src/share/vm/opto/compile.cpp

Tue, 15 Jun 2010 18:07:27 -0700

author
kvn
date
Tue, 15 Jun 2010 18:07:27 -0700
changeset 1964
4311f23817fd
parent 1934
e9ff18c4ace7
child 1989
60a14ad85270
permissions
-rw-r--r--

6959430: Make sure raw loads have control edge
Summary: check that raw loads have control edge
Reviewed-by: never, twisti

     1 /*
     2  * Copyright (c) 1997, 2010, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * 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       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
   106     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
   107     if (cg != NULL) {
   108       // Save it for next time:
   109       register_intrinsic(cg);
   110       return cg;
   111     } else {
   112       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
   113     }
   114   }
   115   return NULL;
   116 }
   118 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
   119 // in library_call.cpp.
   122 #ifndef PRODUCT
   123 // statistics gathering...
   125 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
   126 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
   128 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
   129   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
   130   int oflags = _intrinsic_hist_flags[id];
   131   assert(flags != 0, "what happened?");
   132   if (is_virtual) {
   133     flags |= _intrinsic_virtual;
   134   }
   135   bool changed = (flags != oflags);
   136   if ((flags & _intrinsic_worked) != 0) {
   137     juint count = (_intrinsic_hist_count[id] += 1);
   138     if (count == 1) {
   139       changed = true;           // first time
   140     }
   141     // increment the overall count also:
   142     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
   143   }
   144   if (changed) {
   145     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
   146       // Something changed about the intrinsic's virtuality.
   147       if ((flags & _intrinsic_virtual) != 0) {
   148         // This is the first use of this intrinsic as a virtual call.
   149         if (oflags != 0) {
   150           // We already saw it as a non-virtual, so note both cases.
   151           flags |= _intrinsic_both;
   152         }
   153       } else if ((oflags & _intrinsic_both) == 0) {
   154         // This is the first use of this intrinsic as a non-virtual
   155         flags |= _intrinsic_both;
   156       }
   157     }
   158     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
   159   }
   160   // update the overall flags also:
   161   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
   162   return changed;
   163 }
   165 static char* format_flags(int flags, char* buf) {
   166   buf[0] = 0;
   167   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
   168   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
   169   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
   170   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
   171   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
   172   if (buf[0] == 0)  strcat(buf, ",");
   173   assert(buf[0] == ',', "must be");
   174   return &buf[1];
   175 }
   177 void Compile::print_intrinsic_statistics() {
   178   char flagsbuf[100];
   179   ttyLocker ttyl;
   180   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
   181   tty->print_cr("Compiler intrinsic usage:");
   182   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
   183   if (total == 0)  total = 1;  // avoid div0 in case of no successes
   184   #define PRINT_STAT_LINE(name, c, f) \
   185     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
   186   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
   187     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
   188     int   flags = _intrinsic_hist_flags[id];
   189     juint count = _intrinsic_hist_count[id];
   190     if ((flags | count) != 0) {
   191       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
   192     }
   193   }
   194   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
   195   if (xtty != NULL)  xtty->tail("statistics");
   196 }
   198 void Compile::print_statistics() {
   199   { ttyLocker ttyl;
   200     if (xtty != NULL)  xtty->head("statistics type='opto'");
   201     Parse::print_statistics();
   202     PhaseCCP::print_statistics();
   203     PhaseRegAlloc::print_statistics();
   204     Scheduling::print_statistics();
   205     PhasePeephole::print_statistics();
   206     PhaseIdealLoop::print_statistics();
   207     if (xtty != NULL)  xtty->tail("statistics");
   208   }
   209   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
   210     // put this under its own <statistics> element.
   211     print_intrinsic_statistics();
   212   }
   213 }
   214 #endif //PRODUCT
   216 // Support for bundling info
   217 Bundle* Compile::node_bundling(const Node *n) {
   218   assert(valid_bundle_info(n), "oob");
   219   return &_node_bundling_base[n->_idx];
   220 }
   222 bool Compile::valid_bundle_info(const Node *n) {
   223   return (_node_bundling_limit > n->_idx);
   224 }
   227 void Compile::gvn_replace_by(Node* n, Node* nn) {
   228   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
   229     Node* use = n->last_out(i);
   230     bool is_in_table = initial_gvn()->hash_delete(use);
   231     uint uses_found = 0;
   232     for (uint j = 0; j < use->len(); j++) {
   233       if (use->in(j) == n) {
   234         if (j < use->req())
   235           use->set_req(j, nn);
   236         else
   237           use->set_prec(j, nn);
   238         uses_found++;
   239       }
   240     }
   241     if (is_in_table) {
   242       // reinsert into table
   243       initial_gvn()->hash_find_insert(use);
   244     }
   245     record_for_igvn(use);
   246     i -= uses_found;    // we deleted 1 or more copies of this edge
   247   }
   248 }
   253 // Identify all nodes that are reachable from below, useful.
   254 // Use breadth-first pass that records state in a Unique_Node_List,
   255 // recursive traversal is slower.
   256 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
   257   int estimated_worklist_size = unique();
   258   useful.map( estimated_worklist_size, NULL );  // preallocate space
   260   // Initialize worklist
   261   if (root() != NULL)     { useful.push(root()); }
   262   // If 'top' is cached, declare it useful to preserve cached node
   263   if( cached_top_node() ) { useful.push(cached_top_node()); }
   265   // Push all useful nodes onto the list, breadthfirst
   266   for( uint next = 0; next < useful.size(); ++next ) {
   267     assert( next < unique(), "Unique useful nodes < total nodes");
   268     Node *n  = useful.at(next);
   269     uint max = n->len();
   270     for( uint i = 0; i < max; ++i ) {
   271       Node *m = n->in(i);
   272       if( m == NULL ) continue;
   273       useful.push(m);
   274     }
   275   }
   276 }
   278 // Disconnect all useless nodes by disconnecting those at the boundary.
   279 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
   280   uint next = 0;
   281   while( next < useful.size() ) {
   282     Node *n = useful.at(next++);
   283     // Use raw traversal of out edges since this code removes out edges
   284     int max = n->outcnt();
   285     for (int j = 0; j < max; ++j ) {
   286       Node* child = n->raw_out(j);
   287       if( ! useful.member(child) ) {
   288         assert( !child->is_top() || child != top(),
   289                 "If top is cached in Compile object it is in useful list");
   290         // Only need to remove this out-edge to the useless node
   291         n->raw_del_out(j);
   292         --j;
   293         --max;
   294       }
   295     }
   296     if (n->outcnt() == 1 && n->has_special_unique_user()) {
   297       record_for_igvn( n->unique_out() );
   298     }
   299   }
   300   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
   301 }
   303 //------------------------------frame_size_in_words-----------------------------
   304 // frame_slots in units of words
   305 int Compile::frame_size_in_words() const {
   306   // shift is 0 in LP32 and 1 in LP64
   307   const int shift = (LogBytesPerWord - LogBytesPerInt);
   308   int words = _frame_slots >> shift;
   309   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
   310   return words;
   311 }
   313 // ============================================================================
   314 //------------------------------CompileWrapper---------------------------------
   315 class CompileWrapper : public StackObj {
   316   Compile *const _compile;
   317  public:
   318   CompileWrapper(Compile* compile);
   320   ~CompileWrapper();
   321 };
   323 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
   324   // the Compile* pointer is stored in the current ciEnv:
   325   ciEnv* env = compile->env();
   326   assert(env == ciEnv::current(), "must already be a ciEnv active");
   327   assert(env->compiler_data() == NULL, "compile already active?");
   328   env->set_compiler_data(compile);
   329   assert(compile == Compile::current(), "sanity");
   331   compile->set_type_dict(NULL);
   332   compile->set_type_hwm(NULL);
   333   compile->set_type_last_size(0);
   334   compile->set_last_tf(NULL, NULL);
   335   compile->set_indexSet_arena(NULL);
   336   compile->set_indexSet_free_block_list(NULL);
   337   compile->init_type_arena();
   338   Type::Initialize(compile);
   339   _compile->set_scratch_buffer_blob(NULL);
   340   _compile->begin_method();
   341 }
   342 CompileWrapper::~CompileWrapper() {
   343   _compile->end_method();
   344   if (_compile->scratch_buffer_blob() != NULL)
   345     BufferBlob::free(_compile->scratch_buffer_blob());
   346   _compile->env()->set_compiler_data(NULL);
   347 }
   350 //----------------------------print_compile_messages---------------------------
   351 void Compile::print_compile_messages() {
   352 #ifndef PRODUCT
   353   // Check if recompiling
   354   if (_subsume_loads == false && PrintOpto) {
   355     // Recompiling without allowing machine instructions to subsume loads
   356     tty->print_cr("*********************************************************");
   357     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
   358     tty->print_cr("*********************************************************");
   359   }
   360   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
   361     // Recompiling without escape analysis
   362     tty->print_cr("*********************************************************");
   363     tty->print_cr("** Bailout: Recompile without escape analysis          **");
   364     tty->print_cr("*********************************************************");
   365   }
   366   if (env()->break_at_compile()) {
   367     // Open the debugger when compiling this method.
   368     tty->print("### Breaking when compiling: ");
   369     method()->print_short_name();
   370     tty->cr();
   371     BREAKPOINT;
   372   }
   374   if( PrintOpto ) {
   375     if (is_osr_compilation()) {
   376       tty->print("[OSR]%3d", _compile_id);
   377     } else {
   378       tty->print("%3d", _compile_id);
   379     }
   380   }
   381 #endif
   382 }
   385 void Compile::init_scratch_buffer_blob() {
   386   if( scratch_buffer_blob() != NULL )  return;
   388   // Construct a temporary CodeBuffer to have it construct a BufferBlob
   389   // Cache this BufferBlob for this compile.
   390   ResourceMark rm;
   391   int size = (MAX_inst_size + MAX_stubs_size + MAX_const_size);
   392   BufferBlob* blob = BufferBlob::create("Compile::scratch_buffer", size);
   393   // Record the buffer blob for next time.
   394   set_scratch_buffer_blob(blob);
   395   // Have we run out of code space?
   396   if (scratch_buffer_blob() == NULL) {
   397     // Let CompilerBroker disable further compilations.
   398     record_failure("Not enough space for scratch buffer in CodeCache");
   399     return;
   400   }
   402   // Initialize the relocation buffers
   403   relocInfo* locs_buf = (relocInfo*) blob->instructions_end() - MAX_locs_size;
   404   set_scratch_locs_memory(locs_buf);
   405 }
   408 //-----------------------scratch_emit_size-------------------------------------
   409 // Helper function that computes size by emitting code
   410 uint Compile::scratch_emit_size(const Node* n) {
   411   // Emit into a trash buffer and count bytes emitted.
   412   // This is a pretty expensive way to compute a size,
   413   // but it works well enough if seldom used.
   414   // All common fixed-size instructions are given a size
   415   // method by the AD file.
   416   // Note that the scratch buffer blob and locs memory are
   417   // allocated at the beginning of the compile task, and
   418   // may be shared by several calls to scratch_emit_size.
   419   // The allocation of the scratch buffer blob is particularly
   420   // expensive, since it has to grab the code cache lock.
   421   BufferBlob* blob = this->scratch_buffer_blob();
   422   assert(blob != NULL, "Initialize BufferBlob at start");
   423   assert(blob->size() > MAX_inst_size, "sanity");
   424   relocInfo* locs_buf = scratch_locs_memory();
   425   address blob_begin = blob->instructions_begin();
   426   address blob_end   = (address)locs_buf;
   427   assert(blob->instructions_contains(blob_end), "sanity");
   428   CodeBuffer buf(blob_begin, blob_end - blob_begin);
   429   buf.initialize_consts_size(MAX_const_size);
   430   buf.initialize_stubs_size(MAX_stubs_size);
   431   assert(locs_buf != NULL, "sanity");
   432   int lsize = MAX_locs_size / 2;
   433   buf.insts()->initialize_shared_locs(&locs_buf[0],     lsize);
   434   buf.stubs()->initialize_shared_locs(&locs_buf[lsize], lsize);
   435   n->emit(buf, this->regalloc());
   436   return buf.code_size();
   437 }
   440 // ============================================================================
   441 //------------------------------Compile standard-------------------------------
   442 debug_only( int Compile::_debug_idx = 100000; )
   444 // Compile a method.  entry_bci is -1 for normal compilations and indicates
   445 // the continuation bci for on stack replacement.
   448 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci, bool subsume_loads, bool do_escape_analysis )
   449                 : Phase(Compiler),
   450                   _env(ci_env),
   451                   _log(ci_env->log()),
   452                   _compile_id(ci_env->compile_id()),
   453                   _save_argument_registers(false),
   454                   _stub_name(NULL),
   455                   _stub_function(NULL),
   456                   _stub_entry_point(NULL),
   457                   _method(target),
   458                   _entry_bci(osr_bci),
   459                   _initial_gvn(NULL),
   460                   _for_igvn(NULL),
   461                   _warm_calls(NULL),
   462                   _subsume_loads(subsume_loads),
   463                   _do_escape_analysis(do_escape_analysis),
   464                   _failure_reason(NULL),
   465                   _code_buffer("Compile::Fill_buffer"),
   466                   _orig_pc_slot(0),
   467                   _orig_pc_slot_offset_in_bytes(0),
   468                   _has_method_handle_invokes(false),
   469                   _node_bundling_limit(0),
   470                   _node_bundling_base(NULL),
   471                   _java_calls(0),
   472                   _inner_loops(0),
   473 #ifndef PRODUCT
   474                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
   475                   _printer(IdealGraphPrinter::printer()),
   476 #endif
   477                   _congraph(NULL) {
   478   C = this;
   480   CompileWrapper cw(this);
   481 #ifndef PRODUCT
   482   if (TimeCompiler2) {
   483     tty->print(" ");
   484     target->holder()->name()->print();
   485     tty->print(".");
   486     target->print_short_name();
   487     tty->print("  ");
   488   }
   489   TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
   490   TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
   491   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
   492   if (!print_opto_assembly) {
   493     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
   494     if (print_assembly && !Disassembler::can_decode()) {
   495       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
   496       print_opto_assembly = true;
   497     }
   498   }
   499   set_print_assembly(print_opto_assembly);
   500   set_parsed_irreducible_loop(false);
   501 #endif
   503   if (ProfileTraps) {
   504     // Make sure the method being compiled gets its own MDO,
   505     // so we can at least track the decompile_count().
   506     method()->build_method_data();
   507   }
   509   Init(::AliasLevel);
   512   print_compile_messages();
   514   if (UseOldInlining || PrintCompilation NOT_PRODUCT( || PrintOpto) )
   515     _ilt = InlineTree::build_inline_tree_root();
   516   else
   517     _ilt = NULL;
   519   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
   520   assert(num_alias_types() >= AliasIdxRaw, "");
   522 #define MINIMUM_NODE_HASH  1023
   523   // Node list that Iterative GVN will start with
   524   Unique_Node_List for_igvn(comp_arena());
   525   set_for_igvn(&for_igvn);
   527   // GVN that will be run immediately on new nodes
   528   uint estimated_size = method()->code_size()*4+64;
   529   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
   530   PhaseGVN gvn(node_arena(), estimated_size);
   531   set_initial_gvn(&gvn);
   533   { // Scope for timing the parser
   534     TracePhase t3("parse", &_t_parser, true);
   536     // Put top into the hash table ASAP.
   537     initial_gvn()->transform_no_reclaim(top());
   539     // Set up tf(), start(), and find a CallGenerator.
   540     CallGenerator* cg;
   541     if (is_osr_compilation()) {
   542       const TypeTuple *domain = StartOSRNode::osr_domain();
   543       const TypeTuple *range = TypeTuple::make_range(method()->signature());
   544       init_tf(TypeFunc::make(domain, range));
   545       StartNode* s = new (this, 2) StartOSRNode(root(), domain);
   546       initial_gvn()->set_type_bottom(s);
   547       init_start(s);
   548       cg = CallGenerator::for_osr(method(), entry_bci());
   549     } else {
   550       // Normal case.
   551       init_tf(TypeFunc::make(method()));
   552       StartNode* s = new (this, 2) StartNode(root(), tf()->domain());
   553       initial_gvn()->set_type_bottom(s);
   554       init_start(s);
   555       float past_uses = method()->interpreter_invocation_count();
   556       float expected_uses = past_uses;
   557       cg = CallGenerator::for_inline(method(), expected_uses);
   558     }
   559     if (failing())  return;
   560     if (cg == NULL) {
   561       record_method_not_compilable_all_tiers("cannot parse method");
   562       return;
   563     }
   564     JVMState* jvms = build_start_state(start(), tf());
   565     if ((jvms = cg->generate(jvms)) == NULL) {
   566       record_method_not_compilable("method parse failed");
   567       return;
   568     }
   569     GraphKit kit(jvms);
   571     if (!kit.stopped()) {
   572       // Accept return values, and transfer control we know not where.
   573       // This is done by a special, unique ReturnNode bound to root.
   574       return_values(kit.jvms());
   575     }
   577     if (kit.has_exceptions()) {
   578       // Any exceptions that escape from this call must be rethrown
   579       // to whatever caller is dynamically above us on the stack.
   580       // This is done by a special, unique RethrowNode bound to root.
   581       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
   582     }
   584     if (!failing() && has_stringbuilder()) {
   585       {
   586         // remove useless nodes to make the usage analysis simpler
   587         ResourceMark rm;
   588         PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
   589       }
   591       {
   592         ResourceMark rm;
   593         print_method("Before StringOpts", 3);
   594         PhaseStringOpts pso(initial_gvn(), &for_igvn);
   595         print_method("After StringOpts", 3);
   596       }
   598       // now inline anything that we skipped the first time around
   599       while (_late_inlines.length() > 0) {
   600         CallGenerator* cg = _late_inlines.pop();
   601         cg->do_late_inline();
   602       }
   603     }
   604     assert(_late_inlines.length() == 0, "should have been processed");
   606     print_method("Before RemoveUseless", 3);
   608     // Remove clutter produced by parsing.
   609     if (!failing()) {
   610       ResourceMark rm;
   611       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
   612     }
   613   }
   615   // Note:  Large methods are capped off in do_one_bytecode().
   616   if (failing())  return;
   618   // After parsing, node notes are no longer automagic.
   619   // They must be propagated by register_new_node_with_optimizer(),
   620   // clone(), or the like.
   621   set_default_node_notes(NULL);
   623   for (;;) {
   624     int successes = Inline_Warm();
   625     if (failing())  return;
   626     if (successes == 0)  break;
   627   }
   629   // Drain the list.
   630   Finish_Warm();
   631 #ifndef PRODUCT
   632   if (_printer) {
   633     _printer->print_inlining(this);
   634   }
   635 #endif
   637   if (failing())  return;
   638   NOT_PRODUCT( verify_graph_edges(); )
   640   // Perform escape analysis
   641   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
   642     TracePhase t2("escapeAnalysis", &_t_escapeAnalysis, true);
   643     // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction.
   644     PhaseGVN* igvn = initial_gvn();
   645     Node* oop_null = igvn->zerocon(T_OBJECT);
   646     Node* noop_null = igvn->zerocon(T_NARROWOOP);
   648     _congraph = new(comp_arena()) ConnectionGraph(this);
   649     bool has_non_escaping_obj = _congraph->compute_escape();
   651 #ifndef PRODUCT
   652     if (PrintEscapeAnalysis) {
   653       _congraph->dump();
   654     }
   655 #endif
   656     // Cleanup.
   657     if (oop_null->outcnt() == 0)
   658       igvn->hash_delete(oop_null);
   659     if (noop_null->outcnt() == 0)
   660       igvn->hash_delete(noop_null);
   662     if (!has_non_escaping_obj) {
   663       _congraph = NULL;
   664     }
   666     if (failing())  return;
   667   }
   668   // Now optimize
   669   Optimize();
   670   if (failing())  return;
   671   NOT_PRODUCT( verify_graph_edges(); )
   673 #ifndef PRODUCT
   674   if (PrintIdeal) {
   675     ttyLocker ttyl;  // keep the following output all in one block
   676     // This output goes directly to the tty, not the compiler log.
   677     // To enable tools to match it up with the compilation activity,
   678     // be sure to tag this tty output with the compile ID.
   679     if (xtty != NULL) {
   680       xtty->head("ideal compile_id='%d'%s", compile_id(),
   681                  is_osr_compilation()    ? " compile_kind='osr'" :
   682                  "");
   683     }
   684     root()->dump(9999);
   685     if (xtty != NULL) {
   686       xtty->tail("ideal");
   687     }
   688   }
   689 #endif
   691   // Now that we know the size of all the monitors we can add a fixed slot
   692   // for the original deopt pc.
   694   _orig_pc_slot =  fixed_slots();
   695   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
   696   set_fixed_slots(next_slot);
   698   // Now generate code
   699   Code_Gen();
   700   if (failing())  return;
   702   // Check if we want to skip execution of all compiled code.
   703   {
   704 #ifndef PRODUCT
   705     if (OptoNoExecute) {
   706       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
   707       return;
   708     }
   709     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
   710 #endif
   712     if (is_osr_compilation()) {
   713       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
   714       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
   715     } else {
   716       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
   717       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
   718     }
   720     env()->register_method(_method, _entry_bci,
   721                            &_code_offsets,
   722                            _orig_pc_slot_offset_in_bytes,
   723                            code_buffer(),
   724                            frame_size_in_words(), _oop_map_set,
   725                            &_handler_table, &_inc_table,
   726                            compiler,
   727                            env()->comp_level(),
   728                            true, /*has_debug_info*/
   729                            has_unsafe_access()
   730                            );
   731   }
   732 }
   734 //------------------------------Compile----------------------------------------
   735 // Compile a runtime stub
   736 Compile::Compile( ciEnv* ci_env,
   737                   TypeFunc_generator generator,
   738                   address stub_function,
   739                   const char *stub_name,
   740                   int is_fancy_jump,
   741                   bool pass_tls,
   742                   bool save_arg_registers,
   743                   bool return_pc )
   744   : Phase(Compiler),
   745     _env(ci_env),
   746     _log(ci_env->log()),
   747     _compile_id(-1),
   748     _save_argument_registers(save_arg_registers),
   749     _method(NULL),
   750     _stub_name(stub_name),
   751     _stub_function(stub_function),
   752     _stub_entry_point(NULL),
   753     _entry_bci(InvocationEntryBci),
   754     _initial_gvn(NULL),
   755     _for_igvn(NULL),
   756     _warm_calls(NULL),
   757     _orig_pc_slot(0),
   758     _orig_pc_slot_offset_in_bytes(0),
   759     _subsume_loads(true),
   760     _do_escape_analysis(false),
   761     _failure_reason(NULL),
   762     _code_buffer("Compile::Fill_buffer"),
   763     _has_method_handle_invokes(false),
   764     _node_bundling_limit(0),
   765     _node_bundling_base(NULL),
   766     _java_calls(0),
   767     _inner_loops(0),
   768 #ifndef PRODUCT
   769     _trace_opto_output(TraceOptoOutput),
   770     _printer(NULL),
   771 #endif
   772     _congraph(NULL) {
   773   C = this;
   775 #ifndef PRODUCT
   776   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
   777   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
   778   set_print_assembly(PrintFrameConverterAssembly);
   779   set_parsed_irreducible_loop(false);
   780 #endif
   781   CompileWrapper cw(this);
   782   Init(/*AliasLevel=*/ 0);
   783   init_tf((*generator)());
   785   {
   786     // The following is a dummy for the sake of GraphKit::gen_stub
   787     Unique_Node_List for_igvn(comp_arena());
   788     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
   789     PhaseGVN gvn(Thread::current()->resource_area(),255);
   790     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
   791     gvn.transform_no_reclaim(top());
   793     GraphKit kit;
   794     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
   795   }
   797   NOT_PRODUCT( verify_graph_edges(); )
   798   Code_Gen();
   799   if (failing())  return;
   802   // Entry point will be accessed using compile->stub_entry_point();
   803   if (code_buffer() == NULL) {
   804     Matcher::soft_match_failure();
   805   } else {
   806     if (PrintAssembly && (WizardMode || Verbose))
   807       tty->print_cr("### Stub::%s", stub_name);
   809     if (!failing()) {
   810       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
   812       // Make the NMethod
   813       // For now we mark the frame as never safe for profile stackwalking
   814       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
   815                                                       code_buffer(),
   816                                                       CodeOffsets::frame_never_safe,
   817                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
   818                                                       frame_size_in_words(),
   819                                                       _oop_map_set,
   820                                                       save_arg_registers);
   821       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
   823       _stub_entry_point = rs->entry_point();
   824     }
   825   }
   826 }
   828 #ifndef PRODUCT
   829 void print_opto_verbose_signature( const TypeFunc *j_sig, const char *stub_name ) {
   830   if(PrintOpto && Verbose) {
   831     tty->print("%s   ", stub_name); j_sig->print_flattened(); tty->cr();
   832   }
   833 }
   834 #endif
   836 void Compile::print_codes() {
   837 }
   839 //------------------------------Init-------------------------------------------
   840 // Prepare for a single compilation
   841 void Compile::Init(int aliaslevel) {
   842   _unique  = 0;
   843   _regalloc = NULL;
   845   _tf      = NULL;  // filled in later
   846   _top     = NULL;  // cached later
   847   _matcher = NULL;  // filled in later
   848   _cfg     = NULL;  // filled in later
   850   set_24_bit_selection_and_mode(Use24BitFP, false);
   852   _node_note_array = NULL;
   853   _default_node_notes = NULL;
   855   _immutable_memory = NULL; // filled in at first inquiry
   857   // Globally visible Nodes
   858   // First set TOP to NULL to give safe behavior during creation of RootNode
   859   set_cached_top_node(NULL);
   860   set_root(new (this, 3) RootNode());
   861   // Now that you have a Root to point to, create the real TOP
   862   set_cached_top_node( new (this, 1) ConNode(Type::TOP) );
   863   set_recent_alloc(NULL, NULL);
   865   // Create Debug Information Recorder to record scopes, oopmaps, etc.
   866   env()->set_oop_recorder(new OopRecorder(comp_arena()));
   867   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
   868   env()->set_dependencies(new Dependencies(env()));
   870   _fixed_slots = 0;
   871   set_has_split_ifs(false);
   872   set_has_loops(has_method() && method()->has_loops()); // first approximation
   873   set_has_stringbuilder(false);
   874   _trap_can_recompile = false;  // no traps emitted yet
   875   _major_progress = true; // start out assuming good things will happen
   876   set_has_unsafe_access(false);
   877   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
   878   set_decompile_count(0);
   880   set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
   881   // Compilation level related initialization
   882   if (env()->comp_level() == CompLevel_fast_compile) {
   883     set_num_loop_opts(Tier1LoopOptsCount);
   884     set_do_inlining(Tier1Inline != 0);
   885     set_max_inline_size(Tier1MaxInlineSize);
   886     set_freq_inline_size(Tier1FreqInlineSize);
   887     set_do_scheduling(false);
   888     set_do_count_invocations(Tier1CountInvocations);
   889     set_do_method_data_update(Tier1UpdateMethodData);
   890   } else {
   891     assert(env()->comp_level() == CompLevel_full_optimization, "unknown comp level");
   892     set_num_loop_opts(LoopOptsCount);
   893     set_do_inlining(Inline);
   894     set_max_inline_size(MaxInlineSize);
   895     set_freq_inline_size(FreqInlineSize);
   896     set_do_scheduling(OptoScheduling);
   897     set_do_count_invocations(false);
   898     set_do_method_data_update(false);
   899   }
   901   if (debug_info()->recording_non_safepoints()) {
   902     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
   903                         (comp_arena(), 8, 0, NULL));
   904     set_default_node_notes(Node_Notes::make(this));
   905   }
   907   // // -- Initialize types before each compile --
   908   // // Update cached type information
   909   // if( _method && _method->constants() )
   910   //   Type::update_loaded_types(_method, _method->constants());
   912   // Init alias_type map.
   913   if (!_do_escape_analysis && aliaslevel == 3)
   914     aliaslevel = 2;  // No unique types without escape analysis
   915   _AliasLevel = aliaslevel;
   916   const int grow_ats = 16;
   917   _max_alias_types = grow_ats;
   918   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
   919   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
   920   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
   921   {
   922     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
   923   }
   924   // Initialize the first few types.
   925   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
   926   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
   927   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
   928   _num_alias_types = AliasIdxRaw+1;
   929   // Zero out the alias type cache.
   930   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
   931   // A NULL adr_type hits in the cache right away.  Preload the right answer.
   932   probe_alias_cache(NULL)->_index = AliasIdxTop;
   934   _intrinsics = NULL;
   935   _macro_nodes = new GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
   936   _predicate_opaqs = new GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
   937   register_library_intrinsics();
   938 }
   940 //---------------------------init_start----------------------------------------
   941 // Install the StartNode on this compile object.
   942 void Compile::init_start(StartNode* s) {
   943   if (failing())
   944     return; // already failing
   945   assert(s == start(), "");
   946 }
   948 StartNode* Compile::start() const {
   949   assert(!failing(), "");
   950   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
   951     Node* start = root()->fast_out(i);
   952     if( start->is_Start() )
   953       return start->as_Start();
   954   }
   955   ShouldNotReachHere();
   956   return NULL;
   957 }
   959 //-------------------------------immutable_memory-------------------------------------
   960 // Access immutable memory
   961 Node* Compile::immutable_memory() {
   962   if (_immutable_memory != NULL) {
   963     return _immutable_memory;
   964   }
   965   StartNode* s = start();
   966   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
   967     Node *p = s->fast_out(i);
   968     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
   969       _immutable_memory = p;
   970       return _immutable_memory;
   971     }
   972   }
   973   ShouldNotReachHere();
   974   return NULL;
   975 }
   977 //----------------------set_cached_top_node------------------------------------
   978 // Install the cached top node, and make sure Node::is_top works correctly.
   979 void Compile::set_cached_top_node(Node* tn) {
   980   if (tn != NULL)  verify_top(tn);
   981   Node* old_top = _top;
   982   _top = tn;
   983   // Calling Node::setup_is_top allows the nodes the chance to adjust
   984   // their _out arrays.
   985   if (_top != NULL)     _top->setup_is_top();
   986   if (old_top != NULL)  old_top->setup_is_top();
   987   assert(_top == NULL || top()->is_top(), "");
   988 }
   990 #ifndef PRODUCT
   991 void Compile::verify_top(Node* tn) const {
   992   if (tn != NULL) {
   993     assert(tn->is_Con(), "top node must be a constant");
   994     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
   995     assert(tn->in(0) != NULL, "must have live top node");
   996   }
   997 }
   998 #endif
  1001 ///-------------------Managing Per-Node Debug & Profile Info-------------------
  1003 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
  1004   guarantee(arr != NULL, "");
  1005   int num_blocks = arr->length();
  1006   if (grow_by < num_blocks)  grow_by = num_blocks;
  1007   int num_notes = grow_by * _node_notes_block_size;
  1008   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
  1009   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
  1010   while (num_notes > 0) {
  1011     arr->append(notes);
  1012     notes     += _node_notes_block_size;
  1013     num_notes -= _node_notes_block_size;
  1015   assert(num_notes == 0, "exact multiple, please");
  1018 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
  1019   if (source == NULL || dest == NULL)  return false;
  1021   if (dest->is_Con())
  1022     return false;               // Do not push debug info onto constants.
  1024 #ifdef ASSERT
  1025   // Leave a bread crumb trail pointing to the original node:
  1026   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
  1027     dest->set_debug_orig(source);
  1029 #endif
  1031   if (node_note_array() == NULL)
  1032     return false;               // Not collecting any notes now.
  1034   // This is a copy onto a pre-existing node, which may already have notes.
  1035   // If both nodes have notes, do not overwrite any pre-existing notes.
  1036   Node_Notes* source_notes = node_notes_at(source->_idx);
  1037   if (source_notes == NULL || source_notes->is_clear())  return false;
  1038   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
  1039   if (dest_notes == NULL || dest_notes->is_clear()) {
  1040     return set_node_notes_at(dest->_idx, source_notes);
  1043   Node_Notes merged_notes = (*source_notes);
  1044   // The order of operations here ensures that dest notes will win...
  1045   merged_notes.update_from(dest_notes);
  1046   return set_node_notes_at(dest->_idx, &merged_notes);
  1050 //--------------------------allow_range_check_smearing-------------------------
  1051 // Gating condition for coalescing similar range checks.
  1052 // Sometimes we try 'speculatively' replacing a series of a range checks by a
  1053 // single covering check that is at least as strong as any of them.
  1054 // If the optimization succeeds, the simplified (strengthened) range check
  1055 // will always succeed.  If it fails, we will deopt, and then give up
  1056 // on the optimization.
  1057 bool Compile::allow_range_check_smearing() const {
  1058   // If this method has already thrown a range-check,
  1059   // assume it was because we already tried range smearing
  1060   // and it failed.
  1061   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
  1062   return !already_trapped;
  1066 //------------------------------flatten_alias_type-----------------------------
  1067 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
  1068   int offset = tj->offset();
  1069   TypePtr::PTR ptr = tj->ptr();
  1071   // Known instance (scalarizable allocation) alias only with itself.
  1072   bool is_known_inst = tj->isa_oopptr() != NULL &&
  1073                        tj->is_oopptr()->is_known_instance();
  1075   // Process weird unsafe references.
  1076   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
  1077     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
  1078     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
  1079     tj = TypeOopPtr::BOTTOM;
  1080     ptr = tj->ptr();
  1081     offset = tj->offset();
  1084   // Array pointers need some flattening
  1085   const TypeAryPtr *ta = tj->isa_aryptr();
  1086   if( ta && is_known_inst ) {
  1087     if ( offset != Type::OffsetBot &&
  1088          offset > arrayOopDesc::length_offset_in_bytes() ) {
  1089       offset = Type::OffsetBot; // Flatten constant access into array body only
  1090       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
  1092   } else if( ta && _AliasLevel >= 2 ) {
  1093     // For arrays indexed by constant indices, we flatten the alias
  1094     // space to include all of the array body.  Only the header, klass
  1095     // and array length can be accessed un-aliased.
  1096     if( offset != Type::OffsetBot ) {
  1097       if( ta->const_oop() ) { // methodDataOop or methodOop
  1098         offset = Type::OffsetBot;   // Flatten constant access into array body
  1099         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
  1100       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
  1101         // range is OK as-is.
  1102         tj = ta = TypeAryPtr::RANGE;
  1103       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
  1104         tj = TypeInstPtr::KLASS; // all klass loads look alike
  1105         ta = TypeAryPtr::RANGE; // generic ignored junk
  1106         ptr = TypePtr::BotPTR;
  1107       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
  1108         tj = TypeInstPtr::MARK;
  1109         ta = TypeAryPtr::RANGE; // generic ignored junk
  1110         ptr = TypePtr::BotPTR;
  1111       } else {                  // Random constant offset into array body
  1112         offset = Type::OffsetBot;   // Flatten constant access into array body
  1113         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
  1116     // Arrays of fixed size alias with arrays of unknown size.
  1117     if (ta->size() != TypeInt::POS) {
  1118       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
  1119       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
  1121     // Arrays of known objects become arrays of unknown objects.
  1122     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
  1123       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
  1124       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
  1126     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
  1127       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
  1128       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
  1130     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
  1131     // cannot be distinguished by bytecode alone.
  1132     if (ta->elem() == TypeInt::BOOL) {
  1133       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
  1134       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
  1135       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
  1137     // During the 2nd round of IterGVN, NotNull castings are removed.
  1138     // Make sure the Bottom and NotNull variants alias the same.
  1139     // Also, make sure exact and non-exact variants alias the same.
  1140     if( ptr == TypePtr::NotNull || ta->klass_is_exact() ) {
  1141       if (ta->const_oop()) {
  1142         tj = ta = TypeAryPtr::make(TypePtr::Constant,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
  1143       } else {
  1144         tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
  1149   // Oop pointers need some flattening
  1150   const TypeInstPtr *to = tj->isa_instptr();
  1151   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
  1152     if( ptr == TypePtr::Constant ) {
  1153       // No constant oop pointers (such as Strings); they alias with
  1154       // unknown strings.
  1155       assert(!is_known_inst, "not scalarizable allocation");
  1156       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1157     } else if( is_known_inst ) {
  1158       tj = to; // Keep NotNull and klass_is_exact for instance type
  1159     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
  1160       // During the 2nd round of IterGVN, NotNull castings are removed.
  1161       // Make sure the Bottom and NotNull variants alias the same.
  1162       // Also, make sure exact and non-exact variants alias the same.
  1163       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1165     // Canonicalize the holder of this field
  1166     ciInstanceKlass *k = to->klass()->as_instance_klass();
  1167     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
  1168       // First handle header references such as a LoadKlassNode, even if the
  1169       // object's klass is unloaded at compile time (4965979).
  1170       if (!is_known_inst) { // Do it only for non-instance types
  1171         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
  1173     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
  1174       to = NULL;
  1175       tj = TypeOopPtr::BOTTOM;
  1176       offset = tj->offset();
  1177     } else {
  1178       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
  1179       if (!k->equals(canonical_holder) || tj->offset() != offset) {
  1180         if( is_known_inst ) {
  1181           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
  1182         } else {
  1183           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
  1189   // Klass pointers to object array klasses need some flattening
  1190   const TypeKlassPtr *tk = tj->isa_klassptr();
  1191   if( tk ) {
  1192     // If we are referencing a field within a Klass, we need
  1193     // to assume the worst case of an Object.  Both exact and
  1194     // inexact types must flatten to the same alias class.
  1195     // Since the flattened result for a klass is defined to be
  1196     // precisely java.lang.Object, use a constant ptr.
  1197     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
  1199       tj = tk = TypeKlassPtr::make(TypePtr::Constant,
  1200                                    TypeKlassPtr::OBJECT->klass(),
  1201                                    offset);
  1204     ciKlass* klass = tk->klass();
  1205     if( klass->is_obj_array_klass() ) {
  1206       ciKlass* k = TypeAryPtr::OOPS->klass();
  1207       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
  1208         k = TypeInstPtr::BOTTOM->klass();
  1209       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
  1212     // Check for precise loads from the primary supertype array and force them
  1213     // to the supertype cache alias index.  Check for generic array loads from
  1214     // the primary supertype array and also force them to the supertype cache
  1215     // alias index.  Since the same load can reach both, we need to merge
  1216     // these 2 disparate memories into the same alias class.  Since the
  1217     // primary supertype array is read-only, there's no chance of confusion
  1218     // where we bypass an array load and an array store.
  1219     uint off2 = offset - Klass::primary_supers_offset_in_bytes();
  1220     if( offset == Type::OffsetBot ||
  1221         off2 < Klass::primary_super_limit()*wordSize ) {
  1222       offset = sizeof(oopDesc) +Klass::secondary_super_cache_offset_in_bytes();
  1223       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
  1227   // Flatten all Raw pointers together.
  1228   if (tj->base() == Type::RawPtr)
  1229     tj = TypeRawPtr::BOTTOM;
  1231   if (tj->base() == Type::AnyPtr)
  1232     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
  1234   // Flatten all to bottom for now
  1235   switch( _AliasLevel ) {
  1236   case 0:
  1237     tj = TypePtr::BOTTOM;
  1238     break;
  1239   case 1:                       // Flatten to: oop, static, field or array
  1240     switch (tj->base()) {
  1241     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
  1242     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
  1243     case Type::AryPtr:   // do not distinguish arrays at all
  1244     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
  1245     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
  1246     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
  1247     default: ShouldNotReachHere();
  1249     break;
  1250   case 2:                       // No collapsing at level 2; keep all splits
  1251   case 3:                       // No collapsing at level 3; keep all splits
  1252     break;
  1253   default:
  1254     Unimplemented();
  1257   offset = tj->offset();
  1258   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
  1260   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
  1261           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
  1262           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
  1263           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
  1264           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1265           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1266           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
  1267           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
  1268   assert( tj->ptr() != TypePtr::TopPTR &&
  1269           tj->ptr() != TypePtr::AnyNull &&
  1270           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
  1271 //    assert( tj->ptr() != TypePtr::Constant ||
  1272 //            tj->base() == Type::RawPtr ||
  1273 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
  1275   return tj;
  1278 void Compile::AliasType::Init(int i, const TypePtr* at) {
  1279   _index = i;
  1280   _adr_type = at;
  1281   _field = NULL;
  1282   _is_rewritable = true; // default
  1283   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
  1284   if (atoop != NULL && atoop->is_known_instance()) {
  1285     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
  1286     _general_index = Compile::current()->get_alias_index(gt);
  1287   } else {
  1288     _general_index = 0;
  1292 //---------------------------------print_on------------------------------------
  1293 #ifndef PRODUCT
  1294 void Compile::AliasType::print_on(outputStream* st) {
  1295   if (index() < 10)
  1296         st->print("@ <%d> ", index());
  1297   else  st->print("@ <%d>",  index());
  1298   st->print(is_rewritable() ? "   " : " RO");
  1299   int offset = adr_type()->offset();
  1300   if (offset == Type::OffsetBot)
  1301         st->print(" +any");
  1302   else  st->print(" +%-3d", offset);
  1303   st->print(" in ");
  1304   adr_type()->dump_on(st);
  1305   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
  1306   if (field() != NULL && tjp) {
  1307     if (tjp->klass()  != field()->holder() ||
  1308         tjp->offset() != field()->offset_in_bytes()) {
  1309       st->print(" != ");
  1310       field()->print();
  1311       st->print(" ***");
  1316 void print_alias_types() {
  1317   Compile* C = Compile::current();
  1318   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
  1319   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
  1320     C->alias_type(idx)->print_on(tty);
  1321     tty->cr();
  1324 #endif
  1327 //----------------------------probe_alias_cache--------------------------------
  1328 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
  1329   intptr_t key = (intptr_t) adr_type;
  1330   key ^= key >> logAliasCacheSize;
  1331   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
  1335 //-----------------------------grow_alias_types--------------------------------
  1336 void Compile::grow_alias_types() {
  1337   const int old_ats  = _max_alias_types; // how many before?
  1338   const int new_ats  = old_ats;          // how many more?
  1339   const int grow_ats = old_ats+new_ats;  // how many now?
  1340   _max_alias_types = grow_ats;
  1341   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
  1342   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
  1343   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
  1344   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
  1348 //--------------------------------find_alias_type------------------------------
  1349 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create) {
  1350   if (_AliasLevel == 0)
  1351     return alias_type(AliasIdxBot);
  1353   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1354   if (ace->_adr_type == adr_type) {
  1355     return alias_type(ace->_index);
  1358   // Handle special cases.
  1359   if (adr_type == NULL)             return alias_type(AliasIdxTop);
  1360   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
  1362   // Do it the slow way.
  1363   const TypePtr* flat = flatten_alias_type(adr_type);
  1365 #ifdef ASSERT
  1366   assert(flat == flatten_alias_type(flat), "idempotent");
  1367   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
  1368   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
  1369     const TypeOopPtr* foop = flat->is_oopptr();
  1370     // Scalarizable allocations have exact klass always.
  1371     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
  1372     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
  1373     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
  1375   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
  1376 #endif
  1378   int idx = AliasIdxTop;
  1379   for (int i = 0; i < num_alias_types(); i++) {
  1380     if (alias_type(i)->adr_type() == flat) {
  1381       idx = i;
  1382       break;
  1386   if (idx == AliasIdxTop) {
  1387     if (no_create)  return NULL;
  1388     // Grow the array if necessary.
  1389     if (_num_alias_types == _max_alias_types)  grow_alias_types();
  1390     // Add a new alias type.
  1391     idx = _num_alias_types++;
  1392     _alias_types[idx]->Init(idx, flat);
  1393     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
  1394     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
  1395     if (flat->isa_instptr()) {
  1396       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
  1397           && flat->is_instptr()->klass() == env()->Class_klass())
  1398         alias_type(idx)->set_rewritable(false);
  1400     if (flat->isa_klassptr()) {
  1401       if (flat->offset() == Klass::super_check_offset_offset_in_bytes() + (int)sizeof(oopDesc))
  1402         alias_type(idx)->set_rewritable(false);
  1403       if (flat->offset() == Klass::modifier_flags_offset_in_bytes() + (int)sizeof(oopDesc))
  1404         alias_type(idx)->set_rewritable(false);
  1405       if (flat->offset() == Klass::access_flags_offset_in_bytes() + (int)sizeof(oopDesc))
  1406         alias_type(idx)->set_rewritable(false);
  1407       if (flat->offset() == Klass::java_mirror_offset_in_bytes() + (int)sizeof(oopDesc))
  1408         alias_type(idx)->set_rewritable(false);
  1410     // %%% (We would like to finalize JavaThread::threadObj_offset(),
  1411     // but the base pointer type is not distinctive enough to identify
  1412     // references into JavaThread.)
  1414     // Check for final instance fields.
  1415     const TypeInstPtr* tinst = flat->isa_instptr();
  1416     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
  1417       ciInstanceKlass *k = tinst->klass()->as_instance_klass();
  1418       ciField* field = k->get_field_by_offset(tinst->offset(), false);
  1419       // Set field() and is_rewritable() attributes.
  1420       if (field != NULL)  alias_type(idx)->set_field(field);
  1422     const TypeKlassPtr* tklass = flat->isa_klassptr();
  1423     // Check for final static fields.
  1424     if (tklass && tklass->klass()->is_instance_klass()) {
  1425       ciInstanceKlass *k = tklass->klass()->as_instance_klass();
  1426       ciField* field = k->get_field_by_offset(tklass->offset(), true);
  1427       // Set field() and is_rewritable() attributes.
  1428       if (field != NULL)   alias_type(idx)->set_field(field);
  1432   // Fill the cache for next time.
  1433   ace->_adr_type = adr_type;
  1434   ace->_index    = idx;
  1435   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
  1437   // Might as well try to fill the cache for the flattened version, too.
  1438   AliasCacheEntry* face = probe_alias_cache(flat);
  1439   if (face->_adr_type == NULL) {
  1440     face->_adr_type = flat;
  1441     face->_index    = idx;
  1442     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
  1445   return alias_type(idx);
  1449 Compile::AliasType* Compile::alias_type(ciField* field) {
  1450   const TypeOopPtr* t;
  1451   if (field->is_static())
  1452     t = TypeKlassPtr::make(field->holder());
  1453   else
  1454     t = TypeOopPtr::make_from_klass_raw(field->holder());
  1455   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()));
  1456   assert(field->is_final() == !atp->is_rewritable(), "must get the rewritable bits correct");
  1457   return atp;
  1461 //------------------------------have_alias_type--------------------------------
  1462 bool Compile::have_alias_type(const TypePtr* adr_type) {
  1463   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1464   if (ace->_adr_type == adr_type) {
  1465     return true;
  1468   // Handle special cases.
  1469   if (adr_type == NULL)             return true;
  1470   if (adr_type == TypePtr::BOTTOM)  return true;
  1472   return find_alias_type(adr_type, true) != NULL;
  1475 //-----------------------------must_alias--------------------------------------
  1476 // True if all values of the given address type are in the given alias category.
  1477 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
  1478   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1479   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
  1480   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1481   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
  1483   // the only remaining possible overlap is identity
  1484   int adr_idx = get_alias_index(adr_type);
  1485   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1486   assert(adr_idx == alias_idx ||
  1487          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
  1488           && adr_type                       != TypeOopPtr::BOTTOM),
  1489          "should not be testing for overlap with an unsafe pointer");
  1490   return adr_idx == alias_idx;
  1493 //------------------------------can_alias--------------------------------------
  1494 // True if any values of the given address type are in the given alias category.
  1495 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
  1496   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1497   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
  1498   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1499   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
  1501   // the only remaining possible overlap is identity
  1502   int adr_idx = get_alias_index(adr_type);
  1503   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1504   return adr_idx == alias_idx;
  1509 //---------------------------pop_warm_call-------------------------------------
  1510 WarmCallInfo* Compile::pop_warm_call() {
  1511   WarmCallInfo* wci = _warm_calls;
  1512   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
  1513   return wci;
  1516 //----------------------------Inline_Warm--------------------------------------
  1517 int Compile::Inline_Warm() {
  1518   // If there is room, try to inline some more warm call sites.
  1519   // %%% Do a graph index compaction pass when we think we're out of space?
  1520   if (!InlineWarmCalls)  return 0;
  1522   int calls_made_hot = 0;
  1523   int room_to_grow   = NodeCountInliningCutoff - unique();
  1524   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
  1525   int amount_grown   = 0;
  1526   WarmCallInfo* call;
  1527   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
  1528     int est_size = (int)call->size();
  1529     if (est_size > (room_to_grow - amount_grown)) {
  1530       // This one won't fit anyway.  Get rid of it.
  1531       call->make_cold();
  1532       continue;
  1534     call->make_hot();
  1535     calls_made_hot++;
  1536     amount_grown   += est_size;
  1537     amount_to_grow -= est_size;
  1540   if (calls_made_hot > 0)  set_major_progress();
  1541   return calls_made_hot;
  1545 //----------------------------Finish_Warm--------------------------------------
  1546 void Compile::Finish_Warm() {
  1547   if (!InlineWarmCalls)  return;
  1548   if (failing())  return;
  1549   if (warm_calls() == NULL)  return;
  1551   // Clean up loose ends, if we are out of space for inlining.
  1552   WarmCallInfo* call;
  1553   while ((call = pop_warm_call()) != NULL) {
  1554     call->make_cold();
  1558 //---------------------cleanup_loop_predicates-----------------------
  1559 // Remove the opaque nodes that protect the predicates so that all unused
  1560 // checks and uncommon_traps will be eliminated from the ideal graph
  1561 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
  1562   if (predicate_count()==0) return;
  1563   for (int i = predicate_count(); i > 0; i--) {
  1564     Node * n = predicate_opaque1_node(i-1);
  1565     assert(n->Opcode() == Op_Opaque1, "must be");
  1566     igvn.replace_node(n, n->in(1));
  1568   assert(predicate_count()==0, "should be clean!");
  1569   igvn.optimize();
  1572 //------------------------------Optimize---------------------------------------
  1573 // Given a graph, optimize it.
  1574 void Compile::Optimize() {
  1575   TracePhase t1("optimizer", &_t_optimizer, true);
  1577 #ifndef PRODUCT
  1578   if (env()->break_at_compile()) {
  1579     BREAKPOINT;
  1582 #endif
  1584   ResourceMark rm;
  1585   int          loop_opts_cnt;
  1587   NOT_PRODUCT( verify_graph_edges(); )
  1589   print_method("After Parsing");
  1592   // Iterative Global Value Numbering, including ideal transforms
  1593   // Initialize IterGVN with types and values from parse-time GVN
  1594   PhaseIterGVN igvn(initial_gvn());
  1596     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
  1597     igvn.optimize();
  1600   print_method("Iter GVN 1", 2);
  1602   if (failing())  return;
  1604   // Loop transforms on the ideal graph.  Range Check Elimination,
  1605   // peeling, unrolling, etc.
  1607   // Set loop opts counter
  1608   loop_opts_cnt = num_loop_opts();
  1609   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
  1611       TracePhase t2("idealLoop", &_t_idealLoop, true);
  1612       PhaseIdealLoop ideal_loop( igvn, true, UseLoopPredicate);
  1613       loop_opts_cnt--;
  1614       if (major_progress()) print_method("PhaseIdealLoop 1", 2);
  1615       if (failing())  return;
  1617     // Loop opts pass if partial peeling occurred in previous pass
  1618     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
  1619       TracePhase t3("idealLoop", &_t_idealLoop, true);
  1620       PhaseIdealLoop ideal_loop( igvn, false, UseLoopPredicate);
  1621       loop_opts_cnt--;
  1622       if (major_progress()) print_method("PhaseIdealLoop 2", 2);
  1623       if (failing())  return;
  1625     // Loop opts pass for loop-unrolling before CCP
  1626     if(major_progress() && (loop_opts_cnt > 0)) {
  1627       TracePhase t4("idealLoop", &_t_idealLoop, true);
  1628       PhaseIdealLoop ideal_loop( igvn, false, UseLoopPredicate);
  1629       loop_opts_cnt--;
  1630       if (major_progress()) print_method("PhaseIdealLoop 3", 2);
  1632     if (!failing()) {
  1633       // Verify that last round of loop opts produced a valid graph
  1634       NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
  1635       PhaseIdealLoop::verify(igvn);
  1638   if (failing())  return;
  1640   // Conditional Constant Propagation;
  1641   PhaseCCP ccp( &igvn );
  1642   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
  1644     TracePhase t2("ccp", &_t_ccp, true);
  1645     ccp.do_transform();
  1647   print_method("PhaseCPP 1", 2);
  1649   assert( true, "Break here to ccp.dump_old2new_map()");
  1651   // Iterative Global Value Numbering, including ideal transforms
  1653     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
  1654     igvn = ccp;
  1655     igvn.optimize();
  1658   print_method("Iter GVN 2", 2);
  1660   if (failing())  return;
  1662   // Loop transforms on the ideal graph.  Range Check Elimination,
  1663   // peeling, unrolling, etc.
  1664   if(loop_opts_cnt > 0) {
  1665     debug_only( int cnt = 0; );
  1666     bool loop_predication = UseLoopPredicate;
  1667     while(major_progress() && (loop_opts_cnt > 0)) {
  1668       TracePhase t2("idealLoop", &_t_idealLoop, true);
  1669       assert( cnt++ < 40, "infinite cycle in loop optimization" );
  1670       PhaseIdealLoop ideal_loop( igvn, true, loop_predication);
  1671       loop_opts_cnt--;
  1672       if (major_progress()) print_method("PhaseIdealLoop iterations", 2);
  1673       if (failing())  return;
  1674       // Perform loop predication optimization during first iteration after CCP.
  1675       // After that switch it off and cleanup unused loop predicates.
  1676       if (loop_predication) {
  1677         loop_predication = false;
  1678         cleanup_loop_predicates(igvn);
  1679         if (failing())  return;
  1685     // Verify that all previous optimizations produced a valid graph
  1686     // at least to this point, even if no loop optimizations were done.
  1687     NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
  1688     PhaseIdealLoop::verify(igvn);
  1692     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
  1693     PhaseMacroExpand  mex(igvn);
  1694     if (mex.expand_macro_nodes()) {
  1695       assert(failing(), "must bail out w/ explicit message");
  1696       return;
  1700  } // (End scope of igvn; run destructor if necessary for asserts.)
  1702   // A method with only infinite loops has no edges entering loops from root
  1704     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
  1705     if (final_graph_reshaping()) {
  1706       assert(failing(), "must bail out w/ explicit message");
  1707       return;
  1711   print_method("Optimize finished", 2);
  1715 //------------------------------Code_Gen---------------------------------------
  1716 // Given a graph, generate code for it
  1717 void Compile::Code_Gen() {
  1718   if (failing())  return;
  1720   // Perform instruction selection.  You might think we could reclaim Matcher
  1721   // memory PDQ, but actually the Matcher is used in generating spill code.
  1722   // Internals of the Matcher (including some VectorSets) must remain live
  1723   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
  1724   // set a bit in reclaimed memory.
  1726   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  1727   // nodes.  Mapping is only valid at the root of each matched subtree.
  1728   NOT_PRODUCT( verify_graph_edges(); )
  1730   Node_List proj_list;
  1731   Matcher m(proj_list);
  1732   _matcher = &m;
  1734     TracePhase t2("matcher", &_t_matcher, true);
  1735     m.match();
  1737   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  1738   // nodes.  Mapping is only valid at the root of each matched subtree.
  1739   NOT_PRODUCT( verify_graph_edges(); )
  1741   // If you have too many nodes, or if matching has failed, bail out
  1742   check_node_count(0, "out of nodes matching instructions");
  1743   if (failing())  return;
  1745   // Build a proper-looking CFG
  1746   PhaseCFG cfg(node_arena(), root(), m);
  1747   _cfg = &cfg;
  1749     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
  1750     cfg.Dominators();
  1751     if (failing())  return;
  1753     NOT_PRODUCT( verify_graph_edges(); )
  1755     cfg.Estimate_Block_Frequency();
  1756     cfg.GlobalCodeMotion(m,unique(),proj_list);
  1758     print_method("Global code motion", 2);
  1760     if (failing())  return;
  1761     NOT_PRODUCT( verify_graph_edges(); )
  1763     debug_only( cfg.verify(); )
  1765   NOT_PRODUCT( verify_graph_edges(); )
  1767   PhaseChaitin regalloc(unique(),cfg,m);
  1768   _regalloc = &regalloc;
  1770     TracePhase t2("regalloc", &_t_registerAllocation, true);
  1771     // Perform any platform dependent preallocation actions.  This is used,
  1772     // for example, to avoid taking an implicit null pointer exception
  1773     // using the frame pointer on win95.
  1774     _regalloc->pd_preallocate_hook();
  1776     // Perform register allocation.  After Chaitin, use-def chains are
  1777     // no longer accurate (at spill code) and so must be ignored.
  1778     // Node->LRG->reg mappings are still accurate.
  1779     _regalloc->Register_Allocate();
  1781     // Bail out if the allocator builds too many nodes
  1782     if (failing())  return;
  1785   // Prior to register allocation we kept empty basic blocks in case the
  1786   // the allocator needed a place to spill.  After register allocation we
  1787   // are not adding any new instructions.  If any basic block is empty, we
  1788   // can now safely remove it.
  1790     NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
  1791     cfg.remove_empty();
  1792     if (do_freq_based_layout()) {
  1793       PhaseBlockLayout layout(cfg);
  1794     } else {
  1795       cfg.set_loop_alignment();
  1797     cfg.fixup_flow();
  1800   // Perform any platform dependent postallocation verifications.
  1801   debug_only( _regalloc->pd_postallocate_verify_hook(); )
  1803   // Apply peephole optimizations
  1804   if( OptoPeephole ) {
  1805     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
  1806     PhasePeephole peep( _regalloc, cfg);
  1807     peep.do_transform();
  1810   // Convert Nodes to instruction bits in a buffer
  1812     // %%%% workspace merge brought two timers together for one job
  1813     TracePhase t2a("output", &_t_output, true);
  1814     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
  1815     Output();
  1818   print_method("Final Code");
  1820   // He's dead, Jim.
  1821   _cfg     = (PhaseCFG*)0xdeadbeef;
  1822   _regalloc = (PhaseChaitin*)0xdeadbeef;
  1826 //------------------------------dump_asm---------------------------------------
  1827 // Dump formatted assembly
  1828 #ifndef PRODUCT
  1829 void Compile::dump_asm(int *pcs, uint pc_limit) {
  1830   bool cut_short = false;
  1831   tty->print_cr("#");
  1832   tty->print("#  ");  _tf->dump();  tty->cr();
  1833   tty->print_cr("#");
  1835   // For all blocks
  1836   int pc = 0x0;                 // Program counter
  1837   char starts_bundle = ' ';
  1838   _regalloc->dump_frame();
  1840   Node *n = NULL;
  1841   for( uint i=0; i<_cfg->_num_blocks; i++ ) {
  1842     if (VMThread::should_terminate()) { cut_short = true; break; }
  1843     Block *b = _cfg->_blocks[i];
  1844     if (b->is_connector() && !Verbose) continue;
  1845     n = b->_nodes[0];
  1846     if (pcs && n->_idx < pc_limit)
  1847       tty->print("%3.3x   ", pcs[n->_idx]);
  1848     else
  1849       tty->print("      ");
  1850     b->dump_head( &_cfg->_bbs );
  1851     if (b->is_connector()) {
  1852       tty->print_cr("        # Empty connector block");
  1853     } else if (b->num_preds() == 2 && b->pred(1)->is_CatchProj() && b->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
  1854       tty->print_cr("        # Block is sole successor of call");
  1857     // For all instructions
  1858     Node *delay = NULL;
  1859     for( uint j = 0; j<b->_nodes.size(); j++ ) {
  1860       if (VMThread::should_terminate()) { cut_short = true; break; }
  1861       n = b->_nodes[j];
  1862       if (valid_bundle_info(n)) {
  1863         Bundle *bundle = node_bundling(n);
  1864         if (bundle->used_in_unconditional_delay()) {
  1865           delay = n;
  1866           continue;
  1868         if (bundle->starts_bundle())
  1869           starts_bundle = '+';
  1872       if (WizardMode) n->dump();
  1874       if( !n->is_Region() &&    // Dont print in the Assembly
  1875           !n->is_Phi() &&       // a few noisely useless nodes
  1876           !n->is_Proj() &&
  1877           !n->is_MachTemp() &&
  1878           !n->is_SafePointScalarObject() &&
  1879           !n->is_Catch() &&     // Would be nice to print exception table targets
  1880           !n->is_MergeMem() &&  // Not very interesting
  1881           !n->is_top() &&       // Debug info table constants
  1882           !(n->is_Con() && !n->is_Mach())// Debug info table constants
  1883           ) {
  1884         if (pcs && n->_idx < pc_limit)
  1885           tty->print("%3.3x", pcs[n->_idx]);
  1886         else
  1887           tty->print("   ");
  1888         tty->print(" %c ", starts_bundle);
  1889         starts_bundle = ' ';
  1890         tty->print("\t");
  1891         n->format(_regalloc, tty);
  1892         tty->cr();
  1895       // If we have an instruction with a delay slot, and have seen a delay,
  1896       // then back up and print it
  1897       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
  1898         assert(delay != NULL, "no unconditional delay instruction");
  1899         if (WizardMode) delay->dump();
  1901         if (node_bundling(delay)->starts_bundle())
  1902           starts_bundle = '+';
  1903         if (pcs && n->_idx < pc_limit)
  1904           tty->print("%3.3x", pcs[n->_idx]);
  1905         else
  1906           tty->print("   ");
  1907         tty->print(" %c ", starts_bundle);
  1908         starts_bundle = ' ';
  1909         tty->print("\t");
  1910         delay->format(_regalloc, tty);
  1911         tty->print_cr("");
  1912         delay = NULL;
  1915       // Dump the exception table as well
  1916       if( n->is_Catch() && (Verbose || WizardMode) ) {
  1917         // Print the exception table for this offset
  1918         _handler_table.print_subtable_for(pc);
  1922     if (pcs && n->_idx < pc_limit)
  1923       tty->print_cr("%3.3x", pcs[n->_idx]);
  1924     else
  1925       tty->print_cr("");
  1927     assert(cut_short || delay == NULL, "no unconditional delay branch");
  1929   } // End of per-block dump
  1930   tty->print_cr("");
  1932   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
  1934 #endif
  1936 //------------------------------Final_Reshape_Counts---------------------------
  1937 // This class defines counters to help identify when a method
  1938 // may/must be executed using hardware with only 24-bit precision.
  1939 struct Final_Reshape_Counts : public StackObj {
  1940   int  _call_count;             // count non-inlined 'common' calls
  1941   int  _float_count;            // count float ops requiring 24-bit precision
  1942   int  _double_count;           // count double ops requiring more precision
  1943   int  _java_call_count;        // count non-inlined 'java' calls
  1944   int  _inner_loop_count;       // count loops which need alignment
  1945   VectorSet _visited;           // Visitation flags
  1946   Node_List _tests;             // Set of IfNodes & PCTableNodes
  1948   Final_Reshape_Counts() :
  1949     _call_count(0), _float_count(0), _double_count(0),
  1950     _java_call_count(0), _inner_loop_count(0),
  1951     _visited( Thread::current()->resource_area() ) { }
  1953   void inc_call_count  () { _call_count  ++; }
  1954   void inc_float_count () { _float_count ++; }
  1955   void inc_double_count() { _double_count++; }
  1956   void inc_java_call_count() { _java_call_count++; }
  1957   void inc_inner_loop_count() { _inner_loop_count++; }
  1959   int  get_call_count  () const { return _call_count  ; }
  1960   int  get_float_count () const { return _float_count ; }
  1961   int  get_double_count() const { return _double_count; }
  1962   int  get_java_call_count() const { return _java_call_count; }
  1963   int  get_inner_loop_count() const { return _inner_loop_count; }
  1964 };
  1966 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
  1967   ciInstanceKlass *k = tp->klass()->as_instance_klass();
  1968   // Make sure the offset goes inside the instance layout.
  1969   return k->contains_field_offset(tp->offset());
  1970   // Note that OffsetBot and OffsetTop are very negative.
  1973 //------------------------------final_graph_reshaping_impl----------------------
  1974 // Implement items 1-5 from final_graph_reshaping below.
  1975 static void final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc ) {
  1977   if ( n->outcnt() == 0 ) return; // dead node
  1978   uint nop = n->Opcode();
  1980   // Check for 2-input instruction with "last use" on right input.
  1981   // Swap to left input.  Implements item (2).
  1982   if( n->req() == 3 &&          // two-input instruction
  1983       n->in(1)->outcnt() > 1 && // left use is NOT a last use
  1984       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
  1985       n->in(2)->outcnt() == 1 &&// right use IS a last use
  1986       !n->in(2)->is_Con() ) {   // right use is not a constant
  1987     // Check for commutative opcode
  1988     switch( nop ) {
  1989     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
  1990     case Op_MaxI:  case Op_MinI:
  1991     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
  1992     case Op_AndL:  case Op_XorL:  case Op_OrL:
  1993     case Op_AndI:  case Op_XorI:  case Op_OrI: {
  1994       // Move "last use" input to left by swapping inputs
  1995       n->swap_edges(1, 2);
  1996       break;
  1998     default:
  1999       break;
  2003 #ifdef ASSERT
  2004   if( n->is_Mem() ) {
  2005     Compile* C = Compile::current();
  2006     int alias_idx = C->get_alias_index(n->as_Mem()->adr_type());
  2007     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
  2008             // oop will be recorded in oop map if load crosses safepoint
  2009             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
  2010                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
  2011             "raw memory operations should have control edge");
  2013 #endif
  2014   // Count FPU ops and common calls, implements item (3)
  2015   switch( nop ) {
  2016   // Count all float operations that may use FPU
  2017   case Op_AddF:
  2018   case Op_SubF:
  2019   case Op_MulF:
  2020   case Op_DivF:
  2021   case Op_NegF:
  2022   case Op_ModF:
  2023   case Op_ConvI2F:
  2024   case Op_ConF:
  2025   case Op_CmpF:
  2026   case Op_CmpF3:
  2027   // case Op_ConvL2F: // longs are split into 32-bit halves
  2028     frc.inc_float_count();
  2029     break;
  2031   case Op_ConvF2D:
  2032   case Op_ConvD2F:
  2033     frc.inc_float_count();
  2034     frc.inc_double_count();
  2035     break;
  2037   // Count all double operations that may use FPU
  2038   case Op_AddD:
  2039   case Op_SubD:
  2040   case Op_MulD:
  2041   case Op_DivD:
  2042   case Op_NegD:
  2043   case Op_ModD:
  2044   case Op_ConvI2D:
  2045   case Op_ConvD2I:
  2046   // case Op_ConvL2D: // handled by leaf call
  2047   // case Op_ConvD2L: // handled by leaf call
  2048   case Op_ConD:
  2049   case Op_CmpD:
  2050   case Op_CmpD3:
  2051     frc.inc_double_count();
  2052     break;
  2053   case Op_Opaque1:              // Remove Opaque Nodes before matching
  2054   case Op_Opaque2:              // Remove Opaque Nodes before matching
  2055     n->subsume_by(n->in(1));
  2056     break;
  2057   case Op_CallStaticJava:
  2058   case Op_CallJava:
  2059   case Op_CallDynamicJava:
  2060     frc.inc_java_call_count(); // Count java call site;
  2061   case Op_CallRuntime:
  2062   case Op_CallLeaf:
  2063   case Op_CallLeafNoFP: {
  2064     assert( n->is_Call(), "" );
  2065     CallNode *call = n->as_Call();
  2066     // Count call sites where the FP mode bit would have to be flipped.
  2067     // Do not count uncommon runtime calls:
  2068     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
  2069     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
  2070     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
  2071       frc.inc_call_count();   // Count the call site
  2072     } else {                  // See if uncommon argument is shared
  2073       Node *n = call->in(TypeFunc::Parms);
  2074       int nop = n->Opcode();
  2075       // Clone shared simple arguments to uncommon calls, item (1).
  2076       if( n->outcnt() > 1 &&
  2077           !n->is_Proj() &&
  2078           nop != Op_CreateEx &&
  2079           nop != Op_CheckCastPP &&
  2080           nop != Op_DecodeN &&
  2081           !n->is_Mem() ) {
  2082         Node *x = n->clone();
  2083         call->set_req( TypeFunc::Parms, x );
  2086     break;
  2089   case Op_StoreD:
  2090   case Op_LoadD:
  2091   case Op_LoadD_unaligned:
  2092     frc.inc_double_count();
  2093     goto handle_mem;
  2094   case Op_StoreF:
  2095   case Op_LoadF:
  2096     frc.inc_float_count();
  2097     goto handle_mem;
  2099   case Op_StoreB:
  2100   case Op_StoreC:
  2101   case Op_StoreCM:
  2102   case Op_StorePConditional:
  2103   case Op_StoreI:
  2104   case Op_StoreL:
  2105   case Op_StoreIConditional:
  2106   case Op_StoreLConditional:
  2107   case Op_CompareAndSwapI:
  2108   case Op_CompareAndSwapL:
  2109   case Op_CompareAndSwapP:
  2110   case Op_CompareAndSwapN:
  2111   case Op_StoreP:
  2112   case Op_StoreN:
  2113   case Op_LoadB:
  2114   case Op_LoadUB:
  2115   case Op_LoadUS:
  2116   case Op_LoadI:
  2117   case Op_LoadUI2L:
  2118   case Op_LoadKlass:
  2119   case Op_LoadNKlass:
  2120   case Op_LoadL:
  2121   case Op_LoadL_unaligned:
  2122   case Op_LoadPLocked:
  2123   case Op_LoadLLocked:
  2124   case Op_LoadP:
  2125   case Op_LoadN:
  2126   case Op_LoadRange:
  2127   case Op_LoadS: {
  2128   handle_mem:
  2129 #ifdef ASSERT
  2130     if( VerifyOptoOopOffsets ) {
  2131       assert( n->is_Mem(), "" );
  2132       MemNode *mem  = (MemNode*)n;
  2133       // Check to see if address types have grounded out somehow.
  2134       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
  2135       assert( !tp || oop_offset_is_sane(tp), "" );
  2137 #endif
  2138     break;
  2141   case Op_AddP: {               // Assert sane base pointers
  2142     Node *addp = n->in(AddPNode::Address);
  2143     assert( !addp->is_AddP() ||
  2144             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
  2145             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
  2146             "Base pointers must match" );
  2147 #ifdef _LP64
  2148     if (UseCompressedOops &&
  2149         addp->Opcode() == Op_ConP &&
  2150         addp == n->in(AddPNode::Base) &&
  2151         n->in(AddPNode::Offset)->is_Con()) {
  2152       // Use addressing with narrow klass to load with offset on x86.
  2153       // On sparc loading 32-bits constant and decoding it have less
  2154       // instructions (4) then load 64-bits constant (7).
  2155       // Do this transformation here since IGVN will convert ConN back to ConP.
  2156       const Type* t = addp->bottom_type();
  2157       if (t->isa_oopptr()) {
  2158         Node* nn = NULL;
  2160         // Look for existing ConN node of the same exact type.
  2161         Compile* C = Compile::current();
  2162         Node* r  = C->root();
  2163         uint cnt = r->outcnt();
  2164         for (uint i = 0; i < cnt; i++) {
  2165           Node* m = r->raw_out(i);
  2166           if (m!= NULL && m->Opcode() == Op_ConN &&
  2167               m->bottom_type()->make_ptr() == t) {
  2168             nn = m;
  2169             break;
  2172         if (nn != NULL) {
  2173           // Decode a narrow oop to match address
  2174           // [R12 + narrow_oop_reg<<3 + offset]
  2175           nn = new (C,  2) DecodeNNode(nn, t);
  2176           n->set_req(AddPNode::Base, nn);
  2177           n->set_req(AddPNode::Address, nn);
  2178           if (addp->outcnt() == 0) {
  2179             addp->disconnect_inputs(NULL);
  2184 #endif
  2185     break;
  2188 #ifdef _LP64
  2189   case Op_CastPP:
  2190     if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
  2191       Compile* C = Compile::current();
  2192       Node* in1 = n->in(1);
  2193       const Type* t = n->bottom_type();
  2194       Node* new_in1 = in1->clone();
  2195       new_in1->as_DecodeN()->set_type(t);
  2197       if (!Matcher::narrow_oop_use_complex_address()) {
  2198         //
  2199         // x86, ARM and friends can handle 2 adds in addressing mode
  2200         // and Matcher can fold a DecodeN node into address by using
  2201         // a narrow oop directly and do implicit NULL check in address:
  2202         //
  2203         // [R12 + narrow_oop_reg<<3 + offset]
  2204         // NullCheck narrow_oop_reg
  2205         //
  2206         // On other platforms (Sparc) we have to keep new DecodeN node and
  2207         // use it to do implicit NULL check in address:
  2208         //
  2209         // decode_not_null narrow_oop_reg, base_reg
  2210         // [base_reg + offset]
  2211         // NullCheck base_reg
  2212         //
  2213         // Pin the new DecodeN node to non-null path on these platform (Sparc)
  2214         // to keep the information to which NULL check the new DecodeN node
  2215         // corresponds to use it as value in implicit_null_check().
  2216         //
  2217         new_in1->set_req(0, n->in(0));
  2220       n->subsume_by(new_in1);
  2221       if (in1->outcnt() == 0) {
  2222         in1->disconnect_inputs(NULL);
  2225     break;
  2227   case Op_CmpP:
  2228     // Do this transformation here to preserve CmpPNode::sub() and
  2229     // other TypePtr related Ideal optimizations (for example, ptr nullness).
  2230     if (n->in(1)->is_DecodeN() || n->in(2)->is_DecodeN()) {
  2231       Node* in1 = n->in(1);
  2232       Node* in2 = n->in(2);
  2233       if (!in1->is_DecodeN()) {
  2234         in2 = in1;
  2235         in1 = n->in(2);
  2237       assert(in1->is_DecodeN(), "sanity");
  2239       Compile* C = Compile::current();
  2240       Node* new_in2 = NULL;
  2241       if (in2->is_DecodeN()) {
  2242         new_in2 = in2->in(1);
  2243       } else if (in2->Opcode() == Op_ConP) {
  2244         const Type* t = in2->bottom_type();
  2245         if (t == TypePtr::NULL_PTR) {
  2246           // Don't convert CmpP null check into CmpN if compressed
  2247           // oops implicit null check is not generated.
  2248           // This will allow to generate normal oop implicit null check.
  2249           if (Matcher::gen_narrow_oop_implicit_null_checks())
  2250             new_in2 = ConNode::make(C, TypeNarrowOop::NULL_PTR);
  2251           //
  2252           // This transformation together with CastPP transformation above
  2253           // will generated code for implicit NULL checks for compressed oops.
  2254           //
  2255           // The original code after Optimize()
  2256           //
  2257           //    LoadN memory, narrow_oop_reg
  2258           //    decode narrow_oop_reg, base_reg
  2259           //    CmpP base_reg, NULL
  2260           //    CastPP base_reg // NotNull
  2261           //    Load [base_reg + offset], val_reg
  2262           //
  2263           // after these transformations will be
  2264           //
  2265           //    LoadN memory, narrow_oop_reg
  2266           //    CmpN narrow_oop_reg, NULL
  2267           //    decode_not_null narrow_oop_reg, base_reg
  2268           //    Load [base_reg + offset], val_reg
  2269           //
  2270           // and the uncommon path (== NULL) will use narrow_oop_reg directly
  2271           // since narrow oops can be used in debug info now (see the code in
  2272           // final_graph_reshaping_walk()).
  2273           //
  2274           // At the end the code will be matched to
  2275           // on x86:
  2276           //
  2277           //    Load_narrow_oop memory, narrow_oop_reg
  2278           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
  2279           //    NullCheck narrow_oop_reg
  2280           //
  2281           // and on sparc:
  2282           //
  2283           //    Load_narrow_oop memory, narrow_oop_reg
  2284           //    decode_not_null narrow_oop_reg, base_reg
  2285           //    Load [base_reg + offset], val_reg
  2286           //    NullCheck base_reg
  2287           //
  2288         } else if (t->isa_oopptr()) {
  2289           new_in2 = ConNode::make(C, t->make_narrowoop());
  2292       if (new_in2 != NULL) {
  2293         Node* cmpN = new (C, 3) CmpNNode(in1->in(1), new_in2);
  2294         n->subsume_by( cmpN );
  2295         if (in1->outcnt() == 0) {
  2296           in1->disconnect_inputs(NULL);
  2298         if (in2->outcnt() == 0) {
  2299           in2->disconnect_inputs(NULL);
  2303     break;
  2305   case Op_DecodeN:
  2306     assert(!n->in(1)->is_EncodeP(), "should be optimized out");
  2307     // DecodeN could be pinned when it can't be fold into
  2308     // an address expression, see the code for Op_CastPP above.
  2309     assert(n->in(0) == NULL || !Matcher::narrow_oop_use_complex_address(), "no control");
  2310     break;
  2312   case Op_EncodeP: {
  2313     Node* in1 = n->in(1);
  2314     if (in1->is_DecodeN()) {
  2315       n->subsume_by(in1->in(1));
  2316     } else if (in1->Opcode() == Op_ConP) {
  2317       Compile* C = Compile::current();
  2318       const Type* t = in1->bottom_type();
  2319       if (t == TypePtr::NULL_PTR) {
  2320         n->subsume_by(ConNode::make(C, TypeNarrowOop::NULL_PTR));
  2321       } else if (t->isa_oopptr()) {
  2322         n->subsume_by(ConNode::make(C, t->make_narrowoop()));
  2325     if (in1->outcnt() == 0) {
  2326       in1->disconnect_inputs(NULL);
  2328     break;
  2331   case Op_Proj: {
  2332     if (OptimizeStringConcat) {
  2333       ProjNode* p = n->as_Proj();
  2334       if (p->_is_io_use) {
  2335         // Separate projections were used for the exception path which
  2336         // are normally removed by a late inline.  If it wasn't inlined
  2337         // then they will hang around and should just be replaced with
  2338         // the original one.
  2339         Node* proj = NULL;
  2340         // Replace with just one
  2341         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
  2342           Node *use = i.get();
  2343           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
  2344             proj = use;
  2345             break;
  2348         assert(p != NULL, "must be found");
  2349         p->subsume_by(proj);
  2352     break;
  2355   case Op_Phi:
  2356     if (n->as_Phi()->bottom_type()->isa_narrowoop()) {
  2357       // The EncodeP optimization may create Phi with the same edges
  2358       // for all paths. It is not handled well by Register Allocator.
  2359       Node* unique_in = n->in(1);
  2360       assert(unique_in != NULL, "");
  2361       uint cnt = n->req();
  2362       for (uint i = 2; i < cnt; i++) {
  2363         Node* m = n->in(i);
  2364         assert(m != NULL, "");
  2365         if (unique_in != m)
  2366           unique_in = NULL;
  2368       if (unique_in != NULL) {
  2369         n->subsume_by(unique_in);
  2372     break;
  2374 #endif
  2376   case Op_ModI:
  2377     if (UseDivMod) {
  2378       // Check if a%b and a/b both exist
  2379       Node* d = n->find_similar(Op_DivI);
  2380       if (d) {
  2381         // Replace them with a fused divmod if supported
  2382         Compile* C = Compile::current();
  2383         if (Matcher::has_match_rule(Op_DivModI)) {
  2384           DivModINode* divmod = DivModINode::make(C, n);
  2385           d->subsume_by(divmod->div_proj());
  2386           n->subsume_by(divmod->mod_proj());
  2387         } else {
  2388           // replace a%b with a-((a/b)*b)
  2389           Node* mult = new (C, 3) MulINode(d, d->in(2));
  2390           Node* sub  = new (C, 3) SubINode(d->in(1), mult);
  2391           n->subsume_by( sub );
  2395     break;
  2397   case Op_ModL:
  2398     if (UseDivMod) {
  2399       // Check if a%b and a/b both exist
  2400       Node* d = n->find_similar(Op_DivL);
  2401       if (d) {
  2402         // Replace them with a fused divmod if supported
  2403         Compile* C = Compile::current();
  2404         if (Matcher::has_match_rule(Op_DivModL)) {
  2405           DivModLNode* divmod = DivModLNode::make(C, n);
  2406           d->subsume_by(divmod->div_proj());
  2407           n->subsume_by(divmod->mod_proj());
  2408         } else {
  2409           // replace a%b with a-((a/b)*b)
  2410           Node* mult = new (C, 3) MulLNode(d, d->in(2));
  2411           Node* sub  = new (C, 3) SubLNode(d->in(1), mult);
  2412           n->subsume_by( sub );
  2416     break;
  2418   case Op_Load16B:
  2419   case Op_Load8B:
  2420   case Op_Load4B:
  2421   case Op_Load8S:
  2422   case Op_Load4S:
  2423   case Op_Load2S:
  2424   case Op_Load8C:
  2425   case Op_Load4C:
  2426   case Op_Load2C:
  2427   case Op_Load4I:
  2428   case Op_Load2I:
  2429   case Op_Load2L:
  2430   case Op_Load4F:
  2431   case Op_Load2F:
  2432   case Op_Load2D:
  2433   case Op_Store16B:
  2434   case Op_Store8B:
  2435   case Op_Store4B:
  2436   case Op_Store8C:
  2437   case Op_Store4C:
  2438   case Op_Store2C:
  2439   case Op_Store4I:
  2440   case Op_Store2I:
  2441   case Op_Store2L:
  2442   case Op_Store4F:
  2443   case Op_Store2F:
  2444   case Op_Store2D:
  2445     break;
  2447   case Op_PackB:
  2448   case Op_PackS:
  2449   case Op_PackC:
  2450   case Op_PackI:
  2451   case Op_PackF:
  2452   case Op_PackL:
  2453   case Op_PackD:
  2454     if (n->req()-1 > 2) {
  2455       // Replace many operand PackNodes with a binary tree for matching
  2456       PackNode* p = (PackNode*) n;
  2457       Node* btp = p->binaryTreePack(Compile::current(), 1, n->req());
  2458       n->subsume_by(btp);
  2460     break;
  2461   case Op_Loop:
  2462   case Op_CountedLoop:
  2463     if (n->as_Loop()->is_inner_loop()) {
  2464       frc.inc_inner_loop_count();
  2466     break;
  2467   default:
  2468     assert( !n->is_Call(), "" );
  2469     assert( !n->is_Mem(), "" );
  2470     break;
  2473   // Collect CFG split points
  2474   if (n->is_MultiBranch())
  2475     frc._tests.push(n);
  2478 //------------------------------final_graph_reshaping_walk---------------------
  2479 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
  2480 // requires that the walk visits a node's inputs before visiting the node.
  2481 static void final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
  2482   ResourceArea *area = Thread::current()->resource_area();
  2483   Unique_Node_List sfpt(area);
  2485   frc._visited.set(root->_idx); // first, mark node as visited
  2486   uint cnt = root->req();
  2487   Node *n = root;
  2488   uint  i = 0;
  2489   while (true) {
  2490     if (i < cnt) {
  2491       // Place all non-visited non-null inputs onto stack
  2492       Node* m = n->in(i);
  2493       ++i;
  2494       if (m != NULL && !frc._visited.test_set(m->_idx)) {
  2495         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL)
  2496           sfpt.push(m);
  2497         cnt = m->req();
  2498         nstack.push(n, i); // put on stack parent and next input's index
  2499         n = m;
  2500         i = 0;
  2502     } else {
  2503       // Now do post-visit work
  2504       final_graph_reshaping_impl( n, frc );
  2505       if (nstack.is_empty())
  2506         break;             // finished
  2507       n = nstack.node();   // Get node from stack
  2508       cnt = n->req();
  2509       i = nstack.index();
  2510       nstack.pop();        // Shift to the next node on stack
  2514   // Skip next transformation if compressed oops are not used.
  2515   if (!UseCompressedOops || !Matcher::gen_narrow_oop_implicit_null_checks())
  2516     return;
  2518   // Go over safepoints nodes to skip DecodeN nodes for debug edges.
  2519   // It could be done for an uncommon traps or any safepoints/calls
  2520   // if the DecodeN node is referenced only in a debug info.
  2521   while (sfpt.size() > 0) {
  2522     n = sfpt.pop();
  2523     JVMState *jvms = n->as_SafePoint()->jvms();
  2524     assert(jvms != NULL, "sanity");
  2525     int start = jvms->debug_start();
  2526     int end   = n->req();
  2527     bool is_uncommon = (n->is_CallStaticJava() &&
  2528                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
  2529     for (int j = start; j < end; j++) {
  2530       Node* in = n->in(j);
  2531       if (in->is_DecodeN()) {
  2532         bool safe_to_skip = true;
  2533         if (!is_uncommon ) {
  2534           // Is it safe to skip?
  2535           for (uint i = 0; i < in->outcnt(); i++) {
  2536             Node* u = in->raw_out(i);
  2537             if (!u->is_SafePoint() ||
  2538                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
  2539               safe_to_skip = false;
  2543         if (safe_to_skip) {
  2544           n->set_req(j, in->in(1));
  2546         if (in->outcnt() == 0) {
  2547           in->disconnect_inputs(NULL);
  2554 //------------------------------final_graph_reshaping--------------------------
  2555 // Final Graph Reshaping.
  2556 //
  2557 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
  2558 //     and not commoned up and forced early.  Must come after regular
  2559 //     optimizations to avoid GVN undoing the cloning.  Clone constant
  2560 //     inputs to Loop Phis; these will be split by the allocator anyways.
  2561 //     Remove Opaque nodes.
  2562 // (2) Move last-uses by commutative operations to the left input to encourage
  2563 //     Intel update-in-place two-address operations and better register usage
  2564 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
  2565 //     calls canonicalizing them back.
  2566 // (3) Count the number of double-precision FP ops, single-precision FP ops
  2567 //     and call sites.  On Intel, we can get correct rounding either by
  2568 //     forcing singles to memory (requires extra stores and loads after each
  2569 //     FP bytecode) or we can set a rounding mode bit (requires setting and
  2570 //     clearing the mode bit around call sites).  The mode bit is only used
  2571 //     if the relative frequency of single FP ops to calls is low enough.
  2572 //     This is a key transform for SPEC mpeg_audio.
  2573 // (4) Detect infinite loops; blobs of code reachable from above but not
  2574 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
  2575 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
  2576 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
  2577 //     Detection is by looking for IfNodes where only 1 projection is
  2578 //     reachable from below or CatchNodes missing some targets.
  2579 // (5) Assert for insane oop offsets in debug mode.
  2581 bool Compile::final_graph_reshaping() {
  2582   // an infinite loop may have been eliminated by the optimizer,
  2583   // in which case the graph will be empty.
  2584   if (root()->req() == 1) {
  2585     record_method_not_compilable("trivial infinite loop");
  2586     return true;
  2589   Final_Reshape_Counts frc;
  2591   // Visit everybody reachable!
  2592   // Allocate stack of size C->unique()/2 to avoid frequent realloc
  2593   Node_Stack nstack(unique() >> 1);
  2594   final_graph_reshaping_walk(nstack, root(), frc);
  2596   // Check for unreachable (from below) code (i.e., infinite loops).
  2597   for( uint i = 0; i < frc._tests.size(); i++ ) {
  2598     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
  2599     // Get number of CFG targets.
  2600     // Note that PCTables include exception targets after calls.
  2601     uint required_outcnt = n->required_outcnt();
  2602     if (n->outcnt() != required_outcnt) {
  2603       // Check for a few special cases.  Rethrow Nodes never take the
  2604       // 'fall-thru' path, so expected kids is 1 less.
  2605       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
  2606         if (n->in(0)->in(0)->is_Call()) {
  2607           CallNode *call = n->in(0)->in(0)->as_Call();
  2608           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
  2609             required_outcnt--;      // Rethrow always has 1 less kid
  2610           } else if (call->req() > TypeFunc::Parms &&
  2611                      call->is_CallDynamicJava()) {
  2612             // Check for null receiver. In such case, the optimizer has
  2613             // detected that the virtual call will always result in a null
  2614             // pointer exception. The fall-through projection of this CatchNode
  2615             // will not be populated.
  2616             Node *arg0 = call->in(TypeFunc::Parms);
  2617             if (arg0->is_Type() &&
  2618                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
  2619               required_outcnt--;
  2621           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
  2622                      call->req() > TypeFunc::Parms+1 &&
  2623                      call->is_CallStaticJava()) {
  2624             // Check for negative array length. In such case, the optimizer has
  2625             // detected that the allocation attempt will always result in an
  2626             // exception. There is no fall-through projection of this CatchNode .
  2627             Node *arg1 = call->in(TypeFunc::Parms+1);
  2628             if (arg1->is_Type() &&
  2629                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
  2630               required_outcnt--;
  2635       // Recheck with a better notion of 'required_outcnt'
  2636       if (n->outcnt() != required_outcnt) {
  2637         record_method_not_compilable("malformed control flow");
  2638         return true;            // Not all targets reachable!
  2641     // Check that I actually visited all kids.  Unreached kids
  2642     // must be infinite loops.
  2643     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
  2644       if (!frc._visited.test(n->fast_out(j)->_idx)) {
  2645         record_method_not_compilable("infinite loop");
  2646         return true;            // Found unvisited kid; must be unreach
  2650   // If original bytecodes contained a mixture of floats and doubles
  2651   // check if the optimizer has made it homogenous, item (3).
  2652   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
  2653       frc.get_float_count() > 32 &&
  2654       frc.get_double_count() == 0 &&
  2655       (10 * frc.get_call_count() < frc.get_float_count()) ) {
  2656     set_24_bit_selection_and_mode( false,  true );
  2659   set_java_calls(frc.get_java_call_count());
  2660   set_inner_loops(frc.get_inner_loop_count());
  2662   // No infinite loops, no reason to bail out.
  2663   return false;
  2666 //-----------------------------too_many_traps----------------------------------
  2667 // Report if there are too many traps at the current method and bci.
  2668 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
  2669 bool Compile::too_many_traps(ciMethod* method,
  2670                              int bci,
  2671                              Deoptimization::DeoptReason reason) {
  2672   ciMethodData* md = method->method_data();
  2673   if (md->is_empty()) {
  2674     // Assume the trap has not occurred, or that it occurred only
  2675     // because of a transient condition during start-up in the interpreter.
  2676     return false;
  2678   if (md->has_trap_at(bci, reason) != 0) {
  2679     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
  2680     // Also, if there are multiple reasons, or if there is no per-BCI record,
  2681     // assume the worst.
  2682     if (log())
  2683       log()->elem("observe trap='%s' count='%d'",
  2684                   Deoptimization::trap_reason_name(reason),
  2685                   md->trap_count(reason));
  2686     return true;
  2687   } else {
  2688     // Ignore method/bci and see if there have been too many globally.
  2689     return too_many_traps(reason, md);
  2693 // Less-accurate variant which does not require a method and bci.
  2694 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
  2695                              ciMethodData* logmd) {
  2696  if (trap_count(reason) >= (uint)PerMethodTrapLimit) {
  2697     // Too many traps globally.
  2698     // Note that we use cumulative trap_count, not just md->trap_count.
  2699     if (log()) {
  2700       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
  2701       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
  2702                   Deoptimization::trap_reason_name(reason),
  2703                   mcount, trap_count(reason));
  2705     return true;
  2706   } else {
  2707     // The coast is clear.
  2708     return false;
  2712 //--------------------------too_many_recompiles--------------------------------
  2713 // Report if there are too many recompiles at the current method and bci.
  2714 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
  2715 // Is not eager to return true, since this will cause the compiler to use
  2716 // Action_none for a trap point, to avoid too many recompilations.
  2717 bool Compile::too_many_recompiles(ciMethod* method,
  2718                                   int bci,
  2719                                   Deoptimization::DeoptReason reason) {
  2720   ciMethodData* md = method->method_data();
  2721   if (md->is_empty()) {
  2722     // Assume the trap has not occurred, or that it occurred only
  2723     // because of a transient condition during start-up in the interpreter.
  2724     return false;
  2726   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
  2727   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
  2728   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
  2729   Deoptimization::DeoptReason per_bc_reason
  2730     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
  2731   if ((per_bc_reason == Deoptimization::Reason_none
  2732        || md->has_trap_at(bci, reason) != 0)
  2733       // The trap frequency measure we care about is the recompile count:
  2734       && md->trap_recompiled_at(bci)
  2735       && md->overflow_recompile_count() >= bc_cutoff) {
  2736     // Do not emit a trap here if it has already caused recompilations.
  2737     // Also, if there are multiple reasons, or if there is no per-BCI record,
  2738     // assume the worst.
  2739     if (log())
  2740       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
  2741                   Deoptimization::trap_reason_name(reason),
  2742                   md->trap_count(reason),
  2743                   md->overflow_recompile_count());
  2744     return true;
  2745   } else if (trap_count(reason) != 0
  2746              && decompile_count() >= m_cutoff) {
  2747     // Too many recompiles globally, and we have seen this sort of trap.
  2748     // Use cumulative decompile_count, not just md->decompile_count.
  2749     if (log())
  2750       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
  2751                   Deoptimization::trap_reason_name(reason),
  2752                   md->trap_count(reason), trap_count(reason),
  2753                   md->decompile_count(), decompile_count());
  2754     return true;
  2755   } else {
  2756     // The coast is clear.
  2757     return false;
  2762 #ifndef PRODUCT
  2763 //------------------------------verify_graph_edges---------------------------
  2764 // Walk the Graph and verify that there is a one-to-one correspondence
  2765 // between Use-Def edges and Def-Use edges in the graph.
  2766 void Compile::verify_graph_edges(bool no_dead_code) {
  2767   if (VerifyGraphEdges) {
  2768     ResourceArea *area = Thread::current()->resource_area();
  2769     Unique_Node_List visited(area);
  2770     // Call recursive graph walk to check edges
  2771     _root->verify_edges(visited);
  2772     if (no_dead_code) {
  2773       // Now make sure that no visited node is used by an unvisited node.
  2774       bool dead_nodes = 0;
  2775       Unique_Node_List checked(area);
  2776       while (visited.size() > 0) {
  2777         Node* n = visited.pop();
  2778         checked.push(n);
  2779         for (uint i = 0; i < n->outcnt(); i++) {
  2780           Node* use = n->raw_out(i);
  2781           if (checked.member(use))  continue;  // already checked
  2782           if (visited.member(use))  continue;  // already in the graph
  2783           if (use->is_Con())        continue;  // a dead ConNode is OK
  2784           // At this point, we have found a dead node which is DU-reachable.
  2785           if (dead_nodes++ == 0)
  2786             tty->print_cr("*** Dead nodes reachable via DU edges:");
  2787           use->dump(2);
  2788           tty->print_cr("---");
  2789           checked.push(use);  // No repeats; pretend it is now checked.
  2792       assert(dead_nodes == 0, "using nodes must be reachable from root");
  2796 #endif
  2798 // The Compile object keeps track of failure reasons separately from the ciEnv.
  2799 // This is required because there is not quite a 1-1 relation between the
  2800 // ciEnv and its compilation task and the Compile object.  Note that one
  2801 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
  2802 // to backtrack and retry without subsuming loads.  Other than this backtracking
  2803 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
  2804 // by the logic in C2Compiler.
  2805 void Compile::record_failure(const char* reason) {
  2806   if (log() != NULL) {
  2807     log()->elem("failure reason='%s' phase='compile'", reason);
  2809   if (_failure_reason == NULL) {
  2810     // Record the first failure reason.
  2811     _failure_reason = reason;
  2813   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
  2814     C->print_method(_failure_reason);
  2816   _root = NULL;  // flush the graph, too
  2819 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
  2820   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false)
  2822   if (dolog) {
  2823     C = Compile::current();
  2824     _log = C->log();
  2825   } else {
  2826     C = NULL;
  2827     _log = NULL;
  2829   if (_log != NULL) {
  2830     _log->begin_head("phase name='%s' nodes='%d'", name, C->unique());
  2831     _log->stamp();
  2832     _log->end_head();
  2836 Compile::TracePhase::~TracePhase() {
  2837   if (_log != NULL) {
  2838     _log->done("phase nodes='%d'", C->unique());

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