src/share/vm/opto/matcher.cpp

Mon, 21 Mar 2011 11:28:14 -0700

author
kvn
date
Mon, 21 Mar 2011 11:28:14 -0700
changeset 2665
9dc311b8473e
parent 2322
828eafbd85cc
child 2683
7e88bdae86ec
permissions
-rw-r--r--

7008866: Missing loop predicate for loop with multiple entries
Summary: Add predicates when loop head bytecode is parsed instead of when back branch bytecode is parsed.
Reviewed-by: never

     1 /*
     2  * Copyright (c) 1997, 2010, 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
    53 OptoReg::Name OptoReg::c_frame_pointer;
    57 const int Matcher::base2reg[Type::lastype] = {
    58   Node::NotAMachineReg,0,0, Op_RegI, Op_RegL, 0, Op_RegN,
    59   Node::NotAMachineReg, Node::NotAMachineReg, /* tuple, array */
    60   Op_RegP, Op_RegP, Op_RegP, Op_RegP, Op_RegP, Op_RegP, /* the pointers */
    61   0, 0/*abio*/,
    62   Op_RegP /* Return address */, 0, /* the memories */
    63   Op_RegF, Op_RegF, Op_RegF, Op_RegD, Op_RegD, Op_RegD,
    64   0  /*bottom*/
    65 };
    67 const RegMask *Matcher::idealreg2regmask[_last_machine_leaf];
    68 RegMask Matcher::mreg2regmask[_last_Mach_Reg];
    69 RegMask Matcher::STACK_ONLY_mask;
    70 RegMask Matcher::c_frame_ptr_mask;
    71 const uint Matcher::_begin_rematerialize = _BEGIN_REMATERIALIZE;
    72 const uint Matcher::_end_rematerialize   = _END_REMATERIALIZE;
    74 //---------------------------Matcher-------------------------------------------
    75 Matcher::Matcher( Node_List &proj_list ) :
    76   PhaseTransform( Phase::Ins_Select ),
    77 #ifdef ASSERT
    78   _old2new_map(C->comp_arena()),
    79   _new2old_map(C->comp_arena()),
    80 #endif
    81   _shared_nodes(C->comp_arena()),
    82   _reduceOp(reduceOp), _leftOp(leftOp), _rightOp(rightOp),
    83   _swallowed(swallowed),
    84   _begin_inst_chain_rule(_BEGIN_INST_CHAIN_RULE),
    85   _end_inst_chain_rule(_END_INST_CHAIN_RULE),
    86   _must_clone(must_clone), _proj_list(proj_list),
    87   _register_save_policy(register_save_policy),
    88   _c_reg_save_policy(c_reg_save_policy),
    89   _register_save_type(register_save_type),
    90   _ruleName(ruleName),
    91   _allocation_started(false),
    92   _states_arena(Chunk::medium_size),
    93   _visited(&_states_arena),
    94   _shared(&_states_arena),
    95   _dontcare(&_states_arena) {
    96   C->set_matcher(this);
    98   idealreg2spillmask  [Op_RegI] = NULL;
    99   idealreg2spillmask  [Op_RegN] = NULL;
   100   idealreg2spillmask  [Op_RegL] = NULL;
   101   idealreg2spillmask  [Op_RegF] = NULL;
   102   idealreg2spillmask  [Op_RegD] = NULL;
   103   idealreg2spillmask  [Op_RegP] = NULL;
   105   idealreg2debugmask  [Op_RegI] = NULL;
   106   idealreg2debugmask  [Op_RegN] = NULL;
   107   idealreg2debugmask  [Op_RegL] = NULL;
   108   idealreg2debugmask  [Op_RegF] = NULL;
   109   idealreg2debugmask  [Op_RegD] = NULL;
   110   idealreg2debugmask  [Op_RegP] = NULL;
   112   idealreg2mhdebugmask[Op_RegI] = NULL;
   113   idealreg2mhdebugmask[Op_RegN] = NULL;
   114   idealreg2mhdebugmask[Op_RegL] = NULL;
   115   idealreg2mhdebugmask[Op_RegF] = NULL;
   116   idealreg2mhdebugmask[Op_RegD] = NULL;
   117   idealreg2mhdebugmask[Op_RegP] = NULL;
   119   debug_only(_mem_node = NULL;)   // Ideal memory node consumed by mach node
   120 }
   122 //------------------------------warp_incoming_stk_arg------------------------
   123 // This warps a VMReg into an OptoReg::Name
   124 OptoReg::Name Matcher::warp_incoming_stk_arg( VMReg reg ) {
   125   OptoReg::Name warped;
   126   if( reg->is_stack() ) {  // Stack slot argument?
   127     warped = OptoReg::add(_old_SP, reg->reg2stack() );
   128     warped = OptoReg::add(warped, C->out_preserve_stack_slots());
   129     if( warped >= _in_arg_limit )
   130       _in_arg_limit = OptoReg::add(warped, 1); // Bump max stack slot seen
   131     if (!RegMask::can_represent(warped)) {
   132       // the compiler cannot represent this method's calling sequence
   133       C->record_method_not_compilable_all_tiers("unsupported incoming calling sequence");
   134       return OptoReg::Bad;
   135     }
   136     return warped;
   137   }
   138   return OptoReg::as_OptoReg(reg);
   139 }
   141 //---------------------------compute_old_SP------------------------------------
   142 OptoReg::Name Compile::compute_old_SP() {
   143   int fixed    = fixed_slots();
   144   int preserve = in_preserve_stack_slots();
   145   return OptoReg::stack2reg(round_to(fixed + preserve, Matcher::stack_alignment_in_slots()));
   146 }
   150 #ifdef ASSERT
   151 void Matcher::verify_new_nodes_only(Node* xroot) {
   152   // Make sure that the new graph only references new nodes
   153   ResourceMark rm;
   154   Unique_Node_List worklist;
   155   VectorSet visited(Thread::current()->resource_area());
   156   worklist.push(xroot);
   157   while (worklist.size() > 0) {
   158     Node* n = worklist.pop();
   159     visited <<= n->_idx;
   160     assert(C->node_arena()->contains(n), "dead node");
   161     for (uint j = 0; j < n->req(); j++) {
   162       Node* in = n->in(j);
   163       if (in != NULL) {
   164         assert(C->node_arena()->contains(in), "dead node");
   165         if (!visited.test(in->_idx)) {
   166           worklist.push(in);
   167         }
   168       }
   169     }
   170   }
   171 }
   172 #endif
   175 //---------------------------match---------------------------------------------
   176 void Matcher::match( ) {
   177   if( MaxLabelRootDepth < 100 ) { // Too small?
   178     assert(false, "invalid MaxLabelRootDepth, increase it to 100 minimum");
   179     MaxLabelRootDepth = 100;
   180   }
   181   // One-time initialization of some register masks.
   182   init_spill_mask( C->root()->in(1) );
   183   _return_addr_mask = return_addr();
   184 #ifdef _LP64
   185   // Pointers take 2 slots in 64-bit land
   186   _return_addr_mask.Insert(OptoReg::add(return_addr(),1));
   187 #endif
   189   // Map a Java-signature return type into return register-value
   190   // machine registers for 0, 1 and 2 returned values.
   191   const TypeTuple *range = C->tf()->range();
   192   if( range->cnt() > TypeFunc::Parms ) { // If not a void function
   193     // Get ideal-register return type
   194     int ireg = base2reg[range->field_at(TypeFunc::Parms)->base()];
   195     // Get machine return register
   196     uint sop = C->start()->Opcode();
   197     OptoRegPair regs = return_value(ireg, false);
   199     // And mask for same
   200     _return_value_mask = RegMask(regs.first());
   201     if( OptoReg::is_valid(regs.second()) )
   202       _return_value_mask.Insert(regs.second());
   203   }
   205   // ---------------
   206   // Frame Layout
   208   // Need the method signature to determine the incoming argument types,
   209   // because the types determine which registers the incoming arguments are
   210   // in, and this affects the matched code.
   211   const TypeTuple *domain = C->tf()->domain();
   212   uint             argcnt = domain->cnt() - TypeFunc::Parms;
   213   BasicType *sig_bt        = NEW_RESOURCE_ARRAY( BasicType, argcnt );
   214   VMRegPair *vm_parm_regs  = NEW_RESOURCE_ARRAY( VMRegPair, argcnt );
   215   _parm_regs               = NEW_RESOURCE_ARRAY( OptoRegPair, argcnt );
   216   _calling_convention_mask = NEW_RESOURCE_ARRAY( RegMask, argcnt );
   217   uint i;
   218   for( i = 0; i<argcnt; i++ ) {
   219     sig_bt[i] = domain->field_at(i+TypeFunc::Parms)->basic_type();
   220   }
   222   // Pass array of ideal registers and length to USER code (from the AD file)
   223   // that will convert this to an array of register numbers.
   224   const StartNode *start = C->start();
   225   start->calling_convention( sig_bt, vm_parm_regs, argcnt );
   226 #ifdef ASSERT
   227   // Sanity check users' calling convention.  Real handy while trying to
   228   // get the initial port correct.
   229   { for (uint i = 0; i<argcnt; i++) {
   230       if( !vm_parm_regs[i].first()->is_valid() && !vm_parm_regs[i].second()->is_valid() ) {
   231         assert(domain->field_at(i+TypeFunc::Parms)==Type::HALF, "only allowed on halve" );
   232         _parm_regs[i].set_bad();
   233         continue;
   234       }
   235       VMReg parm_reg = vm_parm_regs[i].first();
   236       assert(parm_reg->is_valid(), "invalid arg?");
   237       if (parm_reg->is_reg()) {
   238         OptoReg::Name opto_parm_reg = OptoReg::as_OptoReg(parm_reg);
   239         assert(can_be_java_arg(opto_parm_reg) ||
   240                C->stub_function() == CAST_FROM_FN_PTR(address, OptoRuntime::rethrow_C) ||
   241                opto_parm_reg == inline_cache_reg(),
   242                "parameters in register must be preserved by runtime stubs");
   243       }
   244       for (uint j = 0; j < i; j++) {
   245         assert(parm_reg != vm_parm_regs[j].first(),
   246                "calling conv. must produce distinct regs");
   247       }
   248     }
   249   }
   250 #endif
   252   // Do some initial frame layout.
   254   // Compute the old incoming SP (may be called FP) as
   255   //   OptoReg::stack0() + locks + in_preserve_stack_slots + pad2.
   256   _old_SP = C->compute_old_SP();
   257   assert( is_even(_old_SP), "must be even" );
   259   // Compute highest incoming stack argument as
   260   //   _old_SP + out_preserve_stack_slots + incoming argument size.
   261   _in_arg_limit = OptoReg::add(_old_SP, C->out_preserve_stack_slots());
   262   assert( is_even(_in_arg_limit), "out_preserve must be even" );
   263   for( i = 0; i < argcnt; i++ ) {
   264     // Permit args to have no register
   265     _calling_convention_mask[i].Clear();
   266     if( !vm_parm_regs[i].first()->is_valid() && !vm_parm_regs[i].second()->is_valid() ) {
   267       continue;
   268     }
   269     // calling_convention returns stack arguments as a count of
   270     // slots beyond OptoReg::stack0()/VMRegImpl::stack0.  We need to convert this to
   271     // the allocators point of view, taking into account all the
   272     // preserve area, locks & pad2.
   274     OptoReg::Name reg1 = warp_incoming_stk_arg(vm_parm_regs[i].first());
   275     if( OptoReg::is_valid(reg1))
   276       _calling_convention_mask[i].Insert(reg1);
   278     OptoReg::Name reg2 = warp_incoming_stk_arg(vm_parm_regs[i].second());
   279     if( OptoReg::is_valid(reg2))
   280       _calling_convention_mask[i].Insert(reg2);
   282     // Saved biased stack-slot register number
   283     _parm_regs[i].set_pair(reg2, reg1);
   284   }
   286   // Finally, make sure the incoming arguments take up an even number of
   287   // words, in case the arguments or locals need to contain doubleword stack
   288   // slots.  The rest of the system assumes that stack slot pairs (in
   289   // particular, in the spill area) which look aligned will in fact be
   290   // aligned relative to the stack pointer in the target machine.  Double
   291   // stack slots will always be allocated aligned.
   292   _new_SP = OptoReg::Name(round_to(_in_arg_limit, RegMask::SlotsPerLong));
   294   // Compute highest outgoing stack argument as
   295   //   _new_SP + out_preserve_stack_slots + max(outgoing argument size).
   296   _out_arg_limit = OptoReg::add(_new_SP, C->out_preserve_stack_slots());
   297   assert( is_even(_out_arg_limit), "out_preserve must be even" );
   299   if (!RegMask::can_represent(OptoReg::add(_out_arg_limit,-1))) {
   300     // the compiler cannot represent this method's calling sequence
   301     C->record_method_not_compilable("must be able to represent all call arguments in reg mask");
   302   }
   304   if (C->failing())  return;  // bailed out on incoming arg failure
   306   // ---------------
   307   // Collect roots of matcher trees.  Every node for which
   308   // _shared[_idx] is cleared is guaranteed to not be shared, and thus
   309   // can be a valid interior of some tree.
   310   find_shared( C->root() );
   311   find_shared( C->top() );
   313   C->print_method("Before Matching");
   315   // Create new ideal node ConP #NULL even if it does exist in old space
   316   // to avoid false sharing if the corresponding mach node is not used.
   317   // The corresponding mach node is only used in rare cases for derived
   318   // pointers.
   319   Node* new_ideal_null = ConNode::make(C, TypePtr::NULL_PTR);
   321   // Swap out to old-space; emptying new-space
   322   Arena *old = C->node_arena()->move_contents(C->old_arena());
   324   // Save debug and profile information for nodes in old space:
   325   _old_node_note_array = C->node_note_array();
   326   if (_old_node_note_array != NULL) {
   327     C->set_node_note_array(new(C->comp_arena()) GrowableArray<Node_Notes*>
   328                            (C->comp_arena(), _old_node_note_array->length(),
   329                             0, NULL));
   330   }
   332   // Pre-size the new_node table to avoid the need for range checks.
   333   grow_new_node_array(C->unique());
   335   // Reset node counter so MachNodes start with _idx at 0
   336   int nodes = C->unique(); // save value
   337   C->set_unique(0);
   339   // Recursively match trees from old space into new space.
   340   // Correct leaves of new-space Nodes; they point to old-space.
   341   _visited.Clear();             // Clear visit bits for xform call
   342   C->set_cached_top_node(xform( C->top(), nodes ));
   343   if (!C->failing()) {
   344     Node* xroot =        xform( C->root(), 1 );
   345     if (xroot == NULL) {
   346       Matcher::soft_match_failure();  // recursive matching process failed
   347       C->record_method_not_compilable("instruction match failed");
   348     } else {
   349       // During matching shared constants were attached to C->root()
   350       // because xroot wasn't available yet, so transfer the uses to
   351       // the xroot.
   352       for( DUIterator_Fast jmax, j = C->root()->fast_outs(jmax); j < jmax; j++ ) {
   353         Node* n = C->root()->fast_out(j);
   354         if (C->node_arena()->contains(n)) {
   355           assert(n->in(0) == C->root(), "should be control user");
   356           n->set_req(0, xroot);
   357           --j;
   358           --jmax;
   359         }
   360       }
   362       // Generate new mach node for ConP #NULL
   363       assert(new_ideal_null != NULL, "sanity");
   364       _mach_null = match_tree(new_ideal_null);
   365       // Don't set control, it will confuse GCM since there are no uses.
   366       // The control will be set when this node is used first time
   367       // in find_base_for_derived().
   368       assert(_mach_null != NULL, "");
   370       C->set_root(xroot->is_Root() ? xroot->as_Root() : NULL);
   372 #ifdef ASSERT
   373       verify_new_nodes_only(xroot);
   374 #endif
   375     }
   376   }
   377   if (C->top() == NULL || C->root() == NULL) {
   378     C->record_method_not_compilable("graph lost"); // %%% cannot happen?
   379   }
   380   if (C->failing()) {
   381     // delete old;
   382     old->destruct_contents();
   383     return;
   384   }
   385   assert( C->top(), "" );
   386   assert( C->root(), "" );
   387   validate_null_checks();
   389   // Now smoke old-space
   390   NOT_DEBUG( old->destruct_contents() );
   392   // ------------------------
   393   // Set up save-on-entry registers
   394   Fixup_Save_On_Entry( );
   395 }
   398 //------------------------------Fixup_Save_On_Entry----------------------------
   399 // The stated purpose of this routine is to take care of save-on-entry
   400 // registers.  However, the overall goal of the Match phase is to convert into
   401 // machine-specific instructions which have RegMasks to guide allocation.
   402 // So what this procedure really does is put a valid RegMask on each input
   403 // to the machine-specific variations of all Return, TailCall and Halt
   404 // instructions.  It also adds edgs to define the save-on-entry values (and of
   405 // course gives them a mask).
   407 static RegMask *init_input_masks( uint size, RegMask &ret_adr, RegMask &fp ) {
   408   RegMask *rms = NEW_RESOURCE_ARRAY( RegMask, size );
   409   // Do all the pre-defined register masks
   410   rms[TypeFunc::Control  ] = RegMask::Empty;
   411   rms[TypeFunc::I_O      ] = RegMask::Empty;
   412   rms[TypeFunc::Memory   ] = RegMask::Empty;
   413   rms[TypeFunc::ReturnAdr] = ret_adr;
   414   rms[TypeFunc::FramePtr ] = fp;
   415   return rms;
   416 }
   418 //---------------------------init_first_stack_mask-----------------------------
   419 // Create the initial stack mask used by values spilling to the stack.
   420 // Disallow any debug info in outgoing argument areas by setting the
   421 // initial mask accordingly.
   422 void Matcher::init_first_stack_mask() {
   424   // Allocate storage for spill masks as masks for the appropriate load type.
   425   RegMask *rms = (RegMask*)C->comp_arena()->Amalloc_D(sizeof(RegMask) * 3*6);
   427   idealreg2spillmask  [Op_RegN] = &rms[0];
   428   idealreg2spillmask  [Op_RegI] = &rms[1];
   429   idealreg2spillmask  [Op_RegL] = &rms[2];
   430   idealreg2spillmask  [Op_RegF] = &rms[3];
   431   idealreg2spillmask  [Op_RegD] = &rms[4];
   432   idealreg2spillmask  [Op_RegP] = &rms[5];
   434   idealreg2debugmask  [Op_RegN] = &rms[6];
   435   idealreg2debugmask  [Op_RegI] = &rms[7];
   436   idealreg2debugmask  [Op_RegL] = &rms[8];
   437   idealreg2debugmask  [Op_RegF] = &rms[9];
   438   idealreg2debugmask  [Op_RegD] = &rms[10];
   439   idealreg2debugmask  [Op_RegP] = &rms[11];
   441   idealreg2mhdebugmask[Op_RegN] = &rms[12];
   442   idealreg2mhdebugmask[Op_RegI] = &rms[13];
   443   idealreg2mhdebugmask[Op_RegL] = &rms[14];
   444   idealreg2mhdebugmask[Op_RegF] = &rms[15];
   445   idealreg2mhdebugmask[Op_RegD] = &rms[16];
   446   idealreg2mhdebugmask[Op_RegP] = &rms[17];
   448   OptoReg::Name i;
   450   // At first, start with the empty mask
   451   C->FIRST_STACK_mask().Clear();
   453   // Add in the incoming argument area
   454   OptoReg::Name init = OptoReg::add(_old_SP, C->out_preserve_stack_slots());
   455   for (i = init; i < _in_arg_limit; i = OptoReg::add(i,1))
   456     C->FIRST_STACK_mask().Insert(i);
   458   // Add in all bits past the outgoing argument area
   459   guarantee(RegMask::can_represent(OptoReg::add(_out_arg_limit,-1)),
   460             "must be able to represent all call arguments in reg mask");
   461   init = _out_arg_limit;
   462   for (i = init; RegMask::can_represent(i); i = OptoReg::add(i,1))
   463     C->FIRST_STACK_mask().Insert(i);
   465   // Finally, set the "infinite stack" bit.
   466   C->FIRST_STACK_mask().set_AllStack();
   468   // Make spill masks.  Registers for their class, plus FIRST_STACK_mask.
   469 #ifdef _LP64
   470   *idealreg2spillmask[Op_RegN] = *idealreg2regmask[Op_RegN];
   471    idealreg2spillmask[Op_RegN]->OR(C->FIRST_STACK_mask());
   472 #endif
   473   *idealreg2spillmask[Op_RegI] = *idealreg2regmask[Op_RegI];
   474    idealreg2spillmask[Op_RegI]->OR(C->FIRST_STACK_mask());
   475   *idealreg2spillmask[Op_RegL] = *idealreg2regmask[Op_RegL];
   476    idealreg2spillmask[Op_RegL]->OR(C->FIRST_STACK_mask());
   477   *idealreg2spillmask[Op_RegF] = *idealreg2regmask[Op_RegF];
   478    idealreg2spillmask[Op_RegF]->OR(C->FIRST_STACK_mask());
   479   *idealreg2spillmask[Op_RegD] = *idealreg2regmask[Op_RegD];
   480    idealreg2spillmask[Op_RegD]->OR(C->FIRST_STACK_mask());
   481   *idealreg2spillmask[Op_RegP] = *idealreg2regmask[Op_RegP];
   482    idealreg2spillmask[Op_RegP]->OR(C->FIRST_STACK_mask());
   484    if (UseFPUForSpilling) {
   485      // This mask logic assumes that the spill operations are
   486      // symmetric and that the registers involved are the same size.
   487      // On sparc for instance we may have to use 64 bit moves will
   488      // kill 2 registers when used with F0-F31.
   489      idealreg2spillmask[Op_RegI]->OR(*idealreg2regmask[Op_RegF]);
   490      idealreg2spillmask[Op_RegF]->OR(*idealreg2regmask[Op_RegI]);
   491 #ifdef _LP64
   492      idealreg2spillmask[Op_RegN]->OR(*idealreg2regmask[Op_RegF]);
   493      idealreg2spillmask[Op_RegL]->OR(*idealreg2regmask[Op_RegD]);
   494      idealreg2spillmask[Op_RegD]->OR(*idealreg2regmask[Op_RegL]);
   495      idealreg2spillmask[Op_RegP]->OR(*idealreg2regmask[Op_RegD]);
   496 #else
   497      idealreg2spillmask[Op_RegP]->OR(*idealreg2regmask[Op_RegF]);
   498 #endif
   499    }
   501   // Make up debug masks.  Any spill slot plus callee-save registers.
   502   // Caller-save registers are assumed to be trashable by the various
   503   // inline-cache fixup routines.
   504   *idealreg2debugmask  [Op_RegN]= *idealreg2spillmask[Op_RegN];
   505   *idealreg2debugmask  [Op_RegI]= *idealreg2spillmask[Op_RegI];
   506   *idealreg2debugmask  [Op_RegL]= *idealreg2spillmask[Op_RegL];
   507   *idealreg2debugmask  [Op_RegF]= *idealreg2spillmask[Op_RegF];
   508   *idealreg2debugmask  [Op_RegD]= *idealreg2spillmask[Op_RegD];
   509   *idealreg2debugmask  [Op_RegP]= *idealreg2spillmask[Op_RegP];
   511   *idealreg2mhdebugmask[Op_RegN]= *idealreg2spillmask[Op_RegN];
   512   *idealreg2mhdebugmask[Op_RegI]= *idealreg2spillmask[Op_RegI];
   513   *idealreg2mhdebugmask[Op_RegL]= *idealreg2spillmask[Op_RegL];
   514   *idealreg2mhdebugmask[Op_RegF]= *idealreg2spillmask[Op_RegF];
   515   *idealreg2mhdebugmask[Op_RegD]= *idealreg2spillmask[Op_RegD];
   516   *idealreg2mhdebugmask[Op_RegP]= *idealreg2spillmask[Op_RegP];
   518   // Prevent stub compilations from attempting to reference
   519   // callee-saved registers from debug info
   520   bool exclude_soe = !Compile::current()->is_method_compilation();
   522   for( i=OptoReg::Name(0); i<OptoReg::Name(_last_Mach_Reg); i = OptoReg::add(i,1) ) {
   523     // registers the caller has to save do not work
   524     if( _register_save_policy[i] == 'C' ||
   525         _register_save_policy[i] == 'A' ||
   526         (_register_save_policy[i] == 'E' && exclude_soe) ) {
   527       idealreg2debugmask  [Op_RegN]->Remove(i);
   528       idealreg2debugmask  [Op_RegI]->Remove(i); // Exclude save-on-call
   529       idealreg2debugmask  [Op_RegL]->Remove(i); // registers from debug
   530       idealreg2debugmask  [Op_RegF]->Remove(i); // masks
   531       idealreg2debugmask  [Op_RegD]->Remove(i);
   532       idealreg2debugmask  [Op_RegP]->Remove(i);
   534       idealreg2mhdebugmask[Op_RegN]->Remove(i);
   535       idealreg2mhdebugmask[Op_RegI]->Remove(i);
   536       idealreg2mhdebugmask[Op_RegL]->Remove(i);
   537       idealreg2mhdebugmask[Op_RegF]->Remove(i);
   538       idealreg2mhdebugmask[Op_RegD]->Remove(i);
   539       idealreg2mhdebugmask[Op_RegP]->Remove(i);
   540     }
   541   }
   543   // Subtract the register we use to save the SP for MethodHandle
   544   // invokes to from the debug mask.
   545   const RegMask save_mask = method_handle_invoke_SP_save_mask();
   546   idealreg2mhdebugmask[Op_RegN]->SUBTRACT(save_mask);
   547   idealreg2mhdebugmask[Op_RegI]->SUBTRACT(save_mask);
   548   idealreg2mhdebugmask[Op_RegL]->SUBTRACT(save_mask);
   549   idealreg2mhdebugmask[Op_RegF]->SUBTRACT(save_mask);
   550   idealreg2mhdebugmask[Op_RegD]->SUBTRACT(save_mask);
   551   idealreg2mhdebugmask[Op_RegP]->SUBTRACT(save_mask);
   552 }
   554 //---------------------------is_save_on_entry----------------------------------
   555 bool Matcher::is_save_on_entry( int reg ) {
   556   return
   557     _register_save_policy[reg] == 'E' ||
   558     _register_save_policy[reg] == 'A' || // Save-on-entry register?
   559     // Also save argument registers in the trampolining stubs
   560     (C->save_argument_registers() && is_spillable_arg(reg));
   561 }
   563 //---------------------------Fixup_Save_On_Entry-------------------------------
   564 void Matcher::Fixup_Save_On_Entry( ) {
   565   init_first_stack_mask();
   567   Node *root = C->root();       // Short name for root
   568   // Count number of save-on-entry registers.
   569   uint soe_cnt = number_of_saved_registers();
   570   uint i;
   572   // Find the procedure Start Node
   573   StartNode *start = C->start();
   574   assert( start, "Expect a start node" );
   576   // Save argument registers in the trampolining stubs
   577   if( C->save_argument_registers() )
   578     for( i = 0; i < _last_Mach_Reg; i++ )
   579       if( is_spillable_arg(i) )
   580         soe_cnt++;
   582   // Input RegMask array shared by all Returns.
   583   // The type for doubles and longs has a count of 2, but
   584   // there is only 1 returned value
   585   uint ret_edge_cnt = TypeFunc::Parms + ((C->tf()->range()->cnt() == TypeFunc::Parms) ? 0 : 1);
   586   RegMask *ret_rms  = init_input_masks( ret_edge_cnt + soe_cnt, _return_addr_mask, c_frame_ptr_mask );
   587   // Returns have 0 or 1 returned values depending on call signature.
   588   // Return register is specified by return_value in the AD file.
   589   if (ret_edge_cnt > TypeFunc::Parms)
   590     ret_rms[TypeFunc::Parms+0] = _return_value_mask;
   592   // Input RegMask array shared by all Rethrows.
   593   uint reth_edge_cnt = TypeFunc::Parms+1;
   594   RegMask *reth_rms  = init_input_masks( reth_edge_cnt + soe_cnt, _return_addr_mask, c_frame_ptr_mask );
   595   // Rethrow takes exception oop only, but in the argument 0 slot.
   596   reth_rms[TypeFunc::Parms] = mreg2regmask[find_receiver(false)];
   597 #ifdef _LP64
   598   // Need two slots for ptrs in 64-bit land
   599   reth_rms[TypeFunc::Parms].Insert(OptoReg::add(OptoReg::Name(find_receiver(false)),1));
   600 #endif
   602   // Input RegMask array shared by all TailCalls
   603   uint tail_call_edge_cnt = TypeFunc::Parms+2;
   604   RegMask *tail_call_rms = init_input_masks( tail_call_edge_cnt + soe_cnt, _return_addr_mask, c_frame_ptr_mask );
   606   // Input RegMask array shared by all TailJumps
   607   uint tail_jump_edge_cnt = TypeFunc::Parms+2;
   608   RegMask *tail_jump_rms = init_input_masks( tail_jump_edge_cnt + soe_cnt, _return_addr_mask, c_frame_ptr_mask );
   610   // TailCalls have 2 returned values (target & moop), whose masks come
   611   // from the usual MachNode/MachOper mechanism.  Find a sample
   612   // TailCall to extract these masks and put the correct masks into
   613   // the tail_call_rms array.
   614   for( i=1; i < root->req(); i++ ) {
   615     MachReturnNode *m = root->in(i)->as_MachReturn();
   616     if( m->ideal_Opcode() == Op_TailCall ) {
   617       tail_call_rms[TypeFunc::Parms+0] = m->MachNode::in_RegMask(TypeFunc::Parms+0);
   618       tail_call_rms[TypeFunc::Parms+1] = m->MachNode::in_RegMask(TypeFunc::Parms+1);
   619       break;
   620     }
   621   }
   623   // TailJumps have 2 returned values (target & ex_oop), whose masks come
   624   // from the usual MachNode/MachOper mechanism.  Find a sample
   625   // TailJump to extract these masks and put the correct masks into
   626   // the tail_jump_rms array.
   627   for( i=1; i < root->req(); i++ ) {
   628     MachReturnNode *m = root->in(i)->as_MachReturn();
   629     if( m->ideal_Opcode() == Op_TailJump ) {
   630       tail_jump_rms[TypeFunc::Parms+0] = m->MachNode::in_RegMask(TypeFunc::Parms+0);
   631       tail_jump_rms[TypeFunc::Parms+1] = m->MachNode::in_RegMask(TypeFunc::Parms+1);
   632       break;
   633     }
   634   }
   636   // Input RegMask array shared by all Halts
   637   uint halt_edge_cnt = TypeFunc::Parms;
   638   RegMask *halt_rms = init_input_masks( halt_edge_cnt + soe_cnt, _return_addr_mask, c_frame_ptr_mask );
   640   // Capture the return input masks into each exit flavor
   641   for( i=1; i < root->req(); i++ ) {
   642     MachReturnNode *exit = root->in(i)->as_MachReturn();
   643     switch( exit->ideal_Opcode() ) {
   644       case Op_Return   : exit->_in_rms = ret_rms;  break;
   645       case Op_Rethrow  : exit->_in_rms = reth_rms; break;
   646       case Op_TailCall : exit->_in_rms = tail_call_rms; break;
   647       case Op_TailJump : exit->_in_rms = tail_jump_rms; break;
   648       case Op_Halt     : exit->_in_rms = halt_rms; break;
   649       default          : ShouldNotReachHere();
   650     }
   651   }
   653   // Next unused projection number from Start.
   654   int proj_cnt = C->tf()->domain()->cnt();
   656   // Do all the save-on-entry registers.  Make projections from Start for
   657   // them, and give them a use at the exit points.  To the allocator, they
   658   // look like incoming register arguments.
   659   for( i = 0; i < _last_Mach_Reg; i++ ) {
   660     if( is_save_on_entry(i) ) {
   662       // Add the save-on-entry to the mask array
   663       ret_rms      [      ret_edge_cnt] = mreg2regmask[i];
   664       reth_rms     [     reth_edge_cnt] = mreg2regmask[i];
   665       tail_call_rms[tail_call_edge_cnt] = mreg2regmask[i];
   666       tail_jump_rms[tail_jump_edge_cnt] = mreg2regmask[i];
   667       // Halts need the SOE registers, but only in the stack as debug info.
   668       // A just-prior uncommon-trap or deoptimization will use the SOE regs.
   669       halt_rms     [     halt_edge_cnt] = *idealreg2spillmask[_register_save_type[i]];
   671       Node *mproj;
   673       // Is this a RegF low half of a RegD?  Double up 2 adjacent RegF's
   674       // into a single RegD.
   675       if( (i&1) == 0 &&
   676           _register_save_type[i  ] == Op_RegF &&
   677           _register_save_type[i+1] == Op_RegF &&
   678           is_save_on_entry(i+1) ) {
   679         // Add other bit for double
   680         ret_rms      [      ret_edge_cnt].Insert(OptoReg::Name(i+1));
   681         reth_rms     [     reth_edge_cnt].Insert(OptoReg::Name(i+1));
   682         tail_call_rms[tail_call_edge_cnt].Insert(OptoReg::Name(i+1));
   683         tail_jump_rms[tail_jump_edge_cnt].Insert(OptoReg::Name(i+1));
   684         halt_rms     [     halt_edge_cnt].Insert(OptoReg::Name(i+1));
   685         mproj = new (C, 1) MachProjNode( start, proj_cnt, ret_rms[ret_edge_cnt], Op_RegD );
   686         proj_cnt += 2;          // Skip 2 for doubles
   687       }
   688       else if( (i&1) == 1 &&    // Else check for high half of double
   689                _register_save_type[i-1] == Op_RegF &&
   690                _register_save_type[i  ] == Op_RegF &&
   691                is_save_on_entry(i-1) ) {
   692         ret_rms      [      ret_edge_cnt] = RegMask::Empty;
   693         reth_rms     [     reth_edge_cnt] = RegMask::Empty;
   694         tail_call_rms[tail_call_edge_cnt] = RegMask::Empty;
   695         tail_jump_rms[tail_jump_edge_cnt] = RegMask::Empty;
   696         halt_rms     [     halt_edge_cnt] = RegMask::Empty;
   697         mproj = C->top();
   698       }
   699       // Is this a RegI low half of a RegL?  Double up 2 adjacent RegI's
   700       // into a single RegL.
   701       else if( (i&1) == 0 &&
   702           _register_save_type[i  ] == Op_RegI &&
   703           _register_save_type[i+1] == Op_RegI &&
   704         is_save_on_entry(i+1) ) {
   705         // Add other bit for long
   706         ret_rms      [      ret_edge_cnt].Insert(OptoReg::Name(i+1));
   707         reth_rms     [     reth_edge_cnt].Insert(OptoReg::Name(i+1));
   708         tail_call_rms[tail_call_edge_cnt].Insert(OptoReg::Name(i+1));
   709         tail_jump_rms[tail_jump_edge_cnt].Insert(OptoReg::Name(i+1));
   710         halt_rms     [     halt_edge_cnt].Insert(OptoReg::Name(i+1));
   711         mproj = new (C, 1) MachProjNode( start, proj_cnt, ret_rms[ret_edge_cnt], Op_RegL );
   712         proj_cnt += 2;          // Skip 2 for longs
   713       }
   714       else if( (i&1) == 1 &&    // Else check for high half of long
   715                _register_save_type[i-1] == Op_RegI &&
   716                _register_save_type[i  ] == Op_RegI &&
   717                is_save_on_entry(i-1) ) {
   718         ret_rms      [      ret_edge_cnt] = RegMask::Empty;
   719         reth_rms     [     reth_edge_cnt] = RegMask::Empty;
   720         tail_call_rms[tail_call_edge_cnt] = RegMask::Empty;
   721         tail_jump_rms[tail_jump_edge_cnt] = RegMask::Empty;
   722         halt_rms     [     halt_edge_cnt] = RegMask::Empty;
   723         mproj = C->top();
   724       } else {
   725         // Make a projection for it off the Start
   726         mproj = new (C, 1) MachProjNode( start, proj_cnt++, ret_rms[ret_edge_cnt], _register_save_type[i] );
   727       }
   729       ret_edge_cnt ++;
   730       reth_edge_cnt ++;
   731       tail_call_edge_cnt ++;
   732       tail_jump_edge_cnt ++;
   733       halt_edge_cnt ++;
   735       // Add a use of the SOE register to all exit paths
   736       for( uint j=1; j < root->req(); j++ )
   737         root->in(j)->add_req(mproj);
   738     } // End of if a save-on-entry register
   739   } // End of for all machine registers
   740 }
   742 //------------------------------init_spill_mask--------------------------------
   743 void Matcher::init_spill_mask( Node *ret ) {
   744   if( idealreg2regmask[Op_RegI] ) return; // One time only init
   746   OptoReg::c_frame_pointer = c_frame_pointer();
   747   c_frame_ptr_mask = c_frame_pointer();
   748 #ifdef _LP64
   749   // pointers are twice as big
   750   c_frame_ptr_mask.Insert(OptoReg::add(c_frame_pointer(),1));
   751 #endif
   753   // Start at OptoReg::stack0()
   754   STACK_ONLY_mask.Clear();
   755   OptoReg::Name init = OptoReg::stack2reg(0);
   756   // STACK_ONLY_mask is all stack bits
   757   OptoReg::Name i;
   758   for (i = init; RegMask::can_represent(i); i = OptoReg::add(i,1))
   759     STACK_ONLY_mask.Insert(i);
   760   // Also set the "infinite stack" bit.
   761   STACK_ONLY_mask.set_AllStack();
   763   // Copy the register names over into the shared world
   764   for( i=OptoReg::Name(0); i<OptoReg::Name(_last_Mach_Reg); i = OptoReg::add(i,1) ) {
   765     // SharedInfo::regName[i] = regName[i];
   766     // Handy RegMasks per machine register
   767     mreg2regmask[i].Insert(i);
   768   }
   770   // Grab the Frame Pointer
   771   Node *fp  = ret->in(TypeFunc::FramePtr);
   772   Node *mem = ret->in(TypeFunc::Memory);
   773   const TypePtr* atp = TypePtr::BOTTOM;
   774   // Share frame pointer while making spill ops
   775   set_shared(fp);
   777   // Compute generic short-offset Loads
   778 #ifdef _LP64
   779   MachNode *spillCP = match_tree(new (C, 3) LoadNNode(NULL,mem,fp,atp,TypeInstPtr::BOTTOM));
   780 #endif
   781   MachNode *spillI  = match_tree(new (C, 3) LoadINode(NULL,mem,fp,atp));
   782   MachNode *spillL  = match_tree(new (C, 3) LoadLNode(NULL,mem,fp,atp));
   783   MachNode *spillF  = match_tree(new (C, 3) LoadFNode(NULL,mem,fp,atp));
   784   MachNode *spillD  = match_tree(new (C, 3) LoadDNode(NULL,mem,fp,atp));
   785   MachNode *spillP  = match_tree(new (C, 3) LoadPNode(NULL,mem,fp,atp,TypeInstPtr::BOTTOM));
   786   assert(spillI != NULL && spillL != NULL && spillF != NULL &&
   787          spillD != NULL && spillP != NULL, "");
   789   // Get the ADLC notion of the right regmask, for each basic type.
   790 #ifdef _LP64
   791   idealreg2regmask[Op_RegN] = &spillCP->out_RegMask();
   792 #endif
   793   idealreg2regmask[Op_RegI] = &spillI->out_RegMask();
   794   idealreg2regmask[Op_RegL] = &spillL->out_RegMask();
   795   idealreg2regmask[Op_RegF] = &spillF->out_RegMask();
   796   idealreg2regmask[Op_RegD] = &spillD->out_RegMask();
   797   idealreg2regmask[Op_RegP] = &spillP->out_RegMask();
   798 }
   800 #ifdef ASSERT
   801 static void match_alias_type(Compile* C, Node* n, Node* m) {
   802   if (!VerifyAliases)  return;  // do not go looking for trouble by default
   803   const TypePtr* nat = n->adr_type();
   804   const TypePtr* mat = m->adr_type();
   805   int nidx = C->get_alias_index(nat);
   806   int midx = C->get_alias_index(mat);
   807   // Detune the assert for cases like (AndI 0xFF (LoadB p)).
   808   if (nidx == Compile::AliasIdxTop && midx >= Compile::AliasIdxRaw) {
   809     for (uint i = 1; i < n->req(); i++) {
   810       Node* n1 = n->in(i);
   811       const TypePtr* n1at = n1->adr_type();
   812       if (n1at != NULL) {
   813         nat = n1at;
   814         nidx = C->get_alias_index(n1at);
   815       }
   816     }
   817   }
   818   // %%% Kludgery.  Instead, fix ideal adr_type methods for all these cases:
   819   if (nidx == Compile::AliasIdxTop && midx == Compile::AliasIdxRaw) {
   820     switch (n->Opcode()) {
   821     case Op_PrefetchRead:
   822     case Op_PrefetchWrite:
   823       nidx = Compile::AliasIdxRaw;
   824       nat = TypeRawPtr::BOTTOM;
   825       break;
   826     }
   827   }
   828   if (nidx == Compile::AliasIdxRaw && midx == Compile::AliasIdxTop) {
   829     switch (n->Opcode()) {
   830     case Op_ClearArray:
   831       midx = Compile::AliasIdxRaw;
   832       mat = TypeRawPtr::BOTTOM;
   833       break;
   834     }
   835   }
   836   if (nidx == Compile::AliasIdxTop && midx == Compile::AliasIdxBot) {
   837     switch (n->Opcode()) {
   838     case Op_Return:
   839     case Op_Rethrow:
   840     case Op_Halt:
   841     case Op_TailCall:
   842     case Op_TailJump:
   843       nidx = Compile::AliasIdxBot;
   844       nat = TypePtr::BOTTOM;
   845       break;
   846     }
   847   }
   848   if (nidx == Compile::AliasIdxBot && midx == Compile::AliasIdxTop) {
   849     switch (n->Opcode()) {
   850     case Op_StrComp:
   851     case Op_StrEquals:
   852     case Op_StrIndexOf:
   853     case Op_AryEq:
   854     case Op_MemBarVolatile:
   855     case Op_MemBarCPUOrder: // %%% these ideals should have narrower adr_type?
   856       nidx = Compile::AliasIdxTop;
   857       nat = NULL;
   858       break;
   859     }
   860   }
   861   if (nidx != midx) {
   862     if (PrintOpto || (PrintMiscellaneous && (WizardMode || Verbose))) {
   863       tty->print_cr("==== Matcher alias shift %d => %d", nidx, midx);
   864       n->dump();
   865       m->dump();
   866     }
   867     assert(C->subsume_loads() && C->must_alias(nat, midx),
   868            "must not lose alias info when matching");
   869   }
   870 }
   871 #endif
   874 //------------------------------MStack-----------------------------------------
   875 // State and MStack class used in xform() and find_shared() iterative methods.
   876 enum Node_State { Pre_Visit,  // node has to be pre-visited
   877                       Visit,  // visit node
   878                  Post_Visit,  // post-visit node
   879              Alt_Post_Visit   // alternative post-visit path
   880                 };
   882 class MStack: public Node_Stack {
   883   public:
   884     MStack(int size) : Node_Stack(size) { }
   886     void push(Node *n, Node_State ns) {
   887       Node_Stack::push(n, (uint)ns);
   888     }
   889     void push(Node *n, Node_State ns, Node *parent, int indx) {
   890       ++_inode_top;
   891       if ((_inode_top + 1) >= _inode_max) grow();
   892       _inode_top->node = parent;
   893       _inode_top->indx = (uint)indx;
   894       ++_inode_top;
   895       _inode_top->node = n;
   896       _inode_top->indx = (uint)ns;
   897     }
   898     Node *parent() {
   899       pop();
   900       return node();
   901     }
   902     Node_State state() const {
   903       return (Node_State)index();
   904     }
   905     void set_state(Node_State ns) {
   906       set_index((uint)ns);
   907     }
   908 };
   911 //------------------------------xform------------------------------------------
   912 // Given a Node in old-space, Match him (Label/Reduce) to produce a machine
   913 // Node in new-space.  Given a new-space Node, recursively walk his children.
   914 Node *Matcher::transform( Node *n ) { ShouldNotCallThis(); return n; }
   915 Node *Matcher::xform( Node *n, int max_stack ) {
   916   // Use one stack to keep both: child's node/state and parent's node/index
   917   MStack mstack(max_stack * 2 * 2); // C->unique() * 2 * 2
   918   mstack.push(n, Visit, NULL, -1);  // set NULL as parent to indicate root
   920   while (mstack.is_nonempty()) {
   921     n = mstack.node();          // Leave node on stack
   922     Node_State nstate = mstack.state();
   923     if (nstate == Visit) {
   924       mstack.set_state(Post_Visit);
   925       Node *oldn = n;
   926       // Old-space or new-space check
   927       if (!C->node_arena()->contains(n)) {
   928         // Old space!
   929         Node* m;
   930         if (has_new_node(n)) {  // Not yet Label/Reduced
   931           m = new_node(n);
   932         } else {
   933           if (!is_dontcare(n)) { // Matcher can match this guy
   934             // Calls match special.  They match alone with no children.
   935             // Their children, the incoming arguments, match normally.
   936             m = n->is_SafePoint() ? match_sfpt(n->as_SafePoint()):match_tree(n);
   937             if (C->failing())  return NULL;
   938             if (m == NULL) { Matcher::soft_match_failure(); return NULL; }
   939           } else {                  // Nothing the matcher cares about
   940             if( n->is_Proj() && n->in(0)->is_Multi()) {       // Projections?
   941               // Convert to machine-dependent projection
   942               m = n->in(0)->as_Multi()->match( n->as_Proj(), this );
   943 #ifdef ASSERT
   944               _new2old_map.map(m->_idx, n);
   945 #endif
   946               if (m->in(0) != NULL) // m might be top
   947                 collect_null_checks(m, n);
   948             } else {                // Else just a regular 'ol guy
   949               m = n->clone();       // So just clone into new-space
   950 #ifdef ASSERT
   951               _new2old_map.map(m->_idx, n);
   952 #endif
   953               // Def-Use edges will be added incrementally as Uses
   954               // of this node are matched.
   955               assert(m->outcnt() == 0, "no Uses of this clone yet");
   956             }
   957           }
   959           set_new_node(n, m);       // Map old to new
   960           if (_old_node_note_array != NULL) {
   961             Node_Notes* nn = C->locate_node_notes(_old_node_note_array,
   962                                                   n->_idx);
   963             C->set_node_notes_at(m->_idx, nn);
   964           }
   965           debug_only(match_alias_type(C, n, m));
   966         }
   967         n = m;    // n is now a new-space node
   968         mstack.set_node(n);
   969       }
   971       // New space!
   972       if (_visited.test_set(n->_idx)) continue; // while(mstack.is_nonempty())
   974       int i;
   975       // Put precedence edges on stack first (match them last).
   976       for (i = oldn->req(); (uint)i < oldn->len(); i++) {
   977         Node *m = oldn->in(i);
   978         if (m == NULL) break;
   979         // set -1 to call add_prec() instead of set_req() during Step1
   980         mstack.push(m, Visit, n, -1);
   981       }
   983       // For constant debug info, I'd rather have unmatched constants.
   984       int cnt = n->req();
   985       JVMState* jvms = n->jvms();
   986       int debug_cnt = jvms ? jvms->debug_start() : cnt;
   988       // Now do only debug info.  Clone constants rather than matching.
   989       // Constants are represented directly in the debug info without
   990       // the need for executable machine instructions.
   991       // Monitor boxes are also represented directly.
   992       for (i = cnt - 1; i >= debug_cnt; --i) { // For all debug inputs do
   993         Node *m = n->in(i);          // Get input
   994         int op = m->Opcode();
   995         assert((op == Op_BoxLock) == jvms->is_monitor_use(i), "boxes only at monitor sites");
   996         if( op == Op_ConI || op == Op_ConP || op == Op_ConN ||
   997             op == Op_ConF || op == Op_ConD || op == Op_ConL
   998             // || op == Op_BoxLock  // %%%% enable this and remove (+++) in chaitin.cpp
   999             ) {
  1000           m = m->clone();
  1001 #ifdef ASSERT
  1002           _new2old_map.map(m->_idx, n);
  1003 #endif
  1004           mstack.push(m, Post_Visit, n, i); // Don't need to visit
  1005           mstack.push(m->in(0), Visit, m, 0);
  1006         } else {
  1007           mstack.push(m, Visit, n, i);
  1011       // And now walk his children, and convert his inputs to new-space.
  1012       for( ; i >= 0; --i ) { // For all normal inputs do
  1013         Node *m = n->in(i);  // Get input
  1014         if(m != NULL)
  1015           mstack.push(m, Visit, n, i);
  1019     else if (nstate == Post_Visit) {
  1020       // Set xformed input
  1021       Node *p = mstack.parent();
  1022       if (p != NULL) { // root doesn't have parent
  1023         int i = (int)mstack.index();
  1024         if (i >= 0)
  1025           p->set_req(i, n); // required input
  1026         else if (i == -1)
  1027           p->add_prec(n);   // precedence input
  1028         else
  1029           ShouldNotReachHere();
  1031       mstack.pop(); // remove processed node from stack
  1033     else {
  1034       ShouldNotReachHere();
  1036   } // while (mstack.is_nonempty())
  1037   return n; // Return new-space Node
  1040 //------------------------------warp_outgoing_stk_arg------------------------
  1041 OptoReg::Name Matcher::warp_outgoing_stk_arg( VMReg reg, OptoReg::Name begin_out_arg_area, OptoReg::Name &out_arg_limit_per_call ) {
  1042   // Convert outgoing argument location to a pre-biased stack offset
  1043   if (reg->is_stack()) {
  1044     OptoReg::Name warped = reg->reg2stack();
  1045     // Adjust the stack slot offset to be the register number used
  1046     // by the allocator.
  1047     warped = OptoReg::add(begin_out_arg_area, warped);
  1048     // Keep track of the largest numbered stack slot used for an arg.
  1049     // Largest used slot per call-site indicates the amount of stack
  1050     // that is killed by the call.
  1051     if( warped >= out_arg_limit_per_call )
  1052       out_arg_limit_per_call = OptoReg::add(warped,1);
  1053     if (!RegMask::can_represent(warped)) {
  1054       C->record_method_not_compilable_all_tiers("unsupported calling sequence");
  1055       return OptoReg::Bad;
  1057     return warped;
  1059   return OptoReg::as_OptoReg(reg);
  1063 //------------------------------match_sfpt-------------------------------------
  1064 // Helper function to match call instructions.  Calls match special.
  1065 // They match alone with no children.  Their children, the incoming
  1066 // arguments, match normally.
  1067 MachNode *Matcher::match_sfpt( SafePointNode *sfpt ) {
  1068   MachSafePointNode *msfpt = NULL;
  1069   MachCallNode      *mcall = NULL;
  1070   uint               cnt;
  1071   // Split out case for SafePoint vs Call
  1072   CallNode *call;
  1073   const TypeTuple *domain;
  1074   ciMethod*        method = NULL;
  1075   bool             is_method_handle_invoke = false;  // for special kill effects
  1076   if( sfpt->is_Call() ) {
  1077     call = sfpt->as_Call();
  1078     domain = call->tf()->domain();
  1079     cnt = domain->cnt();
  1081     // Match just the call, nothing else
  1082     MachNode *m = match_tree(call);
  1083     if (C->failing())  return NULL;
  1084     if( m == NULL ) { Matcher::soft_match_failure(); return NULL; }
  1086     // Copy data from the Ideal SafePoint to the machine version
  1087     mcall = m->as_MachCall();
  1089     mcall->set_tf(         call->tf());
  1090     mcall->set_entry_point(call->entry_point());
  1091     mcall->set_cnt(        call->cnt());
  1093     if( mcall->is_MachCallJava() ) {
  1094       MachCallJavaNode *mcall_java  = mcall->as_MachCallJava();
  1095       const CallJavaNode *call_java =  call->as_CallJava();
  1096       method = call_java->method();
  1097       mcall_java->_method = method;
  1098       mcall_java->_bci = call_java->_bci;
  1099       mcall_java->_optimized_virtual = call_java->is_optimized_virtual();
  1100       is_method_handle_invoke = call_java->is_method_handle_invoke();
  1101       mcall_java->_method_handle_invoke = is_method_handle_invoke;
  1102       if( mcall_java->is_MachCallStaticJava() )
  1103         mcall_java->as_MachCallStaticJava()->_name =
  1104          call_java->as_CallStaticJava()->_name;
  1105       if( mcall_java->is_MachCallDynamicJava() )
  1106         mcall_java->as_MachCallDynamicJava()->_vtable_index =
  1107          call_java->as_CallDynamicJava()->_vtable_index;
  1109     else if( mcall->is_MachCallRuntime() ) {
  1110       mcall->as_MachCallRuntime()->_name = call->as_CallRuntime()->_name;
  1112     msfpt = mcall;
  1114   // This is a non-call safepoint
  1115   else {
  1116     call = NULL;
  1117     domain = NULL;
  1118     MachNode *mn = match_tree(sfpt);
  1119     if (C->failing())  return NULL;
  1120     msfpt = mn->as_MachSafePoint();
  1121     cnt = TypeFunc::Parms;
  1124   // Advertise the correct memory effects (for anti-dependence computation).
  1125   msfpt->set_adr_type(sfpt->adr_type());
  1127   // Allocate a private array of RegMasks.  These RegMasks are not shared.
  1128   msfpt->_in_rms = NEW_RESOURCE_ARRAY( RegMask, cnt );
  1129   // Empty them all.
  1130   memset( msfpt->_in_rms, 0, sizeof(RegMask)*cnt );
  1132   // Do all the pre-defined non-Empty register masks
  1133   msfpt->_in_rms[TypeFunc::ReturnAdr] = _return_addr_mask;
  1134   msfpt->_in_rms[TypeFunc::FramePtr ] = c_frame_ptr_mask;
  1136   // Place first outgoing argument can possibly be put.
  1137   OptoReg::Name begin_out_arg_area = OptoReg::add(_new_SP, C->out_preserve_stack_slots());
  1138   assert( is_even(begin_out_arg_area), "" );
  1139   // Compute max outgoing register number per call site.
  1140   OptoReg::Name out_arg_limit_per_call = begin_out_arg_area;
  1141   // Calls to C may hammer extra stack slots above and beyond any arguments.
  1142   // These are usually backing store for register arguments for varargs.
  1143   if( call != NULL && call->is_CallRuntime() )
  1144     out_arg_limit_per_call = OptoReg::add(out_arg_limit_per_call,C->varargs_C_out_slots_killed());
  1147   // Do the normal argument list (parameters) register masks
  1148   int argcnt = cnt - TypeFunc::Parms;
  1149   if( argcnt > 0 ) {          // Skip it all if we have no args
  1150     BasicType *sig_bt  = NEW_RESOURCE_ARRAY( BasicType, argcnt );
  1151     VMRegPair *parm_regs = NEW_RESOURCE_ARRAY( VMRegPair, argcnt );
  1152     int i;
  1153     for( i = 0; i < argcnt; i++ ) {
  1154       sig_bt[i] = domain->field_at(i+TypeFunc::Parms)->basic_type();
  1156     // V-call to pick proper calling convention
  1157     call->calling_convention( sig_bt, parm_regs, argcnt );
  1159 #ifdef ASSERT
  1160     // Sanity check users' calling convention.  Really handy during
  1161     // the initial porting effort.  Fairly expensive otherwise.
  1162     { for (int i = 0; i<argcnt; i++) {
  1163       if( !parm_regs[i].first()->is_valid() &&
  1164           !parm_regs[i].second()->is_valid() ) continue;
  1165       VMReg reg1 = parm_regs[i].first();
  1166       VMReg reg2 = parm_regs[i].second();
  1167       for (int j = 0; j < i; j++) {
  1168         if( !parm_regs[j].first()->is_valid() &&
  1169             !parm_regs[j].second()->is_valid() ) continue;
  1170         VMReg reg3 = parm_regs[j].first();
  1171         VMReg reg4 = parm_regs[j].second();
  1172         if( !reg1->is_valid() ) {
  1173           assert( !reg2->is_valid(), "valid halvsies" );
  1174         } else if( !reg3->is_valid() ) {
  1175           assert( !reg4->is_valid(), "valid halvsies" );
  1176         } else {
  1177           assert( reg1 != reg2, "calling conv. must produce distinct regs");
  1178           assert( reg1 != reg3, "calling conv. must produce distinct regs");
  1179           assert( reg1 != reg4, "calling conv. must produce distinct regs");
  1180           assert( reg2 != reg3, "calling conv. must produce distinct regs");
  1181           assert( reg2 != reg4 || !reg2->is_valid(), "calling conv. must produce distinct regs");
  1182           assert( reg3 != reg4, "calling conv. must produce distinct regs");
  1187 #endif
  1189     // Visit each argument.  Compute its outgoing register mask.
  1190     // Return results now can have 2 bits returned.
  1191     // Compute max over all outgoing arguments both per call-site
  1192     // and over the entire method.
  1193     for( i = 0; i < argcnt; i++ ) {
  1194       // Address of incoming argument mask to fill in
  1195       RegMask *rm = &mcall->_in_rms[i+TypeFunc::Parms];
  1196       if( !parm_regs[i].first()->is_valid() &&
  1197           !parm_regs[i].second()->is_valid() ) {
  1198         continue;               // Avoid Halves
  1200       // Grab first register, adjust stack slots and insert in mask.
  1201       OptoReg::Name reg1 = warp_outgoing_stk_arg(parm_regs[i].first(), begin_out_arg_area, out_arg_limit_per_call );
  1202       if (OptoReg::is_valid(reg1))
  1203         rm->Insert( reg1 );
  1204       // Grab second register (if any), adjust stack slots and insert in mask.
  1205       OptoReg::Name reg2 = warp_outgoing_stk_arg(parm_regs[i].second(), begin_out_arg_area, out_arg_limit_per_call );
  1206       if (OptoReg::is_valid(reg2))
  1207         rm->Insert( reg2 );
  1208     } // End of for all arguments
  1210     // Compute number of stack slots needed to restore stack in case of
  1211     // Pascal-style argument popping.
  1212     mcall->_argsize = out_arg_limit_per_call - begin_out_arg_area;
  1215   if (is_method_handle_invoke) {
  1216     // Kill some extra stack space in case method handles want to do
  1217     // a little in-place argument insertion.
  1218     int regs_per_word  = NOT_LP64(1) LP64_ONLY(2); // %%% make a global const!
  1219     out_arg_limit_per_call += MethodHandlePushLimit * regs_per_word;
  1220     // Do not update mcall->_argsize because (a) the extra space is not
  1221     // pushed as arguments and (b) _argsize is dead (not used anywhere).
  1224   // Compute the max stack slot killed by any call.  These will not be
  1225   // available for debug info, and will be used to adjust FIRST_STACK_mask
  1226   // after all call sites have been visited.
  1227   if( _out_arg_limit < out_arg_limit_per_call)
  1228     _out_arg_limit = out_arg_limit_per_call;
  1230   if (mcall) {
  1231     // Kill the outgoing argument area, including any non-argument holes and
  1232     // any legacy C-killed slots.  Use Fat-Projections to do the killing.
  1233     // Since the max-per-method covers the max-per-call-site and debug info
  1234     // is excluded on the max-per-method basis, debug info cannot land in
  1235     // this killed area.
  1236     uint r_cnt = mcall->tf()->range()->cnt();
  1237     MachProjNode *proj = new (C, 1) MachProjNode( mcall, r_cnt+10000, RegMask::Empty, MachProjNode::fat_proj );
  1238     if (!RegMask::can_represent(OptoReg::Name(out_arg_limit_per_call-1))) {
  1239       C->record_method_not_compilable_all_tiers("unsupported outgoing calling sequence");
  1240     } else {
  1241       for (int i = begin_out_arg_area; i < out_arg_limit_per_call; i++)
  1242         proj->_rout.Insert(OptoReg::Name(i));
  1244     if( proj->_rout.is_NotEmpty() )
  1245       _proj_list.push(proj);
  1247   // Transfer the safepoint information from the call to the mcall
  1248   // Move the JVMState list
  1249   msfpt->set_jvms(sfpt->jvms());
  1250   for (JVMState* jvms = msfpt->jvms(); jvms; jvms = jvms->caller()) {
  1251     jvms->set_map(sfpt);
  1254   // Debug inputs begin just after the last incoming parameter
  1255   assert( (mcall == NULL) || (mcall->jvms() == NULL) ||
  1256           (mcall->jvms()->debug_start() + mcall->_jvmadj == mcall->tf()->domain()->cnt()), "" );
  1258   // Move the OopMap
  1259   msfpt->_oop_map = sfpt->_oop_map;
  1261   // Registers killed by the call are set in the local scheduling pass
  1262   // of Global Code Motion.
  1263   return msfpt;
  1266 //---------------------------match_tree----------------------------------------
  1267 // Match a Ideal Node DAG - turn it into a tree; Label & Reduce.  Used as part
  1268 // of the whole-sale conversion from Ideal to Mach Nodes.  Also used for
  1269 // making GotoNodes while building the CFG and in init_spill_mask() to identify
  1270 // a Load's result RegMask for memoization in idealreg2regmask[]
  1271 MachNode *Matcher::match_tree( const Node *n ) {
  1272   assert( n->Opcode() != Op_Phi, "cannot match" );
  1273   assert( !n->is_block_start(), "cannot match" );
  1274   // Set the mark for all locally allocated State objects.
  1275   // When this call returns, the _states_arena arena will be reset
  1276   // freeing all State objects.
  1277   ResourceMark rm( &_states_arena );
  1279   LabelRootDepth = 0;
  1281   // StoreNodes require their Memory input to match any LoadNodes
  1282   Node *mem = n->is_Store() ? n->in(MemNode::Memory) : (Node*)1 ;
  1283 #ifdef ASSERT
  1284   Node* save_mem_node = _mem_node;
  1285   _mem_node = n->is_Store() ? (Node*)n : NULL;
  1286 #endif
  1287   // State object for root node of match tree
  1288   // Allocate it on _states_arena - stack allocation can cause stack overflow.
  1289   State *s = new (&_states_arena) State;
  1290   s->_kids[0] = NULL;
  1291   s->_kids[1] = NULL;
  1292   s->_leaf = (Node*)n;
  1293   // Label the input tree, allocating labels from top-level arena
  1294   Label_Root( n, s, n->in(0), mem );
  1295   if (C->failing())  return NULL;
  1297   // The minimum cost match for the whole tree is found at the root State
  1298   uint mincost = max_juint;
  1299   uint cost = max_juint;
  1300   uint i;
  1301   for( i = 0; i < NUM_OPERANDS; i++ ) {
  1302     if( s->valid(i) &&                // valid entry and
  1303         s->_cost[i] < cost &&         // low cost and
  1304         s->_rule[i] >= NUM_OPERANDS ) // not an operand
  1305       cost = s->_cost[mincost=i];
  1307   if (mincost == max_juint) {
  1308 #ifndef PRODUCT
  1309     tty->print("No matching rule for:");
  1310     s->dump();
  1311 #endif
  1312     Matcher::soft_match_failure();
  1313     return NULL;
  1315   // Reduce input tree based upon the state labels to machine Nodes
  1316   MachNode *m = ReduceInst( s, s->_rule[mincost], mem );
  1317 #ifdef ASSERT
  1318   _old2new_map.map(n->_idx, m);
  1319   _new2old_map.map(m->_idx, (Node*)n);
  1320 #endif
  1322   // Add any Matcher-ignored edges
  1323   uint cnt = n->req();
  1324   uint start = 1;
  1325   if( mem != (Node*)1 ) start = MemNode::Memory+1;
  1326   if( n->is_AddP() ) {
  1327     assert( mem == (Node*)1, "" );
  1328     start = AddPNode::Base+1;
  1330   for( i = start; i < cnt; i++ ) {
  1331     if( !n->match_edge(i) ) {
  1332       if( i < m->req() )
  1333         m->ins_req( i, n->in(i) );
  1334       else
  1335         m->add_req( n->in(i) );
  1339   debug_only( _mem_node = save_mem_node; )
  1340   return m;
  1344 //------------------------------match_into_reg---------------------------------
  1345 // Choose to either match this Node in a register or part of the current
  1346 // match tree.  Return true for requiring a register and false for matching
  1347 // as part of the current match tree.
  1348 static bool match_into_reg( const Node *n, Node *m, Node *control, int i, bool shared ) {
  1350   const Type *t = m->bottom_type();
  1352   if( t->singleton() ) {
  1353     // Never force constants into registers.  Allow them to match as
  1354     // constants or registers.  Copies of the same value will share
  1355     // the same register.  See find_shared_node.
  1356     return false;
  1357   } else {                      // Not a constant
  1358     // Stop recursion if they have different Controls.
  1359     // Slot 0 of constants is not really a Control.
  1360     if( control && m->in(0) && control != m->in(0) ) {
  1362       // Actually, we can live with the most conservative control we
  1363       // find, if it post-dominates the others.  This allows us to
  1364       // pick up load/op/store trees where the load can float a little
  1365       // above the store.
  1366       Node *x = control;
  1367       const uint max_scan = 6;   // Arbitrary scan cutoff
  1368       uint j;
  1369       for( j=0; j<max_scan; j++ ) {
  1370         if( x->is_Region() )    // Bail out at merge points
  1371           return true;
  1372         x = x->in(0);
  1373         if( x == m->in(0) )     // Does 'control' post-dominate
  1374           break;                // m->in(0)?  If so, we can use it
  1376       if( j == max_scan )       // No post-domination before scan end?
  1377         return true;            // Then break the match tree up
  1379     if (m->is_DecodeN() && Matcher::narrow_oop_use_complex_address()) {
  1380       // These are commonly used in address expressions and can
  1381       // efficiently fold into them on X64 in some cases.
  1382       return false;
  1386   // Not forceable cloning.  If shared, put it into a register.
  1387   return shared;
  1391 //------------------------------Instruction Selection--------------------------
  1392 // Label method walks a "tree" of nodes, using the ADLC generated DFA to match
  1393 // ideal nodes to machine instructions.  Trees are delimited by shared Nodes,
  1394 // things the Matcher does not match (e.g., Memory), and things with different
  1395 // Controls (hence forced into different blocks).  We pass in the Control
  1396 // selected for this entire State tree.
  1398 // The Matcher works on Trees, but an Intel add-to-memory requires a DAG: the
  1399 // Store and the Load must have identical Memories (as well as identical
  1400 // pointers).  Since the Matcher does not have anything for Memory (and
  1401 // does not handle DAGs), I have to match the Memory input myself.  If the
  1402 // Tree root is a Store, I require all Loads to have the identical memory.
  1403 Node *Matcher::Label_Root( const Node *n, State *svec, Node *control, const Node *mem){
  1404   // Since Label_Root is a recursive function, its possible that we might run
  1405   // out of stack space.  See bugs 6272980 & 6227033 for more info.
  1406   LabelRootDepth++;
  1407   if (LabelRootDepth > MaxLabelRootDepth) {
  1408     C->record_method_not_compilable_all_tiers("Out of stack space, increase MaxLabelRootDepth");
  1409     return NULL;
  1411   uint care = 0;                // Edges matcher cares about
  1412   uint cnt = n->req();
  1413   uint i = 0;
  1415   // Examine children for memory state
  1416   // Can only subsume a child into your match-tree if that child's memory state
  1417   // is not modified along the path to another input.
  1418   // It is unsafe even if the other inputs are separate roots.
  1419   Node *input_mem = NULL;
  1420   for( i = 1; i < cnt; i++ ) {
  1421     if( !n->match_edge(i) ) continue;
  1422     Node *m = n->in(i);         // Get ith input
  1423     assert( m, "expect non-null children" );
  1424     if( m->is_Load() ) {
  1425       if( input_mem == NULL ) {
  1426         input_mem = m->in(MemNode::Memory);
  1427       } else if( input_mem != m->in(MemNode::Memory) ) {
  1428         input_mem = NodeSentinel;
  1433   for( i = 1; i < cnt; i++ ){// For my children
  1434     if( !n->match_edge(i) ) continue;
  1435     Node *m = n->in(i);         // Get ith input
  1436     // Allocate states out of a private arena
  1437     State *s = new (&_states_arena) State;
  1438     svec->_kids[care++] = s;
  1439     assert( care <= 2, "binary only for now" );
  1441     // Recursively label the State tree.
  1442     s->_kids[0] = NULL;
  1443     s->_kids[1] = NULL;
  1444     s->_leaf = m;
  1446     // Check for leaves of the State Tree; things that cannot be a part of
  1447     // the current tree.  If it finds any, that value is matched as a
  1448     // register operand.  If not, then the normal matching is used.
  1449     if( match_into_reg(n, m, control, i, is_shared(m)) ||
  1450         //
  1451         // Stop recursion if this is LoadNode and the root of this tree is a
  1452         // StoreNode and the load & store have different memories.
  1453         ((mem!=(Node*)1) && m->is_Load() && m->in(MemNode::Memory) != mem) ||
  1454         // Can NOT include the match of a subtree when its memory state
  1455         // is used by any of the other subtrees
  1456         (input_mem == NodeSentinel) ) {
  1457 #ifndef PRODUCT
  1458       // Print when we exclude matching due to different memory states at input-loads
  1459       if( PrintOpto && (Verbose && WizardMode) && (input_mem == NodeSentinel)
  1460         && !((mem!=(Node*)1) && m->is_Load() && m->in(MemNode::Memory) != mem) ) {
  1461         tty->print_cr("invalid input_mem");
  1463 #endif
  1464       // Switch to a register-only opcode; this value must be in a register
  1465       // and cannot be subsumed as part of a larger instruction.
  1466       s->DFA( m->ideal_reg(), m );
  1468     } else {
  1469       // If match tree has no control and we do, adopt it for entire tree
  1470       if( control == NULL && m->in(0) != NULL && m->req() > 1 )
  1471         control = m->in(0);         // Pick up control
  1472       // Else match as a normal part of the match tree.
  1473       control = Label_Root(m,s,control,mem);
  1474       if (C->failing()) return NULL;
  1479   // Call DFA to match this node, and return
  1480   svec->DFA( n->Opcode(), n );
  1482 #ifdef ASSERT
  1483   uint x;
  1484   for( x = 0; x < _LAST_MACH_OPER; x++ )
  1485     if( svec->valid(x) )
  1486       break;
  1488   if (x >= _LAST_MACH_OPER) {
  1489     n->dump();
  1490     svec->dump();
  1491     assert( false, "bad AD file" );
  1493 #endif
  1494   return control;
  1498 // Con nodes reduced using the same rule can share their MachNode
  1499 // which reduces the number of copies of a constant in the final
  1500 // program.  The register allocator is free to split uses later to
  1501 // split live ranges.
  1502 MachNode* Matcher::find_shared_node(Node* leaf, uint rule) {
  1503   if (!leaf->is_Con() && !leaf->is_DecodeN()) return NULL;
  1505   // See if this Con has already been reduced using this rule.
  1506   if (_shared_nodes.Size() <= leaf->_idx) return NULL;
  1507   MachNode* last = (MachNode*)_shared_nodes.at(leaf->_idx);
  1508   if (last != NULL && rule == last->rule()) {
  1509     // Don't expect control change for DecodeN
  1510     if (leaf->is_DecodeN())
  1511       return last;
  1512     // Get the new space root.
  1513     Node* xroot = new_node(C->root());
  1514     if (xroot == NULL) {
  1515       // This shouldn't happen give the order of matching.
  1516       return NULL;
  1519     // Shared constants need to have their control be root so they
  1520     // can be scheduled properly.
  1521     Node* control = last->in(0);
  1522     if (control != xroot) {
  1523       if (control == NULL || control == C->root()) {
  1524         last->set_req(0, xroot);
  1525       } else {
  1526         assert(false, "unexpected control");
  1527         return NULL;
  1530     return last;
  1532   return NULL;
  1536 //------------------------------ReduceInst-------------------------------------
  1537 // Reduce a State tree (with given Control) into a tree of MachNodes.
  1538 // This routine (and it's cohort ReduceOper) convert Ideal Nodes into
  1539 // complicated machine Nodes.  Each MachNode covers some tree of Ideal Nodes.
  1540 // Each MachNode has a number of complicated MachOper operands; each
  1541 // MachOper also covers a further tree of Ideal Nodes.
  1543 // The root of the Ideal match tree is always an instruction, so we enter
  1544 // the recursion here.  After building the MachNode, we need to recurse
  1545 // the tree checking for these cases:
  1546 // (1) Child is an instruction -
  1547 //     Build the instruction (recursively), add it as an edge.
  1548 //     Build a simple operand (register) to hold the result of the instruction.
  1549 // (2) Child is an interior part of an instruction -
  1550 //     Skip over it (do nothing)
  1551 // (3) Child is the start of a operand -
  1552 //     Build the operand, place it inside the instruction
  1553 //     Call ReduceOper.
  1554 MachNode *Matcher::ReduceInst( State *s, int rule, Node *&mem ) {
  1555   assert( rule >= NUM_OPERANDS, "called with operand rule" );
  1557   MachNode* shared_node = find_shared_node(s->_leaf, rule);
  1558   if (shared_node != NULL) {
  1559     return shared_node;
  1562   // Build the object to represent this state & prepare for recursive calls
  1563   MachNode *mach = s->MachNodeGenerator( rule, C );
  1564   mach->_opnds[0] = s->MachOperGenerator( _reduceOp[rule], C );
  1565   assert( mach->_opnds[0] != NULL, "Missing result operand" );
  1566   Node *leaf = s->_leaf;
  1567   // Check for instruction or instruction chain rule
  1568   if( rule >= _END_INST_CHAIN_RULE || rule < _BEGIN_INST_CHAIN_RULE ) {
  1569     assert(C->node_arena()->contains(s->_leaf) || !has_new_node(s->_leaf),
  1570            "duplicating node that's already been matched");
  1571     // Instruction
  1572     mach->add_req( leaf->in(0) ); // Set initial control
  1573     // Reduce interior of complex instruction
  1574     ReduceInst_Interior( s, rule, mem, mach, 1 );
  1575   } else {
  1576     // Instruction chain rules are data-dependent on their inputs
  1577     mach->add_req(0);             // Set initial control to none
  1578     ReduceInst_Chain_Rule( s, rule, mem, mach );
  1581   // If a Memory was used, insert a Memory edge
  1582   if( mem != (Node*)1 ) {
  1583     mach->ins_req(MemNode::Memory,mem);
  1584 #ifdef ASSERT
  1585     // Verify adr type after matching memory operation
  1586     const MachOper* oper = mach->memory_operand();
  1587     if (oper != NULL && oper != (MachOper*)-1) {
  1588       // It has a unique memory operand.  Find corresponding ideal mem node.
  1589       Node* m = NULL;
  1590       if (leaf->is_Mem()) {
  1591         m = leaf;
  1592       } else {
  1593         m = _mem_node;
  1594         assert(m != NULL && m->is_Mem(), "expecting memory node");
  1596       const Type* mach_at = mach->adr_type();
  1597       // DecodeN node consumed by an address may have different type
  1598       // then its input. Don't compare types for such case.
  1599       if (m->adr_type() != mach_at &&
  1600           (m->in(MemNode::Address)->is_DecodeN() ||
  1601            m->in(MemNode::Address)->is_AddP() &&
  1602            m->in(MemNode::Address)->in(AddPNode::Address)->is_DecodeN() ||
  1603            m->in(MemNode::Address)->is_AddP() &&
  1604            m->in(MemNode::Address)->in(AddPNode::Address)->is_AddP() &&
  1605            m->in(MemNode::Address)->in(AddPNode::Address)->in(AddPNode::Address)->is_DecodeN())) {
  1606         mach_at = m->adr_type();
  1608       if (m->adr_type() != mach_at) {
  1609         m->dump();
  1610         tty->print_cr("mach:");
  1611         mach->dump(1);
  1613       assert(m->adr_type() == mach_at, "matcher should not change adr type");
  1615 #endif
  1618   // If the _leaf is an AddP, insert the base edge
  1619   if( leaf->is_AddP() )
  1620     mach->ins_req(AddPNode::Base,leaf->in(AddPNode::Base));
  1622   uint num_proj = _proj_list.size();
  1624   // Perform any 1-to-many expansions required
  1625   MachNode *ex = mach->Expand(s,_proj_list, mem);
  1626   if( ex != mach ) {
  1627     assert(ex->ideal_reg() == mach->ideal_reg(), "ideal types should match");
  1628     if( ex->in(1)->is_Con() )
  1629       ex->in(1)->set_req(0, C->root());
  1630     // Remove old node from the graph
  1631     for( uint i=0; i<mach->req(); i++ ) {
  1632       mach->set_req(i,NULL);
  1634 #ifdef ASSERT
  1635     _new2old_map.map(ex->_idx, s->_leaf);
  1636 #endif
  1639   // PhaseChaitin::fixup_spills will sometimes generate spill code
  1640   // via the matcher.  By the time, nodes have been wired into the CFG,
  1641   // and any further nodes generated by expand rules will be left hanging
  1642   // in space, and will not get emitted as output code.  Catch this.
  1643   // Also, catch any new register allocation constraints ("projections")
  1644   // generated belatedly during spill code generation.
  1645   if (_allocation_started) {
  1646     guarantee(ex == mach, "no expand rules during spill generation");
  1647     guarantee(_proj_list.size() == num_proj, "no allocation during spill generation");
  1650   if (leaf->is_Con() || leaf->is_DecodeN()) {
  1651     // Record the con for sharing
  1652     _shared_nodes.map(leaf->_idx, ex);
  1655   return ex;
  1658 void Matcher::ReduceInst_Chain_Rule( State *s, int rule, Node *&mem, MachNode *mach ) {
  1659   // 'op' is what I am expecting to receive
  1660   int op = _leftOp[rule];
  1661   // Operand type to catch childs result
  1662   // This is what my child will give me.
  1663   int opnd_class_instance = s->_rule[op];
  1664   // Choose between operand class or not.
  1665   // This is what I will receive.
  1666   int catch_op = (FIRST_OPERAND_CLASS <= op && op < NUM_OPERANDS) ? opnd_class_instance : op;
  1667   // New rule for child.  Chase operand classes to get the actual rule.
  1668   int newrule = s->_rule[catch_op];
  1670   if( newrule < NUM_OPERANDS ) {
  1671     // Chain from operand or operand class, may be output of shared node
  1672     assert( 0 <= opnd_class_instance && opnd_class_instance < NUM_OPERANDS,
  1673             "Bad AD file: Instruction chain rule must chain from operand");
  1674     // Insert operand into array of operands for this instruction
  1675     mach->_opnds[1] = s->MachOperGenerator( opnd_class_instance, C );
  1677     ReduceOper( s, newrule, mem, mach );
  1678   } else {
  1679     // Chain from the result of an instruction
  1680     assert( newrule >= _LAST_MACH_OPER, "Do NOT chain from internal operand");
  1681     mach->_opnds[1] = s->MachOperGenerator( _reduceOp[catch_op], C );
  1682     Node *mem1 = (Node*)1;
  1683     debug_only(Node *save_mem_node = _mem_node;)
  1684     mach->add_req( ReduceInst(s, newrule, mem1) );
  1685     debug_only(_mem_node = save_mem_node;)
  1687   return;
  1691 uint Matcher::ReduceInst_Interior( State *s, int rule, Node *&mem, MachNode *mach, uint num_opnds ) {
  1692   if( s->_leaf->is_Load() ) {
  1693     Node *mem2 = s->_leaf->in(MemNode::Memory);
  1694     assert( mem == (Node*)1 || mem == mem2, "multiple Memories being matched at once?" );
  1695     debug_only( if( mem == (Node*)1 ) _mem_node = s->_leaf;)
  1696     mem = mem2;
  1698   if( s->_leaf->in(0) != NULL && s->_leaf->req() > 1) {
  1699     if( mach->in(0) == NULL )
  1700       mach->set_req(0, s->_leaf->in(0));
  1703   // Now recursively walk the state tree & add operand list.
  1704   for( uint i=0; i<2; i++ ) {   // binary tree
  1705     State *newstate = s->_kids[i];
  1706     if( newstate == NULL ) break;      // Might only have 1 child
  1707     // 'op' is what I am expecting to receive
  1708     int op;
  1709     if( i == 0 ) {
  1710       op = _leftOp[rule];
  1711     } else {
  1712       op = _rightOp[rule];
  1714     // Operand type to catch childs result
  1715     // This is what my child will give me.
  1716     int opnd_class_instance = newstate->_rule[op];
  1717     // Choose between operand class or not.
  1718     // This is what I will receive.
  1719     int catch_op = (op >= FIRST_OPERAND_CLASS && op < NUM_OPERANDS) ? opnd_class_instance : op;
  1720     // New rule for child.  Chase operand classes to get the actual rule.
  1721     int newrule = newstate->_rule[catch_op];
  1723     if( newrule < NUM_OPERANDS ) { // Operand/operandClass or internalOp/instruction?
  1724       // Operand/operandClass
  1725       // Insert operand into array of operands for this instruction
  1726       mach->_opnds[num_opnds++] = newstate->MachOperGenerator( opnd_class_instance, C );
  1727       ReduceOper( newstate, newrule, mem, mach );
  1729     } else {                    // Child is internal operand or new instruction
  1730       if( newrule < _LAST_MACH_OPER ) { // internal operand or instruction?
  1731         // internal operand --> call ReduceInst_Interior
  1732         // Interior of complex instruction.  Do nothing but recurse.
  1733         num_opnds = ReduceInst_Interior( newstate, newrule, mem, mach, num_opnds );
  1734       } else {
  1735         // instruction --> call build operand(  ) to catch result
  1736         //             --> ReduceInst( newrule )
  1737         mach->_opnds[num_opnds++] = s->MachOperGenerator( _reduceOp[catch_op], C );
  1738         Node *mem1 = (Node*)1;
  1739         debug_only(Node *save_mem_node = _mem_node;)
  1740         mach->add_req( ReduceInst( newstate, newrule, mem1 ) );
  1741         debug_only(_mem_node = save_mem_node;)
  1744     assert( mach->_opnds[num_opnds-1], "" );
  1746   return num_opnds;
  1749 // This routine walks the interior of possible complex operands.
  1750 // At each point we check our children in the match tree:
  1751 // (1) No children -
  1752 //     We are a leaf; add _leaf field as an input to the MachNode
  1753 // (2) Child is an internal operand -
  1754 //     Skip over it ( do nothing )
  1755 // (3) Child is an instruction -
  1756 //     Call ReduceInst recursively and
  1757 //     and instruction as an input to the MachNode
  1758 void Matcher::ReduceOper( State *s, int rule, Node *&mem, MachNode *mach ) {
  1759   assert( rule < _LAST_MACH_OPER, "called with operand rule" );
  1760   State *kid = s->_kids[0];
  1761   assert( kid == NULL || s->_leaf->in(0) == NULL, "internal operands have no control" );
  1763   // Leaf?  And not subsumed?
  1764   if( kid == NULL && !_swallowed[rule] ) {
  1765     mach->add_req( s->_leaf );  // Add leaf pointer
  1766     return;                     // Bail out
  1769   if( s->_leaf->is_Load() ) {
  1770     assert( mem == (Node*)1, "multiple Memories being matched at once?" );
  1771     mem = s->_leaf->in(MemNode::Memory);
  1772     debug_only(_mem_node = s->_leaf;)
  1774   if( s->_leaf->in(0) && s->_leaf->req() > 1) {
  1775     if( !mach->in(0) )
  1776       mach->set_req(0,s->_leaf->in(0));
  1777     else {
  1778       assert( s->_leaf->in(0) == mach->in(0), "same instruction, differing controls?" );
  1782   for( uint i=0; kid != NULL && i<2; kid = s->_kids[1], i++ ) {   // binary tree
  1783     int newrule;
  1784     if( i == 0 )
  1785       newrule = kid->_rule[_leftOp[rule]];
  1786     else
  1787       newrule = kid->_rule[_rightOp[rule]];
  1789     if( newrule < _LAST_MACH_OPER ) { // Operand or instruction?
  1790       // Internal operand; recurse but do nothing else
  1791       ReduceOper( kid, newrule, mem, mach );
  1793     } else {                    // Child is a new instruction
  1794       // Reduce the instruction, and add a direct pointer from this
  1795       // machine instruction to the newly reduced one.
  1796       Node *mem1 = (Node*)1;
  1797       debug_only(Node *save_mem_node = _mem_node;)
  1798       mach->add_req( ReduceInst( kid, newrule, mem1 ) );
  1799       debug_only(_mem_node = save_mem_node;)
  1805 // -------------------------------------------------------------------------
  1806 // Java-Java calling convention
  1807 // (what you use when Java calls Java)
  1809 //------------------------------find_receiver----------------------------------
  1810 // For a given signature, return the OptoReg for parameter 0.
  1811 OptoReg::Name Matcher::find_receiver( bool is_outgoing ) {
  1812   VMRegPair regs;
  1813   BasicType sig_bt = T_OBJECT;
  1814   calling_convention(&sig_bt, &regs, 1, is_outgoing);
  1815   // Return argument 0 register.  In the LP64 build pointers
  1816   // take 2 registers, but the VM wants only the 'main' name.
  1817   return OptoReg::as_OptoReg(regs.first());
  1820 // A method-klass-holder may be passed in the inline_cache_reg
  1821 // and then expanded into the inline_cache_reg and a method_oop register
  1822 //   defined in ad_<arch>.cpp
  1825 //------------------------------find_shared------------------------------------
  1826 // Set bits if Node is shared or otherwise a root
  1827 void Matcher::find_shared( Node *n ) {
  1828   // Allocate stack of size C->unique() * 2 to avoid frequent realloc
  1829   MStack mstack(C->unique() * 2);
  1830   // Mark nodes as address_visited if they are inputs to an address expression
  1831   VectorSet address_visited(Thread::current()->resource_area());
  1832   mstack.push(n, Visit);     // Don't need to pre-visit root node
  1833   while (mstack.is_nonempty()) {
  1834     n = mstack.node();       // Leave node on stack
  1835     Node_State nstate = mstack.state();
  1836     uint nop = n->Opcode();
  1837     if (nstate == Pre_Visit) {
  1838       if (address_visited.test(n->_idx)) { // Visited in address already?
  1839         // Flag as visited and shared now.
  1840         set_visited(n);
  1842       if (is_visited(n)) {   // Visited already?
  1843         // Node is shared and has no reason to clone.  Flag it as shared.
  1844         // This causes it to match into a register for the sharing.
  1845         set_shared(n);       // Flag as shared and
  1846         mstack.pop();        // remove node from stack
  1847         continue;
  1849       nstate = Visit; // Not already visited; so visit now
  1851     if (nstate == Visit) {
  1852       mstack.set_state(Post_Visit);
  1853       set_visited(n);   // Flag as visited now
  1854       bool mem_op = false;
  1856       switch( nop ) {  // Handle some opcodes special
  1857       case Op_Phi:             // Treat Phis as shared roots
  1858       case Op_Parm:
  1859       case Op_Proj:            // All handled specially during matching
  1860       case Op_SafePointScalarObject:
  1861         set_shared(n);
  1862         set_dontcare(n);
  1863         break;
  1864       case Op_If:
  1865       case Op_CountedLoopEnd:
  1866         mstack.set_state(Alt_Post_Visit); // Alternative way
  1867         // Convert (If (Bool (CmpX A B))) into (If (Bool) (CmpX A B)).  Helps
  1868         // with matching cmp/branch in 1 instruction.  The Matcher needs the
  1869         // Bool and CmpX side-by-side, because it can only get at constants
  1870         // that are at the leaves of Match trees, and the Bool's condition acts
  1871         // as a constant here.
  1872         mstack.push(n->in(1), Visit);         // Clone the Bool
  1873         mstack.push(n->in(0), Pre_Visit);     // Visit control input
  1874         continue; // while (mstack.is_nonempty())
  1875       case Op_ConvI2D:         // These forms efficiently match with a prior
  1876       case Op_ConvI2F:         //   Load but not a following Store
  1877         if( n->in(1)->is_Load() &&        // Prior load
  1878             n->outcnt() == 1 &&           // Not already shared
  1879             n->unique_out()->is_Store() ) // Following store
  1880           set_shared(n);       // Force it to be a root
  1881         break;
  1882       case Op_ReverseBytesI:
  1883       case Op_ReverseBytesL:
  1884         if( n->in(1)->is_Load() &&        // Prior load
  1885             n->outcnt() == 1 )            // Not already shared
  1886           set_shared(n);                  // Force it to be a root
  1887         break;
  1888       case Op_BoxLock:         // Cant match until we get stack-regs in ADLC
  1889       case Op_IfFalse:
  1890       case Op_IfTrue:
  1891       case Op_MachProj:
  1892       case Op_MergeMem:
  1893       case Op_Catch:
  1894       case Op_CatchProj:
  1895       case Op_CProj:
  1896       case Op_JumpProj:
  1897       case Op_JProj:
  1898       case Op_NeverBranch:
  1899         set_dontcare(n);
  1900         break;
  1901       case Op_Jump:
  1902         mstack.push(n->in(1), Visit);         // Switch Value
  1903         mstack.push(n->in(0), Pre_Visit);     // Visit Control input
  1904         continue;                             // while (mstack.is_nonempty())
  1905       case Op_StrComp:
  1906       case Op_StrEquals:
  1907       case Op_StrIndexOf:
  1908       case Op_AryEq:
  1909         set_shared(n); // Force result into register (it will be anyways)
  1910         break;
  1911       case Op_ConP: {  // Convert pointers above the centerline to NUL
  1912         TypeNode *tn = n->as_Type(); // Constants derive from type nodes
  1913         const TypePtr* tp = tn->type()->is_ptr();
  1914         if (tp->_ptr == TypePtr::AnyNull) {
  1915           tn->set_type(TypePtr::NULL_PTR);
  1917         break;
  1919       case Op_ConN: {  // Convert narrow pointers above the centerline to NUL
  1920         TypeNode *tn = n->as_Type(); // Constants derive from type nodes
  1921         const TypePtr* tp = tn->type()->make_ptr();
  1922         if (tp && tp->_ptr == TypePtr::AnyNull) {
  1923           tn->set_type(TypeNarrowOop::NULL_PTR);
  1925         break;
  1927       case Op_Binary:         // These are introduced in the Post_Visit state.
  1928         ShouldNotReachHere();
  1929         break;
  1930       case Op_ClearArray:
  1931       case Op_SafePoint:
  1932         mem_op = true;
  1933         break;
  1934       default:
  1935         if( n->is_Store() ) {
  1936           // Do match stores, despite no ideal reg
  1937           mem_op = true;
  1938           break;
  1940         if( n->is_Mem() ) { // Loads and LoadStores
  1941           mem_op = true;
  1942           // Loads must be root of match tree due to prior load conflict
  1943           if( C->subsume_loads() == false )
  1944             set_shared(n);
  1946         // Fall into default case
  1947         if( !n->ideal_reg() )
  1948           set_dontcare(n);  // Unmatchable Nodes
  1949       } // end_switch
  1951       for(int i = n->req() - 1; i >= 0; --i) { // For my children
  1952         Node *m = n->in(i); // Get ith input
  1953         if (m == NULL) continue;  // Ignore NULLs
  1954         uint mop = m->Opcode();
  1956         // Must clone all producers of flags, or we will not match correctly.
  1957         // Suppose a compare setting int-flags is shared (e.g., a switch-tree)
  1958         // then it will match into an ideal Op_RegFlags.  Alas, the fp-flags
  1959         // are also there, so we may match a float-branch to int-flags and
  1960         // expect the allocator to haul the flags from the int-side to the
  1961         // fp-side.  No can do.
  1962         if( _must_clone[mop] ) {
  1963           mstack.push(m, Visit);
  1964           continue; // for(int i = ...)
  1967         if( mop == Op_AddP && m->in(AddPNode::Base)->Opcode() == Op_DecodeN ) {
  1968           // Bases used in addresses must be shared but since
  1969           // they are shared through a DecodeN they may appear
  1970           // to have a single use so force sharing here.
  1971           set_shared(m->in(AddPNode::Base)->in(1));
  1974         // Clone addressing expressions as they are "free" in memory access instructions
  1975         if( mem_op && i == MemNode::Address && mop == Op_AddP ) {
  1976           // Some inputs for address expression are not put on stack
  1977           // to avoid marking them as shared and forcing them into register
  1978           // if they are used only in address expressions.
  1979           // But they should be marked as shared if there are other uses
  1980           // besides address expressions.
  1982           Node *off = m->in(AddPNode::Offset);
  1983           if( off->is_Con() &&
  1984               // When there are other uses besides address expressions
  1985               // put it on stack and mark as shared.
  1986               !is_visited(m) ) {
  1987             address_visited.test_set(m->_idx); // Flag as address_visited
  1988             Node *adr = m->in(AddPNode::Address);
  1990             // Intel, ARM and friends can handle 2 adds in addressing mode
  1991             if( clone_shift_expressions && adr->is_AddP() &&
  1992                 // AtomicAdd is not an addressing expression.
  1993                 // Cheap to find it by looking for screwy base.
  1994                 !adr->in(AddPNode::Base)->is_top() &&
  1995                 // Are there other uses besides address expressions?
  1996                 !is_visited(adr) ) {
  1997               address_visited.set(adr->_idx); // Flag as address_visited
  1998               Node *shift = adr->in(AddPNode::Offset);
  1999               // Check for shift by small constant as well
  2000               if( shift->Opcode() == Op_LShiftX && shift->in(2)->is_Con() &&
  2001                   shift->in(2)->get_int() <= 3 &&
  2002                   // Are there other uses besides address expressions?
  2003                   !is_visited(shift) ) {
  2004                 address_visited.set(shift->_idx); // Flag as address_visited
  2005                 mstack.push(shift->in(2), Visit);
  2006                 Node *conv = shift->in(1);
  2007 #ifdef _LP64
  2008                 // Allow Matcher to match the rule which bypass
  2009                 // ConvI2L operation for an array index on LP64
  2010                 // if the index value is positive.
  2011                 if( conv->Opcode() == Op_ConvI2L &&
  2012                     conv->as_Type()->type()->is_long()->_lo >= 0 &&
  2013                     // Are there other uses besides address expressions?
  2014                     !is_visited(conv) ) {
  2015                   address_visited.set(conv->_idx); // Flag as address_visited
  2016                   mstack.push(conv->in(1), Pre_Visit);
  2017                 } else
  2018 #endif
  2019                 mstack.push(conv, Pre_Visit);
  2020               } else {
  2021                 mstack.push(shift, Pre_Visit);
  2023               mstack.push(adr->in(AddPNode::Address), Pre_Visit);
  2024               mstack.push(adr->in(AddPNode::Base), Pre_Visit);
  2025             } else {  // Sparc, Alpha, PPC and friends
  2026               mstack.push(adr, Pre_Visit);
  2029             // Clone X+offset as it also folds into most addressing expressions
  2030             mstack.push(off, Visit);
  2031             mstack.push(m->in(AddPNode::Base), Pre_Visit);
  2032             continue; // for(int i = ...)
  2033           } // if( off->is_Con() )
  2034         }   // if( mem_op &&
  2035         mstack.push(m, Pre_Visit);
  2036       }     // for(int i = ...)
  2038     else if (nstate == Alt_Post_Visit) {
  2039       mstack.pop(); // Remove node from stack
  2040       // We cannot remove the Cmp input from the Bool here, as the Bool may be
  2041       // shared and all users of the Bool need to move the Cmp in parallel.
  2042       // This leaves both the Bool and the If pointing at the Cmp.  To
  2043       // prevent the Matcher from trying to Match the Cmp along both paths
  2044       // BoolNode::match_edge always returns a zero.
  2046       // We reorder the Op_If in a pre-order manner, so we can visit without
  2047       // accidentally sharing the Cmp (the Bool and the If make 2 users).
  2048       n->add_req( n->in(1)->in(1) ); // Add the Cmp next to the Bool
  2050     else if (nstate == Post_Visit) {
  2051       mstack.pop(); // Remove node from stack
  2053       // Now hack a few special opcodes
  2054       switch( n->Opcode() ) {       // Handle some opcodes special
  2055       case Op_StorePConditional:
  2056       case Op_StoreIConditional:
  2057       case Op_StoreLConditional:
  2058       case Op_CompareAndSwapI:
  2059       case Op_CompareAndSwapL:
  2060       case Op_CompareAndSwapP:
  2061       case Op_CompareAndSwapN: {   // Convert trinary to binary-tree
  2062         Node *newval = n->in(MemNode::ValueIn );
  2063         Node *oldval  = n->in(LoadStoreNode::ExpectedIn);
  2064         Node *pair = new (C, 3) BinaryNode( oldval, newval );
  2065         n->set_req(MemNode::ValueIn,pair);
  2066         n->del_req(LoadStoreNode::ExpectedIn);
  2067         break;
  2069       case Op_CMoveD:              // Convert trinary to binary-tree
  2070       case Op_CMoveF:
  2071       case Op_CMoveI:
  2072       case Op_CMoveL:
  2073       case Op_CMoveN:
  2074       case Op_CMoveP: {
  2075         // Restructure into a binary tree for Matching.  It's possible that
  2076         // we could move this code up next to the graph reshaping for IfNodes
  2077         // or vice-versa, but I do not want to debug this for Ladybird.
  2078         // 10/2/2000 CNC.
  2079         Node *pair1 = new (C, 3) BinaryNode(n->in(1),n->in(1)->in(1));
  2080         n->set_req(1,pair1);
  2081         Node *pair2 = new (C, 3) BinaryNode(n->in(2),n->in(3));
  2082         n->set_req(2,pair2);
  2083         n->del_req(3);
  2084         break;
  2086       case Op_StrEquals: {
  2087         Node *pair1 = new (C, 3) BinaryNode(n->in(2),n->in(3));
  2088         n->set_req(2,pair1);
  2089         n->set_req(3,n->in(4));
  2090         n->del_req(4);
  2091         break;
  2093       case Op_StrComp:
  2094       case Op_StrIndexOf: {
  2095         Node *pair1 = new (C, 3) BinaryNode(n->in(2),n->in(3));
  2096         n->set_req(2,pair1);
  2097         Node *pair2 = new (C, 3) BinaryNode(n->in(4),n->in(5));
  2098         n->set_req(3,pair2);
  2099         n->del_req(5);
  2100         n->del_req(4);
  2101         break;
  2103       default:
  2104         break;
  2107     else {
  2108       ShouldNotReachHere();
  2110   } // end of while (mstack.is_nonempty())
  2113 #ifdef ASSERT
  2114 // machine-independent root to machine-dependent root
  2115 void Matcher::dump_old2new_map() {
  2116   _old2new_map.dump();
  2118 #endif
  2120 //---------------------------collect_null_checks-------------------------------
  2121 // Find null checks in the ideal graph; write a machine-specific node for
  2122 // it.  Used by later implicit-null-check handling.  Actually collects
  2123 // either an IfTrue or IfFalse for the common NOT-null path, AND the ideal
  2124 // value being tested.
  2125 void Matcher::collect_null_checks( Node *proj, Node *orig_proj ) {
  2126   Node *iff = proj->in(0);
  2127   if( iff->Opcode() == Op_If ) {
  2128     // During matching If's have Bool & Cmp side-by-side
  2129     BoolNode *b = iff->in(1)->as_Bool();
  2130     Node *cmp = iff->in(2);
  2131     int opc = cmp->Opcode();
  2132     if (opc != Op_CmpP && opc != Op_CmpN) return;
  2134     const Type* ct = cmp->in(2)->bottom_type();
  2135     if (ct == TypePtr::NULL_PTR ||
  2136         (opc == Op_CmpN && ct == TypeNarrowOop::NULL_PTR)) {
  2138       bool push_it = false;
  2139       if( proj->Opcode() == Op_IfTrue ) {
  2140         extern int all_null_checks_found;
  2141         all_null_checks_found++;
  2142         if( b->_test._test == BoolTest::ne ) {
  2143           push_it = true;
  2145       } else {
  2146         assert( proj->Opcode() == Op_IfFalse, "" );
  2147         if( b->_test._test == BoolTest::eq ) {
  2148           push_it = true;
  2151       if( push_it ) {
  2152         _null_check_tests.push(proj);
  2153         Node* val = cmp->in(1);
  2154 #ifdef _LP64
  2155         if (val->bottom_type()->isa_narrowoop() &&
  2156             !Matcher::narrow_oop_use_complex_address()) {
  2157           //
  2158           // Look for DecodeN node which should be pinned to orig_proj.
  2159           // On platforms (Sparc) which can not handle 2 adds
  2160           // in addressing mode we have to keep a DecodeN node and
  2161           // use it to do implicit NULL check in address.
  2162           //
  2163           // DecodeN node was pinned to non-null path (orig_proj) during
  2164           // CastPP transformation in final_graph_reshaping_impl().
  2165           //
  2166           uint cnt = orig_proj->outcnt();
  2167           for (uint i = 0; i < orig_proj->outcnt(); i++) {
  2168             Node* d = orig_proj->raw_out(i);
  2169             if (d->is_DecodeN() && d->in(1) == val) {
  2170               val = d;
  2171               val->set_req(0, NULL); // Unpin now.
  2172               // Mark this as special case to distinguish from
  2173               // a regular case: CmpP(DecodeN, NULL).
  2174               val = (Node*)(((intptr_t)val) | 1);
  2175               break;
  2179 #endif
  2180         _null_check_tests.push(val);
  2186 //---------------------------validate_null_checks------------------------------
  2187 // Its possible that the value being NULL checked is not the root of a match
  2188 // tree.  If so, I cannot use the value in an implicit null check.
  2189 void Matcher::validate_null_checks( ) {
  2190   uint cnt = _null_check_tests.size();
  2191   for( uint i=0; i < cnt; i+=2 ) {
  2192     Node *test = _null_check_tests[i];
  2193     Node *val = _null_check_tests[i+1];
  2194     bool is_decoden = ((intptr_t)val) & 1;
  2195     val = (Node*)(((intptr_t)val) & ~1);
  2196     if (has_new_node(val)) {
  2197       Node* new_val = new_node(val);
  2198       if (is_decoden) {
  2199         assert(val->is_DecodeN() && val->in(0) == NULL, "sanity");
  2200         // Note: new_val may have a control edge if
  2201         // the original ideal node DecodeN was matched before
  2202         // it was unpinned in Matcher::collect_null_checks().
  2203         // Unpin the mach node and mark it.
  2204         new_val->set_req(0, NULL);
  2205         new_val = (Node*)(((intptr_t)new_val) | 1);
  2207       // Is a match-tree root, so replace with the matched value
  2208       _null_check_tests.map(i+1, new_val);
  2209     } else {
  2210       // Yank from candidate list
  2211       _null_check_tests.map(i+1,_null_check_tests[--cnt]);
  2212       _null_check_tests.map(i,_null_check_tests[--cnt]);
  2213       _null_check_tests.pop();
  2214       _null_check_tests.pop();
  2215       i-=2;
  2221 // Used by the DFA in dfa_sparc.cpp.  Check for a prior FastLock
  2222 // acting as an Acquire and thus we don't need an Acquire here.  We
  2223 // retain the Node to act as a compiler ordering barrier.
  2224 bool Matcher::prior_fast_lock( const Node *acq ) {
  2225   Node *r = acq->in(0);
  2226   if( !r->is_Region() || r->req() <= 1 ) return false;
  2227   Node *proj = r->in(1);
  2228   if( !proj->is_Proj() ) return false;
  2229   Node *call = proj->in(0);
  2230   if( !call->is_Call() || call->as_Call()->entry_point() != OptoRuntime::complete_monitor_locking_Java() )
  2231     return false;
  2233   return true;
  2236 // Used by the DFA in dfa_sparc.cpp.  Check for a following FastUnLock
  2237 // acting as a Release and thus we don't need a Release here.  We
  2238 // retain the Node to act as a compiler ordering barrier.
  2239 bool Matcher::post_fast_unlock( const Node *rel ) {
  2240   Compile *C = Compile::current();
  2241   assert( rel->Opcode() == Op_MemBarRelease, "" );
  2242   const MemBarReleaseNode *mem = (const MemBarReleaseNode*)rel;
  2243   DUIterator_Fast imax, i = mem->fast_outs(imax);
  2244   Node *ctrl = NULL;
  2245   while( true ) {
  2246     ctrl = mem->fast_out(i);            // Throw out-of-bounds if proj not found
  2247     assert( ctrl->is_Proj(), "only projections here" );
  2248     ProjNode *proj = (ProjNode*)ctrl;
  2249     if( proj->_con == TypeFunc::Control &&
  2250         !C->node_arena()->contains(ctrl) ) // Unmatched old-space only
  2251       break;
  2252     i++;
  2254   Node *iff = NULL;
  2255   for( DUIterator_Fast jmax, j = ctrl->fast_outs(jmax); j < jmax; j++ ) {
  2256     Node *x = ctrl->fast_out(j);
  2257     if( x->is_If() && x->req() > 1 &&
  2258         !C->node_arena()->contains(x) ) { // Unmatched old-space only
  2259       iff = x;
  2260       break;
  2263   if( !iff ) return false;
  2264   Node *bol = iff->in(1);
  2265   // The iff might be some random subclass of If or bol might be Con-Top
  2266   if (!bol->is_Bool())  return false;
  2267   assert( bol->req() > 1, "" );
  2268   return (bol->in(1)->Opcode() == Op_FastUnlock);
  2271 // Used by the DFA in dfa_xxx.cpp.  Check for a following barrier or
  2272 // atomic instruction acting as a store_load barrier without any
  2273 // intervening volatile load, and thus we don't need a barrier here.
  2274 // We retain the Node to act as a compiler ordering barrier.
  2275 bool Matcher::post_store_load_barrier(const Node *vmb) {
  2276   Compile *C = Compile::current();
  2277   assert( vmb->is_MemBar(), "" );
  2278   assert( vmb->Opcode() != Op_MemBarAcquire, "" );
  2279   const MemBarNode *mem = (const MemBarNode*)vmb;
  2281   // Get the Proj node, ctrl, that can be used to iterate forward
  2282   Node *ctrl = NULL;
  2283   DUIterator_Fast imax, i = mem->fast_outs(imax);
  2284   while( true ) {
  2285     ctrl = mem->fast_out(i);            // Throw out-of-bounds if proj not found
  2286     assert( ctrl->is_Proj(), "only projections here" );
  2287     ProjNode *proj = (ProjNode*)ctrl;
  2288     if( proj->_con == TypeFunc::Control &&
  2289         !C->node_arena()->contains(ctrl) ) // Unmatched old-space only
  2290       break;
  2291     i++;
  2294   for( DUIterator_Fast jmax, j = ctrl->fast_outs(jmax); j < jmax; j++ ) {
  2295     Node *x = ctrl->fast_out(j);
  2296     int xop = x->Opcode();
  2298     // We don't need current barrier if we see another or a lock
  2299     // before seeing volatile load.
  2300     //
  2301     // Op_Fastunlock previously appeared in the Op_* list below.
  2302     // With the advent of 1-0 lock operations we're no longer guaranteed
  2303     // that a monitor exit operation contains a serializing instruction.
  2305     if (xop == Op_MemBarVolatile ||
  2306         xop == Op_FastLock ||
  2307         xop == Op_CompareAndSwapL ||
  2308         xop == Op_CompareAndSwapP ||
  2309         xop == Op_CompareAndSwapN ||
  2310         xop == Op_CompareAndSwapI)
  2311       return true;
  2313     if (x->is_MemBar()) {
  2314       // We must retain this membar if there is an upcoming volatile
  2315       // load, which will be preceded by acquire membar.
  2316       if (xop == Op_MemBarAcquire)
  2317         return false;
  2318       // For other kinds of barriers, check by pretending we
  2319       // are them, and seeing if we can be removed.
  2320       else
  2321         return post_store_load_barrier((const MemBarNode*)x);
  2324     // Delicate code to detect case of an upcoming fastlock block
  2325     if( x->is_If() && x->req() > 1 &&
  2326         !C->node_arena()->contains(x) ) { // Unmatched old-space only
  2327       Node *iff = x;
  2328       Node *bol = iff->in(1);
  2329       // The iff might be some random subclass of If or bol might be Con-Top
  2330       if (!bol->is_Bool())  return false;
  2331       assert( bol->req() > 1, "" );
  2332       return (bol->in(1)->Opcode() == Op_FastUnlock);
  2334     // probably not necessary to check for these
  2335     if (x->is_Call() || x->is_SafePoint() || x->is_block_proj())
  2336       return false;
  2338   return false;
  2341 //=============================================================================
  2342 //---------------------------State---------------------------------------------
  2343 State::State(void) {
  2344 #ifdef ASSERT
  2345   _id = 0;
  2346   _kids[0] = _kids[1] = (State*)(intptr_t) CONST64(0xcafebabecafebabe);
  2347   _leaf = (Node*)(intptr_t) CONST64(0xbaadf00dbaadf00d);
  2348   //memset(_cost, -1, sizeof(_cost));
  2349   //memset(_rule, -1, sizeof(_rule));
  2350 #endif
  2351   memset(_valid, 0, sizeof(_valid));
  2354 #ifdef ASSERT
  2355 State::~State() {
  2356   _id = 99;
  2357   _kids[0] = _kids[1] = (State*)(intptr_t) CONST64(0xcafebabecafebabe);
  2358   _leaf = (Node*)(intptr_t) CONST64(0xbaadf00dbaadf00d);
  2359   memset(_cost, -3, sizeof(_cost));
  2360   memset(_rule, -3, sizeof(_rule));
  2362 #endif
  2364 #ifndef PRODUCT
  2365 //---------------------------dump----------------------------------------------
  2366 void State::dump() {
  2367   tty->print("\n");
  2368   dump(0);
  2371 void State::dump(int depth) {
  2372   for( int j = 0; j < depth; j++ )
  2373     tty->print("   ");
  2374   tty->print("--N: ");
  2375   _leaf->dump();
  2376   uint i;
  2377   for( i = 0; i < _LAST_MACH_OPER; i++ )
  2378     // Check for valid entry
  2379     if( valid(i) ) {
  2380       for( int j = 0; j < depth; j++ )
  2381         tty->print("   ");
  2382         assert(_cost[i] != max_juint, "cost must be a valid value");
  2383         assert(_rule[i] < _last_Mach_Node, "rule[i] must be valid rule");
  2384         tty->print_cr("%s  %d  %s",
  2385                       ruleName[i], _cost[i], ruleName[_rule[i]] );
  2387   tty->print_cr("");
  2389   for( i=0; i<2; i++ )
  2390     if( _kids[i] )
  2391       _kids[i]->dump(depth+1);
  2393 #endif

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