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src/hotspot/share/opto/macroArrayCopy.cpp

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   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 "gc/shared/barrierSet.hpp"
  26 #include "gc/shared/tlab_globals.hpp"
  27 #include "oops/objArrayKlass.hpp"
  28 #include "opto/arraycopynode.hpp"
  29 #include "opto/castnode.hpp"
  30 #include "opto/convertnode.hpp"
  31 #include "opto/graphKit.hpp"
  32 #include "opto/macro.hpp"
  33 #include "opto/runtime.hpp"
  34 #include "opto/vectornode.hpp"
  35 #include "runtime/stubRoutines.hpp"
  36 #include "utilities/align.hpp"
  37 #include "utilities/powerOfTwo.hpp"
  38 
  39 void PhaseMacroExpand::insert_mem_bar(Node** ctrl, Node** mem, int opcode, int alias_idx, Node* precedent) {
  40   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
  41   mb->init_req(TypeFunc::Control, *ctrl);
  42   mb->init_req(TypeFunc::Memory, *mem);
  43   transform_later(mb);
  44   *ctrl = new ProjNode(mb,TypeFunc::Control);
  45   transform_later(*ctrl);
  46   Node* mem_proj = new ProjNode(mb,TypeFunc::Memory);
  47   transform_later(mem_proj);
  48   if (alias_idx == Compile::AliasIdxBot) {
  49     *mem = mem_proj;
  50   } else {
  51     MergeMemNode* mm = (*mem)->clone()->as_MergeMem();
  52     mm->set_memory_at(alias_idx, mem_proj);
  53     transform_later(mm);
  54     *mem = mm;
  55   }
  56 }
  57 
  58 Node* PhaseMacroExpand::array_element_address(Node* ary, Node* idx, BasicType elembt, bool raw_base) {
  59   uint shift  = exact_log2(type2aelembytes(elembt));





  60   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
  61   Node* base =  basic_plus_adr(ary, header, raw_base);
  62 #ifdef _LP64
  63   // see comment in GraphKit::array_element_address
  64   int index_max = max_jint - 1;  // array size is max_jint, index is one less
  65   const TypeLong* lidxtype = TypeLong::make(CONST64(0), index_max, Type::WidenMax);
  66   idx = transform_later( new ConvI2LNode(idx, lidxtype) );
  67 #endif
  68   Node* scale = new LShiftXNode(idx, intcon(shift));
  69   transform_later(scale);
  70   return basic_plus_adr(raw_base ? top() : ary, base, scale);
  71 }
  72 
  73 Node* PhaseMacroExpand::ConvI2L(Node* offset) {
  74   return transform_later(new ConvI2LNode(offset));
  75 }
  76 
  77 Node* PhaseMacroExpand::make_leaf_call(Node* ctrl, Node* mem,
  78                                        const TypeFunc* call_type, address call_addr,
  79                                        const char* call_name,

 128   }
 129 
 130   IfNode* iff = new IfNode(*ctrl, test, true_prob, COUNT_UNKNOWN);
 131   transform_later(iff);
 132 
 133   Node* if_slow = new IfTrueNode(iff);
 134   transform_later(if_slow);
 135 
 136   if (region != nullptr) {
 137     region->add_req(if_slow);
 138   }
 139 
 140   Node* if_fast = new IfFalseNode(iff);
 141   transform_later(if_fast);
 142 
 143   *ctrl = if_fast;
 144 
 145   return if_slow;
 146 }
 147 
 148 inline Node* PhaseMacroExpand::generate_slow_guard(Node** ctrl, Node* test, RegionNode* region) {
 149   return generate_guard(ctrl, test, region, PROB_UNLIKELY_MAG(3));
 150 }
 151 




 152 void PhaseMacroExpand::generate_negative_guard(Node** ctrl, Node* index, RegionNode* region) {
 153   if ((*ctrl)->is_top())
 154     return;                // already stopped
 155   if (_igvn.type(index)->higher_equal(TypeInt::POS)) // [0,maxint]
 156     return;                // index is already adequately typed
 157   Node* cmp_lt = new CmpINode(index, intcon(0));
 158   transform_later(cmp_lt);
 159   Node* bol_lt = new BoolNode(cmp_lt, BoolTest::lt);
 160   transform_later(bol_lt);
 161   generate_guard(ctrl, bol_lt, region, PROB_MIN);
 162 }
 163 
 164 void PhaseMacroExpand::generate_limit_guard(Node** ctrl, Node* offset, Node* subseq_length, Node* array_length, RegionNode* region) {
 165   if ((*ctrl)->is_top())
 166     return;                // already stopped
 167   bool zero_offset = _igvn.type(offset) == TypeInt::ZERO;
 168   if (zero_offset && subseq_length->eqv_uncast(array_length))
 169     return;                // common case of whole-array copy
 170   Node* last = subseq_length;
 171   if (!zero_offset) {            // last += offset

 265 
 266   *ctrl = stub_block;
 267 }
 268 
 269 
 270 Node* PhaseMacroExpand::generate_nonpositive_guard(Node** ctrl, Node* index, bool never_negative) {
 271   if ((*ctrl)->is_top())  return nullptr;
 272 
 273   if (_igvn.type(index)->higher_equal(TypeInt::POS1)) // [1,maxint]
 274     return nullptr;                // index is already adequately typed
 275   Node* cmp_le = new CmpINode(index, intcon(0));
 276   transform_later(cmp_le);
 277   BoolTest::mask le_or_eq = (never_negative ? BoolTest::eq : BoolTest::le);
 278   Node* bol_le = new BoolNode(cmp_le, le_or_eq);
 279   transform_later(bol_le);
 280   Node* is_notp = generate_guard(ctrl, bol_le, nullptr, PROB_MIN);
 281 
 282   return is_notp;
 283 }
 284 











































 285 void PhaseMacroExpand::finish_arraycopy_call(Node* call, Node** ctrl, MergeMemNode** mem, const TypePtr* adr_type) {
 286   transform_later(call);
 287 
 288   *ctrl = new ProjNode(call,TypeFunc::Control);
 289   transform_later(*ctrl);
 290   Node* newmem = new ProjNode(call, TypeFunc::Memory);
 291   transform_later(newmem);
 292 
 293   uint alias_idx = C->get_alias_index(adr_type);
 294   if (alias_idx != Compile::AliasIdxBot) {
 295     *mem = MergeMemNode::make(*mem);
 296     (*mem)->set_memory_at(alias_idx, newmem);
 297   } else {
 298     *mem = MergeMemNode::make(newmem);
 299   }
 300   transform_later(*mem);
 301 }
 302 
 303 address PhaseMacroExpand::basictype2arraycopy(BasicType t,
 304                                               Node* src_offset,

 359 //       }
 360 //     }
 361 //     // adjust params for remaining work:
 362 //     if (slowval != -1) {
 363 //       n = -1^slowval; src_offset += n; dest_offset += n; length -= n
 364 //     }
 365 //   slow_region:
 366 //     call slow arraycopy(src, src_offset, dest, dest_offset, length)
 367 //     return  // via slow_call_path
 368 //
 369 // This routine is used from several intrinsics:  System.arraycopy,
 370 // Object.clone (the array subcase), and Arrays.copyOf[Range].
 371 //
 372 Node* PhaseMacroExpand::generate_arraycopy(ArrayCopyNode *ac, AllocateArrayNode* alloc,
 373                                            Node** ctrl, MergeMemNode* mem, Node** io,
 374                                            const TypePtr* adr_type,
 375                                            BasicType basic_elem_type,
 376                                            Node* src,  Node* src_offset,
 377                                            Node* dest, Node* dest_offset,
 378                                            Node* copy_length,


 379                                            bool disjoint_bases,
 380                                            bool length_never_negative,
 381                                            RegionNode* slow_region) {
 382   Node* orig_dest = dest;
 383   if (slow_region == nullptr) {
 384     slow_region = new RegionNode(1);
 385     transform_later(slow_region);
 386   }
 387 
 388   bool  dest_needs_zeroing   = false;
 389   bool  acopy_to_uninitialized = false;


 390 
 391   // See if this is the initialization of a newly-allocated array.
 392   // If so, we will take responsibility here for initializing it to zero.
 393   // (Note:  Because tightly_coupled_allocation performs checks on the
 394   // out-edges of the dest, we need to avoid making derived pointers
 395   // from it until we have checked its uses.)
 396   if (ReduceBulkZeroing
 397       && !(UseTLAB && ZeroTLAB) // pointless if already zeroed
 398       && basic_elem_type != T_CONFLICT // avoid corner case
 399       && !src->eqv_uncast(dest)
 400       && alloc != nullptr
 401       && _igvn.find_int_con(alloc->in(AllocateNode::ALength), 1) > 0) {
 402     assert(ac->is_alloc_tightly_coupled(), "sanity");
 403     // acopy to uninitialized tightly coupled allocations
 404     // needs zeroing outside the copy range
 405     // and the acopy itself will be to uninitialized memory
 406     acopy_to_uninitialized = true;
 407     if (alloc->maybe_set_complete(&_igvn)) {
 408       // "You break it, you buy it."
 409       InitializeNode* init = alloc->initialization();
 410       assert(init->is_complete(), "we just did this");
 411       init->set_complete_with_arraycopy();
 412       assert(dest->is_CheckCastPP(), "sanity");
 413       assert(dest->in(0)->in(0) == init, "dest pinned");
 414       adr_type = TypeRawPtr::BOTTOM;  // all initializations are into raw memory

 415       dest = dest->in(1); // writing to raw memory requires a raw base
 416       // From this point on, every exit path is responsible for
 417       // initializing any non-copied parts of the object to zero.
 418       // Also, if this flag is set we make sure that arraycopy interacts properly
 419       // with G1, eliding pre-barriers. See CR 6627983.
 420       dest_needs_zeroing = true;


 421     } else {
 422       // dest_need_zeroing = false;
 423     }
 424   } else {
 425     // No zeroing elimination needed here.
 426     alloc                  = nullptr;
 427     acopy_to_uninitialized = false;
 428     //dest_needs_zeroing   = false;
 429   }
 430 
 431   uint alias_idx = C->get_alias_index(adr_type);
 432 
 433   // Results are placed here:
 434   enum { fast_path        = 1,  // normal void-returning assembly stub
 435          checked_path     = 2,  // special assembly stub with cleanup
 436          slow_call_path   = 3,  // something went wrong; call the VM
 437          zero_path        = 4,  // bypass when length of copy is zero
 438          bcopy_path       = 5,  // copy primitive array by 64-bit blocks
 439          PATH_LIMIT       = 6
 440   };

 469     checked_i_o     = *io;
 470     checked_mem     = mem->memory_at(alias_idx);
 471     checked_value   = cv;
 472     *ctrl = top();
 473   }
 474 
 475   Node* not_pos = generate_nonpositive_guard(ctrl, copy_length, length_never_negative);
 476   if (not_pos != nullptr) {
 477     Node* local_ctrl = not_pos, *local_io = *io;
 478     MergeMemNode* local_mem = MergeMemNode::make(mem);
 479     transform_later(local_mem);
 480 
 481     // (6) length must not be negative.
 482     if (!length_never_negative) {
 483       generate_negative_guard(&local_ctrl, copy_length, slow_region);
 484     }
 485 
 486     // copy_length is 0.
 487     if (dest_needs_zeroing) {
 488       assert(!local_ctrl->is_top(), "no ctrl?");
 489       Node* dest_length = alloc->in(AllocateNode::ALength);
 490       if (copy_length->eqv_uncast(dest_length)
 491           || _igvn.find_int_con(dest_length, 1) <= 0) {
 492         // There is no zeroing to do. No need for a secondary raw memory barrier.
 493       } else {
 494         // Clear the whole thing since there are no source elements to copy.
 495         generate_clear_array(local_ctrl, local_mem,
 496                              adr_type, dest, basic_elem_type,


 497                              intcon(0), nullptr,
 498                              alloc->in(AllocateNode::AllocSize));
 499         // Use a secondary InitializeNode as raw memory barrier.
 500         // Currently it is needed only on this path since other
 501         // paths have stub or runtime calls as raw memory barriers.
 502         MemBarNode* mb = MemBarNode::make(C, Op_Initialize,
 503                                           Compile::AliasIdxRaw,
 504                                           top());
 505         transform_later(mb);
 506         mb->set_req(TypeFunc::Control,local_ctrl);
 507         mb->set_req(TypeFunc::Memory, local_mem->memory_at(Compile::AliasIdxRaw));
 508         local_ctrl = transform_later(new ProjNode(mb, TypeFunc::Control));
 509         local_mem->set_memory_at(Compile::AliasIdxRaw, transform_later(new ProjNode(mb, TypeFunc::Memory)));
 510 
 511         InitializeNode* init = mb->as_Initialize();
 512         init->set_complete(&_igvn);  // (there is no corresponding AllocateNode)
 513       }
 514     }
 515 
 516     // Present the results of the fast call.
 517     result_region->init_req(zero_path, local_ctrl);
 518     result_i_o   ->init_req(zero_path, local_io);
 519     result_memory->init_req(zero_path, local_mem->memory_at(alias_idx));
 520   }
 521 
 522   if (!(*ctrl)->is_top() && dest_needs_zeroing) {
 523     // We have to initialize the *uncopied* part of the array to zero.
 524     // The copy destination is the slice dest[off..off+len].  The other slices
 525     // are dest_head = dest[0..off] and dest_tail = dest[off+len..dest.length].
 526     Node* dest_size   = alloc->in(AllocateNode::AllocSize);
 527     Node* dest_length = alloc->in(AllocateNode::ALength);
 528     Node* dest_tail   = transform_later( new AddINode(dest_offset, copy_length));
 529 
 530     // If there is a head section that needs zeroing, do it now.
 531     if (_igvn.find_int_con(dest_offset, -1) != 0) {
 532       generate_clear_array(*ctrl, mem,
 533                            adr_type, dest, basic_elem_type,


 534                            intcon(0), dest_offset,
 535                            nullptr);
 536     }
 537 
 538     // Next, perform a dynamic check on the tail length.
 539     // It is often zero, and we can win big if we prove this.
 540     // There are two wins:  Avoid generating the ClearArray
 541     // with its attendant messy index arithmetic, and upgrade
 542     // the copy to a more hardware-friendly word size of 64 bits.
 543     Node* tail_ctl = nullptr;
 544     if (!(*ctrl)->is_top() && !dest_tail->eqv_uncast(dest_length)) {
 545       Node* cmp_lt   = transform_later( new CmpINode(dest_tail, dest_length) );
 546       Node* bol_lt   = transform_later( new BoolNode(cmp_lt, BoolTest::lt) );
 547       tail_ctl = generate_slow_guard(ctrl, bol_lt, nullptr);
 548       assert(tail_ctl != nullptr || !(*ctrl)->is_top(), "must be an outcome");
 549     }
 550 
 551     // At this point, let's assume there is no tail.
 552     if (!(*ctrl)->is_top() && alloc != nullptr && basic_elem_type != T_OBJECT) {
 553       // There is no tail.  Try an upgrade to a 64-bit copy.
 554       bool didit = false;
 555       {
 556         Node* local_ctrl = *ctrl, *local_io = *io;
 557         MergeMemNode* local_mem = MergeMemNode::make(mem);
 558         transform_later(local_mem);
 559 
 560         didit = generate_block_arraycopy(&local_ctrl, &local_mem, adr_type,
 561                                          basic_elem_type, src, src_offset,
 562                                          dest, dest_offset, dest_size, acopy_to_uninitialized);
 563         if (didit) {
 564           // Present the results of the block-copying fast call.
 565           result_region->init_req(bcopy_path, local_ctrl);
 566           result_i_o   ->init_req(bcopy_path, local_io);
 567           result_memory->init_req(bcopy_path, local_mem->memory_at(alias_idx));
 568         }
 569       }
 570       if (didit) {
 571         *ctrl = top();     // no regular fast path
 572       }
 573     }
 574 
 575     // Clear the tail, if any.
 576     if (tail_ctl != nullptr) {
 577       Node* notail_ctl = (*ctrl)->is_top() ? nullptr : *ctrl;
 578       *ctrl = tail_ctl;
 579       if (notail_ctl == nullptr) {
 580         generate_clear_array(*ctrl, mem,
 581                              adr_type, dest, basic_elem_type,


 582                              dest_tail, nullptr,
 583                              dest_size);
 584       } else {
 585         // Make a local merge.
 586         Node* done_ctl = transform_later(new RegionNode(3));
 587         Node* done_mem = transform_later(new PhiNode(done_ctl, Type::MEMORY, adr_type));
 588         done_ctl->init_req(1, notail_ctl);
 589         done_mem->init_req(1, mem->memory_at(alias_idx));
 590         generate_clear_array(*ctrl, mem,
 591                              adr_type, dest, basic_elem_type,


 592                              dest_tail, nullptr,
 593                              dest_size);
 594         done_ctl->init_req(2, *ctrl);
 595         done_mem->init_req(2, mem->memory_at(alias_idx));
 596         *ctrl = done_ctl;
 597         mem->set_memory_at(alias_idx, done_mem);
 598       }
 599     }
 600   }
 601 
 602   BasicType copy_type = basic_elem_type;
 603   assert(basic_elem_type != T_ARRAY, "caller must fix this");
 604   if (!(*ctrl)->is_top() && copy_type == T_OBJECT) {
 605     // If src and dest have compatible element types, we can copy bits.
 606     // Types S[] and D[] are compatible if D is a supertype of S.
 607     //
 608     // If they are not, we will use checked_oop_disjoint_arraycopy,
 609     // which performs a fast optimistic per-oop check, and backs off
 610     // further to JVM_ArrayCopy on the first per-oop check that fails.
 611     // (Actually, we don't move raw bits only; the GC requires card marks.)
 612 
 613     // We don't need a subtype check for validated copies and Object[].clone()

 630       //
 631       // Test S[] against D[], not S against D, because (probably)
 632       // the secondary supertype cache is less busy for S[] than S.
 633       // This usually only matters when D is an interface.
 634       Node* not_subtype_ctrl = Phase::gen_subtype_check(src_klass, dest_klass, ctrl, mem, _igvn, nullptr, -1);
 635       // Plug failing path into checked_oop_disjoint_arraycopy
 636       if (not_subtype_ctrl != top()) {
 637         Node* local_ctrl = not_subtype_ctrl;
 638         MergeMemNode* local_mem = MergeMemNode::make(mem);
 639         transform_later(local_mem);
 640 
 641         // (At this point we can assume disjoint_bases, since types differ.)
 642         int ek_offset = in_bytes(ObjArrayKlass::element_klass_offset());
 643         Node* p1 = off_heap_plus_addr(dest_klass, ek_offset);
 644         Node* n1 = LoadKlassNode::make(_igvn, C->immutable_memory(), p1, TypeRawPtr::BOTTOM);
 645         Node* dest_elem_klass = transform_later(n1);
 646         Node* cv = generate_checkcast_arraycopy(&local_ctrl, &local_mem,
 647                                                 adr_type,
 648                                                 dest_elem_klass,
 649                                                 src, src_offset, dest, dest_offset,
 650                                                 ConvI2X(copy_length), acopy_to_uninitialized);
 651         if (cv == nullptr)  cv = intcon(-1);  // failure (no stub available)
 652         checked_control = local_ctrl;
 653         checked_i_o     = *io;
 654         checked_mem     = local_mem->memory_at(alias_idx);
 655         checked_value   = cv;
 656       }
 657     }
 658     // At this point we know we do not need type checks on oop stores.
 659 
 660     BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 661     if (!bs->array_copy_requires_gc_barriers(alloc != nullptr, copy_type, false, false, BarrierSetC2::Expansion)) {
 662       // If we do not need gc barriers, copy using the jint or jlong stub.
 663       copy_type = LP64_ONLY(UseCompressedOops ? T_INT : T_LONG) NOT_LP64(T_INT);
 664       assert(type2aelembytes(basic_elem_type) == type2aelembytes(copy_type),
 665              "sizes agree");
 666     }
 667   }
 668 
 669   if (!(*ctrl)->is_top()) {
 670     // Generate the fast path, if possible.
 671     Node* local_ctrl = *ctrl;
 672     MergeMemNode* local_mem = MergeMemNode::make(mem);
 673     transform_later(local_mem);
 674     generate_unchecked_arraycopy(&local_ctrl, &local_mem,
 675                                  adr_type, copy_type, disjoint_bases,
 676                                  src, src_offset, dest, dest_offset,
 677                                  ConvI2X(copy_length), acopy_to_uninitialized);

 678 
 679     // Present the results of the fast call.
 680     result_region->init_req(fast_path, local_ctrl);
 681     result_i_o   ->init_req(fast_path, *io);
 682     result_memory->init_req(fast_path, local_mem->memory_at(alias_idx));
 683   }
 684 
 685   // Here are all the slow paths up to this point, in one bundle:
 686   assert(slow_region != nullptr, "allocated on entry");
 687   slow_control = slow_region;
 688   DEBUG_ONLY(slow_region = (RegionNode*)badAddress);
 689 
 690   *ctrl = checked_control;
 691   if (!(*ctrl)->is_top()) {
 692     // Clean up after the checked call.
 693     // The returned value is either 0 or -1^K,
 694     // where K = number of partially transferred array elements.
 695     Node* cmp = new CmpINode(checked_value, intcon(0));
 696     transform_later(cmp);
 697     Node* bol = new BoolNode(cmp, BoolTest::eq);

 748       Node* length_minus  = new SubINode(copy_length, slow_offset);
 749       transform_later(length_minus);
 750 
 751       // Tweak the node variables to adjust the code produced below:
 752       src_offset  = src_off_plus;
 753       dest_offset = dest_off_plus;
 754       copy_length = length_minus;
 755     }
 756   }
 757   *ctrl = slow_control;
 758   if (!(*ctrl)->is_top()) {
 759     Node* local_ctrl = *ctrl, *local_io = slow_i_o;
 760     MergeMemNode* local_mem = MergeMemNode::make(mem);
 761     transform_later(local_mem);
 762 
 763     // Generate the slow path, if needed.
 764     local_mem->set_memory_at(alias_idx, slow_mem);
 765 
 766     if (dest_needs_zeroing) {
 767       generate_clear_array(local_ctrl, local_mem,
 768                            adr_type, dest, basic_elem_type,


 769                            intcon(0), nullptr,
 770                            alloc->in(AllocateNode::AllocSize));

 771     }
 772 
 773     local_mem = generate_slow_arraycopy(ac,
 774                                         &local_ctrl, local_mem, &local_io,
 775                                         adr_type,
 776                                         src, src_offset, orig_dest, dest_offset,
 777                                         copy_length, /*dest_uninitialized*/false);
 778 
 779     result_region->init_req(slow_call_path, local_ctrl);
 780     result_i_o   ->init_req(slow_call_path, local_io);
 781     result_memory->init_req(slow_call_path, local_mem->memory_at(alias_idx));
 782   } else {
 783     ShouldNotReachHere(); // no call to generate_slow_arraycopy:
 784                           // projections were not extracted
 785   }
 786 
 787   // Remove unused edges.
 788   for (uint i = 1; i < result_region->req(); i++) {
 789     if (result_region->in(i) == nullptr) {
 790       result_region->init_req(i, top());
 791     }
 792   }
 793 
 794   // Finished; return the combined state.
 795   *ctrl = result_region;
 796   *io = result_i_o;
 797   mem->set_memory_at(alias_idx, result_memory);
 798 
 799   // mem no longer guaranteed to stay a MergeMemNode
 800   Node* out_mem = mem;
 801   DEBUG_ONLY(mem = nullptr);
 802 
 803   // The memory edges above are precise in order to model effects around
 804   // array copies accurately to allow value numbering of field loads around
 805   // arraycopy.  Such field loads, both before and after, are common in Java
 806   // collections and similar classes involving header/array data structures.
 807   //
 808   // But with low number of register or when some registers are used or killed
 809   // by arraycopy calls it causes registers spilling on stack. See 6544710.
 810   // The next memory barrier is added to avoid it. If the arraycopy can be
 811   // optimized away (which it can, sometimes) then we can manually remove
 812   // the membar also.
 813   //
 814   // Do not let reads from the cloned object float above the arraycopy.
 815   if (alloc != nullptr && !alloc->initialization()->does_not_escape()) {
 816     // Do not let stores that initialize this object be reordered with
 817     // a subsequent store that would make this object accessible by
 818     // other threads.
 819     assert(ac->_dest_type == TypeOopPtr::BOTTOM, "non escaping destination shouldn't have narrow slice");
 820     insert_mem_bar(ctrl, &out_mem, Op_MemBarStoreStore, Compile::AliasIdxBot);
 821   } else {
 822     int mem_bar_alias_idx = Compile::AliasIdxBot;
 823     if (ac->_dest_type != TypeOopPtr::BOTTOM) {
 824       // The graph was transformed under the assumption the ArrayCopy node only had an effect on a narrow slice. We can't
 825       // insert a wide membar now that it's being expanded: a load that uses the input memory state of the ArrayCopy
 826       // could then become anti dependent on the membar when it was not anti dependent on the ArrayCopy leading to a
 827       // broken graph.
 828       mem_bar_alias_idx = C->get_alias_index(ac->_dest_type->add_offset(Type::OffsetBot)->is_ptr());
 829     }
 830     insert_mem_bar(ctrl, &out_mem, Op_MemBarCPUOrder, mem_bar_alias_idx);
 831   }
 832 
 833   assert((*ctrl)->is_Proj(), "MemBar control projection");
 834   assert((*ctrl)->in(0)->isa_MemBar(), "MemBar node");
 835   (*ctrl)->in(0)->isa_MemBar()->set_trailing_expanded_array_copy();
 836 
 837   _igvn.replace_node(_callprojs.fallthrough_memproj, out_mem);
 838   if (_callprojs.fallthrough_ioproj != nullptr) {
 839     _igvn.replace_node(_callprojs.fallthrough_ioproj, *io);
 840   }
 841   _igvn.replace_node(_callprojs.fallthrough_catchproj, *ctrl);
 842 
 843 #ifdef ASSERT
 844   const TypeOopPtr* dest_t = _igvn.type(orig_dest)->is_oopptr();
 845   if (dest_t->is_known_instance()) {
 846     ArrayCopyNode* ac = nullptr;
 847     assert(ArrayCopyNode::may_modify(dest_t, (*ctrl)->in(0)->as_MemBar(), &_igvn, ac), "dependency on arraycopy lost");
 848     assert(ac == nullptr, "no arraycopy anymore");
 849   }
 850 #endif
 851 
 852   return out_mem;
 853 }
 854 
 855 // Helper for initialization of arrays, creating a ClearArray.
 856 // It writes zero bits in [start..end), within the body of an array object.
 857 // The memory effects are all chained onto the 'adr_type' alias category.
 858 //
 859 // Since the object is otherwise uninitialized, we are free
 860 // to put a little "slop" around the edges of the cleared area,
 861 // as long as it does not go back into the array's header,
 862 // or beyond the array end within the heap.
 863 //
 864 // The lower edge can be rounded down to the nearest jint and the
 865 // upper edge can be rounded up to the nearest MinObjAlignmentInBytes.
 866 //
 867 // Arguments:
 868 //   adr_type           memory slice where writes are generated
 869 //   dest               oop of the destination array
 870 //   basic_elem_type    element type of the destination
 871 //   slice_idx          array index of first element to store
 872 //   slice_len          number of elements to store (or null)
 873 //   dest_size          total size in bytes of the array object
 874 //
 875 // Exactly one of slice_len or dest_size must be non-null.
 876 // If dest_size is non-null, zeroing extends to the end of the object.
 877 // If slice_len is non-null, the slice_idx value must be a constant.
 878 void PhaseMacroExpand::generate_clear_array(Node* ctrl, MergeMemNode* merge_mem,
 879                                             const TypePtr* adr_type,
 880                                             Node* dest,


 881                                             BasicType basic_elem_type,
 882                                             Node* slice_idx,
 883                                             Node* slice_len,
 884                                             Node* dest_size) {

 885   // one or the other but not both of slice_len and dest_size:
 886   assert((slice_len != nullptr? 1: 0) + (dest_size != nullptr? 1: 0) == 1, "");
 887   if (slice_len == nullptr)  slice_len = top();
 888   if (dest_size == nullptr)  dest_size = top();
 889 
 890   uint alias_idx = C->get_alias_index(adr_type);
 891 
 892   // operate on this memory slice:
 893   Node* mem = merge_mem->memory_at(alias_idx); // memory slice to operate on
 894 
 895   // scaling and rounding of indexes:
 896   int scale = exact_log2(type2aelembytes(basic_elem_type));
 897   int abase = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
 898   int clear_low = (-1 << scale) & (BytesPerInt  - 1);
 899   int bump_bit  = (-1 << scale) & BytesPerInt;
 900 
 901   // determine constant starts and ends
 902   const intptr_t BIG_NEG = -128;
 903   assert(BIG_NEG + 2*abase < 0, "neg enough");
 904   intptr_t slice_idx_con = (intptr_t) _igvn.find_int_con(slice_idx, BIG_NEG);
 905   intptr_t slice_len_con = (intptr_t) _igvn.find_int_con(slice_len, BIG_NEG);
 906   if (slice_len_con == 0) {
 907     return;                     // nothing to do here
 908   }
 909   intptr_t start_con = (abase + (slice_idx_con << scale)) & ~clear_low;
 910   intptr_t end_con   = _igvn.find_intptr_t_con(dest_size, -1);
 911   if (slice_idx_con >= 0 && slice_len_con >= 0) {
 912     assert(end_con < 0, "not two cons");
 913     end_con = align_up(abase + ((slice_idx_con + slice_len_con) << scale),
 914                        BytesPerLong);
 915   }
 916 
 917   if (start_con >= 0 && end_con >= 0) {
 918     // Constant start and end.  Simple.
 919     mem = ClearArrayNode::clear_memory(ctrl, mem, dest,
 920                                        start_con, end_con, adr_type == TypeRawPtr::BOTTOM, &_igvn);
 921   } else if (start_con >= 0 && dest_size != top()) {
 922     // Constant start, pre-rounded end after the tail of the array.
 923     Node* end = dest_size;
 924     mem = ClearArrayNode::clear_memory(ctrl, mem, dest,
 925                                        start_con, end, adr_type == TypeRawPtr::BOTTOM, &_igvn);
 926   } else if (start_con >= 0 && slice_len != top()) {
 927     // Constant start, non-constant end.  End needs rounding up.
 928     // End offset = round_up(abase + ((slice_idx_con + slice_len) << scale), 8)
 929     intptr_t end_base  = abase + (slice_idx_con << scale);
 930     int      end_round = (-1 << scale) & (BytesPerLong  - 1);
 931     Node*    end       = ConvI2X(slice_len);
 932     if (scale != 0)
 933       end = transform_later(new LShiftXNode(end, intcon(scale) ));
 934     end_base += end_round;
 935     end = transform_later(new AddXNode(end, MakeConX(end_base)) );
 936     end = transform_later(new AndXNode(end, MakeConX(~end_round)) );
 937     mem = ClearArrayNode::clear_memory(ctrl, mem, dest,
 938                                        start_con, end, adr_type == TypeRawPtr::BOTTOM, &_igvn);
 939   } else if (start_con < 0 && dest_size != top()) {
 940     // Non-constant start, pre-rounded end after the tail of the array.
 941     // This is almost certainly a "round-to-end" operation.
 942     Node* start = slice_idx;
 943     start = ConvI2X(start);
 944     if (scale != 0)
 945       start = transform_later(new LShiftXNode( start, intcon(scale) ));
 946     start = transform_later(new AddXNode(start, MakeConX(abase)) );
 947     if ((bump_bit | clear_low) != 0) {
 948       int to_clear = (bump_bit | clear_low);
 949       // Align up mod 8, then store a jint zero unconditionally
 950       // just before the mod-8 boundary.
 951       if (((abase + bump_bit) & ~to_clear) - bump_bit
 952           < arrayOopDesc::length_offset_in_bytes() + BytesPerInt) {
 953         bump_bit = 0;
 954         assert((abase & to_clear) == 0, "array base must be long-aligned");
 955       } else {
 956         // Bump 'start' up to (or past) the next jint boundary:
 957         start = transform_later( new AddXNode(start, MakeConX(bump_bit)) );
 958         assert((abase & clear_low) == 0, "array base must be int-aligned");
 959       }
 960       // Round bumped 'start' down to jlong boundary in body of array.
 961       start = transform_later(new AndXNode(start, MakeConX(~to_clear)) );
 962       if (bump_bit != 0) {
 963         // Store a zero to the immediately preceding jint:
 964         Node* x1 = transform_later(new AddXNode(start, MakeConX(-bump_bit)) );
 965         Node* p1 = basic_plus_adr(dest, x1, adr_type == TypeRawPtr::BOTTOM);
 966         mem = StoreNode::make(_igvn, ctrl, mem, p1, adr_type, intcon(0), T_INT, MemNode::unordered);






 967         mem = transform_later(mem);
 968       }
 969     }
 970     Node* end = dest_size; // pre-rounded
 971     mem = ClearArrayNode::clear_memory(ctrl, mem, dest,
 972                                        start, end, adr_type == TypeRawPtr::BOTTOM, &_igvn);
 973   } else {
 974     // Non-constant start, unrounded non-constant end.
 975     // (Nobody zeroes a random midsection of an array using this routine.)
 976     ShouldNotReachHere();       // fix caller
 977   }
 978 
 979   // Done.
 980   merge_mem->set_memory_at(alias_idx, mem);
 981 }
 982 
 983 bool PhaseMacroExpand::generate_block_arraycopy(Node** ctrl, MergeMemNode** mem,
 984                                                 const TypePtr* adr_type,
 985                                                 BasicType basic_elem_type,
 986                                                 Node* src, Node* src_offset,
 987                                                 Node* dest, Node* dest_offset,
 988                                                 Node* dest_size, bool dest_uninitialized) {

 989   // See if there is an advantage from block transfer.
 990   int scale = exact_log2(type2aelembytes(basic_elem_type));
 991   if (scale >= LogBytesPerLong)
 992     return false;               // it is already a block transfer
 993 
 994   // Look at the alignment of the starting offsets.
 995   int abase = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
 996 
 997   intptr_t src_off_con  = (intptr_t) _igvn.find_int_con(src_offset, -1);
 998   intptr_t dest_off_con = (intptr_t) _igvn.find_int_con(dest_offset, -1);
 999   if (src_off_con < 0 || dest_off_con < 0) {
1000     // At present, we can only understand constants.
1001     return false;
1002   }
1003 
1004   intptr_t src_off  = abase + (src_off_con  << scale);
1005   intptr_t dest_off = abase + (dest_off_con << scale);
1006 
1007   if (((src_off | dest_off) & (BytesPerLong-1)) != 0) {
1008     // Non-aligned; too bad.
1009     // One more chance:  Pick off an initial 32-bit word.
1010     // This is a common case, since abase can be odd mod 8.
1011     if (((src_off | dest_off) & (BytesPerLong-1)) == BytesPerInt &&
1012         ((src_off ^ dest_off) & (BytesPerLong-1)) == 0) {
1013       Node* sptr = basic_plus_adr(src,  src_off);
1014       Node* dptr = basic_plus_adr(dest, dest_off, adr_type == TypeRawPtr::BOTTOM);
1015       const TypePtr* s_adr_type = _igvn.type(sptr)->is_ptr();
1016       assert(s_adr_type->isa_aryptr(), "impossible slice");
1017       uint s_alias_idx = C->get_alias_index(s_adr_type);
1018       uint d_alias_idx = C->get_alias_index(adr_type);
1019       bool is_mismatched = (basic_elem_type != T_INT);
1020       Node* sval = transform_later(
1021           LoadNode::make(_igvn, *ctrl, (*mem)->memory_at(s_alias_idx), sptr, s_adr_type,
1022                          TypeInt::INT, T_INT, MemNode::unordered, LoadNode::DependsOnlyOnTest,
1023                          false /*require_atomic_access*/, false /*unaligned*/, is_mismatched));
1024       Node* st = transform_later(
1025           StoreNode::make(_igvn, *ctrl, (*mem)->memory_at(d_alias_idx), dptr, adr_type,
1026                           sval, T_INT, MemNode::unordered));
1027       if (is_mismatched) {
1028         st->as_Store()->set_mismatched_access();
1029       }
1030       (*mem)->set_memory_at(d_alias_idx, st);
1031       src_off += BytesPerInt;
1032       dest_off += BytesPerInt;
1033     } else {
1034       return false;
1035     }
1036   }
1037   assert(src_off % BytesPerLong == 0, "");
1038   assert(dest_off % BytesPerLong == 0, "");
1039 
1040   // Do this copy by giant steps.
1041   Node* sptr  = basic_plus_adr(src,  src_off);
1042   Node* dptr  = basic_plus_adr(dest, dest_off, adr_type == TypeRawPtr::BOTTOM);
1043   Node* countx = dest_size;
1044   countx = transform_later(new SubXNode(countx, MakeConX(dest_off)));
1045   countx = transform_later(new URShiftXNode(countx, intcon(LogBytesPerLong)));
1046 
1047   bool disjoint_bases = true;   // since alloc isn't null
1048   generate_unchecked_arraycopy(ctrl, mem,
1049                                adr_type, T_LONG, disjoint_bases,
1050                                sptr, nullptr, dptr, nullptr, countx, dest_uninitialized);
1051 
1052   return true;
1053 }
1054 
1055 // Helper function; generates code for the slow case.
1056 // We make a call to a runtime method which emulates the native method,
1057 // but without the native wrapper overhead.
1058 MergeMemNode* PhaseMacroExpand::generate_slow_arraycopy(ArrayCopyNode *ac,
1059                                                         Node** ctrl, Node* mem, Node** io,
1060                                                         const TypePtr* adr_type,
1061                                                         Node* src,  Node* src_offset,
1062                                                         Node* dest, Node* dest_offset,
1063                                                         Node* copy_length, bool dest_uninitialized) {
1064   assert(!dest_uninitialized, "Invariant");
1065 
1066   const TypeFunc* call_type = OptoRuntime::slow_arraycopy_Type();
1067   CallNode* call = new CallStaticJavaNode(call_type, OptoRuntime::slow_arraycopy_Java(),
1068                                           "slow_arraycopy", TypePtr::BOTTOM);
1069 
1070   call->init_req(TypeFunc::Control, *ctrl);
1071   call->init_req(TypeFunc::I_O    , *io);
1072   call->init_req(TypeFunc::Memory , mem);
1073   call->init_req(TypeFunc::ReturnAdr, top());
1074   call->init_req(TypeFunc::FramePtr, top());
1075   call->init_req(TypeFunc::Parms+0, src);
1076   call->init_req(TypeFunc::Parms+1, src_offset);
1077   call->init_req(TypeFunc::Parms+2, dest);
1078   call->init_req(TypeFunc::Parms+3, dest_offset);
1079   call->init_req(TypeFunc::Parms+4, copy_length);
1080   call->copy_call_debug_info(&_igvn, ac);
1081 
1082   call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
1083   _igvn.replace_node(ac, call);
1084   transform_later(call);
1085 
1086   call->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/);
1087   *ctrl = _callprojs.fallthrough_catchproj->clone();
1088   transform_later(*ctrl);
1089 
1090   Node* m = _callprojs.fallthrough_memproj->clone();
1091   transform_later(m);
1092 
1093   uint alias_idx = C->get_alias_index(adr_type);
1094   MergeMemNode* out_mem;
1095   if (alias_idx != Compile::AliasIdxBot) {
1096     out_mem = MergeMemNode::make(mem);
1097     out_mem->set_memory_at(alias_idx, m);
1098   } else {
1099     out_mem = MergeMemNode::make(m);
1100   }
1101   transform_later(out_mem);
1102 
1103   // When src is negative and arraycopy is before an infinite loop,_callprojs.fallthrough_ioproj
1104   // could be null. Skip clone and update null fallthrough_ioproj.
1105   if (_callprojs.fallthrough_ioproj != nullptr) {
1106     *io = _callprojs.fallthrough_ioproj->clone();
1107     transform_later(*io);
1108   } else {
1109     *io = nullptr;
1110   }
1111 
1112   return out_mem;
1113 }
1114 
1115 // Helper function; generates code for cases requiring runtime checks.
1116 Node* PhaseMacroExpand::generate_checkcast_arraycopy(Node** ctrl, MergeMemNode** mem,
1117                                                      const TypePtr* adr_type,
1118                                                      Node* dest_elem_klass,
1119                                                      Node* src,  Node* src_offset,
1120                                                      Node* dest, Node* dest_offset,
1121                                                      Node* copy_length, bool dest_uninitialized) {

1122   if ((*ctrl)->is_top())  return nullptr;
1123 
1124   address copyfunc_addr = StubRoutines::checkcast_arraycopy(dest_uninitialized);
1125   if (copyfunc_addr == nullptr) { // Stub was not generated, go slow path.
1126     return nullptr;
1127   }
1128 
1129   // Pick out the parameters required to perform a store-check
1130   // for the target array.  This is an optimistic check.  It will
1131   // look in each non-null element's class, at the desired klass's
1132   // super_check_offset, for the desired klass.
1133   int sco_offset = in_bytes(Klass::super_check_offset_offset());
1134   Node* p3 = off_heap_plus_addr(dest_elem_klass, sco_offset);
1135   Node* n3 = new LoadINode(nullptr, *mem /*memory(p3)*/, p3, _igvn.type(p3)->is_ptr(), TypeInt::INT, MemNode::unordered);
1136   Node* check_offset = ConvI2X(transform_later(n3));
1137   Node* check_value  = dest_elem_klass;
1138 
1139   Node* src_start  = array_element_address(src,  src_offset,  T_OBJECT, false);
1140   Node* dest_start = array_element_address(dest, dest_offset, T_OBJECT, adr_type == TypeRawPtr::BOTTOM);
1141 
1142   const TypeFunc* call_type = OptoRuntime::checkcast_arraycopy_Type();
1143   Node* call = make_leaf_call(*ctrl, *mem, call_type, copyfunc_addr, "checkcast_arraycopy", adr_type,
1144                               src_start, dest_start, copy_length XTOP, check_offset XTOP, check_value);
1145 
1146   finish_arraycopy_call(call, ctrl, mem, adr_type);
1147 
1148   Node* proj =  new ProjNode(call, TypeFunc::Parms);
1149   transform_later(proj);
1150 
1151   return proj;
1152 }
1153 
1154 // Helper function; generates code for cases requiring runtime checks.
1155 Node* PhaseMacroExpand::generate_generic_arraycopy(Node** ctrl, MergeMemNode** mem,
1156                                                    const TypePtr* adr_type,
1157                                                    Node* src,  Node* src_offset,
1158                                                    Node* dest, Node* dest_offset,
1159                                                    Node* copy_length, bool dest_uninitialized) {
1160   if ((*ctrl)->is_top()) return nullptr;

1167 
1168   const TypeFunc* call_type = OptoRuntime::generic_arraycopy_Type();
1169   Node* call = make_leaf_call(*ctrl, *mem, call_type, copyfunc_addr, "generic_arraycopy", adr_type,
1170                               src, src_offset, dest, dest_offset, copy_length);
1171 
1172   finish_arraycopy_call(call, ctrl, mem, adr_type);
1173 
1174   Node* proj =  new ProjNode(call, TypeFunc::Parms);
1175   transform_later(proj);
1176 
1177   return proj;
1178 }
1179 
1180 // Helper function; generates the fast out-of-line call to an arraycopy stub.
1181 void PhaseMacroExpand::generate_unchecked_arraycopy(Node** ctrl, MergeMemNode** mem,
1182                                                     const TypePtr* adr_type,
1183                                                     BasicType basic_elem_type,
1184                                                     bool disjoint_bases,
1185                                                     Node* src,  Node* src_offset,
1186                                                     Node* dest, Node* dest_offset,
1187                                                     Node* copy_length, bool dest_uninitialized) {

1188   if ((*ctrl)->is_top()) {
1189     return;
1190   }
1191 
1192   Node* src_start  = src;
1193   Node* dest_start = dest;
1194   if (src_offset != nullptr || dest_offset != nullptr) {
1195     src_start =  array_element_address(src, src_offset, basic_elem_type, false);
1196     dest_start = array_element_address(dest, dest_offset, basic_elem_type, adr_type == TypeRawPtr::BOTTOM);
1197   }
1198 
1199   // Figure out which arraycopy runtime method to call.
1200   const char* copyfunc_name = "arraycopy";
1201   address     copyfunc_addr =
1202       basictype2arraycopy(basic_elem_type, src_offset, dest_offset,
1203                           disjoint_bases, copyfunc_name, dest_uninitialized);
1204 
1205   Node* result_memory = nullptr;
1206   RegionNode* exit_block = nullptr;
1207   if (ArrayOperationPartialInlineSize > 0 && is_subword_type(basic_elem_type) &&
1208     Matcher::vector_width_in_bytes(basic_elem_type) >= 16) {
1209     generate_partial_inlining_block(ctrl, mem, adr_type, &exit_block, &result_memory,
1210                                     copy_length, src_start, dest_start, basic_elem_type);
1211   }
1212 
1213   const TypeFunc* call_type = OptoRuntime::fast_arraycopy_Type();
1214   Node* call = make_leaf_call(*ctrl, *mem, call_type, copyfunc_addr, copyfunc_name, adr_type,
1215                               src_start, dest_start, copy_length XTOP);
1216 

1218 
1219   // Connecting remaining edges for exit_block coming from stub_block.
1220   if (exit_block) {
1221     exit_block->init_req(2, *ctrl);
1222 
1223     // Memory edge corresponding to stub_region.
1224     result_memory->init_req(2, *mem);
1225 
1226     uint alias_idx = C->get_alias_index(adr_type);
1227     if (alias_idx != Compile::AliasIdxBot) {
1228       *mem = MergeMemNode::make(*mem);
1229       (*mem)->set_memory_at(alias_idx, result_memory);
1230     } else {
1231       *mem = MergeMemNode::make(result_memory);
1232     }
1233     transform_later(*mem);
1234     *ctrl = exit_block;
1235   }
1236 }
1237 




































1238 #undef XTOP
1239 
1240 void PhaseMacroExpand::expand_arraycopy_node(ArrayCopyNode *ac) {
1241   Node* ctrl = ac->in(TypeFunc::Control);
1242   Node* io = ac->in(TypeFunc::I_O);
1243   Node* src = ac->in(ArrayCopyNode::Src);
1244   Node* src_offset = ac->in(ArrayCopyNode::SrcPos);
1245   Node* dest = ac->in(ArrayCopyNode::Dest);
1246   Node* dest_offset = ac->in(ArrayCopyNode::DestPos);
1247   Node* length = ac->in(ArrayCopyNode::Length);
1248   MergeMemNode* merge_mem = nullptr;
1249 
1250   if (ac->is_clonebasic()) {
1251     BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1252     bs->clone_at_expansion(this, ac);
1253     return;
1254   } else if (ac->is_copyof() || ac->is_copyofrange() || ac->is_clone_oop_array()) {
1255     Node* mem = ac->in(TypeFunc::Memory);
1256     merge_mem = MergeMemNode::make(mem);
1257     transform_later(merge_mem);













1258 
1259     AllocateArrayNode* alloc = nullptr;

1260     if (ac->is_alloc_tightly_coupled()) {
1261       alloc = AllocateArrayNode::Ideal_array_allocation(dest);
1262       assert(alloc != nullptr, "expect alloc");

1263     }
1264 
1265     const TypePtr* adr_type = _igvn.type(dest)->is_oopptr()->add_offset(Type::OffsetBot);
1266     if (ac->_dest_type != TypeOopPtr::BOTTOM) {
1267       adr_type = ac->_dest_type->add_offset(Type::OffsetBot)->is_ptr();



















1268     }



1269     generate_arraycopy(ac, alloc, &ctrl, merge_mem, &io,
1270                        adr_type, T_OBJECT,
1271                        src, src_offset, dest, dest_offset, length,
1272                        true, ac->has_negative_length_guard());

1273 
1274     return;
1275   }
1276 
1277   AllocateArrayNode* alloc = nullptr;
1278   if (ac->is_alloc_tightly_coupled()) {
1279     alloc = AllocateArrayNode::Ideal_array_allocation(dest);
1280     assert(alloc != nullptr, "expect alloc");
1281   }
1282 
1283   assert(ac->is_arraycopy() || ac->is_arraycopy_validated(), "should be an arraycopy");
1284 
1285   // Compile time checks.  If any of these checks cannot be verified at compile time,
1286   // we do not make a fast path for this call.  Instead, we let the call remain as it
1287   // is.  The checks we choose to mandate at compile time are:
1288   //
1289   // (1) src and dest are arrays.
1290   const Type* src_type = src->Value(&_igvn);
1291   const Type* dest_type = dest->Value(&_igvn);
1292   const TypeAryPtr* top_src = src_type->isa_aryptr();
1293   const TypeAryPtr* top_dest = dest_type->isa_aryptr();
1294 
1295   BasicType src_elem = T_CONFLICT;
1296   BasicType dest_elem = T_CONFLICT;
1297 
1298   if (top_src != nullptr && top_src->elem() != Type::BOTTOM) {
1299     src_elem = top_src->elem()->array_element_basic_type();
1300   }
1301   if (top_dest != nullptr && top_dest->elem() != Type::BOTTOM) {
1302     dest_elem = top_dest->elem()->array_element_basic_type();
1303   }
1304   if (is_reference_type(src_elem, true)) src_elem = T_OBJECT;
1305   if (is_reference_type(dest_elem, true)) dest_elem = T_OBJECT;
1306 
1307   if (ac->is_arraycopy_validated() &&
1308       dest_elem != T_CONFLICT &&
1309       src_elem == T_CONFLICT) {
1310     src_elem = dest_elem;
1311   }
1312 
1313   if (src_elem == T_CONFLICT || dest_elem == T_CONFLICT) {
1314     // Conservatively insert a memory barrier on all memory slices.
1315     // Do not let writes into the source float below the arraycopy.
1316     {
1317       Node* mem = ac->in(TypeFunc::Memory);
1318       insert_mem_bar(&ctrl, &mem, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1319 
1320       merge_mem = MergeMemNode::make(mem);
1321       transform_later(merge_mem);
1322     }
1323 
1324     // Call StubRoutines::generic_arraycopy stub.
1325     Node* mem = generate_arraycopy(ac, nullptr, &ctrl, merge_mem, &io,
1326                                    TypeRawPtr::BOTTOM, T_CONFLICT,
1327                                    src, src_offset, dest, dest_offset, length,
1328                                    // If a  negative length guard was generated for the ArrayCopyNode,
1329                                    // the length of the array can never be negative.
1330                                    false, ac->has_negative_length_guard());

1331     return;
1332   }
1333 
1334   assert(!ac->is_arraycopy_validated() || (src_elem == dest_elem && dest_elem != T_VOID), "validated but different basic types");
1335 
1336   // (2) src and dest arrays must have elements of the same BasicType
1337   // Figure out the size and type of the elements we will be copying.
1338   if (src_elem != dest_elem || dest_elem == T_VOID) {







1339     // The component types are not the same or are not recognized.  Punt.
1340     // (But, avoid the native method wrapper to JVM_ArrayCopy.)
1341     {
1342       Node* mem = ac->in(TypeFunc::Memory);
1343       merge_mem = generate_slow_arraycopy(ac, &ctrl, mem, &io, TypePtr::BOTTOM, src, src_offset, dest, dest_offset, length, false);
1344     }
1345 
1346     _igvn.replace_node(_callprojs.fallthrough_memproj, merge_mem);
1347     if (_callprojs.fallthrough_ioproj != nullptr) {
1348       _igvn.replace_node(_callprojs.fallthrough_ioproj, io);
1349     }
1350     _igvn.replace_node(_callprojs.fallthrough_catchproj, ctrl);
1351     return;
1352   }
1353 
1354   //---------------------------------------------------------------------------
1355   // We will make a fast path for this call to arraycopy.
1356 
1357   // We have the following tests left to perform:
1358   //
1359   // (3) src and dest must not be null.
1360   // (4) src_offset must not be negative.
1361   // (5) dest_offset must not be negative.
1362   // (6) length must not be negative.
1363   // (7) src_offset + length must not exceed length of src.
1364   // (8) dest_offset + length must not exceed length of dest.
1365   // (9) each element of an oop array must be assignable
1366 
1367   {
1368     Node* mem = ac->in(TypeFunc::Memory);
1369     merge_mem = MergeMemNode::make(mem);
1370     transform_later(merge_mem);





1371   }


1372 
1373   RegionNode* slow_region = new RegionNode(1);
1374   transform_later(slow_region);
1375 
1376   if (!ac->is_arraycopy_validated()) {
1377     // (3) operands must not be null
1378     // We currently perform our null checks with the null_check routine.
1379     // This means that the null exceptions will be reported in the caller
1380     // rather than (correctly) reported inside of the native arraycopy call.
1381     // This should be corrected, given time.  We do our null check with the
1382     // stack pointer restored.
1383     // null checks done library_call.cpp
1384 
1385     // (4) src_offset must not be negative.
1386     generate_negative_guard(&ctrl, src_offset, slow_region);
1387 
1388     // (5) dest_offset must not be negative.
1389     generate_negative_guard(&ctrl, dest_offset, slow_region);
1390 
1391     // (6) length must not be negative (moved to generate_arraycopy()).
1392     // generate_negative_guard(length, slow_region);
1393 
1394     // (7) src_offset + length must not exceed length of src.
1395     Node* alen = ac->in(ArrayCopyNode::SrcLen);
1396     assert(alen != nullptr, "need src len");
1397     generate_limit_guard(&ctrl,
1398                          src_offset, length,
1399                          alen,
1400                          slow_region);
1401 
1402     // (8) dest_offset + length must not exceed length of dest.
1403     alen = ac->in(ArrayCopyNode::DestLen);
1404     assert(alen != nullptr, "need dest len");
1405     generate_limit_guard(&ctrl,
1406                          dest_offset, length,
1407                          alen,
1408                          slow_region);
1409 
1410     // (9) each element of an oop array must be assignable
1411     // The generate_arraycopy subroutine checks this.








1412   }

1413   // This is where the memory effects are placed:
1414   const TypePtr* adr_type = nullptr;
1415   if (ac->_dest_type != TypeOopPtr::BOTTOM) {




1416     adr_type = ac->_dest_type->add_offset(Type::OffsetBot)->is_ptr();
1417   } else {
1418     adr_type = TypeAryPtr::get_array_body_type(dest_elem);
1419   }
1420 
1421   generate_arraycopy(ac, alloc, &ctrl, merge_mem, &io,
1422                      adr_type, dest_elem,
1423                      src, src_offset, dest, dest_offset, length,

1424                      // If a  negative length guard was generated for the ArrayCopyNode,
1425                      // the length of the array can never be negative.
1426                      false, ac->has_negative_length_guard(), slow_region);

1427 }

   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 "gc/shared/barrierSet.hpp"
  27 #include "gc/shared/tlab_globals.hpp"
  28 #include "oops/objArrayKlass.hpp"
  29 #include "opto/arraycopynode.hpp"
  30 #include "opto/castnode.hpp"
  31 #include "opto/convertnode.hpp"
  32 #include "opto/graphKit.hpp"
  33 #include "opto/macro.hpp"
  34 #include "opto/runtime.hpp"
  35 #include "opto/vectornode.hpp"
  36 #include "runtime/stubRoutines.hpp"
  37 #include "utilities/align.hpp"
  38 #include "utilities/powerOfTwo.hpp"
  39 
  40 void PhaseMacroExpand::insert_mem_bar(Node** ctrl, Node** mem, int opcode, int alias_idx, Node* precedent) {
  41   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
  42   mb->init_req(TypeFunc::Control, *ctrl);
  43   mb->init_req(TypeFunc::Memory, *mem);
  44   transform_later(mb);
  45   *ctrl = new ProjNode(mb,TypeFunc::Control);
  46   transform_later(*ctrl);
  47   Node* mem_proj = new ProjNode(mb,TypeFunc::Memory);
  48   transform_later(mem_proj);
  49   if (alias_idx == Compile::AliasIdxBot) {
  50     *mem = mem_proj;
  51   } else {
  52     MergeMemNode* mm = (*mem)->clone()->as_MergeMem();
  53     mm->set_memory_at(alias_idx, mem_proj);
  54     transform_later(mm);
  55     *mem = mm;
  56   }
  57 }
  58 
  59 Node* PhaseMacroExpand::array_element_address(Node* ary, Node* idx, BasicType elembt, bool raw_base) {
  60   uint shift  = exact_log2(type2aelembytes(elembt));
  61   const TypeAryPtr* array_type = _igvn.type(ary)->isa_aryptr();
  62   if (array_type != nullptr && array_type->is_aryptr()->is_flat()) {
  63     // Use T_FLAT_ELEMENT to get proper alignment with COH when fetching the array element address.
  64     elembt = T_FLAT_ELEMENT;
  65   }
  66   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
  67   Node* base =  basic_plus_adr(ary, header, raw_base);
  68 #ifdef _LP64
  69   // see comment in GraphKit::array_element_address
  70   int index_max = max_jint - 1;  // array size is max_jint, index is one less
  71   const TypeLong* lidxtype = TypeLong::make(CONST64(0), index_max, Type::WidenMax);
  72   idx = transform_later( new ConvI2LNode(idx, lidxtype) );
  73 #endif
  74   Node* scale = new LShiftXNode(idx, intcon(shift));
  75   transform_later(scale);
  76   return basic_plus_adr(raw_base ? top() : ary, base, scale);
  77 }
  78 
  79 Node* PhaseMacroExpand::ConvI2L(Node* offset) {
  80   return transform_later(new ConvI2LNode(offset));
  81 }
  82 
  83 Node* PhaseMacroExpand::make_leaf_call(Node* ctrl, Node* mem,
  84                                        const TypeFunc* call_type, address call_addr,
  85                                        const char* call_name,

 134   }
 135 
 136   IfNode* iff = new IfNode(*ctrl, test, true_prob, COUNT_UNKNOWN);
 137   transform_later(iff);
 138 
 139   Node* if_slow = new IfTrueNode(iff);
 140   transform_later(if_slow);
 141 
 142   if (region != nullptr) {
 143     region->add_req(if_slow);
 144   }
 145 
 146   Node* if_fast = new IfFalseNode(iff);
 147   transform_later(if_fast);
 148 
 149   *ctrl = if_fast;
 150 
 151   return if_slow;
 152 }
 153 
 154 Node* PhaseMacroExpand::generate_slow_guard(Node** ctrl, Node* test, RegionNode* region) {
 155   return generate_guard(ctrl, test, region, PROB_UNLIKELY_MAG(3));
 156 }
 157 
 158 inline Node* PhaseMacroExpand::generate_fair_guard(Node** ctrl, Node* test, RegionNode* region) {
 159   return generate_guard(ctrl, test, region, PROB_FAIR);
 160 }
 161 
 162 void PhaseMacroExpand::generate_negative_guard(Node** ctrl, Node* index, RegionNode* region) {
 163   if ((*ctrl)->is_top())
 164     return;                // already stopped
 165   if (_igvn.type(index)->higher_equal(TypeInt::POS)) // [0,maxint]
 166     return;                // index is already adequately typed
 167   Node* cmp_lt = new CmpINode(index, intcon(0));
 168   transform_later(cmp_lt);
 169   Node* bol_lt = new BoolNode(cmp_lt, BoolTest::lt);
 170   transform_later(bol_lt);
 171   generate_guard(ctrl, bol_lt, region, PROB_MIN);
 172 }
 173 
 174 void PhaseMacroExpand::generate_limit_guard(Node** ctrl, Node* offset, Node* subseq_length, Node* array_length, RegionNode* region) {
 175   if ((*ctrl)->is_top())
 176     return;                // already stopped
 177   bool zero_offset = _igvn.type(offset) == TypeInt::ZERO;
 178   if (zero_offset && subseq_length->eqv_uncast(array_length))
 179     return;                // common case of whole-array copy
 180   Node* last = subseq_length;
 181   if (!zero_offset) {            // last += offset

 275 
 276   *ctrl = stub_block;
 277 }
 278 
 279 
 280 Node* PhaseMacroExpand::generate_nonpositive_guard(Node** ctrl, Node* index, bool never_negative) {
 281   if ((*ctrl)->is_top())  return nullptr;
 282 
 283   if (_igvn.type(index)->higher_equal(TypeInt::POS1)) // [1,maxint]
 284     return nullptr;                // index is already adequately typed
 285   Node* cmp_le = new CmpINode(index, intcon(0));
 286   transform_later(cmp_le);
 287   BoolTest::mask le_or_eq = (never_negative ? BoolTest::eq : BoolTest::le);
 288   Node* bol_le = new BoolNode(cmp_le, le_or_eq);
 289   transform_later(bol_le);
 290   Node* is_notp = generate_guard(ctrl, bol_le, nullptr, PROB_MIN);
 291 
 292   return is_notp;
 293 }
 294 
 295 Node* PhaseMacroExpand::mark_word_test(Node** ctrl, Node* obj, MergeMemNode* mem, uintptr_t mask_val, RegionNode* region) {
 296   // Load markword and check if obj is locked
 297   Node* mark = make_load_raw(nullptr, mem->memory_at(Compile::AliasIdxRaw), obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
 298   Node* locked_bit = MakeConX(markWord::unlocked_value);
 299   locked_bit = transform_later(new AndXNode(locked_bit, mark));
 300   Node* cmp = transform_later(new CmpXNode(locked_bit, MakeConX(0)));
 301   Node* is_unlocked = transform_later(new BoolNode(cmp, BoolTest::ne));
 302   IfNode* iff = transform_later(new IfNode(*ctrl, is_unlocked, PROB_MAX, COUNT_UNKNOWN))->as_If();
 303   Node* locked_region = transform_later(new RegionNode(3));
 304   Node* mark_phi = transform_later(new PhiNode(locked_region, TypeX_X));
 305 
 306   // Unlocked: Use bits from mark word
 307   locked_region->init_req(1, transform_later(new IfTrueNode(iff)));
 308   mark_phi->init_req(1, mark);
 309 
 310   // Locked: Load prototype header from klass
 311   *ctrl = transform_later(new IfFalseNode(iff));
 312   // Make loads control dependent to make sure they are only executed if array is locked
 313   Node* klass_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
 314   Node* klass = transform_later(LoadKlassNode::make(_igvn, C->immutable_memory(), klass_adr, TypeInstPtr::KLASS, TypeInstKlassPtr::OBJECT));
 315   Node* proto_adr = basic_plus_adr(top(), klass, in_bytes(Klass::prototype_header_offset()));
 316   Node* proto = transform_later(LoadNode::make(_igvn, *ctrl, C->immutable_memory(), proto_adr, proto_adr->bottom_type()->is_ptr(), TypeX_X, TypeX_X->basic_type(), MemNode::unordered));
 317 
 318   locked_region->init_req(2, *ctrl);
 319   mark_phi->init_req(2, proto);
 320   *ctrl = locked_region;
 321 
 322   // Now check if mark word bits are set
 323   Node* mask = MakeConX(mask_val);
 324   Node* masked = transform_later(new AndXNode(mark_phi, mask));
 325   cmp = transform_later(new CmpXNode(masked, mask));
 326   Node* bol = transform_later(new BoolNode(cmp, BoolTest::eq));
 327   return generate_fair_guard(ctrl, bol, region);
 328 }
 329 
 330 Node* PhaseMacroExpand::generate_flat_array_guard(Node** ctrl, Node* array, MergeMemNode* mem, RegionNode* region) {
 331   return mark_word_test(ctrl, array, mem, markWord::flat_array_bit_in_place, region);
 332 }
 333 
 334 Node* PhaseMacroExpand::generate_null_free_array_guard(Node** ctrl, Node* array, MergeMemNode* mem, RegionNode* region) {
 335   return mark_word_test(ctrl, array, mem, markWord::null_free_array_bit_in_place, region);
 336 }
 337 
 338 void PhaseMacroExpand::finish_arraycopy_call(Node* call, Node** ctrl, MergeMemNode** mem, const TypePtr* adr_type) {
 339   transform_later(call);
 340 
 341   *ctrl = new ProjNode(call,TypeFunc::Control);
 342   transform_later(*ctrl);
 343   Node* newmem = new ProjNode(call, TypeFunc::Memory);
 344   transform_later(newmem);
 345 
 346   uint alias_idx = C->get_alias_index(adr_type);
 347   if (alias_idx != Compile::AliasIdxBot) {
 348     *mem = MergeMemNode::make(*mem);
 349     (*mem)->set_memory_at(alias_idx, newmem);
 350   } else {
 351     *mem = MergeMemNode::make(newmem);
 352   }
 353   transform_later(*mem);
 354 }
 355 
 356 address PhaseMacroExpand::basictype2arraycopy(BasicType t,
 357                                               Node* src_offset,

 412 //       }
 413 //     }
 414 //     // adjust params for remaining work:
 415 //     if (slowval != -1) {
 416 //       n = -1^slowval; src_offset += n; dest_offset += n; length -= n
 417 //     }
 418 //   slow_region:
 419 //     call slow arraycopy(src, src_offset, dest, dest_offset, length)
 420 //     return  // via slow_call_path
 421 //
 422 // This routine is used from several intrinsics:  System.arraycopy,
 423 // Object.clone (the array subcase), and Arrays.copyOf[Range].
 424 //
 425 Node* PhaseMacroExpand::generate_arraycopy(ArrayCopyNode *ac, AllocateArrayNode* alloc,
 426                                            Node** ctrl, MergeMemNode* mem, Node** io,
 427                                            const TypePtr* adr_type,
 428                                            BasicType basic_elem_type,
 429                                            Node* src,  Node* src_offset,
 430                                            Node* dest, Node* dest_offset,
 431                                            Node* copy_length,
 432                                            Node* dest_length,
 433                                            bool raw_base,
 434                                            bool disjoint_bases,
 435                                            bool length_never_negative,
 436                                            RegionNode* slow_region) {
 437   Node* orig_dest = dest;
 438   if (slow_region == nullptr) {
 439     slow_region = new RegionNode(1);
 440     transform_later(slow_region);
 441   }
 442 
 443   bool  dest_needs_zeroing   = false;
 444   bool  acopy_to_uninitialized = false;
 445   Node* init_value = nullptr;
 446   Node* raw_init_value = nullptr;
 447 
 448   // See if this is the initialization of a newly-allocated array.
 449   // If so, we will take responsibility here for initializing it to zero.
 450   // (Note:  Because tightly_coupled_allocation performs checks on the
 451   // out-edges of the dest, we need to avoid making derived pointers
 452   // from it until we have checked its uses.)
 453   if (ReduceBulkZeroing
 454       && !(UseTLAB && ZeroTLAB) // pointless if already zeroed
 455       && basic_elem_type != T_CONFLICT // avoid corner case
 456       && !src->eqv_uncast(dest)
 457       && alloc != nullptr
 458       && _igvn.find_int_con(alloc->in(AllocateNode::ALength), 1) > 0) {
 459     assert(ac->is_alloc_tightly_coupled(), "sanity");
 460     // acopy to uninitialized tightly coupled allocations
 461     // needs zeroing outside the copy range
 462     // and the acopy itself will be to uninitialized memory
 463     acopy_to_uninitialized = true;
 464     if (alloc->maybe_set_complete(&_igvn)) {
 465       // "You break it, you buy it."
 466       InitializeNode* init = alloc->initialization();
 467       assert(init->is_complete(), "we just did this");
 468       init->set_complete_with_arraycopy();
 469       assert(dest->is_CheckCastPP(), "sanity");
 470       assert(dest->in(0)->in(0) == init, "dest pinned");
 471       adr_type = TypeRawPtr::BOTTOM;  // all initializations are into raw memory
 472       raw_base = true;
 473       dest = dest->in(1); // writing to raw memory requires a raw base
 474       // From this point on, every exit path is responsible for
 475       // initializing any non-copied parts of the object to zero.
 476       // Also, if this flag is set we make sure that arraycopy interacts properly
 477       // with G1, eliding pre-barriers. See CR 6627983.
 478       dest_needs_zeroing = true;
 479       init_value = alloc->in(AllocateNode::InitValue);
 480       raw_init_value = alloc->in(AllocateNode::RawInitValue);
 481     } else {
 482       // dest_need_zeroing = false;
 483     }
 484   } else {
 485     // No zeroing elimination needed here.
 486     alloc                  = nullptr;
 487     acopy_to_uninitialized = false;
 488     //dest_needs_zeroing   = false;
 489   }
 490 
 491   uint alias_idx = C->get_alias_index(adr_type);
 492 
 493   // Results are placed here:
 494   enum { fast_path        = 1,  // normal void-returning assembly stub
 495          checked_path     = 2,  // special assembly stub with cleanup
 496          slow_call_path   = 3,  // something went wrong; call the VM
 497          zero_path        = 4,  // bypass when length of copy is zero
 498          bcopy_path       = 5,  // copy primitive array by 64-bit blocks
 499          PATH_LIMIT       = 6
 500   };

 529     checked_i_o     = *io;
 530     checked_mem     = mem->memory_at(alias_idx);
 531     checked_value   = cv;
 532     *ctrl = top();
 533   }
 534 
 535   Node* not_pos = generate_nonpositive_guard(ctrl, copy_length, length_never_negative);
 536   if (not_pos != nullptr) {
 537     Node* local_ctrl = not_pos, *local_io = *io;
 538     MergeMemNode* local_mem = MergeMemNode::make(mem);
 539     transform_later(local_mem);
 540 
 541     // (6) length must not be negative.
 542     if (!length_never_negative) {
 543       generate_negative_guard(&local_ctrl, copy_length, slow_region);
 544     }
 545 
 546     // copy_length is 0.
 547     if (dest_needs_zeroing) {
 548       assert(!local_ctrl->is_top(), "no ctrl?");

 549       if (copy_length->eqv_uncast(dest_length)
 550           || _igvn.find_int_con(dest_length, 1) <= 0) {
 551         // There is no zeroing to do. No need for a secondary raw memory barrier.
 552       } else {
 553         // Clear the whole thing since there are no source elements to copy.
 554         generate_clear_array(local_ctrl, local_mem,
 555                              adr_type, dest,
 556                              init_value, raw_init_value,
 557                              basic_elem_type,
 558                              intcon(0), nullptr,
 559                              alloc->in(AllocateNode::AllocSize), raw_base);
 560         // Use a secondary InitializeNode as raw memory barrier.
 561         // Currently it is needed only on this path since other
 562         // paths have stub or runtime calls as raw memory barriers.
 563         MemBarNode* mb = MemBarNode::make(C, Op_Initialize,
 564                                           Compile::AliasIdxRaw,
 565                                           top());
 566         transform_later(mb);
 567         mb->set_req(TypeFunc::Control,local_ctrl);
 568         mb->set_req(TypeFunc::Memory, local_mem->memory_at(Compile::AliasIdxRaw));
 569         local_ctrl = transform_later(new ProjNode(mb, TypeFunc::Control));
 570         local_mem->set_memory_at(Compile::AliasIdxRaw, transform_later(new ProjNode(mb, TypeFunc::Memory)));
 571 
 572         InitializeNode* init = mb->as_Initialize();
 573         init->set_complete(&_igvn);  // (there is no corresponding AllocateNode)
 574       }
 575     }
 576 
 577     // Present the results of the fast call.
 578     result_region->init_req(zero_path, local_ctrl);
 579     result_i_o   ->init_req(zero_path, local_io);
 580     result_memory->init_req(zero_path, local_mem->memory_at(alias_idx));
 581   }
 582 
 583   if (!(*ctrl)->is_top() && dest_needs_zeroing) {
 584     // We have to initialize the *uncopied* part of the array to zero.
 585     // The copy destination is the slice dest[off..off+len].  The other slices
 586     // are dest_head = dest[0..off] and dest_tail = dest[off+len..dest.length].
 587     Node* dest_size   = alloc->in(AllocateNode::AllocSize);

 588     Node* dest_tail   = transform_later( new AddINode(dest_offset, copy_length));
 589 
 590     // If there is a head section that needs zeroing, do it now.
 591     if (_igvn.find_int_con(dest_offset, -1) != 0) {
 592       generate_clear_array(*ctrl, mem,
 593                            adr_type, dest,
 594                            init_value, raw_init_value,
 595                            basic_elem_type,
 596                            intcon(0), dest_offset,
 597                            nullptr, raw_base);
 598     }
 599 
 600     // Next, perform a dynamic check on the tail length.
 601     // It is often zero, and we can win big if we prove this.
 602     // There are two wins:  Avoid generating the ClearArray
 603     // with its attendant messy index arithmetic, and upgrade
 604     // the copy to a more hardware-friendly word size of 64 bits.
 605     Node* tail_ctl = nullptr;
 606     if (!(*ctrl)->is_top() && !dest_tail->eqv_uncast(dest_length)) {
 607       Node* cmp_lt   = transform_later( new CmpINode(dest_tail, dest_length) );
 608       Node* bol_lt   = transform_later( new BoolNode(cmp_lt, BoolTest::lt) );
 609       tail_ctl = generate_slow_guard(ctrl, bol_lt, nullptr);
 610       assert(tail_ctl != nullptr || !(*ctrl)->is_top(), "must be an outcome");
 611     }
 612 
 613     // At this point, let's assume there is no tail.
 614     if (!(*ctrl)->is_top() && alloc != nullptr && basic_elem_type != T_OBJECT) {
 615       // There is no tail.  Try an upgrade to a 64-bit copy.
 616       bool didit = false;
 617       {
 618         Node* local_ctrl = *ctrl, *local_io = *io;
 619         MergeMemNode* local_mem = MergeMemNode::make(mem);
 620         transform_later(local_mem);
 621 
 622         didit = generate_block_arraycopy(&local_ctrl, &local_mem, adr_type,
 623                                          basic_elem_type, src, src_offset,
 624                                          dest, dest_offset, dest_size, acopy_to_uninitialized, raw_base);
 625         if (didit) {
 626           // Present the results of the block-copying fast call.
 627           result_region->init_req(bcopy_path, local_ctrl);
 628           result_i_o   ->init_req(bcopy_path, local_io);
 629           result_memory->init_req(bcopy_path, local_mem->memory_at(alias_idx));
 630         }
 631       }
 632       if (didit) {
 633         *ctrl = top();     // no regular fast path
 634       }
 635     }
 636 
 637     // Clear the tail, if any.
 638     if (tail_ctl != nullptr) {
 639       Node* notail_ctl = (*ctrl)->is_top() ? nullptr : *ctrl;
 640       *ctrl = tail_ctl;
 641       if (notail_ctl == nullptr) {
 642         generate_clear_array(*ctrl, mem,
 643                              adr_type, dest,
 644                              init_value, raw_init_value,
 645                              basic_elem_type,
 646                              dest_tail, nullptr,
 647                              dest_size, raw_base);
 648       } else {
 649         // Make a local merge.
 650         Node* done_ctl = transform_later(new RegionNode(3));
 651         Node* done_mem = transform_later(new PhiNode(done_ctl, Type::MEMORY, adr_type));
 652         done_ctl->init_req(1, notail_ctl);
 653         done_mem->init_req(1, mem->memory_at(alias_idx));
 654         generate_clear_array(*ctrl, mem,
 655                              adr_type, dest,
 656                              init_value, raw_init_value,
 657                              basic_elem_type,
 658                              dest_tail, nullptr,
 659                              dest_size, raw_base);
 660         done_ctl->init_req(2, *ctrl);
 661         done_mem->init_req(2, mem->memory_at(alias_idx));
 662         *ctrl = done_ctl;
 663         mem->set_memory_at(alias_idx, done_mem);
 664       }
 665     }
 666   }
 667 
 668   BasicType copy_type = basic_elem_type;
 669   assert(basic_elem_type != T_ARRAY, "caller must fix this");
 670   if (!(*ctrl)->is_top() && copy_type == T_OBJECT) {
 671     // If src and dest have compatible element types, we can copy bits.
 672     // Types S[] and D[] are compatible if D is a supertype of S.
 673     //
 674     // If they are not, we will use checked_oop_disjoint_arraycopy,
 675     // which performs a fast optimistic per-oop check, and backs off
 676     // further to JVM_ArrayCopy on the first per-oop check that fails.
 677     // (Actually, we don't move raw bits only; the GC requires card marks.)
 678 
 679     // We don't need a subtype check for validated copies and Object[].clone()

 696       //
 697       // Test S[] against D[], not S against D, because (probably)
 698       // the secondary supertype cache is less busy for S[] than S.
 699       // This usually only matters when D is an interface.
 700       Node* not_subtype_ctrl = Phase::gen_subtype_check(src_klass, dest_klass, ctrl, mem, _igvn, nullptr, -1);
 701       // Plug failing path into checked_oop_disjoint_arraycopy
 702       if (not_subtype_ctrl != top()) {
 703         Node* local_ctrl = not_subtype_ctrl;
 704         MergeMemNode* local_mem = MergeMemNode::make(mem);
 705         transform_later(local_mem);
 706 
 707         // (At this point we can assume disjoint_bases, since types differ.)
 708         int ek_offset = in_bytes(ObjArrayKlass::element_klass_offset());
 709         Node* p1 = off_heap_plus_addr(dest_klass, ek_offset);
 710         Node* n1 = LoadKlassNode::make(_igvn, C->immutable_memory(), p1, TypeRawPtr::BOTTOM);
 711         Node* dest_elem_klass = transform_later(n1);
 712         Node* cv = generate_checkcast_arraycopy(&local_ctrl, &local_mem,
 713                                                 adr_type,
 714                                                 dest_elem_klass,
 715                                                 src, src_offset, dest, dest_offset,
 716                                                 ConvI2X(copy_length), acopy_to_uninitialized, raw_base);
 717         if (cv == nullptr)  cv = intcon(-1);  // failure (no stub available)
 718         checked_control = local_ctrl;
 719         checked_i_o     = *io;
 720         checked_mem     = local_mem->memory_at(alias_idx);
 721         checked_value   = cv;
 722       }
 723     }
 724     // At this point we know we do not need type checks on oop stores.
 725 
 726     BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 727     if (!bs->array_copy_requires_gc_barriers(alloc != nullptr, copy_type, false, false, BarrierSetC2::Expansion)) {
 728       // If we do not need gc barriers, copy using the jint or jlong stub.
 729       copy_type = LP64_ONLY(UseCompressedOops ? T_INT : T_LONG) NOT_LP64(T_INT);
 730       assert(type2aelembytes(basic_elem_type) == type2aelembytes(copy_type),
 731              "sizes agree");
 732     }
 733   }
 734 
 735   if (!(*ctrl)->is_top()) {
 736     // Generate the fast path, if possible.
 737     Node* local_ctrl = *ctrl;
 738     MergeMemNode* local_mem = MergeMemNode::make(mem);
 739     transform_later(local_mem);
 740     generate_unchecked_arraycopy(&local_ctrl, &local_mem,
 741                                  adr_type, copy_type, disjoint_bases,
 742                                  src, src_offset, dest, dest_offset,
 743                                  ConvI2X(copy_length), acopy_to_uninitialized,
 744                                  raw_base);
 745 
 746     // Present the results of the fast call.
 747     result_region->init_req(fast_path, local_ctrl);
 748     result_i_o   ->init_req(fast_path, *io);
 749     result_memory->init_req(fast_path, local_mem->memory_at(alias_idx));
 750   }
 751 
 752   // Here are all the slow paths up to this point, in one bundle:
 753   assert(slow_region != nullptr, "allocated on entry");
 754   slow_control = slow_region;
 755   DEBUG_ONLY(slow_region = (RegionNode*)badAddress);
 756 
 757   *ctrl = checked_control;
 758   if (!(*ctrl)->is_top()) {
 759     // Clean up after the checked call.
 760     // The returned value is either 0 or -1^K,
 761     // where K = number of partially transferred array elements.
 762     Node* cmp = new CmpINode(checked_value, intcon(0));
 763     transform_later(cmp);
 764     Node* bol = new BoolNode(cmp, BoolTest::eq);

 815       Node* length_minus  = new SubINode(copy_length, slow_offset);
 816       transform_later(length_minus);
 817 
 818       // Tweak the node variables to adjust the code produced below:
 819       src_offset  = src_off_plus;
 820       dest_offset = dest_off_plus;
 821       copy_length = length_minus;
 822     }
 823   }
 824   *ctrl = slow_control;
 825   if (!(*ctrl)->is_top()) {
 826     Node* local_ctrl = *ctrl, *local_io = slow_i_o;
 827     MergeMemNode* local_mem = MergeMemNode::make(mem);
 828     transform_later(local_mem);
 829 
 830     // Generate the slow path, if needed.
 831     local_mem->set_memory_at(alias_idx, slow_mem);
 832 
 833     if (dest_needs_zeroing) {
 834       generate_clear_array(local_ctrl, local_mem,
 835                            adr_type, dest,
 836                            init_value, raw_init_value,
 837                            basic_elem_type,
 838                            intcon(0), nullptr,
 839                            alloc->in(AllocateNode::AllocSize),
 840                            raw_base);
 841     }
 842 
 843     local_mem = generate_slow_arraycopy(ac,
 844                                         &local_ctrl, local_mem, &local_io,
 845                                         adr_type,
 846                                         src, src_offset, orig_dest, dest_offset,
 847                                         copy_length, /*dest_uninitialized*/false);
 848 
 849     result_region->init_req(slow_call_path, local_ctrl);
 850     result_i_o   ->init_req(slow_call_path, local_io);
 851     result_memory->init_req(slow_call_path, local_mem->memory_at(alias_idx));
 852   } else {
 853     ShouldNotReachHere(); // no call to generate_slow_arraycopy:
 854                           // projections were not extracted
 855   }
 856 
 857   // Remove unused edges.
 858   for (uint i = 1; i < result_region->req(); i++) {
 859     if (result_region->in(i) == nullptr) {
 860       result_region->init_req(i, top());
 861     }
 862   }
 863 
 864   // Finished; return the combined state.
 865   *ctrl = result_region;
 866   *io = result_i_o;
 867   mem->set_memory_at(alias_idx, result_memory);
 868 
 869   // mem no longer guaranteed to stay a MergeMemNode
 870   Node* out_mem = mem;
 871   DEBUG_ONLY(mem = nullptr);
 872 
 873   // The memory edges above are precise in order to model effects around
 874   // array copies accurately to allow value numbering of field loads around
 875   // arraycopy.  Such field loads, both before and after, are common in Java
 876   // collections and similar classes involving header/array data structures.
 877   //
 878   // But with low number of register or when some registers are used or killed
 879   // by arraycopy calls it causes registers spilling on stack. See 6544710.
 880   // The next memory barrier is added to avoid it. If the arraycopy can be
 881   // optimized away (which it can, sometimes) then we can manually remove  // Do not let reads from the cloned object float above the arrayco
 882   // the membar also.
 883   //
 884   // Do not let reads from the cloned object float above the arraycopy.
 885   if (alloc != nullptr && !alloc->initialization()->does_not_escape()) {
 886     // Do not let stores that initialize this object be reordered with
 887     // a subsequent store that would make this object accessible by
 888     // other threads.
 889     assert(ac->_dest_type == TypeOopPtr::BOTTOM, "non escaping destination shouldn't have narrow slice");
 890     insert_mem_bar(ctrl, &out_mem, Op_MemBarStoreStore, Compile::AliasIdxBot);
 891   } else {
 892     int mem_bar_alias_idx = Compile::AliasIdxBot;
 893     if (ac->_dest_type != TypeOopPtr::BOTTOM) {
 894       // The graph was transformed under the assumption the ArrayCopy node only had an effect on a narrow slice. We can't
 895       // insert a wide membar now that it's being expanded: a load that uses the input memory state of the ArrayCopy
 896       // could then become anti dependent on the membar when it was not anti dependent on the ArrayCopy leading to a
 897       // broken graph.
 898       mem_bar_alias_idx = C->get_alias_index(ac->_dest_type->add_offset(Type::OffsetBot)->is_ptr());
 899     }
 900     insert_mem_bar(ctrl, &out_mem, Op_MemBarCPUOrder, mem_bar_alias_idx);
 901   }
 902 
 903   assert((*ctrl)->is_Proj(), "MemBar control projection");
 904   assert((*ctrl)->in(0)->isa_MemBar(), "MemBar node");
 905   (*ctrl)->in(0)->isa_MemBar()->set_trailing_expanded_array_copy();
 906 
 907   _igvn.replace_node(_callprojs->fallthrough_memproj, out_mem);
 908   if (_callprojs->fallthrough_ioproj != nullptr) {
 909     _igvn.replace_node(_callprojs->fallthrough_ioproj, *io);
 910   }
 911   _igvn.replace_node(_callprojs->fallthrough_catchproj, *ctrl);
 912 
 913 #ifdef ASSERT
 914   const TypeOopPtr* dest_t = _igvn.type(orig_dest)->is_oopptr();
 915   if (dest_t->is_known_instance()) {
 916     ArrayCopyNode* ac = nullptr;
 917     assert(ArrayCopyNode::may_modify(dest_t, (*ctrl)->in(0)->as_MemBar(), &_igvn, ac), "dependency on arraycopy lost");
 918     assert(ac == nullptr, "no arraycopy anymore");
 919   }
 920 #endif
 921 
 922   return out_mem;
 923 }
 924 
 925 // Helper for initialization of arrays, creating a ClearArray.
 926 // It writes zero bits in [start..end), within the body of an array object.
 927 // The memory effects are all chained onto the 'adr_type' alias category.
 928 //
 929 // Since the object is otherwise uninitialized, we are free
 930 // to put a little "slop" around the edges of the cleared area,
 931 // as long as it does not go back into the array's header,
 932 // or beyond the array end within the heap.
 933 //
 934 // The lower edge can be rounded down to the nearest jint and the
 935 // upper edge can be rounded up to the nearest MinObjAlignmentInBytes.
 936 //
 937 // Arguments:
 938 //   adr_type           memory slice where writes are generated
 939 //   dest               oop of the destination array
 940 //   basic_elem_type    element type of the destination
 941 //   slice_idx          array index of first element to store
 942 //   slice_len          number of elements to store (or null)
 943 //   dest_size          total size in bytes of the array object
 944 //
 945 // Exactly one of slice_len or dest_size must be non-null.
 946 // If dest_size is non-null, zeroing extends to the end of the object.
 947 // If slice_len is non-null, the slice_idx value must be a constant.
 948 void PhaseMacroExpand::generate_clear_array(Node* ctrl, MergeMemNode* merge_mem,
 949                                             const TypePtr* adr_type,
 950                                             Node* dest,
 951                                             Node* val,
 952                                             Node* raw_val,
 953                                             BasicType basic_elem_type,
 954                                             Node* slice_idx,
 955                                             Node* slice_len,
 956                                             Node* dest_size,
 957                                             const bool raw_base) {
 958   // one or the other but not both of slice_len and dest_size:
 959   assert((slice_len != nullptr? 1: 0) + (dest_size != nullptr? 1: 0) == 1, "");
 960   if (slice_len == nullptr)  slice_len = top();
 961   if (dest_size == nullptr)  dest_size = top();
 962 
 963   uint alias_idx = C->get_alias_index(adr_type);
 964 
 965   // operate on this memory slice:
 966   Node* mem = merge_mem->memory_at(alias_idx); // memory slice to operate on
 967 
 968   // scaling and rounding of indexes:
 969   int scale = exact_log2(type2aelembytes(basic_elem_type));
 970   int abase = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
 971   int clear_low = (-1 << scale) & (BytesPerInt  - 1);
 972   int bump_bit  = (-1 << scale) & BytesPerInt;
 973 
 974   // determine constant starts and ends
 975   const intptr_t BIG_NEG = -128;
 976   assert(BIG_NEG + 2*abase < 0, "neg enough");
 977   intptr_t slice_idx_con = (intptr_t) _igvn.find_int_con(slice_idx, BIG_NEG);
 978   intptr_t slice_len_con = (intptr_t) _igvn.find_int_con(slice_len, BIG_NEG);
 979   if (slice_len_con == 0) {
 980     return;                     // nothing to do here
 981   }
 982   intptr_t start_con = (abase + (slice_idx_con << scale)) & ~clear_low;
 983   intptr_t end_con   = _igvn.find_intptr_t_con(dest_size, -1);
 984   if (slice_idx_con >= 0 && slice_len_con >= 0) {
 985     assert(end_con < 0, "not two cons");
 986     end_con = align_up(abase + ((slice_idx_con + slice_len_con) << scale),
 987                        BytesPerLong);
 988   }
 989 
 990   if (start_con >= 0 && end_con >= 0) {
 991     // Constant start and end.  Simple.
 992     mem = ClearArrayNode::clear_memory(ctrl, mem, dest, val, raw_val,
 993                                        start_con, end_con, raw_base, &_igvn);
 994   } else if (start_con >= 0 && dest_size != top()) {
 995     // Constant start, pre-rounded end after the tail of the array.
 996     Node* end = dest_size;
 997     mem = ClearArrayNode::clear_memory(ctrl, mem, dest, val, raw_val,
 998                                        start_con, end, raw_base, &_igvn);
 999   } else if (start_con >= 0 && slice_len != top()) {
1000     // Constant start, non-constant end.  End needs rounding up.
1001     // End offset = round_up(abase + ((slice_idx_con + slice_len) << scale), 8)
1002     intptr_t end_base  = abase + (slice_idx_con << scale);
1003     int      end_round = (-1 << scale) & (BytesPerLong  - 1);
1004     Node*    end       = ConvI2X(slice_len);
1005     if (scale != 0)
1006       end = transform_later(new LShiftXNode(end, intcon(scale) ));
1007     end_base += end_round;
1008     end = transform_later(new AddXNode(end, MakeConX(end_base)) );
1009     end = transform_later(new AndXNode(end, MakeConX(~end_round)) );
1010     mem = ClearArrayNode::clear_memory(ctrl, mem, dest, val, raw_val,
1011                                        start_con, end, raw_base, &_igvn);
1012   } else if (start_con < 0 && dest_size != top()) {
1013     // Non-constant start, pre-rounded end after the tail of the array.
1014     // This is almost certainly a "round-to-end" operation.
1015     Node* start = slice_idx;
1016     start = ConvI2X(start);
1017     if (scale != 0)
1018       start = transform_later(new LShiftXNode( start, intcon(scale) ));
1019     start = transform_later(new AddXNode(start, MakeConX(abase)) );
1020     if ((bump_bit | clear_low) != 0) {
1021       int to_clear = (bump_bit | clear_low);
1022       // Align up mod 8, then store a jint zero unconditionally
1023       // just before the mod-8 boundary.
1024       if (((abase + bump_bit) & ~to_clear) - bump_bit
1025           < arrayOopDesc::length_offset_in_bytes() + BytesPerInt) {
1026         bump_bit = 0;
1027         assert((abase & to_clear) == 0, "array base must be long-aligned");
1028       } else {
1029         // Bump 'start' up to (or past) the next jint boundary:
1030         start = transform_later( new AddXNode(start, MakeConX(bump_bit)) );
1031         assert((abase & clear_low) == 0, "array base must be int-aligned");
1032       }
1033       // Round bumped 'start' down to jlong boundary in body of array.
1034       start = transform_later(new AndXNode(start, MakeConX(~to_clear)) );
1035       if (bump_bit != 0) {
1036         // Store a zero to the immediately preceding jint:
1037         Node* x1 = transform_later(new AddXNode(start, MakeConX(-bump_bit)) );
1038         Node* p1 = basic_plus_adr(dest, x1, raw_base);
1039         if (val == nullptr) {
1040           assert(raw_val == nullptr, "val may not be null");
1041           mem = StoreNode::make(_igvn, ctrl, mem, p1, adr_type, intcon(0), T_INT, MemNode::unordered);
1042         } else {
1043           assert(_igvn.type(val)->isa_narrowoop(), "should be narrow oop");
1044           mem = new StoreNNode(ctrl, mem, p1, adr_type, val, MemNode::unordered);
1045         }
1046         mem = transform_later(mem);
1047       }
1048     }
1049     Node* end = dest_size; // pre-rounded
1050     mem = ClearArrayNode::clear_memory(ctrl, mem, dest, raw_val,
1051                                        start, end, raw_base, &_igvn);
1052   } else {
1053     // Non-constant start, unrounded non-constant end.
1054     // (Nobody zeroes a random midsection of an array using this routine.)
1055     ShouldNotReachHere();       // fix caller
1056   }
1057 
1058   // Done.
1059   merge_mem->set_memory_at(alias_idx, mem);
1060 }
1061 
1062 bool PhaseMacroExpand::generate_block_arraycopy(Node** ctrl, MergeMemNode** mem,
1063                                                 const TypePtr* adr_type,
1064                                                 BasicType basic_elem_type,
1065                                                 Node* src, Node* src_offset,
1066                                                 Node* dest, Node* dest_offset,
1067                                                 Node* dest_size, bool dest_uninitialized,
1068                                                 const bool raw_base) {
1069   // See if there is an advantage from block transfer.
1070   int scale = exact_log2(type2aelembytes(basic_elem_type));
1071   if (scale >= LogBytesPerLong)
1072     return false;               // it is already a block transfer
1073 
1074   // Look at the alignment of the starting offsets.
1075   int abase = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
1076 
1077   intptr_t src_off_con  = (intptr_t) _igvn.find_int_con(src_offset, -1);
1078   intptr_t dest_off_con = (intptr_t) _igvn.find_int_con(dest_offset, -1);
1079   if (src_off_con < 0 || dest_off_con < 0) {
1080     // At present, we can only understand constants.
1081     return false;
1082   }
1083 
1084   intptr_t src_off  = abase + (src_off_con  << scale);
1085   intptr_t dest_off = abase + (dest_off_con << scale);
1086 
1087   if (((src_off | dest_off) & (BytesPerLong-1)) != 0) {
1088     // Non-aligned; too bad.
1089     // One more chance:  Pick off an initial 32-bit word.
1090     // This is a common case, since abase can be odd mod 8.
1091     if (((src_off | dest_off) & (BytesPerLong-1)) == BytesPerInt &&
1092         ((src_off ^ dest_off) & (BytesPerLong-1)) == 0) {
1093       Node* sptr = basic_plus_adr(src,  src_off);
1094       Node* dptr = basic_plus_adr(dest, dest_off, raw_base);
1095       const TypePtr* s_adr_type = _igvn.type(sptr)->is_ptr();
1096       assert(s_adr_type->isa_aryptr(), "impossible slice");
1097       uint s_alias_idx = C->get_alias_index(s_adr_type);
1098       uint d_alias_idx = C->get_alias_index(adr_type);
1099       bool is_mismatched = (basic_elem_type != T_INT);
1100       Node* sval = transform_later(
1101           LoadNode::make(_igvn, *ctrl, (*mem)->memory_at(s_alias_idx), sptr, s_adr_type,
1102                          TypeInt::INT, T_INT, MemNode::unordered, LoadNode::DependsOnlyOnTest,
1103                          false /*require_atomic_access*/, false /*unaligned*/, is_mismatched));
1104       Node* st = transform_later(
1105           StoreNode::make(_igvn, *ctrl, (*mem)->memory_at(d_alias_idx), dptr, adr_type,
1106                           sval, T_INT, MemNode::unordered));
1107       if (is_mismatched) {
1108         st->as_Store()->set_mismatched_access();
1109       }
1110       (*mem)->set_memory_at(d_alias_idx, st);
1111       src_off += BytesPerInt;
1112       dest_off += BytesPerInt;
1113     } else {
1114       return false;
1115     }
1116   }
1117   assert(src_off % BytesPerLong == 0, "");
1118   assert(dest_off % BytesPerLong == 0, "");
1119 
1120   // Do this copy by giant steps.
1121   Node* sptr  = basic_plus_adr(src,  src_off);
1122   Node* dptr  = basic_plus_adr(dest, dest_off, raw_base);
1123   Node* countx = dest_size;
1124   countx = transform_later(new SubXNode(countx, MakeConX(dest_off)));
1125   countx = transform_later(new URShiftXNode(countx, intcon(LogBytesPerLong)));
1126 
1127   bool disjoint_bases = true;   // since alloc isn't null
1128   generate_unchecked_arraycopy(ctrl, mem,
1129                                adr_type, T_LONG, disjoint_bases,
1130                                sptr, nullptr, dptr, nullptr, countx, dest_uninitialized, raw_base);
1131 
1132   return true;
1133 }
1134 
1135 // Helper function; generates code for the slow case.
1136 // We make a call to a runtime method which emulates the native method,
1137 // but without the native wrapper overhead.
1138 MergeMemNode* PhaseMacroExpand::generate_slow_arraycopy(ArrayCopyNode *ac,
1139                                                         Node** ctrl, Node* mem, Node** io,
1140                                                         const TypePtr* adr_type,
1141                                                         Node* src,  Node* src_offset,
1142                                                         Node* dest, Node* dest_offset,
1143                                                         Node* copy_length, bool dest_uninitialized) {
1144   assert(!dest_uninitialized, "Invariant");
1145 
1146   const TypeFunc* call_type = OptoRuntime::slow_arraycopy_Type();
1147   CallNode* call = new CallStaticJavaNode(call_type, OptoRuntime::slow_arraycopy_Java(),
1148                                           "slow_arraycopy", TypePtr::BOTTOM);
1149 
1150   call->init_req(TypeFunc::Control, *ctrl);
1151   call->init_req(TypeFunc::I_O    , *io);
1152   call->init_req(TypeFunc::Memory , mem);
1153   call->init_req(TypeFunc::ReturnAdr, top());
1154   call->init_req(TypeFunc::FramePtr, top());
1155   call->init_req(TypeFunc::Parms+0, src);
1156   call->init_req(TypeFunc::Parms+1, src_offset);
1157   call->init_req(TypeFunc::Parms+2, dest);
1158   call->init_req(TypeFunc::Parms+3, dest_offset);
1159   call->init_req(TypeFunc::Parms+4, copy_length);
1160   call->copy_call_debug_info(&_igvn, ac);
1161 
1162   call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
1163   _igvn.replace_node(ac, call);
1164   transform_later(call);
1165 
1166   _callprojs = call->extract_projections(false /*separate_io_proj*/, false /*do_asserts*/);
1167   *ctrl = _callprojs->fallthrough_catchproj->clone();
1168   transform_later(*ctrl);
1169 
1170   Node* m = _callprojs->fallthrough_memproj->clone();
1171   transform_later(m);
1172 
1173   uint alias_idx = C->get_alias_index(adr_type);
1174   MergeMemNode* out_mem;
1175   if (alias_idx != Compile::AliasIdxBot) {
1176     out_mem = MergeMemNode::make(mem);
1177     out_mem->set_memory_at(alias_idx, m);
1178   } else {
1179     out_mem = MergeMemNode::make(m);
1180   }
1181   transform_later(out_mem);
1182 
1183   // When src is negative and arraycopy is before an infinite loop,_callprojs.fallthrough_ioproj
1184   // could be nullptr. Skip clone and update nullptr fallthrough_ioproj.
1185   if (_callprojs->fallthrough_ioproj != nullptr) {
1186     *io = _callprojs->fallthrough_ioproj->clone();
1187     transform_later(*io);
1188   } else {
1189     *io = nullptr;
1190   }
1191 
1192   return out_mem;
1193 }
1194 
1195 // Helper function; generates code for cases requiring runtime checks.
1196 Node* PhaseMacroExpand::generate_checkcast_arraycopy(Node** ctrl, MergeMemNode** mem,
1197                                                      const TypePtr* adr_type,
1198                                                      Node* dest_elem_klass,
1199                                                      Node* src,  Node* src_offset,
1200                                                      Node* dest, Node* dest_offset,
1201                                                      Node* copy_length, bool dest_uninitialized,
1202                                                      const bool raw_base) {
1203   if ((*ctrl)->is_top())  return nullptr;
1204 
1205   address copyfunc_addr = StubRoutines::checkcast_arraycopy(dest_uninitialized);
1206   if (copyfunc_addr == nullptr) { // Stub was not generated, go slow path.
1207     return nullptr;
1208   }
1209 
1210   // Pick out the parameters required to perform a store-check
1211   // for the target array.  This is an optimistic check.  It will
1212   // look in each non-null element's class, at the desired klass's
1213   // super_check_offset, for the desired klass.
1214   int sco_offset = in_bytes(Klass::super_check_offset_offset());
1215   Node* p3 = off_heap_plus_addr(dest_elem_klass, sco_offset);
1216   Node* n3 = new LoadINode(nullptr, *mem /*memory(p3)*/, p3, _igvn.type(p3)->is_ptr(), TypeInt::INT, MemNode::unordered);
1217   Node* check_offset = ConvI2X(transform_later(n3));
1218   Node* check_value  = dest_elem_klass;
1219 
1220   Node* src_start  = array_element_address(src,  src_offset,  T_OBJECT, false);
1221   Node* dest_start = array_element_address(dest, dest_offset, T_OBJECT, raw_base);
1222 
1223   const TypeFunc* call_type = OptoRuntime::checkcast_arraycopy_Type();
1224   Node* call = make_leaf_call(*ctrl, *mem, call_type, copyfunc_addr, "checkcast_arraycopy", adr_type,
1225                               src_start, dest_start, copy_length XTOP, check_offset XTOP, check_value);
1226 
1227   finish_arraycopy_call(call, ctrl, mem, adr_type);
1228 
1229   Node* proj =  new ProjNode(call, TypeFunc::Parms);
1230   transform_later(proj);
1231 
1232   return proj;
1233 }
1234 
1235 // Helper function; generates code for cases requiring runtime checks.
1236 Node* PhaseMacroExpand::generate_generic_arraycopy(Node** ctrl, MergeMemNode** mem,
1237                                                    const TypePtr* adr_type,
1238                                                    Node* src,  Node* src_offset,
1239                                                    Node* dest, Node* dest_offset,
1240                                                    Node* copy_length, bool dest_uninitialized) {
1241   if ((*ctrl)->is_top()) return nullptr;

1248 
1249   const TypeFunc* call_type = OptoRuntime::generic_arraycopy_Type();
1250   Node* call = make_leaf_call(*ctrl, *mem, call_type, copyfunc_addr, "generic_arraycopy", adr_type,
1251                               src, src_offset, dest, dest_offset, copy_length);
1252 
1253   finish_arraycopy_call(call, ctrl, mem, adr_type);
1254 
1255   Node* proj =  new ProjNode(call, TypeFunc::Parms);
1256   transform_later(proj);
1257 
1258   return proj;
1259 }
1260 
1261 // Helper function; generates the fast out-of-line call to an arraycopy stub.
1262 void PhaseMacroExpand::generate_unchecked_arraycopy(Node** ctrl, MergeMemNode** mem,
1263                                                     const TypePtr* adr_type,
1264                                                     BasicType basic_elem_type,
1265                                                     bool disjoint_bases,
1266                                                     Node* src,  Node* src_offset,
1267                                                     Node* dest, Node* dest_offset,
1268                                                     Node* copy_length, bool dest_uninitialized,
1269                                                     const bool raw_base) {
1270   if ((*ctrl)->is_top()) {
1271     return;
1272   }
1273 
1274   Node* src_start  = src;
1275   Node* dest_start = dest;
1276   if (src_offset != nullptr || dest_offset != nullptr) {
1277     src_start =  array_element_address(src, src_offset, basic_elem_type, false);
1278     dest_start = array_element_address(dest, dest_offset, basic_elem_type, raw_base);
1279   }
1280 
1281   // Figure out which arraycopy runtime method to call.
1282   const char* copyfunc_name = "arraycopy";
1283   address     copyfunc_addr =
1284       basictype2arraycopy(basic_elem_type, src_offset, dest_offset,
1285                           disjoint_bases, copyfunc_name, dest_uninitialized);
1286 
1287   Node* result_memory = nullptr;
1288   RegionNode* exit_block = nullptr;
1289   if (ArrayOperationPartialInlineSize > 0 && is_subword_type(basic_elem_type) &&
1290     Matcher::vector_width_in_bytes(basic_elem_type) >= 16) {
1291     generate_partial_inlining_block(ctrl, mem, adr_type, &exit_block, &result_memory,
1292                                     copy_length, src_start, dest_start, basic_elem_type);
1293   }
1294 
1295   const TypeFunc* call_type = OptoRuntime::fast_arraycopy_Type();
1296   Node* call = make_leaf_call(*ctrl, *mem, call_type, copyfunc_addr, copyfunc_name, adr_type,
1297                               src_start, dest_start, copy_length XTOP);
1298 

1300 
1301   // Connecting remaining edges for exit_block coming from stub_block.
1302   if (exit_block) {
1303     exit_block->init_req(2, *ctrl);
1304 
1305     // Memory edge corresponding to stub_region.
1306     result_memory->init_req(2, *mem);
1307 
1308     uint alias_idx = C->get_alias_index(adr_type);
1309     if (alias_idx != Compile::AliasIdxBot) {
1310       *mem = MergeMemNode::make(*mem);
1311       (*mem)->set_memory_at(alias_idx, result_memory);
1312     } else {
1313       *mem = MergeMemNode::make(result_memory);
1314     }
1315     transform_later(*mem);
1316     *ctrl = exit_block;
1317   }
1318 }
1319 
1320 const TypePtr* PhaseMacroExpand::adjust_for_flat_array(const TypeAryPtr* top_dest, Node*& src_offset,
1321                                                        Node*& dest_offset, Node*& length, BasicType& dest_elem,
1322                                                        Node*& dest_length) {
1323 #ifdef ASSERT
1324   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1325   bool needs_barriers = top_dest->elem()->inline_klass()->contains_oops() &&
1326     bs->array_copy_requires_gc_barriers(dest_length != nullptr, T_OBJECT, false, false, BarrierSetC2::Optimization);
1327   assert(!needs_barriers || StressReflectiveCode, "Flat arracopy would require GC barriers");
1328 #endif
1329   int elem_size = top_dest->flat_elem_size();
1330   if (elem_size >= 8) {
1331     if (elem_size > 8) {
1332       // treat as array of long but scale length, src offset and dest offset
1333       assert((elem_size % 8) == 0, "not a power of 2?");
1334       int factor = elem_size / 8;
1335       length = transform_later(new MulINode(length, intcon(factor)));
1336       src_offset = transform_later(new MulINode(src_offset, intcon(factor)));
1337       dest_offset = transform_later(new MulINode(dest_offset, intcon(factor)));
1338       if (dest_length != nullptr) {
1339         dest_length = transform_later(new MulINode(dest_length, intcon(factor)));
1340       }
1341       elem_size = 8;
1342     }
1343     dest_elem = T_LONG;
1344   } else if (elem_size == 4) {
1345     dest_elem = T_INT;
1346   } else if (elem_size == 2) {
1347     dest_elem = T_CHAR;
1348   } else if (elem_size == 1) {
1349     dest_elem = T_BYTE;
1350   } else {
1351     ShouldNotReachHere();
1352   }
1353   return TypeRawPtr::BOTTOM;
1354 }
1355 
1356 #undef XTOP
1357 
1358 void PhaseMacroExpand::expand_arraycopy_node(ArrayCopyNode *ac) {
1359   Node* ctrl = ac->in(TypeFunc::Control);
1360   Node* io = ac->in(TypeFunc::I_O);
1361   Node* src = ac->in(ArrayCopyNode::Src);
1362   Node* src_offset = ac->in(ArrayCopyNode::SrcPos);
1363   Node* dest = ac->in(ArrayCopyNode::Dest);
1364   Node* dest_offset = ac->in(ArrayCopyNode::DestPos);
1365   Node* length = ac->in(ArrayCopyNode::Length);
1366   MergeMemNode* merge_mem = nullptr;
1367 
1368   if (ac->is_clonebasic()) {
1369     BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1370     bs->clone_at_expansion(this, ac);
1371     return;
1372   } else if (ac->is_copyof() || ac->is_copyofrange() || ac->is_clone_oop_array()) {
1373     const Type* src_type = _igvn.type(src);
1374     const Type* dest_type = _igvn.type(dest);
1375     const TypeAryPtr* top_src = src_type->isa_aryptr();
1376     // Note: The destination could have type Object (i.e. non-array) when directly invoking the protected method
1377     //       Object::clone() with reflection on a declared Object that is an array at runtime. top_dest is then null.
1378     const TypeAryPtr* top_dest = dest_type->isa_aryptr();
1379     BasicType dest_elem = T_OBJECT;
1380     if (top_dest != nullptr && top_dest->elem() != Type::BOTTOM) {
1381       dest_elem = top_dest->elem()->array_element_basic_type();
1382     }
1383     if (is_reference_type(dest_elem, true)) dest_elem = T_OBJECT;
1384 
1385     if (top_src != nullptr && top_src->is_flat()) {
1386       // If src is flat, dest is guaranteed to be flat as well
1387       top_dest = top_src;
1388     }
1389 
1390     AllocateArrayNode* alloc = nullptr;
1391     Node* dest_length = nullptr;
1392     if (ac->is_alloc_tightly_coupled()) {
1393       alloc = AllocateArrayNode::Ideal_array_allocation(dest);
1394       assert(alloc != nullptr, "expect alloc");
1395       dest_length = alloc->in(AllocateNode::ALength);
1396     }
1397 
1398     Node* mem = ac->in(TypeFunc::Memory);
1399     const TypePtr* adr_type = nullptr;
1400     bool raw_base = false;
1401     if (top_dest != nullptr && top_dest->is_flat()) {
1402       assert(dest_length != nullptr || StressReflectiveCode, "must be tightly coupled");
1403       // Copy to a flat array modifies multiple memory slices. Conservatively insert a barrier
1404       // on all slices to prevent writes into the source from floating below the arraycopy.
1405       int mem_bar_alias_idx = Compile::AliasIdxBot;
1406       if (ac->_dest_type != TypeOopPtr::BOTTOM) {
1407         mem_bar_alias_idx = C->get_alias_index(ac->_dest_type->add_offset(Type::OffsetBot)->is_ptr());
1408       }
1409       insert_mem_bar(&ctrl, &mem, Op_MemBarCPUOrder, mem_bar_alias_idx);
1410       adr_type = adjust_for_flat_array(top_dest, src_offset, dest_offset, length, dest_elem, dest_length);
1411     } else {
1412       adr_type = dest_type->is_oopptr()->add_offset(Type::OffsetBot);
1413       if (ac->_dest_type != TypeOopPtr::BOTTOM) {
1414         adr_type = ac->_dest_type->add_offset(Type::OffsetBot)->is_ptr();
1415       }
1416       if (ac->_src_type != ac->_dest_type) {
1417         adr_type = TypeRawPtr::BOTTOM;
1418         raw_base = true;
1419       }
1420     }
1421     merge_mem = MergeMemNode::make(mem);
1422     transform_later(merge_mem);
1423 
1424     generate_arraycopy(ac, alloc, &ctrl, merge_mem, &io,
1425                        adr_type, dest_elem,
1426                        src, src_offset, dest, dest_offset, length,
1427                        dest_length,
1428                        raw_base, true, ac->has_negative_length_guard());
1429 
1430     return;
1431   }
1432 
1433   AllocateArrayNode* alloc = nullptr;
1434   if (ac->is_alloc_tightly_coupled()) {
1435     alloc = AllocateArrayNode::Ideal_array_allocation(dest);
1436     assert(alloc != nullptr, "expect alloc");
1437   }
1438 
1439   assert(ac->is_arraycopy() || ac->is_arraycopy_validated(), "should be an arraycopy");
1440 
1441   // Compile time checks.  If any of these checks cannot be verified at compile time,
1442   // we do not make a fast path for this call.  Instead, we let the call remain as it
1443   // is.  The checks we choose to mandate at compile time are:
1444   //
1445   // (1) src and dest are arrays.
1446   const Type* src_type = src->Value(&_igvn);
1447   const Type* dest_type = dest->Value(&_igvn);
1448   const TypeAryPtr* top_src = src_type->isa_aryptr();
1449   const TypeAryPtr* top_dest = dest_type->isa_aryptr();
1450 
1451   BasicType src_elem = T_CONFLICT;
1452   BasicType dest_elem = T_CONFLICT;
1453 
1454   if (top_src != nullptr && top_src->elem() != Type::BOTTOM) {
1455     src_elem = top_src->elem()->array_element_basic_type();
1456   }
1457   if (top_dest != nullptr && top_dest->elem() != Type::BOTTOM) {
1458     dest_elem = top_dest->elem()->array_element_basic_type();
1459   }
1460   if (is_reference_type(src_elem, true)) src_elem = T_OBJECT;
1461   if (is_reference_type(dest_elem, true)) dest_elem = T_OBJECT;
1462 
1463   if (ac->is_arraycopy_validated() && dest_elem != T_CONFLICT && src_elem == T_CONFLICT) {


1464     src_elem = dest_elem;
1465   }
1466 
1467   if (src_elem == T_CONFLICT || dest_elem == T_CONFLICT) {
1468     // Conservatively insert a memory barrier on all memory slices.
1469     // Do not let writes into the source float below the arraycopy.
1470     {
1471       Node* mem = ac->in(TypeFunc::Memory);
1472       insert_mem_bar(&ctrl, &mem, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1473 
1474       merge_mem = MergeMemNode::make(mem);
1475       transform_later(merge_mem);
1476     }
1477 
1478     // Call StubRoutines::generic_arraycopy stub.
1479     generate_arraycopy(ac, nullptr, &ctrl, merge_mem, &io,
1480                        TypeRawPtr::BOTTOM, T_CONFLICT,
1481                        src, src_offset, dest, dest_offset, length,
1482                        nullptr,
1483                        // If a  negative length guard was generated for the ArrayCopyNode,
1484                        // the length of the array can never be negative.
1485                        true, false, ac->has_negative_length_guard());
1486     return;
1487   }
1488 
1489   assert(!ac->is_arraycopy_validated() || (src_elem == dest_elem && dest_elem != T_VOID), "validated but different basic types");
1490 
1491   // (2) src and dest arrays must have elements of the same BasicType
1492   // Figure out the size and type of the elements we will be copying.
1493   //
1494   // We have no stub to copy flat inline type arrays with oop
1495   // fields if we need to emit write barriers.
1496   //
1497   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1498   if (src_elem != dest_elem || top_src->is_flat() != top_dest->is_flat() || dest_elem == T_VOID ||
1499       (top_src->is_flat() && top_dest->elem()->inline_klass()->contains_oops() &&
1500        bs->array_copy_requires_gc_barriers(alloc != nullptr, T_OBJECT, false, false, BarrierSetC2::Optimization))) {
1501     // The component types are not the same or are not recognized.  Punt.
1502     // (But, avoid the native method wrapper to JVM_ArrayCopy.)
1503     {
1504       Node* mem = ac->in(TypeFunc::Memory);
1505       merge_mem = generate_slow_arraycopy(ac, &ctrl, mem, &io, TypePtr::BOTTOM, src, src_offset, dest, dest_offset, length, false);
1506     }
1507 
1508     _igvn.replace_node(_callprojs->fallthrough_memproj, merge_mem);
1509     if (_callprojs->fallthrough_ioproj != nullptr) {
1510       _igvn.replace_node(_callprojs->fallthrough_ioproj, io);
1511     }
1512     _igvn.replace_node(_callprojs->fallthrough_catchproj, ctrl);
1513     return;
1514   }
1515 
1516   //---------------------------------------------------------------------------
1517   // We will make a fast path for this call to arraycopy.
1518 
1519   // We have the following tests left to perform:
1520   //
1521   // (3) src and dest must not be null.
1522   // (4) src_offset must not be negative.
1523   // (5) dest_offset must not be negative.
1524   // (6) length must not be negative.
1525   // (7) src_offset + length must not exceed length of src.
1526   // (8) dest_offset + length must not exceed length of dest.
1527   // (9) each element of an oop array must be assignable
1528 
1529   Node* mem = ac->in(TypeFunc::Memory);
1530   if (top_dest->is_flat()) {
1531     // Copy to a flat array modifies multiple memory slices. Conservatively insert a barrier
1532     // on all slices to prevent writes into the source from floating below the arraycopy.
1533     int mem_bar_alias_idx = Compile::AliasIdxBot;
1534     if (ac->_dest_type != TypeOopPtr::BOTTOM) {
1535       mem_bar_alias_idx = C->get_alias_index(ac->_dest_type->add_offset(Type::OffsetBot)->is_ptr());
1536     }
1537     insert_mem_bar(&ctrl, &mem, Op_MemBarCPUOrder, mem_bar_alias_idx);
1538   }
1539   merge_mem = MergeMemNode::make(mem);
1540   transform_later(merge_mem);
1541 
1542   RegionNode* slow_region = new RegionNode(1);
1543   transform_later(slow_region);
1544 
1545   if (!ac->is_arraycopy_validated()) {
1546     // (3) operands must not be null
1547     // We currently perform our null checks with the null_check routine.
1548     // This means that the null exceptions will be reported in the caller
1549     // rather than (correctly) reported inside of the native arraycopy call.
1550     // This should be corrected, given time.  We do our null check with the
1551     // stack pointer restored.
1552     // null checks done library_call.cpp
1553 
1554     // (4) src_offset must not be negative.
1555     generate_negative_guard(&ctrl, src_offset, slow_region);
1556 
1557     // (5) dest_offset must not be negative.
1558     generate_negative_guard(&ctrl, dest_offset, slow_region);
1559 
1560     // (6) length must not be negative (moved to generate_arraycopy()).
1561     // generate_negative_guard(length, slow_region);
1562 
1563     // (7) src_offset + length must not exceed length of src.
1564     Node* alen = ac->in(ArrayCopyNode::SrcLen);
1565     assert(alen != nullptr, "need src len");
1566     generate_limit_guard(&ctrl,
1567                          src_offset, length,
1568                          alen,
1569                          slow_region);
1570 
1571     // (8) dest_offset + length must not exceed length of dest.
1572     alen = ac->in(ArrayCopyNode::DestLen);
1573     assert(alen != nullptr, "need dest len");
1574     generate_limit_guard(&ctrl,
1575                          dest_offset, length,
1576                          alen,
1577                          slow_region);
1578 
1579     // (9) each element of an oop array must be assignable
1580     // The generate_arraycopy subroutine checks this.
1581 
1582     // TODO 8350865 This is too strong
1583     // We need to be careful here because 'adjust_for_flat_array' will adjust offsets/length etc. which then does not work anymore for the slow call to SharedRuntime::slow_arraycopy_C.
1584     if (!(top_src->is_flat() && top_dest->is_flat() && top_src->is_null_free() == top_dest->is_null_free())) {
1585       generate_flat_array_guard(&ctrl, src, merge_mem, slow_region);
1586       generate_flat_array_guard(&ctrl, dest, merge_mem, slow_region);
1587       generate_null_free_array_guard(&ctrl, dest, merge_mem, slow_region);
1588     }
1589   }
1590 
1591   // This is where the memory effects are placed:
1592   const TypePtr* adr_type = nullptr;
1593   Node* dest_length = (alloc != nullptr) ? alloc->in(AllocateNode::ALength) : nullptr;
1594   if (top_src->is_flat() && top_dest->is_flat() &&
1595       top_src->is_null_free() == top_dest->is_null_free()) {
1596     adr_type = adjust_for_flat_array(top_dest, src_offset, dest_offset, length, dest_elem, dest_length);
1597   } else if (ac->_dest_type != TypeOopPtr::BOTTOM) {
1598     adr_type = ac->_dest_type->add_offset(Type::OffsetBot)->is_ptr();
1599   } else {
1600     adr_type = TypeAryPtr::get_array_body_type(dest_elem);
1601   }
1602 
1603   generate_arraycopy(ac, alloc, &ctrl, merge_mem, &io,
1604                      adr_type, dest_elem,
1605                      src, src_offset, dest, dest_offset, length,
1606                      dest_length,
1607                      // If a  negative length guard was generated for the ArrayCopyNode,
1608                      // the length of the array can never be negative.
1609                      false, false, ac->has_negative_length_guard(),
1610                      slow_region);
1611 }
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