src/share/vm/opto/matcher.cpp

Wed, 16 Nov 2011 09:13:57 -0800

author
kvn
date
Wed, 16 Nov 2011 09:13:57 -0800
changeset 3311
1bd45abaa507
parent 3260
670a74b863fc
child 3390
65149e74c706
permissions
-rw-r--r--

6890673: Eliminate allocations immediately after EA
Summary: Try to eliminate allocations and related locks immediately after escape analysis.
Reviewed-by: never

     1 /*
     2  * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 #include "precompiled.hpp"
    26 #include "memory/allocation.inline.hpp"
    27 #include "opto/addnode.hpp"
    28 #include "opto/callnode.hpp"
    29 #include "opto/connode.hpp"
    30 #include "opto/idealGraphPrinter.hpp"
    31 #include "opto/matcher.hpp"
    32 #include "opto/memnode.hpp"
    33 #include "opto/opcodes.hpp"
    34 #include "opto/regmask.hpp"
    35 #include "opto/rootnode.hpp"
    36 #include "opto/runtime.hpp"
    37 #include "opto/type.hpp"
    38 #include "runtime/atomic.hpp"
    39 #include "runtime/os.hpp"
    40 #ifdef TARGET_ARCH_MODEL_x86_32
    41 # include "adfiles/ad_x86_32.hpp"
    42 #endif
    43 #ifdef TARGET_ARCH_MODEL_x86_64
    44 # include "adfiles/ad_x86_64.hpp"
    45 #endif
    46 #ifdef TARGET_ARCH_MODEL_sparc
    47 # include "adfiles/ad_sparc.hpp"
    48 #endif
    49 #ifdef TARGET_ARCH_MODEL_zero
    50 # include "adfiles/ad_zero.hpp"
    51 #endif
    52 #ifdef TARGET_ARCH_MODEL_arm
    53 # include "adfiles/ad_arm.hpp"
    54 #endif
    55 #ifdef TARGET_ARCH_MODEL_ppc
    56 # include "adfiles/ad_ppc.hpp"
    57 #endif
    59 OptoReg::Name OptoReg::c_frame_pointer;
    63 const int Matcher::base2reg[Type::lastype] = {
    64   Node::NotAMachineReg,0,0, Op_RegI, Op_RegL, 0, Op_RegN,
    65   Node::NotAMachineReg, Node::NotAMachineReg, /* tuple, array */
    66   Op_RegP, Op_RegP, Op_RegP, Op_RegP, Op_RegP, Op_RegP, /* the pointers */
    67   0, 0/*abio*/,
    68   Op_RegP /* Return address */, 0, /* the memories */
    69   Op_RegF, Op_RegF, Op_RegF, Op_RegD, Op_RegD, Op_RegD,
    70   0  /*bottom*/
    71 };
    73 const RegMask *Matcher::idealreg2regmask[_last_machine_leaf];
    74 RegMask Matcher::mreg2regmask[_last_Mach_Reg];
    75 RegMask Matcher::STACK_ONLY_mask;
    76 RegMask Matcher::c_frame_ptr_mask;
    77 const uint Matcher::_begin_rematerialize = _BEGIN_REMATERIALIZE;
    78 const uint Matcher::_end_rematerialize   = _END_REMATERIALIZE;
    80 //---------------------------Matcher-------------------------------------------
    81 Matcher::Matcher( Node_List &proj_list ) :
    82   PhaseTransform( Phase::Ins_Select ),
    83 #ifdef ASSERT
    84   _old2new_map(C->comp_arena()),
    85   _new2old_map(C->comp_arena()),
    86 #endif
    87   _shared_nodes(C->comp_arena()),
    88   _reduceOp(reduceOp), _leftOp(leftOp), _rightOp(rightOp),
    89   _swallowed(swallowed),
    90   _begin_inst_chain_rule(_BEGIN_INST_CHAIN_RULE),
    91   _end_inst_chain_rule(_END_INST_CHAIN_RULE),
    92   _must_clone(must_clone), _proj_list(proj_list),
    93   _register_save_policy(register_save_policy),
    94   _c_reg_save_policy(c_reg_save_policy),
    95   _register_save_type(register_save_type),
    96   _ruleName(ruleName),
    97   _allocation_started(false),
    98   _states_arena(Chunk::medium_size),
    99   _visited(&_states_arena),
   100   _shared(&_states_arena),
   101   _dontcare(&_states_arena) {
   102   C->set_matcher(this);
   104   idealreg2spillmask  [Op_RegI] = NULL;
   105   idealreg2spillmask  [Op_RegN] = NULL;
   106   idealreg2spillmask  [Op_RegL] = NULL;
   107   idealreg2spillmask  [Op_RegF] = NULL;
   108   idealreg2spillmask  [Op_RegD] = NULL;
   109   idealreg2spillmask  [Op_RegP] = NULL;
   111   idealreg2debugmask  [Op_RegI] = NULL;
   112   idealreg2debugmask  [Op_RegN] = NULL;
   113   idealreg2debugmask  [Op_RegL] = NULL;
   114   idealreg2debugmask  [Op_RegF] = NULL;
   115   idealreg2debugmask  [Op_RegD] = NULL;
   116   idealreg2debugmask  [Op_RegP] = NULL;
   118   idealreg2mhdebugmask[Op_RegI] = NULL;
   119   idealreg2mhdebugmask[Op_RegN] = NULL;
   120   idealreg2mhdebugmask[Op_RegL] = NULL;
   121   idealreg2mhdebugmask[Op_RegF] = NULL;
   122   idealreg2mhdebugmask[Op_RegD] = NULL;
   123   idealreg2mhdebugmask[Op_RegP] = NULL;
   125   debug_only(_mem_node = NULL;)   // Ideal memory node consumed by mach node
   126 }
   128 //------------------------------warp_incoming_stk_arg------------------------
   129 // This warps a VMReg into an OptoReg::Name
   130 OptoReg::Name Matcher::warp_incoming_stk_arg( VMReg reg ) {
   131   OptoReg::Name warped;
   132   if( reg->is_stack() ) {  // Stack slot argument?
   133     warped = OptoReg::add(_old_SP, reg->reg2stack() );
   134     warped = OptoReg::add(warped, C->out_preserve_stack_slots());
   135     if( warped >= _in_arg_limit )
   136       _in_arg_limit = OptoReg::add(warped, 1); // Bump max stack slot seen
   137     if (!RegMask::can_represent(warped)) {
   138       // the compiler cannot represent this method's calling sequence
   139       C->record_method_not_compilable_all_tiers("unsupported incoming calling sequence");
   140       return OptoReg::Bad;
   141     }
   142     return warped;
   143   }
   144   return OptoReg::as_OptoReg(reg);
   145 }
   147 //---------------------------compute_old_SP------------------------------------
   148 OptoReg::Name Compile::compute_old_SP() {
   149   int fixed    = fixed_slots();
   150   int preserve = in_preserve_stack_slots();
   151   return OptoReg::stack2reg(round_to(fixed + preserve, Matcher::stack_alignment_in_slots()));
   152 }
   156 #ifdef ASSERT
   157 void Matcher::verify_new_nodes_only(Node* xroot) {
   158   // Make sure that the new graph only references new nodes
   159   ResourceMark rm;
   160   Unique_Node_List worklist;
   161   VectorSet visited(Thread::current()->resource_area());
   162   worklist.push(xroot);
   163   while (worklist.size() > 0) {
   164     Node* n = worklist.pop();
   165     visited <<= n->_idx;
   166     assert(C->node_arena()->contains(n), "dead node");
   167     for (uint j = 0; j < n->req(); j++) {
   168       Node* in = n->in(j);
   169       if (in != NULL) {
   170         assert(C->node_arena()->contains(in), "dead node");
   171         if (!visited.test(in->_idx)) {
   172           worklist.push(in);
   173         }
   174       }
   175     }
   176   }
   177 }
   178 #endif
   181 //---------------------------match---------------------------------------------
   182 void Matcher::match( ) {
   183   if( MaxLabelRootDepth < 100 ) { // Too small?
   184     assert(false, "invalid MaxLabelRootDepth, increase it to 100 minimum");
   185     MaxLabelRootDepth = 100;
   186   }
   187   // One-time initialization of some register masks.
   188   init_spill_mask( C->root()->in(1) );
   189   _return_addr_mask = return_addr();
   190 #ifdef _LP64
   191   // Pointers take 2 slots in 64-bit land
   192   _return_addr_mask.Insert(OptoReg::add(return_addr(),1));
   193 #endif
   195   // Map a Java-signature return type into return register-value
   196   // machine registers for 0, 1 and 2 returned values.
   197   const TypeTuple *range = C->tf()->range();
   198   if( range->cnt() > TypeFunc::Parms ) { // If not a void function
   199     // Get ideal-register return type
   200     int ireg = base2reg[range->field_at(TypeFunc::Parms)->base()];
   201     // Get machine return register
   202     uint sop = C->start()->Opcode();
   203     OptoRegPair regs = return_value(ireg, false);
   205     // And mask for same
   206     _return_value_mask = RegMask(regs.first());
   207     if( OptoReg::is_valid(regs.second()) )
   208       _return_value_mask.Insert(regs.second());
   209   }
   211   // ---------------
   212   // Frame Layout
   214   // Need the method signature to determine the incoming argument types,
   215   // because the types determine which registers the incoming arguments are
   216   // in, and this affects the matched code.
   217   const TypeTuple *domain = C->tf()->domain();
   218   uint             argcnt = domain->cnt() - TypeFunc::Parms;
   219   BasicType *sig_bt        = NEW_RESOURCE_ARRAY( BasicType, argcnt );
   220   VMRegPair *vm_parm_regs  = NEW_RESOURCE_ARRAY( VMRegPair, argcnt );
   221   _parm_regs               = NEW_RESOURCE_ARRAY( OptoRegPair, argcnt );
   222   _calling_convention_mask = NEW_RESOURCE_ARRAY( RegMask, argcnt );
   223   uint i;
   224   for( i = 0; i<argcnt; i++ ) {
   225     sig_bt[i] = domain->field_at(i+TypeFunc::Parms)->basic_type();
   226   }
   228   // Pass array of ideal registers and length to USER code (from the AD file)
   229   // that will convert this to an array of register numbers.
   230   const StartNode *start = C->start();
   231   start->calling_convention( sig_bt, vm_parm_regs, argcnt );
   232 #ifdef ASSERT
   233   // Sanity check users' calling convention.  Real handy while trying to
   234   // get the initial port correct.
   235   { for (uint i = 0; i<argcnt; i++) {
   236       if( !vm_parm_regs[i].first()->is_valid() && !vm_parm_regs[i].second()->is_valid() ) {
   237         assert(domain->field_at(i+TypeFunc::Parms)==Type::HALF, "only allowed on halve" );
   238         _parm_regs[i].set_bad();
   239         continue;
   240       }
   241       VMReg parm_reg = vm_parm_regs[i].first();
   242       assert(parm_reg->is_valid(), "invalid arg?");
   243       if (parm_reg->is_reg()) {
   244         OptoReg::Name opto_parm_reg = OptoReg::as_OptoReg(parm_reg);
   245         assert(can_be_java_arg(opto_parm_reg) ||
   246                C->stub_function() == CAST_FROM_FN_PTR(address, OptoRuntime::rethrow_C) ||
   247                opto_parm_reg == inline_cache_reg(),
   248                "parameters in register must be preserved by runtime stubs");
   249       }
   250       for (uint j = 0; j < i; j++) {
   251         assert(parm_reg != vm_parm_regs[j].first(),
   252                "calling conv. must produce distinct regs");
   253       }
   254     }
   255   }
   256 #endif
   258   // Do some initial frame layout.
   260   // Compute the old incoming SP (may be called FP) as
   261   //   OptoReg::stack0() + locks + in_preserve_stack_slots + pad2.
   262   _old_SP = C->compute_old_SP();
   263   assert( is_even(_old_SP), "must be even" );
   265   // Compute highest incoming stack argument as
   266   //   _old_SP + out_preserve_stack_slots + incoming argument size.
   267   _in_arg_limit = OptoReg::add(_old_SP, C->out_preserve_stack_slots());
   268   assert( is_even(_in_arg_limit), "out_preserve must be even" );
   269   for( i = 0; i < argcnt; i++ ) {
   270     // Permit args to have no register
   271     _calling_convention_mask[i].Clear();
   272     if( !vm_parm_regs[i].first()->is_valid() && !vm_parm_regs[i].second()->is_valid() ) {
   273       continue;
   274     }
   275     // calling_convention returns stack arguments as a count of
   276     // slots beyond OptoReg::stack0()/VMRegImpl::stack0.  We need to convert this to
   277     // the allocators point of view, taking into account all the
   278     // preserve area, locks & pad2.
   280     OptoReg::Name reg1 = warp_incoming_stk_arg(vm_parm_regs[i].first());
   281     if( OptoReg::is_valid(reg1))
   282       _calling_convention_mask[i].Insert(reg1);
   284     OptoReg::Name reg2 = warp_incoming_stk_arg(vm_parm_regs[i].second());
   285     if( OptoReg::is_valid(reg2))
   286       _calling_convention_mask[i].Insert(reg2);
   288     // Saved biased stack-slot register number
   289     _parm_regs[i].set_pair(reg2, reg1);
   290   }
   292   // Finally, make sure the incoming arguments take up an even number of
   293   // words, in case the arguments or locals need to contain doubleword stack
   294   // slots.  The rest of the system assumes that stack slot pairs (in
   295   // particular, in the spill area) which look aligned will in fact be
   296   // aligned relative to the stack pointer in the target machine.  Double
   297   // stack slots will always be allocated aligned.
   298   _new_SP = OptoReg::Name(round_to(_in_arg_limit, RegMask::SlotsPerLong));
   300   // Compute highest outgoing stack argument as
   301   //   _new_SP + out_preserve_stack_slots + max(outgoing argument size).
   302   _out_arg_limit = OptoReg::add(_new_SP, C->out_preserve_stack_slots());
   303   assert( is_even(_out_arg_limit), "out_preserve must be even" );
   305   if (!RegMask::can_represent(OptoReg::add(_out_arg_limit,-1))) {
   306     // the compiler cannot represent this method's calling sequence
   307     C->record_method_not_compilable("must be able to represent all call arguments in reg mask");
   308   }
   310   if (C->failing())  return;  // bailed out on incoming arg failure
   312   // ---------------
   313   // Collect roots of matcher trees.  Every node for which
   314   // _shared[_idx] is cleared is guaranteed to not be shared, and thus
   315   // can be a valid interior of some tree.
   316   find_shared( C->root() );
   317   find_shared( C->top() );
   319   C->print_method("Before Matching");
   321   // Create new ideal node ConP #NULL even if it does exist in old space
   322   // to avoid false sharing if the corresponding mach node is not used.
   323   // The corresponding mach node is only used in rare cases for derived
   324   // pointers.
   325   Node* new_ideal_null = ConNode::make(C, TypePtr::NULL_PTR);
   327   // Swap out to old-space; emptying new-space
   328   Arena *old = C->node_arena()->move_contents(C->old_arena());
   330   // Save debug and profile information for nodes in old space:
   331   _old_node_note_array = C->node_note_array();
   332   if (_old_node_note_array != NULL) {
   333     C->set_node_note_array(new(C->comp_arena()) GrowableArray<Node_Notes*>
   334                            (C->comp_arena(), _old_node_note_array->length(),
   335                             0, NULL));
   336   }
   338   // Pre-size the new_node table to avoid the need for range checks.
   339   grow_new_node_array(C->unique());
   341   // Reset node counter so MachNodes start with _idx at 0
   342   int nodes = C->unique(); // save value
   343   C->set_unique(0);
   345   // Recursively match trees from old space into new space.
   346   // Correct leaves of new-space Nodes; they point to old-space.
   347   _visited.Clear();             // Clear visit bits for xform call
   348   C->set_cached_top_node(xform( C->top(), nodes ));
   349   if (!C->failing()) {
   350     Node* xroot =        xform( C->root(), 1 );
   351     if (xroot == NULL) {
   352       Matcher::soft_match_failure();  // recursive matching process failed
   353       C->record_method_not_compilable("instruction match failed");
   354     } else {
   355       // During matching shared constants were attached to C->root()
   356       // because xroot wasn't available yet, so transfer the uses to
   357       // the xroot.
   358       for( DUIterator_Fast jmax, j = C->root()->fast_outs(jmax); j < jmax; j++ ) {
   359         Node* n = C->root()->fast_out(j);
   360         if (C->node_arena()->contains(n)) {
   361           assert(n->in(0) == C->root(), "should be control user");
   362           n->set_req(0, xroot);
   363           --j;
   364           --jmax;
   365         }
   366       }
   368       // Generate new mach node for ConP #NULL
   369       assert(new_ideal_null != NULL, "sanity");
   370       _mach_null = match_tree(new_ideal_null);
   371       // Don't set control, it will confuse GCM since there are no uses.
   372       // The control will be set when this node is used first time
   373       // in find_base_for_derived().
   374       assert(_mach_null != NULL, "");
   376       C->set_root(xroot->is_Root() ? xroot->as_Root() : NULL);
   378 #ifdef ASSERT
   379       verify_new_nodes_only(xroot);
   380 #endif
   381     }
   382   }
   383   if (C->top() == NULL || C->root() == NULL) {
   384     C->record_method_not_compilable("graph lost"); // %%% cannot happen?
   385   }
   386   if (C->failing()) {
   387     // delete old;
   388     old->destruct_contents();
   389     return;
   390   }
   391   assert( C->top(), "" );
   392   assert( C->root(), "" );
   393   validate_null_checks();
   395   // Now smoke old-space
   396   NOT_DEBUG( old->destruct_contents() );
   398   // ------------------------
   399   // Set up save-on-entry registers
   400   Fixup_Save_On_Entry( );
   401 }
   404 //------------------------------Fixup_Save_On_Entry----------------------------
   405 // The stated purpose of this routine is to take care of save-on-entry
   406 // registers.  However, the overall goal of the Match phase is to convert into
   407 // machine-specific instructions which have RegMasks to guide allocation.
   408 // So what this procedure really does is put a valid RegMask on each input
   409 // to the machine-specific variations of all Return, TailCall and Halt
   410 // instructions.  It also adds edgs to define the save-on-entry values (and of
   411 // course gives them a mask).
   413 static RegMask *init_input_masks( uint size, RegMask &ret_adr, RegMask &fp ) {
   414   RegMask *rms = NEW_RESOURCE_ARRAY( RegMask, size );
   415   // Do all the pre-defined register masks
   416   rms[TypeFunc::Control  ] = RegMask::Empty;
   417   rms[TypeFunc::I_O      ] = RegMask::Empty;
   418   rms[TypeFunc::Memory   ] = RegMask::Empty;
   419   rms[TypeFunc::ReturnAdr] = ret_adr;
   420   rms[TypeFunc::FramePtr ] = fp;
   421   return rms;
   422 }
   424 //---------------------------init_first_stack_mask-----------------------------
   425 // Create the initial stack mask used by values spilling to the stack.
   426 // Disallow any debug info in outgoing argument areas by setting the
   427 // initial mask accordingly.
   428 void Matcher::init_first_stack_mask() {
   430   // Allocate storage for spill masks as masks for the appropriate load type.
   431   RegMask *rms = (RegMask*)C->comp_arena()->Amalloc_D(sizeof(RegMask) * 3*6);
   433   idealreg2spillmask  [Op_RegN] = &rms[0];
   434   idealreg2spillmask  [Op_RegI] = &rms[1];
   435   idealreg2spillmask  [Op_RegL] = &rms[2];
   436   idealreg2spillmask  [Op_RegF] = &rms[3];
   437   idealreg2spillmask  [Op_RegD] = &rms[4];
   438   idealreg2spillmask  [Op_RegP] = &rms[5];
   440   idealreg2debugmask  [Op_RegN] = &rms[6];
   441   idealreg2debugmask  [Op_RegI] = &rms[7];
   442   idealreg2debugmask  [Op_RegL] = &rms[8];
   443   idealreg2debugmask  [Op_RegF] = &rms[9];
   444   idealreg2debugmask  [Op_RegD] = &rms[10];
   445   idealreg2debugmask  [Op_RegP] = &rms[11];
   447   idealreg2mhdebugmask[Op_RegN] = &rms[12];
   448   idealreg2mhdebugmask[Op_RegI] = &rms[13];
   449   idealreg2mhdebugmask[Op_RegL] = &rms[14];
   450   idealreg2mhdebugmask[Op_RegF] = &rms[15];
   451   idealreg2mhdebugmask[Op_RegD] = &rms[16];
   452   idealreg2mhdebugmask[Op_RegP] = &rms[17];
   454   OptoReg::Name i;
   456   // At first, start with the empty mask
   457   C->FIRST_STACK_mask().Clear();
   459   // Add in the incoming argument area
   460   OptoReg::Name init = OptoReg::add(_old_SP, C->out_preserve_stack_slots());
   461   for (i = init; i < _in_arg_limit; i = OptoReg::add(i,1))
   462     C->FIRST_STACK_mask().Insert(i);
   464   // Add in all bits past the outgoing argument area
   465   guarantee(RegMask::can_represent(OptoReg::add(_out_arg_limit,-1)),
   466             "must be able to represent all call arguments in reg mask");
   467   init = _out_arg_limit;
   468   for (i = init; RegMask::can_represent(i); i = OptoReg::add(i,1))
   469     C->FIRST_STACK_mask().Insert(i);
   471   // Finally, set the "infinite stack" bit.
   472   C->FIRST_STACK_mask().set_AllStack();
   474   // Make spill masks.  Registers for their class, plus FIRST_STACK_mask.
   475 #ifdef _LP64
   476   *idealreg2spillmask[Op_RegN] = *idealreg2regmask[Op_RegN];
   477    idealreg2spillmask[Op_RegN]->OR(C->FIRST_STACK_mask());
   478 #endif
   479   *idealreg2spillmask[Op_RegI] = *idealreg2regmask[Op_RegI];
   480    idealreg2spillmask[Op_RegI]->OR(C->FIRST_STACK_mask());
   481   *idealreg2spillmask[Op_RegL] = *idealreg2regmask[Op_RegL];
   482    idealreg2spillmask[Op_RegL]->OR(C->FIRST_STACK_mask());
   483   *idealreg2spillmask[Op_RegF] = *idealreg2regmask[Op_RegF];
   484    idealreg2spillmask[Op_RegF]->OR(C->FIRST_STACK_mask());
   485   *idealreg2spillmask[Op_RegD] = *idealreg2regmask[Op_RegD];
   486    idealreg2spillmask[Op_RegD]->OR(C->FIRST_STACK_mask());
   487   *idealreg2spillmask[Op_RegP] = *idealreg2regmask[Op_RegP];
   488    idealreg2spillmask[Op_RegP]->OR(C->FIRST_STACK_mask());
   490    if (UseFPUForSpilling) {
   491      // This mask logic assumes that the spill operations are
   492      // symmetric and that the registers involved are the same size.
   493      // On sparc for instance we may have to use 64 bit moves will
   494      // kill 2 registers when used with F0-F31.
   495      idealreg2spillmask[Op_RegI]->OR(*idealreg2regmask[Op_RegF]);
   496      idealreg2spillmask[Op_RegF]->OR(*idealreg2regmask[Op_RegI]);
   497 #ifdef _LP64
   498      idealreg2spillmask[Op_RegN]->OR(*idealreg2regmask[Op_RegF]);
   499      idealreg2spillmask[Op_RegL]->OR(*idealreg2regmask[Op_RegD]);
   500      idealreg2spillmask[Op_RegD]->OR(*idealreg2regmask[Op_RegL]);
   501      idealreg2spillmask[Op_RegP]->OR(*idealreg2regmask[Op_RegD]);
   502 #else
   503      idealreg2spillmask[Op_RegP]->OR(*idealreg2regmask[Op_RegF]);
   504 #ifdef ARM
   505      // ARM has support for moving 64bit values between a pair of
   506      // integer registers and a double register
   507      idealreg2spillmask[Op_RegL]->OR(*idealreg2regmask[Op_RegD]);
   508      idealreg2spillmask[Op_RegD]->OR(*idealreg2regmask[Op_RegL]);
   509 #endif
   510 #endif
   511    }
   513   // Make up debug masks.  Any spill slot plus callee-save registers.
   514   // Caller-save registers are assumed to be trashable by the various
   515   // inline-cache fixup routines.
   516   *idealreg2debugmask  [Op_RegN]= *idealreg2spillmask[Op_RegN];
   517   *idealreg2debugmask  [Op_RegI]= *idealreg2spillmask[Op_RegI];
   518   *idealreg2debugmask  [Op_RegL]= *idealreg2spillmask[Op_RegL];
   519   *idealreg2debugmask  [Op_RegF]= *idealreg2spillmask[Op_RegF];
   520   *idealreg2debugmask  [Op_RegD]= *idealreg2spillmask[Op_RegD];
   521   *idealreg2debugmask  [Op_RegP]= *idealreg2spillmask[Op_RegP];
   523   *idealreg2mhdebugmask[Op_RegN]= *idealreg2spillmask[Op_RegN];
   524   *idealreg2mhdebugmask[Op_RegI]= *idealreg2spillmask[Op_RegI];
   525   *idealreg2mhdebugmask[Op_RegL]= *idealreg2spillmask[Op_RegL];
   526   *idealreg2mhdebugmask[Op_RegF]= *idealreg2spillmask[Op_RegF];
   527   *idealreg2mhdebugmask[Op_RegD]= *idealreg2spillmask[Op_RegD];
   528   *idealreg2mhdebugmask[Op_RegP]= *idealreg2spillmask[Op_RegP];
   530   // Prevent stub compilations from attempting to reference
   531   // callee-saved registers from debug info
   532   bool exclude_soe = !Compile::current()->is_method_compilation();
   534   for( i=OptoReg::Name(0); i<OptoReg::Name(_last_Mach_Reg); i = OptoReg::add(i,1) ) {
   535     // registers the caller has to save do not work
   536     if( _register_save_policy[i] == 'C' ||
   537         _register_save_policy[i] == 'A' ||
   538         (_register_save_policy[i] == 'E' && exclude_soe) ) {
   539       idealreg2debugmask  [Op_RegN]->Remove(i);
   540       idealreg2debugmask  [Op_RegI]->Remove(i); // Exclude save-on-call
   541       idealreg2debugmask  [Op_RegL]->Remove(i); // registers from debug
   542       idealreg2debugmask  [Op_RegF]->Remove(i); // masks
   543       idealreg2debugmask  [Op_RegD]->Remove(i);
   544       idealreg2debugmask  [Op_RegP]->Remove(i);
   546       idealreg2mhdebugmask[Op_RegN]->Remove(i);
   547       idealreg2mhdebugmask[Op_RegI]->Remove(i);
   548       idealreg2mhdebugmask[Op_RegL]->Remove(i);
   549       idealreg2mhdebugmask[Op_RegF]->Remove(i);
   550       idealreg2mhdebugmask[Op_RegD]->Remove(i);
   551       idealreg2mhdebugmask[Op_RegP]->Remove(i);
   552     }
   553   }
   555   // Subtract the register we use to save the SP for MethodHandle
   556   // invokes to from the debug mask.
   557   const RegMask save_mask = method_handle_invoke_SP_save_mask();
   558   idealreg2mhdebugmask[Op_RegN]->SUBTRACT(save_mask);
   559   idealreg2mhdebugmask[Op_RegI]->SUBTRACT(save_mask);
   560   idealreg2mhdebugmask[Op_RegL]->SUBTRACT(save_mask);
   561   idealreg2mhdebugmask[Op_RegF]->SUBTRACT(save_mask);
   562   idealreg2mhdebugmask[Op_RegD]->SUBTRACT(save_mask);
   563   idealreg2mhdebugmask[Op_RegP]->SUBTRACT(save_mask);
   564 }
   566 //---------------------------is_save_on_entry----------------------------------
   567 bool Matcher::is_save_on_entry( int reg ) {
   568   return
   569     _register_save_policy[reg] == 'E' ||
   570     _register_save_policy[reg] == 'A' || // Save-on-entry register?
   571     // Also save argument registers in the trampolining stubs
   572     (C->save_argument_registers() && is_spillable_arg(reg));
   573 }
   575 //---------------------------Fixup_Save_On_Entry-------------------------------
   576 void Matcher::Fixup_Save_On_Entry( ) {
   577   init_first_stack_mask();
   579   Node *root = C->root();       // Short name for root
   580   // Count number of save-on-entry registers.
   581   uint soe_cnt = number_of_saved_registers();
   582   uint i;
   584   // Find the procedure Start Node
   585   StartNode *start = C->start();
   586   assert( start, "Expect a start node" );
   588   // Save argument registers in the trampolining stubs
   589   if( C->save_argument_registers() )
   590     for( i = 0; i < _last_Mach_Reg; i++ )
   591       if( is_spillable_arg(i) )
   592         soe_cnt++;
   594   // Input RegMask array shared by all Returns.
   595   // The type for doubles and longs has a count of 2, but
   596   // there is only 1 returned value
   597   uint ret_edge_cnt = TypeFunc::Parms + ((C->tf()->range()->cnt() == TypeFunc::Parms) ? 0 : 1);
   598   RegMask *ret_rms  = init_input_masks( ret_edge_cnt + soe_cnt, _return_addr_mask, c_frame_ptr_mask );
   599   // Returns have 0 or 1 returned values depending on call signature.
   600   // Return register is specified by return_value in the AD file.
   601   if (ret_edge_cnt > TypeFunc::Parms)
   602     ret_rms[TypeFunc::Parms+0] = _return_value_mask;
   604   // Input RegMask array shared by all Rethrows.
   605   uint reth_edge_cnt = TypeFunc::Parms+1;
   606   RegMask *reth_rms  = init_input_masks( reth_edge_cnt + soe_cnt, _return_addr_mask, c_frame_ptr_mask );
   607   // Rethrow takes exception oop only, but in the argument 0 slot.
   608   reth_rms[TypeFunc::Parms] = mreg2regmask[find_receiver(false)];
   609 #ifdef _LP64
   610   // Need two slots for ptrs in 64-bit land
   611   reth_rms[TypeFunc::Parms].Insert(OptoReg::add(OptoReg::Name(find_receiver(false)),1));
   612 #endif
   614   // Input RegMask array shared by all TailCalls
   615   uint tail_call_edge_cnt = TypeFunc::Parms+2;
   616   RegMask *tail_call_rms = init_input_masks( tail_call_edge_cnt + soe_cnt, _return_addr_mask, c_frame_ptr_mask );
   618   // Input RegMask array shared by all TailJumps
   619   uint tail_jump_edge_cnt = TypeFunc::Parms+2;
   620   RegMask *tail_jump_rms = init_input_masks( tail_jump_edge_cnt + soe_cnt, _return_addr_mask, c_frame_ptr_mask );
   622   // TailCalls have 2 returned values (target & moop), whose masks come
   623   // from the usual MachNode/MachOper mechanism.  Find a sample
   624   // TailCall to extract these masks and put the correct masks into
   625   // the tail_call_rms array.
   626   for( i=1; i < root->req(); i++ ) {
   627     MachReturnNode *m = root->in(i)->as_MachReturn();
   628     if( m->ideal_Opcode() == Op_TailCall ) {
   629       tail_call_rms[TypeFunc::Parms+0] = m->MachNode::in_RegMask(TypeFunc::Parms+0);
   630       tail_call_rms[TypeFunc::Parms+1] = m->MachNode::in_RegMask(TypeFunc::Parms+1);
   631       break;
   632     }
   633   }
   635   // TailJumps have 2 returned values (target & ex_oop), whose masks come
   636   // from the usual MachNode/MachOper mechanism.  Find a sample
   637   // TailJump to extract these masks and put the correct masks into
   638   // the tail_jump_rms array.
   639   for( i=1; i < root->req(); i++ ) {
   640     MachReturnNode *m = root->in(i)->as_MachReturn();
   641     if( m->ideal_Opcode() == Op_TailJump ) {
   642       tail_jump_rms[TypeFunc::Parms+0] = m->MachNode::in_RegMask(TypeFunc::Parms+0);
   643       tail_jump_rms[TypeFunc::Parms+1] = m->MachNode::in_RegMask(TypeFunc::Parms+1);
   644       break;
   645     }
   646   }
   648   // Input RegMask array shared by all Halts
   649   uint halt_edge_cnt = TypeFunc::Parms;
   650   RegMask *halt_rms = init_input_masks( halt_edge_cnt + soe_cnt, _return_addr_mask, c_frame_ptr_mask );
   652   // Capture the return input masks into each exit flavor
   653   for( i=1; i < root->req(); i++ ) {
   654     MachReturnNode *exit = root->in(i)->as_MachReturn();
   655     switch( exit->ideal_Opcode() ) {
   656       case Op_Return   : exit->_in_rms = ret_rms;  break;
   657       case Op_Rethrow  : exit->_in_rms = reth_rms; break;
   658       case Op_TailCall : exit->_in_rms = tail_call_rms; break;
   659       case Op_TailJump : exit->_in_rms = tail_jump_rms; break;
   660       case Op_Halt     : exit->_in_rms = halt_rms; break;
   661       default          : ShouldNotReachHere();
   662     }
   663   }
   665   // Next unused projection number from Start.
   666   int proj_cnt = C->tf()->domain()->cnt();
   668   // Do all the save-on-entry registers.  Make projections from Start for
   669   // them, and give them a use at the exit points.  To the allocator, they
   670   // look like incoming register arguments.
   671   for( i = 0; i < _last_Mach_Reg; i++ ) {
   672     if( is_save_on_entry(i) ) {
   674       // Add the save-on-entry to the mask array
   675       ret_rms      [      ret_edge_cnt] = mreg2regmask[i];
   676       reth_rms     [     reth_edge_cnt] = mreg2regmask[i];
   677       tail_call_rms[tail_call_edge_cnt] = mreg2regmask[i];
   678       tail_jump_rms[tail_jump_edge_cnt] = mreg2regmask[i];
   679       // Halts need the SOE registers, but only in the stack as debug info.
   680       // A just-prior uncommon-trap or deoptimization will use the SOE regs.
   681       halt_rms     [     halt_edge_cnt] = *idealreg2spillmask[_register_save_type[i]];
   683       Node *mproj;
   685       // Is this a RegF low half of a RegD?  Double up 2 adjacent RegF's
   686       // into a single RegD.
   687       if( (i&1) == 0 &&
   688           _register_save_type[i  ] == Op_RegF &&
   689           _register_save_type[i+1] == Op_RegF &&
   690           is_save_on_entry(i+1) ) {
   691         // Add other bit for double
   692         ret_rms      [      ret_edge_cnt].Insert(OptoReg::Name(i+1));
   693         reth_rms     [     reth_edge_cnt].Insert(OptoReg::Name(i+1));
   694         tail_call_rms[tail_call_edge_cnt].Insert(OptoReg::Name(i+1));
   695         tail_jump_rms[tail_jump_edge_cnt].Insert(OptoReg::Name(i+1));
   696         halt_rms     [     halt_edge_cnt].Insert(OptoReg::Name(i+1));
   697         mproj = new (C, 1) MachProjNode( start, proj_cnt, ret_rms[ret_edge_cnt], Op_RegD );
   698         proj_cnt += 2;          // Skip 2 for doubles
   699       }
   700       else if( (i&1) == 1 &&    // Else check for high half of double
   701                _register_save_type[i-1] == Op_RegF &&
   702                _register_save_type[i  ] == Op_RegF &&
   703                is_save_on_entry(i-1) ) {
   704         ret_rms      [      ret_edge_cnt] = RegMask::Empty;
   705         reth_rms     [     reth_edge_cnt] = RegMask::Empty;
   706         tail_call_rms[tail_call_edge_cnt] = RegMask::Empty;
   707         tail_jump_rms[tail_jump_edge_cnt] = RegMask::Empty;
   708         halt_rms     [     halt_edge_cnt] = RegMask::Empty;
   709         mproj = C->top();
   710       }
   711       // Is this a RegI low half of a RegL?  Double up 2 adjacent RegI's
   712       // into a single RegL.
   713       else if( (i&1) == 0 &&
   714           _register_save_type[i  ] == Op_RegI &&
   715           _register_save_type[i+1] == Op_RegI &&
   716         is_save_on_entry(i+1) ) {
   717         // Add other bit for long
   718         ret_rms      [      ret_edge_cnt].Insert(OptoReg::Name(i+1));
   719         reth_rms     [     reth_edge_cnt].Insert(OptoReg::Name(i+1));
   720         tail_call_rms[tail_call_edge_cnt].Insert(OptoReg::Name(i+1));
   721         tail_jump_rms[tail_jump_edge_cnt].Insert(OptoReg::Name(i+1));
   722         halt_rms     [     halt_edge_cnt].Insert(OptoReg::Name(i+1));
   723         mproj = new (C, 1) MachProjNode( start, proj_cnt, ret_rms[ret_edge_cnt], Op_RegL );
   724         proj_cnt += 2;          // Skip 2 for longs
   725       }
   726       else if( (i&1) == 1 &&    // Else check for high half of long
   727                _register_save_type[i-1] == Op_RegI &&
   728                _register_save_type[i  ] == Op_RegI &&
   729                is_save_on_entry(i-1) ) {
   730         ret_rms      [      ret_edge_cnt] = RegMask::Empty;
   731         reth_rms     [     reth_edge_cnt] = RegMask::Empty;
   732         tail_call_rms[tail_call_edge_cnt] = RegMask::Empty;
   733         tail_jump_rms[tail_jump_edge_cnt] = RegMask::Empty;
   734         halt_rms     [     halt_edge_cnt] = RegMask::Empty;
   735         mproj = C->top();
   736       } else {
   737         // Make a projection for it off the Start
   738         mproj = new (C, 1) MachProjNode( start, proj_cnt++, ret_rms[ret_edge_cnt], _register_save_type[i] );
   739       }
   741       ret_edge_cnt ++;
   742       reth_edge_cnt ++;
   743       tail_call_edge_cnt ++;
   744       tail_jump_edge_cnt ++;
   745       halt_edge_cnt ++;
   747       // Add a use of the SOE register to all exit paths
   748       for( uint j=1; j < root->req(); j++ )
   749         root->in(j)->add_req(mproj);
   750     } // End of if a save-on-entry register
   751   } // End of for all machine registers
   752 }
   754 //------------------------------init_spill_mask--------------------------------
   755 void Matcher::init_spill_mask( Node *ret ) {
   756   if( idealreg2regmask[Op_RegI] ) return; // One time only init
   758   OptoReg::c_frame_pointer = c_frame_pointer();
   759   c_frame_ptr_mask = c_frame_pointer();
   760 #ifdef _LP64
   761   // pointers are twice as big
   762   c_frame_ptr_mask.Insert(OptoReg::add(c_frame_pointer(),1));
   763 #endif
   765   // Start at OptoReg::stack0()
   766   STACK_ONLY_mask.Clear();
   767   OptoReg::Name init = OptoReg::stack2reg(0);
   768   // STACK_ONLY_mask is all stack bits
   769   OptoReg::Name i;
   770   for (i = init; RegMask::can_represent(i); i = OptoReg::add(i,1))
   771     STACK_ONLY_mask.Insert(i);
   772   // Also set the "infinite stack" bit.
   773   STACK_ONLY_mask.set_AllStack();
   775   // Copy the register names over into the shared world
   776   for( i=OptoReg::Name(0); i<OptoReg::Name(_last_Mach_Reg); i = OptoReg::add(i,1) ) {
   777     // SharedInfo::regName[i] = regName[i];
   778     // Handy RegMasks per machine register
   779     mreg2regmask[i].Insert(i);
   780   }
   782   // Grab the Frame Pointer
   783   Node *fp  = ret->in(TypeFunc::FramePtr);
   784   Node *mem = ret->in(TypeFunc::Memory);
   785   const TypePtr* atp = TypePtr::BOTTOM;
   786   // Share frame pointer while making spill ops
   787   set_shared(fp);
   789   // Compute generic short-offset Loads
   790 #ifdef _LP64
   791   MachNode *spillCP = match_tree(new (C, 3) LoadNNode(NULL,mem,fp,atp,TypeInstPtr::BOTTOM));
   792 #endif
   793   MachNode *spillI  = match_tree(new (C, 3) LoadINode(NULL,mem,fp,atp));
   794   MachNode *spillL  = match_tree(new (C, 3) LoadLNode(NULL,mem,fp,atp));
   795   MachNode *spillF  = match_tree(new (C, 3) LoadFNode(NULL,mem,fp,atp));
   796   MachNode *spillD  = match_tree(new (C, 3) LoadDNode(NULL,mem,fp,atp));
   797   MachNode *spillP  = match_tree(new (C, 3) LoadPNode(NULL,mem,fp,atp,TypeInstPtr::BOTTOM));
   798   assert(spillI != NULL && spillL != NULL && spillF != NULL &&
   799          spillD != NULL && spillP != NULL, "");
   801   // Get the ADLC notion of the right regmask, for each basic type.
   802 #ifdef _LP64
   803   idealreg2regmask[Op_RegN] = &spillCP->out_RegMask();
   804 #endif
   805   idealreg2regmask[Op_RegI] = &spillI->out_RegMask();
   806   idealreg2regmask[Op_RegL] = &spillL->out_RegMask();
   807   idealreg2regmask[Op_RegF] = &spillF->out_RegMask();
   808   idealreg2regmask[Op_RegD] = &spillD->out_RegMask();
   809   idealreg2regmask[Op_RegP] = &spillP->out_RegMask();
   810 }
   812 #ifdef ASSERT
   813 static void match_alias_type(Compile* C, Node* n, Node* m) {
   814   if (!VerifyAliases)  return;  // do not go looking for trouble by default
   815   const TypePtr* nat = n->adr_type();
   816   const TypePtr* mat = m->adr_type();
   817   int nidx = C->get_alias_index(nat);
   818   int midx = C->get_alias_index(mat);
   819   // Detune the assert for cases like (AndI 0xFF (LoadB p)).
   820   if (nidx == Compile::AliasIdxTop && midx >= Compile::AliasIdxRaw) {
   821     for (uint i = 1; i < n->req(); i++) {
   822       Node* n1 = n->in(i);
   823       const TypePtr* n1at = n1->adr_type();
   824       if (n1at != NULL) {
   825         nat = n1at;
   826         nidx = C->get_alias_index(n1at);
   827       }
   828     }
   829   }
   830   // %%% Kludgery.  Instead, fix ideal adr_type methods for all these cases:
   831   if (nidx == Compile::AliasIdxTop && midx == Compile::AliasIdxRaw) {
   832     switch (n->Opcode()) {
   833     case Op_PrefetchRead:
   834     case Op_PrefetchWrite:
   835     case Op_PrefetchAllocation:
   836       nidx = Compile::AliasIdxRaw;
   837       nat = TypeRawPtr::BOTTOM;
   838       break;
   839     }
   840   }
   841   if (nidx == Compile::AliasIdxRaw && midx == Compile::AliasIdxTop) {
   842     switch (n->Opcode()) {
   843     case Op_ClearArray:
   844       midx = Compile::AliasIdxRaw;
   845       mat = TypeRawPtr::BOTTOM;
   846       break;
   847     }
   848   }
   849   if (nidx == Compile::AliasIdxTop && midx == Compile::AliasIdxBot) {
   850     switch (n->Opcode()) {
   851     case Op_Return:
   852     case Op_Rethrow:
   853     case Op_Halt:
   854     case Op_TailCall:
   855     case Op_TailJump:
   856       nidx = Compile::AliasIdxBot;
   857       nat = TypePtr::BOTTOM;
   858       break;
   859     }
   860   }
   861   if (nidx == Compile::AliasIdxBot && midx == Compile::AliasIdxTop) {
   862     switch (n->Opcode()) {
   863     case Op_StrComp:
   864     case Op_StrEquals:
   865     case Op_StrIndexOf:
   866     case Op_AryEq:
   867     case Op_MemBarVolatile:
   868     case Op_MemBarCPUOrder: // %%% these ideals should have narrower adr_type?
   869       nidx = Compile::AliasIdxTop;
   870       nat = NULL;
   871       break;
   872     }
   873   }
   874   if (nidx != midx) {
   875     if (PrintOpto || (PrintMiscellaneous && (WizardMode || Verbose))) {
   876       tty->print_cr("==== Matcher alias shift %d => %d", nidx, midx);
   877       n->dump();
   878       m->dump();
   879     }
   880     assert(C->subsume_loads() && C->must_alias(nat, midx),
   881            "must not lose alias info when matching");
   882   }
   883 }
   884 #endif
   887 //------------------------------MStack-----------------------------------------
   888 // State and MStack class used in xform() and find_shared() iterative methods.
   889 enum Node_State { Pre_Visit,  // node has to be pre-visited
   890                       Visit,  // visit node
   891                  Post_Visit,  // post-visit node
   892              Alt_Post_Visit   // alternative post-visit path
   893                 };
   895 class MStack: public Node_Stack {
   896   public:
   897     MStack(int size) : Node_Stack(size) { }
   899     void push(Node *n, Node_State ns) {
   900       Node_Stack::push(n, (uint)ns);
   901     }
   902     void push(Node *n, Node_State ns, Node *parent, int indx) {
   903       ++_inode_top;
   904       if ((_inode_top + 1) >= _inode_max) grow();
   905       _inode_top->node = parent;
   906       _inode_top->indx = (uint)indx;
   907       ++_inode_top;
   908       _inode_top->node = n;
   909       _inode_top->indx = (uint)ns;
   910     }
   911     Node *parent() {
   912       pop();
   913       return node();
   914     }
   915     Node_State state() const {
   916       return (Node_State)index();
   917     }
   918     void set_state(Node_State ns) {
   919       set_index((uint)ns);
   920     }
   921 };
   924 //------------------------------xform------------------------------------------
   925 // Given a Node in old-space, Match him (Label/Reduce) to produce a machine
   926 // Node in new-space.  Given a new-space Node, recursively walk his children.
   927 Node *Matcher::transform( Node *n ) { ShouldNotCallThis(); return n; }
   928 Node *Matcher::xform( Node *n, int max_stack ) {
   929   // Use one stack to keep both: child's node/state and parent's node/index
   930   MStack mstack(max_stack * 2 * 2); // C->unique() * 2 * 2
   931   mstack.push(n, Visit, NULL, -1);  // set NULL as parent to indicate root
   933   while (mstack.is_nonempty()) {
   934     n = mstack.node();          // Leave node on stack
   935     Node_State nstate = mstack.state();
   936     if (nstate == Visit) {
   937       mstack.set_state(Post_Visit);
   938       Node *oldn = n;
   939       // Old-space or new-space check
   940       if (!C->node_arena()->contains(n)) {
   941         // Old space!
   942         Node* m;
   943         if (has_new_node(n)) {  // Not yet Label/Reduced
   944           m = new_node(n);
   945         } else {
   946           if (!is_dontcare(n)) { // Matcher can match this guy
   947             // Calls match special.  They match alone with no children.
   948             // Their children, the incoming arguments, match normally.
   949             m = n->is_SafePoint() ? match_sfpt(n->as_SafePoint()):match_tree(n);
   950             if (C->failing())  return NULL;
   951             if (m == NULL) { Matcher::soft_match_failure(); return NULL; }
   952           } else {                  // Nothing the matcher cares about
   953             if( n->is_Proj() && n->in(0)->is_Multi()) {       // Projections?
   954               // Convert to machine-dependent projection
   955               m = n->in(0)->as_Multi()->match( n->as_Proj(), this );
   956 #ifdef ASSERT
   957               _new2old_map.map(m->_idx, n);
   958 #endif
   959               if (m->in(0) != NULL) // m might be top
   960                 collect_null_checks(m, n);
   961             } else {                // Else just a regular 'ol guy
   962               m = n->clone();       // So just clone into new-space
   963 #ifdef ASSERT
   964               _new2old_map.map(m->_idx, n);
   965 #endif
   966               // Def-Use edges will be added incrementally as Uses
   967               // of this node are matched.
   968               assert(m->outcnt() == 0, "no Uses of this clone yet");
   969             }
   970           }
   972           set_new_node(n, m);       // Map old to new
   973           if (_old_node_note_array != NULL) {
   974             Node_Notes* nn = C->locate_node_notes(_old_node_note_array,
   975                                                   n->_idx);
   976             C->set_node_notes_at(m->_idx, nn);
   977           }
   978           debug_only(match_alias_type(C, n, m));
   979         }
   980         n = m;    // n is now a new-space node
   981         mstack.set_node(n);
   982       }
   984       // New space!
   985       if (_visited.test_set(n->_idx)) continue; // while(mstack.is_nonempty())
   987       int i;
   988       // Put precedence edges on stack first (match them last).
   989       for (i = oldn->req(); (uint)i < oldn->len(); i++) {
   990         Node *m = oldn->in(i);
   991         if (m == NULL) break;
   992         // set -1 to call add_prec() instead of set_req() during Step1
   993         mstack.push(m, Visit, n, -1);
   994       }
   996       // For constant debug info, I'd rather have unmatched constants.
   997       int cnt = n->req();
   998       JVMState* jvms = n->jvms();
   999       int debug_cnt = jvms ? jvms->debug_start() : cnt;
  1001       // Now do only debug info.  Clone constants rather than matching.
  1002       // Constants are represented directly in the debug info without
  1003       // the need for executable machine instructions.
  1004       // Monitor boxes are also represented directly.
  1005       for (i = cnt - 1; i >= debug_cnt; --i) { // For all debug inputs do
  1006         Node *m = n->in(i);          // Get input
  1007         int op = m->Opcode();
  1008         assert((op == Op_BoxLock) == jvms->is_monitor_use(i), "boxes only at monitor sites");
  1009         if( op == Op_ConI || op == Op_ConP || op == Op_ConN ||
  1010             op == Op_ConF || op == Op_ConD || op == Op_ConL
  1011             // || op == Op_BoxLock  // %%%% enable this and remove (+++) in chaitin.cpp
  1012             ) {
  1013           m = m->clone();
  1014 #ifdef ASSERT
  1015           _new2old_map.map(m->_idx, n);
  1016 #endif
  1017           mstack.push(m, Post_Visit, n, i); // Don't need to visit
  1018           mstack.push(m->in(0), Visit, m, 0);
  1019         } else {
  1020           mstack.push(m, Visit, n, i);
  1024       // And now walk his children, and convert his inputs to new-space.
  1025       for( ; i >= 0; --i ) { // For all normal inputs do
  1026         Node *m = n->in(i);  // Get input
  1027         if(m != NULL)
  1028           mstack.push(m, Visit, n, i);
  1032     else if (nstate == Post_Visit) {
  1033       // Set xformed input
  1034       Node *p = mstack.parent();
  1035       if (p != NULL) { // root doesn't have parent
  1036         int i = (int)mstack.index();
  1037         if (i >= 0)
  1038           p->set_req(i, n); // required input
  1039         else if (i == -1)
  1040           p->add_prec(n);   // precedence input
  1041         else
  1042           ShouldNotReachHere();
  1044       mstack.pop(); // remove processed node from stack
  1046     else {
  1047       ShouldNotReachHere();
  1049   } // while (mstack.is_nonempty())
  1050   return n; // Return new-space Node
  1053 //------------------------------warp_outgoing_stk_arg------------------------
  1054 OptoReg::Name Matcher::warp_outgoing_stk_arg( VMReg reg, OptoReg::Name begin_out_arg_area, OptoReg::Name &out_arg_limit_per_call ) {
  1055   // Convert outgoing argument location to a pre-biased stack offset
  1056   if (reg->is_stack()) {
  1057     OptoReg::Name warped = reg->reg2stack();
  1058     // Adjust the stack slot offset to be the register number used
  1059     // by the allocator.
  1060     warped = OptoReg::add(begin_out_arg_area, warped);
  1061     // Keep track of the largest numbered stack slot used for an arg.
  1062     // Largest used slot per call-site indicates the amount of stack
  1063     // that is killed by the call.
  1064     if( warped >= out_arg_limit_per_call )
  1065       out_arg_limit_per_call = OptoReg::add(warped,1);
  1066     if (!RegMask::can_represent(warped)) {
  1067       C->record_method_not_compilable_all_tiers("unsupported calling sequence");
  1068       return OptoReg::Bad;
  1070     return warped;
  1072   return OptoReg::as_OptoReg(reg);
  1076 //------------------------------match_sfpt-------------------------------------
  1077 // Helper function to match call instructions.  Calls match special.
  1078 // They match alone with no children.  Their children, the incoming
  1079 // arguments, match normally.
  1080 MachNode *Matcher::match_sfpt( SafePointNode *sfpt ) {
  1081   MachSafePointNode *msfpt = NULL;
  1082   MachCallNode      *mcall = NULL;
  1083   uint               cnt;
  1084   // Split out case for SafePoint vs Call
  1085   CallNode *call;
  1086   const TypeTuple *domain;
  1087   ciMethod*        method = NULL;
  1088   bool             is_method_handle_invoke = false;  // for special kill effects
  1089   if( sfpt->is_Call() ) {
  1090     call = sfpt->as_Call();
  1091     domain = call->tf()->domain();
  1092     cnt = domain->cnt();
  1094     // Match just the call, nothing else
  1095     MachNode *m = match_tree(call);
  1096     if (C->failing())  return NULL;
  1097     if( m == NULL ) { Matcher::soft_match_failure(); return NULL; }
  1099     // Copy data from the Ideal SafePoint to the machine version
  1100     mcall = m->as_MachCall();
  1102     mcall->set_tf(         call->tf());
  1103     mcall->set_entry_point(call->entry_point());
  1104     mcall->set_cnt(        call->cnt());
  1106     if( mcall->is_MachCallJava() ) {
  1107       MachCallJavaNode *mcall_java  = mcall->as_MachCallJava();
  1108       const CallJavaNode *call_java =  call->as_CallJava();
  1109       method = call_java->method();
  1110       mcall_java->_method = method;
  1111       mcall_java->_bci = call_java->_bci;
  1112       mcall_java->_optimized_virtual = call_java->is_optimized_virtual();
  1113       is_method_handle_invoke = call_java->is_method_handle_invoke();
  1114       mcall_java->_method_handle_invoke = is_method_handle_invoke;
  1115       if (is_method_handle_invoke) {
  1116         C->set_has_method_handle_invokes(true);
  1118       if( mcall_java->is_MachCallStaticJava() )
  1119         mcall_java->as_MachCallStaticJava()->_name =
  1120          call_java->as_CallStaticJava()->_name;
  1121       if( mcall_java->is_MachCallDynamicJava() )
  1122         mcall_java->as_MachCallDynamicJava()->_vtable_index =
  1123          call_java->as_CallDynamicJava()->_vtable_index;
  1125     else if( mcall->is_MachCallRuntime() ) {
  1126       mcall->as_MachCallRuntime()->_name = call->as_CallRuntime()->_name;
  1128     msfpt = mcall;
  1130   // This is a non-call safepoint
  1131   else {
  1132     call = NULL;
  1133     domain = NULL;
  1134     MachNode *mn = match_tree(sfpt);
  1135     if (C->failing())  return NULL;
  1136     msfpt = mn->as_MachSafePoint();
  1137     cnt = TypeFunc::Parms;
  1140   // Advertise the correct memory effects (for anti-dependence computation).
  1141   msfpt->set_adr_type(sfpt->adr_type());
  1143   // Allocate a private array of RegMasks.  These RegMasks are not shared.
  1144   msfpt->_in_rms = NEW_RESOURCE_ARRAY( RegMask, cnt );
  1145   // Empty them all.
  1146   memset( msfpt->_in_rms, 0, sizeof(RegMask)*cnt );
  1148   // Do all the pre-defined non-Empty register masks
  1149   msfpt->_in_rms[TypeFunc::ReturnAdr] = _return_addr_mask;
  1150   msfpt->_in_rms[TypeFunc::FramePtr ] = c_frame_ptr_mask;
  1152   // Place first outgoing argument can possibly be put.
  1153   OptoReg::Name begin_out_arg_area = OptoReg::add(_new_SP, C->out_preserve_stack_slots());
  1154   assert( is_even(begin_out_arg_area), "" );
  1155   // Compute max outgoing register number per call site.
  1156   OptoReg::Name out_arg_limit_per_call = begin_out_arg_area;
  1157   // Calls to C may hammer extra stack slots above and beyond any arguments.
  1158   // These are usually backing store for register arguments for varargs.
  1159   if( call != NULL && call->is_CallRuntime() )
  1160     out_arg_limit_per_call = OptoReg::add(out_arg_limit_per_call,C->varargs_C_out_slots_killed());
  1163   // Do the normal argument list (parameters) register masks
  1164   int argcnt = cnt - TypeFunc::Parms;
  1165   if( argcnt > 0 ) {          // Skip it all if we have no args
  1166     BasicType *sig_bt  = NEW_RESOURCE_ARRAY( BasicType, argcnt );
  1167     VMRegPair *parm_regs = NEW_RESOURCE_ARRAY( VMRegPair, argcnt );
  1168     int i;
  1169     for( i = 0; i < argcnt; i++ ) {
  1170       sig_bt[i] = domain->field_at(i+TypeFunc::Parms)->basic_type();
  1172     // V-call to pick proper calling convention
  1173     call->calling_convention( sig_bt, parm_regs, argcnt );
  1175 #ifdef ASSERT
  1176     // Sanity check users' calling convention.  Really handy during
  1177     // the initial porting effort.  Fairly expensive otherwise.
  1178     { for (int i = 0; i<argcnt; i++) {
  1179       if( !parm_regs[i].first()->is_valid() &&
  1180           !parm_regs[i].second()->is_valid() ) continue;
  1181       VMReg reg1 = parm_regs[i].first();
  1182       VMReg reg2 = parm_regs[i].second();
  1183       for (int j = 0; j < i; j++) {
  1184         if( !parm_regs[j].first()->is_valid() &&
  1185             !parm_regs[j].second()->is_valid() ) continue;
  1186         VMReg reg3 = parm_regs[j].first();
  1187         VMReg reg4 = parm_regs[j].second();
  1188         if( !reg1->is_valid() ) {
  1189           assert( !reg2->is_valid(), "valid halvsies" );
  1190         } else if( !reg3->is_valid() ) {
  1191           assert( !reg4->is_valid(), "valid halvsies" );
  1192         } else {
  1193           assert( reg1 != reg2, "calling conv. must produce distinct regs");
  1194           assert( reg1 != reg3, "calling conv. must produce distinct regs");
  1195           assert( reg1 != reg4, "calling conv. must produce distinct regs");
  1196           assert( reg2 != reg3, "calling conv. must produce distinct regs");
  1197           assert( reg2 != reg4 || !reg2->is_valid(), "calling conv. must produce distinct regs");
  1198           assert( reg3 != reg4, "calling conv. must produce distinct regs");
  1203 #endif
  1205     // Visit each argument.  Compute its outgoing register mask.
  1206     // Return results now can have 2 bits returned.
  1207     // Compute max over all outgoing arguments both per call-site
  1208     // and over the entire method.
  1209     for( i = 0; i < argcnt; i++ ) {
  1210       // Address of incoming argument mask to fill in
  1211       RegMask *rm = &mcall->_in_rms[i+TypeFunc::Parms];
  1212       if( !parm_regs[i].first()->is_valid() &&
  1213           !parm_regs[i].second()->is_valid() ) {
  1214         continue;               // Avoid Halves
  1216       // Grab first register, adjust stack slots and insert in mask.
  1217       OptoReg::Name reg1 = warp_outgoing_stk_arg(parm_regs[i].first(), begin_out_arg_area, out_arg_limit_per_call );
  1218       if (OptoReg::is_valid(reg1))
  1219         rm->Insert( reg1 );
  1220       // Grab second register (if any), adjust stack slots and insert in mask.
  1221       OptoReg::Name reg2 = warp_outgoing_stk_arg(parm_regs[i].second(), begin_out_arg_area, out_arg_limit_per_call );
  1222       if (OptoReg::is_valid(reg2))
  1223         rm->Insert( reg2 );
  1224     } // End of for all arguments
  1226     // Compute number of stack slots needed to restore stack in case of
  1227     // Pascal-style argument popping.
  1228     mcall->_argsize = out_arg_limit_per_call - begin_out_arg_area;
  1231   if (is_method_handle_invoke) {
  1232     // Kill some extra stack space in case method handles want to do
  1233     // a little in-place argument insertion.
  1234     int regs_per_word  = NOT_LP64(1) LP64_ONLY(2); // %%% make a global const!
  1235     out_arg_limit_per_call += MethodHandlePushLimit * regs_per_word;
  1236     // Do not update mcall->_argsize because (a) the extra space is not
  1237     // pushed as arguments and (b) _argsize is dead (not used anywhere).
  1240   // Compute the max stack slot killed by any call.  These will not be
  1241   // available for debug info, and will be used to adjust FIRST_STACK_mask
  1242   // after all call sites have been visited.
  1243   if( _out_arg_limit < out_arg_limit_per_call)
  1244     _out_arg_limit = out_arg_limit_per_call;
  1246   if (mcall) {
  1247     // Kill the outgoing argument area, including any non-argument holes and
  1248     // any legacy C-killed slots.  Use Fat-Projections to do the killing.
  1249     // Since the max-per-method covers the max-per-call-site and debug info
  1250     // is excluded on the max-per-method basis, debug info cannot land in
  1251     // this killed area.
  1252     uint r_cnt = mcall->tf()->range()->cnt();
  1253     MachProjNode *proj = new (C, 1) MachProjNode( mcall, r_cnt+10000, RegMask::Empty, MachProjNode::fat_proj );
  1254     if (!RegMask::can_represent(OptoReg::Name(out_arg_limit_per_call-1))) {
  1255       C->record_method_not_compilable_all_tiers("unsupported outgoing calling sequence");
  1256     } else {
  1257       for (int i = begin_out_arg_area; i < out_arg_limit_per_call; i++)
  1258         proj->_rout.Insert(OptoReg::Name(i));
  1260     if( proj->_rout.is_NotEmpty() )
  1261       _proj_list.push(proj);
  1263   // Transfer the safepoint information from the call to the mcall
  1264   // Move the JVMState list
  1265   msfpt->set_jvms(sfpt->jvms());
  1266   for (JVMState* jvms = msfpt->jvms(); jvms; jvms = jvms->caller()) {
  1267     jvms->set_map(sfpt);
  1270   // Debug inputs begin just after the last incoming parameter
  1271   assert( (mcall == NULL) || (mcall->jvms() == NULL) ||
  1272           (mcall->jvms()->debug_start() + mcall->_jvmadj == mcall->tf()->domain()->cnt()), "" );
  1274   // Move the OopMap
  1275   msfpt->_oop_map = sfpt->_oop_map;
  1277   // Registers killed by the call are set in the local scheduling pass
  1278   // of Global Code Motion.
  1279   return msfpt;
  1282 //---------------------------match_tree----------------------------------------
  1283 // Match a Ideal Node DAG - turn it into a tree; Label & Reduce.  Used as part
  1284 // of the whole-sale conversion from Ideal to Mach Nodes.  Also used for
  1285 // making GotoNodes while building the CFG and in init_spill_mask() to identify
  1286 // a Load's result RegMask for memoization in idealreg2regmask[]
  1287 MachNode *Matcher::match_tree( const Node *n ) {
  1288   assert( n->Opcode() != Op_Phi, "cannot match" );
  1289   assert( !n->is_block_start(), "cannot match" );
  1290   // Set the mark for all locally allocated State objects.
  1291   // When this call returns, the _states_arena arena will be reset
  1292   // freeing all State objects.
  1293   ResourceMark rm( &_states_arena );
  1295   LabelRootDepth = 0;
  1297   // StoreNodes require their Memory input to match any LoadNodes
  1298   Node *mem = n->is_Store() ? n->in(MemNode::Memory) : (Node*)1 ;
  1299 #ifdef ASSERT
  1300   Node* save_mem_node = _mem_node;
  1301   _mem_node = n->is_Store() ? (Node*)n : NULL;
  1302 #endif
  1303   // State object for root node of match tree
  1304   // Allocate it on _states_arena - stack allocation can cause stack overflow.
  1305   State *s = new (&_states_arena) State;
  1306   s->_kids[0] = NULL;
  1307   s->_kids[1] = NULL;
  1308   s->_leaf = (Node*)n;
  1309   // Label the input tree, allocating labels from top-level arena
  1310   Label_Root( n, s, n->in(0), mem );
  1311   if (C->failing())  return NULL;
  1313   // The minimum cost match for the whole tree is found at the root State
  1314   uint mincost = max_juint;
  1315   uint cost = max_juint;
  1316   uint i;
  1317   for( i = 0; i < NUM_OPERANDS; i++ ) {
  1318     if( s->valid(i) &&                // valid entry and
  1319         s->_cost[i] < cost &&         // low cost and
  1320         s->_rule[i] >= NUM_OPERANDS ) // not an operand
  1321       cost = s->_cost[mincost=i];
  1323   if (mincost == max_juint) {
  1324 #ifndef PRODUCT
  1325     tty->print("No matching rule for:");
  1326     s->dump();
  1327 #endif
  1328     Matcher::soft_match_failure();
  1329     return NULL;
  1331   // Reduce input tree based upon the state labels to machine Nodes
  1332   MachNode *m = ReduceInst( s, s->_rule[mincost], mem );
  1333 #ifdef ASSERT
  1334   _old2new_map.map(n->_idx, m);
  1335   _new2old_map.map(m->_idx, (Node*)n);
  1336 #endif
  1338   // Add any Matcher-ignored edges
  1339   uint cnt = n->req();
  1340   uint start = 1;
  1341   if( mem != (Node*)1 ) start = MemNode::Memory+1;
  1342   if( n->is_AddP() ) {
  1343     assert( mem == (Node*)1, "" );
  1344     start = AddPNode::Base+1;
  1346   for( i = start; i < cnt; i++ ) {
  1347     if( !n->match_edge(i) ) {
  1348       if( i < m->req() )
  1349         m->ins_req( i, n->in(i) );
  1350       else
  1351         m->add_req( n->in(i) );
  1355   debug_only( _mem_node = save_mem_node; )
  1356   return m;
  1360 //------------------------------match_into_reg---------------------------------
  1361 // Choose to either match this Node in a register or part of the current
  1362 // match tree.  Return true for requiring a register and false for matching
  1363 // as part of the current match tree.
  1364 static bool match_into_reg( const Node *n, Node *m, Node *control, int i, bool shared ) {
  1366   const Type *t = m->bottom_type();
  1368   if( t->singleton() ) {
  1369     // Never force constants into registers.  Allow them to match as
  1370     // constants or registers.  Copies of the same value will share
  1371     // the same register.  See find_shared_node.
  1372     return false;
  1373   } else {                      // Not a constant
  1374     // Stop recursion if they have different Controls.
  1375     // Slot 0 of constants is not really a Control.
  1376     if( control && m->in(0) && control != m->in(0) ) {
  1378       // Actually, we can live with the most conservative control we
  1379       // find, if it post-dominates the others.  This allows us to
  1380       // pick up load/op/store trees where the load can float a little
  1381       // above the store.
  1382       Node *x = control;
  1383       const uint max_scan = 6;   // Arbitrary scan cutoff
  1384       uint j;
  1385       for( j=0; j<max_scan; j++ ) {
  1386         if( x->is_Region() )    // Bail out at merge points
  1387           return true;
  1388         x = x->in(0);
  1389         if( x == m->in(0) )     // Does 'control' post-dominate
  1390           break;                // m->in(0)?  If so, we can use it
  1392       if( j == max_scan )       // No post-domination before scan end?
  1393         return true;            // Then break the match tree up
  1395     if (m->is_DecodeN() && Matcher::narrow_oop_use_complex_address()) {
  1396       // These are commonly used in address expressions and can
  1397       // efficiently fold into them on X64 in some cases.
  1398       return false;
  1402   // Not forceable cloning.  If shared, put it into a register.
  1403   return shared;
  1407 //------------------------------Instruction Selection--------------------------
  1408 // Label method walks a "tree" of nodes, using the ADLC generated DFA to match
  1409 // ideal nodes to machine instructions.  Trees are delimited by shared Nodes,
  1410 // things the Matcher does not match (e.g., Memory), and things with different
  1411 // Controls (hence forced into different blocks).  We pass in the Control
  1412 // selected for this entire State tree.
  1414 // The Matcher works on Trees, but an Intel add-to-memory requires a DAG: the
  1415 // Store and the Load must have identical Memories (as well as identical
  1416 // pointers).  Since the Matcher does not have anything for Memory (and
  1417 // does not handle DAGs), I have to match the Memory input myself.  If the
  1418 // Tree root is a Store, I require all Loads to have the identical memory.
  1419 Node *Matcher::Label_Root( const Node *n, State *svec, Node *control, const Node *mem){
  1420   // Since Label_Root is a recursive function, its possible that we might run
  1421   // out of stack space.  See bugs 6272980 & 6227033 for more info.
  1422   LabelRootDepth++;
  1423   if (LabelRootDepth > MaxLabelRootDepth) {
  1424     C->record_method_not_compilable_all_tiers("Out of stack space, increase MaxLabelRootDepth");
  1425     return NULL;
  1427   uint care = 0;                // Edges matcher cares about
  1428   uint cnt = n->req();
  1429   uint i = 0;
  1431   // Examine children for memory state
  1432   // Can only subsume a child into your match-tree if that child's memory state
  1433   // is not modified along the path to another input.
  1434   // It is unsafe even if the other inputs are separate roots.
  1435   Node *input_mem = NULL;
  1436   for( i = 1; i < cnt; i++ ) {
  1437     if( !n->match_edge(i) ) continue;
  1438     Node *m = n->in(i);         // Get ith input
  1439     assert( m, "expect non-null children" );
  1440     if( m->is_Load() ) {
  1441       if( input_mem == NULL ) {
  1442         input_mem = m->in(MemNode::Memory);
  1443       } else if( input_mem != m->in(MemNode::Memory) ) {
  1444         input_mem = NodeSentinel;
  1449   for( i = 1; i < cnt; i++ ){// For my children
  1450     if( !n->match_edge(i) ) continue;
  1451     Node *m = n->in(i);         // Get ith input
  1452     // Allocate states out of a private arena
  1453     State *s = new (&_states_arena) State;
  1454     svec->_kids[care++] = s;
  1455     assert( care <= 2, "binary only for now" );
  1457     // Recursively label the State tree.
  1458     s->_kids[0] = NULL;
  1459     s->_kids[1] = NULL;
  1460     s->_leaf = m;
  1462     // Check for leaves of the State Tree; things that cannot be a part of
  1463     // the current tree.  If it finds any, that value is matched as a
  1464     // register operand.  If not, then the normal matching is used.
  1465     if( match_into_reg(n, m, control, i, is_shared(m)) ||
  1466         //
  1467         // Stop recursion if this is LoadNode and the root of this tree is a
  1468         // StoreNode and the load & store have different memories.
  1469         ((mem!=(Node*)1) && m->is_Load() && m->in(MemNode::Memory) != mem) ||
  1470         // Can NOT include the match of a subtree when its memory state
  1471         // is used by any of the other subtrees
  1472         (input_mem == NodeSentinel) ) {
  1473 #ifndef PRODUCT
  1474       // Print when we exclude matching due to different memory states at input-loads
  1475       if( PrintOpto && (Verbose && WizardMode) && (input_mem == NodeSentinel)
  1476         && !((mem!=(Node*)1) && m->is_Load() && m->in(MemNode::Memory) != mem) ) {
  1477         tty->print_cr("invalid input_mem");
  1479 #endif
  1480       // Switch to a register-only opcode; this value must be in a register
  1481       // and cannot be subsumed as part of a larger instruction.
  1482       s->DFA( m->ideal_reg(), m );
  1484     } else {
  1485       // If match tree has no control and we do, adopt it for entire tree
  1486       if( control == NULL && m->in(0) != NULL && m->req() > 1 )
  1487         control = m->in(0);         // Pick up control
  1488       // Else match as a normal part of the match tree.
  1489       control = Label_Root(m,s,control,mem);
  1490       if (C->failing()) return NULL;
  1495   // Call DFA to match this node, and return
  1496   svec->DFA( n->Opcode(), n );
  1498 #ifdef ASSERT
  1499   uint x;
  1500   for( x = 0; x < _LAST_MACH_OPER; x++ )
  1501     if( svec->valid(x) )
  1502       break;
  1504   if (x >= _LAST_MACH_OPER) {
  1505     n->dump();
  1506     svec->dump();
  1507     assert( false, "bad AD file" );
  1509 #endif
  1510   return control;
  1514 // Con nodes reduced using the same rule can share their MachNode
  1515 // which reduces the number of copies of a constant in the final
  1516 // program.  The register allocator is free to split uses later to
  1517 // split live ranges.
  1518 MachNode* Matcher::find_shared_node(Node* leaf, uint rule) {
  1519   if (!leaf->is_Con() && !leaf->is_DecodeN()) return NULL;
  1521   // See if this Con has already been reduced using this rule.
  1522   if (_shared_nodes.Size() <= leaf->_idx) return NULL;
  1523   MachNode* last = (MachNode*)_shared_nodes.at(leaf->_idx);
  1524   if (last != NULL && rule == last->rule()) {
  1525     // Don't expect control change for DecodeN
  1526     if (leaf->is_DecodeN())
  1527       return last;
  1528     // Get the new space root.
  1529     Node* xroot = new_node(C->root());
  1530     if (xroot == NULL) {
  1531       // This shouldn't happen give the order of matching.
  1532       return NULL;
  1535     // Shared constants need to have their control be root so they
  1536     // can be scheduled properly.
  1537     Node* control = last->in(0);
  1538     if (control != xroot) {
  1539       if (control == NULL || control == C->root()) {
  1540         last->set_req(0, xroot);
  1541       } else {
  1542         assert(false, "unexpected control");
  1543         return NULL;
  1546     return last;
  1548   return NULL;
  1552 //------------------------------ReduceInst-------------------------------------
  1553 // Reduce a State tree (with given Control) into a tree of MachNodes.
  1554 // This routine (and it's cohort ReduceOper) convert Ideal Nodes into
  1555 // complicated machine Nodes.  Each MachNode covers some tree of Ideal Nodes.
  1556 // Each MachNode has a number of complicated MachOper operands; each
  1557 // MachOper also covers a further tree of Ideal Nodes.
  1559 // The root of the Ideal match tree is always an instruction, so we enter
  1560 // the recursion here.  After building the MachNode, we need to recurse
  1561 // the tree checking for these cases:
  1562 // (1) Child is an instruction -
  1563 //     Build the instruction (recursively), add it as an edge.
  1564 //     Build a simple operand (register) to hold the result of the instruction.
  1565 // (2) Child is an interior part of an instruction -
  1566 //     Skip over it (do nothing)
  1567 // (3) Child is the start of a operand -
  1568 //     Build the operand, place it inside the instruction
  1569 //     Call ReduceOper.
  1570 MachNode *Matcher::ReduceInst( State *s, int rule, Node *&mem ) {
  1571   assert( rule >= NUM_OPERANDS, "called with operand rule" );
  1573   MachNode* shared_node = find_shared_node(s->_leaf, rule);
  1574   if (shared_node != NULL) {
  1575     return shared_node;
  1578   // Build the object to represent this state & prepare for recursive calls
  1579   MachNode *mach = s->MachNodeGenerator( rule, C );
  1580   mach->_opnds[0] = s->MachOperGenerator( _reduceOp[rule], C );
  1581   assert( mach->_opnds[0] != NULL, "Missing result operand" );
  1582   Node *leaf = s->_leaf;
  1583   // Check for instruction or instruction chain rule
  1584   if( rule >= _END_INST_CHAIN_RULE || rule < _BEGIN_INST_CHAIN_RULE ) {
  1585     assert(C->node_arena()->contains(s->_leaf) || !has_new_node(s->_leaf),
  1586            "duplicating node that's already been matched");
  1587     // Instruction
  1588     mach->add_req( leaf->in(0) ); // Set initial control
  1589     // Reduce interior of complex instruction
  1590     ReduceInst_Interior( s, rule, mem, mach, 1 );
  1591   } else {
  1592     // Instruction chain rules are data-dependent on their inputs
  1593     mach->add_req(0);             // Set initial control to none
  1594     ReduceInst_Chain_Rule( s, rule, mem, mach );
  1597   // If a Memory was used, insert a Memory edge
  1598   if( mem != (Node*)1 ) {
  1599     mach->ins_req(MemNode::Memory,mem);
  1600 #ifdef ASSERT
  1601     // Verify adr type after matching memory operation
  1602     const MachOper* oper = mach->memory_operand();
  1603     if (oper != NULL && oper != (MachOper*)-1) {
  1604       // It has a unique memory operand.  Find corresponding ideal mem node.
  1605       Node* m = NULL;
  1606       if (leaf->is_Mem()) {
  1607         m = leaf;
  1608       } else {
  1609         m = _mem_node;
  1610         assert(m != NULL && m->is_Mem(), "expecting memory node");
  1612       const Type* mach_at = mach->adr_type();
  1613       // DecodeN node consumed by an address may have different type
  1614       // then its input. Don't compare types for such case.
  1615       if (m->adr_type() != mach_at &&
  1616           (m->in(MemNode::Address)->is_DecodeN() ||
  1617            m->in(MemNode::Address)->is_AddP() &&
  1618            m->in(MemNode::Address)->in(AddPNode::Address)->is_DecodeN() ||
  1619            m->in(MemNode::Address)->is_AddP() &&
  1620            m->in(MemNode::Address)->in(AddPNode::Address)->is_AddP() &&
  1621            m->in(MemNode::Address)->in(AddPNode::Address)->in(AddPNode::Address)->is_DecodeN())) {
  1622         mach_at = m->adr_type();
  1624       if (m->adr_type() != mach_at) {
  1625         m->dump();
  1626         tty->print_cr("mach:");
  1627         mach->dump(1);
  1629       assert(m->adr_type() == mach_at, "matcher should not change adr type");
  1631 #endif
  1634   // If the _leaf is an AddP, insert the base edge
  1635   if( leaf->is_AddP() )
  1636     mach->ins_req(AddPNode::Base,leaf->in(AddPNode::Base));
  1638   uint num_proj = _proj_list.size();
  1640   // Perform any 1-to-many expansions required
  1641   MachNode *ex = mach->Expand(s,_proj_list, mem);
  1642   if( ex != mach ) {
  1643     assert(ex->ideal_reg() == mach->ideal_reg(), "ideal types should match");
  1644     if( ex->in(1)->is_Con() )
  1645       ex->in(1)->set_req(0, C->root());
  1646     // Remove old node from the graph
  1647     for( uint i=0; i<mach->req(); i++ ) {
  1648       mach->set_req(i,NULL);
  1650 #ifdef ASSERT
  1651     _new2old_map.map(ex->_idx, s->_leaf);
  1652 #endif
  1655   // PhaseChaitin::fixup_spills will sometimes generate spill code
  1656   // via the matcher.  By the time, nodes have been wired into the CFG,
  1657   // and any further nodes generated by expand rules will be left hanging
  1658   // in space, and will not get emitted as output code.  Catch this.
  1659   // Also, catch any new register allocation constraints ("projections")
  1660   // generated belatedly during spill code generation.
  1661   if (_allocation_started) {
  1662     guarantee(ex == mach, "no expand rules during spill generation");
  1663     guarantee(_proj_list.size() == num_proj, "no allocation during spill generation");
  1666   if (leaf->is_Con() || leaf->is_DecodeN()) {
  1667     // Record the con for sharing
  1668     _shared_nodes.map(leaf->_idx, ex);
  1671   return ex;
  1674 void Matcher::ReduceInst_Chain_Rule( State *s, int rule, Node *&mem, MachNode *mach ) {
  1675   // 'op' is what I am expecting to receive
  1676   int op = _leftOp[rule];
  1677   // Operand type to catch childs result
  1678   // This is what my child will give me.
  1679   int opnd_class_instance = s->_rule[op];
  1680   // Choose between operand class or not.
  1681   // This is what I will receive.
  1682   int catch_op = (FIRST_OPERAND_CLASS <= op && op < NUM_OPERANDS) ? opnd_class_instance : op;
  1683   // New rule for child.  Chase operand classes to get the actual rule.
  1684   int newrule = s->_rule[catch_op];
  1686   if( newrule < NUM_OPERANDS ) {
  1687     // Chain from operand or operand class, may be output of shared node
  1688     assert( 0 <= opnd_class_instance && opnd_class_instance < NUM_OPERANDS,
  1689             "Bad AD file: Instruction chain rule must chain from operand");
  1690     // Insert operand into array of operands for this instruction
  1691     mach->_opnds[1] = s->MachOperGenerator( opnd_class_instance, C );
  1693     ReduceOper( s, newrule, mem, mach );
  1694   } else {
  1695     // Chain from the result of an instruction
  1696     assert( newrule >= _LAST_MACH_OPER, "Do NOT chain from internal operand");
  1697     mach->_opnds[1] = s->MachOperGenerator( _reduceOp[catch_op], C );
  1698     Node *mem1 = (Node*)1;
  1699     debug_only(Node *save_mem_node = _mem_node;)
  1700     mach->add_req( ReduceInst(s, newrule, mem1) );
  1701     debug_only(_mem_node = save_mem_node;)
  1703   return;
  1707 uint Matcher::ReduceInst_Interior( State *s, int rule, Node *&mem, MachNode *mach, uint num_opnds ) {
  1708   if( s->_leaf->is_Load() ) {
  1709     Node *mem2 = s->_leaf->in(MemNode::Memory);
  1710     assert( mem == (Node*)1 || mem == mem2, "multiple Memories being matched at once?" );
  1711     debug_only( if( mem == (Node*)1 ) _mem_node = s->_leaf;)
  1712     mem = mem2;
  1714   if( s->_leaf->in(0) != NULL && s->_leaf->req() > 1) {
  1715     if( mach->in(0) == NULL )
  1716       mach->set_req(0, s->_leaf->in(0));
  1719   // Now recursively walk the state tree & add operand list.
  1720   for( uint i=0; i<2; i++ ) {   // binary tree
  1721     State *newstate = s->_kids[i];
  1722     if( newstate == NULL ) break;      // Might only have 1 child
  1723     // 'op' is what I am expecting to receive
  1724     int op;
  1725     if( i == 0 ) {
  1726       op = _leftOp[rule];
  1727     } else {
  1728       op = _rightOp[rule];
  1730     // Operand type to catch childs result
  1731     // This is what my child will give me.
  1732     int opnd_class_instance = newstate->_rule[op];
  1733     // Choose between operand class or not.
  1734     // This is what I will receive.
  1735     int catch_op = (op >= FIRST_OPERAND_CLASS && op < NUM_OPERANDS) ? opnd_class_instance : op;
  1736     // New rule for child.  Chase operand classes to get the actual rule.
  1737     int newrule = newstate->_rule[catch_op];
  1739     if( newrule < NUM_OPERANDS ) { // Operand/operandClass or internalOp/instruction?
  1740       // Operand/operandClass
  1741       // Insert operand into array of operands for this instruction
  1742       mach->_opnds[num_opnds++] = newstate->MachOperGenerator( opnd_class_instance, C );
  1743       ReduceOper( newstate, newrule, mem, mach );
  1745     } else {                    // Child is internal operand or new instruction
  1746       if( newrule < _LAST_MACH_OPER ) { // internal operand or instruction?
  1747         // internal operand --> call ReduceInst_Interior
  1748         // Interior of complex instruction.  Do nothing but recurse.
  1749         num_opnds = ReduceInst_Interior( newstate, newrule, mem, mach, num_opnds );
  1750       } else {
  1751         // instruction --> call build operand(  ) to catch result
  1752         //             --> ReduceInst( newrule )
  1753         mach->_opnds[num_opnds++] = s->MachOperGenerator( _reduceOp[catch_op], C );
  1754         Node *mem1 = (Node*)1;
  1755         debug_only(Node *save_mem_node = _mem_node;)
  1756         mach->add_req( ReduceInst( newstate, newrule, mem1 ) );
  1757         debug_only(_mem_node = save_mem_node;)
  1760     assert( mach->_opnds[num_opnds-1], "" );
  1762   return num_opnds;
  1765 // This routine walks the interior of possible complex operands.
  1766 // At each point we check our children in the match tree:
  1767 // (1) No children -
  1768 //     We are a leaf; add _leaf field as an input to the MachNode
  1769 // (2) Child is an internal operand -
  1770 //     Skip over it ( do nothing )
  1771 // (3) Child is an instruction -
  1772 //     Call ReduceInst recursively and
  1773 //     and instruction as an input to the MachNode
  1774 void Matcher::ReduceOper( State *s, int rule, Node *&mem, MachNode *mach ) {
  1775   assert( rule < _LAST_MACH_OPER, "called with operand rule" );
  1776   State *kid = s->_kids[0];
  1777   assert( kid == NULL || s->_leaf->in(0) == NULL, "internal operands have no control" );
  1779   // Leaf?  And not subsumed?
  1780   if( kid == NULL && !_swallowed[rule] ) {
  1781     mach->add_req( s->_leaf );  // Add leaf pointer
  1782     return;                     // Bail out
  1785   if( s->_leaf->is_Load() ) {
  1786     assert( mem == (Node*)1, "multiple Memories being matched at once?" );
  1787     mem = s->_leaf->in(MemNode::Memory);
  1788     debug_only(_mem_node = s->_leaf;)
  1790   if( s->_leaf->in(0) && s->_leaf->req() > 1) {
  1791     if( !mach->in(0) )
  1792       mach->set_req(0,s->_leaf->in(0));
  1793     else {
  1794       assert( s->_leaf->in(0) == mach->in(0), "same instruction, differing controls?" );
  1798   for( uint i=0; kid != NULL && i<2; kid = s->_kids[1], i++ ) {   // binary tree
  1799     int newrule;
  1800     if( i == 0 )
  1801       newrule = kid->_rule[_leftOp[rule]];
  1802     else
  1803       newrule = kid->_rule[_rightOp[rule]];
  1805     if( newrule < _LAST_MACH_OPER ) { // Operand or instruction?
  1806       // Internal operand; recurse but do nothing else
  1807       ReduceOper( kid, newrule, mem, mach );
  1809     } else {                    // Child is a new instruction
  1810       // Reduce the instruction, and add a direct pointer from this
  1811       // machine instruction to the newly reduced one.
  1812       Node *mem1 = (Node*)1;
  1813       debug_only(Node *save_mem_node = _mem_node;)
  1814       mach->add_req( ReduceInst( kid, newrule, mem1 ) );
  1815       debug_only(_mem_node = save_mem_node;)
  1821 // -------------------------------------------------------------------------
  1822 // Java-Java calling convention
  1823 // (what you use when Java calls Java)
  1825 //------------------------------find_receiver----------------------------------
  1826 // For a given signature, return the OptoReg for parameter 0.
  1827 OptoReg::Name Matcher::find_receiver( bool is_outgoing ) {
  1828   VMRegPair regs;
  1829   BasicType sig_bt = T_OBJECT;
  1830   calling_convention(&sig_bt, &regs, 1, is_outgoing);
  1831   // Return argument 0 register.  In the LP64 build pointers
  1832   // take 2 registers, but the VM wants only the 'main' name.
  1833   return OptoReg::as_OptoReg(regs.first());
  1836 // A method-klass-holder may be passed in the inline_cache_reg
  1837 // and then expanded into the inline_cache_reg and a method_oop register
  1838 //   defined in ad_<arch>.cpp
  1841 //------------------------------find_shared------------------------------------
  1842 // Set bits if Node is shared or otherwise a root
  1843 void Matcher::find_shared( Node *n ) {
  1844   // Allocate stack of size C->unique() * 2 to avoid frequent realloc
  1845   MStack mstack(C->unique() * 2);
  1846   // Mark nodes as address_visited if they are inputs to an address expression
  1847   VectorSet address_visited(Thread::current()->resource_area());
  1848   mstack.push(n, Visit);     // Don't need to pre-visit root node
  1849   while (mstack.is_nonempty()) {
  1850     n = mstack.node();       // Leave node on stack
  1851     Node_State nstate = mstack.state();
  1852     uint nop = n->Opcode();
  1853     if (nstate == Pre_Visit) {
  1854       if (address_visited.test(n->_idx)) { // Visited in address already?
  1855         // Flag as visited and shared now.
  1856         set_visited(n);
  1858       if (is_visited(n)) {   // Visited already?
  1859         // Node is shared and has no reason to clone.  Flag it as shared.
  1860         // This causes it to match into a register for the sharing.
  1861         set_shared(n);       // Flag as shared and
  1862         mstack.pop();        // remove node from stack
  1863         continue;
  1865       nstate = Visit; // Not already visited; so visit now
  1867     if (nstate == Visit) {
  1868       mstack.set_state(Post_Visit);
  1869       set_visited(n);   // Flag as visited now
  1870       bool mem_op = false;
  1872       switch( nop ) {  // Handle some opcodes special
  1873       case Op_Phi:             // Treat Phis as shared roots
  1874       case Op_Parm:
  1875       case Op_Proj:            // All handled specially during matching
  1876       case Op_SafePointScalarObject:
  1877         set_shared(n);
  1878         set_dontcare(n);
  1879         break;
  1880       case Op_If:
  1881       case Op_CountedLoopEnd:
  1882         mstack.set_state(Alt_Post_Visit); // Alternative way
  1883         // Convert (If (Bool (CmpX A B))) into (If (Bool) (CmpX A B)).  Helps
  1884         // with matching cmp/branch in 1 instruction.  The Matcher needs the
  1885         // Bool and CmpX side-by-side, because it can only get at constants
  1886         // that are at the leaves of Match trees, and the Bool's condition acts
  1887         // as a constant here.
  1888         mstack.push(n->in(1), Visit);         // Clone the Bool
  1889         mstack.push(n->in(0), Pre_Visit);     // Visit control input
  1890         continue; // while (mstack.is_nonempty())
  1891       case Op_ConvI2D:         // These forms efficiently match with a prior
  1892       case Op_ConvI2F:         //   Load but not a following Store
  1893         if( n->in(1)->is_Load() &&        // Prior load
  1894             n->outcnt() == 1 &&           // Not already shared
  1895             n->unique_out()->is_Store() ) // Following store
  1896           set_shared(n);       // Force it to be a root
  1897         break;
  1898       case Op_ReverseBytesI:
  1899       case Op_ReverseBytesL:
  1900         if( n->in(1)->is_Load() &&        // Prior load
  1901             n->outcnt() == 1 )            // Not already shared
  1902           set_shared(n);                  // Force it to be a root
  1903         break;
  1904       case Op_BoxLock:         // Cant match until we get stack-regs in ADLC
  1905       case Op_IfFalse:
  1906       case Op_IfTrue:
  1907       case Op_MachProj:
  1908       case Op_MergeMem:
  1909       case Op_Catch:
  1910       case Op_CatchProj:
  1911       case Op_CProj:
  1912       case Op_JumpProj:
  1913       case Op_JProj:
  1914       case Op_NeverBranch:
  1915         set_dontcare(n);
  1916         break;
  1917       case Op_Jump:
  1918         mstack.push(n->in(1), Pre_Visit);     // Switch Value (could be shared)
  1919         mstack.push(n->in(0), Pre_Visit);     // Visit Control input
  1920         continue;                             // while (mstack.is_nonempty())
  1921       case Op_StrComp:
  1922       case Op_StrEquals:
  1923       case Op_StrIndexOf:
  1924       case Op_AryEq:
  1925         set_shared(n); // Force result into register (it will be anyways)
  1926         break;
  1927       case Op_ConP: {  // Convert pointers above the centerline to NUL
  1928         TypeNode *tn = n->as_Type(); // Constants derive from type nodes
  1929         const TypePtr* tp = tn->type()->is_ptr();
  1930         if (tp->_ptr == TypePtr::AnyNull) {
  1931           tn->set_type(TypePtr::NULL_PTR);
  1933         break;
  1935       case Op_ConN: {  // Convert narrow pointers above the centerline to NUL
  1936         TypeNode *tn = n->as_Type(); // Constants derive from type nodes
  1937         const TypePtr* tp = tn->type()->make_ptr();
  1938         if (tp && tp->_ptr == TypePtr::AnyNull) {
  1939           tn->set_type(TypeNarrowOop::NULL_PTR);
  1941         break;
  1943       case Op_Binary:         // These are introduced in the Post_Visit state.
  1944         ShouldNotReachHere();
  1945         break;
  1946       case Op_ClearArray:
  1947       case Op_SafePoint:
  1948         mem_op = true;
  1949         break;
  1950       default:
  1951         if( n->is_Store() ) {
  1952           // Do match stores, despite no ideal reg
  1953           mem_op = true;
  1954           break;
  1956         if( n->is_Mem() ) { // Loads and LoadStores
  1957           mem_op = true;
  1958           // Loads must be root of match tree due to prior load conflict
  1959           if( C->subsume_loads() == false )
  1960             set_shared(n);
  1962         // Fall into default case
  1963         if( !n->ideal_reg() )
  1964           set_dontcare(n);  // Unmatchable Nodes
  1965       } // end_switch
  1967       for(int i = n->req() - 1; i >= 0; --i) { // For my children
  1968         Node *m = n->in(i); // Get ith input
  1969         if (m == NULL) continue;  // Ignore NULLs
  1970         uint mop = m->Opcode();
  1972         // Must clone all producers of flags, or we will not match correctly.
  1973         // Suppose a compare setting int-flags is shared (e.g., a switch-tree)
  1974         // then it will match into an ideal Op_RegFlags.  Alas, the fp-flags
  1975         // are also there, so we may match a float-branch to int-flags and
  1976         // expect the allocator to haul the flags from the int-side to the
  1977         // fp-side.  No can do.
  1978         if( _must_clone[mop] ) {
  1979           mstack.push(m, Visit);
  1980           continue; // for(int i = ...)
  1983         if( mop == Op_AddP && m->in(AddPNode::Base)->Opcode() == Op_DecodeN ) {
  1984           // Bases used in addresses must be shared but since
  1985           // they are shared through a DecodeN they may appear
  1986           // to have a single use so force sharing here.
  1987           set_shared(m->in(AddPNode::Base)->in(1));
  1990         // Clone addressing expressions as they are "free" in memory access instructions
  1991         if( mem_op && i == MemNode::Address && mop == Op_AddP ) {
  1992           // Some inputs for address expression are not put on stack
  1993           // to avoid marking them as shared and forcing them into register
  1994           // if they are used only in address expressions.
  1995           // But they should be marked as shared if there are other uses
  1996           // besides address expressions.
  1998           Node *off = m->in(AddPNode::Offset);
  1999           if( off->is_Con() &&
  2000               // When there are other uses besides address expressions
  2001               // put it on stack and mark as shared.
  2002               !is_visited(m) ) {
  2003             address_visited.test_set(m->_idx); // Flag as address_visited
  2004             Node *adr = m->in(AddPNode::Address);
  2006             // Intel, ARM and friends can handle 2 adds in addressing mode
  2007             if( clone_shift_expressions && adr->is_AddP() &&
  2008                 // AtomicAdd is not an addressing expression.
  2009                 // Cheap to find it by looking for screwy base.
  2010                 !adr->in(AddPNode::Base)->is_top() &&
  2011                 // Are there other uses besides address expressions?
  2012                 !is_visited(adr) ) {
  2013               address_visited.set(adr->_idx); // Flag as address_visited
  2014               Node *shift = adr->in(AddPNode::Offset);
  2015               // Check for shift by small constant as well
  2016               if( shift->Opcode() == Op_LShiftX && shift->in(2)->is_Con() &&
  2017                   shift->in(2)->get_int() <= 3 &&
  2018                   // Are there other uses besides address expressions?
  2019                   !is_visited(shift) ) {
  2020                 address_visited.set(shift->_idx); // Flag as address_visited
  2021                 mstack.push(shift->in(2), Visit);
  2022                 Node *conv = shift->in(1);
  2023 #ifdef _LP64
  2024                 // Allow Matcher to match the rule which bypass
  2025                 // ConvI2L operation for an array index on LP64
  2026                 // if the index value is positive.
  2027                 if( conv->Opcode() == Op_ConvI2L &&
  2028                     conv->as_Type()->type()->is_long()->_lo >= 0 &&
  2029                     // Are there other uses besides address expressions?
  2030                     !is_visited(conv) ) {
  2031                   address_visited.set(conv->_idx); // Flag as address_visited
  2032                   mstack.push(conv->in(1), Pre_Visit);
  2033                 } else
  2034 #endif
  2035                 mstack.push(conv, Pre_Visit);
  2036               } else {
  2037                 mstack.push(shift, Pre_Visit);
  2039               mstack.push(adr->in(AddPNode::Address), Pre_Visit);
  2040               mstack.push(adr->in(AddPNode::Base), Pre_Visit);
  2041             } else {  // Sparc, Alpha, PPC and friends
  2042               mstack.push(adr, Pre_Visit);
  2045             // Clone X+offset as it also folds into most addressing expressions
  2046             mstack.push(off, Visit);
  2047             mstack.push(m->in(AddPNode::Base), Pre_Visit);
  2048             continue; // for(int i = ...)
  2049           } // if( off->is_Con() )
  2050         }   // if( mem_op &&
  2051         mstack.push(m, Pre_Visit);
  2052       }     // for(int i = ...)
  2054     else if (nstate == Alt_Post_Visit) {
  2055       mstack.pop(); // Remove node from stack
  2056       // We cannot remove the Cmp input from the Bool here, as the Bool may be
  2057       // shared and all users of the Bool need to move the Cmp in parallel.
  2058       // This leaves both the Bool and the If pointing at the Cmp.  To
  2059       // prevent the Matcher from trying to Match the Cmp along both paths
  2060       // BoolNode::match_edge always returns a zero.
  2062       // We reorder the Op_If in a pre-order manner, so we can visit without
  2063       // accidentally sharing the Cmp (the Bool and the If make 2 users).
  2064       n->add_req( n->in(1)->in(1) ); // Add the Cmp next to the Bool
  2066     else if (nstate == Post_Visit) {
  2067       mstack.pop(); // Remove node from stack
  2069       // Now hack a few special opcodes
  2070       switch( n->Opcode() ) {       // Handle some opcodes special
  2071       case Op_StorePConditional:
  2072       case Op_StoreIConditional:
  2073       case Op_StoreLConditional:
  2074       case Op_CompareAndSwapI:
  2075       case Op_CompareAndSwapL:
  2076       case Op_CompareAndSwapP:
  2077       case Op_CompareAndSwapN: {   // Convert trinary to binary-tree
  2078         Node *newval = n->in(MemNode::ValueIn );
  2079         Node *oldval  = n->in(LoadStoreNode::ExpectedIn);
  2080         Node *pair = new (C, 3) BinaryNode( oldval, newval );
  2081         n->set_req(MemNode::ValueIn,pair);
  2082         n->del_req(LoadStoreNode::ExpectedIn);
  2083         break;
  2085       case Op_CMoveD:              // Convert trinary to binary-tree
  2086       case Op_CMoveF:
  2087       case Op_CMoveI:
  2088       case Op_CMoveL:
  2089       case Op_CMoveN:
  2090       case Op_CMoveP: {
  2091         // Restructure into a binary tree for Matching.  It's possible that
  2092         // we could move this code up next to the graph reshaping for IfNodes
  2093         // or vice-versa, but I do not want to debug this for Ladybird.
  2094         // 10/2/2000 CNC.
  2095         Node *pair1 = new (C, 3) BinaryNode(n->in(1),n->in(1)->in(1));
  2096         n->set_req(1,pair1);
  2097         Node *pair2 = new (C, 3) BinaryNode(n->in(2),n->in(3));
  2098         n->set_req(2,pair2);
  2099         n->del_req(3);
  2100         break;
  2102       case Op_LoopLimit: {
  2103         Node *pair1 = new (C, 3) BinaryNode(n->in(1),n->in(2));
  2104         n->set_req(1,pair1);
  2105         n->set_req(2,n->in(3));
  2106         n->del_req(3);
  2107         break;
  2109       case Op_StrEquals: {
  2110         Node *pair1 = new (C, 3) BinaryNode(n->in(2),n->in(3));
  2111         n->set_req(2,pair1);
  2112         n->set_req(3,n->in(4));
  2113         n->del_req(4);
  2114         break;
  2116       case Op_StrComp:
  2117       case Op_StrIndexOf: {
  2118         Node *pair1 = new (C, 3) BinaryNode(n->in(2),n->in(3));
  2119         n->set_req(2,pair1);
  2120         Node *pair2 = new (C, 3) BinaryNode(n->in(4),n->in(5));
  2121         n->set_req(3,pair2);
  2122         n->del_req(5);
  2123         n->del_req(4);
  2124         break;
  2126       default:
  2127         break;
  2130     else {
  2131       ShouldNotReachHere();
  2133   } // end of while (mstack.is_nonempty())
  2136 #ifdef ASSERT
  2137 // machine-independent root to machine-dependent root
  2138 void Matcher::dump_old2new_map() {
  2139   _old2new_map.dump();
  2141 #endif
  2143 //---------------------------collect_null_checks-------------------------------
  2144 // Find null checks in the ideal graph; write a machine-specific node for
  2145 // it.  Used by later implicit-null-check handling.  Actually collects
  2146 // either an IfTrue or IfFalse for the common NOT-null path, AND the ideal
  2147 // value being tested.
  2148 void Matcher::collect_null_checks( Node *proj, Node *orig_proj ) {
  2149   Node *iff = proj->in(0);
  2150   if( iff->Opcode() == Op_If ) {
  2151     // During matching If's have Bool & Cmp side-by-side
  2152     BoolNode *b = iff->in(1)->as_Bool();
  2153     Node *cmp = iff->in(2);
  2154     int opc = cmp->Opcode();
  2155     if (opc != Op_CmpP && opc != Op_CmpN) return;
  2157     const Type* ct = cmp->in(2)->bottom_type();
  2158     if (ct == TypePtr::NULL_PTR ||
  2159         (opc == Op_CmpN && ct == TypeNarrowOop::NULL_PTR)) {
  2161       bool push_it = false;
  2162       if( proj->Opcode() == Op_IfTrue ) {
  2163         extern int all_null_checks_found;
  2164         all_null_checks_found++;
  2165         if( b->_test._test == BoolTest::ne ) {
  2166           push_it = true;
  2168       } else {
  2169         assert( proj->Opcode() == Op_IfFalse, "" );
  2170         if( b->_test._test == BoolTest::eq ) {
  2171           push_it = true;
  2174       if( push_it ) {
  2175         _null_check_tests.push(proj);
  2176         Node* val = cmp->in(1);
  2177 #ifdef _LP64
  2178         if (val->bottom_type()->isa_narrowoop() &&
  2179             !Matcher::narrow_oop_use_complex_address()) {
  2180           //
  2181           // Look for DecodeN node which should be pinned to orig_proj.
  2182           // On platforms (Sparc) which can not handle 2 adds
  2183           // in addressing mode we have to keep a DecodeN node and
  2184           // use it to do implicit NULL check in address.
  2185           //
  2186           // DecodeN node was pinned to non-null path (orig_proj) during
  2187           // CastPP transformation in final_graph_reshaping_impl().
  2188           //
  2189           uint cnt = orig_proj->outcnt();
  2190           for (uint i = 0; i < orig_proj->outcnt(); i++) {
  2191             Node* d = orig_proj->raw_out(i);
  2192             if (d->is_DecodeN() && d->in(1) == val) {
  2193               val = d;
  2194               val->set_req(0, NULL); // Unpin now.
  2195               // Mark this as special case to distinguish from
  2196               // a regular case: CmpP(DecodeN, NULL).
  2197               val = (Node*)(((intptr_t)val) | 1);
  2198               break;
  2202 #endif
  2203         _null_check_tests.push(val);
  2209 //---------------------------validate_null_checks------------------------------
  2210 // Its possible that the value being NULL checked is not the root of a match
  2211 // tree.  If so, I cannot use the value in an implicit null check.
  2212 void Matcher::validate_null_checks( ) {
  2213   uint cnt = _null_check_tests.size();
  2214   for( uint i=0; i < cnt; i+=2 ) {
  2215     Node *test = _null_check_tests[i];
  2216     Node *val = _null_check_tests[i+1];
  2217     bool is_decoden = ((intptr_t)val) & 1;
  2218     val = (Node*)(((intptr_t)val) & ~1);
  2219     if (has_new_node(val)) {
  2220       Node* new_val = new_node(val);
  2221       if (is_decoden) {
  2222         assert(val->is_DecodeN() && val->in(0) == NULL, "sanity");
  2223         // Note: new_val may have a control edge if
  2224         // the original ideal node DecodeN was matched before
  2225         // it was unpinned in Matcher::collect_null_checks().
  2226         // Unpin the mach node and mark it.
  2227         new_val->set_req(0, NULL);
  2228         new_val = (Node*)(((intptr_t)new_val) | 1);
  2230       // Is a match-tree root, so replace with the matched value
  2231       _null_check_tests.map(i+1, new_val);
  2232     } else {
  2233       // Yank from candidate list
  2234       _null_check_tests.map(i+1,_null_check_tests[--cnt]);
  2235       _null_check_tests.map(i,_null_check_tests[--cnt]);
  2236       _null_check_tests.pop();
  2237       _null_check_tests.pop();
  2238       i-=2;
  2243 // Used by the DFA in dfa_xxx.cpp.  Check for a following barrier or
  2244 // atomic instruction acting as a store_load barrier without any
  2245 // intervening volatile load, and thus we don't need a barrier here.
  2246 // We retain the Node to act as a compiler ordering barrier.
  2247 bool Matcher::post_store_load_barrier(const Node *vmb) {
  2248   Compile *C = Compile::current();
  2249   assert( vmb->is_MemBar(), "" );
  2250   assert( vmb->Opcode() != Op_MemBarAcquire, "" );
  2251   const MemBarNode *mem = (const MemBarNode*)vmb;
  2253   // Get the Proj node, ctrl, that can be used to iterate forward
  2254   Node *ctrl = NULL;
  2255   DUIterator_Fast imax, i = mem->fast_outs(imax);
  2256   while( true ) {
  2257     ctrl = mem->fast_out(i);            // Throw out-of-bounds if proj not found
  2258     assert( ctrl->is_Proj(), "only projections here" );
  2259     ProjNode *proj = (ProjNode*)ctrl;
  2260     if( proj->_con == TypeFunc::Control &&
  2261         !C->node_arena()->contains(ctrl) ) // Unmatched old-space only
  2262       break;
  2263     i++;
  2266   for( DUIterator_Fast jmax, j = ctrl->fast_outs(jmax); j < jmax; j++ ) {
  2267     Node *x = ctrl->fast_out(j);
  2268     int xop = x->Opcode();
  2270     // We don't need current barrier if we see another or a lock
  2271     // before seeing volatile load.
  2272     //
  2273     // Op_Fastunlock previously appeared in the Op_* list below.
  2274     // With the advent of 1-0 lock operations we're no longer guaranteed
  2275     // that a monitor exit operation contains a serializing instruction.
  2277     if (xop == Op_MemBarVolatile ||
  2278         xop == Op_FastLock ||
  2279         xop == Op_CompareAndSwapL ||
  2280         xop == Op_CompareAndSwapP ||
  2281         xop == Op_CompareAndSwapN ||
  2282         xop == Op_CompareAndSwapI)
  2283       return true;
  2285     if (x->is_MemBar()) {
  2286       // We must retain this membar if there is an upcoming volatile
  2287       // load, which will be preceded by acquire membar.
  2288       if (xop == Op_MemBarAcquire)
  2289         return false;
  2290       // For other kinds of barriers, check by pretending we
  2291       // are them, and seeing if we can be removed.
  2292       else
  2293         return post_store_load_barrier((const MemBarNode*)x);
  2296     // Delicate code to detect case of an upcoming fastlock block
  2297     if( x->is_If() && x->req() > 1 &&
  2298         !C->node_arena()->contains(x) ) { // Unmatched old-space only
  2299       Node *iff = x;
  2300       Node *bol = iff->in(1);
  2301       // The iff might be some random subclass of If or bol might be Con-Top
  2302       if (!bol->is_Bool())  return false;
  2303       assert( bol->req() > 1, "" );
  2304       return (bol->in(1)->Opcode() == Op_FastUnlock);
  2306     // probably not necessary to check for these
  2307     if (x->is_Call() || x->is_SafePoint() || x->is_block_proj())
  2308       return false;
  2310   return false;
  2313 //=============================================================================
  2314 //---------------------------State---------------------------------------------
  2315 State::State(void) {
  2316 #ifdef ASSERT
  2317   _id = 0;
  2318   _kids[0] = _kids[1] = (State*)(intptr_t) CONST64(0xcafebabecafebabe);
  2319   _leaf = (Node*)(intptr_t) CONST64(0xbaadf00dbaadf00d);
  2320   //memset(_cost, -1, sizeof(_cost));
  2321   //memset(_rule, -1, sizeof(_rule));
  2322 #endif
  2323   memset(_valid, 0, sizeof(_valid));
  2326 #ifdef ASSERT
  2327 State::~State() {
  2328   _id = 99;
  2329   _kids[0] = _kids[1] = (State*)(intptr_t) CONST64(0xcafebabecafebabe);
  2330   _leaf = (Node*)(intptr_t) CONST64(0xbaadf00dbaadf00d);
  2331   memset(_cost, -3, sizeof(_cost));
  2332   memset(_rule, -3, sizeof(_rule));
  2334 #endif
  2336 #ifndef PRODUCT
  2337 //---------------------------dump----------------------------------------------
  2338 void State::dump() {
  2339   tty->print("\n");
  2340   dump(0);
  2343 void State::dump(int depth) {
  2344   for( int j = 0; j < depth; j++ )
  2345     tty->print("   ");
  2346   tty->print("--N: ");
  2347   _leaf->dump();
  2348   uint i;
  2349   for( i = 0; i < _LAST_MACH_OPER; i++ )
  2350     // Check for valid entry
  2351     if( valid(i) ) {
  2352       for( int j = 0; j < depth; j++ )
  2353         tty->print("   ");
  2354         assert(_cost[i] != max_juint, "cost must be a valid value");
  2355         assert(_rule[i] < _last_Mach_Node, "rule[i] must be valid rule");
  2356         tty->print_cr("%s  %d  %s",
  2357                       ruleName[i], _cost[i], ruleName[_rule[i]] );
  2359   tty->print_cr("");
  2361   for( i=0; i<2; i++ )
  2362     if( _kids[i] )
  2363       _kids[i]->dump(depth+1);
  2365 #endif

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