src/share/vm/opto/compile.cpp

Thu, 12 Nov 2009 09:24:21 -0800

author
never
date
Thu, 12 Nov 2009 09:24:21 -0800
changeset 1515
7c57aead6d3e
parent 1364
cd18bd5e667c
child 1535
f96a1a986f7b
permissions
-rw-r--r--

6892658: C2 should optimize some stringbuilder patterns
Reviewed-by: kvn, twisti

     1 /*
     2  * Copyright 1997-2009 Sun Microsystems, Inc.  All Rights Reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 #include "incls/_precompiled.incl"
    26 #include "incls/_compile.cpp.incl"
    28 /// Support for intrinsics.
    30 // Return the index at which m must be inserted (or already exists).
    31 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
    32 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
    33 #ifdef ASSERT
    34   for (int i = 1; i < _intrinsics->length(); i++) {
    35     CallGenerator* cg1 = _intrinsics->at(i-1);
    36     CallGenerator* cg2 = _intrinsics->at(i);
    37     assert(cg1->method() != cg2->method()
    38            ? cg1->method()     < cg2->method()
    39            : cg1->is_virtual() < cg2->is_virtual(),
    40            "compiler intrinsics list must stay sorted");
    41   }
    42 #endif
    43   // Binary search sorted list, in decreasing intervals [lo, hi].
    44   int lo = 0, hi = _intrinsics->length()-1;
    45   while (lo <= hi) {
    46     int mid = (uint)(hi + lo) / 2;
    47     ciMethod* mid_m = _intrinsics->at(mid)->method();
    48     if (m < mid_m) {
    49       hi = mid-1;
    50     } else if (m > mid_m) {
    51       lo = mid+1;
    52     } else {
    53       // look at minor sort key
    54       bool mid_virt = _intrinsics->at(mid)->is_virtual();
    55       if (is_virtual < mid_virt) {
    56         hi = mid-1;
    57       } else if (is_virtual > mid_virt) {
    58         lo = mid+1;
    59       } else {
    60         return mid;  // exact match
    61       }
    62     }
    63   }
    64   return lo;  // inexact match
    65 }
    67 void Compile::register_intrinsic(CallGenerator* cg) {
    68   if (_intrinsics == NULL) {
    69     _intrinsics = new GrowableArray<CallGenerator*>(60);
    70   }
    71   // This code is stolen from ciObjectFactory::insert.
    72   // Really, GrowableArray should have methods for
    73   // insert_at, remove_at, and binary_search.
    74   int len = _intrinsics->length();
    75   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
    76   if (index == len) {
    77     _intrinsics->append(cg);
    78   } else {
    79 #ifdef ASSERT
    80     CallGenerator* oldcg = _intrinsics->at(index);
    81     assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
    82 #endif
    83     _intrinsics->append(_intrinsics->at(len-1));
    84     int pos;
    85     for (pos = len-2; pos >= index; pos--) {
    86       _intrinsics->at_put(pos+1,_intrinsics->at(pos));
    87     }
    88     _intrinsics->at_put(index, cg);
    89   }
    90   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
    91 }
    93 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
    94   assert(m->is_loaded(), "don't try this on unloaded methods");
    95   if (_intrinsics != NULL) {
    96     int index = intrinsic_insertion_index(m, is_virtual);
    97     if (index < _intrinsics->length()
    98         && _intrinsics->at(index)->method() == m
    99         && _intrinsics->at(index)->is_virtual() == is_virtual) {
   100       return _intrinsics->at(index);
   101     }
   102   }
   103   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
   104   if (m->intrinsic_id() != vmIntrinsics::_none &&
   105       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                   _node_bundling_limit(0),
   469                   _node_bundling_base(NULL),
   470                   _java_calls(0),
   471                   _inner_loops(0),
   472 #ifndef PRODUCT
   473                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
   474                   _printer(IdealGraphPrinter::printer()),
   475 #endif
   476                   _congraph(NULL) {
   477   C = this;
   479   CompileWrapper cw(this);
   480 #ifndef PRODUCT
   481   if (TimeCompiler2) {
   482     tty->print(" ");
   483     target->holder()->name()->print();
   484     tty->print(".");
   485     target->print_short_name();
   486     tty->print("  ");
   487   }
   488   TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
   489   TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
   490   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
   491   if (!print_opto_assembly) {
   492     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
   493     if (print_assembly && !Disassembler::can_decode()) {
   494       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
   495       print_opto_assembly = true;
   496     }
   497   }
   498   set_print_assembly(print_opto_assembly);
   499   set_parsed_irreducible_loop(false);
   500 #endif
   502   if (ProfileTraps) {
   503     // Make sure the method being compiled gets its own MDO,
   504     // so we can at least track the decompile_count().
   505     method()->build_method_data();
   506   }
   508   Init(::AliasLevel);
   511   print_compile_messages();
   513   if (UseOldInlining || PrintCompilation NOT_PRODUCT( || PrintOpto) )
   514     _ilt = InlineTree::build_inline_tree_root();
   515   else
   516     _ilt = NULL;
   518   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
   519   assert(num_alias_types() >= AliasIdxRaw, "");
   521 #define MINIMUM_NODE_HASH  1023
   522   // Node list that Iterative GVN will start with
   523   Unique_Node_List for_igvn(comp_arena());
   524   set_for_igvn(&for_igvn);
   526   // GVN that will be run immediately on new nodes
   527   uint estimated_size = method()->code_size()*4+64;
   528   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
   529   PhaseGVN gvn(node_arena(), estimated_size);
   530   set_initial_gvn(&gvn);
   532   { // Scope for timing the parser
   533     TracePhase t3("parse", &_t_parser, true);
   535     // Put top into the hash table ASAP.
   536     initial_gvn()->transform_no_reclaim(top());
   538     // Set up tf(), start(), and find a CallGenerator.
   539     CallGenerator* cg;
   540     if (is_osr_compilation()) {
   541       const TypeTuple *domain = StartOSRNode::osr_domain();
   542       const TypeTuple *range = TypeTuple::make_range(method()->signature());
   543       init_tf(TypeFunc::make(domain, range));
   544       StartNode* s = new (this, 2) StartOSRNode(root(), domain);
   545       initial_gvn()->set_type_bottom(s);
   546       init_start(s);
   547       cg = CallGenerator::for_osr(method(), entry_bci());
   548     } else {
   549       // Normal case.
   550       init_tf(TypeFunc::make(method()));
   551       StartNode* s = new (this, 2) StartNode(root(), tf()->domain());
   552       initial_gvn()->set_type_bottom(s);
   553       init_start(s);
   554       float past_uses = method()->interpreter_invocation_count();
   555       float expected_uses = past_uses;
   556       cg = CallGenerator::for_inline(method(), expected_uses);
   557     }
   558     if (failing())  return;
   559     if (cg == NULL) {
   560       record_method_not_compilable_all_tiers("cannot parse method");
   561       return;
   562     }
   563     JVMState* jvms = build_start_state(start(), tf());
   564     if ((jvms = cg->generate(jvms)) == NULL) {
   565       record_method_not_compilable("method parse failed");
   566       return;
   567     }
   568     GraphKit kit(jvms);
   570     if (!kit.stopped()) {
   571       // Accept return values, and transfer control we know not where.
   572       // This is done by a special, unique ReturnNode bound to root.
   573       return_values(kit.jvms());
   574     }
   576     if (kit.has_exceptions()) {
   577       // Any exceptions that escape from this call must be rethrown
   578       // to whatever caller is dynamically above us on the stack.
   579       // This is done by a special, unique RethrowNode bound to root.
   580       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
   581     }
   583     if (!failing() && has_stringbuilder()) {
   584       {
   585         // remove useless nodes to make the usage analysis simpler
   586         ResourceMark rm;
   587         PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
   588       }
   590       {
   591         ResourceMark rm;
   592         print_method("Before StringOpts", 3);
   593         PhaseStringOpts pso(initial_gvn(), &for_igvn);
   594         print_method("After StringOpts", 3);
   595       }
   597       // now inline anything that we skipped the first time around
   598       while (_late_inlines.length() > 0) {
   599         CallGenerator* cg = _late_inlines.pop();
   600         cg->do_late_inline();
   601       }
   602     }
   603     assert(_late_inlines.length() == 0, "should have been processed");
   605     print_method("Before RemoveUseless", 3);
   607     // Remove clutter produced by parsing.
   608     if (!failing()) {
   609       ResourceMark rm;
   610       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
   611     }
   612   }
   614   // Note:  Large methods are capped off in do_one_bytecode().
   615   if (failing())  return;
   617   // After parsing, node notes are no longer automagic.
   618   // They must be propagated by register_new_node_with_optimizer(),
   619   // clone(), or the like.
   620   set_default_node_notes(NULL);
   622   for (;;) {
   623     int successes = Inline_Warm();
   624     if (failing())  return;
   625     if (successes == 0)  break;
   626   }
   628   // Drain the list.
   629   Finish_Warm();
   630 #ifndef PRODUCT
   631   if (_printer) {
   632     _printer->print_inlining(this);
   633   }
   634 #endif
   636   if (failing())  return;
   637   NOT_PRODUCT( verify_graph_edges(); )
   639   // Perform escape analysis
   640   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
   641     TracePhase t2("escapeAnalysis", &_t_escapeAnalysis, true);
   642     // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction.
   643     PhaseGVN* igvn = initial_gvn();
   644     Node* oop_null = igvn->zerocon(T_OBJECT);
   645     Node* noop_null = igvn->zerocon(T_NARROWOOP);
   647     _congraph = new(comp_arena()) ConnectionGraph(this);
   648     bool has_non_escaping_obj = _congraph->compute_escape();
   650 #ifndef PRODUCT
   651     if (PrintEscapeAnalysis) {
   652       _congraph->dump();
   653     }
   654 #endif
   655     // Cleanup.
   656     if (oop_null->outcnt() == 0)
   657       igvn->hash_delete(oop_null);
   658     if (noop_null->outcnt() == 0)
   659       igvn->hash_delete(noop_null);
   661     if (!has_non_escaping_obj) {
   662       _congraph = NULL;
   663     }
   665     if (failing())  return;
   666   }
   667   // Now optimize
   668   Optimize();
   669   if (failing())  return;
   670   NOT_PRODUCT( verify_graph_edges(); )
   672 #ifndef PRODUCT
   673   if (PrintIdeal) {
   674     ttyLocker ttyl;  // keep the following output all in one block
   675     // This output goes directly to the tty, not the compiler log.
   676     // To enable tools to match it up with the compilation activity,
   677     // be sure to tag this tty output with the compile ID.
   678     if (xtty != NULL) {
   679       xtty->head("ideal compile_id='%d'%s", compile_id(),
   680                  is_osr_compilation()    ? " compile_kind='osr'" :
   681                  "");
   682     }
   683     root()->dump(9999);
   684     if (xtty != NULL) {
   685       xtty->tail("ideal");
   686     }
   687   }
   688 #endif
   690   // Now that we know the size of all the monitors we can add a fixed slot
   691   // for the original deopt pc.
   693   _orig_pc_slot =  fixed_slots();
   694   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
   695   set_fixed_slots(next_slot);
   697   // Now generate code
   698   Code_Gen();
   699   if (failing())  return;
   701   // Check if we want to skip execution of all compiled code.
   702   {
   703 #ifndef PRODUCT
   704     if (OptoNoExecute) {
   705       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
   706       return;
   707     }
   708     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
   709 #endif
   711     if (is_osr_compilation()) {
   712       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
   713       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
   714     } else {
   715       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
   716       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
   717     }
   719     env()->register_method(_method, _entry_bci,
   720                            &_code_offsets,
   721                            _orig_pc_slot_offset_in_bytes,
   722                            code_buffer(),
   723                            frame_size_in_words(), _oop_map_set,
   724                            &_handler_table, &_inc_table,
   725                            compiler,
   726                            env()->comp_level(),
   727                            true, /*has_debug_info*/
   728                            has_unsafe_access()
   729                            );
   730   }
   731 }
   733 //------------------------------Compile----------------------------------------
   734 // Compile a runtime stub
   735 Compile::Compile( ciEnv* ci_env,
   736                   TypeFunc_generator generator,
   737                   address stub_function,
   738                   const char *stub_name,
   739                   int is_fancy_jump,
   740                   bool pass_tls,
   741                   bool save_arg_registers,
   742                   bool return_pc )
   743   : Phase(Compiler),
   744     _env(ci_env),
   745     _log(ci_env->log()),
   746     _compile_id(-1),
   747     _save_argument_registers(save_arg_registers),
   748     _method(NULL),
   749     _stub_name(stub_name),
   750     _stub_function(stub_function),
   751     _stub_entry_point(NULL),
   752     _entry_bci(InvocationEntryBci),
   753     _initial_gvn(NULL),
   754     _for_igvn(NULL),
   755     _warm_calls(NULL),
   756     _orig_pc_slot(0),
   757     _orig_pc_slot_offset_in_bytes(0),
   758     _subsume_loads(true),
   759     _do_escape_analysis(false),
   760     _failure_reason(NULL),
   761     _code_buffer("Compile::Fill_buffer"),
   762     _node_bundling_limit(0),
   763     _node_bundling_base(NULL),
   764     _java_calls(0),
   765     _inner_loops(0),
   766 #ifndef PRODUCT
   767     _trace_opto_output(TraceOptoOutput),
   768     _printer(NULL),
   769 #endif
   770     _congraph(NULL) {
   771   C = this;
   773 #ifndef PRODUCT
   774   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
   775   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
   776   set_print_assembly(PrintFrameConverterAssembly);
   777   set_parsed_irreducible_loop(false);
   778 #endif
   779   CompileWrapper cw(this);
   780   Init(/*AliasLevel=*/ 0);
   781   init_tf((*generator)());
   783   {
   784     // The following is a dummy for the sake of GraphKit::gen_stub
   785     Unique_Node_List for_igvn(comp_arena());
   786     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
   787     PhaseGVN gvn(Thread::current()->resource_area(),255);
   788     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
   789     gvn.transform_no_reclaim(top());
   791     GraphKit kit;
   792     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
   793   }
   795   NOT_PRODUCT( verify_graph_edges(); )
   796   Code_Gen();
   797   if (failing())  return;
   800   // Entry point will be accessed using compile->stub_entry_point();
   801   if (code_buffer() == NULL) {
   802     Matcher::soft_match_failure();
   803   } else {
   804     if (PrintAssembly && (WizardMode || Verbose))
   805       tty->print_cr("### Stub::%s", stub_name);
   807     if (!failing()) {
   808       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
   810       // Make the NMethod
   811       // For now we mark the frame as never safe for profile stackwalking
   812       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
   813                                                       code_buffer(),
   814                                                       CodeOffsets::frame_never_safe,
   815                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
   816                                                       frame_size_in_words(),
   817                                                       _oop_map_set,
   818                                                       save_arg_registers);
   819       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
   821       _stub_entry_point = rs->entry_point();
   822     }
   823   }
   824 }
   826 #ifndef PRODUCT
   827 void print_opto_verbose_signature( const TypeFunc *j_sig, const char *stub_name ) {
   828   if(PrintOpto && Verbose) {
   829     tty->print("%s   ", stub_name); j_sig->print_flattened(); tty->cr();
   830   }
   831 }
   832 #endif
   834 void Compile::print_codes() {
   835 }
   837 //------------------------------Init-------------------------------------------
   838 // Prepare for a single compilation
   839 void Compile::Init(int aliaslevel) {
   840   _unique  = 0;
   841   _regalloc = NULL;
   843   _tf      = NULL;  // filled in later
   844   _top     = NULL;  // cached later
   845   _matcher = NULL;  // filled in later
   846   _cfg     = NULL;  // filled in later
   848   set_24_bit_selection_and_mode(Use24BitFP, false);
   850   _node_note_array = NULL;
   851   _default_node_notes = NULL;
   853   _immutable_memory = NULL; // filled in at first inquiry
   855   // Globally visible Nodes
   856   // First set TOP to NULL to give safe behavior during creation of RootNode
   857   set_cached_top_node(NULL);
   858   set_root(new (this, 3) RootNode());
   859   // Now that you have a Root to point to, create the real TOP
   860   set_cached_top_node( new (this, 1) ConNode(Type::TOP) );
   861   set_recent_alloc(NULL, NULL);
   863   // Create Debug Information Recorder to record scopes, oopmaps, etc.
   864   env()->set_oop_recorder(new OopRecorder(comp_arena()));
   865   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
   866   env()->set_dependencies(new Dependencies(env()));
   868   _fixed_slots = 0;
   869   set_has_split_ifs(false);
   870   set_has_loops(has_method() && method()->has_loops()); // first approximation
   871   set_has_stringbuilder(false);
   872   _deopt_happens = true;  // start out assuming the worst
   873   _trap_can_recompile = false;  // no traps emitted yet
   874   _major_progress = true; // start out assuming good things will happen
   875   set_has_unsafe_access(false);
   876   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
   877   set_decompile_count(0);
   879   set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
   880   // Compilation level related initialization
   881   if (env()->comp_level() == CompLevel_fast_compile) {
   882     set_num_loop_opts(Tier1LoopOptsCount);
   883     set_do_inlining(Tier1Inline != 0);
   884     set_max_inline_size(Tier1MaxInlineSize);
   885     set_freq_inline_size(Tier1FreqInlineSize);
   886     set_do_scheduling(false);
   887     set_do_count_invocations(Tier1CountInvocations);
   888     set_do_method_data_update(Tier1UpdateMethodData);
   889   } else {
   890     assert(env()->comp_level() == CompLevel_full_optimization, "unknown comp level");
   891     set_num_loop_opts(LoopOptsCount);
   892     set_do_inlining(Inline);
   893     set_max_inline_size(MaxInlineSize);
   894     set_freq_inline_size(FreqInlineSize);
   895     set_do_scheduling(OptoScheduling);
   896     set_do_count_invocations(false);
   897     set_do_method_data_update(false);
   898   }
   900   if (debug_info()->recording_non_safepoints()) {
   901     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
   902                         (comp_arena(), 8, 0, NULL));
   903     set_default_node_notes(Node_Notes::make(this));
   904   }
   906   // // -- Initialize types before each compile --
   907   // // Update cached type information
   908   // if( _method && _method->constants() )
   909   //   Type::update_loaded_types(_method, _method->constants());
   911   // Init alias_type map.
   912   if (!_do_escape_analysis && aliaslevel == 3)
   913     aliaslevel = 2;  // No unique types without escape analysis
   914   _AliasLevel = aliaslevel;
   915   const int grow_ats = 16;
   916   _max_alias_types = grow_ats;
   917   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
   918   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
   919   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
   920   {
   921     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
   922   }
   923   // Initialize the first few types.
   924   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
   925   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
   926   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
   927   _num_alias_types = AliasIdxRaw+1;
   928   // Zero out the alias type cache.
   929   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
   930   // A NULL adr_type hits in the cache right away.  Preload the right answer.
   931   probe_alias_cache(NULL)->_index = AliasIdxTop;
   933   _intrinsics = NULL;
   934   _macro_nodes = new GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
   935   register_library_intrinsics();
   936 }
   938 //---------------------------init_start----------------------------------------
   939 // Install the StartNode on this compile object.
   940 void Compile::init_start(StartNode* s) {
   941   if (failing())
   942     return; // already failing
   943   assert(s == start(), "");
   944 }
   946 StartNode* Compile::start() const {
   947   assert(!failing(), "");
   948   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
   949     Node* start = root()->fast_out(i);
   950     if( start->is_Start() )
   951       return start->as_Start();
   952   }
   953   ShouldNotReachHere();
   954   return NULL;
   955 }
   957 //-------------------------------immutable_memory-------------------------------------
   958 // Access immutable memory
   959 Node* Compile::immutable_memory() {
   960   if (_immutable_memory != NULL) {
   961     return _immutable_memory;
   962   }
   963   StartNode* s = start();
   964   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
   965     Node *p = s->fast_out(i);
   966     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
   967       _immutable_memory = p;
   968       return _immutable_memory;
   969     }
   970   }
   971   ShouldNotReachHere();
   972   return NULL;
   973 }
   975 //----------------------set_cached_top_node------------------------------------
   976 // Install the cached top node, and make sure Node::is_top works correctly.
   977 void Compile::set_cached_top_node(Node* tn) {
   978   if (tn != NULL)  verify_top(tn);
   979   Node* old_top = _top;
   980   _top = tn;
   981   // Calling Node::setup_is_top allows the nodes the chance to adjust
   982   // their _out arrays.
   983   if (_top != NULL)     _top->setup_is_top();
   984   if (old_top != NULL)  old_top->setup_is_top();
   985   assert(_top == NULL || top()->is_top(), "");
   986 }
   988 #ifndef PRODUCT
   989 void Compile::verify_top(Node* tn) const {
   990   if (tn != NULL) {
   991     assert(tn->is_Con(), "top node must be a constant");
   992     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
   993     assert(tn->in(0) != NULL, "must have live top node");
   994   }
   995 }
   996 #endif
   999 ///-------------------Managing Per-Node Debug & Profile Info-------------------
  1001 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
  1002   guarantee(arr != NULL, "");
  1003   int num_blocks = arr->length();
  1004   if (grow_by < num_blocks)  grow_by = num_blocks;
  1005   int num_notes = grow_by * _node_notes_block_size;
  1006   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
  1007   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
  1008   while (num_notes > 0) {
  1009     arr->append(notes);
  1010     notes     += _node_notes_block_size;
  1011     num_notes -= _node_notes_block_size;
  1013   assert(num_notes == 0, "exact multiple, please");
  1016 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
  1017   if (source == NULL || dest == NULL)  return false;
  1019   if (dest->is_Con())
  1020     return false;               // Do not push debug info onto constants.
  1022 #ifdef ASSERT
  1023   // Leave a bread crumb trail pointing to the original node:
  1024   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
  1025     dest->set_debug_orig(source);
  1027 #endif
  1029   if (node_note_array() == NULL)
  1030     return false;               // Not collecting any notes now.
  1032   // This is a copy onto a pre-existing node, which may already have notes.
  1033   // If both nodes have notes, do not overwrite any pre-existing notes.
  1034   Node_Notes* source_notes = node_notes_at(source->_idx);
  1035   if (source_notes == NULL || source_notes->is_clear())  return false;
  1036   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
  1037   if (dest_notes == NULL || dest_notes->is_clear()) {
  1038     return set_node_notes_at(dest->_idx, source_notes);
  1041   Node_Notes merged_notes = (*source_notes);
  1042   // The order of operations here ensures that dest notes will win...
  1043   merged_notes.update_from(dest_notes);
  1044   return set_node_notes_at(dest->_idx, &merged_notes);
  1048 //--------------------------allow_range_check_smearing-------------------------
  1049 // Gating condition for coalescing similar range checks.
  1050 // Sometimes we try 'speculatively' replacing a series of a range checks by a
  1051 // single covering check that is at least as strong as any of them.
  1052 // If the optimization succeeds, the simplified (strengthened) range check
  1053 // will always succeed.  If it fails, we will deopt, and then give up
  1054 // on the optimization.
  1055 bool Compile::allow_range_check_smearing() const {
  1056   // If this method has already thrown a range-check,
  1057   // assume it was because we already tried range smearing
  1058   // and it failed.
  1059   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
  1060   return !already_trapped;
  1064 //------------------------------flatten_alias_type-----------------------------
  1065 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
  1066   int offset = tj->offset();
  1067   TypePtr::PTR ptr = tj->ptr();
  1069   // Known instance (scalarizable allocation) alias only with itself.
  1070   bool is_known_inst = tj->isa_oopptr() != NULL &&
  1071                        tj->is_oopptr()->is_known_instance();
  1073   // Process weird unsafe references.
  1074   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
  1075     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
  1076     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
  1077     tj = TypeOopPtr::BOTTOM;
  1078     ptr = tj->ptr();
  1079     offset = tj->offset();
  1082   // Array pointers need some flattening
  1083   const TypeAryPtr *ta = tj->isa_aryptr();
  1084   if( ta && is_known_inst ) {
  1085     if ( offset != Type::OffsetBot &&
  1086          offset > arrayOopDesc::length_offset_in_bytes() ) {
  1087       offset = Type::OffsetBot; // Flatten constant access into array body only
  1088       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
  1090   } else if( ta && _AliasLevel >= 2 ) {
  1091     // For arrays indexed by constant indices, we flatten the alias
  1092     // space to include all of the array body.  Only the header, klass
  1093     // and array length can be accessed un-aliased.
  1094     if( offset != Type::OffsetBot ) {
  1095       if( ta->const_oop() ) { // methodDataOop or methodOop
  1096         offset = Type::OffsetBot;   // Flatten constant access into array body
  1097         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
  1098       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
  1099         // range is OK as-is.
  1100         tj = ta = TypeAryPtr::RANGE;
  1101       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
  1102         tj = TypeInstPtr::KLASS; // all klass loads look alike
  1103         ta = TypeAryPtr::RANGE; // generic ignored junk
  1104         ptr = TypePtr::BotPTR;
  1105       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
  1106         tj = TypeInstPtr::MARK;
  1107         ta = TypeAryPtr::RANGE; // generic ignored junk
  1108         ptr = TypePtr::BotPTR;
  1109       } else {                  // Random constant offset into array body
  1110         offset = Type::OffsetBot;   // Flatten constant access into array body
  1111         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
  1114     // Arrays of fixed size alias with arrays of unknown size.
  1115     if (ta->size() != TypeInt::POS) {
  1116       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
  1117       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
  1119     // Arrays of known objects become arrays of unknown objects.
  1120     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
  1121       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
  1122       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
  1124     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
  1125       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
  1126       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
  1128     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
  1129     // cannot be distinguished by bytecode alone.
  1130     if (ta->elem() == TypeInt::BOOL) {
  1131       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
  1132       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
  1133       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
  1135     // During the 2nd round of IterGVN, NotNull castings are removed.
  1136     // Make sure the Bottom and NotNull variants alias the same.
  1137     // Also, make sure exact and non-exact variants alias the same.
  1138     if( ptr == TypePtr::NotNull || ta->klass_is_exact() ) {
  1139       if (ta->const_oop()) {
  1140         tj = ta = TypeAryPtr::make(TypePtr::Constant,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
  1141       } else {
  1142         tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
  1147   // Oop pointers need some flattening
  1148   const TypeInstPtr *to = tj->isa_instptr();
  1149   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
  1150     if( ptr == TypePtr::Constant ) {
  1151       // No constant oop pointers (such as Strings); they alias with
  1152       // unknown strings.
  1153       assert(!is_known_inst, "not scalarizable allocation");
  1154       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1155     } else if( is_known_inst ) {
  1156       tj = to; // Keep NotNull and klass_is_exact for instance type
  1157     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
  1158       // During the 2nd round of IterGVN, NotNull castings are removed.
  1159       // Make sure the Bottom and NotNull variants alias the same.
  1160       // Also, make sure exact and non-exact variants alias the same.
  1161       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1163     // Canonicalize the holder of this field
  1164     ciInstanceKlass *k = to->klass()->as_instance_klass();
  1165     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
  1166       // First handle header references such as a LoadKlassNode, even if the
  1167       // object's klass is unloaded at compile time (4965979).
  1168       if (!is_known_inst) { // Do it only for non-instance types
  1169         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
  1171     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
  1172       to = NULL;
  1173       tj = TypeOopPtr::BOTTOM;
  1174       offset = tj->offset();
  1175     } else {
  1176       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
  1177       if (!k->equals(canonical_holder) || tj->offset() != offset) {
  1178         if( is_known_inst ) {
  1179           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
  1180         } else {
  1181           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
  1187   // Klass pointers to object array klasses need some flattening
  1188   const TypeKlassPtr *tk = tj->isa_klassptr();
  1189   if( tk ) {
  1190     // If we are referencing a field within a Klass, we need
  1191     // to assume the worst case of an Object.  Both exact and
  1192     // inexact types must flatten to the same alias class.
  1193     // Since the flattened result for a klass is defined to be
  1194     // precisely java.lang.Object, use a constant ptr.
  1195     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
  1197       tj = tk = TypeKlassPtr::make(TypePtr::Constant,
  1198                                    TypeKlassPtr::OBJECT->klass(),
  1199                                    offset);
  1202     ciKlass* klass = tk->klass();
  1203     if( klass->is_obj_array_klass() ) {
  1204       ciKlass* k = TypeAryPtr::OOPS->klass();
  1205       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
  1206         k = TypeInstPtr::BOTTOM->klass();
  1207       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
  1210     // Check for precise loads from the primary supertype array and force them
  1211     // to the supertype cache alias index.  Check for generic array loads from
  1212     // the primary supertype array and also force them to the supertype cache
  1213     // alias index.  Since the same load can reach both, we need to merge
  1214     // these 2 disparate memories into the same alias class.  Since the
  1215     // primary supertype array is read-only, there's no chance of confusion
  1216     // where we bypass an array load and an array store.
  1217     uint off2 = offset - Klass::primary_supers_offset_in_bytes();
  1218     if( offset == Type::OffsetBot ||
  1219         off2 < Klass::primary_super_limit()*wordSize ) {
  1220       offset = sizeof(oopDesc) +Klass::secondary_super_cache_offset_in_bytes();
  1221       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
  1225   // Flatten all Raw pointers together.
  1226   if (tj->base() == Type::RawPtr)
  1227     tj = TypeRawPtr::BOTTOM;
  1229   if (tj->base() == Type::AnyPtr)
  1230     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
  1232   // Flatten all to bottom for now
  1233   switch( _AliasLevel ) {
  1234   case 0:
  1235     tj = TypePtr::BOTTOM;
  1236     break;
  1237   case 1:                       // Flatten to: oop, static, field or array
  1238     switch (tj->base()) {
  1239     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
  1240     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
  1241     case Type::AryPtr:   // do not distinguish arrays at all
  1242     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
  1243     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
  1244     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
  1245     default: ShouldNotReachHere();
  1247     break;
  1248   case 2:                       // No collapsing at level 2; keep all splits
  1249   case 3:                       // No collapsing at level 3; keep all splits
  1250     break;
  1251   default:
  1252     Unimplemented();
  1255   offset = tj->offset();
  1256   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
  1258   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
  1259           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
  1260           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
  1261           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
  1262           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1263           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1264           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
  1265           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
  1266   assert( tj->ptr() != TypePtr::TopPTR &&
  1267           tj->ptr() != TypePtr::AnyNull &&
  1268           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
  1269 //    assert( tj->ptr() != TypePtr::Constant ||
  1270 //            tj->base() == Type::RawPtr ||
  1271 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
  1273   return tj;
  1276 void Compile::AliasType::Init(int i, const TypePtr* at) {
  1277   _index = i;
  1278   _adr_type = at;
  1279   _field = NULL;
  1280   _is_rewritable = true; // default
  1281   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
  1282   if (atoop != NULL && atoop->is_known_instance()) {
  1283     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
  1284     _general_index = Compile::current()->get_alias_index(gt);
  1285   } else {
  1286     _general_index = 0;
  1290 //---------------------------------print_on------------------------------------
  1291 #ifndef PRODUCT
  1292 void Compile::AliasType::print_on(outputStream* st) {
  1293   if (index() < 10)
  1294         st->print("@ <%d> ", index());
  1295   else  st->print("@ <%d>",  index());
  1296   st->print(is_rewritable() ? "   " : " RO");
  1297   int offset = adr_type()->offset();
  1298   if (offset == Type::OffsetBot)
  1299         st->print(" +any");
  1300   else  st->print(" +%-3d", offset);
  1301   st->print(" in ");
  1302   adr_type()->dump_on(st);
  1303   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
  1304   if (field() != NULL && tjp) {
  1305     if (tjp->klass()  != field()->holder() ||
  1306         tjp->offset() != field()->offset_in_bytes()) {
  1307       st->print(" != ");
  1308       field()->print();
  1309       st->print(" ***");
  1314 void print_alias_types() {
  1315   Compile* C = Compile::current();
  1316   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
  1317   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
  1318     C->alias_type(idx)->print_on(tty);
  1319     tty->cr();
  1322 #endif
  1325 //----------------------------probe_alias_cache--------------------------------
  1326 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
  1327   intptr_t key = (intptr_t) adr_type;
  1328   key ^= key >> logAliasCacheSize;
  1329   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
  1333 //-----------------------------grow_alias_types--------------------------------
  1334 void Compile::grow_alias_types() {
  1335   const int old_ats  = _max_alias_types; // how many before?
  1336   const int new_ats  = old_ats;          // how many more?
  1337   const int grow_ats = old_ats+new_ats;  // how many now?
  1338   _max_alias_types = grow_ats;
  1339   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
  1340   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
  1341   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
  1342   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
  1346 //--------------------------------find_alias_type------------------------------
  1347 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create) {
  1348   if (_AliasLevel == 0)
  1349     return alias_type(AliasIdxBot);
  1351   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1352   if (ace->_adr_type == adr_type) {
  1353     return alias_type(ace->_index);
  1356   // Handle special cases.
  1357   if (adr_type == NULL)             return alias_type(AliasIdxTop);
  1358   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
  1360   // Do it the slow way.
  1361   const TypePtr* flat = flatten_alias_type(adr_type);
  1363 #ifdef ASSERT
  1364   assert(flat == flatten_alias_type(flat), "idempotent");
  1365   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
  1366   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
  1367     const TypeOopPtr* foop = flat->is_oopptr();
  1368     // Scalarizable allocations have exact klass always.
  1369     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
  1370     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
  1371     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
  1373   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
  1374 #endif
  1376   int idx = AliasIdxTop;
  1377   for (int i = 0; i < num_alias_types(); i++) {
  1378     if (alias_type(i)->adr_type() == flat) {
  1379       idx = i;
  1380       break;
  1384   if (idx == AliasIdxTop) {
  1385     if (no_create)  return NULL;
  1386     // Grow the array if necessary.
  1387     if (_num_alias_types == _max_alias_types)  grow_alias_types();
  1388     // Add a new alias type.
  1389     idx = _num_alias_types++;
  1390     _alias_types[idx]->Init(idx, flat);
  1391     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
  1392     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
  1393     if (flat->isa_instptr()) {
  1394       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
  1395           && flat->is_instptr()->klass() == env()->Class_klass())
  1396         alias_type(idx)->set_rewritable(false);
  1398     if (flat->isa_klassptr()) {
  1399       if (flat->offset() == Klass::super_check_offset_offset_in_bytes() + (int)sizeof(oopDesc))
  1400         alias_type(idx)->set_rewritable(false);
  1401       if (flat->offset() == Klass::modifier_flags_offset_in_bytes() + (int)sizeof(oopDesc))
  1402         alias_type(idx)->set_rewritable(false);
  1403       if (flat->offset() == Klass::access_flags_offset_in_bytes() + (int)sizeof(oopDesc))
  1404         alias_type(idx)->set_rewritable(false);
  1405       if (flat->offset() == Klass::java_mirror_offset_in_bytes() + (int)sizeof(oopDesc))
  1406         alias_type(idx)->set_rewritable(false);
  1408     // %%% (We would like to finalize JavaThread::threadObj_offset(),
  1409     // but the base pointer type is not distinctive enough to identify
  1410     // references into JavaThread.)
  1412     // Check for final instance fields.
  1413     const TypeInstPtr* tinst = flat->isa_instptr();
  1414     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
  1415       ciInstanceKlass *k = tinst->klass()->as_instance_klass();
  1416       ciField* field = k->get_field_by_offset(tinst->offset(), false);
  1417       // Set field() and is_rewritable() attributes.
  1418       if (field != NULL)  alias_type(idx)->set_field(field);
  1420     const TypeKlassPtr* tklass = flat->isa_klassptr();
  1421     // Check for final static fields.
  1422     if (tklass && tklass->klass()->is_instance_klass()) {
  1423       ciInstanceKlass *k = tklass->klass()->as_instance_klass();
  1424       ciField* field = k->get_field_by_offset(tklass->offset(), true);
  1425       // Set field() and is_rewritable() attributes.
  1426       if (field != NULL)   alias_type(idx)->set_field(field);
  1430   // Fill the cache for next time.
  1431   ace->_adr_type = adr_type;
  1432   ace->_index    = idx;
  1433   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
  1435   // Might as well try to fill the cache for the flattened version, too.
  1436   AliasCacheEntry* face = probe_alias_cache(flat);
  1437   if (face->_adr_type == NULL) {
  1438     face->_adr_type = flat;
  1439     face->_index    = idx;
  1440     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
  1443   return alias_type(idx);
  1447 Compile::AliasType* Compile::alias_type(ciField* field) {
  1448   const TypeOopPtr* t;
  1449   if (field->is_static())
  1450     t = TypeKlassPtr::make(field->holder());
  1451   else
  1452     t = TypeOopPtr::make_from_klass_raw(field->holder());
  1453   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()));
  1454   assert(field->is_final() == !atp->is_rewritable(), "must get the rewritable bits correct");
  1455   return atp;
  1459 //------------------------------have_alias_type--------------------------------
  1460 bool Compile::have_alias_type(const TypePtr* adr_type) {
  1461   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1462   if (ace->_adr_type == adr_type) {
  1463     return true;
  1466   // Handle special cases.
  1467   if (adr_type == NULL)             return true;
  1468   if (adr_type == TypePtr::BOTTOM)  return true;
  1470   return find_alias_type(adr_type, true) != NULL;
  1473 //-----------------------------must_alias--------------------------------------
  1474 // True if all values of the given address type are in the given alias category.
  1475 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
  1476   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1477   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
  1478   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1479   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
  1481   // the only remaining possible overlap is identity
  1482   int adr_idx = get_alias_index(adr_type);
  1483   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1484   assert(adr_idx == alias_idx ||
  1485          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
  1486           && adr_type                       != TypeOopPtr::BOTTOM),
  1487          "should not be testing for overlap with an unsafe pointer");
  1488   return adr_idx == alias_idx;
  1491 //------------------------------can_alias--------------------------------------
  1492 // True if any values of the given address type are in the given alias category.
  1493 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
  1494   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1495   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
  1496   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1497   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
  1499   // the only remaining possible overlap is identity
  1500   int adr_idx = get_alias_index(adr_type);
  1501   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1502   return adr_idx == alias_idx;
  1507 //---------------------------pop_warm_call-------------------------------------
  1508 WarmCallInfo* Compile::pop_warm_call() {
  1509   WarmCallInfo* wci = _warm_calls;
  1510   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
  1511   return wci;
  1514 //----------------------------Inline_Warm--------------------------------------
  1515 int Compile::Inline_Warm() {
  1516   // If there is room, try to inline some more warm call sites.
  1517   // %%% Do a graph index compaction pass when we think we're out of space?
  1518   if (!InlineWarmCalls)  return 0;
  1520   int calls_made_hot = 0;
  1521   int room_to_grow   = NodeCountInliningCutoff - unique();
  1522   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
  1523   int amount_grown   = 0;
  1524   WarmCallInfo* call;
  1525   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
  1526     int est_size = (int)call->size();
  1527     if (est_size > (room_to_grow - amount_grown)) {
  1528       // This one won't fit anyway.  Get rid of it.
  1529       call->make_cold();
  1530       continue;
  1532     call->make_hot();
  1533     calls_made_hot++;
  1534     amount_grown   += est_size;
  1535     amount_to_grow -= est_size;
  1538   if (calls_made_hot > 0)  set_major_progress();
  1539   return calls_made_hot;
  1543 //----------------------------Finish_Warm--------------------------------------
  1544 void Compile::Finish_Warm() {
  1545   if (!InlineWarmCalls)  return;
  1546   if (failing())  return;
  1547   if (warm_calls() == NULL)  return;
  1549   // Clean up loose ends, if we are out of space for inlining.
  1550   WarmCallInfo* call;
  1551   while ((call = pop_warm_call()) != NULL) {
  1552     call->make_cold();
  1557 //------------------------------Optimize---------------------------------------
  1558 // Given a graph, optimize it.
  1559 void Compile::Optimize() {
  1560   TracePhase t1("optimizer", &_t_optimizer, true);
  1562 #ifndef PRODUCT
  1563   if (env()->break_at_compile()) {
  1564     BREAKPOINT;
  1567 #endif
  1569   ResourceMark rm;
  1570   int          loop_opts_cnt;
  1572   NOT_PRODUCT( verify_graph_edges(); )
  1574   print_method("After Parsing");
  1577   // Iterative Global Value Numbering, including ideal transforms
  1578   // Initialize IterGVN with types and values from parse-time GVN
  1579   PhaseIterGVN igvn(initial_gvn());
  1581     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
  1582     igvn.optimize();
  1585   print_method("Iter GVN 1", 2);
  1587   if (failing())  return;
  1589   // Loop transforms on the ideal graph.  Range Check Elimination,
  1590   // peeling, unrolling, etc.
  1592   // Set loop opts counter
  1593   loop_opts_cnt = num_loop_opts();
  1594   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
  1596       TracePhase t2("idealLoop", &_t_idealLoop, true);
  1597       PhaseIdealLoop ideal_loop( igvn, true );
  1598       loop_opts_cnt--;
  1599       if (major_progress()) print_method("PhaseIdealLoop 1", 2);
  1600       if (failing())  return;
  1602     // Loop opts pass if partial peeling occurred in previous pass
  1603     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
  1604       TracePhase t3("idealLoop", &_t_idealLoop, true);
  1605       PhaseIdealLoop ideal_loop( igvn, false );
  1606       loop_opts_cnt--;
  1607       if (major_progress()) print_method("PhaseIdealLoop 2", 2);
  1608       if (failing())  return;
  1610     // Loop opts pass for loop-unrolling before CCP
  1611     if(major_progress() && (loop_opts_cnt > 0)) {
  1612       TracePhase t4("idealLoop", &_t_idealLoop, true);
  1613       PhaseIdealLoop ideal_loop( igvn, false );
  1614       loop_opts_cnt--;
  1615       if (major_progress()) print_method("PhaseIdealLoop 3", 2);
  1617     if (!failing()) {
  1618       // Verify that last round of loop opts produced a valid graph
  1619       NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
  1620       PhaseIdealLoop::verify(igvn);
  1623   if (failing())  return;
  1625   // Conditional Constant Propagation;
  1626   PhaseCCP ccp( &igvn );
  1627   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
  1629     TracePhase t2("ccp", &_t_ccp, true);
  1630     ccp.do_transform();
  1632   print_method("PhaseCPP 1", 2);
  1634   assert( true, "Break here to ccp.dump_old2new_map()");
  1636   // Iterative Global Value Numbering, including ideal transforms
  1638     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
  1639     igvn = ccp;
  1640     igvn.optimize();
  1643   print_method("Iter GVN 2", 2);
  1645   if (failing())  return;
  1647   // Loop transforms on the ideal graph.  Range Check Elimination,
  1648   // peeling, unrolling, etc.
  1649   if(loop_opts_cnt > 0) {
  1650     debug_only( int cnt = 0; );
  1651     while(major_progress() && (loop_opts_cnt > 0)) {
  1652       TracePhase t2("idealLoop", &_t_idealLoop, true);
  1653       assert( cnt++ < 40, "infinite cycle in loop optimization" );
  1654       PhaseIdealLoop ideal_loop( igvn, true );
  1655       loop_opts_cnt--;
  1656       if (major_progress()) print_method("PhaseIdealLoop iterations", 2);
  1657       if (failing())  return;
  1662     // Verify that all previous optimizations produced a valid graph
  1663     // at least to this point, even if no loop optimizations were done.
  1664     NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
  1665     PhaseIdealLoop::verify(igvn);
  1669     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
  1670     PhaseMacroExpand  mex(igvn);
  1671     if (mex.expand_macro_nodes()) {
  1672       assert(failing(), "must bail out w/ explicit message");
  1673       return;
  1677  } // (End scope of igvn; run destructor if necessary for asserts.)
  1679   // A method with only infinite loops has no edges entering loops from root
  1681     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
  1682     if (final_graph_reshaping()) {
  1683       assert(failing(), "must bail out w/ explicit message");
  1684       return;
  1688   print_method("Optimize finished", 2);
  1692 //------------------------------Code_Gen---------------------------------------
  1693 // Given a graph, generate code for it
  1694 void Compile::Code_Gen() {
  1695   if (failing())  return;
  1697   // Perform instruction selection.  You might think we could reclaim Matcher
  1698   // memory PDQ, but actually the Matcher is used in generating spill code.
  1699   // Internals of the Matcher (including some VectorSets) must remain live
  1700   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
  1701   // set a bit in reclaimed memory.
  1703   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  1704   // nodes.  Mapping is only valid at the root of each matched subtree.
  1705   NOT_PRODUCT( verify_graph_edges(); )
  1707   Node_List proj_list;
  1708   Matcher m(proj_list);
  1709   _matcher = &m;
  1711     TracePhase t2("matcher", &_t_matcher, true);
  1712     m.match();
  1714   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  1715   // nodes.  Mapping is only valid at the root of each matched subtree.
  1716   NOT_PRODUCT( verify_graph_edges(); )
  1718   // If you have too many nodes, or if matching has failed, bail out
  1719   check_node_count(0, "out of nodes matching instructions");
  1720   if (failing())  return;
  1722   // Build a proper-looking CFG
  1723   PhaseCFG cfg(node_arena(), root(), m);
  1724   _cfg = &cfg;
  1726     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
  1727     cfg.Dominators();
  1728     if (failing())  return;
  1730     NOT_PRODUCT( verify_graph_edges(); )
  1732     cfg.Estimate_Block_Frequency();
  1733     cfg.GlobalCodeMotion(m,unique(),proj_list);
  1735     print_method("Global code motion", 2);
  1737     if (failing())  return;
  1738     NOT_PRODUCT( verify_graph_edges(); )
  1740     debug_only( cfg.verify(); )
  1742   NOT_PRODUCT( verify_graph_edges(); )
  1744   PhaseChaitin regalloc(unique(),cfg,m);
  1745   _regalloc = &regalloc;
  1747     TracePhase t2("regalloc", &_t_registerAllocation, true);
  1748     // Perform any platform dependent preallocation actions.  This is used,
  1749     // for example, to avoid taking an implicit null pointer exception
  1750     // using the frame pointer on win95.
  1751     _regalloc->pd_preallocate_hook();
  1753     // Perform register allocation.  After Chaitin, use-def chains are
  1754     // no longer accurate (at spill code) and so must be ignored.
  1755     // Node->LRG->reg mappings are still accurate.
  1756     _regalloc->Register_Allocate();
  1758     // Bail out if the allocator builds too many nodes
  1759     if (failing())  return;
  1762   // Prior to register allocation we kept empty basic blocks in case the
  1763   // the allocator needed a place to spill.  After register allocation we
  1764   // are not adding any new instructions.  If any basic block is empty, we
  1765   // can now safely remove it.
  1767     NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
  1768     cfg.remove_empty();
  1769     if (do_freq_based_layout()) {
  1770       PhaseBlockLayout layout(cfg);
  1771     } else {
  1772       cfg.set_loop_alignment();
  1774     cfg.fixup_flow();
  1777   // Perform any platform dependent postallocation verifications.
  1778   debug_only( _regalloc->pd_postallocate_verify_hook(); )
  1780   // Apply peephole optimizations
  1781   if( OptoPeephole ) {
  1782     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
  1783     PhasePeephole peep( _regalloc, cfg);
  1784     peep.do_transform();
  1787   // Convert Nodes to instruction bits in a buffer
  1789     // %%%% workspace merge brought two timers together for one job
  1790     TracePhase t2a("output", &_t_output, true);
  1791     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
  1792     Output();
  1795   print_method("Final Code");
  1797   // He's dead, Jim.
  1798   _cfg     = (PhaseCFG*)0xdeadbeef;
  1799   _regalloc = (PhaseChaitin*)0xdeadbeef;
  1803 //------------------------------dump_asm---------------------------------------
  1804 // Dump formatted assembly
  1805 #ifndef PRODUCT
  1806 void Compile::dump_asm(int *pcs, uint pc_limit) {
  1807   bool cut_short = false;
  1808   tty->print_cr("#");
  1809   tty->print("#  ");  _tf->dump();  tty->cr();
  1810   tty->print_cr("#");
  1812   // For all blocks
  1813   int pc = 0x0;                 // Program counter
  1814   char starts_bundle = ' ';
  1815   _regalloc->dump_frame();
  1817   Node *n = NULL;
  1818   for( uint i=0; i<_cfg->_num_blocks; i++ ) {
  1819     if (VMThread::should_terminate()) { cut_short = true; break; }
  1820     Block *b = _cfg->_blocks[i];
  1821     if (b->is_connector() && !Verbose) continue;
  1822     n = b->_nodes[0];
  1823     if (pcs && n->_idx < pc_limit)
  1824       tty->print("%3.3x   ", pcs[n->_idx]);
  1825     else
  1826       tty->print("      ");
  1827     b->dump_head( &_cfg->_bbs );
  1828     if (b->is_connector()) {
  1829       tty->print_cr("        # Empty connector block");
  1830     } else if (b->num_preds() == 2 && b->pred(1)->is_CatchProj() && b->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
  1831       tty->print_cr("        # Block is sole successor of call");
  1834     // For all instructions
  1835     Node *delay = NULL;
  1836     for( uint j = 0; j<b->_nodes.size(); j++ ) {
  1837       if (VMThread::should_terminate()) { cut_short = true; break; }
  1838       n = b->_nodes[j];
  1839       if (valid_bundle_info(n)) {
  1840         Bundle *bundle = node_bundling(n);
  1841         if (bundle->used_in_unconditional_delay()) {
  1842           delay = n;
  1843           continue;
  1845         if (bundle->starts_bundle())
  1846           starts_bundle = '+';
  1849       if (WizardMode) n->dump();
  1851       if( !n->is_Region() &&    // Dont print in the Assembly
  1852           !n->is_Phi() &&       // a few noisely useless nodes
  1853           !n->is_Proj() &&
  1854           !n->is_MachTemp() &&
  1855           !n->is_Catch() &&     // Would be nice to print exception table targets
  1856           !n->is_MergeMem() &&  // Not very interesting
  1857           !n->is_top() &&       // Debug info table constants
  1858           !(n->is_Con() && !n->is_Mach())// Debug info table constants
  1859           ) {
  1860         if (pcs && n->_idx < pc_limit)
  1861           tty->print("%3.3x", pcs[n->_idx]);
  1862         else
  1863           tty->print("   ");
  1864         tty->print(" %c ", starts_bundle);
  1865         starts_bundle = ' ';
  1866         tty->print("\t");
  1867         n->format(_regalloc, tty);
  1868         tty->cr();
  1871       // If we have an instruction with a delay slot, and have seen a delay,
  1872       // then back up and print it
  1873       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
  1874         assert(delay != NULL, "no unconditional delay instruction");
  1875         if (WizardMode) delay->dump();
  1877         if (node_bundling(delay)->starts_bundle())
  1878           starts_bundle = '+';
  1879         if (pcs && n->_idx < pc_limit)
  1880           tty->print("%3.3x", pcs[n->_idx]);
  1881         else
  1882           tty->print("   ");
  1883         tty->print(" %c ", starts_bundle);
  1884         starts_bundle = ' ';
  1885         tty->print("\t");
  1886         delay->format(_regalloc, tty);
  1887         tty->print_cr("");
  1888         delay = NULL;
  1891       // Dump the exception table as well
  1892       if( n->is_Catch() && (Verbose || WizardMode) ) {
  1893         // Print the exception table for this offset
  1894         _handler_table.print_subtable_for(pc);
  1898     if (pcs && n->_idx < pc_limit)
  1899       tty->print_cr("%3.3x", pcs[n->_idx]);
  1900     else
  1901       tty->print_cr("");
  1903     assert(cut_short || delay == NULL, "no unconditional delay branch");
  1905   } // End of per-block dump
  1906   tty->print_cr("");
  1908   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
  1910 #endif
  1912 //------------------------------Final_Reshape_Counts---------------------------
  1913 // This class defines counters to help identify when a method
  1914 // may/must be executed using hardware with only 24-bit precision.
  1915 struct Final_Reshape_Counts : public StackObj {
  1916   int  _call_count;             // count non-inlined 'common' calls
  1917   int  _float_count;            // count float ops requiring 24-bit precision
  1918   int  _double_count;           // count double ops requiring more precision
  1919   int  _java_call_count;        // count non-inlined 'java' calls
  1920   int  _inner_loop_count;       // count loops which need alignment
  1921   VectorSet _visited;           // Visitation flags
  1922   Node_List _tests;             // Set of IfNodes & PCTableNodes
  1924   Final_Reshape_Counts() :
  1925     _call_count(0), _float_count(0), _double_count(0),
  1926     _java_call_count(0), _inner_loop_count(0),
  1927     _visited( Thread::current()->resource_area() ) { }
  1929   void inc_call_count  () { _call_count  ++; }
  1930   void inc_float_count () { _float_count ++; }
  1931   void inc_double_count() { _double_count++; }
  1932   void inc_java_call_count() { _java_call_count++; }
  1933   void inc_inner_loop_count() { _inner_loop_count++; }
  1935   int  get_call_count  () const { return _call_count  ; }
  1936   int  get_float_count () const { return _float_count ; }
  1937   int  get_double_count() const { return _double_count; }
  1938   int  get_java_call_count() const { return _java_call_count; }
  1939   int  get_inner_loop_count() const { return _inner_loop_count; }
  1940 };
  1942 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
  1943   ciInstanceKlass *k = tp->klass()->as_instance_klass();
  1944   // Make sure the offset goes inside the instance layout.
  1945   return k->contains_field_offset(tp->offset());
  1946   // Note that OffsetBot and OffsetTop are very negative.
  1949 //------------------------------final_graph_reshaping_impl----------------------
  1950 // Implement items 1-5 from final_graph_reshaping below.
  1951 static void final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc ) {
  1953   if ( n->outcnt() == 0 ) return; // dead node
  1954   uint nop = n->Opcode();
  1956   // Check for 2-input instruction with "last use" on right input.
  1957   // Swap to left input.  Implements item (2).
  1958   if( n->req() == 3 &&          // two-input instruction
  1959       n->in(1)->outcnt() > 1 && // left use is NOT a last use
  1960       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
  1961       n->in(2)->outcnt() == 1 &&// right use IS a last use
  1962       !n->in(2)->is_Con() ) {   // right use is not a constant
  1963     // Check for commutative opcode
  1964     switch( nop ) {
  1965     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
  1966     case Op_MaxI:  case Op_MinI:
  1967     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
  1968     case Op_AndL:  case Op_XorL:  case Op_OrL:
  1969     case Op_AndI:  case Op_XorI:  case Op_OrI: {
  1970       // Move "last use" input to left by swapping inputs
  1971       n->swap_edges(1, 2);
  1972       break;
  1974     default:
  1975       break;
  1979   // Count FPU ops and common calls, implements item (3)
  1980   switch( nop ) {
  1981   // Count all float operations that may use FPU
  1982   case Op_AddF:
  1983   case Op_SubF:
  1984   case Op_MulF:
  1985   case Op_DivF:
  1986   case Op_NegF:
  1987   case Op_ModF:
  1988   case Op_ConvI2F:
  1989   case Op_ConF:
  1990   case Op_CmpF:
  1991   case Op_CmpF3:
  1992   // case Op_ConvL2F: // longs are split into 32-bit halves
  1993     frc.inc_float_count();
  1994     break;
  1996   case Op_ConvF2D:
  1997   case Op_ConvD2F:
  1998     frc.inc_float_count();
  1999     frc.inc_double_count();
  2000     break;
  2002   // Count all double operations that may use FPU
  2003   case Op_AddD:
  2004   case Op_SubD:
  2005   case Op_MulD:
  2006   case Op_DivD:
  2007   case Op_NegD:
  2008   case Op_ModD:
  2009   case Op_ConvI2D:
  2010   case Op_ConvD2I:
  2011   // case Op_ConvL2D: // handled by leaf call
  2012   // case Op_ConvD2L: // handled by leaf call
  2013   case Op_ConD:
  2014   case Op_CmpD:
  2015   case Op_CmpD3:
  2016     frc.inc_double_count();
  2017     break;
  2018   case Op_Opaque1:              // Remove Opaque Nodes before matching
  2019   case Op_Opaque2:              // Remove Opaque Nodes before matching
  2020     n->subsume_by(n->in(1));
  2021     break;
  2022   case Op_CallStaticJava:
  2023   case Op_CallJava:
  2024   case Op_CallDynamicJava:
  2025     frc.inc_java_call_count(); // Count java call site;
  2026   case Op_CallRuntime:
  2027   case Op_CallLeaf:
  2028   case Op_CallLeafNoFP: {
  2029     assert( n->is_Call(), "" );
  2030     CallNode *call = n->as_Call();
  2031     // Count call sites where the FP mode bit would have to be flipped.
  2032     // Do not count uncommon runtime calls:
  2033     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
  2034     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
  2035     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
  2036       frc.inc_call_count();   // Count the call site
  2037     } else {                  // See if uncommon argument is shared
  2038       Node *n = call->in(TypeFunc::Parms);
  2039       int nop = n->Opcode();
  2040       // Clone shared simple arguments to uncommon calls, item (1).
  2041       if( n->outcnt() > 1 &&
  2042           !n->is_Proj() &&
  2043           nop != Op_CreateEx &&
  2044           nop != Op_CheckCastPP &&
  2045           nop != Op_DecodeN &&
  2046           !n->is_Mem() ) {
  2047         Node *x = n->clone();
  2048         call->set_req( TypeFunc::Parms, x );
  2051     break;
  2054   case Op_StoreD:
  2055   case Op_LoadD:
  2056   case Op_LoadD_unaligned:
  2057     frc.inc_double_count();
  2058     goto handle_mem;
  2059   case Op_StoreF:
  2060   case Op_LoadF:
  2061     frc.inc_float_count();
  2062     goto handle_mem;
  2064   case Op_StoreB:
  2065   case Op_StoreC:
  2066   case Op_StoreCM:
  2067   case Op_StorePConditional:
  2068   case Op_StoreI:
  2069   case Op_StoreL:
  2070   case Op_StoreIConditional:
  2071   case Op_StoreLConditional:
  2072   case Op_CompareAndSwapI:
  2073   case Op_CompareAndSwapL:
  2074   case Op_CompareAndSwapP:
  2075   case Op_CompareAndSwapN:
  2076   case Op_StoreP:
  2077   case Op_StoreN:
  2078   case Op_LoadB:
  2079   case Op_LoadUB:
  2080   case Op_LoadUS:
  2081   case Op_LoadI:
  2082   case Op_LoadUI2L:
  2083   case Op_LoadKlass:
  2084   case Op_LoadNKlass:
  2085   case Op_LoadL:
  2086   case Op_LoadL_unaligned:
  2087   case Op_LoadPLocked:
  2088   case Op_LoadLLocked:
  2089   case Op_LoadP:
  2090   case Op_LoadN:
  2091   case Op_LoadRange:
  2092   case Op_LoadS: {
  2093   handle_mem:
  2094 #ifdef ASSERT
  2095     if( VerifyOptoOopOffsets ) {
  2096       assert( n->is_Mem(), "" );
  2097       MemNode *mem  = (MemNode*)n;
  2098       // Check to see if address types have grounded out somehow.
  2099       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
  2100       assert( !tp || oop_offset_is_sane(tp), "" );
  2102 #endif
  2103     break;
  2106   case Op_AddP: {               // Assert sane base pointers
  2107     Node *addp = n->in(AddPNode::Address);
  2108     assert( !addp->is_AddP() ||
  2109             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
  2110             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
  2111             "Base pointers must match" );
  2112 #ifdef _LP64
  2113     if (UseCompressedOops &&
  2114         addp->Opcode() == Op_ConP &&
  2115         addp == n->in(AddPNode::Base) &&
  2116         n->in(AddPNode::Offset)->is_Con()) {
  2117       // Use addressing with narrow klass to load with offset on x86.
  2118       // On sparc loading 32-bits constant and decoding it have less
  2119       // instructions (4) then load 64-bits constant (7).
  2120       // Do this transformation here since IGVN will convert ConN back to ConP.
  2121       const Type* t = addp->bottom_type();
  2122       if (t->isa_oopptr()) {
  2123         Node* nn = NULL;
  2125         // Look for existing ConN node of the same exact type.
  2126         Compile* C = Compile::current();
  2127         Node* r  = C->root();
  2128         uint cnt = r->outcnt();
  2129         for (uint i = 0; i < cnt; i++) {
  2130           Node* m = r->raw_out(i);
  2131           if (m!= NULL && m->Opcode() == Op_ConN &&
  2132               m->bottom_type()->make_ptr() == t) {
  2133             nn = m;
  2134             break;
  2137         if (nn != NULL) {
  2138           // Decode a narrow oop to match address
  2139           // [R12 + narrow_oop_reg<<3 + offset]
  2140           nn = new (C,  2) DecodeNNode(nn, t);
  2141           n->set_req(AddPNode::Base, nn);
  2142           n->set_req(AddPNode::Address, nn);
  2143           if (addp->outcnt() == 0) {
  2144             addp->disconnect_inputs(NULL);
  2149 #endif
  2150     break;
  2153 #ifdef _LP64
  2154   case Op_CastPP:
  2155     if (n->in(1)->is_DecodeN() && Universe::narrow_oop_use_implicit_null_checks()) {
  2156       Compile* C = Compile::current();
  2157       Node* in1 = n->in(1);
  2158       const Type* t = n->bottom_type();
  2159       Node* new_in1 = in1->clone();
  2160       new_in1->as_DecodeN()->set_type(t);
  2162       if (!Matcher::clone_shift_expressions) {
  2163         //
  2164         // x86, ARM and friends can handle 2 adds in addressing mode
  2165         // and Matcher can fold a DecodeN node into address by using
  2166         // a narrow oop directly and do implicit NULL check in address:
  2167         //
  2168         // [R12 + narrow_oop_reg<<3 + offset]
  2169         // NullCheck narrow_oop_reg
  2170         //
  2171         // On other platforms (Sparc) we have to keep new DecodeN node and
  2172         // use it to do implicit NULL check in address:
  2173         //
  2174         // decode_not_null narrow_oop_reg, base_reg
  2175         // [base_reg + offset]
  2176         // NullCheck base_reg
  2177         //
  2178         // Pin the new DecodeN node to non-null path on these platform (Sparc)
  2179         // to keep the information to which NULL check the new DecodeN node
  2180         // corresponds to use it as value in implicit_null_check().
  2181         //
  2182         new_in1->set_req(0, n->in(0));
  2185       n->subsume_by(new_in1);
  2186       if (in1->outcnt() == 0) {
  2187         in1->disconnect_inputs(NULL);
  2190     break;
  2192   case Op_CmpP:
  2193     // Do this transformation here to preserve CmpPNode::sub() and
  2194     // other TypePtr related Ideal optimizations (for example, ptr nullness).
  2195     if (n->in(1)->is_DecodeN() || n->in(2)->is_DecodeN()) {
  2196       Node* in1 = n->in(1);
  2197       Node* in2 = n->in(2);
  2198       if (!in1->is_DecodeN()) {
  2199         in2 = in1;
  2200         in1 = n->in(2);
  2202       assert(in1->is_DecodeN(), "sanity");
  2204       Compile* C = Compile::current();
  2205       Node* new_in2 = NULL;
  2206       if (in2->is_DecodeN()) {
  2207         new_in2 = in2->in(1);
  2208       } else if (in2->Opcode() == Op_ConP) {
  2209         const Type* t = in2->bottom_type();
  2210         if (t == TypePtr::NULL_PTR && Universe::narrow_oop_use_implicit_null_checks()) {
  2211           new_in2 = ConNode::make(C, TypeNarrowOop::NULL_PTR);
  2212           //
  2213           // This transformation together with CastPP transformation above
  2214           // will generated code for implicit NULL checks for compressed oops.
  2215           //
  2216           // The original code after Optimize()
  2217           //
  2218           //    LoadN memory, narrow_oop_reg
  2219           //    decode narrow_oop_reg, base_reg
  2220           //    CmpP base_reg, NULL
  2221           //    CastPP base_reg // NotNull
  2222           //    Load [base_reg + offset], val_reg
  2223           //
  2224           // after these transformations will be
  2225           //
  2226           //    LoadN memory, narrow_oop_reg
  2227           //    CmpN narrow_oop_reg, NULL
  2228           //    decode_not_null narrow_oop_reg, base_reg
  2229           //    Load [base_reg + offset], val_reg
  2230           //
  2231           // and the uncommon path (== NULL) will use narrow_oop_reg directly
  2232           // since narrow oops can be used in debug info now (see the code in
  2233           // final_graph_reshaping_walk()).
  2234           //
  2235           // At the end the code will be matched to
  2236           // on x86:
  2237           //
  2238           //    Load_narrow_oop memory, narrow_oop_reg
  2239           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
  2240           //    NullCheck narrow_oop_reg
  2241           //
  2242           // and on sparc:
  2243           //
  2244           //    Load_narrow_oop memory, narrow_oop_reg
  2245           //    decode_not_null narrow_oop_reg, base_reg
  2246           //    Load [base_reg + offset], val_reg
  2247           //    NullCheck base_reg
  2248           //
  2249         } else if (t->isa_oopptr()) {
  2250           new_in2 = ConNode::make(C, t->make_narrowoop());
  2253       if (new_in2 != NULL) {
  2254         Node* cmpN = new (C, 3) CmpNNode(in1->in(1), new_in2);
  2255         n->subsume_by( cmpN );
  2256         if (in1->outcnt() == 0) {
  2257           in1->disconnect_inputs(NULL);
  2259         if (in2->outcnt() == 0) {
  2260           in2->disconnect_inputs(NULL);
  2264     break;
  2266   case Op_DecodeN:
  2267     assert(!n->in(1)->is_EncodeP(), "should be optimized out");
  2268     // DecodeN could be pinned on Sparc where it can't be fold into
  2269     // an address expression, see the code for Op_CastPP above.
  2270     assert(n->in(0) == NULL || !Matcher::clone_shift_expressions, "no control except on sparc");
  2271     break;
  2273   case Op_EncodeP: {
  2274     Node* in1 = n->in(1);
  2275     if (in1->is_DecodeN()) {
  2276       n->subsume_by(in1->in(1));
  2277     } else if (in1->Opcode() == Op_ConP) {
  2278       Compile* C = Compile::current();
  2279       const Type* t = in1->bottom_type();
  2280       if (t == TypePtr::NULL_PTR) {
  2281         n->subsume_by(ConNode::make(C, TypeNarrowOop::NULL_PTR));
  2282       } else if (t->isa_oopptr()) {
  2283         n->subsume_by(ConNode::make(C, t->make_narrowoop()));
  2286     if (in1->outcnt() == 0) {
  2287       in1->disconnect_inputs(NULL);
  2289     break;
  2292   case Op_Proj: {
  2293     if (OptimizeStringConcat) {
  2294       ProjNode* p = n->as_Proj();
  2295       if (p->_is_io_use) {
  2296         // Separate projections were used for the exception path which
  2297         // are normally removed by a late inline.  If it wasn't inlined
  2298         // then they will hang around and should just be replaced with
  2299         // the original one.
  2300         Node* proj = NULL;
  2301         // Replace with just one
  2302         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
  2303           Node *use = i.get();
  2304           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
  2305             proj = use;
  2306             break;
  2309         assert(p != NULL, "must be found");
  2310         p->subsume_by(proj);
  2313     break;
  2316   case Op_Phi:
  2317     if (n->as_Phi()->bottom_type()->isa_narrowoop()) {
  2318       // The EncodeP optimization may create Phi with the same edges
  2319       // for all paths. It is not handled well by Register Allocator.
  2320       Node* unique_in = n->in(1);
  2321       assert(unique_in != NULL, "");
  2322       uint cnt = n->req();
  2323       for (uint i = 2; i < cnt; i++) {
  2324         Node* m = n->in(i);
  2325         assert(m != NULL, "");
  2326         if (unique_in != m)
  2327           unique_in = NULL;
  2329       if (unique_in != NULL) {
  2330         n->subsume_by(unique_in);
  2333     break;
  2335 #endif
  2337   case Op_ModI:
  2338     if (UseDivMod) {
  2339       // Check if a%b and a/b both exist
  2340       Node* d = n->find_similar(Op_DivI);
  2341       if (d) {
  2342         // Replace them with a fused divmod if supported
  2343         Compile* C = Compile::current();
  2344         if (Matcher::has_match_rule(Op_DivModI)) {
  2345           DivModINode* divmod = DivModINode::make(C, n);
  2346           d->subsume_by(divmod->div_proj());
  2347           n->subsume_by(divmod->mod_proj());
  2348         } else {
  2349           // replace a%b with a-((a/b)*b)
  2350           Node* mult = new (C, 3) MulINode(d, d->in(2));
  2351           Node* sub  = new (C, 3) SubINode(d->in(1), mult);
  2352           n->subsume_by( sub );
  2356     break;
  2358   case Op_ModL:
  2359     if (UseDivMod) {
  2360       // Check if a%b and a/b both exist
  2361       Node* d = n->find_similar(Op_DivL);
  2362       if (d) {
  2363         // Replace them with a fused divmod if supported
  2364         Compile* C = Compile::current();
  2365         if (Matcher::has_match_rule(Op_DivModL)) {
  2366           DivModLNode* divmod = DivModLNode::make(C, n);
  2367           d->subsume_by(divmod->div_proj());
  2368           n->subsume_by(divmod->mod_proj());
  2369         } else {
  2370           // replace a%b with a-((a/b)*b)
  2371           Node* mult = new (C, 3) MulLNode(d, d->in(2));
  2372           Node* sub  = new (C, 3) SubLNode(d->in(1), mult);
  2373           n->subsume_by( sub );
  2377     break;
  2379   case Op_Load16B:
  2380   case Op_Load8B:
  2381   case Op_Load4B:
  2382   case Op_Load8S:
  2383   case Op_Load4S:
  2384   case Op_Load2S:
  2385   case Op_Load8C:
  2386   case Op_Load4C:
  2387   case Op_Load2C:
  2388   case Op_Load4I:
  2389   case Op_Load2I:
  2390   case Op_Load2L:
  2391   case Op_Load4F:
  2392   case Op_Load2F:
  2393   case Op_Load2D:
  2394   case Op_Store16B:
  2395   case Op_Store8B:
  2396   case Op_Store4B:
  2397   case Op_Store8C:
  2398   case Op_Store4C:
  2399   case Op_Store2C:
  2400   case Op_Store4I:
  2401   case Op_Store2I:
  2402   case Op_Store2L:
  2403   case Op_Store4F:
  2404   case Op_Store2F:
  2405   case Op_Store2D:
  2406     break;
  2408   case Op_PackB:
  2409   case Op_PackS:
  2410   case Op_PackC:
  2411   case Op_PackI:
  2412   case Op_PackF:
  2413   case Op_PackL:
  2414   case Op_PackD:
  2415     if (n->req()-1 > 2) {
  2416       // Replace many operand PackNodes with a binary tree for matching
  2417       PackNode* p = (PackNode*) n;
  2418       Node* btp = p->binaryTreePack(Compile::current(), 1, n->req());
  2419       n->subsume_by(btp);
  2421     break;
  2422   case Op_Loop:
  2423   case Op_CountedLoop:
  2424     if (n->as_Loop()->is_inner_loop()) {
  2425       frc.inc_inner_loop_count();
  2427     break;
  2428   default:
  2429     assert( !n->is_Call(), "" );
  2430     assert( !n->is_Mem(), "" );
  2431     break;
  2434   // Collect CFG split points
  2435   if (n->is_MultiBranch())
  2436     frc._tests.push(n);
  2439 //------------------------------final_graph_reshaping_walk---------------------
  2440 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
  2441 // requires that the walk visits a node's inputs before visiting the node.
  2442 static void final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
  2443   ResourceArea *area = Thread::current()->resource_area();
  2444   Unique_Node_List sfpt(area);
  2446   frc._visited.set(root->_idx); // first, mark node as visited
  2447   uint cnt = root->req();
  2448   Node *n = root;
  2449   uint  i = 0;
  2450   while (true) {
  2451     if (i < cnt) {
  2452       // Place all non-visited non-null inputs onto stack
  2453       Node* m = n->in(i);
  2454       ++i;
  2455       if (m != NULL && !frc._visited.test_set(m->_idx)) {
  2456         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL)
  2457           sfpt.push(m);
  2458         cnt = m->req();
  2459         nstack.push(n, i); // put on stack parent and next input's index
  2460         n = m;
  2461         i = 0;
  2463     } else {
  2464       // Now do post-visit work
  2465       final_graph_reshaping_impl( n, frc );
  2466       if (nstack.is_empty())
  2467         break;             // finished
  2468       n = nstack.node();   // Get node from stack
  2469       cnt = n->req();
  2470       i = nstack.index();
  2471       nstack.pop();        // Shift to the next node on stack
  2475   // Go over safepoints nodes to skip DecodeN nodes for debug edges.
  2476   // It could be done for an uncommon traps or any safepoints/calls
  2477   // if the DecodeN node is referenced only in a debug info.
  2478   while (sfpt.size() > 0) {
  2479     n = sfpt.pop();
  2480     JVMState *jvms = n->as_SafePoint()->jvms();
  2481     assert(jvms != NULL, "sanity");
  2482     int start = jvms->debug_start();
  2483     int end   = n->req();
  2484     bool is_uncommon = (n->is_CallStaticJava() &&
  2485                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
  2486     for (int j = start; j < end; j++) {
  2487       Node* in = n->in(j);
  2488       if (in->is_DecodeN()) {
  2489         bool safe_to_skip = true;
  2490         if (!is_uncommon ) {
  2491           // Is it safe to skip?
  2492           for (uint i = 0; i < in->outcnt(); i++) {
  2493             Node* u = in->raw_out(i);
  2494             if (!u->is_SafePoint() ||
  2495                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
  2496               safe_to_skip = false;
  2500         if (safe_to_skip) {
  2501           n->set_req(j, in->in(1));
  2503         if (in->outcnt() == 0) {
  2504           in->disconnect_inputs(NULL);
  2511 //------------------------------final_graph_reshaping--------------------------
  2512 // Final Graph Reshaping.
  2513 //
  2514 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
  2515 //     and not commoned up and forced early.  Must come after regular
  2516 //     optimizations to avoid GVN undoing the cloning.  Clone constant
  2517 //     inputs to Loop Phis; these will be split by the allocator anyways.
  2518 //     Remove Opaque nodes.
  2519 // (2) Move last-uses by commutative operations to the left input to encourage
  2520 //     Intel update-in-place two-address operations and better register usage
  2521 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
  2522 //     calls canonicalizing them back.
  2523 // (3) Count the number of double-precision FP ops, single-precision FP ops
  2524 //     and call sites.  On Intel, we can get correct rounding either by
  2525 //     forcing singles to memory (requires extra stores and loads after each
  2526 //     FP bytecode) or we can set a rounding mode bit (requires setting and
  2527 //     clearing the mode bit around call sites).  The mode bit is only used
  2528 //     if the relative frequency of single FP ops to calls is low enough.
  2529 //     This is a key transform for SPEC mpeg_audio.
  2530 // (4) Detect infinite loops; blobs of code reachable from above but not
  2531 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
  2532 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
  2533 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
  2534 //     Detection is by looking for IfNodes where only 1 projection is
  2535 //     reachable from below or CatchNodes missing some targets.
  2536 // (5) Assert for insane oop offsets in debug mode.
  2538 bool Compile::final_graph_reshaping() {
  2539   // an infinite loop may have been eliminated by the optimizer,
  2540   // in which case the graph will be empty.
  2541   if (root()->req() == 1) {
  2542     record_method_not_compilable("trivial infinite loop");
  2543     return true;
  2546   Final_Reshape_Counts frc;
  2548   // Visit everybody reachable!
  2549   // Allocate stack of size C->unique()/2 to avoid frequent realloc
  2550   Node_Stack nstack(unique() >> 1);
  2551   final_graph_reshaping_walk(nstack, root(), frc);
  2553   // Check for unreachable (from below) code (i.e., infinite loops).
  2554   for( uint i = 0; i < frc._tests.size(); i++ ) {
  2555     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
  2556     // Get number of CFG targets.
  2557     // Note that PCTables include exception targets after calls.
  2558     uint required_outcnt = n->required_outcnt();
  2559     if (n->outcnt() != required_outcnt) {
  2560       // Check for a few special cases.  Rethrow Nodes never take the
  2561       // 'fall-thru' path, so expected kids is 1 less.
  2562       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
  2563         if (n->in(0)->in(0)->is_Call()) {
  2564           CallNode *call = n->in(0)->in(0)->as_Call();
  2565           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
  2566             required_outcnt--;      // Rethrow always has 1 less kid
  2567           } else if (call->req() > TypeFunc::Parms &&
  2568                      call->is_CallDynamicJava()) {
  2569             // Check for null receiver. In such case, the optimizer has
  2570             // detected that the virtual call will always result in a null
  2571             // pointer exception. The fall-through projection of this CatchNode
  2572             // will not be populated.
  2573             Node *arg0 = call->in(TypeFunc::Parms);
  2574             if (arg0->is_Type() &&
  2575                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
  2576               required_outcnt--;
  2578           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
  2579                      call->req() > TypeFunc::Parms+1 &&
  2580                      call->is_CallStaticJava()) {
  2581             // Check for negative array length. In such case, the optimizer has
  2582             // detected that the allocation attempt will always result in an
  2583             // exception. There is no fall-through projection of this CatchNode .
  2584             Node *arg1 = call->in(TypeFunc::Parms+1);
  2585             if (arg1->is_Type() &&
  2586                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
  2587               required_outcnt--;
  2592       // Recheck with a better notion of 'required_outcnt'
  2593       if (n->outcnt() != required_outcnt) {
  2594         record_method_not_compilable("malformed control flow");
  2595         return true;            // Not all targets reachable!
  2598     // Check that I actually visited all kids.  Unreached kids
  2599     // must be infinite loops.
  2600     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
  2601       if (!frc._visited.test(n->fast_out(j)->_idx)) {
  2602         record_method_not_compilable("infinite loop");
  2603         return true;            // Found unvisited kid; must be unreach
  2607   // If original bytecodes contained a mixture of floats and doubles
  2608   // check if the optimizer has made it homogenous, item (3).
  2609   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
  2610       frc.get_float_count() > 32 &&
  2611       frc.get_double_count() == 0 &&
  2612       (10 * frc.get_call_count() < frc.get_float_count()) ) {
  2613     set_24_bit_selection_and_mode( false,  true );
  2616   set_java_calls(frc.get_java_call_count());
  2617   set_inner_loops(frc.get_inner_loop_count());
  2619   // No infinite loops, no reason to bail out.
  2620   return false;
  2623 //-----------------------------too_many_traps----------------------------------
  2624 // Report if there are too many traps at the current method and bci.
  2625 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
  2626 bool Compile::too_many_traps(ciMethod* method,
  2627                              int bci,
  2628                              Deoptimization::DeoptReason reason) {
  2629   ciMethodData* md = method->method_data();
  2630   if (md->is_empty()) {
  2631     // Assume the trap has not occurred, or that it occurred only
  2632     // because of a transient condition during start-up in the interpreter.
  2633     return false;
  2635   if (md->has_trap_at(bci, reason) != 0) {
  2636     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
  2637     // Also, if there are multiple reasons, or if there is no per-BCI record,
  2638     // assume the worst.
  2639     if (log())
  2640       log()->elem("observe trap='%s' count='%d'",
  2641                   Deoptimization::trap_reason_name(reason),
  2642                   md->trap_count(reason));
  2643     return true;
  2644   } else {
  2645     // Ignore method/bci and see if there have been too many globally.
  2646     return too_many_traps(reason, md);
  2650 // Less-accurate variant which does not require a method and bci.
  2651 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
  2652                              ciMethodData* logmd) {
  2653  if (trap_count(reason) >= (uint)PerMethodTrapLimit) {
  2654     // Too many traps globally.
  2655     // Note that we use cumulative trap_count, not just md->trap_count.
  2656     if (log()) {
  2657       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
  2658       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
  2659                   Deoptimization::trap_reason_name(reason),
  2660                   mcount, trap_count(reason));
  2662     return true;
  2663   } else {
  2664     // The coast is clear.
  2665     return false;
  2669 //--------------------------too_many_recompiles--------------------------------
  2670 // Report if there are too many recompiles at the current method and bci.
  2671 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
  2672 // Is not eager to return true, since this will cause the compiler to use
  2673 // Action_none for a trap point, to avoid too many recompilations.
  2674 bool Compile::too_many_recompiles(ciMethod* method,
  2675                                   int bci,
  2676                                   Deoptimization::DeoptReason reason) {
  2677   ciMethodData* md = method->method_data();
  2678   if (md->is_empty()) {
  2679     // Assume the trap has not occurred, or that it occurred only
  2680     // because of a transient condition during start-up in the interpreter.
  2681     return false;
  2683   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
  2684   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
  2685   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
  2686   Deoptimization::DeoptReason per_bc_reason
  2687     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
  2688   if ((per_bc_reason == Deoptimization::Reason_none
  2689        || md->has_trap_at(bci, reason) != 0)
  2690       // The trap frequency measure we care about is the recompile count:
  2691       && md->trap_recompiled_at(bci)
  2692       && md->overflow_recompile_count() >= bc_cutoff) {
  2693     // Do not emit a trap here if it has already caused recompilations.
  2694     // Also, if there are multiple reasons, or if there is no per-BCI record,
  2695     // assume the worst.
  2696     if (log())
  2697       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
  2698                   Deoptimization::trap_reason_name(reason),
  2699                   md->trap_count(reason),
  2700                   md->overflow_recompile_count());
  2701     return true;
  2702   } else if (trap_count(reason) != 0
  2703              && decompile_count() >= m_cutoff) {
  2704     // Too many recompiles globally, and we have seen this sort of trap.
  2705     // Use cumulative decompile_count, not just md->decompile_count.
  2706     if (log())
  2707       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
  2708                   Deoptimization::trap_reason_name(reason),
  2709                   md->trap_count(reason), trap_count(reason),
  2710                   md->decompile_count(), decompile_count());
  2711     return true;
  2712   } else {
  2713     // The coast is clear.
  2714     return false;
  2719 #ifndef PRODUCT
  2720 //------------------------------verify_graph_edges---------------------------
  2721 // Walk the Graph and verify that there is a one-to-one correspondence
  2722 // between Use-Def edges and Def-Use edges in the graph.
  2723 void Compile::verify_graph_edges(bool no_dead_code) {
  2724   if (VerifyGraphEdges) {
  2725     ResourceArea *area = Thread::current()->resource_area();
  2726     Unique_Node_List visited(area);
  2727     // Call recursive graph walk to check edges
  2728     _root->verify_edges(visited);
  2729     if (no_dead_code) {
  2730       // Now make sure that no visited node is used by an unvisited node.
  2731       bool dead_nodes = 0;
  2732       Unique_Node_List checked(area);
  2733       while (visited.size() > 0) {
  2734         Node* n = visited.pop();
  2735         checked.push(n);
  2736         for (uint i = 0; i < n->outcnt(); i++) {
  2737           Node* use = n->raw_out(i);
  2738           if (checked.member(use))  continue;  // already checked
  2739           if (visited.member(use))  continue;  // already in the graph
  2740           if (use->is_Con())        continue;  // a dead ConNode is OK
  2741           // At this point, we have found a dead node which is DU-reachable.
  2742           if (dead_nodes++ == 0)
  2743             tty->print_cr("*** Dead nodes reachable via DU edges:");
  2744           use->dump(2);
  2745           tty->print_cr("---");
  2746           checked.push(use);  // No repeats; pretend it is now checked.
  2749       assert(dead_nodes == 0, "using nodes must be reachable from root");
  2753 #endif
  2755 // The Compile object keeps track of failure reasons separately from the ciEnv.
  2756 // This is required because there is not quite a 1-1 relation between the
  2757 // ciEnv and its compilation task and the Compile object.  Note that one
  2758 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
  2759 // to backtrack and retry without subsuming loads.  Other than this backtracking
  2760 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
  2761 // by the logic in C2Compiler.
  2762 void Compile::record_failure(const char* reason) {
  2763   if (log() != NULL) {
  2764     log()->elem("failure reason='%s' phase='compile'", reason);
  2766   if (_failure_reason == NULL) {
  2767     // Record the first failure reason.
  2768     _failure_reason = reason;
  2770   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
  2771     C->print_method(_failure_reason);
  2773   _root = NULL;  // flush the graph, too
  2776 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
  2777   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false)
  2779   if (dolog) {
  2780     C = Compile::current();
  2781     _log = C->log();
  2782   } else {
  2783     C = NULL;
  2784     _log = NULL;
  2786   if (_log != NULL) {
  2787     _log->begin_head("phase name='%s' nodes='%d'", name, C->unique());
  2788     _log->stamp();
  2789     _log->end_head();
  2793 Compile::TracePhase::~TracePhase() {
  2794   if (_log != NULL) {
  2795     _log->done("phase nodes='%d'", C->unique());

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