src/share/vm/opto/chaitin.cpp

Thu, 05 Feb 2009 11:42:10 -0800

author
never
date
Thu, 05 Feb 2009 11:42:10 -0800
changeset 979
82a980778b92
parent 854
0bf25c4807f9
child 985
96964ebdb154
permissions
-rw-r--r--

6793828: G1: invariant: queues are empty when activated
Reviewed-by: jrose, kvn

     1 /*
     2  * Copyright 2000-2008 Sun Microsystems, Inc.  All Rights Reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 #include "incls/_precompiled.incl"
    26 #include "incls/_chaitin.cpp.incl"
    28 //=============================================================================
    30 #ifndef PRODUCT
    31 void LRG::dump( ) const {
    32   ttyLocker ttyl;
    33   tty->print("%d ",num_regs());
    34   _mask.dump();
    35   if( _msize_valid ) {
    36     if( mask_size() == compute_mask_size() ) tty->print(", #%d ",_mask_size);
    37     else tty->print(", #!!!_%d_vs_%d ",_mask_size,_mask.Size());
    38   } else {
    39     tty->print(", #?(%d) ",_mask.Size());
    40   }
    42   tty->print("EffDeg: ");
    43   if( _degree_valid ) tty->print( "%d ", _eff_degree );
    44   else tty->print("? ");
    46   if( is_multidef() ) {
    47     tty->print("MultiDef ");
    48     if (_defs != NULL) {
    49       tty->print("(");
    50       for (int i = 0; i < _defs->length(); i++) {
    51         tty->print("N%d ", _defs->at(i)->_idx);
    52       }
    53       tty->print(") ");
    54     }
    55   }
    56   else if( _def == 0 ) tty->print("Dead ");
    57   else tty->print("Def: N%d ",_def->_idx);
    59   tty->print("Cost:%4.2g Area:%4.2g Score:%4.2g ",_cost,_area, score());
    60   // Flags
    61   if( _is_oop ) tty->print("Oop ");
    62   if( _is_float ) tty->print("Float ");
    63   if( _was_spilled1 ) tty->print("Spilled ");
    64   if( _was_spilled2 ) tty->print("Spilled2 ");
    65   if( _direct_conflict ) tty->print("Direct_conflict ");
    66   if( _fat_proj ) tty->print("Fat ");
    67   if( _was_lo ) tty->print("Lo ");
    68   if( _has_copy ) tty->print("Copy ");
    69   if( _at_risk ) tty->print("Risk ");
    71   if( _must_spill ) tty->print("Must_spill ");
    72   if( _is_bound ) tty->print("Bound ");
    73   if( _msize_valid ) {
    74     if( _degree_valid && lo_degree() ) tty->print("Trivial ");
    75   }
    77   tty->cr();
    78 }
    79 #endif
    81 //------------------------------score------------------------------------------
    82 // Compute score from cost and area.  Low score is best to spill.
    83 static double raw_score( double cost, double area ) {
    84   return cost - (area*RegisterCostAreaRatio) * 1.52588e-5;
    85 }
    87 double LRG::score() const {
    88   // Scale _area by RegisterCostAreaRatio/64K then subtract from cost.
    89   // Bigger area lowers score, encourages spilling this live range.
    90   // Bigger cost raise score, prevents spilling this live range.
    91   // (Note: 1/65536 is the magic constant below; I dont trust the C optimizer
    92   // to turn a divide by a constant into a multiply by the reciprical).
    93   double score = raw_score( _cost, _area);
    95   // Account for area.  Basically, LRGs covering large areas are better
    96   // to spill because more other LRGs get freed up.
    97   if( _area == 0.0 )            // No area?  Then no progress to spill
    98     return 1e35;
   100   if( _was_spilled2 )           // If spilled once before, we are unlikely
   101     return score + 1e30;        // to make progress again.
   103   if( _cost >= _area*3.0 )      // Tiny area relative to cost
   104     return score + 1e17;        // Probably no progress to spill
   106   if( (_cost+_cost) >= _area*3.0 ) // Small area relative to cost
   107     return score + 1e10;        // Likely no progress to spill
   109   return score;
   110 }
   112 //------------------------------LRG_List---------------------------------------
   113 LRG_List::LRG_List( uint max ) : _cnt(max), _max(max), _lidxs(NEW_RESOURCE_ARRAY(uint,max)) {
   114   memset( _lidxs, 0, sizeof(uint)*max );
   115 }
   117 void LRG_List::extend( uint nidx, uint lidx ) {
   118   _nesting.check();
   119   if( nidx >= _max ) {
   120     uint size = 16;
   121     while( size <= nidx ) size <<=1;
   122     _lidxs = REALLOC_RESOURCE_ARRAY( uint, _lidxs, _max, size );
   123     _max = size;
   124   }
   125   while( _cnt <= nidx )
   126     _lidxs[_cnt++] = 0;
   127   _lidxs[nidx] = lidx;
   128 }
   130 #define NUMBUCKS 3
   132 //------------------------------Chaitin----------------------------------------
   133 PhaseChaitin::PhaseChaitin(uint unique, PhaseCFG &cfg, Matcher &matcher)
   134   : PhaseRegAlloc(unique, cfg, matcher,
   135 #ifndef PRODUCT
   136        print_chaitin_statistics
   137 #else
   138        NULL
   139 #endif
   140        ),
   141     _names(unique), _uf_map(unique),
   142     _maxlrg(0), _live(0),
   143     _spilled_once(Thread::current()->resource_area()),
   144     _spilled_twice(Thread::current()->resource_area()),
   145     _lo_degree(0), _lo_stk_degree(0), _hi_degree(0), _simplified(0),
   146     _oldphi(unique)
   147 #ifndef PRODUCT
   148   , _trace_spilling(TraceSpilling || C->method_has_option("TraceSpilling"))
   149 #endif
   150 {
   151   NOT_PRODUCT( Compile::TracePhase t3("ctorChaitin", &_t_ctorChaitin, TimeCompiler); )
   152   uint i,j;
   153   // Build a list of basic blocks, sorted by frequency
   154   _blks = NEW_RESOURCE_ARRAY( Block *, _cfg._num_blocks );
   155   // Experiment with sorting strategies to speed compilation
   156   double  cutoff = BLOCK_FREQUENCY(1.0); // Cutoff for high frequency bucket
   157   Block **buckets[NUMBUCKS];             // Array of buckets
   158   uint    buckcnt[NUMBUCKS];             // Array of bucket counters
   159   double  buckval[NUMBUCKS];             // Array of bucket value cutoffs
   160   for( i = 0; i < NUMBUCKS; i++ ) {
   161     buckets[i] = NEW_RESOURCE_ARRAY( Block *, _cfg._num_blocks );
   162     buckcnt[i] = 0;
   163     // Bump by three orders of magnitude each time
   164     cutoff *= 0.001;
   165     buckval[i] = cutoff;
   166     for( j = 0; j < _cfg._num_blocks; j++ ) {
   167       buckets[i][j] = NULL;
   168     }
   169   }
   170   // Sort blocks into buckets
   171   for( i = 0; i < _cfg._num_blocks; i++ ) {
   172     for( j = 0; j < NUMBUCKS; j++ ) {
   173       if( (j == NUMBUCKS-1) || (_cfg._blocks[i]->_freq > buckval[j]) ) {
   174         // Assign block to end of list for appropriate bucket
   175         buckets[j][buckcnt[j]++] = _cfg._blocks[i];
   176         break;                      // kick out of inner loop
   177       }
   178     }
   179   }
   180   // Dump buckets into final block array
   181   uint blkcnt = 0;
   182   for( i = 0; i < NUMBUCKS; i++ ) {
   183     for( j = 0; j < buckcnt[i]; j++ ) {
   184       _blks[blkcnt++] = buckets[i][j];
   185     }
   186   }
   188   assert(blkcnt == _cfg._num_blocks, "Block array not totally filled");
   189 }
   191 void PhaseChaitin::Register_Allocate() {
   193   // Above the OLD FP (and in registers) are the incoming arguments.  Stack
   194   // slots in this area are called "arg_slots".  Above the NEW FP (and in
   195   // registers) is the outgoing argument area; above that is the spill/temp
   196   // area.  These are all "frame_slots".  Arg_slots start at the zero
   197   // stack_slots and count up to the known arg_size.  Frame_slots start at
   198   // the stack_slot #arg_size and go up.  After allocation I map stack
   199   // slots to actual offsets.  Stack-slots in the arg_slot area are biased
   200   // by the frame_size; stack-slots in the frame_slot area are biased by 0.
   202   _trip_cnt = 0;
   203   _alternate = 0;
   204   _matcher._allocation_started = true;
   206   ResourceArea live_arena;      // Arena for liveness & IFG info
   207   ResourceMark rm(&live_arena);
   209   // Need live-ness for the IFG; need the IFG for coalescing.  If the
   210   // liveness is JUST for coalescing, then I can get some mileage by renaming
   211   // all copy-related live ranges low and then using the max copy-related
   212   // live range as a cut-off for LIVE and the IFG.  In other words, I can
   213   // build a subset of LIVE and IFG just for copies.
   214   PhaseLive live(_cfg,_names,&live_arena);
   216   // Need IFG for coalescing and coloring
   217   PhaseIFG ifg( &live_arena );
   218   _ifg = &ifg;
   220   if (C->unique() > _names.Size())  _names.extend(C->unique()-1, 0);
   222   // Come out of SSA world to the Named world.  Assign (virtual) registers to
   223   // Nodes.  Use the same register for all inputs and the output of PhiNodes
   224   // - effectively ending SSA form.  This requires either coalescing live
   225   // ranges or inserting copies.  For the moment, we insert "virtual copies"
   226   // - we pretend there is a copy prior to each Phi in predecessor blocks.
   227   // We will attempt to coalesce such "virtual copies" before we manifest
   228   // them for real.
   229   de_ssa();
   231   {
   232     NOT_PRODUCT( Compile::TracePhase t3("computeLive", &_t_computeLive, TimeCompiler); )
   233     _live = NULL;                 // Mark live as being not available
   234     rm.reset_to_mark();           // Reclaim working storage
   235     IndexSet::reset_memory(C, &live_arena);
   236     ifg.init(_maxlrg);            // Empty IFG
   237     gather_lrg_masks( false );    // Collect LRG masks
   238     live.compute( _maxlrg );      // Compute liveness
   239     _live = &live;                // Mark LIVE as being available
   240   }
   242   // Base pointers are currently "used" by instructions which define new
   243   // derived pointers.  This makes base pointers live up to the where the
   244   // derived pointer is made, but not beyond.  Really, they need to be live
   245   // across any GC point where the derived value is live.  So this code looks
   246   // at all the GC points, and "stretches" the live range of any base pointer
   247   // to the GC point.
   248   if( stretch_base_pointer_live_ranges(&live_arena) ) {
   249     NOT_PRODUCT( Compile::TracePhase t3("computeLive (sbplr)", &_t_computeLive, TimeCompiler); )
   250     // Since some live range stretched, I need to recompute live
   251     _live = NULL;
   252     rm.reset_to_mark();         // Reclaim working storage
   253     IndexSet::reset_memory(C, &live_arena);
   254     ifg.init(_maxlrg);
   255     gather_lrg_masks( false );
   256     live.compute( _maxlrg );
   257     _live = &live;
   258   }
   259   // Create the interference graph using virtual copies
   260   build_ifg_virtual( );  // Include stack slots this time
   262   // Aggressive (but pessimistic) copy coalescing.
   263   // This pass works on virtual copies.  Any virtual copies which are not
   264   // coalesced get manifested as actual copies
   265   {
   266     // The IFG is/was triangular.  I am 'squaring it up' so Union can run
   267     // faster.  Union requires a 'for all' operation which is slow on the
   268     // triangular adjacency matrix (quick reminder: the IFG is 'sparse' -
   269     // meaning I can visit all the Nodes neighbors less than a Node in time
   270     // O(# of neighbors), but I have to visit all the Nodes greater than a
   271     // given Node and search them for an instance, i.e., time O(#MaxLRG)).
   272     _ifg->SquareUp();
   274     PhaseAggressiveCoalesce coalesce( *this );
   275     coalesce.coalesce_driver( );
   276     // Insert un-coalesced copies.  Visit all Phis.  Where inputs to a Phi do
   277     // not match the Phi itself, insert a copy.
   278     coalesce.insert_copies(_matcher);
   279   }
   281   // After aggressive coalesce, attempt a first cut at coloring.
   282   // To color, we need the IFG and for that we need LIVE.
   283   {
   284     NOT_PRODUCT( Compile::TracePhase t3("computeLive", &_t_computeLive, TimeCompiler); )
   285     _live = NULL;
   286     rm.reset_to_mark();           // Reclaim working storage
   287     IndexSet::reset_memory(C, &live_arena);
   288     ifg.init(_maxlrg);
   289     gather_lrg_masks( true );
   290     live.compute( _maxlrg );
   291     _live = &live;
   292   }
   294   // Build physical interference graph
   295   uint must_spill = 0;
   296   must_spill = build_ifg_physical( &live_arena );
   297   // If we have a guaranteed spill, might as well spill now
   298   if( must_spill ) {
   299     if( !_maxlrg ) return;
   300     // Bail out if unique gets too large (ie - unique > MaxNodeLimit)
   301     C->check_node_count(10*must_spill, "out of nodes before split");
   302     if (C->failing())  return;
   303     _maxlrg = Split( _maxlrg );        // Split spilling LRG everywhere
   304     // Bail out if unique gets too large (ie - unique > MaxNodeLimit - 2*NodeLimitFudgeFactor)
   305     // or we failed to split
   306     C->check_node_count(2*NodeLimitFudgeFactor, "out of nodes after physical split");
   307     if (C->failing())  return;
   309 #ifdef ASSERT
   310     if( VerifyOpto ) {
   311       _cfg.verify();
   312       verify_base_ptrs(&live_arena);
   313     }
   314 #endif
   315     NOT_PRODUCT( C->verify_graph_edges(); )
   317     compact();                  // Compact LRGs; return new lower max lrg
   319     {
   320       NOT_PRODUCT( Compile::TracePhase t3("computeLive", &_t_computeLive, TimeCompiler); )
   321       _live = NULL;
   322       rm.reset_to_mark();         // Reclaim working storage
   323       IndexSet::reset_memory(C, &live_arena);
   324       ifg.init(_maxlrg);          // Build a new interference graph
   325       gather_lrg_masks( true );   // Collect intersect mask
   326       live.compute( _maxlrg );    // Compute LIVE
   327       _live = &live;
   328     }
   329     build_ifg_physical( &live_arena );
   330     _ifg->SquareUp();
   331     _ifg->Compute_Effective_Degree();
   332     // Only do conservative coalescing if requested
   333     if( OptoCoalesce ) {
   334       // Conservative (and pessimistic) copy coalescing of those spills
   335       PhaseConservativeCoalesce coalesce( *this );
   336       // If max live ranges greater than cutoff, don't color the stack.
   337       // This cutoff can be larger than below since it is only done once.
   338       coalesce.coalesce_driver( );
   339     }
   340     compress_uf_map_for_nodes();
   342 #ifdef ASSERT
   343     if( VerifyOpto ) _ifg->verify(this);
   344 #endif
   345   } else {
   346     ifg.SquareUp();
   347     ifg.Compute_Effective_Degree();
   348 #ifdef ASSERT
   349     set_was_low();
   350 #endif
   351   }
   353   // Prepare for Simplify & Select
   354   cache_lrg_info();           // Count degree of LRGs
   356   // Simplify the InterFerence Graph by removing LRGs of low degree.
   357   // LRGs of low degree are trivially colorable.
   358   Simplify();
   360   // Select colors by re-inserting LRGs back into the IFG in reverse order.
   361   // Return whether or not something spills.
   362   uint spills = Select( );
   364   // If we spill, split and recycle the entire thing
   365   while( spills ) {
   366     if( _trip_cnt++ > 24 ) {
   367       DEBUG_ONLY( dump_for_spill_split_recycle(); )
   368       if( _trip_cnt > 27 ) {
   369         C->record_method_not_compilable("failed spill-split-recycle sanity check");
   370         return;
   371       }
   372     }
   374     if( !_maxlrg ) return;
   375     _maxlrg = Split( _maxlrg );        // Split spilling LRG everywhere
   376     // Bail out if unique gets too large (ie - unique > MaxNodeLimit - 2*NodeLimitFudgeFactor)
   377     C->check_node_count(2*NodeLimitFudgeFactor, "out of nodes after split");
   378     if (C->failing())  return;
   379 #ifdef ASSERT
   380     if( VerifyOpto ) {
   381       _cfg.verify();
   382       verify_base_ptrs(&live_arena);
   383     }
   384 #endif
   386     compact();                  // Compact LRGs; return new lower max lrg
   388     // Nuke the live-ness and interference graph and LiveRanGe info
   389     {
   390       NOT_PRODUCT( Compile::TracePhase t3("computeLive", &_t_computeLive, TimeCompiler); )
   391       _live = NULL;
   392       rm.reset_to_mark();         // Reclaim working storage
   393       IndexSet::reset_memory(C, &live_arena);
   394       ifg.init(_maxlrg);
   396       // Create LiveRanGe array.
   397       // Intersect register masks for all USEs and DEFs
   398       gather_lrg_masks( true );
   399       live.compute( _maxlrg );
   400       _live = &live;
   401     }
   402     must_spill = build_ifg_physical( &live_arena );
   403     _ifg->SquareUp();
   404     _ifg->Compute_Effective_Degree();
   406     // Only do conservative coalescing if requested
   407     if( OptoCoalesce ) {
   408       // Conservative (and pessimistic) copy coalescing
   409       PhaseConservativeCoalesce coalesce( *this );
   410       // Check for few live ranges determines how aggressive coalesce is.
   411       coalesce.coalesce_driver( );
   412     }
   413     compress_uf_map_for_nodes();
   414 #ifdef ASSERT
   415     if( VerifyOpto ) _ifg->verify(this);
   416 #endif
   417     cache_lrg_info();           // Count degree of LRGs
   419     // Simplify the InterFerence Graph by removing LRGs of low degree.
   420     // LRGs of low degree are trivially colorable.
   421     Simplify();
   423     // Select colors by re-inserting LRGs back into the IFG in reverse order.
   424     // Return whether or not something spills.
   425     spills = Select( );
   426   }
   428   // Count number of Simplify-Select trips per coloring success.
   429   _allocator_attempts += _trip_cnt + 1;
   430   _allocator_successes += 1;
   432   // Peephole remove copies
   433   post_allocate_copy_removal();
   435   // max_reg is past the largest *register* used.
   436   // Convert that to a frame_slot number.
   437   if( _max_reg <= _matcher._new_SP )
   438     _framesize = C->out_preserve_stack_slots();
   439   else _framesize = _max_reg -_matcher._new_SP;
   440   assert((int)(_matcher._new_SP+_framesize) >= (int)_matcher._out_arg_limit, "framesize must be large enough");
   442   // This frame must preserve the required fp alignment
   443   _framesize = round_to(_framesize, Matcher::stack_alignment_in_slots());
   444   assert( _framesize >= 0 && _framesize <= 1000000, "sanity check" );
   445 #ifndef PRODUCT
   446   _total_framesize += _framesize;
   447   if( (int)_framesize > _max_framesize )
   448     _max_framesize = _framesize;
   449 #endif
   451   // Convert CISC spills
   452   fixup_spills();
   454   // Log regalloc results
   455   CompileLog* log = Compile::current()->log();
   456   if (log != NULL) {
   457     log->elem("regalloc attempts='%d' success='%d'", _trip_cnt, !C->failing());
   458   }
   460   if (C->failing())  return;
   462   NOT_PRODUCT( C->verify_graph_edges(); )
   464   // Move important info out of the live_arena to longer lasting storage.
   465   alloc_node_regs(_names.Size());
   466   for( uint i=0; i < _names.Size(); i++ ) {
   467     if( _names[i] ) {           // Live range associated with Node?
   468       LRG &lrg = lrgs( _names[i] );
   469       if( lrg.num_regs() == 1 ) {
   470         _node_regs[i].set1( lrg.reg() );
   471       } else {                  // Must be a register-pair
   472         if( !lrg._fat_proj ) {  // Must be aligned adjacent register pair
   473           // Live ranges record the highest register in their mask.
   474           // We want the low register for the AD file writer's convenience.
   475           _node_regs[i].set2( OptoReg::add(lrg.reg(),-1) );
   476         } else {                // Misaligned; extract 2 bits
   477           OptoReg::Name hi = lrg.reg(); // Get hi register
   478           lrg.Remove(hi);       // Yank from mask
   479           int lo = lrg.mask().find_first_elem(); // Find lo
   480           _node_regs[i].set_pair( hi, lo );
   481         }
   482       }
   483       if( lrg._is_oop ) _node_oops.set(i);
   484     } else {
   485       _node_regs[i].set_bad();
   486     }
   487   }
   489   // Done!
   490   _live = NULL;
   491   _ifg = NULL;
   492   C->set_indexSet_arena(NULL);  // ResourceArea is at end of scope
   493 }
   495 //------------------------------de_ssa-----------------------------------------
   496 void PhaseChaitin::de_ssa() {
   497   // Set initial Names for all Nodes.  Most Nodes get the virtual register
   498   // number.  A few get the ZERO live range number.  These do not
   499   // get allocated, but instead rely on correct scheduling to ensure that
   500   // only one instance is simultaneously live at a time.
   501   uint lr_counter = 1;
   502   for( uint i = 0; i < _cfg._num_blocks; i++ ) {
   503     Block *b = _cfg._blocks[i];
   504     uint cnt = b->_nodes.size();
   506     // Handle all the normal Nodes in the block
   507     for( uint j = 0; j < cnt; j++ ) {
   508       Node *n = b->_nodes[j];
   509       // Pre-color to the zero live range, or pick virtual register
   510       const RegMask &rm = n->out_RegMask();
   511       _names.map( n->_idx, rm.is_NotEmpty() ? lr_counter++ : 0 );
   512     }
   513   }
   514   // Reset the Union-Find mapping to be identity
   515   reset_uf_map(lr_counter);
   516 }
   519 //------------------------------gather_lrg_masks-------------------------------
   520 // Gather LiveRanGe information, including register masks.  Modification of
   521 // cisc spillable in_RegMasks should not be done before AggressiveCoalesce.
   522 void PhaseChaitin::gather_lrg_masks( bool after_aggressive ) {
   524   // Nail down the frame pointer live range
   525   uint fp_lrg = n2lidx(_cfg._root->in(1)->in(TypeFunc::FramePtr));
   526   lrgs(fp_lrg)._cost += 1e12;   // Cost is infinite
   528   // For all blocks
   529   for( uint i = 0; i < _cfg._num_blocks; i++ ) {
   530     Block *b = _cfg._blocks[i];
   532     // For all instructions
   533     for( uint j = 1; j < b->_nodes.size(); j++ ) {
   534       Node *n = b->_nodes[j];
   535       uint input_edge_start =1; // Skip control most nodes
   536       if( n->is_Mach() ) input_edge_start = n->as_Mach()->oper_input_base();
   537       uint idx = n->is_Copy();
   539       // Get virtual register number, same as LiveRanGe index
   540       uint vreg = n2lidx(n);
   541       LRG &lrg = lrgs(vreg);
   542       if( vreg ) {              // No vreg means un-allocable (e.g. memory)
   544         // Collect has-copy bit
   545         if( idx ) {
   546           lrg._has_copy = 1;
   547           uint clidx = n2lidx(n->in(idx));
   548           LRG &copy_src = lrgs(clidx);
   549           copy_src._has_copy = 1;
   550         }
   552         // Check for float-vs-int live range (used in register-pressure
   553         // calculations)
   554         const Type *n_type = n->bottom_type();
   555         if( n_type->is_floatingpoint() )
   556           lrg._is_float = 1;
   558         // Check for twice prior spilling.  Once prior spilling might have
   559         // spilled 'soft', 2nd prior spill should have spilled 'hard' and
   560         // further spilling is unlikely to make progress.
   561         if( _spilled_once.test(n->_idx) ) {
   562           lrg._was_spilled1 = 1;
   563           if( _spilled_twice.test(n->_idx) )
   564             lrg._was_spilled2 = 1;
   565         }
   567 #ifndef PRODUCT
   568         if (trace_spilling() && lrg._def != NULL) {
   569           // collect defs for MultiDef printing
   570           if (lrg._defs == NULL) {
   571             lrg._defs = new (_ifg->_arena) GrowableArray<Node*>();
   572             lrg._defs->append(lrg._def);
   573           }
   574           lrg._defs->append(n);
   575         }
   576 #endif
   578         // Check for a single def LRG; these can spill nicely
   579         // via rematerialization.  Flag as NULL for no def found
   580         // yet, or 'n' for single def or -1 for many defs.
   581         lrg._def = lrg._def ? NodeSentinel : n;
   583         // Limit result register mask to acceptable registers
   584         const RegMask &rm = n->out_RegMask();
   585         lrg.AND( rm );
   586         // Check for bound register masks
   587         const RegMask &lrgmask = lrg.mask();
   588         if( lrgmask.is_bound1() || lrgmask.is_bound2() )
   589           lrg._is_bound = 1;
   591         // Check for maximum frequency value
   592         if( lrg._maxfreq < b->_freq )
   593           lrg._maxfreq = b->_freq;
   595         int ireg = n->ideal_reg();
   596         assert( !n->bottom_type()->isa_oop_ptr() || ireg == Op_RegP,
   597                 "oops must be in Op_RegP's" );
   598         // Check for oop-iness, or long/double
   599         // Check for multi-kill projection
   600         switch( ireg ) {
   601         case MachProjNode::fat_proj:
   602           // Fat projections have size equal to number of registers killed
   603           lrg.set_num_regs(rm.Size());
   604           lrg.set_reg_pressure(lrg.num_regs());
   605           lrg._fat_proj = 1;
   606           lrg._is_bound = 1;
   607           break;
   608         case Op_RegP:
   609 #ifdef _LP64
   610           lrg.set_num_regs(2);  // Size is 2 stack words
   611 #else
   612           lrg.set_num_regs(1);  // Size is 1 stack word
   613 #endif
   614           // Register pressure is tracked relative to the maximum values
   615           // suggested for that platform, INTPRESSURE and FLOATPRESSURE,
   616           // and relative to other types which compete for the same regs.
   617           //
   618           // The following table contains suggested values based on the
   619           // architectures as defined in each .ad file.
   620           // INTPRESSURE and FLOATPRESSURE may be tuned differently for
   621           // compile-speed or performance.
   622           // Note1:
   623           // SPARC and SPARCV9 reg_pressures are at 2 instead of 1
   624           // since .ad registers are defined as high and low halves.
   625           // These reg_pressure values remain compatible with the code
   626           // in is_high_pressure() which relates get_invalid_mask_size(),
   627           // Block::_reg_pressure and INTPRESSURE, FLOATPRESSURE.
   628           // Note2:
   629           // SPARC -d32 has 24 registers available for integral values,
   630           // but only 10 of these are safe for 64-bit longs.
   631           // Using set_reg_pressure(2) for both int and long means
   632           // the allocator will believe it can fit 26 longs into
   633           // registers.  Using 2 for longs and 1 for ints means the
   634           // allocator will attempt to put 52 integers into registers.
   635           // The settings below limit this problem to methods with
   636           // many long values which are being run on 32-bit SPARC.
   637           //
   638           // ------------------- reg_pressure --------------------
   639           // Each entry is reg_pressure_per_value,number_of_regs
   640           //         RegL  RegI  RegFlags   RegF RegD    INTPRESSURE  FLOATPRESSURE
   641           // IA32     2     1     1          1    1          6           6
   642           // IA64     1     1     1          1    1         50          41
   643           // SPARC    2     2     2          2    2         48 (24)     52 (26)
   644           // SPARCV9  2     2     2          2    2         48 (24)     52 (26)
   645           // AMD64    1     1     1          1    1         14          15
   646           // -----------------------------------------------------
   647 #if defined(SPARC)
   648           lrg.set_reg_pressure(2);  // use for v9 as well
   649 #else
   650           lrg.set_reg_pressure(1);  // normally one value per register
   651 #endif
   652           if( n_type->isa_oop_ptr() ) {
   653             lrg._is_oop = 1;
   654           }
   655           break;
   656         case Op_RegL:           // Check for long or double
   657         case Op_RegD:
   658           lrg.set_num_regs(2);
   659           // Define platform specific register pressure
   660 #ifdef SPARC
   661           lrg.set_reg_pressure(2);
   662 #elif defined(IA32)
   663           if( ireg == Op_RegL ) {
   664             lrg.set_reg_pressure(2);
   665           } else {
   666             lrg.set_reg_pressure(1);
   667           }
   668 #else
   669           lrg.set_reg_pressure(1);  // normally one value per register
   670 #endif
   671           // If this def of a double forces a mis-aligned double,
   672           // flag as '_fat_proj' - really flag as allowing misalignment
   673           // AND changes how we count interferences.  A mis-aligned
   674           // double can interfere with TWO aligned pairs, or effectively
   675           // FOUR registers!
   676           if( rm.is_misaligned_Pair() ) {
   677             lrg._fat_proj = 1;
   678             lrg._is_bound = 1;
   679           }
   680           break;
   681         case Op_RegF:
   682         case Op_RegI:
   683         case Op_RegN:
   684         case Op_RegFlags:
   685         case 0:                 // not an ideal register
   686           lrg.set_num_regs(1);
   687 #ifdef SPARC
   688           lrg.set_reg_pressure(2);
   689 #else
   690           lrg.set_reg_pressure(1);
   691 #endif
   692           break;
   693         default:
   694           ShouldNotReachHere();
   695         }
   696       }
   698       // Now do the same for inputs
   699       uint cnt = n->req();
   700       // Setup for CISC SPILLING
   701       uint inp = (uint)AdlcVMDeps::Not_cisc_spillable;
   702       if( UseCISCSpill && after_aggressive ) {
   703         inp = n->cisc_operand();
   704         if( inp != (uint)AdlcVMDeps::Not_cisc_spillable )
   705           // Convert operand number to edge index number
   706           inp = n->as_Mach()->operand_index(inp);
   707       }
   708       // Prepare register mask for each input
   709       for( uint k = input_edge_start; k < cnt; k++ ) {
   710         uint vreg = n2lidx(n->in(k));
   711         if( !vreg ) continue;
   713         // If this instruction is CISC Spillable, add the flags
   714         // bit to its appropriate input
   715         if( UseCISCSpill && after_aggressive && inp == k ) {
   716 #ifndef PRODUCT
   717           if( TraceCISCSpill ) {
   718             tty->print("  use_cisc_RegMask: ");
   719             n->dump();
   720           }
   721 #endif
   722           n->as_Mach()->use_cisc_RegMask();
   723         }
   725         LRG &lrg = lrgs(vreg);
   726         // // Testing for floating point code shape
   727         // Node *test = n->in(k);
   728         // if( test->is_Mach() ) {
   729         //   MachNode *m = test->as_Mach();
   730         //   int  op = m->ideal_Opcode();
   731         //   if (n->is_Call() && (op == Op_AddF || op == Op_MulF) ) {
   732         //     int zzz = 1;
   733         //   }
   734         // }
   736         // Limit result register mask to acceptable registers.
   737         // Do not limit registers from uncommon uses before
   738         // AggressiveCoalesce.  This effectively pre-virtual-splits
   739         // around uncommon uses of common defs.
   740         const RegMask &rm = n->in_RegMask(k);
   741         if( !after_aggressive &&
   742           _cfg._bbs[n->in(k)->_idx]->_freq > 1000*b->_freq ) {
   743           // Since we are BEFORE aggressive coalesce, leave the register
   744           // mask untrimmed by the call.  This encourages more coalescing.
   745           // Later, AFTER aggressive, this live range will have to spill
   746           // but the spiller handles slow-path calls very nicely.
   747         } else {
   748           lrg.AND( rm );
   749         }
   750         // Check for bound register masks
   751         const RegMask &lrgmask = lrg.mask();
   752         if( lrgmask.is_bound1() || lrgmask.is_bound2() )
   753           lrg._is_bound = 1;
   754         // If this use of a double forces a mis-aligned double,
   755         // flag as '_fat_proj' - really flag as allowing misalignment
   756         // AND changes how we count interferences.  A mis-aligned
   757         // double can interfere with TWO aligned pairs, or effectively
   758         // FOUR registers!
   759         if( lrg.num_regs() == 2 && !lrg._fat_proj && rm.is_misaligned_Pair() ) {
   760           lrg._fat_proj = 1;
   761           lrg._is_bound = 1;
   762         }
   763         // if the LRG is an unaligned pair, we will have to spill
   764         // so clear the LRG's register mask if it is not already spilled
   765         if ( !n->is_SpillCopy() &&
   766                (lrg._def == NULL || lrg.is_multidef() || !lrg._def->is_SpillCopy()) &&
   767                lrgmask.is_misaligned_Pair()) {
   768           lrg.Clear();
   769         }
   771         // Check for maximum frequency value
   772         if( lrg._maxfreq < b->_freq )
   773           lrg._maxfreq = b->_freq;
   775       } // End for all allocated inputs
   776     } // end for all instructions
   777   } // end for all blocks
   779   // Final per-liverange setup
   780   for( uint i2=0; i2<_maxlrg; i2++ ) {
   781     LRG &lrg = lrgs(i2);
   782     if( lrg.num_regs() == 2 && !lrg._fat_proj )
   783       lrg.ClearToPairs();
   784     lrg.compute_set_mask_size();
   785     if( lrg.not_free() ) {      // Handle case where we lose from the start
   786       lrg.set_reg(OptoReg::Name(LRG::SPILL_REG));
   787       lrg._direct_conflict = 1;
   788     }
   789     lrg.set_degree(0);          // no neighbors in IFG yet
   790   }
   791 }
   793 //------------------------------set_was_low------------------------------------
   794 // Set the was-lo-degree bit.  Conservative coalescing should not change the
   795 // colorability of the graph.  If any live range was of low-degree before
   796 // coalescing, it should Simplify.  This call sets the was-lo-degree bit.
   797 // The bit is checked in Simplify.
   798 void PhaseChaitin::set_was_low() {
   799 #ifdef ASSERT
   800   for( uint i = 1; i < _maxlrg; i++ ) {
   801     int size = lrgs(i).num_regs();
   802     uint old_was_lo = lrgs(i)._was_lo;
   803     lrgs(i)._was_lo = 0;
   804     if( lrgs(i).lo_degree() ) {
   805       lrgs(i)._was_lo = 1;      // Trivially of low degree
   806     } else {                    // Else check the Brigg's assertion
   807       // Brigg's observation is that the lo-degree neighbors of a
   808       // hi-degree live range will not interfere with the color choices
   809       // of said hi-degree live range.  The Simplify reverse-stack-coloring
   810       // order takes care of the details.  Hence you do not have to count
   811       // low-degree neighbors when determining if this guy colors.
   812       int briggs_degree = 0;
   813       IndexSet *s = _ifg->neighbors(i);
   814       IndexSetIterator elements(s);
   815       uint lidx;
   816       while((lidx = elements.next()) != 0) {
   817         if( !lrgs(lidx).lo_degree() )
   818           briggs_degree += MAX2(size,lrgs(lidx).num_regs());
   819       }
   820       if( briggs_degree < lrgs(i).degrees_of_freedom() )
   821         lrgs(i)._was_lo = 1;    // Low degree via the briggs assertion
   822     }
   823     assert(old_was_lo <= lrgs(i)._was_lo, "_was_lo may not decrease");
   824   }
   825 #endif
   826 }
   828 #define REGISTER_CONSTRAINED 16
   830 //------------------------------cache_lrg_info---------------------------------
   831 // Compute cost/area ratio, in case we spill.  Build the lo-degree list.
   832 void PhaseChaitin::cache_lrg_info( ) {
   834   for( uint i = 1; i < _maxlrg; i++ ) {
   835     LRG &lrg = lrgs(i);
   837     // Check for being of low degree: means we can be trivially colored.
   838     // Low degree, dead or must-spill guys just get to simplify right away
   839     if( lrg.lo_degree() ||
   840        !lrg.alive() ||
   841         lrg._must_spill ) {
   842       // Split low degree list into those guys that must get a
   843       // register and those that can go to register or stack.
   844       // The idea is LRGs that can go register or stack color first when
   845       // they have a good chance of getting a register.  The register-only
   846       // lo-degree live ranges always get a register.
   847       OptoReg::Name hi_reg = lrg.mask().find_last_elem();
   848       if( OptoReg::is_stack(hi_reg)) { // Can go to stack?
   849         lrg._next = _lo_stk_degree;
   850         _lo_stk_degree = i;
   851       } else {
   852         lrg._next = _lo_degree;
   853         _lo_degree = i;
   854       }
   855     } else {                    // Else high degree
   856       lrgs(_hi_degree)._prev = i;
   857       lrg._next = _hi_degree;
   858       lrg._prev = 0;
   859       _hi_degree = i;
   860     }
   861   }
   862 }
   864 //------------------------------Pre-Simplify-----------------------------------
   865 // Simplify the IFG by removing LRGs of low degree that have NO copies
   866 void PhaseChaitin::Pre_Simplify( ) {
   868   // Warm up the lo-degree no-copy list
   869   int lo_no_copy = 0;
   870   for( uint i = 1; i < _maxlrg; i++ ) {
   871     if( (lrgs(i).lo_degree() && !lrgs(i)._has_copy) ||
   872         !lrgs(i).alive() ||
   873         lrgs(i)._must_spill ) {
   874       lrgs(i)._next = lo_no_copy;
   875       lo_no_copy = i;
   876     }
   877   }
   879   while( lo_no_copy ) {
   880     uint lo = lo_no_copy;
   881     lo_no_copy = lrgs(lo)._next;
   882     int size = lrgs(lo).num_regs();
   884     // Put the simplified guy on the simplified list.
   885     lrgs(lo)._next = _simplified;
   886     _simplified = lo;
   888     // Yank this guy from the IFG.
   889     IndexSet *adj = _ifg->remove_node( lo );
   891     // If any neighbors' degrees fall below their number of
   892     // allowed registers, then put that neighbor on the low degree
   893     // list.  Note that 'degree' can only fall and 'numregs' is
   894     // unchanged by this action.  Thus the two are equal at most once,
   895     // so LRGs hit the lo-degree worklists at most once.
   896     IndexSetIterator elements(adj);
   897     uint neighbor;
   898     while ((neighbor = elements.next()) != 0) {
   899       LRG *n = &lrgs(neighbor);
   900       assert( _ifg->effective_degree(neighbor) == n->degree(), "" );
   902       // Check for just becoming of-low-degree
   903       if( n->just_lo_degree() && !n->_has_copy ) {
   904         assert(!(*_ifg->_yanked)[neighbor],"Cannot move to lo degree twice");
   905         // Put on lo-degree list
   906         n->_next = lo_no_copy;
   907         lo_no_copy = neighbor;
   908       }
   909     }
   910   } // End of while lo-degree no_copy worklist not empty
   912   // No more lo-degree no-copy live ranges to simplify
   913 }
   915 //------------------------------Simplify---------------------------------------
   916 // Simplify the IFG by removing LRGs of low degree.
   917 void PhaseChaitin::Simplify( ) {
   919   while( 1 ) {                  // Repeat till simplified it all
   920     // May want to explore simplifying lo_degree before _lo_stk_degree.
   921     // This might result in more spills coloring into registers during
   922     // Select().
   923     while( _lo_degree || _lo_stk_degree ) {
   924       // If possible, pull from lo_stk first
   925       uint lo;
   926       if( _lo_degree ) {
   927         lo = _lo_degree;
   928         _lo_degree = lrgs(lo)._next;
   929       } else {
   930         lo = _lo_stk_degree;
   931         _lo_stk_degree = lrgs(lo)._next;
   932       }
   934       // Put the simplified guy on the simplified list.
   935       lrgs(lo)._next = _simplified;
   936       _simplified = lo;
   937       // If this guy is "at risk" then mark his current neighbors
   938       if( lrgs(lo)._at_risk ) {
   939         IndexSetIterator elements(_ifg->neighbors(lo));
   940         uint datum;
   941         while ((datum = elements.next()) != 0) {
   942           lrgs(datum)._risk_bias = lo;
   943         }
   944       }
   946       // Yank this guy from the IFG.
   947       IndexSet *adj = _ifg->remove_node( lo );
   949       // If any neighbors' degrees fall below their number of
   950       // allowed registers, then put that neighbor on the low degree
   951       // list.  Note that 'degree' can only fall and 'numregs' is
   952       // unchanged by this action.  Thus the two are equal at most once,
   953       // so LRGs hit the lo-degree worklist at most once.
   954       IndexSetIterator elements(adj);
   955       uint neighbor;
   956       while ((neighbor = elements.next()) != 0) {
   957         LRG *n = &lrgs(neighbor);
   958 #ifdef ASSERT
   959         if( VerifyOpto ) {
   960           assert( _ifg->effective_degree(neighbor) == n->degree(), "" );
   961         }
   962 #endif
   964         // Check for just becoming of-low-degree just counting registers.
   965         // _must_spill live ranges are already on the low degree list.
   966         if( n->just_lo_degree() && !n->_must_spill ) {
   967           assert(!(*_ifg->_yanked)[neighbor],"Cannot move to lo degree twice");
   968           // Pull from hi-degree list
   969           uint prev = n->_prev;
   970           uint next = n->_next;
   971           if( prev ) lrgs(prev)._next = next;
   972           else _hi_degree = next;
   973           lrgs(next)._prev = prev;
   974           n->_next = _lo_degree;
   975           _lo_degree = neighbor;
   976         }
   977       }
   978     } // End of while lo-degree/lo_stk_degree worklist not empty
   980     // Check for got everything: is hi-degree list empty?
   981     if( !_hi_degree ) break;
   983     // Time to pick a potential spill guy
   984     uint lo_score = _hi_degree;
   985     double score = lrgs(lo_score).score();
   986     double area = lrgs(lo_score)._area;
   988     // Find cheapest guy
   989     debug_only( int lo_no_simplify=0; );
   990     for( uint i = _hi_degree; i; i = lrgs(i)._next ) {
   991       assert( !(*_ifg->_yanked)[i], "" );
   992       // It's just vaguely possible to move hi-degree to lo-degree without
   993       // going through a just-lo-degree stage: If you remove a double from
   994       // a float live range it's degree will drop by 2 and you can skip the
   995       // just-lo-degree stage.  It's very rare (shows up after 5000+ methods
   996       // in -Xcomp of Java2Demo).  So just choose this guy to simplify next.
   997       if( lrgs(i).lo_degree() ) {
   998         lo_score = i;
   999         break;
  1001       debug_only( if( lrgs(i)._was_lo ) lo_no_simplify=i; );
  1002       double iscore = lrgs(i).score();
  1003       double iarea = lrgs(i)._area;
  1005       // Compare cost/area of i vs cost/area of lo_score.  Smaller cost/area
  1006       // wins.  Ties happen because all live ranges in question have spilled
  1007       // a few times before and the spill-score adds a huge number which
  1008       // washes out the low order bits.  We are choosing the lesser of 2
  1009       // evils; in this case pick largest area to spill.
  1010       if( iscore < score ||
  1011           (iscore == score && iarea > area && lrgs(lo_score)._was_spilled2) ) {
  1012         lo_score = i;
  1013         score = iscore;
  1014         area = iarea;
  1017     LRG *lo_lrg = &lrgs(lo_score);
  1018     // The live range we choose for spilling is either hi-degree, or very
  1019     // rarely it can be low-degree.  If we choose a hi-degree live range
  1020     // there better not be any lo-degree choices.
  1021     assert( lo_lrg->lo_degree() || !lo_no_simplify, "Live range was lo-degree before coalesce; should simplify" );
  1023     // Pull from hi-degree list
  1024     uint prev = lo_lrg->_prev;
  1025     uint next = lo_lrg->_next;
  1026     if( prev ) lrgs(prev)._next = next;
  1027     else _hi_degree = next;
  1028     lrgs(next)._prev = prev;
  1029     // Jam him on the lo-degree list, despite his high degree.
  1030     // Maybe he'll get a color, and maybe he'll spill.
  1031     // Only Select() will know.
  1032     lrgs(lo_score)._at_risk = true;
  1033     _lo_degree = lo_score;
  1034     lo_lrg->_next = 0;
  1036   } // End of while not simplified everything
  1040 //------------------------------bias_color-------------------------------------
  1041 // Choose a color using the biasing heuristic
  1042 OptoReg::Name PhaseChaitin::bias_color( LRG &lrg, int chunk ) {
  1044   // Check for "at_risk" LRG's
  1045   uint risk_lrg = Find(lrg._risk_bias);
  1046   if( risk_lrg != 0 ) {
  1047     // Walk the colored neighbors of the "at_risk" candidate
  1048     // Choose a color which is both legal and already taken by a neighbor
  1049     // of the "at_risk" candidate in order to improve the chances of the
  1050     // "at_risk" candidate of coloring
  1051     IndexSetIterator elements(_ifg->neighbors(risk_lrg));
  1052     uint datum;
  1053     while ((datum = elements.next()) != 0) {
  1054       OptoReg::Name reg = lrgs(datum).reg();
  1055       // If this LRG's register is legal for us, choose it
  1056       if( reg >= chunk && reg < chunk + RegMask::CHUNK_SIZE &&
  1057           lrg.mask().Member(OptoReg::add(reg,-chunk)) &&
  1058           (lrg.num_regs()==1 || // either size 1
  1059            (reg&1) == 1) )      // or aligned (adjacent reg is available since we already cleared-to-pairs)
  1060         return reg;
  1064   uint copy_lrg = Find(lrg._copy_bias);
  1065   if( copy_lrg != 0 ) {
  1066     // If he has a color,
  1067     if( !(*(_ifg->_yanked))[copy_lrg] ) {
  1068       OptoReg::Name reg = lrgs(copy_lrg).reg();
  1069       //  And it is legal for you,
  1070       if( reg >= chunk && reg < chunk + RegMask::CHUNK_SIZE &&
  1071           lrg.mask().Member(OptoReg::add(reg,-chunk)) &&
  1072           (lrg.num_regs()==1 || // either size 1
  1073            (reg&1) == 1) )      // or aligned (adjacent reg is available since we already cleared-to-pairs)
  1074         return reg;
  1075     } else if( chunk == 0 ) {
  1076       // Choose a color which is legal for him
  1077       RegMask tempmask = lrg.mask();
  1078       tempmask.AND(lrgs(copy_lrg).mask());
  1079       OptoReg::Name reg;
  1080       if( lrg.num_regs() == 1 ) {
  1081         reg = tempmask.find_first_elem();
  1082       } else {
  1083         tempmask.ClearToPairs();
  1084         reg = tempmask.find_first_pair();
  1086       if( OptoReg::is_valid(reg) )
  1087         return reg;
  1091   // If no bias info exists, just go with the register selection ordering
  1092   if( lrg.num_regs() == 2 ) {
  1093     // Find an aligned pair
  1094     return OptoReg::add(lrg.mask().find_first_pair(),chunk);
  1097   // CNC - Fun hack.  Alternate 1st and 2nd selection.  Enables post-allocate
  1098   // copy removal to remove many more copies, by preventing a just-assigned
  1099   // register from being repeatedly assigned.
  1100   OptoReg::Name reg = lrg.mask().find_first_elem();
  1101   if( (++_alternate & 1) && OptoReg::is_valid(reg) ) {
  1102     // This 'Remove; find; Insert' idiom is an expensive way to find the
  1103     // SECOND element in the mask.
  1104     lrg.Remove(reg);
  1105     OptoReg::Name reg2 = lrg.mask().find_first_elem();
  1106     lrg.Insert(reg);
  1107     if( OptoReg::is_reg(reg2))
  1108       reg = reg2;
  1110   return OptoReg::add( reg, chunk );
  1113 //------------------------------choose_color-----------------------------------
  1114 // Choose a color in the current chunk
  1115 OptoReg::Name PhaseChaitin::choose_color( LRG &lrg, int chunk ) {
  1116   assert( C->in_preserve_stack_slots() == 0 || chunk != 0 || lrg._is_bound || lrg.mask().is_bound1() || !lrg.mask().Member(OptoReg::Name(_matcher._old_SP-1)), "must not allocate stack0 (inside preserve area)");
  1117   assert(C->out_preserve_stack_slots() == 0 || chunk != 0 || lrg._is_bound || lrg.mask().is_bound1() || !lrg.mask().Member(OptoReg::Name(_matcher._old_SP+0)), "must not allocate stack0 (inside preserve area)");
  1119   if( lrg.num_regs() == 1 ||    // Common Case
  1120       !lrg._fat_proj )          // Aligned+adjacent pairs ok
  1121     // Use a heuristic to "bias" the color choice
  1122     return bias_color(lrg, chunk);
  1124   assert( lrg.num_regs() >= 2, "dead live ranges do not color" );
  1126   // Fat-proj case or misaligned double argument.
  1127   assert(lrg.compute_mask_size() == lrg.num_regs() ||
  1128          lrg.num_regs() == 2,"fat projs exactly color" );
  1129   assert( !chunk, "always color in 1st chunk" );
  1130   // Return the highest element in the set.
  1131   return lrg.mask().find_last_elem();
  1134 //------------------------------Select-----------------------------------------
  1135 // Select colors by re-inserting LRGs back into the IFG.  LRGs are re-inserted
  1136 // in reverse order of removal.  As long as nothing of hi-degree was yanked,
  1137 // everything going back is guaranteed a color.  Select that color.  If some
  1138 // hi-degree LRG cannot get a color then we record that we must spill.
  1139 uint PhaseChaitin::Select( ) {
  1140   uint spill_reg = LRG::SPILL_REG;
  1141   _max_reg = OptoReg::Name(0);  // Past max register used
  1142   while( _simplified ) {
  1143     // Pull next LRG from the simplified list - in reverse order of removal
  1144     uint lidx = _simplified;
  1145     LRG *lrg = &lrgs(lidx);
  1146     _simplified = lrg->_next;
  1149 #ifndef PRODUCT
  1150     if (trace_spilling()) {
  1151       ttyLocker ttyl;
  1152       tty->print_cr("L%d selecting degree %d degrees_of_freedom %d", lidx, lrg->degree(),
  1153                     lrg->degrees_of_freedom());
  1154       lrg->dump();
  1156 #endif
  1158     // Re-insert into the IFG
  1159     _ifg->re_insert(lidx);
  1160     if( !lrg->alive() ) continue;
  1161     // capture allstackedness flag before mask is hacked
  1162     const int is_allstack = lrg->mask().is_AllStack();
  1164     // Yeah, yeah, yeah, I know, I know.  I can refactor this
  1165     // to avoid the GOTO, although the refactored code will not
  1166     // be much clearer.  We arrive here IFF we have a stack-based
  1167     // live range that cannot color in the current chunk, and it
  1168     // has to move into the next free stack chunk.
  1169     int chunk = 0;              // Current chunk is first chunk
  1170     retry_next_chunk:
  1172     // Remove neighbor colors
  1173     IndexSet *s = _ifg->neighbors(lidx);
  1175     debug_only(RegMask orig_mask = lrg->mask();)
  1176     IndexSetIterator elements(s);
  1177     uint neighbor;
  1178     while ((neighbor = elements.next()) != 0) {
  1179       // Note that neighbor might be a spill_reg.  In this case, exclusion
  1180       // of its color will be a no-op, since the spill_reg chunk is in outer
  1181       // space.  Also, if neighbor is in a different chunk, this exclusion
  1182       // will be a no-op.  (Later on, if lrg runs out of possible colors in
  1183       // its chunk, a new chunk of color may be tried, in which case
  1184       // examination of neighbors is started again, at retry_next_chunk.)
  1185       LRG &nlrg = lrgs(neighbor);
  1186       OptoReg::Name nreg = nlrg.reg();
  1187       // Only subtract masks in the same chunk
  1188       if( nreg >= chunk && nreg < chunk + RegMask::CHUNK_SIZE ) {
  1189 #ifndef PRODUCT
  1190         uint size = lrg->mask().Size();
  1191         RegMask rm = lrg->mask();
  1192 #endif
  1193         lrg->SUBTRACT(nlrg.mask());
  1194 #ifndef PRODUCT
  1195         if (trace_spilling() && lrg->mask().Size() != size) {
  1196           ttyLocker ttyl;
  1197           tty->print("L%d ", lidx);
  1198           rm.dump();
  1199           tty->print(" intersected L%d ", neighbor);
  1200           nlrg.mask().dump();
  1201           tty->print(" removed ");
  1202           rm.SUBTRACT(lrg->mask());
  1203           rm.dump();
  1204           tty->print(" leaving ");
  1205           lrg->mask().dump();
  1206           tty->cr();
  1208 #endif
  1211     //assert(is_allstack == lrg->mask().is_AllStack(), "nbrs must not change AllStackedness");
  1212     // Aligned pairs need aligned masks
  1213     if( lrg->num_regs() == 2 && !lrg->_fat_proj )
  1214       lrg->ClearToPairs();
  1216     // Check if a color is available and if so pick the color
  1217     OptoReg::Name reg = choose_color( *lrg, chunk );
  1218 #ifdef SPARC
  1219     debug_only(lrg->compute_set_mask_size());
  1220     assert(lrg->num_regs() != 2 || lrg->is_bound() || is_even(reg-1), "allocate all doubles aligned");
  1221 #endif
  1223     //---------------
  1224     // If we fail to color and the AllStack flag is set, trigger
  1225     // a chunk-rollover event
  1226     if(!OptoReg::is_valid(OptoReg::add(reg,-chunk)) && is_allstack) {
  1227       // Bump register mask up to next stack chunk
  1228       chunk += RegMask::CHUNK_SIZE;
  1229       lrg->Set_All();
  1231       goto retry_next_chunk;
  1234     //---------------
  1235     // Did we get a color?
  1236     else if( OptoReg::is_valid(reg)) {
  1237 #ifndef PRODUCT
  1238       RegMask avail_rm = lrg->mask();
  1239 #endif
  1241       // Record selected register
  1242       lrg->set_reg(reg);
  1244       if( reg >= _max_reg )     // Compute max register limit
  1245         _max_reg = OptoReg::add(reg,1);
  1246       // Fold reg back into normal space
  1247       reg = OptoReg::add(reg,-chunk);
  1249       // If the live range is not bound, then we actually had some choices
  1250       // to make.  In this case, the mask has more bits in it than the colors
  1251       // choosen.  Restrict the mask to just what was picked.
  1252       if( lrg->num_regs() == 1 ) { // Size 1 live range
  1253         lrg->Clear();           // Clear the mask
  1254         lrg->Insert(reg);       // Set regmask to match selected reg
  1255         lrg->set_mask_size(1);
  1256       } else if( !lrg->_fat_proj ) {
  1257         // For pairs, also insert the low bit of the pair
  1258         assert( lrg->num_regs() == 2, "unbound fatproj???" );
  1259         lrg->Clear();           // Clear the mask
  1260         lrg->Insert(reg);       // Set regmask to match selected reg
  1261         lrg->Insert(OptoReg::add(reg,-1));
  1262         lrg->set_mask_size(2);
  1263       } else {                  // Else fatproj
  1264         // mask must be equal to fatproj bits, by definition
  1266 #ifndef PRODUCT
  1267       if (trace_spilling()) {
  1268         ttyLocker ttyl;
  1269         tty->print("L%d selected ", lidx);
  1270         lrg->mask().dump();
  1271         tty->print(" from ");
  1272         avail_rm.dump();
  1273         tty->cr();
  1275 #endif
  1276       // Note that reg is the highest-numbered register in the newly-bound mask.
  1277     } // end color available case
  1279     //---------------
  1280     // Live range is live and no colors available
  1281     else {
  1282       assert( lrg->alive(), "" );
  1283       assert( !lrg->_fat_proj || lrg->is_multidef() ||
  1284               lrg->_def->outcnt() > 0, "fat_proj cannot spill");
  1285       assert( !orig_mask.is_AllStack(), "All Stack does not spill" );
  1287       // Assign the special spillreg register
  1288       lrg->set_reg(OptoReg::Name(spill_reg++));
  1289       // Do not empty the regmask; leave mask_size lying around
  1290       // for use during Spilling
  1291 #ifndef PRODUCT
  1292       if( trace_spilling() ) {
  1293         ttyLocker ttyl;
  1294         tty->print("L%d spilling with neighbors: ", lidx);
  1295         s->dump();
  1296         debug_only(tty->print(" original mask: "));
  1297         debug_only(orig_mask.dump());
  1298         dump_lrg(lidx);
  1300 #endif
  1301     } // end spill case
  1305   return spill_reg-LRG::SPILL_REG;      // Return number of spills
  1309 //------------------------------copy_was_spilled-------------------------------
  1310 // Copy 'was_spilled'-edness from the source Node to the dst Node.
  1311 void PhaseChaitin::copy_was_spilled( Node *src, Node *dst ) {
  1312   if( _spilled_once.test(src->_idx) ) {
  1313     _spilled_once.set(dst->_idx);
  1314     lrgs(Find(dst))._was_spilled1 = 1;
  1315     if( _spilled_twice.test(src->_idx) ) {
  1316       _spilled_twice.set(dst->_idx);
  1317       lrgs(Find(dst))._was_spilled2 = 1;
  1322 //------------------------------set_was_spilled--------------------------------
  1323 // Set the 'spilled_once' or 'spilled_twice' flag on a node.
  1324 void PhaseChaitin::set_was_spilled( Node *n ) {
  1325   if( _spilled_once.test_set(n->_idx) )
  1326     _spilled_twice.set(n->_idx);
  1329 //------------------------------fixup_spills-----------------------------------
  1330 // Convert Ideal spill instructions into proper FramePtr + offset Loads and
  1331 // Stores.  Use-def chains are NOT preserved, but Node->LRG->reg maps are.
  1332 void PhaseChaitin::fixup_spills() {
  1333   // This function does only cisc spill work.
  1334   if( !UseCISCSpill ) return;
  1336   NOT_PRODUCT( Compile::TracePhase t3("fixupSpills", &_t_fixupSpills, TimeCompiler); )
  1338   // Grab the Frame Pointer
  1339   Node *fp = _cfg._broot->head()->in(1)->in(TypeFunc::FramePtr);
  1341   // For all blocks
  1342   for( uint i = 0; i < _cfg._num_blocks; i++ ) {
  1343     Block *b = _cfg._blocks[i];
  1345     // For all instructions in block
  1346     uint last_inst = b->end_idx();
  1347     for( uint j = 1; j <= last_inst; j++ ) {
  1348       Node *n = b->_nodes[j];
  1350       // Dead instruction???
  1351       assert( n->outcnt() != 0 ||// Nothing dead after post alloc
  1352               C->top() == n ||  // Or the random TOP node
  1353               n->is_Proj(),     // Or a fat-proj kill node
  1354               "No dead instructions after post-alloc" );
  1356       int inp = n->cisc_operand();
  1357       if( inp != AdlcVMDeps::Not_cisc_spillable ) {
  1358         // Convert operand number to edge index number
  1359         MachNode *mach = n->as_Mach();
  1360         inp = mach->operand_index(inp);
  1361         Node *src = n->in(inp);   // Value to load or store
  1362         LRG &lrg_cisc = lrgs( Find_const(src) );
  1363         OptoReg::Name src_reg = lrg_cisc.reg();
  1364         // Doubles record the HIGH register of an adjacent pair.
  1365         src_reg = OptoReg::add(src_reg,1-lrg_cisc.num_regs());
  1366         if( OptoReg::is_stack(src_reg) ) { // If input is on stack
  1367           // This is a CISC Spill, get stack offset and construct new node
  1368 #ifndef PRODUCT
  1369           if( TraceCISCSpill ) {
  1370             tty->print("    reg-instr:  ");
  1371             n->dump();
  1373 #endif
  1374           int stk_offset = reg2offset(src_reg);
  1375           // Bailout if we might exceed node limit when spilling this instruction
  1376           C->check_node_count(0, "out of nodes fixing spills");
  1377           if (C->failing())  return;
  1378           // Transform node
  1379           MachNode *cisc = mach->cisc_version(stk_offset, C)->as_Mach();
  1380           cisc->set_req(inp,fp);          // Base register is frame pointer
  1381           if( cisc->oper_input_base() > 1 && mach->oper_input_base() <= 1 ) {
  1382             assert( cisc->oper_input_base() == 2, "Only adding one edge");
  1383             cisc->ins_req(1,src);         // Requires a memory edge
  1385           b->_nodes.map(j,cisc);          // Insert into basic block
  1386           n->subsume_by(cisc); // Correct graph
  1387           //
  1388           ++_used_cisc_instructions;
  1389 #ifndef PRODUCT
  1390           if( TraceCISCSpill ) {
  1391             tty->print("    cisc-instr: ");
  1392             cisc->dump();
  1394 #endif
  1395         } else {
  1396 #ifndef PRODUCT
  1397           if( TraceCISCSpill ) {
  1398             tty->print("    using reg-instr: ");
  1399             n->dump();
  1401 #endif
  1402           ++_unused_cisc_instructions;    // input can be on stack
  1406     } // End of for all instructions
  1408   } // End of for all blocks
  1411 //------------------------------find_base_for_derived--------------------------
  1412 // Helper to stretch above; recursively discover the base Node for a
  1413 // given derived Node.  Easy for AddP-related machine nodes, but needs
  1414 // to be recursive for derived Phis.
  1415 Node *PhaseChaitin::find_base_for_derived( Node **derived_base_map, Node *derived, uint &maxlrg ) {
  1416   // See if already computed; if so return it
  1417   if( derived_base_map[derived->_idx] )
  1418     return derived_base_map[derived->_idx];
  1420   // See if this happens to be a base.
  1421   // NOTE: we use TypePtr instead of TypeOopPtr because we can have
  1422   // pointers derived from NULL!  These are always along paths that
  1423   // can't happen at run-time but the optimizer cannot deduce it so
  1424   // we have to handle it gracefully.
  1425   const TypePtr *tj = derived->bottom_type()->isa_ptr();
  1426   // If its an OOP with a non-zero offset, then it is derived.
  1427   if( tj->_offset == 0 ) {
  1428     derived_base_map[derived->_idx] = derived;
  1429     return derived;
  1431   // Derived is NULL+offset?  Base is NULL!
  1432   if( derived->is_Con() ) {
  1433     Node *base = new (C, 1) ConPNode( TypePtr::NULL_PTR );
  1434     uint no_lidx = 0;  // an unmatched constant in debug info has no LRG
  1435     _names.extend(base->_idx, no_lidx);
  1436     derived_base_map[derived->_idx] = base;
  1437     return base;
  1440   // Check for AddP-related opcodes
  1441   if( !derived->is_Phi() ) {
  1442     assert( derived->as_Mach()->ideal_Opcode() == Op_AddP, "" );
  1443     Node *base = derived->in(AddPNode::Base);
  1444     derived_base_map[derived->_idx] = base;
  1445     return base;
  1448   // Recursively find bases for Phis.
  1449   // First check to see if we can avoid a base Phi here.
  1450   Node *base = find_base_for_derived( derived_base_map, derived->in(1),maxlrg);
  1451   uint i;
  1452   for( i = 2; i < derived->req(); i++ )
  1453     if( base != find_base_for_derived( derived_base_map,derived->in(i),maxlrg))
  1454       break;
  1455   // Went to the end without finding any different bases?
  1456   if( i == derived->req() ) {   // No need for a base Phi here
  1457     derived_base_map[derived->_idx] = base;
  1458     return base;
  1461   // Now we see we need a base-Phi here to merge the bases
  1462   base = new (C, derived->req()) PhiNode( derived->in(0), base->bottom_type() );
  1463   for( i = 1; i < derived->req(); i++ )
  1464     base->init_req(i, find_base_for_derived(derived_base_map, derived->in(i), maxlrg));
  1466   // Search the current block for an existing base-Phi
  1467   Block *b = _cfg._bbs[derived->_idx];
  1468   for( i = 1; i <= b->end_idx(); i++ ) {// Search for matching Phi
  1469     Node *phi = b->_nodes[i];
  1470     if( !phi->is_Phi() ) {      // Found end of Phis with no match?
  1471       b->_nodes.insert( i, base ); // Must insert created Phi here as base
  1472       _cfg._bbs.map( base->_idx, b );
  1473       new_lrg(base,maxlrg++);
  1474       break;
  1476     // See if Phi matches.
  1477     uint j;
  1478     for( j = 1; j < base->req(); j++ )
  1479       if( phi->in(j) != base->in(j) &&
  1480           !(phi->in(j)->is_Con() && base->in(j)->is_Con()) ) // allow different NULLs
  1481         break;
  1482     if( j == base->req() ) {    // All inputs match?
  1483       base = phi;               // Then use existing 'phi' and drop 'base'
  1484       break;
  1489   // Cache info for later passes
  1490   derived_base_map[derived->_idx] = base;
  1491   return base;
  1495 //------------------------------stretch_base_pointer_live_ranges---------------
  1496 // At each Safepoint, insert extra debug edges for each pair of derived value/
  1497 // base pointer that is live across the Safepoint for oopmap building.  The
  1498 // edge pairs get added in after sfpt->jvmtail()->oopoff(), but are in the
  1499 // required edge set.
  1500 bool PhaseChaitin::stretch_base_pointer_live_ranges( ResourceArea *a ) {
  1501   int must_recompute_live = false;
  1502   uint maxlrg = _maxlrg;
  1503   Node **derived_base_map = (Node**)a->Amalloc(sizeof(Node*)*C->unique());
  1504   memset( derived_base_map, 0, sizeof(Node*)*C->unique() );
  1506   // For all blocks in RPO do...
  1507   for( uint i=0; i<_cfg._num_blocks; i++ ) {
  1508     Block *b = _cfg._blocks[i];
  1509     // Note use of deep-copy constructor.  I cannot hammer the original
  1510     // liveout bits, because they are needed by the following coalesce pass.
  1511     IndexSet liveout(_live->live(b));
  1513     for( uint j = b->end_idx() + 1; j > 1; j-- ) {
  1514       Node *n = b->_nodes[j-1];
  1516       // Pre-split compares of loop-phis.  Loop-phis form a cycle we would
  1517       // like to see in the same register.  Compare uses the loop-phi and so
  1518       // extends its live range BUT cannot be part of the cycle.  If this
  1519       // extended live range overlaps with the update of the loop-phi value
  1520       // we need both alive at the same time -- which requires at least 1
  1521       // copy.  But because Intel has only 2-address registers we end up with
  1522       // at least 2 copies, one before the loop-phi update instruction and
  1523       // one after.  Instead we split the input to the compare just after the
  1524       // phi.
  1525       if( n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_CmpI ) {
  1526         Node *phi = n->in(1);
  1527         if( phi->is_Phi() && phi->as_Phi()->region()->is_Loop() ) {
  1528           Block *phi_block = _cfg._bbs[phi->_idx];
  1529           if( _cfg._bbs[phi_block->pred(2)->_idx] == b ) {
  1530             const RegMask *mask = C->matcher()->idealreg2spillmask[Op_RegI];
  1531             Node *spill = new (C) MachSpillCopyNode( phi, *mask, *mask );
  1532             insert_proj( phi_block, 1, spill, maxlrg++ );
  1533             n->set_req(1,spill);
  1534             must_recompute_live = true;
  1539       // Get value being defined
  1540       uint lidx = n2lidx(n);
  1541       if( lidx && lidx < _maxlrg /* Ignore the occasional brand-new live range */) {
  1542         // Remove from live-out set
  1543         liveout.remove(lidx);
  1545         // Copies do not define a new value and so do not interfere.
  1546         // Remove the copies source from the liveout set before interfering.
  1547         uint idx = n->is_Copy();
  1548         if( idx ) liveout.remove( n2lidx(n->in(idx)) );
  1551       // Found a safepoint?
  1552       JVMState *jvms = n->jvms();
  1553       if( jvms ) {
  1554         // Now scan for a live derived pointer
  1555         IndexSetIterator elements(&liveout);
  1556         uint neighbor;
  1557         while ((neighbor = elements.next()) != 0) {
  1558           // Find reaching DEF for base and derived values
  1559           // This works because we are still in SSA during this call.
  1560           Node *derived = lrgs(neighbor)._def;
  1561           const TypePtr *tj = derived->bottom_type()->isa_ptr();
  1562           // If its an OOP with a non-zero offset, then it is derived.
  1563           if( tj && tj->_offset != 0 && tj->isa_oop_ptr() ) {
  1564             Node *base = find_base_for_derived( derived_base_map, derived, maxlrg );
  1565             assert( base->_idx < _names.Size(), "" );
  1566             // Add reaching DEFs of derived pointer and base pointer as a
  1567             // pair of inputs
  1568             n->add_req( derived );
  1569             n->add_req( base );
  1571             // See if the base pointer is already live to this point.
  1572             // Since I'm working on the SSA form, live-ness amounts to
  1573             // reaching def's.  So if I find the base's live range then
  1574             // I know the base's def reaches here.
  1575             if( (n2lidx(base) >= _maxlrg ||// (Brand new base (hence not live) or
  1576                  !liveout.member( n2lidx(base) ) ) && // not live) AND
  1577                  (n2lidx(base) > 0)                && // not a constant
  1578                  _cfg._bbs[base->_idx] != b ) {     //  base not def'd in blk)
  1579               // Base pointer is not currently live.  Since I stretched
  1580               // the base pointer to here and it crosses basic-block
  1581               // boundaries, the global live info is now incorrect.
  1582               // Recompute live.
  1583               must_recompute_live = true;
  1584             } // End of if base pointer is not live to debug info
  1586         } // End of scan all live data for derived ptrs crossing GC point
  1587       } // End of if found a GC point
  1589       // Make all inputs live
  1590       if( !n->is_Phi() ) {      // Phi function uses come from prior block
  1591         for( uint k = 1; k < n->req(); k++ ) {
  1592           uint lidx = n2lidx(n->in(k));
  1593           if( lidx < _maxlrg )
  1594             liveout.insert( lidx );
  1598     } // End of forall instructions in block
  1599     liveout.clear();  // Free the memory used by liveout.
  1601   } // End of forall blocks
  1602   _maxlrg = maxlrg;
  1604   // If I created a new live range I need to recompute live
  1605   if( maxlrg != _ifg->_maxlrg )
  1606     must_recompute_live = true;
  1608   return must_recompute_live != 0;
  1612 //------------------------------add_reference----------------------------------
  1613 // Extend the node to LRG mapping
  1614 void PhaseChaitin::add_reference( const Node *node, const Node *old_node ) {
  1615   _names.extend( node->_idx, n2lidx(old_node) );
  1618 //------------------------------dump-------------------------------------------
  1619 #ifndef PRODUCT
  1620 void PhaseChaitin::dump( const Node *n ) const {
  1621   uint r = (n->_idx < _names.Size() ) ? Find_const(n) : 0;
  1622   tty->print("L%d",r);
  1623   if( r && n->Opcode() != Op_Phi ) {
  1624     if( _node_regs ) {          // Got a post-allocation copy of allocation?
  1625       tty->print("[");
  1626       OptoReg::Name second = get_reg_second(n);
  1627       if( OptoReg::is_valid(second) ) {
  1628         if( OptoReg::is_reg(second) )
  1629           tty->print("%s:",Matcher::regName[second]);
  1630         else
  1631           tty->print("%s+%d:",OptoReg::regname(OptoReg::c_frame_pointer), reg2offset_unchecked(second));
  1633       OptoReg::Name first = get_reg_first(n);
  1634       if( OptoReg::is_reg(first) )
  1635         tty->print("%s]",Matcher::regName[first]);
  1636       else
  1637          tty->print("%s+%d]",OptoReg::regname(OptoReg::c_frame_pointer), reg2offset_unchecked(first));
  1638     } else
  1639     n->out_RegMask().dump();
  1641   tty->print("/N%d\t",n->_idx);
  1642   tty->print("%s === ", n->Name());
  1643   uint k;
  1644   for( k = 0; k < n->req(); k++) {
  1645     Node *m = n->in(k);
  1646     if( !m ) tty->print("_ ");
  1647     else {
  1648       uint r = (m->_idx < _names.Size() ) ? Find_const(m) : 0;
  1649       tty->print("L%d",r);
  1650       // Data MultiNode's can have projections with no real registers.
  1651       // Don't die while dumping them.
  1652       int op = n->Opcode();
  1653       if( r && op != Op_Phi && op != Op_Proj && op != Op_SCMemProj) {
  1654         if( _node_regs ) {
  1655           tty->print("[");
  1656           OptoReg::Name second = get_reg_second(n->in(k));
  1657           if( OptoReg::is_valid(second) ) {
  1658             if( OptoReg::is_reg(second) )
  1659               tty->print("%s:",Matcher::regName[second]);
  1660             else
  1661               tty->print("%s+%d:",OptoReg::regname(OptoReg::c_frame_pointer),
  1662                          reg2offset_unchecked(second));
  1664           OptoReg::Name first = get_reg_first(n->in(k));
  1665           if( OptoReg::is_reg(first) )
  1666             tty->print("%s]",Matcher::regName[first]);
  1667           else
  1668             tty->print("%s+%d]",OptoReg::regname(OptoReg::c_frame_pointer),
  1669                        reg2offset_unchecked(first));
  1670         } else
  1671           n->in_RegMask(k).dump();
  1673       tty->print("/N%d ",m->_idx);
  1676   if( k < n->len() && n->in(k) ) tty->print("| ");
  1677   for( ; k < n->len(); k++ ) {
  1678     Node *m = n->in(k);
  1679     if( !m ) break;
  1680     uint r = (m->_idx < _names.Size() ) ? Find_const(m) : 0;
  1681     tty->print("L%d",r);
  1682     tty->print("/N%d ",m->_idx);
  1684   if( n->is_Mach() ) n->as_Mach()->dump_spec(tty);
  1685   else n->dump_spec(tty);
  1686   if( _spilled_once.test(n->_idx ) ) {
  1687     tty->print(" Spill_1");
  1688     if( _spilled_twice.test(n->_idx ) )
  1689       tty->print(" Spill_2");
  1691   tty->print("\n");
  1694 void PhaseChaitin::dump( const Block * b ) const {
  1695   b->dump_head( &_cfg._bbs );
  1697   // For all instructions
  1698   for( uint j = 0; j < b->_nodes.size(); j++ )
  1699     dump(b->_nodes[j]);
  1700   // Print live-out info at end of block
  1701   if( _live ) {
  1702     tty->print("Liveout: ");
  1703     IndexSet *live = _live->live(b);
  1704     IndexSetIterator elements(live);
  1705     tty->print("{");
  1706     uint i;
  1707     while ((i = elements.next()) != 0) {
  1708       tty->print("L%d ", Find_const(i));
  1710     tty->print_cr("}");
  1712   tty->print("\n");
  1715 void PhaseChaitin::dump() const {
  1716   tty->print( "--- Chaitin -- argsize: %d  framesize: %d ---\n",
  1717               _matcher._new_SP, _framesize );
  1719   // For all blocks
  1720   for( uint i = 0; i < _cfg._num_blocks; i++ )
  1721     dump(_cfg._blocks[i]);
  1722   // End of per-block dump
  1723   tty->print("\n");
  1725   if (!_ifg) {
  1726     tty->print("(No IFG.)\n");
  1727     return;
  1730   // Dump LRG array
  1731   tty->print("--- Live RanGe Array ---\n");
  1732   for(uint i2 = 1; i2 < _maxlrg; i2++ ) {
  1733     tty->print("L%d: ",i2);
  1734     if( i2 < _ifg->_maxlrg ) lrgs(i2).dump( );
  1735     else tty->print("new LRG");
  1737   tty->print_cr("");
  1739   // Dump lo-degree list
  1740   tty->print("Lo degree: ");
  1741   for(uint i3 = _lo_degree; i3; i3 = lrgs(i3)._next )
  1742     tty->print("L%d ",i3);
  1743   tty->print_cr("");
  1745   // Dump lo-stk-degree list
  1746   tty->print("Lo stk degree: ");
  1747   for(uint i4 = _lo_stk_degree; i4; i4 = lrgs(i4)._next )
  1748     tty->print("L%d ",i4);
  1749   tty->print_cr("");
  1751   // Dump lo-degree list
  1752   tty->print("Hi degree: ");
  1753   for(uint i5 = _hi_degree; i5; i5 = lrgs(i5)._next )
  1754     tty->print("L%d ",i5);
  1755   tty->print_cr("");
  1758 //------------------------------dump_degree_lists------------------------------
  1759 void PhaseChaitin::dump_degree_lists() const {
  1760   // Dump lo-degree list
  1761   tty->print("Lo degree: ");
  1762   for( uint i = _lo_degree; i; i = lrgs(i)._next )
  1763     tty->print("L%d ",i);
  1764   tty->print_cr("");
  1766   // Dump lo-stk-degree list
  1767   tty->print("Lo stk degree: ");
  1768   for(uint i2 = _lo_stk_degree; i2; i2 = lrgs(i2)._next )
  1769     tty->print("L%d ",i2);
  1770   tty->print_cr("");
  1772   // Dump lo-degree list
  1773   tty->print("Hi degree: ");
  1774   for(uint i3 = _hi_degree; i3; i3 = lrgs(i3)._next )
  1775     tty->print("L%d ",i3);
  1776   tty->print_cr("");
  1779 //------------------------------dump_simplified--------------------------------
  1780 void PhaseChaitin::dump_simplified() const {
  1781   tty->print("Simplified: ");
  1782   for( uint i = _simplified; i; i = lrgs(i)._next )
  1783     tty->print("L%d ",i);
  1784   tty->print_cr("");
  1787 static char *print_reg( OptoReg::Name reg, const PhaseChaitin *pc, char *buf ) {
  1788   if ((int)reg < 0)
  1789     sprintf(buf, "<OptoReg::%d>", (int)reg);
  1790   else if (OptoReg::is_reg(reg))
  1791     strcpy(buf, Matcher::regName[reg]);
  1792   else
  1793     sprintf(buf,"%s + #%d",OptoReg::regname(OptoReg::c_frame_pointer),
  1794             pc->reg2offset(reg));
  1795   return buf+strlen(buf);
  1798 //------------------------------dump_register----------------------------------
  1799 // Dump a register name into a buffer.  Be intelligent if we get called
  1800 // before allocation is complete.
  1801 char *PhaseChaitin::dump_register( const Node *n, char *buf  ) const {
  1802   if( !this ) {                 // Not got anything?
  1803     sprintf(buf,"N%d",n->_idx); // Then use Node index
  1804   } else if( _node_regs ) {
  1805     // Post allocation, use direct mappings, no LRG info available
  1806     print_reg( get_reg_first(n), this, buf );
  1807   } else {
  1808     uint lidx = Find_const(n); // Grab LRG number
  1809     if( !_ifg ) {
  1810       sprintf(buf,"L%d",lidx);  // No register binding yet
  1811     } else if( !lidx ) {        // Special, not allocated value
  1812       strcpy(buf,"Special");
  1813     } else if( (lrgs(lidx).num_regs() == 1)
  1814                 ? !lrgs(lidx).mask().is_bound1()
  1815                 : !lrgs(lidx).mask().is_bound2() ) {
  1816       sprintf(buf,"L%d",lidx); // No register binding yet
  1817     } else {                    // Hah!  We have a bound machine register
  1818       print_reg( lrgs(lidx).reg(), this, buf );
  1821   return buf+strlen(buf);
  1824 //----------------------dump_for_spill_split_recycle--------------------------
  1825 void PhaseChaitin::dump_for_spill_split_recycle() const {
  1826   if( WizardMode && (PrintCompilation || PrintOpto) ) {
  1827     // Display which live ranges need to be split and the allocator's state
  1828     tty->print_cr("Graph-Coloring Iteration %d will split the following live ranges", _trip_cnt);
  1829     for( uint bidx = 1; bidx < _maxlrg; bidx++ ) {
  1830       if( lrgs(bidx).alive() && lrgs(bidx).reg() >= LRG::SPILL_REG ) {
  1831         tty->print("L%d: ", bidx);
  1832         lrgs(bidx).dump();
  1835     tty->cr();
  1836     dump();
  1840 //------------------------------dump_frame------------------------------------
  1841 void PhaseChaitin::dump_frame() const {
  1842   const char *fp = OptoReg::regname(OptoReg::c_frame_pointer);
  1843   const TypeTuple *domain = C->tf()->domain();
  1844   const int        argcnt = domain->cnt() - TypeFunc::Parms;
  1846   // Incoming arguments in registers dump
  1847   for( int k = 0; k < argcnt; k++ ) {
  1848     OptoReg::Name parmreg = _matcher._parm_regs[k].first();
  1849     if( OptoReg::is_reg(parmreg))  {
  1850       const char *reg_name = OptoReg::regname(parmreg);
  1851       tty->print("#r%3.3d %s", parmreg, reg_name);
  1852       parmreg = _matcher._parm_regs[k].second();
  1853       if( OptoReg::is_reg(parmreg))  {
  1854         tty->print(":%s", OptoReg::regname(parmreg));
  1856       tty->print("   : parm %d: ", k);
  1857       domain->field_at(k + TypeFunc::Parms)->dump();
  1858       tty->print_cr("");
  1862   // Check for un-owned padding above incoming args
  1863   OptoReg::Name reg = _matcher._new_SP;
  1864   if( reg > _matcher._in_arg_limit ) {
  1865     reg = OptoReg::add(reg, -1);
  1866     tty->print_cr("#r%3.3d %s+%2d: pad0, owned by CALLER", reg, fp, reg2offset_unchecked(reg));
  1869   // Incoming argument area dump
  1870   OptoReg::Name begin_in_arg = OptoReg::add(_matcher._old_SP,C->out_preserve_stack_slots());
  1871   while( reg > begin_in_arg ) {
  1872     reg = OptoReg::add(reg, -1);
  1873     tty->print("#r%3.3d %s+%2d: ",reg,fp,reg2offset_unchecked(reg));
  1874     int j;
  1875     for( j = 0; j < argcnt; j++) {
  1876       if( _matcher._parm_regs[j].first() == reg ||
  1877           _matcher._parm_regs[j].second() == reg ) {
  1878         tty->print("parm %d: ",j);
  1879         domain->field_at(j + TypeFunc::Parms)->dump();
  1880         tty->print_cr("");
  1881         break;
  1884     if( j >= argcnt )
  1885       tty->print_cr("HOLE, owned by SELF");
  1888   // Old outgoing preserve area
  1889   while( reg > _matcher._old_SP ) {
  1890     reg = OptoReg::add(reg, -1);
  1891     tty->print_cr("#r%3.3d %s+%2d: old out preserve",reg,fp,reg2offset_unchecked(reg));
  1894   // Old SP
  1895   tty->print_cr("# -- Old %s -- Framesize: %d --",fp,
  1896     reg2offset_unchecked(OptoReg::add(_matcher._old_SP,-1)) - reg2offset_unchecked(_matcher._new_SP)+jintSize);
  1898   // Preserve area dump
  1899   reg = OptoReg::add(reg, -1);
  1900   while( OptoReg::is_stack(reg)) {
  1901     tty->print("#r%3.3d %s+%2d: ",reg,fp,reg2offset_unchecked(reg));
  1902     if( _matcher.return_addr() == reg )
  1903       tty->print_cr("return address");
  1904     else if( _matcher.return_addr() == OptoReg::add(reg,1) &&
  1905              VerifyStackAtCalls )
  1906       tty->print_cr("0xBADB100D   +VerifyStackAtCalls");
  1907     else if ((int)OptoReg::reg2stack(reg) < C->fixed_slots())
  1908       tty->print_cr("Fixed slot %d", OptoReg::reg2stack(reg));
  1909     else
  1910       tty->print_cr("pad2, in_preserve");
  1911     reg = OptoReg::add(reg, -1);
  1914   // Spill area dump
  1915   reg = OptoReg::add(_matcher._new_SP, _framesize );
  1916   while( reg > _matcher._out_arg_limit ) {
  1917     reg = OptoReg::add(reg, -1);
  1918     tty->print_cr("#r%3.3d %s+%2d: spill",reg,fp,reg2offset_unchecked(reg));
  1921   // Outgoing argument area dump
  1922   while( reg > OptoReg::add(_matcher._new_SP, C->out_preserve_stack_slots()) ) {
  1923     reg = OptoReg::add(reg, -1);
  1924     tty->print_cr("#r%3.3d %s+%2d: outgoing argument",reg,fp,reg2offset_unchecked(reg));
  1927   // Outgoing new preserve area
  1928   while( reg > _matcher._new_SP ) {
  1929     reg = OptoReg::add(reg, -1);
  1930     tty->print_cr("#r%3.3d %s+%2d: new out preserve",reg,fp,reg2offset_unchecked(reg));
  1932   tty->print_cr("#");
  1935 //------------------------------dump_bb----------------------------------------
  1936 void PhaseChaitin::dump_bb( uint pre_order ) const {
  1937   tty->print_cr("---dump of B%d---",pre_order);
  1938   for( uint i = 0; i < _cfg._num_blocks; i++ ) {
  1939     Block *b = _cfg._blocks[i];
  1940     if( b->_pre_order == pre_order )
  1941       dump(b);
  1945 //------------------------------dump_lrg---------------------------------------
  1946 void PhaseChaitin::dump_lrg( uint lidx ) const {
  1947   tty->print_cr("---dump of L%d---",lidx);
  1949   if( _ifg ) {
  1950     if( lidx >= _maxlrg ) {
  1951       tty->print("Attempt to print live range index beyond max live range.\n");
  1952       return;
  1954     tty->print("L%d: ",lidx);
  1955     lrgs(lidx).dump( );
  1957   if( _ifg ) {    tty->print("Neighbors: %d - ", _ifg->neighbor_cnt(lidx));
  1958     _ifg->neighbors(lidx)->dump();
  1959     tty->cr();
  1961   // For all blocks
  1962   for( uint i = 0; i < _cfg._num_blocks; i++ ) {
  1963     Block *b = _cfg._blocks[i];
  1964     int dump_once = 0;
  1966     // For all instructions
  1967     for( uint j = 0; j < b->_nodes.size(); j++ ) {
  1968       Node *n = b->_nodes[j];
  1969       if( Find_const(n) == lidx ) {
  1970         if( !dump_once++ ) {
  1971           tty->cr();
  1972           b->dump_head( &_cfg._bbs );
  1974         dump(n);
  1975         continue;
  1977       uint cnt = n->req();
  1978       for( uint k = 1; k < cnt; k++ ) {
  1979         Node *m = n->in(k);
  1980         if (!m)  continue;  // be robust in the dumper
  1981         if( Find_const(m) == lidx ) {
  1982           if( !dump_once++ ) {
  1983             tty->cr();
  1984             b->dump_head( &_cfg._bbs );
  1986           dump(n);
  1990   } // End of per-block dump
  1991   tty->cr();
  1993 #endif // not PRODUCT
  1995 //------------------------------print_chaitin_statistics-------------------------------
  1996 int PhaseChaitin::_final_loads  = 0;
  1997 int PhaseChaitin::_final_stores = 0;
  1998 int PhaseChaitin::_final_memoves= 0;
  1999 int PhaseChaitin::_final_copies = 0;
  2000 double PhaseChaitin::_final_load_cost  = 0;
  2001 double PhaseChaitin::_final_store_cost = 0;
  2002 double PhaseChaitin::_final_memove_cost= 0;
  2003 double PhaseChaitin::_final_copy_cost  = 0;
  2004 int PhaseChaitin::_conserv_coalesce = 0;
  2005 int PhaseChaitin::_conserv_coalesce_pair = 0;
  2006 int PhaseChaitin::_conserv_coalesce_trie = 0;
  2007 int PhaseChaitin::_conserv_coalesce_quad = 0;
  2008 int PhaseChaitin::_post_alloc = 0;
  2009 int PhaseChaitin::_lost_opp_pp_coalesce = 0;
  2010 int PhaseChaitin::_lost_opp_cflow_coalesce = 0;
  2011 int PhaseChaitin::_used_cisc_instructions   = 0;
  2012 int PhaseChaitin::_unused_cisc_instructions = 0;
  2013 int PhaseChaitin::_allocator_attempts       = 0;
  2014 int PhaseChaitin::_allocator_successes      = 0;
  2016 #ifndef PRODUCT
  2017 uint PhaseChaitin::_high_pressure           = 0;
  2018 uint PhaseChaitin::_low_pressure            = 0;
  2020 void PhaseChaitin::print_chaitin_statistics() {
  2021   tty->print_cr("Inserted %d spill loads, %d spill stores, %d mem-mem moves and %d copies.", _final_loads, _final_stores, _final_memoves, _final_copies);
  2022   tty->print_cr("Total load cost= %6.0f, store cost = %6.0f, mem-mem cost = %5.2f, copy cost = %5.0f.", _final_load_cost, _final_store_cost, _final_memove_cost, _final_copy_cost);
  2023   tty->print_cr("Adjusted spill cost = %7.0f.",
  2024                 _final_load_cost*4.0 + _final_store_cost  * 2.0 +
  2025                 _final_copy_cost*1.0 + _final_memove_cost*12.0);
  2026   tty->print("Conservatively coalesced %d copies, %d pairs",
  2027                 _conserv_coalesce, _conserv_coalesce_pair);
  2028   if( _conserv_coalesce_trie || _conserv_coalesce_quad )
  2029     tty->print(", %d tries, %d quads", _conserv_coalesce_trie, _conserv_coalesce_quad);
  2030   tty->print_cr(", %d post alloc.", _post_alloc);
  2031   if( _lost_opp_pp_coalesce || _lost_opp_cflow_coalesce )
  2032     tty->print_cr("Lost coalesce opportunity, %d private-private, and %d cflow interfered.",
  2033                   _lost_opp_pp_coalesce, _lost_opp_cflow_coalesce );
  2034   if( _used_cisc_instructions || _unused_cisc_instructions )
  2035     tty->print_cr("Used cisc instruction  %d,  remained in register %d",
  2036                    _used_cisc_instructions, _unused_cisc_instructions);
  2037   if( _allocator_successes != 0 )
  2038     tty->print_cr("Average allocation trips %f", (float)_allocator_attempts/(float)_allocator_successes);
  2039   tty->print_cr("High Pressure Blocks = %d, Low Pressure Blocks = %d", _high_pressure, _low_pressure);
  2041 #endif // not PRODUCT

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