src/share/vm/opto/compile.cpp

Wed, 16 Jul 2008 16:04:39 -0700

author
kvn
date
Wed, 16 Jul 2008 16:04:39 -0700
changeset 682
02a35ad4adf8
parent 680
4a4c365f777d
child 688
b0fe4deeb9fb
permissions
-rw-r--r--

6723160: Nightly failure: Error: meet not symmetric
Summary: Add missing _instance_id settings and other EA fixes.
Reviewed-by: rasbold

     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);
   589     _congraph = new(comp_arena()) ConnectionGraph(this);
   590     bool has_non_escaping_obj = _congraph->compute_escape();
   592 #ifndef PRODUCT
   593     if (PrintEscapeAnalysis) {
   594       _congraph->dump();
   595     }
   596 #endif
   597     if (!has_non_escaping_obj) {
   598       _congraph = NULL;
   599     }
   601     if (failing())  return;
   602   }
   603   // Now optimize
   604   Optimize();
   605   if (failing())  return;
   606   NOT_PRODUCT( verify_graph_edges(); )
   608   print_method("Before Matching");
   610 #ifndef PRODUCT
   611   if (PrintIdeal) {
   612     ttyLocker ttyl;  // keep the following output all in one block
   613     // This output goes directly to the tty, not the compiler log.
   614     // To enable tools to match it up with the compilation activity,
   615     // be sure to tag this tty output with the compile ID.
   616     if (xtty != NULL) {
   617       xtty->head("ideal compile_id='%d'%s", compile_id(),
   618                  is_osr_compilation()    ? " compile_kind='osr'" :
   619                  "");
   620     }
   621     root()->dump(9999);
   622     if (xtty != NULL) {
   623       xtty->tail("ideal");
   624     }
   625   }
   626 #endif
   628   // Now that we know the size of all the monitors we can add a fixed slot
   629   // for the original deopt pc.
   631   _orig_pc_slot =  fixed_slots();
   632   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
   633   set_fixed_slots(next_slot);
   635   // Now generate code
   636   Code_Gen();
   637   if (failing())  return;
   639   // Check if we want to skip execution of all compiled code.
   640   {
   641 #ifndef PRODUCT
   642     if (OptoNoExecute) {
   643       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
   644       return;
   645     }
   646     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
   647 #endif
   649     if (is_osr_compilation()) {
   650       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
   651       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
   652     } else {
   653       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
   654       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
   655     }
   657     env()->register_method(_method, _entry_bci,
   658                            &_code_offsets,
   659                            _orig_pc_slot_offset_in_bytes,
   660                            code_buffer(),
   661                            frame_size_in_words(), _oop_map_set,
   662                            &_handler_table, &_inc_table,
   663                            compiler,
   664                            env()->comp_level(),
   665                            true, /*has_debug_info*/
   666                            has_unsafe_access()
   667                            );
   668   }
   669 }
   671 //------------------------------Compile----------------------------------------
   672 // Compile a runtime stub
   673 Compile::Compile( ciEnv* ci_env,
   674                   TypeFunc_generator generator,
   675                   address stub_function,
   676                   const char *stub_name,
   677                   int is_fancy_jump,
   678                   bool pass_tls,
   679                   bool save_arg_registers,
   680                   bool return_pc )
   681   : Phase(Compiler),
   682     _env(ci_env),
   683     _log(ci_env->log()),
   684     _compile_id(-1),
   685     _save_argument_registers(save_arg_registers),
   686     _method(NULL),
   687     _stub_name(stub_name),
   688     _stub_function(stub_function),
   689     _stub_entry_point(NULL),
   690     _entry_bci(InvocationEntryBci),
   691     _initial_gvn(NULL),
   692     _for_igvn(NULL),
   693     _warm_calls(NULL),
   694     _orig_pc_slot(0),
   695     _orig_pc_slot_offset_in_bytes(0),
   696     _subsume_loads(true),
   697     _do_escape_analysis(false),
   698     _failure_reason(NULL),
   699     _code_buffer("Compile::Fill_buffer"),
   700     _node_bundling_limit(0),
   701     _node_bundling_base(NULL),
   702 #ifndef PRODUCT
   703     _trace_opto_output(TraceOptoOutput),
   704     _printer(NULL),
   705 #endif
   706     _congraph(NULL) {
   707   C = this;
   709 #ifndef PRODUCT
   710   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
   711   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
   712   set_print_assembly(PrintFrameConverterAssembly);
   713 #endif
   714   CompileWrapper cw(this);
   715   Init(/*AliasLevel=*/ 0);
   716   init_tf((*generator)());
   718   {
   719     // The following is a dummy for the sake of GraphKit::gen_stub
   720     Unique_Node_List for_igvn(comp_arena());
   721     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
   722     PhaseGVN gvn(Thread::current()->resource_area(),255);
   723     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
   724     gvn.transform_no_reclaim(top());
   726     GraphKit kit;
   727     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
   728   }
   730   NOT_PRODUCT( verify_graph_edges(); )
   731   Code_Gen();
   732   if (failing())  return;
   735   // Entry point will be accessed using compile->stub_entry_point();
   736   if (code_buffer() == NULL) {
   737     Matcher::soft_match_failure();
   738   } else {
   739     if (PrintAssembly && (WizardMode || Verbose))
   740       tty->print_cr("### Stub::%s", stub_name);
   742     if (!failing()) {
   743       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
   745       // Make the NMethod
   746       // For now we mark the frame as never safe for profile stackwalking
   747       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
   748                                                       code_buffer(),
   749                                                       CodeOffsets::frame_never_safe,
   750                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
   751                                                       frame_size_in_words(),
   752                                                       _oop_map_set,
   753                                                       save_arg_registers);
   754       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
   756       _stub_entry_point = rs->entry_point();
   757     }
   758   }
   759 }
   761 #ifndef PRODUCT
   762 void print_opto_verbose_signature( const TypeFunc *j_sig, const char *stub_name ) {
   763   if(PrintOpto && Verbose) {
   764     tty->print("%s   ", stub_name); j_sig->print_flattened(); tty->cr();
   765   }
   766 }
   767 #endif
   769 void Compile::print_codes() {
   770 }
   772 //------------------------------Init-------------------------------------------
   773 // Prepare for a single compilation
   774 void Compile::Init(int aliaslevel) {
   775   _unique  = 0;
   776   _regalloc = NULL;
   778   _tf      = NULL;  // filled in later
   779   _top     = NULL;  // cached later
   780   _matcher = NULL;  // filled in later
   781   _cfg     = NULL;  // filled in later
   783   set_24_bit_selection_and_mode(Use24BitFP, false);
   785   _node_note_array = NULL;
   786   _default_node_notes = NULL;
   788   _immutable_memory = NULL; // filled in at first inquiry
   790   // Globally visible Nodes
   791   // First set TOP to NULL to give safe behavior during creation of RootNode
   792   set_cached_top_node(NULL);
   793   set_root(new (this, 3) RootNode());
   794   // Now that you have a Root to point to, create the real TOP
   795   set_cached_top_node( new (this, 1) ConNode(Type::TOP) );
   796   set_recent_alloc(NULL, NULL);
   798   // Create Debug Information Recorder to record scopes, oopmaps, etc.
   799   env()->set_oop_recorder(new OopRecorder(comp_arena()));
   800   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
   801   env()->set_dependencies(new Dependencies(env()));
   803   _fixed_slots = 0;
   804   set_has_split_ifs(false);
   805   set_has_loops(has_method() && method()->has_loops()); // first approximation
   806   _deopt_happens = true;  // start out assuming the worst
   807   _trap_can_recompile = false;  // no traps emitted yet
   808   _major_progress = true; // start out assuming good things will happen
   809   set_has_unsafe_access(false);
   810   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
   811   set_decompile_count(0);
   813   // Compilation level related initialization
   814   if (env()->comp_level() == CompLevel_fast_compile) {
   815     set_num_loop_opts(Tier1LoopOptsCount);
   816     set_do_inlining(Tier1Inline != 0);
   817     set_max_inline_size(Tier1MaxInlineSize);
   818     set_freq_inline_size(Tier1FreqInlineSize);
   819     set_do_scheduling(false);
   820     set_do_count_invocations(Tier1CountInvocations);
   821     set_do_method_data_update(Tier1UpdateMethodData);
   822   } else {
   823     assert(env()->comp_level() == CompLevel_full_optimization, "unknown comp level");
   824     set_num_loop_opts(LoopOptsCount);
   825     set_do_inlining(Inline);
   826     set_max_inline_size(MaxInlineSize);
   827     set_freq_inline_size(FreqInlineSize);
   828     set_do_scheduling(OptoScheduling);
   829     set_do_count_invocations(false);
   830     set_do_method_data_update(false);
   831   }
   833   if (debug_info()->recording_non_safepoints()) {
   834     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
   835                         (comp_arena(), 8, 0, NULL));
   836     set_default_node_notes(Node_Notes::make(this));
   837   }
   839   // // -- Initialize types before each compile --
   840   // // Update cached type information
   841   // if( _method && _method->constants() )
   842   //   Type::update_loaded_types(_method, _method->constants());
   844   // Init alias_type map.
   845   if (!_do_escape_analysis && aliaslevel == 3)
   846     aliaslevel = 2;  // No unique types without escape analysis
   847   _AliasLevel = aliaslevel;
   848   const int grow_ats = 16;
   849   _max_alias_types = grow_ats;
   850   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
   851   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
   852   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
   853   {
   854     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
   855   }
   856   // Initialize the first few types.
   857   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
   858   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
   859   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
   860   _num_alias_types = AliasIdxRaw+1;
   861   // Zero out the alias type cache.
   862   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
   863   // A NULL adr_type hits in the cache right away.  Preload the right answer.
   864   probe_alias_cache(NULL)->_index = AliasIdxTop;
   866   _intrinsics = NULL;
   867   _macro_nodes = new GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
   868   register_library_intrinsics();
   869 }
   871 //---------------------------init_start----------------------------------------
   872 // Install the StartNode on this compile object.
   873 void Compile::init_start(StartNode* s) {
   874   if (failing())
   875     return; // already failing
   876   assert(s == start(), "");
   877 }
   879 StartNode* Compile::start() const {
   880   assert(!failing(), "");
   881   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
   882     Node* start = root()->fast_out(i);
   883     if( start->is_Start() )
   884       return start->as_Start();
   885   }
   886   ShouldNotReachHere();
   887   return NULL;
   888 }
   890 //-------------------------------immutable_memory-------------------------------------
   891 // Access immutable memory
   892 Node* Compile::immutable_memory() {
   893   if (_immutable_memory != NULL) {
   894     return _immutable_memory;
   895   }
   896   StartNode* s = start();
   897   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
   898     Node *p = s->fast_out(i);
   899     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
   900       _immutable_memory = p;
   901       return _immutable_memory;
   902     }
   903   }
   904   ShouldNotReachHere();
   905   return NULL;
   906 }
   908 //----------------------set_cached_top_node------------------------------------
   909 // Install the cached top node, and make sure Node::is_top works correctly.
   910 void Compile::set_cached_top_node(Node* tn) {
   911   if (tn != NULL)  verify_top(tn);
   912   Node* old_top = _top;
   913   _top = tn;
   914   // Calling Node::setup_is_top allows the nodes the chance to adjust
   915   // their _out arrays.
   916   if (_top != NULL)     _top->setup_is_top();
   917   if (old_top != NULL)  old_top->setup_is_top();
   918   assert(_top == NULL || top()->is_top(), "");
   919 }
   921 #ifndef PRODUCT
   922 void Compile::verify_top(Node* tn) const {
   923   if (tn != NULL) {
   924     assert(tn->is_Con(), "top node must be a constant");
   925     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
   926     assert(tn->in(0) != NULL, "must have live top node");
   927   }
   928 }
   929 #endif
   932 ///-------------------Managing Per-Node Debug & Profile Info-------------------
   934 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
   935   guarantee(arr != NULL, "");
   936   int num_blocks = arr->length();
   937   if (grow_by < num_blocks)  grow_by = num_blocks;
   938   int num_notes = grow_by * _node_notes_block_size;
   939   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
   940   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
   941   while (num_notes > 0) {
   942     arr->append(notes);
   943     notes     += _node_notes_block_size;
   944     num_notes -= _node_notes_block_size;
   945   }
   946   assert(num_notes == 0, "exact multiple, please");
   947 }
   949 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
   950   if (source == NULL || dest == NULL)  return false;
   952   if (dest->is_Con())
   953     return false;               // Do not push debug info onto constants.
   955 #ifdef ASSERT
   956   // Leave a bread crumb trail pointing to the original node:
   957   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
   958     dest->set_debug_orig(source);
   959   }
   960 #endif
   962   if (node_note_array() == NULL)
   963     return false;               // Not collecting any notes now.
   965   // This is a copy onto a pre-existing node, which may already have notes.
   966   // If both nodes have notes, do not overwrite any pre-existing notes.
   967   Node_Notes* source_notes = node_notes_at(source->_idx);
   968   if (source_notes == NULL || source_notes->is_clear())  return false;
   969   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
   970   if (dest_notes == NULL || dest_notes->is_clear()) {
   971     return set_node_notes_at(dest->_idx, source_notes);
   972   }
   974   Node_Notes merged_notes = (*source_notes);
   975   // The order of operations here ensures that dest notes will win...
   976   merged_notes.update_from(dest_notes);
   977   return set_node_notes_at(dest->_idx, &merged_notes);
   978 }
   981 //--------------------------allow_range_check_smearing-------------------------
   982 // Gating condition for coalescing similar range checks.
   983 // Sometimes we try 'speculatively' replacing a series of a range checks by a
   984 // single covering check that is at least as strong as any of them.
   985 // If the optimization succeeds, the simplified (strengthened) range check
   986 // will always succeed.  If it fails, we will deopt, and then give up
   987 // on the optimization.
   988 bool Compile::allow_range_check_smearing() const {
   989   // If this method has already thrown a range-check,
   990   // assume it was because we already tried range smearing
   991   // and it failed.
   992   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
   993   return !already_trapped;
   994 }
   997 //------------------------------flatten_alias_type-----------------------------
   998 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
   999   int offset = tj->offset();
  1000   TypePtr::PTR ptr = tj->ptr();
  1002   // Known instance (scalarizable allocation) alias only with itself.
  1003   bool is_known_inst = tj->isa_oopptr() != NULL &&
  1004                        tj->is_oopptr()->is_known_instance();
  1006   // Process weird unsafe references.
  1007   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
  1008     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
  1009     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
  1010     tj = TypeOopPtr::BOTTOM;
  1011     ptr = tj->ptr();
  1012     offset = tj->offset();
  1015   // Array pointers need some flattening
  1016   const TypeAryPtr *ta = tj->isa_aryptr();
  1017   if( ta && is_known_inst ) {
  1018     if ( offset != Type::OffsetBot &&
  1019          offset > arrayOopDesc::length_offset_in_bytes() ) {
  1020       offset = Type::OffsetBot; // Flatten constant access into array body only
  1021       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
  1023   } else if( ta && _AliasLevel >= 2 ) {
  1024     // For arrays indexed by constant indices, we flatten the alias
  1025     // space to include all of the array body.  Only the header, klass
  1026     // and array length can be accessed un-aliased.
  1027     if( offset != Type::OffsetBot ) {
  1028       if( ta->const_oop() ) { // methodDataOop or methodOop
  1029         offset = Type::OffsetBot;   // Flatten constant access into array body
  1030         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
  1031       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
  1032         // range is OK as-is.
  1033         tj = ta = TypeAryPtr::RANGE;
  1034       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
  1035         tj = TypeInstPtr::KLASS; // all klass loads look alike
  1036         ta = TypeAryPtr::RANGE; // generic ignored junk
  1037         ptr = TypePtr::BotPTR;
  1038       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
  1039         tj = TypeInstPtr::MARK;
  1040         ta = TypeAryPtr::RANGE; // generic ignored junk
  1041         ptr = TypePtr::BotPTR;
  1042       } else {                  // Random constant offset into array body
  1043         offset = Type::OffsetBot;   // Flatten constant access into array body
  1044         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
  1047     // Arrays of fixed size alias with arrays of unknown size.
  1048     if (ta->size() != TypeInt::POS) {
  1049       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
  1050       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
  1052     // Arrays of known objects become arrays of unknown objects.
  1053     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
  1054       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
  1055       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
  1057     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
  1058       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
  1059       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
  1061     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
  1062     // cannot be distinguished by bytecode alone.
  1063     if (ta->elem() == TypeInt::BOOL) {
  1064       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
  1065       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
  1066       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
  1068     // During the 2nd round of IterGVN, NotNull castings are removed.
  1069     // Make sure the Bottom and NotNull variants alias the same.
  1070     // Also, make sure exact and non-exact variants alias the same.
  1071     if( ptr == TypePtr::NotNull || ta->klass_is_exact() ) {
  1072       if (ta->const_oop()) {
  1073         tj = ta = TypeAryPtr::make(TypePtr::Constant,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
  1074       } else {
  1075         tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
  1080   // Oop pointers need some flattening
  1081   const TypeInstPtr *to = tj->isa_instptr();
  1082   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
  1083     if( ptr == TypePtr::Constant ) {
  1084       // No constant oop pointers (such as Strings); they alias with
  1085       // unknown strings.
  1086       assert(!is_known_inst, "not scalarizable allocation");
  1087       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1088     } else if( is_known_inst ) {
  1089       tj = to; // Keep NotNull and klass_is_exact for instance type
  1090     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
  1091       // During the 2nd round of IterGVN, NotNull castings are removed.
  1092       // Make sure the Bottom and NotNull variants alias the same.
  1093       // Also, make sure exact and non-exact variants alias the same.
  1094       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1096     // Canonicalize the holder of this field
  1097     ciInstanceKlass *k = to->klass()->as_instance_klass();
  1098     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
  1099       // First handle header references such as a LoadKlassNode, even if the
  1100       // object's klass is unloaded at compile time (4965979).
  1101       if (!is_known_inst) { // Do it only for non-instance types
  1102         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
  1104     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
  1105       to = NULL;
  1106       tj = TypeOopPtr::BOTTOM;
  1107       offset = tj->offset();
  1108     } else {
  1109       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
  1110       if (!k->equals(canonical_holder) || tj->offset() != offset) {
  1111         if( is_known_inst ) {
  1112           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
  1113         } else {
  1114           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
  1120   // Klass pointers to object array klasses need some flattening
  1121   const TypeKlassPtr *tk = tj->isa_klassptr();
  1122   if( tk ) {
  1123     // If we are referencing a field within a Klass, we need
  1124     // to assume the worst case of an Object.  Both exact and
  1125     // inexact types must flatten to the same alias class.
  1126     // Since the flattened result for a klass is defined to be
  1127     // precisely java.lang.Object, use a constant ptr.
  1128     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
  1130       tj = tk = TypeKlassPtr::make(TypePtr::Constant,
  1131                                    TypeKlassPtr::OBJECT->klass(),
  1132                                    offset);
  1135     ciKlass* klass = tk->klass();
  1136     if( klass->is_obj_array_klass() ) {
  1137       ciKlass* k = TypeAryPtr::OOPS->klass();
  1138       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
  1139         k = TypeInstPtr::BOTTOM->klass();
  1140       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
  1143     // Check for precise loads from the primary supertype array and force them
  1144     // to the supertype cache alias index.  Check for generic array loads from
  1145     // the primary supertype array and also force them to the supertype cache
  1146     // alias index.  Since the same load can reach both, we need to merge
  1147     // these 2 disparate memories into the same alias class.  Since the
  1148     // primary supertype array is read-only, there's no chance of confusion
  1149     // where we bypass an array load and an array store.
  1150     uint off2 = offset - Klass::primary_supers_offset_in_bytes();
  1151     if( offset == Type::OffsetBot ||
  1152         off2 < Klass::primary_super_limit()*wordSize ) {
  1153       offset = sizeof(oopDesc) +Klass::secondary_super_cache_offset_in_bytes();
  1154       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
  1158   // Flatten all Raw pointers together.
  1159   if (tj->base() == Type::RawPtr)
  1160     tj = TypeRawPtr::BOTTOM;
  1162   if (tj->base() == Type::AnyPtr)
  1163     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
  1165   // Flatten all to bottom for now
  1166   switch( _AliasLevel ) {
  1167   case 0:
  1168     tj = TypePtr::BOTTOM;
  1169     break;
  1170   case 1:                       // Flatten to: oop, static, field or array
  1171     switch (tj->base()) {
  1172     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
  1173     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
  1174     case Type::AryPtr:   // do not distinguish arrays at all
  1175     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
  1176     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
  1177     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
  1178     default: ShouldNotReachHere();
  1180     break;
  1181   case 2:                       // No collasping at level 2; keep all splits
  1182   case 3:                       // No collasping at level 3; keep all splits
  1183     break;
  1184   default:
  1185     Unimplemented();
  1188   offset = tj->offset();
  1189   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
  1191   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
  1192           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
  1193           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
  1194           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
  1195           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1196           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1197           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
  1198           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
  1199   assert( tj->ptr() != TypePtr::TopPTR &&
  1200           tj->ptr() != TypePtr::AnyNull &&
  1201           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
  1202 //    assert( tj->ptr() != TypePtr::Constant ||
  1203 //            tj->base() == Type::RawPtr ||
  1204 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
  1206   return tj;
  1209 void Compile::AliasType::Init(int i, const TypePtr* at) {
  1210   _index = i;
  1211   _adr_type = at;
  1212   _field = NULL;
  1213   _is_rewritable = true; // default
  1214   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
  1215   if (atoop != NULL && atoop->is_known_instance()) {
  1216     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
  1217     _general_index = Compile::current()->get_alias_index(gt);
  1218   } else {
  1219     _general_index = 0;
  1223 //---------------------------------print_on------------------------------------
  1224 #ifndef PRODUCT
  1225 void Compile::AliasType::print_on(outputStream* st) {
  1226   if (index() < 10)
  1227         st->print("@ <%d> ", index());
  1228   else  st->print("@ <%d>",  index());
  1229   st->print(is_rewritable() ? "   " : " RO");
  1230   int offset = adr_type()->offset();
  1231   if (offset == Type::OffsetBot)
  1232         st->print(" +any");
  1233   else  st->print(" +%-3d", offset);
  1234   st->print(" in ");
  1235   adr_type()->dump_on(st);
  1236   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
  1237   if (field() != NULL && tjp) {
  1238     if (tjp->klass()  != field()->holder() ||
  1239         tjp->offset() != field()->offset_in_bytes()) {
  1240       st->print(" != ");
  1241       field()->print();
  1242       st->print(" ***");
  1247 void print_alias_types() {
  1248   Compile* C = Compile::current();
  1249   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
  1250   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
  1251     C->alias_type(idx)->print_on(tty);
  1252     tty->cr();
  1255 #endif
  1258 //----------------------------probe_alias_cache--------------------------------
  1259 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
  1260   intptr_t key = (intptr_t) adr_type;
  1261   key ^= key >> logAliasCacheSize;
  1262   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
  1266 //-----------------------------grow_alias_types--------------------------------
  1267 void Compile::grow_alias_types() {
  1268   const int old_ats  = _max_alias_types; // how many before?
  1269   const int new_ats  = old_ats;          // how many more?
  1270   const int grow_ats = old_ats+new_ats;  // how many now?
  1271   _max_alias_types = grow_ats;
  1272   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
  1273   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
  1274   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
  1275   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
  1279 //--------------------------------find_alias_type------------------------------
  1280 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create) {
  1281   if (_AliasLevel == 0)
  1282     return alias_type(AliasIdxBot);
  1284   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1285   if (ace->_adr_type == adr_type) {
  1286     return alias_type(ace->_index);
  1289   // Handle special cases.
  1290   if (adr_type == NULL)             return alias_type(AliasIdxTop);
  1291   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
  1293   // Do it the slow way.
  1294   const TypePtr* flat = flatten_alias_type(adr_type);
  1296 #ifdef ASSERT
  1297   assert(flat == flatten_alias_type(flat), "idempotent");
  1298   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
  1299   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
  1300     const TypeOopPtr* foop = flat->is_oopptr();
  1301     // Scalarizable allocations have exact klass always.
  1302     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
  1303     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
  1304     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
  1306   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
  1307 #endif
  1309   int idx = AliasIdxTop;
  1310   for (int i = 0; i < num_alias_types(); i++) {
  1311     if (alias_type(i)->adr_type() == flat) {
  1312       idx = i;
  1313       break;
  1317   if (idx == AliasIdxTop) {
  1318     if (no_create)  return NULL;
  1319     // Grow the array if necessary.
  1320     if (_num_alias_types == _max_alias_types)  grow_alias_types();
  1321     // Add a new alias type.
  1322     idx = _num_alias_types++;
  1323     _alias_types[idx]->Init(idx, flat);
  1324     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
  1325     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
  1326     if (flat->isa_instptr()) {
  1327       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
  1328           && flat->is_instptr()->klass() == env()->Class_klass())
  1329         alias_type(idx)->set_rewritable(false);
  1331     if (flat->isa_klassptr()) {
  1332       if (flat->offset() == Klass::super_check_offset_offset_in_bytes() + (int)sizeof(oopDesc))
  1333         alias_type(idx)->set_rewritable(false);
  1334       if (flat->offset() == Klass::modifier_flags_offset_in_bytes() + (int)sizeof(oopDesc))
  1335         alias_type(idx)->set_rewritable(false);
  1336       if (flat->offset() == Klass::access_flags_offset_in_bytes() + (int)sizeof(oopDesc))
  1337         alias_type(idx)->set_rewritable(false);
  1338       if (flat->offset() == Klass::java_mirror_offset_in_bytes() + (int)sizeof(oopDesc))
  1339         alias_type(idx)->set_rewritable(false);
  1341     // %%% (We would like to finalize JavaThread::threadObj_offset(),
  1342     // but the base pointer type is not distinctive enough to identify
  1343     // references into JavaThread.)
  1345     // Check for final instance fields.
  1346     const TypeInstPtr* tinst = flat->isa_instptr();
  1347     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
  1348       ciInstanceKlass *k = tinst->klass()->as_instance_klass();
  1349       ciField* field = k->get_field_by_offset(tinst->offset(), false);
  1350       // Set field() and is_rewritable() attributes.
  1351       if (field != NULL)  alias_type(idx)->set_field(field);
  1353     const TypeKlassPtr* tklass = flat->isa_klassptr();
  1354     // Check for final static fields.
  1355     if (tklass && tklass->klass()->is_instance_klass()) {
  1356       ciInstanceKlass *k = tklass->klass()->as_instance_klass();
  1357       ciField* field = k->get_field_by_offset(tklass->offset(), true);
  1358       // Set field() and is_rewritable() attributes.
  1359       if (field != NULL)   alias_type(idx)->set_field(field);
  1363   // Fill the cache for next time.
  1364   ace->_adr_type = adr_type;
  1365   ace->_index    = idx;
  1366   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
  1368   // Might as well try to fill the cache for the flattened version, too.
  1369   AliasCacheEntry* face = probe_alias_cache(flat);
  1370   if (face->_adr_type == NULL) {
  1371     face->_adr_type = flat;
  1372     face->_index    = idx;
  1373     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
  1376   return alias_type(idx);
  1380 Compile::AliasType* Compile::alias_type(ciField* field) {
  1381   const TypeOopPtr* t;
  1382   if (field->is_static())
  1383     t = TypeKlassPtr::make(field->holder());
  1384   else
  1385     t = TypeOopPtr::make_from_klass_raw(field->holder());
  1386   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()));
  1387   assert(field->is_final() == !atp->is_rewritable(), "must get the rewritable bits correct");
  1388   return atp;
  1392 //------------------------------have_alias_type--------------------------------
  1393 bool Compile::have_alias_type(const TypePtr* adr_type) {
  1394   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1395   if (ace->_adr_type == adr_type) {
  1396     return true;
  1399   // Handle special cases.
  1400   if (adr_type == NULL)             return true;
  1401   if (adr_type == TypePtr::BOTTOM)  return true;
  1403   return find_alias_type(adr_type, true) != NULL;
  1406 //-----------------------------must_alias--------------------------------------
  1407 // True if all values of the given address type are in the given alias category.
  1408 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
  1409   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1410   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
  1411   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1412   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
  1414   // the only remaining possible overlap is identity
  1415   int adr_idx = get_alias_index(adr_type);
  1416   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1417   assert(adr_idx == alias_idx ||
  1418          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
  1419           && adr_type                       != TypeOopPtr::BOTTOM),
  1420          "should not be testing for overlap with an unsafe pointer");
  1421   return adr_idx == alias_idx;
  1424 //------------------------------can_alias--------------------------------------
  1425 // True if any values of the given address type are in the given alias category.
  1426 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
  1427   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1428   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
  1429   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1430   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
  1432   // the only remaining possible overlap is identity
  1433   int adr_idx = get_alias_index(adr_type);
  1434   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1435   return adr_idx == alias_idx;
  1440 //---------------------------pop_warm_call-------------------------------------
  1441 WarmCallInfo* Compile::pop_warm_call() {
  1442   WarmCallInfo* wci = _warm_calls;
  1443   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
  1444   return wci;
  1447 //----------------------------Inline_Warm--------------------------------------
  1448 int Compile::Inline_Warm() {
  1449   // If there is room, try to inline some more warm call sites.
  1450   // %%% Do a graph index compaction pass when we think we're out of space?
  1451   if (!InlineWarmCalls)  return 0;
  1453   int calls_made_hot = 0;
  1454   int room_to_grow   = NodeCountInliningCutoff - unique();
  1455   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
  1456   int amount_grown   = 0;
  1457   WarmCallInfo* call;
  1458   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
  1459     int est_size = (int)call->size();
  1460     if (est_size > (room_to_grow - amount_grown)) {
  1461       // This one won't fit anyway.  Get rid of it.
  1462       call->make_cold();
  1463       continue;
  1465     call->make_hot();
  1466     calls_made_hot++;
  1467     amount_grown   += est_size;
  1468     amount_to_grow -= est_size;
  1471   if (calls_made_hot > 0)  set_major_progress();
  1472   return calls_made_hot;
  1476 //----------------------------Finish_Warm--------------------------------------
  1477 void Compile::Finish_Warm() {
  1478   if (!InlineWarmCalls)  return;
  1479   if (failing())  return;
  1480   if (warm_calls() == NULL)  return;
  1482   // Clean up loose ends, if we are out of space for inlining.
  1483   WarmCallInfo* call;
  1484   while ((call = pop_warm_call()) != NULL) {
  1485     call->make_cold();
  1490 //------------------------------Optimize---------------------------------------
  1491 // Given a graph, optimize it.
  1492 void Compile::Optimize() {
  1493   TracePhase t1("optimizer", &_t_optimizer, true);
  1495 #ifndef PRODUCT
  1496   if (env()->break_at_compile()) {
  1497     BREAKPOINT;
  1500 #endif
  1502   ResourceMark rm;
  1503   int          loop_opts_cnt;
  1505   NOT_PRODUCT( verify_graph_edges(); )
  1507   print_method("After Parsing");
  1510   // Iterative Global Value Numbering, including ideal transforms
  1511   // Initialize IterGVN with types and values from parse-time GVN
  1512   PhaseIterGVN igvn(initial_gvn());
  1514     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
  1515     igvn.optimize();
  1518   print_method("Iter GVN 1", 2);
  1520   if (failing())  return;
  1522   // get rid of the connection graph since it's information is not
  1523   // updated by optimizations
  1524   _congraph = NULL;
  1527   // Loop transforms on the ideal graph.  Range Check Elimination,
  1528   // peeling, unrolling, etc.
  1530   // Set loop opts counter
  1531   loop_opts_cnt = num_loop_opts();
  1532   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
  1534       TracePhase t2("idealLoop", &_t_idealLoop, true);
  1535       PhaseIdealLoop ideal_loop( igvn, NULL, true );
  1536       loop_opts_cnt--;
  1537       if (major_progress()) print_method("PhaseIdealLoop 1", 2);
  1538       if (failing())  return;
  1540     // Loop opts pass if partial peeling occurred in previous pass
  1541     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
  1542       TracePhase t3("idealLoop", &_t_idealLoop, true);
  1543       PhaseIdealLoop ideal_loop( igvn, NULL, false );
  1544       loop_opts_cnt--;
  1545       if (major_progress()) print_method("PhaseIdealLoop 2", 2);
  1546       if (failing())  return;
  1548     // Loop opts pass for loop-unrolling before CCP
  1549     if(major_progress() && (loop_opts_cnt > 0)) {
  1550       TracePhase t4("idealLoop", &_t_idealLoop, true);
  1551       PhaseIdealLoop ideal_loop( igvn, NULL, false );
  1552       loop_opts_cnt--;
  1553       if (major_progress()) print_method("PhaseIdealLoop 3", 2);
  1556   if (failing())  return;
  1558   // Conditional Constant Propagation;
  1559   PhaseCCP ccp( &igvn );
  1560   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
  1562     TracePhase t2("ccp", &_t_ccp, true);
  1563     ccp.do_transform();
  1565   print_method("PhaseCPP 1", 2);
  1567   assert( true, "Break here to ccp.dump_old2new_map()");
  1569   // Iterative Global Value Numbering, including ideal transforms
  1571     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
  1572     igvn = ccp;
  1573     igvn.optimize();
  1576   print_method("Iter GVN 2", 2);
  1578   if (failing())  return;
  1580   // Loop transforms on the ideal graph.  Range Check Elimination,
  1581   // peeling, unrolling, etc.
  1582   if(loop_opts_cnt > 0) {
  1583     debug_only( int cnt = 0; );
  1584     while(major_progress() && (loop_opts_cnt > 0)) {
  1585       TracePhase t2("idealLoop", &_t_idealLoop, true);
  1586       assert( cnt++ < 40, "infinite cycle in loop optimization" );
  1587       PhaseIdealLoop ideal_loop( igvn, NULL, true );
  1588       loop_opts_cnt--;
  1589       if (major_progress()) print_method("PhaseIdealLoop iterations", 2);
  1590       if (failing())  return;
  1594     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
  1595     PhaseMacroExpand  mex(igvn);
  1596     if (mex.expand_macro_nodes()) {
  1597       assert(failing(), "must bail out w/ explicit message");
  1598       return;
  1602  } // (End scope of igvn; run destructor if necessary for asserts.)
  1604   // A method with only infinite loops has no edges entering loops from root
  1606     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
  1607     if (final_graph_reshaping()) {
  1608       assert(failing(), "must bail out w/ explicit message");
  1609       return;
  1613   print_method("Optimize finished", 2);
  1617 //------------------------------Code_Gen---------------------------------------
  1618 // Given a graph, generate code for it
  1619 void Compile::Code_Gen() {
  1620   if (failing())  return;
  1622   // Perform instruction selection.  You might think we could reclaim Matcher
  1623   // memory PDQ, but actually the Matcher is used in generating spill code.
  1624   // Internals of the Matcher (including some VectorSets) must remain live
  1625   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
  1626   // set a bit in reclaimed memory.
  1628   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  1629   // nodes.  Mapping is only valid at the root of each matched subtree.
  1630   NOT_PRODUCT( verify_graph_edges(); )
  1632   Node_List proj_list;
  1633   Matcher m(proj_list);
  1634   _matcher = &m;
  1636     TracePhase t2("matcher", &_t_matcher, true);
  1637     m.match();
  1639   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  1640   // nodes.  Mapping is only valid at the root of each matched subtree.
  1641   NOT_PRODUCT( verify_graph_edges(); )
  1643   // If you have too many nodes, or if matching has failed, bail out
  1644   check_node_count(0, "out of nodes matching instructions");
  1645   if (failing())  return;
  1647   // Build a proper-looking CFG
  1648   PhaseCFG cfg(node_arena(), root(), m);
  1649   _cfg = &cfg;
  1651     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
  1652     cfg.Dominators();
  1653     if (failing())  return;
  1655     NOT_PRODUCT( verify_graph_edges(); )
  1657     cfg.Estimate_Block_Frequency();
  1658     cfg.GlobalCodeMotion(m,unique(),proj_list);
  1660     print_method("Global code motion", 2);
  1662     if (failing())  return;
  1663     NOT_PRODUCT( verify_graph_edges(); )
  1665     debug_only( cfg.verify(); )
  1667   NOT_PRODUCT( verify_graph_edges(); )
  1669   PhaseChaitin regalloc(unique(),cfg,m);
  1670   _regalloc = &regalloc;
  1672     TracePhase t2("regalloc", &_t_registerAllocation, true);
  1673     // Perform any platform dependent preallocation actions.  This is used,
  1674     // for example, to avoid taking an implicit null pointer exception
  1675     // using the frame pointer on win95.
  1676     _regalloc->pd_preallocate_hook();
  1678     // Perform register allocation.  After Chaitin, use-def chains are
  1679     // no longer accurate (at spill code) and so must be ignored.
  1680     // Node->LRG->reg mappings are still accurate.
  1681     _regalloc->Register_Allocate();
  1683     // Bail out if the allocator builds too many nodes
  1684     if (failing())  return;
  1687   // Prior to register allocation we kept empty basic blocks in case the
  1688   // the allocator needed a place to spill.  After register allocation we
  1689   // are not adding any new instructions.  If any basic block is empty, we
  1690   // can now safely remove it.
  1692     NOT_PRODUCT( TracePhase t2("removeEmpty", &_t_removeEmptyBlocks, TimeCompiler); )
  1693     cfg.RemoveEmpty();
  1696   // Perform any platform dependent postallocation verifications.
  1697   debug_only( _regalloc->pd_postallocate_verify_hook(); )
  1699   // Apply peephole optimizations
  1700   if( OptoPeephole ) {
  1701     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
  1702     PhasePeephole peep( _regalloc, cfg);
  1703     peep.do_transform();
  1706   // Convert Nodes to instruction bits in a buffer
  1708     // %%%% workspace merge brought two timers together for one job
  1709     TracePhase t2a("output", &_t_output, true);
  1710     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
  1711     Output();
  1714   print_method("Final Code");
  1716   // He's dead, Jim.
  1717   _cfg     = (PhaseCFG*)0xdeadbeef;
  1718   _regalloc = (PhaseChaitin*)0xdeadbeef;
  1722 //------------------------------dump_asm---------------------------------------
  1723 // Dump formatted assembly
  1724 #ifndef PRODUCT
  1725 void Compile::dump_asm(int *pcs, uint pc_limit) {
  1726   bool cut_short = false;
  1727   tty->print_cr("#");
  1728   tty->print("#  ");  _tf->dump();  tty->cr();
  1729   tty->print_cr("#");
  1731   // For all blocks
  1732   int pc = 0x0;                 // Program counter
  1733   char starts_bundle = ' ';
  1734   _regalloc->dump_frame();
  1736   Node *n = NULL;
  1737   for( uint i=0; i<_cfg->_num_blocks; i++ ) {
  1738     if (VMThread::should_terminate()) { cut_short = true; break; }
  1739     Block *b = _cfg->_blocks[i];
  1740     if (b->is_connector() && !Verbose) continue;
  1741     n = b->_nodes[0];
  1742     if (pcs && n->_idx < pc_limit)
  1743       tty->print("%3.3x   ", pcs[n->_idx]);
  1744     else
  1745       tty->print("      ");
  1746     b->dump_head( &_cfg->_bbs );
  1747     if (b->is_connector()) {
  1748       tty->print_cr("        # Empty connector block");
  1749     } else if (b->num_preds() == 2 && b->pred(1)->is_CatchProj() && b->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
  1750       tty->print_cr("        # Block is sole successor of call");
  1753     // For all instructions
  1754     Node *delay = NULL;
  1755     for( uint j = 0; j<b->_nodes.size(); j++ ) {
  1756       if (VMThread::should_terminate()) { cut_short = true; break; }
  1757       n = b->_nodes[j];
  1758       if (valid_bundle_info(n)) {
  1759         Bundle *bundle = node_bundling(n);
  1760         if (bundle->used_in_unconditional_delay()) {
  1761           delay = n;
  1762           continue;
  1764         if (bundle->starts_bundle())
  1765           starts_bundle = '+';
  1768       if (WizardMode) n->dump();
  1770       if( !n->is_Region() &&    // Dont print in the Assembly
  1771           !n->is_Phi() &&       // a few noisely useless nodes
  1772           !n->is_Proj() &&
  1773           !n->is_MachTemp() &&
  1774           !n->is_Catch() &&     // Would be nice to print exception table targets
  1775           !n->is_MergeMem() &&  // Not very interesting
  1776           !n->is_top() &&       // Debug info table constants
  1777           !(n->is_Con() && !n->is_Mach())// Debug info table constants
  1778           ) {
  1779         if (pcs && n->_idx < pc_limit)
  1780           tty->print("%3.3x", pcs[n->_idx]);
  1781         else
  1782           tty->print("   ");
  1783         tty->print(" %c ", starts_bundle);
  1784         starts_bundle = ' ';
  1785         tty->print("\t");
  1786         n->format(_regalloc, tty);
  1787         tty->cr();
  1790       // If we have an instruction with a delay slot, and have seen a delay,
  1791       // then back up and print it
  1792       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
  1793         assert(delay != NULL, "no unconditional delay instruction");
  1794         if (WizardMode) delay->dump();
  1796         if (node_bundling(delay)->starts_bundle())
  1797           starts_bundle = '+';
  1798         if (pcs && n->_idx < pc_limit)
  1799           tty->print("%3.3x", pcs[n->_idx]);
  1800         else
  1801           tty->print("   ");
  1802         tty->print(" %c ", starts_bundle);
  1803         starts_bundle = ' ';
  1804         tty->print("\t");
  1805         delay->format(_regalloc, tty);
  1806         tty->print_cr("");
  1807         delay = NULL;
  1810       // Dump the exception table as well
  1811       if( n->is_Catch() && (Verbose || WizardMode) ) {
  1812         // Print the exception table for this offset
  1813         _handler_table.print_subtable_for(pc);
  1817     if (pcs && n->_idx < pc_limit)
  1818       tty->print_cr("%3.3x", pcs[n->_idx]);
  1819     else
  1820       tty->print_cr("");
  1822     assert(cut_short || delay == NULL, "no unconditional delay branch");
  1824   } // End of per-block dump
  1825   tty->print_cr("");
  1827   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
  1829 #endif
  1831 //------------------------------Final_Reshape_Counts---------------------------
  1832 // This class defines counters to help identify when a method
  1833 // may/must be executed using hardware with only 24-bit precision.
  1834 struct Final_Reshape_Counts : public StackObj {
  1835   int  _call_count;             // count non-inlined 'common' calls
  1836   int  _float_count;            // count float ops requiring 24-bit precision
  1837   int  _double_count;           // count double ops requiring more precision
  1838   int  _java_call_count;        // count non-inlined 'java' calls
  1839   VectorSet _visited;           // Visitation flags
  1840   Node_List _tests;             // Set of IfNodes & PCTableNodes
  1842   Final_Reshape_Counts() :
  1843     _call_count(0), _float_count(0), _double_count(0), _java_call_count(0),
  1844     _visited( Thread::current()->resource_area() ) { }
  1846   void inc_call_count  () { _call_count  ++; }
  1847   void inc_float_count () { _float_count ++; }
  1848   void inc_double_count() { _double_count++; }
  1849   void inc_java_call_count() { _java_call_count++; }
  1851   int  get_call_count  () const { return _call_count  ; }
  1852   int  get_float_count () const { return _float_count ; }
  1853   int  get_double_count() const { return _double_count; }
  1854   int  get_java_call_count() const { return _java_call_count; }
  1855 };
  1857 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
  1858   ciInstanceKlass *k = tp->klass()->as_instance_klass();
  1859   // Make sure the offset goes inside the instance layout.
  1860   return k->contains_field_offset(tp->offset());
  1861   // Note that OffsetBot and OffsetTop are very negative.
  1864 //------------------------------final_graph_reshaping_impl----------------------
  1865 // Implement items 1-5 from final_graph_reshaping below.
  1866 static void final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &fpu ) {
  1868   if ( n->outcnt() == 0 ) return; // dead node
  1869   uint nop = n->Opcode();
  1871   // Check for 2-input instruction with "last use" on right input.
  1872   // Swap to left input.  Implements item (2).
  1873   if( n->req() == 3 &&          // two-input instruction
  1874       n->in(1)->outcnt() > 1 && // left use is NOT a last use
  1875       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
  1876       n->in(2)->outcnt() == 1 &&// right use IS a last use
  1877       !n->in(2)->is_Con() ) {   // right use is not a constant
  1878     // Check for commutative opcode
  1879     switch( nop ) {
  1880     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
  1881     case Op_MaxI:  case Op_MinI:
  1882     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
  1883     case Op_AndL:  case Op_XorL:  case Op_OrL:
  1884     case Op_AndI:  case Op_XorI:  case Op_OrI: {
  1885       // Move "last use" input to left by swapping inputs
  1886       n->swap_edges(1, 2);
  1887       break;
  1889     default:
  1890       break;
  1894   // Count FPU ops and common calls, implements item (3)
  1895   switch( nop ) {
  1896   // Count all float operations that may use FPU
  1897   case Op_AddF:
  1898   case Op_SubF:
  1899   case Op_MulF:
  1900   case Op_DivF:
  1901   case Op_NegF:
  1902   case Op_ModF:
  1903   case Op_ConvI2F:
  1904   case Op_ConF:
  1905   case Op_CmpF:
  1906   case Op_CmpF3:
  1907   // case Op_ConvL2F: // longs are split into 32-bit halves
  1908     fpu.inc_float_count();
  1909     break;
  1911   case Op_ConvF2D:
  1912   case Op_ConvD2F:
  1913     fpu.inc_float_count();
  1914     fpu.inc_double_count();
  1915     break;
  1917   // Count all double operations that may use FPU
  1918   case Op_AddD:
  1919   case Op_SubD:
  1920   case Op_MulD:
  1921   case Op_DivD:
  1922   case Op_NegD:
  1923   case Op_ModD:
  1924   case Op_ConvI2D:
  1925   case Op_ConvD2I:
  1926   // case Op_ConvL2D: // handled by leaf call
  1927   // case Op_ConvD2L: // handled by leaf call
  1928   case Op_ConD:
  1929   case Op_CmpD:
  1930   case Op_CmpD3:
  1931     fpu.inc_double_count();
  1932     break;
  1933   case Op_Opaque1:              // Remove Opaque Nodes before matching
  1934   case Op_Opaque2:              // Remove Opaque Nodes before matching
  1935     n->subsume_by(n->in(1));
  1936     break;
  1937   case Op_CallStaticJava:
  1938   case Op_CallJava:
  1939   case Op_CallDynamicJava:
  1940     fpu.inc_java_call_count(); // Count java call site;
  1941   case Op_CallRuntime:
  1942   case Op_CallLeaf:
  1943   case Op_CallLeafNoFP: {
  1944     assert( n->is_Call(), "" );
  1945     CallNode *call = n->as_Call();
  1946     // Count call sites where the FP mode bit would have to be flipped.
  1947     // Do not count uncommon runtime calls:
  1948     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
  1949     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
  1950     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
  1951       fpu.inc_call_count();   // Count the call site
  1952     } else {                  // See if uncommon argument is shared
  1953       Node *n = call->in(TypeFunc::Parms);
  1954       int nop = n->Opcode();
  1955       // Clone shared simple arguments to uncommon calls, item (1).
  1956       if( n->outcnt() > 1 &&
  1957           !n->is_Proj() &&
  1958           nop != Op_CreateEx &&
  1959           nop != Op_CheckCastPP &&
  1960           !n->is_Mem() ) {
  1961         Node *x = n->clone();
  1962         call->set_req( TypeFunc::Parms, x );
  1965     break;
  1968   case Op_StoreD:
  1969   case Op_LoadD:
  1970   case Op_LoadD_unaligned:
  1971     fpu.inc_double_count();
  1972     goto handle_mem;
  1973   case Op_StoreF:
  1974   case Op_LoadF:
  1975     fpu.inc_float_count();
  1976     goto handle_mem;
  1978   case Op_StoreB:
  1979   case Op_StoreC:
  1980   case Op_StoreCM:
  1981   case Op_StorePConditional:
  1982   case Op_StoreI:
  1983   case Op_StoreL:
  1984   case Op_StoreLConditional:
  1985   case Op_CompareAndSwapI:
  1986   case Op_CompareAndSwapL:
  1987   case Op_CompareAndSwapP:
  1988   case Op_CompareAndSwapN:
  1989   case Op_StoreP:
  1990   case Op_StoreN:
  1991   case Op_LoadB:
  1992   case Op_LoadC:
  1993   case Op_LoadI:
  1994   case Op_LoadKlass:
  1995   case Op_LoadNKlass:
  1996   case Op_LoadL:
  1997   case Op_LoadL_unaligned:
  1998   case Op_LoadPLocked:
  1999   case Op_LoadLLocked:
  2000   case Op_LoadP:
  2001   case Op_LoadN:
  2002   case Op_LoadRange:
  2003   case Op_LoadS: {
  2004   handle_mem:
  2005 #ifdef ASSERT
  2006     if( VerifyOptoOopOffsets ) {
  2007       assert( n->is_Mem(), "" );
  2008       MemNode *mem  = (MemNode*)n;
  2009       // Check to see if address types have grounded out somehow.
  2010       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
  2011       assert( !tp || oop_offset_is_sane(tp), "" );
  2013 #endif
  2014     break;
  2017   case Op_AddP: {               // Assert sane base pointers
  2018     Node *addp = n->in(AddPNode::Address);
  2019     assert( !addp->is_AddP() ||
  2020             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
  2021             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
  2022             "Base pointers must match" );
  2023 #ifdef _LP64
  2024     if (UseCompressedOops &&
  2025         addp->Opcode() == Op_ConP &&
  2026         addp == n->in(AddPNode::Base) &&
  2027         n->in(AddPNode::Offset)->is_Con()) {
  2028       // Use addressing with narrow klass to load with offset on x86.
  2029       // On sparc loading 32-bits constant and decoding it have less
  2030       // instructions (4) then load 64-bits constant (7).
  2031       // Do this transformation here since IGVN will convert ConN back to ConP.
  2032       const Type* t = addp->bottom_type();
  2033       if (t->isa_oopptr()) {
  2034         Node* nn = NULL;
  2036         // Look for existing ConN node of the same exact type.
  2037         Compile* C = Compile::current();
  2038         Node* r  = C->root();
  2039         uint cnt = r->outcnt();
  2040         for (uint i = 0; i < cnt; i++) {
  2041           Node* m = r->raw_out(i);
  2042           if (m!= NULL && m->Opcode() == Op_ConN &&
  2043               m->bottom_type()->make_ptr() == t) {
  2044             nn = m;
  2045             break;
  2048         if (nn != NULL) {
  2049           // Decode a narrow oop to match address
  2050           // [R12 + narrow_oop_reg<<3 + offset]
  2051           nn = new (C,  2) DecodeNNode(nn, t);
  2052           n->set_req(AddPNode::Base, nn);
  2053           n->set_req(AddPNode::Address, nn);
  2054           if (addp->outcnt() == 0) {
  2055             addp->disconnect_inputs(NULL);
  2060 #endif
  2061     break;
  2064 #ifdef _LP64
  2065   case Op_CmpP:
  2066     // Do this transformation here to preserve CmpPNode::sub() and
  2067     // other TypePtr related Ideal optimizations (for example, ptr nullness).
  2068     if( n->in(1)->is_DecodeN() ) {
  2069       Compile* C = Compile::current();
  2070       Node* in2 = NULL;
  2071       if( n->in(2)->is_DecodeN() ) {
  2072         in2 = n->in(2)->in(1);
  2073       } else if ( n->in(2)->Opcode() == Op_ConP ) {
  2074         const Type* t = n->in(2)->bottom_type();
  2075         if (t == TypePtr::NULL_PTR) {
  2076           Node *in1 = n->in(1);
  2077           if (Matcher::clone_shift_expressions) {
  2078             // x86, ARM and friends can handle 2 adds in addressing mode.
  2079             // Decode a narrow oop and do implicit NULL check in address
  2080             // [R12 + narrow_oop_reg<<3 + offset]
  2081             in2 = ConNode::make(C, TypeNarrowOop::NULL_PTR);
  2082           } else {
  2083             // Don't replace CmpP(o ,null) if 'o' is used in AddP
  2084             // to generate implicit NULL check on Sparc where
  2085             // narrow oops can't be used in address.
  2086             uint i = 0;
  2087             for (; i < in1->outcnt(); i++) {
  2088               if (in1->raw_out(i)->is_AddP())
  2089                 break;
  2091             if (i >= in1->outcnt()) {
  2092               in2 = ConNode::make(C, TypeNarrowOop::NULL_PTR);
  2095         } else if (t->isa_oopptr()) {
  2096           in2 = ConNode::make(C, t->make_narrowoop());
  2099       if( in2 != NULL ) {
  2100         Node* cmpN = new (C, 3) CmpNNode(n->in(1)->in(1), in2);
  2101         n->subsume_by( cmpN );
  2104 #endif
  2106   case Op_ModI:
  2107     if (UseDivMod) {
  2108       // Check if a%b and a/b both exist
  2109       Node* d = n->find_similar(Op_DivI);
  2110       if (d) {
  2111         // Replace them with a fused divmod if supported
  2112         Compile* C = Compile::current();
  2113         if (Matcher::has_match_rule(Op_DivModI)) {
  2114           DivModINode* divmod = DivModINode::make(C, n);
  2115           d->subsume_by(divmod->div_proj());
  2116           n->subsume_by(divmod->mod_proj());
  2117         } else {
  2118           // replace a%b with a-((a/b)*b)
  2119           Node* mult = new (C, 3) MulINode(d, d->in(2));
  2120           Node* sub  = new (C, 3) SubINode(d->in(1), mult);
  2121           n->subsume_by( sub );
  2125     break;
  2127   case Op_ModL:
  2128     if (UseDivMod) {
  2129       // Check if a%b and a/b both exist
  2130       Node* d = n->find_similar(Op_DivL);
  2131       if (d) {
  2132         // Replace them with a fused divmod if supported
  2133         Compile* C = Compile::current();
  2134         if (Matcher::has_match_rule(Op_DivModL)) {
  2135           DivModLNode* divmod = DivModLNode::make(C, n);
  2136           d->subsume_by(divmod->div_proj());
  2137           n->subsume_by(divmod->mod_proj());
  2138         } else {
  2139           // replace a%b with a-((a/b)*b)
  2140           Node* mult = new (C, 3) MulLNode(d, d->in(2));
  2141           Node* sub  = new (C, 3) SubLNode(d->in(1), mult);
  2142           n->subsume_by( sub );
  2146     break;
  2148   case Op_Load16B:
  2149   case Op_Load8B:
  2150   case Op_Load4B:
  2151   case Op_Load8S:
  2152   case Op_Load4S:
  2153   case Op_Load2S:
  2154   case Op_Load8C:
  2155   case Op_Load4C:
  2156   case Op_Load2C:
  2157   case Op_Load4I:
  2158   case Op_Load2I:
  2159   case Op_Load2L:
  2160   case Op_Load4F:
  2161   case Op_Load2F:
  2162   case Op_Load2D:
  2163   case Op_Store16B:
  2164   case Op_Store8B:
  2165   case Op_Store4B:
  2166   case Op_Store8C:
  2167   case Op_Store4C:
  2168   case Op_Store2C:
  2169   case Op_Store4I:
  2170   case Op_Store2I:
  2171   case Op_Store2L:
  2172   case Op_Store4F:
  2173   case Op_Store2F:
  2174   case Op_Store2D:
  2175     break;
  2177   case Op_PackB:
  2178   case Op_PackS:
  2179   case Op_PackC:
  2180   case Op_PackI:
  2181   case Op_PackF:
  2182   case Op_PackL:
  2183   case Op_PackD:
  2184     if (n->req()-1 > 2) {
  2185       // Replace many operand PackNodes with a binary tree for matching
  2186       PackNode* p = (PackNode*) n;
  2187       Node* btp = p->binaryTreePack(Compile::current(), 1, n->req());
  2188       n->subsume_by(btp);
  2190     break;
  2191   default:
  2192     assert( !n->is_Call(), "" );
  2193     assert( !n->is_Mem(), "" );
  2194     break;
  2197   // Collect CFG split points
  2198   if (n->is_MultiBranch())
  2199     fpu._tests.push(n);
  2202 //------------------------------final_graph_reshaping_walk---------------------
  2203 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
  2204 // requires that the walk visits a node's inputs before visiting the node.
  2205 static void final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &fpu ) {
  2206   fpu._visited.set(root->_idx); // first, mark node as visited
  2207   uint cnt = root->req();
  2208   Node *n = root;
  2209   uint  i = 0;
  2210   while (true) {
  2211     if (i < cnt) {
  2212       // Place all non-visited non-null inputs onto stack
  2213       Node* m = n->in(i);
  2214       ++i;
  2215       if (m != NULL && !fpu._visited.test_set(m->_idx)) {
  2216         cnt = m->req();
  2217         nstack.push(n, i); // put on stack parent and next input's index
  2218         n = m;
  2219         i = 0;
  2221     } else {
  2222       // Now do post-visit work
  2223       final_graph_reshaping_impl( n, fpu );
  2224       if (nstack.is_empty())
  2225         break;             // finished
  2226       n = nstack.node();   // Get node from stack
  2227       cnt = n->req();
  2228       i = nstack.index();
  2229       nstack.pop();        // Shift to the next node on stack
  2234 //------------------------------final_graph_reshaping--------------------------
  2235 // Final Graph Reshaping.
  2236 //
  2237 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
  2238 //     and not commoned up and forced early.  Must come after regular
  2239 //     optimizations to avoid GVN undoing the cloning.  Clone constant
  2240 //     inputs to Loop Phis; these will be split by the allocator anyways.
  2241 //     Remove Opaque nodes.
  2242 // (2) Move last-uses by commutative operations to the left input to encourage
  2243 //     Intel update-in-place two-address operations and better register usage
  2244 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
  2245 //     calls canonicalizing them back.
  2246 // (3) Count the number of double-precision FP ops, single-precision FP ops
  2247 //     and call sites.  On Intel, we can get correct rounding either by
  2248 //     forcing singles to memory (requires extra stores and loads after each
  2249 //     FP bytecode) or we can set a rounding mode bit (requires setting and
  2250 //     clearing the mode bit around call sites).  The mode bit is only used
  2251 //     if the relative frequency of single FP ops to calls is low enough.
  2252 //     This is a key transform for SPEC mpeg_audio.
  2253 // (4) Detect infinite loops; blobs of code reachable from above but not
  2254 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
  2255 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
  2256 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
  2257 //     Detection is by looking for IfNodes where only 1 projection is
  2258 //     reachable from below or CatchNodes missing some targets.
  2259 // (5) Assert for insane oop offsets in debug mode.
  2261 bool Compile::final_graph_reshaping() {
  2262   // an infinite loop may have been eliminated by the optimizer,
  2263   // in which case the graph will be empty.
  2264   if (root()->req() == 1) {
  2265     record_method_not_compilable("trivial infinite loop");
  2266     return true;
  2269   Final_Reshape_Counts fpu;
  2271   // Visit everybody reachable!
  2272   // Allocate stack of size C->unique()/2 to avoid frequent realloc
  2273   Node_Stack nstack(unique() >> 1);
  2274   final_graph_reshaping_walk(nstack, root(), fpu);
  2276   // Check for unreachable (from below) code (i.e., infinite loops).
  2277   for( uint i = 0; i < fpu._tests.size(); i++ ) {
  2278     MultiBranchNode *n = fpu._tests[i]->as_MultiBranch();
  2279     // Get number of CFG targets.
  2280     // Note that PCTables include exception targets after calls.
  2281     uint required_outcnt = n->required_outcnt();
  2282     if (n->outcnt() != required_outcnt) {
  2283       // Check for a few special cases.  Rethrow Nodes never take the
  2284       // 'fall-thru' path, so expected kids is 1 less.
  2285       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
  2286         if (n->in(0)->in(0)->is_Call()) {
  2287           CallNode *call = n->in(0)->in(0)->as_Call();
  2288           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
  2289             required_outcnt--;      // Rethrow always has 1 less kid
  2290           } else if (call->req() > TypeFunc::Parms &&
  2291                      call->is_CallDynamicJava()) {
  2292             // Check for null receiver. In such case, the optimizer has
  2293             // detected that the virtual call will always result in a null
  2294             // pointer exception. The fall-through projection of this CatchNode
  2295             // will not be populated.
  2296             Node *arg0 = call->in(TypeFunc::Parms);
  2297             if (arg0->is_Type() &&
  2298                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
  2299               required_outcnt--;
  2301           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
  2302                      call->req() > TypeFunc::Parms+1 &&
  2303                      call->is_CallStaticJava()) {
  2304             // Check for negative array length. In such case, the optimizer has
  2305             // detected that the allocation attempt will always result in an
  2306             // exception. There is no fall-through projection of this CatchNode .
  2307             Node *arg1 = call->in(TypeFunc::Parms+1);
  2308             if (arg1->is_Type() &&
  2309                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
  2310               required_outcnt--;
  2315       // Recheck with a better notion of 'required_outcnt'
  2316       if (n->outcnt() != required_outcnt) {
  2317         record_method_not_compilable("malformed control flow");
  2318         return true;            // Not all targets reachable!
  2321     // Check that I actually visited all kids.  Unreached kids
  2322     // must be infinite loops.
  2323     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
  2324       if (!fpu._visited.test(n->fast_out(j)->_idx)) {
  2325         record_method_not_compilable("infinite loop");
  2326         return true;            // Found unvisited kid; must be unreach
  2330   // If original bytecodes contained a mixture of floats and doubles
  2331   // check if the optimizer has made it homogenous, item (3).
  2332   if( Use24BitFPMode && Use24BitFP &&
  2333       fpu.get_float_count() > 32 &&
  2334       fpu.get_double_count() == 0 &&
  2335       (10 * fpu.get_call_count() < fpu.get_float_count()) ) {
  2336     set_24_bit_selection_and_mode( false,  true );
  2339   set_has_java_calls(fpu.get_java_call_count() > 0);
  2341   // No infinite loops, no reason to bail out.
  2342   return false;
  2345 //-----------------------------too_many_traps----------------------------------
  2346 // Report if there are too many traps at the current method and bci.
  2347 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
  2348 bool Compile::too_many_traps(ciMethod* method,
  2349                              int bci,
  2350                              Deoptimization::DeoptReason reason) {
  2351   ciMethodData* md = method->method_data();
  2352   if (md->is_empty()) {
  2353     // Assume the trap has not occurred, or that it occurred only
  2354     // because of a transient condition during start-up in the interpreter.
  2355     return false;
  2357   if (md->has_trap_at(bci, reason) != 0) {
  2358     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
  2359     // Also, if there are multiple reasons, or if there is no per-BCI record,
  2360     // assume the worst.
  2361     if (log())
  2362       log()->elem("observe trap='%s' count='%d'",
  2363                   Deoptimization::trap_reason_name(reason),
  2364                   md->trap_count(reason));
  2365     return true;
  2366   } else {
  2367     // Ignore method/bci and see if there have been too many globally.
  2368     return too_many_traps(reason, md);
  2372 // Less-accurate variant which does not require a method and bci.
  2373 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
  2374                              ciMethodData* logmd) {
  2375  if (trap_count(reason) >= (uint)PerMethodTrapLimit) {
  2376     // Too many traps globally.
  2377     // Note that we use cumulative trap_count, not just md->trap_count.
  2378     if (log()) {
  2379       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
  2380       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
  2381                   Deoptimization::trap_reason_name(reason),
  2382                   mcount, trap_count(reason));
  2384     return true;
  2385   } else {
  2386     // The coast is clear.
  2387     return false;
  2391 //--------------------------too_many_recompiles--------------------------------
  2392 // Report if there are too many recompiles at the current method and bci.
  2393 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
  2394 // Is not eager to return true, since this will cause the compiler to use
  2395 // Action_none for a trap point, to avoid too many recompilations.
  2396 bool Compile::too_many_recompiles(ciMethod* method,
  2397                                   int bci,
  2398                                   Deoptimization::DeoptReason reason) {
  2399   ciMethodData* md = method->method_data();
  2400   if (md->is_empty()) {
  2401     // Assume the trap has not occurred, or that it occurred only
  2402     // because of a transient condition during start-up in the interpreter.
  2403     return false;
  2405   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
  2406   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
  2407   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
  2408   Deoptimization::DeoptReason per_bc_reason
  2409     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
  2410   if ((per_bc_reason == Deoptimization::Reason_none
  2411        || md->has_trap_at(bci, reason) != 0)
  2412       // The trap frequency measure we care about is the recompile count:
  2413       && md->trap_recompiled_at(bci)
  2414       && md->overflow_recompile_count() >= bc_cutoff) {
  2415     // Do not emit a trap here if it has already caused recompilations.
  2416     // Also, if there are multiple reasons, or if there is no per-BCI record,
  2417     // assume the worst.
  2418     if (log())
  2419       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
  2420                   Deoptimization::trap_reason_name(reason),
  2421                   md->trap_count(reason),
  2422                   md->overflow_recompile_count());
  2423     return true;
  2424   } else if (trap_count(reason) != 0
  2425              && decompile_count() >= m_cutoff) {
  2426     // Too many recompiles globally, and we have seen this sort of trap.
  2427     // Use cumulative decompile_count, not just md->decompile_count.
  2428     if (log())
  2429       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
  2430                   Deoptimization::trap_reason_name(reason),
  2431                   md->trap_count(reason), trap_count(reason),
  2432                   md->decompile_count(), decompile_count());
  2433     return true;
  2434   } else {
  2435     // The coast is clear.
  2436     return false;
  2441 #ifndef PRODUCT
  2442 //------------------------------verify_graph_edges---------------------------
  2443 // Walk the Graph and verify that there is a one-to-one correspondence
  2444 // between Use-Def edges and Def-Use edges in the graph.
  2445 void Compile::verify_graph_edges(bool no_dead_code) {
  2446   if (VerifyGraphEdges) {
  2447     ResourceArea *area = Thread::current()->resource_area();
  2448     Unique_Node_List visited(area);
  2449     // Call recursive graph walk to check edges
  2450     _root->verify_edges(visited);
  2451     if (no_dead_code) {
  2452       // Now make sure that no visited node is used by an unvisited node.
  2453       bool dead_nodes = 0;
  2454       Unique_Node_List checked(area);
  2455       while (visited.size() > 0) {
  2456         Node* n = visited.pop();
  2457         checked.push(n);
  2458         for (uint i = 0; i < n->outcnt(); i++) {
  2459           Node* use = n->raw_out(i);
  2460           if (checked.member(use))  continue;  // already checked
  2461           if (visited.member(use))  continue;  // already in the graph
  2462           if (use->is_Con())        continue;  // a dead ConNode is OK
  2463           // At this point, we have found a dead node which is DU-reachable.
  2464           if (dead_nodes++ == 0)
  2465             tty->print_cr("*** Dead nodes reachable via DU edges:");
  2466           use->dump(2);
  2467           tty->print_cr("---");
  2468           checked.push(use);  // No repeats; pretend it is now checked.
  2471       assert(dead_nodes == 0, "using nodes must be reachable from root");
  2475 #endif
  2477 // The Compile object keeps track of failure reasons separately from the ciEnv.
  2478 // This is required because there is not quite a 1-1 relation between the
  2479 // ciEnv and its compilation task and the Compile object.  Note that one
  2480 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
  2481 // to backtrack and retry without subsuming loads.  Other than this backtracking
  2482 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
  2483 // by the logic in C2Compiler.
  2484 void Compile::record_failure(const char* reason) {
  2485   if (log() != NULL) {
  2486     log()->elem("failure reason='%s' phase='compile'", reason);
  2488   if (_failure_reason == NULL) {
  2489     // Record the first failure reason.
  2490     _failure_reason = reason;
  2492   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
  2493     C->print_method(_failure_reason);
  2495   _root = NULL;  // flush the graph, too
  2498 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
  2499   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false)
  2501   if (dolog) {
  2502     C = Compile::current();
  2503     _log = C->log();
  2504   } else {
  2505     C = NULL;
  2506     _log = NULL;
  2508   if (_log != NULL) {
  2509     _log->begin_head("phase name='%s' nodes='%d'", name, C->unique());
  2510     _log->stamp();
  2511     _log->end_head();
  2515 Compile::TracePhase::~TracePhase() {
  2516   if (_log != NULL) {
  2517     _log->done("phase nodes='%d'", C->unique());

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