src/share/vm/opto/compile.cpp

Tue, 02 Sep 2008 15:18:26 -0400

author
coleenp
date
Tue, 02 Sep 2008 15:18:26 -0400
changeset 760
93befa083681
parent 728
c3e045194476
child 768
7484fa4b8825
permissions
-rw-r--r--

6741004: UseLargePages + UseCompressedOops breaks implicit null checking guard page
Summary: Turn off c2 implicit null checking on windows and large pages specified.
Reviewed-by: jrose, xlu

     1 /*
     2  * Copyright 1997-2008 Sun Microsystems, Inc.  All Rights Reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 #include "incls/_precompiled.incl"
    26 #include "incls/_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   _compile->end_method();
   317   if (_compile->scratch_buffer_blob() != NULL)
   318     BufferBlob::free(_compile->scratch_buffer_blob());
   319   _compile->env()->set_compiler_data(NULL);
   320 }
   323 //----------------------------print_compile_messages---------------------------
   324 void Compile::print_compile_messages() {
   325 #ifndef PRODUCT
   326   // Check if recompiling
   327   if (_subsume_loads == false && PrintOpto) {
   328     // Recompiling without allowing machine instructions to subsume loads
   329     tty->print_cr("*********************************************************");
   330     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
   331     tty->print_cr("*********************************************************");
   332   }
   333   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
   334     // Recompiling without escape analysis
   335     tty->print_cr("*********************************************************");
   336     tty->print_cr("** Bailout: Recompile without escape analysis          **");
   337     tty->print_cr("*********************************************************");
   338   }
   339   if (env()->break_at_compile()) {
   340     // Open the debugger when compiing this method.
   341     tty->print("### Breaking when compiling: ");
   342     method()->print_short_name();
   343     tty->cr();
   344     BREAKPOINT;
   345   }
   347   if( PrintOpto ) {
   348     if (is_osr_compilation()) {
   349       tty->print("[OSR]%3d", _compile_id);
   350     } else {
   351       tty->print("%3d", _compile_id);
   352     }
   353   }
   354 #endif
   355 }
   358 void Compile::init_scratch_buffer_blob() {
   359   if( scratch_buffer_blob() != NULL )  return;
   361   // Construct a temporary CodeBuffer to have it construct a BufferBlob
   362   // Cache this BufferBlob for this compile.
   363   ResourceMark rm;
   364   int size = (MAX_inst_size + MAX_stubs_size + MAX_const_size);
   365   BufferBlob* blob = BufferBlob::create("Compile::scratch_buffer", size);
   366   // Record the buffer blob for next time.
   367   set_scratch_buffer_blob(blob);
   368   // Have we run out of code space?
   369   if (scratch_buffer_blob() == NULL) {
   370     // Let CompilerBroker disable further compilations.
   371     record_failure("Not enough space for scratch buffer in CodeCache");
   372     return;
   373   }
   375   // Initialize the relocation buffers
   376   relocInfo* locs_buf = (relocInfo*) blob->instructions_end() - MAX_locs_size;
   377   set_scratch_locs_memory(locs_buf);
   378 }
   381 //-----------------------scratch_emit_size-------------------------------------
   382 // Helper function that computes size by emitting code
   383 uint Compile::scratch_emit_size(const Node* n) {
   384   // Emit into a trash buffer and count bytes emitted.
   385   // This is a pretty expensive way to compute a size,
   386   // but it works well enough if seldom used.
   387   // All common fixed-size instructions are given a size
   388   // method by the AD file.
   389   // Note that the scratch buffer blob and locs memory are
   390   // allocated at the beginning of the compile task, and
   391   // may be shared by several calls to scratch_emit_size.
   392   // The allocation of the scratch buffer blob is particularly
   393   // expensive, since it has to grab the code cache lock.
   394   BufferBlob* blob = this->scratch_buffer_blob();
   395   assert(blob != NULL, "Initialize BufferBlob at start");
   396   assert(blob->size() > MAX_inst_size, "sanity");
   397   relocInfo* locs_buf = scratch_locs_memory();
   398   address blob_begin = blob->instructions_begin();
   399   address blob_end   = (address)locs_buf;
   400   assert(blob->instructions_contains(blob_end), "sanity");
   401   CodeBuffer buf(blob_begin, blob_end - blob_begin);
   402   buf.initialize_consts_size(MAX_const_size);
   403   buf.initialize_stubs_size(MAX_stubs_size);
   404   assert(locs_buf != NULL, "sanity");
   405   int lsize = MAX_locs_size / 2;
   406   buf.insts()->initialize_shared_locs(&locs_buf[0],     lsize);
   407   buf.stubs()->initialize_shared_locs(&locs_buf[lsize], lsize);
   408   n->emit(buf, this->regalloc());
   409   return buf.code_size();
   410 }
   413 // ============================================================================
   414 //------------------------------Compile standard-------------------------------
   415 debug_only( int Compile::_debug_idx = 100000; )
   417 // Compile a method.  entry_bci is -1 for normal compilations and indicates
   418 // the continuation bci for on stack replacement.
   421 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci, bool subsume_loads, bool do_escape_analysis )
   422                 : Phase(Compiler),
   423                   _env(ci_env),
   424                   _log(ci_env->log()),
   425                   _compile_id(ci_env->compile_id()),
   426                   _save_argument_registers(false),
   427                   _stub_name(NULL),
   428                   _stub_function(NULL),
   429                   _stub_entry_point(NULL),
   430                   _method(target),
   431                   _entry_bci(osr_bci),
   432                   _initial_gvn(NULL),
   433                   _for_igvn(NULL),
   434                   _warm_calls(NULL),
   435                   _subsume_loads(subsume_loads),
   436                   _do_escape_analysis(do_escape_analysis),
   437                   _failure_reason(NULL),
   438                   _code_buffer("Compile::Fill_buffer"),
   439                   _orig_pc_slot(0),
   440                   _orig_pc_slot_offset_in_bytes(0),
   441                   _node_bundling_limit(0),
   442                   _node_bundling_base(NULL),
   443 #ifndef PRODUCT
   444                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
   445                   _printer(IdealGraphPrinter::printer()),
   446 #endif
   447                   _congraph(NULL) {
   448   C = this;
   450   CompileWrapper cw(this);
   451 #ifndef PRODUCT
   452   if (TimeCompiler2) {
   453     tty->print(" ");
   454     target->holder()->name()->print();
   455     tty->print(".");
   456     target->print_short_name();
   457     tty->print("  ");
   458   }
   459   TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
   460   TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
   461   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
   462   if (!print_opto_assembly) {
   463     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
   464     if (print_assembly && !Disassembler::can_decode()) {
   465       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
   466       print_opto_assembly = true;
   467     }
   468   }
   469   set_print_assembly(print_opto_assembly);
   470 #endif
   472   if (ProfileTraps) {
   473     // Make sure the method being compiled gets its own MDO,
   474     // so we can at least track the decompile_count().
   475     method()->build_method_data();
   476   }
   478   Init(::AliasLevel);
   481   print_compile_messages();
   483   if (UseOldInlining || PrintCompilation NOT_PRODUCT( || PrintOpto) )
   484     _ilt = InlineTree::build_inline_tree_root();
   485   else
   486     _ilt = NULL;
   488   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
   489   assert(num_alias_types() >= AliasIdxRaw, "");
   491 #define MINIMUM_NODE_HASH  1023
   492   // Node list that Iterative GVN will start with
   493   Unique_Node_List for_igvn(comp_arena());
   494   set_for_igvn(&for_igvn);
   496   // GVN that will be run immediately on new nodes
   497   uint estimated_size = method()->code_size()*4+64;
   498   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
   499   PhaseGVN gvn(node_arena(), estimated_size);
   500   set_initial_gvn(&gvn);
   502   { // Scope for timing the parser
   503     TracePhase t3("parse", &_t_parser, true);
   505     // Put top into the hash table ASAP.
   506     initial_gvn()->transform_no_reclaim(top());
   508     // Set up tf(), start(), and find a CallGenerator.
   509     CallGenerator* cg;
   510     if (is_osr_compilation()) {
   511       const TypeTuple *domain = StartOSRNode::osr_domain();
   512       const TypeTuple *range = TypeTuple::make_range(method()->signature());
   513       init_tf(TypeFunc::make(domain, range));
   514       StartNode* s = new (this, 2) StartOSRNode(root(), domain);
   515       initial_gvn()->set_type_bottom(s);
   516       init_start(s);
   517       cg = CallGenerator::for_osr(method(), entry_bci());
   518     } else {
   519       // Normal case.
   520       init_tf(TypeFunc::make(method()));
   521       StartNode* s = new (this, 2) StartNode(root(), tf()->domain());
   522       initial_gvn()->set_type_bottom(s);
   523       init_start(s);
   524       float past_uses = method()->interpreter_invocation_count();
   525       float expected_uses = past_uses;
   526       cg = CallGenerator::for_inline(method(), expected_uses);
   527     }
   528     if (failing())  return;
   529     if (cg == NULL) {
   530       record_method_not_compilable_all_tiers("cannot parse method");
   531       return;
   532     }
   533     JVMState* jvms = build_start_state(start(), tf());
   534     if ((jvms = cg->generate(jvms)) == NULL) {
   535       record_method_not_compilable("method parse failed");
   536       return;
   537     }
   538     GraphKit kit(jvms);
   540     if (!kit.stopped()) {
   541       // Accept return values, and transfer control we know not where.
   542       // This is done by a special, unique ReturnNode bound to root.
   543       return_values(kit.jvms());
   544     }
   546     if (kit.has_exceptions()) {
   547       // Any exceptions that escape from this call must be rethrown
   548       // to whatever caller is dynamically above us on the stack.
   549       // This is done by a special, unique RethrowNode bound to root.
   550       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
   551     }
   553     // Remove clutter produced by parsing.
   554     if (!failing()) {
   555       ResourceMark rm;
   556       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
   557     }
   558   }
   560   // Note:  Large methods are capped off in do_one_bytecode().
   561   if (failing())  return;
   563   // After parsing, node notes are no longer automagic.
   564   // They must be propagated by register_new_node_with_optimizer(),
   565   // clone(), or the like.
   566   set_default_node_notes(NULL);
   568   for (;;) {
   569     int successes = Inline_Warm();
   570     if (failing())  return;
   571     if (successes == 0)  break;
   572   }
   574   // Drain the list.
   575   Finish_Warm();
   576 #ifndef PRODUCT
   577   if (_printer) {
   578     _printer->print_inlining(this);
   579   }
   580 #endif
   582   if (failing())  return;
   583   NOT_PRODUCT( verify_graph_edges(); )
   585   // Perform escape analysis
   586   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
   587     TracePhase t2("escapeAnalysis", &_t_escapeAnalysis, true);
   588     // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction.
   589     PhaseGVN* igvn = initial_gvn();
   590     Node* oop_null = igvn->zerocon(T_OBJECT);
   591     Node* noop_null = igvn->zerocon(T_NARROWOOP);
   593     _congraph = new(comp_arena()) ConnectionGraph(this);
   594     bool has_non_escaping_obj = _congraph->compute_escape();
   596 #ifndef PRODUCT
   597     if (PrintEscapeAnalysis) {
   598       _congraph->dump();
   599     }
   600 #endif
   601     // Cleanup.
   602     if (oop_null->outcnt() == 0)
   603       igvn->hash_delete(oop_null);
   604     if (noop_null->outcnt() == 0)
   605       igvn->hash_delete(noop_null);
   607     if (!has_non_escaping_obj) {
   608       _congraph = NULL;
   609     }
   611     if (failing())  return;
   612   }
   613   // Now optimize
   614   Optimize();
   615   if (failing())  return;
   616   NOT_PRODUCT( verify_graph_edges(); )
   618   print_method("Before Matching");
   620 #ifndef PRODUCT
   621   if (PrintIdeal) {
   622     ttyLocker ttyl;  // keep the following output all in one block
   623     // This output goes directly to the tty, not the compiler log.
   624     // To enable tools to match it up with the compilation activity,
   625     // be sure to tag this tty output with the compile ID.
   626     if (xtty != NULL) {
   627       xtty->head("ideal compile_id='%d'%s", compile_id(),
   628                  is_osr_compilation()    ? " compile_kind='osr'" :
   629                  "");
   630     }
   631     root()->dump(9999);
   632     if (xtty != NULL) {
   633       xtty->tail("ideal");
   634     }
   635   }
   636 #endif
   638   // Now that we know the size of all the monitors we can add a fixed slot
   639   // for the original deopt pc.
   641   _orig_pc_slot =  fixed_slots();
   642   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
   643   set_fixed_slots(next_slot);
   645   // Now generate code
   646   Code_Gen();
   647   if (failing())  return;
   649   // Check if we want to skip execution of all compiled code.
   650   {
   651 #ifndef PRODUCT
   652     if (OptoNoExecute) {
   653       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
   654       return;
   655     }
   656     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
   657 #endif
   659     if (is_osr_compilation()) {
   660       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
   661       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
   662     } else {
   663       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
   664       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
   665     }
   667     env()->register_method(_method, _entry_bci,
   668                            &_code_offsets,
   669                            _orig_pc_slot_offset_in_bytes,
   670                            code_buffer(),
   671                            frame_size_in_words(), _oop_map_set,
   672                            &_handler_table, &_inc_table,
   673                            compiler,
   674                            env()->comp_level(),
   675                            true, /*has_debug_info*/
   676                            has_unsafe_access()
   677                            );
   678   }
   679 }
   681 //------------------------------Compile----------------------------------------
   682 // Compile a runtime stub
   683 Compile::Compile( ciEnv* ci_env,
   684                   TypeFunc_generator generator,
   685                   address stub_function,
   686                   const char *stub_name,
   687                   int is_fancy_jump,
   688                   bool pass_tls,
   689                   bool save_arg_registers,
   690                   bool return_pc )
   691   : Phase(Compiler),
   692     _env(ci_env),
   693     _log(ci_env->log()),
   694     _compile_id(-1),
   695     _save_argument_registers(save_arg_registers),
   696     _method(NULL),
   697     _stub_name(stub_name),
   698     _stub_function(stub_function),
   699     _stub_entry_point(NULL),
   700     _entry_bci(InvocationEntryBci),
   701     _initial_gvn(NULL),
   702     _for_igvn(NULL),
   703     _warm_calls(NULL),
   704     _orig_pc_slot(0),
   705     _orig_pc_slot_offset_in_bytes(0),
   706     _subsume_loads(true),
   707     _do_escape_analysis(false),
   708     _failure_reason(NULL),
   709     _code_buffer("Compile::Fill_buffer"),
   710     _node_bundling_limit(0),
   711     _node_bundling_base(NULL),
   712 #ifndef PRODUCT
   713     _trace_opto_output(TraceOptoOutput),
   714     _printer(NULL),
   715 #endif
   716     _congraph(NULL) {
   717   C = this;
   719 #ifndef PRODUCT
   720   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
   721   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
   722   set_print_assembly(PrintFrameConverterAssembly);
   723 #endif
   724   CompileWrapper cw(this);
   725   Init(/*AliasLevel=*/ 0);
   726   init_tf((*generator)());
   728   {
   729     // The following is a dummy for the sake of GraphKit::gen_stub
   730     Unique_Node_List for_igvn(comp_arena());
   731     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
   732     PhaseGVN gvn(Thread::current()->resource_area(),255);
   733     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
   734     gvn.transform_no_reclaim(top());
   736     GraphKit kit;
   737     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
   738   }
   740   NOT_PRODUCT( verify_graph_edges(); )
   741   Code_Gen();
   742   if (failing())  return;
   745   // Entry point will be accessed using compile->stub_entry_point();
   746   if (code_buffer() == NULL) {
   747     Matcher::soft_match_failure();
   748   } else {
   749     if (PrintAssembly && (WizardMode || Verbose))
   750       tty->print_cr("### Stub::%s", stub_name);
   752     if (!failing()) {
   753       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
   755       // Make the NMethod
   756       // For now we mark the frame as never safe for profile stackwalking
   757       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
   758                                                       code_buffer(),
   759                                                       CodeOffsets::frame_never_safe,
   760                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
   761                                                       frame_size_in_words(),
   762                                                       _oop_map_set,
   763                                                       save_arg_registers);
   764       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
   766       _stub_entry_point = rs->entry_point();
   767     }
   768   }
   769 }
   771 #ifndef PRODUCT
   772 void print_opto_verbose_signature( const TypeFunc *j_sig, const char *stub_name ) {
   773   if(PrintOpto && Verbose) {
   774     tty->print("%s   ", stub_name); j_sig->print_flattened(); tty->cr();
   775   }
   776 }
   777 #endif
   779 void Compile::print_codes() {
   780 }
   782 //------------------------------Init-------------------------------------------
   783 // Prepare for a single compilation
   784 void Compile::Init(int aliaslevel) {
   785   _unique  = 0;
   786   _regalloc = NULL;
   788   _tf      = NULL;  // filled in later
   789   _top     = NULL;  // cached later
   790   _matcher = NULL;  // filled in later
   791   _cfg     = NULL;  // filled in later
   793   set_24_bit_selection_and_mode(Use24BitFP, false);
   795   _node_note_array = NULL;
   796   _default_node_notes = NULL;
   798   _immutable_memory = NULL; // filled in at first inquiry
   800   // Globally visible Nodes
   801   // First set TOP to NULL to give safe behavior during creation of RootNode
   802   set_cached_top_node(NULL);
   803   set_root(new (this, 3) RootNode());
   804   // Now that you have a Root to point to, create the real TOP
   805   set_cached_top_node( new (this, 1) ConNode(Type::TOP) );
   806   set_recent_alloc(NULL, NULL);
   808   // Create Debug Information Recorder to record scopes, oopmaps, etc.
   809   env()->set_oop_recorder(new OopRecorder(comp_arena()));
   810   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
   811   env()->set_dependencies(new Dependencies(env()));
   813   _fixed_slots = 0;
   814   set_has_split_ifs(false);
   815   set_has_loops(has_method() && method()->has_loops()); // first approximation
   816   _deopt_happens = true;  // start out assuming the worst
   817   _trap_can_recompile = false;  // no traps emitted yet
   818   _major_progress = true; // start out assuming good things will happen
   819   set_has_unsafe_access(false);
   820   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
   821   set_decompile_count(0);
   823   // Compilation level related initialization
   824   if (env()->comp_level() == CompLevel_fast_compile) {
   825     set_num_loop_opts(Tier1LoopOptsCount);
   826     set_do_inlining(Tier1Inline != 0);
   827     set_max_inline_size(Tier1MaxInlineSize);
   828     set_freq_inline_size(Tier1FreqInlineSize);
   829     set_do_scheduling(false);
   830     set_do_count_invocations(Tier1CountInvocations);
   831     set_do_method_data_update(Tier1UpdateMethodData);
   832   } else {
   833     assert(env()->comp_level() == CompLevel_full_optimization, "unknown comp level");
   834     set_num_loop_opts(LoopOptsCount);
   835     set_do_inlining(Inline);
   836     set_max_inline_size(MaxInlineSize);
   837     set_freq_inline_size(FreqInlineSize);
   838     set_do_scheduling(OptoScheduling);
   839     set_do_count_invocations(false);
   840     set_do_method_data_update(false);
   841   }
   843   if (debug_info()->recording_non_safepoints()) {
   844     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
   845                         (comp_arena(), 8, 0, NULL));
   846     set_default_node_notes(Node_Notes::make(this));
   847   }
   849   // // -- Initialize types before each compile --
   850   // // Update cached type information
   851   // if( _method && _method->constants() )
   852   //   Type::update_loaded_types(_method, _method->constants());
   854   // Init alias_type map.
   855   if (!_do_escape_analysis && aliaslevel == 3)
   856     aliaslevel = 2;  // No unique types without escape analysis
   857   _AliasLevel = aliaslevel;
   858   const int grow_ats = 16;
   859   _max_alias_types = grow_ats;
   860   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
   861   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
   862   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
   863   {
   864     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
   865   }
   866   // Initialize the first few types.
   867   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
   868   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
   869   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
   870   _num_alias_types = AliasIdxRaw+1;
   871   // Zero out the alias type cache.
   872   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
   873   // A NULL adr_type hits in the cache right away.  Preload the right answer.
   874   probe_alias_cache(NULL)->_index = AliasIdxTop;
   876   _intrinsics = NULL;
   877   _macro_nodes = new GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
   878   register_library_intrinsics();
   879 }
   881 //---------------------------init_start----------------------------------------
   882 // Install the StartNode on this compile object.
   883 void Compile::init_start(StartNode* s) {
   884   if (failing())
   885     return; // already failing
   886   assert(s == start(), "");
   887 }
   889 StartNode* Compile::start() const {
   890   assert(!failing(), "");
   891   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
   892     Node* start = root()->fast_out(i);
   893     if( start->is_Start() )
   894       return start->as_Start();
   895   }
   896   ShouldNotReachHere();
   897   return NULL;
   898 }
   900 //-------------------------------immutable_memory-------------------------------------
   901 // Access immutable memory
   902 Node* Compile::immutable_memory() {
   903   if (_immutable_memory != NULL) {
   904     return _immutable_memory;
   905   }
   906   StartNode* s = start();
   907   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
   908     Node *p = s->fast_out(i);
   909     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
   910       _immutable_memory = p;
   911       return _immutable_memory;
   912     }
   913   }
   914   ShouldNotReachHere();
   915   return NULL;
   916 }
   918 //----------------------set_cached_top_node------------------------------------
   919 // Install the cached top node, and make sure Node::is_top works correctly.
   920 void Compile::set_cached_top_node(Node* tn) {
   921   if (tn != NULL)  verify_top(tn);
   922   Node* old_top = _top;
   923   _top = tn;
   924   // Calling Node::setup_is_top allows the nodes the chance to adjust
   925   // their _out arrays.
   926   if (_top != NULL)     _top->setup_is_top();
   927   if (old_top != NULL)  old_top->setup_is_top();
   928   assert(_top == NULL || top()->is_top(), "");
   929 }
   931 #ifndef PRODUCT
   932 void Compile::verify_top(Node* tn) const {
   933   if (tn != NULL) {
   934     assert(tn->is_Con(), "top node must be a constant");
   935     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
   936     assert(tn->in(0) != NULL, "must have live top node");
   937   }
   938 }
   939 #endif
   942 ///-------------------Managing Per-Node Debug & Profile Info-------------------
   944 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
   945   guarantee(arr != NULL, "");
   946   int num_blocks = arr->length();
   947   if (grow_by < num_blocks)  grow_by = num_blocks;
   948   int num_notes = grow_by * _node_notes_block_size;
   949   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
   950   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
   951   while (num_notes > 0) {
   952     arr->append(notes);
   953     notes     += _node_notes_block_size;
   954     num_notes -= _node_notes_block_size;
   955   }
   956   assert(num_notes == 0, "exact multiple, please");
   957 }
   959 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
   960   if (source == NULL || dest == NULL)  return false;
   962   if (dest->is_Con())
   963     return false;               // Do not push debug info onto constants.
   965 #ifdef ASSERT
   966   // Leave a bread crumb trail pointing to the original node:
   967   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
   968     dest->set_debug_orig(source);
   969   }
   970 #endif
   972   if (node_note_array() == NULL)
   973     return false;               // Not collecting any notes now.
   975   // This is a copy onto a pre-existing node, which may already have notes.
   976   // If both nodes have notes, do not overwrite any pre-existing notes.
   977   Node_Notes* source_notes = node_notes_at(source->_idx);
   978   if (source_notes == NULL || source_notes->is_clear())  return false;
   979   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
   980   if (dest_notes == NULL || dest_notes->is_clear()) {
   981     return set_node_notes_at(dest->_idx, source_notes);
   982   }
   984   Node_Notes merged_notes = (*source_notes);
   985   // The order of operations here ensures that dest notes will win...
   986   merged_notes.update_from(dest_notes);
   987   return set_node_notes_at(dest->_idx, &merged_notes);
   988 }
   991 //--------------------------allow_range_check_smearing-------------------------
   992 // Gating condition for coalescing similar range checks.
   993 // Sometimes we try 'speculatively' replacing a series of a range checks by a
   994 // single covering check that is at least as strong as any of them.
   995 // If the optimization succeeds, the simplified (strengthened) range check
   996 // will always succeed.  If it fails, we will deopt, and then give up
   997 // on the optimization.
   998 bool Compile::allow_range_check_smearing() const {
   999   // If this method has already thrown a range-check,
  1000   // assume it was because we already tried range smearing
  1001   // and it failed.
  1002   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
  1003   return !already_trapped;
  1007 //------------------------------flatten_alias_type-----------------------------
  1008 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
  1009   int offset = tj->offset();
  1010   TypePtr::PTR ptr = tj->ptr();
  1012   // Known instance (scalarizable allocation) alias only with itself.
  1013   bool is_known_inst = tj->isa_oopptr() != NULL &&
  1014                        tj->is_oopptr()->is_known_instance();
  1016   // Process weird unsafe references.
  1017   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
  1018     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
  1019     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
  1020     tj = TypeOopPtr::BOTTOM;
  1021     ptr = tj->ptr();
  1022     offset = tj->offset();
  1025   // Array pointers need some flattening
  1026   const TypeAryPtr *ta = tj->isa_aryptr();
  1027   if( ta && is_known_inst ) {
  1028     if ( offset != Type::OffsetBot &&
  1029          offset > arrayOopDesc::length_offset_in_bytes() ) {
  1030       offset = Type::OffsetBot; // Flatten constant access into array body only
  1031       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
  1033   } else if( ta && _AliasLevel >= 2 ) {
  1034     // For arrays indexed by constant indices, we flatten the alias
  1035     // space to include all of the array body.  Only the header, klass
  1036     // and array length can be accessed un-aliased.
  1037     if( offset != Type::OffsetBot ) {
  1038       if( ta->const_oop() ) { // methodDataOop or methodOop
  1039         offset = Type::OffsetBot;   // Flatten constant access into array body
  1040         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
  1041       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
  1042         // range is OK as-is.
  1043         tj = ta = TypeAryPtr::RANGE;
  1044       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
  1045         tj = TypeInstPtr::KLASS; // all klass loads look alike
  1046         ta = TypeAryPtr::RANGE; // generic ignored junk
  1047         ptr = TypePtr::BotPTR;
  1048       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
  1049         tj = TypeInstPtr::MARK;
  1050         ta = TypeAryPtr::RANGE; // generic ignored junk
  1051         ptr = TypePtr::BotPTR;
  1052       } else {                  // Random constant offset into array body
  1053         offset = Type::OffsetBot;   // Flatten constant access into array body
  1054         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
  1057     // Arrays of fixed size alias with arrays of unknown size.
  1058     if (ta->size() != TypeInt::POS) {
  1059       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
  1060       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
  1062     // Arrays of known objects become arrays of unknown objects.
  1063     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
  1064       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
  1065       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
  1067     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
  1068       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
  1069       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
  1071     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
  1072     // cannot be distinguished by bytecode alone.
  1073     if (ta->elem() == TypeInt::BOOL) {
  1074       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
  1075       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
  1076       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
  1078     // During the 2nd round of IterGVN, NotNull castings are removed.
  1079     // Make sure the Bottom and NotNull variants alias the same.
  1080     // Also, make sure exact and non-exact variants alias the same.
  1081     if( ptr == TypePtr::NotNull || ta->klass_is_exact() ) {
  1082       if (ta->const_oop()) {
  1083         tj = ta = TypeAryPtr::make(TypePtr::Constant,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
  1084       } else {
  1085         tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
  1090   // Oop pointers need some flattening
  1091   const TypeInstPtr *to = tj->isa_instptr();
  1092   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
  1093     if( ptr == TypePtr::Constant ) {
  1094       // No constant oop pointers (such as Strings); they alias with
  1095       // unknown strings.
  1096       assert(!is_known_inst, "not scalarizable allocation");
  1097       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1098     } else if( is_known_inst ) {
  1099       tj = to; // Keep NotNull and klass_is_exact for instance type
  1100     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
  1101       // During the 2nd round of IterGVN, NotNull castings are removed.
  1102       // Make sure the Bottom and NotNull variants alias the same.
  1103       // Also, make sure exact and non-exact variants alias the same.
  1104       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1106     // Canonicalize the holder of this field
  1107     ciInstanceKlass *k = to->klass()->as_instance_klass();
  1108     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
  1109       // First handle header references such as a LoadKlassNode, even if the
  1110       // object's klass is unloaded at compile time (4965979).
  1111       if (!is_known_inst) { // Do it only for non-instance types
  1112         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
  1114     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
  1115       to = NULL;
  1116       tj = TypeOopPtr::BOTTOM;
  1117       offset = tj->offset();
  1118     } else {
  1119       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
  1120       if (!k->equals(canonical_holder) || tj->offset() != offset) {
  1121         if( is_known_inst ) {
  1122           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
  1123         } else {
  1124           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
  1130   // Klass pointers to object array klasses need some flattening
  1131   const TypeKlassPtr *tk = tj->isa_klassptr();
  1132   if( tk ) {
  1133     // If we are referencing a field within a Klass, we need
  1134     // to assume the worst case of an Object.  Both exact and
  1135     // inexact types must flatten to the same alias class.
  1136     // Since the flattened result for a klass is defined to be
  1137     // precisely java.lang.Object, use a constant ptr.
  1138     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
  1140       tj = tk = TypeKlassPtr::make(TypePtr::Constant,
  1141                                    TypeKlassPtr::OBJECT->klass(),
  1142                                    offset);
  1145     ciKlass* klass = tk->klass();
  1146     if( klass->is_obj_array_klass() ) {
  1147       ciKlass* k = TypeAryPtr::OOPS->klass();
  1148       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
  1149         k = TypeInstPtr::BOTTOM->klass();
  1150       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
  1153     // Check for precise loads from the primary supertype array and force them
  1154     // to the supertype cache alias index.  Check for generic array loads from
  1155     // the primary supertype array and also force them to the supertype cache
  1156     // alias index.  Since the same load can reach both, we need to merge
  1157     // these 2 disparate memories into the same alias class.  Since the
  1158     // primary supertype array is read-only, there's no chance of confusion
  1159     // where we bypass an array load and an array store.
  1160     uint off2 = offset - Klass::primary_supers_offset_in_bytes();
  1161     if( offset == Type::OffsetBot ||
  1162         off2 < Klass::primary_super_limit()*wordSize ) {
  1163       offset = sizeof(oopDesc) +Klass::secondary_super_cache_offset_in_bytes();
  1164       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
  1168   // Flatten all Raw pointers together.
  1169   if (tj->base() == Type::RawPtr)
  1170     tj = TypeRawPtr::BOTTOM;
  1172   if (tj->base() == Type::AnyPtr)
  1173     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
  1175   // Flatten all to bottom for now
  1176   switch( _AliasLevel ) {
  1177   case 0:
  1178     tj = TypePtr::BOTTOM;
  1179     break;
  1180   case 1:                       // Flatten to: oop, static, field or array
  1181     switch (tj->base()) {
  1182     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
  1183     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
  1184     case Type::AryPtr:   // do not distinguish arrays at all
  1185     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
  1186     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
  1187     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
  1188     default: ShouldNotReachHere();
  1190     break;
  1191   case 2:                       // No collasping at level 2; keep all splits
  1192   case 3:                       // No collasping at level 3; keep all splits
  1193     break;
  1194   default:
  1195     Unimplemented();
  1198   offset = tj->offset();
  1199   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
  1201   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
  1202           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
  1203           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
  1204           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
  1205           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1206           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1207           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
  1208           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
  1209   assert( tj->ptr() != TypePtr::TopPTR &&
  1210           tj->ptr() != TypePtr::AnyNull &&
  1211           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
  1212 //    assert( tj->ptr() != TypePtr::Constant ||
  1213 //            tj->base() == Type::RawPtr ||
  1214 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
  1216   return tj;
  1219 void Compile::AliasType::Init(int i, const TypePtr* at) {
  1220   _index = i;
  1221   _adr_type = at;
  1222   _field = NULL;
  1223   _is_rewritable = true; // default
  1224   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
  1225   if (atoop != NULL && atoop->is_known_instance()) {
  1226     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
  1227     _general_index = Compile::current()->get_alias_index(gt);
  1228   } else {
  1229     _general_index = 0;
  1233 //---------------------------------print_on------------------------------------
  1234 #ifndef PRODUCT
  1235 void Compile::AliasType::print_on(outputStream* st) {
  1236   if (index() < 10)
  1237         st->print("@ <%d> ", index());
  1238   else  st->print("@ <%d>",  index());
  1239   st->print(is_rewritable() ? "   " : " RO");
  1240   int offset = adr_type()->offset();
  1241   if (offset == Type::OffsetBot)
  1242         st->print(" +any");
  1243   else  st->print(" +%-3d", offset);
  1244   st->print(" in ");
  1245   adr_type()->dump_on(st);
  1246   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
  1247   if (field() != NULL && tjp) {
  1248     if (tjp->klass()  != field()->holder() ||
  1249         tjp->offset() != field()->offset_in_bytes()) {
  1250       st->print(" != ");
  1251       field()->print();
  1252       st->print(" ***");
  1257 void print_alias_types() {
  1258   Compile* C = Compile::current();
  1259   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
  1260   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
  1261     C->alias_type(idx)->print_on(tty);
  1262     tty->cr();
  1265 #endif
  1268 //----------------------------probe_alias_cache--------------------------------
  1269 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
  1270   intptr_t key = (intptr_t) adr_type;
  1271   key ^= key >> logAliasCacheSize;
  1272   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
  1276 //-----------------------------grow_alias_types--------------------------------
  1277 void Compile::grow_alias_types() {
  1278   const int old_ats  = _max_alias_types; // how many before?
  1279   const int new_ats  = old_ats;          // how many more?
  1280   const int grow_ats = old_ats+new_ats;  // how many now?
  1281   _max_alias_types = grow_ats;
  1282   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
  1283   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
  1284   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
  1285   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
  1289 //--------------------------------find_alias_type------------------------------
  1290 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create) {
  1291   if (_AliasLevel == 0)
  1292     return alias_type(AliasIdxBot);
  1294   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1295   if (ace->_adr_type == adr_type) {
  1296     return alias_type(ace->_index);
  1299   // Handle special cases.
  1300   if (adr_type == NULL)             return alias_type(AliasIdxTop);
  1301   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
  1303   // Do it the slow way.
  1304   const TypePtr* flat = flatten_alias_type(adr_type);
  1306 #ifdef ASSERT
  1307   assert(flat == flatten_alias_type(flat), "idempotent");
  1308   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
  1309   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
  1310     const TypeOopPtr* foop = flat->is_oopptr();
  1311     // Scalarizable allocations have exact klass always.
  1312     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
  1313     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
  1314     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
  1316   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
  1317 #endif
  1319   int idx = AliasIdxTop;
  1320   for (int i = 0; i < num_alias_types(); i++) {
  1321     if (alias_type(i)->adr_type() == flat) {
  1322       idx = i;
  1323       break;
  1327   if (idx == AliasIdxTop) {
  1328     if (no_create)  return NULL;
  1329     // Grow the array if necessary.
  1330     if (_num_alias_types == _max_alias_types)  grow_alias_types();
  1331     // Add a new alias type.
  1332     idx = _num_alias_types++;
  1333     _alias_types[idx]->Init(idx, flat);
  1334     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
  1335     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
  1336     if (flat->isa_instptr()) {
  1337       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
  1338           && flat->is_instptr()->klass() == env()->Class_klass())
  1339         alias_type(idx)->set_rewritable(false);
  1341     if (flat->isa_klassptr()) {
  1342       if (flat->offset() == Klass::super_check_offset_offset_in_bytes() + (int)sizeof(oopDesc))
  1343         alias_type(idx)->set_rewritable(false);
  1344       if (flat->offset() == Klass::modifier_flags_offset_in_bytes() + (int)sizeof(oopDesc))
  1345         alias_type(idx)->set_rewritable(false);
  1346       if (flat->offset() == Klass::access_flags_offset_in_bytes() + (int)sizeof(oopDesc))
  1347         alias_type(idx)->set_rewritable(false);
  1348       if (flat->offset() == Klass::java_mirror_offset_in_bytes() + (int)sizeof(oopDesc))
  1349         alias_type(idx)->set_rewritable(false);
  1351     // %%% (We would like to finalize JavaThread::threadObj_offset(),
  1352     // but the base pointer type is not distinctive enough to identify
  1353     // references into JavaThread.)
  1355     // Check for final instance fields.
  1356     const TypeInstPtr* tinst = flat->isa_instptr();
  1357     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
  1358       ciInstanceKlass *k = tinst->klass()->as_instance_klass();
  1359       ciField* field = k->get_field_by_offset(tinst->offset(), false);
  1360       // Set field() and is_rewritable() attributes.
  1361       if (field != NULL)  alias_type(idx)->set_field(field);
  1363     const TypeKlassPtr* tklass = flat->isa_klassptr();
  1364     // Check for final static fields.
  1365     if (tklass && tklass->klass()->is_instance_klass()) {
  1366       ciInstanceKlass *k = tklass->klass()->as_instance_klass();
  1367       ciField* field = k->get_field_by_offset(tklass->offset(), true);
  1368       // Set field() and is_rewritable() attributes.
  1369       if (field != NULL)   alias_type(idx)->set_field(field);
  1373   // Fill the cache for next time.
  1374   ace->_adr_type = adr_type;
  1375   ace->_index    = idx;
  1376   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
  1378   // Might as well try to fill the cache for the flattened version, too.
  1379   AliasCacheEntry* face = probe_alias_cache(flat);
  1380   if (face->_adr_type == NULL) {
  1381     face->_adr_type = flat;
  1382     face->_index    = idx;
  1383     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
  1386   return alias_type(idx);
  1390 Compile::AliasType* Compile::alias_type(ciField* field) {
  1391   const TypeOopPtr* t;
  1392   if (field->is_static())
  1393     t = TypeKlassPtr::make(field->holder());
  1394   else
  1395     t = TypeOopPtr::make_from_klass_raw(field->holder());
  1396   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()));
  1397   assert(field->is_final() == !atp->is_rewritable(), "must get the rewritable bits correct");
  1398   return atp;
  1402 //------------------------------have_alias_type--------------------------------
  1403 bool Compile::have_alias_type(const TypePtr* adr_type) {
  1404   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1405   if (ace->_adr_type == adr_type) {
  1406     return true;
  1409   // Handle special cases.
  1410   if (adr_type == NULL)             return true;
  1411   if (adr_type == TypePtr::BOTTOM)  return true;
  1413   return find_alias_type(adr_type, true) != NULL;
  1416 //-----------------------------must_alias--------------------------------------
  1417 // True if all values of the given address type are in the given alias category.
  1418 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
  1419   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1420   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
  1421   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1422   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
  1424   // the only remaining possible overlap is identity
  1425   int adr_idx = get_alias_index(adr_type);
  1426   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1427   assert(adr_idx == alias_idx ||
  1428          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
  1429           && adr_type                       != TypeOopPtr::BOTTOM),
  1430          "should not be testing for overlap with an unsafe pointer");
  1431   return adr_idx == alias_idx;
  1434 //------------------------------can_alias--------------------------------------
  1435 // True if any values of the given address type are in the given alias category.
  1436 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
  1437   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1438   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
  1439   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1440   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
  1442   // the only remaining possible overlap is identity
  1443   int adr_idx = get_alias_index(adr_type);
  1444   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1445   return adr_idx == alias_idx;
  1450 //---------------------------pop_warm_call-------------------------------------
  1451 WarmCallInfo* Compile::pop_warm_call() {
  1452   WarmCallInfo* wci = _warm_calls;
  1453   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
  1454   return wci;
  1457 //----------------------------Inline_Warm--------------------------------------
  1458 int Compile::Inline_Warm() {
  1459   // If there is room, try to inline some more warm call sites.
  1460   // %%% Do a graph index compaction pass when we think we're out of space?
  1461   if (!InlineWarmCalls)  return 0;
  1463   int calls_made_hot = 0;
  1464   int room_to_grow   = NodeCountInliningCutoff - unique();
  1465   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
  1466   int amount_grown   = 0;
  1467   WarmCallInfo* call;
  1468   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
  1469     int est_size = (int)call->size();
  1470     if (est_size > (room_to_grow - amount_grown)) {
  1471       // This one won't fit anyway.  Get rid of it.
  1472       call->make_cold();
  1473       continue;
  1475     call->make_hot();
  1476     calls_made_hot++;
  1477     amount_grown   += est_size;
  1478     amount_to_grow -= est_size;
  1481   if (calls_made_hot > 0)  set_major_progress();
  1482   return calls_made_hot;
  1486 //----------------------------Finish_Warm--------------------------------------
  1487 void Compile::Finish_Warm() {
  1488   if (!InlineWarmCalls)  return;
  1489   if (failing())  return;
  1490   if (warm_calls() == NULL)  return;
  1492   // Clean up loose ends, if we are out of space for inlining.
  1493   WarmCallInfo* call;
  1494   while ((call = pop_warm_call()) != NULL) {
  1495     call->make_cold();
  1500 //------------------------------Optimize---------------------------------------
  1501 // Given a graph, optimize it.
  1502 void Compile::Optimize() {
  1503   TracePhase t1("optimizer", &_t_optimizer, true);
  1505 #ifndef PRODUCT
  1506   if (env()->break_at_compile()) {
  1507     BREAKPOINT;
  1510 #endif
  1512   ResourceMark rm;
  1513   int          loop_opts_cnt;
  1515   NOT_PRODUCT( verify_graph_edges(); )
  1517   print_method("After Parsing");
  1520   // Iterative Global Value Numbering, including ideal transforms
  1521   // Initialize IterGVN with types and values from parse-time GVN
  1522   PhaseIterGVN igvn(initial_gvn());
  1524     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
  1525     igvn.optimize();
  1528   print_method("Iter GVN 1", 2);
  1530   if (failing())  return;
  1532   // get rid of the connection graph since it's information is not
  1533   // updated by optimizations
  1534   _congraph = NULL;
  1537   // Loop transforms on the ideal graph.  Range Check Elimination,
  1538   // peeling, unrolling, etc.
  1540   // Set loop opts counter
  1541   loop_opts_cnt = num_loop_opts();
  1542   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
  1544       TracePhase t2("idealLoop", &_t_idealLoop, true);
  1545       PhaseIdealLoop ideal_loop( igvn, NULL, true );
  1546       loop_opts_cnt--;
  1547       if (major_progress()) print_method("PhaseIdealLoop 1", 2);
  1548       if (failing())  return;
  1550     // Loop opts pass if partial peeling occurred in previous pass
  1551     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
  1552       TracePhase t3("idealLoop", &_t_idealLoop, true);
  1553       PhaseIdealLoop ideal_loop( igvn, NULL, false );
  1554       loop_opts_cnt--;
  1555       if (major_progress()) print_method("PhaseIdealLoop 2", 2);
  1556       if (failing())  return;
  1558     // Loop opts pass for loop-unrolling before CCP
  1559     if(major_progress() && (loop_opts_cnt > 0)) {
  1560       TracePhase t4("idealLoop", &_t_idealLoop, true);
  1561       PhaseIdealLoop ideal_loop( igvn, NULL, false );
  1562       loop_opts_cnt--;
  1563       if (major_progress()) print_method("PhaseIdealLoop 3", 2);
  1566   if (failing())  return;
  1568   // Conditional Constant Propagation;
  1569   PhaseCCP ccp( &igvn );
  1570   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
  1572     TracePhase t2("ccp", &_t_ccp, true);
  1573     ccp.do_transform();
  1575   print_method("PhaseCPP 1", 2);
  1577   assert( true, "Break here to ccp.dump_old2new_map()");
  1579   // Iterative Global Value Numbering, including ideal transforms
  1581     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
  1582     igvn = ccp;
  1583     igvn.optimize();
  1586   print_method("Iter GVN 2", 2);
  1588   if (failing())  return;
  1590   // Loop transforms on the ideal graph.  Range Check Elimination,
  1591   // peeling, unrolling, etc.
  1592   if(loop_opts_cnt > 0) {
  1593     debug_only( int cnt = 0; );
  1594     while(major_progress() && (loop_opts_cnt > 0)) {
  1595       TracePhase t2("idealLoop", &_t_idealLoop, true);
  1596       assert( cnt++ < 40, "infinite cycle in loop optimization" );
  1597       PhaseIdealLoop ideal_loop( igvn, NULL, true );
  1598       loop_opts_cnt--;
  1599       if (major_progress()) print_method("PhaseIdealLoop iterations", 2);
  1600       if (failing())  return;
  1604     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
  1605     PhaseMacroExpand  mex(igvn);
  1606     if (mex.expand_macro_nodes()) {
  1607       assert(failing(), "must bail out w/ explicit message");
  1608       return;
  1612  } // (End scope of igvn; run destructor if necessary for asserts.)
  1614   // A method with only infinite loops has no edges entering loops from root
  1616     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
  1617     if (final_graph_reshaping()) {
  1618       assert(failing(), "must bail out w/ explicit message");
  1619       return;
  1623   print_method("Optimize finished", 2);
  1627 //------------------------------Code_Gen---------------------------------------
  1628 // Given a graph, generate code for it
  1629 void Compile::Code_Gen() {
  1630   if (failing())  return;
  1632   // Perform instruction selection.  You might think we could reclaim Matcher
  1633   // memory PDQ, but actually the Matcher is used in generating spill code.
  1634   // Internals of the Matcher (including some VectorSets) must remain live
  1635   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
  1636   // set a bit in reclaimed memory.
  1638   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  1639   // nodes.  Mapping is only valid at the root of each matched subtree.
  1640   NOT_PRODUCT( verify_graph_edges(); )
  1642   Node_List proj_list;
  1643   Matcher m(proj_list);
  1644   _matcher = &m;
  1646     TracePhase t2("matcher", &_t_matcher, true);
  1647     m.match();
  1649   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  1650   // nodes.  Mapping is only valid at the root of each matched subtree.
  1651   NOT_PRODUCT( verify_graph_edges(); )
  1653   // If you have too many nodes, or if matching has failed, bail out
  1654   check_node_count(0, "out of nodes matching instructions");
  1655   if (failing())  return;
  1657   // Build a proper-looking CFG
  1658   PhaseCFG cfg(node_arena(), root(), m);
  1659   _cfg = &cfg;
  1661     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
  1662     cfg.Dominators();
  1663     if (failing())  return;
  1665     NOT_PRODUCT( verify_graph_edges(); )
  1667     cfg.Estimate_Block_Frequency();
  1668     cfg.GlobalCodeMotion(m,unique(),proj_list);
  1670     print_method("Global code motion", 2);
  1672     if (failing())  return;
  1673     NOT_PRODUCT( verify_graph_edges(); )
  1675     debug_only( cfg.verify(); )
  1677   NOT_PRODUCT( verify_graph_edges(); )
  1679   PhaseChaitin regalloc(unique(),cfg,m);
  1680   _regalloc = &regalloc;
  1682     TracePhase t2("regalloc", &_t_registerAllocation, true);
  1683     // Perform any platform dependent preallocation actions.  This is used,
  1684     // for example, to avoid taking an implicit null pointer exception
  1685     // using the frame pointer on win95.
  1686     _regalloc->pd_preallocate_hook();
  1688     // Perform register allocation.  After Chaitin, use-def chains are
  1689     // no longer accurate (at spill code) and so must be ignored.
  1690     // Node->LRG->reg mappings are still accurate.
  1691     _regalloc->Register_Allocate();
  1693     // Bail out if the allocator builds too many nodes
  1694     if (failing())  return;
  1697   // Prior to register allocation we kept empty basic blocks in case the
  1698   // the allocator needed a place to spill.  After register allocation we
  1699   // are not adding any new instructions.  If any basic block is empty, we
  1700   // can now safely remove it.
  1702     NOT_PRODUCT( TracePhase t2("removeEmpty", &_t_removeEmptyBlocks, TimeCompiler); )
  1703     cfg.RemoveEmpty();
  1706   // Perform any platform dependent postallocation verifications.
  1707   debug_only( _regalloc->pd_postallocate_verify_hook(); )
  1709   // Apply peephole optimizations
  1710   if( OptoPeephole ) {
  1711     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
  1712     PhasePeephole peep( _regalloc, cfg);
  1713     peep.do_transform();
  1716   // Convert Nodes to instruction bits in a buffer
  1718     // %%%% workspace merge brought two timers together for one job
  1719     TracePhase t2a("output", &_t_output, true);
  1720     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
  1721     Output();
  1724   print_method("Final Code");
  1726   // He's dead, Jim.
  1727   _cfg     = (PhaseCFG*)0xdeadbeef;
  1728   _regalloc = (PhaseChaitin*)0xdeadbeef;
  1732 //------------------------------dump_asm---------------------------------------
  1733 // Dump formatted assembly
  1734 #ifndef PRODUCT
  1735 void Compile::dump_asm(int *pcs, uint pc_limit) {
  1736   bool cut_short = false;
  1737   tty->print_cr("#");
  1738   tty->print("#  ");  _tf->dump();  tty->cr();
  1739   tty->print_cr("#");
  1741   // For all blocks
  1742   int pc = 0x0;                 // Program counter
  1743   char starts_bundle = ' ';
  1744   _regalloc->dump_frame();
  1746   Node *n = NULL;
  1747   for( uint i=0; i<_cfg->_num_blocks; i++ ) {
  1748     if (VMThread::should_terminate()) { cut_short = true; break; }
  1749     Block *b = _cfg->_blocks[i];
  1750     if (b->is_connector() && !Verbose) continue;
  1751     n = b->_nodes[0];
  1752     if (pcs && n->_idx < pc_limit)
  1753       tty->print("%3.3x   ", pcs[n->_idx]);
  1754     else
  1755       tty->print("      ");
  1756     b->dump_head( &_cfg->_bbs );
  1757     if (b->is_connector()) {
  1758       tty->print_cr("        # Empty connector block");
  1759     } else if (b->num_preds() == 2 && b->pred(1)->is_CatchProj() && b->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
  1760       tty->print_cr("        # Block is sole successor of call");
  1763     // For all instructions
  1764     Node *delay = NULL;
  1765     for( uint j = 0; j<b->_nodes.size(); j++ ) {
  1766       if (VMThread::should_terminate()) { cut_short = true; break; }
  1767       n = b->_nodes[j];
  1768       if (valid_bundle_info(n)) {
  1769         Bundle *bundle = node_bundling(n);
  1770         if (bundle->used_in_unconditional_delay()) {
  1771           delay = n;
  1772           continue;
  1774         if (bundle->starts_bundle())
  1775           starts_bundle = '+';
  1778       if (WizardMode) n->dump();
  1780       if( !n->is_Region() &&    // Dont print in the Assembly
  1781           !n->is_Phi() &&       // a few noisely useless nodes
  1782           !n->is_Proj() &&
  1783           !n->is_MachTemp() &&
  1784           !n->is_Catch() &&     // Would be nice to print exception table targets
  1785           !n->is_MergeMem() &&  // Not very interesting
  1786           !n->is_top() &&       // Debug info table constants
  1787           !(n->is_Con() && !n->is_Mach())// Debug info table constants
  1788           ) {
  1789         if (pcs && n->_idx < pc_limit)
  1790           tty->print("%3.3x", pcs[n->_idx]);
  1791         else
  1792           tty->print("   ");
  1793         tty->print(" %c ", starts_bundle);
  1794         starts_bundle = ' ';
  1795         tty->print("\t");
  1796         n->format(_regalloc, tty);
  1797         tty->cr();
  1800       // If we have an instruction with a delay slot, and have seen a delay,
  1801       // then back up and print it
  1802       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
  1803         assert(delay != NULL, "no unconditional delay instruction");
  1804         if (WizardMode) delay->dump();
  1806         if (node_bundling(delay)->starts_bundle())
  1807           starts_bundle = '+';
  1808         if (pcs && n->_idx < pc_limit)
  1809           tty->print("%3.3x", pcs[n->_idx]);
  1810         else
  1811           tty->print("   ");
  1812         tty->print(" %c ", starts_bundle);
  1813         starts_bundle = ' ';
  1814         tty->print("\t");
  1815         delay->format(_regalloc, tty);
  1816         tty->print_cr("");
  1817         delay = NULL;
  1820       // Dump the exception table as well
  1821       if( n->is_Catch() && (Verbose || WizardMode) ) {
  1822         // Print the exception table for this offset
  1823         _handler_table.print_subtable_for(pc);
  1827     if (pcs && n->_idx < pc_limit)
  1828       tty->print_cr("%3.3x", pcs[n->_idx]);
  1829     else
  1830       tty->print_cr("");
  1832     assert(cut_short || delay == NULL, "no unconditional delay branch");
  1834   } // End of per-block dump
  1835   tty->print_cr("");
  1837   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
  1839 #endif
  1841 //------------------------------Final_Reshape_Counts---------------------------
  1842 // This class defines counters to help identify when a method
  1843 // may/must be executed using hardware with only 24-bit precision.
  1844 struct Final_Reshape_Counts : public StackObj {
  1845   int  _call_count;             // count non-inlined 'common' calls
  1846   int  _float_count;            // count float ops requiring 24-bit precision
  1847   int  _double_count;           // count double ops requiring more precision
  1848   int  _java_call_count;        // count non-inlined 'java' calls
  1849   VectorSet _visited;           // Visitation flags
  1850   Node_List _tests;             // Set of IfNodes & PCTableNodes
  1852   Final_Reshape_Counts() :
  1853     _call_count(0), _float_count(0), _double_count(0), _java_call_count(0),
  1854     _visited( Thread::current()->resource_area() ) { }
  1856   void inc_call_count  () { _call_count  ++; }
  1857   void inc_float_count () { _float_count ++; }
  1858   void inc_double_count() { _double_count++; }
  1859   void inc_java_call_count() { _java_call_count++; }
  1861   int  get_call_count  () const { return _call_count  ; }
  1862   int  get_float_count () const { return _float_count ; }
  1863   int  get_double_count() const { return _double_count; }
  1864   int  get_java_call_count() const { return _java_call_count; }
  1865 };
  1867 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
  1868   ciInstanceKlass *k = tp->klass()->as_instance_klass();
  1869   // Make sure the offset goes inside the instance layout.
  1870   return k->contains_field_offset(tp->offset());
  1871   // Note that OffsetBot and OffsetTop are very negative.
  1874 //------------------------------final_graph_reshaping_impl----------------------
  1875 // Implement items 1-5 from final_graph_reshaping below.
  1876 static void final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &fpu ) {
  1878   if ( n->outcnt() == 0 ) return; // dead node
  1879   uint nop = n->Opcode();
  1881   // Check for 2-input instruction with "last use" on right input.
  1882   // Swap to left input.  Implements item (2).
  1883   if( n->req() == 3 &&          // two-input instruction
  1884       n->in(1)->outcnt() > 1 && // left use is NOT a last use
  1885       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
  1886       n->in(2)->outcnt() == 1 &&// right use IS a last use
  1887       !n->in(2)->is_Con() ) {   // right use is not a constant
  1888     // Check for commutative opcode
  1889     switch( nop ) {
  1890     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
  1891     case Op_MaxI:  case Op_MinI:
  1892     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
  1893     case Op_AndL:  case Op_XorL:  case Op_OrL:
  1894     case Op_AndI:  case Op_XorI:  case Op_OrI: {
  1895       // Move "last use" input to left by swapping inputs
  1896       n->swap_edges(1, 2);
  1897       break;
  1899     default:
  1900       break;
  1904   // Count FPU ops and common calls, implements item (3)
  1905   switch( nop ) {
  1906   // Count all float operations that may use FPU
  1907   case Op_AddF:
  1908   case Op_SubF:
  1909   case Op_MulF:
  1910   case Op_DivF:
  1911   case Op_NegF:
  1912   case Op_ModF:
  1913   case Op_ConvI2F:
  1914   case Op_ConF:
  1915   case Op_CmpF:
  1916   case Op_CmpF3:
  1917   // case Op_ConvL2F: // longs are split into 32-bit halves
  1918     fpu.inc_float_count();
  1919     break;
  1921   case Op_ConvF2D:
  1922   case Op_ConvD2F:
  1923     fpu.inc_float_count();
  1924     fpu.inc_double_count();
  1925     break;
  1927   // Count all double operations that may use FPU
  1928   case Op_AddD:
  1929   case Op_SubD:
  1930   case Op_MulD:
  1931   case Op_DivD:
  1932   case Op_NegD:
  1933   case Op_ModD:
  1934   case Op_ConvI2D:
  1935   case Op_ConvD2I:
  1936   // case Op_ConvL2D: // handled by leaf call
  1937   // case Op_ConvD2L: // handled by leaf call
  1938   case Op_ConD:
  1939   case Op_CmpD:
  1940   case Op_CmpD3:
  1941     fpu.inc_double_count();
  1942     break;
  1943   case Op_Opaque1:              // Remove Opaque Nodes before matching
  1944   case Op_Opaque2:              // Remove Opaque Nodes before matching
  1945     n->subsume_by(n->in(1));
  1946     break;
  1947   case Op_CallStaticJava:
  1948   case Op_CallJava:
  1949   case Op_CallDynamicJava:
  1950     fpu.inc_java_call_count(); // Count java call site;
  1951   case Op_CallRuntime:
  1952   case Op_CallLeaf:
  1953   case Op_CallLeafNoFP: {
  1954     assert( n->is_Call(), "" );
  1955     CallNode *call = n->as_Call();
  1956     // Count call sites where the FP mode bit would have to be flipped.
  1957     // Do not count uncommon runtime calls:
  1958     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
  1959     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
  1960     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
  1961       fpu.inc_call_count();   // Count the call site
  1962     } else {                  // See if uncommon argument is shared
  1963       Node *n = call->in(TypeFunc::Parms);
  1964       int nop = n->Opcode();
  1965       // Clone shared simple arguments to uncommon calls, item (1).
  1966       if( n->outcnt() > 1 &&
  1967           !n->is_Proj() &&
  1968           nop != Op_CreateEx &&
  1969           nop != Op_CheckCastPP &&
  1970           !n->is_Mem() ) {
  1971         Node *x = n->clone();
  1972         call->set_req( TypeFunc::Parms, x );
  1975     break;
  1978   case Op_StoreD:
  1979   case Op_LoadD:
  1980   case Op_LoadD_unaligned:
  1981     fpu.inc_double_count();
  1982     goto handle_mem;
  1983   case Op_StoreF:
  1984   case Op_LoadF:
  1985     fpu.inc_float_count();
  1986     goto handle_mem;
  1988   case Op_StoreB:
  1989   case Op_StoreC:
  1990   case Op_StoreCM:
  1991   case Op_StorePConditional:
  1992   case Op_StoreI:
  1993   case Op_StoreL:
  1994   case Op_StoreLConditional:
  1995   case Op_CompareAndSwapI:
  1996   case Op_CompareAndSwapL:
  1997   case Op_CompareAndSwapP:
  1998   case Op_CompareAndSwapN:
  1999   case Op_StoreP:
  2000   case Op_StoreN:
  2001   case Op_LoadB:
  2002   case Op_LoadC:
  2003   case Op_LoadI:
  2004   case Op_LoadKlass:
  2005   case Op_LoadNKlass:
  2006   case Op_LoadL:
  2007   case Op_LoadL_unaligned:
  2008   case Op_LoadPLocked:
  2009   case Op_LoadLLocked:
  2010   case Op_LoadP:
  2011   case Op_LoadN:
  2012   case Op_LoadRange:
  2013   case Op_LoadS: {
  2014   handle_mem:
  2015 #ifdef ASSERT
  2016     if( VerifyOptoOopOffsets ) {
  2017       assert( n->is_Mem(), "" );
  2018       MemNode *mem  = (MemNode*)n;
  2019       // Check to see if address types have grounded out somehow.
  2020       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
  2021       assert( !tp || oop_offset_is_sane(tp), "" );
  2023 #endif
  2024     break;
  2027   case Op_AddP: {               // Assert sane base pointers
  2028     Node *addp = n->in(AddPNode::Address);
  2029     assert( !addp->is_AddP() ||
  2030             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
  2031             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
  2032             "Base pointers must match" );
  2033 #ifdef _LP64
  2034     if (UseCompressedOops &&
  2035         addp->Opcode() == Op_ConP &&
  2036         addp == n->in(AddPNode::Base) &&
  2037         n->in(AddPNode::Offset)->is_Con()) {
  2038       // Use addressing with narrow klass to load with offset on x86.
  2039       // On sparc loading 32-bits constant and decoding it have less
  2040       // instructions (4) then load 64-bits constant (7).
  2041       // Do this transformation here since IGVN will convert ConN back to ConP.
  2042       const Type* t = addp->bottom_type();
  2043       if (t->isa_oopptr()) {
  2044         Node* nn = NULL;
  2046         // Look for existing ConN node of the same exact type.
  2047         Compile* C = Compile::current();
  2048         Node* r  = C->root();
  2049         uint cnt = r->outcnt();
  2050         for (uint i = 0; i < cnt; i++) {
  2051           Node* m = r->raw_out(i);
  2052           if (m!= NULL && m->Opcode() == Op_ConN &&
  2053               m->bottom_type()->make_ptr() == t) {
  2054             nn = m;
  2055             break;
  2058         if (nn != NULL) {
  2059           // Decode a narrow oop to match address
  2060           // [R12 + narrow_oop_reg<<3 + offset]
  2061           nn = new (C,  2) DecodeNNode(nn, t);
  2062           n->set_req(AddPNode::Base, nn);
  2063           n->set_req(AddPNode::Address, nn);
  2064           if (addp->outcnt() == 0) {
  2065             addp->disconnect_inputs(NULL);
  2070 #endif
  2071     break;
  2074 #ifdef _LP64
  2075   case Op_CmpP:
  2076     // Do this transformation here to preserve CmpPNode::sub() and
  2077     // other TypePtr related Ideal optimizations (for example, ptr nullness).
  2078     if( n->in(1)->is_DecodeN() ) {
  2079       Compile* C = Compile::current();
  2080       Node* in2 = NULL;
  2081       if( n->in(2)->is_DecodeN() ) {
  2082         in2 = n->in(2)->in(1);
  2083       } else if ( n->in(2)->Opcode() == Op_ConP ) {
  2084         const Type* t = n->in(2)->bottom_type();
  2085         if (t == TypePtr::NULL_PTR && UseImplicitNullCheckForNarrowOop) {
  2086           Node *in1 = n->in(1);
  2087           if (Matcher::clone_shift_expressions) {
  2088             // x86, ARM and friends can handle 2 adds in addressing mode.
  2089             // Decode a narrow oop and do implicit NULL check in address
  2090             // [R12 + narrow_oop_reg<<3 + offset]
  2091             in2 = ConNode::make(C, TypeNarrowOop::NULL_PTR);
  2092           } else {
  2093             // Don't replace CmpP(o ,null) if 'o' is used in AddP
  2094             // to generate implicit NULL check on Sparc where
  2095             // narrow oops can't be used in address.
  2096             uint i = 0;
  2097             for (; i < in1->outcnt(); i++) {
  2098               if (in1->raw_out(i)->is_AddP())
  2099                 break;
  2101             if (i >= in1->outcnt()) {
  2102               in2 = ConNode::make(C, TypeNarrowOop::NULL_PTR);
  2105         } else if (t->isa_oopptr()) {
  2106           in2 = ConNode::make(C, t->make_narrowoop());
  2109       if( in2 != NULL ) {
  2110         Node* cmpN = new (C, 3) CmpNNode(n->in(1)->in(1), in2);
  2111         n->subsume_by( cmpN );
  2114     break;
  2115 #endif
  2117   case Op_ModI:
  2118     if (UseDivMod) {
  2119       // Check if a%b and a/b both exist
  2120       Node* d = n->find_similar(Op_DivI);
  2121       if (d) {
  2122         // Replace them with a fused divmod if supported
  2123         Compile* C = Compile::current();
  2124         if (Matcher::has_match_rule(Op_DivModI)) {
  2125           DivModINode* divmod = DivModINode::make(C, n);
  2126           d->subsume_by(divmod->div_proj());
  2127           n->subsume_by(divmod->mod_proj());
  2128         } else {
  2129           // replace a%b with a-((a/b)*b)
  2130           Node* mult = new (C, 3) MulINode(d, d->in(2));
  2131           Node* sub  = new (C, 3) SubINode(d->in(1), mult);
  2132           n->subsume_by( sub );
  2136     break;
  2138   case Op_ModL:
  2139     if (UseDivMod) {
  2140       // Check if a%b and a/b both exist
  2141       Node* d = n->find_similar(Op_DivL);
  2142       if (d) {
  2143         // Replace them with a fused divmod if supported
  2144         Compile* C = Compile::current();
  2145         if (Matcher::has_match_rule(Op_DivModL)) {
  2146           DivModLNode* divmod = DivModLNode::make(C, n);
  2147           d->subsume_by(divmod->div_proj());
  2148           n->subsume_by(divmod->mod_proj());
  2149         } else {
  2150           // replace a%b with a-((a/b)*b)
  2151           Node* mult = new (C, 3) MulLNode(d, d->in(2));
  2152           Node* sub  = new (C, 3) SubLNode(d->in(1), mult);
  2153           n->subsume_by( sub );
  2157     break;
  2159   case Op_Load16B:
  2160   case Op_Load8B:
  2161   case Op_Load4B:
  2162   case Op_Load8S:
  2163   case Op_Load4S:
  2164   case Op_Load2S:
  2165   case Op_Load8C:
  2166   case Op_Load4C:
  2167   case Op_Load2C:
  2168   case Op_Load4I:
  2169   case Op_Load2I:
  2170   case Op_Load2L:
  2171   case Op_Load4F:
  2172   case Op_Load2F:
  2173   case Op_Load2D:
  2174   case Op_Store16B:
  2175   case Op_Store8B:
  2176   case Op_Store4B:
  2177   case Op_Store8C:
  2178   case Op_Store4C:
  2179   case Op_Store2C:
  2180   case Op_Store4I:
  2181   case Op_Store2I:
  2182   case Op_Store2L:
  2183   case Op_Store4F:
  2184   case Op_Store2F:
  2185   case Op_Store2D:
  2186     break;
  2188   case Op_PackB:
  2189   case Op_PackS:
  2190   case Op_PackC:
  2191   case Op_PackI:
  2192   case Op_PackF:
  2193   case Op_PackL:
  2194   case Op_PackD:
  2195     if (n->req()-1 > 2) {
  2196       // Replace many operand PackNodes with a binary tree for matching
  2197       PackNode* p = (PackNode*) n;
  2198       Node* btp = p->binaryTreePack(Compile::current(), 1, n->req());
  2199       n->subsume_by(btp);
  2201     break;
  2202   default:
  2203     assert( !n->is_Call(), "" );
  2204     assert( !n->is_Mem(), "" );
  2205     break;
  2208   // Collect CFG split points
  2209   if (n->is_MultiBranch())
  2210     fpu._tests.push(n);
  2213 //------------------------------final_graph_reshaping_walk---------------------
  2214 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
  2215 // requires that the walk visits a node's inputs before visiting the node.
  2216 static void final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &fpu ) {
  2217   fpu._visited.set(root->_idx); // first, mark node as visited
  2218   uint cnt = root->req();
  2219   Node *n = root;
  2220   uint  i = 0;
  2221   while (true) {
  2222     if (i < cnt) {
  2223       // Place all non-visited non-null inputs onto stack
  2224       Node* m = n->in(i);
  2225       ++i;
  2226       if (m != NULL && !fpu._visited.test_set(m->_idx)) {
  2227         cnt = m->req();
  2228         nstack.push(n, i); // put on stack parent and next input's index
  2229         n = m;
  2230         i = 0;
  2232     } else {
  2233       // Now do post-visit work
  2234       final_graph_reshaping_impl( n, fpu );
  2235       if (nstack.is_empty())
  2236         break;             // finished
  2237       n = nstack.node();   // Get node from stack
  2238       cnt = n->req();
  2239       i = nstack.index();
  2240       nstack.pop();        // Shift to the next node on stack
  2245 //------------------------------final_graph_reshaping--------------------------
  2246 // Final Graph Reshaping.
  2247 //
  2248 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
  2249 //     and not commoned up and forced early.  Must come after regular
  2250 //     optimizations to avoid GVN undoing the cloning.  Clone constant
  2251 //     inputs to Loop Phis; these will be split by the allocator anyways.
  2252 //     Remove Opaque nodes.
  2253 // (2) Move last-uses by commutative operations to the left input to encourage
  2254 //     Intel update-in-place two-address operations and better register usage
  2255 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
  2256 //     calls canonicalizing them back.
  2257 // (3) Count the number of double-precision FP ops, single-precision FP ops
  2258 //     and call sites.  On Intel, we can get correct rounding either by
  2259 //     forcing singles to memory (requires extra stores and loads after each
  2260 //     FP bytecode) or we can set a rounding mode bit (requires setting and
  2261 //     clearing the mode bit around call sites).  The mode bit is only used
  2262 //     if the relative frequency of single FP ops to calls is low enough.
  2263 //     This is a key transform for SPEC mpeg_audio.
  2264 // (4) Detect infinite loops; blobs of code reachable from above but not
  2265 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
  2266 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
  2267 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
  2268 //     Detection is by looking for IfNodes where only 1 projection is
  2269 //     reachable from below or CatchNodes missing some targets.
  2270 // (5) Assert for insane oop offsets in debug mode.
  2272 bool Compile::final_graph_reshaping() {
  2273   // an infinite loop may have been eliminated by the optimizer,
  2274   // in which case the graph will be empty.
  2275   if (root()->req() == 1) {
  2276     record_method_not_compilable("trivial infinite loop");
  2277     return true;
  2280   Final_Reshape_Counts fpu;
  2282   // Visit everybody reachable!
  2283   // Allocate stack of size C->unique()/2 to avoid frequent realloc
  2284   Node_Stack nstack(unique() >> 1);
  2285   final_graph_reshaping_walk(nstack, root(), fpu);
  2287   // Check for unreachable (from below) code (i.e., infinite loops).
  2288   for( uint i = 0; i < fpu._tests.size(); i++ ) {
  2289     MultiBranchNode *n = fpu._tests[i]->as_MultiBranch();
  2290     // Get number of CFG targets.
  2291     // Note that PCTables include exception targets after calls.
  2292     uint required_outcnt = n->required_outcnt();
  2293     if (n->outcnt() != required_outcnt) {
  2294       // Check for a few special cases.  Rethrow Nodes never take the
  2295       // 'fall-thru' path, so expected kids is 1 less.
  2296       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
  2297         if (n->in(0)->in(0)->is_Call()) {
  2298           CallNode *call = n->in(0)->in(0)->as_Call();
  2299           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
  2300             required_outcnt--;      // Rethrow always has 1 less kid
  2301           } else if (call->req() > TypeFunc::Parms &&
  2302                      call->is_CallDynamicJava()) {
  2303             // Check for null receiver. In such case, the optimizer has
  2304             // detected that the virtual call will always result in a null
  2305             // pointer exception. The fall-through projection of this CatchNode
  2306             // will not be populated.
  2307             Node *arg0 = call->in(TypeFunc::Parms);
  2308             if (arg0->is_Type() &&
  2309                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
  2310               required_outcnt--;
  2312           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
  2313                      call->req() > TypeFunc::Parms+1 &&
  2314                      call->is_CallStaticJava()) {
  2315             // Check for negative array length. In such case, the optimizer has
  2316             // detected that the allocation attempt will always result in an
  2317             // exception. There is no fall-through projection of this CatchNode .
  2318             Node *arg1 = call->in(TypeFunc::Parms+1);
  2319             if (arg1->is_Type() &&
  2320                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
  2321               required_outcnt--;
  2326       // Recheck with a better notion of 'required_outcnt'
  2327       if (n->outcnt() != required_outcnt) {
  2328         record_method_not_compilable("malformed control flow");
  2329         return true;            // Not all targets reachable!
  2332     // Check that I actually visited all kids.  Unreached kids
  2333     // must be infinite loops.
  2334     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
  2335       if (!fpu._visited.test(n->fast_out(j)->_idx)) {
  2336         record_method_not_compilable("infinite loop");
  2337         return true;            // Found unvisited kid; must be unreach
  2341   // If original bytecodes contained a mixture of floats and doubles
  2342   // check if the optimizer has made it homogenous, item (3).
  2343   if( Use24BitFPMode && Use24BitFP &&
  2344       fpu.get_float_count() > 32 &&
  2345       fpu.get_double_count() == 0 &&
  2346       (10 * fpu.get_call_count() < fpu.get_float_count()) ) {
  2347     set_24_bit_selection_and_mode( false,  true );
  2350   set_has_java_calls(fpu.get_java_call_count() > 0);
  2352   // No infinite loops, no reason to bail out.
  2353   return false;
  2356 //-----------------------------too_many_traps----------------------------------
  2357 // Report if there are too many traps at the current method and bci.
  2358 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
  2359 bool Compile::too_many_traps(ciMethod* method,
  2360                              int bci,
  2361                              Deoptimization::DeoptReason reason) {
  2362   ciMethodData* md = method->method_data();
  2363   if (md->is_empty()) {
  2364     // Assume the trap has not occurred, or that it occurred only
  2365     // because of a transient condition during start-up in the interpreter.
  2366     return false;
  2368   if (md->has_trap_at(bci, reason) != 0) {
  2369     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
  2370     // Also, if there are multiple reasons, or if there is no per-BCI record,
  2371     // assume the worst.
  2372     if (log())
  2373       log()->elem("observe trap='%s' count='%d'",
  2374                   Deoptimization::trap_reason_name(reason),
  2375                   md->trap_count(reason));
  2376     return true;
  2377   } else {
  2378     // Ignore method/bci and see if there have been too many globally.
  2379     return too_many_traps(reason, md);
  2383 // Less-accurate variant which does not require a method and bci.
  2384 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
  2385                              ciMethodData* logmd) {
  2386  if (trap_count(reason) >= (uint)PerMethodTrapLimit) {
  2387     // Too many traps globally.
  2388     // Note that we use cumulative trap_count, not just md->trap_count.
  2389     if (log()) {
  2390       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
  2391       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
  2392                   Deoptimization::trap_reason_name(reason),
  2393                   mcount, trap_count(reason));
  2395     return true;
  2396   } else {
  2397     // The coast is clear.
  2398     return false;
  2402 //--------------------------too_many_recompiles--------------------------------
  2403 // Report if there are too many recompiles at the current method and bci.
  2404 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
  2405 // Is not eager to return true, since this will cause the compiler to use
  2406 // Action_none for a trap point, to avoid too many recompilations.
  2407 bool Compile::too_many_recompiles(ciMethod* method,
  2408                                   int bci,
  2409                                   Deoptimization::DeoptReason reason) {
  2410   ciMethodData* md = method->method_data();
  2411   if (md->is_empty()) {
  2412     // Assume the trap has not occurred, or that it occurred only
  2413     // because of a transient condition during start-up in the interpreter.
  2414     return false;
  2416   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
  2417   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
  2418   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
  2419   Deoptimization::DeoptReason per_bc_reason
  2420     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
  2421   if ((per_bc_reason == Deoptimization::Reason_none
  2422        || md->has_trap_at(bci, reason) != 0)
  2423       // The trap frequency measure we care about is the recompile count:
  2424       && md->trap_recompiled_at(bci)
  2425       && md->overflow_recompile_count() >= bc_cutoff) {
  2426     // Do not emit a trap here if it has already caused recompilations.
  2427     // Also, if there are multiple reasons, or if there is no per-BCI record,
  2428     // assume the worst.
  2429     if (log())
  2430       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
  2431                   Deoptimization::trap_reason_name(reason),
  2432                   md->trap_count(reason),
  2433                   md->overflow_recompile_count());
  2434     return true;
  2435   } else if (trap_count(reason) != 0
  2436              && decompile_count() >= m_cutoff) {
  2437     // Too many recompiles globally, and we have seen this sort of trap.
  2438     // Use cumulative decompile_count, not just md->decompile_count.
  2439     if (log())
  2440       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
  2441                   Deoptimization::trap_reason_name(reason),
  2442                   md->trap_count(reason), trap_count(reason),
  2443                   md->decompile_count(), decompile_count());
  2444     return true;
  2445   } else {
  2446     // The coast is clear.
  2447     return false;
  2452 #ifndef PRODUCT
  2453 //------------------------------verify_graph_edges---------------------------
  2454 // Walk the Graph and verify that there is a one-to-one correspondence
  2455 // between Use-Def edges and Def-Use edges in the graph.
  2456 void Compile::verify_graph_edges(bool no_dead_code) {
  2457   if (VerifyGraphEdges) {
  2458     ResourceArea *area = Thread::current()->resource_area();
  2459     Unique_Node_List visited(area);
  2460     // Call recursive graph walk to check edges
  2461     _root->verify_edges(visited);
  2462     if (no_dead_code) {
  2463       // Now make sure that no visited node is used by an unvisited node.
  2464       bool dead_nodes = 0;
  2465       Unique_Node_List checked(area);
  2466       while (visited.size() > 0) {
  2467         Node* n = visited.pop();
  2468         checked.push(n);
  2469         for (uint i = 0; i < n->outcnt(); i++) {
  2470           Node* use = n->raw_out(i);
  2471           if (checked.member(use))  continue;  // already checked
  2472           if (visited.member(use))  continue;  // already in the graph
  2473           if (use->is_Con())        continue;  // a dead ConNode is OK
  2474           // At this point, we have found a dead node which is DU-reachable.
  2475           if (dead_nodes++ == 0)
  2476             tty->print_cr("*** Dead nodes reachable via DU edges:");
  2477           use->dump(2);
  2478           tty->print_cr("---");
  2479           checked.push(use);  // No repeats; pretend it is now checked.
  2482       assert(dead_nodes == 0, "using nodes must be reachable from root");
  2486 #endif
  2488 // The Compile object keeps track of failure reasons separately from the ciEnv.
  2489 // This is required because there is not quite a 1-1 relation between the
  2490 // ciEnv and its compilation task and the Compile object.  Note that one
  2491 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
  2492 // to backtrack and retry without subsuming loads.  Other than this backtracking
  2493 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
  2494 // by the logic in C2Compiler.
  2495 void Compile::record_failure(const char* reason) {
  2496   if (log() != NULL) {
  2497     log()->elem("failure reason='%s' phase='compile'", reason);
  2499   if (_failure_reason == NULL) {
  2500     // Record the first failure reason.
  2501     _failure_reason = reason;
  2503   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
  2504     C->print_method(_failure_reason);
  2506   _root = NULL;  // flush the graph, too
  2509 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
  2510   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false)
  2512   if (dolog) {
  2513     C = Compile::current();
  2514     _log = C->log();
  2515   } else {
  2516     C = NULL;
  2517     _log = NULL;
  2519   if (_log != NULL) {
  2520     _log->begin_head("phase name='%s' nodes='%d'", name, C->unique());
  2521     _log->stamp();
  2522     _log->end_head();
  2526 Compile::TracePhase::~TracePhase() {
  2527   if (_log != NULL) {
  2528     _log->done("phase nodes='%d'", C->unique());

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