1 /*
   2  * Copyright 1997-2007 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/_matcher.cpp.incl"
  27 
  28 OptoReg::Name OptoReg::c_frame_pointer;
  29 
  30 
  31 
  32 const int Matcher::base2reg[Type::lastype] = {
  33   Node::NotAMachineReg,0,0, Op_RegI, Op_RegL, 0, Op_RegN,
  34   Node::NotAMachineReg, Node::NotAMachineReg, /* tuple, array */
  35   Op_RegP, Op_RegP, Op_RegP, Op_RegP, Op_RegP, Op_RegP, /* the pointers */
  36   0, 0/*abio*/,
  37   Op_RegP /* Return address */, 0, /* the memories */
  38   Op_RegF, Op_RegF, Op_RegF, Op_RegD, Op_RegD, Op_RegD,
  39   0  /*bottom*/
  40 };
  41 
  42 const RegMask *Matcher::idealreg2regmask[_last_machine_leaf];
  43 RegMask Matcher::mreg2regmask[_last_Mach_Reg];
  44 RegMask Matcher::STACK_ONLY_mask;
  45 RegMask Matcher::c_frame_ptr_mask;
  46 const uint Matcher::_begin_rematerialize = _BEGIN_REMATERIALIZE;
  47 const uint Matcher::_end_rematerialize   = _END_REMATERIALIZE;
  48 
  49 //---------------------------Matcher-------------------------------------------
  50 Matcher::Matcher( Node_List &proj_list ) :
  51   PhaseTransform( Phase::Ins_Select ),
  52 #ifdef ASSERT
  53   _old2new_map(C->comp_arena()),
  54   _new2old_map(C->comp_arena()),
  55 #endif
  56   _shared_nodes(C->comp_arena()),
  57   _reduceOp(reduceOp), _leftOp(leftOp), _rightOp(rightOp),
  58   _swallowed(swallowed),
  59   _begin_inst_chain_rule(_BEGIN_INST_CHAIN_RULE),
  60   _end_inst_chain_rule(_END_INST_CHAIN_RULE),
  61   _must_clone(must_clone), _proj_list(proj_list),
  62   _register_save_policy(register_save_policy),
  63   _c_reg_save_policy(c_reg_save_policy),
  64   _register_save_type(register_save_type),
  65   _ruleName(ruleName),
  66   _allocation_started(false),
  67   _states_arena(Chunk::medium_size),
  68   _visited(&_states_arena),
  69   _shared(&_states_arena),
  70   _dontcare(&_states_arena) {
  71   C->set_matcher(this);
  72 
  73   idealreg2spillmask[Op_RegI] = NULL;
  74   idealreg2spillmask[Op_RegN] = NULL;
  75   idealreg2spillmask[Op_RegL] = NULL;
  76   idealreg2spillmask[Op_RegF] = NULL;
  77   idealreg2spillmask[Op_RegD] = NULL;
  78   idealreg2spillmask[Op_RegP] = NULL;
  79 
  80   idealreg2debugmask[Op_RegI] = NULL;
  81   idealreg2debugmask[Op_RegN] = NULL;
  82   idealreg2debugmask[Op_RegL] = NULL;
  83   idealreg2debugmask[Op_RegF] = NULL;
  84   idealreg2debugmask[Op_RegD] = NULL;
  85   idealreg2debugmask[Op_RegP] = NULL;
  86 }
  87 
  88 //------------------------------warp_incoming_stk_arg------------------------
  89 // This warps a VMReg into an OptoReg::Name
  90 OptoReg::Name Matcher::warp_incoming_stk_arg( VMReg reg ) {
  91   OptoReg::Name warped;
  92   if( reg->is_stack() ) {  // Stack slot argument?
  93     warped = OptoReg::add(_old_SP, reg->reg2stack() );
  94     warped = OptoReg::add(warped, C->out_preserve_stack_slots());
  95     if( warped >= _in_arg_limit )
  96       _in_arg_limit = OptoReg::add(warped, 1); // Bump max stack slot seen
  97     if (!RegMask::can_represent(warped)) {
  98       // the compiler cannot represent this method's calling sequence
  99       C->record_method_not_compilable_all_tiers("unsupported incoming calling sequence");
 100       return OptoReg::Bad;
 101     }
 102     return warped;
 103   }
 104   return OptoReg::as_OptoReg(reg);
 105 }
 106 
 107 //---------------------------compute_old_SP------------------------------------
 108 OptoReg::Name Compile::compute_old_SP() {
 109   int fixed    = fixed_slots();
 110   int preserve = in_preserve_stack_slots();
 111   return OptoReg::stack2reg(round_to(fixed + preserve, Matcher::stack_alignment_in_slots()));
 112 }
 113 
 114 
 115 
 116 #ifdef ASSERT
 117 void Matcher::verify_new_nodes_only(Node* xroot) {
 118   // Make sure that the new graph only references new nodes
 119   ResourceMark rm;
 120   Unique_Node_List worklist;
 121   VectorSet visited(Thread::current()->resource_area());
 122   worklist.push(xroot);
 123   while (worklist.size() > 0) {
 124     Node* n = worklist.pop();
 125     visited <<= n->_idx;
 126     assert(C->node_arena()->contains(n), "dead node");
 127     for (uint j = 0; j < n->req(); j++) {
 128       Node* in = n->in(j);
 129       if (in != NULL) {
 130         assert(C->node_arena()->contains(in), "dead node");
 131         if (!visited.test(in->_idx)) {
 132           worklist.push(in);
 133         }
 134       }
 135     }
 136   }
 137 }
 138 #endif
 139 
 140 
 141 //---------------------------match---------------------------------------------
 142 void Matcher::match( ) {
 143   // One-time initialization of some register masks.
 144   init_spill_mask( C->root()->in(1) );
 145   _return_addr_mask = return_addr();
 146 #ifdef _LP64
 147   // Pointers take 2 slots in 64-bit land
 148   _return_addr_mask.Insert(OptoReg::add(return_addr(),1));
 149 #endif
 150 
 151   // Map a Java-signature return type into return register-value
 152   // machine registers for 0, 1 and 2 returned values.
 153   const TypeTuple *range = C->tf()->range();
 154   if( range->cnt() > TypeFunc::Parms ) { // If not a void function
 155     // Get ideal-register return type
 156     int ireg = base2reg[range->field_at(TypeFunc::Parms)->base()];
 157     // Get machine return register
 158     uint sop = C->start()->Opcode();
 159     OptoRegPair regs = return_value(ireg, false);
 160 
 161     // And mask for same
 162     _return_value_mask = RegMask(regs.first());
 163     if( OptoReg::is_valid(regs.second()) )
 164       _return_value_mask.Insert(regs.second());
 165   }
 166 
 167   // ---------------
 168   // Frame Layout
 169 
 170   // Need the method signature to determine the incoming argument types,
 171   // because the types determine which registers the incoming arguments are
 172   // in, and this affects the matched code.
 173   const TypeTuple *domain = C->tf()->domain();
 174   uint             argcnt = domain->cnt() - TypeFunc::Parms;
 175   BasicType *sig_bt        = NEW_RESOURCE_ARRAY( BasicType, argcnt );
 176   VMRegPair *vm_parm_regs  = NEW_RESOURCE_ARRAY( VMRegPair, argcnt );
 177   _parm_regs               = NEW_RESOURCE_ARRAY( OptoRegPair, argcnt );
 178   _calling_convention_mask = NEW_RESOURCE_ARRAY( RegMask, argcnt );
 179   uint i;
 180   for( i = 0; i<argcnt; i++ ) {
 181     sig_bt[i] = domain->field_at(i+TypeFunc::Parms)->basic_type();
 182   }
 183 
 184   // Pass array of ideal registers and length to USER code (from the AD file)
 185   // that will convert this to an array of register numbers.
 186   const StartNode *start = C->start();
 187   start->calling_convention( sig_bt, vm_parm_regs, argcnt );
 188 #ifdef ASSERT
 189   // Sanity check users' calling convention.  Real handy while trying to
 190   // get the initial port correct.
 191   { for (uint i = 0; i<argcnt; i++) {
 192       if( !vm_parm_regs[i].first()->is_valid() && !vm_parm_regs[i].second()->is_valid() ) {
 193         assert(domain->field_at(i+TypeFunc::Parms)==Type::HALF, "only allowed on halve" );
 194         _parm_regs[i].set_bad();
 195         continue;
 196       }
 197       VMReg parm_reg = vm_parm_regs[i].first();
 198       assert(parm_reg->is_valid(), "invalid arg?");
 199       if (parm_reg->is_reg()) {
 200         OptoReg::Name opto_parm_reg = OptoReg::as_OptoReg(parm_reg);
 201         assert(can_be_java_arg(opto_parm_reg) ||
 202                C->stub_function() == CAST_FROM_FN_PTR(address, OptoRuntime::rethrow_C) ||
 203                opto_parm_reg == inline_cache_reg(),
 204                "parameters in register must be preserved by runtime stubs");
 205       }
 206       for (uint j = 0; j < i; j++) {
 207         assert(parm_reg != vm_parm_regs[j].first(),
 208                "calling conv. must produce distinct regs");
 209       }
 210     }
 211   }
 212 #endif
 213 
 214   // Do some initial frame layout.
 215 
 216   // Compute the old incoming SP (may be called FP) as
 217   //   OptoReg::stack0() + locks + in_preserve_stack_slots + pad2.
 218   _old_SP = C->compute_old_SP();
 219   assert( is_even(_old_SP), "must be even" );
 220 
 221   // Compute highest incoming stack argument as
 222   //   _old_SP + out_preserve_stack_slots + incoming argument size.
 223   _in_arg_limit = OptoReg::add(_old_SP, C->out_preserve_stack_slots());
 224   assert( is_even(_in_arg_limit), "out_preserve must be even" );
 225   for( i = 0; i < argcnt; i++ ) {
 226     // Permit args to have no register
 227     _calling_convention_mask[i].Clear();
 228     if( !vm_parm_regs[i].first()->is_valid() && !vm_parm_regs[i].second()->is_valid() ) {
 229       continue;
 230     }
 231     // calling_convention returns stack arguments as a count of
 232     // slots beyond OptoReg::stack0()/VMRegImpl::stack0.  We need to convert this to
 233     // the allocators point of view, taking into account all the
 234     // preserve area, locks & pad2.
 235 
 236     OptoReg::Name reg1 = warp_incoming_stk_arg(vm_parm_regs[i].first());
 237     if( OptoReg::is_valid(reg1))
 238       _calling_convention_mask[i].Insert(reg1);
 239 
 240     OptoReg::Name reg2 = warp_incoming_stk_arg(vm_parm_regs[i].second());
 241     if( OptoReg::is_valid(reg2))
 242       _calling_convention_mask[i].Insert(reg2);
 243 
 244     // Saved biased stack-slot register number
 245     _parm_regs[i].set_pair(reg2, reg1);
 246   }
 247 
 248   // Finally, make sure the incoming arguments take up an even number of
 249   // words, in case the arguments or locals need to contain doubleword stack
 250   // slots.  The rest of the system assumes that stack slot pairs (in
 251   // particular, in the spill area) which look aligned will in fact be
 252   // aligned relative to the stack pointer in the target machine.  Double
 253   // stack slots will always be allocated aligned.
 254   _new_SP = OptoReg::Name(round_to(_in_arg_limit, RegMask::SlotsPerLong));
 255 
 256   // Compute highest outgoing stack argument as
 257   //   _new_SP + out_preserve_stack_slots + max(outgoing argument size).
 258   _out_arg_limit = OptoReg::add(_new_SP, C->out_preserve_stack_slots());
 259   assert( is_even(_out_arg_limit), "out_preserve must be even" );
 260 
 261   if (!RegMask::can_represent(OptoReg::add(_out_arg_limit,-1))) {
 262     // the compiler cannot represent this method's calling sequence
 263     C->record_method_not_compilable("must be able to represent all call arguments in reg mask");
 264   }
 265 
 266   if (C->failing())  return;  // bailed out on incoming arg failure
 267 
 268   // ---------------
 269   // Collect roots of matcher trees.  Every node for which
 270   // _shared[_idx] is cleared is guaranteed to not be shared, and thus
 271   // can be a valid interior of some tree.
 272   find_shared( C->root() );
 273   find_shared( C->top() );
 274 
 275   C->print_method("Before Matching", 2);
 276 
 277   // Swap out to old-space; emptying new-space
 278   Arena *old = C->node_arena()->move_contents(C->old_arena());
 279 
 280   // Save debug and profile information for nodes in old space:
 281   _old_node_note_array = C->node_note_array();
 282   if (_old_node_note_array != NULL) {
 283     C->set_node_note_array(new(C->comp_arena()) GrowableArray<Node_Notes*>
 284                            (C->comp_arena(), _old_node_note_array->length(),
 285                             0, NULL));
 286   }
 287 
 288   // Pre-size the new_node table to avoid the need for range checks.
 289   grow_new_node_array(C->unique());
 290 
 291   // Reset node counter so MachNodes start with _idx at 0
 292   int nodes = C->unique(); // save value
 293   C->set_unique(0);
 294 
 295   // Recursively match trees from old space into new space.
 296   // Correct leaves of new-space Nodes; they point to old-space.
 297   _visited.Clear();             // Clear visit bits for xform call
 298   C->set_cached_top_node(xform( C->top(), nodes ));
 299   if (!C->failing()) {
 300     Node* xroot =        xform( C->root(), 1 );
 301     if (xroot == NULL) {
 302       Matcher::soft_match_failure();  // recursive matching process failed
 303       C->record_method_not_compilable("instruction match failed");
 304     } else {
 305       // During matching shared constants were attached to C->root()
 306       // because xroot wasn't available yet, so transfer the uses to
 307       // the xroot.
 308       for( DUIterator_Fast jmax, j = C->root()->fast_outs(jmax); j < jmax; j++ ) {
 309         Node* n = C->root()->fast_out(j);
 310         if (C->node_arena()->contains(n)) {
 311           assert(n->in(0) == C->root(), "should be control user");
 312           n->set_req(0, xroot);
 313           --j;
 314           --jmax;
 315         }
 316       }
 317 
 318       C->set_root(xroot->is_Root() ? xroot->as_Root() : NULL);
 319 #ifdef ASSERT
 320       verify_new_nodes_only(xroot);
 321 #endif
 322     }
 323   }
 324   if (C->top() == NULL || C->root() == NULL) {
 325     C->record_method_not_compilable("graph lost"); // %%% cannot happen?
 326   }
 327   if (C->failing()) {
 328     // delete old;
 329     old->destruct_contents();
 330     return;
 331   }
 332   assert( C->top(), "" );
 333   assert( C->root(), "" );
 334   validate_null_checks();
 335 
 336   // Now smoke old-space
 337   NOT_DEBUG( old->destruct_contents() );
 338 
 339   // ------------------------
 340   // Set up save-on-entry registers
 341   Fixup_Save_On_Entry( );
 342 }
 343 
 344 
 345 //------------------------------Fixup_Save_On_Entry----------------------------
 346 // The stated purpose of this routine is to take care of save-on-entry
 347 // registers.  However, the overall goal of the Match phase is to convert into
 348 // machine-specific instructions which have RegMasks to guide allocation.
 349 // So what this procedure really does is put a valid RegMask on each input
 350 // to the machine-specific variations of all Return, TailCall and Halt
 351 // instructions.  It also adds edgs to define the save-on-entry values (and of
 352 // course gives them a mask).
 353 
 354 static RegMask *init_input_masks( uint size, RegMask &ret_adr, RegMask &fp ) {
 355   RegMask *rms = NEW_RESOURCE_ARRAY( RegMask, size );
 356   // Do all the pre-defined register masks
 357   rms[TypeFunc::Control  ] = RegMask::Empty;
 358   rms[TypeFunc::I_O      ] = RegMask::Empty;
 359   rms[TypeFunc::Memory   ] = RegMask::Empty;
 360   rms[TypeFunc::ReturnAdr] = ret_adr;
 361   rms[TypeFunc::FramePtr ] = fp;
 362   return rms;
 363 }
 364 
 365 //---------------------------init_first_stack_mask-----------------------------
 366 // Create the initial stack mask used by values spilling to the stack.
 367 // Disallow any debug info in outgoing argument areas by setting the
 368 // initial mask accordingly.
 369 void Matcher::init_first_stack_mask() {
 370 
 371   // Allocate storage for spill masks as masks for the appropriate load type.
 372   RegMask *rms = (RegMask*)C->comp_arena()->Amalloc_D(sizeof(RegMask)*12);
 373   idealreg2spillmask[Op_RegN] = &rms[0];
 374   idealreg2spillmask[Op_RegI] = &rms[1];
 375   idealreg2spillmask[Op_RegL] = &rms[2];
 376   idealreg2spillmask[Op_RegF] = &rms[3];
 377   idealreg2spillmask[Op_RegD] = &rms[4];
 378   idealreg2spillmask[Op_RegP] = &rms[5];
 379   idealreg2debugmask[Op_RegN] = &rms[6];
 380   idealreg2debugmask[Op_RegI] = &rms[7];
 381   idealreg2debugmask[Op_RegL] = &rms[8];
 382   idealreg2debugmask[Op_RegF] = &rms[9];
 383   idealreg2debugmask[Op_RegD] = &rms[10];
 384   idealreg2debugmask[Op_RegP] = &rms[11];
 385 
 386   OptoReg::Name i;
 387 
 388   // At first, start with the empty mask
 389   C->FIRST_STACK_mask().Clear();
 390 
 391   // Add in the incoming argument area
 392   OptoReg::Name init = OptoReg::add(_old_SP, C->out_preserve_stack_slots());
 393   for (i = init; i < _in_arg_limit; i = OptoReg::add(i,1))
 394     C->FIRST_STACK_mask().Insert(i);
 395 
 396   // Add in all bits past the outgoing argument area
 397   guarantee(RegMask::can_represent(OptoReg::add(_out_arg_limit,-1)),
 398             "must be able to represent all call arguments in reg mask");
 399   init = _out_arg_limit;
 400   for (i = init; RegMask::can_represent(i); i = OptoReg::add(i,1))
 401     C->FIRST_STACK_mask().Insert(i);
 402 
 403   // Finally, set the "infinite stack" bit.
 404   C->FIRST_STACK_mask().set_AllStack();
 405 
 406   // Make spill masks.  Registers for their class, plus FIRST_STACK_mask.
 407 #ifdef _LP64
 408   *idealreg2spillmask[Op_RegN] = *idealreg2regmask[Op_RegN];
 409    idealreg2spillmask[Op_RegN]->OR(C->FIRST_STACK_mask());
 410 #endif
 411   *idealreg2spillmask[Op_RegI] = *idealreg2regmask[Op_RegI];
 412    idealreg2spillmask[Op_RegI]->OR(C->FIRST_STACK_mask());
 413   *idealreg2spillmask[Op_RegL] = *idealreg2regmask[Op_RegL];
 414    idealreg2spillmask[Op_RegL]->OR(C->FIRST_STACK_mask());
 415   *idealreg2spillmask[Op_RegF] = *idealreg2regmask[Op_RegF];
 416    idealreg2spillmask[Op_RegF]->OR(C->FIRST_STACK_mask());
 417   *idealreg2spillmask[Op_RegD] = *idealreg2regmask[Op_RegD];
 418    idealreg2spillmask[Op_RegD]->OR(C->FIRST_STACK_mask());
 419   *idealreg2spillmask[Op_RegP] = *idealreg2regmask[Op_RegP];
 420    idealreg2spillmask[Op_RegP]->OR(C->FIRST_STACK_mask());
 421 
 422   // Make up debug masks.  Any spill slot plus callee-save registers.
 423   // Caller-save registers are assumed to be trashable by the various
 424   // inline-cache fixup routines.
 425   *idealreg2debugmask[Op_RegN]= *idealreg2spillmask[Op_RegN];
 426   *idealreg2debugmask[Op_RegI]= *idealreg2spillmask[Op_RegI];
 427   *idealreg2debugmask[Op_RegL]= *idealreg2spillmask[Op_RegL];
 428   *idealreg2debugmask[Op_RegF]= *idealreg2spillmask[Op_RegF];
 429   *idealreg2debugmask[Op_RegD]= *idealreg2spillmask[Op_RegD];
 430   *idealreg2debugmask[Op_RegP]= *idealreg2spillmask[Op_RegP];
 431 
 432   // Prevent stub compilations from attempting to reference
 433   // callee-saved registers from debug info
 434   bool exclude_soe = !Compile::current()->is_method_compilation();
 435 
 436   for( i=OptoReg::Name(0); i<OptoReg::Name(_last_Mach_Reg); i = OptoReg::add(i,1) ) {
 437     // registers the caller has to save do not work
 438     if( _register_save_policy[i] == 'C' ||
 439         _register_save_policy[i] == 'A' ||
 440         (_register_save_policy[i] == 'E' && exclude_soe) ) {
 441       idealreg2debugmask[Op_RegN]->Remove(i);
 442       idealreg2debugmask[Op_RegI]->Remove(i); // Exclude save-on-call
 443       idealreg2debugmask[Op_RegL]->Remove(i); // registers from debug
 444       idealreg2debugmask[Op_RegF]->Remove(i); // masks
 445       idealreg2debugmask[Op_RegD]->Remove(i);
 446       idealreg2debugmask[Op_RegP]->Remove(i);
 447     }
 448   }
 449 }
 450 
 451 //---------------------------is_save_on_entry----------------------------------
 452 bool Matcher::is_save_on_entry( int reg ) {
 453   return
 454     _register_save_policy[reg] == 'E' ||
 455     _register_save_policy[reg] == 'A' || // Save-on-entry register?
 456     // Also save argument registers in the trampolining stubs
 457     (C->save_argument_registers() && is_spillable_arg(reg));
 458 }
 459 
 460 //---------------------------Fixup_Save_On_Entry-------------------------------
 461 void Matcher::Fixup_Save_On_Entry( ) {
 462   init_first_stack_mask();
 463 
 464   Node *root = C->root();       // Short name for root
 465   // Count number of save-on-entry registers.
 466   uint soe_cnt = number_of_saved_registers();
 467   uint i;
 468 
 469   // Find the procedure Start Node
 470   StartNode *start = C->start();
 471   assert( start, "Expect a start node" );
 472 
 473   // Save argument registers in the trampolining stubs
 474   if( C->save_argument_registers() )
 475     for( i = 0; i < _last_Mach_Reg; i++ )
 476       if( is_spillable_arg(i) )
 477         soe_cnt++;
 478 
 479   // Input RegMask array shared by all Returns.
 480   // The type for doubles and longs has a count of 2, but
 481   // there is only 1 returned value
 482   uint ret_edge_cnt = TypeFunc::Parms + ((C->tf()->range()->cnt() == TypeFunc::Parms) ? 0 : 1);
 483   RegMask *ret_rms  = init_input_masks( ret_edge_cnt + soe_cnt, _return_addr_mask, c_frame_ptr_mask );
 484   // Returns have 0 or 1 returned values depending on call signature.
 485   // Return register is specified by return_value in the AD file.
 486   if (ret_edge_cnt > TypeFunc::Parms)
 487     ret_rms[TypeFunc::Parms+0] = _return_value_mask;
 488 
 489   // Input RegMask array shared by all Rethrows.
 490   uint reth_edge_cnt = TypeFunc::Parms+1;
 491   RegMask *reth_rms  = init_input_masks( reth_edge_cnt + soe_cnt, _return_addr_mask, c_frame_ptr_mask );
 492   // Rethrow takes exception oop only, but in the argument 0 slot.
 493   reth_rms[TypeFunc::Parms] = mreg2regmask[find_receiver(false)];
 494 #ifdef _LP64
 495   // Need two slots for ptrs in 64-bit land
 496   reth_rms[TypeFunc::Parms].Insert(OptoReg::add(OptoReg::Name(find_receiver(false)),1));
 497 #endif
 498 
 499   // Input RegMask array shared by all TailCalls
 500   uint tail_call_edge_cnt = TypeFunc::Parms+2;
 501   RegMask *tail_call_rms = init_input_masks( tail_call_edge_cnt + soe_cnt, _return_addr_mask, c_frame_ptr_mask );
 502 
 503   // Input RegMask array shared by all TailJumps
 504   uint tail_jump_edge_cnt = TypeFunc::Parms+2;
 505   RegMask *tail_jump_rms = init_input_masks( tail_jump_edge_cnt + soe_cnt, _return_addr_mask, c_frame_ptr_mask );
 506 
 507   // TailCalls have 2 returned values (target & moop), whose masks come
 508   // from the usual MachNode/MachOper mechanism.  Find a sample
 509   // TailCall to extract these masks and put the correct masks into
 510   // the tail_call_rms array.
 511   for( i=1; i < root->req(); i++ ) {
 512     MachReturnNode *m = root->in(i)->as_MachReturn();
 513     if( m->ideal_Opcode() == Op_TailCall ) {
 514       tail_call_rms[TypeFunc::Parms+0] = m->MachNode::in_RegMask(TypeFunc::Parms+0);
 515       tail_call_rms[TypeFunc::Parms+1] = m->MachNode::in_RegMask(TypeFunc::Parms+1);
 516       break;
 517     }
 518   }
 519 
 520   // TailJumps have 2 returned values (target & ex_oop), whose masks come
 521   // from the usual MachNode/MachOper mechanism.  Find a sample
 522   // TailJump to extract these masks and put the correct masks into
 523   // the tail_jump_rms array.
 524   for( i=1; i < root->req(); i++ ) {
 525     MachReturnNode *m = root->in(i)->as_MachReturn();
 526     if( m->ideal_Opcode() == Op_TailJump ) {
 527       tail_jump_rms[TypeFunc::Parms+0] = m->MachNode::in_RegMask(TypeFunc::Parms+0);
 528       tail_jump_rms[TypeFunc::Parms+1] = m->MachNode::in_RegMask(TypeFunc::Parms+1);
 529       break;
 530     }
 531   }
 532 
 533   // Input RegMask array shared by all Halts
 534   uint halt_edge_cnt = TypeFunc::Parms;
 535   RegMask *halt_rms = init_input_masks( halt_edge_cnt + soe_cnt, _return_addr_mask, c_frame_ptr_mask );
 536 
 537   // Capture the return input masks into each exit flavor
 538   for( i=1; i < root->req(); i++ ) {
 539     MachReturnNode *exit = root->in(i)->as_MachReturn();
 540     switch( exit->ideal_Opcode() ) {
 541       case Op_Return   : exit->_in_rms = ret_rms;  break;
 542       case Op_Rethrow  : exit->_in_rms = reth_rms; break;
 543       case Op_TailCall : exit->_in_rms = tail_call_rms; break;
 544       case Op_TailJump : exit->_in_rms = tail_jump_rms; break;
 545       case Op_Halt     : exit->_in_rms = halt_rms; break;
 546       default          : ShouldNotReachHere();
 547     }
 548   }
 549 
 550   // Next unused projection number from Start.
 551   int proj_cnt = C->tf()->domain()->cnt();
 552 
 553   // Do all the save-on-entry registers.  Make projections from Start for
 554   // them, and give them a use at the exit points.  To the allocator, they
 555   // look like incoming register arguments.
 556   for( i = 0; i < _last_Mach_Reg; i++ ) {
 557     if( is_save_on_entry(i) ) {
 558 
 559       // Add the save-on-entry to the mask array
 560       ret_rms      [      ret_edge_cnt] = mreg2regmask[i];
 561       reth_rms     [     reth_edge_cnt] = mreg2regmask[i];
 562       tail_call_rms[tail_call_edge_cnt] = mreg2regmask[i];
 563       tail_jump_rms[tail_jump_edge_cnt] = mreg2regmask[i];
 564       // Halts need the SOE registers, but only in the stack as debug info.
 565       // A just-prior uncommon-trap or deoptimization will use the SOE regs.
 566       halt_rms     [     halt_edge_cnt] = *idealreg2spillmask[_register_save_type[i]];
 567 
 568       Node *mproj;
 569 
 570       // Is this a RegF low half of a RegD?  Double up 2 adjacent RegF's
 571       // into a single RegD.
 572       if( (i&1) == 0 &&
 573           _register_save_type[i  ] == Op_RegF &&
 574           _register_save_type[i+1] == Op_RegF &&
 575           is_save_on_entry(i+1) ) {
 576         // Add other bit for double
 577         ret_rms      [      ret_edge_cnt].Insert(OptoReg::Name(i+1));
 578         reth_rms     [     reth_edge_cnt].Insert(OptoReg::Name(i+1));
 579         tail_call_rms[tail_call_edge_cnt].Insert(OptoReg::Name(i+1));
 580         tail_jump_rms[tail_jump_edge_cnt].Insert(OptoReg::Name(i+1));
 581         halt_rms     [     halt_edge_cnt].Insert(OptoReg::Name(i+1));
 582         mproj = new (C, 1) MachProjNode( start, proj_cnt, ret_rms[ret_edge_cnt], Op_RegD );
 583         proj_cnt += 2;          // Skip 2 for doubles
 584       }
 585       else if( (i&1) == 1 &&    // Else check for high half of double
 586                _register_save_type[i-1] == Op_RegF &&
 587                _register_save_type[i  ] == Op_RegF &&
 588                is_save_on_entry(i-1) ) {
 589         ret_rms      [      ret_edge_cnt] = RegMask::Empty;
 590         reth_rms     [     reth_edge_cnt] = RegMask::Empty;
 591         tail_call_rms[tail_call_edge_cnt] = RegMask::Empty;
 592         tail_jump_rms[tail_jump_edge_cnt] = RegMask::Empty;
 593         halt_rms     [     halt_edge_cnt] = RegMask::Empty;
 594         mproj = C->top();
 595       }
 596       // Is this a RegI low half of a RegL?  Double up 2 adjacent RegI's
 597       // into a single RegL.
 598       else if( (i&1) == 0 &&
 599           _register_save_type[i  ] == Op_RegI &&
 600           _register_save_type[i+1] == Op_RegI &&
 601         is_save_on_entry(i+1) ) {
 602         // Add other bit for long
 603         ret_rms      [      ret_edge_cnt].Insert(OptoReg::Name(i+1));
 604         reth_rms     [     reth_edge_cnt].Insert(OptoReg::Name(i+1));
 605         tail_call_rms[tail_call_edge_cnt].Insert(OptoReg::Name(i+1));
 606         tail_jump_rms[tail_jump_edge_cnt].Insert(OptoReg::Name(i+1));
 607         halt_rms     [     halt_edge_cnt].Insert(OptoReg::Name(i+1));
 608         mproj = new (C, 1) MachProjNode( start, proj_cnt, ret_rms[ret_edge_cnt], Op_RegL );
 609         proj_cnt += 2;          // Skip 2 for longs
 610       }
 611       else if( (i&1) == 1 &&    // Else check for high half of long
 612                _register_save_type[i-1] == Op_RegI &&
 613                _register_save_type[i  ] == Op_RegI &&
 614                is_save_on_entry(i-1) ) {
 615         ret_rms      [      ret_edge_cnt] = RegMask::Empty;
 616         reth_rms     [     reth_edge_cnt] = RegMask::Empty;
 617         tail_call_rms[tail_call_edge_cnt] = RegMask::Empty;
 618         tail_jump_rms[tail_jump_edge_cnt] = RegMask::Empty;
 619         halt_rms     [     halt_edge_cnt] = RegMask::Empty;
 620         mproj = C->top();
 621       } else {
 622         // Make a projection for it off the Start
 623         mproj = new (C, 1) MachProjNode( start, proj_cnt++, ret_rms[ret_edge_cnt], _register_save_type[i] );
 624       }
 625 
 626       ret_edge_cnt ++;
 627       reth_edge_cnt ++;
 628       tail_call_edge_cnt ++;
 629       tail_jump_edge_cnt ++;
 630       halt_edge_cnt ++;
 631 
 632       // Add a use of the SOE register to all exit paths
 633       for( uint j=1; j < root->req(); j++ )
 634         root->in(j)->add_req(mproj);
 635     } // End of if a save-on-entry register
 636   } // End of for all machine registers
 637 }
 638 
 639 //------------------------------init_spill_mask--------------------------------
 640 void Matcher::init_spill_mask( Node *ret ) {
 641   if( idealreg2regmask[Op_RegI] ) return; // One time only init
 642 
 643   OptoReg::c_frame_pointer = c_frame_pointer();
 644   c_frame_ptr_mask = c_frame_pointer();
 645 #ifdef _LP64
 646   // pointers are twice as big
 647   c_frame_ptr_mask.Insert(OptoReg::add(c_frame_pointer(),1));
 648 #endif
 649 
 650   // Start at OptoReg::stack0()
 651   STACK_ONLY_mask.Clear();
 652   OptoReg::Name init = OptoReg::stack2reg(0);
 653   // STACK_ONLY_mask is all stack bits
 654   OptoReg::Name i;
 655   for (i = init; RegMask::can_represent(i); i = OptoReg::add(i,1))
 656     STACK_ONLY_mask.Insert(i);
 657   // Also set the "infinite stack" bit.
 658   STACK_ONLY_mask.set_AllStack();
 659 
 660   // Copy the register names over into the shared world
 661   for( i=OptoReg::Name(0); i<OptoReg::Name(_last_Mach_Reg); i = OptoReg::add(i,1) ) {
 662     // SharedInfo::regName[i] = regName[i];
 663     // Handy RegMasks per machine register
 664     mreg2regmask[i].Insert(i);
 665   }
 666 
 667   // Grab the Frame Pointer
 668   Node *fp  = ret->in(TypeFunc::FramePtr);
 669   Node *mem = ret->in(TypeFunc::Memory);
 670   const TypePtr* atp = TypePtr::BOTTOM;
 671   // Share frame pointer while making spill ops
 672   set_shared(fp);
 673 
 674   // Compute generic short-offset Loads
 675 #ifdef _LP64
 676   MachNode *spillCP = match_tree(new (C, 3) LoadNNode(NULL,mem,fp,atp,TypeInstPtr::BOTTOM));
 677 #endif
 678   MachNode *spillI  = match_tree(new (C, 3) LoadINode(NULL,mem,fp,atp));
 679   MachNode *spillL  = match_tree(new (C, 3) LoadLNode(NULL,mem,fp,atp));
 680   MachNode *spillF  = match_tree(new (C, 3) LoadFNode(NULL,mem,fp,atp));
 681   MachNode *spillD  = match_tree(new (C, 3) LoadDNode(NULL,mem,fp,atp));
 682   MachNode *spillP  = match_tree(new (C, 3) LoadPNode(NULL,mem,fp,atp,TypeInstPtr::BOTTOM));
 683   assert(spillI != NULL && spillL != NULL && spillF != NULL &&
 684          spillD != NULL && spillP != NULL, "");
 685 
 686   // Get the ADLC notion of the right regmask, for each basic type.
 687 #ifdef _LP64
 688   idealreg2regmask[Op_RegN] = &spillCP->out_RegMask();
 689 #endif
 690   idealreg2regmask[Op_RegI] = &spillI->out_RegMask();
 691   idealreg2regmask[Op_RegL] = &spillL->out_RegMask();
 692   idealreg2regmask[Op_RegF] = &spillF->out_RegMask();
 693   idealreg2regmask[Op_RegD] = &spillD->out_RegMask();
 694   idealreg2regmask[Op_RegP] = &spillP->out_RegMask();
 695 }
 696 
 697 #ifdef ASSERT
 698 static void match_alias_type(Compile* C, Node* n, Node* m) {
 699   if (!VerifyAliases)  return;  // do not go looking for trouble by default
 700   const TypePtr* nat = n->adr_type();
 701   const TypePtr* mat = m->adr_type();
 702   int nidx = C->get_alias_index(nat);
 703   int midx = C->get_alias_index(mat);
 704   // Detune the assert for cases like (AndI 0xFF (LoadB p)).
 705   if (nidx == Compile::AliasIdxTop && midx >= Compile::AliasIdxRaw) {
 706     for (uint i = 1; i < n->req(); i++) {
 707       Node* n1 = n->in(i);
 708       const TypePtr* n1at = n1->adr_type();
 709       if (n1at != NULL) {
 710         nat = n1at;
 711         nidx = C->get_alias_index(n1at);
 712       }
 713     }
 714   }
 715   // %%% Kludgery.  Instead, fix ideal adr_type methods for all these cases:
 716   if (nidx == Compile::AliasIdxTop && midx == Compile::AliasIdxRaw) {
 717     switch (n->Opcode()) {
 718     case Op_PrefetchRead:
 719     case Op_PrefetchWrite:
 720       nidx = Compile::AliasIdxRaw;
 721       nat = TypeRawPtr::BOTTOM;
 722       break;
 723     }
 724   }
 725   if (nidx == Compile::AliasIdxRaw && midx == Compile::AliasIdxTop) {
 726     switch (n->Opcode()) {
 727     case Op_ClearArray:
 728       midx = Compile::AliasIdxRaw;
 729       mat = TypeRawPtr::BOTTOM;
 730       break;
 731     }
 732   }
 733   if (nidx == Compile::AliasIdxTop && midx == Compile::AliasIdxBot) {
 734     switch (n->Opcode()) {
 735     case Op_Return:
 736     case Op_Rethrow:
 737     case Op_Halt:
 738     case Op_TailCall:
 739     case Op_TailJump:
 740       nidx = Compile::AliasIdxBot;
 741       nat = TypePtr::BOTTOM;
 742       break;
 743     }
 744   }
 745   if (nidx == Compile::AliasIdxBot && midx == Compile::AliasIdxTop) {
 746     switch (n->Opcode()) {
 747     case Op_StrComp:
 748     case Op_AryEq:
 749     case Op_MemBarVolatile:
 750     case Op_MemBarCPUOrder: // %%% these ideals should have narrower adr_type?
 751       nidx = Compile::AliasIdxTop;
 752       nat = NULL;
 753       break;
 754     }
 755   }
 756   if (nidx != midx) {
 757     if (PrintOpto || (PrintMiscellaneous && (WizardMode || Verbose))) {
 758       tty->print_cr("==== Matcher alias shift %d => %d", nidx, midx);
 759       n->dump();
 760       m->dump();
 761     }
 762     assert(C->subsume_loads() && C->must_alias(nat, midx),
 763            "must not lose alias info when matching");
 764   }
 765 }
 766 #endif
 767 
 768 
 769 //------------------------------MStack-----------------------------------------
 770 // State and MStack class used in xform() and find_shared() iterative methods.
 771 enum Node_State { Pre_Visit,  // node has to be pre-visited
 772                       Visit,  // visit node
 773                  Post_Visit,  // post-visit node
 774              Alt_Post_Visit   // alternative post-visit path
 775                 };
 776 
 777 class MStack: public Node_Stack {
 778   public:
 779     MStack(int size) : Node_Stack(size) { }
 780 
 781     void push(Node *n, Node_State ns) {
 782       Node_Stack::push(n, (uint)ns);
 783     }
 784     void push(Node *n, Node_State ns, Node *parent, int indx) {
 785       ++_inode_top;
 786       if ((_inode_top + 1) >= _inode_max) grow();
 787       _inode_top->node = parent;
 788       _inode_top->indx = (uint)indx;
 789       ++_inode_top;
 790       _inode_top->node = n;
 791       _inode_top->indx = (uint)ns;
 792     }
 793     Node *parent() {
 794       pop();
 795       return node();
 796     }
 797     Node_State state() const {
 798       return (Node_State)index();
 799     }
 800     void set_state(Node_State ns) {
 801       set_index((uint)ns);
 802     }
 803 };
 804 
 805 
 806 //------------------------------xform------------------------------------------
 807 // Given a Node in old-space, Match him (Label/Reduce) to produce a machine
 808 // Node in new-space.  Given a new-space Node, recursively walk his children.
 809 Node *Matcher::transform( Node *n ) { ShouldNotCallThis(); return n; }
 810 Node *Matcher::xform( Node *n, int max_stack ) {
 811   // Use one stack to keep both: child's node/state and parent's node/index
 812   MStack mstack(max_stack * 2 * 2); // C->unique() * 2 * 2
 813   mstack.push(n, Visit, NULL, -1);  // set NULL as parent to indicate root
 814 
 815   while (mstack.is_nonempty()) {
 816     n = mstack.node();          // Leave node on stack
 817     Node_State nstate = mstack.state();
 818     if (nstate == Visit) {
 819       mstack.set_state(Post_Visit);
 820       Node *oldn = n;
 821       // Old-space or new-space check
 822       if (!C->node_arena()->contains(n)) {
 823         // Old space!
 824         Node* m;
 825         if (has_new_node(n)) {  // Not yet Label/Reduced
 826           m = new_node(n);
 827         } else {
 828           if (!is_dontcare(n)) { // Matcher can match this guy
 829             // Calls match special.  They match alone with no children.
 830             // Their children, the incoming arguments, match normally.
 831             m = n->is_SafePoint() ? match_sfpt(n->as_SafePoint()):match_tree(n);
 832             if (C->failing())  return NULL;
 833             if (m == NULL) { Matcher::soft_match_failure(); return NULL; }
 834           } else {                  // Nothing the matcher cares about
 835             if( n->is_Proj() && n->in(0)->is_Multi()) {       // Projections?
 836               // Convert to machine-dependent projection
 837               m = n->in(0)->as_Multi()->match( n->as_Proj(), this );
 838 #ifdef ASSERT
 839               _new2old_map.map(m->_idx, n);
 840 #endif
 841               if (m->in(0) != NULL) // m might be top
 842                 collect_null_checks(m);
 843             } else {                // Else just a regular 'ol guy
 844               m = n->clone();       // So just clone into new-space
 845 #ifdef ASSERT
 846               _new2old_map.map(m->_idx, n);
 847 #endif
 848               // Def-Use edges will be added incrementally as Uses
 849               // of this node are matched.
 850               assert(m->outcnt() == 0, "no Uses of this clone yet");
 851             }
 852           }
 853 
 854           set_new_node(n, m);       // Map old to new
 855           if (_old_node_note_array != NULL) {
 856             Node_Notes* nn = C->locate_node_notes(_old_node_note_array,
 857                                                   n->_idx);
 858             C->set_node_notes_at(m->_idx, nn);
 859           }
 860           debug_only(match_alias_type(C, n, m));
 861         }
 862         n = m;    // n is now a new-space node
 863         mstack.set_node(n);
 864       }
 865 
 866       // New space!
 867       if (_visited.test_set(n->_idx)) continue; // while(mstack.is_nonempty())
 868 
 869       int i;
 870       // Put precedence edges on stack first (match them last).
 871       for (i = oldn->req(); (uint)i < oldn->len(); i++) {
 872         Node *m = oldn->in(i);
 873         if (m == NULL) break;
 874         // set -1 to call add_prec() instead of set_req() during Step1
 875         mstack.push(m, Visit, n, -1);
 876       }
 877 
 878       // For constant debug info, I'd rather have unmatched constants.
 879       int cnt = n->req();
 880       JVMState* jvms = n->jvms();
 881       int debug_cnt = jvms ? jvms->debug_start() : cnt;
 882 
 883       // Now do only debug info.  Clone constants rather than matching.
 884       // Constants are represented directly in the debug info without
 885       // the need for executable machine instructions.
 886       // Monitor boxes are also represented directly.
 887       for (i = cnt - 1; i >= debug_cnt; --i) { // For all debug inputs do
 888         Node *m = n->in(i);          // Get input
 889         int op = m->Opcode();
 890         assert((op == Op_BoxLock) == jvms->is_monitor_use(i), "boxes only at monitor sites");
 891         if( op == Op_ConI || op == Op_ConP || op == Op_ConN ||
 892             op == Op_ConF || op == Op_ConD || op == Op_ConL
 893             // || op == Op_BoxLock  // %%%% enable this and remove (+++) in chaitin.cpp
 894             ) {
 895           m = m->clone();
 896 #ifdef ASSERT
 897           _new2old_map.map(m->_idx, n);
 898 #endif
 899           mstack.push(m, Post_Visit, n, i); // Don't neet to visit
 900           mstack.push(m->in(0), Visit, m, 0);
 901         } else {
 902           mstack.push(m, Visit, n, i);
 903         }
 904       }
 905 
 906       // And now walk his children, and convert his inputs to new-space.
 907       for( ; i >= 0; --i ) { // For all normal inputs do
 908         Node *m = n->in(i);  // Get input
 909         if(m != NULL)
 910           mstack.push(m, Visit, n, i);
 911       }
 912 
 913     }
 914     else if (nstate == Post_Visit) {
 915       // Set xformed input
 916       Node *p = mstack.parent();
 917       if (p != NULL) { // root doesn't have parent
 918         int i = (int)mstack.index();
 919         if (i >= 0)
 920           p->set_req(i, n); // required input
 921         else if (i == -1)
 922           p->add_prec(n);   // precedence input
 923         else
 924           ShouldNotReachHere();
 925       }
 926       mstack.pop(); // remove processed node from stack
 927     }
 928     else {
 929       ShouldNotReachHere();
 930     }
 931   } // while (mstack.is_nonempty())
 932   return n; // Return new-space Node
 933 }
 934 
 935 //------------------------------warp_outgoing_stk_arg------------------------
 936 OptoReg::Name Matcher::warp_outgoing_stk_arg( VMReg reg, OptoReg::Name begin_out_arg_area, OptoReg::Name &out_arg_limit_per_call ) {
 937   // Convert outgoing argument location to a pre-biased stack offset
 938   if (reg->is_stack()) {
 939     OptoReg::Name warped = reg->reg2stack();
 940     // Adjust the stack slot offset to be the register number used
 941     // by the allocator.
 942     warped = OptoReg::add(begin_out_arg_area, warped);
 943     // Keep track of the largest numbered stack slot used for an arg.
 944     // Largest used slot per call-site indicates the amount of stack
 945     // that is killed by the call.
 946     if( warped >= out_arg_limit_per_call )
 947       out_arg_limit_per_call = OptoReg::add(warped,1);
 948     if (!RegMask::can_represent(warped)) {
 949       C->record_method_not_compilable_all_tiers("unsupported calling sequence");
 950       return OptoReg::Bad;
 951     }
 952     return warped;
 953   }
 954   return OptoReg::as_OptoReg(reg);
 955 }
 956 
 957 
 958 //------------------------------match_sfpt-------------------------------------
 959 // Helper function to match call instructions.  Calls match special.
 960 // They match alone with no children.  Their children, the incoming
 961 // arguments, match normally.
 962 MachNode *Matcher::match_sfpt( SafePointNode *sfpt ) {
 963   MachSafePointNode *msfpt = NULL;
 964   MachCallNode      *mcall = NULL;
 965   uint               cnt;
 966   // Split out case for SafePoint vs Call
 967   CallNode *call;
 968   const TypeTuple *domain;
 969   ciMethod*        method = NULL;
 970   if( sfpt->is_Call() ) {
 971     call = sfpt->as_Call();
 972     domain = call->tf()->domain();
 973     cnt = domain->cnt();
 974 
 975     // Match just the call, nothing else
 976     MachNode *m = match_tree(call);
 977     if (C->failing())  return NULL;
 978     if( m == NULL ) { Matcher::soft_match_failure(); return NULL; }
 979 
 980     // Copy data from the Ideal SafePoint to the machine version
 981     mcall = m->as_MachCall();
 982 
 983     mcall->set_tf(         call->tf());
 984     mcall->set_entry_point(call->entry_point());
 985     mcall->set_cnt(        call->cnt());
 986 
 987     if( mcall->is_MachCallJava() ) {
 988       MachCallJavaNode *mcall_java  = mcall->as_MachCallJava();
 989       const CallJavaNode *call_java =  call->as_CallJava();
 990       method = call_java->method();
 991       mcall_java->_method = method;
 992       mcall_java->_bci = call_java->_bci;
 993       mcall_java->_optimized_virtual = call_java->is_optimized_virtual();
 994       if( mcall_java->is_MachCallStaticJava() )
 995         mcall_java->as_MachCallStaticJava()->_name =
 996          call_java->as_CallStaticJava()->_name;
 997       if( mcall_java->is_MachCallDynamicJava() )
 998         mcall_java->as_MachCallDynamicJava()->_vtable_index =
 999          call_java->as_CallDynamicJava()->_vtable_index;
1000     }
1001     else if( mcall->is_MachCallRuntime() ) {
1002       mcall->as_MachCallRuntime()->_name = call->as_CallRuntime()->_name;
1003     }
1004     msfpt = mcall;
1005   }
1006   // This is a non-call safepoint
1007   else {
1008     call = NULL;
1009     domain = NULL;
1010     MachNode *mn = match_tree(sfpt);
1011     if (C->failing())  return NULL;
1012     msfpt = mn->as_MachSafePoint();
1013     cnt = TypeFunc::Parms;
1014   }
1015 
1016   // Advertise the correct memory effects (for anti-dependence computation).
1017   msfpt->set_adr_type(sfpt->adr_type());
1018 
1019   // Allocate a private array of RegMasks.  These RegMasks are not shared.
1020   msfpt->_in_rms = NEW_RESOURCE_ARRAY( RegMask, cnt );
1021   // Empty them all.
1022   memset( msfpt->_in_rms, 0, sizeof(RegMask)*cnt );
1023 
1024   // Do all the pre-defined non-Empty register masks
1025   msfpt->_in_rms[TypeFunc::ReturnAdr] = _return_addr_mask;
1026   msfpt->_in_rms[TypeFunc::FramePtr ] = c_frame_ptr_mask;
1027 
1028   // Place first outgoing argument can possibly be put.
1029   OptoReg::Name begin_out_arg_area = OptoReg::add(_new_SP, C->out_preserve_stack_slots());
1030   assert( is_even(begin_out_arg_area), "" );
1031   // Compute max outgoing register number per call site.
1032   OptoReg::Name out_arg_limit_per_call = begin_out_arg_area;
1033   // Calls to C may hammer extra stack slots above and beyond any arguments.
1034   // These are usually backing store for register arguments for varargs.
1035   if( call != NULL && call->is_CallRuntime() )
1036     out_arg_limit_per_call = OptoReg::add(out_arg_limit_per_call,C->varargs_C_out_slots_killed());
1037 
1038 
1039   // Do the normal argument list (parameters) register masks
1040   int argcnt = cnt - TypeFunc::Parms;
1041   if( argcnt > 0 ) {          // Skip it all if we have no args
1042     BasicType *sig_bt  = NEW_RESOURCE_ARRAY( BasicType, argcnt );
1043     VMRegPair *parm_regs = NEW_RESOURCE_ARRAY( VMRegPair, argcnt );
1044     int i;
1045     for( i = 0; i < argcnt; i++ ) {
1046       sig_bt[i] = domain->field_at(i+TypeFunc::Parms)->basic_type();
1047     }
1048     // V-call to pick proper calling convention
1049     call->calling_convention( sig_bt, parm_regs, argcnt );
1050 
1051 #ifdef ASSERT
1052     // Sanity check users' calling convention.  Really handy during
1053     // the initial porting effort.  Fairly expensive otherwise.
1054     { for (int i = 0; i<argcnt; i++) {
1055       if( !parm_regs[i].first()->is_valid() &&
1056           !parm_regs[i].second()->is_valid() ) continue;
1057       VMReg reg1 = parm_regs[i].first();
1058       VMReg reg2 = parm_regs[i].second();
1059       for (int j = 0; j < i; j++) {
1060         if( !parm_regs[j].first()->is_valid() &&
1061             !parm_regs[j].second()->is_valid() ) continue;
1062         VMReg reg3 = parm_regs[j].first();
1063         VMReg reg4 = parm_regs[j].second();
1064         if( !reg1->is_valid() ) {
1065           assert( !reg2->is_valid(), "valid halvsies" );
1066         } else if( !reg3->is_valid() ) {
1067           assert( !reg4->is_valid(), "valid halvsies" );
1068         } else {
1069           assert( reg1 != reg2, "calling conv. must produce distinct regs");
1070           assert( reg1 != reg3, "calling conv. must produce distinct regs");
1071           assert( reg1 != reg4, "calling conv. must produce distinct regs");
1072           assert( reg2 != reg3, "calling conv. must produce distinct regs");
1073           assert( reg2 != reg4 || !reg2->is_valid(), "calling conv. must produce distinct regs");
1074           assert( reg3 != reg4, "calling conv. must produce distinct regs");
1075         }
1076       }
1077     }
1078     }
1079 #endif
1080 
1081     // Visit each argument.  Compute its outgoing register mask.
1082     // Return results now can have 2 bits returned.
1083     // Compute max over all outgoing arguments both per call-site
1084     // and over the entire method.
1085     for( i = 0; i < argcnt; i++ ) {
1086       // Address of incoming argument mask to fill in
1087       RegMask *rm = &mcall->_in_rms[i+TypeFunc::Parms];
1088       if( !parm_regs[i].first()->is_valid() &&
1089           !parm_regs[i].second()->is_valid() ) {
1090         continue;               // Avoid Halves
1091       }
1092       // Grab first register, adjust stack slots and insert in mask.
1093       OptoReg::Name reg1 = warp_outgoing_stk_arg(parm_regs[i].first(), begin_out_arg_area, out_arg_limit_per_call );
1094       if (OptoReg::is_valid(reg1))
1095         rm->Insert( reg1 );
1096       // Grab second register (if any), adjust stack slots and insert in mask.
1097       OptoReg::Name reg2 = warp_outgoing_stk_arg(parm_regs[i].second(), begin_out_arg_area, out_arg_limit_per_call );
1098       if (OptoReg::is_valid(reg2))
1099         rm->Insert( reg2 );
1100     } // End of for all arguments
1101 
1102     // Compute number of stack slots needed to restore stack in case of
1103     // Pascal-style argument popping.
1104     mcall->_argsize = out_arg_limit_per_call - begin_out_arg_area;
1105   }
1106 
1107   // Compute the max stack slot killed by any call.  These will not be
1108   // available for debug info, and will be used to adjust FIRST_STACK_mask
1109   // after all call sites have been visited.
1110   if( _out_arg_limit < out_arg_limit_per_call)
1111     _out_arg_limit = out_arg_limit_per_call;
1112 
1113   if (mcall) {
1114     // Kill the outgoing argument area, including any non-argument holes and
1115     // any legacy C-killed slots.  Use Fat-Projections to do the killing.
1116     // Since the max-per-method covers the max-per-call-site and debug info
1117     // is excluded on the max-per-method basis, debug info cannot land in
1118     // this killed area.
1119     uint r_cnt = mcall->tf()->range()->cnt();
1120     MachProjNode *proj = new (C, 1) MachProjNode( mcall, r_cnt+10000, RegMask::Empty, MachProjNode::fat_proj );
1121     if (!RegMask::can_represent(OptoReg::Name(out_arg_limit_per_call-1))) {
1122       C->record_method_not_compilable_all_tiers("unsupported outgoing calling sequence");
1123     } else {
1124       for (int i = begin_out_arg_area; i < out_arg_limit_per_call; i++)
1125         proj->_rout.Insert(OptoReg::Name(i));
1126     }
1127     if( proj->_rout.is_NotEmpty() )
1128       _proj_list.push(proj);
1129   }
1130   // Transfer the safepoint information from the call to the mcall
1131   // Move the JVMState list
1132   msfpt->set_jvms(sfpt->jvms());
1133   for (JVMState* jvms = msfpt->jvms(); jvms; jvms = jvms->caller()) {
1134     jvms->set_map(sfpt);
1135   }
1136 
1137   // Debug inputs begin just after the last incoming parameter
1138   assert( (mcall == NULL) || (mcall->jvms() == NULL) ||
1139           (mcall->jvms()->debug_start() + mcall->_jvmadj == mcall->tf()->domain()->cnt()), "" );
1140 
1141   // Move the OopMap
1142   msfpt->_oop_map = sfpt->_oop_map;
1143 
1144   // Registers killed by the call are set in the local scheduling pass
1145   // of Global Code Motion.
1146   return msfpt;
1147 }
1148 
1149 //---------------------------match_tree----------------------------------------
1150 // Match a Ideal Node DAG - turn it into a tree; Label & Reduce.  Used as part
1151 // of the whole-sale conversion from Ideal to Mach Nodes.  Also used for
1152 // making GotoNodes while building the CFG and in init_spill_mask() to identify
1153 // a Load's result RegMask for memoization in idealreg2regmask[]
1154 MachNode *Matcher::match_tree( const Node *n ) {
1155   assert( n->Opcode() != Op_Phi, "cannot match" );
1156   assert( !n->is_block_start(), "cannot match" );
1157   // Set the mark for all locally allocated State objects.
1158   // When this call returns, the _states_arena arena will be reset
1159   // freeing all State objects.
1160   ResourceMark rm( &_states_arena );
1161 
1162   LabelRootDepth = 0;
1163 
1164   // StoreNodes require their Memory input to match any LoadNodes
1165   Node *mem = n->is_Store() ? n->in(MemNode::Memory) : (Node*)1 ;
1166 
1167   // State object for root node of match tree
1168   // Allocate it on _states_arena - stack allocation can cause stack overflow.
1169   State *s = new (&_states_arena) State;
1170   s->_kids[0] = NULL;
1171   s->_kids[1] = NULL;
1172   s->_leaf = (Node*)n;
1173   // Label the input tree, allocating labels from top-level arena
1174   Label_Root( n, s, n->in(0), mem );
1175   if (C->failing())  return NULL;
1176 
1177   // The minimum cost match for the whole tree is found at the root State
1178   uint mincost = max_juint;
1179   uint cost = max_juint;
1180   uint i;
1181   for( i = 0; i < NUM_OPERANDS; i++ ) {
1182     if( s->valid(i) &&                // valid entry and
1183         s->_cost[i] < cost &&         // low cost and
1184         s->_rule[i] >= NUM_OPERANDS ) // not an operand
1185       cost = s->_cost[mincost=i];
1186   }
1187   if (mincost == max_juint) {
1188 #ifndef PRODUCT
1189     tty->print("No matching rule for:");
1190     s->dump();
1191 #endif
1192     Matcher::soft_match_failure();
1193     return NULL;
1194   }
1195   // Reduce input tree based upon the state labels to machine Nodes
1196   MachNode *m = ReduceInst( s, s->_rule[mincost], mem );
1197 #ifdef ASSERT
1198   _old2new_map.map(n->_idx, m);
1199   _new2old_map.map(m->_idx, (Node*)n);
1200 #endif
1201 
1202   // Add any Matcher-ignored edges
1203   uint cnt = n->req();
1204   uint start = 1;
1205   if( mem != (Node*)1 ) start = MemNode::Memory+1;
1206   if( n->is_AddP() ) {
1207     assert( mem == (Node*)1, "" );
1208     start = AddPNode::Base+1;
1209   }
1210   for( i = start; i < cnt; i++ ) {
1211     if( !n->match_edge(i) ) {
1212       if( i < m->req() )
1213         m->ins_req( i, n->in(i) );
1214       else
1215         m->add_req( n->in(i) );
1216     }
1217   }
1218 
1219   return m;
1220 }
1221 
1222 
1223 //------------------------------match_into_reg---------------------------------
1224 // Choose to either match this Node in a register or part of the current
1225 // match tree.  Return true for requiring a register and false for matching
1226 // as part of the current match tree.
1227 static bool match_into_reg( const Node *n, Node *m, Node *control, int i, bool shared ) {
1228 
1229   const Type *t = m->bottom_type();
1230 
1231   if( t->singleton() ) {
1232     // Never force constants into registers.  Allow them to match as
1233     // constants or registers.  Copies of the same value will share
1234     // the same register.  See find_shared_node.
1235     return false;
1236   } else {                      // Not a constant
1237     // Stop recursion if they have different Controls.
1238     // Slot 0 of constants is not really a Control.
1239     if( control && m->in(0) && control != m->in(0) ) {
1240 
1241       // Actually, we can live with the most conservative control we
1242       // find, if it post-dominates the others.  This allows us to
1243       // pick up load/op/store trees where the load can float a little
1244       // above the store.
1245       Node *x = control;
1246       const uint max_scan = 6;   // Arbitrary scan cutoff
1247       uint j;
1248       for( j=0; j<max_scan; j++ ) {
1249         if( x->is_Region() )    // Bail out at merge points
1250           return true;
1251         x = x->in(0);
1252         if( x == m->in(0) )     // Does 'control' post-dominate
1253           break;                // m->in(0)?  If so, we can use it
1254       }
1255       if( j == max_scan )       // No post-domination before scan end?
1256         return true;            // Then break the match tree up
1257     }
1258     if (m->is_DecodeN() && Matcher::clone_shift_expressions) {
1259       // These are commonly used in address expressions and can
1260       // efficiently fold into them on X64 in some cases.
1261       return false;
1262     }
1263   }
1264 
1265   // Not forceably cloning.  If shared, put it into a register.
1266   return shared;
1267 }
1268 
1269 
1270 //------------------------------Instruction Selection--------------------------
1271 // Label method walks a "tree" of nodes, using the ADLC generated DFA to match
1272 // ideal nodes to machine instructions.  Trees are delimited by shared Nodes,
1273 // things the Matcher does not match (e.g., Memory), and things with different
1274 // Controls (hence forced into different blocks).  We pass in the Control
1275 // selected for this entire State tree.
1276 
1277 // The Matcher works on Trees, but an Intel add-to-memory requires a DAG: the
1278 // Store and the Load must have identical Memories (as well as identical
1279 // pointers).  Since the Matcher does not have anything for Memory (and
1280 // does not handle DAGs), I have to match the Memory input myself.  If the
1281 // Tree root is a Store, I require all Loads to have the identical memory.
1282 Node *Matcher::Label_Root( const Node *n, State *svec, Node *control, const Node *mem){
1283   // Since Label_Root is a recursive function, its possible that we might run
1284   // out of stack space.  See bugs 6272980 & 6227033 for more info.
1285   LabelRootDepth++;
1286   if (LabelRootDepth > MaxLabelRootDepth) {
1287     C->record_method_not_compilable_all_tiers("Out of stack space, increase MaxLabelRootDepth");
1288     return NULL;
1289   }
1290   uint care = 0;                // Edges matcher cares about
1291   uint cnt = n->req();
1292   uint i = 0;
1293 
1294   // Examine children for memory state
1295   // Can only subsume a child into your match-tree if that child's memory state
1296   // is not modified along the path to another input.
1297   // It is unsafe even if the other inputs are separate roots.
1298   Node *input_mem = NULL;
1299   for( i = 1; i < cnt; i++ ) {
1300     if( !n->match_edge(i) ) continue;
1301     Node *m = n->in(i);         // Get ith input
1302     assert( m, "expect non-null children" );
1303     if( m->is_Load() ) {
1304       if( input_mem == NULL ) {
1305         input_mem = m->in(MemNode::Memory);
1306       } else if( input_mem != m->in(MemNode::Memory) ) {
1307         input_mem = NodeSentinel;
1308       }
1309     }
1310   }
1311 
1312   for( i = 1; i < cnt; i++ ){// For my children
1313     if( !n->match_edge(i) ) continue;
1314     Node *m = n->in(i);         // Get ith input
1315     // Allocate states out of a private arena
1316     State *s = new (&_states_arena) State;
1317     svec->_kids[care++] = s;
1318     assert( care <= 2, "binary only for now" );
1319 
1320     // Recursively label the State tree.
1321     s->_kids[0] = NULL;
1322     s->_kids[1] = NULL;
1323     s->_leaf = m;
1324 
1325     // Check for leaves of the State Tree; things that cannot be a part of
1326     // the current tree.  If it finds any, that value is matched as a
1327     // register operand.  If not, then the normal matching is used.
1328     if( match_into_reg(n, m, control, i, is_shared(m)) ||
1329         //
1330         // Stop recursion if this is LoadNode and the root of this tree is a
1331         // StoreNode and the load & store have different memories.
1332         ((mem!=(Node*)1) && m->is_Load() && m->in(MemNode::Memory) != mem) ||
1333         // Can NOT include the match of a subtree when its memory state
1334         // is used by any of the other subtrees
1335         (input_mem == NodeSentinel) ) {
1336 #ifndef PRODUCT
1337       // Print when we exclude matching due to different memory states at input-loads
1338       if( PrintOpto && (Verbose && WizardMode) && (input_mem == NodeSentinel)
1339         && !((mem!=(Node*)1) && m->is_Load() && m->in(MemNode::Memory) != mem) ) {
1340         tty->print_cr("invalid input_mem");
1341       }
1342 #endif
1343       // Switch to a register-only opcode; this value must be in a register
1344       // and cannot be subsumed as part of a larger instruction.
1345       s->DFA( m->ideal_reg(), m );
1346 
1347     } else {
1348       // If match tree has no control and we do, adopt it for entire tree
1349       if( control == NULL && m->in(0) != NULL && m->req() > 1 )
1350         control = m->in(0);         // Pick up control
1351       // Else match as a normal part of the match tree.
1352       control = Label_Root(m,s,control,mem);
1353       if (C->failing()) return NULL;
1354     }
1355   }
1356 
1357 
1358   // Call DFA to match this node, and return
1359   svec->DFA( n->Opcode(), n );
1360 
1361 #ifdef ASSERT
1362   uint x;
1363   for( x = 0; x < _LAST_MACH_OPER; x++ )
1364     if( svec->valid(x) )
1365       break;
1366 
1367   if (x >= _LAST_MACH_OPER) {
1368     n->dump();
1369     svec->dump();
1370     assert( false, "bad AD file" );
1371   }
1372 #endif
1373   return control;
1374 }
1375 
1376 
1377 // Con nodes reduced using the same rule can share their MachNode
1378 // which reduces the number of copies of a constant in the final
1379 // program.  The register allocator is free to split uses later to
1380 // split live ranges.
1381 MachNode* Matcher::find_shared_node(Node* leaf, uint rule) {
1382   if (!leaf->is_Con() && !leaf->is_DecodeN()) return NULL;
1383 
1384   // See if this Con has already been reduced using this rule.
1385   if (_shared_nodes.Size() <= leaf->_idx) return NULL;
1386   MachNode* last = (MachNode*)_shared_nodes.at(leaf->_idx);
1387   if (last != NULL && rule == last->rule()) {
1388     // Don't expect control change for DecodeN
1389     if (leaf->is_DecodeN())
1390       return last;
1391     // Get the new space root.
1392     Node* xroot = new_node(C->root());
1393     if (xroot == NULL) {
1394       // This shouldn't happen give the order of matching.
1395       return NULL;
1396     }
1397 
1398     // Shared constants need to have their control be root so they
1399     // can be scheduled properly.
1400     Node* control = last->in(0);
1401     if (control != xroot) {
1402       if (control == NULL || control == C->root()) {
1403         last->set_req(0, xroot);
1404       } else {
1405         assert(false, "unexpected control");
1406         return NULL;
1407       }
1408     }
1409     return last;
1410   }
1411   return NULL;
1412 }
1413 
1414 
1415 //------------------------------ReduceInst-------------------------------------
1416 // Reduce a State tree (with given Control) into a tree of MachNodes.
1417 // This routine (and it's cohort ReduceOper) convert Ideal Nodes into
1418 // complicated machine Nodes.  Each MachNode covers some tree of Ideal Nodes.
1419 // Each MachNode has a number of complicated MachOper operands; each
1420 // MachOper also covers a further tree of Ideal Nodes.
1421 
1422 // The root of the Ideal match tree is always an instruction, so we enter
1423 // the recursion here.  After building the MachNode, we need to recurse
1424 // the tree checking for these cases:
1425 // (1) Child is an instruction -
1426 //     Build the instruction (recursively), add it as an edge.
1427 //     Build a simple operand (register) to hold the result of the instruction.
1428 // (2) Child is an interior part of an instruction -
1429 //     Skip over it (do nothing)
1430 // (3) Child is the start of a operand -
1431 //     Build the operand, place it inside the instruction
1432 //     Call ReduceOper.
1433 MachNode *Matcher::ReduceInst( State *s, int rule, Node *&mem ) {
1434   assert( rule >= NUM_OPERANDS, "called with operand rule" );
1435 
1436   MachNode* shared_node = find_shared_node(s->_leaf, rule);
1437   if (shared_node != NULL) {
1438     return shared_node;
1439   }
1440 
1441   // Build the object to represent this state & prepare for recursive calls
1442   MachNode *mach = s->MachNodeGenerator( rule, C );
1443   mach->_opnds[0] = s->MachOperGenerator( _reduceOp[rule], C );
1444   assert( mach->_opnds[0] != NULL, "Missing result operand" );
1445   Node *leaf = s->_leaf;
1446   // Check for instruction or instruction chain rule
1447   if( rule >= _END_INST_CHAIN_RULE || rule < _BEGIN_INST_CHAIN_RULE ) {
1448     // Instruction
1449     mach->add_req( leaf->in(0) ); // Set initial control
1450     // Reduce interior of complex instruction
1451     ReduceInst_Interior( s, rule, mem, mach, 1 );
1452   } else {
1453     // Instruction chain rules are data-dependent on their inputs
1454     mach->add_req(0);             // Set initial control to none
1455     ReduceInst_Chain_Rule( s, rule, mem, mach );
1456   }
1457 
1458   // If a Memory was used, insert a Memory edge
1459   if( mem != (Node*)1 )
1460     mach->ins_req(MemNode::Memory,mem);
1461 
1462   // If the _leaf is an AddP, insert the base edge
1463   if( leaf->is_AddP() )
1464     mach->ins_req(AddPNode::Base,leaf->in(AddPNode::Base));
1465 
1466   uint num_proj = _proj_list.size();
1467 
1468   // Perform any 1-to-many expansions required
1469   MachNode *ex = mach->Expand(s,_proj_list);
1470   if( ex != mach ) {
1471     assert(ex->ideal_reg() == mach->ideal_reg(), "ideal types should match");
1472     if( ex->in(1)->is_Con() )
1473       ex->in(1)->set_req(0, C->root());
1474     // Remove old node from the graph
1475     for( uint i=0; i<mach->req(); i++ ) {
1476       mach->set_req(i,NULL);
1477     }
1478 #ifdef ASSERT
1479     _new2old_map.map(ex->_idx, s->_leaf);
1480 #endif
1481   }
1482 
1483   // PhaseChaitin::fixup_spills will sometimes generate spill code
1484   // via the matcher.  By the time, nodes have been wired into the CFG,
1485   // and any further nodes generated by expand rules will be left hanging
1486   // in space, and will not get emitted as output code.  Catch this.
1487   // Also, catch any new register allocation constraints ("projections")
1488   // generated belatedly during spill code generation.
1489   if (_allocation_started) {
1490     guarantee(ex == mach, "no expand rules during spill generation");
1491     guarantee(_proj_list.size() == num_proj, "no allocation during spill generation");
1492   }
1493 
1494   if (leaf->is_Con() || leaf->is_DecodeN()) {
1495     // Record the con for sharing
1496     _shared_nodes.map(leaf->_idx, ex);
1497   }
1498 
1499   return ex;
1500 }
1501 
1502 void Matcher::ReduceInst_Chain_Rule( State *s, int rule, Node *&mem, MachNode *mach ) {
1503   // 'op' is what I am expecting to receive
1504   int op = _leftOp[rule];
1505   // Operand type to catch childs result
1506   // This is what my child will give me.
1507   int opnd_class_instance = s->_rule[op];
1508   // Choose between operand class or not.
1509   // This is what I will recieve.
1510   int catch_op = (FIRST_OPERAND_CLASS <= op && op < NUM_OPERANDS) ? opnd_class_instance : op;
1511   // New rule for child.  Chase operand classes to get the actual rule.
1512   int newrule = s->_rule[catch_op];
1513 
1514   if( newrule < NUM_OPERANDS ) {
1515     // Chain from operand or operand class, may be output of shared node
1516     assert( 0 <= opnd_class_instance && opnd_class_instance < NUM_OPERANDS,
1517             "Bad AD file: Instruction chain rule must chain from operand");
1518     // Insert operand into array of operands for this instruction
1519     mach->_opnds[1] = s->MachOperGenerator( opnd_class_instance, C );
1520 
1521     ReduceOper( s, newrule, mem, mach );
1522   } else {
1523     // Chain from the result of an instruction
1524     assert( newrule >= _LAST_MACH_OPER, "Do NOT chain from internal operand");
1525     mach->_opnds[1] = s->MachOperGenerator( _reduceOp[catch_op], C );
1526     Node *mem1 = (Node*)1;
1527     mach->add_req( ReduceInst(s, newrule, mem1) );
1528   }
1529   return;
1530 }
1531 
1532 
1533 uint Matcher::ReduceInst_Interior( State *s, int rule, Node *&mem, MachNode *mach, uint num_opnds ) {
1534   if( s->_leaf->is_Load() ) {
1535     Node *mem2 = s->_leaf->in(MemNode::Memory);
1536     assert( mem == (Node*)1 || mem == mem2, "multiple Memories being matched at once?" );
1537     mem = mem2;
1538   }
1539   if( s->_leaf->in(0) != NULL && s->_leaf->req() > 1) {
1540     if( mach->in(0) == NULL )
1541       mach->set_req(0, s->_leaf->in(0));
1542   }
1543 
1544   // Now recursively walk the state tree & add operand list.
1545   for( uint i=0; i<2; i++ ) {   // binary tree
1546     State *newstate = s->_kids[i];
1547     if( newstate == NULL ) break;      // Might only have 1 child
1548     // 'op' is what I am expecting to receive
1549     int op;
1550     if( i == 0 ) {
1551       op = _leftOp[rule];
1552     } else {
1553       op = _rightOp[rule];
1554     }
1555     // Operand type to catch childs result
1556     // This is what my child will give me.
1557     int opnd_class_instance = newstate->_rule[op];
1558     // Choose between operand class or not.
1559     // This is what I will receive.
1560     int catch_op = (op >= FIRST_OPERAND_CLASS && op < NUM_OPERANDS) ? opnd_class_instance : op;
1561     // New rule for child.  Chase operand classes to get the actual rule.
1562     int newrule = newstate->_rule[catch_op];
1563 
1564     if( newrule < NUM_OPERANDS ) { // Operand/operandClass or internalOp/instruction?
1565       // Operand/operandClass
1566       // Insert operand into array of operands for this instruction
1567       mach->_opnds[num_opnds++] = newstate->MachOperGenerator( opnd_class_instance, C );
1568       ReduceOper( newstate, newrule, mem, mach );
1569 
1570     } else {                    // Child is internal operand or new instruction
1571       if( newrule < _LAST_MACH_OPER ) { // internal operand or instruction?
1572         // internal operand --> call ReduceInst_Interior
1573         // Interior of complex instruction.  Do nothing but recurse.
1574         num_opnds = ReduceInst_Interior( newstate, newrule, mem, mach, num_opnds );
1575       } else {
1576         // instruction --> call build operand(  ) to catch result
1577         //             --> ReduceInst( newrule )
1578         mach->_opnds[num_opnds++] = s->MachOperGenerator( _reduceOp[catch_op], C );
1579         Node *mem1 = (Node*)1;
1580         mach->add_req( ReduceInst( newstate, newrule, mem1 ) );
1581       }
1582     }
1583     assert( mach->_opnds[num_opnds-1], "" );
1584   }
1585   return num_opnds;
1586 }
1587 
1588 // This routine walks the interior of possible complex operands.
1589 // At each point we check our children in the match tree:
1590 // (1) No children -
1591 //     We are a leaf; add _leaf field as an input to the MachNode
1592 // (2) Child is an internal operand -
1593 //     Skip over it ( do nothing )
1594 // (3) Child is an instruction -
1595 //     Call ReduceInst recursively and
1596 //     and instruction as an input to the MachNode
1597 void Matcher::ReduceOper( State *s, int rule, Node *&mem, MachNode *mach ) {
1598   assert( rule < _LAST_MACH_OPER, "called with operand rule" );
1599   State *kid = s->_kids[0];
1600   assert( kid == NULL || s->_leaf->in(0) == NULL, "internal operands have no control" );
1601 
1602   // Leaf?  And not subsumed?
1603   if( kid == NULL && !_swallowed[rule] ) {
1604     mach->add_req( s->_leaf );  // Add leaf pointer
1605     return;                     // Bail out
1606   }
1607 
1608   if( s->_leaf->is_Load() ) {
1609     assert( mem == (Node*)1, "multiple Memories being matched at once?" );
1610     mem = s->_leaf->in(MemNode::Memory);
1611   }
1612   if( s->_leaf->in(0) && s->_leaf->req() > 1) {
1613     if( !mach->in(0) )
1614       mach->set_req(0,s->_leaf->in(0));
1615     else {
1616       assert( s->_leaf->in(0) == mach->in(0), "same instruction, differing controls?" );
1617     }
1618   }
1619 
1620   for( uint i=0; kid != NULL && i<2; kid = s->_kids[1], i++ ) {   // binary tree
1621     int newrule;
1622     if( i == 0 )
1623       newrule = kid->_rule[_leftOp[rule]];
1624     else
1625       newrule = kid->_rule[_rightOp[rule]];
1626 
1627     if( newrule < _LAST_MACH_OPER ) { // Operand or instruction?
1628       // Internal operand; recurse but do nothing else
1629       ReduceOper( kid, newrule, mem, mach );
1630 
1631     } else {                    // Child is a new instruction
1632       // Reduce the instruction, and add a direct pointer from this
1633       // machine instruction to the newly reduced one.
1634       Node *mem1 = (Node*)1;
1635       mach->add_req( ReduceInst( kid, newrule, mem1 ) );
1636     }
1637   }
1638 }
1639 
1640 
1641 // -------------------------------------------------------------------------
1642 // Java-Java calling convention
1643 // (what you use when Java calls Java)
1644 
1645 //------------------------------find_receiver----------------------------------
1646 // For a given signature, return the OptoReg for parameter 0.
1647 OptoReg::Name Matcher::find_receiver( bool is_outgoing ) {
1648   VMRegPair regs;
1649   BasicType sig_bt = T_OBJECT;
1650   calling_convention(&sig_bt, &regs, 1, is_outgoing);
1651   // Return argument 0 register.  In the LP64 build pointers
1652   // take 2 registers, but the VM wants only the 'main' name.
1653   return OptoReg::as_OptoReg(regs.first());
1654 }
1655 
1656 // A method-klass-holder may be passed in the inline_cache_reg
1657 // and then expanded into the inline_cache_reg and a method_oop register
1658 //   defined in ad_<arch>.cpp
1659 
1660 
1661 //------------------------------find_shared------------------------------------
1662 // Set bits if Node is shared or otherwise a root
1663 void Matcher::find_shared( Node *n ) {
1664   // Allocate stack of size C->unique() * 2 to avoid frequent realloc
1665   MStack mstack(C->unique() * 2);
1666   mstack.push(n, Visit);     // Don't need to pre-visit root node
1667   while (mstack.is_nonempty()) {
1668     n = mstack.node();       // Leave node on stack
1669     Node_State nstate = mstack.state();
1670     if (nstate == Pre_Visit) {
1671       if (is_visited(n)) {   // Visited already?
1672         // Node is shared and has no reason to clone.  Flag it as shared.
1673         // This causes it to match into a register for the sharing.
1674         set_shared(n);       // Flag as shared and
1675         mstack.pop();        // remove node from stack
1676         continue;
1677       }
1678       nstate = Visit; // Not already visited; so visit now
1679     }
1680     if (nstate == Visit) {
1681       mstack.set_state(Post_Visit);
1682       set_visited(n);   // Flag as visited now
1683       bool mem_op = false;
1684 
1685       switch( n->Opcode() ) {  // Handle some opcodes special
1686       case Op_Phi:             // Treat Phis as shared roots
1687       case Op_Parm:
1688       case Op_Proj:            // All handled specially during matching
1689       case Op_SafePointScalarObject:
1690         set_shared(n);
1691         set_dontcare(n);
1692         break;
1693       case Op_If:
1694       case Op_CountedLoopEnd:
1695         mstack.set_state(Alt_Post_Visit); // Alternative way
1696         // Convert (If (Bool (CmpX A B))) into (If (Bool) (CmpX A B)).  Helps
1697         // with matching cmp/branch in 1 instruction.  The Matcher needs the
1698         // Bool and CmpX side-by-side, because it can only get at constants
1699         // that are at the leaves of Match trees, and the Bool's condition acts
1700         // as a constant here.
1701         mstack.push(n->in(1), Visit);         // Clone the Bool
1702         mstack.push(n->in(0), Pre_Visit);     // Visit control input
1703         continue; // while (mstack.is_nonempty())
1704       case Op_ConvI2D:         // These forms efficiently match with a prior
1705       case Op_ConvI2F:         //   Load but not a following Store
1706         if( n->in(1)->is_Load() &&        // Prior load
1707             n->outcnt() == 1 &&           // Not already shared
1708             n->unique_out()->is_Store() ) // Following store
1709           set_shared(n);       // Force it to be a root
1710         break;
1711       case Op_ReverseBytesI:
1712       case Op_ReverseBytesL:
1713         if( n->in(1)->is_Load() &&        // Prior load
1714             n->outcnt() == 1 )            // Not already shared
1715           set_shared(n);                  // Force it to be a root
1716         break;
1717       case Op_BoxLock:         // Cant match until we get stack-regs in ADLC
1718       case Op_IfFalse:
1719       case Op_IfTrue:
1720       case Op_MachProj:
1721       case Op_MergeMem:
1722       case Op_Catch:
1723       case Op_CatchProj:
1724       case Op_CProj:
1725       case Op_JumpProj:
1726       case Op_JProj:
1727       case Op_NeverBranch:
1728         set_dontcare(n);
1729         break;
1730       case Op_Jump:
1731         mstack.push(n->in(1), Visit);         // Switch Value
1732         mstack.push(n->in(0), Pre_Visit);     // Visit Control input
1733         continue;                             // while (mstack.is_nonempty())
1734       case Op_StrComp:
1735       case Op_AryEq:
1736         set_shared(n); // Force result into register (it will be anyways)
1737         break;
1738       case Op_ConP: {  // Convert pointers above the centerline to NUL
1739         TypeNode *tn = n->as_Type(); // Constants derive from type nodes
1740         const TypePtr* tp = tn->type()->is_ptr();
1741         if (tp->_ptr == TypePtr::AnyNull) {
1742           tn->set_type(TypePtr::NULL_PTR);
1743         }
1744         break;
1745       }
1746       case Op_ConN: {  // Convert narrow pointers above the centerline to NUL
1747         TypeNode *tn = n->as_Type(); // Constants derive from type nodes
1748         const TypePtr* tp = tn->type()->is_narrowoop()->make_oopptr();
1749         if (tp->_ptr == TypePtr::AnyNull) {
1750           tn->set_type(TypeNarrowOop::NULL_PTR);
1751         }
1752         break;
1753       }
1754       case Op_Binary:         // These are introduced in the Post_Visit state.
1755         ShouldNotReachHere();
1756         break;
1757       case Op_StoreB:         // Do match these, despite no ideal reg
1758       case Op_StoreC:
1759       case Op_StoreCM:
1760       case Op_StoreD:
1761       case Op_StoreF:
1762       case Op_StoreI:
1763       case Op_StoreL:
1764       case Op_StoreP:
1765       case Op_StoreN:
1766       case Op_Store16B:
1767       case Op_Store8B:
1768       case Op_Store4B:
1769       case Op_Store8C:
1770       case Op_Store4C:
1771       case Op_Store2C:
1772       case Op_Store4I:
1773       case Op_Store2I:
1774       case Op_Store2L:
1775       case Op_Store4F:
1776       case Op_Store2F:
1777       case Op_Store2D:
1778       case Op_ClearArray:
1779       case Op_SafePoint:
1780         mem_op = true;
1781         break;
1782       case Op_LoadB:
1783       case Op_LoadC:
1784       case Op_LoadD:
1785       case Op_LoadF:
1786       case Op_LoadI:
1787       case Op_LoadKlass:
1788       case Op_LoadNKlass:
1789       case Op_LoadL:
1790       case Op_LoadS:
1791       case Op_LoadP:
1792       case Op_LoadN:
1793       case Op_LoadRange:
1794       case Op_LoadD_unaligned:
1795       case Op_LoadL_unaligned:
1796       case Op_Load16B:
1797       case Op_Load8B:
1798       case Op_Load4B:
1799       case Op_Load4C:
1800       case Op_Load2C:
1801       case Op_Load8C:
1802       case Op_Load8S:
1803       case Op_Load4S:
1804       case Op_Load2S:
1805       case Op_Load4I:
1806       case Op_Load2I:
1807       case Op_Load2L:
1808       case Op_Load4F:
1809       case Op_Load2F:
1810       case Op_Load2D:
1811         mem_op = true;
1812         // Must be root of match tree due to prior load conflict
1813         if( C->subsume_loads() == false ) {
1814           set_shared(n);
1815         }
1816         // Fall into default case
1817       default:
1818         if( !n->ideal_reg() )
1819           set_dontcare(n);  // Unmatchable Nodes
1820       } // end_switch
1821 
1822       for(int i = n->req() - 1; i >= 0; --i) { // For my children
1823         Node *m = n->in(i); // Get ith input
1824         if (m == NULL) continue;  // Ignore NULLs
1825         uint mop = m->Opcode();
1826 
1827         // Must clone all producers of flags, or we will not match correctly.
1828         // Suppose a compare setting int-flags is shared (e.g., a switch-tree)
1829         // then it will match into an ideal Op_RegFlags.  Alas, the fp-flags
1830         // are also there, so we may match a float-branch to int-flags and
1831         // expect the allocator to haul the flags from the int-side to the
1832         // fp-side.  No can do.
1833         if( _must_clone[mop] ) {
1834           mstack.push(m, Visit);
1835           continue; // for(int i = ...)
1836         }
1837 
1838         // Clone addressing expressions as they are "free" in most instructions
1839         if( mem_op && i == MemNode::Address && mop == Op_AddP ) {
1840           Node *off = m->in(AddPNode::Offset);
1841           if( off->is_Con() ) {
1842             set_visited(m);  // Flag as visited now
1843             Node *adr = m->in(AddPNode::Address);
1844 
1845             // Intel, ARM and friends can handle 2 adds in addressing mode
1846             if( clone_shift_expressions && adr->is_AddP() &&
1847                 // AtomicAdd is not an addressing expression.
1848                 // Cheap to find it by looking for screwy base.
1849                 !adr->in(AddPNode::Base)->is_top() ) {
1850               set_visited(adr);  // Flag as visited now
1851               Node *shift = adr->in(AddPNode::Offset);
1852               // Check for shift by small constant as well
1853               if( shift->Opcode() == Op_LShiftX && shift->in(2)->is_Con() &&
1854                   shift->in(2)->get_int() <= 3 ) {
1855                 set_visited(shift);  // Flag as visited now
1856                 mstack.push(shift->in(2), Visit);
1857 #ifdef _LP64
1858                 // Allow Matcher to match the rule which bypass
1859                 // ConvI2L operation for an array index on LP64
1860                 // if the index value is positive.
1861                 if( shift->in(1)->Opcode() == Op_ConvI2L &&
1862                     shift->in(1)->as_Type()->type()->is_long()->_lo >= 0 ) {
1863                   set_visited(shift->in(1));  // Flag as visited now
1864                   mstack.push(shift->in(1)->in(1), Pre_Visit);
1865                 } else
1866 #endif
1867                 mstack.push(shift->in(1), Pre_Visit);
1868               } else {
1869                 mstack.push(shift, Pre_Visit);
1870               }
1871               mstack.push(adr->in(AddPNode::Address), Pre_Visit);
1872               mstack.push(adr->in(AddPNode::Base), Pre_Visit);
1873             } else {  // Sparc, Alpha, PPC and friends
1874               mstack.push(adr, Pre_Visit);
1875             }
1876 
1877             // Clone X+offset as it also folds into most addressing expressions
1878             mstack.push(off, Visit);
1879             mstack.push(m->in(AddPNode::Base), Pre_Visit);
1880             continue; // for(int i = ...)
1881           } // if( off->is_Con() )
1882         }   // if( mem_op &&
1883         mstack.push(m, Pre_Visit);
1884       }     // for(int i = ...)
1885     }
1886     else if (nstate == Alt_Post_Visit) {
1887       mstack.pop(); // Remove node from stack
1888       // We cannot remove the Cmp input from the Bool here, as the Bool may be
1889       // shared and all users of the Bool need to move the Cmp in parallel.
1890       // This leaves both the Bool and the If pointing at the Cmp.  To
1891       // prevent the Matcher from trying to Match the Cmp along both paths
1892       // BoolNode::match_edge always returns a zero.
1893 
1894       // We reorder the Op_If in a pre-order manner, so we can visit without
1895       // accidently sharing the Cmp (the Bool and the If make 2 users).
1896       n->add_req( n->in(1)->in(1) ); // Add the Cmp next to the Bool
1897     }
1898     else if (nstate == Post_Visit) {
1899       mstack.pop(); // Remove node from stack
1900 
1901       // Now hack a few special opcodes
1902       switch( n->Opcode() ) {       // Handle some opcodes special
1903       case Op_StorePConditional:
1904       case Op_StoreLConditional:
1905       case Op_CompareAndSwapI:
1906       case Op_CompareAndSwapL:
1907       case Op_CompareAndSwapP:
1908       case Op_CompareAndSwapN: {   // Convert trinary to binary-tree
1909         Node *newval = n->in(MemNode::ValueIn );
1910         Node *oldval  = n->in(LoadStoreNode::ExpectedIn);
1911         Node *pair = new (C, 3) BinaryNode( oldval, newval );
1912         n->set_req(MemNode::ValueIn,pair);
1913         n->del_req(LoadStoreNode::ExpectedIn);
1914         break;
1915       }
1916       case Op_CMoveD:              // Convert trinary to binary-tree
1917       case Op_CMoveF:
1918       case Op_CMoveI:
1919       case Op_CMoveL:
1920       case Op_CMoveN:
1921       case Op_CMoveP: {
1922         // Restructure into a binary tree for Matching.  It's possible that
1923         // we could move this code up next to the graph reshaping for IfNodes
1924         // or vice-versa, but I do not want to debug this for Ladybird.
1925         // 10/2/2000 CNC.
1926         Node *pair1 = new (C, 3) BinaryNode(n->in(1),n->in(1)->in(1));
1927         n->set_req(1,pair1);
1928         Node *pair2 = new (C, 3) BinaryNode(n->in(2),n->in(3));
1929         n->set_req(2,pair2);
1930         n->del_req(3);
1931         break;
1932       }
1933       default:
1934         break;
1935       }
1936     }
1937     else {
1938       ShouldNotReachHere();
1939     }
1940   } // end of while (mstack.is_nonempty())
1941 }
1942 
1943 #ifdef ASSERT
1944 // machine-independent root to machine-dependent root
1945 void Matcher::dump_old2new_map() {
1946   _old2new_map.dump();
1947 }
1948 #endif
1949 
1950 //---------------------------collect_null_checks-------------------------------
1951 // Find null checks in the ideal graph; write a machine-specific node for
1952 // it.  Used by later implicit-null-check handling.  Actually collects
1953 // either an IfTrue or IfFalse for the common NOT-null path, AND the ideal
1954 // value being tested.
1955 void Matcher::collect_null_checks( Node *proj ) {
1956   Node *iff = proj->in(0);
1957   if( iff->Opcode() == Op_If ) {
1958     // During matching If's have Bool & Cmp side-by-side
1959     BoolNode *b = iff->in(1)->as_Bool();
1960     Node *cmp = iff->in(2);
1961     int opc = cmp->Opcode();
1962     if (opc != Op_CmpP && opc != Op_CmpN) return;
1963 
1964     const Type* ct = cmp->in(2)->bottom_type();
1965     if (ct == TypePtr::NULL_PTR ||
1966         (opc == Op_CmpN && ct == TypeNarrowOop::NULL_PTR)) {
1967 
1968       if( proj->Opcode() == Op_IfTrue ) {
1969         extern int all_null_checks_found;
1970         all_null_checks_found++;
1971         if( b->_test._test == BoolTest::ne ) {
1972           _null_check_tests.push(proj);
1973           _null_check_tests.push(cmp->in(1));
1974         }
1975       } else {
1976         assert( proj->Opcode() == Op_IfFalse, "" );
1977         if( b->_test._test == BoolTest::eq ) {
1978           _null_check_tests.push(proj);
1979           _null_check_tests.push(cmp->in(1));
1980         }
1981       }
1982     }
1983   }
1984 }
1985 
1986 //---------------------------validate_null_checks------------------------------
1987 // Its possible that the value being NULL checked is not the root of a match
1988 // tree.  If so, I cannot use the value in an implicit null check.
1989 void Matcher::validate_null_checks( ) {
1990   uint cnt = _null_check_tests.size();
1991   for( uint i=0; i < cnt; i+=2 ) {
1992     Node *test = _null_check_tests[i];
1993     Node *val = _null_check_tests[i+1];
1994     if (has_new_node(val)) {
1995       // Is a match-tree root, so replace with the matched value
1996       _null_check_tests.map(i+1, new_node(val));
1997     } else {
1998       // Yank from candidate list
1999       _null_check_tests.map(i+1,_null_check_tests[--cnt]);
2000       _null_check_tests.map(i,_null_check_tests[--cnt]);
2001       _null_check_tests.pop();
2002       _null_check_tests.pop();
2003       i-=2;
2004     }
2005   }
2006 }
2007 
2008 
2009 // Used by the DFA in dfa_sparc.cpp.  Check for a prior FastLock
2010 // acting as an Acquire and thus we don't need an Acquire here.  We
2011 // retain the Node to act as a compiler ordering barrier.
2012 bool Matcher::prior_fast_lock( const Node *acq ) {
2013   Node *r = acq->in(0);
2014   if( !r->is_Region() || r->req() <= 1 ) return false;
2015   Node *proj = r->in(1);
2016   if( !proj->is_Proj() ) return false;
2017   Node *call = proj->in(0);
2018   if( !call->is_Call() || call->as_Call()->entry_point() != OptoRuntime::complete_monitor_locking_Java() )
2019     return false;
2020 
2021   return true;
2022 }
2023 
2024 // Used by the DFA in dfa_sparc.cpp.  Check for a following FastUnLock
2025 // acting as a Release and thus we don't need a Release here.  We
2026 // retain the Node to act as a compiler ordering barrier.
2027 bool Matcher::post_fast_unlock( const Node *rel ) {
2028   Compile *C = Compile::current();
2029   assert( rel->Opcode() == Op_MemBarRelease, "" );
2030   const MemBarReleaseNode *mem = (const MemBarReleaseNode*)rel;
2031   DUIterator_Fast imax, i = mem->fast_outs(imax);
2032   Node *ctrl = NULL;
2033   while( true ) {
2034     ctrl = mem->fast_out(i);            // Throw out-of-bounds if proj not found
2035     assert( ctrl->is_Proj(), "only projections here" );
2036     ProjNode *proj = (ProjNode*)ctrl;
2037     if( proj->_con == TypeFunc::Control &&
2038         !C->node_arena()->contains(ctrl) ) // Unmatched old-space only
2039       break;
2040     i++;
2041   }
2042   Node *iff = NULL;
2043   for( DUIterator_Fast jmax, j = ctrl->fast_outs(jmax); j < jmax; j++ ) {
2044     Node *x = ctrl->fast_out(j);
2045     if( x->is_If() && x->req() > 1 &&
2046         !C->node_arena()->contains(x) ) { // Unmatched old-space only
2047       iff = x;
2048       break;
2049     }
2050   }
2051   if( !iff ) return false;
2052   Node *bol = iff->in(1);
2053   // The iff might be some random subclass of If or bol might be Con-Top
2054   if (!bol->is_Bool())  return false;
2055   assert( bol->req() > 1, "" );
2056   return (bol->in(1)->Opcode() == Op_FastUnlock);
2057 }
2058 
2059 // Used by the DFA in dfa_xxx.cpp.  Check for a following barrier or
2060 // atomic instruction acting as a store_load barrier without any
2061 // intervening volatile load, and thus we don't need a barrier here.
2062 // We retain the Node to act as a compiler ordering barrier.
2063 bool Matcher::post_store_load_barrier(const Node *vmb) {
2064   Compile *C = Compile::current();
2065   assert( vmb->is_MemBar(), "" );
2066   assert( vmb->Opcode() != Op_MemBarAcquire, "" );
2067   const MemBarNode *mem = (const MemBarNode*)vmb;
2068 
2069   // Get the Proj node, ctrl, that can be used to iterate forward
2070   Node *ctrl = NULL;
2071   DUIterator_Fast imax, i = mem->fast_outs(imax);
2072   while( true ) {
2073     ctrl = mem->fast_out(i);            // Throw out-of-bounds if proj not found
2074     assert( ctrl->is_Proj(), "only projections here" );
2075     ProjNode *proj = (ProjNode*)ctrl;
2076     if( proj->_con == TypeFunc::Control &&
2077         !C->node_arena()->contains(ctrl) ) // Unmatched old-space only
2078       break;
2079     i++;
2080   }
2081 
2082   for( DUIterator_Fast jmax, j = ctrl->fast_outs(jmax); j < jmax; j++ ) {
2083     Node *x = ctrl->fast_out(j);
2084     int xop = x->Opcode();
2085 
2086     // We don't need current barrier if we see another or a lock
2087     // before seeing volatile load.
2088     //
2089     // Op_Fastunlock previously appeared in the Op_* list below.
2090     // With the advent of 1-0 lock operations we're no longer guaranteed
2091     // that a monitor exit operation contains a serializing instruction.
2092 
2093     if (xop == Op_MemBarVolatile ||
2094         xop == Op_FastLock ||
2095         xop == Op_CompareAndSwapL ||
2096         xop == Op_CompareAndSwapP ||
2097         xop == Op_CompareAndSwapN ||
2098         xop == Op_CompareAndSwapI)
2099       return true;
2100 
2101     if (x->is_MemBar()) {
2102       // We must retain this membar if there is an upcoming volatile
2103       // load, which will be preceded by acquire membar.
2104       if (xop == Op_MemBarAcquire)
2105         return false;
2106       // For other kinds of barriers, check by pretending we
2107       // are them, and seeing if we can be removed.
2108       else
2109         return post_store_load_barrier((const MemBarNode*)x);
2110     }
2111 
2112     // Delicate code to detect case of an upcoming fastlock block
2113     if( x->is_If() && x->req() > 1 &&
2114         !C->node_arena()->contains(x) ) { // Unmatched old-space only
2115       Node *iff = x;
2116       Node *bol = iff->in(1);
2117       // The iff might be some random subclass of If or bol might be Con-Top
2118       if (!bol->is_Bool())  return false;
2119       assert( bol->req() > 1, "" );
2120       return (bol->in(1)->Opcode() == Op_FastUnlock);
2121     }
2122     // probably not necessary to check for these
2123     if (x->is_Call() || x->is_SafePoint() || x->is_block_proj())
2124       return false;
2125   }
2126   return false;
2127 }
2128 
2129 //=============================================================================
2130 //---------------------------State---------------------------------------------
2131 State::State(void) {
2132 #ifdef ASSERT
2133   _id = 0;
2134   _kids[0] = _kids[1] = (State*)(intptr_t) CONST64(0xcafebabecafebabe);
2135   _leaf = (Node*)(intptr_t) CONST64(0xbaadf00dbaadf00d);
2136   //memset(_cost, -1, sizeof(_cost));
2137   //memset(_rule, -1, sizeof(_rule));
2138 #endif
2139   memset(_valid, 0, sizeof(_valid));
2140 }
2141 
2142 #ifdef ASSERT
2143 State::~State() {
2144   _id = 99;
2145   _kids[0] = _kids[1] = (State*)(intptr_t) CONST64(0xcafebabecafebabe);
2146   _leaf = (Node*)(intptr_t) CONST64(0xbaadf00dbaadf00d);
2147   memset(_cost, -3, sizeof(_cost));
2148   memset(_rule, -3, sizeof(_rule));
2149 }
2150 #endif
2151 
2152 #ifndef PRODUCT
2153 //---------------------------dump----------------------------------------------
2154 void State::dump() {
2155   tty->print("\n");
2156   dump(0);
2157 }
2158 
2159 void State::dump(int depth) {
2160   for( int j = 0; j < depth; j++ )
2161     tty->print("   ");
2162   tty->print("--N: ");
2163   _leaf->dump();
2164   uint i;
2165   for( i = 0; i < _LAST_MACH_OPER; i++ )
2166     // Check for valid entry
2167     if( valid(i) ) {
2168       for( int j = 0; j < depth; j++ )
2169         tty->print("   ");
2170         assert(_cost[i] != max_juint, "cost must be a valid value");
2171         assert(_rule[i] < _last_Mach_Node, "rule[i] must be valid rule");
2172         tty->print_cr("%s  %d  %s",
2173                       ruleName[i], _cost[i], ruleName[_rule[i]] );
2174       }
2175   tty->print_cr("");
2176 
2177   for( i=0; i<2; i++ )
2178     if( _kids[i] )
2179       _kids[i]->dump(depth+1);
2180 }
2181 #endif