src/share/vm/opto/compile.cpp

Mon, 28 Apr 2008 08:08:12 -0700

author
rasbold
date
Mon, 28 Apr 2008 08:08:12 -0700
changeset 563
a76240c8b133
parent 562
e0bd2e08e3d0
child 598
885ed790ecf0
permissions
-rw-r--r--

Merge

     1 /*
     2  * Copyright 1997-2007 Sun Microsystems, Inc.  All Rights Reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 #include "incls/_precompiled.incl"
    26 #include "incls/_compile.cpp.incl"
    28 /// Support for intrinsics.
    30 // Return the index at which m must be inserted (or already exists).
    31 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
    32 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
    33 #ifdef ASSERT
    34   for (int i = 1; i < _intrinsics->length(); i++) {
    35     CallGenerator* cg1 = _intrinsics->at(i-1);
    36     CallGenerator* cg2 = _intrinsics->at(i);
    37     assert(cg1->method() != cg2->method()
    38            ? cg1->method()     < cg2->method()
    39            : cg1->is_virtual() < cg2->is_virtual(),
    40            "compiler intrinsics list must stay sorted");
    41   }
    42 #endif
    43   // Binary search sorted list, in decreasing intervals [lo, hi].
    44   int lo = 0, hi = _intrinsics->length()-1;
    45   while (lo <= hi) {
    46     int mid = (uint)(hi + lo) / 2;
    47     ciMethod* mid_m = _intrinsics->at(mid)->method();
    48     if (m < mid_m) {
    49       hi = mid-1;
    50     } else if (m > mid_m) {
    51       lo = mid+1;
    52     } else {
    53       // look at minor sort key
    54       bool mid_virt = _intrinsics->at(mid)->is_virtual();
    55       if (is_virtual < mid_virt) {
    56         hi = mid-1;
    57       } else if (is_virtual > mid_virt) {
    58         lo = mid+1;
    59       } else {
    60         return mid;  // exact match
    61       }
    62     }
    63   }
    64   return lo;  // inexact match
    65 }
    67 void Compile::register_intrinsic(CallGenerator* cg) {
    68   if (_intrinsics == NULL) {
    69     _intrinsics = new GrowableArray<CallGenerator*>(60);
    70   }
    71   // This code is stolen from ciObjectFactory::insert.
    72   // Really, GrowableArray should have methods for
    73   // insert_at, remove_at, and binary_search.
    74   int len = _intrinsics->length();
    75   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
    76   if (index == len) {
    77     _intrinsics->append(cg);
    78   } else {
    79 #ifdef ASSERT
    80     CallGenerator* oldcg = _intrinsics->at(index);
    81     assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
    82 #endif
    83     _intrinsics->append(_intrinsics->at(len-1));
    84     int pos;
    85     for (pos = len-2; pos >= index; pos--) {
    86       _intrinsics->at_put(pos+1,_intrinsics->at(pos));
    87     }
    88     _intrinsics->at_put(index, cg);
    89   }
    90   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
    91 }
    93 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
    94   assert(m->is_loaded(), "don't try this on unloaded methods");
    95   if (_intrinsics != NULL) {
    96     int index = intrinsic_insertion_index(m, is_virtual);
    97     if (index < _intrinsics->length()
    98         && _intrinsics->at(index)->method() == m
    99         && _intrinsics->at(index)->is_virtual() == is_virtual) {
   100       return _intrinsics->at(index);
   101     }
   102   }
   103   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
   104   if (m->intrinsic_id() != vmIntrinsics::_none) {
   105     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
   106     if (cg != NULL) {
   107       // Save it for next time:
   108       register_intrinsic(cg);
   109       return cg;
   110     } else {
   111       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
   112     }
   113   }
   114   return NULL;
   115 }
   117 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
   118 // in library_call.cpp.
   121 #ifndef PRODUCT
   122 // statistics gathering...
   124 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
   125 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
   127 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
   128   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
   129   int oflags = _intrinsic_hist_flags[id];
   130   assert(flags != 0, "what happened?");
   131   if (is_virtual) {
   132     flags |= _intrinsic_virtual;
   133   }
   134   bool changed = (flags != oflags);
   135   if ((flags & _intrinsic_worked) != 0) {
   136     juint count = (_intrinsic_hist_count[id] += 1);
   137     if (count == 1) {
   138       changed = true;           // first time
   139     }
   140     // increment the overall count also:
   141     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
   142   }
   143   if (changed) {
   144     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
   145       // Something changed about the intrinsic's virtuality.
   146       if ((flags & _intrinsic_virtual) != 0) {
   147         // This is the first use of this intrinsic as a virtual call.
   148         if (oflags != 0) {
   149           // We already saw it as a non-virtual, so note both cases.
   150           flags |= _intrinsic_both;
   151         }
   152       } else if ((oflags & _intrinsic_both) == 0) {
   153         // This is the first use of this intrinsic as a non-virtual
   154         flags |= _intrinsic_both;
   155       }
   156     }
   157     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
   158   }
   159   // update the overall flags also:
   160   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
   161   return changed;
   162 }
   164 static char* format_flags(int flags, char* buf) {
   165   buf[0] = 0;
   166   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
   167   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
   168   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
   169   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
   170   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
   171   if (buf[0] == 0)  strcat(buf, ",");
   172   assert(buf[0] == ',', "must be");
   173   return &buf[1];
   174 }
   176 void Compile::print_intrinsic_statistics() {
   177   char flagsbuf[100];
   178   ttyLocker ttyl;
   179   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
   180   tty->print_cr("Compiler intrinsic usage:");
   181   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
   182   if (total == 0)  total = 1;  // avoid div0 in case of no successes
   183   #define PRINT_STAT_LINE(name, c, f) \
   184     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
   185   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
   186     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
   187     int   flags = _intrinsic_hist_flags[id];
   188     juint count = _intrinsic_hist_count[id];
   189     if ((flags | count) != 0) {
   190       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
   191     }
   192   }
   193   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
   194   if (xtty != NULL)  xtty->tail("statistics");
   195 }
   197 void Compile::print_statistics() {
   198   { ttyLocker ttyl;
   199     if (xtty != NULL)  xtty->head("statistics type='opto'");
   200     Parse::print_statistics();
   201     PhaseCCP::print_statistics();
   202     PhaseRegAlloc::print_statistics();
   203     Scheduling::print_statistics();
   204     PhasePeephole::print_statistics();
   205     PhaseIdealLoop::print_statistics();
   206     if (xtty != NULL)  xtty->tail("statistics");
   207   }
   208   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
   209     // put this under its own <statistics> element.
   210     print_intrinsic_statistics();
   211   }
   212 }
   213 #endif //PRODUCT
   215 // Support for bundling info
   216 Bundle* Compile::node_bundling(const Node *n) {
   217   assert(valid_bundle_info(n), "oob");
   218   return &_node_bundling_base[n->_idx];
   219 }
   221 bool Compile::valid_bundle_info(const Node *n) {
   222   return (_node_bundling_limit > n->_idx);
   223 }
   226 // Identify all nodes that are reachable from below, useful.
   227 // Use breadth-first pass that records state in a Unique_Node_List,
   228 // recursive traversal is slower.
   229 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
   230   int estimated_worklist_size = unique();
   231   useful.map( estimated_worklist_size, NULL );  // preallocate space
   233   // Initialize worklist
   234   if (root() != NULL)     { useful.push(root()); }
   235   // If 'top' is cached, declare it useful to preserve cached node
   236   if( cached_top_node() ) { useful.push(cached_top_node()); }
   238   // Push all useful nodes onto the list, breadthfirst
   239   for( uint next = 0; next < useful.size(); ++next ) {
   240     assert( next < unique(), "Unique useful nodes < total nodes");
   241     Node *n  = useful.at(next);
   242     uint max = n->len();
   243     for( uint i = 0; i < max; ++i ) {
   244       Node *m = n->in(i);
   245       if( m == NULL ) continue;
   246       useful.push(m);
   247     }
   248   }
   249 }
   251 // Disconnect all useless nodes by disconnecting those at the boundary.
   252 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
   253   uint next = 0;
   254   while( next < useful.size() ) {
   255     Node *n = useful.at(next++);
   256     // Use raw traversal of out edges since this code removes out edges
   257     int max = n->outcnt();
   258     for (int j = 0; j < max; ++j ) {
   259       Node* child = n->raw_out(j);
   260       if( ! useful.member(child) ) {
   261         assert( !child->is_top() || child != top(),
   262                 "If top is cached in Compile object it is in useful list");
   263         // Only need to remove this out-edge to the useless node
   264         n->raw_del_out(j);
   265         --j;
   266         --max;
   267       }
   268     }
   269     if (n->outcnt() == 1 && n->has_special_unique_user()) {
   270       record_for_igvn( n->unique_out() );
   271     }
   272   }
   273   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
   274 }
   276 //------------------------------frame_size_in_words-----------------------------
   277 // frame_slots in units of words
   278 int Compile::frame_size_in_words() const {
   279   // shift is 0 in LP32 and 1 in LP64
   280   const int shift = (LogBytesPerWord - LogBytesPerInt);
   281   int words = _frame_slots >> shift;
   282   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
   283   return words;
   284 }
   286 // ============================================================================
   287 //------------------------------CompileWrapper---------------------------------
   288 class CompileWrapper : public StackObj {
   289   Compile *const _compile;
   290  public:
   291   CompileWrapper(Compile* compile);
   293   ~CompileWrapper();
   294 };
   296 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
   297   // the Compile* pointer is stored in the current ciEnv:
   298   ciEnv* env = compile->env();
   299   assert(env == ciEnv::current(), "must already be a ciEnv active");
   300   assert(env->compiler_data() == NULL, "compile already active?");
   301   env->set_compiler_data(compile);
   302   assert(compile == Compile::current(), "sanity");
   304   compile->set_type_dict(NULL);
   305   compile->set_type_hwm(NULL);
   306   compile->set_type_last_size(0);
   307   compile->set_last_tf(NULL, NULL);
   308   compile->set_indexSet_arena(NULL);
   309   compile->set_indexSet_free_block_list(NULL);
   310   compile->init_type_arena();
   311   Type::Initialize(compile);
   312   _compile->set_scratch_buffer_blob(NULL);
   313   _compile->begin_method();
   314 }
   315 CompileWrapper::~CompileWrapper() {
   316   if (_compile->failing()) {
   317     _compile->print_method("Failed");
   318   }
   319   _compile->end_method();
   320   if (_compile->scratch_buffer_blob() != NULL)
   321     BufferBlob::free(_compile->scratch_buffer_blob());
   322   _compile->env()->set_compiler_data(NULL);
   323 }
   326 //----------------------------print_compile_messages---------------------------
   327 void Compile::print_compile_messages() {
   328 #ifndef PRODUCT
   329   // Check if recompiling
   330   if (_subsume_loads == false && PrintOpto) {
   331     // Recompiling without allowing machine instructions to subsume loads
   332     tty->print_cr("*********************************************************");
   333     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
   334     tty->print_cr("*********************************************************");
   335   }
   336   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
   337     // Recompiling without escape analysis
   338     tty->print_cr("*********************************************************");
   339     tty->print_cr("** Bailout: Recompile without escape analysis          **");
   340     tty->print_cr("*********************************************************");
   341   }
   342   if (env()->break_at_compile()) {
   343     // Open the debugger when compiing this method.
   344     tty->print("### Breaking when compiling: ");
   345     method()->print_short_name();
   346     tty->cr();
   347     BREAKPOINT;
   348   }
   350   if( PrintOpto ) {
   351     if (is_osr_compilation()) {
   352       tty->print("[OSR]%3d", _compile_id);
   353     } else {
   354       tty->print("%3d", _compile_id);
   355     }
   356   }
   357 #endif
   358 }
   361 void Compile::init_scratch_buffer_blob() {
   362   if( scratch_buffer_blob() != NULL )  return;
   364   // Construct a temporary CodeBuffer to have it construct a BufferBlob
   365   // Cache this BufferBlob for this compile.
   366   ResourceMark rm;
   367   int size = (MAX_inst_size + MAX_stubs_size + MAX_const_size);
   368   BufferBlob* blob = BufferBlob::create("Compile::scratch_buffer", size);
   369   // Record the buffer blob for next time.
   370   set_scratch_buffer_blob(blob);
   371   guarantee(scratch_buffer_blob() != NULL, "Need BufferBlob for code generation");
   373   // Initialize the relocation buffers
   374   relocInfo* locs_buf = (relocInfo*) blob->instructions_end() - MAX_locs_size;
   375   set_scratch_locs_memory(locs_buf);
   376 }
   379 //-----------------------scratch_emit_size-------------------------------------
   380 // Helper function that computes size by emitting code
   381 uint Compile::scratch_emit_size(const Node* n) {
   382   // Emit into a trash buffer and count bytes emitted.
   383   // This is a pretty expensive way to compute a size,
   384   // but it works well enough if seldom used.
   385   // All common fixed-size instructions are given a size
   386   // method by the AD file.
   387   // Note that the scratch buffer blob and locs memory are
   388   // allocated at the beginning of the compile task, and
   389   // may be shared by several calls to scratch_emit_size.
   390   // The allocation of the scratch buffer blob is particularly
   391   // expensive, since it has to grab the code cache lock.
   392   BufferBlob* blob = this->scratch_buffer_blob();
   393   assert(blob != NULL, "Initialize BufferBlob at start");
   394   assert(blob->size() > MAX_inst_size, "sanity");
   395   relocInfo* locs_buf = scratch_locs_memory();
   396   address blob_begin = blob->instructions_begin();
   397   address blob_end   = (address)locs_buf;
   398   assert(blob->instructions_contains(blob_end), "sanity");
   399   CodeBuffer buf(blob_begin, blob_end - blob_begin);
   400   buf.initialize_consts_size(MAX_const_size);
   401   buf.initialize_stubs_size(MAX_stubs_size);
   402   assert(locs_buf != NULL, "sanity");
   403   int lsize = MAX_locs_size / 2;
   404   buf.insts()->initialize_shared_locs(&locs_buf[0],     lsize);
   405   buf.stubs()->initialize_shared_locs(&locs_buf[lsize], lsize);
   406   n->emit(buf, this->regalloc());
   407   return buf.code_size();
   408 }
   411 // ============================================================================
   412 //------------------------------Compile standard-------------------------------
   413 debug_only( int Compile::_debug_idx = 100000; )
   415 // Compile a method.  entry_bci is -1 for normal compilations and indicates
   416 // the continuation bci for on stack replacement.
   419 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci, bool subsume_loads, bool do_escape_analysis )
   420                 : Phase(Compiler),
   421                   _env(ci_env),
   422                   _log(ci_env->log()),
   423                   _compile_id(ci_env->compile_id()),
   424                   _save_argument_registers(false),
   425                   _stub_name(NULL),
   426                   _stub_function(NULL),
   427                   _stub_entry_point(NULL),
   428                   _method(target),
   429                   _entry_bci(osr_bci),
   430                   _initial_gvn(NULL),
   431                   _for_igvn(NULL),
   432                   _warm_calls(NULL),
   433                   _subsume_loads(subsume_loads),
   434                   _do_escape_analysis(do_escape_analysis),
   435                   _failure_reason(NULL),
   436                   _code_buffer("Compile::Fill_buffer"),
   437                   _orig_pc_slot(0),
   438                   _orig_pc_slot_offset_in_bytes(0),
   439                   _node_bundling_limit(0),
   440                   _node_bundling_base(NULL),
   441 #ifndef PRODUCT
   442                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
   443                   _printer(IdealGraphPrinter::printer()),
   444 #endif
   445                   _congraph(NULL) {
   446   C = this;
   448   CompileWrapper cw(this);
   449 #ifndef PRODUCT
   450   if (TimeCompiler2) {
   451     tty->print(" ");
   452     target->holder()->name()->print();
   453     tty->print(".");
   454     target->print_short_name();
   455     tty->print("  ");
   456   }
   457   TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
   458   TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
   459   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
   460   if (!print_opto_assembly) {
   461     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
   462     if (print_assembly && !Disassembler::can_decode()) {
   463       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
   464       print_opto_assembly = true;
   465     }
   466   }
   467   set_print_assembly(print_opto_assembly);
   468 #endif
   470   if (ProfileTraps) {
   471     // Make sure the method being compiled gets its own MDO,
   472     // so we can at least track the decompile_count().
   473     method()->build_method_data();
   474   }
   476   Init(::AliasLevel);
   479   print_compile_messages();
   481   if (UseOldInlining || PrintCompilation NOT_PRODUCT( || PrintOpto) )
   482     _ilt = InlineTree::build_inline_tree_root();
   483   else
   484     _ilt = NULL;
   486   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
   487   assert(num_alias_types() >= AliasIdxRaw, "");
   489 #define MINIMUM_NODE_HASH  1023
   490   // Node list that Iterative GVN will start with
   491   Unique_Node_List for_igvn(comp_arena());
   492   set_for_igvn(&for_igvn);
   494   // GVN that will be run immediately on new nodes
   495   uint estimated_size = method()->code_size()*4+64;
   496   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
   497   PhaseGVN gvn(node_arena(), estimated_size);
   498   set_initial_gvn(&gvn);
   500   { // Scope for timing the parser
   501     TracePhase t3("parse", &_t_parser, true);
   503     // Put top into the hash table ASAP.
   504     initial_gvn()->transform_no_reclaim(top());
   506     // Set up tf(), start(), and find a CallGenerator.
   507     CallGenerator* cg;
   508     if (is_osr_compilation()) {
   509       const TypeTuple *domain = StartOSRNode::osr_domain();
   510       const TypeTuple *range = TypeTuple::make_range(method()->signature());
   511       init_tf(TypeFunc::make(domain, range));
   512       StartNode* s = new (this, 2) StartOSRNode(root(), domain);
   513       initial_gvn()->set_type_bottom(s);
   514       init_start(s);
   515       cg = CallGenerator::for_osr(method(), entry_bci());
   516     } else {
   517       // Normal case.
   518       init_tf(TypeFunc::make(method()));
   519       StartNode* s = new (this, 2) StartNode(root(), tf()->domain());
   520       initial_gvn()->set_type_bottom(s);
   521       init_start(s);
   522       float past_uses = method()->interpreter_invocation_count();
   523       float expected_uses = past_uses;
   524       cg = CallGenerator::for_inline(method(), expected_uses);
   525     }
   526     if (failing())  return;
   527     if (cg == NULL) {
   528       record_method_not_compilable_all_tiers("cannot parse method");
   529       return;
   530     }
   531     JVMState* jvms = build_start_state(start(), tf());
   532     if ((jvms = cg->generate(jvms)) == NULL) {
   533       record_method_not_compilable("method parse failed");
   534       return;
   535     }
   536     GraphKit kit(jvms);
   538     if (!kit.stopped()) {
   539       // Accept return values, and transfer control we know not where.
   540       // This is done by a special, unique ReturnNode bound to root.
   541       return_values(kit.jvms());
   542     }
   544     if (kit.has_exceptions()) {
   545       // Any exceptions that escape from this call must be rethrown
   546       // to whatever caller is dynamically above us on the stack.
   547       // This is done by a special, unique RethrowNode bound to root.
   548       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
   549     }
   551     // Remove clutter produced by parsing.
   552     if (!failing()) {
   553       ResourceMark rm;
   554       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
   555     }
   556   }
   558   // Note:  Large methods are capped off in do_one_bytecode().
   559   if (failing())  return;
   561   // After parsing, node notes are no longer automagic.
   562   // They must be propagated by register_new_node_with_optimizer(),
   563   // clone(), or the like.
   564   set_default_node_notes(NULL);
   566   for (;;) {
   567     int successes = Inline_Warm();
   568     if (failing())  return;
   569     if (successes == 0)  break;
   570   }
   572   // Drain the list.
   573   Finish_Warm();
   574 #ifndef PRODUCT
   575   if (_printer) {
   576     _printer->print_inlining(this);
   577   }
   578 #endif
   580   if (failing())  return;
   581   NOT_PRODUCT( verify_graph_edges(); )
   583   // Perform escape analysis
   584   if (_do_escape_analysis)
   585     _congraph = new ConnectionGraph(this);
   586   if (_congraph != NULL) {
   587     NOT_PRODUCT( TracePhase t2("escapeAnalysis", &_t_escapeAnalysis, TimeCompiler); )
   588     _congraph->compute_escape();
   589     if (failing())  return;
   591 #ifndef PRODUCT
   592     if (PrintEscapeAnalysis) {
   593       _congraph->dump();
   594     }
   595 #endif
   596   }
   597   // Now optimize
   598   Optimize();
   599   if (failing())  return;
   600   NOT_PRODUCT( verify_graph_edges(); )
   602 #ifndef PRODUCT
   603   if (PrintIdeal) {
   604     ttyLocker ttyl;  // keep the following output all in one block
   605     // This output goes directly to the tty, not the compiler log.
   606     // To enable tools to match it up with the compilation activity,
   607     // be sure to tag this tty output with the compile ID.
   608     if (xtty != NULL) {
   609       xtty->head("ideal compile_id='%d'%s", compile_id(),
   610                  is_osr_compilation()    ? " compile_kind='osr'" :
   611                  "");
   612     }
   613     root()->dump(9999);
   614     if (xtty != NULL) {
   615       xtty->tail("ideal");
   616     }
   617   }
   618 #endif
   620   // Now that we know the size of all the monitors we can add a fixed slot
   621   // for the original deopt pc.
   623   _orig_pc_slot =  fixed_slots();
   624   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
   625   set_fixed_slots(next_slot);
   627   // Now generate code
   628   Code_Gen();
   629   if (failing())  return;
   631   // Check if we want to skip execution of all compiled code.
   632   {
   633 #ifndef PRODUCT
   634     if (OptoNoExecute) {
   635       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
   636       return;
   637     }
   638     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
   639 #endif
   641     if (is_osr_compilation()) {
   642       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
   643       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
   644     } else {
   645       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
   646       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
   647     }
   649     env()->register_method(_method, _entry_bci,
   650                            &_code_offsets,
   651                            _orig_pc_slot_offset_in_bytes,
   652                            code_buffer(),
   653                            frame_size_in_words(), _oop_map_set,
   654                            &_handler_table, &_inc_table,
   655                            compiler,
   656                            env()->comp_level(),
   657                            true, /*has_debug_info*/
   658                            has_unsafe_access()
   659                            );
   660   }
   661 }
   663 //------------------------------Compile----------------------------------------
   664 // Compile a runtime stub
   665 Compile::Compile( ciEnv* ci_env,
   666                   TypeFunc_generator generator,
   667                   address stub_function,
   668                   const char *stub_name,
   669                   int is_fancy_jump,
   670                   bool pass_tls,
   671                   bool save_arg_registers,
   672                   bool return_pc )
   673   : Phase(Compiler),
   674     _env(ci_env),
   675     _log(ci_env->log()),
   676     _compile_id(-1),
   677     _save_argument_registers(save_arg_registers),
   678     _method(NULL),
   679     _stub_name(stub_name),
   680     _stub_function(stub_function),
   681     _stub_entry_point(NULL),
   682     _entry_bci(InvocationEntryBci),
   683     _initial_gvn(NULL),
   684     _for_igvn(NULL),
   685     _warm_calls(NULL),
   686     _orig_pc_slot(0),
   687     _orig_pc_slot_offset_in_bytes(0),
   688     _subsume_loads(true),
   689     _do_escape_analysis(false),
   690     _failure_reason(NULL),
   691     _code_buffer("Compile::Fill_buffer"),
   692     _node_bundling_limit(0),
   693     _node_bundling_base(NULL),
   694 #ifndef PRODUCT
   695     _trace_opto_output(TraceOptoOutput),
   696     _printer(NULL),
   697 #endif
   698     _congraph(NULL) {
   699   C = this;
   701 #ifndef PRODUCT
   702   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
   703   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
   704   set_print_assembly(PrintFrameConverterAssembly);
   705 #endif
   706   CompileWrapper cw(this);
   707   Init(/*AliasLevel=*/ 0);
   708   init_tf((*generator)());
   710   {
   711     // The following is a dummy for the sake of GraphKit::gen_stub
   712     Unique_Node_List for_igvn(comp_arena());
   713     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
   714     PhaseGVN gvn(Thread::current()->resource_area(),255);
   715     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
   716     gvn.transform_no_reclaim(top());
   718     GraphKit kit;
   719     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
   720   }
   722   NOT_PRODUCT( verify_graph_edges(); )
   723   Code_Gen();
   724   if (failing())  return;
   727   // Entry point will be accessed using compile->stub_entry_point();
   728   if (code_buffer() == NULL) {
   729     Matcher::soft_match_failure();
   730   } else {
   731     if (PrintAssembly && (WizardMode || Verbose))
   732       tty->print_cr("### Stub::%s", stub_name);
   734     if (!failing()) {
   735       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
   737       // Make the NMethod
   738       // For now we mark the frame as never safe for profile stackwalking
   739       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
   740                                                       code_buffer(),
   741                                                       CodeOffsets::frame_never_safe,
   742                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
   743                                                       frame_size_in_words(),
   744                                                       _oop_map_set,
   745                                                       save_arg_registers);
   746       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
   748       _stub_entry_point = rs->entry_point();
   749     }
   750   }
   751 }
   753 #ifndef PRODUCT
   754 void print_opto_verbose_signature( const TypeFunc *j_sig, const char *stub_name ) {
   755   if(PrintOpto && Verbose) {
   756     tty->print("%s   ", stub_name); j_sig->print_flattened(); tty->cr();
   757   }
   758 }
   759 #endif
   761 void Compile::print_codes() {
   762 }
   764 //------------------------------Init-------------------------------------------
   765 // Prepare for a single compilation
   766 void Compile::Init(int aliaslevel) {
   767   _unique  = 0;
   768   _regalloc = NULL;
   770   _tf      = NULL;  // filled in later
   771   _top     = NULL;  // cached later
   772   _matcher = NULL;  // filled in later
   773   _cfg     = NULL;  // filled in later
   775   set_24_bit_selection_and_mode(Use24BitFP, false);
   777   _node_note_array = NULL;
   778   _default_node_notes = NULL;
   780   _immutable_memory = NULL; // filled in at first inquiry
   782   // Globally visible Nodes
   783   // First set TOP to NULL to give safe behavior during creation of RootNode
   784   set_cached_top_node(NULL);
   785   set_root(new (this, 3) RootNode());
   786   // Now that you have a Root to point to, create the real TOP
   787   set_cached_top_node( new (this, 1) ConNode(Type::TOP) );
   788   set_recent_alloc(NULL, NULL);
   790   // Create Debug Information Recorder to record scopes, oopmaps, etc.
   791   env()->set_oop_recorder(new OopRecorder(comp_arena()));
   792   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
   793   env()->set_dependencies(new Dependencies(env()));
   795   _fixed_slots = 0;
   796   set_has_split_ifs(false);
   797   set_has_loops(has_method() && method()->has_loops()); // first approximation
   798   _deopt_happens = true;  // start out assuming the worst
   799   _trap_can_recompile = false;  // no traps emitted yet
   800   _major_progress = true; // start out assuming good things will happen
   801   set_has_unsafe_access(false);
   802   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
   803   set_decompile_count(0);
   805   // Compilation level related initialization
   806   if (env()->comp_level() == CompLevel_fast_compile) {
   807     set_num_loop_opts(Tier1LoopOptsCount);
   808     set_do_inlining(Tier1Inline != 0);
   809     set_max_inline_size(Tier1MaxInlineSize);
   810     set_freq_inline_size(Tier1FreqInlineSize);
   811     set_do_scheduling(false);
   812     set_do_count_invocations(Tier1CountInvocations);
   813     set_do_method_data_update(Tier1UpdateMethodData);
   814   } else {
   815     assert(env()->comp_level() == CompLevel_full_optimization, "unknown comp level");
   816     set_num_loop_opts(LoopOptsCount);
   817     set_do_inlining(Inline);
   818     set_max_inline_size(MaxInlineSize);
   819     set_freq_inline_size(FreqInlineSize);
   820     set_do_scheduling(OptoScheduling);
   821     set_do_count_invocations(false);
   822     set_do_method_data_update(false);
   823   }
   825   if (debug_info()->recording_non_safepoints()) {
   826     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
   827                         (comp_arena(), 8, 0, NULL));
   828     set_default_node_notes(Node_Notes::make(this));
   829   }
   831   // // -- Initialize types before each compile --
   832   // // Update cached type information
   833   // if( _method && _method->constants() )
   834   //   Type::update_loaded_types(_method, _method->constants());
   836   // Init alias_type map.
   837   if (!_do_escape_analysis && aliaslevel == 3)
   838     aliaslevel = 2;  // No unique types without escape analysis
   839   _AliasLevel = aliaslevel;
   840   const int grow_ats = 16;
   841   _max_alias_types = grow_ats;
   842   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
   843   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
   844   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
   845   {
   846     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
   847   }
   848   // Initialize the first few types.
   849   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
   850   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
   851   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
   852   _num_alias_types = AliasIdxRaw+1;
   853   // Zero out the alias type cache.
   854   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
   855   // A NULL adr_type hits in the cache right away.  Preload the right answer.
   856   probe_alias_cache(NULL)->_index = AliasIdxTop;
   858   _intrinsics = NULL;
   859   _macro_nodes = new GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
   860   register_library_intrinsics();
   861 }
   863 //---------------------------init_start----------------------------------------
   864 // Install the StartNode on this compile object.
   865 void Compile::init_start(StartNode* s) {
   866   if (failing())
   867     return; // already failing
   868   assert(s == start(), "");
   869 }
   871 StartNode* Compile::start() const {
   872   assert(!failing(), "");
   873   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
   874     Node* start = root()->fast_out(i);
   875     if( start->is_Start() )
   876       return start->as_Start();
   877   }
   878   ShouldNotReachHere();
   879   return NULL;
   880 }
   882 //-------------------------------immutable_memory-------------------------------------
   883 // Access immutable memory
   884 Node* Compile::immutable_memory() {
   885   if (_immutable_memory != NULL) {
   886     return _immutable_memory;
   887   }
   888   StartNode* s = start();
   889   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
   890     Node *p = s->fast_out(i);
   891     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
   892       _immutable_memory = p;
   893       return _immutable_memory;
   894     }
   895   }
   896   ShouldNotReachHere();
   897   return NULL;
   898 }
   900 //----------------------set_cached_top_node------------------------------------
   901 // Install the cached top node, and make sure Node::is_top works correctly.
   902 void Compile::set_cached_top_node(Node* tn) {
   903   if (tn != NULL)  verify_top(tn);
   904   Node* old_top = _top;
   905   _top = tn;
   906   // Calling Node::setup_is_top allows the nodes the chance to adjust
   907   // their _out arrays.
   908   if (_top != NULL)     _top->setup_is_top();
   909   if (old_top != NULL)  old_top->setup_is_top();
   910   assert(_top == NULL || top()->is_top(), "");
   911 }
   913 #ifndef PRODUCT
   914 void Compile::verify_top(Node* tn) const {
   915   if (tn != NULL) {
   916     assert(tn->is_Con(), "top node must be a constant");
   917     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
   918     assert(tn->in(0) != NULL, "must have live top node");
   919   }
   920 }
   921 #endif
   924 ///-------------------Managing Per-Node Debug & Profile Info-------------------
   926 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
   927   guarantee(arr != NULL, "");
   928   int num_blocks = arr->length();
   929   if (grow_by < num_blocks)  grow_by = num_blocks;
   930   int num_notes = grow_by * _node_notes_block_size;
   931   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
   932   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
   933   while (num_notes > 0) {
   934     arr->append(notes);
   935     notes     += _node_notes_block_size;
   936     num_notes -= _node_notes_block_size;
   937   }
   938   assert(num_notes == 0, "exact multiple, please");
   939 }
   941 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
   942   if (source == NULL || dest == NULL)  return false;
   944   if (dest->is_Con())
   945     return false;               // Do not push debug info onto constants.
   947 #ifdef ASSERT
   948   // Leave a bread crumb trail pointing to the original node:
   949   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
   950     dest->set_debug_orig(source);
   951   }
   952 #endif
   954   if (node_note_array() == NULL)
   955     return false;               // Not collecting any notes now.
   957   // This is a copy onto a pre-existing node, which may already have notes.
   958   // If both nodes have notes, do not overwrite any pre-existing notes.
   959   Node_Notes* source_notes = node_notes_at(source->_idx);
   960   if (source_notes == NULL || source_notes->is_clear())  return false;
   961   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
   962   if (dest_notes == NULL || dest_notes->is_clear()) {
   963     return set_node_notes_at(dest->_idx, source_notes);
   964   }
   966   Node_Notes merged_notes = (*source_notes);
   967   // The order of operations here ensures that dest notes will win...
   968   merged_notes.update_from(dest_notes);
   969   return set_node_notes_at(dest->_idx, &merged_notes);
   970 }
   973 //--------------------------allow_range_check_smearing-------------------------
   974 // Gating condition for coalescing similar range checks.
   975 // Sometimes we try 'speculatively' replacing a series of a range checks by a
   976 // single covering check that is at least as strong as any of them.
   977 // If the optimization succeeds, the simplified (strengthened) range check
   978 // will always succeed.  If it fails, we will deopt, and then give up
   979 // on the optimization.
   980 bool Compile::allow_range_check_smearing() const {
   981   // If this method has already thrown a range-check,
   982   // assume it was because we already tried range smearing
   983   // and it failed.
   984   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
   985   return !already_trapped;
   986 }
   989 //------------------------------flatten_alias_type-----------------------------
   990 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
   991   int offset = tj->offset();
   992   TypePtr::PTR ptr = tj->ptr();
   994   // Process weird unsafe references.
   995   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
   996     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
   997     tj = TypeOopPtr::BOTTOM;
   998     ptr = tj->ptr();
   999     offset = tj->offset();
  1002   // Array pointers need some flattening
  1003   const TypeAryPtr *ta = tj->isa_aryptr();
  1004   if( ta && _AliasLevel >= 2 ) {
  1005     // For arrays indexed by constant indices, we flatten the alias
  1006     // space to include all of the array body.  Only the header, klass
  1007     // and array length can be accessed un-aliased.
  1008     if( offset != Type::OffsetBot ) {
  1009       if( ta->const_oop() ) { // methodDataOop or methodOop
  1010         offset = Type::OffsetBot;   // Flatten constant access into array body
  1011         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,Type::OffsetBot, ta->instance_id());
  1012       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
  1013         // range is OK as-is.
  1014         tj = ta = TypeAryPtr::RANGE;
  1015       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
  1016         tj = TypeInstPtr::KLASS; // all klass loads look alike
  1017         ta = TypeAryPtr::RANGE; // generic ignored junk
  1018         ptr = TypePtr::BotPTR;
  1019       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
  1020         tj = TypeInstPtr::MARK;
  1021         ta = TypeAryPtr::RANGE; // generic ignored junk
  1022         ptr = TypePtr::BotPTR;
  1023       } else {                  // Random constant offset into array body
  1024         offset = Type::OffsetBot;   // Flatten constant access into array body
  1025         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,Type::OffsetBot, ta->instance_id());
  1028     // Arrays of fixed size alias with arrays of unknown size.
  1029     if (ta->size() != TypeInt::POS) {
  1030       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
  1031       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset, ta->instance_id());
  1033     // Arrays of known objects become arrays of unknown objects.
  1034     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
  1035       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
  1036       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset, ta->instance_id());
  1038     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
  1039       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
  1040       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset, ta->instance_id());
  1042     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
  1043     // cannot be distinguished by bytecode alone.
  1044     if (ta->elem() == TypeInt::BOOL) {
  1045       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
  1046       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
  1047       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset, ta->instance_id());
  1049     // During the 2nd round of IterGVN, NotNull castings are removed.
  1050     // Make sure the Bottom and NotNull variants alias the same.
  1051     // Also, make sure exact and non-exact variants alias the same.
  1052     if( ptr == TypePtr::NotNull || ta->klass_is_exact() ) {
  1053       if (ta->const_oop()) {
  1054         tj = ta = TypeAryPtr::make(TypePtr::Constant,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
  1055       } else {
  1056         tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
  1061   // Oop pointers need some flattening
  1062   const TypeInstPtr *to = tj->isa_instptr();
  1063   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
  1064     if( ptr == TypePtr::Constant ) {
  1065       // No constant oop pointers (such as Strings); they alias with
  1066       // unknown strings.
  1067       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1068     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
  1069       // During the 2nd round of IterGVN, NotNull castings are removed.
  1070       // Make sure the Bottom and NotNull variants alias the same.
  1071       // Also, make sure exact and non-exact variants alias the same.
  1072       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset, to->instance_id());
  1074     // Canonicalize the holder of this field
  1075     ciInstanceKlass *k = to->klass()->as_instance_klass();
  1076     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
  1077       // First handle header references such as a LoadKlassNode, even if the
  1078       // object's klass is unloaded at compile time (4965979).
  1079       tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset, to->instance_id());
  1080     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
  1081       to = NULL;
  1082       tj = TypeOopPtr::BOTTOM;
  1083       offset = tj->offset();
  1084     } else {
  1085       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
  1086       if (!k->equals(canonical_holder) || tj->offset() != offset) {
  1087         tj = to = TypeInstPtr::make(TypePtr::BotPTR, canonical_holder, false, NULL, offset, to->instance_id());
  1092   // Klass pointers to object array klasses need some flattening
  1093   const TypeKlassPtr *tk = tj->isa_klassptr();
  1094   if( tk ) {
  1095     // If we are referencing a field within a Klass, we need
  1096     // to assume the worst case of an Object.  Both exact and
  1097     // inexact types must flatten to the same alias class.
  1098     // Since the flattened result for a klass is defined to be
  1099     // precisely java.lang.Object, use a constant ptr.
  1100     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
  1102       tj = tk = TypeKlassPtr::make(TypePtr::Constant,
  1103                                    TypeKlassPtr::OBJECT->klass(),
  1104                                    offset);
  1107     ciKlass* klass = tk->klass();
  1108     if( klass->is_obj_array_klass() ) {
  1109       ciKlass* k = TypeAryPtr::OOPS->klass();
  1110       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
  1111         k = TypeInstPtr::BOTTOM->klass();
  1112       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
  1115     // Check for precise loads from the primary supertype array and force them
  1116     // to the supertype cache alias index.  Check for generic array loads from
  1117     // the primary supertype array and also force them to the supertype cache
  1118     // alias index.  Since the same load can reach both, we need to merge
  1119     // these 2 disparate memories into the same alias class.  Since the
  1120     // primary supertype array is read-only, there's no chance of confusion
  1121     // where we bypass an array load and an array store.
  1122     uint off2 = offset - Klass::primary_supers_offset_in_bytes();
  1123     if( offset == Type::OffsetBot ||
  1124         off2 < Klass::primary_super_limit()*wordSize ) {
  1125       offset = sizeof(oopDesc) +Klass::secondary_super_cache_offset_in_bytes();
  1126       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
  1130   // Flatten all Raw pointers together.
  1131   if (tj->base() == Type::RawPtr)
  1132     tj = TypeRawPtr::BOTTOM;
  1134   if (tj->base() == Type::AnyPtr)
  1135     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
  1137   // Flatten all to bottom for now
  1138   switch( _AliasLevel ) {
  1139   case 0:
  1140     tj = TypePtr::BOTTOM;
  1141     break;
  1142   case 1:                       // Flatten to: oop, static, field or array
  1143     switch (tj->base()) {
  1144     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
  1145     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
  1146     case Type::AryPtr:   // do not distinguish arrays at all
  1147     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
  1148     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
  1149     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
  1150     default: ShouldNotReachHere();
  1152     break;
  1153   case 2:                       // No collasping at level 2; keep all splits
  1154   case 3:                       // No collasping at level 3; keep all splits
  1155     break;
  1156   default:
  1157     Unimplemented();
  1160   offset = tj->offset();
  1161   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
  1163   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
  1164           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
  1165           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
  1166           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
  1167           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1168           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1169           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
  1170           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
  1171   assert( tj->ptr() != TypePtr::TopPTR &&
  1172           tj->ptr() != TypePtr::AnyNull &&
  1173           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
  1174 //    assert( tj->ptr() != TypePtr::Constant ||
  1175 //            tj->base() == Type::RawPtr ||
  1176 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
  1178   return tj;
  1181 void Compile::AliasType::Init(int i, const TypePtr* at) {
  1182   _index = i;
  1183   _adr_type = at;
  1184   _field = NULL;
  1185   _is_rewritable = true; // default
  1186   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
  1187   if (atoop != NULL && atoop->is_instance()) {
  1188     const TypeOopPtr *gt = atoop->cast_to_instance(TypeOopPtr::UNKNOWN_INSTANCE);
  1189     _general_index = Compile::current()->get_alias_index(gt);
  1190   } else {
  1191     _general_index = 0;
  1195 //---------------------------------print_on------------------------------------
  1196 #ifndef PRODUCT
  1197 void Compile::AliasType::print_on(outputStream* st) {
  1198   if (index() < 10)
  1199         st->print("@ <%d> ", index());
  1200   else  st->print("@ <%d>",  index());
  1201   st->print(is_rewritable() ? "   " : " RO");
  1202   int offset = adr_type()->offset();
  1203   if (offset == Type::OffsetBot)
  1204         st->print(" +any");
  1205   else  st->print(" +%-3d", offset);
  1206   st->print(" in ");
  1207   adr_type()->dump_on(st);
  1208   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
  1209   if (field() != NULL && tjp) {
  1210     if (tjp->klass()  != field()->holder() ||
  1211         tjp->offset() != field()->offset_in_bytes()) {
  1212       st->print(" != ");
  1213       field()->print();
  1214       st->print(" ***");
  1219 void print_alias_types() {
  1220   Compile* C = Compile::current();
  1221   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
  1222   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
  1223     C->alias_type(idx)->print_on(tty);
  1224     tty->cr();
  1227 #endif
  1230 //----------------------------probe_alias_cache--------------------------------
  1231 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
  1232   intptr_t key = (intptr_t) adr_type;
  1233   key ^= key >> logAliasCacheSize;
  1234   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
  1238 //-----------------------------grow_alias_types--------------------------------
  1239 void Compile::grow_alias_types() {
  1240   const int old_ats  = _max_alias_types; // how many before?
  1241   const int new_ats  = old_ats;          // how many more?
  1242   const int grow_ats = old_ats+new_ats;  // how many now?
  1243   _max_alias_types = grow_ats;
  1244   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
  1245   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
  1246   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
  1247   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
  1251 //--------------------------------find_alias_type------------------------------
  1252 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create) {
  1253   if (_AliasLevel == 0)
  1254     return alias_type(AliasIdxBot);
  1256   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1257   if (ace->_adr_type == adr_type) {
  1258     return alias_type(ace->_index);
  1261   // Handle special cases.
  1262   if (adr_type == NULL)             return alias_type(AliasIdxTop);
  1263   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
  1265   // Do it the slow way.
  1266   const TypePtr* flat = flatten_alias_type(adr_type);
  1268 #ifdef ASSERT
  1269   assert(flat == flatten_alias_type(flat), "idempotent");
  1270   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
  1271   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
  1272     const TypeOopPtr* foop = flat->is_oopptr();
  1273     const TypePtr* xoop = foop->cast_to_exactness(!foop->klass_is_exact())->is_ptr();
  1274     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
  1276   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
  1277 #endif
  1279   int idx = AliasIdxTop;
  1280   for (int i = 0; i < num_alias_types(); i++) {
  1281     if (alias_type(i)->adr_type() == flat) {
  1282       idx = i;
  1283       break;
  1287   if (idx == AliasIdxTop) {
  1288     if (no_create)  return NULL;
  1289     // Grow the array if necessary.
  1290     if (_num_alias_types == _max_alias_types)  grow_alias_types();
  1291     // Add a new alias type.
  1292     idx = _num_alias_types++;
  1293     _alias_types[idx]->Init(idx, flat);
  1294     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
  1295     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
  1296     if (flat->isa_instptr()) {
  1297       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
  1298           && flat->is_instptr()->klass() == env()->Class_klass())
  1299         alias_type(idx)->set_rewritable(false);
  1301     if (flat->isa_klassptr()) {
  1302       if (flat->offset() == Klass::super_check_offset_offset_in_bytes() + (int)sizeof(oopDesc))
  1303         alias_type(idx)->set_rewritable(false);
  1304       if (flat->offset() == Klass::modifier_flags_offset_in_bytes() + (int)sizeof(oopDesc))
  1305         alias_type(idx)->set_rewritable(false);
  1306       if (flat->offset() == Klass::access_flags_offset_in_bytes() + (int)sizeof(oopDesc))
  1307         alias_type(idx)->set_rewritable(false);
  1308       if (flat->offset() == Klass::java_mirror_offset_in_bytes() + (int)sizeof(oopDesc))
  1309         alias_type(idx)->set_rewritable(false);
  1311     // %%% (We would like to finalize JavaThread::threadObj_offset(),
  1312     // but the base pointer type is not distinctive enough to identify
  1313     // references into JavaThread.)
  1315     // Check for final instance fields.
  1316     const TypeInstPtr* tinst = flat->isa_instptr();
  1317     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
  1318       ciInstanceKlass *k = tinst->klass()->as_instance_klass();
  1319       ciField* field = k->get_field_by_offset(tinst->offset(), false);
  1320       // Set field() and is_rewritable() attributes.
  1321       if (field != NULL)  alias_type(idx)->set_field(field);
  1323     const TypeKlassPtr* tklass = flat->isa_klassptr();
  1324     // Check for final static fields.
  1325     if (tklass && tklass->klass()->is_instance_klass()) {
  1326       ciInstanceKlass *k = tklass->klass()->as_instance_klass();
  1327       ciField* field = k->get_field_by_offset(tklass->offset(), true);
  1328       // Set field() and is_rewritable() attributes.
  1329       if (field != NULL)   alias_type(idx)->set_field(field);
  1333   // Fill the cache for next time.
  1334   ace->_adr_type = adr_type;
  1335   ace->_index    = idx;
  1336   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
  1338   // Might as well try to fill the cache for the flattened version, too.
  1339   AliasCacheEntry* face = probe_alias_cache(flat);
  1340   if (face->_adr_type == NULL) {
  1341     face->_adr_type = flat;
  1342     face->_index    = idx;
  1343     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
  1346   return alias_type(idx);
  1350 Compile::AliasType* Compile::alias_type(ciField* field) {
  1351   const TypeOopPtr* t;
  1352   if (field->is_static())
  1353     t = TypeKlassPtr::make(field->holder());
  1354   else
  1355     t = TypeOopPtr::make_from_klass_raw(field->holder());
  1356   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()));
  1357   assert(field->is_final() == !atp->is_rewritable(), "must get the rewritable bits correct");
  1358   return atp;
  1362 //------------------------------have_alias_type--------------------------------
  1363 bool Compile::have_alias_type(const TypePtr* adr_type) {
  1364   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1365   if (ace->_adr_type == adr_type) {
  1366     return true;
  1369   // Handle special cases.
  1370   if (adr_type == NULL)             return true;
  1371   if (adr_type == TypePtr::BOTTOM)  return true;
  1373   return find_alias_type(adr_type, true) != NULL;
  1376 //-----------------------------must_alias--------------------------------------
  1377 // True if all values of the given address type are in the given alias category.
  1378 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
  1379   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1380   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
  1381   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1382   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
  1384   // the only remaining possible overlap is identity
  1385   int adr_idx = get_alias_index(adr_type);
  1386   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1387   assert(adr_idx == alias_idx ||
  1388          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
  1389           && adr_type                       != TypeOopPtr::BOTTOM),
  1390          "should not be testing for overlap with an unsafe pointer");
  1391   return adr_idx == alias_idx;
  1394 //------------------------------can_alias--------------------------------------
  1395 // True if any values of the given address type are in the given alias category.
  1396 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
  1397   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1398   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
  1399   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1400   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
  1402   // the only remaining possible overlap is identity
  1403   int adr_idx = get_alias_index(adr_type);
  1404   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1405   return adr_idx == alias_idx;
  1410 //---------------------------pop_warm_call-------------------------------------
  1411 WarmCallInfo* Compile::pop_warm_call() {
  1412   WarmCallInfo* wci = _warm_calls;
  1413   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
  1414   return wci;
  1417 //----------------------------Inline_Warm--------------------------------------
  1418 int Compile::Inline_Warm() {
  1419   // If there is room, try to inline some more warm call sites.
  1420   // %%% Do a graph index compaction pass when we think we're out of space?
  1421   if (!InlineWarmCalls)  return 0;
  1423   int calls_made_hot = 0;
  1424   int room_to_grow   = NodeCountInliningCutoff - unique();
  1425   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
  1426   int amount_grown   = 0;
  1427   WarmCallInfo* call;
  1428   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
  1429     int est_size = (int)call->size();
  1430     if (est_size > (room_to_grow - amount_grown)) {
  1431       // This one won't fit anyway.  Get rid of it.
  1432       call->make_cold();
  1433       continue;
  1435     call->make_hot();
  1436     calls_made_hot++;
  1437     amount_grown   += est_size;
  1438     amount_to_grow -= est_size;
  1441   if (calls_made_hot > 0)  set_major_progress();
  1442   return calls_made_hot;
  1446 //----------------------------Finish_Warm--------------------------------------
  1447 void Compile::Finish_Warm() {
  1448   if (!InlineWarmCalls)  return;
  1449   if (failing())  return;
  1450   if (warm_calls() == NULL)  return;
  1452   // Clean up loose ends, if we are out of space for inlining.
  1453   WarmCallInfo* call;
  1454   while ((call = pop_warm_call()) != NULL) {
  1455     call->make_cold();
  1460 //------------------------------Optimize---------------------------------------
  1461 // Given a graph, optimize it.
  1462 void Compile::Optimize() {
  1463   TracePhase t1("optimizer", &_t_optimizer, true);
  1465 #ifndef PRODUCT
  1466   if (env()->break_at_compile()) {
  1467     BREAKPOINT;
  1470 #endif
  1472   ResourceMark rm;
  1473   int          loop_opts_cnt;
  1475   NOT_PRODUCT( verify_graph_edges(); )
  1477   print_method("Start");
  1480   // Iterative Global Value Numbering, including ideal transforms
  1481   // Initialize IterGVN with types and values from parse-time GVN
  1482   PhaseIterGVN igvn(initial_gvn());
  1484     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
  1485     igvn.optimize();
  1488   print_method("Iter GVN 1", 2);
  1490   if (failing())  return;
  1492   // get rid of the connection graph since it's information is not
  1493   // updated by optimizations
  1494   _congraph = NULL;
  1497   // Loop transforms on the ideal graph.  Range Check Elimination,
  1498   // peeling, unrolling, etc.
  1500   // Set loop opts counter
  1501   loop_opts_cnt = num_loop_opts();
  1502   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
  1504       TracePhase t2("idealLoop", &_t_idealLoop, true);
  1505       PhaseIdealLoop ideal_loop( igvn, NULL, true );
  1506       loop_opts_cnt--;
  1507       if (major_progress()) print_method("PhaseIdealLoop 1", 2);
  1508       if (failing())  return;
  1510     // Loop opts pass if partial peeling occurred in previous pass
  1511     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
  1512       TracePhase t3("idealLoop", &_t_idealLoop, true);
  1513       PhaseIdealLoop ideal_loop( igvn, NULL, false );
  1514       loop_opts_cnt--;
  1515       if (major_progress()) print_method("PhaseIdealLoop 2", 2);
  1516       if (failing())  return;
  1518     // Loop opts pass for loop-unrolling before CCP
  1519     if(major_progress() && (loop_opts_cnt > 0)) {
  1520       TracePhase t4("idealLoop", &_t_idealLoop, true);
  1521       PhaseIdealLoop ideal_loop( igvn, NULL, false );
  1522       loop_opts_cnt--;
  1523       if (major_progress()) print_method("PhaseIdealLoop 3", 2);
  1526   if (failing())  return;
  1528   // Conditional Constant Propagation;
  1529   PhaseCCP ccp( &igvn );
  1530   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
  1532     TracePhase t2("ccp", &_t_ccp, true);
  1533     ccp.do_transform();
  1535   print_method("PhaseCPP 1", 2);
  1537   assert( true, "Break here to ccp.dump_old2new_map()");
  1539   // Iterative Global Value Numbering, including ideal transforms
  1541     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
  1542     igvn = ccp;
  1543     igvn.optimize();
  1546   print_method("Iter GVN 2", 2);
  1548   if (failing())  return;
  1550   // Loop transforms on the ideal graph.  Range Check Elimination,
  1551   // peeling, unrolling, etc.
  1552   if(loop_opts_cnt > 0) {
  1553     debug_only( int cnt = 0; );
  1554     while(major_progress() && (loop_opts_cnt > 0)) {
  1555       TracePhase t2("idealLoop", &_t_idealLoop, true);
  1556       assert( cnt++ < 40, "infinite cycle in loop optimization" );
  1557       PhaseIdealLoop ideal_loop( igvn, NULL, true );
  1558       loop_opts_cnt--;
  1559       if (major_progress()) print_method("PhaseIdealLoop iterations", 2);
  1560       if (failing())  return;
  1564     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
  1565     PhaseMacroExpand  mex(igvn);
  1566     if (mex.expand_macro_nodes()) {
  1567       assert(failing(), "must bail out w/ explicit message");
  1568       return;
  1572  } // (End scope of igvn; run destructor if necessary for asserts.)
  1574   // A method with only infinite loops has no edges entering loops from root
  1576     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
  1577     if (final_graph_reshaping()) {
  1578       assert(failing(), "must bail out w/ explicit message");
  1579       return;
  1583   print_method("Optimize finished", 2);
  1587 //------------------------------Code_Gen---------------------------------------
  1588 // Given a graph, generate code for it
  1589 void Compile::Code_Gen() {
  1590   if (failing())  return;
  1592   // Perform instruction selection.  You might think we could reclaim Matcher
  1593   // memory PDQ, but actually the Matcher is used in generating spill code.
  1594   // Internals of the Matcher (including some VectorSets) must remain live
  1595   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
  1596   // set a bit in reclaimed memory.
  1598   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  1599   // nodes.  Mapping is only valid at the root of each matched subtree.
  1600   NOT_PRODUCT( verify_graph_edges(); )
  1602   Node_List proj_list;
  1603   Matcher m(proj_list);
  1604   _matcher = &m;
  1606     TracePhase t2("matcher", &_t_matcher, true);
  1607     m.match();
  1609   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  1610   // nodes.  Mapping is only valid at the root of each matched subtree.
  1611   NOT_PRODUCT( verify_graph_edges(); )
  1613   // If you have too many nodes, or if matching has failed, bail out
  1614   check_node_count(0, "out of nodes matching instructions");
  1615   if (failing())  return;
  1617   // Build a proper-looking CFG
  1618   PhaseCFG cfg(node_arena(), root(), m);
  1619   _cfg = &cfg;
  1621     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
  1622     cfg.Dominators();
  1623     if (failing())  return;
  1625     NOT_PRODUCT( verify_graph_edges(); )
  1627     cfg.Estimate_Block_Frequency();
  1628     cfg.GlobalCodeMotion(m,unique(),proj_list);
  1630     print_method("Global code motion", 2);
  1632     if (failing())  return;
  1633     NOT_PRODUCT( verify_graph_edges(); )
  1635     debug_only( cfg.verify(); )
  1637   NOT_PRODUCT( verify_graph_edges(); )
  1639   PhaseChaitin regalloc(unique(),cfg,m);
  1640   _regalloc = &regalloc;
  1642     TracePhase t2("regalloc", &_t_registerAllocation, true);
  1643     // Perform any platform dependent preallocation actions.  This is used,
  1644     // for example, to avoid taking an implicit null pointer exception
  1645     // using the frame pointer on win95.
  1646     _regalloc->pd_preallocate_hook();
  1648     // Perform register allocation.  After Chaitin, use-def chains are
  1649     // no longer accurate (at spill code) and so must be ignored.
  1650     // Node->LRG->reg mappings are still accurate.
  1651     _regalloc->Register_Allocate();
  1653     // Bail out if the allocator builds too many nodes
  1654     if (failing())  return;
  1657   // Prior to register allocation we kept empty basic blocks in case the
  1658   // the allocator needed a place to spill.  After register allocation we
  1659   // are not adding any new instructions.  If any basic block is empty, we
  1660   // can now safely remove it.
  1662     NOT_PRODUCT( TracePhase t2("removeEmpty", &_t_removeEmptyBlocks, TimeCompiler); )
  1663     cfg.RemoveEmpty();
  1666   // Perform any platform dependent postallocation verifications.
  1667   debug_only( _regalloc->pd_postallocate_verify_hook(); )
  1669   // Apply peephole optimizations
  1670   if( OptoPeephole ) {
  1671     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
  1672     PhasePeephole peep( _regalloc, cfg);
  1673     peep.do_transform();
  1676   // Convert Nodes to instruction bits in a buffer
  1678     // %%%% workspace merge brought two timers together for one job
  1679     TracePhase t2a("output", &_t_output, true);
  1680     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
  1681     Output();
  1684   print_method("End");
  1686   // He's dead, Jim.
  1687   _cfg     = (PhaseCFG*)0xdeadbeef;
  1688   _regalloc = (PhaseChaitin*)0xdeadbeef;
  1692 //------------------------------dump_asm---------------------------------------
  1693 // Dump formatted assembly
  1694 #ifndef PRODUCT
  1695 void Compile::dump_asm(int *pcs, uint pc_limit) {
  1696   bool cut_short = false;
  1697   tty->print_cr("#");
  1698   tty->print("#  ");  _tf->dump();  tty->cr();
  1699   tty->print_cr("#");
  1701   // For all blocks
  1702   int pc = 0x0;                 // Program counter
  1703   char starts_bundle = ' ';
  1704   _regalloc->dump_frame();
  1706   Node *n = NULL;
  1707   for( uint i=0; i<_cfg->_num_blocks; i++ ) {
  1708     if (VMThread::should_terminate()) { cut_short = true; break; }
  1709     Block *b = _cfg->_blocks[i];
  1710     if (b->is_connector() && !Verbose) continue;
  1711     n = b->_nodes[0];
  1712     if (pcs && n->_idx < pc_limit)
  1713       tty->print("%3.3x   ", pcs[n->_idx]);
  1714     else
  1715       tty->print("      ");
  1716     b->dump_head( &_cfg->_bbs );
  1717     if (b->is_connector()) {
  1718       tty->print_cr("        # Empty connector block");
  1719     } else if (b->num_preds() == 2 && b->pred(1)->is_CatchProj() && b->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
  1720       tty->print_cr("        # Block is sole successor of call");
  1723     // For all instructions
  1724     Node *delay = NULL;
  1725     for( uint j = 0; j<b->_nodes.size(); j++ ) {
  1726       if (VMThread::should_terminate()) { cut_short = true; break; }
  1727       n = b->_nodes[j];
  1728       if (valid_bundle_info(n)) {
  1729         Bundle *bundle = node_bundling(n);
  1730         if (bundle->used_in_unconditional_delay()) {
  1731           delay = n;
  1732           continue;
  1734         if (bundle->starts_bundle())
  1735           starts_bundle = '+';
  1738       if (WizardMode) n->dump();
  1740       if( !n->is_Region() &&    // Dont print in the Assembly
  1741           !n->is_Phi() &&       // a few noisely useless nodes
  1742           !n->is_Proj() &&
  1743           !n->is_MachTemp() &&
  1744           !n->is_Catch() &&     // Would be nice to print exception table targets
  1745           !n->is_MergeMem() &&  // Not very interesting
  1746           !n->is_top() &&       // Debug info table constants
  1747           !(n->is_Con() && !n->is_Mach())// Debug info table constants
  1748           ) {
  1749         if (pcs && n->_idx < pc_limit)
  1750           tty->print("%3.3x", pcs[n->_idx]);
  1751         else
  1752           tty->print("   ");
  1753         tty->print(" %c ", starts_bundle);
  1754         starts_bundle = ' ';
  1755         tty->print("\t");
  1756         n->format(_regalloc, tty);
  1757         tty->cr();
  1760       // If we have an instruction with a delay slot, and have seen a delay,
  1761       // then back up and print it
  1762       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
  1763         assert(delay != NULL, "no unconditional delay instruction");
  1764         if (WizardMode) delay->dump();
  1766         if (node_bundling(delay)->starts_bundle())
  1767           starts_bundle = '+';
  1768         if (pcs && n->_idx < pc_limit)
  1769           tty->print("%3.3x", pcs[n->_idx]);
  1770         else
  1771           tty->print("   ");
  1772         tty->print(" %c ", starts_bundle);
  1773         starts_bundle = ' ';
  1774         tty->print("\t");
  1775         delay->format(_regalloc, tty);
  1776         tty->print_cr("");
  1777         delay = NULL;
  1780       // Dump the exception table as well
  1781       if( n->is_Catch() && (Verbose || WizardMode) ) {
  1782         // Print the exception table for this offset
  1783         _handler_table.print_subtable_for(pc);
  1787     if (pcs && n->_idx < pc_limit)
  1788       tty->print_cr("%3.3x", pcs[n->_idx]);
  1789     else
  1790       tty->print_cr("");
  1792     assert(cut_short || delay == NULL, "no unconditional delay branch");
  1794   } // End of per-block dump
  1795   tty->print_cr("");
  1797   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
  1799 #endif
  1801 //------------------------------Final_Reshape_Counts---------------------------
  1802 // This class defines counters to help identify when a method
  1803 // may/must be executed using hardware with only 24-bit precision.
  1804 struct Final_Reshape_Counts : public StackObj {
  1805   int  _call_count;             // count non-inlined 'common' calls
  1806   int  _float_count;            // count float ops requiring 24-bit precision
  1807   int  _double_count;           // count double ops requiring more precision
  1808   int  _java_call_count;        // count non-inlined 'java' calls
  1809   VectorSet _visited;           // Visitation flags
  1810   Node_List _tests;             // Set of IfNodes & PCTableNodes
  1812   Final_Reshape_Counts() :
  1813     _call_count(0), _float_count(0), _double_count(0), _java_call_count(0),
  1814     _visited( Thread::current()->resource_area() ) { }
  1816   void inc_call_count  () { _call_count  ++; }
  1817   void inc_float_count () { _float_count ++; }
  1818   void inc_double_count() { _double_count++; }
  1819   void inc_java_call_count() { _java_call_count++; }
  1821   int  get_call_count  () const { return _call_count  ; }
  1822   int  get_float_count () const { return _float_count ; }
  1823   int  get_double_count() const { return _double_count; }
  1824   int  get_java_call_count() const { return _java_call_count; }
  1825 };
  1827 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
  1828   ciInstanceKlass *k = tp->klass()->as_instance_klass();
  1829   // Make sure the offset goes inside the instance layout.
  1830   return k->contains_field_offset(tp->offset());
  1831   // Note that OffsetBot and OffsetTop are very negative.
  1834 //------------------------------final_graph_reshaping_impl----------------------
  1835 // Implement items 1-5 from final_graph_reshaping below.
  1836 static void final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &fpu ) {
  1838   uint nop = n->Opcode();
  1840   // Check for 2-input instruction with "last use" on right input.
  1841   // Swap to left input.  Implements item (2).
  1842   if( n->req() == 3 &&          // two-input instruction
  1843       n->in(1)->outcnt() > 1 && // left use is NOT a last use
  1844       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
  1845       n->in(2)->outcnt() == 1 &&// right use IS a last use
  1846       !n->in(2)->is_Con() ) {   // right use is not a constant
  1847     // Check for commutative opcode
  1848     switch( nop ) {
  1849     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
  1850     case Op_MaxI:  case Op_MinI:
  1851     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
  1852     case Op_AndL:  case Op_XorL:  case Op_OrL:
  1853     case Op_AndI:  case Op_XorI:  case Op_OrI: {
  1854       // Move "last use" input to left by swapping inputs
  1855       n->swap_edges(1, 2);
  1856       break;
  1858     default:
  1859       break;
  1863   // Count FPU ops and common calls, implements item (3)
  1864   switch( nop ) {
  1865   // Count all float operations that may use FPU
  1866   case Op_AddF:
  1867   case Op_SubF:
  1868   case Op_MulF:
  1869   case Op_DivF:
  1870   case Op_NegF:
  1871   case Op_ModF:
  1872   case Op_ConvI2F:
  1873   case Op_ConF:
  1874   case Op_CmpF:
  1875   case Op_CmpF3:
  1876   // case Op_ConvL2F: // longs are split into 32-bit halves
  1877     fpu.inc_float_count();
  1878     break;
  1880   case Op_ConvF2D:
  1881   case Op_ConvD2F:
  1882     fpu.inc_float_count();
  1883     fpu.inc_double_count();
  1884     break;
  1886   // Count all double operations that may use FPU
  1887   case Op_AddD:
  1888   case Op_SubD:
  1889   case Op_MulD:
  1890   case Op_DivD:
  1891   case Op_NegD:
  1892   case Op_ModD:
  1893   case Op_ConvI2D:
  1894   case Op_ConvD2I:
  1895   // case Op_ConvL2D: // handled by leaf call
  1896   // case Op_ConvD2L: // handled by leaf call
  1897   case Op_ConD:
  1898   case Op_CmpD:
  1899   case Op_CmpD3:
  1900     fpu.inc_double_count();
  1901     break;
  1902   case Op_Opaque1:              // Remove Opaque Nodes before matching
  1903   case Op_Opaque2:              // Remove Opaque Nodes before matching
  1904     n->replace_by(n->in(1));
  1905     break;
  1906   case Op_CallStaticJava:
  1907   case Op_CallJava:
  1908   case Op_CallDynamicJava:
  1909     fpu.inc_java_call_count(); // Count java call site;
  1910   case Op_CallRuntime:
  1911   case Op_CallLeaf:
  1912   case Op_CallLeafNoFP: {
  1913     assert( n->is_Call(), "" );
  1914     CallNode *call = n->as_Call();
  1915     // Count call sites where the FP mode bit would have to be flipped.
  1916     // Do not count uncommon runtime calls:
  1917     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
  1918     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
  1919     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
  1920       fpu.inc_call_count();   // Count the call site
  1921     } else {                  // See if uncommon argument is shared
  1922       Node *n = call->in(TypeFunc::Parms);
  1923       int nop = n->Opcode();
  1924       // Clone shared simple arguments to uncommon calls, item (1).
  1925       if( n->outcnt() > 1 &&
  1926           !n->is_Proj() &&
  1927           nop != Op_CreateEx &&
  1928           nop != Op_CheckCastPP &&
  1929           !n->is_Mem() ) {
  1930         Node *x = n->clone();
  1931         call->set_req( TypeFunc::Parms, x );
  1934     break;
  1937   case Op_StoreD:
  1938   case Op_LoadD:
  1939   case Op_LoadD_unaligned:
  1940     fpu.inc_double_count();
  1941     goto handle_mem;
  1942   case Op_StoreF:
  1943   case Op_LoadF:
  1944     fpu.inc_float_count();
  1945     goto handle_mem;
  1947   case Op_StoreB:
  1948   case Op_StoreC:
  1949   case Op_StoreCM:
  1950   case Op_StorePConditional:
  1951   case Op_StoreI:
  1952   case Op_StoreL:
  1953   case Op_StoreLConditional:
  1954   case Op_CompareAndSwapI:
  1955   case Op_CompareAndSwapL:
  1956   case Op_CompareAndSwapP:
  1957   case Op_CompareAndSwapN:
  1958   case Op_StoreP:
  1959   case Op_StoreN:
  1960   case Op_LoadB:
  1961   case Op_LoadC:
  1962   case Op_LoadI:
  1963   case Op_LoadKlass:
  1964   case Op_LoadL:
  1965   case Op_LoadL_unaligned:
  1966   case Op_LoadPLocked:
  1967   case Op_LoadLLocked:
  1968   case Op_LoadP:
  1969   case Op_LoadN:
  1970   case Op_LoadRange:
  1971   case Op_LoadS: {
  1972   handle_mem:
  1973 #ifdef ASSERT
  1974     if( VerifyOptoOopOffsets ) {
  1975       assert( n->is_Mem(), "" );
  1976       MemNode *mem  = (MemNode*)n;
  1977       // Check to see if address types have grounded out somehow.
  1978       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
  1979       assert( !tp || oop_offset_is_sane(tp), "" );
  1981 #endif
  1982     break;
  1985   case Op_AddP: {               // Assert sane base pointers
  1986     const Node *addp = n->in(AddPNode::Address);
  1987     assert( !addp->is_AddP() ||
  1988             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
  1989             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
  1990             "Base pointers must match" );
  1991     break;
  1994   case Op_ModI:
  1995     if (UseDivMod) {
  1996       // Check if a%b and a/b both exist
  1997       Node* d = n->find_similar(Op_DivI);
  1998       if (d) {
  1999         // Replace them with a fused divmod if supported
  2000         Compile* C = Compile::current();
  2001         if (Matcher::has_match_rule(Op_DivModI)) {
  2002           DivModINode* divmod = DivModINode::make(C, n);
  2003           d->replace_by(divmod->div_proj());
  2004           n->replace_by(divmod->mod_proj());
  2005         } else {
  2006           // replace a%b with a-((a/b)*b)
  2007           Node* mult = new (C, 3) MulINode(d, d->in(2));
  2008           Node* sub  = new (C, 3) SubINode(d->in(1), mult);
  2009           n->replace_by( sub );
  2013     break;
  2015   case Op_ModL:
  2016     if (UseDivMod) {
  2017       // Check if a%b and a/b both exist
  2018       Node* d = n->find_similar(Op_DivL);
  2019       if (d) {
  2020         // Replace them with a fused divmod if supported
  2021         Compile* C = Compile::current();
  2022         if (Matcher::has_match_rule(Op_DivModL)) {
  2023           DivModLNode* divmod = DivModLNode::make(C, n);
  2024           d->replace_by(divmod->div_proj());
  2025           n->replace_by(divmod->mod_proj());
  2026         } else {
  2027           // replace a%b with a-((a/b)*b)
  2028           Node* mult = new (C, 3) MulLNode(d, d->in(2));
  2029           Node* sub  = new (C, 3) SubLNode(d->in(1), mult);
  2030           n->replace_by( sub );
  2034     break;
  2036   case Op_Load16B:
  2037   case Op_Load8B:
  2038   case Op_Load4B:
  2039   case Op_Load8S:
  2040   case Op_Load4S:
  2041   case Op_Load2S:
  2042   case Op_Load8C:
  2043   case Op_Load4C:
  2044   case Op_Load2C:
  2045   case Op_Load4I:
  2046   case Op_Load2I:
  2047   case Op_Load2L:
  2048   case Op_Load4F:
  2049   case Op_Load2F:
  2050   case Op_Load2D:
  2051   case Op_Store16B:
  2052   case Op_Store8B:
  2053   case Op_Store4B:
  2054   case Op_Store8C:
  2055   case Op_Store4C:
  2056   case Op_Store2C:
  2057   case Op_Store4I:
  2058   case Op_Store2I:
  2059   case Op_Store2L:
  2060   case Op_Store4F:
  2061   case Op_Store2F:
  2062   case Op_Store2D:
  2063     break;
  2065   case Op_PackB:
  2066   case Op_PackS:
  2067   case Op_PackC:
  2068   case Op_PackI:
  2069   case Op_PackF:
  2070   case Op_PackL:
  2071   case Op_PackD:
  2072     if (n->req()-1 > 2) {
  2073       // Replace many operand PackNodes with a binary tree for matching
  2074       PackNode* p = (PackNode*) n;
  2075       Node* btp = p->binaryTreePack(Compile::current(), 1, n->req());
  2076       n->replace_by(btp);
  2078     break;
  2079   default:
  2080     assert( !n->is_Call(), "" );
  2081     assert( !n->is_Mem(), "" );
  2082     break;
  2085   // Collect CFG split points
  2086   if (n->is_MultiBranch())
  2087     fpu._tests.push(n);
  2090 //------------------------------final_graph_reshaping_walk---------------------
  2091 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
  2092 // requires that the walk visits a node's inputs before visiting the node.
  2093 static void final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &fpu ) {
  2094   fpu._visited.set(root->_idx); // first, mark node as visited
  2095   uint cnt = root->req();
  2096   Node *n = root;
  2097   uint  i = 0;
  2098   while (true) {
  2099     if (i < cnt) {
  2100       // Place all non-visited non-null inputs onto stack
  2101       Node* m = n->in(i);
  2102       ++i;
  2103       if (m != NULL && !fpu._visited.test_set(m->_idx)) {
  2104         cnt = m->req();
  2105         nstack.push(n, i); // put on stack parent and next input's index
  2106         n = m;
  2107         i = 0;
  2109     } else {
  2110       // Now do post-visit work
  2111       final_graph_reshaping_impl( n, fpu );
  2112       if (nstack.is_empty())
  2113         break;             // finished
  2114       n = nstack.node();   // Get node from stack
  2115       cnt = n->req();
  2116       i = nstack.index();
  2117       nstack.pop();        // Shift to the next node on stack
  2122 //------------------------------final_graph_reshaping--------------------------
  2123 // Final Graph Reshaping.
  2124 //
  2125 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
  2126 //     and not commoned up and forced early.  Must come after regular
  2127 //     optimizations to avoid GVN undoing the cloning.  Clone constant
  2128 //     inputs to Loop Phis; these will be split by the allocator anyways.
  2129 //     Remove Opaque nodes.
  2130 // (2) Move last-uses by commutative operations to the left input to encourage
  2131 //     Intel update-in-place two-address operations and better register usage
  2132 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
  2133 //     calls canonicalizing them back.
  2134 // (3) Count the number of double-precision FP ops, single-precision FP ops
  2135 //     and call sites.  On Intel, we can get correct rounding either by
  2136 //     forcing singles to memory (requires extra stores and loads after each
  2137 //     FP bytecode) or we can set a rounding mode bit (requires setting and
  2138 //     clearing the mode bit around call sites).  The mode bit is only used
  2139 //     if the relative frequency of single FP ops to calls is low enough.
  2140 //     This is a key transform for SPEC mpeg_audio.
  2141 // (4) Detect infinite loops; blobs of code reachable from above but not
  2142 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
  2143 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
  2144 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
  2145 //     Detection is by looking for IfNodes where only 1 projection is
  2146 //     reachable from below or CatchNodes missing some targets.
  2147 // (5) Assert for insane oop offsets in debug mode.
  2149 bool Compile::final_graph_reshaping() {
  2150   // an infinite loop may have been eliminated by the optimizer,
  2151   // in which case the graph will be empty.
  2152   if (root()->req() == 1) {
  2153     record_method_not_compilable("trivial infinite loop");
  2154     return true;
  2157   Final_Reshape_Counts fpu;
  2159   // Visit everybody reachable!
  2160   // Allocate stack of size C->unique()/2 to avoid frequent realloc
  2161   Node_Stack nstack(unique() >> 1);
  2162   final_graph_reshaping_walk(nstack, root(), fpu);
  2164   // Check for unreachable (from below) code (i.e., infinite loops).
  2165   for( uint i = 0; i < fpu._tests.size(); i++ ) {
  2166     MultiBranchNode *n = fpu._tests[i]->as_MultiBranch();
  2167     // Get number of CFG targets.
  2168     // Note that PCTables include exception targets after calls.
  2169     uint required_outcnt = n->required_outcnt();
  2170     if (n->outcnt() != required_outcnt) {
  2171       // Check for a few special cases.  Rethrow Nodes never take the
  2172       // 'fall-thru' path, so expected kids is 1 less.
  2173       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
  2174         if (n->in(0)->in(0)->is_Call()) {
  2175           CallNode *call = n->in(0)->in(0)->as_Call();
  2176           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
  2177             required_outcnt--;      // Rethrow always has 1 less kid
  2178           } else if (call->req() > TypeFunc::Parms &&
  2179                      call->is_CallDynamicJava()) {
  2180             // Check for null receiver. In such case, the optimizer has
  2181             // detected that the virtual call will always result in a null
  2182             // pointer exception. The fall-through projection of this CatchNode
  2183             // will not be populated.
  2184             Node *arg0 = call->in(TypeFunc::Parms);
  2185             if (arg0->is_Type() &&
  2186                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
  2187               required_outcnt--;
  2189           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
  2190                      call->req() > TypeFunc::Parms+1 &&
  2191                      call->is_CallStaticJava()) {
  2192             // Check for negative array length. In such case, the optimizer has
  2193             // detected that the allocation attempt will always result in an
  2194             // exception. There is no fall-through projection of this CatchNode .
  2195             Node *arg1 = call->in(TypeFunc::Parms+1);
  2196             if (arg1->is_Type() &&
  2197                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
  2198               required_outcnt--;
  2203       // Recheck with a better notion of 'required_outcnt'
  2204       if (n->outcnt() != required_outcnt) {
  2205         record_method_not_compilable("malformed control flow");
  2206         return true;            // Not all targets reachable!
  2209     // Check that I actually visited all kids.  Unreached kids
  2210     // must be infinite loops.
  2211     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
  2212       if (!fpu._visited.test(n->fast_out(j)->_idx)) {
  2213         record_method_not_compilable("infinite loop");
  2214         return true;            // Found unvisited kid; must be unreach
  2218   // If original bytecodes contained a mixture of floats and doubles
  2219   // check if the optimizer has made it homogenous, item (3).
  2220   if( Use24BitFPMode && Use24BitFP &&
  2221       fpu.get_float_count() > 32 &&
  2222       fpu.get_double_count() == 0 &&
  2223       (10 * fpu.get_call_count() < fpu.get_float_count()) ) {
  2224     set_24_bit_selection_and_mode( false,  true );
  2227   set_has_java_calls(fpu.get_java_call_count() > 0);
  2229   // No infinite loops, no reason to bail out.
  2230   return false;
  2233 //-----------------------------too_many_traps----------------------------------
  2234 // Report if there are too many traps at the current method and bci.
  2235 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
  2236 bool Compile::too_many_traps(ciMethod* method,
  2237                              int bci,
  2238                              Deoptimization::DeoptReason reason) {
  2239   ciMethodData* md = method->method_data();
  2240   if (md->is_empty()) {
  2241     // Assume the trap has not occurred, or that it occurred only
  2242     // because of a transient condition during start-up in the interpreter.
  2243     return false;
  2245   if (md->has_trap_at(bci, reason) != 0) {
  2246     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
  2247     // Also, if there are multiple reasons, or if there is no per-BCI record,
  2248     // assume the worst.
  2249     if (log())
  2250       log()->elem("observe trap='%s' count='%d'",
  2251                   Deoptimization::trap_reason_name(reason),
  2252                   md->trap_count(reason));
  2253     return true;
  2254   } else {
  2255     // Ignore method/bci and see if there have been too many globally.
  2256     return too_many_traps(reason, md);
  2260 // Less-accurate variant which does not require a method and bci.
  2261 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
  2262                              ciMethodData* logmd) {
  2263  if (trap_count(reason) >= (uint)PerMethodTrapLimit) {
  2264     // Too many traps globally.
  2265     // Note that we use cumulative trap_count, not just md->trap_count.
  2266     if (log()) {
  2267       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
  2268       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
  2269                   Deoptimization::trap_reason_name(reason),
  2270                   mcount, trap_count(reason));
  2272     return true;
  2273   } else {
  2274     // The coast is clear.
  2275     return false;
  2279 //--------------------------too_many_recompiles--------------------------------
  2280 // Report if there are too many recompiles at the current method and bci.
  2281 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
  2282 // Is not eager to return true, since this will cause the compiler to use
  2283 // Action_none for a trap point, to avoid too many recompilations.
  2284 bool Compile::too_many_recompiles(ciMethod* method,
  2285                                   int bci,
  2286                                   Deoptimization::DeoptReason reason) {
  2287   ciMethodData* md = method->method_data();
  2288   if (md->is_empty()) {
  2289     // Assume the trap has not occurred, or that it occurred only
  2290     // because of a transient condition during start-up in the interpreter.
  2291     return false;
  2293   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
  2294   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
  2295   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
  2296   Deoptimization::DeoptReason per_bc_reason
  2297     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
  2298   if ((per_bc_reason == Deoptimization::Reason_none
  2299        || md->has_trap_at(bci, reason) != 0)
  2300       // The trap frequency measure we care about is the recompile count:
  2301       && md->trap_recompiled_at(bci)
  2302       && md->overflow_recompile_count() >= bc_cutoff) {
  2303     // Do not emit a trap here if it has already caused recompilations.
  2304     // Also, if there are multiple reasons, or if there is no per-BCI record,
  2305     // assume the worst.
  2306     if (log())
  2307       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
  2308                   Deoptimization::trap_reason_name(reason),
  2309                   md->trap_count(reason),
  2310                   md->overflow_recompile_count());
  2311     return true;
  2312   } else if (trap_count(reason) != 0
  2313              && decompile_count() >= m_cutoff) {
  2314     // Too many recompiles globally, and we have seen this sort of trap.
  2315     // Use cumulative decompile_count, not just md->decompile_count.
  2316     if (log())
  2317       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
  2318                   Deoptimization::trap_reason_name(reason),
  2319                   md->trap_count(reason), trap_count(reason),
  2320                   md->decompile_count(), decompile_count());
  2321     return true;
  2322   } else {
  2323     // The coast is clear.
  2324     return false;
  2329 #ifndef PRODUCT
  2330 //------------------------------verify_graph_edges---------------------------
  2331 // Walk the Graph and verify that there is a one-to-one correspondence
  2332 // between Use-Def edges and Def-Use edges in the graph.
  2333 void Compile::verify_graph_edges(bool no_dead_code) {
  2334   if (VerifyGraphEdges) {
  2335     ResourceArea *area = Thread::current()->resource_area();
  2336     Unique_Node_List visited(area);
  2337     // Call recursive graph walk to check edges
  2338     _root->verify_edges(visited);
  2339     if (no_dead_code) {
  2340       // Now make sure that no visited node is used by an unvisited node.
  2341       bool dead_nodes = 0;
  2342       Unique_Node_List checked(area);
  2343       while (visited.size() > 0) {
  2344         Node* n = visited.pop();
  2345         checked.push(n);
  2346         for (uint i = 0; i < n->outcnt(); i++) {
  2347           Node* use = n->raw_out(i);
  2348           if (checked.member(use))  continue;  // already checked
  2349           if (visited.member(use))  continue;  // already in the graph
  2350           if (use->is_Con())        continue;  // a dead ConNode is OK
  2351           // At this point, we have found a dead node which is DU-reachable.
  2352           if (dead_nodes++ == 0)
  2353             tty->print_cr("*** Dead nodes reachable via DU edges:");
  2354           use->dump(2);
  2355           tty->print_cr("---");
  2356           checked.push(use);  // No repeats; pretend it is now checked.
  2359       assert(dead_nodes == 0, "using nodes must be reachable from root");
  2363 #endif
  2365 // The Compile object keeps track of failure reasons separately from the ciEnv.
  2366 // This is required because there is not quite a 1-1 relation between the
  2367 // ciEnv and its compilation task and the Compile object.  Note that one
  2368 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
  2369 // to backtrack and retry without subsuming loads.  Other than this backtracking
  2370 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
  2371 // by the logic in C2Compiler.
  2372 void Compile::record_failure(const char* reason) {
  2373   if (log() != NULL) {
  2374     log()->elem("failure reason='%s' phase='compile'", reason);
  2376   if (_failure_reason == NULL) {
  2377     // Record the first failure reason.
  2378     _failure_reason = reason;
  2380   _root = NULL;  // flush the graph, too
  2383 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
  2384   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false)
  2386   if (dolog) {
  2387     C = Compile::current();
  2388     _log = C->log();
  2389   } else {
  2390     C = NULL;
  2391     _log = NULL;
  2393   if (_log != NULL) {
  2394     _log->begin_head("phase name='%s' nodes='%d'", name, C->unique());
  2395     _log->stamp();
  2396     _log->end_head();
  2400 Compile::TracePhase::~TracePhase() {
  2401   if (_log != NULL) {
  2402     _log->done("phase nodes='%d'", C->unique());

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