->as_Proj()->is_uncommon_trap_proj()) {
 573         // pin the loads in the uncommon trap path
 574         ctl = sfpt_ctl;
 575         m = sfpt_mem;
 576       }
 577       return make_arraycopy_load(mem->as_ArrayCopy(), offset, ctl, m, ft, ftype, alloc);
 578     }
 579   }
 580   // Something went wrong.
 581   return nullptr;
 582 }
 583 
 584 // Search the last value stored into the inline type's fields (for flat arrays).
 585 Node* PhaseMacroExpand::inline_type_from_mem(ciInlineKlass* vk, const TypeAryPtr* elem_adr_type, int elem_idx, int offset_in_element, bool null_free, AllocateNode* alloc, SafePointNode* sfpt) {
 586   auto report_failure = [&](int field_offset_in_element) {
 587 #ifndef PRODUCT
 588     if (PrintEliminateAllocations) {
 589       ciInlineKlass* elem_klass = elem_adr_type->elem()->inline_klass();
 590       int offset = field_offset_in_element + elem_klass->payload_offset();
 591       ciField* flattened_field = elem_klass->get_field_by_offset(offset, false);
 592       assert(flattened_field != nullptr, "must have a field of type %s at offset %d", elem_klass->name()->as_utf8(), offset);
 593       tty->print("=== At SafePoint node %d can't find value of field [%s] of array element [%d]", sfpt->_idx, flattened_field->name()->as_utf8(), elem_idx);
 594       tty->print(", which prevents elimination of: ");
 595       alloc->dump();
 596     }
 597 #endif // PRODUCT
 598   };
 599 
 600   // Create a new InlineTypeNode and retrieve the field values from memory
 601   InlineTypeNode* vt = InlineTypeNode::make_uninitialized(_igvn, vk, false);
 602   transform_later(vt);
 603   if (null_free) {
 604     vt->set_null_marker(_igvn);
 605   } else {
 606     int nm_offset_in_element = offset_in_element + vk->null_marker_offset_in_payload();
 607     const TypeAryPtr* nm_adr_type = elem_adr_type->with_field_offset(nm_offset_in_element);
 608     Node* nm_value = value_from_mem(sfpt->memory(), sfpt->control(), T_BOOLEAN, TypeInt::BOOL, nm_adr_type, alloc);
 609     if (nm_value != nullptr) {
 610       vt->set_null_marker(_igvn, nm_value);
 611     } else {
 612       report_failure(nm_offset_in_element);
 613       return nullptr;
 614     }
 615   }
 616 
 617   for (int i = 0; i < vk->nof_declared_nonstatic_fields(); ++i) {
 618     ciType* field_type = vt->field_type(i);
 619     int field_offset_in_element = offset_in_element + vt->field_offset(i) - vk->payload_offset();
 620     Node* field_value = nullptr;
 621     if (vt->field_is_flat(i)) {
 622       field_value = inline_type_from_mem(field_type->as_inline_klass(), elem_adr_type, elem_idx, field_offset_in_element, vt->field_is_null_free(i), alloc, sfpt);
 623     } else {
 624       const Type* ft = Type::get_const_type(field_type);
 625       BasicType bt = type2field[field_type->basic_type()];
 626       if (UseCompressedOops && !is_java_primitive(bt)) {
 627         ft = ft->make_narrowoop();
 628         bt = T_NARROWOOP;
 629       }
 630       // Each inline type field has its own memory slice
 631       const TypeAryPtr* field_adr_type = elem_adr_type->with_field_offset(field_offset_in_element);
 632       field_value = value_from_mem(sfpt->memory(), sfpt->control(), bt, ft, field_adr_type, alloc);
 633       if (field_value == nullptr) {
 634         report_failure(field_offset_in_element);
 635       } else if (ft->isa_narrowoop()) {
 636         assert(UseCompressedOops, "unexpected narrow oop");
 637         if (field_value->is_EncodeP()) {
 638           field_value = field_value->in(1);
 639         } else if (!field_value->is_InlineType()) {
 640           field_value = transform_later(new DecodeNNode(field_value, field_value->get_ptr_type()));
 641         }
 642       }
 643     }
 644     if (field_value != nullptr) {
 645       vt->set_field_value(i, field_value);
 646     } else {
 647       return nullptr;
 648     }
 649   }
 650   return vt;
 651 }
 652 
 653 // Check the possibility of scalar replacement.
 654 bool PhaseMacroExpand::can_eliminate_allocation(PhaseIterGVN* igvn, AllocateNode *alloc, GrowableArray <SafePointNode *>* safepoints) {
 655   //  Scan the uses of the allocation to check for anything that would
 656   //  prevent us from eliminating it.
 657   NOT_PRODUCT( const char* fail_eliminate = nullptr; )
 658   DEBUG_ONLY( Node* disq_node = nullptr; )
 659   bool can_eliminate = true;
 660   bool reduce_merge_precheck = (safepoints == nullptr);
 661 
 662   Unique_Node_List worklist;
 663   Node* res = alloc->result_cast();
 664   const TypeOopPtr* res_type = nullptr;
 665   if (res == nullptr) {
 666     // All users were eliminated.
 667   } else if (!res->is_CheckCastPP()) {
 668     NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)
 669     can_eliminate = false;
 670   } else {
 671     worklist.push(res);
 672     res_type = igvn->type(res)->isa_oopptr();
 673     if (res_type == nullptr) {
 674       NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)
 675       can_eliminate = false;
 676     } else if (!res_type->klass_is_exact()) {
 677       NOT_PRODUCT(fail_eliminate = "Not an exact type.";)
 678       can_eliminate = false;
 679     } else if (res_type->isa_aryptr()) {
 680       int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
 681       if (length < 0) {
 682         NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)
 683         can_eliminate = false;
 684       }
 685     }
 686   }
 687 
 688   while (can_eliminate && worklist.size() > 0) {
 689     BarrierSetC2 *bs = BarrierSet::barrier_set()->barrier_set_c2();
 690     res = worklist.pop();
 691     for (DUIterator_Fast jmax, j = res->fast_outs(jmax); j < jmax && can_eliminate; j++) {
 692       Node* use = res->fast_out(j);
 693 
 694       if (use->is_AddP()) {
 695         const TypePtr* addp_type = igvn->type(use)->is_ptr();
 696         int offset = addp_type->offset();
 697 
 698         if (offset == Type::OffsetTop || offset == Type::OffsetBot) {
 699           NOT_PRODUCT(fail_eliminate = "Undefined field reference";)
 700           can_eliminate = false;
 701           break;
 702         }
 703         for (DUIterator_Fast kmax, k = use->fast_outs(kmax);
 704                                    k < kmax && can_eliminate; k++) {
 705           Node* n = use->fast_out(k);
 706           if (!n->is_Store() && n->Opcode() != Op_CastP2X && !bs->is_gc_pre_barrier_node(n) && !reduce_merge_precheck) {
 707             DEBUG_ONLY(disq_node = n;)
 708             if (n->is_Load() || n->is_LoadStore()) {
 709               NOT_PRODUCT(fail_eliminate = "Field load";)
 710             } else {
 711               NOT_PRODUCT(fail_eliminate = "Not store field reference";)
 712             }
 713             can_eliminate = false;
 714           }
 715         }
 716       } else if (use->is_ArrayCopy() &&
 717                  (use->as_ArrayCopy()->is_clonebasic() ||
 718                   use->as_ArrayCopy()->is_arraycopy_validated() ||
 719                   use->as_ArrayCopy()->is_copyof_validated() ||
 720                   use->as_ArrayCopy()->is_copyofrange_validated()) &&
 721                  use->in(ArrayCopyNode::Dest) == res) {
 722         // ok to eliminate
 723       } else if (use->is_SafePoint()) {
 724         SafePointNode* sfpt = use->as_SafePoint();
 725         if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) {
 726           // Object is passed as argument.
 727           DEBUG_ONLY(disq_node = use;)
 728           NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)
 729           can_eliminate = false;
 730         }
 731         Node* sfptMem = sfpt->memory();
 732         if (sfptMem == nullptr || sfptMem->is_top()) {
 733           DEBUG_ONLY(disq_node = use;)
 734           NOT_PRODUCT(fail_eliminate = "null or TOP memory";)
 735           can_eliminate = false;
 736         } else if (!reduce_merge_precheck) {
 737           assert(!res->is_Phi() || !res->as_Phi()->can_be_inline_type(), "Inline type allocations should not have safepoint uses");
 738           safepoints->append_if_missing(sfpt);
 739         }
 740       } else if (use->is_InlineType() && use->as_InlineType()->get_oop() == res) {
 741         // Look at uses
 742         for (DUIterator_Fast kmax, k = use->fast_outs(kmax); k < kmax; k++) {
 743           Node* u = use->fast_out(k);
 744           if (u->is_InlineType()) {
 745             // Use in flat field can be eliminated
 746             InlineTypeNode* vt = u->as_InlineType();
 747             for (uint i = 0; i < vt->field_count(); ++i) {
 748               if (vt->field_value(i) == use && !vt->field_is_flat(i)) {
 749                 can_eliminate = false; // Use in non-flat field
 750                 break;
 751               }
 752             }
 753           } else {
 754             // Add other uses to the worklist to process individually
 755             worklist.push(use);
 756           }
 757         }
 758       } else if (use->Opcode() == Op_StoreX && use->in(MemNode::Address) == res) {
 759         // Store to mark word of inline type larval buffer
 760         assert(res_type->is_inlinetypeptr(), "Unexpected store to mark word");
 761       } else if (res_type->is_inlinetypeptr() && (use->Opcode() == Op_MemBarRelease || use->Opcode() == Op_MemBarStoreStore)) {
 762         // Inline type buffer allocations are followed by a membar
 763       } else if (reduce_merge_precheck &&
 764                  (use->is_Phi() || use->is_EncodeP() ||
 765                   use->Opcode() == Op_MemBarRelease ||
 766                   (UseStoreStoreForCtor && use->Opcode() == Op_MemBarStoreStore))) {
 767         // Nothing to do
 768       } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark
 769         if (use->is_Phi()) {
 770           if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {
 771             NOT_PRODUCT(fail_eliminate = "Object is return value";)
 772           } else {
 773             NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)
 774           }
 775           DEBUG_ONLY(disq_node = use;)
 776         } else {
 777           if (use->Opcode() == Op_Return) {
 778             NOT_PRODUCT(fail_eliminate = "Object is return value";)
 779           } else {
 780             NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)
 781           }
 782           DEBUG_ONLY(disq_node = use;)
 783         }
 784         can_eliminate = false;
 785       } else {
 786         assert(use->Opcode() == Op_CastP2X, "should be");
 787         assert(!use->has_out_with(Op_OrL), "should have been removed because oop is never null");
 788       }
 789     }
 790   }
 791 
 792 #ifndef PRODUCT
 793   if (PrintEliminateAllocations && safepoints != nullptr) {
 794     if (can_eliminate) {
 795       tty->print("Scalar ");
 796       if (res == nullptr)
 797         alloc->dump();
 798       else
 799         res->dump();
 800     } else {
 801       tty->print("NotScalar (%s)", fail_eliminate);
 802       if (res == nullptr)
 803         alloc->dump();
 804       else
 805         res->dump();
 806 #ifdef ASSERT
 807       if (disq_node != nullptr) {
 808           tty->print("  >>>> ");
 809           disq_node->dump();
 810       }
 811 #endif /*ASSERT*/
 812     }
 813   }
 814 
 815   if (TraceReduceAllocationMerges && !can_eliminate && reduce_merge_precheck) {
 816     tty->print_cr("\tCan't eliminate allocation because '%s': ", fail_eliminate != nullptr ? fail_eliminate : "");
 817     DEBUG_ONLY(if (disq_node != nullptr) disq_node->dump();)
 818   }
 819 #endif
 820   return can_eliminate;
 821 }
 822 
 823 void PhaseMacroExpand::undo_previous_scalarizations(GrowableArray <SafePointNode *> safepoints_done, AllocateNode* alloc) {
 824   Node* res = alloc->result_cast();
 825   int nfields = 0;
 826   assert(res == nullptr || res->is_CheckCastPP(), "unexpected AllocateNode result");
 827 
 828   if (res != nullptr) {
 829     const TypeOopPtr* res_type = _igvn.type(res)->isa_oopptr();
 830 
 831     if (res_type->isa_instptr()) {
 832       // find the fields of the class which will be needed for safepoint debug information
 833       ciInstanceKlass* iklass = res_type->is_instptr()->instance_klass();
 834       nfields = iklass->nof_nonstatic_fields();
 835     } else {
 836       // find the array's elements which will be needed for safepoint debug information
 837       nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
 838       assert(nfields >= 0, "must be an array klass.");
 839     }
 840   }
 841 
 842   // rollback processed safepoints
 843   while (safepoints_done.length() > 0) {
 844     SafePointNode* sfpt_done = safepoints_done.pop();
 845     // remove any extra entries we added to the safepoint
 846     uint last = sfpt_done->req() - 1;
 847     for (int k = 0;  k < nfields; k++) {
 848       sfpt_done->del_req(last--);
 849     }
 850     JVMState *jvms = sfpt_done->jvms();
 851     jvms->set_endoff(sfpt_done->req());
 852     // Now make a pass over the debug information replacing any references
 853     // to SafePointScalarObjectNode with the allocated object.
 854     int start = jvms->debug_start();
 855     int end   = jvms->debug_end();
 856     for (int i = start; i < end; i++) {
 857       if (sfpt_done->in(i)->is_SafePointScalarObject()) {
 858         SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
 859         if (scobj->first_index(jvms) == sfpt_done->req() &&
 860             scobj->n_fields() == (uint)nfields) {
 861           assert(scobj->alloc() == alloc, "sanity");
 862           sfpt_done->set_req(i, res);
 863         }
 864       }
 865     }
 866     _igvn._worklist.push(sfpt_done);
 867   }
 868 }
 869 
 870 void PhaseMacroExpand::process_field_value_at_safepoint(const Type* field_type, Node* field_val, SafePointNode* sfpt, Unique_Node_List* value_worklist) {
 871   if (UseCompressedOops && field_type->isa_narrowoop()) {
 872     // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation
 873     // to be able scalar replace the allocation.
 874     if (field_val->is_EncodeP()) {
 875       field_val = field_val->in(1);
 876     } else if (!field_val->is_InlineType()) {
 877       field_val = transform_later(new DecodeNNode(field_val, field_val->get_ptr_type()));
 878     }
 879   }
 880 
 881   // Keep track of inline types to scalarize them later
 882   if (field_val->is_InlineType()) {
 883     value_worklist->push(field_val);
 884   } else if (field_val->is_Phi()) {
 885     PhiNode* phi = field_val->as_Phi();
 886     // Eagerly replace inline type phis now since we could be removing an inline type allocation where we must
 887     // scalarize all its fields in safepoints.
 888     field_val = phi->try_push_inline_types_down(&_igvn, true);
 889     if (field_val->is_InlineType()) {
 890       value_worklist->push(field_val);
 891     }
 892   }
 893   sfpt->add_req(field_val);
 894 }
 895 
 896 bool PhaseMacroExpand::add_array_elems_to_safepoint(AllocateNode* alloc, const TypeAryPtr* array_type, SafePointNode* sfpt, Unique_Node_List* value_worklist) {
 897   const Type* elem_type = array_type->elem();
 898   BasicType basic_elem_type = elem_type->array_element_basic_type();
 899 
 900   intptr_t elem_size;
 901   uint header_size;
 902   if (array_type->is_flat()) {
 903     elem_size = array_type->flat_elem_size();
 904     header_size = arrayOopDesc::base_offset_in_bytes(T_FLAT_ELEMENT);
 905   } else {
 906     elem_size = type2aelembytes(basic_elem_type);
 907     header_size = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
 908   }
 909 
 910   int n_elems = alloc->in(AllocateNode::ALength)->get_int();
 911   for (int elem_idx = 0; elem_idx < n_elems; elem_idx++) {
 912     intptr_t elem_offset = header_size + elem_idx * elem_size;
 913     const TypeAryPtr* elem_adr_type = array_type->with_offset(elem_offset);
 914     Node* elem_val;
 915     if (array_type->is_flat()) {
 916       ciInlineKlass* elem_klass = elem_type->inline_klass();
 917       assert(elem_klass->maybe_flat_in_array(), "must be flat in array");
 918       elem_val = inline_type_from_mem(elem_klass, elem_adr_type, elem_idx, 0, array_type->is_null_free(), alloc, sfpt);
 919     } else {
 920       elem_val = value_from_mem(sfpt->memory(), sfpt->control(), basic_elem_type, elem_type, elem_adr_type, alloc);
 921 #ifndef PRODUCT
 922       if (PrintEliminateAllocations && elem_val == nullptr) {
 923         tty->print("=== At SafePoint node %d can't find value of array element [%d]", sfpt->_idx, elem_idx);
 924         tty->print(", which prevents elimination of: ");
 925         alloc->dump();
 926       }
 927 #endif // PRODUCT
 928     }
 929     if (elem_val == nullptr) {
 930       return false;
 931     }
 932 
 933     process_field_value_at_safepoint(elem_type, elem_val, sfpt, value_worklist);
 934   }
 935 
 936   return true;
 937 }
 938 
 939 // Recursively adds all flattened fields of a type 'iklass' inside 'base' to 'sfpt'.
 940 // 'offset_minus_header' refers to the offset of the payload of 'iklass' inside 'base' minus the
 941 // payload offset of 'iklass'. If 'base' is of type 'iklass' then 'offset_minus_header' == 0.
 942 bool PhaseMacroExpand::add_inst_fields_to_safepoint(ciInstanceKlass* iklass, AllocateNode* alloc, Node* base, int offset_minus_header, SafePointNode* sfpt, Unique_Node_List* value_worklist) {
 943   const TypeInstPtr* base_type = _igvn.type(base)->is_instptr();
 944   auto report_failure = [&](int offset) {
 945 #ifndef PRODUCT
 946     if (PrintEliminateAllocations) {
 947       ciInstanceKlass* base_klass = base_type->instance_klass();
 948       ciField* flattened_field = base_klass->get_field_by_offset(offset, false);
 949       assert(flattened_field != nullptr, "must have a field of type %s at offset %d", base_klass->name()->as_utf8(), offset);
 950       tty->print("=== At SafePoint node %d can't find value of field: ", sfpt->_idx);
 951       flattened_field->print();
 952       int field_idx = C->alias_type(flattened_field)->index();
 953       tty->print(" (alias_idx=%d)", field_idx);
 954       tty->print(", which prevents elimination of: ");
 955       base->dump();
 956     }
 957 #endif // PRODUCT
 958   };
 959 
 960   for (int i = 0; i < iklass->nof_declared_nonstatic_fields(); i++) {
 961     ciField* field = iklass->declared_nonstatic_field_at(i);
 962     if (field->is_flat()) {
 963       ciInlineKlass* fvk = field->type()->as_inline_klass();
 964       int field_offset_minus_header = offset_minus_header + field->offset_in_bytes() - fvk->payload_offset();
 965       bool success = add_inst_fields_to_safepoint(fvk, alloc, base, field_offset_minus_header, sfpt, value_worklist);
 966       if (!success) {
 967         return false;
 968       }
 969 
 970       // The null marker of a field is added right after we scalarize that field
 971       if (!field->is_null_free()) {
 972         int nm_offset = offset_minus_header + field->null_marker_offset();
 973         Node* null_marker = value_from_mem(sfpt->memory(), sfpt->control(), T_BOOLEAN, TypeInt::BOOL, base_type->with_offset(nm_offset), alloc);
 974         if (null_marker == nullptr) {
 975           report_failure(nm_offset);
 976           return false;
 977         }
 978         process_field_value_at_safepoint(TypeInt::BOOL, null_marker, sfpt, value_worklist);
 979       }
 980 
 981       continue;
 982     }
 983 
 984     int offset = offset_minus_header + field->offset_in_bytes();
 985     ciType* elem_type = field->type();
 986     BasicType basic_elem_type = field->layout_type();
 987 
 988     const Type* field_type;
 989     if (is_reference_type(basic_elem_type)) {
 990       if (!elem_type->is_loaded()) {
 991         field_type = TypeInstPtr::BOTTOM;
 992       } else {
 993         field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
 994       }
 995       if (UseCompressedOops) {
 996         field_type = field_type->make_narrowoop();
 997         basic_elem_type = T_NARROWOOP;
 998       }
 999     } else {
1000       field_type = Type::get_const_basic_type(basic_elem_type);
1001     }
1002 
1003     const TypeInstPtr* field_addr_type = base_type->add_offset(offset)->isa_instptr();
1004     Node* field_val = value_from_mem(sfpt->memory(), sfpt->control(), basic_elem_type, field_type, field_addr_type, alloc);
1005     if (field_val == nullptr) {
1006       report_failure(offset);
1007       return false;
1008     }
1009     process_field_value_at_safepoint(field_type, field_val, sfpt, value_worklist);
1010   }
1011 
1012   return true;
1013 }
1014 
1015 SafePointScalarObjectNode* PhaseMacroExpand::create_scalarized_object_description(AllocateNode* alloc, SafePointNode* sfpt,
1016                                                                                   Unique_Node_List* value_worklist) {
1017   // Fields of scalar objs are referenced only at the end
1018   // of regular debuginfo at the last (youngest) JVMS.
1019   // Record relative start index.
1020   ciInstanceKlass* iklass    = nullptr;
1021   const TypeOopPtr* res_type = nullptr;
1022   int nfields                = 0;
1023   uint first_ind             = (sfpt->req() - sfpt->jvms()->scloff());
1024   Node* res                  = alloc->result_cast();
1025 
1026   assert(res == nullptr || res->is_CheckCastPP(), "unexpected AllocateNode result");
1027   assert(sfpt->jvms() != nullptr, "missed JVMS");
1028   uint before_sfpt_req = sfpt->req();
1029 
1030   if (res != nullptr) { // Could be null when there are no users
1031     res_type = _igvn.type(res)->isa_oopptr();
1032 
1033     if (res_type->isa_instptr()) {
1034       // find the fields of the class which will be needed for safepoint debug information
1035       iklass = res_type->is_instptr()->instance_klass();
1036       nfields = iklass->nof_nonstatic_fields();
1037     } else {
1038       // find the array's elements which will be needed for safepoint debug information
1039       nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
1040       assert(nfields >= 0, "must be an array klass.");
1041     }
1042 
1043     if (res->bottom_type()->is_inlinetypeptr()) {
1044       // Nullable inline types have a null marker field which is added to the safepoint when scalarizing them (see
1045       // InlineTypeNode::make_scalar_in_safepoint()). When having circular inline types, we stop scalarizing at depth 1
1046       // to avoid an endless recursion. Therefore, we do not have a SafePointScalarObjectNode node here, yet.
1047       // We are about to create a SafePointScalarObjectNode as if this is a normal object. Add an additional int input
1048       // with value 1 which sets the null marker to true to indicate that the object is always non-null. This input is checked
1049       // later in PhaseOutput::filLocArray() for inline types.
1050       sfpt->add_req(_igvn.intcon(1));
1051     }
1052   }
1053 
1054   SafePointScalarObjectNode* sobj = new SafePointScalarObjectNode(res_type, alloc, first_ind, sfpt->jvms()->depth(), nfields);
1055   sobj->init_req(0, C->root());
1056   transform_later(sobj);
1057 
1058   if (res == nullptr) {
1059     sfpt->jvms()->set_endoff(sfpt->req());
1060     return sobj;
1061   }
1062 
1063   bool success;
1064   if (iklass == nullptr) {
1065     success = add_array_elems_to_safepoint(alloc, res_type->is_aryptr(), sfpt, value_worklist);
1066   } else {
1067     success = add_inst_fields_to_safepoint(iklass, alloc, res, 0, sfpt, value_worklist);
1068   }
1069 
1070   // We weren't able to find a value for this field, remove all the fields added to the safepoint
1071   if (!success) {
1072     for (uint i = sfpt->req() - 1; i >= before_sfpt_req; i--) {
1073       sfpt->del_req(i);
1074     }
1075     _igvn._worklist.push(sfpt);
1076     return nullptr;
1077   }
1078 
1079   sfpt->jvms()->set_endoff(sfpt->req());
1080   return sobj;
1081 }
1082 
1083 // Do scalar replacement.
1084 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
1085   GrowableArray <SafePointNode *> safepoints_done;
1086   Node* res = alloc->result_cast();
1087   assert(res == nullptr || res->is_CheckCastPP(), "unexpected AllocateNode result");
1088   const TypeOopPtr* res_type = nullptr;
1089   if (res != nullptr) { // Could be null when there are no users
1090     res_type = _igvn.type(res)->isa_oopptr();
1091   }
1092 
1093   // Process the safepoint uses
1094   Unique_Node_List value_worklist;
1095   while (safepoints.length() > 0) {
1096     SafePointNode* sfpt = safepoints.pop();
1097     SafePointScalarObjectNode* sobj = create_scalarized_object_description(alloc, sfpt, &value_worklist);
1098 
1099     if (sobj == nullptr) {
1100       undo_previous_scalarizations(safepoints_done, alloc);
1101       return false;
1102     }
1103 
1104     // Now make a pass over the debug information replacing any references
1105     // to the allocated object with "sobj"
1106     JVMState *jvms = sfpt->jvms();
1107     sfpt->replace_edges_in_range(res, sobj, jvms->debug_start(), jvms->debug_end(), &_igvn);
1108     _igvn._worklist.push(sfpt);
1109 
1110     // keep it for rollback
1111     safepoints_done.append_if_missing(sfpt);
1112   }
1113   // Scalarize inline types that were added to the safepoint.
1114   // Don't allow linking a constant oop (if available) for flat array elements
1115   // because Deoptimization::reassign_flat_array_elements needs field values.
1116   bool allow_oop = (res_type != nullptr) && !res_type->is_flat();
1117   for (uint i = 0; i < value_worklist.size(); ++i) {
1118     InlineTypeNode* vt = value_worklist.at(i)->as_InlineType();
1119     vt->make_scalar_in_safepoints(&_igvn, allow_oop);
1120   }
1121   return true;
1122 }
1123 
1124 static void disconnect_projections(MultiNode* n, PhaseIterGVN& igvn) {
1125   Node* ctl_proj = n->proj_out_or_null(TypeFunc::Control);
1126   Node* mem_proj = n->proj_out_or_null(TypeFunc::Memory);
1127   if (ctl_proj != nullptr) {
1128     igvn.replace_node(ctl_proj, n->in(0));
1129   }
1130   if (mem_proj != nullptr) {
1131     igvn.replace_node(mem_proj, n->in(TypeFunc::Memory));
1132   }
1133 }
1134 
1135 // Process users of eliminated allocation.
1136 void PhaseMacroExpand::process_users_of_allocation(CallNode *alloc, bool inline_alloc) {
1137   Unique_Node_List worklist;
1138   Node* res = alloc->result_cast();
1139   if (res != nullptr) {
1140     worklist.push(res);
1141   }
1142   while (worklist.size() > 0) {
1143     res = worklist.pop();
1144     for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
1145       Node *use = res->last_out(j);
1146       uint oc1 = res->outcnt();
1147 
1148       if (use->is_AddP()) {
1149         for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
1150           Node *n = use->last_out(k);
1151           uint oc2 = use->outcnt();
1152           if (n->is_Store()) {
1153             for (DUIterator_Fast pmax, p = n->fast_outs(pmax); p < pmax; p++) {
1154               MemBarNode* mb = n->fast_out(p)->isa_MemBar();
1155               if (mb != nullptr && mb->req() <= MemBarNode::Precedent && mb->in(MemBarNode::Precedent) == n) {
1156                 // MemBarVolatiles should have been removed by MemBarNode::Ideal() for non-inline allocations
1157                 assert(inline_alloc, "MemBarVolatile should be eliminated for non-escaping object");
1158                 mb->remove(&_igvn);
1159               }
1160             }
1161             _igvn.replace_node(n, n->in(MemNode::Memory));
1162           } else {
1163             eliminate_gc_barrier(n);
1164           }
1165           k -= (oc2 - use->outcnt());
1166         }
1167         _igvn.remove_dead_node(use);
1168       } else if (use->is_ArrayCopy()) {
1169         // Disconnect ArrayCopy node
1170         ArrayCopyNode* ac = use->as_ArrayCopy();
1171         if (ac->is_clonebasic()) {
1172           Node* membar_after = ac->proj_out(TypeFunc::Control)->unique_ctrl_out();
1173           disconnect_projections(ac, _igvn);
1174           assert(alloc->in(TypeFunc::Memory)->is_Proj() && alloc->in(TypeFunc::Memory)->in(0)->Opcode() == Op_MemBarCPUOrder, "mem barrier expected before allocation");
1175           Node* membar_before = alloc->in(TypeFunc::Memory)->in(0);
1176           disconnect_projections(membar_before->as_MemBar(), _igvn);
1177           if (membar_after->is_MemBar()) {
1178             disconnect_projections(membar_after->as_MemBar(), _igvn);
1179           }
1180         } else {
1181           assert(ac->is_arraycopy_validated() ||
1182                  ac->is_copyof_validated() ||
1183                  ac->is_copyofrange_validated(), "unsupported");
1184           CallProjections* callprojs = ac->extract_projections(true);
1185 
1186           _igvn.replace_node(callprojs->fallthrough_ioproj, ac->in(TypeFunc::I_O));
1187           _igvn.replace_node(callprojs->fallthrough_memproj, ac->in(TypeFunc::Memory));
1188           _igvn.replace_node(callprojs->fallthrough_catchproj, ac->in(TypeFunc::Control));
1189 
1190           // Set control to top. IGVN will remove the remaining projections
1191           ac->set_req(0, top());
1192           ac->replace_edge(res, top(), &_igvn);
1193 
1194           // Disconnect src right away: it can help find new
1195           // opportunities for allocation elimination
1196           Node* src = ac->in(ArrayCopyNode::Src);
1197           ac->replace_edge(src, top(), &_igvn);
1198           // src can be top at this point if src and dest of the
1199           // arraycopy were the same
1200           if (src->outcnt() == 0 && !src->is_top()) {
1201             _igvn.remove_dead_node(src);
1202           }
1203         }
1204         _igvn._worklist.push(ac);
1205       } else if (use->is_InlineType()) {
1206         assert(use->as_InlineType()->get_oop() == res, "unexpected inline type ptr use");
1207         // Cut off oop input and remove known instance id from type
1208         _igvn.rehash_node_delayed(use);
1209         use->as_InlineType()->set_oop(_igvn, _igvn.zerocon(T_OBJECT));
1210         const TypeOopPtr* toop = _igvn.type(use)->is_oopptr()->cast_to_instance_id(TypeOopPtr::InstanceBot);
1211         _igvn.set_type(use, toop);
1212         use->as_InlineType()->set_type(toop);
1213         // Process users
1214         for (DUIterator_Fast kmax, k = use->fast_outs(kmax); k < kmax; k++) {
1215           Node* u = use->fast_out(k);
1216           if (!u->is_InlineType()) {
1217             worklist.push(u);
1218           }
1219         }
1220       } else if (use->Opcode() == Op_StoreX && use->in(MemNode::Address) == res) {
1221         // Store to mark word of inline type larval buffer
1222         assert(inline_alloc, "Unexpected store to mark word");
1223         _igvn.replace_node(use, use->in(MemNode::Memory));
1224       } else if (use->Opcode() == Op_MemBarRelease || use->Opcode() == Op_MemBarStoreStore) {
1225         // Inline type buffer allocations are followed by a membar
1226         assert(inline_alloc, "Unexpected MemBarRelease");
1227         use->as_MemBar()->remove(&_igvn);
1228       } else {
1229         eliminate_gc_barrier(use);
1230       }
1231       j -= (oc1 - res->outcnt());
1232     }
1233     assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
1234     _igvn.remove_dead_node(res);
1235   }
1236 
1237   //
1238   // Process other users of allocation's projections
1239   //
1240   if (_callprojs->resproj[0] != nullptr && _callprojs->resproj[0]->outcnt() != 0) {
1241     // First disconnect stores captured by Initialize node.
1242     // If Initialize node is eliminated first in the following code,
1243     // it will kill such stores and DUIterator_Last will assert.
1244     for (DUIterator_Fast jmax, j = _callprojs->resproj[0]->fast_outs(jmax);  j < jmax; j++) {
1245       Node* use = _callprojs->resproj[0]->fast_out(j);
1246       if (use->is_AddP()) {
1247         // raw memory addresses used only by the initialization
1248         _igvn.replace_node(use, C->top());
1249         --j; --jmax;
1250       }
1251     }
1252     for (DUIterator_Last jmin, j = _callprojs->resproj[0]->last_outs(jmin); j >= jmin; ) {
1253       Node* use = _callprojs->resproj[0]->last_out(j);
1254       uint oc1 = _callprojs->resproj[0]->outcnt();
1255       if (use->is_Initialize()) {
1256         // Eliminate Initialize node.
1257         InitializeNode *init = use->as_Initialize();
1258         assert(init->outcnt() <= 2, "only a control and memory projection expected");
1259         Node *ctrl_proj = init->proj_out_or_null(TypeFunc::Control);
1260         if (ctrl_proj != nullptr) {
1261           _igvn.replace_node(ctrl_proj, init->in(TypeFunc::Control));
1262 #ifdef ASSERT
1263           // If the InitializeNode has no memory out, it will die, and tmp will become null
1264           Node* tmp = init->in(TypeFunc::Control);
1265           assert(tmp == nullptr || tmp == _callprojs->fallthrough_catchproj, "allocation control projection");
1266 #endif
1267         }
1268         Node *mem_proj = init->proj_out_or_null(TypeFunc::Memory);
1269         if (mem_proj != nullptr) {
1270           Node *mem = init->in(TypeFunc::Memory);
1271 #ifdef ASSERT
1272           if (mem->is_MergeMem()) {
1273             assert(mem->in(TypeFunc::Memory) == _callprojs->fallthrough_memproj, "allocation memory projection");
1274           } else {
1275             assert(mem == _callprojs->fallthrough_memproj, "allocation memory projection");
1276           }
1277 #endif
1278           _igvn.replace_node(mem_proj, mem);
1279         }
1280       } else if (use->Opcode() == Op_MemBarStoreStore) {
1281         // Inline type buffer allocations are followed by a membar
1282         assert(inline_alloc, "Unexpected MemBarStoreStore");
1283         use->as_MemBar()->remove(&_igvn);
1284       } else  {
1285         assert(false, "only Initialize or AddP expected");
1286       }
1287       j -= (oc1 - _callprojs->resproj[0]->outcnt());
1288     }
1289   }
1290   if (_callprojs->fallthrough_catchproj != nullptr) {
1291     _igvn.replace_node(_callprojs->fallthrough_catchproj, alloc->in(TypeFunc::Control));
1292   }
1293   if (_callprojs->fallthrough_memproj != nullptr) {
1294     _igvn.replace_node(_callprojs->fallthrough_memproj, alloc->in(TypeFunc::Memory));
1295   }
1296   if (_callprojs->catchall_memproj != nullptr) {
1297     _igvn.replace_node(_callprojs->catchall_memproj, C->top());
1298   }
1299   if (_callprojs->fallthrough_ioproj != nullptr) {
1300     _igvn.replace_node(_callprojs->fallthrough_ioproj, alloc->in(TypeFunc::I_O));
1301   }
1302   if (_callprojs->catchall_ioproj != nullptr) {
1303     _igvn.replace_node(_callprojs->catchall_ioproj, C->top());
1304   }
1305   if (_callprojs->catchall_catchproj != nullptr) {
1306     _igvn.replace_node(_callprojs->catchall_catchproj, C->top());
1307   }
1308 }
1309 
1310 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
1311   // If reallocation fails during deoptimization we'll pop all
1312   // interpreter frames for this compiled frame and that won't play
1313   // nice with JVMTI popframe.
1314   // We avoid this issue by eager reallocation when the popframe request
1315   // is received.
1316   if (!EliminateAllocations) {
1317     return false;
1318   }
1319   Node* klass = alloc->in(AllocateNode::KlassNode);
1320   const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr();
1321 
1322   // Attempt to eliminate inline type buffer allocations
1323   // regardless of usage and escape/replaceable status.
1324   bool inline_alloc = tklass->isa_instklassptr() &&
1325                       tklass->is_instklassptr()->instance_klass()->is_inlinetype();
1326   if (!alloc->_is_non_escaping && !inline_alloc) {
1327     return false;
1328   }
1329   // Eliminate boxing allocations which are not used
1330   // regardless scalar replaceable status.
1331   Node* res = alloc->result_cast();
1332   bool boxing_alloc = (res == nullptr) && C->eliminate_boxing() &&
1333                       tklass->isa_instklassptr() &&
1334                       tklass->is_instklassptr()->instance_klass()->is_box_klass();
1335   if (!alloc->_is_scalar_replaceable && !boxing_alloc && !inline_alloc) {
1336     return false;
1337   }
1338 
1339   _callprojs = alloc->extract_projections(false /*separate_io_proj*/, false /*do_asserts*/);
1340 
1341   GrowableArray <SafePointNode *> safepoints;
1342   if (!can_eliminate_allocation(&_igvn, alloc, &safepoints)) {
1343     return false;
1344   }
1345 
1346   if (!alloc->_is_scalar_replaceable) {
1347     assert(res == nullptr || inline_alloc, "sanity");
1348     // We can only eliminate allocation if all debug info references
1349     // are already replaced with SafePointScalarObject because
1350     // we can't search for a fields value without instance_id.
1351     if (safepoints.length() > 0) {
1352       return false;
1353     }
1354   }
1355 
1356   if (!scalar_replacement(alloc, safepoints)) {
1357     return false;
1358   }
1359 
1360   CompileLog* log = C->log();
1361   if (log != nullptr) {
1362     log->head("eliminate_allocation type='%d'",
1363               log->identify(tklass->exact_klass()));
1364     JVMState* p = alloc->jvms();
1365     while (p != nullptr) {
1366       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1367       p = p->caller();
1368     }
1369     log->tail("eliminate_allocation");
1370   }
1371 
1372   process_users_of_allocation(alloc, inline_alloc);
1373 
1374 #ifndef PRODUCT
1375   if (PrintEliminateAllocations) {
1376     if (alloc->is_AllocateArray())
1377       tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
1378     else
1379       tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
1380   }
1381 #endif
1382 
1383   return true;
1384 }
1385 
1386 bool PhaseMacroExpand::eliminate_boxing_node(CallStaticJavaNode *boxing) {
1387   // EA should remove all uses of non-escaping boxing node.
1388   if (!C->eliminate_boxing() || boxing->proj_out_or_null(TypeFunc::Parms) != nullptr) {
1389     return false;
1390   }
1391 
1392   assert(boxing->result_cast() == nullptr, "unexpected boxing node result");
1393 
1394   _callprojs = boxing->extract_projections(false /*separate_io_proj*/, false /*do_asserts*/);
1395 
1396   const TypeTuple* r = boxing->tf()->range_sig();
1397   assert(r->cnt() > TypeFunc::Parms, "sanity");
1398   const TypeInstPtr* t = r->field_at(TypeFunc::Parms)->isa_instptr();
1399   assert(t != nullptr, "sanity");
1400 
1401   CompileLog* log = C->log();
1402   if (log != nullptr) {
1403     log->head("eliminate_boxing type='%d'",
1404               log->identify(t->instance_klass()));
1405     JVMState* p = boxing->jvms();
1406     while (p != nullptr) {
1407       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1408       p = p->caller();
1409     }
1410     log->tail("eliminate_boxing");
1411   }
1412 
1413   process_users_of_allocation(boxing);
1414 
1415 #ifndef PRODUCT
1416   if (PrintEliminateAllocations) {
1417     tty->print("++++ Eliminated: %d ", boxing->_idx);
1418     boxing->method()->print_short_name(tty);
1419     tty->cr();
1420   }
1421 #endif
1422 
1423   return true;
1424 }
1425 
1426 
1427 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
1428   Node* adr = basic_plus_adr(base, offset);
1429   const TypePtr* adr_type = adr->bottom_type()->is_ptr();
1430   Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt, MemNode::unordered);
1431   transform_later(value);
1432   return value;
1433 }
1434 
1435 
1436 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
1437   Node* adr = basic_plus_adr(base, offset);
1438   mem = StoreNode::make(_igvn, ctl, mem, adr, nullptr, value, bt, MemNode::unordered);
1439   transform_later(mem);
1440   return mem;
1441 }
1442 
1443 //=============================================================================
1444 //
1445 //                              A L L O C A T I O N
1446 //
1447 // Allocation attempts to be fast in the case of frequent small objects.
1448 // It breaks down like this:
1449 //
1450 // 1) Size in doublewords is computed.  This is a constant for objects and
1451 // variable for most arrays.  Doubleword units are used to avoid size
1452 // overflow of huge doubleword arrays.  We need doublewords in the end for
1453 // rounding.
1454 //
1455 // 2) Size is checked for being 'too large'.  Too-large allocations will go
1456 // the slow path into the VM.  The slow path can throw any required
1457 // exceptions, and does all the special checks for very large arrays.  The
1458 // size test can constant-fold away for objects.  For objects with
1459 // finalizers it constant-folds the otherway: you always go slow with
1460 // finalizers.
1461 //
1462 // 3) If NOT using TLABs, this is the contended loop-back point.
1463 // Load-Locked the heap top.  If using TLABs normal-load the heap top.
1464 //
1465 // 4) Check that heap top + size*8 < max.  If we fail go the slow ` route.
1466 // NOTE: "top+size*8" cannot wrap the 4Gig line!  Here's why: for largish
1467 // "size*8" we always enter the VM, where "largish" is a constant picked small
1468 // enough that there's always space between the eden max and 4Gig (old space is
1469 // there so it's quite large) and large enough that the cost of entering the VM
1470 // is dwarfed by the cost to initialize the space.
1471 //
1472 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
1473 // down.  If contended, repeat at step 3.  If using TLABs normal-store
1474 // adjusted heap top back down; there is no contention.
1475 //
1476 // 6) If !ZeroTLAB then Bulk-clear the object/array.  Fill in klass & mark
1477 // fields.
1478 //
1479 // 7) Merge with the slow-path; cast the raw memory pointer to the correct
1480 // oop flavor.
1481 //
1482 //=============================================================================
1483 // FastAllocateSizeLimit value is in DOUBLEWORDS.
1484 // Allocations bigger than this always go the slow route.
1485 // This value must be small enough that allocation attempts that need to
1486 // trigger exceptions go the slow route.  Also, it must be small enough so
1487 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.
1488 //=============================================================================j//
1489 // %%% Here is an old comment from parseHelper.cpp; is it outdated?
1490 // The allocator will coalesce int->oop copies away.  See comment in
1491 // coalesce.cpp about how this works.  It depends critically on the exact
1492 // code shape produced here, so if you are changing this code shape
1493 // make sure the GC info for the heap-top is correct in and around the
1494 // slow-path call.
1495 //
1496 
1497 void PhaseMacroExpand::expand_allocate_common(
1498             AllocateNode* alloc, // allocation node to be expanded
1499             Node* length,  // array length for an array allocation
1500             Node* init_val, // value to initialize the array with
1501             const TypeFunc* slow_call_type, // Type of slow call
1502             address slow_call_address,  // Address of slow call
1503             Node* valid_length_test // whether length is valid or not
1504     )
1505 {
1506   Node* ctrl = alloc->in(TypeFunc::Control);
1507   Node* mem  = alloc->in(TypeFunc::Memory);
1508   Node* i_o  = alloc->in(TypeFunc::I_O);
1509   Node* size_in_bytes     = alloc->in(AllocateNode::AllocSize);
1510   Node* klass_node        = alloc->in(AllocateNode::KlassNode);
1511   Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
1512   assert(ctrl != nullptr, "must have control");
1513 
1514   // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
1515   // they will not be used if "always_slow" is set
1516   enum { slow_result_path = 1, fast_result_path = 2 };
1517   Node *result_region = nullptr;
1518   Node *result_phi_rawmem = nullptr;
1519   Node *result_phi_rawoop = nullptr;
1520   Node *result_phi_i_o = nullptr;
1521 
1522   // The initial slow comparison is a size check, the comparison
1523   // we want to do is a BoolTest::gt
1524   bool expand_fast_path = true;
1525   int tv = _igvn.find_int_con(initial_slow_test, -1);
1526   if (tv >= 0) {
1527     // InitialTest has constant result
1528     //   0 - can fit in TLAB
1529     //   1 - always too big or negative
1530     assert(tv <= 1, "0 or 1 if a constant");
1531     expand_fast_path = (tv == 0);
1532     initial_slow_test = nullptr;
1533   } else {
1534     initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
1535   }
1536 
1537   if (!UseTLAB) {
1538     // Force slow-path allocation
1539     expand_fast_path = false;
1540     initial_slow_test = nullptr;
1541   }
1542 
1543   bool allocation_has_use = (alloc->result_cast() != nullptr);
1544   if (!allocation_has_use) {
1545     InitializeNode* init = alloc->initialization();
1546     if (init != nullptr) {
1547       init->remove(&_igvn);
1548     }
1549     if (expand_fast_path && (initial_slow_test == nullptr)) {
1550       // Remove allocation node and return.
1551       // Size is a non-negative constant -> no initial check needed -> directly to fast path.
1552       // Also, no usages -> empty fast path -> no fall out to slow path -> nothing left.
1553 #ifndef PRODUCT
1554       if (PrintEliminateAllocations) {
1555         tty->print("NotUsed ");
1556         Node* res = alloc->proj_out_or_null(TypeFunc::Parms);
1557         if (res != nullptr) {
1558           res->dump();
1559         } else {
1560           alloc->dump();
1561         }
1562       }
1563 #endif
1564       yank_alloc_node(alloc);
1565       return;
1566     }
1567   }
1568 
1569   enum { too_big_or_final_path = 1, need_gc_path = 2 };
1570   Node *slow_region = nullptr;
1571   Node *toobig_false = ctrl;
1572 
1573   // generate the initial test if necessary
1574   if (initial_slow_test != nullptr ) {
1575     assert (expand_fast_path, "Only need test if there is a fast path");
1576     slow_region = new RegionNode(3);
1577 
1578     // Now make the initial failure test.  Usually a too-big test but
1579     // might be a TRUE for finalizers.
1580     IfNode *toobig_iff = new IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
1581     transform_later(toobig_iff);
1582     // Plug the failing-too-big test into the slow-path region
1583     Node* toobig_true = new IfTrueNode(toobig_iff);
1584     transform_later(toobig_true);
1585     slow_region    ->init_req( too_big_or_final_path, toobig_true );
1586     toobig_false = new IfFalseNode(toobig_iff);
1587     transform_later(toobig_false);
1588   } else {
1589     // No initial test, just fall into next case
1590     assert(allocation_has_use || !expand_fast_path, "Should already have been handled");
1591     toobig_false = ctrl;
1592     DEBUG_ONLY(slow_region = NodeSentinel);
1593   }
1594 
1595   // If we are here there are several possibilities
1596   // - expand_fast_path is false - then only a slow path is expanded. That's it.
1597   // no_initial_check means a constant allocation.
1598   // - If check always evaluates to false -> expand_fast_path is false (see above)
1599   // - If check always evaluates to true -> directly into fast path (but may bailout to slowpath)
1600   // if !allocation_has_use the fast path is empty
1601   // if !allocation_has_use && no_initial_check
1602   // - Then there are no fastpath that can fall out to slowpath -> no allocation code at all.
1603   //   removed by yank_alloc_node above.
1604 
1605   Node *slow_mem = mem;  // save the current memory state for slow path
1606   // generate the fast allocation code unless we know that the initial test will always go slow
1607   if (expand_fast_path) {
1608     // Fast path modifies only raw memory.
1609     if (mem->is_MergeMem()) {
1610       mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
1611     }
1612 
1613     // allocate the Region and Phi nodes for the result
1614     result_region = new RegionNode(3);
1615     result_phi_rawmem = new PhiNode(result_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1616     result_phi_i_o    = new PhiNode(result_region, Type::ABIO); // I/O is used for Prefetch
1617 
1618     // Grab regular I/O before optional prefetch may change it.
1619     // Slow-path does no I/O so just set it to the original I/O.
1620     result_phi_i_o->init_req(slow_result_path, i_o);
1621 
1622     // Name successful fast-path variables
1623     Node* fast_oop_ctrl;
1624     Node* fast_oop_rawmem;
1625 
1626     if (allocation_has_use) {
1627       Node* needgc_ctrl = nullptr;
1628       result_phi_rawoop = new PhiNode(result_region, TypeRawPtr::BOTTOM);
1629 
1630       intx prefetch_lines = length != nullptr ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1631       BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1632       Node* fast_oop = bs->obj_allocate(this, mem, toobig_false, size_in_bytes, i_o, needgc_ctrl,
1633                                         fast_oop_ctrl, fast_oop_rawmem,
1634                                         prefetch_lines);
1635 
1636       if (initial_slow_test != nullptr) {
1637         // This completes all paths into the slow merge point
1638         slow_region->init_req(need_gc_path, needgc_ctrl);
1639         transform_later(slow_region);
1640       } else {
1641         // No initial slow path needed!
1642         // Just fall from the need-GC path straight into the VM call.
1643         slow_region = needgc_ctrl;
1644       }
1645 
1646       InitializeNode* init = alloc->initialization();
1647       fast_oop_rawmem = initialize_object(alloc,
1648                                           fast_oop_ctrl, fast_oop_rawmem, fast_oop,
1649                                           klass_node, length, size_in_bytes);
1650       expand_initialize_membar(alloc, init, fast_oop_ctrl, fast_oop_rawmem);
1651       expand_dtrace_alloc_probe(alloc, fast_oop, fast_oop_ctrl, fast_oop_rawmem);
1652 
1653       result_phi_rawoop->init_req(fast_result_path, fast_oop);
1654     } else {
1655       assert (initial_slow_test != nullptr, "sanity");
1656       fast_oop_ctrl   = toobig_false;
1657       fast_oop_rawmem = mem;
1658       transform_later(slow_region);
1659     }
1660 
1661     // Plug in the successful fast-path into the result merge point
1662     result_region    ->init_req(fast_result_path, fast_oop_ctrl);
1663     result_phi_i_o   ->init_req(fast_result_path, i_o);
1664     result_phi_rawmem->init_req(fast_result_path, fast_oop_rawmem);
1665   } else {
1666     slow_region = ctrl;
1667     result_phi_i_o = i_o; // Rename it to use in the following code.
1668   }
1669 
1670   // Generate slow-path call
1671   CallNode *call = new CallStaticJavaNode(slow_call_type, slow_call_address,
1672                                OptoRuntime::stub_name(slow_call_address),
1673                                TypePtr::BOTTOM);
1674   call->init_req(TypeFunc::Control,   slow_region);
1675   call->init_req(TypeFunc::I_O,       top());    // does no i/o
1676   call->init_req(TypeFunc::Memory,    slow_mem); // may gc ptrs
1677   call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr));
1678   call->init_req(TypeFunc::FramePtr,  alloc->in(TypeFunc::FramePtr));
1679 
1680   call->init_req(TypeFunc::Parms+0, klass_node);
1681   if (length != nullptr) {
1682     call->init_req(TypeFunc::Parms+1, length);
1683     if (init_val != nullptr) {
1684       call->init_req(TypeFunc::Parms+2, init_val);
1685     }
1686   } else {
1687     // Let the runtime know if this is a larval allocation
1688     call->init_req(TypeFunc::Parms+1, _igvn.intcon(alloc->_larval));
1689   }
1690 
1691   // Copy debug information and adjust JVMState information, then replace
1692   // allocate node with the call
1693   call->copy_call_debug_info(&_igvn, alloc);
1694   // For array allocations, copy the valid length check to the call node so Compile::final_graph_reshaping() can verify
1695   // that the call has the expected number of CatchProj nodes (in case the allocation always fails and the fallthrough
1696   // path dies).
1697   if (valid_length_test != nullptr) {
1698     call->add_req(valid_length_test);
1699   }
1700   if (expand_fast_path) {
1701     call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
1702   } else {
1703     // Hook i_o projection to avoid its elimination during allocation
1704     // replacement (when only a slow call is generated).
1705     call->set_req(TypeFunc::I_O, result_phi_i_o);
1706   }
1707   _igvn.replace_node(alloc, call);
1708   transform_later(call);
1709 
1710   // Identify the output projections from the allocate node and
1711   // adjust any references to them.
1712   // The control and io projections look like:
1713   //
1714   //        v---Proj(ctrl) <-----+   v---CatchProj(ctrl)
1715   //  Allocate                   Catch
1716   //        ^---Proj(io) <-------+   ^---CatchProj(io)
1717   //
1718   //  We are interested in the CatchProj nodes.
1719   //
1720   _callprojs = call->extract_projections(false /*separate_io_proj*/, false /*do_asserts*/);
1721 
1722   // An allocate node has separate memory projections for the uses on
1723   // the control and i_o paths. Replace the control memory projection with
1724   // result_phi_rawmem (unless we are only generating a slow call when
1725   // both memory projections are combined)
1726   if (expand_fast_path && _callprojs->fallthrough_memproj != nullptr) {
1727     _igvn.replace_in_uses(_callprojs->fallthrough_memproj, result_phi_rawmem);
1728   }
1729   // Now change uses of catchall_memproj to use fallthrough_memproj and delete
1730   // catchall_memproj so we end up with a call that has only 1 memory projection.
1731   if (_callprojs->catchall_memproj != nullptr) {
1732     if (_callprojs->fallthrough_memproj == nullptr) {
1733       _callprojs->fallthrough_memproj = new ProjNode(call, TypeFunc::Memory);
1734       transform_later(_callprojs->fallthrough_memproj);
1735     }
1736     _igvn.replace_in_uses(_callprojs->catchall_memproj, _callprojs->fallthrough_memproj);
1737     _igvn.remove_dead_node(_callprojs->catchall_memproj);
1738   }
1739 
1740   // An allocate node has separate i_o projections for the uses on the control
1741   // and i_o paths. Always replace the control i_o projection with result i_o
1742   // otherwise incoming i_o become dead when only a slow call is generated
1743   // (it is different from memory projections where both projections are
1744   // combined in such case).
1745   if (_callprojs->fallthrough_ioproj != nullptr) {
1746     _igvn.replace_in_uses(_callprojs->fallthrough_ioproj, result_phi_i_o);
1747   }
1748   // Now change uses of catchall_ioproj to use fallthrough_ioproj and delete
1749   // catchall_ioproj so we end up with a call that has only 1 i_o projection.
1750   if (_callprojs->catchall_ioproj != nullptr) {
1751     if (_callprojs->fallthrough_ioproj == nullptr) {
1752       _callprojs->fallthrough_ioproj = new ProjNode(call, TypeFunc::I_O);
1753       transform_later(_callprojs->fallthrough_ioproj);
1754     }
1755     _igvn.replace_in_uses(_callprojs->catchall_ioproj, _callprojs->fallthrough_ioproj);
1756     _igvn.remove_dead_node(_callprojs->catchall_ioproj);
1757   }
1758 
1759   // if we generated only a slow call, we are done
1760   if (!expand_fast_path) {
1761     // Now we can unhook i_o.
1762     if (result_phi_i_o->outcnt() > 1) {
1763       call->set_req(TypeFunc::I_O, top());
1764     } else {
1765       assert(result_phi_i_o->unique_ctrl_out() == call, "sanity");
1766       // Case of new array with negative size known during compilation.
1767       // AllocateArrayNode::Ideal() optimization disconnect unreachable
1768       // following code since call to runtime will throw exception.
1769       // As result there will be no users of i_o after the call.
1770       // Leave i_o attached to this call to avoid problems in preceding graph.
1771     }
1772     return;
1773   }
1774 
1775   if (_callprojs->fallthrough_catchproj != nullptr) {
1776     ctrl = _callprojs->fallthrough_catchproj->clone();
1777     transform_later(ctrl);
1778     _igvn.replace_node(_callprojs->fallthrough_catchproj, result_region);
1779   } else {
1780     ctrl = top();
1781   }
1782   Node *slow_result;
1783   if (_callprojs->resproj[0] == nullptr) {
1784     // no uses of the allocation result
1785     slow_result = top();
1786   } else {
1787     slow_result = _callprojs->resproj[0]->clone();
1788     transform_later(slow_result);
1789     _igvn.replace_node(_callprojs->resproj[0], result_phi_rawoop);
1790   }
1791 
1792   // Plug slow-path into result merge point
1793   result_region->init_req( slow_result_path, ctrl);
1794   transform_later(result_region);
1795   if (allocation_has_use) {
1796     result_phi_rawoop->init_req(slow_result_path, slow_result);
1797     transform_later(result_phi_rawoop);
1798   }
1799   result_phi_rawmem->init_req(slow_result_path, _callprojs->fallthrough_memproj);
1800   transform_later(result_phi_rawmem);
1801   transform_later(result_phi_i_o);
1802   // This completes all paths into the result merge point
1803 }
1804 
1805 // Remove alloc node that has no uses.
1806 void PhaseMacroExpand::yank_alloc_node(AllocateNode* alloc) {
1807   Node* ctrl = alloc->in(TypeFunc::Control);
1808   Node* mem  = alloc->in(TypeFunc::Memory);
1809   Node* i_o  = alloc->in(TypeFunc::I_O);
1810 
1811   _callprojs = alloc->extract_projections(false /*separate_io_proj*/, false /*do_asserts*/);
1812   if (_callprojs->resproj[0] != nullptr) {
1813     for (DUIterator_Fast imax, i = _callprojs->resproj[0]->fast_outs(imax); i < imax; i++) {
1814       Node* use = _callprojs->resproj[0]->fast_out(i);
1815       use->isa_MemBar()->remove(&_igvn);
1816       --imax;
1817       --i; // back up iterator
1818     }
1819     assert(_callprojs->resproj[0]->outcnt() == 0, "all uses must be deleted");
1820     _igvn.remove_dead_node(_callprojs->resproj[0]);
1821   }
1822   if (_callprojs->fallthrough_catchproj != nullptr) {
1823     _igvn.replace_in_uses(_callprojs->fallthrough_catchproj, ctrl);
1824     _igvn.remove_dead_node(_callprojs->fallthrough_catchproj);
1825   }
1826   if (_callprojs->catchall_catchproj != nullptr) {
1827     _igvn.rehash_node_delayed(_callprojs->catchall_catchproj);
1828     _callprojs->catchall_catchproj->set_req(0, top());
1829   }
1830   if (_callprojs->fallthrough_proj != nullptr) {
1831     Node* catchnode = _callprojs->fallthrough_proj->unique_ctrl_out();
1832     _igvn.remove_dead_node(catchnode);
1833     _igvn.remove_dead_node(_callprojs->fallthrough_proj);
1834   }
1835   if (_callprojs->fallthrough_memproj != nullptr) {
1836     _igvn.replace_in_uses(_callprojs->fallthrough_memproj, mem);
1837     _igvn.remove_dead_node(_callprojs->fallthrough_memproj);
1838   }
1839   if (_callprojs->fallthrough_ioproj != nullptr) {
1840     _igvn.replace_in_uses(_callprojs->fallthrough_ioproj, i_o);
1841     _igvn.remove_dead_node(_callprojs->fallthrough_ioproj);
1842   }
1843   if (_callprojs->catchall_memproj != nullptr) {
1844     _igvn.rehash_node_delayed(_callprojs->catchall_memproj);
1845     _callprojs->catchall_memproj->set_req(0, top());
1846   }
1847   if (_callprojs->catchall_ioproj != nullptr) {
1848     _igvn.rehash_node_delayed(_callprojs->catchall_ioproj);
1849     _callprojs->catchall_ioproj->set_req(0, top());
1850   }
1851 #ifndef PRODUCT
1852   if (PrintEliminateAllocations) {
1853     if (alloc->is_AllocateArray()) {
1854       tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
1855     } else {
1856       tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
1857     }
1858   }
1859 #endif
1860   _igvn.remove_dead_node(alloc);
1861 }
1862 
1863 void PhaseMacroExpand::expand_initialize_membar(AllocateNode* alloc, InitializeNode* init,
1864                                                 Node*& fast_oop_ctrl, Node*& fast_oop_rawmem) {
1865   // If initialization is performed by an array copy, any required
1866   // MemBarStoreStore was already added. If the object does not
1867   // escape no need for a MemBarStoreStore. If the object does not
1868   // escape in its initializer and memory barrier (MemBarStoreStore or
1869   // stronger) is already added at exit of initializer, also no need
1870   // for a MemBarStoreStore. Otherwise we need a MemBarStoreStore
1871   // so that stores that initialize this object can't be reordered
1872   // with a subsequent store that makes this object accessible by
1873   // other threads.
1874   // Other threads include java threads and JVM internal threads
1875   // (for example concurrent GC threads). Current concurrent GC
1876   // implementation: G1 will not scan newly created object,
1877   // so it's safe to skip storestore barrier when allocation does
1878   // not escape.
1879   if (!alloc->does_not_escape_thread() &&
1880     !alloc->is_allocation_MemBar_redundant() &&
1881     (init == nullptr || !init->is_complete_with_arraycopy())) {
1882     if (init == nullptr || init->req() < InitializeNode::RawStores) {
1883       // No InitializeNode or no stores captured by zeroing
1884       // elimination. Simply add the MemBarStoreStore after object
1885       // initialization.
1886       MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1887       transform_later(mb);
1888 
1889       mb->init_req(TypeFunc::Memory, fast_oop_rawmem);
1890       mb->init_req(TypeFunc::Control, fast_oop_ctrl);
1891       fast_oop_ctrl = new ProjNode(mb, TypeFunc::Control);
1892       transform_later(fast_oop_ctrl);
1893       fast_oop_rawmem = new ProjNode(mb, TypeFunc::Memory);
1894       transform_later(fast_oop_rawmem);
1895     } else {
1896       // Add the MemBarStoreStore after the InitializeNode so that
1897       // all stores performing the initialization that were moved
1898       // before the InitializeNode happen before the storestore
1899       // barrier.
1900 
1901       Node* init_ctrl = init->proj_out_or_null(TypeFunc::Control);
1902       Node* init_mem = init->proj_out_or_null(TypeFunc::Memory);
1903 
1904       MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1905       transform_later(mb);
1906 
1907       Node* ctrl = new ProjNode(init, TypeFunc::Control);
1908       transform_later(ctrl);
1909       Node* mem = new ProjNode(init, TypeFunc::Memory);
1910       transform_later(mem);
1911 
1912       // The MemBarStoreStore depends on control and memory coming
1913       // from the InitializeNode
1914       mb->init_req(TypeFunc::Memory, mem);
1915       mb->init_req(TypeFunc::Control, ctrl);
1916 
1917       ctrl = new ProjNode(mb, TypeFunc::Control);
1918       transform_later(ctrl);
1919       mem = new ProjNode(mb, TypeFunc::Memory);
1920       transform_later(mem);
1921 
1922       // All nodes that depended on the InitializeNode for control
1923       // and memory must now depend on the MemBarNode that itself
1924       // depends on the InitializeNode
1925       if (init_ctrl != nullptr) {
1926         _igvn.replace_node(init_ctrl, ctrl);
1927       }
1928       if (init_mem != nullptr) {
1929         _igvn.replace_node(init_mem, mem);
1930       }
1931     }
1932   }
1933 }
1934 
1935 void PhaseMacroExpand::expand_dtrace_alloc_probe(AllocateNode* alloc, Node* oop,
1936                                                 Node*& ctrl, Node*& rawmem) {
1937   if (C->env()->dtrace_alloc_probes()) {
1938     // Slow-path call
1939     int size = TypeFunc::Parms + 2;
1940     CallLeafNode *call = new CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
1941                                           CAST_FROM_FN_PTR(address,
1942                                           static_cast<int (*)(JavaThread*, oopDesc*)>(SharedRuntime::dtrace_object_alloc)),
1943                                           "dtrace_object_alloc",
1944                                           TypeRawPtr::BOTTOM);
1945 
1946     // Get base of thread-local storage area
1947     Node* thread = new ThreadLocalNode();
1948     transform_later(thread);
1949 
1950     call->init_req(TypeFunc::Parms + 0, thread);
1951     call->init_req(TypeFunc::Parms + 1, oop);
1952     call->init_req(TypeFunc::Control, ctrl);
1953     call->init_req(TypeFunc::I_O    , top()); // does no i/o
1954     call->init_req(TypeFunc::Memory , rawmem);
1955     call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr));
1956     call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr));
1957     transform_later(call);
1958     ctrl = new ProjNode(call, TypeFunc::Control);
1959     transform_later(ctrl);
1960     rawmem = new ProjNode(call, TypeFunc::Memory);
1961     transform_later(rawmem);
1962   }
1963 }
1964 
1965 // Helper for PhaseMacroExpand::expand_allocate_common.
1966 // Initializes the newly-allocated storage.
1967 Node* PhaseMacroExpand::initialize_object(AllocateNode* alloc,
1968                                           Node* control, Node* rawmem, Node* object,
1969                                           Node* klass_node, Node* length,
1970                                           Node* size_in_bytes) {
1971   InitializeNode* init = alloc->initialization();
1972   // Store the klass & mark bits
1973   Node* mark_node = alloc->make_ideal_mark(&_igvn, control, rawmem);
1974   if (!mark_node->is_Con()) {
1975     transform_later(mark_node);
1976   }
1977   rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, TypeX_X->basic_type());
1978 
1979   if (!UseCompactObjectHeaders) {
1980     rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_METADATA);
1981   }
1982   int header_size = alloc->minimum_header_size();  // conservatively small
1983 
1984   // Array length
1985   if (length != nullptr) {         // Arrays need length field
1986     rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
1987     // conservatively small header size:
1988     header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1989     if (_igvn.type(klass_node)->isa_aryklassptr()) {   // we know the exact header size in most cases:
1990       BasicType elem = _igvn.type(klass_node)->is_klassptr()->as_instance_type()->isa_aryptr()->elem()->array_element_basic_type();
1991       if (is_reference_type(elem, true)) {
1992         elem = T_OBJECT;
1993       }
1994       header_size = Klass::layout_helper_header_size(Klass::array_layout_helper(elem));
1995     }
1996   }
1997 
1998   // Clear the object body, if necessary.
1999   if (init == nullptr) {
2000     // The init has somehow disappeared; be cautious and clear everything.
2001     //
2002     // This can happen if a node is allocated but an uncommon trap occurs
2003     // immediately.  In this case, the Initialize gets associated with the
2004     // trap, and may be placed in a different (outer) loop, if the Allocate
2005     // is in a loop.  If (this is rare) the inner loop gets unrolled, then
2006     // there can be two Allocates to one Initialize.  The answer in all these
2007     // edge cases is safety first.  It is always safe to clear immediately
2008     // within an Allocate, and then (maybe or maybe not) clear some more later.
2009     if (!(UseTLAB && ZeroTLAB)) {
2010       rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
2011                                             alloc->in(AllocateNode::InitValue),
2012                                             alloc->in(AllocateNode::RawInitValue),
2013                                             header_size, size_in_bytes,
2014                                             &_igvn);
2015     }
2016   } else {
2017     if (!init->is_complete()) {
2018       // Try to win by zeroing only what the init does not store.
2019       // We can also try to do some peephole optimizations,
2020       // such as combining some adjacent subword stores.
2021       rawmem = init->complete_stores(control, rawmem, object,
2022                                      header_size, size_in_bytes, &_igvn);
2023     }
2024     // We have no more use for this link, since the AllocateNode goes away:
2025     init->set_req(InitializeNode::RawAddress, top());
2026     // (If we keep the link, it just confuses the register allocator,
2027     // who thinks he sees a real use of the address by the membar.)
2028   }
2029 
2030   return rawmem;
2031 }
2032 
2033 // Generate prefetch instructions for next allocations.
2034 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
2035                                         Node*& contended_phi_rawmem,
2036                                         Node* old_eden_top, Node* new_eden_top,
2037                                         intx lines) {
2038    enum { fall_in_path = 1, pf_path = 2 };
2039    if( UseTLAB && AllocatePrefetchStyle == 2 ) {
2040       // Generate prefetch allocation with watermark check.
2041       // As an allocation hits the watermark, we will prefetch starting
2042       // at a "distance" away from watermark.
2043 
2044       Node *pf_region = new RegionNode(3);
2045       Node *pf_phi_rawmem = new PhiNode( pf_region, Type::MEMORY,
2046                                                 TypeRawPtr::BOTTOM );
2047       // I/O is used for Prefetch
2048       Node *pf_phi_abio = new PhiNode( pf_region, Type::ABIO );
2049 
2050       Node *thread = new ThreadLocalNode();
2051       transform_later(thread);
2052 
2053       Node *eden_pf_adr = new AddPNode( top()/*not oop*/, thread,
2054                    _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
2055       transform_later(eden_pf_adr);
2056 
2057       Node *old_pf_wm = new LoadPNode(needgc_false,
2058                                    contended_phi_rawmem, eden_pf_adr,
2059                                    TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM,
2060                                    MemNode::unordered);
2061       transform_later(old_pf_wm);
2062 
2063       // check against new_eden_top
2064       Node *need_pf_cmp = new CmpPNode( new_eden_top, old_pf_wm );
2065       transform_later(need_pf_cmp);
2066       Node *need_pf_bol = new BoolNode( need_pf_cmp, BoolTest::ge );
2067       transform_later(need_pf_bol);
2068       IfNode *need_pf_iff = new IfNode( needgc_false, need_pf_bol,
2069                                        PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
2070       transform_later(need_pf_iff);
2071 
2072       // true node, add prefetchdistance
2073       Node *need_pf_true = new IfTrueNode( need_pf_iff );
2074       transform_later(need_pf_true);
2075 
2076       Node *need_pf_false = new IfFalseNode( need_pf_iff );
2077       transform_later(need_pf_false);
2078 
2079       Node *new_pf_wmt = new AddPNode( top(), old_pf_wm,
2080                                     _igvn.MakeConX(AllocatePrefetchDistance) );
2081       transform_later(new_pf_wmt );
2082       new_pf_wmt->set_req(0, need_pf_true);
2083 
2084       Node *store_new_wmt = new StorePNode(need_pf_true,
2085                                        contended_phi_rawmem, eden_pf_adr,
2086                                        TypeRawPtr::BOTTOM, new_pf_wmt,
2087                                        MemNode::unordered);
2088       transform_later(store_new_wmt);
2089 
2090       // adding prefetches
2091       pf_phi_abio->init_req( fall_in_path, i_o );
2092 
2093       Node *prefetch_adr;
2094       Node *prefetch;
2095       uint step_size = AllocatePrefetchStepSize;
2096       uint distance = 0;
2097 
2098       for ( intx i = 0; i < lines; i++ ) {
2099         prefetch_adr = new AddPNode( old_pf_wm, new_pf_wmt,
2100                                             _igvn.MakeConX(distance) );
2101         transform_later(prefetch_adr);
2102         prefetch = new PrefetchAllocationNode( i_o, prefetch_adr );
2103         transform_later(prefetch);
2104         distance += step_size;
2105         i_o = prefetch;
2106       }
2107       pf_phi_abio->set_req( pf_path, i_o );
2108 
2109       pf_region->init_req( fall_in_path, need_pf_false );
2110       pf_region->init_req( pf_path, need_pf_true );
2111 
2112       pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
2113       pf_phi_rawmem->init_req( pf_path, store_new_wmt );
2114 
2115       transform_later(pf_region);
2116       transform_later(pf_phi_rawmem);
2117       transform_later(pf_phi_abio);
2118 
2119       needgc_false = pf_region;
2120       contended_phi_rawmem = pf_phi_rawmem;
2121       i_o = pf_phi_abio;
2122    } else if( UseTLAB && AllocatePrefetchStyle == 3 ) {
2123       // Insert a prefetch instruction for each allocation.
2124       // This code is used to generate 1 prefetch instruction per cache line.
2125 
2126       // Generate several prefetch instructions.
2127       uint step_size = AllocatePrefetchStepSize;
2128       uint distance = AllocatePrefetchDistance;
2129 
2130       // Next cache address.
2131       Node *cache_adr = new AddPNode(old_eden_top, old_eden_top,
2132                                      _igvn.MakeConX(step_size + distance));
2133       transform_later(cache_adr);
2134       cache_adr = new CastP2XNode(needgc_false, cache_adr);
2135       transform_later(cache_adr);
2136       // Address is aligned to execute prefetch to the beginning of cache line size
2137       // (it is important when BIS instruction is used on SPARC as prefetch).
2138       Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1));
2139       cache_adr = new AndXNode(cache_adr, mask);
2140       transform_later(cache_adr);
2141       cache_adr = new CastX2PNode(cache_adr);
2142       transform_later(cache_adr);
2143 
2144       // Prefetch
2145       Node *prefetch = new PrefetchAllocationNode( contended_phi_rawmem, cache_adr );
2146       prefetch->set_req(0, needgc_false);
2147       transform_later(prefetch);
2148       contended_phi_rawmem = prefetch;
2149       Node *prefetch_adr;
2150       distance = step_size;
2151       for ( intx i = 1; i < lines; i++ ) {
2152         prefetch_adr = new AddPNode( cache_adr, cache_adr,
2153                                             _igvn.MakeConX(distance) );
2154         transform_later(prefetch_adr);
2155         prefetch = new PrefetchAllocationNode( contended_phi_rawmem, prefetch_adr );
2156         transform_later(prefetch);
2157         distance += step_size;
2158         contended_phi_rawmem = prefetch;
2159       }
2160    } else if( AllocatePrefetchStyle > 0 ) {
2161       // Insert a prefetch for each allocation only on the fast-path
2162       Node *prefetch_adr;
2163       Node *prefetch;
2164       // Generate several prefetch instructions.
2165       uint step_size = AllocatePrefetchStepSize;
2166       uint distance = AllocatePrefetchDistance;
2167       for ( intx i = 0; i < lines; i++ ) {
2168         prefetch_adr = new AddPNode( old_eden_top, new_eden_top,
2169                                             _igvn.MakeConX(distance) );
2170         transform_later(prefetch_adr);
2171         prefetch = new PrefetchAllocationNode( i_o, prefetch_adr );
2172         // Do not let it float too high, since if eden_top == eden_end,
2173         // both might be null.
2174         if( i == 0 ) { // Set control for first prefetch, next follows it
2175           prefetch->init_req(0, needgc_false);
2176         }
2177         transform_later(prefetch);
2178         distance += step_size;
2179         i_o = prefetch;
2180       }
2181    }
2182    return i_o;
2183 }
2184 
2185 
2186 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
2187   expand_allocate_common(alloc, nullptr, nullptr,
2188                          OptoRuntime::new_instance_Type(),
2189                          OptoRuntime::new_instance_Java(), nullptr);
2190 }
2191 
2192 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
2193   Node* length = alloc->in(AllocateNode::ALength);
2194   Node* valid_length_test = alloc->in(AllocateNode::ValidLengthTest);
2195   InitializeNode* init = alloc->initialization();
2196   Node* klass_node = alloc->in(AllocateNode::KlassNode);
2197   Node* init_value = alloc->in(AllocateNode::InitValue);
2198   const TypeAryKlassPtr* ary_klass_t = _igvn.type(klass_node)->isa_aryklassptr();
2199   // TODO 8366668 Compute the VM type, is this even needed now that we set it earlier? Should we assert instead?
2200   if (ary_klass_t && ary_klass_t->klass_is_exact() && ary_klass_t->exact_klass()->is_obj_array_klass()) {
2201     ary_klass_t = ary_klass_t->get_vm_type();
2202     klass_node = makecon(ary_klass_t);
2203     _igvn.replace_input_of(alloc, AllocateNode::KlassNode, klass_node);
2204   }
2205   const TypeFunc* slow_call_type;
2206   address slow_call_address;  // Address of slow call
2207   if (init != nullptr && init->is_complete_with_arraycopy() &&
2208       ary_klass_t && ary_klass_t->elem()->isa_klassptr() == nullptr) {
2209     // Don't zero type array during slow allocation in VM since
2210     // it will be initialized later by arraycopy in compiled code.
2211     slow_call_address = OptoRuntime::new_array_nozero_Java();
2212     slow_call_type = OptoRuntime::new_array_nozero_Type();
2213   } else {
2214     slow_call_address = OptoRuntime::new_array_Java();
2215     slow_call_type = OptoRuntime::new_array_Type();
2216 
2217     if (init_value == nullptr) {
2218       init_value = _igvn.zerocon(T_OBJECT);
2219     } else if (UseCompressedOops) {
2220       init_value = transform_later(new DecodeNNode(init_value, init_value->bottom_type()->make_ptr()));
2221     }
2222   }
2223   expand_allocate_common(alloc, length, init_value,
2224                          slow_call_type,
2225                          slow_call_address, valid_length_test);
2226 }
2227 
2228 //-------------------mark_eliminated_box----------------------------------
2229 //
2230 // During EA obj may point to several objects but after few ideal graph
2231 // transformations (CCP) it may point to only one non escaping object
2232 // (but still using phi), corresponding locks and unlocks will be marked
2233 // for elimination. Later obj could be replaced with a new node (new phi)
2234 // and which does not have escape information. And later after some graph
2235 // reshape other locks and unlocks (which were not marked for elimination
2236 // before) are connected to this new obj (phi) but they still will not be
2237 // marked for elimination since new obj has no escape information.
2238 // Mark all associated (same box and obj) lock and unlock nodes for
2239 // elimination if some of them marked already.
2240 void PhaseMacroExpand::mark_eliminated_box(Node* box, Node* obj) {
2241   BoxLockNode* oldbox = box->as_BoxLock();
2242   if (oldbox->is_eliminated()) {
2243     return; // This BoxLock node was processed already.
2244   }
2245   assert(!oldbox->is_unbalanced(), "this should not be called for unbalanced region");
2246   // New implementation (EliminateNestedLocks) has separate BoxLock
2247   // node for each locked region so mark all associated locks/unlocks as
2248   // eliminated even if different objects are referenced in one locked region
2249   // (for example, OSR compilation of nested loop inside locked scope).
2250   if (EliminateNestedLocks ||
2251       oldbox->as_BoxLock()->is_simple_lock_region(nullptr, obj, nullptr)) {
2252     // Box is used only in one lock region. Mark this box as eliminated.
2253     oldbox->set_local();      // This verifies correct state of BoxLock
2254     _igvn.hash_delete(oldbox);
2255     oldbox->set_eliminated(); // This changes box's hash value
2256      _igvn.hash_insert(oldbox);
2257 
2258     for (uint i = 0; i < oldbox->outcnt(); i++) {
2259       Node* u = oldbox->raw_out(i);
2260       if (u->is_AbstractLock() && !u->as_AbstractLock()->is_non_esc_obj()) {
2261         AbstractLockNode* alock = u->as_AbstractLock();
2262         // Check lock's box since box could be referenced by Lock's debug info.
2263         if (alock->box_node() == oldbox) {
2264           // Mark eliminated all related locks and unlocks.
2265 #ifdef ASSERT
2266           alock->log_lock_optimization(C, "eliminate_lock_set_non_esc4");
2267 #endif
2268           alock->set_non_esc_obj();
2269         }
2270       }
2271     }
2272     return;
2273   }
2274 
2275   // Create new "eliminated" BoxLock node and use it in monitor debug info
2276   // instead of oldbox for the same object.
2277   BoxLockNode* newbox = oldbox->clone()->as_BoxLock();
2278 
2279   // Note: BoxLock node is marked eliminated only here and it is used
2280   // to indicate that all associated lock and unlock nodes are marked
2281   // for elimination.
2282   newbox->set_local(); // This verifies correct state of BoxLock
2283   newbox->set_eliminated();
2284   transform_later(newbox);
2285 
2286   // Replace old box node with new box for all users of the same object.
2287   for (uint i = 0; i < oldbox->outcnt();) {
2288     bool next_edge = true;
2289 
2290     Node* u = oldbox->raw_out(i);
2291     if (u->is_AbstractLock()) {
2292       AbstractLockNode* alock = u->as_AbstractLock();
2293       if (alock->box_node() == oldbox && alock->obj_node()->eqv_uncast(obj)) {
2294         // Replace Box and mark eliminated all related locks and unlocks.
2295 #ifdef ASSERT
2296         alock->log_lock_optimization(C, "eliminate_lock_set_non_esc5");
2297 #endif
2298         alock->set_non_esc_obj();
2299         _igvn.rehash_node_delayed(alock);
2300         alock->set_box_node(newbox);
2301         next_edge = false;
2302       }
2303     }
2304     if (u->is_FastLock() && u->as_FastLock()->obj_node()->eqv_uncast(obj)) {
2305       FastLockNode* flock = u->as_FastLock();
2306       assert(flock->box_node() == oldbox, "sanity");
2307       _igvn.rehash_node_delayed(flock);
2308       flock->set_box_node(newbox);
2309       next_edge = false;
2310     }
2311 
2312     // Replace old box in monitor debug info.
2313     if (u->is_SafePoint() && u->as_SafePoint()->jvms()) {
2314       SafePointNode* sfn = u->as_SafePoint();
2315       JVMState* youngest_jvms = sfn->jvms();
2316       int max_depth = youngest_jvms->depth();
2317       for (int depth = 1; depth <= max_depth; depth++) {
2318         JVMState* jvms = youngest_jvms->of_depth(depth);
2319         int num_mon  = jvms->nof_monitors();
2320         // Loop over monitors
2321         for (int idx = 0; idx < num_mon; idx++) {
2322           Node* obj_node = sfn->monitor_obj(jvms, idx);
2323           Node* box_node = sfn->monitor_box(jvms, idx);
2324           if (box_node == oldbox && obj_node->eqv_uncast(obj)) {
2325             int j = jvms->monitor_box_offset(idx);
2326             _igvn.replace_input_of(u, j, newbox);
2327             next_edge = false;
2328           }
2329         }
2330       }
2331     }
2332     if (next_edge) i++;
2333   }
2334 }
2335 
2336 //-----------------------mark_eliminated_locking_nodes-----------------------
2337 void PhaseMacroExpand::mark_eliminated_locking_nodes(AbstractLockNode *alock) {
2338   if (!alock->is_balanced()) {
2339     return; // Can't do any more elimination for this locking region
2340   }
2341   if (EliminateNestedLocks) {
2342     if (alock->is_nested()) {
2343        assert(alock->box_node()->as_BoxLock()->is_eliminated(), "sanity");
2344        return;
2345     } else if (!alock->is_non_esc_obj()) { // Not eliminated or coarsened
2346       // Only Lock node has JVMState needed here.
2347       // Not that preceding claim is documented anywhere else.
2348       if (alock->jvms() != nullptr) {
2349         if (alock->as_Lock()->is_nested_lock_region()) {
2350           // Mark eliminated related nested locks and unlocks.
2351           Node* obj = alock->obj_node();
2352           BoxLockNode* box_node = alock->box_node()->as_BoxLock();
2353           assert(!box_node->is_eliminated(), "should not be marked yet");
2354           // Note: BoxLock node is marked eliminated only here
2355           // and it is used to indicate that all associated lock
2356           // and unlock nodes are marked for elimination.
2357           box_node->set_eliminated(); // Box's hash is always NO_HASH here
2358           for (uint i = 0; i < box_node->outcnt(); i++) {
2359             Node* u = box_node->raw_out(i);
2360             if (u->is_AbstractLock()) {
2361               alock = u->as_AbstractLock();
2362               if (alock->box_node() == box_node) {
2363                 // Verify that this Box is referenced only by related locks.
2364                 assert(alock->obj_node()->eqv_uncast(obj), "");
2365                 // Mark all related locks and unlocks.
2366 #ifdef ASSERT
2367                 alock->log_lock_optimization(C, "eliminate_lock_set_nested");
2368 #endif
2369                 alock->set_nested();
2370               }
2371             }
2372           }
2373         } else {
2374 #ifdef ASSERT
2375           alock->log_lock_optimization(C, "eliminate_lock_NOT_nested_lock_region");
2376           if (C->log() != nullptr)
2377             alock->as_Lock()->is_nested_lock_region(C); // rerun for debugging output
2378 #endif
2379         }
2380       }
2381       return;
2382     }
2383     // Process locks for non escaping object
2384     assert(alock->is_non_esc_obj(), "");
2385   } // EliminateNestedLocks
2386 
2387   if (alock->is_non_esc_obj()) { // Lock is used for non escaping object
2388     // Look for all locks of this object and mark them and
2389     // corresponding BoxLock nodes as eliminated.
2390     Node* obj = alock->obj_node();
2391     for (uint j = 0; j < obj->outcnt(); j++) {
2392       Node* o = obj->raw_out(j);
2393       if (o->is_AbstractLock() &&
2394           o->as_AbstractLock()->obj_node()->eqv_uncast(obj)) {
2395         alock = o->as_AbstractLock();
2396         Node* box = alock->box_node();
2397         // Replace old box node with new eliminated box for all users
2398         // of the same object and mark related locks as eliminated.
2399         mark_eliminated_box(box, obj);
2400       }
2401     }
2402   }
2403 }
2404 
2405 // we have determined that this lock/unlock can be eliminated, we simply
2406 // eliminate the node without expanding it.
2407 //
2408 // Note:  The membar's associated with the lock/unlock are currently not
2409 //        eliminated.  This should be investigated as a future enhancement.
2410 //
2411 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
2412 
2413   if (!alock->is_eliminated()) {
2414     return false;
2415   }
2416 #ifdef ASSERT
2417   if (!alock->is_coarsened()) {
2418     // Check that new "eliminated" BoxLock node is created.
2419     BoxLockNode* oldbox = alock->box_node()->as_BoxLock();
2420     assert(oldbox->is_eliminated(), "should be done already");
2421   }
2422 #endif
2423 
2424   alock->log_lock_optimization(C, "eliminate_lock");
2425 
2426 #ifndef PRODUCT
2427   if (PrintEliminateLocks) {
2428     tty->print_cr("++++ Eliminated: %d %s '%s'", alock->_idx, (alock->is_Lock() ? "Lock" : "Unlock"), alock->kind_as_string());
2429   }
2430 #endif
2431 
2432   Node* mem  = alock->in(TypeFunc::Memory);
2433   Node* ctrl = alock->in(TypeFunc::Control);
2434   guarantee(ctrl != nullptr, "missing control projection, cannot replace_node() with null");
2435 
2436   _callprojs = alock->extract_projections(false /*separate_io_proj*/, false /*do_asserts*/);
2437   // There are 2 projections from the lock.  The lock node will
2438   // be deleted when its last use is subsumed below.
2439   assert(alock->outcnt() == 2 &&
2440          _callprojs->fallthrough_proj != nullptr &&
2441          _callprojs->fallthrough_memproj != nullptr,
2442          "Unexpected projections from Lock/Unlock");
2443 
2444   Node* fallthroughproj = _callprojs->fallthrough_proj;
2445   Node* memproj_fallthrough = _callprojs->fallthrough_memproj;
2446 
2447   // The memory projection from a lock/unlock is RawMem
2448   // The input to a Lock is merged memory, so extract its RawMem input
2449   // (unless the MergeMem has been optimized away.)
2450   if (alock->is_Lock()) {
2451     // Search for MemBarAcquireLock node and delete it also.
2452     MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
2453     assert(membar != nullptr && membar->Opcode() == Op_MemBarAcquireLock, "");
2454     Node* ctrlproj = membar->proj_out(TypeFunc::Control);
2455     Node* memproj = membar->proj_out(TypeFunc::Memory);
2456     _igvn.replace_node(ctrlproj, fallthroughproj);
2457     _igvn.replace_node(memproj, memproj_fallthrough);
2458 
2459     // Delete FastLock node also if this Lock node is unique user
2460     // (a loop peeling may clone a Lock node).
2461     Node* flock = alock->as_Lock()->fastlock_node();
2462     if (flock->outcnt() == 1) {
2463       assert(flock->unique_out() == alock, "sanity");
2464       _igvn.replace_node(flock, top());
2465     }
2466   }
2467 
2468   // Search for MemBarReleaseLock node and delete it also.
2469   if (alock->is_Unlock() && ctrl->is_Proj() && ctrl->in(0)->is_MemBar()) {
2470     MemBarNode* membar = ctrl->in(0)->as_MemBar();
2471     assert(membar->Opcode() == Op_MemBarReleaseLock &&
2472            mem->is_Proj() && membar == mem->in(0), "");
2473     _igvn.replace_node(fallthroughproj, ctrl);
2474     _igvn.replace_node(memproj_fallthrough, mem);
2475     fallthroughproj = ctrl;
2476     memproj_fallthrough = mem;
2477     ctrl = membar->in(TypeFunc::Control);
2478     mem  = membar->in(TypeFunc::Memory);
2479   }
2480 
2481   _igvn.replace_node(fallthroughproj, ctrl);
2482   _igvn.replace_node(memproj_fallthrough, mem);
2483   return true;
2484 }
2485 
2486 
2487 //------------------------------expand_lock_node----------------------
2488 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
2489 
2490   Node* ctrl = lock->in(TypeFunc::Control);
2491   Node* mem = lock->in(TypeFunc::Memory);
2492   Node* obj = lock->obj_node();
2493   Node* box = lock->box_node();
2494   Node* flock = lock->fastlock_node();
2495 
2496   assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2497 
2498   // Make the merge point
2499   Node *region;
2500   Node *mem_phi;
2501   Node *slow_path;
2502 
2503   region  = new RegionNode(3);
2504   // create a Phi for the memory state
2505   mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2506 
2507   // Optimize test; set region slot 2
2508   slow_path = opt_bits_test(ctrl, region, 2, flock);
2509   mem_phi->init_req(2, mem);
2510 
2511   // Make slow path call
2512   CallNode* call = make_slow_call(lock, OptoRuntime::complete_monitor_enter_Type(),
2513                                   OptoRuntime::complete_monitor_locking_Java(), nullptr, slow_path,
2514                                   obj, box, nullptr);
2515 
2516   _callprojs = call->extract_projections(false /*separate_io_proj*/, false /*do_asserts*/);
2517 
2518   // Slow path can only throw asynchronous exceptions, which are always
2519   // de-opted.  So the compiler thinks the slow-call can never throw an
2520   // exception.  If it DOES throw an exception we would need the debug
2521   // info removed first (since if it throws there is no monitor).
2522   assert(_callprojs->fallthrough_ioproj == nullptr && _callprojs->catchall_ioproj == nullptr &&
2523          _callprojs->catchall_memproj == nullptr && _callprojs->catchall_catchproj == nullptr, "Unexpected projection from Lock");
2524 
2525   // Capture slow path
2526   // disconnect fall-through projection from call and create a new one
2527   // hook up users of fall-through projection to region
2528   Node *slow_ctrl = _callprojs->fallthrough_proj->clone();
2529   transform_later(slow_ctrl);
2530   _igvn.hash_delete(_callprojs->fallthrough_proj);
2531   _callprojs->fallthrough_proj->disconnect_inputs(C);
2532   region->init_req(1, slow_ctrl);
2533   // region inputs are now complete
2534   transform_later(region);
2535   _igvn.replace_node(_callprojs->fallthrough_proj, region);
2536 
2537   Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory));
2538 
2539   mem_phi->init_req(1, memproj);
2540 
2541   transform_later(mem_phi);
2542 
2543   _igvn.replace_node(_callprojs->fallthrough_memproj, mem_phi);
2544 }
2545 
2546 //------------------------------expand_unlock_node----------------------
2547 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
2548 
2549   Node* ctrl = unlock->in(TypeFunc::Control);
2550   Node* mem = unlock->in(TypeFunc::Memory);
2551   Node* obj = unlock->obj_node();
2552   Node* box = unlock->box_node();
2553 
2554   assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2555 
2556   // No need for a null check on unlock
2557 
2558   // Make the merge point
2559   Node *region;
2560   Node *mem_phi;
2561 
2562   region  = new RegionNode(3);
2563   // create a Phi for the memory state
2564   mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2565 
2566   FastUnlockNode *funlock = new FastUnlockNode( ctrl, obj, box );
2567   funlock = transform_later( funlock )->as_FastUnlock();
2568   // Optimize test; set region slot 2
2569   Node *slow_path = opt_bits_test(ctrl, region, 2, funlock);
2570   Node *thread = transform_later(new ThreadLocalNode());
2571 
2572   CallNode *call = make_slow_call((CallNode *) unlock, OptoRuntime::complete_monitor_exit_Type(),
2573                                   CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_unlocking_C),
2574                                   "complete_monitor_unlocking_C", slow_path, obj, box, thread);
2575 
2576   _callprojs = call->extract_projections(false /*separate_io_proj*/, false /*do_asserts*/);
2577   assert(_callprojs->fallthrough_ioproj == nullptr && _callprojs->catchall_ioproj == nullptr &&
2578          _callprojs->catchall_memproj == nullptr && _callprojs->catchall_catchproj == nullptr, "Unexpected projection from Lock");
2579 
2580   // No exceptions for unlocking
2581   // Capture slow path
2582   // disconnect fall-through projection from call and create a new one
2583   // hook up users of fall-through projection to region
2584   Node *slow_ctrl = _callprojs->fallthrough_proj->clone();
2585   transform_later(slow_ctrl);
2586   _igvn.hash_delete(_callprojs->fallthrough_proj);
2587   _callprojs->fallthrough_proj->disconnect_inputs(C);
2588   region->init_req(1, slow_ctrl);
2589   // region inputs are now complete
2590   transform_later(region);
2591   _igvn.replace_node(_callprojs->fallthrough_proj, region);
2592 
2593   Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory) );
2594   mem_phi->init_req(1, memproj );
2595   mem_phi->init_req(2, mem);
2596   transform_later(mem_phi);
2597 
2598   _igvn.replace_node(_callprojs->fallthrough_memproj, mem_phi);
2599 }
2600 
2601 // An inline type might be returned from the call but we don't know its
2602 // type. Either we get a buffered inline type (and nothing needs to be done)
2603 // or one of the values being returned is the klass of the inline type
2604 // and we need to allocate an inline type instance of that type and
2605 // initialize it with other values being returned. In that case, we
2606 // first try a fast path allocation and initialize the value with the
2607 // inline klass's pack handler or we fall back to a runtime call.
2608 void PhaseMacroExpand::expand_mh_intrinsic_return(CallStaticJavaNode* call) {
2609   assert(call->method()->is_method_handle_intrinsic(), "must be a method handle intrinsic call");
2610   Node* ret = call->proj_out_or_null(TypeFunc::Parms);
2611   if (ret == nullptr) {
2612     return;
2613   }
2614   const TypeFunc* tf = call->_tf;
2615   const TypeTuple* domain = OptoRuntime::store_inline_type_fields_Type()->domain_cc();
2616   const TypeFunc* new_tf = TypeFunc::make(tf->domain_sig(), tf->domain_cc(), tf->range_sig(), domain);
2617   call->_tf = new_tf;
2618   // Make sure the change of type is applied before projections are processed by igvn
2619   _igvn.set_type(call, call->Value(&_igvn));
2620   _igvn.set_type(ret, ret->Value(&_igvn));
2621 
2622   // Before any new projection is added:
2623   CallProjections* projs = call->extract_projections(true, true);
2624 
2625   // Create temporary hook nodes that will be replaced below.
2626   // Add an input to prevent hook nodes from being dead.
2627   Node* ctl = new Node(call);
2628   Node* mem = new Node(ctl);
2629   Node* io = new Node(ctl);
2630   Node* ex_ctl = new Node(ctl);
2631   Node* ex_mem = new Node(ctl);
2632   Node* ex_io = new Node(ctl);
2633   Node* res = new Node(ctl);
2634 
2635   // Allocate a new buffered inline type only if a new one is not returned
2636   Node* cast = transform_later(new CastP2XNode(ctl, res));
2637   Node* mask = MakeConX(0x1);
2638   Node* masked = transform_later(new AndXNode(cast, mask));
2639   Node* cmp = transform_later(new CmpXNode(masked, mask));
2640   Node* bol = transform_later(new BoolNode(cmp, BoolTest::eq));
2641   IfNode* allocation_iff = new IfNode(ctl, bol, PROB_MAX, COUNT_UNKNOWN);
2642   transform_later(allocation_iff);
2643   Node* allocation_ctl = transform_later(new IfTrueNode(allocation_iff));
2644   Node* no_allocation_ctl = transform_later(new IfFalseNode(allocation_iff));
2645   Node* no_allocation_res = transform_later(new CheckCastPPNode(no_allocation_ctl, res, TypeInstPtr::BOTTOM));
2646 
2647   // Try to allocate a new buffered inline instance either from TLAB or eden space
2648   Node* needgc_ctrl = nullptr; // needgc means slowcase, i.e. allocation failed
2649   CallLeafNoFPNode* handler_call;
2650   const bool alloc_in_place = UseTLAB;
2651   if (alloc_in_place) {
2652     Node* fast_oop_ctrl = nullptr;
2653     Node* fast_oop_rawmem = nullptr;
2654     Node* mask2 = MakeConX(-2);
2655     Node* masked2 = transform_later(new AndXNode(cast, mask2));
2656     Node* rawklassptr = transform_later(new CastX2PNode(masked2));
2657     Node* klass_node = transform_later(new CheckCastPPNode(allocation_ctl, rawklassptr, TypeInstKlassPtr::OBJECT_OR_NULL));
2658     Node* layout_val = make_load(nullptr, mem, klass_node, in_bytes(Klass::layout_helper_offset()), TypeInt::INT, T_INT);
2659     Node* size_in_bytes = ConvI2X(layout_val);
2660     BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2661     Node* fast_oop = bs->obj_allocate(this, mem, allocation_ctl, size_in_bytes, io, needgc_ctrl,
2662                                       fast_oop_ctrl, fast_oop_rawmem,
2663                                       AllocateInstancePrefetchLines);
2664     // Allocation succeed, initialize buffered inline instance header firstly,
2665     // and then initialize its fields with an inline class specific handler
2666     Node* mark_word_node;
2667     if (UseCompactObjectHeaders) {
2668       // COH: We need to load the prototype from the klass at runtime since it encodes the klass pointer already.
2669       mark_word_node = make_load(fast_oop_ctrl, fast_oop_rawmem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeRawPtr::BOTTOM, T_ADDRESS);
2670     } else {
2671       // Otherwise, use the static prototype.
2672       mark_word_node = makecon(TypeRawPtr::make((address)markWord::inline_type_prototype().value()));
2673     }
2674 
2675     fast_oop_rawmem = make_store(fast_oop_ctrl, fast_oop_rawmem, fast_oop, oopDesc::mark_offset_in_bytes(), mark_word_node, T_ADDRESS);
2676     if (!UseCompactObjectHeaders) {
2677       // COH: Everything is encoded in the mark word, so nothing left to do.
2678       fast_oop_rawmem = make_store(fast_oop_ctrl, fast_oop_rawmem, fast_oop, oopDesc::klass_offset_in_bytes(), klass_node, T_METADATA);
2679       if (UseCompressedClassPointers) {
2680         fast_oop_rawmem = make_store(fast_oop_ctrl, fast_oop_rawmem, fast_oop, oopDesc::klass_gap_offset_in_bytes(), intcon(0), T_INT);
2681       }
2682     }
2683     Node* fixed_block  = make_load(fast_oop_ctrl, fast_oop_rawmem, klass_node, in_bytes(InstanceKlass::adr_inlineklass_fixed_block_offset()), TypeRawPtr::BOTTOM, T_ADDRESS);
2684     Node* pack_handler = make_load(fast_oop_ctrl, fast_oop_rawmem, fixed_block, in_bytes(InlineKlass::pack_handler_offset()), TypeRawPtr::BOTTOM, T_ADDRESS);
2685     handler_call = new CallLeafNoFPNode(OptoRuntime::pack_inline_type_Type(),
2686                                         nullptr,
2687                                         "pack handler",
2688                                         TypeRawPtr::BOTTOM);
2689     handler_call->init_req(TypeFunc::Control, fast_oop_ctrl);
2690     handler_call->init_req(TypeFunc::Memory, fast_oop_rawmem);
2691     handler_call->init_req(TypeFunc::I_O, top());
2692     handler_call->init_req(TypeFunc::FramePtr, call->in(TypeFunc::FramePtr));
2693     handler_call->init_req(TypeFunc::ReturnAdr, top());
2694     handler_call->init_req(TypeFunc::Parms, pack_handler);
2695     handler_call->init_req(TypeFunc::Parms+1, fast_oop);
2696   } else {
2697     needgc_ctrl = allocation_ctl;
2698   }
2699 
2700   // Allocation failed, fall back to a runtime call
2701   CallStaticJavaNode* slow_call = new CallStaticJavaNode(OptoRuntime::store_inline_type_fields_Type(),
2702                                                          StubRoutines::store_inline_type_fields_to_buf(),
2703                                                          "store_inline_type_fields",
2704                                                          TypePtr::BOTTOM);
2705   slow_call->init_req(TypeFunc::Control, needgc_ctrl);
2706   slow_call->init_req(TypeFunc::Memory, mem);
2707   slow_call->init_req(TypeFunc::I_O, io);
2708   slow_call->init_req(TypeFunc::FramePtr, call->in(TypeFunc::FramePtr));
2709   slow_call->init_req(TypeFunc::ReturnAdr, call->in(TypeFunc::ReturnAdr));
2710   slow_call->init_req(TypeFunc::Parms, res);
2711 
2712   Node* slow_ctl = transform_later(new ProjNode(slow_call, TypeFunc::Control));
2713   Node* slow_mem = transform_later(new ProjNode(slow_call, TypeFunc::Memory));
2714   Node* slow_io = transform_later(new ProjNode(slow_call, TypeFunc::I_O));
2715   Node* slow_res = transform_later(new ProjNode(slow_call, TypeFunc::Parms));
2716   Node* slow_catc = transform_later(new CatchNode(slow_ctl, slow_io, 2));
2717   Node* slow_norm = transform_later(new CatchProjNode(slow_catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci));
2718   Node* slow_excp = transform_later(new CatchProjNode(slow_catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci));
2719 
2720   Node* ex_r = new RegionNode(3);
2721   Node* ex_mem_phi = new PhiNode(ex_r, Type::MEMORY, TypePtr::BOTTOM);
2722   Node* ex_io_phi = new PhiNode(ex_r, Type::ABIO);
2723   ex_r->init_req(1, slow_excp);
2724   ex_mem_phi->init_req(1, slow_mem);
2725   ex_io_phi->init_req(1, slow_io);
2726   ex_r->init_req(2, ex_ctl);
2727   ex_mem_phi->init_req(2, ex_mem);
2728   ex_io_phi->init_req(2, ex_io);
2729   transform_later(ex_r);
2730   transform_later(ex_mem_phi);
2731   transform_later(ex_io_phi);
2732 
2733   // We don't know how many values are returned. This assumes the
2734   // worst case, that all available registers are used.
2735   for (uint i = TypeFunc::Parms+1; i < domain->cnt(); i++) {
2736     if (domain->field_at(i) == Type::HALF) {
2737       slow_call->init_req(i, top());
2738       if (alloc_in_place) {
2739         handler_call->init_req(i+1, top());
2740       }
2741       continue;
2742     }
2743     Node* proj = transform_later(new ProjNode(call, i));
2744     slow_call->init_req(i, proj);
2745     if (alloc_in_place) {
2746       handler_call->init_req(i+1, proj);
2747     }
2748   }
2749   // We can safepoint at that new call
2750   slow_call->copy_call_debug_info(&_igvn, call);
2751   transform_later(slow_call);
2752   if (alloc_in_place) {
2753     transform_later(handler_call);
2754   }
2755 
2756   Node* fast_ctl = nullptr;
2757   Node* fast_res = nullptr;
2758   MergeMemNode* fast_mem = nullptr;
2759   if (alloc_in_place) {
2760     fast_ctl = transform_later(new ProjNode(handler_call, TypeFunc::Control));
2761     Node* rawmem = transform_later(new ProjNode(handler_call, TypeFunc::Memory));
2762     fast_res = transform_later(new ProjNode(handler_call, TypeFunc::Parms));
2763     fast_mem = MergeMemNode::make(mem);
2764     fast_mem->set_memory_at(Compile::AliasIdxRaw, rawmem);
2765     transform_later(fast_mem);
2766   }
2767 
2768   Node* r = new RegionNode(alloc_in_place ? 4 : 3);
2769   Node* mem_phi = new PhiNode(r, Type::MEMORY, TypePtr::BOTTOM);
2770   Node* io_phi = new PhiNode(r, Type::ABIO);
2771   Node* res_phi = new PhiNode(r, TypeInstPtr::BOTTOM);
2772   r->init_req(1, no_allocation_ctl);
2773   mem_phi->init_req(1, mem);
2774   io_phi->init_req(1, io);
2775   res_phi->init_req(1, no_allocation_res);
2776   r->init_req(2, slow_norm);
2777   mem_phi->init_req(2, slow_mem);
2778   io_phi->init_req(2, slow_io);
2779   res_phi->init_req(2, slow_res);
2780   if (alloc_in_place) {
2781     r->init_req(3, fast_ctl);
2782     mem_phi->init_req(3, fast_mem);
2783     io_phi->init_req(3, io);
2784     res_phi->init_req(3, fast_res);
2785   }
2786   transform_later(r);
2787   transform_later(mem_phi);
2788   transform_later(io_phi);
2789   transform_later(res_phi);
2790 
2791   // Do not let stores that initialize this buffer be reordered with a subsequent
2792   // store that would make this buffer accessible by other threads.
2793   MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
2794   transform_later(mb);
2795   mb->init_req(TypeFunc::Memory, mem_phi);
2796   mb->init_req(TypeFunc::Control, r);
2797   r = new ProjNode(mb, TypeFunc::Control);
2798   transform_later(r);
2799   mem_phi = new ProjNode(mb, TypeFunc::Memory);
2800   transform_later(mem_phi);
2801 
2802   assert(projs->nb_resproj == 1, "unexpected number of results");
2803   _igvn.replace_in_uses(projs->fallthrough_catchproj, r);
2804   _igvn.replace_in_uses(projs->fallthrough_memproj, mem_phi);
2805   _igvn.replace_in_uses(projs->fallthrough_ioproj, io_phi);
2806   _igvn.replace_in_uses(projs->resproj[0], res_phi);
2807   _igvn.replace_in_uses(projs->catchall_catchproj, ex_r);
2808   _igvn.replace_in_uses(projs->catchall_memproj, ex_mem_phi);
2809   _igvn.replace_in_uses(projs->catchall_ioproj, ex_io_phi);
2810   // The CatchNode should not use the ex_io_phi. Re-connect it to the catchall_ioproj.
2811   Node* cn = projs->fallthrough_catchproj->in(0);
2812   _igvn.replace_input_of(cn, 1, projs->catchall_ioproj);
2813 
2814   _igvn.replace_node(ctl, projs->fallthrough_catchproj);
2815   _igvn.replace_node(mem, projs->fallthrough_memproj);
2816   _igvn.replace_node(io, projs->fallthrough_ioproj);
2817   _igvn.replace_node(res, projs->resproj[0]);
2818   _igvn.replace_node(ex_ctl, projs->catchall_catchproj);
2819   _igvn.replace_node(ex_mem, projs->catchall_memproj);
2820   _igvn.replace_node(ex_io, projs->catchall_ioproj);
2821  }
2822 
2823 void PhaseMacroExpand::expand_subtypecheck_node(SubTypeCheckNode *check) {
2824   assert(check->in(SubTypeCheckNode::Control) == nullptr, "should be pinned");
2825   Node* bol = check->unique_out();
2826   Node* obj_or_subklass = check->in(SubTypeCheckNode::ObjOrSubKlass);
2827   Node* superklass = check->in(SubTypeCheckNode::SuperKlass);
2828   assert(bol->is_Bool() && bol->as_Bool()->_test._test == BoolTest::ne, "unexpected bool node");
2829 
2830   for (DUIterator_Last imin, i = bol->last_outs(imin); i >= imin; --i) {
2831     Node* iff = bol->last_out(i);
2832     assert(iff->is_If(), "where's the if?");
2833 
2834     if (iff->in(0)->is_top()) {
2835       _igvn.replace_input_of(iff, 1, C->top());
2836       continue;
2837     }
2838 
2839     Node* iftrue = iff->as_If()->proj_out(1);
2840     Node* iffalse = iff->as_If()->proj_out(0);
2841     Node* ctrl = iff->in(0);
2842 
2843     Node* subklass = nullptr;
2844     if (_igvn.type(obj_or_subklass)->isa_klassptr()) {
2845       subklass = obj_or_subklass;
2846     } else {
2847       Node* k_adr = basic_plus_adr(obj_or_subklass, oopDesc::klass_offset_in_bytes());
2848       subklass = _igvn.transform(LoadKlassNode::make(_igvn, C->immutable_memory(), k_adr, TypeInstPtr::KLASS, TypeInstKlassPtr::OBJECT));
2849     }
2850 
2851     Node* not_subtype_ctrl = Phase::gen_subtype_check(subklass, superklass, &ctrl, nullptr, _igvn, check->method(), check->bci());
2852 
2853     _igvn.replace_input_of(iff, 0, C->top());
2854     _igvn.replace_node(iftrue, not_subtype_ctrl);
2855     _igvn.replace_node(iffalse, ctrl);
2856   }
2857   _igvn.replace_node(check, C->top());
2858 }
2859 
2860 // FlatArrayCheckNode (array1 array2 ...) is expanded into:
2861 //
2862 // long mark = array1.mark | array2.mark | ...;
2863 // long locked_bit = markWord::unlocked_value & array1.mark & array2.mark & ...;
2864 // if (locked_bit == 0) {
2865 //   // One array is locked, load prototype header from the klass
2866 //   mark = array1.klass.proto | array2.klass.proto | ...
2867 // }
2868 // if ((mark & markWord::flat_array_bit_in_place) == 0) {
2869 //    ...
2870 // }
2871 void PhaseMacroExpand::expand_flatarraycheck_node(FlatArrayCheckNode* check) {
2872   bool array_inputs = _igvn.type(check->in(FlatArrayCheckNode::ArrayOrKlass))->isa_oopptr() != nullptr;
2873   if (array_inputs) {
2874     Node* mark = MakeConX(0);
2875     Node* locked_bit = MakeConX(markWord::unlocked_value);
2876     Node* mem = check->in(FlatArrayCheckNode::Memory);
2877     for (uint i = FlatArrayCheckNode::ArrayOrKlass; i < check->req(); ++i) {
2878       Node* ary = check->in(i);
2879       const TypeOopPtr* t = _igvn.type(ary)->isa_oopptr();
2880       assert(t != nullptr, "Mixing array and klass inputs");
2881       assert(!t->is_flat() && !t->is_not_flat(), "Should have been optimized out");
2882       Node* mark_adr = basic_plus_adr(ary, oopDesc::mark_offset_in_bytes());
2883       Node* mark_load = _igvn.transform(LoadNode::make(_igvn, nullptr, mem, mark_adr, mark_adr->bottom_type()->is_ptr(), TypeX_X, TypeX_X->basic_type(), MemNode::unordered));
2884       mark = _igvn.transform(new OrXNode(mark, mark_load));
2885       locked_bit = _igvn.transform(new AndXNode(locked_bit, mark_load));
2886     }
2887     assert(!mark->is_Con(), "Should have been optimized out");
2888     Node* cmp = _igvn.transform(new CmpXNode(locked_bit, MakeConX(0)));
2889     Node* is_unlocked = _igvn.transform(new BoolNode(cmp, BoolTest::ne));
2890 
2891     // BoolNode might be shared, replace each if user
2892     Node* old_bol = check->unique_out();
2893     assert(old_bol->is_Bool() && old_bol->as_Bool()->_test._test == BoolTest::ne, "unexpected condition");
2894     for (DUIterator_Last imin, i = old_bol->last_outs(imin); i >= imin; --i) {
2895       IfNode* old_iff = old_bol->last_out(i)->as_If();
2896       Node* ctrl = old_iff->in(0);
2897       RegionNode* region = new RegionNode(3);
2898       Node* mark_phi = new PhiNode(region, TypeX_X);
2899 
2900       // Check if array is unlocked
2901       IfNode* iff = _igvn.transform(new IfNode(ctrl, is_unlocked, PROB_MAX, COUNT_UNKNOWN))->as_If();
2902 
2903       // Unlocked: Use bits from mark word
2904       region->init_req(1, _igvn.transform(new IfTrueNode(iff)));
2905       mark_phi->init_req(1, mark);
2906 
2907       // Locked: Load prototype header from klass
2908       ctrl = _igvn.transform(new IfFalseNode(iff));
2909       Node* proto = MakeConX(0);
2910       for (uint i = FlatArrayCheckNode::ArrayOrKlass; i < check->req(); ++i) {
2911         Node* ary = check->in(i);
2912         // Make loads control dependent to make sure they are only executed if array is locked
2913         Node* klass_adr = basic_plus_adr(ary, oopDesc::klass_offset_in_bytes());
2914         Node* klass = _igvn.transform(LoadKlassNode::make(_igvn, C->immutable_memory(), klass_adr, TypeInstPtr::KLASS, TypeInstKlassPtr::OBJECT));
2915         Node* proto_adr = basic_plus_adr(klass, in_bytes(Klass::prototype_header_offset()));
2916         Node* proto_load = _igvn.transform(LoadNode::make(_igvn, ctrl, C->immutable_memory(), proto_adr, proto_adr->bottom_type()->is_ptr(), TypeX_X, TypeX_X->basic_type(), MemNode::unordered));
2917         proto = _igvn.transform(new OrXNode(proto, proto_load));
2918       }
2919       region->init_req(2, ctrl);
2920       mark_phi->init_req(2, proto);
2921 
2922       // Check if flat array bits are set
2923       Node* mask = MakeConX(markWord::flat_array_bit_in_place);
2924       Node* masked = _igvn.transform(new AndXNode(_igvn.transform(mark_phi), mask));
2925       cmp = _igvn.transform(new CmpXNode(masked, MakeConX(0)));
2926       Node* is_not_flat = _igvn.transform(new BoolNode(cmp, BoolTest::eq));
2927 
2928       ctrl = _igvn.transform(region);
2929       iff = _igvn.transform(new IfNode(ctrl, is_not_flat, PROB_MAX, COUNT_UNKNOWN))->as_If();
2930       _igvn.replace_node(old_iff, iff);
2931     }
2932     _igvn.replace_node(check, C->top());
2933   } else {
2934     // Fall back to layout helper check
2935     Node* lhs = intcon(0);
2936     for (uint i = FlatArrayCheckNode::ArrayOrKlass; i < check->req(); ++i) {
2937       Node* array_or_klass = check->in(i);
2938       Node* klass = nullptr;
2939       const TypePtr* t = _igvn.type(array_or_klass)->is_ptr();
2940       assert(!t->is_flat() && !t->is_not_flat(), "Should have been optimized out");
2941       if (t->isa_oopptr() != nullptr) {
2942         Node* klass_adr = basic_plus_adr(array_or_klass, oopDesc::klass_offset_in_bytes());
2943         klass = transform_later(LoadKlassNode::make(_igvn, C->immutable_memory(), klass_adr, TypeInstPtr::KLASS, TypeInstKlassPtr::OBJECT));
2944       } else {
2945         assert(t->isa_klassptr(), "Unexpected input type");
2946         klass = array_or_klass;
2947       }
2948       Node* lh_addr = basic_plus_adr(klass, in_bytes(Klass::layout_helper_offset()));
2949       Node* lh_val = _igvn.transform(LoadNode::make(_igvn, nullptr, C->immutable_memory(), lh_addr, lh_addr->bottom_type()->is_ptr(), TypeInt::INT, T_INT, MemNode::unordered));
2950       lhs = _igvn.transform(new OrINode(lhs, lh_val));
2951     }
2952     Node* masked = transform_later(new AndINode(lhs, intcon(Klass::_lh_array_tag_flat_value_bit_inplace)));
2953     Node* cmp = transform_later(new CmpINode(masked, intcon(0)));
2954     Node* bol = transform_later(new BoolNode(cmp, BoolTest::eq));
2955     Node* m2b = transform_later(new Conv2BNode(masked));
2956     // The matcher expects the input to If nodes to be produced by a Bool(CmpI..)
2957     // pattern, but the input to other potential users (e.g. Phi) to be some
2958     // other pattern (e.g. a Conv2B node, possibly idealized as a CMoveI).
2959     Node* old_bol = check->unique_out();
2960     for (DUIterator_Last imin, i = old_bol->last_outs(imin); i >= imin; --i) {
2961       Node* user = old_bol->last_out(i);
2962       for (uint j = 0; j < user->req(); j++) {
2963         Node* n = user->in(j);
2964         if (n == old_bol) {
2965           _igvn.replace_input_of(user, j, user->is_If() ? bol : m2b);
2966         }
2967       }
2968     }
2969     _igvn.replace_node(check, C->top());
2970   }
2971 }
2972 
2973 // Perform refining of strip mined loop nodes in the macro nodes list.
2974 void PhaseMacroExpand::refine_strip_mined_loop_macro_nodes() {
2975    for (int i = C->macro_count(); i > 0; i--) {
2976     Node* n = C->macro_node(i - 1);
2977     if (n->is_OuterStripMinedLoop()) {
2978       n->as_OuterStripMinedLoop()->adjust_strip_mined_loop(&_igvn);
2979     }
2980   }
2981 }
2982 
2983 //---------------------------eliminate_macro_nodes----------------------
2984 // Eliminate scalar replaced allocations and associated locks.
2985 void PhaseMacroExpand::eliminate_macro_nodes(bool eliminate_locks) {
2986   if (C->macro_count() == 0) {
2987     return;
2988   }
2989 
2990   if (StressMacroElimination) {
2991     C->shuffle_macro_nodes();
2992   }
2993   NOT_PRODUCT(int membar_before = count_MemBar(C);)
2994 
2995   int iteration = 0;
2996   while (C->macro_count() > 0) {
2997     if (iteration++ > 100) {
2998       assert(false, "Too slow convergence of macro elimination");
2999       break;
3000     }
3001 
3002     // Postpone lock elimination to after EA when most allocations are eliminated
3003     // because they might block lock elimination if their escape state isn't
3004     // determined yet and we only got one chance at eliminating the lock.
3005     if (eliminate_locks) {
3006       // Before elimination may re-mark (change to Nested or NonEscObj)
3007       // all associated (same box and obj) lock and unlock nodes.
3008       int cnt = C->macro_count();
3009       for (int i=0; i < cnt; i++) {
3010         Node *n = C->macro_node(i);
3011         if (n->is_AbstractLock()) { // Lock and Unlock nodes
3012           mark_eliminated_locking_nodes(n->as_AbstractLock());
3013         }
3014       }
3015       // Re-marking may break consistency of Coarsened locks.
3016       if (!C->coarsened_locks_consistent()) {
3017         return; // recompile without Coarsened locks if broken
3018       } else {
3019         // After coarsened locks are eliminated locking regions
3020         // become unbalanced. We should not execute any more
3021         // locks elimination optimizations on them.
3022         C->mark_unbalanced_boxes();
3023       }
3024     }
3025 
3026     bool progress = false;
3027     for (int i = C->macro_count(); i > 0; i = MIN2(i - 1, C->macro_count())) { // more than 1 element can be eliminated at once
3028       Node* n = C->macro_node(i - 1);
3029       bool success = false;
3030       DEBUG_ONLY(int old_macro_count = C->macro_count();)
3031       switch (n->class_id()) {
3032       case Node::Class_Allocate:
3033       case Node::Class_AllocateArray:
3034         success = eliminate_allocate_node(n->as_Allocate());
3035 #ifndef PRODUCT
3036         if (success && PrintOptoStatistics) {
3037           Atomic::inc(&PhaseMacroExpand::_objs_scalar_replaced_counter);
3038         }
3039 #endif
3040         break;
3041       case Node::Class_CallStaticJava: {
3042         CallStaticJavaNode* call = n->as_CallStaticJava();
3043         if (!call->method()->is_method_handle_intrinsic()) {
3044           success = eliminate_boxing_node(n->as_CallStaticJava());
3045         }
3046         break;
3047       }
3048       case Node::Class_Lock:
3049       case Node::Class_Unlock:
3050         if (eliminate_locks) {
3051           success = eliminate_locking_node(n->as_AbstractLock());
3052 #ifndef PRODUCT
3053           if (success && PrintOptoStatistics) {
3054             Atomic::inc(&PhaseMacroExpand::_monitor_objects_removed_counter);
3055           }
3056 #endif
3057         }
3058         break;
3059       case Node::Class_ArrayCopy:
3060         break;
3061       case Node::Class_OuterStripMinedLoop:
3062         break;
3063       case Node::Class_SubTypeCheck:
3064         break;
3065       case Node::Class_Opaque1:
3066         break;
3067       case Node::Class_FlatArrayCheck:
3068         break;
3069       default:
3070         assert(n->Opcode() == Op_LoopLimit ||
3071                n->Opcode() == Op_ModD ||
3072                n->Opcode() == Op_ModF ||
3073                n->is_OpaqueNotNull()       ||
3074                n->is_OpaqueInitializedAssertionPredicate() ||
3075                n->Opcode() == Op_MaxL      ||
3076                n->Opcode() == Op_MinL      ||
3077                BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(n),
3078                "unknown node type in macro list");
3079       }
3080       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
3081       progress = progress || success;
3082       if (success) {
3083         C->print_method(PHASE_AFTER_MACRO_ELIMINATION_STEP, 5, n);
3084       }
3085     }
3086 
3087     // Ensure the graph after PhaseMacroExpand::eliminate_macro_nodes is canonical (no igvn
3088     // transformation is pending). If an allocation is used only in safepoints, elimination of
3089     // other macro nodes can remove all these safepoints, allowing the allocation to be removed.
3090     // Hence after igvn we retry removing macro nodes if some progress that has been made in this
3091     // iteration.
3092     _igvn.set_delay_transform(false);
3093     _igvn.optimize();
3094     if (C->failing()) {
3095       return;
3096     }
3097     _igvn.set_delay_transform(true);
3098 
3099     if (!progress) {
3100       break;
3101     }
3102   }
3103 #ifndef PRODUCT
3104   if (PrintOptoStatistics) {
3105     int membar_after = count_MemBar(C);
3106     Atomic::add(&PhaseMacroExpand::_memory_barriers_removed_counter, membar_before - membar_after);
3107   }
3108 #endif
3109 }
3110 
3111 void PhaseMacroExpand::eliminate_opaque_looplimit_macro_nodes() {
3112   if (C->macro_count() == 0) {
3113     return;
3114   }
3115   refine_strip_mined_loop_macro_nodes();
3116   // Eliminate Opaque and LoopLimit nodes. Do it after all loop optimizations.
3117   bool progress = true;
3118   while (progress) {
3119     progress = false;
3120     for (int i = C->macro_count(); i > 0; i--) {
3121       Node* n = C->macro_node(i-1);
3122       bool success = false;
3123       DEBUG_ONLY(int old_macro_count = C->macro_count();)
3124       if (n->Opcode() == Op_LoopLimit) {
3125         // Remove it from macro list and put on IGVN worklist to optimize.
3126         C->remove_macro_node(n);
3127         _igvn._worklist.push(n);
3128         success = true;
3129       } else if (n->Opcode() == Op_CallStaticJava) {
3130         CallStaticJavaNode* call = n->as_CallStaticJava();
3131         if (!call->method()->is_method_handle_intrinsic()) {
3132           // Remove it from macro list and put on IGVN worklist to optimize.
3133           C->remove_macro_node(n);
3134           _igvn._worklist.push(n);
3135           success = true;
3136         }
3137       } else if (n->is_Opaque1()) {
3138         _igvn.replace_node(n, n->in(1));
3139         success = true;
3140       } else if (n->is_OpaqueNotNull()) {
3141         // Tests with OpaqueNotNull nodes are implicitly known to be true. Replace the node with true. In debug builds,
3142         // we leave the test in the graph to have an additional sanity check at runtime. If the test fails (i.e. a bug),
3143         // we will execute a Halt node.
3144 #ifdef ASSERT
3145         _igvn.replace_node(n, n->in(1));
3146 #else
3147         _igvn.replace_node(n, _igvn.intcon(1));
3148 #endif
3149         success = true;
3150       } else if (n->is_OpaqueInitializedAssertionPredicate()) {
3151           // Initialized Assertion Predicates must always evaluate to true. Therefore, we get rid of them in product
3152           // builds as they are useless. In debug builds we keep them as additional verification code. Even though
3153           // loop opts are already over, we want to keep Initialized Assertion Predicates alive as long as possible to
3154           // enable folding of dead control paths within which cast nodes become top after due to impossible types -
3155           // even after loop opts are over. Therefore, we delay the removal of these opaque nodes until now.
3156 #ifdef ASSERT
3157         _igvn.replace_node(n, n->in(1));
3158 #else
3159         _igvn.replace_node(n, _igvn.intcon(1));
3160 #endif // ASSERT
3161       } else if (n->Opcode() == Op_OuterStripMinedLoop) {
3162         C->remove_macro_node(n);
3163         success = true;
3164       } else if (n->Opcode() == Op_MaxL) {
3165         // Since MaxL and MinL are not implemented in the backend, we expand them to
3166         // a CMoveL construct now. At least until here, the type could be computed
3167         // precisely. CMoveL is not so smart, but we can give it at least the best
3168         // type we know abouot n now.
3169         Node* repl = MaxNode::signed_max(n->in(1), n->in(2), _igvn.type(n), _igvn);
3170         _igvn.replace_node(n, repl);
3171         success = true;
3172       } else if (n->Opcode() == Op_MinL) {
3173         Node* repl = MaxNode::signed_min(n->in(1), n->in(2), _igvn.type(n), _igvn);
3174         _igvn.replace_node(n, repl);
3175         success = true;
3176       }
3177       assert(!success || (C->macro_count() == (old_macro_count - 1)), "elimination must have deleted one node from macro list");
3178       progress = progress || success;
3179       if (success) {
3180         C->print_method(PHASE_AFTER_MACRO_ELIMINATION_STEP, 5, n);
3181       }
3182     }
3183   }
3184 }
3185 
3186 //------------------------------expand_macro_nodes----------------------
3187 //  Returns true if a failure occurred.
3188 bool PhaseMacroExpand::expand_macro_nodes() {
3189   if (StressMacroExpansion) {
3190     C->shuffle_macro_nodes();
3191   }
3192 
3193   // Clean up the graph so we're less likely to hit the maximum node
3194   // limit
3195   _igvn.set_delay_transform(false);
3196   _igvn.optimize();
3197   if (C->failing())  return true;
3198   _igvn.set_delay_transform(true);
3199 
3200 
3201   // Because we run IGVN after each expansion, some macro nodes may go
3202   // dead and be removed from the list as we iterate over it. Move
3203   // Allocate nodes (processed in a second pass) at the beginning of
3204   // the list and then iterate from the last element of the list until
3205   // an Allocate node is seen. This is robust to random deletion in
3206   // the list due to nodes going dead.
3207   C->sort_macro_nodes();
3208 
3209   // expand arraycopy "macro" nodes first
3210   // For ReduceBulkZeroing, we must first process all arraycopy nodes
3211   // before the allocate nodes are expanded.
3212   while (C->macro_count() > 0) {
3213     int macro_count = C->macro_count();
3214     Node * n = C->macro_node(macro_count-1);
3215     assert(n->is_macro(), "only macro nodes expected here");
3216     if (_igvn.type(n) == Type::TOP || (n->in(0) != nullptr && n->in(0)->is_top())) {
3217       // node is unreachable, so don't try to expand it
3218       C->remove_macro_node(n);
3219       continue;
3220     }
3221     if (n->is_Allocate()) {
3222       break;
3223     }
3224     // Make sure expansion will not cause node limit to be exceeded.
3225     // Worst case is a macro node gets expanded into about 200 nodes.
3226     // Allow 50% more for optimization.
3227     if (C->check_node_count(300, "out of nodes before macro expansion")) {
3228       return true;
3229     }
3230 
3231     DEBUG_ONLY(int old_macro_count = C->macro_count();)
3232     switch (n->class_id()) {
3233     case Node::Class_Lock:
3234       expand_lock_node(n->as_Lock());
3235       break;
3236     case Node::Class_Unlock:
3237       expand_unlock_node(n->as_Unlock());
3238       break;
3239     case Node::Class_ArrayCopy:
3240       expand_arraycopy_node(n->as_ArrayCopy());
3241       break;
3242     case Node::Class_SubTypeCheck:
3243       expand_subtypecheck_node(n->as_SubTypeCheck());
3244       break;
3245     case Node::Class_CallStaticJava:
3246       expand_mh_intrinsic_return(n->as_CallStaticJava());
3247       C->remove_macro_node(n);
3248       break;
3249     case Node::Class_FlatArrayCheck:
3250       expand_flatarraycheck_node(n->as_FlatArrayCheck());
3251       break;
3252     default:
3253       switch (n->Opcode()) {
3254       case Op_ModD:
3255       case Op_ModF: {
3256         CallNode* mod_macro = n->as_Call();
3257         CallNode* call = new CallLeafPureNode(mod_macro->tf(), mod_macro->entry_point(),
3258                                               mod_macro->_name, TypeRawPtr::BOTTOM);
3259         call->init_req(TypeFunc::Control, mod_macro->in(TypeFunc::Control));
3260         call->init_req(TypeFunc::I_O, C->top());
3261         call->init_req(TypeFunc::Memory, C->top());
3262         call->init_req(TypeFunc::ReturnAdr, C->top());
3263         call->init_req(TypeFunc::FramePtr, C->top());
3264         for (unsigned int i = 0; i < mod_macro->tf()->domain_cc()->cnt() - TypeFunc::Parms; i++) {
3265           call->init_req(TypeFunc::Parms + i, mod_macro->in(TypeFunc::Parms + i));
3266         }
3267         _igvn.replace_node(mod_macro, call);
3268         transform_later(call);
3269         break;
3270       }
3271       default:
3272         assert(false, "unknown node type in macro list");
3273       }
3274     }
3275     assert(C->macro_count() == (old_macro_count - 1), "expansion must have deleted one node from macro list");
3276     if (C->failing())  return true;
3277     C->print_method(PHASE_AFTER_MACRO_EXPANSION_STEP, 5, n);
3278 
3279     // Clean up the graph so we're less likely to hit the maximum node
3280     // limit
3281     _igvn.set_delay_transform(false);
3282     _igvn.optimize();
3283     if (C->failing())  return true;
3284     _igvn.set_delay_transform(true);
3285   }
3286 
3287   // All nodes except Allocate nodes are expanded now. There could be
3288   // new optimization opportunities (such as folding newly created
3289   // load from a just allocated object). Run IGVN.
3290 
3291   // expand "macro" nodes
3292   // nodes are removed from the macro list as they are processed
3293   while (C->macro_count() > 0) {
3294     int macro_count = C->macro_count();
3295     Node * n = C->macro_node(macro_count-1);
3296     assert(n->is_macro(), "only macro nodes expected here");
3297     if (_igvn.type(n) == Type::TOP || (n->in(0) != nullptr && n->in(0)->is_top())) {
3298       // node is unreachable, so don't try to expand it
3299       C->remove_macro_node(n);
3300       continue;
3301     }
3302     // Make sure expansion will not cause node limit to be exceeded.
3303     // Worst case is a macro node gets expanded into about 200 nodes.
3304     // Allow 50% more for optimization.
3305     if (C->check_node_count(300, "out of nodes before macro expansion")) {
3306       return true;
3307     }
3308     switch (n->class_id()) {
3309     case Node::Class_Allocate:
3310       expand_allocate(n->as_Allocate());
3311       break;
3312     case Node::Class_AllocateArray:
3313       expand_allocate_array(n->as_AllocateArray());
3314       break;
3315     default:
3316       assert(false, "unknown node type in macro list");
3317     }
3318     assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
3319     if (C->failing())  return true;
3320     C->print_method(PHASE_AFTER_MACRO_EXPANSION_STEP, 5, n);
3321 
3322     // Clean up the graph so we're less likely to hit the maximum node
3323     // limit
3324     _igvn.set_delay_transform(false);
3325     _igvn.optimize();
3326     if (C->failing())  return true;
3327     _igvn.set_delay_transform(true);
3328   }
3329 
3330   _igvn.set_delay_transform(false);
3331   return false;
3332 }
3333 
3334 #ifndef PRODUCT
3335 int PhaseMacroExpand::_objs_scalar_replaced_counter = 0;
3336 int PhaseMacroExpand::_monitor_objects_removed_counter = 0;
3337 int PhaseMacroExpand::_GC_barriers_removed_counter = 0;
3338 int PhaseMacroExpand::_memory_barriers_removed_counter = 0;
3339 
3340 void PhaseMacroExpand::print_statistics() {
3341   tty->print("Objects scalar replaced = %d, ", Atomic::load(&_objs_scalar_replaced_counter));
3342   tty->print("Monitor objects removed = %d, ", Atomic::load(&_monitor_objects_removed_counter));
3343   tty->print("GC barriers removed = %d, ", Atomic::load(&_GC_barriers_removed_counter));
3344   tty->print_cr("Memory barriers removed = %d", Atomic::load(&_memory_barriers_removed_counter));
3345 }
3346 
3347 int PhaseMacroExpand::count_MemBar(Compile *C) {
3348   if (!PrintOptoStatistics) {
3349     return 0;
3350   }
3351   Unique_Node_List ideal_nodes;
3352   int total = 0;
3353   ideal_nodes.map(C->live_nodes(), nullptr);
3354   ideal_nodes.push(C->root());
3355   for (uint next = 0; next < ideal_nodes.size(); ++next) {
3356     Node* n = ideal_nodes.at(next);
3357     if (n->is_MemBar()) {
3358       total++;
3359     }
3360     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3361       Node* m = n->fast_out(i);
3362       ideal_nodes.push(m);
3363     }
3364   }
3365   return total;
3366 }
3367 #endif