1 /*
   2  * Copyright (c) 1998, 2014, 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 "code/compiledIC.hpp"
  28 #include "code/debugInfo.hpp"
  29 #include "code/debugInfoRec.hpp"
  30 #include "compiler/compileBroker.hpp"
  31 #include "compiler/oopMap.hpp"
  32 #include "memory/allocation.inline.hpp"
  33 #include "opto/ad.hpp"
  34 #include "opto/callnode.hpp"
  35 #include "opto/cfgnode.hpp"
  36 #include "opto/locknode.hpp"
  37 #include "opto/machnode.hpp"
  38 #include "opto/optoreg.hpp"
  39 #include "opto/output.hpp"
  40 #include "opto/regalloc.hpp"
  41 #include "opto/runtime.hpp"
  42 #include "opto/subnode.hpp"
  43 #include "opto/type.hpp"
  44 #include "runtime/handles.inline.hpp"
  45 #include "utilities/xmlstream.hpp"
  46 
  47 #ifndef PRODUCT
  48 #define DEBUG_ARG(x) , x
  49 #else
  50 #define DEBUG_ARG(x)
  51 #endif
  52 
  53 // Convert Nodes to instruction bits and pass off to the VM
  54 void Compile::Output() {
  55   // RootNode goes
  56   assert( _cfg->get_root_block()->number_of_nodes() == 0, "" );
  57 
  58   // The number of new nodes (mostly MachNop) is proportional to
  59   // the number of java calls and inner loops which are aligned.
  60   if ( C->check_node_count((NodeLimitFudgeFactor + C->java_calls()*3 +
  61                             C->inner_loops()*(OptoLoopAlignment-1)),
  62                            "out of nodes before code generation" ) ) {
  63     return;
  64   }
  65   // Make sure I can find the Start Node
  66   Block *entry = _cfg->get_block(1);
  67   Block *broot = _cfg->get_root_block();
  68 
  69   const StartNode *start = entry->head()->as_Start();
  70 
  71   // Replace StartNode with prolog
  72   MachPrologNode *prolog = new MachPrologNode();
  73   entry->map_node(prolog, 0);
  74   _cfg->map_node_to_block(prolog, entry);
  75   _cfg->unmap_node_from_block(start); // start is no longer in any block
  76 
  77   // Virtual methods need an unverified entry point
  78 
  79   if( is_osr_compilation() ) {
  80     if( PoisonOSREntry ) {
  81       // TODO: Should use a ShouldNotReachHereNode...
  82       _cfg->insert( broot, 0, new MachBreakpointNode() );
  83     }
  84   } else {
  85     if( _method && !_method->flags().is_static() ) {
  86       // Insert unvalidated entry point
  87       _cfg->insert( broot, 0, new MachUEPNode() );
  88     }
  89 
  90   }
  91 
  92 
  93   // Break before main entry point
  94   if( (_method && _method->break_at_execute())
  95 #ifndef PRODUCT
  96     ||(OptoBreakpoint && is_method_compilation())
  97     ||(OptoBreakpointOSR && is_osr_compilation())
  98     ||(OptoBreakpointC2R && !_method)
  99 #endif
 100     ) {
 101     // checking for _method means that OptoBreakpoint does not apply to
 102     // runtime stubs or frame converters
 103     _cfg->insert( entry, 1, new MachBreakpointNode() );
 104   }
 105 
 106   // Insert epilogs before every return
 107   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
 108     Block* block = _cfg->get_block(i);
 109     if (!block->is_connector() && block->non_connector_successor(0) == _cfg->get_root_block()) { // Found a program exit point?
 110       Node* m = block->end();
 111       if (m->is_Mach() && m->as_Mach()->ideal_Opcode() != Op_Halt) {
 112         MachEpilogNode* epilog = new MachEpilogNode(m->as_Mach()->ideal_Opcode() == Op_Return);
 113         block->add_inst(epilog);
 114         _cfg->map_node_to_block(epilog, block);
 115       }
 116     }
 117   }
 118 
 119   uint* blk_starts = NEW_RESOURCE_ARRAY(uint, _cfg->number_of_blocks() + 1);
 120   blk_starts[0] = 0;
 121 
 122   // Initialize code buffer and process short branches.
 123   CodeBuffer* cb = init_buffer(blk_starts);
 124 
 125   if (cb == NULL || failing()) {
 126     return;
 127   }
 128 
 129   ScheduleAndBundle();
 130 
 131 #ifndef PRODUCT
 132   if (trace_opto_output()) {
 133     tty->print("\n---- After ScheduleAndBundle ----\n");
 134     for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
 135       tty->print("\nBB#%03d:\n", i);
 136       Block* block = _cfg->get_block(i);
 137       for (uint j = 0; j < block->number_of_nodes(); j++) {
 138         Node* n = block->get_node(j);
 139         OptoReg::Name reg = _regalloc->get_reg_first(n);
 140         tty->print(" %-6s ", reg >= 0 && reg < REG_COUNT ? Matcher::regName[reg] : "");
 141         n->dump();
 142       }
 143     }
 144   }
 145 #endif
 146 
 147   if (failing()) {
 148     return;
 149   }
 150 
 151   BuildOopMaps();
 152 
 153   if (failing())  {
 154     return;
 155   }
 156 
 157   fill_buffer(cb, blk_starts);
 158 }
 159 
 160 bool Compile::need_stack_bang(int frame_size_in_bytes) const {
 161   // Determine if we need to generate a stack overflow check.
 162   // Do it if the method is not a stub function and
 163   // has java calls or has frame size > vm_page_size/8.
 164   // The debug VM checks that deoptimization doesn't trigger an
 165   // unexpected stack overflow (compiled method stack banging should
 166   // guarantee it doesn't happen) so we always need the stack bang in
 167   // a debug VM.
 168   return (UseStackBanging && stub_function() == NULL &&
 169           (has_java_calls() || frame_size_in_bytes > os::vm_page_size()>>3
 170            DEBUG_ONLY(|| true)));
 171 }
 172 
 173 bool Compile::need_register_stack_bang() const {
 174   // Determine if we need to generate a register stack overflow check.
 175   // This is only used on architectures which have split register
 176   // and memory stacks (ie. IA64).
 177   // Bang if the method is not a stub function and has java calls
 178   return (stub_function() == NULL && has_java_calls());
 179 }
 180 
 181 
 182 // Compute the size of first NumberOfLoopInstrToAlign instructions at the top
 183 // of a loop. When aligning a loop we need to provide enough instructions
 184 // in cpu's fetch buffer to feed decoders. The loop alignment could be
 185 // avoided if we have enough instructions in fetch buffer at the head of a loop.
 186 // By default, the size is set to 999999 by Block's constructor so that
 187 // a loop will be aligned if the size is not reset here.
 188 //
 189 // Note: Mach instructions could contain several HW instructions
 190 // so the size is estimated only.
 191 //
 192 void Compile::compute_loop_first_inst_sizes() {
 193   // The next condition is used to gate the loop alignment optimization.
 194   // Don't aligned a loop if there are enough instructions at the head of a loop
 195   // or alignment padding is larger then MaxLoopPad. By default, MaxLoopPad
 196   // is equal to OptoLoopAlignment-1 except on new Intel cpus, where it is
 197   // equal to 11 bytes which is the largest address NOP instruction.
 198   if (MaxLoopPad < OptoLoopAlignment - 1) {
 199     uint last_block = _cfg->number_of_blocks() - 1;
 200     for (uint i = 1; i <= last_block; i++) {
 201       Block* block = _cfg->get_block(i);
 202       // Check the first loop's block which requires an alignment.
 203       if (block->loop_alignment() > (uint)relocInfo::addr_unit()) {
 204         uint sum_size = 0;
 205         uint inst_cnt = NumberOfLoopInstrToAlign;
 206         inst_cnt = block->compute_first_inst_size(sum_size, inst_cnt, _regalloc);
 207 
 208         // Check subsequent fallthrough blocks if the loop's first
 209         // block(s) does not have enough instructions.
 210         Block *nb = block;
 211         while(inst_cnt > 0 &&
 212               i < last_block &&
 213               !_cfg->get_block(i + 1)->has_loop_alignment() &&
 214               !nb->has_successor(block)) {
 215           i++;
 216           nb = _cfg->get_block(i);
 217           inst_cnt  = nb->compute_first_inst_size(sum_size, inst_cnt, _regalloc);
 218         } // while( inst_cnt > 0 && i < last_block  )
 219 
 220         block->set_first_inst_size(sum_size);
 221       } // f( b->head()->is_Loop() )
 222     } // for( i <= last_block )
 223   } // if( MaxLoopPad < OptoLoopAlignment-1 )
 224 }
 225 
 226 // The architecture description provides short branch variants for some long
 227 // branch instructions. Replace eligible long branches with short branches.
 228 void Compile::shorten_branches(uint* blk_starts, int& code_size, int& reloc_size, int& stub_size) {
 229   // Compute size of each block, method size, and relocation information size
 230   uint nblocks  = _cfg->number_of_blocks();
 231 
 232   uint*      jmp_offset = NEW_RESOURCE_ARRAY(uint,nblocks);
 233   uint*      jmp_size   = NEW_RESOURCE_ARRAY(uint,nblocks);
 234   int*       jmp_nidx   = NEW_RESOURCE_ARRAY(int ,nblocks);
 235 
 236   // Collect worst case block paddings
 237   int* block_worst_case_pad = NEW_RESOURCE_ARRAY(int, nblocks);
 238   memset(block_worst_case_pad, 0, nblocks * sizeof(int));
 239 
 240   DEBUG_ONLY( uint *jmp_target = NEW_RESOURCE_ARRAY(uint,nblocks); )
 241   DEBUG_ONLY( uint *jmp_rule = NEW_RESOURCE_ARRAY(uint,nblocks); )
 242 
 243   bool has_short_branch_candidate = false;
 244 
 245   // Initialize the sizes to 0
 246   code_size  = 0;          // Size in bytes of generated code
 247   stub_size  = 0;          // Size in bytes of all stub entries
 248   // Size in bytes of all relocation entries, including those in local stubs.
 249   // Start with 2-bytes of reloc info for the unvalidated entry point
 250   reloc_size = 1;          // Number of relocation entries
 251 
 252   // Make three passes.  The first computes pessimistic blk_starts,
 253   // relative jmp_offset and reloc_size information.  The second performs
 254   // short branch substitution using the pessimistic sizing.  The
 255   // third inserts nops where needed.
 256 
 257   // Step one, perform a pessimistic sizing pass.
 258   uint last_call_adr = max_juint;
 259   uint last_avoid_back_to_back_adr = max_juint;
 260   uint nop_size = (new MachNopNode())->size(_regalloc);
 261   for (uint i = 0; i < nblocks; i++) { // For all blocks
 262     Block* block = _cfg->get_block(i);
 263 
 264     // During short branch replacement, we store the relative (to blk_starts)
 265     // offset of jump in jmp_offset, rather than the absolute offset of jump.
 266     // This is so that we do not need to recompute sizes of all nodes when
 267     // we compute correct blk_starts in our next sizing pass.
 268     jmp_offset[i] = 0;
 269     jmp_size[i]   = 0;
 270     jmp_nidx[i]   = -1;
 271     DEBUG_ONLY( jmp_target[i] = 0; )
 272     DEBUG_ONLY( jmp_rule[i]   = 0; )
 273 
 274     // Sum all instruction sizes to compute block size
 275     uint last_inst = block->number_of_nodes();
 276     uint blk_size = 0;
 277     for (uint j = 0; j < last_inst; j++) {
 278       Node* nj = block->get_node(j);
 279       // Handle machine instruction nodes
 280       if (nj->is_Mach()) {
 281         MachNode *mach = nj->as_Mach();
 282         blk_size += (mach->alignment_required() - 1) * relocInfo::addr_unit(); // assume worst case padding
 283         reloc_size += mach->reloc();
 284         if (mach->is_MachCall()) {
 285           // add size information for trampoline stub
 286           // class CallStubImpl is platform-specific and defined in the *.ad files.
 287           stub_size  += CallStubImpl::size_call_trampoline();
 288           reloc_size += CallStubImpl::reloc_call_trampoline();
 289 
 290           MachCallNode *mcall = mach->as_MachCall();
 291           // This destination address is NOT PC-relative
 292 
 293           mcall->method_set((intptr_t)mcall->entry_point());
 294 
 295           if (mcall->is_MachCallJava() && mcall->as_MachCallJava()->_method) {
 296             stub_size  += CompiledStaticCall::to_interp_stub_size();
 297             reloc_size += CompiledStaticCall::reloc_to_interp_stub();
 298           }
 299         } else if (mach->is_MachSafePoint()) {
 300           // If call/safepoint are adjacent, account for possible
 301           // nop to disambiguate the two safepoints.
 302           // ScheduleAndBundle() can rearrange nodes in a block,
 303           // check for all offsets inside this block.
 304           if (last_call_adr >= blk_starts[i]) {
 305             blk_size += nop_size;
 306           }
 307         }
 308         if (mach->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
 309           // Nop is inserted between "avoid back to back" instructions.
 310           // ScheduleAndBundle() can rearrange nodes in a block,
 311           // check for all offsets inside this block.
 312           if (last_avoid_back_to_back_adr >= blk_starts[i]) {
 313             blk_size += nop_size;
 314           }
 315         }
 316         if (mach->may_be_short_branch()) {
 317           if (!nj->is_MachBranch()) {
 318 #ifndef PRODUCT
 319             nj->dump(3);
 320 #endif
 321             Unimplemented();
 322           }
 323           assert(jmp_nidx[i] == -1, "block should have only one branch");
 324           jmp_offset[i] = blk_size;
 325           jmp_size[i]   = nj->size(_regalloc);
 326           jmp_nidx[i]   = j;
 327           has_short_branch_candidate = true;
 328         }
 329       }
 330       blk_size += nj->size(_regalloc);
 331       // Remember end of call offset
 332       if (nj->is_MachCall() && !nj->is_MachCallLeaf()) {
 333         last_call_adr = blk_starts[i]+blk_size;
 334       }
 335       // Remember end of avoid_back_to_back offset
 336       if (nj->is_Mach() && nj->as_Mach()->avoid_back_to_back(MachNode::AVOID_AFTER)) {
 337         last_avoid_back_to_back_adr = blk_starts[i]+blk_size;
 338       }
 339     }
 340 
 341     // When the next block starts a loop, we may insert pad NOP
 342     // instructions.  Since we cannot know our future alignment,
 343     // assume the worst.
 344     if (i < nblocks - 1) {
 345       Block* nb = _cfg->get_block(i + 1);
 346       int max_loop_pad = nb->code_alignment()-relocInfo::addr_unit();
 347       if (max_loop_pad > 0) {
 348         assert(is_power_of_2(max_loop_pad+relocInfo::addr_unit()), "");
 349         // Adjust last_call_adr and/or last_avoid_back_to_back_adr.
 350         // If either is the last instruction in this block, bump by
 351         // max_loop_pad in lock-step with blk_size, so sizing
 352         // calculations in subsequent blocks still can conservatively
 353         // detect that it may the last instruction in this block.
 354         if (last_call_adr == blk_starts[i]+blk_size) {
 355           last_call_adr += max_loop_pad;
 356         }
 357         if (last_avoid_back_to_back_adr == blk_starts[i]+blk_size) {
 358           last_avoid_back_to_back_adr += max_loop_pad;
 359         }
 360         blk_size += max_loop_pad;
 361         block_worst_case_pad[i + 1] = max_loop_pad;
 362       }
 363     }
 364 
 365     // Save block size; update total method size
 366     blk_starts[i+1] = blk_starts[i]+blk_size;
 367   }
 368 
 369   // Step two, replace eligible long jumps.
 370   bool progress = true;
 371   uint last_may_be_short_branch_adr = max_juint;
 372   while (has_short_branch_candidate && progress) {
 373     progress = false;
 374     has_short_branch_candidate = false;
 375     int adjust_block_start = 0;
 376     for (uint i = 0; i < nblocks; i++) {
 377       Block* block = _cfg->get_block(i);
 378       int idx = jmp_nidx[i];
 379       MachNode* mach = (idx == -1) ? NULL: block->get_node(idx)->as_Mach();
 380       if (mach != NULL && mach->may_be_short_branch()) {
 381 #ifdef ASSERT
 382         assert(jmp_size[i] > 0 && mach->is_MachBranch(), "sanity");
 383         int j;
 384         // Find the branch; ignore trailing NOPs.
 385         for (j = block->number_of_nodes()-1; j>=0; j--) {
 386           Node* n = block->get_node(j);
 387           if (!n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con)
 388             break;
 389         }
 390         assert(j >= 0 && j == idx && block->get_node(j) == (Node*)mach, "sanity");
 391 #endif
 392         int br_size = jmp_size[i];
 393         int br_offs = blk_starts[i] + jmp_offset[i];
 394 
 395         // This requires the TRUE branch target be in succs[0]
 396         uint bnum = block->non_connector_successor(0)->_pre_order;
 397         int offset = blk_starts[bnum] - br_offs;
 398         if (bnum > i) { // adjust following block's offset
 399           offset -= adjust_block_start;
 400         }
 401 
 402         // This block can be a loop header, account for the padding
 403         // in the previous block.
 404         int block_padding = block_worst_case_pad[i];
 405         assert(i == 0 || block_padding == 0 || br_offs >= block_padding, "Should have at least a padding on top");
 406         // In the following code a nop could be inserted before
 407         // the branch which will increase the backward distance.
 408         bool needs_padding = ((uint)(br_offs - block_padding) == last_may_be_short_branch_adr);
 409         assert(!needs_padding || jmp_offset[i] == 0, "padding only branches at the beginning of block");
 410 
 411         if (needs_padding && offset <= 0)
 412           offset -= nop_size;
 413 
 414         if (_matcher->is_short_branch_offset(mach->rule(), br_size, offset)) {
 415           // We've got a winner.  Replace this branch.
 416           MachNode* replacement = mach->as_MachBranch()->short_branch_version();
 417 
 418           // Update the jmp_size.
 419           int new_size = replacement->size(_regalloc);
 420           int diff     = br_size - new_size;
 421           assert(diff >= (int)nop_size, "short_branch size should be smaller");
 422           // Conservatively take into account padding between
 423           // avoid_back_to_back branches. Previous branch could be
 424           // converted into avoid_back_to_back branch during next
 425           // rounds.
 426           if (needs_padding && replacement->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
 427             jmp_offset[i] += nop_size;
 428             diff -= nop_size;
 429           }
 430           adjust_block_start += diff;
 431           block->map_node(replacement, idx);
 432           mach->subsume_by(replacement, C);
 433           mach = replacement;
 434           progress = true;
 435 
 436           jmp_size[i] = new_size;
 437           DEBUG_ONLY( jmp_target[i] = bnum; );
 438           DEBUG_ONLY( jmp_rule[i] = mach->rule(); );
 439         } else {
 440           // The jump distance is not short, try again during next iteration.
 441           has_short_branch_candidate = true;
 442         }
 443       } // (mach->may_be_short_branch())
 444       if (mach != NULL && (mach->may_be_short_branch() ||
 445                            mach->avoid_back_to_back(MachNode::AVOID_AFTER))) {
 446         last_may_be_short_branch_adr = blk_starts[i] + jmp_offset[i] + jmp_size[i];
 447       }
 448       blk_starts[i+1] -= adjust_block_start;
 449     }
 450   }
 451 
 452 #ifdef ASSERT
 453   for (uint i = 0; i < nblocks; i++) { // For all blocks
 454     if (jmp_target[i] != 0) {
 455       int br_size = jmp_size[i];
 456       int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_offset[i]);
 457       if (!_matcher->is_short_branch_offset(jmp_rule[i], br_size, offset)) {
 458         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]);
 459       }
 460       assert(_matcher->is_short_branch_offset(jmp_rule[i], br_size, offset), "Displacement too large for short jmp");
 461     }
 462   }
 463 #endif
 464 
 465   // Step 3, compute the offsets of all blocks, will be done in fill_buffer()
 466   // after ScheduleAndBundle().
 467 
 468   // ------------------
 469   // Compute size for code buffer
 470   code_size = blk_starts[nblocks];
 471 
 472   // Relocation records
 473   reloc_size += 1;              // Relo entry for exception handler
 474 
 475   // Adjust reloc_size to number of record of relocation info
 476   // Min is 2 bytes, max is probably 6 or 8, with a tax up to 25% for
 477   // a relocation index.
 478   // The CodeBuffer will expand the locs array if this estimate is too low.
 479   reloc_size *= 10 / sizeof(relocInfo);
 480 }
 481 
 482 //------------------------------FillLocArray-----------------------------------
 483 // Create a bit of debug info and append it to the array.  The mapping is from
 484 // Java local or expression stack to constant, register or stack-slot.  For
 485 // doubles, insert 2 mappings and return 1 (to tell the caller that the next
 486 // entry has been taken care of and caller should skip it).
 487 static LocationValue *new_loc_value( PhaseRegAlloc *ra, OptoReg::Name regnum, Location::Type l_type ) {
 488   // This should never have accepted Bad before
 489   assert(OptoReg::is_valid(regnum), "location must be valid");
 490   return (OptoReg::is_reg(regnum))
 491     ? new LocationValue(Location::new_reg_loc(l_type, OptoReg::as_VMReg(regnum)) )
 492     : new LocationValue(Location::new_stk_loc(l_type,  ra->reg2offset(regnum)));
 493 }
 494 
 495 
 496 ObjectValue*
 497 Compile::sv_for_node_id(GrowableArray<ScopeValue*> *objs, int id) {
 498   for (int i = 0; i < objs->length(); i++) {
 499     assert(objs->at(i)->is_object(), "corrupt object cache");
 500     ObjectValue* sv = (ObjectValue*) objs->at(i);
 501     if (sv->id() == id) {
 502       return sv;
 503     }
 504   }
 505   // Otherwise..
 506   return NULL;
 507 }
 508 
 509 void Compile::set_sv_for_object_node(GrowableArray<ScopeValue*> *objs,
 510                                      ObjectValue* sv ) {
 511   assert(sv_for_node_id(objs, sv->id()) == NULL, "Precondition");
 512   objs->append(sv);
 513 }
 514 
 515 
 516 void Compile::FillLocArray( int idx, MachSafePointNode* sfpt, Node *local,
 517                             GrowableArray<ScopeValue*> *array,
 518                             GrowableArray<ScopeValue*> *objs ) {
 519   assert( local, "use _top instead of null" );
 520   if (array->length() != idx) {
 521     assert(array->length() == idx + 1, "Unexpected array count");
 522     // Old functionality:
 523     //   return
 524     // New functionality:
 525     //   Assert if the local is not top. In product mode let the new node
 526     //   override the old entry.
 527     assert(local == top(), "LocArray collision");
 528     if (local == top()) {
 529       return;
 530     }
 531     array->pop();
 532   }
 533   const Type *t = local->bottom_type();
 534 
 535   // Is it a safepoint scalar object node?
 536   if (local->is_SafePointScalarObject()) {
 537     SafePointScalarObjectNode* spobj = local->as_SafePointScalarObject();
 538 
 539     ObjectValue* sv = Compile::sv_for_node_id(objs, spobj->_idx);
 540     if (sv == NULL) {
 541       ciKlass* cik = t->is_oopptr()->klass();
 542       assert(cik->is_instance_klass() ||
 543              cik->is_array_klass(), "Not supported allocation.");
 544       sv = new ObjectValue(spobj->_idx,
 545                            new ConstantOopWriteValue(cik->java_mirror()->constant_encoding()));
 546       Compile::set_sv_for_object_node(objs, sv);
 547 
 548       uint first_ind = spobj->first_index(sfpt->jvms());
 549       for (uint i = 0; i < spobj->n_fields(); i++) {
 550         Node* fld_node = sfpt->in(first_ind+i);
 551         (void)FillLocArray(sv->field_values()->length(), sfpt, fld_node, sv->field_values(), objs);
 552       }
 553     }
 554     array->append(sv);
 555     return;
 556   }
 557 
 558   // Grab the register number for the local
 559   OptoReg::Name regnum = _regalloc->get_reg_first(local);
 560   if( OptoReg::is_valid(regnum) ) {// Got a register/stack?
 561     // Record the double as two float registers.
 562     // The register mask for such a value always specifies two adjacent
 563     // float registers, with the lower register number even.
 564     // Normally, the allocation of high and low words to these registers
 565     // is irrelevant, because nearly all operations on register pairs
 566     // (e.g., StoreD) treat them as a single unit.
 567     // Here, we assume in addition that the words in these two registers
 568     // stored "naturally" (by operations like StoreD and double stores
 569     // within the interpreter) such that the lower-numbered register
 570     // is written to the lower memory address.  This may seem like
 571     // a machine dependency, but it is not--it is a requirement on
 572     // the author of the <arch>.ad file to ensure that, for every
 573     // even/odd double-register pair to which a double may be allocated,
 574     // the word in the even single-register is stored to the first
 575     // memory word.  (Note that register numbers are completely
 576     // arbitrary, and are not tied to any machine-level encodings.)
 577 #ifdef _LP64
 578     if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon ) {
 579       array->append(new ConstantIntValue(0));
 580       array->append(new_loc_value( _regalloc, regnum, Location::dbl ));
 581     } else if ( t->base() == Type::Long ) {
 582       array->append(new ConstantIntValue(0));
 583       array->append(new_loc_value( _regalloc, regnum, Location::lng ));
 584     } else if ( t->base() == Type::RawPtr ) {
 585       // jsr/ret return address which must be restored into a the full
 586       // width 64-bit stack slot.
 587       array->append(new_loc_value( _regalloc, regnum, Location::lng ));
 588     }
 589 #else //_LP64
 590 #ifdef SPARC
 591     if (t->base() == Type::Long && OptoReg::is_reg(regnum)) {
 592       // For SPARC we have to swap high and low words for
 593       // long values stored in a single-register (g0-g7).
 594       array->append(new_loc_value( _regalloc,              regnum   , Location::normal ));
 595       array->append(new_loc_value( _regalloc, OptoReg::add(regnum,1), Location::normal ));
 596     } else
 597 #endif //SPARC
 598     if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon || t->base() == Type::Long ) {
 599       // Repack the double/long as two jints.
 600       // The convention the interpreter uses is that the second local
 601       // holds the first raw word of the native double representation.
 602       // This is actually reasonable, since locals and stack arrays
 603       // grow downwards in all implementations.
 604       // (If, on some machine, the interpreter's Java locals or stack
 605       // were to grow upwards, the embedded doubles would be word-swapped.)
 606       array->append(new_loc_value( _regalloc, OptoReg::add(regnum,1), Location::normal ));
 607       array->append(new_loc_value( _regalloc,              regnum   , Location::normal ));
 608     }
 609 #endif //_LP64
 610     else if( (t->base() == Type::FloatBot || t->base() == Type::FloatCon) &&
 611                OptoReg::is_reg(regnum) ) {
 612       array->append(new_loc_value( _regalloc, regnum, Matcher::float_in_double()
 613                                    ? Location::float_in_dbl : Location::normal ));
 614     } else if( t->base() == Type::Int && OptoReg::is_reg(regnum) ) {
 615       array->append(new_loc_value( _regalloc, regnum, Matcher::int_in_long
 616                                    ? Location::int_in_long : Location::normal ));
 617     } else if( t->base() == Type::NarrowOop ) {
 618       array->append(new_loc_value( _regalloc, regnum, Location::narrowoop ));
 619     } else {
 620       array->append(new_loc_value( _regalloc, regnum, _regalloc->is_oop(local) ? Location::oop : Location::normal ));
 621     }
 622     return;
 623   }
 624 
 625   // No register.  It must be constant data.
 626   switch (t->base()) {
 627   case Type::Half:              // Second half of a double
 628     ShouldNotReachHere();       // Caller should skip 2nd halves
 629     break;
 630   case Type::AnyPtr:
 631     array->append(new ConstantOopWriteValue(NULL));
 632     break;
 633   case Type::AryPtr:
 634   case Type::InstPtr:          // fall through
 635     array->append(new ConstantOopWriteValue(t->isa_oopptr()->const_oop()->constant_encoding()));
 636     break;
 637   case Type::NarrowOop:
 638     if (t == TypeNarrowOop::NULL_PTR) {
 639       array->append(new ConstantOopWriteValue(NULL));
 640     } else {
 641       array->append(new ConstantOopWriteValue(t->make_ptr()->isa_oopptr()->const_oop()->constant_encoding()));
 642     }
 643     break;
 644   case Type::Int:
 645     array->append(new ConstantIntValue(t->is_int()->get_con()));
 646     break;
 647   case Type::RawPtr:
 648     // A return address (T_ADDRESS).
 649     assert((intptr_t)t->is_ptr()->get_con() < (intptr_t)0x10000, "must be a valid BCI");
 650 #ifdef _LP64
 651     // Must be restored to the full-width 64-bit stack slot.
 652     array->append(new ConstantLongValue(t->is_ptr()->get_con()));
 653 #else
 654     array->append(new ConstantIntValue(t->is_ptr()->get_con()));
 655 #endif
 656     break;
 657   case Type::FloatCon: {
 658     float f = t->is_float_constant()->getf();
 659     array->append(new ConstantIntValue(jint_cast(f)));
 660     break;
 661   }
 662   case Type::DoubleCon: {
 663     jdouble d = t->is_double_constant()->getd();
 664 #ifdef _LP64
 665     array->append(new ConstantIntValue(0));
 666     array->append(new ConstantDoubleValue(d));
 667 #else
 668     // Repack the double as two jints.
 669     // The convention the interpreter uses is that the second local
 670     // holds the first raw word of the native double representation.
 671     // This is actually reasonable, since locals and stack arrays
 672     // grow downwards in all implementations.
 673     // (If, on some machine, the interpreter's Java locals or stack
 674     // were to grow upwards, the embedded doubles would be word-swapped.)
 675     jlong_accessor acc;
 676     acc.long_value = jlong_cast(d);
 677     array->append(new ConstantIntValue(acc.words[1]));
 678     array->append(new ConstantIntValue(acc.words[0]));
 679 #endif
 680     break;
 681   }
 682   case Type::Long: {
 683     jlong d = t->is_long()->get_con();
 684 #ifdef _LP64
 685     array->append(new ConstantIntValue(0));
 686     array->append(new ConstantLongValue(d));
 687 #else
 688     // Repack the long as two jints.
 689     // The convention the interpreter uses is that the second local
 690     // holds the first raw word of the native double representation.
 691     // This is actually reasonable, since locals and stack arrays
 692     // grow downwards in all implementations.
 693     // (If, on some machine, the interpreter's Java locals or stack
 694     // were to grow upwards, the embedded doubles would be word-swapped.)
 695     jlong_accessor acc;
 696     acc.long_value = d;
 697     array->append(new ConstantIntValue(acc.words[1]));
 698     array->append(new ConstantIntValue(acc.words[0]));
 699 #endif
 700     break;
 701   }
 702   case Type::Top:               // Add an illegal value here
 703     array->append(new LocationValue(Location()));
 704     break;
 705   default:
 706     ShouldNotReachHere();
 707     break;
 708   }
 709 }
 710 
 711 // Determine if this node starts a bundle
 712 bool Compile::starts_bundle(const Node *n) const {
 713   return (_node_bundling_limit > n->_idx &&
 714           _node_bundling_base[n->_idx].starts_bundle());
 715 }
 716 
 717 //--------------------------Process_OopMap_Node--------------------------------
 718 void Compile::Process_OopMap_Node(MachNode *mach, int current_offset) {
 719 
 720   // Handle special safepoint nodes for synchronization
 721   MachSafePointNode *sfn   = mach->as_MachSafePoint();
 722   MachCallNode      *mcall;
 723 
 724   int safepoint_pc_offset = current_offset;
 725   bool is_method_handle_invoke = false;
 726   bool return_oop = false;
 727 
 728   // Add the safepoint in the DebugInfoRecorder
 729   if( !mach->is_MachCall() ) {
 730     mcall = NULL;
 731     debug_info()->add_safepoint(safepoint_pc_offset, sfn->_oop_map);
 732   } else {
 733     mcall = mach->as_MachCall();
 734 
 735     // Is the call a MethodHandle call?
 736     if (mcall->is_MachCallJava()) {
 737       if (mcall->as_MachCallJava()->_method_handle_invoke) {
 738         assert(has_method_handle_invokes(), "must have been set during call generation");
 739         is_method_handle_invoke = true;
 740       }
 741     }
 742 
 743     // Check if a call returns an object.
 744     if (mcall->returns_pointer()) {
 745       return_oop = true;
 746     }
 747     safepoint_pc_offset += mcall->ret_addr_offset();
 748     debug_info()->add_safepoint(safepoint_pc_offset, mcall->_oop_map);
 749   }
 750 
 751   // Loop over the JVMState list to add scope information
 752   // Do not skip safepoints with a NULL method, they need monitor info
 753   JVMState* youngest_jvms = sfn->jvms();
 754   int max_depth = youngest_jvms->depth();
 755 
 756   // Allocate the object pool for scalar-replaced objects -- the map from
 757   // small-integer keys (which can be recorded in the local and ostack
 758   // arrays) to descriptions of the object state.
 759   GrowableArray<ScopeValue*> *objs = new GrowableArray<ScopeValue*>();
 760 
 761   // Visit scopes from oldest to youngest.
 762   for (int depth = 1; depth <= max_depth; depth++) {
 763     JVMState* jvms = youngest_jvms->of_depth(depth);
 764     int idx;
 765     ciMethod* method = jvms->has_method() ? jvms->method() : NULL;
 766     // Safepoints that do not have method() set only provide oop-map and monitor info
 767     // to support GC; these do not support deoptimization.
 768     int num_locs = (method == NULL) ? 0 : jvms->loc_size();
 769     int num_exps = (method == NULL) ? 0 : jvms->stk_size();
 770     int num_mon  = jvms->nof_monitors();
 771     assert(method == NULL || jvms->bci() < 0 || num_locs == method->max_locals(),
 772            "JVMS local count must match that of the method");
 773 
 774     // Add Local and Expression Stack Information
 775 
 776     // Insert locals into the locarray
 777     GrowableArray<ScopeValue*> *locarray = new GrowableArray<ScopeValue*>(num_locs);
 778     for( idx = 0; idx < num_locs; idx++ ) {
 779       FillLocArray( idx, sfn, sfn->local(jvms, idx), locarray, objs );
 780     }
 781 
 782     // Insert expression stack entries into the exparray
 783     GrowableArray<ScopeValue*> *exparray = new GrowableArray<ScopeValue*>(num_exps);
 784     for( idx = 0; idx < num_exps; idx++ ) {
 785       FillLocArray( idx,  sfn, sfn->stack(jvms, idx), exparray, objs );
 786     }
 787 
 788     // Add in mappings of the monitors
 789     assert( !method ||
 790             !method->is_synchronized() ||
 791             method->is_native() ||
 792             num_mon > 0 ||
 793             !GenerateSynchronizationCode,
 794             "monitors must always exist for synchronized methods");
 795 
 796     // Build the growable array of ScopeValues for exp stack
 797     GrowableArray<MonitorValue*> *monarray = new GrowableArray<MonitorValue*>(num_mon);
 798 
 799     // Loop over monitors and insert into array
 800     for (idx = 0; idx < num_mon; idx++) {
 801       // Grab the node that defines this monitor
 802       Node* box_node = sfn->monitor_box(jvms, idx);
 803       Node* obj_node = sfn->monitor_obj(jvms, idx);
 804 
 805       // Create ScopeValue for object
 806       ScopeValue *scval = NULL;
 807 
 808       if (obj_node->is_SafePointScalarObject()) {
 809         SafePointScalarObjectNode* spobj = obj_node->as_SafePointScalarObject();
 810         scval = Compile::sv_for_node_id(objs, spobj->_idx);
 811         if (scval == NULL) {
 812           const Type *t = spobj->bottom_type();
 813           ciKlass* cik = t->is_oopptr()->klass();
 814           assert(cik->is_instance_klass() ||
 815                  cik->is_array_klass(), "Not supported allocation.");
 816           ObjectValue* sv = new ObjectValue(spobj->_idx,
 817                                             new ConstantOopWriteValue(cik->java_mirror()->constant_encoding()));
 818           Compile::set_sv_for_object_node(objs, sv);
 819 
 820           uint first_ind = spobj->first_index(youngest_jvms);
 821           for (uint i = 0; i < spobj->n_fields(); i++) {
 822             Node* fld_node = sfn->in(first_ind+i);
 823             (void)FillLocArray(sv->field_values()->length(), sfn, fld_node, sv->field_values(), objs);
 824           }
 825           scval = sv;
 826         }
 827       } else if (!obj_node->is_Con()) {
 828         OptoReg::Name obj_reg = _regalloc->get_reg_first(obj_node);
 829         if( obj_node->bottom_type()->base() == Type::NarrowOop ) {
 830           scval = new_loc_value( _regalloc, obj_reg, Location::narrowoop );
 831         } else {
 832           scval = new_loc_value( _regalloc, obj_reg, Location::oop );
 833         }
 834       } else {
 835         const TypePtr *tp = obj_node->get_ptr_type();
 836         scval = new ConstantOopWriteValue(tp->is_oopptr()->const_oop()->constant_encoding());
 837       }
 838 
 839       OptoReg::Name box_reg = BoxLockNode::reg(box_node);
 840       Location basic_lock = Location::new_stk_loc(Location::normal,_regalloc->reg2offset(box_reg));
 841       bool eliminated = (box_node->is_BoxLock() && box_node->as_BoxLock()->is_eliminated());
 842       monarray->append(new MonitorValue(scval, basic_lock, eliminated));
 843     }
 844 
 845     // We dump the object pool first, since deoptimization reads it in first.
 846     debug_info()->dump_object_pool(objs);
 847 
 848     // Build first class objects to pass to scope
 849     DebugToken *locvals = debug_info()->create_scope_values(locarray);
 850     DebugToken *expvals = debug_info()->create_scope_values(exparray);
 851     DebugToken *monvals = debug_info()->create_monitor_values(monarray);
 852 
 853     // Make method available for all Safepoints
 854     ciMethod* scope_method = method ? method : _method;
 855     // Describe the scope here
 856     assert(jvms->bci() >= InvocationEntryBci && jvms->bci() <= 0x10000, "must be a valid or entry BCI");
 857     assert(!jvms->should_reexecute() || depth == max_depth, "reexecute allowed only for the youngest");
 858     // Now we can describe the scope.
 859     methodHandle null_mh;
 860     bool rethrow_exception = false;
 861     debug_info()->describe_scope(safepoint_pc_offset, null_mh, scope_method, jvms->bci(), jvms->should_reexecute(), rethrow_exception, is_method_handle_invoke, return_oop, locvals, expvals, monvals);
 862   } // End jvms loop
 863 
 864   // Mark the end of the scope set.
 865   debug_info()->end_safepoint(safepoint_pc_offset);
 866 }
 867 
 868 
 869 
 870 // A simplified version of Process_OopMap_Node, to handle non-safepoints.
 871 class NonSafepointEmitter {
 872   Compile*  C;
 873   JVMState* _pending_jvms;
 874   int       _pending_offset;
 875 
 876   void emit_non_safepoint();
 877 
 878  public:
 879   NonSafepointEmitter(Compile* compile) {
 880     this->C = compile;
 881     _pending_jvms = NULL;
 882     _pending_offset = 0;
 883   }
 884 
 885   void observe_instruction(Node* n, int pc_offset) {
 886     if (!C->debug_info()->recording_non_safepoints())  return;
 887 
 888     Node_Notes* nn = C->node_notes_at(n->_idx);
 889     if (nn == NULL || nn->jvms() == NULL)  return;
 890     if (_pending_jvms != NULL &&
 891         _pending_jvms->same_calls_as(nn->jvms())) {
 892       // Repeated JVMS?  Stretch it up here.
 893       _pending_offset = pc_offset;
 894     } else {
 895       if (_pending_jvms != NULL &&
 896           _pending_offset < pc_offset) {
 897         emit_non_safepoint();
 898       }
 899       _pending_jvms = NULL;
 900       if (pc_offset > C->debug_info()->last_pc_offset()) {
 901         // This is the only way _pending_jvms can become non-NULL:
 902         _pending_jvms = nn->jvms();
 903         _pending_offset = pc_offset;
 904       }
 905     }
 906   }
 907 
 908   // Stay out of the way of real safepoints:
 909   void observe_safepoint(JVMState* jvms, int pc_offset) {
 910     if (_pending_jvms != NULL &&
 911         !_pending_jvms->same_calls_as(jvms) &&
 912         _pending_offset < pc_offset) {
 913       emit_non_safepoint();
 914     }
 915     _pending_jvms = NULL;
 916   }
 917 
 918   void flush_at_end() {
 919     if (_pending_jvms != NULL) {
 920       emit_non_safepoint();
 921     }
 922     _pending_jvms = NULL;
 923   }
 924 };
 925 
 926 void NonSafepointEmitter::emit_non_safepoint() {
 927   JVMState* youngest_jvms = _pending_jvms;
 928   int       pc_offset     = _pending_offset;
 929 
 930   // Clear it now:
 931   _pending_jvms = NULL;
 932 
 933   DebugInformationRecorder* debug_info = C->debug_info();
 934   assert(debug_info->recording_non_safepoints(), "sanity");
 935 
 936   debug_info->add_non_safepoint(pc_offset);
 937   int max_depth = youngest_jvms->depth();
 938 
 939   // Visit scopes from oldest to youngest.
 940   for (int depth = 1; depth <= max_depth; depth++) {
 941     JVMState* jvms = youngest_jvms->of_depth(depth);
 942     ciMethod* method = jvms->has_method() ? jvms->method() : NULL;
 943     assert(!jvms->should_reexecute() || depth==max_depth, "reexecute allowed only for the youngest");
 944     methodHandle null_mh;
 945     debug_info->describe_scope(pc_offset, null_mh, method, jvms->bci(), jvms->should_reexecute());
 946   }
 947 
 948   // Mark the end of the scope set.
 949   debug_info->end_non_safepoint(pc_offset);
 950 }
 951 
 952 //------------------------------init_buffer------------------------------------
 953 CodeBuffer* Compile::init_buffer(uint* blk_starts) {
 954 
 955   // Set the initially allocated size
 956   int  code_req   = initial_code_capacity;
 957   int  locs_req   = initial_locs_capacity;
 958   int  stub_req   = TraceJumps ? initial_stub_capacity * 10 : initial_stub_capacity;
 959   int  const_req  = initial_const_capacity;
 960 
 961   int  pad_req    = NativeCall::instruction_size;
 962   // The extra spacing after the code is necessary on some platforms.
 963   // Sometimes we need to patch in a jump after the last instruction,
 964   // if the nmethod has been deoptimized.  (See 4932387, 4894843.)
 965 
 966   // Compute the byte offset where we can store the deopt pc.
 967   if (fixed_slots() != 0) {
 968     _orig_pc_slot_offset_in_bytes = _regalloc->reg2offset(OptoReg::stack2reg(_orig_pc_slot));
 969   }
 970 
 971   // Compute prolog code size
 972   _method_size = 0;
 973   _frame_slots = OptoReg::reg2stack(_matcher->_old_SP)+_regalloc->_framesize;
 974 #if defined(IA64) && !defined(AIX)
 975   if (save_argument_registers()) {
 976     // 4815101: this is a stub with implicit and unknown precision fp args.
 977     // The usual spill mechanism can only generate stfd's in this case, which
 978     // doesn't work if the fp reg to spill contains a single-precision denorm.
 979     // Instead, we hack around the normal spill mechanism using stfspill's and
 980     // ldffill's in the MachProlog and MachEpilog emit methods.  We allocate
 981     // space here for the fp arg regs (f8-f15) we're going to thusly spill.
 982     //
 983     // If we ever implement 16-byte 'registers' == stack slots, we can
 984     // get rid of this hack and have SpillCopy generate stfspill/ldffill
 985     // instead of stfd/stfs/ldfd/ldfs.
 986     _frame_slots += 8*(16/BytesPerInt);
 987   }
 988 #endif
 989   assert(_frame_slots >= 0 && _frame_slots < 1000000, "sanity check");
 990 
 991   if (has_mach_constant_base_node()) {
 992     uint add_size = 0;
 993     // Fill the constant table.
 994     // Note:  This must happen before shorten_branches.
 995     for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
 996       Block* b = _cfg->get_block(i);
 997 
 998       for (uint j = 0; j < b->number_of_nodes(); j++) {
 999         Node* n = b->get_node(j);
1000 
1001         // If the node is a MachConstantNode evaluate the constant
1002         // value section.
1003         if (n->is_MachConstant()) {
1004           MachConstantNode* machcon = n->as_MachConstant();
1005           machcon->eval_constant(C);
1006         } else if (n->is_Mach()) {
1007           // On Power there are more nodes that issue constants.
1008           add_size += (n->as_Mach()->ins_num_consts() * 8);
1009         }
1010       }
1011     }
1012 
1013     // Calculate the offsets of the constants and the size of the
1014     // constant table (including the padding to the next section).
1015     constant_table().calculate_offsets_and_size();
1016     const_req = constant_table().size() + add_size;
1017   }
1018 
1019   // Initialize the space for the BufferBlob used to find and verify
1020   // instruction size in MachNode::emit_size()
1021   init_scratch_buffer_blob(const_req);
1022   if (failing())  return NULL; // Out of memory
1023 
1024   // Pre-compute the length of blocks and replace
1025   // long branches with short if machine supports it.
1026   shorten_branches(blk_starts, code_req, locs_req, stub_req);
1027 
1028   // nmethod and CodeBuffer count stubs & constants as part of method's code.
1029   // class HandlerImpl is platform-specific and defined in the *.ad files.
1030   int exception_handler_req = HandlerImpl::size_exception_handler() + MAX_stubs_size; // add marginal slop for handler
1031   int deopt_handler_req     = HandlerImpl::size_deopt_handler()     + MAX_stubs_size; // add marginal slop for handler
1032   stub_req += MAX_stubs_size;   // ensure per-stub margin
1033   code_req += MAX_inst_size;    // ensure per-instruction margin
1034 
1035   if (StressCodeBuffers)
1036     code_req = const_req = stub_req = exception_handler_req = deopt_handler_req = 0x10;  // force expansion
1037 
1038   int total_req =
1039     const_req +
1040     code_req +
1041     pad_req +
1042     stub_req +
1043     exception_handler_req +
1044     deopt_handler_req;               // deopt handler
1045 
1046   if (has_method_handle_invokes())
1047     total_req += deopt_handler_req;  // deopt MH handler
1048 
1049   CodeBuffer* cb = code_buffer();
1050   cb->initialize(total_req, locs_req);
1051 
1052   // Have we run out of code space?
1053   if ((cb->blob() == NULL) || (!CompileBroker::should_compile_new_jobs())) {
1054     C->record_failure("CodeCache is full");
1055     return NULL;
1056   }
1057   // Configure the code buffer.
1058   cb->initialize_consts_size(const_req);
1059   cb->initialize_stubs_size(stub_req);
1060   cb->initialize_oop_recorder(env()->oop_recorder());
1061 
1062   // fill in the nop array for bundling computations
1063   MachNode *_nop_list[Bundle::_nop_count];
1064   Bundle::initialize_nops(_nop_list);
1065 
1066   return cb;
1067 }
1068 
1069 //------------------------------fill_buffer------------------------------------
1070 void Compile::fill_buffer(CodeBuffer* cb, uint* blk_starts) {
1071   // blk_starts[] contains offsets calculated during short branches processing,
1072   // offsets should not be increased during following steps.
1073 
1074   // Compute the size of first NumberOfLoopInstrToAlign instructions at head
1075   // of a loop. It is used to determine the padding for loop alignment.
1076   compute_loop_first_inst_sizes();
1077 
1078   // Create oopmap set.
1079   _oop_map_set = new OopMapSet();
1080 
1081   // !!!!! This preserves old handling of oopmaps for now
1082   debug_info()->set_oopmaps(_oop_map_set);
1083 
1084   uint nblocks  = _cfg->number_of_blocks();
1085   // Count and start of implicit null check instructions
1086   uint inct_cnt = 0;
1087   uint *inct_starts = NEW_RESOURCE_ARRAY(uint, nblocks+1);
1088 
1089   // Count and start of calls
1090   uint *call_returns = NEW_RESOURCE_ARRAY(uint, nblocks+1);
1091 
1092   uint  return_offset = 0;
1093   int nop_size = (new MachNopNode())->size(_regalloc);
1094 
1095   int previous_offset = 0;
1096   int current_offset  = 0;
1097   int last_call_offset = -1;
1098   int last_avoid_back_to_back_offset = -1;
1099 #ifdef ASSERT
1100   uint* jmp_target = NEW_RESOURCE_ARRAY(uint,nblocks);
1101   uint* jmp_offset = NEW_RESOURCE_ARRAY(uint,nblocks);
1102   uint* jmp_size   = NEW_RESOURCE_ARRAY(uint,nblocks);
1103   uint* jmp_rule   = NEW_RESOURCE_ARRAY(uint,nblocks);
1104 #endif
1105 
1106   // Create an array of unused labels, one for each basic block, if printing is enabled
1107 #ifndef PRODUCT
1108   int *node_offsets      = NULL;
1109   uint node_offset_limit = unique();
1110 
1111   if (print_assembly())
1112     node_offsets         = NEW_RESOURCE_ARRAY(int, node_offset_limit);
1113 #endif
1114 
1115   NonSafepointEmitter non_safepoints(this);  // emit non-safepoints lazily
1116 
1117   // Emit the constant table.
1118   if (has_mach_constant_base_node()) {
1119     constant_table().emit(*cb);
1120   }
1121 
1122   // Create an array of labels, one for each basic block
1123   Label *blk_labels = NEW_RESOURCE_ARRAY(Label, nblocks+1);
1124   for (uint i=0; i <= nblocks; i++) {
1125     blk_labels[i].init();
1126   }
1127 
1128   // ------------------
1129   // Now fill in the code buffer
1130   Node *delay_slot = NULL;
1131 
1132   for (uint i = 0; i < nblocks; i++) {
1133     Block* block = _cfg->get_block(i);
1134     Node* head = block->head();
1135 
1136     // If this block needs to start aligned (i.e, can be reached other
1137     // than by falling-thru from the previous block), then force the
1138     // start of a new bundle.
1139     if (Pipeline::requires_bundling() && starts_bundle(head)) {
1140       cb->flush_bundle(true);
1141     }
1142 
1143 #ifdef ASSERT
1144     if (!block->is_connector()) {
1145       stringStream st;
1146       block->dump_head(_cfg, &st);
1147       MacroAssembler(cb).block_comment(st.as_string());
1148     }
1149     jmp_target[i] = 0;
1150     jmp_offset[i] = 0;
1151     jmp_size[i]   = 0;
1152     jmp_rule[i]   = 0;
1153 #endif
1154     int blk_offset = current_offset;
1155 
1156     // Define the label at the beginning of the basic block
1157     MacroAssembler(cb).bind(blk_labels[block->_pre_order]);
1158 
1159     uint last_inst = block->number_of_nodes();
1160 
1161     // Emit block normally, except for last instruction.
1162     // Emit means "dump code bits into code buffer".
1163     for (uint j = 0; j<last_inst; j++) {
1164 
1165       // Get the node
1166       Node* n = block->get_node(j);
1167 
1168       // See if delay slots are supported
1169       if (valid_bundle_info(n) &&
1170           node_bundling(n)->used_in_unconditional_delay()) {
1171         assert(delay_slot == NULL, "no use of delay slot node");
1172         assert(n->size(_regalloc) == Pipeline::instr_unit_size(), "delay slot instruction wrong size");
1173 
1174         delay_slot = n;
1175         continue;
1176       }
1177 
1178       // If this starts a new instruction group, then flush the current one
1179       // (but allow split bundles)
1180       if (Pipeline::requires_bundling() && starts_bundle(n))
1181         cb->flush_bundle(false);
1182 
1183       // Special handling for SafePoint/Call Nodes
1184       bool is_mcall = false;
1185       if (n->is_Mach()) {
1186         MachNode *mach = n->as_Mach();
1187         is_mcall = n->is_MachCall();
1188         bool is_sfn = n->is_MachSafePoint();
1189 
1190         // If this requires all previous instructions be flushed, then do so
1191         if (is_sfn || is_mcall || mach->alignment_required() != 1) {
1192           cb->flush_bundle(true);
1193           current_offset = cb->insts_size();
1194         }
1195 
1196         // A padding may be needed again since a previous instruction
1197         // could be moved to delay slot.
1198 
1199         // align the instruction if necessary
1200         int padding = mach->compute_padding(current_offset);
1201         // Make sure safepoint node for polling is distinct from a call's
1202         // return by adding a nop if needed.
1203         if (is_sfn && !is_mcall && padding == 0 && current_offset == last_call_offset) {
1204           padding = nop_size;
1205         }
1206         if (padding == 0 && mach->avoid_back_to_back(MachNode::AVOID_BEFORE) &&
1207             current_offset == last_avoid_back_to_back_offset) {
1208           // Avoid back to back some instructions.
1209           padding = nop_size;
1210         }
1211 
1212         if(padding > 0) {
1213           assert((padding % nop_size) == 0, "padding is not a multiple of NOP size");
1214           int nops_cnt = padding / nop_size;
1215           MachNode *nop = new MachNopNode(nops_cnt);
1216           block->insert_node(nop, j++);
1217           last_inst++;
1218           _cfg->map_node_to_block(nop, block);
1219           nop->emit(*cb, _regalloc);
1220           cb->flush_bundle(true);
1221           current_offset = cb->insts_size();
1222         }
1223 
1224         // Remember the start of the last call in a basic block
1225         if (is_mcall) {
1226           MachCallNode *mcall = mach->as_MachCall();
1227 
1228           // This destination address is NOT PC-relative
1229           mcall->method_set((intptr_t)mcall->entry_point());
1230 
1231           // Save the return address
1232           call_returns[block->_pre_order] = current_offset + mcall->ret_addr_offset();
1233 
1234           if (mcall->is_MachCallLeaf()) {
1235             is_mcall = false;
1236             is_sfn = false;
1237           }
1238         }
1239 
1240         // sfn will be valid whenever mcall is valid now because of inheritance
1241         if (is_sfn || is_mcall) {
1242 
1243           // Handle special safepoint nodes for synchronization
1244           if (!is_mcall) {
1245             MachSafePointNode *sfn = mach->as_MachSafePoint();
1246             // !!!!! Stubs only need an oopmap right now, so bail out
1247             if (sfn->jvms()->method() == NULL) {
1248               // Write the oopmap directly to the code blob??!!
1249               continue;
1250             }
1251           } // End synchronization
1252 
1253           non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
1254                                            current_offset);
1255           Process_OopMap_Node(mach, current_offset);
1256         } // End if safepoint
1257 
1258         // If this is a null check, then add the start of the previous instruction to the list
1259         else if( mach->is_MachNullCheck() ) {
1260           inct_starts[inct_cnt++] = previous_offset;
1261         }
1262 
1263         // If this is a branch, then fill in the label with the target BB's label
1264         else if (mach->is_MachBranch()) {
1265           // This requires the TRUE branch target be in succs[0]
1266           uint block_num = block->non_connector_successor(0)->_pre_order;
1267 
1268           // Try to replace long branch if delay slot is not used,
1269           // it is mostly for back branches since forward branch's
1270           // distance is not updated yet.
1271           bool delay_slot_is_used = valid_bundle_info(n) &&
1272                                     node_bundling(n)->use_unconditional_delay();
1273           if (!delay_slot_is_used && mach->may_be_short_branch()) {
1274            assert(delay_slot == NULL, "not expecting delay slot node");
1275            int br_size = n->size(_regalloc);
1276             int offset = blk_starts[block_num] - current_offset;
1277             if (block_num >= i) {
1278               // Current and following block's offset are not
1279               // finalized yet, adjust distance by the difference
1280               // between calculated and final offsets of current block.
1281               offset -= (blk_starts[i] - blk_offset);
1282             }
1283             // In the following code a nop could be inserted before
1284             // the branch which will increase the backward distance.
1285             bool needs_padding = (current_offset == last_avoid_back_to_back_offset);
1286             if (needs_padding && offset <= 0)
1287               offset -= nop_size;
1288 
1289             if (_matcher->is_short_branch_offset(mach->rule(), br_size, offset)) {
1290               // We've got a winner.  Replace this branch.
1291               MachNode* replacement = mach->as_MachBranch()->short_branch_version();
1292 
1293               // Update the jmp_size.
1294               int new_size = replacement->size(_regalloc);
1295               assert((br_size - new_size) >= (int)nop_size, "short_branch size should be smaller");
1296               // Insert padding between avoid_back_to_back branches.
1297               if (needs_padding && replacement->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
1298                 MachNode *nop = new MachNopNode();
1299                 block->insert_node(nop, j++);
1300                 _cfg->map_node_to_block(nop, block);
1301                 last_inst++;
1302                 nop->emit(*cb, _regalloc);
1303                 cb->flush_bundle(true);
1304                 current_offset = cb->insts_size();
1305               }
1306 #ifdef ASSERT
1307               jmp_target[i] = block_num;
1308               jmp_offset[i] = current_offset - blk_offset;
1309               jmp_size[i]   = new_size;
1310               jmp_rule[i]   = mach->rule();
1311 #endif
1312               block->map_node(replacement, j);
1313               mach->subsume_by(replacement, C);
1314               n    = replacement;
1315               mach = replacement;
1316             }
1317           }
1318           mach->as_MachBranch()->label_set( &blk_labels[block_num], block_num );
1319         } else if (mach->ideal_Opcode() == Op_Jump) {
1320           for (uint h = 0; h < block->_num_succs; h++) {
1321             Block* succs_block = block->_succs[h];
1322             for (uint j = 1; j < succs_block->num_preds(); j++) {
1323               Node* jpn = succs_block->pred(j);
1324               if (jpn->is_JumpProj() && jpn->in(0) == mach) {
1325                 uint block_num = succs_block->non_connector()->_pre_order;
1326                 Label *blkLabel = &blk_labels[block_num];
1327                 mach->add_case_label(jpn->as_JumpProj()->proj_no(), blkLabel);
1328               }
1329             }
1330           }
1331         }
1332 #ifdef ASSERT
1333         // Check that oop-store precedes the card-mark
1334         else if (mach->ideal_Opcode() == Op_StoreCM) {
1335           uint storeCM_idx = j;
1336           int count = 0;
1337           for (uint prec = mach->req(); prec < mach->len(); prec++) {
1338             Node *oop_store = mach->in(prec);  // Precedence edge
1339             if (oop_store == NULL) continue;
1340             count++;
1341             uint i4;
1342             for (i4 = 0; i4 < last_inst; ++i4) {
1343               if (block->get_node(i4) == oop_store) {
1344                 break;
1345               }
1346             }
1347             // Note: This test can provide a false failure if other precedence
1348             // edges have been added to the storeCMNode.
1349             assert(i4 == last_inst || i4 < storeCM_idx, "CM card-mark executes before oop-store");
1350           }
1351           assert(count > 0, "storeCM expects at least one precedence edge");
1352         }
1353 #endif
1354         else if (!n->is_Proj()) {
1355           // Remember the beginning of the previous instruction, in case
1356           // it's followed by a flag-kill and a null-check.  Happens on
1357           // Intel all the time, with add-to-memory kind of opcodes.
1358           previous_offset = current_offset;
1359         }
1360 
1361         // Not an else-if!
1362         // If this is a trap based cmp then add its offset to the list.
1363         if (mach->is_TrapBasedCheckNode()) {
1364           inct_starts[inct_cnt++] = current_offset;
1365         }
1366       }
1367 
1368       // Verify that there is sufficient space remaining
1369       cb->insts()->maybe_expand_to_ensure_remaining(MAX_inst_size);
1370       if ((cb->blob() == NULL) || (!CompileBroker::should_compile_new_jobs())) {
1371         C->record_failure("CodeCache is full");
1372         return;
1373       }
1374 
1375       // Save the offset for the listing
1376 #ifndef PRODUCT
1377       if (node_offsets && n->_idx < node_offset_limit)
1378         node_offsets[n->_idx] = cb->insts_size();
1379 #endif
1380 
1381       // "Normal" instruction case
1382       DEBUG_ONLY( uint instr_offset = cb->insts_size(); )
1383       n->emit(*cb, _regalloc);
1384       current_offset  = cb->insts_size();
1385 
1386       // Above we only verified that there is enough space in the instruction section.
1387       // However, the instruction may emit stubs that cause code buffer expansion.
1388       // Bail out here if expansion failed due to a lack of code cache space.
1389       if (failing()) {
1390         return;
1391       }
1392 
1393 #ifdef ASSERT
1394       if (n->size(_regalloc) < (current_offset-instr_offset)) {
1395         n->dump();
1396         assert(false, "wrong size of mach node");
1397       }
1398 #endif
1399       non_safepoints.observe_instruction(n, current_offset);
1400 
1401       // mcall is last "call" that can be a safepoint
1402       // record it so we can see if a poll will directly follow it
1403       // in which case we'll need a pad to make the PcDesc sites unique
1404       // see  5010568. This can be slightly inaccurate but conservative
1405       // in the case that return address is not actually at current_offset.
1406       // This is a small price to pay.
1407 
1408       if (is_mcall) {
1409         last_call_offset = current_offset;
1410       }
1411 
1412       if (n->is_Mach() && n->as_Mach()->avoid_back_to_back(MachNode::AVOID_AFTER)) {
1413         // Avoid back to back some instructions.
1414         last_avoid_back_to_back_offset = current_offset;
1415       }
1416 
1417       // See if this instruction has a delay slot
1418       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
1419         assert(delay_slot != NULL, "expecting delay slot node");
1420 
1421         // Back up 1 instruction
1422         cb->set_insts_end(cb->insts_end() - Pipeline::instr_unit_size());
1423 
1424         // Save the offset for the listing
1425 #ifndef PRODUCT
1426         if (node_offsets && delay_slot->_idx < node_offset_limit)
1427           node_offsets[delay_slot->_idx] = cb->insts_size();
1428 #endif
1429 
1430         // Support a SafePoint in the delay slot
1431         if (delay_slot->is_MachSafePoint()) {
1432           MachNode *mach = delay_slot->as_Mach();
1433           // !!!!! Stubs only need an oopmap right now, so bail out
1434           if (!mach->is_MachCall() && mach->as_MachSafePoint()->jvms()->method() == NULL) {
1435             // Write the oopmap directly to the code blob??!!
1436             delay_slot = NULL;
1437             continue;
1438           }
1439 
1440           int adjusted_offset = current_offset - Pipeline::instr_unit_size();
1441           non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
1442                                            adjusted_offset);
1443           // Generate an OopMap entry
1444           Process_OopMap_Node(mach, adjusted_offset);
1445         }
1446 
1447         // Insert the delay slot instruction
1448         delay_slot->emit(*cb, _regalloc);
1449 
1450         // Don't reuse it
1451         delay_slot = NULL;
1452       }
1453 
1454     } // End for all instructions in block
1455 
1456     // If the next block is the top of a loop, pad this block out to align
1457     // the loop top a little. Helps prevent pipe stalls at loop back branches.
1458     if (i < nblocks-1) {
1459       Block *nb = _cfg->get_block(i + 1);
1460       int padding = nb->alignment_padding(current_offset);
1461       if( padding > 0 ) {
1462         MachNode *nop = new MachNopNode(padding / nop_size);
1463         block->insert_node(nop, block->number_of_nodes());
1464         _cfg->map_node_to_block(nop, block);
1465         nop->emit(*cb, _regalloc);
1466         current_offset = cb->insts_size();
1467       }
1468     }
1469     // Verify that the distance for generated before forward
1470     // short branches is still valid.
1471     guarantee((int)(blk_starts[i+1] - blk_starts[i]) >= (current_offset - blk_offset), "shouldn't increase block size");
1472 
1473     // Save new block start offset
1474     blk_starts[i] = blk_offset;
1475   } // End of for all blocks
1476   blk_starts[nblocks] = current_offset;
1477 
1478   non_safepoints.flush_at_end();
1479 
1480   // Offset too large?
1481   if (failing())  return;
1482 
1483   // Define a pseudo-label at the end of the code
1484   MacroAssembler(cb).bind( blk_labels[nblocks] );
1485 
1486   // Compute the size of the first block
1487   _first_block_size = blk_labels[1].loc_pos() - blk_labels[0].loc_pos();
1488 
1489   assert(cb->insts_size() < 500000, "method is unreasonably large");
1490 
1491 #ifdef ASSERT
1492   for (uint i = 0; i < nblocks; i++) { // For all blocks
1493     if (jmp_target[i] != 0) {
1494       int br_size = jmp_size[i];
1495       int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_offset[i]);
1496       if (!_matcher->is_short_branch_offset(jmp_rule[i], br_size, offset)) {
1497         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]);
1498         assert(false, "Displacement too large for short jmp");
1499       }
1500     }
1501   }
1502 #endif
1503 
1504 #ifndef PRODUCT
1505   // Information on the size of the method, without the extraneous code
1506   Scheduling::increment_method_size(cb->insts_size());
1507 #endif
1508 
1509   // ------------------
1510   // Fill in exception table entries.
1511   FillExceptionTables(inct_cnt, call_returns, inct_starts, blk_labels);
1512 
1513   // Only java methods have exception handlers and deopt handlers
1514   // class HandlerImpl is platform-specific and defined in the *.ad files.
1515   if (_method) {
1516     // Emit the exception handler code.
1517     _code_offsets.set_value(CodeOffsets::Exceptions, HandlerImpl::emit_exception_handler(*cb));
1518     if (failing()) {
1519       return; // CodeBuffer::expand failed
1520     }
1521     // Emit the deopt handler code.
1522     _code_offsets.set_value(CodeOffsets::Deopt, HandlerImpl::emit_deopt_handler(*cb));
1523 
1524     // Emit the MethodHandle deopt handler code (if required).
1525     if (has_method_handle_invokes() && !failing()) {
1526       // We can use the same code as for the normal deopt handler, we
1527       // just need a different entry point address.
1528       _code_offsets.set_value(CodeOffsets::DeoptMH, HandlerImpl::emit_deopt_handler(*cb));
1529     }
1530   }
1531 
1532   // One last check for failed CodeBuffer::expand:
1533   if ((cb->blob() == NULL) || (!CompileBroker::should_compile_new_jobs())) {
1534     C->record_failure("CodeCache is full");
1535     return;
1536   }
1537 
1538 #ifndef PRODUCT
1539   // Dump the assembly code, including basic-block numbers
1540   if (print_assembly()) {
1541     ttyLocker ttyl;  // keep the following output all in one block
1542     if (!VMThread::should_terminate()) {  // test this under the tty lock
1543       // This output goes directly to the tty, not the compiler log.
1544       // To enable tools to match it up with the compilation activity,
1545       // be sure to tag this tty output with the compile ID.
1546       if (xtty != NULL) {
1547         xtty->head("opto_assembly compile_id='%d'%s", compile_id(),
1548                    is_osr_compilation()    ? " compile_kind='osr'" :
1549                    "");
1550       }
1551       if (method() != NULL) {
1552         method()->print_metadata();
1553       }
1554       dump_asm(node_offsets, node_offset_limit);
1555       if (xtty != NULL) {
1556         xtty->tail("opto_assembly");
1557       }
1558     }
1559   }
1560 #endif
1561 
1562 }
1563 
1564 void Compile::FillExceptionTables(uint cnt, uint *call_returns, uint *inct_starts, Label *blk_labels) {
1565   _inc_table.set_size(cnt);
1566 
1567   uint inct_cnt = 0;
1568   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
1569     Block* block = _cfg->get_block(i);
1570     Node *n = NULL;
1571     int j;
1572 
1573     // Find the branch; ignore trailing NOPs.
1574     for (j = block->number_of_nodes() - 1; j >= 0; j--) {
1575       n = block->get_node(j);
1576       if (!n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con) {
1577         break;
1578       }
1579     }
1580 
1581     // If we didn't find anything, continue
1582     if (j < 0) {
1583       continue;
1584     }
1585 
1586     // Compute ExceptionHandlerTable subtable entry and add it
1587     // (skip empty blocks)
1588     if (n->is_Catch()) {
1589 
1590       // Get the offset of the return from the call
1591       uint call_return = call_returns[block->_pre_order];
1592 #ifdef ASSERT
1593       assert( call_return > 0, "no call seen for this basic block" );
1594       while (block->get_node(--j)->is_MachProj()) ;
1595       assert(block->get_node(j)->is_MachCall(), "CatchProj must follow call");
1596 #endif
1597       // last instruction is a CatchNode, find it's CatchProjNodes
1598       int nof_succs = block->_num_succs;
1599       // allocate space
1600       GrowableArray<intptr_t> handler_bcis(nof_succs);
1601       GrowableArray<intptr_t> handler_pcos(nof_succs);
1602       // iterate through all successors
1603       for (int j = 0; j < nof_succs; j++) {
1604         Block* s = block->_succs[j];
1605         bool found_p = false;
1606         for (uint k = 1; k < s->num_preds(); k++) {
1607           Node* pk = s->pred(k);
1608           if (pk->is_CatchProj() && pk->in(0) == n) {
1609             const CatchProjNode* p = pk->as_CatchProj();
1610             found_p = true;
1611             // add the corresponding handler bci & pco information
1612             if (p->_con != CatchProjNode::fall_through_index) {
1613               // p leads to an exception handler (and is not fall through)
1614               assert(s == _cfg->get_block(s->_pre_order), "bad numbering");
1615               // no duplicates, please
1616               if (!handler_bcis.contains(p->handler_bci())) {
1617                 uint block_num = s->non_connector()->_pre_order;
1618                 handler_bcis.append(p->handler_bci());
1619                 handler_pcos.append(blk_labels[block_num].loc_pos());
1620               }
1621             }
1622           }
1623         }
1624         assert(found_p, "no matching predecessor found");
1625         // Note:  Due to empty block removal, one block may have
1626         // several CatchProj inputs, from the same Catch.
1627       }
1628 
1629       // Set the offset of the return from the call
1630       _handler_table.add_subtable(call_return, &handler_bcis, NULL, &handler_pcos);
1631       continue;
1632     }
1633 
1634     // Handle implicit null exception table updates
1635     if (n->is_MachNullCheck()) {
1636       uint block_num = block->non_connector_successor(0)->_pre_order;
1637       _inc_table.append(inct_starts[inct_cnt++], blk_labels[block_num].loc_pos());
1638       continue;
1639     }
1640     // Handle implicit exception table updates: trap instructions.
1641     if (n->is_Mach() && n->as_Mach()->is_TrapBasedCheckNode()) {
1642       uint block_num = block->non_connector_successor(0)->_pre_order;
1643       _inc_table.append(inct_starts[inct_cnt++], blk_labels[block_num].loc_pos());
1644       continue;
1645     }
1646   } // End of for all blocks fill in exception table entries
1647 }
1648 
1649 // Static Variables
1650 #ifndef PRODUCT
1651 uint Scheduling::_total_nop_size = 0;
1652 uint Scheduling::_total_method_size = 0;
1653 uint Scheduling::_total_branches = 0;
1654 uint Scheduling::_total_unconditional_delays = 0;
1655 uint Scheduling::_total_instructions_per_bundle[Pipeline::_max_instrs_per_cycle+1];
1656 #endif
1657 
1658 // Initializer for class Scheduling
1659 
1660 Scheduling::Scheduling(Arena *arena, Compile &compile)
1661   : _arena(arena),
1662     _cfg(compile.cfg()),
1663     _regalloc(compile.regalloc()),
1664     _reg_node(arena),
1665     _bundle_instr_count(0),
1666     _bundle_cycle_number(0),
1667     _scheduled(arena),
1668     _available(arena),
1669     _next_node(NULL),
1670     _bundle_use(0, 0, resource_count, &_bundle_use_elements[0]),
1671     _pinch_free_list(arena)
1672 #ifndef PRODUCT
1673   , _branches(0)
1674   , _unconditional_delays(0)
1675 #endif
1676 {
1677   // Create a MachNopNode
1678   _nop = new MachNopNode();
1679 
1680   // Now that the nops are in the array, save the count
1681   // (but allow entries for the nops)
1682   _node_bundling_limit = compile.unique();
1683   uint node_max = _regalloc->node_regs_max_index();
1684 
1685   compile.set_node_bundling_limit(_node_bundling_limit);
1686 
1687   // This one is persistent within the Compile class
1688   _node_bundling_base = NEW_ARENA_ARRAY(compile.comp_arena(), Bundle, node_max);
1689 
1690   // Allocate space for fixed-size arrays
1691   _node_latency    = NEW_ARENA_ARRAY(arena, unsigned short, node_max);
1692   _uses            = NEW_ARENA_ARRAY(arena, short,          node_max);
1693   _current_latency = NEW_ARENA_ARRAY(arena, unsigned short, node_max);
1694 
1695   // Clear the arrays
1696   memset(_node_bundling_base, 0, node_max * sizeof(Bundle));
1697   memset(_node_latency,       0, node_max * sizeof(unsigned short));
1698   memset(_uses,               0, node_max * sizeof(short));
1699   memset(_current_latency,    0, node_max * sizeof(unsigned short));
1700 
1701   // Clear the bundling information
1702   memcpy(_bundle_use_elements, Pipeline_Use::elaborated_elements, sizeof(Pipeline_Use::elaborated_elements));
1703 
1704   // Get the last node
1705   Block* block = _cfg->get_block(_cfg->number_of_blocks() - 1);
1706 
1707   _next_node = block->get_node(block->number_of_nodes() - 1);
1708 }
1709 
1710 #ifndef PRODUCT
1711 // Scheduling destructor
1712 Scheduling::~Scheduling() {
1713   _total_branches             += _branches;
1714   _total_unconditional_delays += _unconditional_delays;
1715 }
1716 #endif
1717 
1718 // Step ahead "i" cycles
1719 void Scheduling::step(uint i) {
1720 
1721   Bundle *bundle = node_bundling(_next_node);
1722   bundle->set_starts_bundle();
1723 
1724   // Update the bundle record, but leave the flags information alone
1725   if (_bundle_instr_count > 0) {
1726     bundle->set_instr_count(_bundle_instr_count);
1727     bundle->set_resources_used(_bundle_use.resourcesUsed());
1728   }
1729 
1730   // Update the state information
1731   _bundle_instr_count = 0;
1732   _bundle_cycle_number += i;
1733   _bundle_use.step(i);
1734 }
1735 
1736 void Scheduling::step_and_clear() {
1737   Bundle *bundle = node_bundling(_next_node);
1738   bundle->set_starts_bundle();
1739 
1740   // Update the bundle record
1741   if (_bundle_instr_count > 0) {
1742     bundle->set_instr_count(_bundle_instr_count);
1743     bundle->set_resources_used(_bundle_use.resourcesUsed());
1744 
1745     _bundle_cycle_number += 1;
1746   }
1747 
1748   // Clear the bundling information
1749   _bundle_instr_count = 0;
1750   _bundle_use.reset();
1751 
1752   memcpy(_bundle_use_elements,
1753     Pipeline_Use::elaborated_elements,
1754     sizeof(Pipeline_Use::elaborated_elements));
1755 }
1756 
1757 // Perform instruction scheduling and bundling over the sequence of
1758 // instructions in backwards order.
1759 void Compile::ScheduleAndBundle() {
1760 
1761   // Don't optimize this if it isn't a method
1762   if (!_method)
1763     return;
1764 
1765   // Don't optimize this if scheduling is disabled
1766   if (!do_scheduling())
1767     return;
1768 
1769   // Scheduling code works only with pairs (16 bytes) maximum.
1770   if (max_vector_size() > 16)
1771     return;
1772 
1773   TracePhase tp("isched", &timers[_t_instrSched]);
1774 
1775   // Create a data structure for all the scheduling information
1776   Scheduling scheduling(Thread::current()->resource_area(), *this);
1777 
1778   // Walk backwards over each basic block, computing the needed alignment
1779   // Walk over all the basic blocks
1780   scheduling.DoScheduling();
1781 }
1782 
1783 // Compute the latency of all the instructions.  This is fairly simple,
1784 // because we already have a legal ordering.  Walk over the instructions
1785 // from first to last, and compute the latency of the instruction based
1786 // on the latency of the preceding instruction(s).
1787 void Scheduling::ComputeLocalLatenciesForward(const Block *bb) {
1788 #ifndef PRODUCT
1789   if (_cfg->C->trace_opto_output())
1790     tty->print("# -> ComputeLocalLatenciesForward\n");
1791 #endif
1792 
1793   // Walk over all the schedulable instructions
1794   for( uint j=_bb_start; j < _bb_end; j++ ) {
1795 
1796     // This is a kludge, forcing all latency calculations to start at 1.
1797     // Used to allow latency 0 to force an instruction to the beginning
1798     // of the bb
1799     uint latency = 1;
1800     Node *use = bb->get_node(j);
1801     uint nlen = use->len();
1802 
1803     // Walk over all the inputs
1804     for ( uint k=0; k < nlen; k++ ) {
1805       Node *def = use->in(k);
1806       if (!def)
1807         continue;
1808 
1809       uint l = _node_latency[def->_idx] + use->latency(k);
1810       if (latency < l)
1811         latency = l;
1812     }
1813 
1814     _node_latency[use->_idx] = latency;
1815 
1816 #ifndef PRODUCT
1817     if (_cfg->C->trace_opto_output()) {
1818       tty->print("# latency %4d: ", latency);
1819       use->dump();
1820     }
1821 #endif
1822   }
1823 
1824 #ifndef PRODUCT
1825   if (_cfg->C->trace_opto_output())
1826     tty->print("# <- ComputeLocalLatenciesForward\n");
1827 #endif
1828 
1829 } // end ComputeLocalLatenciesForward
1830 
1831 // See if this node fits into the present instruction bundle
1832 bool Scheduling::NodeFitsInBundle(Node *n) {
1833   uint n_idx = n->_idx;
1834 
1835   // If this is the unconditional delay instruction, then it fits
1836   if (n == _unconditional_delay_slot) {
1837 #ifndef PRODUCT
1838     if (_cfg->C->trace_opto_output())
1839       tty->print("#     NodeFitsInBundle [%4d]: TRUE; is in unconditional delay slot\n", n->_idx);
1840 #endif
1841     return (true);
1842   }
1843 
1844   // If the node cannot be scheduled this cycle, skip it
1845   if (_current_latency[n_idx] > _bundle_cycle_number) {
1846 #ifndef PRODUCT
1847     if (_cfg->C->trace_opto_output())
1848       tty->print("#     NodeFitsInBundle [%4d]: FALSE; latency %4d > %d\n",
1849         n->_idx, _current_latency[n_idx], _bundle_cycle_number);
1850 #endif
1851     return (false);
1852   }
1853 
1854   const Pipeline *node_pipeline = n->pipeline();
1855 
1856   uint instruction_count = node_pipeline->instructionCount();
1857   if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
1858     instruction_count = 0;
1859   else if (node_pipeline->hasBranchDelay() && !_unconditional_delay_slot)
1860     instruction_count++;
1861 
1862   if (_bundle_instr_count + instruction_count > Pipeline::_max_instrs_per_cycle) {
1863 #ifndef PRODUCT
1864     if (_cfg->C->trace_opto_output())
1865       tty->print("#     NodeFitsInBundle [%4d]: FALSE; too many instructions: %d > %d\n",
1866         n->_idx, _bundle_instr_count + instruction_count, Pipeline::_max_instrs_per_cycle);
1867 #endif
1868     return (false);
1869   }
1870 
1871   // Don't allow non-machine nodes to be handled this way
1872   if (!n->is_Mach() && instruction_count == 0)
1873     return (false);
1874 
1875   // See if there is any overlap
1876   uint delay = _bundle_use.full_latency(0, node_pipeline->resourceUse());
1877 
1878   if (delay > 0) {
1879 #ifndef PRODUCT
1880     if (_cfg->C->trace_opto_output())
1881       tty->print("#     NodeFitsInBundle [%4d]: FALSE; functional units overlap\n", n_idx);
1882 #endif
1883     return false;
1884   }
1885 
1886 #ifndef PRODUCT
1887   if (_cfg->C->trace_opto_output())
1888     tty->print("#     NodeFitsInBundle [%4d]:  TRUE\n", n_idx);
1889 #endif
1890 
1891   return true;
1892 }
1893 
1894 Node * Scheduling::ChooseNodeToBundle() {
1895   uint siz = _available.size();
1896 
1897   if (siz == 0) {
1898 
1899 #ifndef PRODUCT
1900     if (_cfg->C->trace_opto_output())
1901       tty->print("#   ChooseNodeToBundle: NULL\n");
1902 #endif
1903     return (NULL);
1904   }
1905 
1906   // Fast path, if only 1 instruction in the bundle
1907   if (siz == 1) {
1908 #ifndef PRODUCT
1909     if (_cfg->C->trace_opto_output()) {
1910       tty->print("#   ChooseNodeToBundle (only 1): ");
1911       _available[0]->dump();
1912     }
1913 #endif
1914     return (_available[0]);
1915   }
1916 
1917   // Don't bother, if the bundle is already full
1918   if (_bundle_instr_count < Pipeline::_max_instrs_per_cycle) {
1919     for ( uint i = 0; i < siz; i++ ) {
1920       Node *n = _available[i];
1921 
1922       // Skip projections, we'll handle them another way
1923       if (n->is_Proj())
1924         continue;
1925 
1926       // This presupposed that instructions are inserted into the
1927       // available list in a legality order; i.e. instructions that
1928       // must be inserted first are at the head of the list
1929       if (NodeFitsInBundle(n)) {
1930 #ifndef PRODUCT
1931         if (_cfg->C->trace_opto_output()) {
1932           tty->print("#   ChooseNodeToBundle: ");
1933           n->dump();
1934         }
1935 #endif
1936         return (n);
1937       }
1938     }
1939   }
1940 
1941   // Nothing fits in this bundle, choose the highest priority
1942 #ifndef PRODUCT
1943   if (_cfg->C->trace_opto_output()) {
1944     tty->print("#   ChooseNodeToBundle: ");
1945     _available[0]->dump();
1946   }
1947 #endif
1948 
1949   return _available[0];
1950 }
1951 
1952 void Scheduling::AddNodeToAvailableList(Node *n) {
1953   assert( !n->is_Proj(), "projections never directly made available" );
1954 #ifndef PRODUCT
1955   if (_cfg->C->trace_opto_output()) {
1956     tty->print("#   AddNodeToAvailableList: ");
1957     n->dump();
1958   }
1959 #endif
1960 
1961   int latency = _current_latency[n->_idx];
1962 
1963   // Insert in latency order (insertion sort)
1964   uint i;
1965   for ( i=0; i < _available.size(); i++ )
1966     if (_current_latency[_available[i]->_idx] > latency)
1967       break;
1968 
1969   // Special Check for compares following branches
1970   if( n->is_Mach() && _scheduled.size() > 0 ) {
1971     int op = n->as_Mach()->ideal_Opcode();
1972     Node *last = _scheduled[0];
1973     if( last->is_MachIf() && last->in(1) == n &&
1974         ( op == Op_CmpI ||
1975           op == Op_CmpU ||
1976           op == Op_CmpP ||
1977           op == Op_CmpF ||
1978           op == Op_CmpD ||
1979           op == Op_CmpL ) ) {
1980 
1981       // Recalculate position, moving to front of same latency
1982       for ( i=0 ; i < _available.size(); i++ )
1983         if (_current_latency[_available[i]->_idx] >= latency)
1984           break;
1985     }
1986   }
1987 
1988   // Insert the node in the available list
1989   _available.insert(i, n);
1990 
1991 #ifndef PRODUCT
1992   if (_cfg->C->trace_opto_output())
1993     dump_available();
1994 #endif
1995 }
1996 
1997 void Scheduling::DecrementUseCounts(Node *n, const Block *bb) {
1998   for ( uint i=0; i < n->len(); i++ ) {
1999     Node *def = n->in(i);
2000     if (!def) continue;
2001     if( def->is_Proj() )        // If this is a machine projection, then
2002       def = def->in(0);         // propagate usage thru to the base instruction
2003 
2004     if(_cfg->get_block_for_node(def) != bb) { // Ignore if not block-local
2005       continue;
2006     }
2007 
2008     // Compute the latency
2009     uint l = _bundle_cycle_number + n->latency(i);
2010     if (_current_latency[def->_idx] < l)
2011       _current_latency[def->_idx] = l;
2012 
2013     // If this does not have uses then schedule it
2014     if ((--_uses[def->_idx]) == 0)
2015       AddNodeToAvailableList(def);
2016   }
2017 }
2018 
2019 void Scheduling::AddNodeToBundle(Node *n, const Block *bb) {
2020 #ifndef PRODUCT
2021   if (_cfg->C->trace_opto_output()) {
2022     tty->print("#   AddNodeToBundle: ");
2023     n->dump();
2024   }
2025 #endif
2026 
2027   // Remove this from the available list
2028   uint i;
2029   for (i = 0; i < _available.size(); i++)
2030     if (_available[i] == n)
2031       break;
2032   assert(i < _available.size(), "entry in _available list not found");
2033   _available.remove(i);
2034 
2035   // See if this fits in the current bundle
2036   const Pipeline *node_pipeline = n->pipeline();
2037   const Pipeline_Use& node_usage = node_pipeline->resourceUse();
2038 
2039   // Check for instructions to be placed in the delay slot. We
2040   // do this before we actually schedule the current instruction,
2041   // because the delay slot follows the current instruction.
2042   if (Pipeline::_branch_has_delay_slot &&
2043       node_pipeline->hasBranchDelay() &&
2044       !_unconditional_delay_slot) {
2045 
2046     uint siz = _available.size();
2047 
2048     // Conditional branches can support an instruction that
2049     // is unconditionally executed and not dependent by the
2050     // branch, OR a conditionally executed instruction if
2051     // the branch is taken.  In practice, this means that
2052     // the first instruction at the branch target is
2053     // copied to the delay slot, and the branch goes to
2054     // the instruction after that at the branch target
2055     if ( n->is_MachBranch() ) {
2056 
2057       assert( !n->is_MachNullCheck(), "should not look for delay slot for Null Check" );
2058       assert( !n->is_Catch(),         "should not look for delay slot for Catch" );
2059 
2060 #ifndef PRODUCT
2061       _branches++;
2062 #endif
2063 
2064       // At least 1 instruction is on the available list
2065       // that is not dependent on the branch
2066       for (uint i = 0; i < siz; i++) {
2067         Node *d = _available[i];
2068         const Pipeline *avail_pipeline = d->pipeline();
2069 
2070         // Don't allow safepoints in the branch shadow, that will
2071         // cause a number of difficulties
2072         if ( avail_pipeline->instructionCount() == 1 &&
2073             !avail_pipeline->hasMultipleBundles() &&
2074             !avail_pipeline->hasBranchDelay() &&
2075             Pipeline::instr_has_unit_size() &&
2076             d->size(_regalloc) == Pipeline::instr_unit_size() &&
2077             NodeFitsInBundle(d) &&
2078             !node_bundling(d)->used_in_delay()) {
2079 
2080           if (d->is_Mach() && !d->is_MachSafePoint()) {
2081             // A node that fits in the delay slot was found, so we need to
2082             // set the appropriate bits in the bundle pipeline information so
2083             // that it correctly indicates resource usage.  Later, when we
2084             // attempt to add this instruction to the bundle, we will skip
2085             // setting the resource usage.
2086             _unconditional_delay_slot = d;
2087             node_bundling(n)->set_use_unconditional_delay();
2088             node_bundling(d)->set_used_in_unconditional_delay();
2089             _bundle_use.add_usage(avail_pipeline->resourceUse());
2090             _current_latency[d->_idx] = _bundle_cycle_number;
2091             _next_node = d;
2092             ++_bundle_instr_count;
2093 #ifndef PRODUCT
2094             _unconditional_delays++;
2095 #endif
2096             break;
2097           }
2098         }
2099       }
2100     }
2101 
2102     // No delay slot, add a nop to the usage
2103     if (!_unconditional_delay_slot) {
2104       // See if adding an instruction in the delay slot will overflow
2105       // the bundle.
2106       if (!NodeFitsInBundle(_nop)) {
2107 #ifndef PRODUCT
2108         if (_cfg->C->trace_opto_output())
2109           tty->print("#  *** STEP(1 instruction for delay slot) ***\n");
2110 #endif
2111         step(1);
2112       }
2113 
2114       _bundle_use.add_usage(_nop->pipeline()->resourceUse());
2115       _next_node = _nop;
2116       ++_bundle_instr_count;
2117     }
2118 
2119     // See if the instruction in the delay slot requires a
2120     // step of the bundles
2121     if (!NodeFitsInBundle(n)) {
2122 #ifndef PRODUCT
2123         if (_cfg->C->trace_opto_output())
2124           tty->print("#  *** STEP(branch won't fit) ***\n");
2125 #endif
2126         // Update the state information
2127         _bundle_instr_count = 0;
2128         _bundle_cycle_number += 1;
2129         _bundle_use.step(1);
2130     }
2131   }
2132 
2133   // Get the number of instructions
2134   uint instruction_count = node_pipeline->instructionCount();
2135   if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
2136     instruction_count = 0;
2137 
2138   // Compute the latency information
2139   uint delay = 0;
2140 
2141   if (instruction_count > 0 || !node_pipeline->mayHaveNoCode()) {
2142     int relative_latency = _current_latency[n->_idx] - _bundle_cycle_number;
2143     if (relative_latency < 0)
2144       relative_latency = 0;
2145 
2146     delay = _bundle_use.full_latency(relative_latency, node_usage);
2147 
2148     // Does not fit in this bundle, start a new one
2149     if (delay > 0) {
2150       step(delay);
2151 
2152 #ifndef PRODUCT
2153       if (_cfg->C->trace_opto_output())
2154         tty->print("#  *** STEP(%d) ***\n", delay);
2155 #endif
2156     }
2157   }
2158 
2159   // If this was placed in the delay slot, ignore it
2160   if (n != _unconditional_delay_slot) {
2161 
2162     if (delay == 0) {
2163       if (node_pipeline->hasMultipleBundles()) {
2164 #ifndef PRODUCT
2165         if (_cfg->C->trace_opto_output())
2166           tty->print("#  *** STEP(multiple instructions) ***\n");
2167 #endif
2168         step(1);
2169       }
2170 
2171       else if (instruction_count + _bundle_instr_count > Pipeline::_max_instrs_per_cycle) {
2172 #ifndef PRODUCT
2173         if (_cfg->C->trace_opto_output())
2174           tty->print("#  *** STEP(%d >= %d instructions) ***\n",
2175             instruction_count + _bundle_instr_count,
2176             Pipeline::_max_instrs_per_cycle);
2177 #endif
2178         step(1);
2179       }
2180     }
2181 
2182     if (node_pipeline->hasBranchDelay() && !_unconditional_delay_slot)
2183       _bundle_instr_count++;
2184 
2185     // Set the node's latency
2186     _current_latency[n->_idx] = _bundle_cycle_number;
2187 
2188     // Now merge the functional unit information
2189     if (instruction_count > 0 || !node_pipeline->mayHaveNoCode())
2190       _bundle_use.add_usage(node_usage);
2191 
2192     // Increment the number of instructions in this bundle
2193     _bundle_instr_count += instruction_count;
2194 
2195     // Remember this node for later
2196     if (n->is_Mach())
2197       _next_node = n;
2198   }
2199 
2200   // It's possible to have a BoxLock in the graph and in the _bbs mapping but
2201   // not in the bb->_nodes array.  This happens for debug-info-only BoxLocks.
2202   // 'Schedule' them (basically ignore in the schedule) but do not insert them
2203   // into the block.  All other scheduled nodes get put in the schedule here.
2204   int op = n->Opcode();
2205   if( (op == Op_Node && n->req() == 0) || // anti-dependence node OR
2206       (op != Op_Node &&         // Not an unused antidepedence node and
2207        // not an unallocated boxlock
2208        (OptoReg::is_valid(_regalloc->get_reg_first(n)) || op != Op_BoxLock)) ) {
2209 
2210     // Push any trailing projections
2211     if( bb->get_node(bb->number_of_nodes()-1) != n ) {
2212       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2213         Node *foi = n->fast_out(i);
2214         if( foi->is_Proj() )
2215           _scheduled.push(foi);
2216       }
2217     }
2218 
2219     // Put the instruction in the schedule list
2220     _scheduled.push(n);
2221   }
2222 
2223 #ifndef PRODUCT
2224   if (_cfg->C->trace_opto_output())
2225     dump_available();
2226 #endif
2227 
2228   // Walk all the definitions, decrementing use counts, and
2229   // if a definition has a 0 use count, place it in the available list.
2230   DecrementUseCounts(n,bb);
2231 }
2232 
2233 // This method sets the use count within a basic block.  We will ignore all
2234 // uses outside the current basic block.  As we are doing a backwards walk,
2235 // any node we reach that has a use count of 0 may be scheduled.  This also
2236 // avoids the problem of cyclic references from phi nodes, as long as phi
2237 // nodes are at the front of the basic block.  This method also initializes
2238 // the available list to the set of instructions that have no uses within this
2239 // basic block.
2240 void Scheduling::ComputeUseCount(const Block *bb) {
2241 #ifndef PRODUCT
2242   if (_cfg->C->trace_opto_output())
2243     tty->print("# -> ComputeUseCount\n");
2244 #endif
2245 
2246   // Clear the list of available and scheduled instructions, just in case
2247   _available.clear();
2248   _scheduled.clear();
2249 
2250   // No delay slot specified
2251   _unconditional_delay_slot = NULL;
2252 
2253 #ifdef ASSERT
2254   for( uint i=0; i < bb->number_of_nodes(); i++ )
2255     assert( _uses[bb->get_node(i)->_idx] == 0, "_use array not clean" );
2256 #endif
2257 
2258   // Force the _uses count to never go to zero for unscheduable pieces
2259   // of the block
2260   for( uint k = 0; k < _bb_start; k++ )
2261     _uses[bb->get_node(k)->_idx] = 1;
2262   for( uint l = _bb_end; l < bb->number_of_nodes(); l++ )
2263     _uses[bb->get_node(l)->_idx] = 1;
2264 
2265   // Iterate backwards over the instructions in the block.  Don't count the
2266   // branch projections at end or the block header instructions.
2267   for( uint j = _bb_end-1; j >= _bb_start; j-- ) {
2268     Node *n = bb->get_node(j);
2269     if( n->is_Proj() ) continue; // Projections handled another way
2270 
2271     // Account for all uses
2272     for ( uint k = 0; k < n->len(); k++ ) {
2273       Node *inp = n->in(k);
2274       if (!inp) continue;
2275       assert(inp != n, "no cycles allowed" );
2276       if (_cfg->get_block_for_node(inp) == bb) { // Block-local use?
2277         if (inp->is_Proj()) { // Skip through Proj's
2278           inp = inp->in(0);
2279         }
2280         ++_uses[inp->_idx];     // Count 1 block-local use
2281       }
2282     }
2283 
2284     // If this instruction has a 0 use count, then it is available
2285     if (!_uses[n->_idx]) {
2286       _current_latency[n->_idx] = _bundle_cycle_number;
2287       AddNodeToAvailableList(n);
2288     }
2289 
2290 #ifndef PRODUCT
2291     if (_cfg->C->trace_opto_output()) {
2292       tty->print("#   uses: %3d: ", _uses[n->_idx]);
2293       n->dump();
2294     }
2295 #endif
2296   }
2297 
2298 #ifndef PRODUCT
2299   if (_cfg->C->trace_opto_output())
2300     tty->print("# <- ComputeUseCount\n");
2301 #endif
2302 }
2303 
2304 // This routine performs scheduling on each basic block in reverse order,
2305 // using instruction latencies and taking into account function unit
2306 // availability.
2307 void Scheduling::DoScheduling() {
2308 #ifndef PRODUCT
2309   if (_cfg->C->trace_opto_output())
2310     tty->print("# -> DoScheduling\n");
2311 #endif
2312 
2313   Block *succ_bb = NULL;
2314   Block *bb;
2315 
2316   // Walk over all the basic blocks in reverse order
2317   for (int i = _cfg->number_of_blocks() - 1; i >= 0; succ_bb = bb, i--) {
2318     bb = _cfg->get_block(i);
2319 
2320 #ifndef PRODUCT
2321     if (_cfg->C->trace_opto_output()) {
2322       tty->print("#  Schedule BB#%03d (initial)\n", i);
2323       for (uint j = 0; j < bb->number_of_nodes(); j++) {
2324         bb->get_node(j)->dump();
2325       }
2326     }
2327 #endif
2328 
2329     // On the head node, skip processing
2330     if (bb == _cfg->get_root_block()) {
2331       continue;
2332     }
2333 
2334     // Skip empty, connector blocks
2335     if (bb->is_connector())
2336       continue;
2337 
2338     // If the following block is not the sole successor of
2339     // this one, then reset the pipeline information
2340     if (bb->_num_succs != 1 || bb->non_connector_successor(0) != succ_bb) {
2341 #ifndef PRODUCT
2342       if (_cfg->C->trace_opto_output()) {
2343         tty->print("*** bundle start of next BB, node %d, for %d instructions\n",
2344                    _next_node->_idx, _bundle_instr_count);
2345       }
2346 #endif
2347       step_and_clear();
2348     }
2349 
2350     // Leave untouched the starting instruction, any Phis, a CreateEx node
2351     // or Top.  bb->get_node(_bb_start) is the first schedulable instruction.
2352     _bb_end = bb->number_of_nodes()-1;
2353     for( _bb_start=1; _bb_start <= _bb_end; _bb_start++ ) {
2354       Node *n = bb->get_node(_bb_start);
2355       // Things not matched, like Phinodes and ProjNodes don't get scheduled.
2356       // Also, MachIdealNodes do not get scheduled
2357       if( !n->is_Mach() ) continue;     // Skip non-machine nodes
2358       MachNode *mach = n->as_Mach();
2359       int iop = mach->ideal_Opcode();
2360       if( iop == Op_CreateEx ) continue; // CreateEx is pinned
2361       if( iop == Op_Con ) continue;      // Do not schedule Top
2362       if( iop == Op_Node &&     // Do not schedule PhiNodes, ProjNodes
2363           mach->pipeline() == MachNode::pipeline_class() &&
2364           !n->is_SpillCopy() && !n->is_MachMerge() )  // Breakpoints, Prolog, etc
2365         continue;
2366       break;                    // Funny loop structure to be sure...
2367     }
2368     // Compute last "interesting" instruction in block - last instruction we
2369     // might schedule.  _bb_end points just after last schedulable inst.  We
2370     // normally schedule conditional branches (despite them being forced last
2371     // in the block), because they have delay slots we can fill.  Calls all
2372     // have their delay slots filled in the template expansions, so we don't
2373     // bother scheduling them.
2374     Node *last = bb->get_node(_bb_end);
2375     // Ignore trailing NOPs.
2376     while (_bb_end > 0 && last->is_Mach() &&
2377            last->as_Mach()->ideal_Opcode() == Op_Con) {
2378       last = bb->get_node(--_bb_end);
2379     }
2380     assert(!last->is_Mach() || last->as_Mach()->ideal_Opcode() != Op_Con, "");
2381     if( last->is_Catch() ||
2382        // Exclude unreachable path case when Halt node is in a separate block.
2383        (_bb_end > 1 && last->is_Mach() && last->as_Mach()->ideal_Opcode() == Op_Halt) ) {
2384       // There must be a prior call.  Skip it.
2385       while( !bb->get_node(--_bb_end)->is_MachCall() ) {
2386         assert( bb->get_node(_bb_end)->is_MachProj(), "skipping projections after expected call" );
2387       }
2388     } else if( last->is_MachNullCheck() ) {
2389       // Backup so the last null-checked memory instruction is
2390       // outside the schedulable range. Skip over the nullcheck,
2391       // projection, and the memory nodes.
2392       Node *mem = last->in(1);
2393       do {
2394         _bb_end--;
2395       } while (mem != bb->get_node(_bb_end));
2396     } else {
2397       // Set _bb_end to point after last schedulable inst.
2398       _bb_end++;
2399     }
2400 
2401     assert( _bb_start <= _bb_end, "inverted block ends" );
2402 
2403     // Compute the register antidependencies for the basic block
2404     ComputeRegisterAntidependencies(bb);
2405     if (_cfg->C->failing())  return;  // too many D-U pinch points
2406 
2407     // Compute intra-bb latencies for the nodes
2408     ComputeLocalLatenciesForward(bb);
2409 
2410     // Compute the usage within the block, and set the list of all nodes
2411     // in the block that have no uses within the block.
2412     ComputeUseCount(bb);
2413 
2414     // Schedule the remaining instructions in the block
2415     while ( _available.size() > 0 ) {
2416       Node *n = ChooseNodeToBundle();
2417       guarantee(n != NULL, "no nodes available");
2418       AddNodeToBundle(n,bb);
2419     }
2420 
2421     assert( _scheduled.size() == _bb_end - _bb_start, "wrong number of instructions" );
2422 #ifdef ASSERT
2423     for( uint l = _bb_start; l < _bb_end; l++ ) {
2424       Node *n = bb->get_node(l);
2425       uint m;
2426       for( m = 0; m < _bb_end-_bb_start; m++ )
2427         if( _scheduled[m] == n )
2428           break;
2429       assert( m < _bb_end-_bb_start, "instruction missing in schedule" );
2430     }
2431 #endif
2432 
2433     // Now copy the instructions (in reverse order) back to the block
2434     for ( uint k = _bb_start; k < _bb_end; k++ )
2435       bb->map_node(_scheduled[_bb_end-k-1], k);
2436 
2437 #ifndef PRODUCT
2438     if (_cfg->C->trace_opto_output()) {
2439       tty->print("#  Schedule BB#%03d (final)\n", i);
2440       uint current = 0;
2441       for (uint j = 0; j < bb->number_of_nodes(); j++) {
2442         Node *n = bb->get_node(j);
2443         if( valid_bundle_info(n) ) {
2444           Bundle *bundle = node_bundling(n);
2445           if (bundle->instr_count() > 0 || bundle->flags() > 0) {
2446             tty->print("*** Bundle: ");
2447             bundle->dump();
2448           }
2449           n->dump();
2450         }
2451       }
2452     }
2453 #endif
2454 #ifdef ASSERT
2455   verify_good_schedule(bb,"after block local scheduling");
2456 #endif
2457   }
2458 
2459 #ifndef PRODUCT
2460   if (_cfg->C->trace_opto_output())
2461     tty->print("# <- DoScheduling\n");
2462 #endif
2463 
2464   // Record final node-bundling array location
2465   _regalloc->C->set_node_bundling_base(_node_bundling_base);
2466 
2467 } // end DoScheduling
2468 
2469 // Verify that no live-range used in the block is killed in the block by a
2470 // wrong DEF.  This doesn't verify live-ranges that span blocks.
2471 
2472 // Check for edge existence.  Used to avoid adding redundant precedence edges.
2473 static bool edge_from_to( Node *from, Node *to ) {
2474   for( uint i=0; i<from->len(); i++ )
2475     if( from->in(i) == to )
2476       return true;
2477   return false;
2478 }
2479 
2480 #ifdef ASSERT
2481 void Scheduling::verify_do_def( Node *n, OptoReg::Name def, const char *msg ) {
2482   // Check for bad kills
2483   if( OptoReg::is_valid(def) ) { // Ignore stores & control flow
2484     Node *prior_use = _reg_node[def];
2485     if( prior_use && !edge_from_to(prior_use,n) ) {
2486       tty->print("%s = ",OptoReg::as_VMReg(def)->name());
2487       n->dump();
2488       tty->print_cr("...");
2489       prior_use->dump();
2490       assert(edge_from_to(prior_use,n),msg);
2491     }
2492     _reg_node.map(def,NULL); // Kill live USEs
2493   }
2494 }
2495 
2496 void Scheduling::verify_good_schedule( Block *b, const char *msg ) {
2497 
2498   // Zap to something reasonable for the verify code
2499   _reg_node.clear();
2500 
2501   // Walk over the block backwards.  Check to make sure each DEF doesn't
2502   // kill a live value (other than the one it's supposed to).  Add each
2503   // USE to the live set.
2504   for( uint i = b->number_of_nodes()-1; i >= _bb_start; i-- ) {
2505     Node *n = b->get_node(i);
2506     int n_op = n->Opcode();
2507     if( n_op == Op_MachProj && n->ideal_reg() == MachProjNode::fat_proj ) {
2508       // Fat-proj kills a slew of registers
2509       RegMask rm = n->out_RegMask();// Make local copy
2510       while( rm.is_NotEmpty() ) {
2511         OptoReg::Name kill = rm.find_first_elem();
2512         rm.Remove(kill);
2513         verify_do_def( n, kill, msg );
2514       }
2515     } else if( n_op != Op_Node ) { // Avoid brand new antidependence nodes
2516       // Get DEF'd registers the normal way
2517       verify_do_def( n, _regalloc->get_reg_first(n), msg );
2518       verify_do_def( n, _regalloc->get_reg_second(n), msg );
2519     }
2520 
2521     // Now make all USEs live
2522     for( uint i=1; i<n->req(); i++ ) {
2523       Node *def = n->in(i);
2524       assert(def != 0, "input edge required");
2525       OptoReg::Name reg_lo = _regalloc->get_reg_first(def);
2526       OptoReg::Name reg_hi = _regalloc->get_reg_second(def);
2527       if( OptoReg::is_valid(reg_lo) ) {
2528         assert(!_reg_node[reg_lo] || edge_from_to(_reg_node[reg_lo],def), msg);
2529         _reg_node.map(reg_lo,n);
2530       }
2531       if( OptoReg::is_valid(reg_hi) ) {
2532         assert(!_reg_node[reg_hi] || edge_from_to(_reg_node[reg_hi],def), msg);
2533         _reg_node.map(reg_hi,n);
2534       }
2535     }
2536 
2537   }
2538 
2539   // Zap to something reasonable for the Antidependence code
2540   _reg_node.clear();
2541 }
2542 #endif
2543 
2544 // Conditionally add precedence edges.  Avoid putting edges on Projs.
2545 static void add_prec_edge_from_to( Node *from, Node *to ) {
2546   if( from->is_Proj() ) {       // Put precedence edge on Proj's input
2547     assert( from->req() == 1 && (from->len() == 1 || from->in(1)==0), "no precedence edges on projections" );
2548     from = from->in(0);
2549   }
2550   if( from != to &&             // No cycles (for things like LD L0,[L0+4] )
2551       !edge_from_to( from, to ) ) // Avoid duplicate edge
2552     from->add_prec(to);
2553 }
2554 
2555 void Scheduling::anti_do_def( Block *b, Node *def, OptoReg::Name def_reg, int is_def ) {
2556   if( !OptoReg::is_valid(def_reg) ) // Ignore stores & control flow
2557     return;
2558 
2559   Node *pinch = _reg_node[def_reg]; // Get pinch point
2560   if ((pinch == NULL) || _cfg->get_block_for_node(pinch) != b || // No pinch-point yet?
2561       is_def ) {    // Check for a true def (not a kill)
2562     _reg_node.map(def_reg,def); // Record def/kill as the optimistic pinch-point
2563     return;
2564   }
2565 
2566   Node *kill = def;             // Rename 'def' to more descriptive 'kill'
2567   debug_only( def = (Node*)0xdeadbeef; )
2568 
2569   // After some number of kills there _may_ be a later def
2570   Node *later_def = NULL;
2571 
2572   // Finding a kill requires a real pinch-point.
2573   // Check for not already having a pinch-point.
2574   // Pinch points are Op_Node's.
2575   if( pinch->Opcode() != Op_Node ) { // Or later-def/kill as pinch-point?
2576     later_def = pinch;            // Must be def/kill as optimistic pinch-point
2577     if ( _pinch_free_list.size() > 0) {
2578       pinch = _pinch_free_list.pop();
2579     } else {
2580       pinch = new Node(1); // Pinch point to-be
2581     }
2582     if (pinch->_idx >= _regalloc->node_regs_max_index()) {
2583       _cfg->C->record_method_not_compilable("too many D-U pinch points");
2584       return;
2585     }
2586     _cfg->map_node_to_block(pinch, b);      // Pretend it's valid in this block (lazy init)
2587     _reg_node.map(def_reg,pinch); // Record pinch-point
2588     //_regalloc->set_bad(pinch->_idx); // Already initialized this way.
2589     if( later_def->outcnt() == 0 || later_def->ideal_reg() == MachProjNode::fat_proj ) { // Distinguish def from kill
2590       pinch->init_req(0, _cfg->C->top());     // set not NULL for the next call
2591       add_prec_edge_from_to(later_def,pinch); // Add edge from kill to pinch
2592       later_def = NULL;           // and no later def
2593     }
2594     pinch->set_req(0,later_def);  // Hook later def so we can find it
2595   } else {                        // Else have valid pinch point
2596     if( pinch->in(0) )            // If there is a later-def
2597       later_def = pinch->in(0);   // Get it
2598   }
2599 
2600   // Add output-dependence edge from later def to kill
2601   if( later_def )               // If there is some original def
2602     add_prec_edge_from_to(later_def,kill); // Add edge from def to kill
2603 
2604   // See if current kill is also a use, and so is forced to be the pinch-point.
2605   if( pinch->Opcode() == Op_Node ) {
2606     Node *uses = kill->is_Proj() ? kill->in(0) : kill;
2607     for( uint i=1; i<uses->req(); i++ ) {
2608       if( _regalloc->get_reg_first(uses->in(i)) == def_reg ||
2609           _regalloc->get_reg_second(uses->in(i)) == def_reg ) {
2610         // Yes, found a use/kill pinch-point
2611         pinch->set_req(0,NULL);  //
2612         pinch->replace_by(kill); // Move anti-dep edges up
2613         pinch = kill;
2614         _reg_node.map(def_reg,pinch);
2615         return;
2616       }
2617     }
2618   }
2619 
2620   // Add edge from kill to pinch-point
2621   add_prec_edge_from_to(kill,pinch);
2622 }
2623 
2624 void Scheduling::anti_do_use( Block *b, Node *use, OptoReg::Name use_reg ) {
2625   if( !OptoReg::is_valid(use_reg) ) // Ignore stores & control flow
2626     return;
2627   Node *pinch = _reg_node[use_reg]; // Get pinch point
2628   // Check for no later def_reg/kill in block
2629   if ((pinch != NULL) && _cfg->get_block_for_node(pinch) == b &&
2630       // Use has to be block-local as well
2631       _cfg->get_block_for_node(use) == b) {
2632     if( pinch->Opcode() == Op_Node && // Real pinch-point (not optimistic?)
2633         pinch->req() == 1 ) {   // pinch not yet in block?
2634       pinch->del_req(0);        // yank pointer to later-def, also set flag
2635       // Insert the pinch-point in the block just after the last use
2636       b->insert_node(pinch, b->find_node(use) + 1);
2637       _bb_end++;                // Increase size scheduled region in block
2638     }
2639 
2640     add_prec_edge_from_to(pinch,use);
2641   }
2642 }
2643 
2644 // We insert antidependences between the reads and following write of
2645 // allocated registers to prevent illegal code motion. Hopefully, the
2646 // number of added references should be fairly small, especially as we
2647 // are only adding references within the current basic block.
2648 void Scheduling::ComputeRegisterAntidependencies(Block *b) {
2649 
2650 #ifdef ASSERT
2651   verify_good_schedule(b,"before block local scheduling");
2652 #endif
2653 
2654   // A valid schedule, for each register independently, is an endless cycle
2655   // of: a def, then some uses (connected to the def by true dependencies),
2656   // then some kills (defs with no uses), finally the cycle repeats with a new
2657   // def.  The uses are allowed to float relative to each other, as are the
2658   // kills.  No use is allowed to slide past a kill (or def).  This requires
2659   // antidependencies between all uses of a single def and all kills that
2660   // follow, up to the next def.  More edges are redundant, because later defs
2661   // & kills are already serialized with true or antidependencies.  To keep
2662   // the edge count down, we add a 'pinch point' node if there's more than
2663   // one use or more than one kill/def.
2664 
2665   // We add dependencies in one bottom-up pass.
2666 
2667   // For each instruction we handle it's DEFs/KILLs, then it's USEs.
2668 
2669   // For each DEF/KILL, we check to see if there's a prior DEF/KILL for this
2670   // register.  If not, we record the DEF/KILL in _reg_node, the
2671   // register-to-def mapping.  If there is a prior DEF/KILL, we insert a
2672   // "pinch point", a new Node that's in the graph but not in the block.
2673   // We put edges from the prior and current DEF/KILLs to the pinch point.
2674   // We put the pinch point in _reg_node.  If there's already a pinch point
2675   // we merely add an edge from the current DEF/KILL to the pinch point.
2676 
2677   // After doing the DEF/KILLs, we handle USEs.  For each used register, we
2678   // put an edge from the pinch point to the USE.
2679 
2680   // To be expedient, the _reg_node array is pre-allocated for the whole
2681   // compilation.  _reg_node is lazily initialized; it either contains a NULL,
2682   // or a valid def/kill/pinch-point, or a leftover node from some prior
2683   // block.  Leftover node from some prior block is treated like a NULL (no
2684   // prior def, so no anti-dependence needed).  Valid def is distinguished by
2685   // it being in the current block.
2686   bool fat_proj_seen = false;
2687   uint last_safept = _bb_end-1;
2688   Node* end_node         = (_bb_end-1 >= _bb_start) ? b->get_node(last_safept) : NULL;
2689   Node* last_safept_node = end_node;
2690   for( uint i = _bb_end-1; i >= _bb_start; i-- ) {
2691     Node *n = b->get_node(i);
2692     int is_def = n->outcnt();   // def if some uses prior to adding precedence edges
2693     if( n->is_MachProj() && n->ideal_reg() == MachProjNode::fat_proj ) {
2694       // Fat-proj kills a slew of registers
2695       // This can add edges to 'n' and obscure whether or not it was a def,
2696       // hence the is_def flag.
2697       fat_proj_seen = true;
2698       RegMask rm = n->out_RegMask();// Make local copy
2699       while( rm.is_NotEmpty() ) {
2700         OptoReg::Name kill = rm.find_first_elem();
2701         rm.Remove(kill);
2702         anti_do_def( b, n, kill, is_def );
2703       }
2704     } else {
2705       // Get DEF'd registers the normal way
2706       anti_do_def( b, n, _regalloc->get_reg_first(n), is_def );
2707       anti_do_def( b, n, _regalloc->get_reg_second(n), is_def );
2708     }
2709 
2710     // Kill projections on a branch should appear to occur on the
2711     // branch, not afterwards, so grab the masks from the projections
2712     // and process them.
2713     if (n->is_MachBranch() || n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_Jump) {
2714       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2715         Node* use = n->fast_out(i);
2716         if (use->is_Proj()) {
2717           RegMask rm = use->out_RegMask();// Make local copy
2718           while( rm.is_NotEmpty() ) {
2719             OptoReg::Name kill = rm.find_first_elem();
2720             rm.Remove(kill);
2721             anti_do_def( b, n, kill, false );
2722           }
2723         }
2724       }
2725     }
2726 
2727     // Check each register used by this instruction for a following DEF/KILL
2728     // that must occur afterward and requires an anti-dependence edge.
2729     for( uint j=0; j<n->req(); j++ ) {
2730       Node *def = n->in(j);
2731       if( def ) {
2732         assert( !def->is_MachProj() || def->ideal_reg() != MachProjNode::fat_proj, "" );
2733         anti_do_use( b, n, _regalloc->get_reg_first(def) );
2734         anti_do_use( b, n, _regalloc->get_reg_second(def) );
2735       }
2736     }
2737     // Do not allow defs of new derived values to float above GC
2738     // points unless the base is definitely available at the GC point.
2739 
2740     Node *m = b->get_node(i);
2741 
2742     // Add precedence edge from following safepoint to use of derived pointer
2743     if( last_safept_node != end_node &&
2744         m != last_safept_node) {
2745       for (uint k = 1; k < m->req(); k++) {
2746         const Type *t = m->in(k)->bottom_type();
2747         if( t->isa_oop_ptr() &&
2748             t->is_ptr()->offset() != 0 ) {
2749           last_safept_node->add_prec( m );
2750           break;
2751         }
2752       }
2753     }
2754 
2755     if( n->jvms() ) {           // Precedence edge from derived to safept
2756       // Check if last_safept_node was moved by pinch-point insertion in anti_do_use()
2757       if( b->get_node(last_safept) != last_safept_node ) {
2758         last_safept = b->find_node(last_safept_node);
2759       }
2760       for( uint j=last_safept; j > i; j-- ) {
2761         Node *mach = b->get_node(j);
2762         if( mach->is_Mach() && mach->as_Mach()->ideal_Opcode() == Op_AddP )
2763           mach->add_prec( n );
2764       }
2765       last_safept = i;
2766       last_safept_node = m;
2767     }
2768   }
2769 
2770   if (fat_proj_seen) {
2771     // Garbage collect pinch nodes that were not consumed.
2772     // They are usually created by a fat kill MachProj for a call.
2773     garbage_collect_pinch_nodes();
2774   }
2775 }
2776 
2777 // Garbage collect pinch nodes for reuse by other blocks.
2778 //
2779 // The block scheduler's insertion of anti-dependence
2780 // edges creates many pinch nodes when the block contains
2781 // 2 or more Calls.  A pinch node is used to prevent a
2782 // combinatorial explosion of edges.  If a set of kills for a
2783 // register is anti-dependent on a set of uses (or defs), rather
2784 // than adding an edge in the graph between each pair of kill
2785 // and use (or def), a pinch is inserted between them:
2786 //
2787 //            use1   use2  use3
2788 //                \   |   /
2789 //                 \  |  /
2790 //                  pinch
2791 //                 /  |  \
2792 //                /   |   \
2793 //            kill1 kill2 kill3
2794 //
2795 // One pinch node is created per register killed when
2796 // the second call is encountered during a backwards pass
2797 // over the block.  Most of these pinch nodes are never
2798 // wired into the graph because the register is never
2799 // used or def'ed in the block.
2800 //
2801 void Scheduling::garbage_collect_pinch_nodes() {
2802 #ifndef PRODUCT
2803     if (_cfg->C->trace_opto_output()) tty->print("Reclaimed pinch nodes:");
2804 #endif
2805     int trace_cnt = 0;
2806     for (uint k = 0; k < _reg_node.Size(); k++) {
2807       Node* pinch = _reg_node[k];
2808       if ((pinch != NULL) && pinch->Opcode() == Op_Node &&
2809           // no predecence input edges
2810           (pinch->req() == pinch->len() || pinch->in(pinch->req()) == NULL) ) {
2811         cleanup_pinch(pinch);
2812         _pinch_free_list.push(pinch);
2813         _reg_node.map(k, NULL);
2814 #ifndef PRODUCT
2815         if (_cfg->C->trace_opto_output()) {
2816           trace_cnt++;
2817           if (trace_cnt > 40) {
2818             tty->print("\n");
2819             trace_cnt = 0;
2820           }
2821           tty->print(" %d", pinch->_idx);
2822         }
2823 #endif
2824       }
2825     }
2826 #ifndef PRODUCT
2827     if (_cfg->C->trace_opto_output()) tty->print("\n");
2828 #endif
2829 }
2830 
2831 // Clean up a pinch node for reuse.
2832 void Scheduling::cleanup_pinch( Node *pinch ) {
2833   assert (pinch && pinch->Opcode() == Op_Node && pinch->req() == 1, "just checking");
2834 
2835   for (DUIterator_Last imin, i = pinch->last_outs(imin); i >= imin; ) {
2836     Node* use = pinch->last_out(i);
2837     uint uses_found = 0;
2838     for (uint j = use->req(); j < use->len(); j++) {
2839       if (use->in(j) == pinch) {
2840         use->rm_prec(j);
2841         uses_found++;
2842       }
2843     }
2844     assert(uses_found > 0, "must be a precedence edge");
2845     i -= uses_found;    // we deleted 1 or more copies of this edge
2846   }
2847   // May have a later_def entry
2848   pinch->set_req(0, NULL);
2849 }
2850 
2851 #ifndef PRODUCT
2852 
2853 void Scheduling::dump_available() const {
2854   tty->print("#Availist  ");
2855   for (uint i = 0; i < _available.size(); i++)
2856     tty->print(" N%d/l%d", _available[i]->_idx,_current_latency[_available[i]->_idx]);
2857   tty->cr();
2858 }
2859 
2860 // Print Scheduling Statistics
2861 void Scheduling::print_statistics() {
2862   // Print the size added by nops for bundling
2863   tty->print("Nops added %d bytes to total of %d bytes",
2864     _total_nop_size, _total_method_size);
2865   if (_total_method_size > 0)
2866     tty->print(", for %.2f%%",
2867       ((double)_total_nop_size) / ((double) _total_method_size) * 100.0);
2868   tty->print("\n");
2869 
2870   // Print the number of branch shadows filled
2871   if (Pipeline::_branch_has_delay_slot) {
2872     tty->print("Of %d branches, %d had unconditional delay slots filled",
2873       _total_branches, _total_unconditional_delays);
2874     if (_total_branches > 0)
2875       tty->print(", for %.2f%%",
2876         ((double)_total_unconditional_delays) / ((double)_total_branches) * 100.0);
2877     tty->print("\n");
2878   }
2879 
2880   uint total_instructions = 0, total_bundles = 0;
2881 
2882   for (uint i = 1; i <= Pipeline::_max_instrs_per_cycle; i++) {
2883     uint bundle_count   = _total_instructions_per_bundle[i];
2884     total_instructions += bundle_count * i;
2885     total_bundles      += bundle_count;
2886   }
2887 
2888   if (total_bundles > 0)
2889     tty->print("Average ILP (excluding nops) is %.2f\n",
2890       ((double)total_instructions) / ((double)total_bundles));
2891 }
2892 #endif
--- EOF ---