src/share/vm/opto/compile.cpp

Wed, 17 Sep 2008 12:59:52 -0700

author
never
date
Wed, 17 Sep 2008 12:59:52 -0700
changeset 802
194b8e3a2fc4
parent 768
7484fa4b8825
child 803
36ccc817fca4
permissions
-rw-r--r--

6384206: Phis which are later unneeded are impairing our ability to inline based on static types
Reviewed-by: rasbold, jrose

     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   set_parsed_irreducible_loop(false);
   471 #endif
   473   if (ProfileTraps) {
   474     // Make sure the method being compiled gets its own MDO,
   475     // so we can at least track the decompile_count().
   476     method()->build_method_data();
   477   }
   479   Init(::AliasLevel);
   482   print_compile_messages();
   484   if (UseOldInlining || PrintCompilation NOT_PRODUCT( || PrintOpto) )
   485     _ilt = InlineTree::build_inline_tree_root();
   486   else
   487     _ilt = NULL;
   489   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
   490   assert(num_alias_types() >= AliasIdxRaw, "");
   492 #define MINIMUM_NODE_HASH  1023
   493   // Node list that Iterative GVN will start with
   494   Unique_Node_List for_igvn(comp_arena());
   495   set_for_igvn(&for_igvn);
   497   // GVN that will be run immediately on new nodes
   498   uint estimated_size = method()->code_size()*4+64;
   499   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
   500   PhaseGVN gvn(node_arena(), estimated_size);
   501   set_initial_gvn(&gvn);
   503   { // Scope for timing the parser
   504     TracePhase t3("parse", &_t_parser, true);
   506     // Put top into the hash table ASAP.
   507     initial_gvn()->transform_no_reclaim(top());
   509     // Set up tf(), start(), and find a CallGenerator.
   510     CallGenerator* cg;
   511     if (is_osr_compilation()) {
   512       const TypeTuple *domain = StartOSRNode::osr_domain();
   513       const TypeTuple *range = TypeTuple::make_range(method()->signature());
   514       init_tf(TypeFunc::make(domain, range));
   515       StartNode* s = new (this, 2) StartOSRNode(root(), domain);
   516       initial_gvn()->set_type_bottom(s);
   517       init_start(s);
   518       cg = CallGenerator::for_osr(method(), entry_bci());
   519     } else {
   520       // Normal case.
   521       init_tf(TypeFunc::make(method()));
   522       StartNode* s = new (this, 2) StartNode(root(), tf()->domain());
   523       initial_gvn()->set_type_bottom(s);
   524       init_start(s);
   525       float past_uses = method()->interpreter_invocation_count();
   526       float expected_uses = past_uses;
   527       cg = CallGenerator::for_inline(method(), expected_uses);
   528     }
   529     if (failing())  return;
   530     if (cg == NULL) {
   531       record_method_not_compilable_all_tiers("cannot parse method");
   532       return;
   533     }
   534     JVMState* jvms = build_start_state(start(), tf());
   535     if ((jvms = cg->generate(jvms)) == NULL) {
   536       record_method_not_compilable("method parse failed");
   537       return;
   538     }
   539     GraphKit kit(jvms);
   541     if (!kit.stopped()) {
   542       // Accept return values, and transfer control we know not where.
   543       // This is done by a special, unique ReturnNode bound to root.
   544       return_values(kit.jvms());
   545     }
   547     if (kit.has_exceptions()) {
   548       // Any exceptions that escape from this call must be rethrown
   549       // to whatever caller is dynamically above us on the stack.
   550       // This is done by a special, unique RethrowNode bound to root.
   551       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
   552     }
   554     print_method("Before RemoveUseless");
   556     // Remove clutter produced by parsing.
   557     if (!failing()) {
   558       ResourceMark rm;
   559       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
   560     }
   561   }
   563   // Note:  Large methods are capped off in do_one_bytecode().
   564   if (failing())  return;
   566   // After parsing, node notes are no longer automagic.
   567   // They must be propagated by register_new_node_with_optimizer(),
   568   // clone(), or the like.
   569   set_default_node_notes(NULL);
   571   for (;;) {
   572     int successes = Inline_Warm();
   573     if (failing())  return;
   574     if (successes == 0)  break;
   575   }
   577   // Drain the list.
   578   Finish_Warm();
   579 #ifndef PRODUCT
   580   if (_printer) {
   581     _printer->print_inlining(this);
   582   }
   583 #endif
   585   if (failing())  return;
   586   NOT_PRODUCT( verify_graph_edges(); )
   588   // Perform escape analysis
   589   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
   590     TracePhase t2("escapeAnalysis", &_t_escapeAnalysis, true);
   591     // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction.
   592     PhaseGVN* igvn = initial_gvn();
   593     Node* oop_null = igvn->zerocon(T_OBJECT);
   594     Node* noop_null = igvn->zerocon(T_NARROWOOP);
   596     _congraph = new(comp_arena()) ConnectionGraph(this);
   597     bool has_non_escaping_obj = _congraph->compute_escape();
   599 #ifndef PRODUCT
   600     if (PrintEscapeAnalysis) {
   601       _congraph->dump();
   602     }
   603 #endif
   604     // Cleanup.
   605     if (oop_null->outcnt() == 0)
   606       igvn->hash_delete(oop_null);
   607     if (noop_null->outcnt() == 0)
   608       igvn->hash_delete(noop_null);
   610     if (!has_non_escaping_obj) {
   611       _congraph = NULL;
   612     }
   614     if (failing())  return;
   615   }
   616   // Now optimize
   617   Optimize();
   618   if (failing())  return;
   619   NOT_PRODUCT( verify_graph_edges(); )
   621 #ifndef PRODUCT
   622   if (PrintIdeal) {
   623     ttyLocker ttyl;  // keep the following output all in one block
   624     // This output goes directly to the tty, not the compiler log.
   625     // To enable tools to match it up with the compilation activity,
   626     // be sure to tag this tty output with the compile ID.
   627     if (xtty != NULL) {
   628       xtty->head("ideal compile_id='%d'%s", compile_id(),
   629                  is_osr_compilation()    ? " compile_kind='osr'" :
   630                  "");
   631     }
   632     root()->dump(9999);
   633     if (xtty != NULL) {
   634       xtty->tail("ideal");
   635     }
   636   }
   637 #endif
   639   // Now that we know the size of all the monitors we can add a fixed slot
   640   // for the original deopt pc.
   642   _orig_pc_slot =  fixed_slots();
   643   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
   644   set_fixed_slots(next_slot);
   646   // Now generate code
   647   Code_Gen();
   648   if (failing())  return;
   650   // Check if we want to skip execution of all compiled code.
   651   {
   652 #ifndef PRODUCT
   653     if (OptoNoExecute) {
   654       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
   655       return;
   656     }
   657     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
   658 #endif
   660     if (is_osr_compilation()) {
   661       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
   662       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
   663     } else {
   664       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
   665       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
   666     }
   668     env()->register_method(_method, _entry_bci,
   669                            &_code_offsets,
   670                            _orig_pc_slot_offset_in_bytes,
   671                            code_buffer(),
   672                            frame_size_in_words(), _oop_map_set,
   673                            &_handler_table, &_inc_table,
   674                            compiler,
   675                            env()->comp_level(),
   676                            true, /*has_debug_info*/
   677                            has_unsafe_access()
   678                            );
   679   }
   680 }
   682 //------------------------------Compile----------------------------------------
   683 // Compile a runtime stub
   684 Compile::Compile( ciEnv* ci_env,
   685                   TypeFunc_generator generator,
   686                   address stub_function,
   687                   const char *stub_name,
   688                   int is_fancy_jump,
   689                   bool pass_tls,
   690                   bool save_arg_registers,
   691                   bool return_pc )
   692   : Phase(Compiler),
   693     _env(ci_env),
   694     _log(ci_env->log()),
   695     _compile_id(-1),
   696     _save_argument_registers(save_arg_registers),
   697     _method(NULL),
   698     _stub_name(stub_name),
   699     _stub_function(stub_function),
   700     _stub_entry_point(NULL),
   701     _entry_bci(InvocationEntryBci),
   702     _initial_gvn(NULL),
   703     _for_igvn(NULL),
   704     _warm_calls(NULL),
   705     _orig_pc_slot(0),
   706     _orig_pc_slot_offset_in_bytes(0),
   707     _subsume_loads(true),
   708     _do_escape_analysis(false),
   709     _failure_reason(NULL),
   710     _code_buffer("Compile::Fill_buffer"),
   711     _node_bundling_limit(0),
   712     _node_bundling_base(NULL),
   713 #ifndef PRODUCT
   714     _trace_opto_output(TraceOptoOutput),
   715     _printer(NULL),
   716 #endif
   717     _congraph(NULL) {
   718   C = this;
   720 #ifndef PRODUCT
   721   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
   722   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
   723   set_print_assembly(PrintFrameConverterAssembly);
   724   set_parsed_irreducible_loop(false);
   725 #endif
   726   CompileWrapper cw(this);
   727   Init(/*AliasLevel=*/ 0);
   728   init_tf((*generator)());
   730   {
   731     // The following is a dummy for the sake of GraphKit::gen_stub
   732     Unique_Node_List for_igvn(comp_arena());
   733     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
   734     PhaseGVN gvn(Thread::current()->resource_area(),255);
   735     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
   736     gvn.transform_no_reclaim(top());
   738     GraphKit kit;
   739     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
   740   }
   742   NOT_PRODUCT( verify_graph_edges(); )
   743   Code_Gen();
   744   if (failing())  return;
   747   // Entry point will be accessed using compile->stub_entry_point();
   748   if (code_buffer() == NULL) {
   749     Matcher::soft_match_failure();
   750   } else {
   751     if (PrintAssembly && (WizardMode || Verbose))
   752       tty->print_cr("### Stub::%s", stub_name);
   754     if (!failing()) {
   755       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
   757       // Make the NMethod
   758       // For now we mark the frame as never safe for profile stackwalking
   759       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
   760                                                       code_buffer(),
   761                                                       CodeOffsets::frame_never_safe,
   762                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
   763                                                       frame_size_in_words(),
   764                                                       _oop_map_set,
   765                                                       save_arg_registers);
   766       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
   768       _stub_entry_point = rs->entry_point();
   769     }
   770   }
   771 }
   773 #ifndef PRODUCT
   774 void print_opto_verbose_signature( const TypeFunc *j_sig, const char *stub_name ) {
   775   if(PrintOpto && Verbose) {
   776     tty->print("%s   ", stub_name); j_sig->print_flattened(); tty->cr();
   777   }
   778 }
   779 #endif
   781 void Compile::print_codes() {
   782 }
   784 //------------------------------Init-------------------------------------------
   785 // Prepare for a single compilation
   786 void Compile::Init(int aliaslevel) {
   787   _unique  = 0;
   788   _regalloc = NULL;
   790   _tf      = NULL;  // filled in later
   791   _top     = NULL;  // cached later
   792   _matcher = NULL;  // filled in later
   793   _cfg     = NULL;  // filled in later
   795   set_24_bit_selection_and_mode(Use24BitFP, false);
   797   _node_note_array = NULL;
   798   _default_node_notes = NULL;
   800   _immutable_memory = NULL; // filled in at first inquiry
   802   // Globally visible Nodes
   803   // First set TOP to NULL to give safe behavior during creation of RootNode
   804   set_cached_top_node(NULL);
   805   set_root(new (this, 3) RootNode());
   806   // Now that you have a Root to point to, create the real TOP
   807   set_cached_top_node( new (this, 1) ConNode(Type::TOP) );
   808   set_recent_alloc(NULL, NULL);
   810   // Create Debug Information Recorder to record scopes, oopmaps, etc.
   811   env()->set_oop_recorder(new OopRecorder(comp_arena()));
   812   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
   813   env()->set_dependencies(new Dependencies(env()));
   815   _fixed_slots = 0;
   816   set_has_split_ifs(false);
   817   set_has_loops(has_method() && method()->has_loops()); // first approximation
   818   _deopt_happens = true;  // start out assuming the worst
   819   _trap_can_recompile = false;  // no traps emitted yet
   820   _major_progress = true; // start out assuming good things will happen
   821   set_has_unsafe_access(false);
   822   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
   823   set_decompile_count(0);
   825   // Compilation level related initialization
   826   if (env()->comp_level() == CompLevel_fast_compile) {
   827     set_num_loop_opts(Tier1LoopOptsCount);
   828     set_do_inlining(Tier1Inline != 0);
   829     set_max_inline_size(Tier1MaxInlineSize);
   830     set_freq_inline_size(Tier1FreqInlineSize);
   831     set_do_scheduling(false);
   832     set_do_count_invocations(Tier1CountInvocations);
   833     set_do_method_data_update(Tier1UpdateMethodData);
   834   } else {
   835     assert(env()->comp_level() == CompLevel_full_optimization, "unknown comp level");
   836     set_num_loop_opts(LoopOptsCount);
   837     set_do_inlining(Inline);
   838     set_max_inline_size(MaxInlineSize);
   839     set_freq_inline_size(FreqInlineSize);
   840     set_do_scheduling(OptoScheduling);
   841     set_do_count_invocations(false);
   842     set_do_method_data_update(false);
   843   }
   845   if (debug_info()->recording_non_safepoints()) {
   846     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
   847                         (comp_arena(), 8, 0, NULL));
   848     set_default_node_notes(Node_Notes::make(this));
   849   }
   851   // // -- Initialize types before each compile --
   852   // // Update cached type information
   853   // if( _method && _method->constants() )
   854   //   Type::update_loaded_types(_method, _method->constants());
   856   // Init alias_type map.
   857   if (!_do_escape_analysis && aliaslevel == 3)
   858     aliaslevel = 2;  // No unique types without escape analysis
   859   _AliasLevel = aliaslevel;
   860   const int grow_ats = 16;
   861   _max_alias_types = grow_ats;
   862   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
   863   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
   864   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
   865   {
   866     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
   867   }
   868   // Initialize the first few types.
   869   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
   870   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
   871   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
   872   _num_alias_types = AliasIdxRaw+1;
   873   // Zero out the alias type cache.
   874   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
   875   // A NULL adr_type hits in the cache right away.  Preload the right answer.
   876   probe_alias_cache(NULL)->_index = AliasIdxTop;
   878   _intrinsics = NULL;
   879   _macro_nodes = new GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
   880   register_library_intrinsics();
   881 }
   883 //---------------------------init_start----------------------------------------
   884 // Install the StartNode on this compile object.
   885 void Compile::init_start(StartNode* s) {
   886   if (failing())
   887     return; // already failing
   888   assert(s == start(), "");
   889 }
   891 StartNode* Compile::start() const {
   892   assert(!failing(), "");
   893   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
   894     Node* start = root()->fast_out(i);
   895     if( start->is_Start() )
   896       return start->as_Start();
   897   }
   898   ShouldNotReachHere();
   899   return NULL;
   900 }
   902 //-------------------------------immutable_memory-------------------------------------
   903 // Access immutable memory
   904 Node* Compile::immutable_memory() {
   905   if (_immutable_memory != NULL) {
   906     return _immutable_memory;
   907   }
   908   StartNode* s = start();
   909   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
   910     Node *p = s->fast_out(i);
   911     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
   912       _immutable_memory = p;
   913       return _immutable_memory;
   914     }
   915   }
   916   ShouldNotReachHere();
   917   return NULL;
   918 }
   920 //----------------------set_cached_top_node------------------------------------
   921 // Install the cached top node, and make sure Node::is_top works correctly.
   922 void Compile::set_cached_top_node(Node* tn) {
   923   if (tn != NULL)  verify_top(tn);
   924   Node* old_top = _top;
   925   _top = tn;
   926   // Calling Node::setup_is_top allows the nodes the chance to adjust
   927   // their _out arrays.
   928   if (_top != NULL)     _top->setup_is_top();
   929   if (old_top != NULL)  old_top->setup_is_top();
   930   assert(_top == NULL || top()->is_top(), "");
   931 }
   933 #ifndef PRODUCT
   934 void Compile::verify_top(Node* tn) const {
   935   if (tn != NULL) {
   936     assert(tn->is_Con(), "top node must be a constant");
   937     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
   938     assert(tn->in(0) != NULL, "must have live top node");
   939   }
   940 }
   941 #endif
   944 ///-------------------Managing Per-Node Debug & Profile Info-------------------
   946 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
   947   guarantee(arr != NULL, "");
   948   int num_blocks = arr->length();
   949   if (grow_by < num_blocks)  grow_by = num_blocks;
   950   int num_notes = grow_by * _node_notes_block_size;
   951   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
   952   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
   953   while (num_notes > 0) {
   954     arr->append(notes);
   955     notes     += _node_notes_block_size;
   956     num_notes -= _node_notes_block_size;
   957   }
   958   assert(num_notes == 0, "exact multiple, please");
   959 }
   961 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
   962   if (source == NULL || dest == NULL)  return false;
   964   if (dest->is_Con())
   965     return false;               // Do not push debug info onto constants.
   967 #ifdef ASSERT
   968   // Leave a bread crumb trail pointing to the original node:
   969   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
   970     dest->set_debug_orig(source);
   971   }
   972 #endif
   974   if (node_note_array() == NULL)
   975     return false;               // Not collecting any notes now.
   977   // This is a copy onto a pre-existing node, which may already have notes.
   978   // If both nodes have notes, do not overwrite any pre-existing notes.
   979   Node_Notes* source_notes = node_notes_at(source->_idx);
   980   if (source_notes == NULL || source_notes->is_clear())  return false;
   981   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
   982   if (dest_notes == NULL || dest_notes->is_clear()) {
   983     return set_node_notes_at(dest->_idx, source_notes);
   984   }
   986   Node_Notes merged_notes = (*source_notes);
   987   // The order of operations here ensures that dest notes will win...
   988   merged_notes.update_from(dest_notes);
   989   return set_node_notes_at(dest->_idx, &merged_notes);
   990 }
   993 //--------------------------allow_range_check_smearing-------------------------
   994 // Gating condition for coalescing similar range checks.
   995 // Sometimes we try 'speculatively' replacing a series of a range checks by a
   996 // single covering check that is at least as strong as any of them.
   997 // If the optimization succeeds, the simplified (strengthened) range check
   998 // will always succeed.  If it fails, we will deopt, and then give up
   999 // on the optimization.
  1000 bool Compile::allow_range_check_smearing() const {
  1001   // If this method has already thrown a range-check,
  1002   // assume it was because we already tried range smearing
  1003   // and it failed.
  1004   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
  1005   return !already_trapped;
  1009 //------------------------------flatten_alias_type-----------------------------
  1010 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
  1011   int offset = tj->offset();
  1012   TypePtr::PTR ptr = tj->ptr();
  1014   // Known instance (scalarizable allocation) alias only with itself.
  1015   bool is_known_inst = tj->isa_oopptr() != NULL &&
  1016                        tj->is_oopptr()->is_known_instance();
  1018   // Process weird unsafe references.
  1019   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
  1020     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
  1021     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
  1022     tj = TypeOopPtr::BOTTOM;
  1023     ptr = tj->ptr();
  1024     offset = tj->offset();
  1027   // Array pointers need some flattening
  1028   const TypeAryPtr *ta = tj->isa_aryptr();
  1029   if( ta && is_known_inst ) {
  1030     if ( offset != Type::OffsetBot &&
  1031          offset > arrayOopDesc::length_offset_in_bytes() ) {
  1032       offset = Type::OffsetBot; // Flatten constant access into array body only
  1033       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
  1035   } else if( ta && _AliasLevel >= 2 ) {
  1036     // For arrays indexed by constant indices, we flatten the alias
  1037     // space to include all of the array body.  Only the header, klass
  1038     // and array length can be accessed un-aliased.
  1039     if( offset != Type::OffsetBot ) {
  1040       if( ta->const_oop() ) { // methodDataOop or methodOop
  1041         offset = Type::OffsetBot;   // Flatten constant access into array body
  1042         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
  1043       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
  1044         // range is OK as-is.
  1045         tj = ta = TypeAryPtr::RANGE;
  1046       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
  1047         tj = TypeInstPtr::KLASS; // all klass loads look alike
  1048         ta = TypeAryPtr::RANGE; // generic ignored junk
  1049         ptr = TypePtr::BotPTR;
  1050       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
  1051         tj = TypeInstPtr::MARK;
  1052         ta = TypeAryPtr::RANGE; // generic ignored junk
  1053         ptr = TypePtr::BotPTR;
  1054       } else {                  // Random constant offset into array body
  1055         offset = Type::OffsetBot;   // Flatten constant access into array body
  1056         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
  1059     // Arrays of fixed size alias with arrays of unknown size.
  1060     if (ta->size() != TypeInt::POS) {
  1061       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
  1062       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
  1064     // Arrays of known objects become arrays of unknown objects.
  1065     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
  1066       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
  1067       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
  1069     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
  1070       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
  1071       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
  1073     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
  1074     // cannot be distinguished by bytecode alone.
  1075     if (ta->elem() == TypeInt::BOOL) {
  1076       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
  1077       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
  1078       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
  1080     // During the 2nd round of IterGVN, NotNull castings are removed.
  1081     // Make sure the Bottom and NotNull variants alias the same.
  1082     // Also, make sure exact and non-exact variants alias the same.
  1083     if( ptr == TypePtr::NotNull || ta->klass_is_exact() ) {
  1084       if (ta->const_oop()) {
  1085         tj = ta = TypeAryPtr::make(TypePtr::Constant,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
  1086       } else {
  1087         tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
  1092   // Oop pointers need some flattening
  1093   const TypeInstPtr *to = tj->isa_instptr();
  1094   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
  1095     if( ptr == TypePtr::Constant ) {
  1096       // No constant oop pointers (such as Strings); they alias with
  1097       // unknown strings.
  1098       assert(!is_known_inst, "not scalarizable allocation");
  1099       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1100     } else if( is_known_inst ) {
  1101       tj = to; // Keep NotNull and klass_is_exact for instance type
  1102     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
  1103       // During the 2nd round of IterGVN, NotNull castings are removed.
  1104       // Make sure the Bottom and NotNull variants alias the same.
  1105       // Also, make sure exact and non-exact variants alias the same.
  1106       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1108     // Canonicalize the holder of this field
  1109     ciInstanceKlass *k = to->klass()->as_instance_klass();
  1110     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
  1111       // First handle header references such as a LoadKlassNode, even if the
  1112       // object's klass is unloaded at compile time (4965979).
  1113       if (!is_known_inst) { // Do it only for non-instance types
  1114         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
  1116     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
  1117       to = NULL;
  1118       tj = TypeOopPtr::BOTTOM;
  1119       offset = tj->offset();
  1120     } else {
  1121       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
  1122       if (!k->equals(canonical_holder) || tj->offset() != offset) {
  1123         if( is_known_inst ) {
  1124           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
  1125         } else {
  1126           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
  1132   // Klass pointers to object array klasses need some flattening
  1133   const TypeKlassPtr *tk = tj->isa_klassptr();
  1134   if( tk ) {
  1135     // If we are referencing a field within a Klass, we need
  1136     // to assume the worst case of an Object.  Both exact and
  1137     // inexact types must flatten to the same alias class.
  1138     // Since the flattened result for a klass is defined to be
  1139     // precisely java.lang.Object, use a constant ptr.
  1140     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
  1142       tj = tk = TypeKlassPtr::make(TypePtr::Constant,
  1143                                    TypeKlassPtr::OBJECT->klass(),
  1144                                    offset);
  1147     ciKlass* klass = tk->klass();
  1148     if( klass->is_obj_array_klass() ) {
  1149       ciKlass* k = TypeAryPtr::OOPS->klass();
  1150       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
  1151         k = TypeInstPtr::BOTTOM->klass();
  1152       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
  1155     // Check for precise loads from the primary supertype array and force them
  1156     // to the supertype cache alias index.  Check for generic array loads from
  1157     // the primary supertype array and also force them to the supertype cache
  1158     // alias index.  Since the same load can reach both, we need to merge
  1159     // these 2 disparate memories into the same alias class.  Since the
  1160     // primary supertype array is read-only, there's no chance of confusion
  1161     // where we bypass an array load and an array store.
  1162     uint off2 = offset - Klass::primary_supers_offset_in_bytes();
  1163     if( offset == Type::OffsetBot ||
  1164         off2 < Klass::primary_super_limit()*wordSize ) {
  1165       offset = sizeof(oopDesc) +Klass::secondary_super_cache_offset_in_bytes();
  1166       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
  1170   // Flatten all Raw pointers together.
  1171   if (tj->base() == Type::RawPtr)
  1172     tj = TypeRawPtr::BOTTOM;
  1174   if (tj->base() == Type::AnyPtr)
  1175     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
  1177   // Flatten all to bottom for now
  1178   switch( _AliasLevel ) {
  1179   case 0:
  1180     tj = TypePtr::BOTTOM;
  1181     break;
  1182   case 1:                       // Flatten to: oop, static, field or array
  1183     switch (tj->base()) {
  1184     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
  1185     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
  1186     case Type::AryPtr:   // do not distinguish arrays at all
  1187     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
  1188     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
  1189     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
  1190     default: ShouldNotReachHere();
  1192     break;
  1193   case 2:                       // No collasping at level 2; keep all splits
  1194   case 3:                       // No collasping at level 3; keep all splits
  1195     break;
  1196   default:
  1197     Unimplemented();
  1200   offset = tj->offset();
  1201   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
  1203   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
  1204           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
  1205           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
  1206           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
  1207           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1208           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1209           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
  1210           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
  1211   assert( tj->ptr() != TypePtr::TopPTR &&
  1212           tj->ptr() != TypePtr::AnyNull &&
  1213           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
  1214 //    assert( tj->ptr() != TypePtr::Constant ||
  1215 //            tj->base() == Type::RawPtr ||
  1216 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
  1218   return tj;
  1221 void Compile::AliasType::Init(int i, const TypePtr* at) {
  1222   _index = i;
  1223   _adr_type = at;
  1224   _field = NULL;
  1225   _is_rewritable = true; // default
  1226   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
  1227   if (atoop != NULL && atoop->is_known_instance()) {
  1228     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
  1229     _general_index = Compile::current()->get_alias_index(gt);
  1230   } else {
  1231     _general_index = 0;
  1235 //---------------------------------print_on------------------------------------
  1236 #ifndef PRODUCT
  1237 void Compile::AliasType::print_on(outputStream* st) {
  1238   if (index() < 10)
  1239         st->print("@ <%d> ", index());
  1240   else  st->print("@ <%d>",  index());
  1241   st->print(is_rewritable() ? "   " : " RO");
  1242   int offset = adr_type()->offset();
  1243   if (offset == Type::OffsetBot)
  1244         st->print(" +any");
  1245   else  st->print(" +%-3d", offset);
  1246   st->print(" in ");
  1247   adr_type()->dump_on(st);
  1248   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
  1249   if (field() != NULL && tjp) {
  1250     if (tjp->klass()  != field()->holder() ||
  1251         tjp->offset() != field()->offset_in_bytes()) {
  1252       st->print(" != ");
  1253       field()->print();
  1254       st->print(" ***");
  1259 void print_alias_types() {
  1260   Compile* C = Compile::current();
  1261   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
  1262   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
  1263     C->alias_type(idx)->print_on(tty);
  1264     tty->cr();
  1267 #endif
  1270 //----------------------------probe_alias_cache--------------------------------
  1271 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
  1272   intptr_t key = (intptr_t) adr_type;
  1273   key ^= key >> logAliasCacheSize;
  1274   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
  1278 //-----------------------------grow_alias_types--------------------------------
  1279 void Compile::grow_alias_types() {
  1280   const int old_ats  = _max_alias_types; // how many before?
  1281   const int new_ats  = old_ats;          // how many more?
  1282   const int grow_ats = old_ats+new_ats;  // how many now?
  1283   _max_alias_types = grow_ats;
  1284   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
  1285   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
  1286   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
  1287   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
  1291 //--------------------------------find_alias_type------------------------------
  1292 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create) {
  1293   if (_AliasLevel == 0)
  1294     return alias_type(AliasIdxBot);
  1296   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1297   if (ace->_adr_type == adr_type) {
  1298     return alias_type(ace->_index);
  1301   // Handle special cases.
  1302   if (adr_type == NULL)             return alias_type(AliasIdxTop);
  1303   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
  1305   // Do it the slow way.
  1306   const TypePtr* flat = flatten_alias_type(adr_type);
  1308 #ifdef ASSERT
  1309   assert(flat == flatten_alias_type(flat), "idempotent");
  1310   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
  1311   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
  1312     const TypeOopPtr* foop = flat->is_oopptr();
  1313     // Scalarizable allocations have exact klass always.
  1314     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
  1315     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
  1316     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
  1318   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
  1319 #endif
  1321   int idx = AliasIdxTop;
  1322   for (int i = 0; i < num_alias_types(); i++) {
  1323     if (alias_type(i)->adr_type() == flat) {
  1324       idx = i;
  1325       break;
  1329   if (idx == AliasIdxTop) {
  1330     if (no_create)  return NULL;
  1331     // Grow the array if necessary.
  1332     if (_num_alias_types == _max_alias_types)  grow_alias_types();
  1333     // Add a new alias type.
  1334     idx = _num_alias_types++;
  1335     _alias_types[idx]->Init(idx, flat);
  1336     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
  1337     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
  1338     if (flat->isa_instptr()) {
  1339       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
  1340           && flat->is_instptr()->klass() == env()->Class_klass())
  1341         alias_type(idx)->set_rewritable(false);
  1343     if (flat->isa_klassptr()) {
  1344       if (flat->offset() == Klass::super_check_offset_offset_in_bytes() + (int)sizeof(oopDesc))
  1345         alias_type(idx)->set_rewritable(false);
  1346       if (flat->offset() == Klass::modifier_flags_offset_in_bytes() + (int)sizeof(oopDesc))
  1347         alias_type(idx)->set_rewritable(false);
  1348       if (flat->offset() == Klass::access_flags_offset_in_bytes() + (int)sizeof(oopDesc))
  1349         alias_type(idx)->set_rewritable(false);
  1350       if (flat->offset() == Klass::java_mirror_offset_in_bytes() + (int)sizeof(oopDesc))
  1351         alias_type(idx)->set_rewritable(false);
  1353     // %%% (We would like to finalize JavaThread::threadObj_offset(),
  1354     // but the base pointer type is not distinctive enough to identify
  1355     // references into JavaThread.)
  1357     // Check for final instance fields.
  1358     const TypeInstPtr* tinst = flat->isa_instptr();
  1359     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
  1360       ciInstanceKlass *k = tinst->klass()->as_instance_klass();
  1361       ciField* field = k->get_field_by_offset(tinst->offset(), false);
  1362       // Set field() and is_rewritable() attributes.
  1363       if (field != NULL)  alias_type(idx)->set_field(field);
  1365     const TypeKlassPtr* tklass = flat->isa_klassptr();
  1366     // Check for final static fields.
  1367     if (tklass && tklass->klass()->is_instance_klass()) {
  1368       ciInstanceKlass *k = tklass->klass()->as_instance_klass();
  1369       ciField* field = k->get_field_by_offset(tklass->offset(), true);
  1370       // Set field() and is_rewritable() attributes.
  1371       if (field != NULL)   alias_type(idx)->set_field(field);
  1375   // Fill the cache for next time.
  1376   ace->_adr_type = adr_type;
  1377   ace->_index    = idx;
  1378   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
  1380   // Might as well try to fill the cache for the flattened version, too.
  1381   AliasCacheEntry* face = probe_alias_cache(flat);
  1382   if (face->_adr_type == NULL) {
  1383     face->_adr_type = flat;
  1384     face->_index    = idx;
  1385     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
  1388   return alias_type(idx);
  1392 Compile::AliasType* Compile::alias_type(ciField* field) {
  1393   const TypeOopPtr* t;
  1394   if (field->is_static())
  1395     t = TypeKlassPtr::make(field->holder());
  1396   else
  1397     t = TypeOopPtr::make_from_klass_raw(field->holder());
  1398   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()));
  1399   assert(field->is_final() == !atp->is_rewritable(), "must get the rewritable bits correct");
  1400   return atp;
  1404 //------------------------------have_alias_type--------------------------------
  1405 bool Compile::have_alias_type(const TypePtr* adr_type) {
  1406   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1407   if (ace->_adr_type == adr_type) {
  1408     return true;
  1411   // Handle special cases.
  1412   if (adr_type == NULL)             return true;
  1413   if (adr_type == TypePtr::BOTTOM)  return true;
  1415   return find_alias_type(adr_type, true) != NULL;
  1418 //-----------------------------must_alias--------------------------------------
  1419 // True if all values of the given address type are in the given alias category.
  1420 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
  1421   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1422   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
  1423   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1424   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
  1426   // the only remaining possible overlap is identity
  1427   int adr_idx = get_alias_index(adr_type);
  1428   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1429   assert(adr_idx == alias_idx ||
  1430          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
  1431           && adr_type                       != TypeOopPtr::BOTTOM),
  1432          "should not be testing for overlap with an unsafe pointer");
  1433   return adr_idx == alias_idx;
  1436 //------------------------------can_alias--------------------------------------
  1437 // True if any values of the given address type are in the given alias category.
  1438 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
  1439   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1440   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
  1441   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1442   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
  1444   // the only remaining possible overlap is identity
  1445   int adr_idx = get_alias_index(adr_type);
  1446   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1447   return adr_idx == alias_idx;
  1452 //---------------------------pop_warm_call-------------------------------------
  1453 WarmCallInfo* Compile::pop_warm_call() {
  1454   WarmCallInfo* wci = _warm_calls;
  1455   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
  1456   return wci;
  1459 //----------------------------Inline_Warm--------------------------------------
  1460 int Compile::Inline_Warm() {
  1461   // If there is room, try to inline some more warm call sites.
  1462   // %%% Do a graph index compaction pass when we think we're out of space?
  1463   if (!InlineWarmCalls)  return 0;
  1465   int calls_made_hot = 0;
  1466   int room_to_grow   = NodeCountInliningCutoff - unique();
  1467   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
  1468   int amount_grown   = 0;
  1469   WarmCallInfo* call;
  1470   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
  1471     int est_size = (int)call->size();
  1472     if (est_size > (room_to_grow - amount_grown)) {
  1473       // This one won't fit anyway.  Get rid of it.
  1474       call->make_cold();
  1475       continue;
  1477     call->make_hot();
  1478     calls_made_hot++;
  1479     amount_grown   += est_size;
  1480     amount_to_grow -= est_size;
  1483   if (calls_made_hot > 0)  set_major_progress();
  1484   return calls_made_hot;
  1488 //----------------------------Finish_Warm--------------------------------------
  1489 void Compile::Finish_Warm() {
  1490   if (!InlineWarmCalls)  return;
  1491   if (failing())  return;
  1492   if (warm_calls() == NULL)  return;
  1494   // Clean up loose ends, if we are out of space for inlining.
  1495   WarmCallInfo* call;
  1496   while ((call = pop_warm_call()) != NULL) {
  1497     call->make_cold();
  1502 //------------------------------Optimize---------------------------------------
  1503 // Given a graph, optimize it.
  1504 void Compile::Optimize() {
  1505   TracePhase t1("optimizer", &_t_optimizer, true);
  1507 #ifndef PRODUCT
  1508   if (env()->break_at_compile()) {
  1509     BREAKPOINT;
  1512 #endif
  1514   ResourceMark rm;
  1515   int          loop_opts_cnt;
  1517   NOT_PRODUCT( verify_graph_edges(); )
  1519   print_method("After Parsing");
  1522   // Iterative Global Value Numbering, including ideal transforms
  1523   // Initialize IterGVN with types and values from parse-time GVN
  1524   PhaseIterGVN igvn(initial_gvn());
  1526     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
  1527     igvn.optimize();
  1530   print_method("Iter GVN 1", 2);
  1532   if (failing())  return;
  1534   // get rid of the connection graph since it's information is not
  1535   // updated by optimizations
  1536   _congraph = NULL;
  1539   // Loop transforms on the ideal graph.  Range Check Elimination,
  1540   // peeling, unrolling, etc.
  1542   // Set loop opts counter
  1543   loop_opts_cnt = num_loop_opts();
  1544   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
  1546       TracePhase t2("idealLoop", &_t_idealLoop, true);
  1547       PhaseIdealLoop ideal_loop( igvn, NULL, true );
  1548       loop_opts_cnt--;
  1549       if (major_progress()) print_method("PhaseIdealLoop 1", 2);
  1550       if (failing())  return;
  1552     // Loop opts pass if partial peeling occurred in previous pass
  1553     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
  1554       TracePhase t3("idealLoop", &_t_idealLoop, true);
  1555       PhaseIdealLoop ideal_loop( igvn, NULL, false );
  1556       loop_opts_cnt--;
  1557       if (major_progress()) print_method("PhaseIdealLoop 2", 2);
  1558       if (failing())  return;
  1560     // Loop opts pass for loop-unrolling before CCP
  1561     if(major_progress() && (loop_opts_cnt > 0)) {
  1562       TracePhase t4("idealLoop", &_t_idealLoop, true);
  1563       PhaseIdealLoop ideal_loop( igvn, NULL, false );
  1564       loop_opts_cnt--;
  1565       if (major_progress()) print_method("PhaseIdealLoop 3", 2);
  1568   if (failing())  return;
  1570   // Conditional Constant Propagation;
  1571   PhaseCCP ccp( &igvn );
  1572   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
  1574     TracePhase t2("ccp", &_t_ccp, true);
  1575     ccp.do_transform();
  1577   print_method("PhaseCPP 1", 2);
  1579   assert( true, "Break here to ccp.dump_old2new_map()");
  1581   // Iterative Global Value Numbering, including ideal transforms
  1583     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
  1584     igvn = ccp;
  1585     igvn.optimize();
  1588   print_method("Iter GVN 2", 2);
  1590   if (failing())  return;
  1592   // Loop transforms on the ideal graph.  Range Check Elimination,
  1593   // peeling, unrolling, etc.
  1594   if(loop_opts_cnt > 0) {
  1595     debug_only( int cnt = 0; );
  1596     while(major_progress() && (loop_opts_cnt > 0)) {
  1597       TracePhase t2("idealLoop", &_t_idealLoop, true);
  1598       assert( cnt++ < 40, "infinite cycle in loop optimization" );
  1599       PhaseIdealLoop ideal_loop( igvn, NULL, true );
  1600       loop_opts_cnt--;
  1601       if (major_progress()) print_method("PhaseIdealLoop iterations", 2);
  1602       if (failing())  return;
  1606     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
  1607     PhaseMacroExpand  mex(igvn);
  1608     if (mex.expand_macro_nodes()) {
  1609       assert(failing(), "must bail out w/ explicit message");
  1610       return;
  1614  } // (End scope of igvn; run destructor if necessary for asserts.)
  1616   // A method with only infinite loops has no edges entering loops from root
  1618     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
  1619     if (final_graph_reshaping()) {
  1620       assert(failing(), "must bail out w/ explicit message");
  1621       return;
  1625   print_method("Optimize finished", 2);
  1629 //------------------------------Code_Gen---------------------------------------
  1630 // Given a graph, generate code for it
  1631 void Compile::Code_Gen() {
  1632   if (failing())  return;
  1634   // Perform instruction selection.  You might think we could reclaim Matcher
  1635   // memory PDQ, but actually the Matcher is used in generating spill code.
  1636   // Internals of the Matcher (including some VectorSets) must remain live
  1637   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
  1638   // set a bit in reclaimed memory.
  1640   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  1641   // nodes.  Mapping is only valid at the root of each matched subtree.
  1642   NOT_PRODUCT( verify_graph_edges(); )
  1644   Node_List proj_list;
  1645   Matcher m(proj_list);
  1646   _matcher = &m;
  1648     TracePhase t2("matcher", &_t_matcher, true);
  1649     m.match();
  1651   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  1652   // nodes.  Mapping is only valid at the root of each matched subtree.
  1653   NOT_PRODUCT( verify_graph_edges(); )
  1655   // If you have too many nodes, or if matching has failed, bail out
  1656   check_node_count(0, "out of nodes matching instructions");
  1657   if (failing())  return;
  1659   // Build a proper-looking CFG
  1660   PhaseCFG cfg(node_arena(), root(), m);
  1661   _cfg = &cfg;
  1663     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
  1664     cfg.Dominators();
  1665     if (failing())  return;
  1667     NOT_PRODUCT( verify_graph_edges(); )
  1669     cfg.Estimate_Block_Frequency();
  1670     cfg.GlobalCodeMotion(m,unique(),proj_list);
  1672     print_method("Global code motion", 2);
  1674     if (failing())  return;
  1675     NOT_PRODUCT( verify_graph_edges(); )
  1677     debug_only( cfg.verify(); )
  1679   NOT_PRODUCT( verify_graph_edges(); )
  1681   PhaseChaitin regalloc(unique(),cfg,m);
  1682   _regalloc = &regalloc;
  1684     TracePhase t2("regalloc", &_t_registerAllocation, true);
  1685     // Perform any platform dependent preallocation actions.  This is used,
  1686     // for example, to avoid taking an implicit null pointer exception
  1687     // using the frame pointer on win95.
  1688     _regalloc->pd_preallocate_hook();
  1690     // Perform register allocation.  After Chaitin, use-def chains are
  1691     // no longer accurate (at spill code) and so must be ignored.
  1692     // Node->LRG->reg mappings are still accurate.
  1693     _regalloc->Register_Allocate();
  1695     // Bail out if the allocator builds too many nodes
  1696     if (failing())  return;
  1699   // Prior to register allocation we kept empty basic blocks in case the
  1700   // the allocator needed a place to spill.  After register allocation we
  1701   // are not adding any new instructions.  If any basic block is empty, we
  1702   // can now safely remove it.
  1704     NOT_PRODUCT( TracePhase t2("removeEmpty", &_t_removeEmptyBlocks, TimeCompiler); )
  1705     cfg.RemoveEmpty();
  1708   // Perform any platform dependent postallocation verifications.
  1709   debug_only( _regalloc->pd_postallocate_verify_hook(); )
  1711   // Apply peephole optimizations
  1712   if( OptoPeephole ) {
  1713     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
  1714     PhasePeephole peep( _regalloc, cfg);
  1715     peep.do_transform();
  1718   // Convert Nodes to instruction bits in a buffer
  1720     // %%%% workspace merge brought two timers together for one job
  1721     TracePhase t2a("output", &_t_output, true);
  1722     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
  1723     Output();
  1726   print_method("Final Code");
  1728   // He's dead, Jim.
  1729   _cfg     = (PhaseCFG*)0xdeadbeef;
  1730   _regalloc = (PhaseChaitin*)0xdeadbeef;
  1734 //------------------------------dump_asm---------------------------------------
  1735 // Dump formatted assembly
  1736 #ifndef PRODUCT
  1737 void Compile::dump_asm(int *pcs, uint pc_limit) {
  1738   bool cut_short = false;
  1739   tty->print_cr("#");
  1740   tty->print("#  ");  _tf->dump();  tty->cr();
  1741   tty->print_cr("#");
  1743   // For all blocks
  1744   int pc = 0x0;                 // Program counter
  1745   char starts_bundle = ' ';
  1746   _regalloc->dump_frame();
  1748   Node *n = NULL;
  1749   for( uint i=0; i<_cfg->_num_blocks; i++ ) {
  1750     if (VMThread::should_terminate()) { cut_short = true; break; }
  1751     Block *b = _cfg->_blocks[i];
  1752     if (b->is_connector() && !Verbose) continue;
  1753     n = b->_nodes[0];
  1754     if (pcs && n->_idx < pc_limit)
  1755       tty->print("%3.3x   ", pcs[n->_idx]);
  1756     else
  1757       tty->print("      ");
  1758     b->dump_head( &_cfg->_bbs );
  1759     if (b->is_connector()) {
  1760       tty->print_cr("        # Empty connector block");
  1761     } else if (b->num_preds() == 2 && b->pred(1)->is_CatchProj() && b->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
  1762       tty->print_cr("        # Block is sole successor of call");
  1765     // For all instructions
  1766     Node *delay = NULL;
  1767     for( uint j = 0; j<b->_nodes.size(); j++ ) {
  1768       if (VMThread::should_terminate()) { cut_short = true; break; }
  1769       n = b->_nodes[j];
  1770       if (valid_bundle_info(n)) {
  1771         Bundle *bundle = node_bundling(n);
  1772         if (bundle->used_in_unconditional_delay()) {
  1773           delay = n;
  1774           continue;
  1776         if (bundle->starts_bundle())
  1777           starts_bundle = '+';
  1780       if (WizardMode) n->dump();
  1782       if( !n->is_Region() &&    // Dont print in the Assembly
  1783           !n->is_Phi() &&       // a few noisely useless nodes
  1784           !n->is_Proj() &&
  1785           !n->is_MachTemp() &&
  1786           !n->is_Catch() &&     // Would be nice to print exception table targets
  1787           !n->is_MergeMem() &&  // Not very interesting
  1788           !n->is_top() &&       // Debug info table constants
  1789           !(n->is_Con() && !n->is_Mach())// Debug info table constants
  1790           ) {
  1791         if (pcs && n->_idx < pc_limit)
  1792           tty->print("%3.3x", pcs[n->_idx]);
  1793         else
  1794           tty->print("   ");
  1795         tty->print(" %c ", starts_bundle);
  1796         starts_bundle = ' ';
  1797         tty->print("\t");
  1798         n->format(_regalloc, tty);
  1799         tty->cr();
  1802       // If we have an instruction with a delay slot, and have seen a delay,
  1803       // then back up and print it
  1804       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
  1805         assert(delay != NULL, "no unconditional delay instruction");
  1806         if (WizardMode) delay->dump();
  1808         if (node_bundling(delay)->starts_bundle())
  1809           starts_bundle = '+';
  1810         if (pcs && n->_idx < pc_limit)
  1811           tty->print("%3.3x", pcs[n->_idx]);
  1812         else
  1813           tty->print("   ");
  1814         tty->print(" %c ", starts_bundle);
  1815         starts_bundle = ' ';
  1816         tty->print("\t");
  1817         delay->format(_regalloc, tty);
  1818         tty->print_cr("");
  1819         delay = NULL;
  1822       // Dump the exception table as well
  1823       if( n->is_Catch() && (Verbose || WizardMode) ) {
  1824         // Print the exception table for this offset
  1825         _handler_table.print_subtable_for(pc);
  1829     if (pcs && n->_idx < pc_limit)
  1830       tty->print_cr("%3.3x", pcs[n->_idx]);
  1831     else
  1832       tty->print_cr("");
  1834     assert(cut_short || delay == NULL, "no unconditional delay branch");
  1836   } // End of per-block dump
  1837   tty->print_cr("");
  1839   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
  1841 #endif
  1843 //------------------------------Final_Reshape_Counts---------------------------
  1844 // This class defines counters to help identify when a method
  1845 // may/must be executed using hardware with only 24-bit precision.
  1846 struct Final_Reshape_Counts : public StackObj {
  1847   int  _call_count;             // count non-inlined 'common' calls
  1848   int  _float_count;            // count float ops requiring 24-bit precision
  1849   int  _double_count;           // count double ops requiring more precision
  1850   int  _java_call_count;        // count non-inlined 'java' calls
  1851   VectorSet _visited;           // Visitation flags
  1852   Node_List _tests;             // Set of IfNodes & PCTableNodes
  1854   Final_Reshape_Counts() :
  1855     _call_count(0), _float_count(0), _double_count(0), _java_call_count(0),
  1856     _visited( Thread::current()->resource_area() ) { }
  1858   void inc_call_count  () { _call_count  ++; }
  1859   void inc_float_count () { _float_count ++; }
  1860   void inc_double_count() { _double_count++; }
  1861   void inc_java_call_count() { _java_call_count++; }
  1863   int  get_call_count  () const { return _call_count  ; }
  1864   int  get_float_count () const { return _float_count ; }
  1865   int  get_double_count() const { return _double_count; }
  1866   int  get_java_call_count() const { return _java_call_count; }
  1867 };
  1869 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
  1870   ciInstanceKlass *k = tp->klass()->as_instance_klass();
  1871   // Make sure the offset goes inside the instance layout.
  1872   return k->contains_field_offset(tp->offset());
  1873   // Note that OffsetBot and OffsetTop are very negative.
  1876 //------------------------------final_graph_reshaping_impl----------------------
  1877 // Implement items 1-5 from final_graph_reshaping below.
  1878 static void final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &fpu ) {
  1880   if ( n->outcnt() == 0 ) return; // dead node
  1881   uint nop = n->Opcode();
  1883   // Check for 2-input instruction with "last use" on right input.
  1884   // Swap to left input.  Implements item (2).
  1885   if( n->req() == 3 &&          // two-input instruction
  1886       n->in(1)->outcnt() > 1 && // left use is NOT a last use
  1887       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
  1888       n->in(2)->outcnt() == 1 &&// right use IS a last use
  1889       !n->in(2)->is_Con() ) {   // right use is not a constant
  1890     // Check for commutative opcode
  1891     switch( nop ) {
  1892     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
  1893     case Op_MaxI:  case Op_MinI:
  1894     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
  1895     case Op_AndL:  case Op_XorL:  case Op_OrL:
  1896     case Op_AndI:  case Op_XorI:  case Op_OrI: {
  1897       // Move "last use" input to left by swapping inputs
  1898       n->swap_edges(1, 2);
  1899       break;
  1901     default:
  1902       break;
  1906   // Count FPU ops and common calls, implements item (3)
  1907   switch( nop ) {
  1908   // Count all float operations that may use FPU
  1909   case Op_AddF:
  1910   case Op_SubF:
  1911   case Op_MulF:
  1912   case Op_DivF:
  1913   case Op_NegF:
  1914   case Op_ModF:
  1915   case Op_ConvI2F:
  1916   case Op_ConF:
  1917   case Op_CmpF:
  1918   case Op_CmpF3:
  1919   // case Op_ConvL2F: // longs are split into 32-bit halves
  1920     fpu.inc_float_count();
  1921     break;
  1923   case Op_ConvF2D:
  1924   case Op_ConvD2F:
  1925     fpu.inc_float_count();
  1926     fpu.inc_double_count();
  1927     break;
  1929   // Count all double operations that may use FPU
  1930   case Op_AddD:
  1931   case Op_SubD:
  1932   case Op_MulD:
  1933   case Op_DivD:
  1934   case Op_NegD:
  1935   case Op_ModD:
  1936   case Op_ConvI2D:
  1937   case Op_ConvD2I:
  1938   // case Op_ConvL2D: // handled by leaf call
  1939   // case Op_ConvD2L: // handled by leaf call
  1940   case Op_ConD:
  1941   case Op_CmpD:
  1942   case Op_CmpD3:
  1943     fpu.inc_double_count();
  1944     break;
  1945   case Op_Opaque1:              // Remove Opaque Nodes before matching
  1946   case Op_Opaque2:              // Remove Opaque Nodes before matching
  1947     n->subsume_by(n->in(1));
  1948     break;
  1949   case Op_CallStaticJava:
  1950   case Op_CallJava:
  1951   case Op_CallDynamicJava:
  1952     fpu.inc_java_call_count(); // Count java call site;
  1953   case Op_CallRuntime:
  1954   case Op_CallLeaf:
  1955   case Op_CallLeafNoFP: {
  1956     assert( n->is_Call(), "" );
  1957     CallNode *call = n->as_Call();
  1958     // Count call sites where the FP mode bit would have to be flipped.
  1959     // Do not count uncommon runtime calls:
  1960     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
  1961     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
  1962     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
  1963       fpu.inc_call_count();   // Count the call site
  1964     } else {                  // See if uncommon argument is shared
  1965       Node *n = call->in(TypeFunc::Parms);
  1966       int nop = n->Opcode();
  1967       // Clone shared simple arguments to uncommon calls, item (1).
  1968       if( n->outcnt() > 1 &&
  1969           !n->is_Proj() &&
  1970           nop != Op_CreateEx &&
  1971           nop != Op_CheckCastPP &&
  1972           nop != Op_DecodeN &&
  1973           !n->is_Mem() ) {
  1974         Node *x = n->clone();
  1975         call->set_req( TypeFunc::Parms, x );
  1978     break;
  1981   case Op_StoreD:
  1982   case Op_LoadD:
  1983   case Op_LoadD_unaligned:
  1984     fpu.inc_double_count();
  1985     goto handle_mem;
  1986   case Op_StoreF:
  1987   case Op_LoadF:
  1988     fpu.inc_float_count();
  1989     goto handle_mem;
  1991   case Op_StoreB:
  1992   case Op_StoreC:
  1993   case Op_StoreCM:
  1994   case Op_StorePConditional:
  1995   case Op_StoreI:
  1996   case Op_StoreL:
  1997   case Op_StoreLConditional:
  1998   case Op_CompareAndSwapI:
  1999   case Op_CompareAndSwapL:
  2000   case Op_CompareAndSwapP:
  2001   case Op_CompareAndSwapN:
  2002   case Op_StoreP:
  2003   case Op_StoreN:
  2004   case Op_LoadB:
  2005   case Op_LoadC:
  2006   case Op_LoadI:
  2007   case Op_LoadKlass:
  2008   case Op_LoadNKlass:
  2009   case Op_LoadL:
  2010   case Op_LoadL_unaligned:
  2011   case Op_LoadPLocked:
  2012   case Op_LoadLLocked:
  2013   case Op_LoadP:
  2014   case Op_LoadN:
  2015   case Op_LoadRange:
  2016   case Op_LoadS: {
  2017   handle_mem:
  2018 #ifdef ASSERT
  2019     if( VerifyOptoOopOffsets ) {
  2020       assert( n->is_Mem(), "" );
  2021       MemNode *mem  = (MemNode*)n;
  2022       // Check to see if address types have grounded out somehow.
  2023       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
  2024       assert( !tp || oop_offset_is_sane(tp), "" );
  2026 #endif
  2027     break;
  2030   case Op_AddP: {               // Assert sane base pointers
  2031     Node *addp = n->in(AddPNode::Address);
  2032     assert( !addp->is_AddP() ||
  2033             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
  2034             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
  2035             "Base pointers must match" );
  2036 #ifdef _LP64
  2037     if (UseCompressedOops &&
  2038         addp->Opcode() == Op_ConP &&
  2039         addp == n->in(AddPNode::Base) &&
  2040         n->in(AddPNode::Offset)->is_Con()) {
  2041       // Use addressing with narrow klass to load with offset on x86.
  2042       // On sparc loading 32-bits constant and decoding it have less
  2043       // instructions (4) then load 64-bits constant (7).
  2044       // Do this transformation here since IGVN will convert ConN back to ConP.
  2045       const Type* t = addp->bottom_type();
  2046       if (t->isa_oopptr()) {
  2047         Node* nn = NULL;
  2049         // Look for existing ConN node of the same exact type.
  2050         Compile* C = Compile::current();
  2051         Node* r  = C->root();
  2052         uint cnt = r->outcnt();
  2053         for (uint i = 0; i < cnt; i++) {
  2054           Node* m = r->raw_out(i);
  2055           if (m!= NULL && m->Opcode() == Op_ConN &&
  2056               m->bottom_type()->make_ptr() == t) {
  2057             nn = m;
  2058             break;
  2061         if (nn != NULL) {
  2062           // Decode a narrow oop to match address
  2063           // [R12 + narrow_oop_reg<<3 + offset]
  2064           nn = new (C,  2) DecodeNNode(nn, t);
  2065           n->set_req(AddPNode::Base, nn);
  2066           n->set_req(AddPNode::Address, nn);
  2067           if (addp->outcnt() == 0) {
  2068             addp->disconnect_inputs(NULL);
  2073 #endif
  2074     break;
  2077 #ifdef _LP64
  2078   case Op_CmpP:
  2079     // Do this transformation here to preserve CmpPNode::sub() and
  2080     // other TypePtr related Ideal optimizations (for example, ptr nullness).
  2081     if (n->in(1)->is_DecodeN() || n->in(2)->is_DecodeN()) {
  2082       Node* in1 = n->in(1);
  2083       Node* in2 = n->in(2);
  2084       if (!in1->is_DecodeN()) {
  2085         in2 = in1;
  2086         in1 = n->in(2);
  2088       assert(in1->is_DecodeN(), "sanity");
  2090       Compile* C = Compile::current();
  2091       Node* new_in2 = NULL;
  2092       if (in2->is_DecodeN()) {
  2093         new_in2 = in2->in(1);
  2094       } else if (in2->Opcode() == Op_ConP) {
  2095         const Type* t = in2->bottom_type();
  2096         if (t == TypePtr::NULL_PTR && UseImplicitNullCheckForNarrowOop) {
  2097           if (Matcher::clone_shift_expressions) {
  2098             // x86, ARM and friends can handle 2 adds in addressing mode.
  2099             // Decode a narrow oop and do implicit NULL check in address
  2100             // [R12 + narrow_oop_reg<<3 + offset]
  2101             new_in2 = ConNode::make(C, TypeNarrowOop::NULL_PTR);
  2102           } else {
  2103             // Don't replace CmpP(o ,null) if 'o' is used in AddP
  2104             // to generate implicit NULL check on Sparc where
  2105             // narrow oops can't be used in address.
  2106             uint i = 0;
  2107             for (; i < in1->outcnt(); i++) {
  2108               if (in1->raw_out(i)->is_AddP())
  2109                 break;
  2111             if (i >= in1->outcnt()) {
  2112               new_in2 = ConNode::make(C, TypeNarrowOop::NULL_PTR);
  2115         } else if (t->isa_oopptr()) {
  2116           new_in2 = ConNode::make(C, t->make_narrowoop());
  2119       if (new_in2 != NULL) {
  2120         Node* cmpN = new (C, 3) CmpNNode(in1->in(1), new_in2);
  2121         n->subsume_by( cmpN );
  2122         if (in1->outcnt() == 0) {
  2123           in1->disconnect_inputs(NULL);
  2125         if (in2->outcnt() == 0) {
  2126           in2->disconnect_inputs(NULL);
  2130     break;
  2131 #endif
  2133   case Op_ModI:
  2134     if (UseDivMod) {
  2135       // Check if a%b and a/b both exist
  2136       Node* d = n->find_similar(Op_DivI);
  2137       if (d) {
  2138         // Replace them with a fused divmod if supported
  2139         Compile* C = Compile::current();
  2140         if (Matcher::has_match_rule(Op_DivModI)) {
  2141           DivModINode* divmod = DivModINode::make(C, n);
  2142           d->subsume_by(divmod->div_proj());
  2143           n->subsume_by(divmod->mod_proj());
  2144         } else {
  2145           // replace a%b with a-((a/b)*b)
  2146           Node* mult = new (C, 3) MulINode(d, d->in(2));
  2147           Node* sub  = new (C, 3) SubINode(d->in(1), mult);
  2148           n->subsume_by( sub );
  2152     break;
  2154   case Op_ModL:
  2155     if (UseDivMod) {
  2156       // Check if a%b and a/b both exist
  2157       Node* d = n->find_similar(Op_DivL);
  2158       if (d) {
  2159         // Replace them with a fused divmod if supported
  2160         Compile* C = Compile::current();
  2161         if (Matcher::has_match_rule(Op_DivModL)) {
  2162           DivModLNode* divmod = DivModLNode::make(C, n);
  2163           d->subsume_by(divmod->div_proj());
  2164           n->subsume_by(divmod->mod_proj());
  2165         } else {
  2166           // replace a%b with a-((a/b)*b)
  2167           Node* mult = new (C, 3) MulLNode(d, d->in(2));
  2168           Node* sub  = new (C, 3) SubLNode(d->in(1), mult);
  2169           n->subsume_by( sub );
  2173     break;
  2175   case Op_Load16B:
  2176   case Op_Load8B:
  2177   case Op_Load4B:
  2178   case Op_Load8S:
  2179   case Op_Load4S:
  2180   case Op_Load2S:
  2181   case Op_Load8C:
  2182   case Op_Load4C:
  2183   case Op_Load2C:
  2184   case Op_Load4I:
  2185   case Op_Load2I:
  2186   case Op_Load2L:
  2187   case Op_Load4F:
  2188   case Op_Load2F:
  2189   case Op_Load2D:
  2190   case Op_Store16B:
  2191   case Op_Store8B:
  2192   case Op_Store4B:
  2193   case Op_Store8C:
  2194   case Op_Store4C:
  2195   case Op_Store2C:
  2196   case Op_Store4I:
  2197   case Op_Store2I:
  2198   case Op_Store2L:
  2199   case Op_Store4F:
  2200   case Op_Store2F:
  2201   case Op_Store2D:
  2202     break;
  2204   case Op_PackB:
  2205   case Op_PackS:
  2206   case Op_PackC:
  2207   case Op_PackI:
  2208   case Op_PackF:
  2209   case Op_PackL:
  2210   case Op_PackD:
  2211     if (n->req()-1 > 2) {
  2212       // Replace many operand PackNodes with a binary tree for matching
  2213       PackNode* p = (PackNode*) n;
  2214       Node* btp = p->binaryTreePack(Compile::current(), 1, n->req());
  2215       n->subsume_by(btp);
  2217     break;
  2218   default:
  2219     assert( !n->is_Call(), "" );
  2220     assert( !n->is_Mem(), "" );
  2221     break;
  2224   // Collect CFG split points
  2225   if (n->is_MultiBranch())
  2226     fpu._tests.push(n);
  2229 //------------------------------final_graph_reshaping_walk---------------------
  2230 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
  2231 // requires that the walk visits a node's inputs before visiting the node.
  2232 static void final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &fpu ) {
  2233   ResourceArea *area = Thread::current()->resource_area();
  2234   Unique_Node_List sfpt(area);
  2236   fpu._visited.set(root->_idx); // first, mark node as visited
  2237   uint cnt = root->req();
  2238   Node *n = root;
  2239   uint  i = 0;
  2240   while (true) {
  2241     if (i < cnt) {
  2242       // Place all non-visited non-null inputs onto stack
  2243       Node* m = n->in(i);
  2244       ++i;
  2245       if (m != NULL && !fpu._visited.test_set(m->_idx)) {
  2246         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL)
  2247           sfpt.push(m);
  2248         cnt = m->req();
  2249         nstack.push(n, i); // put on stack parent and next input's index
  2250         n = m;
  2251         i = 0;
  2253     } else {
  2254       // Now do post-visit work
  2255       final_graph_reshaping_impl( n, fpu );
  2256       if (nstack.is_empty())
  2257         break;             // finished
  2258       n = nstack.node();   // Get node from stack
  2259       cnt = n->req();
  2260       i = nstack.index();
  2261       nstack.pop();        // Shift to the next node on stack
  2265   // Go over safepoints nodes to skip DecodeN nodes for debug edges.
  2266   // It could be done for an uncommon traps or any safepoints/calls
  2267   // if the DecodeN node is referenced only in a debug info.
  2268   while (sfpt.size() > 0) {
  2269     n = sfpt.pop();
  2270     JVMState *jvms = n->as_SafePoint()->jvms();
  2271     assert(jvms != NULL, "sanity");
  2272     int start = jvms->debug_start();
  2273     int end   = n->req();
  2274     bool is_uncommon = (n->is_CallStaticJava() &&
  2275                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
  2276     for (int j = start; j < end; j++) {
  2277       Node* in = n->in(j);
  2278       if (in->is_DecodeN()) {
  2279         bool safe_to_skip = true;
  2280         if (!is_uncommon ) {
  2281           // Is it safe to skip?
  2282           for (uint i = 0; i < in->outcnt(); i++) {
  2283             Node* u = in->raw_out(i);
  2284             if (!u->is_SafePoint() ||
  2285                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
  2286               safe_to_skip = false;
  2290         if (safe_to_skip) {
  2291           n->set_req(j, in->in(1));
  2293         if (in->outcnt() == 0) {
  2294           in->disconnect_inputs(NULL);
  2301 //------------------------------final_graph_reshaping--------------------------
  2302 // Final Graph Reshaping.
  2303 //
  2304 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
  2305 //     and not commoned up and forced early.  Must come after regular
  2306 //     optimizations to avoid GVN undoing the cloning.  Clone constant
  2307 //     inputs to Loop Phis; these will be split by the allocator anyways.
  2308 //     Remove Opaque nodes.
  2309 // (2) Move last-uses by commutative operations to the left input to encourage
  2310 //     Intel update-in-place two-address operations and better register usage
  2311 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
  2312 //     calls canonicalizing them back.
  2313 // (3) Count the number of double-precision FP ops, single-precision FP ops
  2314 //     and call sites.  On Intel, we can get correct rounding either by
  2315 //     forcing singles to memory (requires extra stores and loads after each
  2316 //     FP bytecode) or we can set a rounding mode bit (requires setting and
  2317 //     clearing the mode bit around call sites).  The mode bit is only used
  2318 //     if the relative frequency of single FP ops to calls is low enough.
  2319 //     This is a key transform for SPEC mpeg_audio.
  2320 // (4) Detect infinite loops; blobs of code reachable from above but not
  2321 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
  2322 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
  2323 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
  2324 //     Detection is by looking for IfNodes where only 1 projection is
  2325 //     reachable from below or CatchNodes missing some targets.
  2326 // (5) Assert for insane oop offsets in debug mode.
  2328 bool Compile::final_graph_reshaping() {
  2329   // an infinite loop may have been eliminated by the optimizer,
  2330   // in which case the graph will be empty.
  2331   if (root()->req() == 1) {
  2332     record_method_not_compilable("trivial infinite loop");
  2333     return true;
  2336   Final_Reshape_Counts fpu;
  2338   // Visit everybody reachable!
  2339   // Allocate stack of size C->unique()/2 to avoid frequent realloc
  2340   Node_Stack nstack(unique() >> 1);
  2341   final_graph_reshaping_walk(nstack, root(), fpu);
  2343   // Check for unreachable (from below) code (i.e., infinite loops).
  2344   for( uint i = 0; i < fpu._tests.size(); i++ ) {
  2345     MultiBranchNode *n = fpu._tests[i]->as_MultiBranch();
  2346     // Get number of CFG targets.
  2347     // Note that PCTables include exception targets after calls.
  2348     uint required_outcnt = n->required_outcnt();
  2349     if (n->outcnt() != required_outcnt) {
  2350       // Check for a few special cases.  Rethrow Nodes never take the
  2351       // 'fall-thru' path, so expected kids is 1 less.
  2352       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
  2353         if (n->in(0)->in(0)->is_Call()) {
  2354           CallNode *call = n->in(0)->in(0)->as_Call();
  2355           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
  2356             required_outcnt--;      // Rethrow always has 1 less kid
  2357           } else if (call->req() > TypeFunc::Parms &&
  2358                      call->is_CallDynamicJava()) {
  2359             // Check for null receiver. In such case, the optimizer has
  2360             // detected that the virtual call will always result in a null
  2361             // pointer exception. The fall-through projection of this CatchNode
  2362             // will not be populated.
  2363             Node *arg0 = call->in(TypeFunc::Parms);
  2364             if (arg0->is_Type() &&
  2365                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
  2366               required_outcnt--;
  2368           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
  2369                      call->req() > TypeFunc::Parms+1 &&
  2370                      call->is_CallStaticJava()) {
  2371             // Check for negative array length. In such case, the optimizer has
  2372             // detected that the allocation attempt will always result in an
  2373             // exception. There is no fall-through projection of this CatchNode .
  2374             Node *arg1 = call->in(TypeFunc::Parms+1);
  2375             if (arg1->is_Type() &&
  2376                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
  2377               required_outcnt--;
  2382       // Recheck with a better notion of 'required_outcnt'
  2383       if (n->outcnt() != required_outcnt) {
  2384         record_method_not_compilable("malformed control flow");
  2385         return true;            // Not all targets reachable!
  2388     // Check that I actually visited all kids.  Unreached kids
  2389     // must be infinite loops.
  2390     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
  2391       if (!fpu._visited.test(n->fast_out(j)->_idx)) {
  2392         record_method_not_compilable("infinite loop");
  2393         return true;            // Found unvisited kid; must be unreach
  2397   // If original bytecodes contained a mixture of floats and doubles
  2398   // check if the optimizer has made it homogenous, item (3).
  2399   if( Use24BitFPMode && Use24BitFP &&
  2400       fpu.get_float_count() > 32 &&
  2401       fpu.get_double_count() == 0 &&
  2402       (10 * fpu.get_call_count() < fpu.get_float_count()) ) {
  2403     set_24_bit_selection_and_mode( false,  true );
  2406   set_has_java_calls(fpu.get_java_call_count() > 0);
  2408   // No infinite loops, no reason to bail out.
  2409   return false;
  2412 //-----------------------------too_many_traps----------------------------------
  2413 // Report if there are too many traps at the current method and bci.
  2414 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
  2415 bool Compile::too_many_traps(ciMethod* method,
  2416                              int bci,
  2417                              Deoptimization::DeoptReason reason) {
  2418   ciMethodData* md = method->method_data();
  2419   if (md->is_empty()) {
  2420     // Assume the trap has not occurred, or that it occurred only
  2421     // because of a transient condition during start-up in the interpreter.
  2422     return false;
  2424   if (md->has_trap_at(bci, reason) != 0) {
  2425     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
  2426     // Also, if there are multiple reasons, or if there is no per-BCI record,
  2427     // assume the worst.
  2428     if (log())
  2429       log()->elem("observe trap='%s' count='%d'",
  2430                   Deoptimization::trap_reason_name(reason),
  2431                   md->trap_count(reason));
  2432     return true;
  2433   } else {
  2434     // Ignore method/bci and see if there have been too many globally.
  2435     return too_many_traps(reason, md);
  2439 // Less-accurate variant which does not require a method and bci.
  2440 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
  2441                              ciMethodData* logmd) {
  2442  if (trap_count(reason) >= (uint)PerMethodTrapLimit) {
  2443     // Too many traps globally.
  2444     // Note that we use cumulative trap_count, not just md->trap_count.
  2445     if (log()) {
  2446       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
  2447       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
  2448                   Deoptimization::trap_reason_name(reason),
  2449                   mcount, trap_count(reason));
  2451     return true;
  2452   } else {
  2453     // The coast is clear.
  2454     return false;
  2458 //--------------------------too_many_recompiles--------------------------------
  2459 // Report if there are too many recompiles at the current method and bci.
  2460 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
  2461 // Is not eager to return true, since this will cause the compiler to use
  2462 // Action_none for a trap point, to avoid too many recompilations.
  2463 bool Compile::too_many_recompiles(ciMethod* method,
  2464                                   int bci,
  2465                                   Deoptimization::DeoptReason reason) {
  2466   ciMethodData* md = method->method_data();
  2467   if (md->is_empty()) {
  2468     // Assume the trap has not occurred, or that it occurred only
  2469     // because of a transient condition during start-up in the interpreter.
  2470     return false;
  2472   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
  2473   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
  2474   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
  2475   Deoptimization::DeoptReason per_bc_reason
  2476     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
  2477   if ((per_bc_reason == Deoptimization::Reason_none
  2478        || md->has_trap_at(bci, reason) != 0)
  2479       // The trap frequency measure we care about is the recompile count:
  2480       && md->trap_recompiled_at(bci)
  2481       && md->overflow_recompile_count() >= bc_cutoff) {
  2482     // Do not emit a trap here if it has already caused recompilations.
  2483     // Also, if there are multiple reasons, or if there is no per-BCI record,
  2484     // assume the worst.
  2485     if (log())
  2486       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
  2487                   Deoptimization::trap_reason_name(reason),
  2488                   md->trap_count(reason),
  2489                   md->overflow_recompile_count());
  2490     return true;
  2491   } else if (trap_count(reason) != 0
  2492              && decompile_count() >= m_cutoff) {
  2493     // Too many recompiles globally, and we have seen this sort of trap.
  2494     // Use cumulative decompile_count, not just md->decompile_count.
  2495     if (log())
  2496       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
  2497                   Deoptimization::trap_reason_name(reason),
  2498                   md->trap_count(reason), trap_count(reason),
  2499                   md->decompile_count(), decompile_count());
  2500     return true;
  2501   } else {
  2502     // The coast is clear.
  2503     return false;
  2508 #ifndef PRODUCT
  2509 //------------------------------verify_graph_edges---------------------------
  2510 // Walk the Graph and verify that there is a one-to-one correspondence
  2511 // between Use-Def edges and Def-Use edges in the graph.
  2512 void Compile::verify_graph_edges(bool no_dead_code) {
  2513   if (VerifyGraphEdges) {
  2514     ResourceArea *area = Thread::current()->resource_area();
  2515     Unique_Node_List visited(area);
  2516     // Call recursive graph walk to check edges
  2517     _root->verify_edges(visited);
  2518     if (no_dead_code) {
  2519       // Now make sure that no visited node is used by an unvisited node.
  2520       bool dead_nodes = 0;
  2521       Unique_Node_List checked(area);
  2522       while (visited.size() > 0) {
  2523         Node* n = visited.pop();
  2524         checked.push(n);
  2525         for (uint i = 0; i < n->outcnt(); i++) {
  2526           Node* use = n->raw_out(i);
  2527           if (checked.member(use))  continue;  // already checked
  2528           if (visited.member(use))  continue;  // already in the graph
  2529           if (use->is_Con())        continue;  // a dead ConNode is OK
  2530           // At this point, we have found a dead node which is DU-reachable.
  2531           if (dead_nodes++ == 0)
  2532             tty->print_cr("*** Dead nodes reachable via DU edges:");
  2533           use->dump(2);
  2534           tty->print_cr("---");
  2535           checked.push(use);  // No repeats; pretend it is now checked.
  2538       assert(dead_nodes == 0, "using nodes must be reachable from root");
  2542 #endif
  2544 // The Compile object keeps track of failure reasons separately from the ciEnv.
  2545 // This is required because there is not quite a 1-1 relation between the
  2546 // ciEnv and its compilation task and the Compile object.  Note that one
  2547 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
  2548 // to backtrack and retry without subsuming loads.  Other than this backtracking
  2549 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
  2550 // by the logic in C2Compiler.
  2551 void Compile::record_failure(const char* reason) {
  2552   if (log() != NULL) {
  2553     log()->elem("failure reason='%s' phase='compile'", reason);
  2555   if (_failure_reason == NULL) {
  2556     // Record the first failure reason.
  2557     _failure_reason = reason;
  2559   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
  2560     C->print_method(_failure_reason);
  2562   _root = NULL;  // flush the graph, too
  2565 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
  2566   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false)
  2568   if (dolog) {
  2569     C = Compile::current();
  2570     _log = C->log();
  2571   } else {
  2572     C = NULL;
  2573     _log = NULL;
  2575   if (_log != NULL) {
  2576     _log->begin_head("phase name='%s' nodes='%d'", name, C->unique());
  2577     _log->stamp();
  2578     _log->end_head();
  2582 Compile::TracePhase::~TracePhase() {
  2583   if (_log != NULL) {
  2584     _log->done("phase nodes='%d'", C->unique());

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