1 /*
   2  * Copyright (c) 1998, 2024, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "asm/assembler.inline.hpp"
  27 #include "asm/macroAssembler.inline.hpp"
  28 #include "code/compiledIC.hpp"
  29 #include "code/debugInfo.hpp"
  30 #include "code/debugInfoRec.hpp"
  31 #include "compiler/compileBroker.hpp"
  32 #include "compiler/compilerDirectives.hpp"
  33 #include "compiler/disassembler.hpp"
  34 #include "compiler/oopMap.hpp"
  35 #include "gc/shared/barrierSet.hpp"
  36 #include "gc/shared/c2/barrierSetC2.hpp"
  37 #include "memory/allocation.inline.hpp"
  38 #include "memory/allocation.hpp"
  39 #include "opto/ad.hpp"
  40 #include "opto/block.hpp"
  41 #include "opto/c2compiler.hpp"
  42 #include "opto/c2_MacroAssembler.hpp"
  43 #include "opto/callnode.hpp"
  44 #include "opto/cfgnode.hpp"
  45 #include "opto/locknode.hpp"
  46 #include "opto/machnode.hpp"
  47 #include "opto/node.hpp"
  48 #include "opto/optoreg.hpp"
  49 #include "opto/output.hpp"
  50 #include "opto/regalloc.hpp"
  51 #include "opto/runtime.hpp"
  52 #include "opto/subnode.hpp"
  53 #include "opto/type.hpp"
  54 #include "runtime/handles.inline.hpp"
  55 #include "runtime/sharedRuntime.hpp"
  56 #include "utilities/macros.hpp"
  57 #include "utilities/powerOfTwo.hpp"
  58 #include "utilities/xmlstream.hpp"
  59 
  60 #ifndef PRODUCT
  61 #define DEBUG_ARG(x) , x
  62 #else
  63 #define DEBUG_ARG(x)
  64 #endif
  65 
  66 //------------------------------Scheduling----------------------------------
  67 // This class contains all the information necessary to implement instruction
  68 // scheduling and bundling.
  69 class Scheduling {
  70 
  71 private:
  72   // Arena to use
  73   Arena *_arena;
  74 
  75   // Control-Flow Graph info
  76   PhaseCFG *_cfg;
  77 
  78   // Register Allocation info
  79   PhaseRegAlloc *_regalloc;
  80 
  81   // Number of nodes in the method
  82   uint _node_bundling_limit;
  83 
  84   // List of scheduled nodes. Generated in reverse order
  85   Node_List _scheduled;
  86 
  87   // List of nodes currently available for choosing for scheduling
  88   Node_List _available;
  89 
  90   // For each instruction beginning a bundle, the number of following
  91   // nodes to be bundled with it.
  92   Bundle *_node_bundling_base;
  93 
  94   // Mapping from register to Node
  95   Node_List _reg_node;
  96 
  97   // Free list for pinch nodes.
  98   Node_List _pinch_free_list;
  99 
 100   // Number of uses of this node within the containing basic block.
 101   short *_uses;
 102 
 103   // Schedulable portion of current block.  Skips Region/Phi/CreateEx up
 104   // front, branch+proj at end.  Also skips Catch/CProj (same as
 105   // branch-at-end), plus just-prior exception-throwing call.
 106   uint _bb_start, _bb_end;
 107 
 108   // Latency from the end of the basic block as scheduled
 109   unsigned short *_current_latency;
 110 
 111   // Remember the next node
 112   Node *_next_node;
 113 
 114   // Use this for an unconditional branch delay slot
 115   Node *_unconditional_delay_slot;
 116 
 117   // Pointer to a Nop
 118   MachNopNode *_nop;
 119 
 120   // Length of the current bundle, in instructions
 121   uint _bundle_instr_count;
 122 
 123   // Current Cycle number, for computing latencies and bundling
 124   uint _bundle_cycle_number;
 125 
 126   // Bundle information
 127   Pipeline_Use_Element _bundle_use_elements[resource_count];
 128   Pipeline_Use         _bundle_use;
 129 
 130   // Dump the available list
 131   void dump_available() const;
 132 
 133 public:
 134   Scheduling(Arena *arena, Compile &compile);
 135 
 136   // Destructor
 137   NOT_PRODUCT( ~Scheduling(); )
 138 
 139   // Step ahead "i" cycles
 140   void step(uint i);
 141 
 142   // Step ahead 1 cycle, and clear the bundle state (for example,
 143   // at a branch target)
 144   void step_and_clear();
 145 
 146   Bundle* node_bundling(const Node *n) {
 147     assert(valid_bundle_info(n), "oob");
 148     return (&_node_bundling_base[n->_idx]);
 149   }
 150 
 151   bool valid_bundle_info(const Node *n) const {
 152     return (_node_bundling_limit > n->_idx);
 153   }
 154 
 155   bool starts_bundle(const Node *n) const {
 156     return (_node_bundling_limit > n->_idx && _node_bundling_base[n->_idx].starts_bundle());
 157   }
 158 
 159   // Do the scheduling
 160   void DoScheduling();
 161 
 162   // Compute the register antidependencies within a basic block
 163   void ComputeRegisterAntidependencies(Block *bb);
 164   void verify_do_def( Node *n, OptoReg::Name def, const char *msg );
 165   void verify_good_schedule( Block *b, const char *msg );
 166   void anti_do_def( Block *b, Node *def, OptoReg::Name def_reg, int is_def );
 167   void anti_do_use( Block *b, Node *use, OptoReg::Name use_reg );
 168 
 169   // Add a node to the current bundle
 170   void AddNodeToBundle(Node *n, const Block *bb);
 171 
 172   // Return an integer less than, equal to, or greater than zero
 173   // if the stack offset of the first argument is respectively
 174   // less than, equal to, or greater than the second.
 175   int compare_two_spill_nodes(Node* first, Node* second);
 176 
 177   // Add a node to the list of available nodes
 178   void AddNodeToAvailableList(Node *n);
 179 
 180   // Compute the local use count for the nodes in a block, and compute
 181   // the list of instructions with no uses in the block as available
 182   void ComputeUseCount(const Block *bb);
 183 
 184   // Choose an instruction from the available list to add to the bundle
 185   Node * ChooseNodeToBundle();
 186 
 187   // See if this Node fits into the currently accumulating bundle
 188   bool NodeFitsInBundle(Node *n);
 189 
 190   // Decrement the use count for a node
 191  void DecrementUseCounts(Node *n, const Block *bb);
 192 
 193   // Garbage collect pinch nodes for reuse by other blocks.
 194   void garbage_collect_pinch_nodes();
 195   // Clean up a pinch node for reuse (helper for above).
 196   void cleanup_pinch( Node *pinch );
 197 
 198   // Information for statistics gathering
 199 #ifndef PRODUCT
 200 private:
 201   // Gather information on size of nops relative to total
 202   uint _branches, _unconditional_delays;
 203 
 204   static uint _total_nop_size, _total_method_size;
 205   static uint _total_branches, _total_unconditional_delays;
 206   static uint _total_instructions_per_bundle[Pipeline::_max_instrs_per_cycle+1];
 207 
 208 public:
 209   static void print_statistics();
 210 
 211   static void increment_instructions_per_bundle(uint i) {
 212     _total_instructions_per_bundle[i]++;
 213   }
 214 
 215   static void increment_nop_size(uint s) {
 216     _total_nop_size += s;
 217   }
 218 
 219   static void increment_method_size(uint s) {
 220     _total_method_size += s;
 221   }
 222 #endif
 223 
 224 };
 225 
 226 PhaseOutput::PhaseOutput()
 227   : Phase(Phase::Output),
 228     _code_buffer("Compile::Fill_buffer"),
 229     _first_block_size(0),
 230     _handler_table(),
 231     _inc_table(),
 232     _stub_list(),
 233     _oop_map_set(nullptr),
 234     _scratch_buffer_blob(nullptr),
 235     _scratch_locs_memory(nullptr),
 236     _scratch_const_size(-1),
 237     _in_scratch_emit_size(false),
 238     _frame_slots(0),
 239     _code_offsets(),
 240     _node_bundling_limit(0),
 241     _node_bundling_base(nullptr),
 242     _orig_pc_slot(0),
 243     _orig_pc_slot_offset_in_bytes(0),
 244     _buf_sizes(),
 245     _block(nullptr),
 246     _index(0) {
 247   C->set_output(this);
 248   if (C->stub_name() == nullptr) {
 249     _orig_pc_slot = C->fixed_slots() - (sizeof(address) / VMRegImpl::stack_slot_size);
 250   }
 251 }
 252 
 253 PhaseOutput::~PhaseOutput() {
 254   C->set_output(nullptr);
 255   if (_scratch_buffer_blob != nullptr) {
 256     BufferBlob::free(_scratch_buffer_blob);
 257   }
 258 }
 259 
 260 void PhaseOutput::perform_mach_node_analysis() {
 261   // Late barrier analysis must be done after schedule and bundle
 262   // Otherwise liveness based spilling will fail
 263   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 264   bs->late_barrier_analysis();
 265 
 266   pd_perform_mach_node_analysis();
 267 
 268   C->print_method(CompilerPhaseType::PHASE_MACH_ANALYSIS, 3);
 269 }
 270 
 271 // Convert Nodes to instruction bits and pass off to the VM
 272 void PhaseOutput::Output() {
 273   // RootNode goes
 274   assert( C->cfg()->get_root_block()->number_of_nodes() == 0, "" );
 275 
 276   // The number of new nodes (mostly MachNop) is proportional to
 277   // the number of java calls and inner loops which are aligned.
 278   if ( C->check_node_count((NodeLimitFudgeFactor + C->java_calls()*3 +
 279                             C->inner_loops()*(OptoLoopAlignment-1)),
 280                            "out of nodes before code generation" ) ) {
 281     return;
 282   }
 283   // Make sure I can find the Start Node
 284   Block *entry = C->cfg()->get_block(1);
 285   Block *broot = C->cfg()->get_root_block();
 286 
 287   const StartNode *start = entry->head()->as_Start();
 288 
 289   // Replace StartNode with prolog
 290   MachPrologNode *prolog = new MachPrologNode();
 291   entry->map_node(prolog, 0);
 292   C->cfg()->map_node_to_block(prolog, entry);
 293   C->cfg()->unmap_node_from_block(start); // start is no longer in any block
 294 
 295   // Virtual methods need an unverified entry point
 296 
 297   if( C->is_osr_compilation() ) {
 298     if( PoisonOSREntry ) {
 299       // TODO: Should use a ShouldNotReachHereNode...
 300       C->cfg()->insert( broot, 0, new MachBreakpointNode() );
 301     }
 302   } else {
 303     if( C->method() && !C->method()->flags().is_static() ) {
 304       // Insert unvalidated entry point
 305       C->cfg()->insert( broot, 0, new MachUEPNode() );
 306     }
 307 
 308   }
 309 
 310   // Break before main entry point
 311   if ((C->method() && C->directive()->BreakAtExecuteOption) ||
 312       (OptoBreakpoint && C->is_method_compilation())       ||
 313       (OptoBreakpointOSR && C->is_osr_compilation())       ||
 314       (OptoBreakpointC2R && !C->method())                   ) {
 315     // checking for C->method() means that OptoBreakpoint does not apply to
 316     // runtime stubs or frame converters
 317     C->cfg()->insert( entry, 1, new MachBreakpointNode() );
 318   }
 319 
 320   // Insert epilogs before every return
 321   for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
 322     Block* block = C->cfg()->get_block(i);
 323     if (!block->is_connector() && block->non_connector_successor(0) == C->cfg()->get_root_block()) { // Found a program exit point?
 324       Node* m = block->end();
 325       if (m->is_Mach() && m->as_Mach()->ideal_Opcode() != Op_Halt) {
 326         MachEpilogNode* epilog = new MachEpilogNode(m->as_Mach()->ideal_Opcode() == Op_Return);
 327         block->add_inst(epilog);
 328         C->cfg()->map_node_to_block(epilog, block);
 329       }
 330     }
 331   }
 332 
 333   // Keeper of sizing aspects
 334   _buf_sizes = BufferSizingData();
 335 
 336   // Initialize code buffer
 337   estimate_buffer_size(_buf_sizes._const);
 338   if (C->failing()) return;
 339 
 340   // Pre-compute the length of blocks and replace
 341   // long branches with short if machine supports it.
 342   // Must be done before ScheduleAndBundle due to SPARC delay slots
 343   uint* blk_starts = NEW_RESOURCE_ARRAY(uint, C->cfg()->number_of_blocks() + 1);
 344   blk_starts[0] = 0;
 345   shorten_branches(blk_starts);
 346 
 347   ScheduleAndBundle();
 348   if (C->failing()) {
 349     return;
 350   }
 351 
 352   perform_mach_node_analysis();
 353 
 354   // Complete sizing of codebuffer
 355   CodeBuffer* cb = init_buffer();
 356   if (cb == nullptr || C->failing()) {
 357     return;
 358   }
 359 
 360   BuildOopMaps();
 361 
 362   if (C->failing())  {
 363     return;
 364   }
 365 
 366   C2_MacroAssembler masm(cb);
 367   fill_buffer(&masm, blk_starts);
 368 }
 369 
 370 bool PhaseOutput::need_stack_bang(int frame_size_in_bytes) const {
 371   // Determine if we need to generate a stack overflow check.
 372   // Do it if the method is not a stub function and
 373   // has java calls or has frame size > vm_page_size/8.
 374   // The debug VM checks that deoptimization doesn't trigger an
 375   // unexpected stack overflow (compiled method stack banging should
 376   // guarantee it doesn't happen) so we always need the stack bang in
 377   // a debug VM.
 378   return (C->stub_function() == nullptr &&
 379           (C->has_java_calls() || frame_size_in_bytes > (int)(os::vm_page_size())>>3
 380            DEBUG_ONLY(|| true)));
 381 }
 382 
 383 bool PhaseOutput::need_register_stack_bang() const {
 384   // Determine if we need to generate a register stack overflow check.
 385   // This is only used on architectures which have split register
 386   // and memory stacks (ie. IA64).
 387   // Bang if the method is not a stub function and has java calls
 388   return (C->stub_function() == nullptr && C->has_java_calls());
 389 }
 390 
 391 
 392 // Compute the size of first NumberOfLoopInstrToAlign instructions at the top
 393 // of a loop. When aligning a loop we need to provide enough instructions
 394 // in cpu's fetch buffer to feed decoders. The loop alignment could be
 395 // avoided if we have enough instructions in fetch buffer at the head of a loop.
 396 // By default, the size is set to 999999 by Block's constructor so that
 397 // a loop will be aligned if the size is not reset here.
 398 //
 399 // Note: Mach instructions could contain several HW instructions
 400 // so the size is estimated only.
 401 //
 402 void PhaseOutput::compute_loop_first_inst_sizes() {
 403   // The next condition is used to gate the loop alignment optimization.
 404   // Don't aligned a loop if there are enough instructions at the head of a loop
 405   // or alignment padding is larger then MaxLoopPad. By default, MaxLoopPad
 406   // is equal to OptoLoopAlignment-1 except on new Intel cpus, where it is
 407   // equal to 11 bytes which is the largest address NOP instruction.
 408   if (MaxLoopPad < OptoLoopAlignment - 1) {
 409     uint last_block = C->cfg()->number_of_blocks() - 1;
 410     for (uint i = 1; i <= last_block; i++) {
 411       Block* block = C->cfg()->get_block(i);
 412       // Check the first loop's block which requires an alignment.
 413       if (block->loop_alignment() > (uint)relocInfo::addr_unit()) {
 414         uint sum_size = 0;
 415         uint inst_cnt = NumberOfLoopInstrToAlign;
 416         inst_cnt = block->compute_first_inst_size(sum_size, inst_cnt, C->regalloc());
 417 
 418         // Check subsequent fallthrough blocks if the loop's first
 419         // block(s) does not have enough instructions.
 420         Block *nb = block;
 421         while(inst_cnt > 0 &&
 422               i < last_block &&
 423               !C->cfg()->get_block(i + 1)->has_loop_alignment() &&
 424               !nb->has_successor(block)) {
 425           i++;
 426           nb = C->cfg()->get_block(i);
 427           inst_cnt  = nb->compute_first_inst_size(sum_size, inst_cnt, C->regalloc());
 428         } // while( inst_cnt > 0 && i < last_block  )
 429 
 430         block->set_first_inst_size(sum_size);
 431       } // f( b->head()->is_Loop() )
 432     } // for( i <= last_block )
 433   } // if( MaxLoopPad < OptoLoopAlignment-1 )
 434 }
 435 
 436 // The architecture description provides short branch variants for some long
 437 // branch instructions. Replace eligible long branches with short branches.
 438 void PhaseOutput::shorten_branches(uint* blk_starts) {
 439 
 440   Compile::TracePhase tp(_t_shortenBranches);
 441 
 442   // Compute size of each block, method size, and relocation information size
 443   uint nblocks  = C->cfg()->number_of_blocks();
 444 
 445   uint*      jmp_offset = NEW_RESOURCE_ARRAY(uint,nblocks);
 446   uint*      jmp_size   = NEW_RESOURCE_ARRAY(uint,nblocks);
 447   int*       jmp_nidx   = NEW_RESOURCE_ARRAY(int ,nblocks);
 448 
 449   // Collect worst case block paddings
 450   int* block_worst_case_pad = NEW_RESOURCE_ARRAY(int, nblocks);
 451   memset(block_worst_case_pad, 0, nblocks * sizeof(int));
 452 
 453   DEBUG_ONLY( uint *jmp_target = NEW_RESOURCE_ARRAY(uint,nblocks); )
 454   DEBUG_ONLY( uint *jmp_rule = NEW_RESOURCE_ARRAY(uint,nblocks); )
 455 
 456   bool has_short_branch_candidate = false;
 457 
 458   // Initialize the sizes to 0
 459   int code_size  = 0;          // Size in bytes of generated code
 460   int stub_size  = 0;          // Size in bytes of all stub entries
 461   // Size in bytes of all relocation entries, including those in local stubs.
 462   // Start with 2-bytes of reloc info for the unvalidated entry point
 463   int reloc_size = 1;          // Number of relocation entries
 464 
 465   // Make three passes.  The first computes pessimistic blk_starts,
 466   // relative jmp_offset and reloc_size information.  The second performs
 467   // short branch substitution using the pessimistic sizing.  The
 468   // third inserts nops where needed.
 469 
 470   // Step one, perform a pessimistic sizing pass.
 471   uint last_call_adr = max_juint;
 472   uint last_avoid_back_to_back_adr = max_juint;
 473   uint nop_size = (new MachNopNode())->size(C->regalloc());
 474   for (uint i = 0; i < nblocks; i++) { // For all blocks
 475     Block* block = C->cfg()->get_block(i);
 476     _block = block;
 477 
 478     // During short branch replacement, we store the relative (to blk_starts)
 479     // offset of jump in jmp_offset, rather than the absolute offset of jump.
 480     // This is so that we do not need to recompute sizes of all nodes when
 481     // we compute correct blk_starts in our next sizing pass.
 482     jmp_offset[i] = 0;
 483     jmp_size[i]   = 0;
 484     jmp_nidx[i]   = -1;
 485     DEBUG_ONLY( jmp_target[i] = 0; )
 486     DEBUG_ONLY( jmp_rule[i]   = 0; )
 487 
 488     // Sum all instruction sizes to compute block size
 489     uint last_inst = block->number_of_nodes();
 490     uint blk_size = 0;
 491     for (uint j = 0; j < last_inst; j++) {
 492       _index = j;
 493       Node* nj = block->get_node(_index);
 494       // Handle machine instruction nodes
 495       if (nj->is_Mach()) {
 496         MachNode* mach = nj->as_Mach();
 497         blk_size += (mach->alignment_required() - 1) * relocInfo::addr_unit(); // assume worst case padding
 498         reloc_size += mach->reloc();
 499         if (mach->is_MachCall()) {
 500           // add size information for trampoline stub
 501           // class CallStubImpl is platform-specific and defined in the *.ad files.
 502           stub_size  += CallStubImpl::size_call_trampoline();
 503           reloc_size += CallStubImpl::reloc_call_trampoline();
 504 
 505           MachCallNode *mcall = mach->as_MachCall();
 506           // This destination address is NOT PC-relative
 507 
 508           mcall->method_set((intptr_t)mcall->entry_point());
 509 
 510           if (mcall->is_MachCallJava() && mcall->as_MachCallJava()->_method) {
 511             stub_size  += CompiledDirectCall::to_interp_stub_size();
 512             reloc_size += CompiledDirectCall::reloc_to_interp_stub();
 513           }
 514         } else if (mach->is_MachSafePoint()) {
 515           // If call/safepoint are adjacent, account for possible
 516           // nop to disambiguate the two safepoints.
 517           // ScheduleAndBundle() can rearrange nodes in a block,
 518           // check for all offsets inside this block.
 519           if (last_call_adr >= blk_starts[i]) {
 520             blk_size += nop_size;
 521           }
 522         }
 523         if (mach->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
 524           // Nop is inserted between "avoid back to back" instructions.
 525           // ScheduleAndBundle() can rearrange nodes in a block,
 526           // check for all offsets inside this block.
 527           if (last_avoid_back_to_back_adr >= blk_starts[i]) {
 528             blk_size += nop_size;
 529           }
 530         }
 531         if (mach->may_be_short_branch()) {
 532           if (!nj->is_MachBranch()) {
 533 #ifndef PRODUCT
 534             nj->dump(3);
 535 #endif
 536             Unimplemented();
 537           }
 538           assert(jmp_nidx[i] == -1, "block should have only one branch");
 539           jmp_offset[i] = blk_size;
 540           jmp_size[i]   = nj->size(C->regalloc());
 541           jmp_nidx[i]   = j;
 542           has_short_branch_candidate = true;
 543         }
 544       }
 545       blk_size += nj->size(C->regalloc());
 546       // Remember end of call offset
 547       if (nj->is_MachCall() && !nj->is_MachCallLeaf()) {
 548         last_call_adr = blk_starts[i]+blk_size;
 549       }
 550       // Remember end of avoid_back_to_back offset
 551       if (nj->is_Mach() && nj->as_Mach()->avoid_back_to_back(MachNode::AVOID_AFTER)) {
 552         last_avoid_back_to_back_adr = blk_starts[i]+blk_size;
 553       }
 554     }
 555 
 556     // When the next block starts a loop, we may insert pad NOP
 557     // instructions.  Since we cannot know our future alignment,
 558     // assume the worst.
 559     if (i < nblocks - 1) {
 560       Block* nb = C->cfg()->get_block(i + 1);
 561       int max_loop_pad = nb->code_alignment()-relocInfo::addr_unit();
 562       if (max_loop_pad > 0) {
 563         assert(is_power_of_2(max_loop_pad+relocInfo::addr_unit()), "");
 564         // Adjust last_call_adr and/or last_avoid_back_to_back_adr.
 565         // If either is the last instruction in this block, bump by
 566         // max_loop_pad in lock-step with blk_size, so sizing
 567         // calculations in subsequent blocks still can conservatively
 568         // detect that it may the last instruction in this block.
 569         if (last_call_adr == blk_starts[i]+blk_size) {
 570           last_call_adr += max_loop_pad;
 571         }
 572         if (last_avoid_back_to_back_adr == blk_starts[i]+blk_size) {
 573           last_avoid_back_to_back_adr += max_loop_pad;
 574         }
 575         blk_size += max_loop_pad;
 576         block_worst_case_pad[i + 1] = max_loop_pad;
 577       }
 578     }
 579 
 580     // Save block size; update total method size
 581     blk_starts[i+1] = blk_starts[i]+blk_size;
 582   }
 583 
 584   // Step two, replace eligible long jumps.
 585   bool progress = true;
 586   uint last_may_be_short_branch_adr = max_juint;
 587   while (has_short_branch_candidate && progress) {
 588     progress = false;
 589     has_short_branch_candidate = false;
 590     int adjust_block_start = 0;
 591     for (uint i = 0; i < nblocks; i++) {
 592       Block* block = C->cfg()->get_block(i);
 593       int idx = jmp_nidx[i];
 594       MachNode* mach = (idx == -1) ? nullptr: block->get_node(idx)->as_Mach();
 595       if (mach != nullptr && mach->may_be_short_branch()) {
 596 #ifdef ASSERT
 597         assert(jmp_size[i] > 0 && mach->is_MachBranch(), "sanity");
 598         int j;
 599         // Find the branch; ignore trailing NOPs.
 600         for (j = block->number_of_nodes()-1; j>=0; j--) {
 601           Node* n = block->get_node(j);
 602           if (!n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con)
 603             break;
 604         }
 605         assert(j >= 0 && j == idx && block->get_node(j) == (Node*)mach, "sanity");
 606 #endif
 607         int br_size = jmp_size[i];
 608         int br_offs = blk_starts[i] + jmp_offset[i];
 609 
 610         // This requires the TRUE branch target be in succs[0]
 611         uint bnum = block->non_connector_successor(0)->_pre_order;
 612         int offset = blk_starts[bnum] - br_offs;
 613         if (bnum > i) { // adjust following block's offset
 614           offset -= adjust_block_start;
 615         }
 616 
 617         // This block can be a loop header, account for the padding
 618         // in the previous block.
 619         int block_padding = block_worst_case_pad[i];
 620         assert(i == 0 || block_padding == 0 || br_offs >= block_padding, "Should have at least a padding on top");
 621         // In the following code a nop could be inserted before
 622         // the branch which will increase the backward distance.
 623         bool needs_padding = ((uint)(br_offs - block_padding) == last_may_be_short_branch_adr);
 624         assert(!needs_padding || jmp_offset[i] == 0, "padding only branches at the beginning of block");
 625 
 626         if (needs_padding && offset <= 0)
 627           offset -= nop_size;
 628 
 629         if (C->matcher()->is_short_branch_offset(mach->rule(), br_size, offset)) {
 630           // We've got a winner.  Replace this branch.
 631           MachNode* replacement = mach->as_MachBranch()->short_branch_version();
 632 
 633           // Update the jmp_size.
 634           int new_size = replacement->size(C->regalloc());
 635           int diff     = br_size - new_size;
 636           assert(diff >= (int)nop_size, "short_branch size should be smaller");
 637           // Conservatively take into account padding between
 638           // avoid_back_to_back branches. Previous branch could be
 639           // converted into avoid_back_to_back branch during next
 640           // rounds.
 641           if (needs_padding && replacement->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
 642             jmp_offset[i] += nop_size;
 643             diff -= nop_size;
 644           }
 645           adjust_block_start += diff;
 646           block->map_node(replacement, idx);
 647           mach->subsume_by(replacement, C);
 648           mach = replacement;
 649           progress = true;
 650 
 651           jmp_size[i] = new_size;
 652           DEBUG_ONLY( jmp_target[i] = bnum; );
 653           DEBUG_ONLY( jmp_rule[i] = mach->rule(); );
 654         } else {
 655           // The jump distance is not short, try again during next iteration.
 656           has_short_branch_candidate = true;
 657         }
 658       } // (mach->may_be_short_branch())
 659       if (mach != nullptr && (mach->may_be_short_branch() ||
 660                            mach->avoid_back_to_back(MachNode::AVOID_AFTER))) {
 661         last_may_be_short_branch_adr = blk_starts[i] + jmp_offset[i] + jmp_size[i];
 662       }
 663       blk_starts[i+1] -= adjust_block_start;
 664     }
 665   }
 666 
 667 #ifdef ASSERT
 668   for (uint i = 0; i < nblocks; i++) { // For all blocks
 669     if (jmp_target[i] != 0) {
 670       int br_size = jmp_size[i];
 671       int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_offset[i]);
 672       if (!C->matcher()->is_short_branch_offset(jmp_rule[i], br_size, offset)) {
 673         tty->print_cr("target (%d) - jmp_offset(%d) = offset (%d), jump_size(%d), jmp_block B%d, target_block B%d", blk_starts[jmp_target[i]], blk_starts[i] + jmp_offset[i], offset, br_size, i, jmp_target[i]);
 674       }
 675       assert(C->matcher()->is_short_branch_offset(jmp_rule[i], br_size, offset), "Displacement too large for short jmp");
 676     }
 677   }
 678 #endif
 679 
 680   // Step 3, compute the offsets of all blocks, will be done in fill_buffer()
 681   // after ScheduleAndBundle().
 682 
 683   // ------------------
 684   // Compute size for code buffer
 685   code_size = blk_starts[nblocks];
 686 
 687   // Relocation records
 688   reloc_size += 1;              // Relo entry for exception handler
 689 
 690   // Adjust reloc_size to number of record of relocation info
 691   // Min is 2 bytes, max is probably 6 or 8, with a tax up to 25% for
 692   // a relocation index.
 693   // The CodeBuffer will expand the locs array if this estimate is too low.
 694   reloc_size *= 10 / sizeof(relocInfo);
 695 
 696   _buf_sizes._reloc = reloc_size;
 697   _buf_sizes._code  = code_size;
 698   _buf_sizes._stub  = stub_size;
 699 }
 700 
 701 //------------------------------FillLocArray-----------------------------------
 702 // Create a bit of debug info and append it to the array.  The mapping is from
 703 // Java local or expression stack to constant, register or stack-slot.  For
 704 // doubles, insert 2 mappings and return 1 (to tell the caller that the next
 705 // entry has been taken care of and caller should skip it).
 706 static LocationValue *new_loc_value( PhaseRegAlloc *ra, OptoReg::Name regnum, Location::Type l_type ) {
 707   // This should never have accepted Bad before
 708   assert(OptoReg::is_valid(regnum), "location must be valid");
 709   return (OptoReg::is_reg(regnum))
 710          ? new LocationValue(Location::new_reg_loc(l_type, OptoReg::as_VMReg(regnum)) )
 711          : new LocationValue(Location::new_stk_loc(l_type,  ra->reg2offset(regnum)));
 712 }
 713 
 714 
 715 ObjectValue*
 716 PhaseOutput::sv_for_node_id(GrowableArray<ScopeValue*> *objs, int id) {
 717   for (int i = 0; i < objs->length(); i++) {
 718     assert(objs->at(i)->is_object(), "corrupt object cache");
 719     ObjectValue* sv = objs->at(i)->as_ObjectValue();
 720     if (sv->id() == id) {
 721       return sv;
 722     }
 723   }
 724   // Otherwise..
 725   return nullptr;
 726 }
 727 
 728 void PhaseOutput::set_sv_for_object_node(GrowableArray<ScopeValue*> *objs,
 729                                      ObjectValue* sv ) {
 730   assert(sv_for_node_id(objs, sv->id()) == nullptr, "Precondition");
 731   objs->append(sv);
 732 }
 733 
 734 
 735 void PhaseOutput::FillLocArray( int idx, MachSafePointNode* sfpt, Node *local,
 736                             GrowableArray<ScopeValue*> *array,
 737                             GrowableArray<ScopeValue*> *objs ) {
 738   assert( local, "use _top instead of null" );
 739   if (array->length() != idx) {
 740     assert(array->length() == idx + 1, "Unexpected array count");
 741     // Old functionality:
 742     //   return
 743     // New functionality:
 744     //   Assert if the local is not top. In product mode let the new node
 745     //   override the old entry.
 746     assert(local == C->top(), "LocArray collision");
 747     if (local == C->top()) {
 748       return;
 749     }
 750     array->pop();
 751   }
 752   const Type *t = local->bottom_type();
 753 
 754   // Is it a safepoint scalar object node?
 755   if (local->is_SafePointScalarObject()) {
 756     SafePointScalarObjectNode* spobj = local->as_SafePointScalarObject();
 757 
 758     ObjectValue* sv = sv_for_node_id(objs, spobj->_idx);
 759     if (sv == nullptr) {
 760       ciKlass* cik = t->is_oopptr()->exact_klass();
 761       assert(cik->is_instance_klass() ||
 762              cik->is_array_klass(), "Not supported allocation.");
 763       sv = new ObjectValue(spobj->_idx,
 764                            new ConstantOopWriteValue(cik->java_mirror()->constant_encoding()));
 765       set_sv_for_object_node(objs, sv);
 766 
 767       uint first_ind = spobj->first_index(sfpt->jvms());
 768       for (uint i = 0; i < spobj->n_fields(); i++) {
 769         Node* fld_node = sfpt->in(first_ind+i);
 770         (void)FillLocArray(sv->field_values()->length(), sfpt, fld_node, sv->field_values(), objs);
 771       }
 772     }
 773     array->append(sv);
 774     return;
 775   } else if (local->is_SafePointScalarMerge()) {
 776     SafePointScalarMergeNode* smerge = local->as_SafePointScalarMerge();
 777     ObjectMergeValue* mv = (ObjectMergeValue*) sv_for_node_id(objs, smerge->_idx);
 778 
 779     if (mv == nullptr) {
 780       GrowableArray<ScopeValue*> deps;
 781 
 782       int merge_pointer_idx = smerge->merge_pointer_idx(sfpt->jvms());
 783       (void)FillLocArray(0, sfpt, sfpt->in(merge_pointer_idx), &deps, objs);
 784       assert(deps.length() == 1, "missing value");
 785 
 786       int selector_idx = smerge->selector_idx(sfpt->jvms());
 787       (void)FillLocArray(1, nullptr, sfpt->in(selector_idx), &deps, nullptr);
 788       assert(deps.length() == 2, "missing value");
 789 
 790       mv = new ObjectMergeValue(smerge->_idx, deps.at(0), deps.at(1));
 791       set_sv_for_object_node(objs, mv);
 792 
 793       for (uint i = 1; i < smerge->req(); i++) {
 794         Node* obj_node = smerge->in(i);
 795         int idx = mv->possible_objects()->length();
 796         (void)FillLocArray(idx, sfpt, obj_node, mv->possible_objects(), objs);
 797 
 798         // By default ObjectValues that are in 'possible_objects' are not root objects.
 799         // They will be marked as root later if they are directly referenced in a JVMS.
 800         assert(mv->possible_objects()->length() > idx, "Didn't add entry to possible_objects?!");
 801         assert(mv->possible_objects()->at(idx)->is_object(), "Entries in possible_objects should be ObjectValue.");
 802         mv->possible_objects()->at(idx)->as_ObjectValue()->set_root(false);
 803       }
 804     }
 805     array->append(mv);
 806     return;
 807   }
 808 
 809   // Grab the register number for the local
 810   OptoReg::Name regnum = C->regalloc()->get_reg_first(local);
 811   if( OptoReg::is_valid(regnum) ) {// Got a register/stack?
 812     // Record the double as two float registers.
 813     // The register mask for such a value always specifies two adjacent
 814     // float registers, with the lower register number even.
 815     // Normally, the allocation of high and low words to these registers
 816     // is irrelevant, because nearly all operations on register pairs
 817     // (e.g., StoreD) treat them as a single unit.
 818     // Here, we assume in addition that the words in these two registers
 819     // stored "naturally" (by operations like StoreD and double stores
 820     // within the interpreter) such that the lower-numbered register
 821     // is written to the lower memory address.  This may seem like
 822     // a machine dependency, but it is not--it is a requirement on
 823     // the author of the <arch>.ad file to ensure that, for every
 824     // even/odd double-register pair to which a double may be allocated,
 825     // the word in the even single-register is stored to the first
 826     // memory word.  (Note that register numbers are completely
 827     // arbitrary, and are not tied to any machine-level encodings.)
 828 #ifdef _LP64
 829     if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon ) {
 830       array->append(new ConstantIntValue((jint)0));
 831       array->append(new_loc_value( C->regalloc(), regnum, Location::dbl ));
 832     } else if ( t->base() == Type::Long ) {
 833       array->append(new ConstantIntValue((jint)0));
 834       array->append(new_loc_value( C->regalloc(), regnum, Location::lng ));
 835     } else if ( t->base() == Type::RawPtr ) {
 836       // jsr/ret return address which must be restored into the full
 837       // width 64-bit stack slot.
 838       array->append(new_loc_value( C->regalloc(), regnum, Location::lng ));
 839     }
 840 #else //_LP64
 841     if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon || t->base() == Type::Long ) {
 842       // Repack the double/long as two jints.
 843       // The convention the interpreter uses is that the second local
 844       // holds the first raw word of the native double representation.
 845       // This is actually reasonable, since locals and stack arrays
 846       // grow downwards in all implementations.
 847       // (If, on some machine, the interpreter's Java locals or stack
 848       // were to grow upwards, the embedded doubles would be word-swapped.)
 849       array->append(new_loc_value( C->regalloc(), OptoReg::add(regnum,1), Location::normal ));
 850       array->append(new_loc_value( C->regalloc(),              regnum   , Location::normal ));
 851     }
 852 #endif //_LP64
 853     else if( (t->base() == Type::FloatBot || t->base() == Type::FloatCon) &&
 854              OptoReg::is_reg(regnum) ) {
 855       array->append(new_loc_value( C->regalloc(), regnum, Matcher::float_in_double()
 856                                                       ? Location::float_in_dbl : Location::normal ));
 857     } else if( t->base() == Type::Int && OptoReg::is_reg(regnum) ) {
 858       array->append(new_loc_value( C->regalloc(), regnum, Matcher::int_in_long
 859                                                       ? Location::int_in_long : Location::normal ));
 860     } else if( t->base() == Type::NarrowOop ) {
 861       array->append(new_loc_value( C->regalloc(), regnum, Location::narrowoop ));
 862     } else if (t->base() == Type::VectorA || t->base() == Type::VectorS ||
 863                t->base() == Type::VectorD || t->base() == Type::VectorX ||
 864                t->base() == Type::VectorY || t->base() == Type::VectorZ) {
 865       array->append(new_loc_value( C->regalloc(), regnum, Location::vector ));
 866     } else if (C->regalloc()->is_oop(local)) {
 867       assert(t->base() == Type::OopPtr || t->base() == Type::InstPtr ||
 868              t->base() == Type::AryPtr,
 869              "Unexpected type: %s", t->msg());
 870       array->append(new_loc_value( C->regalloc(), regnum, Location::oop ));
 871     } else {
 872       assert(t->base() == Type::Int || t->base() == Type::Half ||
 873              t->base() == Type::FloatCon || t->base() == Type::FloatBot,
 874              "Unexpected type: %s", t->msg());
 875       array->append(new_loc_value( C->regalloc(), regnum, Location::normal ));
 876     }
 877     return;
 878   }
 879 
 880   // No register.  It must be constant data.
 881   switch (t->base()) {
 882     case Type::Half:              // Second half of a double
 883       ShouldNotReachHere();       // Caller should skip 2nd halves
 884       break;
 885     case Type::AnyPtr:
 886       array->append(new ConstantOopWriteValue(nullptr));
 887       break;
 888     case Type::AryPtr:
 889     case Type::InstPtr:          // fall through
 890       array->append(new ConstantOopWriteValue(t->isa_oopptr()->const_oop()->constant_encoding()));
 891       break;
 892     case Type::NarrowOop:
 893       if (t == TypeNarrowOop::NULL_PTR) {
 894         array->append(new ConstantOopWriteValue(nullptr));
 895       } else {
 896         array->append(new ConstantOopWriteValue(t->make_ptr()->isa_oopptr()->const_oop()->constant_encoding()));
 897       }
 898       break;
 899     case Type::Int:
 900       array->append(new ConstantIntValue(t->is_int()->get_con()));
 901       break;
 902     case Type::RawPtr:
 903       // A return address (T_ADDRESS).
 904       assert((intptr_t)t->is_ptr()->get_con() < (intptr_t)0x10000, "must be a valid BCI");
 905 #ifdef _LP64
 906       // Must be restored to the full-width 64-bit stack slot.
 907       array->append(new ConstantLongValue(t->is_ptr()->get_con()));
 908 #else
 909       array->append(new ConstantIntValue(t->is_ptr()->get_con()));
 910 #endif
 911       break;
 912     case Type::FloatCon: {
 913       float f = t->is_float_constant()->getf();
 914       array->append(new ConstantIntValue(jint_cast(f)));
 915       break;
 916     }
 917     case Type::DoubleCon: {
 918       jdouble d = t->is_double_constant()->getd();
 919 #ifdef _LP64
 920       array->append(new ConstantIntValue((jint)0));
 921       array->append(new ConstantDoubleValue(d));
 922 #else
 923       // Repack the double as two jints.
 924     // The convention the interpreter uses is that the second local
 925     // holds the first raw word of the native double representation.
 926     // This is actually reasonable, since locals and stack arrays
 927     // grow downwards in all implementations.
 928     // (If, on some machine, the interpreter's Java locals or stack
 929     // were to grow upwards, the embedded doubles would be word-swapped.)
 930     jlong_accessor acc;
 931     acc.long_value = jlong_cast(d);
 932     array->append(new ConstantIntValue(acc.words[1]));
 933     array->append(new ConstantIntValue(acc.words[0]));
 934 #endif
 935       break;
 936     }
 937     case Type::Long: {
 938       jlong d = t->is_long()->get_con();
 939 #ifdef _LP64
 940       array->append(new ConstantIntValue((jint)0));
 941       array->append(new ConstantLongValue(d));
 942 #else
 943       // Repack the long as two jints.
 944     // The convention the interpreter uses is that the second local
 945     // holds the first raw word of the native double representation.
 946     // This is actually reasonable, since locals and stack arrays
 947     // grow downwards in all implementations.
 948     // (If, on some machine, the interpreter's Java locals or stack
 949     // were to grow upwards, the embedded doubles would be word-swapped.)
 950     jlong_accessor acc;
 951     acc.long_value = d;
 952     array->append(new ConstantIntValue(acc.words[1]));
 953     array->append(new ConstantIntValue(acc.words[0]));
 954 #endif
 955       break;
 956     }
 957     case Type::Top:               // Add an illegal value here
 958       array->append(new LocationValue(Location()));
 959       break;
 960     default:
 961       ShouldNotReachHere();
 962       break;
 963   }
 964 }
 965 
 966 // Determine if this node starts a bundle
 967 bool PhaseOutput::starts_bundle(const Node *n) const {
 968   return (_node_bundling_limit > n->_idx &&
 969           _node_bundling_base[n->_idx].starts_bundle());
 970 }
 971 
 972 // Determine if there is a monitor that has 'ov' as its owner.
 973 bool PhaseOutput::contains_as_owner(GrowableArray<MonitorValue*> *monarray, ObjectValue *ov) const {
 974   for (int k = 0; k < monarray->length(); k++) {
 975     MonitorValue* mv = monarray->at(k);
 976     if (mv->owner() == ov) {
 977       return true;
 978     }
 979   }
 980 
 981   return false;
 982 }
 983 
 984 // Determine if there is a scalar replaced object description represented by 'ov'.
 985 bool PhaseOutput::contains_as_scalarized_obj(JVMState* jvms, MachSafePointNode* sfn,
 986                                              GrowableArray<ScopeValue*>* objs,
 987                                              ObjectValue* ov) const {
 988   for (int i = 0; i < jvms->scl_size(); i++) {
 989     Node* n = sfn->scalarized_obj(jvms, i);
 990     // Other kinds of nodes that we may encounter here, for instance constants
 991     // representing values of fields of objects scalarized, aren't relevant for
 992     // us, since they don't map to ObjectValue.
 993     if (!n->is_SafePointScalarObject()) {
 994       continue;
 995     }
 996 
 997     ObjectValue* other = sv_for_node_id(objs, n->_idx);
 998     if (ov == other) {
 999       return true;
1000     }
1001   }
1002   return false;
1003 }
1004 
1005 //--------------------------Process_OopMap_Node--------------------------------
1006 void PhaseOutput::Process_OopMap_Node(MachNode *mach, int current_offset) {
1007   // Handle special safepoint nodes for synchronization
1008   MachSafePointNode *sfn   = mach->as_MachSafePoint();
1009   MachCallNode      *mcall;
1010 
1011   int safepoint_pc_offset = current_offset;
1012   bool is_method_handle_invoke = false;
1013   bool return_oop = false;
1014   bool has_ea_local_in_scope = sfn->_has_ea_local_in_scope;
1015   bool arg_escape = false;
1016 
1017   // Add the safepoint in the DebugInfoRecorder
1018   if( !mach->is_MachCall() ) {
1019     mcall = nullptr;
1020     C->debug_info()->add_safepoint(safepoint_pc_offset, sfn->_oop_map);
1021   } else {
1022     mcall = mach->as_MachCall();
1023 
1024     // Is the call a MethodHandle call?
1025     if (mcall->is_MachCallJava()) {
1026       if (mcall->as_MachCallJava()->_method_handle_invoke) {
1027         assert(C->has_method_handle_invokes(), "must have been set during call generation");
1028         is_method_handle_invoke = true;
1029       }
1030       arg_escape = mcall->as_MachCallJava()->_arg_escape;
1031     }
1032 
1033     // Check if a call returns an object.
1034     if (mcall->returns_pointer()) {
1035       return_oop = true;
1036     }
1037     safepoint_pc_offset += mcall->ret_addr_offset();
1038     C->debug_info()->add_safepoint(safepoint_pc_offset, mcall->_oop_map);
1039   }
1040 
1041   // Loop over the JVMState list to add scope information
1042   // Do not skip safepoints with a null method, they need monitor info
1043   JVMState* youngest_jvms = sfn->jvms();
1044   int max_depth = youngest_jvms->depth();
1045 
1046   // Allocate the object pool for scalar-replaced objects -- the map from
1047   // small-integer keys (which can be recorded in the local and ostack
1048   // arrays) to descriptions of the object state.
1049   GrowableArray<ScopeValue*> *objs = new GrowableArray<ScopeValue*>();
1050 
1051   // Visit scopes from oldest to youngest.
1052   for (int depth = 1; depth <= max_depth; depth++) {
1053     JVMState* jvms = youngest_jvms->of_depth(depth);
1054     int idx;
1055     ciMethod* method = jvms->has_method() ? jvms->method() : nullptr;
1056     // Safepoints that do not have method() set only provide oop-map and monitor info
1057     // to support GC; these do not support deoptimization.
1058     int num_locs = (method == nullptr) ? 0 : jvms->loc_size();
1059     int num_exps = (method == nullptr) ? 0 : jvms->stk_size();
1060     int num_mon  = jvms->nof_monitors();
1061     assert(method == nullptr || jvms->bci() < 0 || num_locs == method->max_locals(),
1062            "JVMS local count must match that of the method");
1063 
1064     // Add Local and Expression Stack Information
1065 
1066     // Insert locals into the locarray
1067     GrowableArray<ScopeValue*> *locarray = new GrowableArray<ScopeValue*>(num_locs);
1068     for( idx = 0; idx < num_locs; idx++ ) {
1069       FillLocArray( idx, sfn, sfn->local(jvms, idx), locarray, objs );
1070     }
1071 
1072     // Insert expression stack entries into the exparray
1073     GrowableArray<ScopeValue*> *exparray = new GrowableArray<ScopeValue*>(num_exps);
1074     for( idx = 0; idx < num_exps; idx++ ) {
1075       FillLocArray( idx,  sfn, sfn->stack(jvms, idx), exparray, objs );
1076     }
1077 
1078     // Add in mappings of the monitors
1079     assert( !method ||
1080             !method->is_synchronized() ||
1081             method->is_native() ||
1082             num_mon > 0 ||
1083             !GenerateSynchronizationCode,
1084             "monitors must always exist for synchronized methods");
1085 
1086     // Build the growable array of ScopeValues for exp stack
1087     GrowableArray<MonitorValue*> *monarray = new GrowableArray<MonitorValue*>(num_mon);
1088 
1089     // Loop over monitors and insert into array
1090     for (idx = 0; idx < num_mon; idx++) {
1091       // Grab the node that defines this monitor
1092       Node* box_node = sfn->monitor_box(jvms, idx);
1093       Node* obj_node = sfn->monitor_obj(jvms, idx);
1094 
1095       // Create ScopeValue for object
1096       ScopeValue *scval = nullptr;
1097 
1098       if (obj_node->is_SafePointScalarObject()) {
1099         SafePointScalarObjectNode* spobj = obj_node->as_SafePointScalarObject();
1100         scval = PhaseOutput::sv_for_node_id(objs, spobj->_idx);
1101         if (scval == nullptr) {
1102           const Type *t = spobj->bottom_type();
1103           ciKlass* cik = t->is_oopptr()->exact_klass();
1104           assert(cik->is_instance_klass() ||
1105                  cik->is_array_klass(), "Not supported allocation.");
1106           ObjectValue* sv = new ObjectValue(spobj->_idx,
1107                                             new ConstantOopWriteValue(cik->java_mirror()->constant_encoding()));
1108           PhaseOutput::set_sv_for_object_node(objs, sv);
1109 
1110           uint first_ind = spobj->first_index(youngest_jvms);
1111           for (uint i = 0; i < spobj->n_fields(); i++) {
1112             Node* fld_node = sfn->in(first_ind+i);
1113             (void)FillLocArray(sv->field_values()->length(), sfn, fld_node, sv->field_values(), objs);
1114           }
1115           scval = sv;
1116         }
1117       } else if (obj_node->is_SafePointScalarMerge()) {
1118         SafePointScalarMergeNode* smerge = obj_node->as_SafePointScalarMerge();
1119         ObjectMergeValue* mv = (ObjectMergeValue*) sv_for_node_id(objs, smerge->_idx);
1120 
1121         if (mv == nullptr) {
1122           GrowableArray<ScopeValue*> deps;
1123 
1124           int merge_pointer_idx = smerge->merge_pointer_idx(youngest_jvms);
1125           FillLocArray(0, sfn, sfn->in(merge_pointer_idx), &deps, objs);
1126           assert(deps.length() == 1, "missing value");
1127 
1128           int selector_idx = smerge->selector_idx(youngest_jvms);
1129           FillLocArray(1, nullptr, sfn->in(selector_idx), &deps, nullptr);
1130           assert(deps.length() == 2, "missing value");
1131 
1132           mv = new ObjectMergeValue(smerge->_idx, deps.at(0), deps.at(1));
1133           set_sv_for_object_node(objs, mv);
1134 
1135           for (uint i = 1; i < smerge->req(); i++) {
1136             Node* obj_node = smerge->in(i);
1137             int idx = mv->possible_objects()->length();
1138             (void)FillLocArray(idx, sfn, obj_node, mv->possible_objects(), objs);
1139 
1140             // By default ObjectValues that are in 'possible_objects' are not root objects.
1141             // They will be marked as root later if they are directly referenced in a JVMS.
1142             assert(mv->possible_objects()->length() > idx, "Didn't add entry to possible_objects?!");
1143             assert(mv->possible_objects()->at(idx)->is_object(), "Entries in possible_objects should be ObjectValue.");
1144             mv->possible_objects()->at(idx)->as_ObjectValue()->set_root(false);
1145           }
1146         }
1147         scval = mv;
1148       } else if (!obj_node->is_Con()) {
1149         OptoReg::Name obj_reg = C->regalloc()->get_reg_first(obj_node);
1150         if( obj_node->bottom_type()->base() == Type::NarrowOop ) {
1151           scval = new_loc_value( C->regalloc(), obj_reg, Location::narrowoop );
1152         } else {
1153           scval = new_loc_value( C->regalloc(), obj_reg, Location::oop );
1154         }
1155       } else {
1156         const TypePtr *tp = obj_node->get_ptr_type();
1157         scval = new ConstantOopWriteValue(tp->is_oopptr()->const_oop()->constant_encoding());
1158       }
1159 
1160       OptoReg::Name box_reg = BoxLockNode::reg(box_node);
1161       Location basic_lock = Location::new_stk_loc(Location::normal,C->regalloc()->reg2offset(box_reg));
1162       bool eliminated = (box_node->is_BoxLock() && box_node->as_BoxLock()->is_eliminated());
1163       monarray->append(new MonitorValue(scval, basic_lock, eliminated));
1164     }
1165 
1166     // Mark ObjectValue nodes as root nodes if they are directly
1167     // referenced in the JVMS.
1168     for (int i = 0; i < objs->length(); i++) {
1169       ScopeValue* sv = objs->at(i);
1170       if (sv->is_object_merge()) {
1171         ObjectMergeValue* merge = sv->as_ObjectMergeValue();
1172 
1173         for (int j = 0; j< merge->possible_objects()->length(); j++) {
1174           ObjectValue* ov = merge->possible_objects()->at(j)->as_ObjectValue();
1175           if (ov->is_root()) {
1176             // Already flagged as 'root' by something else. We shouldn't change it
1177             // to non-root in a younger JVMS because it may need to be alive in
1178             // a younger JVMS.
1179           } else {
1180             bool is_root = locarray->contains(ov) ||
1181                            exparray->contains(ov) ||
1182                            contains_as_owner(monarray, ov) ||
1183                            contains_as_scalarized_obj(jvms, sfn, objs, ov);
1184             ov->set_root(is_root);
1185           }
1186         }
1187       }
1188     }
1189 
1190     // We dump the object pool first, since deoptimization reads it in first.
1191     C->debug_info()->dump_object_pool(objs);
1192 
1193     // Build first class objects to pass to scope
1194     DebugToken *locvals = C->debug_info()->create_scope_values(locarray);
1195     DebugToken *expvals = C->debug_info()->create_scope_values(exparray);
1196     DebugToken *monvals = C->debug_info()->create_monitor_values(monarray);
1197 
1198     // Make method available for all Safepoints
1199     ciMethod* scope_method = method ? method : C->method();
1200     // Describe the scope here
1201     assert(jvms->bci() >= InvocationEntryBci && jvms->bci() <= 0x10000, "must be a valid or entry BCI");
1202     assert(!jvms->should_reexecute() || depth == max_depth, "reexecute allowed only for the youngest");
1203     // Now we can describe the scope.
1204     methodHandle null_mh;
1205     bool rethrow_exception = false;
1206     C->debug_info()->describe_scope(
1207       safepoint_pc_offset,
1208       null_mh,
1209       scope_method,
1210       jvms->bci(),
1211       jvms->should_reexecute(),
1212       rethrow_exception,
1213       is_method_handle_invoke,
1214       return_oop,
1215       has_ea_local_in_scope,
1216       arg_escape,
1217       locvals,
1218       expvals,
1219       monvals
1220     );
1221   } // End jvms loop
1222 
1223   // Mark the end of the scope set.
1224   C->debug_info()->end_safepoint(safepoint_pc_offset);
1225 }
1226 
1227 
1228 
1229 // A simplified version of Process_OopMap_Node, to handle non-safepoints.
1230 class NonSafepointEmitter {
1231     Compile*  C;
1232     JVMState* _pending_jvms;
1233     int       _pending_offset;
1234 
1235     void emit_non_safepoint();
1236 
1237  public:
1238     NonSafepointEmitter(Compile* compile) {
1239       this->C = compile;
1240       _pending_jvms = nullptr;
1241       _pending_offset = 0;
1242     }
1243 
1244     void observe_instruction(Node* n, int pc_offset) {
1245       if (!C->debug_info()->recording_non_safepoints())  return;
1246 
1247       Node_Notes* nn = C->node_notes_at(n->_idx);
1248       if (nn == nullptr || nn->jvms() == nullptr)  return;
1249       if (_pending_jvms != nullptr &&
1250           _pending_jvms->same_calls_as(nn->jvms())) {
1251         // Repeated JVMS?  Stretch it up here.
1252         _pending_offset = pc_offset;
1253       } else {
1254         if (_pending_jvms != nullptr &&
1255             _pending_offset < pc_offset) {
1256           emit_non_safepoint();
1257         }
1258         _pending_jvms = nullptr;
1259         if (pc_offset > C->debug_info()->last_pc_offset()) {
1260           // This is the only way _pending_jvms can become non-null:
1261           _pending_jvms = nn->jvms();
1262           _pending_offset = pc_offset;
1263         }
1264       }
1265     }
1266 
1267     // Stay out of the way of real safepoints:
1268     void observe_safepoint(JVMState* jvms, int pc_offset) {
1269       if (_pending_jvms != nullptr &&
1270           !_pending_jvms->same_calls_as(jvms) &&
1271           _pending_offset < pc_offset) {
1272         emit_non_safepoint();
1273       }
1274       _pending_jvms = nullptr;
1275     }
1276 
1277     void flush_at_end() {
1278       if (_pending_jvms != nullptr) {
1279         emit_non_safepoint();
1280       }
1281       _pending_jvms = nullptr;
1282     }
1283 };
1284 
1285 void NonSafepointEmitter::emit_non_safepoint() {
1286   JVMState* youngest_jvms = _pending_jvms;
1287   int       pc_offset     = _pending_offset;
1288 
1289   // Clear it now:
1290   _pending_jvms = nullptr;
1291 
1292   DebugInformationRecorder* debug_info = C->debug_info();
1293   assert(debug_info->recording_non_safepoints(), "sanity");
1294 
1295   debug_info->add_non_safepoint(pc_offset);
1296   int max_depth = youngest_jvms->depth();
1297 
1298   // Visit scopes from oldest to youngest.
1299   for (int depth = 1; depth <= max_depth; depth++) {
1300     JVMState* jvms = youngest_jvms->of_depth(depth);
1301     ciMethod* method = jvms->has_method() ? jvms->method() : nullptr;
1302     assert(!jvms->should_reexecute() || depth==max_depth, "reexecute allowed only for the youngest");
1303     methodHandle null_mh;
1304     debug_info->describe_scope(pc_offset, null_mh, method, jvms->bci(), jvms->should_reexecute());
1305   }
1306 
1307   // Mark the end of the scope set.
1308   debug_info->end_non_safepoint(pc_offset);
1309 }
1310 
1311 //------------------------------init_buffer------------------------------------
1312 void PhaseOutput::estimate_buffer_size(int& const_req) {
1313 
1314   // Set the initially allocated size
1315   const_req = initial_const_capacity;
1316 
1317   // The extra spacing after the code is necessary on some platforms.
1318   // Sometimes we need to patch in a jump after the last instruction,
1319   // if the nmethod has been deoptimized.  (See 4932387, 4894843.)
1320 
1321   // Compute the byte offset where we can store the deopt pc.
1322   if (C->fixed_slots() != 0) {
1323     _orig_pc_slot_offset_in_bytes = C->regalloc()->reg2offset(OptoReg::stack2reg(_orig_pc_slot));
1324   }
1325 
1326   // Compute prolog code size
1327   _frame_slots = OptoReg::reg2stack(C->matcher()->_old_SP) + C->regalloc()->_framesize;
1328   assert(_frame_slots >= 0 && _frame_slots < 1000000, "sanity check");
1329 
1330   if (C->has_mach_constant_base_node()) {
1331     uint add_size = 0;
1332     // Fill the constant table.
1333     // Note:  This must happen before shorten_branches.
1334     for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
1335       Block* b = C->cfg()->get_block(i);
1336 
1337       for (uint j = 0; j < b->number_of_nodes(); j++) {
1338         Node* n = b->get_node(j);
1339 
1340         // If the node is a MachConstantNode evaluate the constant
1341         // value section.
1342         if (n->is_MachConstant()) {
1343           MachConstantNode* machcon = n->as_MachConstant();
1344           machcon->eval_constant(C);
1345         } else if (n->is_Mach()) {
1346           // On Power there are more nodes that issue constants.
1347           add_size += (n->as_Mach()->ins_num_consts() * 8);
1348         }
1349       }
1350     }
1351 
1352     // Calculate the offsets of the constants and the size of the
1353     // constant table (including the padding to the next section).
1354     constant_table().calculate_offsets_and_size();
1355     const_req = constant_table().size() + add_size;
1356   }
1357 
1358   // Initialize the space for the BufferBlob used to find and verify
1359   // instruction size in MachNode::emit_size()
1360   init_scratch_buffer_blob(const_req);
1361 }
1362 
1363 CodeBuffer* PhaseOutput::init_buffer() {
1364   int stub_req  = _buf_sizes._stub;
1365   int code_req  = _buf_sizes._code;
1366   int const_req = _buf_sizes._const;
1367 
1368   int pad_req   = NativeCall::byte_size();
1369 
1370   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1371   stub_req += bs->estimate_stub_size();
1372 
1373   // nmethod and CodeBuffer count stubs & constants as part of method's code.
1374   // class HandlerImpl is platform-specific and defined in the *.ad files.
1375   int exception_handler_req = HandlerImpl::size_exception_handler() + MAX_stubs_size; // add marginal slop for handler
1376   int deopt_handler_req     = HandlerImpl::size_deopt_handler()     + MAX_stubs_size; // add marginal slop for handler
1377   stub_req += MAX_stubs_size;   // ensure per-stub margin
1378   code_req += MAX_inst_size;    // ensure per-instruction margin
1379 
1380   if (StressCodeBuffers)
1381     code_req = const_req = stub_req = exception_handler_req = deopt_handler_req = 0x10;  // force expansion
1382 
1383   int total_req =
1384           const_req +
1385           code_req +
1386           pad_req +
1387           stub_req +
1388           exception_handler_req +
1389           deopt_handler_req;               // deopt handler
1390 
1391   if (C->has_method_handle_invokes())
1392     total_req += deopt_handler_req;  // deopt MH handler
1393 
1394   CodeBuffer* cb = code_buffer();
1395   cb->initialize(total_req, _buf_sizes._reloc);
1396 
1397   // Have we run out of code space?
1398   if ((cb->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
1399     C->record_failure("CodeCache is full");
1400     return nullptr;
1401   }
1402   // Configure the code buffer.
1403   cb->initialize_consts_size(const_req);
1404   cb->initialize_stubs_size(stub_req);
1405   cb->initialize_oop_recorder(C->env()->oop_recorder());
1406 
1407   // fill in the nop array for bundling computations
1408   MachNode *_nop_list[Bundle::_nop_count];
1409   Bundle::initialize_nops(_nop_list);
1410 
1411   return cb;
1412 }
1413 
1414 //------------------------------fill_buffer------------------------------------
1415 void PhaseOutput::fill_buffer(C2_MacroAssembler* masm, uint* blk_starts) {
1416   // blk_starts[] contains offsets calculated during short branches processing,
1417   // offsets should not be increased during following steps.
1418 
1419   // Compute the size of first NumberOfLoopInstrToAlign instructions at head
1420   // of a loop. It is used to determine the padding for loop alignment.
1421   Compile::TracePhase tp(_t_fillBuffer);
1422 
1423   compute_loop_first_inst_sizes();
1424 
1425   // Create oopmap set.
1426   _oop_map_set = new OopMapSet();
1427 
1428   // !!!!! This preserves old handling of oopmaps for now
1429   C->debug_info()->set_oopmaps(_oop_map_set);
1430 
1431   uint nblocks  = C->cfg()->number_of_blocks();
1432   // Count and start of implicit null check instructions
1433   uint inct_cnt = 0;
1434   uint* inct_starts = NEW_RESOURCE_ARRAY(uint, nblocks+1);
1435 
1436   // Count and start of calls
1437   uint* call_returns = NEW_RESOURCE_ARRAY(uint, nblocks+1);
1438 
1439   uint  return_offset = 0;
1440   int nop_size = (new MachNopNode())->size(C->regalloc());
1441 
1442   int previous_offset = 0;
1443   int current_offset  = 0;
1444   int last_call_offset = -1;
1445   int last_avoid_back_to_back_offset = -1;
1446 #ifdef ASSERT
1447   uint* jmp_target = NEW_RESOURCE_ARRAY(uint,nblocks);
1448   uint* jmp_offset = NEW_RESOURCE_ARRAY(uint,nblocks);
1449   uint* jmp_size   = NEW_RESOURCE_ARRAY(uint,nblocks);
1450   uint* jmp_rule   = NEW_RESOURCE_ARRAY(uint,nblocks);
1451 #endif
1452 
1453   // Create an array of unused labels, one for each basic block, if printing is enabled
1454 #if defined(SUPPORT_OPTO_ASSEMBLY)
1455   int* node_offsets      = nullptr;
1456   uint node_offset_limit = C->unique();
1457 
1458   if (C->print_assembly()) {
1459     node_offsets = NEW_RESOURCE_ARRAY(int, node_offset_limit);
1460   }
1461   if (node_offsets != nullptr) {
1462     // We need to initialize. Unused array elements may contain garbage and mess up PrintOptoAssembly.
1463     memset(node_offsets, 0, node_offset_limit*sizeof(int));
1464   }
1465 #endif
1466 
1467   NonSafepointEmitter non_safepoints(C);  // emit non-safepoints lazily
1468 
1469   // Emit the constant table.
1470   if (C->has_mach_constant_base_node()) {
1471     if (!constant_table().emit(masm)) {
1472       C->record_failure("consts section overflow");
1473       return;
1474     }
1475   }
1476 
1477   // Create an array of labels, one for each basic block
1478   Label* blk_labels = NEW_RESOURCE_ARRAY(Label, nblocks+1);
1479   for (uint i = 0; i <= nblocks; i++) {
1480     blk_labels[i].init();
1481   }
1482 
1483   // Now fill in the code buffer
1484   Node* delay_slot = nullptr;
1485   for (uint i = 0; i < nblocks; i++) {
1486     Block* block = C->cfg()->get_block(i);
1487     _block = block;
1488     Node* head = block->head();
1489 
1490     // If this block needs to start aligned (i.e, can be reached other
1491     // than by falling-thru from the previous block), then force the
1492     // start of a new bundle.
1493     if (Pipeline::requires_bundling() && starts_bundle(head)) {
1494       masm->code()->flush_bundle(true);
1495     }
1496 
1497 #ifdef ASSERT
1498     if (!block->is_connector()) {
1499       stringStream st;
1500       block->dump_head(C->cfg(), &st);
1501       masm->block_comment(st.freeze());
1502     }
1503     jmp_target[i] = 0;
1504     jmp_offset[i] = 0;
1505     jmp_size[i]   = 0;
1506     jmp_rule[i]   = 0;
1507 #endif
1508     int blk_offset = current_offset;
1509 
1510     // Define the label at the beginning of the basic block
1511     masm->bind(blk_labels[block->_pre_order]);
1512 
1513     uint last_inst = block->number_of_nodes();
1514 
1515     // Emit block normally, except for last instruction.
1516     // Emit means "dump code bits into code buffer".
1517     for (uint j = 0; j<last_inst; j++) {
1518       _index = j;
1519 
1520       // Get the node
1521       Node* n = block->get_node(j);
1522 
1523       // See if delay slots are supported
1524       if (valid_bundle_info(n) && node_bundling(n)->used_in_unconditional_delay()) {
1525         assert(delay_slot == nullptr, "no use of delay slot node");
1526         assert(n->size(C->regalloc()) == Pipeline::instr_unit_size(), "delay slot instruction wrong size");
1527 
1528         delay_slot = n;
1529         continue;
1530       }
1531 
1532       // If this starts a new instruction group, then flush the current one
1533       // (but allow split bundles)
1534       if (Pipeline::requires_bundling() && starts_bundle(n))
1535         masm->code()->flush_bundle(false);
1536 
1537       // Special handling for SafePoint/Call Nodes
1538       bool is_mcall = false;
1539       if (n->is_Mach()) {
1540         MachNode *mach = n->as_Mach();
1541         is_mcall = n->is_MachCall();
1542         bool is_sfn = n->is_MachSafePoint();
1543 
1544         // If this requires all previous instructions be flushed, then do so
1545         if (is_sfn || is_mcall || mach->alignment_required() != 1) {
1546           masm->code()->flush_bundle(true);
1547           current_offset = masm->offset();
1548         }
1549 
1550         // A padding may be needed again since a previous instruction
1551         // could be moved to delay slot.
1552 
1553         // align the instruction if necessary
1554         int padding = mach->compute_padding(current_offset);
1555         // Make sure safepoint node for polling is distinct from a call's
1556         // return by adding a nop if needed.
1557         if (is_sfn && !is_mcall && padding == 0 && current_offset == last_call_offset) {
1558           padding = nop_size;
1559         }
1560         if (padding == 0 && mach->avoid_back_to_back(MachNode::AVOID_BEFORE) &&
1561             current_offset == last_avoid_back_to_back_offset) {
1562           // Avoid back to back some instructions.
1563           padding = nop_size;
1564         }
1565 
1566         if (padding > 0) {
1567           assert((padding % nop_size) == 0, "padding is not a multiple of NOP size");
1568           int nops_cnt = padding / nop_size;
1569           MachNode *nop = new MachNopNode(nops_cnt);
1570           block->insert_node(nop, j++);
1571           last_inst++;
1572           C->cfg()->map_node_to_block(nop, block);
1573           // Ensure enough space.
1574           masm->code()->insts()->maybe_expand_to_ensure_remaining(MAX_inst_size);
1575           if ((masm->code()->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
1576             C->record_failure("CodeCache is full");
1577             return;
1578           }
1579           nop->emit(masm, C->regalloc());
1580           masm->code()->flush_bundle(true);
1581           current_offset = masm->offset();
1582         }
1583 
1584         bool observe_safepoint = is_sfn;
1585         // Remember the start of the last call in a basic block
1586         if (is_mcall) {
1587           MachCallNode *mcall = mach->as_MachCall();
1588 
1589           // This destination address is NOT PC-relative
1590           mcall->method_set((intptr_t)mcall->entry_point());
1591 
1592           // Save the return address
1593           call_returns[block->_pre_order] = current_offset + mcall->ret_addr_offset();
1594 
1595           observe_safepoint = mcall->guaranteed_safepoint();
1596         }
1597 
1598         // sfn will be valid whenever mcall is valid now because of inheritance
1599         if (observe_safepoint) {
1600           // Handle special safepoint nodes for synchronization
1601           if (!is_mcall) {
1602             MachSafePointNode *sfn = mach->as_MachSafePoint();
1603             // !!!!! Stubs only need an oopmap right now, so bail out
1604             if (sfn->jvms()->method() == nullptr) {
1605               // Write the oopmap directly to the code blob??!!
1606               continue;
1607             }
1608           } // End synchronization
1609 
1610           non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
1611                                            current_offset);
1612           Process_OopMap_Node(mach, current_offset);
1613         } // End if safepoint
1614 
1615           // If this is a null check, then add the start of the previous instruction to the list
1616         else if( mach->is_MachNullCheck() ) {
1617           inct_starts[inct_cnt++] = previous_offset;
1618         }
1619 
1620           // If this is a branch, then fill in the label with the target BB's label
1621         else if (mach->is_MachBranch()) {
1622           // This requires the TRUE branch target be in succs[0]
1623           uint block_num = block->non_connector_successor(0)->_pre_order;
1624 
1625           // Try to replace long branch if delay slot is not used,
1626           // it is mostly for back branches since forward branch's
1627           // distance is not updated yet.
1628           bool delay_slot_is_used = valid_bundle_info(n) &&
1629                                     C->output()->node_bundling(n)->use_unconditional_delay();
1630           if (!delay_slot_is_used && mach->may_be_short_branch()) {
1631             assert(delay_slot == nullptr, "not expecting delay slot node");
1632             int br_size = n->size(C->regalloc());
1633             int offset = blk_starts[block_num] - current_offset;
1634             if (block_num >= i) {
1635               // Current and following block's offset are not
1636               // finalized yet, adjust distance by the difference
1637               // between calculated and final offsets of current block.
1638               offset -= (blk_starts[i] - blk_offset);
1639             }
1640             // In the following code a nop could be inserted before
1641             // the branch which will increase the backward distance.
1642             bool needs_padding = (current_offset == last_avoid_back_to_back_offset);
1643             if (needs_padding && offset <= 0)
1644               offset -= nop_size;
1645 
1646             if (C->matcher()->is_short_branch_offset(mach->rule(), br_size, offset)) {
1647               // We've got a winner.  Replace this branch.
1648               MachNode* replacement = mach->as_MachBranch()->short_branch_version();
1649 
1650               // Update the jmp_size.
1651               int new_size = replacement->size(C->regalloc());
1652               assert((br_size - new_size) >= (int)nop_size, "short_branch size should be smaller");
1653               // Insert padding between avoid_back_to_back branches.
1654               if (needs_padding && replacement->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
1655                 MachNode *nop = new MachNopNode();
1656                 block->insert_node(nop, j++);
1657                 C->cfg()->map_node_to_block(nop, block);
1658                 last_inst++;
1659                 nop->emit(masm, C->regalloc());
1660                 masm->code()->flush_bundle(true);
1661                 current_offset = masm->offset();
1662               }
1663 #ifdef ASSERT
1664               jmp_target[i] = block_num;
1665               jmp_offset[i] = current_offset - blk_offset;
1666               jmp_size[i]   = new_size;
1667               jmp_rule[i]   = mach->rule();
1668 #endif
1669               block->map_node(replacement, j);
1670               mach->subsume_by(replacement, C);
1671               n    = replacement;
1672               mach = replacement;
1673             }
1674           }
1675           mach->as_MachBranch()->label_set( &blk_labels[block_num], block_num );
1676         } else if (mach->ideal_Opcode() == Op_Jump) {
1677           for (uint h = 0; h < block->_num_succs; h++) {
1678             Block* succs_block = block->_succs[h];
1679             for (uint j = 1; j < succs_block->num_preds(); j++) {
1680               Node* jpn = succs_block->pred(j);
1681               if (jpn->is_JumpProj() && jpn->in(0) == mach) {
1682                 uint block_num = succs_block->non_connector()->_pre_order;
1683                 Label *blkLabel = &blk_labels[block_num];
1684                 mach->add_case_label(jpn->as_JumpProj()->proj_no(), blkLabel);
1685               }
1686             }
1687           }
1688         } else if (!n->is_Proj()) {
1689           // Remember the beginning of the previous instruction, in case
1690           // it's followed by a flag-kill and a null-check.  Happens on
1691           // Intel all the time, with add-to-memory kind of opcodes.
1692           previous_offset = current_offset;
1693         }
1694 
1695         // Not an else-if!
1696         // If this is a trap based cmp then add its offset to the list.
1697         if (mach->is_TrapBasedCheckNode()) {
1698           inct_starts[inct_cnt++] = current_offset;
1699         }
1700       }
1701 
1702       // Verify that there is sufficient space remaining
1703       masm->code()->insts()->maybe_expand_to_ensure_remaining(MAX_inst_size);
1704       if ((masm->code()->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
1705         C->record_failure("CodeCache is full");
1706         return;
1707       }
1708 
1709       // Save the offset for the listing
1710 #if defined(SUPPORT_OPTO_ASSEMBLY)
1711       if ((node_offsets != nullptr) && (n->_idx < node_offset_limit)) {
1712         node_offsets[n->_idx] = masm->offset();
1713       }
1714 #endif
1715       assert(!C->failing_internal() || C->failure_is_artificial(), "Should not reach here if failing.");
1716 
1717       // "Normal" instruction case
1718       DEBUG_ONLY(uint instr_offset = masm->offset());
1719       n->emit(masm, C->regalloc());
1720       current_offset = masm->offset();
1721 
1722       // Above we only verified that there is enough space in the instruction section.
1723       // However, the instruction may emit stubs that cause code buffer expansion.
1724       // Bail out here if expansion failed due to a lack of code cache space.
1725       if (C->failing()) {
1726         return;
1727       }
1728 
1729       assert(!is_mcall || (call_returns[block->_pre_order] <= (uint)current_offset),
1730              "ret_addr_offset() not within emitted code");
1731 
1732 #ifdef ASSERT
1733       uint n_size = n->size(C->regalloc());
1734       if (n_size < (current_offset-instr_offset)) {
1735         MachNode* mach = n->as_Mach();
1736         n->dump();
1737         mach->dump_format(C->regalloc(), tty);
1738         tty->print_cr(" n_size (%d), current_offset (%d), instr_offset (%d)", n_size, current_offset, instr_offset);
1739         Disassembler::decode(masm->code()->insts_begin() + instr_offset, masm->code()->insts_begin() + current_offset + 1, tty);
1740         tty->print_cr(" ------------------- ");
1741         BufferBlob* blob = this->scratch_buffer_blob();
1742         address blob_begin = blob->content_begin();
1743         Disassembler::decode(blob_begin, blob_begin + n_size + 1, tty);
1744         assert(false, "wrong size of mach node");
1745       }
1746 #endif
1747       non_safepoints.observe_instruction(n, current_offset);
1748 
1749       // mcall is last "call" that can be a safepoint
1750       // record it so we can see if a poll will directly follow it
1751       // in which case we'll need a pad to make the PcDesc sites unique
1752       // see  5010568. This can be slightly inaccurate but conservative
1753       // in the case that return address is not actually at current_offset.
1754       // This is a small price to pay.
1755 
1756       if (is_mcall) {
1757         last_call_offset = current_offset;
1758       }
1759 
1760       if (n->is_Mach() && n->as_Mach()->avoid_back_to_back(MachNode::AVOID_AFTER)) {
1761         // Avoid back to back some instructions.
1762         last_avoid_back_to_back_offset = current_offset;
1763       }
1764 
1765       // See if this instruction has a delay slot
1766       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
1767         guarantee(delay_slot != nullptr, "expecting delay slot node");
1768 
1769         // Back up 1 instruction
1770         masm->code()->set_insts_end(masm->code()->insts_end() - Pipeline::instr_unit_size());
1771 
1772         // Save the offset for the listing
1773 #if defined(SUPPORT_OPTO_ASSEMBLY)
1774         if ((node_offsets != nullptr) && (delay_slot->_idx < node_offset_limit)) {
1775           node_offsets[delay_slot->_idx] = masm->offset();
1776         }
1777 #endif
1778 
1779         // Support a SafePoint in the delay slot
1780         if (delay_slot->is_MachSafePoint()) {
1781           MachNode *mach = delay_slot->as_Mach();
1782           // !!!!! Stubs only need an oopmap right now, so bail out
1783           if (!mach->is_MachCall() && mach->as_MachSafePoint()->jvms()->method() == nullptr) {
1784             // Write the oopmap directly to the code blob??!!
1785             delay_slot = nullptr;
1786             continue;
1787           }
1788 
1789           int adjusted_offset = current_offset - Pipeline::instr_unit_size();
1790           non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
1791                                            adjusted_offset);
1792           // Generate an OopMap entry
1793           Process_OopMap_Node(mach, adjusted_offset);
1794         }
1795 
1796         // Insert the delay slot instruction
1797         delay_slot->emit(masm, C->regalloc());
1798 
1799         // Don't reuse it
1800         delay_slot = nullptr;
1801       }
1802 
1803     } // End for all instructions in block
1804 
1805     // If the next block is the top of a loop, pad this block out to align
1806     // the loop top a little. Helps prevent pipe stalls at loop back branches.
1807     if (i < nblocks-1) {
1808       Block *nb = C->cfg()->get_block(i + 1);
1809       int padding = nb->alignment_padding(current_offset);
1810       if( padding > 0 ) {
1811         MachNode *nop = new MachNopNode(padding / nop_size);
1812         block->insert_node(nop, block->number_of_nodes());
1813         C->cfg()->map_node_to_block(nop, block);
1814         nop->emit(masm, C->regalloc());
1815         current_offset = masm->offset();
1816       }
1817     }
1818     // Verify that the distance for generated before forward
1819     // short branches is still valid.
1820     guarantee((int)(blk_starts[i+1] - blk_starts[i]) >= (current_offset - blk_offset), "shouldn't increase block size");
1821 
1822     // Save new block start offset
1823     blk_starts[i] = blk_offset;
1824   } // End of for all blocks
1825   blk_starts[nblocks] = current_offset;
1826 
1827   non_safepoints.flush_at_end();
1828 
1829   // Offset too large?
1830   if (C->failing())  return;
1831 
1832   // Define a pseudo-label at the end of the code
1833   masm->bind( blk_labels[nblocks] );
1834 
1835   // Compute the size of the first block
1836   _first_block_size = blk_labels[1].loc_pos() - blk_labels[0].loc_pos();
1837 
1838 #ifdef ASSERT
1839   for (uint i = 0; i < nblocks; i++) { // For all blocks
1840     if (jmp_target[i] != 0) {
1841       int br_size = jmp_size[i];
1842       int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_offset[i]);
1843       if (!C->matcher()->is_short_branch_offset(jmp_rule[i], br_size, offset)) {
1844         tty->print_cr("target (%d) - jmp_offset(%d) = offset (%d), jump_size(%d), jmp_block B%d, target_block B%d", blk_starts[jmp_target[i]], blk_starts[i] + jmp_offset[i], offset, br_size, i, jmp_target[i]);
1845         assert(false, "Displacement too large for short jmp");
1846       }
1847     }
1848   }
1849 #endif
1850 
1851   if (!masm->code()->finalize_stubs()) {
1852     C->record_failure("CodeCache is full");
1853     return;
1854   }
1855 
1856   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1857   bs->emit_stubs(*masm->code());
1858   if (C->failing())  return;
1859 
1860   // Fill in stubs.
1861   assert(masm->inst_mark() == nullptr, "should be.");
1862   _stub_list.emit(*masm);
1863   if (C->failing())  return;
1864 
1865 #ifndef PRODUCT
1866   // Information on the size of the method, without the extraneous code
1867   Scheduling::increment_method_size(masm->offset());
1868 #endif
1869 
1870   // ------------------
1871   // Fill in exception table entries.
1872   FillExceptionTables(inct_cnt, call_returns, inct_starts, blk_labels);
1873 
1874   // Only java methods have exception handlers and deopt handlers
1875   // class HandlerImpl is platform-specific and defined in the *.ad files.
1876   if (C->method()) {
1877     // Emit the exception handler code.
1878     _code_offsets.set_value(CodeOffsets::Exceptions, HandlerImpl::emit_exception_handler(masm));
1879     if (C->failing()) {
1880       return; // CodeBuffer::expand failed
1881     }
1882     // Emit the deopt handler code.
1883     _code_offsets.set_value(CodeOffsets::Deopt, HandlerImpl::emit_deopt_handler(masm));
1884 
1885     // Emit the MethodHandle deopt handler code (if required).
1886     if (C->has_method_handle_invokes() && !C->failing()) {
1887       // We can use the same code as for the normal deopt handler, we
1888       // just need a different entry point address.
1889       _code_offsets.set_value(CodeOffsets::DeoptMH, HandlerImpl::emit_deopt_handler(masm));
1890     }
1891   }
1892 
1893   // One last check for failed CodeBuffer::expand:
1894   if ((masm->code()->blob() == nullptr) || (!CompileBroker::should_compile_new_jobs())) {
1895     C->record_failure("CodeCache is full");
1896     return;
1897   }
1898 
1899 #if defined(SUPPORT_ABSTRACT_ASSEMBLY) || defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_OPTO_ASSEMBLY)
1900   if (C->print_assembly()) {
1901     tty->cr();
1902     tty->print_cr("============================= C2-compiled nmethod ==============================");
1903   }
1904 #endif
1905 
1906 #if defined(SUPPORT_OPTO_ASSEMBLY)
1907   // Dump the assembly code, including basic-block numbers
1908   if (C->print_assembly()) {
1909     ttyLocker ttyl;  // keep the following output all in one block
1910     if (!VMThread::should_terminate()) {  // test this under the tty lock
1911       // print_metadata and dump_asm may safepoint which makes us loose the ttylock.
1912       // We call them first and write to a stringStream, then we retake the lock to
1913       // make sure the end tag is coherent, and that xmlStream->pop_tag is done thread safe.
1914       ResourceMark rm;
1915       stringStream method_metadata_str;
1916       if (C->method() != nullptr) {
1917         C->method()->print_metadata(&method_metadata_str);
1918       }
1919       stringStream dump_asm_str;
1920       dump_asm_on(&dump_asm_str, node_offsets, node_offset_limit);
1921 
1922       NoSafepointVerifier nsv;
1923       ttyLocker ttyl2;
1924       // This output goes directly to the tty, not the compiler log.
1925       // To enable tools to match it up with the compilation activity,
1926       // be sure to tag this tty output with the compile ID.
1927       if (xtty != nullptr) {
1928         xtty->head("opto_assembly compile_id='%d'%s", C->compile_id(),
1929                    C->is_osr_compilation() ? " compile_kind='osr'" : "");
1930       }
1931       if (C->method() != nullptr) {
1932         tty->print_cr("----------------------- MetaData before Compile_id = %d ------------------------", C->compile_id());
1933         tty->print_raw(method_metadata_str.freeze());
1934       } else if (C->stub_name() != nullptr) {
1935         tty->print_cr("----------------------------- RuntimeStub %s -------------------------------", C->stub_name());
1936       }
1937       tty->cr();
1938       tty->print_cr("------------------------ OptoAssembly for Compile_id = %d -----------------------", C->compile_id());
1939       tty->print_raw(dump_asm_str.freeze());
1940       tty->print_cr("--------------------------------------------------------------------------------");
1941       if (xtty != nullptr) {
1942         xtty->tail("opto_assembly");
1943       }
1944     }
1945   }
1946 #endif
1947 }
1948 
1949 void PhaseOutput::FillExceptionTables(uint cnt, uint *call_returns, uint *inct_starts, Label *blk_labels) {
1950   _inc_table.set_size(cnt);
1951 
1952   uint inct_cnt = 0;
1953   for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
1954     Block* block = C->cfg()->get_block(i);
1955     Node *n = nullptr;
1956     int j;
1957 
1958     // Find the branch; ignore trailing NOPs.
1959     for (j = block->number_of_nodes() - 1; j >= 0; j--) {
1960       n = block->get_node(j);
1961       if (!n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con) {
1962         break;
1963       }
1964     }
1965 
1966     // If we didn't find anything, continue
1967     if (j < 0) {
1968       continue;
1969     }
1970 
1971     // Compute ExceptionHandlerTable subtable entry and add it
1972     // (skip empty blocks)
1973     if (n->is_Catch()) {
1974 
1975       // Get the offset of the return from the call
1976       uint call_return = call_returns[block->_pre_order];
1977 #ifdef ASSERT
1978       assert( call_return > 0, "no call seen for this basic block" );
1979       while (block->get_node(--j)->is_MachProj()) ;
1980       assert(block->get_node(j)->is_MachCall(), "CatchProj must follow call");
1981 #endif
1982       // last instruction is a CatchNode, find it's CatchProjNodes
1983       int nof_succs = block->_num_succs;
1984       // allocate space
1985       GrowableArray<intptr_t> handler_bcis(nof_succs);
1986       GrowableArray<intptr_t> handler_pcos(nof_succs);
1987       // iterate through all successors
1988       for (int j = 0; j < nof_succs; j++) {
1989         Block* s = block->_succs[j];
1990         bool found_p = false;
1991         for (uint k = 1; k < s->num_preds(); k++) {
1992           Node* pk = s->pred(k);
1993           if (pk->is_CatchProj() && pk->in(0) == n) {
1994             const CatchProjNode* p = pk->as_CatchProj();
1995             found_p = true;
1996             // add the corresponding handler bci & pco information
1997             if (p->_con != CatchProjNode::fall_through_index) {
1998               // p leads to an exception handler (and is not fall through)
1999               assert(s == C->cfg()->get_block(s->_pre_order), "bad numbering");
2000               // no duplicates, please
2001               if (!handler_bcis.contains(p->handler_bci())) {
2002                 uint block_num = s->non_connector()->_pre_order;
2003                 handler_bcis.append(p->handler_bci());
2004                 handler_pcos.append(blk_labels[block_num].loc_pos());
2005               }
2006             }
2007           }
2008         }
2009         assert(found_p, "no matching predecessor found");
2010         // Note:  Due to empty block removal, one block may have
2011         // several CatchProj inputs, from the same Catch.
2012       }
2013 
2014       // Set the offset of the return from the call
2015       assert(handler_bcis.find(-1) != -1, "must have default handler");
2016       _handler_table.add_subtable(call_return, &handler_bcis, nullptr, &handler_pcos);
2017       continue;
2018     }
2019 
2020     // Handle implicit null exception table updates
2021     if (n->is_MachNullCheck()) {
2022       assert(n->in(1)->as_Mach()->barrier_data() == 0,
2023              "Implicit null checks on memory accesses with barriers are not yet supported");
2024       uint block_num = block->non_connector_successor(0)->_pre_order;
2025       _inc_table.append(inct_starts[inct_cnt++], blk_labels[block_num].loc_pos());
2026       continue;
2027     }
2028     // Handle implicit exception table updates: trap instructions.
2029     if (n->is_Mach() && n->as_Mach()->is_TrapBasedCheckNode()) {
2030       uint block_num = block->non_connector_successor(0)->_pre_order;
2031       _inc_table.append(inct_starts[inct_cnt++], blk_labels[block_num].loc_pos());
2032       continue;
2033     }
2034   } // End of for all blocks fill in exception table entries
2035 }
2036 
2037 // Static Variables
2038 #ifndef PRODUCT
2039 uint Scheduling::_total_nop_size = 0;
2040 uint Scheduling::_total_method_size = 0;
2041 uint Scheduling::_total_branches = 0;
2042 uint Scheduling::_total_unconditional_delays = 0;
2043 uint Scheduling::_total_instructions_per_bundle[Pipeline::_max_instrs_per_cycle+1];
2044 #endif
2045 
2046 // Initializer for class Scheduling
2047 
2048 Scheduling::Scheduling(Arena *arena, Compile &compile)
2049         : _arena(arena),
2050           _cfg(compile.cfg()),
2051           _regalloc(compile.regalloc()),
2052           _scheduled(arena),
2053           _available(arena),
2054           _reg_node(arena),
2055           _pinch_free_list(arena),
2056           _next_node(nullptr),
2057           _bundle_instr_count(0),
2058           _bundle_cycle_number(0),
2059           _bundle_use(0, 0, resource_count, &_bundle_use_elements[0])
2060 #ifndef PRODUCT
2061         , _branches(0)
2062         , _unconditional_delays(0)
2063 #endif
2064 {
2065   // Create a MachNopNode
2066   _nop = new MachNopNode();
2067 
2068   // Now that the nops are in the array, save the count
2069   // (but allow entries for the nops)
2070   _node_bundling_limit = compile.unique();
2071   uint node_max = _regalloc->node_regs_max_index();
2072 
2073   compile.output()->set_node_bundling_limit(_node_bundling_limit);
2074 
2075   // This one is persistent within the Compile class
2076   _node_bundling_base = NEW_ARENA_ARRAY(compile.comp_arena(), Bundle, node_max);
2077 
2078   // Allocate space for fixed-size arrays
2079   _uses            = NEW_ARENA_ARRAY(arena, short,          node_max);
2080   _current_latency = NEW_ARENA_ARRAY(arena, unsigned short, node_max);
2081 
2082   // Clear the arrays
2083   for (uint i = 0; i < node_max; i++) {
2084     ::new (&_node_bundling_base[i]) Bundle();
2085   }
2086   memset(_uses,               0, node_max * sizeof(short));
2087   memset(_current_latency,    0, node_max * sizeof(unsigned short));
2088 
2089   // Clear the bundling information
2090   memcpy(_bundle_use_elements, Pipeline_Use::elaborated_elements, sizeof(Pipeline_Use::elaborated_elements));
2091 
2092   // Get the last node
2093   Block* block = _cfg->get_block(_cfg->number_of_blocks() - 1);
2094 
2095   _next_node = block->get_node(block->number_of_nodes() - 1);
2096 }
2097 
2098 #ifndef PRODUCT
2099 // Scheduling destructor
2100 Scheduling::~Scheduling() {
2101   _total_branches             += _branches;
2102   _total_unconditional_delays += _unconditional_delays;
2103 }
2104 #endif
2105 
2106 // Step ahead "i" cycles
2107 void Scheduling::step(uint i) {
2108 
2109   Bundle *bundle = node_bundling(_next_node);
2110   bundle->set_starts_bundle();
2111 
2112   // Update the bundle record, but leave the flags information alone
2113   if (_bundle_instr_count > 0) {
2114     bundle->set_instr_count(_bundle_instr_count);
2115     bundle->set_resources_used(_bundle_use.resourcesUsed());
2116   }
2117 
2118   // Update the state information
2119   _bundle_instr_count = 0;
2120   _bundle_cycle_number += i;
2121   _bundle_use.step(i);
2122 }
2123 
2124 void Scheduling::step_and_clear() {
2125   Bundle *bundle = node_bundling(_next_node);
2126   bundle->set_starts_bundle();
2127 
2128   // Update the bundle record
2129   if (_bundle_instr_count > 0) {
2130     bundle->set_instr_count(_bundle_instr_count);
2131     bundle->set_resources_used(_bundle_use.resourcesUsed());
2132 
2133     _bundle_cycle_number += 1;
2134   }
2135 
2136   // Clear the bundling information
2137   _bundle_instr_count = 0;
2138   _bundle_use.reset();
2139 
2140   memcpy(_bundle_use_elements,
2141          Pipeline_Use::elaborated_elements,
2142          sizeof(Pipeline_Use::elaborated_elements));
2143 }
2144 
2145 // Perform instruction scheduling and bundling over the sequence of
2146 // instructions in backwards order.
2147 void PhaseOutput::ScheduleAndBundle() {
2148 
2149   // Don't optimize this if it isn't a method
2150   if (!C->method())
2151     return;
2152 
2153   // Don't optimize this if scheduling is disabled
2154   if (!C->do_scheduling())
2155     return;
2156 
2157   // Scheduling code works only with pairs (8 bytes) maximum.
2158   // And when the scalable vector register is used, we may spill/unspill
2159   // the whole reg regardless of the max vector size.
2160   if (C->max_vector_size() > 8 ||
2161       (C->max_vector_size() > 0 && Matcher::supports_scalable_vector())) {
2162     return;
2163   }
2164 
2165   Compile::TracePhase tp(_t_instrSched);
2166 
2167   // Create a data structure for all the scheduling information
2168   Scheduling scheduling(Thread::current()->resource_area(), *C);
2169 
2170   // Walk backwards over each basic block, computing the needed alignment
2171   // Walk over all the basic blocks
2172   scheduling.DoScheduling();
2173 
2174 #ifndef PRODUCT
2175   if (C->trace_opto_output()) {
2176     // Buffer and print all at once
2177     ResourceMark rm;
2178     stringStream ss;
2179     ss.print("\n---- After ScheduleAndBundle ----\n");
2180     print_scheduling(&ss);
2181     tty->print("%s", ss.as_string());
2182   }
2183 #endif
2184 }
2185 
2186 #ifndef PRODUCT
2187 // Separated out so that it can be called directly from debugger
2188 void PhaseOutput::print_scheduling() {
2189   print_scheduling(tty);
2190 }
2191 
2192 void PhaseOutput::print_scheduling(outputStream* output_stream) {
2193   for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
2194     output_stream->print("\nBB#%03d:\n", i);
2195     Block* block = C->cfg()->get_block(i);
2196     for (uint j = 0; j < block->number_of_nodes(); j++) {
2197       Node* n = block->get_node(j);
2198       OptoReg::Name reg = C->regalloc()->get_reg_first(n);
2199       output_stream->print(" %-6s ", reg >= 0 && reg < REG_COUNT ? Matcher::regName[reg] : "");
2200       n->dump("\n", false, output_stream);
2201     }
2202   }
2203 }
2204 #endif
2205 
2206 // See if this node fits into the present instruction bundle
2207 bool Scheduling::NodeFitsInBundle(Node *n) {
2208   uint n_idx = n->_idx;
2209 
2210   // If this is the unconditional delay instruction, then it fits
2211   if (n == _unconditional_delay_slot) {
2212 #ifndef PRODUCT
2213     if (_cfg->C->trace_opto_output())
2214       tty->print("#     NodeFitsInBundle [%4d]: TRUE; is in unconditional delay slot\n", n->_idx);
2215 #endif
2216     return (true);
2217   }
2218 
2219   // If the node cannot be scheduled this cycle, skip it
2220   if (_current_latency[n_idx] > _bundle_cycle_number) {
2221 #ifndef PRODUCT
2222     if (_cfg->C->trace_opto_output())
2223       tty->print("#     NodeFitsInBundle [%4d]: FALSE; latency %4d > %d\n",
2224                  n->_idx, _current_latency[n_idx], _bundle_cycle_number);
2225 #endif
2226     return (false);
2227   }
2228 
2229   const Pipeline *node_pipeline = n->pipeline();
2230 
2231   uint instruction_count = node_pipeline->instructionCount();
2232   if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
2233     instruction_count = 0;
2234   else if (node_pipeline->hasBranchDelay() && !_unconditional_delay_slot)
2235     instruction_count++;
2236 
2237   if (_bundle_instr_count + instruction_count > Pipeline::_max_instrs_per_cycle) {
2238 #ifndef PRODUCT
2239     if (_cfg->C->trace_opto_output())
2240       tty->print("#     NodeFitsInBundle [%4d]: FALSE; too many instructions: %d > %d\n",
2241                  n->_idx, _bundle_instr_count + instruction_count, Pipeline::_max_instrs_per_cycle);
2242 #endif
2243     return (false);
2244   }
2245 
2246   // Don't allow non-machine nodes to be handled this way
2247   if (!n->is_Mach() && instruction_count == 0)
2248     return (false);
2249 
2250   // See if there is any overlap
2251   uint delay = _bundle_use.full_latency(0, node_pipeline->resourceUse());
2252 
2253   if (delay > 0) {
2254 #ifndef PRODUCT
2255     if (_cfg->C->trace_opto_output())
2256       tty->print("#     NodeFitsInBundle [%4d]: FALSE; functional units overlap\n", n_idx);
2257 #endif
2258     return false;
2259   }
2260 
2261 #ifndef PRODUCT
2262   if (_cfg->C->trace_opto_output())
2263     tty->print("#     NodeFitsInBundle [%4d]:  TRUE\n", n_idx);
2264 #endif
2265 
2266   return true;
2267 }
2268 
2269 Node * Scheduling::ChooseNodeToBundle() {
2270   uint siz = _available.size();
2271 
2272   if (siz == 0) {
2273 
2274 #ifndef PRODUCT
2275     if (_cfg->C->trace_opto_output())
2276       tty->print("#   ChooseNodeToBundle: null\n");
2277 #endif
2278     return (nullptr);
2279   }
2280 
2281   // Fast path, if only 1 instruction in the bundle
2282   if (siz == 1) {
2283 #ifndef PRODUCT
2284     if (_cfg->C->trace_opto_output()) {
2285       tty->print("#   ChooseNodeToBundle (only 1): ");
2286       _available[0]->dump();
2287     }
2288 #endif
2289     return (_available[0]);
2290   }
2291 
2292   // Don't bother, if the bundle is already full
2293   if (_bundle_instr_count < Pipeline::_max_instrs_per_cycle) {
2294     for ( uint i = 0; i < siz; i++ ) {
2295       Node *n = _available[i];
2296 
2297       // Skip projections, we'll handle them another way
2298       if (n->is_Proj())
2299         continue;
2300 
2301       // This presupposed that instructions are inserted into the
2302       // available list in a legality order; i.e. instructions that
2303       // must be inserted first are at the head of the list
2304       if (NodeFitsInBundle(n)) {
2305 #ifndef PRODUCT
2306         if (_cfg->C->trace_opto_output()) {
2307           tty->print("#   ChooseNodeToBundle: ");
2308           n->dump();
2309         }
2310 #endif
2311         return (n);
2312       }
2313     }
2314   }
2315 
2316   // Nothing fits in this bundle, choose the highest priority
2317 #ifndef PRODUCT
2318   if (_cfg->C->trace_opto_output()) {
2319     tty->print("#   ChooseNodeToBundle: ");
2320     _available[0]->dump();
2321   }
2322 #endif
2323 
2324   return _available[0];
2325 }
2326 
2327 int Scheduling::compare_two_spill_nodes(Node* first, Node* second) {
2328   assert(first->is_MachSpillCopy() && second->is_MachSpillCopy(), "");
2329 
2330   OptoReg::Name first_src_lo = _regalloc->get_reg_first(first->in(1));
2331   OptoReg::Name first_dst_lo = _regalloc->get_reg_first(first);
2332   OptoReg::Name second_src_lo = _regalloc->get_reg_first(second->in(1));
2333   OptoReg::Name second_dst_lo = _regalloc->get_reg_first(second);
2334 
2335   // Comparison between stack -> reg and stack -> reg
2336   if (OptoReg::is_stack(first_src_lo) && OptoReg::is_stack(second_src_lo) &&
2337       OptoReg::is_reg(first_dst_lo) && OptoReg::is_reg(second_dst_lo)) {
2338     return _regalloc->reg2offset(first_src_lo) - _regalloc->reg2offset(second_src_lo);
2339   }
2340 
2341   // Comparison between reg -> stack and reg -> stack
2342   if (OptoReg::is_stack(first_dst_lo) && OptoReg::is_stack(second_dst_lo) &&
2343       OptoReg::is_reg(first_src_lo) && OptoReg::is_reg(second_src_lo)) {
2344     return _regalloc->reg2offset(first_dst_lo) - _regalloc->reg2offset(second_dst_lo);
2345   }
2346 
2347   return 0; // Not comparable
2348 }
2349 
2350 void Scheduling::AddNodeToAvailableList(Node *n) {
2351   assert( !n->is_Proj(), "projections never directly made available" );
2352 #ifndef PRODUCT
2353   if (_cfg->C->trace_opto_output()) {
2354     tty->print("#   AddNodeToAvailableList: ");
2355     n->dump();
2356   }
2357 #endif
2358 
2359   int latency = _current_latency[n->_idx];
2360 
2361   // Insert in latency order (insertion sort). If two MachSpillCopyNodes
2362   // for stack spilling or unspilling have the same latency, we sort
2363   // them in the order of stack offset. Some ports (e.g. aarch64) may also
2364   // have more opportunities to do ld/st merging
2365   uint i;
2366   for (i = 0; i < _available.size(); i++) {
2367     if (_current_latency[_available[i]->_idx] > latency) {
2368       break;
2369     } else if (_current_latency[_available[i]->_idx] == latency &&
2370                n->is_MachSpillCopy() && _available[i]->is_MachSpillCopy() &&
2371                compare_two_spill_nodes(n, _available[i]) > 0) {
2372       break;
2373     }
2374   }
2375 
2376   // Special Check for compares following branches
2377   if( n->is_Mach() && _scheduled.size() > 0 ) {
2378     int op = n->as_Mach()->ideal_Opcode();
2379     Node *last = _scheduled[0];
2380     if( last->is_MachIf() && last->in(1) == n &&
2381         ( op == Op_CmpI ||
2382           op == Op_CmpU ||
2383           op == Op_CmpUL ||
2384           op == Op_CmpP ||
2385           op == Op_CmpF ||
2386           op == Op_CmpD ||
2387           op == Op_CmpL ) ) {
2388 
2389       // Recalculate position, moving to front of same latency
2390       for ( i=0 ; i < _available.size(); i++ )
2391         if (_current_latency[_available[i]->_idx] >= latency)
2392           break;
2393     }
2394   }
2395 
2396   // Insert the node in the available list
2397   _available.insert(i, n);
2398 
2399 #ifndef PRODUCT
2400   if (_cfg->C->trace_opto_output())
2401     dump_available();
2402 #endif
2403 }
2404 
2405 void Scheduling::DecrementUseCounts(Node *n, const Block *bb) {
2406   for ( uint i=0; i < n->len(); i++ ) {
2407     Node *def = n->in(i);
2408     if (!def) continue;
2409     if( def->is_Proj() )        // If this is a machine projection, then
2410       def = def->in(0);         // propagate usage thru to the base instruction
2411 
2412     if(_cfg->get_block_for_node(def) != bb) { // Ignore if not block-local
2413       continue;
2414     }
2415 
2416     // Compute the latency
2417     uint l = _bundle_cycle_number + n->latency(i);
2418     if (_current_latency[def->_idx] < l)
2419       _current_latency[def->_idx] = l;
2420 
2421     // If this does not have uses then schedule it
2422     if ((--_uses[def->_idx]) == 0)
2423       AddNodeToAvailableList(def);
2424   }
2425 }
2426 
2427 void Scheduling::AddNodeToBundle(Node *n, const Block *bb) {
2428 #ifndef PRODUCT
2429   if (_cfg->C->trace_opto_output()) {
2430     tty->print("#   AddNodeToBundle: ");
2431     n->dump();
2432   }
2433 #endif
2434 
2435   // Remove this from the available list
2436   uint i;
2437   for (i = 0; i < _available.size(); i++)
2438     if (_available[i] == n)
2439       break;
2440   assert(i < _available.size(), "entry in _available list not found");
2441   _available.remove(i);
2442 
2443   // See if this fits in the current bundle
2444   const Pipeline *node_pipeline = n->pipeline();
2445   const Pipeline_Use& node_usage = node_pipeline->resourceUse();
2446 
2447   // Check for instructions to be placed in the delay slot. We
2448   // do this before we actually schedule the current instruction,
2449   // because the delay slot follows the current instruction.
2450   if (Pipeline::_branch_has_delay_slot &&
2451       node_pipeline->hasBranchDelay() &&
2452       !_unconditional_delay_slot) {
2453 
2454     uint siz = _available.size();
2455 
2456     // Conditional branches can support an instruction that
2457     // is unconditionally executed and not dependent by the
2458     // branch, OR a conditionally executed instruction if
2459     // the branch is taken.  In practice, this means that
2460     // the first instruction at the branch target is
2461     // copied to the delay slot, and the branch goes to
2462     // the instruction after that at the branch target
2463     if ( n->is_MachBranch() ) {
2464 
2465       assert( !n->is_MachNullCheck(), "should not look for delay slot for Null Check" );
2466       assert( !n->is_Catch(),         "should not look for delay slot for Catch" );
2467 
2468 #ifndef PRODUCT
2469       _branches++;
2470 #endif
2471 
2472       // At least 1 instruction is on the available list
2473       // that is not dependent on the branch
2474       for (uint i = 0; i < siz; i++) {
2475         Node *d = _available[i];
2476         const Pipeline *avail_pipeline = d->pipeline();
2477 
2478         // Don't allow safepoints in the branch shadow, that will
2479         // cause a number of difficulties
2480         if ( avail_pipeline->instructionCount() == 1 &&
2481              !avail_pipeline->hasMultipleBundles() &&
2482              !avail_pipeline->hasBranchDelay() &&
2483              Pipeline::instr_has_unit_size() &&
2484              d->size(_regalloc) == Pipeline::instr_unit_size() &&
2485              NodeFitsInBundle(d) &&
2486              !node_bundling(d)->used_in_delay()) {
2487 
2488           if (d->is_Mach() && !d->is_MachSafePoint()) {
2489             // A node that fits in the delay slot was found, so we need to
2490             // set the appropriate bits in the bundle pipeline information so
2491             // that it correctly indicates resource usage.  Later, when we
2492             // attempt to add this instruction to the bundle, we will skip
2493             // setting the resource usage.
2494             _unconditional_delay_slot = d;
2495             node_bundling(n)->set_use_unconditional_delay();
2496             node_bundling(d)->set_used_in_unconditional_delay();
2497             _bundle_use.add_usage(avail_pipeline->resourceUse());
2498             _current_latency[d->_idx] = _bundle_cycle_number;
2499             _next_node = d;
2500             ++_bundle_instr_count;
2501 #ifndef PRODUCT
2502             _unconditional_delays++;
2503 #endif
2504             break;
2505           }
2506         }
2507       }
2508     }
2509 
2510     // No delay slot, add a nop to the usage
2511     if (!_unconditional_delay_slot) {
2512       // See if adding an instruction in the delay slot will overflow
2513       // the bundle.
2514       if (!NodeFitsInBundle(_nop)) {
2515 #ifndef PRODUCT
2516         if (_cfg->C->trace_opto_output())
2517           tty->print("#  *** STEP(1 instruction for delay slot) ***\n");
2518 #endif
2519         step(1);
2520       }
2521 
2522       _bundle_use.add_usage(_nop->pipeline()->resourceUse());
2523       _next_node = _nop;
2524       ++_bundle_instr_count;
2525     }
2526 
2527     // See if the instruction in the delay slot requires a
2528     // step of the bundles
2529     if (!NodeFitsInBundle(n)) {
2530 #ifndef PRODUCT
2531       if (_cfg->C->trace_opto_output())
2532         tty->print("#  *** STEP(branch won't fit) ***\n");
2533 #endif
2534       // Update the state information
2535       _bundle_instr_count = 0;
2536       _bundle_cycle_number += 1;
2537       _bundle_use.step(1);
2538     }
2539   }
2540 
2541   // Get the number of instructions
2542   uint instruction_count = node_pipeline->instructionCount();
2543   if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
2544     instruction_count = 0;
2545 
2546   // Compute the latency information
2547   uint delay = 0;
2548 
2549   if (instruction_count > 0 || !node_pipeline->mayHaveNoCode()) {
2550     int relative_latency = _current_latency[n->_idx] - _bundle_cycle_number;
2551     if (relative_latency < 0)
2552       relative_latency = 0;
2553 
2554     delay = _bundle_use.full_latency(relative_latency, node_usage);
2555 
2556     // Does not fit in this bundle, start a new one
2557     if (delay > 0) {
2558       step(delay);
2559 
2560 #ifndef PRODUCT
2561       if (_cfg->C->trace_opto_output())
2562         tty->print("#  *** STEP(%d) ***\n", delay);
2563 #endif
2564     }
2565   }
2566 
2567   // If this was placed in the delay slot, ignore it
2568   if (n != _unconditional_delay_slot) {
2569 
2570     if (delay == 0) {
2571       if (node_pipeline->hasMultipleBundles()) {
2572 #ifndef PRODUCT
2573         if (_cfg->C->trace_opto_output())
2574           tty->print("#  *** STEP(multiple instructions) ***\n");
2575 #endif
2576         step(1);
2577       }
2578 
2579       else if (instruction_count + _bundle_instr_count > Pipeline::_max_instrs_per_cycle) {
2580 #ifndef PRODUCT
2581         if (_cfg->C->trace_opto_output())
2582           tty->print("#  *** STEP(%d >= %d instructions) ***\n",
2583                      instruction_count + _bundle_instr_count,
2584                      Pipeline::_max_instrs_per_cycle);
2585 #endif
2586         step(1);
2587       }
2588     }
2589 
2590     if (node_pipeline->hasBranchDelay() && !_unconditional_delay_slot)
2591       _bundle_instr_count++;
2592 
2593     // Set the node's latency
2594     _current_latency[n->_idx] = _bundle_cycle_number;
2595 
2596     // Now merge the functional unit information
2597     if (instruction_count > 0 || !node_pipeline->mayHaveNoCode())
2598       _bundle_use.add_usage(node_usage);
2599 
2600     // Increment the number of instructions in this bundle
2601     _bundle_instr_count += instruction_count;
2602 
2603     // Remember this node for later
2604     if (n->is_Mach())
2605       _next_node = n;
2606   }
2607 
2608   // It's possible to have a BoxLock in the graph and in the _bbs mapping but
2609   // not in the bb->_nodes array.  This happens for debug-info-only BoxLocks.
2610   // 'Schedule' them (basically ignore in the schedule) but do not insert them
2611   // into the block.  All other scheduled nodes get put in the schedule here.
2612   int op = n->Opcode();
2613   if( (op == Op_Node && n->req() == 0) || // anti-dependence node OR
2614       (op != Op_Node &&         // Not an unused antidepedence node and
2615        // not an unallocated boxlock
2616        (OptoReg::is_valid(_regalloc->get_reg_first(n)) || op != Op_BoxLock)) ) {
2617 
2618     // Push any trailing projections
2619     if( bb->get_node(bb->number_of_nodes()-1) != n ) {
2620       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2621         Node *foi = n->fast_out(i);
2622         if( foi->is_Proj() )
2623           _scheduled.push(foi);
2624       }
2625     }
2626 
2627     // Put the instruction in the schedule list
2628     _scheduled.push(n);
2629   }
2630 
2631 #ifndef PRODUCT
2632   if (_cfg->C->trace_opto_output())
2633     dump_available();
2634 #endif
2635 
2636   // Walk all the definitions, decrementing use counts, and
2637   // if a definition has a 0 use count, place it in the available list.
2638   DecrementUseCounts(n,bb);
2639 }
2640 
2641 // This method sets the use count within a basic block.  We will ignore all
2642 // uses outside the current basic block.  As we are doing a backwards walk,
2643 // any node we reach that has a use count of 0 may be scheduled.  This also
2644 // avoids the problem of cyclic references from phi nodes, as long as phi
2645 // nodes are at the front of the basic block.  This method also initializes
2646 // the available list to the set of instructions that have no uses within this
2647 // basic block.
2648 void Scheduling::ComputeUseCount(const Block *bb) {
2649 #ifndef PRODUCT
2650   if (_cfg->C->trace_opto_output())
2651     tty->print("# -> ComputeUseCount\n");
2652 #endif
2653 
2654   // Clear the list of available and scheduled instructions, just in case
2655   _available.clear();
2656   _scheduled.clear();
2657 
2658   // No delay slot specified
2659   _unconditional_delay_slot = nullptr;
2660 
2661 #ifdef ASSERT
2662   for( uint i=0; i < bb->number_of_nodes(); i++ )
2663     assert( _uses[bb->get_node(i)->_idx] == 0, "_use array not clean" );
2664 #endif
2665 
2666   // Force the _uses count to never go to zero for unscheduable pieces
2667   // of the block
2668   for( uint k = 0; k < _bb_start; k++ )
2669     _uses[bb->get_node(k)->_idx] = 1;
2670   for( uint l = _bb_end; l < bb->number_of_nodes(); l++ )
2671     _uses[bb->get_node(l)->_idx] = 1;
2672 
2673   // Iterate backwards over the instructions in the block.  Don't count the
2674   // branch projections at end or the block header instructions.
2675   for( uint j = _bb_end-1; j >= _bb_start; j-- ) {
2676     Node *n = bb->get_node(j);
2677     if( n->is_Proj() ) continue; // Projections handled another way
2678 
2679     // Account for all uses
2680     for ( uint k = 0; k < n->len(); k++ ) {
2681       Node *inp = n->in(k);
2682       if (!inp) continue;
2683       assert(inp != n, "no cycles allowed" );
2684       if (_cfg->get_block_for_node(inp) == bb) { // Block-local use?
2685         if (inp->is_Proj()) { // Skip through Proj's
2686           inp = inp->in(0);
2687         }
2688         ++_uses[inp->_idx];     // Count 1 block-local use
2689       }
2690     }
2691 
2692     // If this instruction has a 0 use count, then it is available
2693     if (!_uses[n->_idx]) {
2694       _current_latency[n->_idx] = _bundle_cycle_number;
2695       AddNodeToAvailableList(n);
2696     }
2697 
2698 #ifndef PRODUCT
2699     if (_cfg->C->trace_opto_output()) {
2700       tty->print("#   uses: %3d: ", _uses[n->_idx]);
2701       n->dump();
2702     }
2703 #endif
2704   }
2705 
2706 #ifndef PRODUCT
2707   if (_cfg->C->trace_opto_output())
2708     tty->print("# <- ComputeUseCount\n");
2709 #endif
2710 }
2711 
2712 // This routine performs scheduling on each basic block in reverse order,
2713 // using instruction latencies and taking into account function unit
2714 // availability.
2715 void Scheduling::DoScheduling() {
2716 #ifndef PRODUCT
2717   if (_cfg->C->trace_opto_output())
2718     tty->print("# -> DoScheduling\n");
2719 #endif
2720 
2721   Block *succ_bb = nullptr;
2722   Block *bb;
2723   Compile* C = Compile::current();
2724 
2725   // Walk over all the basic blocks in reverse order
2726   for (int i = _cfg->number_of_blocks() - 1; i >= 0; succ_bb = bb, i--) {
2727     bb = _cfg->get_block(i);
2728 
2729 #ifndef PRODUCT
2730     if (_cfg->C->trace_opto_output()) {
2731       tty->print("#  Schedule BB#%03d (initial)\n", i);
2732       for (uint j = 0; j < bb->number_of_nodes(); j++) {
2733         bb->get_node(j)->dump();
2734       }
2735     }
2736 #endif
2737 
2738     // On the head node, skip processing
2739     if (bb == _cfg->get_root_block()) {
2740       continue;
2741     }
2742 
2743     // Skip empty, connector blocks
2744     if (bb->is_connector())
2745       continue;
2746 
2747     // If the following block is not the sole successor of
2748     // this one, then reset the pipeline information
2749     if (bb->_num_succs != 1 || bb->non_connector_successor(0) != succ_bb) {
2750 #ifndef PRODUCT
2751       if (_cfg->C->trace_opto_output()) {
2752         tty->print("*** bundle start of next BB, node %d, for %d instructions\n",
2753                    _next_node->_idx, _bundle_instr_count);
2754       }
2755 #endif
2756       step_and_clear();
2757     }
2758 
2759     // Leave untouched the starting instruction, any Phis, a CreateEx node
2760     // or Top.  bb->get_node(_bb_start) is the first schedulable instruction.
2761     _bb_end = bb->number_of_nodes()-1;
2762     for( _bb_start=1; _bb_start <= _bb_end; _bb_start++ ) {
2763       Node *n = bb->get_node(_bb_start);
2764       // Things not matched, like Phinodes and ProjNodes don't get scheduled.
2765       // Also, MachIdealNodes do not get scheduled
2766       if( !n->is_Mach() ) continue;     // Skip non-machine nodes
2767       MachNode *mach = n->as_Mach();
2768       int iop = mach->ideal_Opcode();
2769       if( iop == Op_CreateEx ) continue; // CreateEx is pinned
2770       if( iop == Op_Con ) continue;      // Do not schedule Top
2771       if( iop == Op_Node &&     // Do not schedule PhiNodes, ProjNodes
2772           mach->pipeline() == MachNode::pipeline_class() &&
2773           !n->is_SpillCopy() && !n->is_MachMerge() )  // Breakpoints, Prolog, etc
2774         continue;
2775       break;                    // Funny loop structure to be sure...
2776     }
2777     // Compute last "interesting" instruction in block - last instruction we
2778     // might schedule.  _bb_end points just after last schedulable inst.  We
2779     // normally schedule conditional branches (despite them being forced last
2780     // in the block), because they have delay slots we can fill.  Calls all
2781     // have their delay slots filled in the template expansions, so we don't
2782     // bother scheduling them.
2783     Node *last = bb->get_node(_bb_end);
2784     // Ignore trailing NOPs.
2785     while (_bb_end > 0 && last->is_Mach() &&
2786            last->as_Mach()->ideal_Opcode() == Op_Con) {
2787       last = bb->get_node(--_bb_end);
2788     }
2789     assert(!last->is_Mach() || last->as_Mach()->ideal_Opcode() != Op_Con, "");
2790     if( last->is_Catch() ||
2791         (last->is_Mach() && last->as_Mach()->ideal_Opcode() == Op_Halt) ) {
2792       // There might be a prior call.  Skip it.
2793       while (_bb_start < _bb_end && bb->get_node(--_bb_end)->is_MachProj());
2794     } else if( last->is_MachNullCheck() ) {
2795       // Backup so the last null-checked memory instruction is
2796       // outside the schedulable range. Skip over the nullcheck,
2797       // projection, and the memory nodes.
2798       Node *mem = last->in(1);
2799       do {
2800         _bb_end--;
2801       } while (mem != bb->get_node(_bb_end));
2802     } else {
2803       // Set _bb_end to point after last schedulable inst.
2804       _bb_end++;
2805     }
2806 
2807     assert( _bb_start <= _bb_end, "inverted block ends" );
2808 
2809     // Compute the register antidependencies for the basic block
2810     ComputeRegisterAntidependencies(bb);
2811     if (C->failing())  return;  // too many D-U pinch points
2812 
2813     // Compute the usage within the block, and set the list of all nodes
2814     // in the block that have no uses within the block.
2815     ComputeUseCount(bb);
2816 
2817     // Schedule the remaining instructions in the block
2818     while ( _available.size() > 0 ) {
2819       Node *n = ChooseNodeToBundle();
2820       guarantee(n != nullptr, "no nodes available");
2821       AddNodeToBundle(n,bb);
2822     }
2823 
2824     assert( _scheduled.size() == _bb_end - _bb_start, "wrong number of instructions" );
2825 #ifdef ASSERT
2826     for( uint l = _bb_start; l < _bb_end; l++ ) {
2827       Node *n = bb->get_node(l);
2828       uint m;
2829       for( m = 0; m < _bb_end-_bb_start; m++ )
2830         if( _scheduled[m] == n )
2831           break;
2832       assert( m < _bb_end-_bb_start, "instruction missing in schedule" );
2833     }
2834 #endif
2835 
2836     // Now copy the instructions (in reverse order) back to the block
2837     for ( uint k = _bb_start; k < _bb_end; k++ )
2838       bb->map_node(_scheduled[_bb_end-k-1], k);
2839 
2840 #ifndef PRODUCT
2841     if (_cfg->C->trace_opto_output()) {
2842       tty->print("#  Schedule BB#%03d (final)\n", i);
2843       uint current = 0;
2844       for (uint j = 0; j < bb->number_of_nodes(); j++) {
2845         Node *n = bb->get_node(j);
2846         if( valid_bundle_info(n) ) {
2847           Bundle *bundle = node_bundling(n);
2848           if (bundle->instr_count() > 0 || bundle->flags() > 0) {
2849             tty->print("*** Bundle: ");
2850             bundle->dump();
2851           }
2852           n->dump();
2853         }
2854       }
2855     }
2856 #endif
2857 #ifdef ASSERT
2858     verify_good_schedule(bb,"after block local scheduling");
2859 #endif
2860   }
2861 
2862 #ifndef PRODUCT
2863   if (_cfg->C->trace_opto_output())
2864     tty->print("# <- DoScheduling\n");
2865 #endif
2866 
2867   // Record final node-bundling array location
2868   _regalloc->C->output()->set_node_bundling_base(_node_bundling_base);
2869 
2870 } // end DoScheduling
2871 
2872 // Verify that no live-range used in the block is killed in the block by a
2873 // wrong DEF.  This doesn't verify live-ranges that span blocks.
2874 
2875 // Check for edge existence.  Used to avoid adding redundant precedence edges.
2876 static bool edge_from_to( Node *from, Node *to ) {
2877   for( uint i=0; i<from->len(); i++ )
2878     if( from->in(i) == to )
2879       return true;
2880   return false;
2881 }
2882 
2883 #ifdef ASSERT
2884 void Scheduling::verify_do_def( Node *n, OptoReg::Name def, const char *msg ) {
2885   // Check for bad kills
2886   if( OptoReg::is_valid(def) ) { // Ignore stores & control flow
2887     Node *prior_use = _reg_node[def];
2888     if( prior_use && !edge_from_to(prior_use,n) ) {
2889       tty->print("%s = ",OptoReg::as_VMReg(def)->name());
2890       n->dump();
2891       tty->print_cr("...");
2892       prior_use->dump();
2893       assert(edge_from_to(prior_use,n), "%s", msg);
2894     }
2895     _reg_node.map(def,nullptr); // Kill live USEs
2896   }
2897 }
2898 
2899 void Scheduling::verify_good_schedule( Block *b, const char *msg ) {
2900 
2901   // Zap to something reasonable for the verify code
2902   _reg_node.clear();
2903 
2904   // Walk over the block backwards.  Check to make sure each DEF doesn't
2905   // kill a live value (other than the one it's supposed to).  Add each
2906   // USE to the live set.
2907   for( uint i = b->number_of_nodes()-1; i >= _bb_start; i-- ) {
2908     Node *n = b->get_node(i);
2909     int n_op = n->Opcode();
2910     if( n_op == Op_MachProj && n->ideal_reg() == MachProjNode::fat_proj ) {
2911       // Fat-proj kills a slew of registers
2912       RegMaskIterator rmi(n->out_RegMask());
2913       while (rmi.has_next()) {
2914         OptoReg::Name kill = rmi.next();
2915         verify_do_def(n, kill, msg);
2916       }
2917     } else if( n_op != Op_Node ) { // Avoid brand new antidependence nodes
2918       // Get DEF'd registers the normal way
2919       verify_do_def( n, _regalloc->get_reg_first(n), msg );
2920       verify_do_def( n, _regalloc->get_reg_second(n), msg );
2921     }
2922 
2923     // Now make all USEs live
2924     for( uint i=1; i<n->req(); i++ ) {
2925       Node *def = n->in(i);
2926       assert(def != nullptr, "input edge required");
2927       OptoReg::Name reg_lo = _regalloc->get_reg_first(def);
2928       OptoReg::Name reg_hi = _regalloc->get_reg_second(def);
2929       if( OptoReg::is_valid(reg_lo) ) {
2930         assert(!_reg_node[reg_lo] || edge_from_to(_reg_node[reg_lo],def), "%s", msg);
2931         _reg_node.map(reg_lo,n);
2932       }
2933       if( OptoReg::is_valid(reg_hi) ) {
2934         assert(!_reg_node[reg_hi] || edge_from_to(_reg_node[reg_hi],def), "%s", msg);
2935         _reg_node.map(reg_hi,n);
2936       }
2937     }
2938 
2939   }
2940 
2941   // Zap to something reasonable for the Antidependence code
2942   _reg_node.clear();
2943 }
2944 #endif
2945 
2946 // Conditionally add precedence edges.  Avoid putting edges on Projs.
2947 static void add_prec_edge_from_to( Node *from, Node *to ) {
2948   if( from->is_Proj() ) {       // Put precedence edge on Proj's input
2949     assert( from->req() == 1 && (from->len() == 1 || from->in(1) == nullptr), "no precedence edges on projections" );
2950     from = from->in(0);
2951   }
2952   if( from != to &&             // No cycles (for things like LD L0,[L0+4] )
2953       !edge_from_to( from, to ) ) // Avoid duplicate edge
2954     from->add_prec(to);
2955 }
2956 
2957 void Scheduling::anti_do_def( Block *b, Node *def, OptoReg::Name def_reg, int is_def ) {
2958   if( !OptoReg::is_valid(def_reg) ) // Ignore stores & control flow
2959     return;
2960 
2961   if (OptoReg::is_reg(def_reg)) {
2962     VMReg vmreg = OptoReg::as_VMReg(def_reg);
2963     if (vmreg->is_reg() && !vmreg->is_concrete() && !vmreg->prev()->is_concrete()) {
2964       // This is one of the high slots of a vector register.
2965       // ScheduleAndBundle already checked there are no live wide
2966       // vectors in this method so it can be safely ignored.
2967       return;
2968     }
2969   }
2970 
2971   Node *pinch = _reg_node[def_reg]; // Get pinch point
2972   if ((pinch == nullptr) || _cfg->get_block_for_node(pinch) != b || // No pinch-point yet?
2973       is_def ) {    // Check for a true def (not a kill)
2974     _reg_node.map(def_reg,def); // Record def/kill as the optimistic pinch-point
2975     return;
2976   }
2977 
2978   Node *kill = def;             // Rename 'def' to more descriptive 'kill'
2979   debug_only( def = (Node*)((intptr_t)0xdeadbeef); )
2980 
2981   // After some number of kills there _may_ be a later def
2982   Node *later_def = nullptr;
2983 
2984   Compile* C = Compile::current();
2985 
2986   // Finding a kill requires a real pinch-point.
2987   // Check for not already having a pinch-point.
2988   // Pinch points are Op_Node's.
2989   if( pinch->Opcode() != Op_Node ) { // Or later-def/kill as pinch-point?
2990     later_def = pinch;            // Must be def/kill as optimistic pinch-point
2991     if ( _pinch_free_list.size() > 0) {
2992       pinch = _pinch_free_list.pop();
2993     } else {
2994       pinch = new Node(1); // Pinch point to-be
2995     }
2996     if (pinch->_idx >= _regalloc->node_regs_max_index()) {
2997       DEBUG_ONLY( pinch->dump(); );
2998       assert(false, "too many D-U pinch points: %d >= %d", pinch->_idx, _regalloc->node_regs_max_index());
2999       _cfg->C->record_method_not_compilable("too many D-U pinch points");
3000       return;
3001     }
3002     _cfg->map_node_to_block(pinch, b);      // Pretend it's valid in this block (lazy init)
3003     _reg_node.map(def_reg,pinch); // Record pinch-point
3004     //regalloc()->set_bad(pinch->_idx); // Already initialized this way.
3005     if( later_def->outcnt() == 0 || later_def->ideal_reg() == MachProjNode::fat_proj ) { // Distinguish def from kill
3006       pinch->init_req(0, C->top());     // set not null for the next call
3007       add_prec_edge_from_to(later_def,pinch); // Add edge from kill to pinch
3008       later_def = nullptr;           // and no later def
3009     }
3010     pinch->set_req(0,later_def);  // Hook later def so we can find it
3011   } else {                        // Else have valid pinch point
3012     if( pinch->in(0) )            // If there is a later-def
3013       later_def = pinch->in(0);   // Get it
3014   }
3015 
3016   // Add output-dependence edge from later def to kill
3017   if( later_def )               // If there is some original def
3018     add_prec_edge_from_to(later_def,kill); // Add edge from def to kill
3019 
3020   // See if current kill is also a use, and so is forced to be the pinch-point.
3021   if( pinch->Opcode() == Op_Node ) {
3022     Node *uses = kill->is_Proj() ? kill->in(0) : kill;
3023     for( uint i=1; i<uses->req(); i++ ) {
3024       if( _regalloc->get_reg_first(uses->in(i)) == def_reg ||
3025           _regalloc->get_reg_second(uses->in(i)) == def_reg ) {
3026         // Yes, found a use/kill pinch-point
3027         pinch->set_req(0,nullptr);  //
3028         pinch->replace_by(kill); // Move anti-dep edges up
3029         pinch = kill;
3030         _reg_node.map(def_reg,pinch);
3031         return;
3032       }
3033     }
3034   }
3035 
3036   // Add edge from kill to pinch-point
3037   add_prec_edge_from_to(kill,pinch);
3038 }
3039 
3040 void Scheduling::anti_do_use( Block *b, Node *use, OptoReg::Name use_reg ) {
3041   if( !OptoReg::is_valid(use_reg) ) // Ignore stores & control flow
3042     return;
3043   Node *pinch = _reg_node[use_reg]; // Get pinch point
3044   // Check for no later def_reg/kill in block
3045   if ((pinch != nullptr) && _cfg->get_block_for_node(pinch) == b &&
3046       // Use has to be block-local as well
3047       _cfg->get_block_for_node(use) == b) {
3048     if( pinch->Opcode() == Op_Node && // Real pinch-point (not optimistic?)
3049         pinch->req() == 1 ) {   // pinch not yet in block?
3050       pinch->del_req(0);        // yank pointer to later-def, also set flag
3051       // Insert the pinch-point in the block just after the last use
3052       b->insert_node(pinch, b->find_node(use) + 1);
3053       _bb_end++;                // Increase size scheduled region in block
3054     }
3055 
3056     add_prec_edge_from_to(pinch,use);
3057   }
3058 }
3059 
3060 // We insert antidependences between the reads and following write of
3061 // allocated registers to prevent illegal code motion. Hopefully, the
3062 // number of added references should be fairly small, especially as we
3063 // are only adding references within the current basic block.
3064 void Scheduling::ComputeRegisterAntidependencies(Block *b) {
3065 
3066 #ifdef ASSERT
3067   verify_good_schedule(b,"before block local scheduling");
3068 #endif
3069 
3070   // A valid schedule, for each register independently, is an endless cycle
3071   // of: a def, then some uses (connected to the def by true dependencies),
3072   // then some kills (defs with no uses), finally the cycle repeats with a new
3073   // def.  The uses are allowed to float relative to each other, as are the
3074   // kills.  No use is allowed to slide past a kill (or def).  This requires
3075   // antidependencies between all uses of a single def and all kills that
3076   // follow, up to the next def.  More edges are redundant, because later defs
3077   // & kills are already serialized with true or antidependencies.  To keep
3078   // the edge count down, we add a 'pinch point' node if there's more than
3079   // one use or more than one kill/def.
3080 
3081   // We add dependencies in one bottom-up pass.
3082 
3083   // For each instruction we handle it's DEFs/KILLs, then it's USEs.
3084 
3085   // For each DEF/KILL, we check to see if there's a prior DEF/KILL for this
3086   // register.  If not, we record the DEF/KILL in _reg_node, the
3087   // register-to-def mapping.  If there is a prior DEF/KILL, we insert a
3088   // "pinch point", a new Node that's in the graph but not in the block.
3089   // We put edges from the prior and current DEF/KILLs to the pinch point.
3090   // We put the pinch point in _reg_node.  If there's already a pinch point
3091   // we merely add an edge from the current DEF/KILL to the pinch point.
3092 
3093   // After doing the DEF/KILLs, we handle USEs.  For each used register, we
3094   // put an edge from the pinch point to the USE.
3095 
3096   // To be expedient, the _reg_node array is pre-allocated for the whole
3097   // compilation.  _reg_node is lazily initialized; it either contains a null,
3098   // or a valid def/kill/pinch-point, or a leftover node from some prior
3099   // block.  Leftover node from some prior block is treated like a null (no
3100   // prior def, so no anti-dependence needed).  Valid def is distinguished by
3101   // it being in the current block.
3102   bool fat_proj_seen = false;
3103   uint last_safept = _bb_end-1;
3104   Node* end_node         = (_bb_end-1 >= _bb_start) ? b->get_node(last_safept) : nullptr;
3105   Node* last_safept_node = end_node;
3106   for( uint i = _bb_end-1; i >= _bb_start; i-- ) {
3107     Node *n = b->get_node(i);
3108     int is_def = n->outcnt();   // def if some uses prior to adding precedence edges
3109     if( n->is_MachProj() && n->ideal_reg() == MachProjNode::fat_proj ) {
3110       // Fat-proj kills a slew of registers
3111       // This can add edges to 'n' and obscure whether or not it was a def,
3112       // hence the is_def flag.
3113       fat_proj_seen = true;
3114       RegMaskIterator rmi(n->out_RegMask());
3115       while (rmi.has_next()) {
3116         OptoReg::Name kill = rmi.next();
3117         anti_do_def(b, n, kill, is_def);
3118       }
3119     } else {
3120       // Get DEF'd registers the normal way
3121       anti_do_def( b, n, _regalloc->get_reg_first(n), is_def );
3122       anti_do_def( b, n, _regalloc->get_reg_second(n), is_def );
3123     }
3124 
3125     // Kill projections on a branch should appear to occur on the
3126     // branch, not afterwards, so grab the masks from the projections
3127     // and process them.
3128     if (n->is_MachBranch() || (n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_Jump)) {
3129       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3130         Node* use = n->fast_out(i);
3131         if (use->is_Proj()) {
3132           RegMaskIterator rmi(use->out_RegMask());
3133           while (rmi.has_next()) {
3134             OptoReg::Name kill = rmi.next();
3135             anti_do_def(b, n, kill, false);
3136           }
3137         }
3138       }
3139     }
3140 
3141     // Check each register used by this instruction for a following DEF/KILL
3142     // that must occur afterward and requires an anti-dependence edge.
3143     for( uint j=0; j<n->req(); j++ ) {
3144       Node *def = n->in(j);
3145       if( def ) {
3146         assert( !def->is_MachProj() || def->ideal_reg() != MachProjNode::fat_proj, "" );
3147         anti_do_use( b, n, _regalloc->get_reg_first(def) );
3148         anti_do_use( b, n, _regalloc->get_reg_second(def) );
3149       }
3150     }
3151     // Do not allow defs of new derived values to float above GC
3152     // points unless the base is definitely available at the GC point.
3153 
3154     Node *m = b->get_node(i);
3155 
3156     // Add precedence edge from following safepoint to use of derived pointer
3157     if( last_safept_node != end_node &&
3158         m != last_safept_node) {
3159       for (uint k = 1; k < m->req(); k++) {
3160         const Type *t = m->in(k)->bottom_type();
3161         if( t->isa_oop_ptr() &&
3162             t->is_ptr()->offset() != 0 ) {
3163           last_safept_node->add_prec( m );
3164           break;
3165         }
3166       }
3167     }
3168 
3169     if( n->jvms() ) {           // Precedence edge from derived to safept
3170       // Check if last_safept_node was moved by pinch-point insertion in anti_do_use()
3171       if( b->get_node(last_safept) != last_safept_node ) {
3172         last_safept = b->find_node(last_safept_node);
3173       }
3174       for( uint j=last_safept; j > i; j-- ) {
3175         Node *mach = b->get_node(j);
3176         if( mach->is_Mach() && mach->as_Mach()->ideal_Opcode() == Op_AddP )
3177           mach->add_prec( n );
3178       }
3179       last_safept = i;
3180       last_safept_node = m;
3181     }
3182   }
3183 
3184   if (fat_proj_seen) {
3185     // Garbage collect pinch nodes that were not consumed.
3186     // They are usually created by a fat kill MachProj for a call.
3187     garbage_collect_pinch_nodes();
3188   }
3189 }
3190 
3191 // Garbage collect pinch nodes for reuse by other blocks.
3192 //
3193 // The block scheduler's insertion of anti-dependence
3194 // edges creates many pinch nodes when the block contains
3195 // 2 or more Calls.  A pinch node is used to prevent a
3196 // combinatorial explosion of edges.  If a set of kills for a
3197 // register is anti-dependent on a set of uses (or defs), rather
3198 // than adding an edge in the graph between each pair of kill
3199 // and use (or def), a pinch is inserted between them:
3200 //
3201 //            use1   use2  use3
3202 //                \   |   /
3203 //                 \  |  /
3204 //                  pinch
3205 //                 /  |  \
3206 //                /   |   \
3207 //            kill1 kill2 kill3
3208 //
3209 // One pinch node is created per register killed when
3210 // the second call is encountered during a backwards pass
3211 // over the block.  Most of these pinch nodes are never
3212 // wired into the graph because the register is never
3213 // used or def'ed in the block.
3214 //
3215 void Scheduling::garbage_collect_pinch_nodes() {
3216 #ifndef PRODUCT
3217   if (_cfg->C->trace_opto_output()) tty->print("Reclaimed pinch nodes:");
3218 #endif
3219   int trace_cnt = 0;
3220   for (uint k = 0; k < _reg_node.max(); k++) {
3221     Node* pinch = _reg_node[k];
3222     if ((pinch != nullptr) && pinch->Opcode() == Op_Node &&
3223         // no predecence input edges
3224         (pinch->req() == pinch->len() || pinch->in(pinch->req()) == nullptr) ) {
3225       cleanup_pinch(pinch);
3226       _pinch_free_list.push(pinch);
3227       _reg_node.map(k, nullptr);
3228 #ifndef PRODUCT
3229       if (_cfg->C->trace_opto_output()) {
3230         trace_cnt++;
3231         if (trace_cnt > 40) {
3232           tty->print("\n");
3233           trace_cnt = 0;
3234         }
3235         tty->print(" %d", pinch->_idx);
3236       }
3237 #endif
3238     }
3239   }
3240 #ifndef PRODUCT
3241   if (_cfg->C->trace_opto_output()) tty->print("\n");
3242 #endif
3243 }
3244 
3245 // Clean up a pinch node for reuse.
3246 void Scheduling::cleanup_pinch( Node *pinch ) {
3247   assert (pinch && pinch->Opcode() == Op_Node && pinch->req() == 1, "just checking");
3248 
3249   for (DUIterator_Last imin, i = pinch->last_outs(imin); i >= imin; ) {
3250     Node* use = pinch->last_out(i);
3251     uint uses_found = 0;
3252     for (uint j = use->req(); j < use->len(); j++) {
3253       if (use->in(j) == pinch) {
3254         use->rm_prec(j);
3255         uses_found++;
3256       }
3257     }
3258     assert(uses_found > 0, "must be a precedence edge");
3259     i -= uses_found;    // we deleted 1 or more copies of this edge
3260   }
3261   // May have a later_def entry
3262   pinch->set_req(0, nullptr);
3263 }
3264 
3265 #ifndef PRODUCT
3266 
3267 void Scheduling::dump_available() const {
3268   tty->print("#Availist  ");
3269   for (uint i = 0; i < _available.size(); i++)
3270     tty->print(" N%d/l%d", _available[i]->_idx,_current_latency[_available[i]->_idx]);
3271   tty->cr();
3272 }
3273 
3274 // Print Scheduling Statistics
3275 void Scheduling::print_statistics() {
3276   // Print the size added by nops for bundling
3277   tty->print("Nops added %d bytes to total of %d bytes",
3278              _total_nop_size, _total_method_size);
3279   if (_total_method_size > 0)
3280     tty->print(", for %.2f%%",
3281                ((double)_total_nop_size) / ((double) _total_method_size) * 100.0);
3282   tty->print("\n");
3283 
3284   // Print the number of branch shadows filled
3285   if (Pipeline::_branch_has_delay_slot) {
3286     tty->print("Of %d branches, %d had unconditional delay slots filled",
3287                _total_branches, _total_unconditional_delays);
3288     if (_total_branches > 0)
3289       tty->print(", for %.2f%%",
3290                  ((double)_total_unconditional_delays) / ((double)_total_branches) * 100.0);
3291     tty->print("\n");
3292   }
3293 
3294   uint total_instructions = 0, total_bundles = 0;
3295 
3296   for (uint i = 1; i <= Pipeline::_max_instrs_per_cycle; i++) {
3297     uint bundle_count   = _total_instructions_per_bundle[i];
3298     total_instructions += bundle_count * i;
3299     total_bundles      += bundle_count;
3300   }
3301 
3302   if (total_bundles > 0)
3303     tty->print("Average ILP (excluding nops) is %.2f\n",
3304                ((double)total_instructions) / ((double)total_bundles));
3305 }
3306 #endif
3307 
3308 //-----------------------init_scratch_buffer_blob------------------------------
3309 // Construct a temporary BufferBlob and cache it for this compile.
3310 void PhaseOutput::init_scratch_buffer_blob(int const_size) {
3311   // If there is already a scratch buffer blob allocated and the
3312   // constant section is big enough, use it.  Otherwise free the
3313   // current and allocate a new one.
3314   BufferBlob* blob = scratch_buffer_blob();
3315   if ((blob != nullptr) && (const_size <= _scratch_const_size)) {
3316     // Use the current blob.
3317   } else {
3318     if (blob != nullptr) {
3319       BufferBlob::free(blob);
3320     }
3321 
3322     ResourceMark rm;
3323     _scratch_const_size = const_size;
3324     int size = C2Compiler::initial_code_buffer_size(const_size);
3325     blob = BufferBlob::create("Compile::scratch_buffer", size);
3326     // Record the buffer blob for next time.
3327     set_scratch_buffer_blob(blob);
3328     // Have we run out of code space?
3329     if (scratch_buffer_blob() == nullptr) {
3330       // Let CompilerBroker disable further compilations.
3331       C->record_failure("Not enough space for scratch buffer in CodeCache");
3332       return;
3333     }
3334   }
3335 
3336   // Initialize the relocation buffers
3337   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
3338   set_scratch_locs_memory(locs_buf);
3339 }
3340 
3341 
3342 //-----------------------scratch_emit_size-------------------------------------
3343 // Helper function that computes size by emitting code
3344 uint PhaseOutput::scratch_emit_size(const Node* n) {
3345   // Start scratch_emit_size section.
3346   set_in_scratch_emit_size(true);
3347 
3348   // Emit into a trash buffer and count bytes emitted.
3349   // This is a pretty expensive way to compute a size,
3350   // but it works well enough if seldom used.
3351   // All common fixed-size instructions are given a size
3352   // method by the AD file.
3353   // Note that the scratch buffer blob and locs memory are
3354   // allocated at the beginning of the compile task, and
3355   // may be shared by several calls to scratch_emit_size.
3356   // The allocation of the scratch buffer blob is particularly
3357   // expensive, since it has to grab the code cache lock.
3358   BufferBlob* blob = this->scratch_buffer_blob();
3359   assert(blob != nullptr, "Initialize BufferBlob at start");
3360   assert(blob->size() > MAX_inst_size, "sanity");
3361   relocInfo* locs_buf = scratch_locs_memory();
3362   address blob_begin = blob->content_begin();
3363   address blob_end   = (address)locs_buf;
3364   assert(blob->contains(blob_end), "sanity");
3365   CodeBuffer buf(blob_begin, blob_end - blob_begin);
3366   buf.initialize_consts_size(_scratch_const_size);
3367   buf.initialize_stubs_size(MAX_stubs_size);
3368   assert(locs_buf != nullptr, "sanity");
3369   int lsize = MAX_locs_size / 3;
3370   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
3371   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
3372   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
3373   // Mark as scratch buffer.
3374   buf.consts()->set_scratch_emit();
3375   buf.insts()->set_scratch_emit();
3376   buf.stubs()->set_scratch_emit();
3377 
3378   // Do the emission.
3379 
3380   Label fakeL; // Fake label for branch instructions.
3381   Label*   saveL = nullptr;
3382   uint save_bnum = 0;
3383   bool is_branch = n->is_MachBranch();
3384   C2_MacroAssembler masm(&buf);
3385   masm.bind(fakeL);
3386   if (is_branch) {
3387     n->as_MachBranch()->save_label(&saveL, &save_bnum);
3388     n->as_MachBranch()->label_set(&fakeL, 0);
3389   }
3390   n->emit(&masm, C->regalloc());
3391 
3392   // Emitting into the scratch buffer should not fail
3393   assert(!C->failing_internal() || C->failure_is_artificial(), "Must not have pending failure. Reason is: %s", C->failure_reason());
3394 
3395   if (is_branch) // Restore label.
3396     n->as_MachBranch()->label_set(saveL, save_bnum);
3397 
3398   // End scratch_emit_size section.
3399   set_in_scratch_emit_size(false);
3400 
3401   return buf.insts_size();
3402 }
3403 
3404 void PhaseOutput::install() {
3405   if (C->should_install_code() && C->stub_function() != nullptr) {
3406     install_stub(C->stub_name());
3407   } else {
3408     install_code(C->method(),
3409                  C->entry_bci(),
3410                  CompilerThread::current()->compiler(),
3411                  C->has_unsafe_access(),
3412                  SharedRuntime::is_wide_vector(C->max_vector_size()));
3413   }
3414 }
3415 
3416 void PhaseOutput::install_code(ciMethod*         target,
3417                                int               entry_bci,
3418                                AbstractCompiler* compiler,
3419                                bool              has_unsafe_access,
3420                                bool              has_wide_vectors) {
3421   // Check if we want to skip execution of all compiled code.
3422   {
3423 #ifndef PRODUCT
3424     if (OptoNoExecute) {
3425       C->record_method_not_compilable("+OptoNoExecute");  // Flag as failed
3426       return;
3427     }
3428 #endif
3429     Compile::TracePhase tp(_t_registerMethod);
3430 
3431     if (C->is_osr_compilation()) {
3432       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
3433       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
3434     } else {
3435       if (!target->is_static()) {
3436         // The UEP of an nmethod ensures that the VEP is padded. However, the padding of the UEP is placed
3437         // before the inline cache check, so we don't have to execute any nop instructions when dispatching
3438         // through the UEP, yet we can ensure that the VEP is aligned appropriately.
3439         _code_offsets.set_value(CodeOffsets::Entry, _first_block_size - MacroAssembler::ic_check_size());
3440       }
3441       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
3442       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
3443     }
3444 
3445     C->env()->register_method(target,
3446                                      entry_bci,
3447                                      &_code_offsets,
3448                                      _orig_pc_slot_offset_in_bytes,
3449                                      code_buffer(),
3450                                      frame_size_in_words(),
3451                                      oop_map_set(),
3452                                      &_handler_table,
3453                                      inc_table(),
3454                                      compiler,
3455                                      C->has_clinit_barriers(),
3456                                      C->for_preload(),
3457                                      has_unsafe_access,
3458                                      SharedRuntime::is_wide_vector(C->max_vector_size()),
3459                                      C->has_monitors(),
3460                                      C->has_scoped_access(),
3461                                      0,
3462                                      C->should_install_code());
3463 
3464     if (C->log() != nullptr) { // Print code cache state into compiler log
3465       C->log()->code_cache_state();
3466     }
3467     if (C->has_clinit_barriers()) {
3468       assert(C->for_preload(), "sanity");
3469       // Build second version of code without class initialization barriers
3470       if (C->env()->task()->compile_reason() == CompileTask::Reason_PrecompileForPreload) {
3471         // don't automatically precompile a barrier-free version unless explicitly asked
3472       } else {
3473         C->record_failure(C2Compiler::retry_no_clinit_barriers());
3474       }
3475     }
3476   }
3477 }
3478 void PhaseOutput::install_stub(const char* stub_name) {
3479   // Entry point will be accessed using stub_entry_point();
3480   if (code_buffer() == nullptr) {
3481     Matcher::soft_match_failure();
3482   } else {
3483     if (PrintAssembly && (WizardMode || Verbose))
3484       tty->print_cr("### Stub::%s", stub_name);
3485 
3486     if (!C->failing()) {
3487       assert(C->fixed_slots() == 0, "no fixed slots used for runtime stubs");
3488 
3489       // Make the NMethod
3490       // For now we mark the frame as never safe for profile stackwalking
3491       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
3492                                                       code_buffer(),
3493                                                       CodeOffsets::frame_never_safe,
3494                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
3495                                                       frame_size_in_words(),
3496                                                       oop_map_set(),
3497                                                       false);
3498       assert(rs != nullptr && rs->is_runtime_stub(), "sanity check");
3499 
3500       C->set_stub_entry_point(rs->entry_point());
3501     }
3502   }
3503 }
3504 
3505 // Support for bundling info
3506 Bundle* PhaseOutput::node_bundling(const Node *n) {
3507   assert(valid_bundle_info(n), "oob");
3508   return &_node_bundling_base[n->_idx];
3509 }
3510 
3511 bool PhaseOutput::valid_bundle_info(const Node *n) {
3512   return (_node_bundling_limit > n->_idx);
3513 }
3514 
3515 //------------------------------frame_size_in_words-----------------------------
3516 // frame_slots in units of words
3517 int PhaseOutput::frame_size_in_words() const {
3518   // shift is 0 in LP32 and 1 in LP64
3519   const int shift = (LogBytesPerWord - LogBytesPerInt);
3520   int words = _frame_slots >> shift;
3521   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
3522   return words;
3523 }
3524 
3525 // To bang the stack of this compiled method we use the stack size
3526 // that the interpreter would need in case of a deoptimization. This
3527 // removes the need to bang the stack in the deoptimization blob which
3528 // in turn simplifies stack overflow handling.
3529 int PhaseOutput::bang_size_in_bytes() const {
3530   return MAX2(frame_size_in_bytes() + os::extra_bang_size_in_bytes(), C->interpreter_frame_size());
3531 }
3532 
3533 //------------------------------dump_asm---------------------------------------
3534 // Dump formatted assembly
3535 #if defined(SUPPORT_OPTO_ASSEMBLY)
3536 void PhaseOutput::dump_asm_on(outputStream* st, int* pcs, uint pc_limit) {
3537 
3538   int pc_digits = 3; // #chars required for pc
3539   int sb_chars  = 3; // #chars for "start bundle" indicator
3540   int tab_size  = 8;
3541   if (pcs != nullptr) {
3542     int max_pc = 0;
3543     for (uint i = 0; i < pc_limit; i++) {
3544       max_pc = (max_pc < pcs[i]) ? pcs[i] : max_pc;
3545     }
3546     pc_digits  = ((max_pc < 4096) ? 3 : ((max_pc < 65536) ? 4 : ((max_pc < 65536*256) ? 6 : 8))); // #chars required for pc
3547   }
3548   int prefix_len = ((pc_digits + sb_chars + tab_size - 1)/tab_size)*tab_size;
3549 
3550   bool cut_short = false;
3551   st->print_cr("#");
3552   st->print("#  ");  C->tf()->dump_on(st);  st->cr();
3553   st->print_cr("#");
3554 
3555   // For all blocks
3556   int pc = 0x0;                 // Program counter
3557   char starts_bundle = ' ';
3558   C->regalloc()->dump_frame();
3559 
3560   Node *n = nullptr;
3561   for (uint i = 0; i < C->cfg()->number_of_blocks(); i++) {
3562     if (VMThread::should_terminate()) {
3563       cut_short = true;
3564       break;
3565     }
3566     Block* block = C->cfg()->get_block(i);
3567     if (block->is_connector() && !Verbose) {
3568       continue;
3569     }
3570     n = block->head();
3571     if ((pcs != nullptr) && (n->_idx < pc_limit)) {
3572       pc = pcs[n->_idx];
3573       st->print("%*.*x", pc_digits, pc_digits, pc);
3574     }
3575     st->fill_to(prefix_len);
3576     block->dump_head(C->cfg(), st);
3577     if (block->is_connector()) {
3578       st->fill_to(prefix_len);
3579       st->print_cr("# Empty connector block");
3580     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
3581       st->fill_to(prefix_len);
3582       st->print_cr("# Block is sole successor of call");
3583     }
3584 
3585     // For all instructions
3586     Node *delay = nullptr;
3587     for (uint j = 0; j < block->number_of_nodes(); j++) {
3588       if (VMThread::should_terminate()) {
3589         cut_short = true;
3590         break;
3591       }
3592       n = block->get_node(j);
3593       if (valid_bundle_info(n)) {
3594         Bundle* bundle = node_bundling(n);
3595         if (bundle->used_in_unconditional_delay()) {
3596           delay = n;
3597           continue;
3598         }
3599         if (bundle->starts_bundle()) {
3600           starts_bundle = '+';
3601         }
3602       }
3603 
3604       if (WizardMode) {
3605         n->dump();
3606       }
3607 
3608       if( !n->is_Region() &&    // Dont print in the Assembly
3609           !n->is_Phi() &&       // a few noisely useless nodes
3610           !n->is_Proj() &&
3611           !n->is_MachTemp() &&
3612           !n->is_SafePointScalarObject() &&
3613           !n->is_Catch() &&     // Would be nice to print exception table targets
3614           !n->is_MergeMem() &&  // Not very interesting
3615           !n->is_top() &&       // Debug info table constants
3616           !(n->is_Con() && !n->is_Mach())// Debug info table constants
3617           ) {
3618         if ((pcs != nullptr) && (n->_idx < pc_limit)) {
3619           pc = pcs[n->_idx];
3620           st->print("%*.*x", pc_digits, pc_digits, pc);
3621         } else {
3622           st->fill_to(pc_digits);
3623         }
3624         st->print(" %c ", starts_bundle);
3625         starts_bundle = ' ';
3626         st->fill_to(prefix_len);
3627         n->format(C->regalloc(), st);
3628         st->cr();
3629       }
3630 
3631       // If we have an instruction with a delay slot, and have seen a delay,
3632       // then back up and print it
3633       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
3634         // Coverity finding - Explicit null dereferenced.
3635         guarantee(delay != nullptr, "no unconditional delay instruction");
3636         if (WizardMode) delay->dump();
3637 
3638         if (node_bundling(delay)->starts_bundle())
3639           starts_bundle = '+';
3640         if ((pcs != nullptr) && (n->_idx < pc_limit)) {
3641           pc = pcs[n->_idx];
3642           st->print("%*.*x", pc_digits, pc_digits, pc);
3643         } else {
3644           st->fill_to(pc_digits);
3645         }
3646         st->print(" %c ", starts_bundle);
3647         starts_bundle = ' ';
3648         st->fill_to(prefix_len);
3649         delay->format(C->regalloc(), st);
3650         st->cr();
3651         delay = nullptr;
3652       }
3653 
3654       // Dump the exception table as well
3655       if( n->is_Catch() && (Verbose || WizardMode) ) {
3656         // Print the exception table for this offset
3657         _handler_table.print_subtable_for(pc);
3658       }
3659       st->bol(); // Make sure we start on a new line
3660     }
3661     st->cr(); // one empty line between blocks
3662     assert(cut_short || delay == nullptr, "no unconditional delay branch");
3663   } // End of per-block dump
3664 
3665   if (cut_short)  st->print_cr("*** disassembly is cut short ***");
3666 }
3667 #endif
3668 
3669 #ifndef PRODUCT
3670 void PhaseOutput::print_statistics() {
3671   Scheduling::print_statistics();
3672 }
3673 #endif