1 /*
   2  * Copyright 1998-2008 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  20  * CA 95054 USA or visit www.sun.com if you need additional information or
  21  * have any questions.
  22  *
  23  */
  24 
  25 #include "incls/_precompiled.incl"
  26 #include "incls/_output.cpp.incl"
  27 
  28 extern uint size_java_to_interp();
  29 extern uint reloc_java_to_interp();
  30 extern uint size_exception_handler();
  31 extern uint size_deopt_handler();
  32 
  33 #ifndef PRODUCT
  34 #define DEBUG_ARG(x) , x
  35 #else
  36 #define DEBUG_ARG(x)
  37 #endif
  38 
  39 extern int emit_exception_handler(CodeBuffer &cbuf);
  40 extern int emit_deopt_handler(CodeBuffer &cbuf);
  41 
  42 //------------------------------Output-----------------------------------------
  43 // Convert Nodes to instruction bits and pass off to the VM
  44 void Compile::Output() {
  45   // RootNode goes
  46   assert( _cfg->_broot->_nodes.size() == 0, "" );
  47 
  48   // Initialize the space for the BufferBlob used to find and verify
  49   // instruction size in MachNode::emit_size()
  50   init_scratch_buffer_blob();
  51   if (failing())  return; // Out of memory
  52 
  53   // Make sure I can find the Start Node
  54   Block_Array& bbs = _cfg->_bbs;
  55   Block *entry = _cfg->_blocks[1];
  56   Block *broot = _cfg->_broot;
  57 
  58   const StartNode *start = entry->_nodes[0]->as_Start();
  59 
  60   // Replace StartNode with prolog
  61   MachPrologNode *prolog = new (this) MachPrologNode();
  62   entry->_nodes.map( 0, prolog );
  63   bbs.map( prolog->_idx, entry );
  64   bbs.map( start->_idx, NULL ); // start is no longer in any block
  65 
  66   // Virtual methods need an unverified entry point
  67 
  68   if( is_osr_compilation() ) {
  69     if( PoisonOSREntry ) {
  70       // TODO: Should use a ShouldNotReachHereNode...
  71       _cfg->insert( broot, 0, new (this) MachBreakpointNode() );
  72     }
  73   } else {
  74     if( _method && !_method->flags().is_static() ) {
  75       // Insert unvalidated entry point
  76       _cfg->insert( broot, 0, new (this) MachUEPNode() );
  77     }
  78 
  79   }
  80 
  81 
  82   // Break before main entry point
  83   if( (_method && _method->break_at_execute())
  84 #ifndef PRODUCT
  85     ||(OptoBreakpoint && is_method_compilation())
  86     ||(OptoBreakpointOSR && is_osr_compilation())
  87     ||(OptoBreakpointC2R && !_method)
  88 #endif
  89     ) {
  90     // checking for _method means that OptoBreakpoint does not apply to
  91     // runtime stubs or frame converters
  92     _cfg->insert( entry, 1, new (this) MachBreakpointNode() );
  93   }
  94 
  95   // Insert epilogs before every return
  96   for( uint i=0; i<_cfg->_num_blocks; i++ ) {
  97     Block *b = _cfg->_blocks[i];
  98     if( !b->is_connector() && b->non_connector_successor(0) == _cfg->_broot ) { // Found a program exit point?
  99       Node *m = b->end();
 100       if( m->is_Mach() && m->as_Mach()->ideal_Opcode() != Op_Halt ) {
 101         MachEpilogNode *epilog = new (this) MachEpilogNode(m->as_Mach()->ideal_Opcode() == Op_Return);
 102         b->add_inst( epilog );
 103         bbs.map(epilog->_idx, b);
 104         //_regalloc->set_bad(epilog->_idx); // Already initialized this way.
 105       }
 106     }
 107   }
 108 
 109 # ifdef ENABLE_ZAP_DEAD_LOCALS
 110   if ( ZapDeadCompiledLocals )  Insert_zap_nodes();
 111 # endif
 112 
 113   ScheduleAndBundle();
 114 
 115 #ifndef PRODUCT
 116   if (trace_opto_output()) {
 117     tty->print("\n---- After ScheduleAndBundle ----\n");
 118     for (uint i = 0; i < _cfg->_num_blocks; i++) {
 119       tty->print("\nBB#%03d:\n", i);
 120       Block *bb = _cfg->_blocks[i];
 121       for (uint j = 0; j < bb->_nodes.size(); j++) {
 122         Node *n = bb->_nodes[j];
 123         OptoReg::Name reg = _regalloc->get_reg_first(n);
 124         tty->print(" %-6s ", reg >= 0 && reg < REG_COUNT ? Matcher::regName[reg] : "");
 125         n->dump();
 126       }
 127     }
 128   }
 129 #endif
 130 
 131   if (failing())  return;
 132 
 133   BuildOopMaps();
 134 
 135   if (failing())  return;
 136 
 137   Fill_buffer();
 138 }
 139 
 140 bool Compile::need_stack_bang(int frame_size_in_bytes) const {
 141   // Determine if we need to generate a stack overflow check.
 142   // Do it if the method is not a stub function and
 143   // has java calls or has frame size > vm_page_size/8.
 144   return (stub_function() == NULL &&
 145           (has_java_calls() || frame_size_in_bytes > os::vm_page_size()>>3));
 146 }
 147 
 148 bool Compile::need_register_stack_bang() const {
 149   // Determine if we need to generate a register stack overflow check.
 150   // This is only used on architectures which have split register
 151   // and memory stacks (ie. IA64).
 152   // Bang if the method is not a stub function and has java calls
 153   return (stub_function() == NULL && has_java_calls());
 154 }
 155 
 156 # ifdef ENABLE_ZAP_DEAD_LOCALS
 157 
 158 
 159 // In order to catch compiler oop-map bugs, we have implemented
 160 // a debugging mode called ZapDeadCompilerLocals.
 161 // This mode causes the compiler to insert a call to a runtime routine,
 162 // "zap_dead_locals", right before each place in compiled code
 163 // that could potentially be a gc-point (i.e., a safepoint or oop map point).
 164 // The runtime routine checks that locations mapped as oops are really
 165 // oops, that locations mapped as values do not look like oops,
 166 // and that locations mapped as dead are not used later
 167 // (by zapping them to an invalid address).
 168 
 169 int Compile::_CompiledZap_count = 0;
 170 
 171 void Compile::Insert_zap_nodes() {
 172   bool skip = false;
 173 
 174 
 175   // Dink with static counts because code code without the extra
 176   // runtime calls is MUCH faster for debugging purposes
 177 
 178        if ( CompileZapFirst  ==  0  ) ; // nothing special
 179   else if ( CompileZapFirst  >  CompiledZap_count() )  skip = true;
 180   else if ( CompileZapFirst  == CompiledZap_count() )
 181     warning("starting zap compilation after skipping");
 182 
 183        if ( CompileZapLast  ==  -1  ) ; // nothing special
 184   else if ( CompileZapLast  <   CompiledZap_count() )  skip = true;
 185   else if ( CompileZapLast  ==  CompiledZap_count() )
 186     warning("about to compile last zap");
 187 
 188   ++_CompiledZap_count; // counts skipped zaps, too
 189 
 190   if ( skip )  return;
 191 
 192 
 193   if ( _method == NULL )
 194     return; // no safepoints/oopmaps emitted for calls in stubs,so we don't care
 195 
 196   // Insert call to zap runtime stub before every node with an oop map
 197   for( uint i=0; i<_cfg->_num_blocks; i++ ) {
 198     Block *b = _cfg->_blocks[i];
 199     for ( uint j = 0;  j < b->_nodes.size();  ++j ) {
 200       Node *n = b->_nodes[j];
 201 
 202       // Determining if we should insert a zap-a-lot node in output.
 203       // We do that for all nodes that has oopmap info, except for calls
 204       // to allocation.  Calls to allocation passes in the old top-of-eden pointer
 205       // and expect the C code to reset it.  Hence, there can be no safepoints between
 206       // the inlined-allocation and the call to new_Java, etc.
 207       // We also cannot zap monitor calls, as they must hold the microlock
 208       // during the call to Zap, which also wants to grab the microlock.
 209       bool insert = n->is_MachSafePoint() && (n->as_MachSafePoint()->oop_map() != NULL);
 210       if ( insert ) { // it is MachSafePoint
 211         if ( !n->is_MachCall() ) {
 212           insert = false;
 213         } else if ( n->is_MachCall() ) {
 214           MachCallNode* call = n->as_MachCall();
 215           if (call->entry_point() == OptoRuntime::new_instance_Java() ||
 216               call->entry_point() == OptoRuntime::new_array_Java() ||
 217               call->entry_point() == OptoRuntime::multianewarray2_Java() ||
 218               call->entry_point() == OptoRuntime::multianewarray3_Java() ||
 219               call->entry_point() == OptoRuntime::multianewarray4_Java() ||
 220               call->entry_point() == OptoRuntime::multianewarray5_Java() ||
 221               call->entry_point() == OptoRuntime::slow_arraycopy_Java() ||
 222               call->entry_point() == OptoRuntime::complete_monitor_locking_Java()
 223               ) {
 224             insert = false;
 225           }
 226         }
 227         if (insert) {
 228           Node *zap = call_zap_node(n->as_MachSafePoint(), i);
 229           b->_nodes.insert( j, zap );
 230           _cfg->_bbs.map( zap->_idx, b );
 231           ++j;
 232         }
 233       }
 234     }
 235   }
 236 }
 237 
 238 
 239 Node* Compile::call_zap_node(MachSafePointNode* node_to_check, int block_no) {
 240   const TypeFunc *tf = OptoRuntime::zap_dead_locals_Type();
 241   CallStaticJavaNode* ideal_node =
 242     new (this, tf->domain()->cnt()) CallStaticJavaNode( tf,
 243          OptoRuntime::zap_dead_locals_stub(_method->flags().is_native()),
 244                             "call zap dead locals stub", 0, TypePtr::BOTTOM);
 245   // We need to copy the OopMap from the site we're zapping at.
 246   // We have to make a copy, because the zap site might not be
 247   // a call site, and zap_dead is a call site.
 248   OopMap* clone = node_to_check->oop_map()->deep_copy();
 249 
 250   // Add the cloned OopMap to the zap node
 251   ideal_node->set_oop_map(clone);
 252   return _matcher->match_sfpt(ideal_node);
 253 }
 254 
 255 //------------------------------is_node_getting_a_safepoint--------------------
 256 bool Compile::is_node_getting_a_safepoint( Node* n) {
 257   // This code duplicates the logic prior to the call of add_safepoint
 258   // below in this file.
 259   if( n->is_MachSafePoint() ) return true;
 260   return false;
 261 }
 262 
 263 # endif // ENABLE_ZAP_DEAD_LOCALS
 264 
 265 //------------------------------compute_loop_first_inst_sizes------------------
 266 // Compute the size of first NumberOfLoopInstrToAlign instructions at the top
 267 // of a loop. When aligning a loop we need to provide enough instructions
 268 // in cpu's fetch buffer to feed decoders. The loop alignment could be
 269 // avoided if we have enough instructions in fetch buffer at the head of a loop.
 270 // By default, the size is set to 999999 by Block's constructor so that
 271 // a loop will be aligned if the size is not reset here.
 272 //
 273 // Note: Mach instructions could contain several HW instructions
 274 // so the size is estimated only.
 275 //
 276 void Compile::compute_loop_first_inst_sizes() {
 277   // The next condition is used to gate the loop alignment optimization.
 278   // Don't aligned a loop if there are enough instructions at the head of a loop
 279   // or alignment padding is larger then MaxLoopPad. By default, MaxLoopPad
 280   // is equal to OptoLoopAlignment-1 except on new Intel cpus, where it is
 281   // equal to 11 bytes which is the largest address NOP instruction.
 282   if( MaxLoopPad < OptoLoopAlignment-1 ) {
 283     uint last_block = _cfg->_num_blocks-1;
 284     for( uint i=1; i <= last_block; i++ ) {
 285       Block *b = _cfg->_blocks[i];
 286       // Check the first loop's block which requires an alignment.
 287       if( b->loop_alignment() > (uint)relocInfo::addr_unit() ) {
 288         uint sum_size = 0;
 289         uint inst_cnt = NumberOfLoopInstrToAlign;
 290         inst_cnt = b->compute_first_inst_size(sum_size, inst_cnt, _regalloc);
 291 
 292         // Check subsequent fallthrough blocks if the loop's first
 293         // block(s) does not have enough instructions.
 294         Block *nb = b;
 295         while( inst_cnt > 0 &&
 296                i < last_block &&
 297                !_cfg->_blocks[i+1]->has_loop_alignment() &&
 298                !nb->has_successor(b) ) {
 299           i++;
 300           nb = _cfg->_blocks[i];
 301           inst_cnt  = nb->compute_first_inst_size(sum_size, inst_cnt, _regalloc);
 302         } // while( inst_cnt > 0 && i < last_block  )
 303 
 304         b->set_first_inst_size(sum_size);
 305       } // f( b->head()->is_Loop() )
 306     } // for( i <= last_block )
 307   } // if( MaxLoopPad < OptoLoopAlignment-1 )
 308 }
 309 
 310 //----------------------Shorten_branches---------------------------------------
 311 // The architecture description provides short branch variants for some long
 312 // branch instructions. Replace eligible long branches with short branches.
 313 void Compile::Shorten_branches(Label *labels, int& code_size, int& reloc_size, int& stub_size, int& const_size) {
 314 
 315   // fill in the nop array for bundling computations
 316   MachNode *_nop_list[Bundle::_nop_count];
 317   Bundle::initialize_nops(_nop_list, this);
 318 
 319   // ------------------
 320   // Compute size of each block, method size, and relocation information size
 321   uint *jmp_end    = NEW_RESOURCE_ARRAY(uint,_cfg->_num_blocks);
 322   uint *blk_starts = NEW_RESOURCE_ARRAY(uint,_cfg->_num_blocks+1);
 323   DEBUG_ONLY( uint *jmp_target = NEW_RESOURCE_ARRAY(uint,_cfg->_num_blocks); )
 324   DEBUG_ONLY( uint *jmp_rule = NEW_RESOURCE_ARRAY(uint,_cfg->_num_blocks); )
 325   blk_starts[0]    = 0;
 326 
 327   // Initialize the sizes to 0
 328   code_size  = 0;          // Size in bytes of generated code
 329   stub_size  = 0;          // Size in bytes of all stub entries
 330   // Size in bytes of all relocation entries, including those in local stubs.
 331   // Start with 2-bytes of reloc info for the unvalidated entry point
 332   reloc_size = 1;          // Number of relocation entries
 333   const_size = 0;          // size of fp constants in words
 334 
 335   // Make three passes.  The first computes pessimistic blk_starts,
 336   // relative jmp_end, reloc_size and const_size information.
 337   // The second performs short branch substitution using the pessimistic
 338   // sizing. The third inserts nops where needed.
 339 
 340   Node *nj; // tmp
 341 
 342   // Step one, perform a pessimistic sizing pass.
 343   uint i;
 344   uint min_offset_from_last_call = 1;  // init to a positive value
 345   uint nop_size = (new (this) MachNopNode())->size(_regalloc);
 346   for( i=0; i<_cfg->_num_blocks; i++ ) { // For all blocks
 347     Block *b = _cfg->_blocks[i];
 348 
 349     // Sum all instruction sizes to compute block size
 350     uint last_inst = b->_nodes.size();
 351     uint blk_size = 0;
 352     for( uint j = 0; j<last_inst; j++ ) {
 353       nj = b->_nodes[j];
 354       uint inst_size = nj->size(_regalloc);
 355       blk_size += inst_size;
 356       // Handle machine instruction nodes
 357       if( nj->is_Mach() ) {
 358         MachNode *mach = nj->as_Mach();
 359         blk_size += (mach->alignment_required() - 1) * relocInfo::addr_unit(); // assume worst case padding
 360         reloc_size += mach->reloc();
 361         const_size += mach->const_size();
 362         if( mach->is_MachCall() ) {
 363           MachCallNode *mcall = mach->as_MachCall();
 364           // This destination address is NOT PC-relative
 365 
 366           mcall->method_set((intptr_t)mcall->entry_point());
 367 
 368           if( mcall->is_MachCallJava() && mcall->as_MachCallJava()->_method ) {
 369             stub_size  += size_java_to_interp();
 370             reloc_size += reloc_java_to_interp();
 371           }
 372         } else if (mach->is_MachSafePoint()) {
 373           // If call/safepoint are adjacent, account for possible
 374           // nop to disambiguate the two safepoints.
 375           if (min_offset_from_last_call == 0) {
 376             blk_size += nop_size;
 377           }
 378         }
 379       }
 380       min_offset_from_last_call += inst_size;
 381       // Remember end of call offset
 382       if (nj->is_MachCall() && nj->as_MachCall()->is_safepoint_node()) {
 383         min_offset_from_last_call = 0;
 384       }
 385     }
 386 
 387     // During short branch replacement, we store the relative (to blk_starts)
 388     // end of jump in jmp_end, rather than the absolute end of jump.  This
 389     // is so that we do not need to recompute sizes of all nodes when we compute
 390     // correct blk_starts in our next sizing pass.
 391     jmp_end[i] = blk_size;
 392     DEBUG_ONLY( jmp_target[i] = 0; )
 393 
 394     // When the next block starts a loop, we may insert pad NOP
 395     // instructions.  Since we cannot know our future alignment,
 396     // assume the worst.
 397     if( i<_cfg->_num_blocks-1 ) {
 398       Block *nb = _cfg->_blocks[i+1];
 399       int max_loop_pad = nb->code_alignment()-relocInfo::addr_unit();
 400       if( max_loop_pad > 0 ) {
 401         assert(is_power_of_2(max_loop_pad+relocInfo::addr_unit()), "");
 402         blk_size += max_loop_pad;
 403       }
 404     }
 405 
 406     // Save block size; update total method size
 407     blk_starts[i+1] = blk_starts[i]+blk_size;
 408   }
 409 
 410   // Step two, replace eligible long jumps.
 411 
 412   // Note: this will only get the long branches within short branch
 413   //   range. Another pass might detect more branches that became
 414   //   candidates because the shortening in the first pass exposed
 415   //   more opportunities. Unfortunately, this would require
 416   //   recomputing the starting and ending positions for the blocks
 417   for( i=0; i<_cfg->_num_blocks; i++ ) {
 418     Block *b = _cfg->_blocks[i];
 419 
 420     int j;
 421     // Find the branch; ignore trailing NOPs.
 422     for( j = b->_nodes.size()-1; j>=0; j-- ) {
 423       nj = b->_nodes[j];
 424       if( !nj->is_Mach() || nj->as_Mach()->ideal_Opcode() != Op_Con )
 425         break;
 426     }
 427 
 428     if (j >= 0) {
 429       if( nj->is_Mach() && nj->as_Mach()->may_be_short_branch() ) {
 430         MachNode *mach = nj->as_Mach();
 431         // This requires the TRUE branch target be in succs[0]
 432         uint bnum = b->non_connector_successor(0)->_pre_order;
 433         uintptr_t target = blk_starts[bnum];
 434         if( mach->is_pc_relative() ) {
 435           int offset = target-(blk_starts[i] + jmp_end[i]);
 436           if (_matcher->is_short_branch_offset(mach->rule(), offset)) {
 437             // We've got a winner.  Replace this branch.
 438             MachNode* replacement = mach->short_branch_version(this);
 439             b->_nodes.map(j, replacement);
 440             mach->subsume_by(replacement);
 441 
 442             // Update the jmp_end size to save time in our
 443             // next pass.
 444             jmp_end[i] -= (mach->size(_regalloc) - replacement->size(_regalloc));
 445             DEBUG_ONLY( jmp_target[i] = bnum; );
 446             DEBUG_ONLY( jmp_rule[i] = mach->rule(); );
 447           }
 448         } else {
 449 #ifndef PRODUCT
 450           mach->dump(3);
 451 #endif
 452           Unimplemented();
 453         }
 454       }
 455     }
 456   }
 457 
 458   // Compute the size of first NumberOfLoopInstrToAlign instructions at head
 459   // of a loop. It is used to determine the padding for loop alignment.
 460   compute_loop_first_inst_sizes();
 461 
 462   // Step 3, compute the offsets of all the labels
 463   uint last_call_adr = max_uint;
 464   for( i=0; i<_cfg->_num_blocks; i++ ) { // For all blocks
 465     // copy the offset of the beginning to the corresponding label
 466     assert(labels[i].is_unused(), "cannot patch at this point");
 467     labels[i].bind_loc(blk_starts[i], CodeBuffer::SECT_INSTS);
 468 
 469     // insert padding for any instructions that need it
 470     Block *b = _cfg->_blocks[i];
 471     uint last_inst = b->_nodes.size();
 472     uint adr = blk_starts[i];
 473     for( uint j = 0; j<last_inst; j++ ) {
 474       nj = b->_nodes[j];
 475       if( nj->is_Mach() ) {
 476         int padding = nj->as_Mach()->compute_padding(adr);
 477         // If call/safepoint are adjacent insert a nop (5010568)
 478         if (padding == 0 && nj->is_MachSafePoint() && !nj->is_MachCall() &&
 479             adr == last_call_adr ) {
 480           padding = nop_size;
 481         }
 482         if(padding > 0) {
 483           assert((padding % nop_size) == 0, "padding is not a multiple of NOP size");
 484           int nops_cnt = padding / nop_size;
 485           MachNode *nop = new (this) MachNopNode(nops_cnt);
 486           b->_nodes.insert(j++, nop);
 487           _cfg->_bbs.map( nop->_idx, b );
 488           adr += padding;
 489           last_inst++;
 490         }
 491       }
 492       adr += nj->size(_regalloc);
 493 
 494       // Remember end of call offset
 495       if (nj->is_MachCall() && nj->as_MachCall()->is_safepoint_node()) {
 496         last_call_adr = adr;
 497       }
 498     }
 499 
 500     if ( i != _cfg->_num_blocks-1) {
 501       // Get the size of the block
 502       uint blk_size = adr - blk_starts[i];
 503 
 504       // When the next block is the top of a loop, we may insert pad NOP
 505       // instructions.
 506       Block *nb = _cfg->_blocks[i+1];
 507       int current_offset = blk_starts[i] + blk_size;
 508       current_offset += nb->alignment_padding(current_offset);
 509       // Save block size; update total method size
 510       blk_starts[i+1] = current_offset;
 511     }
 512   }
 513 
 514 #ifdef ASSERT
 515   for( i=0; i<_cfg->_num_blocks; i++ ) { // For all blocks
 516     if( jmp_target[i] != 0 ) {
 517       int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_end[i]);
 518       if (!_matcher->is_short_branch_offset(jmp_rule[i], offset)) {
 519         tty->print_cr("target (%d) - jmp_end(%d) = offset (%d), jmp_block B%d, target_block B%d", blk_starts[jmp_target[i]], blk_starts[i] + jmp_end[i], offset, i, jmp_target[i]);
 520       }
 521       assert(_matcher->is_short_branch_offset(jmp_rule[i], offset), "Displacement too large for short jmp");
 522     }
 523   }
 524 #endif
 525 
 526   // ------------------
 527   // Compute size for code buffer
 528   code_size   = blk_starts[i-1] + jmp_end[i-1];
 529 
 530   // Relocation records
 531   reloc_size += 1;              // Relo entry for exception handler
 532 
 533   // Adjust reloc_size to number of record of relocation info
 534   // Min is 2 bytes, max is probably 6 or 8, with a tax up to 25% for
 535   // a relocation index.
 536   // The CodeBuffer will expand the locs array if this estimate is too low.
 537   reloc_size   *= 10 / sizeof(relocInfo);
 538 
 539   // Adjust const_size to number of bytes
 540   const_size   *= 2*jintSize; // both float and double take two words per entry
 541 
 542 }
 543 
 544 //------------------------------FillLocArray-----------------------------------
 545 // Create a bit of debug info and append it to the array.  The mapping is from
 546 // Java local or expression stack to constant, register or stack-slot.  For
 547 // doubles, insert 2 mappings and return 1 (to tell the caller that the next
 548 // entry has been taken care of and caller should skip it).
 549 static LocationValue *new_loc_value( PhaseRegAlloc *ra, OptoReg::Name regnum, Location::Type l_type ) {
 550   // This should never have accepted Bad before
 551   assert(OptoReg::is_valid(regnum), "location must be valid");
 552   return (OptoReg::is_reg(regnum))
 553     ? new LocationValue(Location::new_reg_loc(l_type, OptoReg::as_VMReg(regnum)) )
 554     : new LocationValue(Location::new_stk_loc(l_type,  ra->reg2offset(regnum)));
 555 }
 556 
 557 
 558 ObjectValue*
 559 Compile::sv_for_node_id(GrowableArray<ScopeValue*> *objs, int id) {
 560   for (int i = 0; i < objs->length(); i++) {
 561     assert(objs->at(i)->is_object(), "corrupt object cache");
 562     ObjectValue* sv = (ObjectValue*) objs->at(i);
 563     if (sv->id() == id) {
 564       return sv;
 565     }
 566   }
 567   // Otherwise..
 568   return NULL;
 569 }
 570 
 571 void Compile::set_sv_for_object_node(GrowableArray<ScopeValue*> *objs,
 572                                      ObjectValue* sv ) {
 573   assert(sv_for_node_id(objs, sv->id()) == NULL, "Precondition");
 574   objs->append(sv);
 575 }
 576 
 577 
 578 void Compile::FillLocArray( int idx, MachSafePointNode* sfpt, Node *local,
 579                             GrowableArray<ScopeValue*> *array,
 580                             GrowableArray<ScopeValue*> *objs ) {
 581   assert( local, "use _top instead of null" );
 582   if (array->length() != idx) {
 583     assert(array->length() == idx + 1, "Unexpected array count");
 584     // Old functionality:
 585     //   return
 586     // New functionality:
 587     //   Assert if the local is not top. In product mode let the new node
 588     //   override the old entry.
 589     assert(local == top(), "LocArray collision");
 590     if (local == top()) {
 591       return;
 592     }
 593     array->pop();
 594   }
 595   const Type *t = local->bottom_type();
 596 
 597   // Is it a safepoint scalar object node?
 598   if (local->is_SafePointScalarObject()) {
 599     SafePointScalarObjectNode* spobj = local->as_SafePointScalarObject();
 600 
 601     ObjectValue* sv = Compile::sv_for_node_id(objs, spobj->_idx);
 602     if (sv == NULL) {
 603       ciKlass* cik = t->is_oopptr()->klass();
 604       assert(cik->is_instance_klass() ||
 605              cik->is_array_klass(), "Not supported allocation.");
 606       sv = new ObjectValue(spobj->_idx,
 607                            new ConstantOopWriteValue(cik->encoding()));
 608       Compile::set_sv_for_object_node(objs, sv);
 609 
 610       uint first_ind = spobj->first_index();
 611       for (uint i = 0; i < spobj->n_fields(); i++) {
 612         Node* fld_node = sfpt->in(first_ind+i);
 613         (void)FillLocArray(sv->field_values()->length(), sfpt, fld_node, sv->field_values(), objs);
 614       }
 615     }
 616     array->append(sv);
 617     return;
 618   }
 619 
 620   // Grab the register number for the local
 621   OptoReg::Name regnum = _regalloc->get_reg_first(local);
 622   if( OptoReg::is_valid(regnum) ) {// Got a register/stack?
 623     // Record the double as two float registers.
 624     // The register mask for such a value always specifies two adjacent
 625     // float registers, with the lower register number even.
 626     // Normally, the allocation of high and low words to these registers
 627     // is irrelevant, because nearly all operations on register pairs
 628     // (e.g., StoreD) treat them as a single unit.
 629     // Here, we assume in addition that the words in these two registers
 630     // stored "naturally" (by operations like StoreD and double stores
 631     // within the interpreter) such that the lower-numbered register
 632     // is written to the lower memory address.  This may seem like
 633     // a machine dependency, but it is not--it is a requirement on
 634     // the author of the <arch>.ad file to ensure that, for every
 635     // even/odd double-register pair to which a double may be allocated,
 636     // the word in the even single-register is stored to the first
 637     // memory word.  (Note that register numbers are completely
 638     // arbitrary, and are not tied to any machine-level encodings.)
 639 #ifdef _LP64
 640     if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon ) {
 641       array->append(new ConstantIntValue(0));
 642       array->append(new_loc_value( _regalloc, regnum, Location::dbl ));
 643     } else if ( t->base() == Type::Long ) {
 644       array->append(new ConstantIntValue(0));
 645       array->append(new_loc_value( _regalloc, regnum, Location::lng ));
 646     } else if ( t->base() == Type::RawPtr ) {
 647       // jsr/ret return address which must be restored into a the full
 648       // width 64-bit stack slot.
 649       array->append(new_loc_value( _regalloc, regnum, Location::lng ));
 650     }
 651 #else //_LP64
 652 #ifdef SPARC
 653     if (t->base() == Type::Long && OptoReg::is_reg(regnum)) {
 654       // For SPARC we have to swap high and low words for
 655       // long values stored in a single-register (g0-g7).
 656       array->append(new_loc_value( _regalloc,              regnum   , Location::normal ));
 657       array->append(new_loc_value( _regalloc, OptoReg::add(regnum,1), Location::normal ));
 658     } else
 659 #endif //SPARC
 660     if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon || t->base() == Type::Long ) {
 661       // Repack the double/long as two jints.
 662       // The convention the interpreter uses is that the second local
 663       // holds the first raw word of the native double representation.
 664       // This is actually reasonable, since locals and stack arrays
 665       // grow downwards in all implementations.
 666       // (If, on some machine, the interpreter's Java locals or stack
 667       // were to grow upwards, the embedded doubles would be word-swapped.)
 668       array->append(new_loc_value( _regalloc, OptoReg::add(regnum,1), Location::normal ));
 669       array->append(new_loc_value( _regalloc,              regnum   , Location::normal ));
 670     }
 671 #endif //_LP64
 672     else if( (t->base() == Type::FloatBot || t->base() == Type::FloatCon) &&
 673                OptoReg::is_reg(regnum) ) {
 674       array->append(new_loc_value( _regalloc, regnum, Matcher::float_in_double
 675                                    ? Location::float_in_dbl : Location::normal ));
 676     } else if( t->base() == Type::Int && OptoReg::is_reg(regnum) ) {
 677       array->append(new_loc_value( _regalloc, regnum, Matcher::int_in_long
 678                                    ? Location::int_in_long : Location::normal ));
 679     } else if( t->base() == Type::NarrowOop ) {
 680       array->append(new_loc_value( _regalloc, regnum, Location::narrowoop ));
 681     } else {
 682       array->append(new_loc_value( _regalloc, regnum, _regalloc->is_oop(local) ? Location::oop : Location::normal ));
 683     }
 684     return;
 685   }
 686 
 687   // No register.  It must be constant data.
 688   switch (t->base()) {
 689   case Type::Half:              // Second half of a double
 690     ShouldNotReachHere();       // Caller should skip 2nd halves
 691     break;
 692   case Type::AnyPtr:
 693     array->append(new ConstantOopWriteValue(NULL));
 694     break;
 695   case Type::AryPtr:
 696   case Type::InstPtr:
 697   case Type::KlassPtr:          // fall through
 698     array->append(new ConstantOopWriteValue(t->isa_oopptr()->const_oop()->encoding()));
 699     break;
 700   case Type::NarrowOop:
 701     if (t == TypeNarrowOop::NULL_PTR) {
 702       array->append(new ConstantOopWriteValue(NULL));
 703     } else {
 704       array->append(new ConstantOopWriteValue(t->make_ptr()->isa_oopptr()->const_oop()->encoding()));
 705     }
 706     break;
 707   case Type::Int:
 708     array->append(new ConstantIntValue(t->is_int()->get_con()));
 709     break;
 710   case Type::RawPtr:
 711     // A return address (T_ADDRESS).
 712     assert((intptr_t)t->is_ptr()->get_con() < (intptr_t)0x10000, "must be a valid BCI");
 713 #ifdef _LP64
 714     // Must be restored to the full-width 64-bit stack slot.
 715     array->append(new ConstantLongValue(t->is_ptr()->get_con()));
 716 #else
 717     array->append(new ConstantIntValue(t->is_ptr()->get_con()));
 718 #endif
 719     break;
 720   case Type::FloatCon: {
 721     float f = t->is_float_constant()->getf();
 722     array->append(new ConstantIntValue(jint_cast(f)));
 723     break;
 724   }
 725   case Type::DoubleCon: {
 726     jdouble d = t->is_double_constant()->getd();
 727 #ifdef _LP64
 728     array->append(new ConstantIntValue(0));
 729     array->append(new ConstantDoubleValue(d));
 730 #else
 731     // Repack the double as two jints.
 732     // The convention the interpreter uses is that the second local
 733     // holds the first raw word of the native double representation.
 734     // This is actually reasonable, since locals and stack arrays
 735     // grow downwards in all implementations.
 736     // (If, on some machine, the interpreter's Java locals or stack
 737     // were to grow upwards, the embedded doubles would be word-swapped.)
 738     jint   *dp = (jint*)&d;
 739     array->append(new ConstantIntValue(dp[1]));
 740     array->append(new ConstantIntValue(dp[0]));
 741 #endif
 742     break;
 743   }
 744   case Type::Long: {
 745     jlong d = t->is_long()->get_con();
 746 #ifdef _LP64
 747     array->append(new ConstantIntValue(0));
 748     array->append(new ConstantLongValue(d));
 749 #else
 750     // Repack the long as two jints.
 751     // The convention the interpreter uses is that the second local
 752     // holds the first raw word of the native double representation.
 753     // This is actually reasonable, since locals and stack arrays
 754     // grow downwards in all implementations.
 755     // (If, on some machine, the interpreter's Java locals or stack
 756     // were to grow upwards, the embedded doubles would be word-swapped.)
 757     jint *dp = (jint*)&d;
 758     array->append(new ConstantIntValue(dp[1]));
 759     array->append(new ConstantIntValue(dp[0]));
 760 #endif
 761     break;
 762   }
 763   case Type::Top:               // Add an illegal value here
 764     array->append(new LocationValue(Location()));
 765     break;
 766   default:
 767     ShouldNotReachHere();
 768     break;
 769   }
 770 }
 771 
 772 // Determine if this node starts a bundle
 773 bool Compile::starts_bundle(const Node *n) const {
 774   return (_node_bundling_limit > n->_idx &&
 775           _node_bundling_base[n->_idx].starts_bundle());
 776 }
 777 
 778 //--------------------------Process_OopMap_Node--------------------------------
 779 void Compile::Process_OopMap_Node(MachNode *mach, int current_offset) {
 780 
 781   // Handle special safepoint nodes for synchronization
 782   MachSafePointNode *sfn   = mach->as_MachSafePoint();
 783   MachCallNode      *mcall;
 784 
 785 #ifdef ENABLE_ZAP_DEAD_LOCALS
 786   assert( is_node_getting_a_safepoint(mach),  "logic does not match; false negative");
 787 #endif
 788 
 789   int safepoint_pc_offset = current_offset;
 790 
 791   // Add the safepoint in the DebugInfoRecorder
 792   if( !mach->is_MachCall() ) {
 793     mcall = NULL;
 794     debug_info()->add_safepoint(safepoint_pc_offset, sfn->_oop_map);
 795   } else {
 796     mcall = mach->as_MachCall();
 797     safepoint_pc_offset += mcall->ret_addr_offset();
 798     debug_info()->add_safepoint(safepoint_pc_offset, mcall->_oop_map);
 799   }
 800 
 801   // Loop over the JVMState list to add scope information
 802   // Do not skip safepoints with a NULL method, they need monitor info
 803   JVMState* youngest_jvms = sfn->jvms();
 804   int max_depth = youngest_jvms->depth();
 805 
 806   // Allocate the object pool for scalar-replaced objects -- the map from
 807   // small-integer keys (which can be recorded in the local and ostack
 808   // arrays) to descriptions of the object state.
 809   GrowableArray<ScopeValue*> *objs = new GrowableArray<ScopeValue*>();
 810 
 811   // Visit scopes from oldest to youngest.
 812   for (int depth = 1; depth <= max_depth; depth++) {
 813     JVMState* jvms = youngest_jvms->of_depth(depth);
 814     int idx;
 815     ciMethod* method = jvms->has_method() ? jvms->method() : NULL;
 816     // Safepoints that do not have method() set only provide oop-map and monitor info
 817     // to support GC; these do not support deoptimization.
 818     int num_locs = (method == NULL) ? 0 : jvms->loc_size();
 819     int num_exps = (method == NULL) ? 0 : jvms->stk_size();
 820     int num_mon  = jvms->nof_monitors();
 821     assert(method == NULL || jvms->bci() < 0 || num_locs == method->max_locals(),
 822            "JVMS local count must match that of the method");
 823 
 824     // Add Local and Expression Stack Information
 825 
 826     // Insert locals into the locarray
 827     GrowableArray<ScopeValue*> *locarray = new GrowableArray<ScopeValue*>(num_locs);
 828     for( idx = 0; idx < num_locs; idx++ ) {
 829       FillLocArray( idx, sfn, sfn->local(jvms, idx), locarray, objs );
 830     }
 831 
 832     // Insert expression stack entries into the exparray
 833     GrowableArray<ScopeValue*> *exparray = new GrowableArray<ScopeValue*>(num_exps);
 834     for( idx = 0; idx < num_exps; idx++ ) {
 835       FillLocArray( idx,  sfn, sfn->stack(jvms, idx), exparray, objs );
 836     }
 837 
 838     // Add in mappings of the monitors
 839     assert( !method ||
 840             !method->is_synchronized() ||
 841             method->is_native() ||
 842             num_mon > 0 ||
 843             !GenerateSynchronizationCode,
 844             "monitors must always exist for synchronized methods");
 845 
 846     // Build the growable array of ScopeValues for exp stack
 847     GrowableArray<MonitorValue*> *monarray = new GrowableArray<MonitorValue*>(num_mon);
 848 
 849     // Loop over monitors and insert into array
 850     for(idx = 0; idx < num_mon; idx++) {
 851       // Grab the node that defines this monitor
 852       Node* box_node = sfn->monitor_box(jvms, idx);
 853       Node* obj_node = sfn->monitor_obj(jvms, idx);
 854 
 855       // Create ScopeValue for object
 856       ScopeValue *scval = NULL;
 857 
 858       if( obj_node->is_SafePointScalarObject() ) {
 859         SafePointScalarObjectNode* spobj = obj_node->as_SafePointScalarObject();
 860         scval = Compile::sv_for_node_id(objs, spobj->_idx);
 861         if (scval == NULL) {
 862           const Type *t = obj_node->bottom_type();
 863           ciKlass* cik = t->is_oopptr()->klass();
 864           assert(cik->is_instance_klass() ||
 865                  cik->is_array_klass(), "Not supported allocation.");
 866           ObjectValue* sv = new ObjectValue(spobj->_idx,
 867                                 new ConstantOopWriteValue(cik->encoding()));
 868           Compile::set_sv_for_object_node(objs, sv);
 869 
 870           uint first_ind = spobj->first_index();
 871           for (uint i = 0; i < spobj->n_fields(); i++) {
 872             Node* fld_node = sfn->in(first_ind+i);
 873             (void)FillLocArray(sv->field_values()->length(), sfn, fld_node, sv->field_values(), objs);
 874           }
 875           scval = sv;
 876         }
 877       } else if( !obj_node->is_Con() ) {
 878         OptoReg::Name obj_reg = _regalloc->get_reg_first(obj_node);
 879         if( obj_node->bottom_type()->base() == Type::NarrowOop ) {
 880           scval = new_loc_value( _regalloc, obj_reg, Location::narrowoop );
 881         } else {
 882           scval = new_loc_value( _regalloc, obj_reg, Location::oop );
 883         }
 884       } else {
 885         const TypePtr *tp = obj_node->bottom_type()->make_ptr();
 886         scval = new ConstantOopWriteValue(tp->is_instptr()->const_oop()->encoding());
 887       }
 888 
 889       OptoReg::Name box_reg = BoxLockNode::stack_slot(box_node);
 890       Location basic_lock = Location::new_stk_loc(Location::normal,_regalloc->reg2offset(box_reg));
 891       while( !box_node->is_BoxLock() )  box_node = box_node->in(1);
 892       monarray->append(new MonitorValue(scval, basic_lock, box_node->as_BoxLock()->is_eliminated()));
 893     }
 894 
 895     // We dump the object pool first, since deoptimization reads it in first.
 896     debug_info()->dump_object_pool(objs);
 897 
 898     // Build first class objects to pass to scope
 899     DebugToken *locvals = debug_info()->create_scope_values(locarray);
 900     DebugToken *expvals = debug_info()->create_scope_values(exparray);
 901     DebugToken *monvals = debug_info()->create_monitor_values(monarray);
 902 
 903     // Make method available for all Safepoints
 904     ciMethod* scope_method = method ? method : _method;
 905     // Describe the scope here
 906     assert(jvms->bci() >= InvocationEntryBci && jvms->bci() <= 0x10000, "must be a valid or entry BCI");
 907     // Now we can describe the scope.
 908     debug_info()->describe_scope(safepoint_pc_offset,scope_method,jvms->bci(),locvals,expvals,monvals);
 909   } // End jvms loop
 910 
 911   // Mark the end of the scope set.
 912   debug_info()->end_safepoint(safepoint_pc_offset);
 913 }
 914 
 915 
 916 
 917 // A simplified version of Process_OopMap_Node, to handle non-safepoints.
 918 class NonSafepointEmitter {
 919   Compile*  C;
 920   JVMState* _pending_jvms;
 921   int       _pending_offset;
 922 
 923   void emit_non_safepoint();
 924 
 925  public:
 926   NonSafepointEmitter(Compile* compile) {
 927     this->C = compile;
 928     _pending_jvms = NULL;
 929     _pending_offset = 0;
 930   }
 931 
 932   void observe_instruction(Node* n, int pc_offset) {
 933     if (!C->debug_info()->recording_non_safepoints())  return;
 934 
 935     Node_Notes* nn = C->node_notes_at(n->_idx);
 936     if (nn == NULL || nn->jvms() == NULL)  return;
 937     if (_pending_jvms != NULL &&
 938         _pending_jvms->same_calls_as(nn->jvms())) {
 939       // Repeated JVMS?  Stretch it up here.
 940       _pending_offset = pc_offset;
 941     } else {
 942       if (_pending_jvms != NULL &&
 943           _pending_offset < pc_offset) {
 944         emit_non_safepoint();
 945       }
 946       _pending_jvms = NULL;
 947       if (pc_offset > C->debug_info()->last_pc_offset()) {
 948         // This is the only way _pending_jvms can become non-NULL:
 949         _pending_jvms = nn->jvms();
 950         _pending_offset = pc_offset;
 951       }
 952     }
 953   }
 954 
 955   // Stay out of the way of real safepoints:
 956   void observe_safepoint(JVMState* jvms, int pc_offset) {
 957     if (_pending_jvms != NULL &&
 958         !_pending_jvms->same_calls_as(jvms) &&
 959         _pending_offset < pc_offset) {
 960       emit_non_safepoint();
 961     }
 962     _pending_jvms = NULL;
 963   }
 964 
 965   void flush_at_end() {
 966     if (_pending_jvms != NULL) {
 967       emit_non_safepoint();
 968     }
 969     _pending_jvms = NULL;
 970   }
 971 };
 972 
 973 void NonSafepointEmitter::emit_non_safepoint() {
 974   JVMState* youngest_jvms = _pending_jvms;
 975   int       pc_offset     = _pending_offset;
 976 
 977   // Clear it now:
 978   _pending_jvms = NULL;
 979 
 980   DebugInformationRecorder* debug_info = C->debug_info();
 981   assert(debug_info->recording_non_safepoints(), "sanity");
 982 
 983   debug_info->add_non_safepoint(pc_offset);
 984   int max_depth = youngest_jvms->depth();
 985 
 986   // Visit scopes from oldest to youngest.
 987   for (int depth = 1; depth <= max_depth; depth++) {
 988     JVMState* jvms = youngest_jvms->of_depth(depth);
 989     ciMethod* method = jvms->has_method() ? jvms->method() : NULL;
 990     debug_info->describe_scope(pc_offset, method, jvms->bci());
 991   }
 992 
 993   // Mark the end of the scope set.
 994   debug_info->end_non_safepoint(pc_offset);
 995 }
 996 
 997 
 998 
 999 // helper for Fill_buffer bailout logic
1000 static void turn_off_compiler(Compile* C) {
1001   if (CodeCache::unallocated_capacity() >= CodeCacheMinimumFreeSpace*10) {
1002     // Do not turn off compilation if a single giant method has
1003     // blown the code cache size.
1004     C->record_failure("excessive request to CodeCache");
1005   } else {
1006     // Let CompilerBroker disable further compilations.
1007     C->record_failure("CodeCache is full");
1008   }
1009 }
1010 
1011 
1012 //------------------------------Fill_buffer------------------------------------
1013 void Compile::Fill_buffer() {
1014 
1015   // Set the initially allocated size
1016   int  code_req   = initial_code_capacity;
1017   int  locs_req   = initial_locs_capacity;
1018   int  stub_req   = TraceJumps ? initial_stub_capacity * 10 : initial_stub_capacity;
1019   int  const_req  = initial_const_capacity;
1020   bool labels_not_set = true;
1021 
1022   int  pad_req    = NativeCall::instruction_size;
1023   // The extra spacing after the code is necessary on some platforms.
1024   // Sometimes we need to patch in a jump after the last instruction,
1025   // if the nmethod has been deoptimized.  (See 4932387, 4894843.)
1026 
1027   uint i;
1028   // Compute the byte offset where we can store the deopt pc.
1029   if (fixed_slots() != 0) {
1030     _orig_pc_slot_offset_in_bytes = _regalloc->reg2offset(OptoReg::stack2reg(_orig_pc_slot));
1031   }
1032 
1033   // Compute prolog code size
1034   _method_size = 0;
1035   _frame_slots = OptoReg::reg2stack(_matcher->_old_SP)+_regalloc->_framesize;
1036 #ifdef IA64
1037   if (save_argument_registers()) {
1038     // 4815101: this is a stub with implicit and unknown precision fp args.
1039     // The usual spill mechanism can only generate stfd's in this case, which
1040     // doesn't work if the fp reg to spill contains a single-precision denorm.
1041     // Instead, we hack around the normal spill mechanism using stfspill's and
1042     // ldffill's in the MachProlog and MachEpilog emit methods.  We allocate
1043     // space here for the fp arg regs (f8-f15) we're going to thusly spill.
1044     //
1045     // If we ever implement 16-byte 'registers' == stack slots, we can
1046     // get rid of this hack and have SpillCopy generate stfspill/ldffill
1047     // instead of stfd/stfs/ldfd/ldfs.
1048     _frame_slots += 8*(16/BytesPerInt);
1049   }
1050 #endif
1051   assert( _frame_slots >= 0 && _frame_slots < 1000000, "sanity check" );
1052 
1053   // Create an array of unused labels, one for each basic block
1054   Label *blk_labels = NEW_RESOURCE_ARRAY(Label, _cfg->_num_blocks+1);
1055 
1056   for( i=0; i <= _cfg->_num_blocks; i++ ) {
1057     blk_labels[i].init();
1058   }
1059 
1060   // If this machine supports different size branch offsets, then pre-compute
1061   // the length of the blocks
1062   if( _matcher->is_short_branch_offset(-1, 0) ) {
1063     Shorten_branches(blk_labels, code_req, locs_req, stub_req, const_req);
1064     labels_not_set = false;
1065   }
1066 
1067   // nmethod and CodeBuffer count stubs & constants as part of method's code.
1068   int exception_handler_req = size_exception_handler();
1069   int deopt_handler_req = size_deopt_handler();
1070   exception_handler_req += MAX_stubs_size; // add marginal slop for handler
1071   deopt_handler_req += MAX_stubs_size; // add marginal slop for handler
1072   stub_req += MAX_stubs_size;   // ensure per-stub margin
1073   code_req += MAX_inst_size;    // ensure per-instruction margin
1074   if (StressCodeBuffers)
1075     code_req = const_req = stub_req = exception_handler_req = deopt_handler_req = 0x10;  // force expansion
1076   int total_req = code_req + pad_req + stub_req + exception_handler_req + deopt_handler_req + const_req;
1077   CodeBuffer* cb = code_buffer();
1078   cb->initialize(total_req, locs_req);
1079 
1080   // Have we run out of code space?
1081   if (cb->blob() == NULL) {
1082     turn_off_compiler(this);
1083     return;
1084   }
1085   // Configure the code buffer.
1086   cb->initialize_consts_size(const_req);
1087   cb->initialize_stubs_size(stub_req);
1088   cb->initialize_oop_recorder(env()->oop_recorder());
1089 
1090   // fill in the nop array for bundling computations
1091   MachNode *_nop_list[Bundle::_nop_count];
1092   Bundle::initialize_nops(_nop_list, this);
1093 
1094   // Create oopmap set.
1095   _oop_map_set = new OopMapSet();
1096 
1097   // !!!!! This preserves old handling of oopmaps for now
1098   debug_info()->set_oopmaps(_oop_map_set);
1099 
1100   // Count and start of implicit null check instructions
1101   uint inct_cnt = 0;
1102   uint *inct_starts = NEW_RESOURCE_ARRAY(uint, _cfg->_num_blocks+1);
1103 
1104   // Count and start of calls
1105   uint *call_returns = NEW_RESOURCE_ARRAY(uint, _cfg->_num_blocks+1);
1106 
1107   uint  return_offset = 0;
1108   MachNode *nop = new (this) MachNopNode();
1109 
1110   int previous_offset = 0;
1111   int current_offset  = 0;
1112   int last_call_offset = -1;
1113 
1114   // Create an array of unused labels, one for each basic block, if printing is enabled
1115 #ifndef PRODUCT
1116   int *node_offsets      = NULL;
1117   uint  node_offset_limit = unique();
1118 
1119 
1120   if ( print_assembly() )
1121     node_offsets         = NEW_RESOURCE_ARRAY(int, node_offset_limit);
1122 #endif
1123 
1124   NonSafepointEmitter non_safepoints(this);  // emit non-safepoints lazily
1125 
1126   // ------------------
1127   // Now fill in the code buffer
1128   Node *delay_slot = NULL;
1129 
1130   for( i=0; i < _cfg->_num_blocks; i++ ) {
1131     Block *b = _cfg->_blocks[i];
1132 
1133     Node *head = b->head();
1134 
1135     // If this block needs to start aligned (i.e, can be reached other
1136     // than by falling-thru from the previous block), then force the
1137     // start of a new bundle.
1138     if( Pipeline::requires_bundling() && starts_bundle(head) )
1139       cb->flush_bundle(true);
1140 
1141     // Define the label at the beginning of the basic block
1142     if( labels_not_set )
1143       MacroAssembler(cb).bind( blk_labels[b->_pre_order] );
1144 
1145     else
1146       assert( blk_labels[b->_pre_order].loc_pos() == cb->code_size(),
1147               "label position does not match code offset" );
1148 
1149     uint last_inst = b->_nodes.size();
1150 
1151     // Emit block normally, except for last instruction.
1152     // Emit means "dump code bits into code buffer".
1153     for( uint j = 0; j<last_inst; j++ ) {
1154 
1155       // Get the node
1156       Node* n = b->_nodes[j];
1157 
1158       // See if delay slots are supported
1159       if (valid_bundle_info(n) &&
1160           node_bundling(n)->used_in_unconditional_delay()) {
1161         assert(delay_slot == NULL, "no use of delay slot node");
1162         assert(n->size(_regalloc) == Pipeline::instr_unit_size(), "delay slot instruction wrong size");
1163 
1164         delay_slot = n;
1165         continue;
1166       }
1167 
1168       // If this starts a new instruction group, then flush the current one
1169       // (but allow split bundles)
1170       if( Pipeline::requires_bundling() && starts_bundle(n) )
1171         cb->flush_bundle(false);
1172 
1173       // The following logic is duplicated in the code ifdeffed for
1174       // ENABLE_ZAP_DEAD_LOCALS which appears above in this file.  It
1175       // should be factored out.  Or maybe dispersed to the nodes?
1176 
1177       // Special handling for SafePoint/Call Nodes
1178       bool is_mcall = false;
1179       if( n->is_Mach() ) {
1180         MachNode *mach = n->as_Mach();
1181         is_mcall = n->is_MachCall();
1182         bool is_sfn = n->is_MachSafePoint();
1183 
1184         // If this requires all previous instructions be flushed, then do so
1185         if( is_sfn || is_mcall || mach->alignment_required() != 1) {
1186           cb->flush_bundle(true);
1187           current_offset = cb->code_size();
1188         }
1189 
1190         // align the instruction if necessary
1191         int nop_size = nop->size(_regalloc);
1192         int padding = mach->compute_padding(current_offset);
1193         // Make sure safepoint node for polling is distinct from a call's
1194         // return by adding a nop if needed.
1195         if (is_sfn && !is_mcall && padding == 0 && current_offset == last_call_offset ) {
1196           padding = nop_size;
1197         }
1198         assert( labels_not_set || padding == 0, "instruction should already be aligned")
1199 
1200         if(padding > 0) {
1201           assert((padding % nop_size) == 0, "padding is not a multiple of NOP size");
1202           int nops_cnt = padding / nop_size;
1203           MachNode *nop = new (this) MachNopNode(nops_cnt);
1204           b->_nodes.insert(j++, nop);
1205           last_inst++;
1206           _cfg->_bbs.map( nop->_idx, b );
1207           nop->emit(*cb, _regalloc);
1208           cb->flush_bundle(true);
1209           current_offset = cb->code_size();
1210         }
1211 
1212         // Remember the start of the last call in a basic block
1213         if (is_mcall) {
1214           MachCallNode *mcall = mach->as_MachCall();
1215 
1216           // This destination address is NOT PC-relative
1217           mcall->method_set((intptr_t)mcall->entry_point());
1218 
1219           // Save the return address
1220           call_returns[b->_pre_order] = current_offset + mcall->ret_addr_offset();
1221 
1222           if (!mcall->is_safepoint_node()) {
1223             is_mcall = false;
1224             is_sfn = false;
1225           }
1226         }
1227 
1228         // sfn will be valid whenever mcall is valid now because of inheritance
1229         if( is_sfn || is_mcall ) {
1230 
1231           // Handle special safepoint nodes for synchronization
1232           if( !is_mcall ) {
1233             MachSafePointNode *sfn = mach->as_MachSafePoint();
1234             // !!!!! Stubs only need an oopmap right now, so bail out
1235             if( sfn->jvms()->method() == NULL) {
1236               // Write the oopmap directly to the code blob??!!
1237 #             ifdef ENABLE_ZAP_DEAD_LOCALS
1238               assert( !is_node_getting_a_safepoint(sfn),  "logic does not match; false positive");
1239 #             endif
1240               continue;
1241             }
1242           } // End synchronization
1243 
1244           non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
1245                                            current_offset);
1246           Process_OopMap_Node(mach, current_offset);
1247         } // End if safepoint
1248 
1249         // If this is a null check, then add the start of the previous instruction to the list
1250         else if( mach->is_MachNullCheck() ) {
1251           inct_starts[inct_cnt++] = previous_offset;
1252         }
1253 
1254         // If this is a branch, then fill in the label with the target BB's label
1255         else if ( mach->is_Branch() ) {
1256 
1257           if ( mach->ideal_Opcode() == Op_Jump ) {
1258             for (uint h = 0; h < b->_num_succs; h++ ) {
1259               Block* succs_block = b->_succs[h];
1260               for (uint j = 1; j < succs_block->num_preds(); j++) {
1261                 Node* jpn = succs_block->pred(j);
1262                 if ( jpn->is_JumpProj() && jpn->in(0) == mach ) {
1263                   uint block_num = succs_block->non_connector()->_pre_order;
1264                   Label *blkLabel = &blk_labels[block_num];
1265                   mach->add_case_label(jpn->as_JumpProj()->proj_no(), blkLabel);
1266                 }
1267               }
1268             }
1269           } else {
1270             // For Branchs
1271             // This requires the TRUE branch target be in succs[0]
1272             uint block_num = b->non_connector_successor(0)->_pre_order;
1273             mach->label_set( blk_labels[block_num], block_num );
1274           }
1275         }
1276 
1277 #ifdef ASSERT
1278         // Check that oop-store precedes the card-mark
1279         else if( mach->ideal_Opcode() == Op_StoreCM ) {
1280           uint storeCM_idx = j;
1281           Node *oop_store = mach->in(mach->_cnt);  // First precedence edge
1282           assert( oop_store != NULL, "storeCM expects a precedence edge");
1283           uint i4;
1284           for( i4 = 0; i4 < last_inst; ++i4 ) {
1285             if( b->_nodes[i4] == oop_store ) break;
1286           }
1287           // Note: This test can provide a false failure if other precedence
1288           // edges have been added to the storeCMNode.
1289           assert( i4 == last_inst || i4 < storeCM_idx, "CM card-mark executes before oop-store");
1290         }
1291 #endif
1292 
1293         else if( !n->is_Proj() ) {
1294           // Remember the beginning of the previous instruction, in case
1295           // it's followed by a flag-kill and a null-check.  Happens on
1296           // Intel all the time, with add-to-memory kind of opcodes.
1297           previous_offset = current_offset;
1298         }
1299       }
1300 
1301       // Verify that there is sufficient space remaining
1302       cb->insts()->maybe_expand_to_ensure_remaining(MAX_inst_size);
1303       if (cb->blob() == NULL) {
1304         turn_off_compiler(this);
1305         return;
1306       }
1307 
1308       // Save the offset for the listing
1309 #ifndef PRODUCT
1310       if( node_offsets && n->_idx < node_offset_limit )
1311         node_offsets[n->_idx] = cb->code_size();
1312 #endif
1313 
1314       // "Normal" instruction case
1315       n->emit(*cb, _regalloc);
1316       current_offset  = cb->code_size();
1317       non_safepoints.observe_instruction(n, current_offset);
1318 
1319       // mcall is last "call" that can be a safepoint
1320       // record it so we can see if a poll will directly follow it
1321       // in which case we'll need a pad to make the PcDesc sites unique
1322       // see  5010568. This can be slightly inaccurate but conservative
1323       // in the case that return address is not actually at current_offset.
1324       // This is a small price to pay.
1325 
1326       if (is_mcall) {
1327         last_call_offset = current_offset;
1328       }
1329 
1330       // See if this instruction has a delay slot
1331       if ( valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
1332         assert(delay_slot != NULL, "expecting delay slot node");
1333 
1334         // Back up 1 instruction
1335         cb->set_code_end(
1336           cb->code_end()-Pipeline::instr_unit_size());
1337 
1338         // Save the offset for the listing
1339 #ifndef PRODUCT
1340         if( node_offsets && delay_slot->_idx < node_offset_limit )
1341           node_offsets[delay_slot->_idx] = cb->code_size();
1342 #endif
1343 
1344         // Support a SafePoint in the delay slot
1345         if( delay_slot->is_MachSafePoint() ) {
1346           MachNode *mach = delay_slot->as_Mach();
1347           // !!!!! Stubs only need an oopmap right now, so bail out
1348           if( !mach->is_MachCall() && mach->as_MachSafePoint()->jvms()->method() == NULL ) {
1349             // Write the oopmap directly to the code blob??!!
1350 #           ifdef ENABLE_ZAP_DEAD_LOCALS
1351             assert( !is_node_getting_a_safepoint(mach),  "logic does not match; false positive");
1352 #           endif
1353             delay_slot = NULL;
1354             continue;
1355           }
1356 
1357           int adjusted_offset = current_offset - Pipeline::instr_unit_size();
1358           non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
1359                                            adjusted_offset);
1360           // Generate an OopMap entry
1361           Process_OopMap_Node(mach, adjusted_offset);
1362         }
1363 
1364         // Insert the delay slot instruction
1365         delay_slot->emit(*cb, _regalloc);
1366 
1367         // Don't reuse it
1368         delay_slot = NULL;
1369       }
1370 
1371     } // End for all instructions in block
1372 
1373     // If the next block is the top of a loop, pad this block out to align
1374     // the loop top a little. Helps prevent pipe stalls at loop back branches.
1375     int nop_size = (new (this) MachNopNode())->size(_regalloc);
1376     if( i<_cfg->_num_blocks-1 ) {
1377       Block *nb = _cfg->_blocks[i+1];
1378       uint padding = nb->alignment_padding(current_offset);
1379       if( padding > 0 ) {
1380         MachNode *nop = new (this) MachNopNode(padding / nop_size);
1381         b->_nodes.insert( b->_nodes.size(), nop );
1382         _cfg->_bbs.map( nop->_idx, b );
1383         nop->emit(*cb, _regalloc);
1384         current_offset = cb->code_size();
1385       }
1386     }
1387 
1388   } // End of for all blocks
1389 
1390   non_safepoints.flush_at_end();
1391 
1392   // Offset too large?
1393   if (failing())  return;
1394 
1395   // Define a pseudo-label at the end of the code
1396   MacroAssembler(cb).bind( blk_labels[_cfg->_num_blocks] );
1397 
1398   // Compute the size of the first block
1399   _first_block_size = blk_labels[1].loc_pos() - blk_labels[0].loc_pos();
1400 
1401   assert(cb->code_size() < 500000, "method is unreasonably large");
1402 
1403   // ------------------
1404 
1405 #ifndef PRODUCT
1406   // Information on the size of the method, without the extraneous code
1407   Scheduling::increment_method_size(cb->code_size());
1408 #endif
1409 
1410   // ------------------
1411   // Fill in exception table entries.
1412   FillExceptionTables(inct_cnt, call_returns, inct_starts, blk_labels);
1413 
1414   // Only java methods have exception handlers and deopt handlers
1415   if (_method) {
1416     // Emit the exception handler code.
1417     _code_offsets.set_value(CodeOffsets::Exceptions, emit_exception_handler(*cb));
1418     // Emit the deopt handler code.
1419     _code_offsets.set_value(CodeOffsets::Deopt, emit_deopt_handler(*cb));
1420   }
1421 
1422   // One last check for failed CodeBuffer::expand:
1423   if (cb->blob() == NULL) {
1424     turn_off_compiler(this);
1425     return;
1426   }
1427 
1428 #ifndef PRODUCT
1429   // Dump the assembly code, including basic-block numbers
1430   if (print_assembly()) {
1431     ttyLocker ttyl;  // keep the following output all in one block
1432     if (!VMThread::should_terminate()) {  // test this under the tty lock
1433       // This output goes directly to the tty, not the compiler log.
1434       // To enable tools to match it up with the compilation activity,
1435       // be sure to tag this tty output with the compile ID.
1436       if (xtty != NULL) {
1437         xtty->head("opto_assembly compile_id='%d'%s", compile_id(),
1438                    is_osr_compilation()    ? " compile_kind='osr'" :
1439                    "");
1440       }
1441       if (method() != NULL) {
1442         method()->print_oop();
1443         print_codes();
1444       }
1445       dump_asm(node_offsets, node_offset_limit);
1446       if (xtty != NULL) {
1447         xtty->tail("opto_assembly");
1448       }
1449     }
1450   }
1451 #endif
1452 
1453 }
1454 
1455 void Compile::FillExceptionTables(uint cnt, uint *call_returns, uint *inct_starts, Label *blk_labels) {
1456   _inc_table.set_size(cnt);
1457 
1458   uint inct_cnt = 0;
1459   for( uint i=0; i<_cfg->_num_blocks; i++ ) {
1460     Block *b = _cfg->_blocks[i];
1461     Node *n = NULL;
1462     int j;
1463 
1464     // Find the branch; ignore trailing NOPs.
1465     for( j = b->_nodes.size()-1; j>=0; j-- ) {
1466       n = b->_nodes[j];
1467       if( !n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con )
1468         break;
1469     }
1470 
1471     // If we didn't find anything, continue
1472     if( j < 0 ) continue;
1473 
1474     // Compute ExceptionHandlerTable subtable entry and add it
1475     // (skip empty blocks)
1476     if( n->is_Catch() ) {
1477 
1478       // Get the offset of the return from the call
1479       uint call_return = call_returns[b->_pre_order];
1480 #ifdef ASSERT
1481       assert( call_return > 0, "no call seen for this basic block" );
1482       while( b->_nodes[--j]->Opcode() == Op_MachProj ) ;
1483       assert( b->_nodes[j]->is_Call(), "CatchProj must follow call" );
1484 #endif
1485       // last instruction is a CatchNode, find it's CatchProjNodes
1486       int nof_succs = b->_num_succs;
1487       // allocate space
1488       GrowableArray<intptr_t> handler_bcis(nof_succs);
1489       GrowableArray<intptr_t> handler_pcos(nof_succs);
1490       // iterate through all successors
1491       for (int j = 0; j < nof_succs; j++) {
1492         Block* s = b->_succs[j];
1493         bool found_p = false;
1494         for( uint k = 1; k < s->num_preds(); k++ ) {
1495           Node *pk = s->pred(k);
1496           if( pk->is_CatchProj() && pk->in(0) == n ) {
1497             const CatchProjNode* p = pk->as_CatchProj();
1498             found_p = true;
1499             // add the corresponding handler bci & pco information
1500             if( p->_con != CatchProjNode::fall_through_index ) {
1501               // p leads to an exception handler (and is not fall through)
1502               assert(s == _cfg->_blocks[s->_pre_order],"bad numbering");
1503               // no duplicates, please
1504               if( !handler_bcis.contains(p->handler_bci()) ) {
1505                 uint block_num = s->non_connector()->_pre_order;
1506                 handler_bcis.append(p->handler_bci());
1507                 handler_pcos.append(blk_labels[block_num].loc_pos());
1508               }
1509             }
1510           }
1511         }
1512         assert(found_p, "no matching predecessor found");
1513         // Note:  Due to empty block removal, one block may have
1514         // several CatchProj inputs, from the same Catch.
1515       }
1516 
1517       // Set the offset of the return from the call
1518       _handler_table.add_subtable(call_return, &handler_bcis, NULL, &handler_pcos);
1519       continue;
1520     }
1521 
1522     // Handle implicit null exception table updates
1523     if( n->is_MachNullCheck() ) {
1524       uint block_num = b->non_connector_successor(0)->_pre_order;
1525       _inc_table.append( inct_starts[inct_cnt++], blk_labels[block_num].loc_pos() );
1526       continue;
1527     }
1528   } // End of for all blocks fill in exception table entries
1529 }
1530 
1531 // Static Variables
1532 #ifndef PRODUCT
1533 uint Scheduling::_total_nop_size = 0;
1534 uint Scheduling::_total_method_size = 0;
1535 uint Scheduling::_total_branches = 0;
1536 uint Scheduling::_total_unconditional_delays = 0;
1537 uint Scheduling::_total_instructions_per_bundle[Pipeline::_max_instrs_per_cycle+1];
1538 #endif
1539 
1540 // Initializer for class Scheduling
1541 
1542 Scheduling::Scheduling(Arena *arena, Compile &compile)
1543   : _arena(arena),
1544     _cfg(compile.cfg()),
1545     _bbs(compile.cfg()->_bbs),
1546     _regalloc(compile.regalloc()),
1547     _reg_node(arena),
1548     _bundle_instr_count(0),
1549     _bundle_cycle_number(0),
1550     _scheduled(arena),
1551     _available(arena),
1552     _next_node(NULL),
1553     _bundle_use(0, 0, resource_count, &_bundle_use_elements[0]),
1554     _pinch_free_list(arena)
1555 #ifndef PRODUCT
1556   , _branches(0)
1557   , _unconditional_delays(0)
1558 #endif
1559 {
1560   // Create a MachNopNode
1561   _nop = new (&compile) MachNopNode();
1562 
1563   // Now that the nops are in the array, save the count
1564   // (but allow entries for the nops)
1565   _node_bundling_limit = compile.unique();
1566   uint node_max = _regalloc->node_regs_max_index();
1567 
1568   compile.set_node_bundling_limit(_node_bundling_limit);
1569 
1570   // This one is persistent within the Compile class
1571   _node_bundling_base = NEW_ARENA_ARRAY(compile.comp_arena(), Bundle, node_max);
1572 
1573   // Allocate space for fixed-size arrays
1574   _node_latency    = NEW_ARENA_ARRAY(arena, unsigned short, node_max);
1575   _uses            = NEW_ARENA_ARRAY(arena, short,          node_max);
1576   _current_latency = NEW_ARENA_ARRAY(arena, unsigned short, node_max);
1577 
1578   // Clear the arrays
1579   memset(_node_bundling_base, 0, node_max * sizeof(Bundle));
1580   memset(_node_latency,       0, node_max * sizeof(unsigned short));
1581   memset(_uses,               0, node_max * sizeof(short));
1582   memset(_current_latency,    0, node_max * sizeof(unsigned short));
1583 
1584   // Clear the bundling information
1585   memcpy(_bundle_use_elements,
1586     Pipeline_Use::elaborated_elements,
1587     sizeof(Pipeline_Use::elaborated_elements));
1588 
1589   // Get the last node
1590   Block *bb = _cfg->_blocks[_cfg->_blocks.size()-1];
1591 
1592   _next_node = bb->_nodes[bb->_nodes.size()-1];
1593 }
1594 
1595 #ifndef PRODUCT
1596 // Scheduling destructor
1597 Scheduling::~Scheduling() {
1598   _total_branches             += _branches;
1599   _total_unconditional_delays += _unconditional_delays;
1600 }
1601 #endif
1602 
1603 // Step ahead "i" cycles
1604 void Scheduling::step(uint i) {
1605 
1606   Bundle *bundle = node_bundling(_next_node);
1607   bundle->set_starts_bundle();
1608 
1609   // Update the bundle record, but leave the flags information alone
1610   if (_bundle_instr_count > 0) {
1611     bundle->set_instr_count(_bundle_instr_count);
1612     bundle->set_resources_used(_bundle_use.resourcesUsed());
1613   }
1614 
1615   // Update the state information
1616   _bundle_instr_count = 0;
1617   _bundle_cycle_number += i;
1618   _bundle_use.step(i);
1619 }
1620 
1621 void Scheduling::step_and_clear() {
1622   Bundle *bundle = node_bundling(_next_node);
1623   bundle->set_starts_bundle();
1624 
1625   // Update the bundle record
1626   if (_bundle_instr_count > 0) {
1627     bundle->set_instr_count(_bundle_instr_count);
1628     bundle->set_resources_used(_bundle_use.resourcesUsed());
1629 
1630     _bundle_cycle_number += 1;
1631   }
1632 
1633   // Clear the bundling information
1634   _bundle_instr_count = 0;
1635   _bundle_use.reset();
1636 
1637   memcpy(_bundle_use_elements,
1638     Pipeline_Use::elaborated_elements,
1639     sizeof(Pipeline_Use::elaborated_elements));
1640 }
1641 
1642 //------------------------------ScheduleAndBundle------------------------------
1643 // Perform instruction scheduling and bundling over the sequence of
1644 // instructions in backwards order.
1645 void Compile::ScheduleAndBundle() {
1646 
1647   // Don't optimize this if it isn't a method
1648   if (!_method)
1649     return;
1650 
1651   // Don't optimize this if scheduling is disabled
1652   if (!do_scheduling())
1653     return;
1654 
1655   NOT_PRODUCT( TracePhase t2("isched", &_t_instrSched, TimeCompiler); )
1656 
1657   // Create a data structure for all the scheduling information
1658   Scheduling scheduling(Thread::current()->resource_area(), *this);
1659 
1660   // Walk backwards over each basic block, computing the needed alignment
1661   // Walk over all the basic blocks
1662   scheduling.DoScheduling();
1663 }
1664 
1665 //------------------------------ComputeLocalLatenciesForward-------------------
1666 // Compute the latency of all the instructions.  This is fairly simple,
1667 // because we already have a legal ordering.  Walk over the instructions
1668 // from first to last, and compute the latency of the instruction based
1669 // on the latency of the preceding instruction(s).
1670 void Scheduling::ComputeLocalLatenciesForward(const Block *bb) {
1671 #ifndef PRODUCT
1672   if (_cfg->C->trace_opto_output())
1673     tty->print("# -> ComputeLocalLatenciesForward\n");
1674 #endif
1675 
1676   // Walk over all the schedulable instructions
1677   for( uint j=_bb_start; j < _bb_end; j++ ) {
1678 
1679     // This is a kludge, forcing all latency calculations to start at 1.
1680     // Used to allow latency 0 to force an instruction to the beginning
1681     // of the bb
1682     uint latency = 1;
1683     Node *use = bb->_nodes[j];
1684     uint nlen = use->len();
1685 
1686     // Walk over all the inputs
1687     for ( uint k=0; k < nlen; k++ ) {
1688       Node *def = use->in(k);
1689       if (!def)
1690         continue;
1691 
1692       uint l = _node_latency[def->_idx] + use->latency(k);
1693       if (latency < l)
1694         latency = l;
1695     }
1696 
1697     _node_latency[use->_idx] = latency;
1698 
1699 #ifndef PRODUCT
1700     if (_cfg->C->trace_opto_output()) {
1701       tty->print("# latency %4d: ", latency);
1702       use->dump();
1703     }
1704 #endif
1705   }
1706 
1707 #ifndef PRODUCT
1708   if (_cfg->C->trace_opto_output())
1709     tty->print("# <- ComputeLocalLatenciesForward\n");
1710 #endif
1711 
1712 } // end ComputeLocalLatenciesForward
1713 
1714 // See if this node fits into the present instruction bundle
1715 bool Scheduling::NodeFitsInBundle(Node *n) {
1716   uint n_idx = n->_idx;
1717 
1718   // If this is the unconditional delay instruction, then it fits
1719   if (n == _unconditional_delay_slot) {
1720 #ifndef PRODUCT
1721     if (_cfg->C->trace_opto_output())
1722       tty->print("#     NodeFitsInBundle [%4d]: TRUE; is in unconditional delay slot\n", n->_idx);
1723 #endif
1724     return (true);
1725   }
1726 
1727   // If the node cannot be scheduled this cycle, skip it
1728   if (_current_latency[n_idx] > _bundle_cycle_number) {
1729 #ifndef PRODUCT
1730     if (_cfg->C->trace_opto_output())
1731       tty->print("#     NodeFitsInBundle [%4d]: FALSE; latency %4d > %d\n",
1732         n->_idx, _current_latency[n_idx], _bundle_cycle_number);
1733 #endif
1734     return (false);
1735   }
1736 
1737   const Pipeline *node_pipeline = n->pipeline();
1738 
1739   uint instruction_count = node_pipeline->instructionCount();
1740   if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
1741     instruction_count = 0;
1742   else if (node_pipeline->hasBranchDelay() && !_unconditional_delay_slot)
1743     instruction_count++;
1744 
1745   if (_bundle_instr_count + instruction_count > Pipeline::_max_instrs_per_cycle) {
1746 #ifndef PRODUCT
1747     if (_cfg->C->trace_opto_output())
1748       tty->print("#     NodeFitsInBundle [%4d]: FALSE; too many instructions: %d > %d\n",
1749         n->_idx, _bundle_instr_count + instruction_count, Pipeline::_max_instrs_per_cycle);
1750 #endif
1751     return (false);
1752   }
1753 
1754   // Don't allow non-machine nodes to be handled this way
1755   if (!n->is_Mach() && instruction_count == 0)
1756     return (false);
1757 
1758   // See if there is any overlap
1759   uint delay = _bundle_use.full_latency(0, node_pipeline->resourceUse());
1760 
1761   if (delay > 0) {
1762 #ifndef PRODUCT
1763     if (_cfg->C->trace_opto_output())
1764       tty->print("#     NodeFitsInBundle [%4d]: FALSE; functional units overlap\n", n_idx);
1765 #endif
1766     return false;
1767   }
1768 
1769 #ifndef PRODUCT
1770   if (_cfg->C->trace_opto_output())
1771     tty->print("#     NodeFitsInBundle [%4d]:  TRUE\n", n_idx);
1772 #endif
1773 
1774   return true;
1775 }
1776 
1777 Node * Scheduling::ChooseNodeToBundle() {
1778   uint siz = _available.size();
1779 
1780   if (siz == 0) {
1781 
1782 #ifndef PRODUCT
1783     if (_cfg->C->trace_opto_output())
1784       tty->print("#   ChooseNodeToBundle: NULL\n");
1785 #endif
1786     return (NULL);
1787   }
1788 
1789   // Fast path, if only 1 instruction in the bundle
1790   if (siz == 1) {
1791 #ifndef PRODUCT
1792     if (_cfg->C->trace_opto_output()) {
1793       tty->print("#   ChooseNodeToBundle (only 1): ");
1794       _available[0]->dump();
1795     }
1796 #endif
1797     return (_available[0]);
1798   }
1799 
1800   // Don't bother, if the bundle is already full
1801   if (_bundle_instr_count < Pipeline::_max_instrs_per_cycle) {
1802     for ( uint i = 0; i < siz; i++ ) {
1803       Node *n = _available[i];
1804 
1805       // Skip projections, we'll handle them another way
1806       if (n->is_Proj())
1807         continue;
1808 
1809       // This presupposed that instructions are inserted into the
1810       // available list in a legality order; i.e. instructions that
1811       // must be inserted first are at the head of the list
1812       if (NodeFitsInBundle(n)) {
1813 #ifndef PRODUCT
1814         if (_cfg->C->trace_opto_output()) {
1815           tty->print("#   ChooseNodeToBundle: ");
1816           n->dump();
1817         }
1818 #endif
1819         return (n);
1820       }
1821     }
1822   }
1823 
1824   // Nothing fits in this bundle, choose the highest priority
1825 #ifndef PRODUCT
1826   if (_cfg->C->trace_opto_output()) {
1827     tty->print("#   ChooseNodeToBundle: ");
1828     _available[0]->dump();
1829   }
1830 #endif
1831 
1832   return _available[0];
1833 }
1834 
1835 //------------------------------AddNodeToAvailableList-------------------------
1836 void Scheduling::AddNodeToAvailableList(Node *n) {
1837   assert( !n->is_Proj(), "projections never directly made available" );
1838 #ifndef PRODUCT
1839   if (_cfg->C->trace_opto_output()) {
1840     tty->print("#   AddNodeToAvailableList: ");
1841     n->dump();
1842   }
1843 #endif
1844 
1845   int latency = _current_latency[n->_idx];
1846 
1847   // Insert in latency order (insertion sort)
1848   uint i;
1849   for ( i=0; i < _available.size(); i++ )
1850     if (_current_latency[_available[i]->_idx] > latency)
1851       break;
1852 
1853   // Special Check for compares following branches
1854   if( n->is_Mach() && _scheduled.size() > 0 ) {
1855     int op = n->as_Mach()->ideal_Opcode();
1856     Node *last = _scheduled[0];
1857     if( last->is_MachIf() && last->in(1) == n &&
1858         ( op == Op_CmpI ||
1859           op == Op_CmpU ||
1860           op == Op_CmpP ||
1861           op == Op_CmpF ||
1862           op == Op_CmpD ||
1863           op == Op_CmpL ) ) {
1864 
1865       // Recalculate position, moving to front of same latency
1866       for ( i=0 ; i < _available.size(); i++ )
1867         if (_current_latency[_available[i]->_idx] >= latency)
1868           break;
1869     }
1870   }
1871 
1872   // Insert the node in the available list
1873   _available.insert(i, n);
1874 
1875 #ifndef PRODUCT
1876   if (_cfg->C->trace_opto_output())
1877     dump_available();
1878 #endif
1879 }
1880 
1881 //------------------------------DecrementUseCounts-----------------------------
1882 void Scheduling::DecrementUseCounts(Node *n, const Block *bb) {
1883   for ( uint i=0; i < n->len(); i++ ) {
1884     Node *def = n->in(i);
1885     if (!def) continue;
1886     if( def->is_Proj() )        // If this is a machine projection, then
1887       def = def->in(0);         // propagate usage thru to the base instruction
1888 
1889     if( _bbs[def->_idx] != bb ) // Ignore if not block-local
1890       continue;
1891 
1892     // Compute the latency
1893     uint l = _bundle_cycle_number + n->latency(i);
1894     if (_current_latency[def->_idx] < l)
1895       _current_latency[def->_idx] = l;
1896 
1897     // If this does not have uses then schedule it
1898     if ((--_uses[def->_idx]) == 0)
1899       AddNodeToAvailableList(def);
1900   }
1901 }
1902 
1903 //------------------------------AddNodeToBundle--------------------------------
1904 void Scheduling::AddNodeToBundle(Node *n, const Block *bb) {
1905 #ifndef PRODUCT
1906   if (_cfg->C->trace_opto_output()) {
1907     tty->print("#   AddNodeToBundle: ");
1908     n->dump();
1909   }
1910 #endif
1911 
1912   // Remove this from the available list
1913   uint i;
1914   for (i = 0; i < _available.size(); i++)
1915     if (_available[i] == n)
1916       break;
1917   assert(i < _available.size(), "entry in _available list not found");
1918   _available.remove(i);
1919 
1920   // See if this fits in the current bundle
1921   const Pipeline *node_pipeline = n->pipeline();
1922   const Pipeline_Use& node_usage = node_pipeline->resourceUse();
1923 
1924   // Check for instructions to be placed in the delay slot. We
1925   // do this before we actually schedule the current instruction,
1926   // because the delay slot follows the current instruction.
1927   if (Pipeline::_branch_has_delay_slot &&
1928       node_pipeline->hasBranchDelay() &&
1929       !_unconditional_delay_slot) {
1930 
1931     uint siz = _available.size();
1932 
1933     // Conditional branches can support an instruction that
1934     // is unconditionally executed and not dependent by the
1935     // branch, OR a conditionally executed instruction if
1936     // the branch is taken.  In practice, this means that
1937     // the first instruction at the branch target is
1938     // copied to the delay slot, and the branch goes to
1939     // the instruction after that at the branch target
1940     if ( n->is_Mach() && n->is_Branch() ) {
1941 
1942       assert( !n->is_MachNullCheck(), "should not look for delay slot for Null Check" );
1943       assert( !n->is_Catch(),         "should not look for delay slot for Catch" );
1944 
1945 #ifndef PRODUCT
1946       _branches++;
1947 #endif
1948 
1949       // At least 1 instruction is on the available list
1950       // that is not dependent on the branch
1951       for (uint i = 0; i < siz; i++) {
1952         Node *d = _available[i];
1953         const Pipeline *avail_pipeline = d->pipeline();
1954 
1955         // Don't allow safepoints in the branch shadow, that will
1956         // cause a number of difficulties
1957         if ( avail_pipeline->instructionCount() == 1 &&
1958             !avail_pipeline->hasMultipleBundles() &&
1959             !avail_pipeline->hasBranchDelay() &&
1960             Pipeline::instr_has_unit_size() &&
1961             d->size(_regalloc) == Pipeline::instr_unit_size() &&
1962             NodeFitsInBundle(d) &&
1963             !node_bundling(d)->used_in_delay()) {
1964 
1965           if (d->is_Mach() && !d->is_MachSafePoint()) {
1966             // A node that fits in the delay slot was found, so we need to
1967             // set the appropriate bits in the bundle pipeline information so
1968             // that it correctly indicates resource usage.  Later, when we
1969             // attempt to add this instruction to the bundle, we will skip
1970             // setting the resource usage.
1971             _unconditional_delay_slot = d;
1972             node_bundling(n)->set_use_unconditional_delay();
1973             node_bundling(d)->set_used_in_unconditional_delay();
1974             _bundle_use.add_usage(avail_pipeline->resourceUse());
1975             _current_latency[d->_idx] = _bundle_cycle_number;
1976             _next_node = d;
1977             ++_bundle_instr_count;
1978 #ifndef PRODUCT
1979             _unconditional_delays++;
1980 #endif
1981             break;
1982           }
1983         }
1984       }
1985     }
1986 
1987     // No delay slot, add a nop to the usage
1988     if (!_unconditional_delay_slot) {
1989       // See if adding an instruction in the delay slot will overflow
1990       // the bundle.
1991       if (!NodeFitsInBundle(_nop)) {
1992 #ifndef PRODUCT
1993         if (_cfg->C->trace_opto_output())
1994           tty->print("#  *** STEP(1 instruction for delay slot) ***\n");
1995 #endif
1996         step(1);
1997       }
1998 
1999       _bundle_use.add_usage(_nop->pipeline()->resourceUse());
2000       _next_node = _nop;
2001       ++_bundle_instr_count;
2002     }
2003 
2004     // See if the instruction in the delay slot requires a
2005     // step of the bundles
2006     if (!NodeFitsInBundle(n)) {
2007 #ifndef PRODUCT
2008         if (_cfg->C->trace_opto_output())
2009           tty->print("#  *** STEP(branch won't fit) ***\n");
2010 #endif
2011         // Update the state information
2012         _bundle_instr_count = 0;
2013         _bundle_cycle_number += 1;
2014         _bundle_use.step(1);
2015     }
2016   }
2017 
2018   // Get the number of instructions
2019   uint instruction_count = node_pipeline->instructionCount();
2020   if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
2021     instruction_count = 0;
2022 
2023   // Compute the latency information
2024   uint delay = 0;
2025 
2026   if (instruction_count > 0 || !node_pipeline->mayHaveNoCode()) {
2027     int relative_latency = _current_latency[n->_idx] - _bundle_cycle_number;
2028     if (relative_latency < 0)
2029       relative_latency = 0;
2030 
2031     delay = _bundle_use.full_latency(relative_latency, node_usage);
2032 
2033     // Does not fit in this bundle, start a new one
2034     if (delay > 0) {
2035       step(delay);
2036 
2037 #ifndef PRODUCT
2038       if (_cfg->C->trace_opto_output())
2039         tty->print("#  *** STEP(%d) ***\n", delay);
2040 #endif
2041     }
2042   }
2043 
2044   // If this was placed in the delay slot, ignore it
2045   if (n != _unconditional_delay_slot) {
2046 
2047     if (delay == 0) {
2048       if (node_pipeline->hasMultipleBundles()) {
2049 #ifndef PRODUCT
2050         if (_cfg->C->trace_opto_output())
2051           tty->print("#  *** STEP(multiple instructions) ***\n");
2052 #endif
2053         step(1);
2054       }
2055 
2056       else if (instruction_count + _bundle_instr_count > Pipeline::_max_instrs_per_cycle) {
2057 #ifndef PRODUCT
2058         if (_cfg->C->trace_opto_output())
2059           tty->print("#  *** STEP(%d >= %d instructions) ***\n",
2060             instruction_count + _bundle_instr_count,
2061             Pipeline::_max_instrs_per_cycle);
2062 #endif
2063         step(1);
2064       }
2065     }
2066 
2067     if (node_pipeline->hasBranchDelay() && !_unconditional_delay_slot)
2068       _bundle_instr_count++;
2069 
2070     // Set the node's latency
2071     _current_latency[n->_idx] = _bundle_cycle_number;
2072 
2073     // Now merge the functional unit information
2074     if (instruction_count > 0 || !node_pipeline->mayHaveNoCode())
2075       _bundle_use.add_usage(node_usage);
2076 
2077     // Increment the number of instructions in this bundle
2078     _bundle_instr_count += instruction_count;
2079 
2080     // Remember this node for later
2081     if (n->is_Mach())
2082       _next_node = n;
2083   }
2084 
2085   // It's possible to have a BoxLock in the graph and in the _bbs mapping but
2086   // not in the bb->_nodes array.  This happens for debug-info-only BoxLocks.
2087   // 'Schedule' them (basically ignore in the schedule) but do not insert them
2088   // into the block.  All other scheduled nodes get put in the schedule here.
2089   int op = n->Opcode();
2090   if( (op == Op_Node && n->req() == 0) || // anti-dependence node OR
2091       (op != Op_Node &&         // Not an unused antidepedence node and
2092        // not an unallocated boxlock
2093        (OptoReg::is_valid(_regalloc->get_reg_first(n)) || op != Op_BoxLock)) ) {
2094 
2095     // Push any trailing projections
2096     if( bb->_nodes[bb->_nodes.size()-1] != n ) {
2097       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2098         Node *foi = n->fast_out(i);
2099         if( foi->is_Proj() )
2100           _scheduled.push(foi);
2101       }
2102     }
2103 
2104     // Put the instruction in the schedule list
2105     _scheduled.push(n);
2106   }
2107 
2108 #ifndef PRODUCT
2109   if (_cfg->C->trace_opto_output())
2110     dump_available();
2111 #endif
2112 
2113   // Walk all the definitions, decrementing use counts, and
2114   // if a definition has a 0 use count, place it in the available list.
2115   DecrementUseCounts(n,bb);
2116 }
2117 
2118 //------------------------------ComputeUseCount--------------------------------
2119 // This method sets the use count within a basic block.  We will ignore all
2120 // uses outside the current basic block.  As we are doing a backwards walk,
2121 // any node we reach that has a use count of 0 may be scheduled.  This also
2122 // avoids the problem of cyclic references from phi nodes, as long as phi
2123 // nodes are at the front of the basic block.  This method also initializes
2124 // the available list to the set of instructions that have no uses within this
2125 // basic block.
2126 void Scheduling::ComputeUseCount(const Block *bb) {
2127 #ifndef PRODUCT
2128   if (_cfg->C->trace_opto_output())
2129     tty->print("# -> ComputeUseCount\n");
2130 #endif
2131 
2132   // Clear the list of available and scheduled instructions, just in case
2133   _available.clear();
2134   _scheduled.clear();
2135 
2136   // No delay slot specified
2137   _unconditional_delay_slot = NULL;
2138 
2139 #ifdef ASSERT
2140   for( uint i=0; i < bb->_nodes.size(); i++ )
2141     assert( _uses[bb->_nodes[i]->_idx] == 0, "_use array not clean" );
2142 #endif
2143 
2144   // Force the _uses count to never go to zero for unscheduable pieces
2145   // of the block
2146   for( uint k = 0; k < _bb_start; k++ )
2147     _uses[bb->_nodes[k]->_idx] = 1;
2148   for( uint l = _bb_end; l < bb->_nodes.size(); l++ )
2149     _uses[bb->_nodes[l]->_idx] = 1;
2150 
2151   // Iterate backwards over the instructions in the block.  Don't count the
2152   // branch projections at end or the block header instructions.
2153   for( uint j = _bb_end-1; j >= _bb_start; j-- ) {
2154     Node *n = bb->_nodes[j];
2155     if( n->is_Proj() ) continue; // Projections handled another way
2156 
2157     // Account for all uses
2158     for ( uint k = 0; k < n->len(); k++ ) {
2159       Node *inp = n->in(k);
2160       if (!inp) continue;
2161       assert(inp != n, "no cycles allowed" );
2162       if( _bbs[inp->_idx] == bb ) { // Block-local use?
2163         if( inp->is_Proj() )    // Skip through Proj's
2164           inp = inp->in(0);
2165         ++_uses[inp->_idx];     // Count 1 block-local use
2166       }
2167     }
2168 
2169     // If this instruction has a 0 use count, then it is available
2170     if (!_uses[n->_idx]) {
2171       _current_latency[n->_idx] = _bundle_cycle_number;
2172       AddNodeToAvailableList(n);
2173     }
2174 
2175 #ifndef PRODUCT
2176     if (_cfg->C->trace_opto_output()) {
2177       tty->print("#   uses: %3d: ", _uses[n->_idx]);
2178       n->dump();
2179     }
2180 #endif
2181   }
2182 
2183 #ifndef PRODUCT
2184   if (_cfg->C->trace_opto_output())
2185     tty->print("# <- ComputeUseCount\n");
2186 #endif
2187 }
2188 
2189 // This routine performs scheduling on each basic block in reverse order,
2190 // using instruction latencies and taking into account function unit
2191 // availability.
2192 void Scheduling::DoScheduling() {
2193 #ifndef PRODUCT
2194   if (_cfg->C->trace_opto_output())
2195     tty->print("# -> DoScheduling\n");
2196 #endif
2197 
2198   Block *succ_bb = NULL;
2199   Block *bb;
2200 
2201   // Walk over all the basic blocks in reverse order
2202   for( int i=_cfg->_num_blocks-1; i >= 0; succ_bb = bb, i-- ) {
2203     bb = _cfg->_blocks[i];
2204 
2205 #ifndef PRODUCT
2206     if (_cfg->C->trace_opto_output()) {
2207       tty->print("#  Schedule BB#%03d (initial)\n", i);
2208       for (uint j = 0; j < bb->_nodes.size(); j++)
2209         bb->_nodes[j]->dump();
2210     }
2211 #endif
2212 
2213     // On the head node, skip processing
2214     if( bb == _cfg->_broot )
2215       continue;
2216 
2217     // Skip empty, connector blocks
2218     if (bb->is_connector())
2219       continue;
2220 
2221     // If the following block is not the sole successor of
2222     // this one, then reset the pipeline information
2223     if (bb->_num_succs != 1 || bb->non_connector_successor(0) != succ_bb) {
2224 #ifndef PRODUCT
2225       if (_cfg->C->trace_opto_output()) {
2226         tty->print("*** bundle start of next BB, node %d, for %d instructions\n",
2227                    _next_node->_idx, _bundle_instr_count);
2228       }
2229 #endif
2230       step_and_clear();
2231     }
2232 
2233     // Leave untouched the starting instruction, any Phis, a CreateEx node
2234     // or Top.  bb->_nodes[_bb_start] is the first schedulable instruction.
2235     _bb_end = bb->_nodes.size()-1;
2236     for( _bb_start=1; _bb_start <= _bb_end; _bb_start++ ) {
2237       Node *n = bb->_nodes[_bb_start];
2238       // Things not matched, like Phinodes and ProjNodes don't get scheduled.
2239       // Also, MachIdealNodes do not get scheduled
2240       if( !n->is_Mach() ) continue;     // Skip non-machine nodes
2241       MachNode *mach = n->as_Mach();
2242       int iop = mach->ideal_Opcode();
2243       if( iop == Op_CreateEx ) continue; // CreateEx is pinned
2244       if( iop == Op_Con ) continue;      // Do not schedule Top
2245       if( iop == Op_Node &&     // Do not schedule PhiNodes, ProjNodes
2246           mach->pipeline() == MachNode::pipeline_class() &&
2247           !n->is_SpillCopy() )  // Breakpoints, Prolog, etc
2248         continue;
2249       break;                    // Funny loop structure to be sure...
2250     }
2251     // Compute last "interesting" instruction in block - last instruction we
2252     // might schedule.  _bb_end points just after last schedulable inst.  We
2253     // normally schedule conditional branches (despite them being forced last
2254     // in the block), because they have delay slots we can fill.  Calls all
2255     // have their delay slots filled in the template expansions, so we don't
2256     // bother scheduling them.
2257     Node *last = bb->_nodes[_bb_end];
2258     if( last->is_Catch() ||
2259        // Exclude unreachable path case when Halt node is in a separate block.
2260        (_bb_end > 1 && last->is_Mach() && last->as_Mach()->ideal_Opcode() == Op_Halt) ) {
2261       // There must be a prior call.  Skip it.
2262       while( !bb->_nodes[--_bb_end]->is_Call() ) {
2263         assert( bb->_nodes[_bb_end]->is_Proj(), "skipping projections after expected call" );
2264       }
2265     } else if( last->is_MachNullCheck() ) {
2266       // Backup so the last null-checked memory instruction is
2267       // outside the schedulable range. Skip over the nullcheck,
2268       // projection, and the memory nodes.
2269       Node *mem = last->in(1);
2270       do {
2271         _bb_end--;
2272       } while (mem != bb->_nodes[_bb_end]);
2273     } else {
2274       // Set _bb_end to point after last schedulable inst.
2275       _bb_end++;
2276     }
2277 
2278     assert( _bb_start <= _bb_end, "inverted block ends" );
2279 
2280     // Compute the register antidependencies for the basic block
2281     ComputeRegisterAntidependencies(bb);
2282     if (_cfg->C->failing())  return;  // too many D-U pinch points
2283 
2284     // Compute intra-bb latencies for the nodes
2285     ComputeLocalLatenciesForward(bb);
2286 
2287     // Compute the usage within the block, and set the list of all nodes
2288     // in the block that have no uses within the block.
2289     ComputeUseCount(bb);
2290 
2291     // Schedule the remaining instructions in the block
2292     while ( _available.size() > 0 ) {
2293       Node *n = ChooseNodeToBundle();
2294       AddNodeToBundle(n,bb);
2295     }
2296 
2297     assert( _scheduled.size() == _bb_end - _bb_start, "wrong number of instructions" );
2298 #ifdef ASSERT
2299     for( uint l = _bb_start; l < _bb_end; l++ ) {
2300       Node *n = bb->_nodes[l];
2301       uint m;
2302       for( m = 0; m < _bb_end-_bb_start; m++ )
2303         if( _scheduled[m] == n )
2304           break;
2305       assert( m < _bb_end-_bb_start, "instruction missing in schedule" );
2306     }
2307 #endif
2308 
2309     // Now copy the instructions (in reverse order) back to the block
2310     for ( uint k = _bb_start; k < _bb_end; k++ )
2311       bb->_nodes.map(k, _scheduled[_bb_end-k-1]);
2312 
2313 #ifndef PRODUCT
2314     if (_cfg->C->trace_opto_output()) {
2315       tty->print("#  Schedule BB#%03d (final)\n", i);
2316       uint current = 0;
2317       for (uint j = 0; j < bb->_nodes.size(); j++) {
2318         Node *n = bb->_nodes[j];
2319         if( valid_bundle_info(n) ) {
2320           Bundle *bundle = node_bundling(n);
2321           if (bundle->instr_count() > 0 || bundle->flags() > 0) {
2322             tty->print("*** Bundle: ");
2323             bundle->dump();
2324           }
2325           n->dump();
2326         }
2327       }
2328     }
2329 #endif
2330 #ifdef ASSERT
2331   verify_good_schedule(bb,"after block local scheduling");
2332 #endif
2333   }
2334 
2335 #ifndef PRODUCT
2336   if (_cfg->C->trace_opto_output())
2337     tty->print("# <- DoScheduling\n");
2338 #endif
2339 
2340   // Record final node-bundling array location
2341   _regalloc->C->set_node_bundling_base(_node_bundling_base);
2342 
2343 } // end DoScheduling
2344 
2345 //------------------------------verify_good_schedule---------------------------
2346 // Verify that no live-range used in the block is killed in the block by a
2347 // wrong DEF.  This doesn't verify live-ranges that span blocks.
2348 
2349 // Check for edge existence.  Used to avoid adding redundant precedence edges.
2350 static bool edge_from_to( Node *from, Node *to ) {
2351   for( uint i=0; i<from->len(); i++ )
2352     if( from->in(i) == to )
2353       return true;
2354   return false;
2355 }
2356 
2357 #ifdef ASSERT
2358 //------------------------------verify_do_def----------------------------------
2359 void Scheduling::verify_do_def( Node *n, OptoReg::Name def, const char *msg ) {
2360   // Check for bad kills
2361   if( OptoReg::is_valid(def) ) { // Ignore stores & control flow
2362     Node *prior_use = _reg_node[def];
2363     if( prior_use && !edge_from_to(prior_use,n) ) {
2364       tty->print("%s = ",OptoReg::as_VMReg(def)->name());
2365       n->dump();
2366       tty->print_cr("...");
2367       prior_use->dump();
2368       assert_msg(edge_from_to(prior_use,n),msg);
2369     }
2370     _reg_node.map(def,NULL); // Kill live USEs
2371   }
2372 }
2373 
2374 //------------------------------verify_good_schedule---------------------------
2375 void Scheduling::verify_good_schedule( Block *b, const char *msg ) {
2376 
2377   // Zap to something reasonable for the verify code
2378   _reg_node.clear();
2379 
2380   // Walk over the block backwards.  Check to make sure each DEF doesn't
2381   // kill a live value (other than the one it's supposed to).  Add each
2382   // USE to the live set.
2383   for( uint i = b->_nodes.size()-1; i >= _bb_start; i-- ) {
2384     Node *n = b->_nodes[i];
2385     int n_op = n->Opcode();
2386     if( n_op == Op_MachProj && n->ideal_reg() == MachProjNode::fat_proj ) {
2387       // Fat-proj kills a slew of registers
2388       RegMask rm = n->out_RegMask();// Make local copy
2389       while( rm.is_NotEmpty() ) {
2390         OptoReg::Name kill = rm.find_first_elem();
2391         rm.Remove(kill);
2392         verify_do_def( n, kill, msg );
2393       }
2394     } else if( n_op != Op_Node ) { // Avoid brand new antidependence nodes
2395       // Get DEF'd registers the normal way
2396       verify_do_def( n, _regalloc->get_reg_first(n), msg );
2397       verify_do_def( n, _regalloc->get_reg_second(n), msg );
2398     }
2399 
2400     // Now make all USEs live
2401     for( uint i=1; i<n->req(); i++ ) {
2402       Node *def = n->in(i);
2403       assert(def != 0, "input edge required");
2404       OptoReg::Name reg_lo = _regalloc->get_reg_first(def);
2405       OptoReg::Name reg_hi = _regalloc->get_reg_second(def);
2406       if( OptoReg::is_valid(reg_lo) ) {
2407         assert_msg(!_reg_node[reg_lo] || edge_from_to(_reg_node[reg_lo],def), msg );
2408         _reg_node.map(reg_lo,n);
2409       }
2410       if( OptoReg::is_valid(reg_hi) ) {
2411         assert_msg(!_reg_node[reg_hi] || edge_from_to(_reg_node[reg_hi],def), msg );
2412         _reg_node.map(reg_hi,n);
2413       }
2414     }
2415 
2416   }
2417 
2418   // Zap to something reasonable for the Antidependence code
2419   _reg_node.clear();
2420 }
2421 #endif
2422 
2423 // Conditionally add precedence edges.  Avoid putting edges on Projs.
2424 static void add_prec_edge_from_to( Node *from, Node *to ) {
2425   if( from->is_Proj() ) {       // Put precedence edge on Proj's input
2426     assert( from->req() == 1 && (from->len() == 1 || from->in(1)==0), "no precedence edges on projections" );
2427     from = from->in(0);
2428   }
2429   if( from != to &&             // No cycles (for things like LD L0,[L0+4] )
2430       !edge_from_to( from, to ) ) // Avoid duplicate edge
2431     from->add_prec(to);
2432 }
2433 
2434 //------------------------------anti_do_def------------------------------------
2435 void Scheduling::anti_do_def( Block *b, Node *def, OptoReg::Name def_reg, int is_def ) {
2436   if( !OptoReg::is_valid(def_reg) ) // Ignore stores & control flow
2437     return;
2438 
2439   Node *pinch = _reg_node[def_reg]; // Get pinch point
2440   if( !pinch || _bbs[pinch->_idx] != b || // No pinch-point yet?
2441       is_def ) {    // Check for a true def (not a kill)
2442     _reg_node.map(def_reg,def); // Record def/kill as the optimistic pinch-point
2443     return;
2444   }
2445 
2446   Node *kill = def;             // Rename 'def' to more descriptive 'kill'
2447   debug_only( def = (Node*)0xdeadbeef; )
2448 
2449   // After some number of kills there _may_ be a later def
2450   Node *later_def = NULL;
2451 
2452   // Finding a kill requires a real pinch-point.
2453   // Check for not already having a pinch-point.
2454   // Pinch points are Op_Node's.
2455   if( pinch->Opcode() != Op_Node ) { // Or later-def/kill as pinch-point?
2456     later_def = pinch;            // Must be def/kill as optimistic pinch-point
2457     if ( _pinch_free_list.size() > 0) {
2458       pinch = _pinch_free_list.pop();
2459     } else {
2460       pinch = new (_cfg->C, 1) Node(1); // Pinch point to-be
2461     }
2462     if (pinch->_idx >= _regalloc->node_regs_max_index()) {
2463       _cfg->C->record_method_not_compilable("too many D-U pinch points");
2464       return;
2465     }
2466     _bbs.map(pinch->_idx,b);      // Pretend it's valid in this block (lazy init)
2467     _reg_node.map(def_reg,pinch); // Record pinch-point
2468     //_regalloc->set_bad(pinch->_idx); // Already initialized this way.
2469     if( later_def->outcnt() == 0 || later_def->ideal_reg() == MachProjNode::fat_proj ) { // Distinguish def from kill
2470       pinch->init_req(0, _cfg->C->top());     // set not NULL for the next call
2471       add_prec_edge_from_to(later_def,pinch); // Add edge from kill to pinch
2472       later_def = NULL;           // and no later def
2473     }
2474     pinch->set_req(0,later_def);  // Hook later def so we can find it
2475   } else {                        // Else have valid pinch point
2476     if( pinch->in(0) )            // If there is a later-def
2477       later_def = pinch->in(0);   // Get it
2478   }
2479 
2480   // Add output-dependence edge from later def to kill
2481   if( later_def )               // If there is some original def
2482     add_prec_edge_from_to(later_def,kill); // Add edge from def to kill
2483 
2484   // See if current kill is also a use, and so is forced to be the pinch-point.
2485   if( pinch->Opcode() == Op_Node ) {
2486     Node *uses = kill->is_Proj() ? kill->in(0) : kill;
2487     for( uint i=1; i<uses->req(); i++ ) {
2488       if( _regalloc->get_reg_first(uses->in(i)) == def_reg ||
2489           _regalloc->get_reg_second(uses->in(i)) == def_reg ) {
2490         // Yes, found a use/kill pinch-point
2491         pinch->set_req(0,NULL);  //
2492         pinch->replace_by(kill); // Move anti-dep edges up
2493         pinch = kill;
2494         _reg_node.map(def_reg,pinch);
2495         return;
2496       }
2497     }
2498   }
2499 
2500   // Add edge from kill to pinch-point
2501   add_prec_edge_from_to(kill,pinch);
2502 }
2503 
2504 //------------------------------anti_do_use------------------------------------
2505 void Scheduling::anti_do_use( Block *b, Node *use, OptoReg::Name use_reg ) {
2506   if( !OptoReg::is_valid(use_reg) ) // Ignore stores & control flow
2507     return;
2508   Node *pinch = _reg_node[use_reg]; // Get pinch point
2509   // Check for no later def_reg/kill in block
2510   if( pinch && _bbs[pinch->_idx] == b &&
2511       // Use has to be block-local as well
2512       _bbs[use->_idx] == b ) {
2513     if( pinch->Opcode() == Op_Node && // Real pinch-point (not optimistic?)
2514         pinch->req() == 1 ) {   // pinch not yet in block?
2515       pinch->del_req(0);        // yank pointer to later-def, also set flag
2516       // Insert the pinch-point in the block just after the last use
2517       b->_nodes.insert(b->find_node(use)+1,pinch);
2518       _bb_end++;                // Increase size scheduled region in block
2519     }
2520 
2521     add_prec_edge_from_to(pinch,use);
2522   }
2523 }
2524 
2525 //------------------------------ComputeRegisterAntidependences-----------------
2526 // We insert antidependences between the reads and following write of
2527 // allocated registers to prevent illegal code motion. Hopefully, the
2528 // number of added references should be fairly small, especially as we
2529 // are only adding references within the current basic block.
2530 void Scheduling::ComputeRegisterAntidependencies(Block *b) {
2531 
2532 #ifdef ASSERT
2533   verify_good_schedule(b,"before block local scheduling");
2534 #endif
2535 
2536   // A valid schedule, for each register independently, is an endless cycle
2537   // of: a def, then some uses (connected to the def by true dependencies),
2538   // then some kills (defs with no uses), finally the cycle repeats with a new
2539   // def.  The uses are allowed to float relative to each other, as are the
2540   // kills.  No use is allowed to slide past a kill (or def).  This requires
2541   // antidependencies between all uses of a single def and all kills that
2542   // follow, up to the next def.  More edges are redundant, because later defs
2543   // & kills are already serialized with true or antidependencies.  To keep
2544   // the edge count down, we add a 'pinch point' node if there's more than
2545   // one use or more than one kill/def.
2546 
2547   // We add dependencies in one bottom-up pass.
2548 
2549   // For each instruction we handle it's DEFs/KILLs, then it's USEs.
2550 
2551   // For each DEF/KILL, we check to see if there's a prior DEF/KILL for this
2552   // register.  If not, we record the DEF/KILL in _reg_node, the
2553   // register-to-def mapping.  If there is a prior DEF/KILL, we insert a
2554   // "pinch point", a new Node that's in the graph but not in the block.
2555   // We put edges from the prior and current DEF/KILLs to the pinch point.
2556   // We put the pinch point in _reg_node.  If there's already a pinch point
2557   // we merely add an edge from the current DEF/KILL to the pinch point.
2558 
2559   // After doing the DEF/KILLs, we handle USEs.  For each used register, we
2560   // put an edge from the pinch point to the USE.
2561 
2562   // To be expedient, the _reg_node array is pre-allocated for the whole
2563   // compilation.  _reg_node is lazily initialized; it either contains a NULL,
2564   // or a valid def/kill/pinch-point, or a leftover node from some prior
2565   // block.  Leftover node from some prior block is treated like a NULL (no
2566   // prior def, so no anti-dependence needed).  Valid def is distinguished by
2567   // it being in the current block.
2568   bool fat_proj_seen = false;
2569   uint last_safept = _bb_end-1;
2570   Node* end_node         = (_bb_end-1 >= _bb_start) ? b->_nodes[last_safept] : NULL;
2571   Node* last_safept_node = end_node;
2572   for( uint i = _bb_end-1; i >= _bb_start; i-- ) {
2573     Node *n = b->_nodes[i];
2574     int is_def = n->outcnt();   // def if some uses prior to adding precedence edges
2575     if( n->Opcode() == Op_MachProj && n->ideal_reg() == MachProjNode::fat_proj ) {
2576       // Fat-proj kills a slew of registers
2577       // This can add edges to 'n' and obscure whether or not it was a def,
2578       // hence the is_def flag.
2579       fat_proj_seen = true;
2580       RegMask rm = n->out_RegMask();// Make local copy
2581       while( rm.is_NotEmpty() ) {
2582         OptoReg::Name kill = rm.find_first_elem();
2583         rm.Remove(kill);
2584         anti_do_def( b, n, kill, is_def );
2585       }
2586     } else {
2587       // Get DEF'd registers the normal way
2588       anti_do_def( b, n, _regalloc->get_reg_first(n), is_def );
2589       anti_do_def( b, n, _regalloc->get_reg_second(n), is_def );
2590     }
2591 
2592     // Check each register used by this instruction for a following DEF/KILL
2593     // that must occur afterward and requires an anti-dependence edge.
2594     for( uint j=0; j<n->req(); j++ ) {
2595       Node *def = n->in(j);
2596       if( def ) {
2597         assert( def->Opcode() != Op_MachProj || def->ideal_reg() != MachProjNode::fat_proj, "" );
2598         anti_do_use( b, n, _regalloc->get_reg_first(def) );
2599         anti_do_use( b, n, _regalloc->get_reg_second(def) );
2600       }
2601     }
2602     // Do not allow defs of new derived values to float above GC
2603     // points unless the base is definitely available at the GC point.
2604 
2605     Node *m = b->_nodes[i];
2606 
2607     // Add precedence edge from following safepoint to use of derived pointer
2608     if( last_safept_node != end_node &&
2609         m != last_safept_node) {
2610       for (uint k = 1; k < m->req(); k++) {
2611         const Type *t = m->in(k)->bottom_type();
2612         if( t->isa_oop_ptr() &&
2613             t->is_ptr()->offset() != 0 ) {
2614           last_safept_node->add_prec( m );
2615           break;
2616         }
2617       }
2618     }
2619 
2620     if( n->jvms() ) {           // Precedence edge from derived to safept
2621       // Check if last_safept_node was moved by pinch-point insertion in anti_do_use()
2622       if( b->_nodes[last_safept] != last_safept_node ) {
2623         last_safept = b->find_node(last_safept_node);
2624       }
2625       for( uint j=last_safept; j > i; j-- ) {
2626         Node *mach = b->_nodes[j];
2627         if( mach->is_Mach() && mach->as_Mach()->ideal_Opcode() == Op_AddP )
2628           mach->add_prec( n );
2629       }
2630       last_safept = i;
2631       last_safept_node = m;
2632     }
2633   }
2634 
2635   if (fat_proj_seen) {
2636     // Garbage collect pinch nodes that were not consumed.
2637     // They are usually created by a fat kill MachProj for a call.
2638     garbage_collect_pinch_nodes();
2639   }
2640 }
2641 
2642 //------------------------------garbage_collect_pinch_nodes-------------------------------
2643 
2644 // Garbage collect pinch nodes for reuse by other blocks.
2645 //
2646 // The block scheduler's insertion of anti-dependence
2647 // edges creates many pinch nodes when the block contains
2648 // 2 or more Calls.  A pinch node is used to prevent a
2649 // combinatorial explosion of edges.  If a set of kills for a
2650 // register is anti-dependent on a set of uses (or defs), rather
2651 // than adding an edge in the graph between each pair of kill
2652 // and use (or def), a pinch is inserted between them:
2653 //
2654 //            use1   use2  use3
2655 //                \   |   /
2656 //                 \  |  /
2657 //                  pinch
2658 //                 /  |  \
2659 //                /   |   \
2660 //            kill1 kill2 kill3
2661 //
2662 // One pinch node is created per register killed when
2663 // the second call is encountered during a backwards pass
2664 // over the block.  Most of these pinch nodes are never
2665 // wired into the graph because the register is never
2666 // used or def'ed in the block.
2667 //
2668 void Scheduling::garbage_collect_pinch_nodes() {
2669 #ifndef PRODUCT
2670     if (_cfg->C->trace_opto_output()) tty->print("Reclaimed pinch nodes:");
2671 #endif
2672     int trace_cnt = 0;
2673     for (uint k = 0; k < _reg_node.Size(); k++) {
2674       Node* pinch = _reg_node[k];
2675       if (pinch != NULL && pinch->Opcode() == Op_Node &&
2676           // no predecence input edges
2677           (pinch->req() == pinch->len() || pinch->in(pinch->req()) == NULL) ) {
2678         cleanup_pinch(pinch);
2679         _pinch_free_list.push(pinch);
2680         _reg_node.map(k, NULL);
2681 #ifndef PRODUCT
2682         if (_cfg->C->trace_opto_output()) {
2683           trace_cnt++;
2684           if (trace_cnt > 40) {
2685             tty->print("\n");
2686             trace_cnt = 0;
2687           }
2688           tty->print(" %d", pinch->_idx);
2689         }
2690 #endif
2691       }
2692     }
2693 #ifndef PRODUCT
2694     if (_cfg->C->trace_opto_output()) tty->print("\n");
2695 #endif
2696 }
2697 
2698 // Clean up a pinch node for reuse.
2699 void Scheduling::cleanup_pinch( Node *pinch ) {
2700   assert (pinch && pinch->Opcode() == Op_Node && pinch->req() == 1, "just checking");
2701 
2702   for (DUIterator_Last imin, i = pinch->last_outs(imin); i >= imin; ) {
2703     Node* use = pinch->last_out(i);
2704     uint uses_found = 0;
2705     for (uint j = use->req(); j < use->len(); j++) {
2706       if (use->in(j) == pinch) {
2707         use->rm_prec(j);
2708         uses_found++;
2709       }
2710     }
2711     assert(uses_found > 0, "must be a precedence edge");
2712     i -= uses_found;    // we deleted 1 or more copies of this edge
2713   }
2714   // May have a later_def entry
2715   pinch->set_req(0, NULL);
2716 }
2717 
2718 //------------------------------print_statistics-------------------------------
2719 #ifndef PRODUCT
2720 
2721 void Scheduling::dump_available() const {
2722   tty->print("#Availist  ");
2723   for (uint i = 0; i < _available.size(); i++)
2724     tty->print(" N%d/l%d", _available[i]->_idx,_current_latency[_available[i]->_idx]);
2725   tty->cr();
2726 }
2727 
2728 // Print Scheduling Statistics
2729 void Scheduling::print_statistics() {
2730   // Print the size added by nops for bundling
2731   tty->print("Nops added %d bytes to total of %d bytes",
2732     _total_nop_size, _total_method_size);
2733   if (_total_method_size > 0)
2734     tty->print(", for %.2f%%",
2735       ((double)_total_nop_size) / ((double) _total_method_size) * 100.0);
2736   tty->print("\n");
2737 
2738   // Print the number of branch shadows filled
2739   if (Pipeline::_branch_has_delay_slot) {
2740     tty->print("Of %d branches, %d had unconditional delay slots filled",
2741       _total_branches, _total_unconditional_delays);
2742     if (_total_branches > 0)
2743       tty->print(", for %.2f%%",
2744         ((double)_total_unconditional_delays) / ((double)_total_branches) * 100.0);
2745     tty->print("\n");
2746   }
2747 
2748   uint total_instructions = 0, total_bundles = 0;
2749 
2750   for (uint i = 1; i <= Pipeline::_max_instrs_per_cycle; i++) {
2751     uint bundle_count   = _total_instructions_per_bundle[i];
2752     total_instructions += bundle_count * i;
2753     total_bundles      += bundle_count;
2754   }
2755 
2756   if (total_bundles > 0)
2757     tty->print("Average ILP (excluding nops) is %.2f\n",
2758       ((double)total_instructions) / ((double)total_bundles));
2759 }
2760 #endif
--- EOF ---