1 /*
   2  * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "asm/macroAssembler.hpp"
  27 #include "asm/macroAssembler.inline.hpp"
  28 #include "ci/ciReplay.hpp"
  29 #include "classfile/systemDictionary.hpp"
  30 #include "code/exceptionHandlerTable.hpp"
  31 #include "code/nmethod.hpp"
  32 #include "compiler/compileBroker.hpp"
  33 #include "compiler/compileLog.hpp"
  34 #include "compiler/disassembler.hpp"
  35 #include "compiler/oopMap.hpp"
  36 #include "memory/resourceArea.hpp"
  37 #include "opto/addnode.hpp"
  38 #include "opto/block.hpp"
  39 #include "opto/c2compiler.hpp"
  40 #include "opto/callGenerator.hpp"
  41 #include "opto/callnode.hpp"
  42 #include "opto/castnode.hpp"
  43 #include "opto/cfgnode.hpp"
  44 #include "opto/chaitin.hpp"
  45 #include "opto/compile.hpp"
  46 #include "opto/connode.hpp"
  47 #include "opto/convertnode.hpp"
  48 #include "opto/divnode.hpp"
  49 #include "opto/escape.hpp"
  50 #include "opto/idealGraphPrinter.hpp"
  51 #include "opto/loopnode.hpp"
  52 #include "opto/machnode.hpp"
  53 #include "opto/macro.hpp"
  54 #include "opto/matcher.hpp"
  55 #include "opto/mathexactnode.hpp"
  56 #include "opto/memnode.hpp"
  57 #include "opto/mulnode.hpp"
  58 #include "opto/narrowptrnode.hpp"
  59 #include "opto/node.hpp"
  60 #include "opto/opcodes.hpp"
  61 #include "opto/output.hpp"
  62 #include "opto/parse.hpp"
  63 #include "opto/phaseX.hpp"
  64 #include "opto/rootnode.hpp"
  65 #include "opto/runtime.hpp"
  66 #include "opto/stringopts.hpp"
  67 #include "opto/type.hpp"
  68 #include "opto/vectornode.hpp"
  69 #include "runtime/arguments.hpp"
  70 #include "runtime/sharedRuntime.hpp"
  71 #include "runtime/signature.hpp"
  72 #include "runtime/stubRoutines.hpp"
  73 #include "runtime/timer.hpp"
  74 #include "utilities/align.hpp"
  75 #include "utilities/copy.hpp"
  76 
  77 
  78 // -------------------- Compile::mach_constant_base_node -----------------------
  79 // Constant table base node singleton.
  80 MachConstantBaseNode* Compile::mach_constant_base_node() {
  81   if (_mach_constant_base_node == NULL) {
  82     _mach_constant_base_node = new MachConstantBaseNode();
  83     _mach_constant_base_node->add_req(C->root());
  84   }
  85   return _mach_constant_base_node;
  86 }
  87 
  88 
  89 /// Support for intrinsics.
  90 
  91 // Return the index at which m must be inserted (or already exists).
  92 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
  93 class IntrinsicDescPair {
  94  private:
  95   ciMethod* _m;
  96   bool _is_virtual;
  97  public:
  98   IntrinsicDescPair(ciMethod* m, bool is_virtual) : _m(m), _is_virtual(is_virtual) {}
  99   static int compare(IntrinsicDescPair* const& key, CallGenerator* const& elt) {
 100     ciMethod* m= elt->method();
 101     ciMethod* key_m = key->_m;
 102     if (key_m < m)      return -1;
 103     else if (key_m > m) return 1;
 104     else {
 105       bool is_virtual = elt->is_virtual();
 106       bool key_virtual = key->_is_virtual;
 107       if (key_virtual < is_virtual)      return -1;
 108       else if (key_virtual > is_virtual) return 1;
 109       else                               return 0;
 110     }
 111   }
 112 };
 113 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual, bool& found) {
 114 #ifdef ASSERT
 115   for (int i = 1; i < _intrinsics->length(); i++) {
 116     CallGenerator* cg1 = _intrinsics->at(i-1);
 117     CallGenerator* cg2 = _intrinsics->at(i);
 118     assert(cg1->method() != cg2->method()
 119            ? cg1->method()     < cg2->method()
 120            : cg1->is_virtual() < cg2->is_virtual(),
 121            "compiler intrinsics list must stay sorted");
 122   }
 123 #endif
 124   IntrinsicDescPair pair(m, is_virtual);
 125   return _intrinsics->find_sorted<IntrinsicDescPair*, IntrinsicDescPair::compare>(&pair, found);
 126 }
 127 
 128 void Compile::register_intrinsic(CallGenerator* cg) {
 129   if (_intrinsics == NULL) {
 130     _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
 131   }
 132   int len = _intrinsics->length();
 133   bool found = false;
 134   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual(), found);
 135   assert(!found, "registering twice");
 136   _intrinsics->insert_before(index, cg);
 137   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 138 }
 139 
 140 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 141   assert(m->is_loaded(), "don't try this on unloaded methods");
 142   if (_intrinsics != NULL) {
 143     bool found = false;
 144     int index = intrinsic_insertion_index(m, is_virtual, found);
 145      if (found) {
 146       return _intrinsics->at(index);
 147     }
 148   }
 149   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 150   if (m->intrinsic_id() != vmIntrinsics::_none &&
 151       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 152     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 153     if (cg != NULL) {
 154       // Save it for next time:
 155       register_intrinsic(cg);
 156       return cg;
 157     } else {
 158       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 159     }
 160   }
 161   return NULL;
 162 }
 163 
 164 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
 165 // in library_call.cpp.
 166 
 167 
 168 #ifndef PRODUCT
 169 // statistics gathering...
 170 
 171 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
 172 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
 173 
 174 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 175   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 176   int oflags = _intrinsic_hist_flags[id];
 177   assert(flags != 0, "what happened?");
 178   if (is_virtual) {
 179     flags |= _intrinsic_virtual;
 180   }
 181   bool changed = (flags != oflags);
 182   if ((flags & _intrinsic_worked) != 0) {
 183     juint count = (_intrinsic_hist_count[id] += 1);
 184     if (count == 1) {
 185       changed = true;           // first time
 186     }
 187     // increment the overall count also:
 188     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
 189   }
 190   if (changed) {
 191     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 192       // Something changed about the intrinsic's virtuality.
 193       if ((flags & _intrinsic_virtual) != 0) {
 194         // This is the first use of this intrinsic as a virtual call.
 195         if (oflags != 0) {
 196           // We already saw it as a non-virtual, so note both cases.
 197           flags |= _intrinsic_both;
 198         }
 199       } else if ((oflags & _intrinsic_both) == 0) {
 200         // This is the first use of this intrinsic as a non-virtual
 201         flags |= _intrinsic_both;
 202       }
 203     }
 204     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
 205   }
 206   // update the overall flags also:
 207   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
 208   return changed;
 209 }
 210 
 211 static char* format_flags(int flags, char* buf) {
 212   buf[0] = 0;
 213   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 214   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 215   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 216   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 217   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 218   if (buf[0] == 0)  strcat(buf, ",");
 219   assert(buf[0] == ',', "must be");
 220   return &buf[1];
 221 }
 222 
 223 void Compile::print_intrinsic_statistics() {
 224   char flagsbuf[100];
 225   ttyLocker ttyl;
 226   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
 227   tty->print_cr("Compiler intrinsic usage:");
 228   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
 229   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 230   #define PRINT_STAT_LINE(name, c, f) \
 231     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 232   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
 233     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
 234     int   flags = _intrinsic_hist_flags[id];
 235     juint count = _intrinsic_hist_count[id];
 236     if ((flags | count) != 0) {
 237       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 238     }
 239   }
 240   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
 241   if (xtty != NULL)  xtty->tail("statistics");
 242 }
 243 
 244 void Compile::print_statistics() {
 245   { ttyLocker ttyl;
 246     if (xtty != NULL)  xtty->head("statistics type='opto'");
 247     Parse::print_statistics();
 248     PhaseCCP::print_statistics();
 249     PhaseRegAlloc::print_statistics();
 250     Scheduling::print_statistics();
 251     PhasePeephole::print_statistics();
 252     PhaseIdealLoop::print_statistics();
 253     if (xtty != NULL)  xtty->tail("statistics");
 254   }
 255   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
 256     // put this under its own <statistics> element.
 257     print_intrinsic_statistics();
 258   }
 259 }
 260 #endif //PRODUCT
 261 
 262 // Support for bundling info
 263 Bundle* Compile::node_bundling(const Node *n) {
 264   assert(valid_bundle_info(n), "oob");
 265   return &_node_bundling_base[n->_idx];
 266 }
 267 
 268 bool Compile::valid_bundle_info(const Node *n) {
 269   return (_node_bundling_limit > n->_idx);
 270 }
 271 
 272 
 273 void Compile::gvn_replace_by(Node* n, Node* nn) {
 274   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 275     Node* use = n->last_out(i);
 276     bool is_in_table = initial_gvn()->hash_delete(use);
 277     uint uses_found = 0;
 278     for (uint j = 0; j < use->len(); j++) {
 279       if (use->in(j) == n) {
 280         if (j < use->req())
 281           use->set_req(j, nn);
 282         else
 283           use->set_prec(j, nn);
 284         uses_found++;
 285       }
 286     }
 287     if (is_in_table) {
 288       // reinsert into table
 289       initial_gvn()->hash_find_insert(use);
 290     }
 291     record_for_igvn(use);
 292     i -= uses_found;    // we deleted 1 or more copies of this edge
 293   }
 294 }
 295 
 296 
 297 static inline bool not_a_node(const Node* n) {
 298   if (n == NULL)                   return true;
 299   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
 300   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
 301   return false;
 302 }
 303 
 304 // Identify all nodes that are reachable from below, useful.
 305 // Use breadth-first pass that records state in a Unique_Node_List,
 306 // recursive traversal is slower.
 307 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 308   int estimated_worklist_size = live_nodes();
 309   useful.map( estimated_worklist_size, NULL );  // preallocate space
 310 
 311   // Initialize worklist
 312   if (root() != NULL)     { useful.push(root()); }
 313   // If 'top' is cached, declare it useful to preserve cached node
 314   if( cached_top_node() ) { useful.push(cached_top_node()); }
 315 
 316   // Push all useful nodes onto the list, breadthfirst
 317   for( uint next = 0; next < useful.size(); ++next ) {
 318     assert( next < unique(), "Unique useful nodes < total nodes");
 319     Node *n  = useful.at(next);
 320     uint max = n->len();
 321     for( uint i = 0; i < max; ++i ) {
 322       Node *m = n->in(i);
 323       if (not_a_node(m))  continue;
 324       useful.push(m);
 325     }
 326   }
 327 }
 328 
 329 // Update dead_node_list with any missing dead nodes using useful
 330 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 331 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 332   uint max_idx = unique();
 333   VectorSet& useful_node_set = useful.member_set();
 334 
 335   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 336     // If node with index node_idx is not in useful set,
 337     // mark it as dead in dead node list.
 338     if (! useful_node_set.test(node_idx) ) {
 339       record_dead_node(node_idx);
 340     }
 341   }
 342 }
 343 
 344 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 345   int shift = 0;
 346   for (int i = 0; i < inlines->length(); i++) {
 347     CallGenerator* cg = inlines->at(i);
 348     CallNode* call = cg->call_node();
 349     if (shift > 0) {
 350       inlines->at_put(i-shift, cg);
 351     }
 352     if (!useful.member(call)) {
 353       shift++;
 354     }
 355   }
 356   inlines->trunc_to(inlines->length()-shift);
 357 }
 358 
 359 // Disconnect all useless nodes by disconnecting those at the boundary.
 360 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
 361   uint next = 0;
 362   while (next < useful.size()) {
 363     Node *n = useful.at(next++);
 364     if (n->is_SafePoint()) {
 365       // We're done with a parsing phase. Replaced nodes are not valid
 366       // beyond that point.
 367       n->as_SafePoint()->delete_replaced_nodes();
 368     }
 369     // Use raw traversal of out edges since this code removes out edges
 370     int max = n->outcnt();
 371     for (int j = 0; j < max; ++j) {
 372       Node* child = n->raw_out(j);
 373       if (! useful.member(child)) {
 374         assert(!child->is_top() || child != top(),
 375                "If top is cached in Compile object it is in useful list");
 376         // Only need to remove this out-edge to the useless node
 377         n->raw_del_out(j);
 378         --j;
 379         --max;
 380       }
 381     }
 382     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 383       record_for_igvn(n->unique_out());
 384     }
 385   }
 386   // Remove useless macro and predicate opaq nodes
 387   for (int i = C->macro_count()-1; i >= 0; i--) {
 388     Node* n = C->macro_node(i);
 389     if (!useful.member(n)) {
 390       remove_macro_node(n);
 391     }
 392   }
 393   // Remove useless CastII nodes with range check dependency
 394   for (int i = range_check_cast_count() - 1; i >= 0; i--) {
 395     Node* cast = range_check_cast_node(i);
 396     if (!useful.member(cast)) {
 397       remove_range_check_cast(cast);
 398     }
 399   }
 400   // Remove useless expensive node
 401   for (int i = C->expensive_count()-1; i >= 0; i--) {
 402     Node* n = C->expensive_node(i);
 403     if (!useful.member(n)) {
 404       remove_expensive_node(n);
 405     }
 406   }
 407   // clean up the late inline lists
 408   remove_useless_late_inlines(&_string_late_inlines, useful);
 409   remove_useless_late_inlines(&_boxing_late_inlines, useful);
 410   remove_useless_late_inlines(&_late_inlines, useful);
 411   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 412 }
 413 
 414 //------------------------------frame_size_in_words-----------------------------
 415 // frame_slots in units of words
 416 int Compile::frame_size_in_words() const {
 417   // shift is 0 in LP32 and 1 in LP64
 418   const int shift = (LogBytesPerWord - LogBytesPerInt);
 419   int words = _frame_slots >> shift;
 420   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
 421   return words;
 422 }
 423 
 424 // To bang the stack of this compiled method we use the stack size
 425 // that the interpreter would need in case of a deoptimization. This
 426 // removes the need to bang the stack in the deoptimization blob which
 427 // in turn simplifies stack overflow handling.
 428 int Compile::bang_size_in_bytes() const {
 429   return MAX2(frame_size_in_bytes() + os::extra_bang_size_in_bytes(), _interpreter_frame_size);
 430 }
 431 
 432 // ============================================================================
 433 //------------------------------CompileWrapper---------------------------------
 434 class CompileWrapper : public StackObj {
 435   Compile *const _compile;
 436  public:
 437   CompileWrapper(Compile* compile);
 438 
 439   ~CompileWrapper();
 440 };
 441 
 442 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 443   // the Compile* pointer is stored in the current ciEnv:
 444   ciEnv* env = compile->env();
 445   assert(env == ciEnv::current(), "must already be a ciEnv active");
 446   assert(env->compiler_data() == NULL, "compile already active?");
 447   env->set_compiler_data(compile);
 448   assert(compile == Compile::current(), "sanity");
 449 
 450   compile->set_type_dict(NULL);
 451   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
 452   compile->clone_map().set_clone_idx(0);
 453   compile->set_type_hwm(NULL);
 454   compile->set_type_last_size(0);
 455   compile->set_last_tf(NULL, NULL);
 456   compile->set_indexSet_arena(NULL);
 457   compile->set_indexSet_free_block_list(NULL);
 458   compile->init_type_arena();
 459   Type::Initialize(compile);
 460   _compile->set_scratch_buffer_blob(NULL);
 461   _compile->begin_method();
 462   _compile->clone_map().set_debug(_compile->has_method() && _compile->directive()->CloneMapDebugOption);
 463 }
 464 CompileWrapper::~CompileWrapper() {
 465   _compile->end_method();
 466   if (_compile->scratch_buffer_blob() != NULL)
 467     BufferBlob::free(_compile->scratch_buffer_blob());
 468   _compile->env()->set_compiler_data(NULL);
 469 }
 470 
 471 
 472 //----------------------------print_compile_messages---------------------------
 473 void Compile::print_compile_messages() {
 474 #ifndef PRODUCT
 475   // Check if recompiling
 476   if (_subsume_loads == false && PrintOpto) {
 477     // Recompiling without allowing machine instructions to subsume loads
 478     tty->print_cr("*********************************************************");
 479     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 480     tty->print_cr("*********************************************************");
 481   }
 482   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
 483     // Recompiling without escape analysis
 484     tty->print_cr("*********************************************************");
 485     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 486     tty->print_cr("*********************************************************");
 487   }
 488   if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
 489     // Recompiling without boxing elimination
 490     tty->print_cr("*********************************************************");
 491     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 492     tty->print_cr("*********************************************************");
 493   }
 494   if (C->directive()->BreakAtCompileOption) {
 495     // Open the debugger when compiling this method.
 496     tty->print("### Breaking when compiling: ");
 497     method()->print_short_name();
 498     tty->cr();
 499     BREAKPOINT;
 500   }
 501 
 502   if( PrintOpto ) {
 503     if (is_osr_compilation()) {
 504       tty->print("[OSR]%3d", _compile_id);
 505     } else {
 506       tty->print("%3d", _compile_id);
 507     }
 508   }
 509 #endif
 510 }
 511 
 512 
 513 //-----------------------init_scratch_buffer_blob------------------------------
 514 // Construct a temporary BufferBlob and cache it for this compile.
 515 void Compile::init_scratch_buffer_blob(int const_size) {
 516   // If there is already a scratch buffer blob allocated and the
 517   // constant section is big enough, use it.  Otherwise free the
 518   // current and allocate a new one.
 519   BufferBlob* blob = scratch_buffer_blob();
 520   if ((blob != NULL) && (const_size <= _scratch_const_size)) {
 521     // Use the current blob.
 522   } else {
 523     if (blob != NULL) {
 524       BufferBlob::free(blob);
 525     }
 526 
 527     ResourceMark rm;
 528     _scratch_const_size = const_size;
 529     int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
 530     blob = BufferBlob::create("Compile::scratch_buffer", size);
 531     // Record the buffer blob for next time.
 532     set_scratch_buffer_blob(blob);
 533     // Have we run out of code space?
 534     if (scratch_buffer_blob() == NULL) {
 535       // Let CompilerBroker disable further compilations.
 536       record_failure("Not enough space for scratch buffer in CodeCache");
 537       return;
 538     }
 539   }
 540 
 541   // Initialize the relocation buffers
 542   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
 543   set_scratch_locs_memory(locs_buf);
 544 }
 545 
 546 
 547 //-----------------------scratch_emit_size-------------------------------------
 548 // Helper function that computes size by emitting code
 549 uint Compile::scratch_emit_size(const Node* n) {
 550   // Start scratch_emit_size section.
 551   set_in_scratch_emit_size(true);
 552 
 553   // Emit into a trash buffer and count bytes emitted.
 554   // This is a pretty expensive way to compute a size,
 555   // but it works well enough if seldom used.
 556   // All common fixed-size instructions are given a size
 557   // method by the AD file.
 558   // Note that the scratch buffer blob and locs memory are
 559   // allocated at the beginning of the compile task, and
 560   // may be shared by several calls to scratch_emit_size.
 561   // The allocation of the scratch buffer blob is particularly
 562   // expensive, since it has to grab the code cache lock.
 563   BufferBlob* blob = this->scratch_buffer_blob();
 564   assert(blob != NULL, "Initialize BufferBlob at start");
 565   assert(blob->size() > MAX_inst_size, "sanity");
 566   relocInfo* locs_buf = scratch_locs_memory();
 567   address blob_begin = blob->content_begin();
 568   address blob_end   = (address)locs_buf;
 569   assert(blob->contains(blob_end), "sanity");
 570   CodeBuffer buf(blob_begin, blob_end - blob_begin);
 571   buf.initialize_consts_size(_scratch_const_size);
 572   buf.initialize_stubs_size(MAX_stubs_size);
 573   assert(locs_buf != NULL, "sanity");
 574   int lsize = MAX_locs_size / 3;
 575   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
 576   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
 577   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
 578   // Mark as scratch buffer.
 579   buf.consts()->set_scratch_emit();
 580   buf.insts()->set_scratch_emit();
 581   buf.stubs()->set_scratch_emit();
 582 
 583   // Do the emission.
 584 
 585   Label fakeL; // Fake label for branch instructions.
 586   Label*   saveL = NULL;
 587   uint save_bnum = 0;
 588   bool is_branch = n->is_MachBranch();
 589   if (is_branch) {
 590     MacroAssembler masm(&buf);
 591     masm.bind(fakeL);
 592     n->as_MachBranch()->save_label(&saveL, &save_bnum);
 593     n->as_MachBranch()->label_set(&fakeL, 0);
 594   }
 595   n->emit(buf, this->regalloc());
 596 
 597   // Emitting into the scratch buffer should not fail
 598   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
 599 
 600   if (is_branch) // Restore label.
 601     n->as_MachBranch()->label_set(saveL, save_bnum);
 602 
 603   // End scratch_emit_size section.
 604   set_in_scratch_emit_size(false);
 605 
 606   return buf.insts_size();
 607 }
 608 
 609 
 610 // ============================================================================
 611 //------------------------------Compile standard-------------------------------
 612 debug_only( int Compile::_debug_idx = 100000; )
 613 
 614 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 615 // the continuation bci for on stack replacement.
 616 
 617 
 618 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
 619                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing, DirectiveSet* directive)
 620                 : Phase(Compiler),
 621                   _env(ci_env),
 622                   _directive(directive),
 623                   _log(ci_env->log()),
 624                   _compile_id(ci_env->compile_id()),
 625                   _save_argument_registers(false),
 626                   _stub_name(NULL),
 627                   _stub_function(NULL),
 628                   _stub_entry_point(NULL),
 629                   _method(target),
 630                   _entry_bci(osr_bci),
 631                   _initial_gvn(NULL),
 632                   _for_igvn(NULL),
 633                   _warm_calls(NULL),
 634                   _subsume_loads(subsume_loads),
 635                   _do_escape_analysis(do_escape_analysis),
 636                   _eliminate_boxing(eliminate_boxing),
 637                   _failure_reason(NULL),
 638                   _code_buffer("Compile::Fill_buffer"),
 639                   _orig_pc_slot(0),
 640                   _orig_pc_slot_offset_in_bytes(0),
 641                   _has_method_handle_invokes(false),
 642                   _mach_constant_base_node(NULL),
 643                   _node_bundling_limit(0),
 644                   _node_bundling_base(NULL),
 645                   _java_calls(0),
 646                   _inner_loops(0),
 647                   _scratch_const_size(-1),
 648                   _in_scratch_emit_size(false),
 649                   _dead_node_list(comp_arena()),
 650                   _dead_node_count(0),
 651 #ifndef PRODUCT
 652                   _trace_opto_output(directive->TraceOptoOutputOption),
 653                   _in_dump_cnt(0),
 654                   _printer(IdealGraphPrinter::printer()),
 655 #endif
 656                   _congraph(NULL),
 657                   _comp_arena(mtCompiler),
 658                   _node_arena(mtCompiler),
 659                   _old_arena(mtCompiler),
 660                   _Compile_types(mtCompiler),
 661                   _replay_inline_data(NULL),
 662                   _late_inlines(comp_arena(), 2, 0, NULL),
 663                   _string_late_inlines(comp_arena(), 2, 0, NULL),
 664                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
 665                   _late_inlines_pos(0),
 666                   _number_of_mh_late_inlines(0),
 667                   _inlining_progress(false),
 668                   _inlining_incrementally(false),
 669                   _print_inlining_list(NULL),
 670                   _print_inlining_stream(NULL),
 671                   _print_inlining_idx(0),
 672                   _print_inlining_output(NULL),
 673                   _interpreter_frame_size(0),
 674                   _max_node_limit(MaxNodeLimit),
 675                   _has_reserved_stack_access(target->has_reserved_stack_access()) {
 676   C = this;
 677 #ifndef PRODUCT
 678   if (_printer != NULL) {
 679     _printer->set_compile(this);
 680   }
 681 #endif
 682   CompileWrapper cw(this);
 683 
 684   if (CITimeVerbose) {
 685     tty->print(" ");
 686     target->holder()->name()->print();
 687     tty->print(".");
 688     target->print_short_name();
 689     tty->print("  ");
 690   }
 691   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 692   TraceTime t2(NULL, &_t_methodCompilation, CITime, false);
 693 
 694 #ifndef PRODUCT
 695   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 696   if (!print_opto_assembly) {
 697     bool print_assembly = directive->PrintAssemblyOption;
 698     if (print_assembly && !Disassembler::can_decode()) {
 699       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
 700       print_opto_assembly = true;
 701     }
 702   }
 703   set_print_assembly(print_opto_assembly);
 704   set_parsed_irreducible_loop(false);
 705 
 706   if (directive->ReplayInlineOption) {
 707     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 708   }
 709 #endif
 710   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 711   set_print_intrinsics(directive->PrintIntrinsicsOption);
 712   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 713 
 714   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
 715     // Make sure the method being compiled gets its own MDO,
 716     // so we can at least track the decompile_count().
 717     // Need MDO to record RTM code generation state.
 718     method()->ensure_method_data();
 719   }
 720 
 721   Init(::AliasLevel);
 722 
 723 
 724   print_compile_messages();
 725 
 726   _ilt = InlineTree::build_inline_tree_root();
 727 
 728   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 729   assert(num_alias_types() >= AliasIdxRaw, "");
 730 
 731 #define MINIMUM_NODE_HASH  1023
 732   // Node list that Iterative GVN will start with
 733   Unique_Node_List for_igvn(comp_arena());
 734   set_for_igvn(&for_igvn);
 735 
 736   // GVN that will be run immediately on new nodes
 737   uint estimated_size = method()->code_size()*4+64;
 738   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 739   PhaseGVN gvn(node_arena(), estimated_size);
 740   set_initial_gvn(&gvn);
 741 
 742   print_inlining_init();
 743   { // Scope for timing the parser
 744     TracePhase tp("parse", &timers[_t_parser]);
 745 
 746     // Put top into the hash table ASAP.
 747     initial_gvn()->transform_no_reclaim(top());
 748 
 749     // Set up tf(), start(), and find a CallGenerator.
 750     CallGenerator* cg = NULL;
 751     if (is_osr_compilation()) {
 752       const TypeTuple *domain = StartOSRNode::osr_domain();
 753       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 754       init_tf(TypeFunc::make(domain, range));
 755       StartNode* s = new StartOSRNode(root(), domain);
 756       initial_gvn()->set_type_bottom(s);
 757       init_start(s);
 758       cg = CallGenerator::for_osr(method(), entry_bci());
 759     } else {
 760       // Normal case.
 761       init_tf(TypeFunc::make(method()));
 762       StartNode* s = new StartNode(root(), tf()->domain());
 763       initial_gvn()->set_type_bottom(s);
 764       init_start(s);
 765       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
 766         // With java.lang.ref.reference.get() we must go through the
 767         // intrinsic when G1 is enabled - even when get() is the root
 768         // method of the compile - so that, if necessary, the value in
 769         // the referent field of the reference object gets recorded by
 770         // the pre-barrier code.
 771         // Specifically, if G1 is enabled, the value in the referent
 772         // field is recorded by the G1 SATB pre barrier. This will
 773         // result in the referent being marked live and the reference
 774         // object removed from the list of discovered references during
 775         // reference processing.
 776         cg = find_intrinsic(method(), false);
 777       }
 778       if (cg == NULL) {
 779         float past_uses = method()->interpreter_invocation_count();
 780         float expected_uses = past_uses;
 781         cg = CallGenerator::for_inline(method(), expected_uses);
 782       }
 783     }
 784     if (failing())  return;
 785     if (cg == NULL) {
 786       record_method_not_compilable("cannot parse method");
 787       return;
 788     }
 789     JVMState* jvms = build_start_state(start(), tf());
 790     if ((jvms = cg->generate(jvms)) == NULL) {
 791       if (!failure_reason_is(C2Compiler::retry_class_loading_during_parsing())) {
 792         record_method_not_compilable("method parse failed");
 793       }
 794       return;
 795     }
 796     GraphKit kit(jvms);
 797 
 798     if (!kit.stopped()) {
 799       // Accept return values, and transfer control we know not where.
 800       // This is done by a special, unique ReturnNode bound to root.
 801       return_values(kit.jvms());
 802     }
 803 
 804     if (kit.has_exceptions()) {
 805       // Any exceptions that escape from this call must be rethrown
 806       // to whatever caller is dynamically above us on the stack.
 807       // This is done by a special, unique RethrowNode bound to root.
 808       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 809     }
 810 
 811     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 812 
 813     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 814       inline_string_calls(true);
 815     }
 816 
 817     if (failing())  return;
 818 
 819     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
 820 
 821     // Remove clutter produced by parsing.
 822     if (!failing()) {
 823       ResourceMark rm;
 824       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 825     }
 826   }
 827 
 828   // Note:  Large methods are capped off in do_one_bytecode().
 829   if (failing())  return;
 830 
 831   // After parsing, node notes are no longer automagic.
 832   // They must be propagated by register_new_node_with_optimizer(),
 833   // clone(), or the like.
 834   set_default_node_notes(NULL);
 835 
 836   for (;;) {
 837     int successes = Inline_Warm();
 838     if (failing())  return;
 839     if (successes == 0)  break;
 840   }
 841 
 842   // Drain the list.
 843   Finish_Warm();
 844 #ifndef PRODUCT
 845   if (_printer && _printer->should_print(1)) {
 846     _printer->print_inlining();
 847   }
 848 #endif
 849 
 850   if (failing())  return;
 851   NOT_PRODUCT( verify_graph_edges(); )
 852 
 853   // Now optimize
 854   Optimize();
 855   if (failing())  return;
 856   NOT_PRODUCT( verify_graph_edges(); )
 857 
 858 #ifndef PRODUCT
 859   if (PrintIdeal) {
 860     ttyLocker ttyl;  // keep the following output all in one block
 861     // This output goes directly to the tty, not the compiler log.
 862     // To enable tools to match it up with the compilation activity,
 863     // be sure to tag this tty output with the compile ID.
 864     if (xtty != NULL) {
 865       xtty->head("ideal compile_id='%d'%s", compile_id(),
 866                  is_osr_compilation()    ? " compile_kind='osr'" :
 867                  "");
 868     }
 869     root()->dump(9999);
 870     if (xtty != NULL) {
 871       xtty->tail("ideal");
 872     }
 873   }
 874 #endif
 875 
 876   NOT_PRODUCT( verify_barriers(); )
 877 
 878   // Dump compilation data to replay it.
 879   if (directive->DumpReplayOption) {
 880     env()->dump_replay_data(_compile_id);
 881   }
 882   if (directive->DumpInlineOption && (ilt() != NULL)) {
 883     env()->dump_inline_data(_compile_id);
 884   }
 885 
 886   // Now that we know the size of all the monitors we can add a fixed slot
 887   // for the original deopt pc.
 888 
 889   _orig_pc_slot =  fixed_slots();
 890   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 891   set_fixed_slots(next_slot);
 892 
 893   // Compute when to use implicit null checks. Used by matching trap based
 894   // nodes and NullCheck optimization.
 895   set_allowed_deopt_reasons();
 896 
 897   // Now generate code
 898   Code_Gen();
 899   if (failing())  return;
 900 
 901   // Check if we want to skip execution of all compiled code.
 902   {
 903 #ifndef PRODUCT
 904     if (OptoNoExecute) {
 905       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 906       return;
 907     }
 908 #endif
 909     TracePhase tp("install_code", &timers[_t_registerMethod]);
 910 
 911     if (is_osr_compilation()) {
 912       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 913       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 914     } else {
 915       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 916       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 917     }
 918 
 919     env()->register_method(_method, _entry_bci,
 920                            &_code_offsets,
 921                            _orig_pc_slot_offset_in_bytes,
 922                            code_buffer(),
 923                            frame_size_in_words(), _oop_map_set,
 924                            &_handler_table, &_inc_table,
 925                            compiler,
 926                            has_unsafe_access(),
 927                            SharedRuntime::is_wide_vector(max_vector_size()),
 928                            rtm_state()
 929                            );
 930 
 931     if (log() != NULL) // Print code cache state into compiler log
 932       log()->code_cache_state();
 933   }
 934 }
 935 
 936 //------------------------------Compile----------------------------------------
 937 // Compile a runtime stub
 938 Compile::Compile( ciEnv* ci_env,
 939                   TypeFunc_generator generator,
 940                   address stub_function,
 941                   const char *stub_name,
 942                   int is_fancy_jump,
 943                   bool pass_tls,
 944                   bool save_arg_registers,
 945                   bool return_pc,
 946                   DirectiveSet* directive)
 947   : Phase(Compiler),
 948     _env(ci_env),
 949     _directive(directive),
 950     _log(ci_env->log()),
 951     _compile_id(0),
 952     _save_argument_registers(save_arg_registers),
 953     _method(NULL),
 954     _stub_name(stub_name),
 955     _stub_function(stub_function),
 956     _stub_entry_point(NULL),
 957     _entry_bci(InvocationEntryBci),
 958     _initial_gvn(NULL),
 959     _for_igvn(NULL),
 960     _warm_calls(NULL),
 961     _orig_pc_slot(0),
 962     _orig_pc_slot_offset_in_bytes(0),
 963     _subsume_loads(true),
 964     _do_escape_analysis(false),
 965     _eliminate_boxing(false),
 966     _failure_reason(NULL),
 967     _code_buffer("Compile::Fill_buffer"),
 968     _has_method_handle_invokes(false),
 969     _mach_constant_base_node(NULL),
 970     _node_bundling_limit(0),
 971     _node_bundling_base(NULL),
 972     _java_calls(0),
 973     _inner_loops(0),
 974 #ifndef PRODUCT
 975     _trace_opto_output(directive->TraceOptoOutputOption),
 976     _in_dump_cnt(0),
 977     _printer(NULL),
 978 #endif
 979     _comp_arena(mtCompiler),
 980     _node_arena(mtCompiler),
 981     _old_arena(mtCompiler),
 982     _Compile_types(mtCompiler),
 983     _dead_node_list(comp_arena()),
 984     _dead_node_count(0),
 985     _congraph(NULL),
 986     _replay_inline_data(NULL),
 987     _number_of_mh_late_inlines(0),
 988     _inlining_progress(false),
 989     _inlining_incrementally(false),
 990     _print_inlining_list(NULL),
 991     _print_inlining_stream(NULL),
 992     _print_inlining_idx(0),
 993     _print_inlining_output(NULL),
 994     _allowed_reasons(0),
 995     _interpreter_frame_size(0),
 996     _max_node_limit(MaxNodeLimit),
 997     _has_reserved_stack_access(false) {
 998   C = this;
 999 
1000   TraceTime t1(NULL, &_t_totalCompilation, CITime, false);
1001   TraceTime t2(NULL, &_t_stubCompilation, CITime, false);
1002 
1003 #ifndef PRODUCT
1004   set_print_assembly(PrintFrameConverterAssembly);
1005   set_parsed_irreducible_loop(false);
1006 #endif
1007   set_has_irreducible_loop(false); // no loops
1008 
1009   CompileWrapper cw(this);
1010   Init(/*AliasLevel=*/ 0);
1011   init_tf((*generator)());
1012 
1013   {
1014     // The following is a dummy for the sake of GraphKit::gen_stub
1015     Unique_Node_List for_igvn(comp_arena());
1016     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
1017     PhaseGVN gvn(Thread::current()->resource_area(),255);
1018     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1019     gvn.transform_no_reclaim(top());
1020 
1021     GraphKit kit;
1022     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1023   }
1024 
1025   NOT_PRODUCT( verify_graph_edges(); )
1026   Code_Gen();
1027   if (failing())  return;
1028 
1029 
1030   // Entry point will be accessed using compile->stub_entry_point();
1031   if (code_buffer() == NULL) {
1032     Matcher::soft_match_failure();
1033   } else {
1034     if (PrintAssembly && (WizardMode || Verbose))
1035       tty->print_cr("### Stub::%s", stub_name);
1036 
1037     if (!failing()) {
1038       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1039 
1040       // Make the NMethod
1041       // For now we mark the frame as never safe for profile stackwalking
1042       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1043                                                       code_buffer(),
1044                                                       CodeOffsets::frame_never_safe,
1045                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
1046                                                       frame_size_in_words(),
1047                                                       _oop_map_set,
1048                                                       save_arg_registers);
1049       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1050 
1051       _stub_entry_point = rs->entry_point();
1052     }
1053   }
1054 }
1055 
1056 //------------------------------Init-------------------------------------------
1057 // Prepare for a single compilation
1058 void Compile::Init(int aliaslevel) {
1059   _unique  = 0;
1060   _regalloc = NULL;
1061 
1062   _tf      = NULL;  // filled in later
1063   _top     = NULL;  // cached later
1064   _matcher = NULL;  // filled in later
1065   _cfg     = NULL;  // filled in later
1066 
1067   set_24_bit_selection_and_mode(Use24BitFP, false);
1068 
1069   _node_note_array = NULL;
1070   _default_node_notes = NULL;
1071   DEBUG_ONLY( _modified_nodes = NULL; ) // Used in Optimize()
1072 
1073   _immutable_memory = NULL; // filled in at first inquiry
1074 
1075   // Globally visible Nodes
1076   // First set TOP to NULL to give safe behavior during creation of RootNode
1077   set_cached_top_node(NULL);
1078   set_root(new RootNode());
1079   // Now that you have a Root to point to, create the real TOP
1080   set_cached_top_node( new ConNode(Type::TOP) );
1081   set_recent_alloc(NULL, NULL);
1082 
1083   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1084   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1085   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1086   env()->set_dependencies(new Dependencies(env()));
1087 
1088   _fixed_slots = 0;
1089   set_has_split_ifs(false);
1090   set_has_loops(has_method() && method()->has_loops()); // first approximation
1091   set_has_stringbuilder(false);
1092   set_has_boxed_value(false);
1093   _trap_can_recompile = false;  // no traps emitted yet
1094   _major_progress = true; // start out assuming good things will happen
1095   set_has_unsafe_access(false);
1096   set_max_vector_size(0);
1097   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1098   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1099   set_decompile_count(0);
1100 
1101   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1102   set_num_loop_opts(LoopOptsCount);
1103   set_do_inlining(Inline);
1104   set_max_inline_size(MaxInlineSize);
1105   set_freq_inline_size(FreqInlineSize);
1106   set_do_scheduling(OptoScheduling);
1107   set_do_count_invocations(false);
1108   set_do_method_data_update(false);
1109 
1110   set_do_vector_loop(false);
1111 
1112   if (AllowVectorizeOnDemand) {
1113     if (has_method() && (_directive->VectorizeOption || _directive->VectorizeDebugOption)) {
1114       set_do_vector_loop(true);
1115       NOT_PRODUCT(if (do_vector_loop() && Verbose) {tty->print("Compile::Init: do vectorized loops (SIMD like) for method %s\n",  method()->name()->as_quoted_ascii());})
1116     } else if (has_method() && method()->name() != 0 &&
1117                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1118       set_do_vector_loop(true);
1119     }
1120   }
1121   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1122   NOT_PRODUCT(if (use_cmove() && Verbose && has_method()) {tty->print("Compile::Init: use CMove without profitability tests for method %s\n",  method()->name()->as_quoted_ascii());})
1123 
1124   set_age_code(has_method() && method()->profile_aging());
1125   set_rtm_state(NoRTM); // No RTM lock eliding by default
1126   _max_node_limit = _directive->MaxNodeLimitOption;
1127 
1128 #if INCLUDE_RTM_OPT
1129   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1130     int rtm_state = method()->method_data()->rtm_state();
1131     if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
1132       // Don't generate RTM lock eliding code.
1133       set_rtm_state(NoRTM);
1134     } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1135       // Generate RTM lock eliding code without abort ratio calculation code.
1136       set_rtm_state(UseRTM);
1137     } else if (UseRTMDeopt) {
1138       // Generate RTM lock eliding code and include abort ratio calculation
1139       // code if UseRTMDeopt is on.
1140       set_rtm_state(ProfileRTM);
1141     }
1142   }
1143 #endif
1144   if (debug_info()->recording_non_safepoints()) {
1145     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1146                         (comp_arena(), 8, 0, NULL));
1147     set_default_node_notes(Node_Notes::make(this));
1148   }
1149 
1150   // // -- Initialize types before each compile --
1151   // // Update cached type information
1152   // if( _method && _method->constants() )
1153   //   Type::update_loaded_types(_method, _method->constants());
1154 
1155   // Init alias_type map.
1156   if (!_do_escape_analysis && aliaslevel == 3)
1157     aliaslevel = 2;  // No unique types without escape analysis
1158   _AliasLevel = aliaslevel;
1159   const int grow_ats = 16;
1160   _max_alias_types = grow_ats;
1161   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1162   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1163   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1164   {
1165     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1166   }
1167   // Initialize the first few types.
1168   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1169   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1170   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1171   _num_alias_types = AliasIdxRaw+1;
1172   // Zero out the alias type cache.
1173   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1174   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1175   probe_alias_cache(NULL)->_index = AliasIdxTop;
1176 
1177   _intrinsics = NULL;
1178   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1179   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1180   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1181   _range_check_casts = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1182   register_library_intrinsics();
1183 }
1184 
1185 //---------------------------init_start----------------------------------------
1186 // Install the StartNode on this compile object.
1187 void Compile::init_start(StartNode* s) {
1188   if (failing())
1189     return; // already failing
1190   assert(s == start(), "");
1191 }
1192 
1193 /**
1194  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1195  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1196  * the ideal graph.
1197  */
1198 StartNode* Compile::start() const {
1199   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
1200   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1201     Node* start = root()->fast_out(i);
1202     if (start->is_Start()) {
1203       return start->as_Start();
1204     }
1205   }
1206   fatal("Did not find Start node!");
1207   return NULL;
1208 }
1209 
1210 //-------------------------------immutable_memory-------------------------------------
1211 // Access immutable memory
1212 Node* Compile::immutable_memory() {
1213   if (_immutable_memory != NULL) {
1214     return _immutable_memory;
1215   }
1216   StartNode* s = start();
1217   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1218     Node *p = s->fast_out(i);
1219     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1220       _immutable_memory = p;
1221       return _immutable_memory;
1222     }
1223   }
1224   ShouldNotReachHere();
1225   return NULL;
1226 }
1227 
1228 //----------------------set_cached_top_node------------------------------------
1229 // Install the cached top node, and make sure Node::is_top works correctly.
1230 void Compile::set_cached_top_node(Node* tn) {
1231   if (tn != NULL)  verify_top(tn);
1232   Node* old_top = _top;
1233   _top = tn;
1234   // Calling Node::setup_is_top allows the nodes the chance to adjust
1235   // their _out arrays.
1236   if (_top != NULL)     _top->setup_is_top();
1237   if (old_top != NULL)  old_top->setup_is_top();
1238   assert(_top == NULL || top()->is_top(), "");
1239 }
1240 
1241 #ifdef ASSERT
1242 uint Compile::count_live_nodes_by_graph_walk() {
1243   Unique_Node_List useful(comp_arena());
1244   // Get useful node list by walking the graph.
1245   identify_useful_nodes(useful);
1246   return useful.size();
1247 }
1248 
1249 void Compile::print_missing_nodes() {
1250 
1251   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1252   if ((_log == NULL) && (! PrintIdealNodeCount)) {
1253     return;
1254   }
1255 
1256   // This is an expensive function. It is executed only when the user
1257   // specifies VerifyIdealNodeCount option or otherwise knows the
1258   // additional work that needs to be done to identify reachable nodes
1259   // by walking the flow graph and find the missing ones using
1260   // _dead_node_list.
1261 
1262   Unique_Node_List useful(comp_arena());
1263   // Get useful node list by walking the graph.
1264   identify_useful_nodes(useful);
1265 
1266   uint l_nodes = C->live_nodes();
1267   uint l_nodes_by_walk = useful.size();
1268 
1269   if (l_nodes != l_nodes_by_walk) {
1270     if (_log != NULL) {
1271       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1272       _log->stamp();
1273       _log->end_head();
1274     }
1275     VectorSet& useful_member_set = useful.member_set();
1276     int last_idx = l_nodes_by_walk;
1277     for (int i = 0; i < last_idx; i++) {
1278       if (useful_member_set.test(i)) {
1279         if (_dead_node_list.test(i)) {
1280           if (_log != NULL) {
1281             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1282           }
1283           if (PrintIdealNodeCount) {
1284             // Print the log message to tty
1285               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1286               useful.at(i)->dump();
1287           }
1288         }
1289       }
1290       else if (! _dead_node_list.test(i)) {
1291         if (_log != NULL) {
1292           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1293         }
1294         if (PrintIdealNodeCount) {
1295           // Print the log message to tty
1296           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1297         }
1298       }
1299     }
1300     if (_log != NULL) {
1301       _log->tail("mismatched_nodes");
1302     }
1303   }
1304 }
1305 void Compile::record_modified_node(Node* n) {
1306   if (_modified_nodes != NULL && !_inlining_incrementally &&
1307       n->outcnt() != 0 && !n->is_Con()) {
1308     _modified_nodes->push(n);
1309   }
1310 }
1311 
1312 void Compile::remove_modified_node(Node* n) {
1313   if (_modified_nodes != NULL) {
1314     _modified_nodes->remove(n);
1315   }
1316 }
1317 #endif
1318 
1319 #ifndef PRODUCT
1320 void Compile::verify_top(Node* tn) const {
1321   if (tn != NULL) {
1322     assert(tn->is_Con(), "top node must be a constant");
1323     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1324     assert(tn->in(0) != NULL, "must have live top node");
1325   }
1326 }
1327 #endif
1328 
1329 
1330 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1331 
1332 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1333   guarantee(arr != NULL, "");
1334   int num_blocks = arr->length();
1335   if (grow_by < num_blocks)  grow_by = num_blocks;
1336   int num_notes = grow_by * _node_notes_block_size;
1337   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1338   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1339   while (num_notes > 0) {
1340     arr->append(notes);
1341     notes     += _node_notes_block_size;
1342     num_notes -= _node_notes_block_size;
1343   }
1344   assert(num_notes == 0, "exact multiple, please");
1345 }
1346 
1347 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1348   if (source == NULL || dest == NULL)  return false;
1349 
1350   if (dest->is_Con())
1351     return false;               // Do not push debug info onto constants.
1352 
1353 #ifdef ASSERT
1354   // Leave a bread crumb trail pointing to the original node:
1355   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1356     dest->set_debug_orig(source);
1357   }
1358 #endif
1359 
1360   if (node_note_array() == NULL)
1361     return false;               // Not collecting any notes now.
1362 
1363   // This is a copy onto a pre-existing node, which may already have notes.
1364   // If both nodes have notes, do not overwrite any pre-existing notes.
1365   Node_Notes* source_notes = node_notes_at(source->_idx);
1366   if (source_notes == NULL || source_notes->is_clear())  return false;
1367   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1368   if (dest_notes == NULL || dest_notes->is_clear()) {
1369     return set_node_notes_at(dest->_idx, source_notes);
1370   }
1371 
1372   Node_Notes merged_notes = (*source_notes);
1373   // The order of operations here ensures that dest notes will win...
1374   merged_notes.update_from(dest_notes);
1375   return set_node_notes_at(dest->_idx, &merged_notes);
1376 }
1377 
1378 
1379 //--------------------------allow_range_check_smearing-------------------------
1380 // Gating condition for coalescing similar range checks.
1381 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1382 // single covering check that is at least as strong as any of them.
1383 // If the optimization succeeds, the simplified (strengthened) range check
1384 // will always succeed.  If it fails, we will deopt, and then give up
1385 // on the optimization.
1386 bool Compile::allow_range_check_smearing() const {
1387   // If this method has already thrown a range-check,
1388   // assume it was because we already tried range smearing
1389   // and it failed.
1390   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1391   return !already_trapped;
1392 }
1393 
1394 
1395 //------------------------------flatten_alias_type-----------------------------
1396 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1397   int offset = tj->offset();
1398   TypePtr::PTR ptr = tj->ptr();
1399 
1400   // Known instance (scalarizable allocation) alias only with itself.
1401   bool is_known_inst = tj->isa_oopptr() != NULL &&
1402                        tj->is_oopptr()->is_known_instance();
1403 
1404   // Process weird unsafe references.
1405   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1406     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1407     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1408     tj = TypeOopPtr::BOTTOM;
1409     ptr = tj->ptr();
1410     offset = tj->offset();
1411   }
1412 
1413   // Array pointers need some flattening
1414   const TypeAryPtr *ta = tj->isa_aryptr();
1415   if (ta && ta->is_stable()) {
1416     // Erase stability property for alias analysis.
1417     tj = ta = ta->cast_to_stable(false);
1418   }
1419   if( ta && is_known_inst ) {
1420     if ( offset != Type::OffsetBot &&
1421          offset > arrayOopDesc::length_offset_in_bytes() ) {
1422       offset = Type::OffsetBot; // Flatten constant access into array body only
1423       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1424     }
1425   } else if( ta && _AliasLevel >= 2 ) {
1426     // For arrays indexed by constant indices, we flatten the alias
1427     // space to include all of the array body.  Only the header, klass
1428     // and array length can be accessed un-aliased.
1429     if( offset != Type::OffsetBot ) {
1430       if( ta->const_oop() ) { // MethodData* or Method*
1431         offset = Type::OffsetBot;   // Flatten constant access into array body
1432         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1433       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1434         // range is OK as-is.
1435         tj = ta = TypeAryPtr::RANGE;
1436       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1437         tj = TypeInstPtr::KLASS; // all klass loads look alike
1438         ta = TypeAryPtr::RANGE; // generic ignored junk
1439         ptr = TypePtr::BotPTR;
1440       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1441         tj = TypeInstPtr::MARK;
1442         ta = TypeAryPtr::RANGE; // generic ignored junk
1443         ptr = TypePtr::BotPTR;
1444       } else {                  // Random constant offset into array body
1445         offset = Type::OffsetBot;   // Flatten constant access into array body
1446         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1447       }
1448     }
1449     // Arrays of fixed size alias with arrays of unknown size.
1450     if (ta->size() != TypeInt::POS) {
1451       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1452       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1453     }
1454     // Arrays of known objects become arrays of unknown objects.
1455     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1456       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1457       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1458     }
1459     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1460       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1461       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1462     }
1463     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1464     // cannot be distinguished by bytecode alone.
1465     if (ta->elem() == TypeInt::BOOL) {
1466       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1467       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1468       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1469     }
1470     // During the 2nd round of IterGVN, NotNull castings are removed.
1471     // Make sure the Bottom and NotNull variants alias the same.
1472     // Also, make sure exact and non-exact variants alias the same.
1473     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1474       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1475     }
1476   }
1477 
1478   // Oop pointers need some flattening
1479   const TypeInstPtr *to = tj->isa_instptr();
1480   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1481     ciInstanceKlass *k = to->klass()->as_instance_klass();
1482     if( ptr == TypePtr::Constant ) {
1483       if (to->klass() != ciEnv::current()->Class_klass() ||
1484           offset < k->size_helper() * wordSize) {
1485         // No constant oop pointers (such as Strings); they alias with
1486         // unknown strings.
1487         assert(!is_known_inst, "not scalarizable allocation");
1488         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1489       }
1490     } else if( is_known_inst ) {
1491       tj = to; // Keep NotNull and klass_is_exact for instance type
1492     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1493       // During the 2nd round of IterGVN, NotNull castings are removed.
1494       // Make sure the Bottom and NotNull variants alias the same.
1495       // Also, make sure exact and non-exact variants alias the same.
1496       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1497     }
1498     if (to->speculative() != NULL) {
1499       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
1500     }
1501     // Canonicalize the holder of this field
1502     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1503       // First handle header references such as a LoadKlassNode, even if the
1504       // object's klass is unloaded at compile time (4965979).
1505       if (!is_known_inst) { // Do it only for non-instance types
1506         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1507       }
1508     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1509       // Static fields are in the space above the normal instance
1510       // fields in the java.lang.Class instance.
1511       if (to->klass() != ciEnv::current()->Class_klass()) {
1512         to = NULL;
1513         tj = TypeOopPtr::BOTTOM;
1514         offset = tj->offset();
1515       }
1516     } else {
1517       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1518       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1519         if( is_known_inst ) {
1520           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1521         } else {
1522           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1523         }
1524       }
1525     }
1526   }
1527 
1528   // Klass pointers to object array klasses need some flattening
1529   const TypeKlassPtr *tk = tj->isa_klassptr();
1530   if( tk ) {
1531     // If we are referencing a field within a Klass, we need
1532     // to assume the worst case of an Object.  Both exact and
1533     // inexact types must flatten to the same alias class so
1534     // use NotNull as the PTR.
1535     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1536 
1537       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1538                                    TypeKlassPtr::OBJECT->klass(),
1539                                    offset);
1540     }
1541 
1542     ciKlass* klass = tk->klass();
1543     if( klass->is_obj_array_klass() ) {
1544       ciKlass* k = TypeAryPtr::OOPS->klass();
1545       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1546         k = TypeInstPtr::BOTTOM->klass();
1547       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1548     }
1549 
1550     // Check for precise loads from the primary supertype array and force them
1551     // to the supertype cache alias index.  Check for generic array loads from
1552     // the primary supertype array and also force them to the supertype cache
1553     // alias index.  Since the same load can reach both, we need to merge
1554     // these 2 disparate memories into the same alias class.  Since the
1555     // primary supertype array is read-only, there's no chance of confusion
1556     // where we bypass an array load and an array store.
1557     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1558     if (offset == Type::OffsetBot ||
1559         (offset >= primary_supers_offset &&
1560          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1561         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1562       offset = in_bytes(Klass::secondary_super_cache_offset());
1563       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1564     }
1565   }
1566 
1567   // Flatten all Raw pointers together.
1568   if (tj->base() == Type::RawPtr)
1569     tj = TypeRawPtr::BOTTOM;
1570 
1571   if (tj->base() == Type::AnyPtr)
1572     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1573 
1574   // Flatten all to bottom for now
1575   switch( _AliasLevel ) {
1576   case 0:
1577     tj = TypePtr::BOTTOM;
1578     break;
1579   case 1:                       // Flatten to: oop, static, field or array
1580     switch (tj->base()) {
1581     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1582     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1583     case Type::AryPtr:   // do not distinguish arrays at all
1584     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1585     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1586     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1587     default: ShouldNotReachHere();
1588     }
1589     break;
1590   case 2:                       // No collapsing at level 2; keep all splits
1591   case 3:                       // No collapsing at level 3; keep all splits
1592     break;
1593   default:
1594     Unimplemented();
1595   }
1596 
1597   offset = tj->offset();
1598   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1599 
1600   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1601           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1602           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1603           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1604           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1605           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1606           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
1607           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1608   assert( tj->ptr() != TypePtr::TopPTR &&
1609           tj->ptr() != TypePtr::AnyNull &&
1610           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1611 //    assert( tj->ptr() != TypePtr::Constant ||
1612 //            tj->base() == Type::RawPtr ||
1613 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1614 
1615   return tj;
1616 }
1617 
1618 void Compile::AliasType::Init(int i, const TypePtr* at) {
1619   _index = i;
1620   _adr_type = at;
1621   _field = NULL;
1622   _element = NULL;
1623   _is_rewritable = true; // default
1624   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1625   if (atoop != NULL && atoop->is_known_instance()) {
1626     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1627     _general_index = Compile::current()->get_alias_index(gt);
1628   } else {
1629     _general_index = 0;
1630   }
1631 }
1632 
1633 BasicType Compile::AliasType::basic_type() const {
1634   if (element() != NULL) {
1635     const Type* element = adr_type()->is_aryptr()->elem();
1636     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1637   } if (field() != NULL) {
1638     return field()->layout_type();
1639   } else {
1640     return T_ILLEGAL; // unknown
1641   }
1642 }
1643 
1644 //---------------------------------print_on------------------------------------
1645 #ifndef PRODUCT
1646 void Compile::AliasType::print_on(outputStream* st) {
1647   if (index() < 10)
1648         st->print("@ <%d> ", index());
1649   else  st->print("@ <%d>",  index());
1650   st->print(is_rewritable() ? "   " : " RO");
1651   int offset = adr_type()->offset();
1652   if (offset == Type::OffsetBot)
1653         st->print(" +any");
1654   else  st->print(" +%-3d", offset);
1655   st->print(" in ");
1656   adr_type()->dump_on(st);
1657   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1658   if (field() != NULL && tjp) {
1659     if (tjp->klass()  != field()->holder() ||
1660         tjp->offset() != field()->offset_in_bytes()) {
1661       st->print(" != ");
1662       field()->print();
1663       st->print(" ***");
1664     }
1665   }
1666 }
1667 
1668 void print_alias_types() {
1669   Compile* C = Compile::current();
1670   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1671   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1672     C->alias_type(idx)->print_on(tty);
1673     tty->cr();
1674   }
1675 }
1676 #endif
1677 
1678 
1679 //----------------------------probe_alias_cache--------------------------------
1680 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1681   intptr_t key = (intptr_t) adr_type;
1682   key ^= key >> logAliasCacheSize;
1683   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1684 }
1685 
1686 
1687 //-----------------------------grow_alias_types--------------------------------
1688 void Compile::grow_alias_types() {
1689   const int old_ats  = _max_alias_types; // how many before?
1690   const int new_ats  = old_ats;          // how many more?
1691   const int grow_ats = old_ats+new_ats;  // how many now?
1692   _max_alias_types = grow_ats;
1693   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1694   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1695   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1696   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1697 }
1698 
1699 
1700 //--------------------------------find_alias_type------------------------------
1701 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1702   if (_AliasLevel == 0)
1703     return alias_type(AliasIdxBot);
1704 
1705   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1706   if (ace->_adr_type == adr_type) {
1707     return alias_type(ace->_index);
1708   }
1709 
1710   // Handle special cases.
1711   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1712   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1713 
1714   // Do it the slow way.
1715   const TypePtr* flat = flatten_alias_type(adr_type);
1716 
1717 #ifdef ASSERT
1718   {
1719     ResourceMark rm;
1720     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1721            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1722     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1723            Type::str(adr_type));
1724     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1725       const TypeOopPtr* foop = flat->is_oopptr();
1726       // Scalarizable allocations have exact klass always.
1727       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1728       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1729       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1730              Type::str(foop), Type::str(xoop));
1731     }
1732   }
1733 #endif
1734 
1735   int idx = AliasIdxTop;
1736   for (int i = 0; i < num_alias_types(); i++) {
1737     if (alias_type(i)->adr_type() == flat) {
1738       idx = i;
1739       break;
1740     }
1741   }
1742 
1743   if (idx == AliasIdxTop) {
1744     if (no_create)  return NULL;
1745     // Grow the array if necessary.
1746     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1747     // Add a new alias type.
1748     idx = _num_alias_types++;
1749     _alias_types[idx]->Init(idx, flat);
1750     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1751     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1752     if (flat->isa_instptr()) {
1753       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1754           && flat->is_instptr()->klass() == env()->Class_klass())
1755         alias_type(idx)->set_rewritable(false);
1756     }
1757     if (flat->isa_aryptr()) {
1758 #ifdef ASSERT
1759       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1760       // (T_BYTE has the weakest alignment and size restrictions...)
1761       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1762 #endif
1763       if (flat->offset() == TypePtr::OffsetBot) {
1764         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1765       }
1766     }
1767     if (flat->isa_klassptr()) {
1768       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1769         alias_type(idx)->set_rewritable(false);
1770       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1771         alias_type(idx)->set_rewritable(false);
1772       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1773         alias_type(idx)->set_rewritable(false);
1774       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1775         alias_type(idx)->set_rewritable(false);
1776     }
1777     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1778     // but the base pointer type is not distinctive enough to identify
1779     // references into JavaThread.)
1780 
1781     // Check for final fields.
1782     const TypeInstPtr* tinst = flat->isa_instptr();
1783     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1784       ciField* field;
1785       if (tinst->const_oop() != NULL &&
1786           tinst->klass() == ciEnv::current()->Class_klass() &&
1787           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1788         // static field
1789         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1790         field = k->get_field_by_offset(tinst->offset(), true);
1791       } else {
1792         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1793         field = k->get_field_by_offset(tinst->offset(), false);
1794       }
1795       assert(field == NULL ||
1796              original_field == NULL ||
1797              (field->holder() == original_field->holder() &&
1798               field->offset() == original_field->offset() &&
1799               field->is_static() == original_field->is_static()), "wrong field?");
1800       // Set field() and is_rewritable() attributes.
1801       if (field != NULL)  alias_type(idx)->set_field(field);
1802     }
1803   }
1804 
1805   // Fill the cache for next time.
1806   ace->_adr_type = adr_type;
1807   ace->_index    = idx;
1808   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1809 
1810   // Might as well try to fill the cache for the flattened version, too.
1811   AliasCacheEntry* face = probe_alias_cache(flat);
1812   if (face->_adr_type == NULL) {
1813     face->_adr_type = flat;
1814     face->_index    = idx;
1815     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1816   }
1817 
1818   return alias_type(idx);
1819 }
1820 
1821 
1822 Compile::AliasType* Compile::alias_type(ciField* field) {
1823   const TypeOopPtr* t;
1824   if (field->is_static())
1825     t = TypeInstPtr::make(field->holder()->java_mirror());
1826   else
1827     t = TypeOopPtr::make_from_klass_raw(field->holder());
1828   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1829   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1830   return atp;
1831 }
1832 
1833 
1834 //------------------------------have_alias_type--------------------------------
1835 bool Compile::have_alias_type(const TypePtr* adr_type) {
1836   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1837   if (ace->_adr_type == adr_type) {
1838     return true;
1839   }
1840 
1841   // Handle special cases.
1842   if (adr_type == NULL)             return true;
1843   if (adr_type == TypePtr::BOTTOM)  return true;
1844 
1845   return find_alias_type(adr_type, true, NULL) != NULL;
1846 }
1847 
1848 //-----------------------------must_alias--------------------------------------
1849 // True if all values of the given address type are in the given alias category.
1850 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1851   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1852   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1853   if (alias_idx == AliasIdxTop)         return false; // the empty category
1854   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1855 
1856   // the only remaining possible overlap is identity
1857   int adr_idx = get_alias_index(adr_type);
1858   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1859   assert(adr_idx == alias_idx ||
1860          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1861           && adr_type                       != TypeOopPtr::BOTTOM),
1862          "should not be testing for overlap with an unsafe pointer");
1863   return adr_idx == alias_idx;
1864 }
1865 
1866 //------------------------------can_alias--------------------------------------
1867 // True if any values of the given address type are in the given alias category.
1868 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1869   if (alias_idx == AliasIdxTop)         return false; // the empty category
1870   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1871   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1872   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1873 
1874   // the only remaining possible overlap is identity
1875   int adr_idx = get_alias_index(adr_type);
1876   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1877   return adr_idx == alias_idx;
1878 }
1879 
1880 
1881 
1882 //---------------------------pop_warm_call-------------------------------------
1883 WarmCallInfo* Compile::pop_warm_call() {
1884   WarmCallInfo* wci = _warm_calls;
1885   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1886   return wci;
1887 }
1888 
1889 //----------------------------Inline_Warm--------------------------------------
1890 int Compile::Inline_Warm() {
1891   // If there is room, try to inline some more warm call sites.
1892   // %%% Do a graph index compaction pass when we think we're out of space?
1893   if (!InlineWarmCalls)  return 0;
1894 
1895   int calls_made_hot = 0;
1896   int room_to_grow   = NodeCountInliningCutoff - unique();
1897   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1898   int amount_grown   = 0;
1899   WarmCallInfo* call;
1900   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1901     int est_size = (int)call->size();
1902     if (est_size > (room_to_grow - amount_grown)) {
1903       // This one won't fit anyway.  Get rid of it.
1904       call->make_cold();
1905       continue;
1906     }
1907     call->make_hot();
1908     calls_made_hot++;
1909     amount_grown   += est_size;
1910     amount_to_grow -= est_size;
1911   }
1912 
1913   if (calls_made_hot > 0)  set_major_progress();
1914   return calls_made_hot;
1915 }
1916 
1917 
1918 //----------------------------Finish_Warm--------------------------------------
1919 void Compile::Finish_Warm() {
1920   if (!InlineWarmCalls)  return;
1921   if (failing())  return;
1922   if (warm_calls() == NULL)  return;
1923 
1924   // Clean up loose ends, if we are out of space for inlining.
1925   WarmCallInfo* call;
1926   while ((call = pop_warm_call()) != NULL) {
1927     call->make_cold();
1928   }
1929 }
1930 
1931 //---------------------cleanup_loop_predicates-----------------------
1932 // Remove the opaque nodes that protect the predicates so that all unused
1933 // checks and uncommon_traps will be eliminated from the ideal graph
1934 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1935   if (predicate_count()==0) return;
1936   for (int i = predicate_count(); i > 0; i--) {
1937     Node * n = predicate_opaque1_node(i-1);
1938     assert(n->Opcode() == Op_Opaque1, "must be");
1939     igvn.replace_node(n, n->in(1));
1940   }
1941   assert(predicate_count()==0, "should be clean!");
1942 }
1943 
1944 void Compile::add_range_check_cast(Node* n) {
1945   assert(n->isa_CastII()->has_range_check(), "CastII should have range check dependency");
1946   assert(!_range_check_casts->contains(n), "duplicate entry in range check casts");
1947   _range_check_casts->append(n);
1948 }
1949 
1950 // Remove all range check dependent CastIINodes.
1951 void Compile::remove_range_check_casts(PhaseIterGVN &igvn) {
1952   for (int i = range_check_cast_count(); i > 0; i--) {
1953     Node* cast = range_check_cast_node(i-1);
1954     assert(cast->isa_CastII()->has_range_check(), "CastII should have range check dependency");
1955     igvn.replace_node(cast, cast->in(1));
1956   }
1957   assert(range_check_cast_count() == 0, "should be empty");
1958 }
1959 
1960 // StringOpts and late inlining of string methods
1961 void Compile::inline_string_calls(bool parse_time) {
1962   {
1963     // remove useless nodes to make the usage analysis simpler
1964     ResourceMark rm;
1965     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1966   }
1967 
1968   {
1969     ResourceMark rm;
1970     print_method(PHASE_BEFORE_STRINGOPTS, 3);
1971     PhaseStringOpts pso(initial_gvn(), for_igvn());
1972     print_method(PHASE_AFTER_STRINGOPTS, 3);
1973   }
1974 
1975   // now inline anything that we skipped the first time around
1976   if (!parse_time) {
1977     _late_inlines_pos = _late_inlines.length();
1978   }
1979 
1980   while (_string_late_inlines.length() > 0) {
1981     CallGenerator* cg = _string_late_inlines.pop();
1982     cg->do_late_inline();
1983     if (failing())  return;
1984   }
1985   _string_late_inlines.trunc_to(0);
1986 }
1987 
1988 // Late inlining of boxing methods
1989 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
1990   if (_boxing_late_inlines.length() > 0) {
1991     assert(has_boxed_value(), "inconsistent");
1992 
1993     PhaseGVN* gvn = initial_gvn();
1994     set_inlining_incrementally(true);
1995 
1996     assert( igvn._worklist.size() == 0, "should be done with igvn" );
1997     for_igvn()->clear();
1998     gvn->replace_with(&igvn);
1999 
2000     _late_inlines_pos = _late_inlines.length();
2001 
2002     while (_boxing_late_inlines.length() > 0) {
2003       CallGenerator* cg = _boxing_late_inlines.pop();
2004       cg->do_late_inline();
2005       if (failing())  return;
2006     }
2007     _boxing_late_inlines.trunc_to(0);
2008 
2009     {
2010       ResourceMark rm;
2011       PhaseRemoveUseless pru(gvn, for_igvn());
2012     }
2013 
2014     igvn = PhaseIterGVN(gvn);
2015     igvn.optimize();
2016 
2017     set_inlining_progress(false);
2018     set_inlining_incrementally(false);
2019   }
2020 }
2021 
2022 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
2023   assert(IncrementalInline, "incremental inlining should be on");
2024   PhaseGVN* gvn = initial_gvn();
2025 
2026   set_inlining_progress(false);
2027   for_igvn()->clear();
2028   gvn->replace_with(&igvn);
2029 
2030   {
2031     TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
2032     int i = 0;
2033     for (; i <_late_inlines.length() && !inlining_progress(); i++) {
2034       CallGenerator* cg = _late_inlines.at(i);
2035       _late_inlines_pos = i+1;
2036       cg->do_late_inline();
2037       if (failing())  return;
2038     }
2039     int j = 0;
2040     for (; i < _late_inlines.length(); i++, j++) {
2041       _late_inlines.at_put(j, _late_inlines.at(i));
2042     }
2043     _late_inlines.trunc_to(j);
2044   }
2045 
2046   {
2047     TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2048     ResourceMark rm;
2049     PhaseRemoveUseless pru(gvn, for_igvn());
2050   }
2051 
2052   {
2053     TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2054     igvn = PhaseIterGVN(gvn);
2055   }
2056 }
2057 
2058 // Perform incremental inlining until bound on number of live nodes is reached
2059 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2060   TracePhase tp("incrementalInline", &timers[_t_incrInline]);
2061 
2062   PhaseGVN* gvn = initial_gvn();
2063 
2064   set_inlining_incrementally(true);
2065   set_inlining_progress(true);
2066   uint low_live_nodes = 0;
2067 
2068   while(inlining_progress() && _late_inlines.length() > 0) {
2069 
2070     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2071       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2072         TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
2073         // PhaseIdealLoop is expensive so we only try it once we are
2074         // out of live nodes and we only try it again if the previous
2075         // helped got the number of nodes down significantly
2076         PhaseIdealLoop ideal_loop( igvn, false, true );
2077         if (failing())  return;
2078         low_live_nodes = live_nodes();
2079         _major_progress = true;
2080       }
2081 
2082       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2083         break;
2084       }
2085     }
2086 
2087     inline_incrementally_one(igvn);
2088 
2089     if (failing())  return;
2090 
2091     {
2092       TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2093       igvn.optimize();
2094     }
2095 
2096     if (failing())  return;
2097   }
2098 
2099   assert( igvn._worklist.size() == 0, "should be done with igvn" );
2100 
2101   if (_string_late_inlines.length() > 0) {
2102     assert(has_stringbuilder(), "inconsistent");
2103     for_igvn()->clear();
2104     initial_gvn()->replace_with(&igvn);
2105 
2106     inline_string_calls(false);
2107 
2108     if (failing())  return;
2109 
2110     {
2111       TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2112       ResourceMark rm;
2113       PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2114     }
2115 
2116     {
2117       TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2118       igvn = PhaseIterGVN(gvn);
2119       igvn.optimize();
2120     }
2121   }
2122 
2123   set_inlining_incrementally(false);
2124 }
2125 
2126 
2127 //------------------------------Optimize---------------------------------------
2128 // Given a graph, optimize it.
2129 void Compile::Optimize() {
2130   TracePhase tp("optimizer", &timers[_t_optimizer]);
2131 
2132 #ifndef PRODUCT
2133   if (_directive->BreakAtCompileOption) {
2134     BREAKPOINT;
2135   }
2136 
2137 #endif
2138 
2139   ResourceMark rm;
2140   int          loop_opts_cnt;
2141 
2142   print_inlining_reinit();
2143 
2144   NOT_PRODUCT( verify_graph_edges(); )
2145 
2146   print_method(PHASE_AFTER_PARSING);
2147 
2148  {
2149   // Iterative Global Value Numbering, including ideal transforms
2150   // Initialize IterGVN with types and values from parse-time GVN
2151   PhaseIterGVN igvn(initial_gvn());
2152 #ifdef ASSERT
2153   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2154 #endif
2155   {
2156     TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2157     igvn.optimize();
2158   }
2159 
2160   print_method(PHASE_ITER_GVN1, 2);
2161 
2162   if (failing())  return;
2163 
2164   inline_incrementally(igvn);
2165 
2166   print_method(PHASE_INCREMENTAL_INLINE, 2);
2167 
2168   if (failing())  return;
2169 
2170   if (eliminate_boxing()) {
2171     // Inline valueOf() methods now.
2172     inline_boxing_calls(igvn);
2173 
2174     if (AlwaysIncrementalInline) {
2175       inline_incrementally(igvn);
2176     }
2177 
2178     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2179 
2180     if (failing())  return;
2181   }
2182 
2183   // Remove the speculative part of types and clean up the graph from
2184   // the extra CastPP nodes whose only purpose is to carry them. Do
2185   // that early so that optimizations are not disrupted by the extra
2186   // CastPP nodes.
2187   remove_speculative_types(igvn);
2188 
2189   // No more new expensive nodes will be added to the list from here
2190   // so keep only the actual candidates for optimizations.
2191   cleanup_expensive_nodes(igvn);
2192 
2193   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2194     Compile::TracePhase tp("", &timers[_t_renumberLive]);
2195     initial_gvn()->replace_with(&igvn);
2196     for_igvn()->clear();
2197     Unique_Node_List new_worklist(C->comp_arena());
2198     {
2199       ResourceMark rm;
2200       PhaseRenumberLive prl = PhaseRenumberLive(initial_gvn(), for_igvn(), &new_worklist);
2201     }
2202     set_for_igvn(&new_worklist);
2203     igvn = PhaseIterGVN(initial_gvn());
2204     igvn.optimize();
2205   }
2206 
2207   // Perform escape analysis
2208   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2209     if (has_loops()) {
2210       // Cleanup graph (remove dead nodes).
2211       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2212       PhaseIdealLoop ideal_loop( igvn, false, true );
2213       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2214       if (failing())  return;
2215     }
2216     ConnectionGraph::do_analysis(this, &igvn);
2217 
2218     if (failing())  return;
2219 
2220     // Optimize out fields loads from scalar replaceable allocations.
2221     igvn.optimize();
2222     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2223 
2224     if (failing())  return;
2225 
2226     if (congraph() != NULL && macro_count() > 0) {
2227       TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2228       PhaseMacroExpand mexp(igvn);
2229       mexp.eliminate_macro_nodes();
2230       igvn.set_delay_transform(false);
2231 
2232       igvn.optimize();
2233       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2234 
2235       if (failing())  return;
2236     }
2237   }
2238 
2239   // Loop transforms on the ideal graph.  Range Check Elimination,
2240   // peeling, unrolling, etc.
2241 
2242   // Set loop opts counter
2243   loop_opts_cnt = num_loop_opts();
2244   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2245     {
2246       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2247       PhaseIdealLoop ideal_loop( igvn, true );
2248       loop_opts_cnt--;
2249       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2250       if (failing())  return;
2251     }
2252     // Loop opts pass if partial peeling occurred in previous pass
2253     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
2254       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2255       PhaseIdealLoop ideal_loop( igvn, false );
2256       loop_opts_cnt--;
2257       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2258       if (failing())  return;
2259     }
2260     // Loop opts pass for loop-unrolling before CCP
2261     if(major_progress() && (loop_opts_cnt > 0)) {
2262       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2263       PhaseIdealLoop ideal_loop( igvn, false );
2264       loop_opts_cnt--;
2265       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2266     }
2267     if (!failing()) {
2268       // Verify that last round of loop opts produced a valid graph
2269       TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2270       PhaseIdealLoop::verify(igvn);
2271     }
2272   }
2273   if (failing())  return;
2274 
2275   // Conditional Constant Propagation;
2276   PhaseCCP ccp( &igvn );
2277   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2278   {
2279     TracePhase tp("ccp", &timers[_t_ccp]);
2280     ccp.do_transform();
2281   }
2282   print_method(PHASE_CPP1, 2);
2283 
2284   assert( true, "Break here to ccp.dump_old2new_map()");
2285 
2286   // Iterative Global Value Numbering, including ideal transforms
2287   {
2288     TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2289     igvn = ccp;
2290     igvn.optimize();
2291   }
2292 
2293   print_method(PHASE_ITER_GVN2, 2);
2294 
2295   if (failing())  return;
2296 
2297   // Loop transforms on the ideal graph.  Range Check Elimination,
2298   // peeling, unrolling, etc.
2299   if(loop_opts_cnt > 0) {
2300     debug_only( int cnt = 0; );
2301     while(major_progress() && (loop_opts_cnt > 0)) {
2302       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2303       assert( cnt++ < 40, "infinite cycle in loop optimization" );
2304       PhaseIdealLoop ideal_loop( igvn, true);
2305       loop_opts_cnt--;
2306       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2307       if (failing())  return;
2308     }
2309   }
2310   // Ensure that major progress is now clear
2311   C->clear_major_progress();
2312 
2313   {
2314     // Verify that all previous optimizations produced a valid graph
2315     // at least to this point, even if no loop optimizations were done.
2316     TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2317     PhaseIdealLoop::verify(igvn);
2318   }
2319 
2320   if (range_check_cast_count() > 0) {
2321     // No more loop optimizations. Remove all range check dependent CastIINodes.
2322     C->remove_range_check_casts(igvn);
2323     igvn.optimize();
2324   }
2325 
2326   {
2327     TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2328     PhaseMacroExpand  mex(igvn);
2329     if (mex.expand_macro_nodes()) {
2330       assert(failing(), "must bail out w/ explicit message");
2331       return;
2332     }
2333   }
2334 
2335   DEBUG_ONLY( _modified_nodes = NULL; )
2336  } // (End scope of igvn; run destructor if necessary for asserts.)
2337 
2338  process_print_inlining();
2339  // A method with only infinite loops has no edges entering loops from root
2340  {
2341    TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2342    if (final_graph_reshaping()) {
2343      assert(failing(), "must bail out w/ explicit message");
2344      return;
2345    }
2346  }
2347 
2348  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2349 }
2350 
2351 
2352 //------------------------------Code_Gen---------------------------------------
2353 // Given a graph, generate code for it
2354 void Compile::Code_Gen() {
2355   if (failing()) {
2356     return;
2357   }
2358 
2359   // Perform instruction selection.  You might think we could reclaim Matcher
2360   // memory PDQ, but actually the Matcher is used in generating spill code.
2361   // Internals of the Matcher (including some VectorSets) must remain live
2362   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2363   // set a bit in reclaimed memory.
2364 
2365   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2366   // nodes.  Mapping is only valid at the root of each matched subtree.
2367   NOT_PRODUCT( verify_graph_edges(); )
2368 
2369   Matcher matcher;
2370   _matcher = &matcher;
2371   {
2372     TracePhase tp("matcher", &timers[_t_matcher]);
2373     matcher.match();
2374   }
2375   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2376   // nodes.  Mapping is only valid at the root of each matched subtree.
2377   NOT_PRODUCT( verify_graph_edges(); )
2378 
2379   // If you have too many nodes, or if matching has failed, bail out
2380   check_node_count(0, "out of nodes matching instructions");
2381   if (failing()) {
2382     return;
2383   }
2384 
2385   // Build a proper-looking CFG
2386   PhaseCFG cfg(node_arena(), root(), matcher);
2387   _cfg = &cfg;
2388   {
2389     TracePhase tp("scheduler", &timers[_t_scheduler]);
2390     bool success = cfg.do_global_code_motion();
2391     if (!success) {
2392       return;
2393     }
2394 
2395     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2396     NOT_PRODUCT( verify_graph_edges(); )
2397     debug_only( cfg.verify(); )
2398   }
2399 
2400   PhaseChaitin regalloc(unique(), cfg, matcher, false);
2401   _regalloc = &regalloc;
2402   {
2403     TracePhase tp("regalloc", &timers[_t_registerAllocation]);
2404     // Perform register allocation.  After Chaitin, use-def chains are
2405     // no longer accurate (at spill code) and so must be ignored.
2406     // Node->LRG->reg mappings are still accurate.
2407     _regalloc->Register_Allocate();
2408 
2409     // Bail out if the allocator builds too many nodes
2410     if (failing()) {
2411       return;
2412     }
2413   }
2414 
2415   // Prior to register allocation we kept empty basic blocks in case the
2416   // the allocator needed a place to spill.  After register allocation we
2417   // are not adding any new instructions.  If any basic block is empty, we
2418   // can now safely remove it.
2419   {
2420     TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
2421     cfg.remove_empty_blocks();
2422     if (do_freq_based_layout()) {
2423       PhaseBlockLayout layout(cfg);
2424     } else {
2425       cfg.set_loop_alignment();
2426     }
2427     cfg.fixup_flow();
2428   }
2429 
2430   // Apply peephole optimizations
2431   if( OptoPeephole ) {
2432     TracePhase tp("peephole", &timers[_t_peephole]);
2433     PhasePeephole peep( _regalloc, cfg);
2434     peep.do_transform();
2435   }
2436 
2437   // Do late expand if CPU requires this.
2438   if (Matcher::require_postalloc_expand) {
2439     TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
2440     cfg.postalloc_expand(_regalloc);
2441   }
2442 
2443   // Convert Nodes to instruction bits in a buffer
2444   {
2445     TraceTime tp("output", &timers[_t_output], CITime);
2446     Output();
2447   }
2448 
2449   print_method(PHASE_FINAL_CODE);
2450 
2451   // He's dead, Jim.
2452   _cfg     = (PhaseCFG*)0xdeadbeef;
2453   _regalloc = (PhaseChaitin*)0xdeadbeef;
2454 }
2455 
2456 
2457 //------------------------------dump_asm---------------------------------------
2458 // Dump formatted assembly
2459 #ifndef PRODUCT
2460 void Compile::dump_asm(int *pcs, uint pc_limit) {
2461   bool cut_short = false;
2462   tty->print_cr("#");
2463   tty->print("#  ");  _tf->dump();  tty->cr();
2464   tty->print_cr("#");
2465 
2466   // For all blocks
2467   int pc = 0x0;                 // Program counter
2468   char starts_bundle = ' ';
2469   _regalloc->dump_frame();
2470 
2471   Node *n = NULL;
2472   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2473     if (VMThread::should_terminate()) {
2474       cut_short = true;
2475       break;
2476     }
2477     Block* block = _cfg->get_block(i);
2478     if (block->is_connector() && !Verbose) {
2479       continue;
2480     }
2481     n = block->head();
2482     if (pcs && n->_idx < pc_limit) {
2483       tty->print("%3.3x   ", pcs[n->_idx]);
2484     } else {
2485       tty->print("      ");
2486     }
2487     block->dump_head(_cfg);
2488     if (block->is_connector()) {
2489       tty->print_cr("        # Empty connector block");
2490     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2491       tty->print_cr("        # Block is sole successor of call");
2492     }
2493 
2494     // For all instructions
2495     Node *delay = NULL;
2496     for (uint j = 0; j < block->number_of_nodes(); j++) {
2497       if (VMThread::should_terminate()) {
2498         cut_short = true;
2499         break;
2500       }
2501       n = block->get_node(j);
2502       if (valid_bundle_info(n)) {
2503         Bundle* bundle = node_bundling(n);
2504         if (bundle->used_in_unconditional_delay()) {
2505           delay = n;
2506           continue;
2507         }
2508         if (bundle->starts_bundle()) {
2509           starts_bundle = '+';
2510         }
2511       }
2512 
2513       if (WizardMode) {
2514         n->dump();
2515       }
2516 
2517       if( !n->is_Region() &&    // Dont print in the Assembly
2518           !n->is_Phi() &&       // a few noisely useless nodes
2519           !n->is_Proj() &&
2520           !n->is_MachTemp() &&
2521           !n->is_SafePointScalarObject() &&
2522           !n->is_Catch() &&     // Would be nice to print exception table targets
2523           !n->is_MergeMem() &&  // Not very interesting
2524           !n->is_top() &&       // Debug info table constants
2525           !(n->is_Con() && !n->is_Mach())// Debug info table constants
2526           ) {
2527         if (pcs && n->_idx < pc_limit)
2528           tty->print("%3.3x", pcs[n->_idx]);
2529         else
2530           tty->print("   ");
2531         tty->print(" %c ", starts_bundle);
2532         starts_bundle = ' ';
2533         tty->print("\t");
2534         n->format(_regalloc, tty);
2535         tty->cr();
2536       }
2537 
2538       // If we have an instruction with a delay slot, and have seen a delay,
2539       // then back up and print it
2540       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2541         assert(delay != NULL, "no unconditional delay instruction");
2542         if (WizardMode) delay->dump();
2543 
2544         if (node_bundling(delay)->starts_bundle())
2545           starts_bundle = '+';
2546         if (pcs && n->_idx < pc_limit)
2547           tty->print("%3.3x", pcs[n->_idx]);
2548         else
2549           tty->print("   ");
2550         tty->print(" %c ", starts_bundle);
2551         starts_bundle = ' ';
2552         tty->print("\t");
2553         delay->format(_regalloc, tty);
2554         tty->cr();
2555         delay = NULL;
2556       }
2557 
2558       // Dump the exception table as well
2559       if( n->is_Catch() && (Verbose || WizardMode) ) {
2560         // Print the exception table for this offset
2561         _handler_table.print_subtable_for(pc);
2562       }
2563     }
2564 
2565     if (pcs && n->_idx < pc_limit)
2566       tty->print_cr("%3.3x", pcs[n->_idx]);
2567     else
2568       tty->cr();
2569 
2570     assert(cut_short || delay == NULL, "no unconditional delay branch");
2571 
2572   } // End of per-block dump
2573   tty->cr();
2574 
2575   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
2576 }
2577 #endif
2578 
2579 //------------------------------Final_Reshape_Counts---------------------------
2580 // This class defines counters to help identify when a method
2581 // may/must be executed using hardware with only 24-bit precision.
2582 struct Final_Reshape_Counts : public StackObj {
2583   int  _call_count;             // count non-inlined 'common' calls
2584   int  _float_count;            // count float ops requiring 24-bit precision
2585   int  _double_count;           // count double ops requiring more precision
2586   int  _java_call_count;        // count non-inlined 'java' calls
2587   int  _inner_loop_count;       // count loops which need alignment
2588   VectorSet _visited;           // Visitation flags
2589   Node_List _tests;             // Set of IfNodes & PCTableNodes
2590 
2591   Final_Reshape_Counts() :
2592     _call_count(0), _float_count(0), _double_count(0),
2593     _java_call_count(0), _inner_loop_count(0),
2594     _visited( Thread::current()->resource_area() ) { }
2595 
2596   void inc_call_count  () { _call_count  ++; }
2597   void inc_float_count () { _float_count ++; }
2598   void inc_double_count() { _double_count++; }
2599   void inc_java_call_count() { _java_call_count++; }
2600   void inc_inner_loop_count() { _inner_loop_count++; }
2601 
2602   int  get_call_count  () const { return _call_count  ; }
2603   int  get_float_count () const { return _float_count ; }
2604   int  get_double_count() const { return _double_count; }
2605   int  get_java_call_count() const { return _java_call_count; }
2606   int  get_inner_loop_count() const { return _inner_loop_count; }
2607 };
2608 
2609 #ifdef ASSERT
2610 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2611   ciInstanceKlass *k = tp->klass()->as_instance_klass();
2612   // Make sure the offset goes inside the instance layout.
2613   return k->contains_field_offset(tp->offset());
2614   // Note that OffsetBot and OffsetTop are very negative.
2615 }
2616 #endif
2617 
2618 // Eliminate trivially redundant StoreCMs and accumulate their
2619 // precedence edges.
2620 void Compile::eliminate_redundant_card_marks(Node* n) {
2621   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2622   if (n->in(MemNode::Address)->outcnt() > 1) {
2623     // There are multiple users of the same address so it might be
2624     // possible to eliminate some of the StoreCMs
2625     Node* mem = n->in(MemNode::Memory);
2626     Node* adr = n->in(MemNode::Address);
2627     Node* val = n->in(MemNode::ValueIn);
2628     Node* prev = n;
2629     bool done = false;
2630     // Walk the chain of StoreCMs eliminating ones that match.  As
2631     // long as it's a chain of single users then the optimization is
2632     // safe.  Eliminating partially redundant StoreCMs would require
2633     // cloning copies down the other paths.
2634     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2635       if (adr == mem->in(MemNode::Address) &&
2636           val == mem->in(MemNode::ValueIn)) {
2637         // redundant StoreCM
2638         if (mem->req() > MemNode::OopStore) {
2639           // Hasn't been processed by this code yet.
2640           n->add_prec(mem->in(MemNode::OopStore));
2641         } else {
2642           // Already converted to precedence edge
2643           for (uint i = mem->req(); i < mem->len(); i++) {
2644             // Accumulate any precedence edges
2645             if (mem->in(i) != NULL) {
2646               n->add_prec(mem->in(i));
2647             }
2648           }
2649           // Everything above this point has been processed.
2650           done = true;
2651         }
2652         // Eliminate the previous StoreCM
2653         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2654         assert(mem->outcnt() == 0, "should be dead");
2655         mem->disconnect_inputs(NULL, this);
2656       } else {
2657         prev = mem;
2658       }
2659       mem = prev->in(MemNode::Memory);
2660     }
2661   }
2662 }
2663 
2664 //------------------------------final_graph_reshaping_impl----------------------
2665 // Implement items 1-5 from final_graph_reshaping below.
2666 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2667 
2668   if ( n->outcnt() == 0 ) return; // dead node
2669   uint nop = n->Opcode();
2670 
2671   // Check for 2-input instruction with "last use" on right input.
2672   // Swap to left input.  Implements item (2).
2673   if( n->req() == 3 &&          // two-input instruction
2674       n->in(1)->outcnt() > 1 && // left use is NOT a last use
2675       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2676       n->in(2)->outcnt() == 1 &&// right use IS a last use
2677       !n->in(2)->is_Con() ) {   // right use is not a constant
2678     // Check for commutative opcode
2679     switch( nop ) {
2680     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
2681     case Op_MaxI:  case Op_MinI:
2682     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
2683     case Op_AndL:  case Op_XorL:  case Op_OrL:
2684     case Op_AndI:  case Op_XorI:  case Op_OrI: {
2685       // Move "last use" input to left by swapping inputs
2686       n->swap_edges(1, 2);
2687       break;
2688     }
2689     default:
2690       break;
2691     }
2692   }
2693 
2694 #ifdef ASSERT
2695   if( n->is_Mem() ) {
2696     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2697     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2698             // oop will be recorded in oop map if load crosses safepoint
2699             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2700                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
2701             "raw memory operations should have control edge");
2702   }
2703 #endif
2704   // Count FPU ops and common calls, implements item (3)
2705   switch( nop ) {
2706   // Count all float operations that may use FPU
2707   case Op_AddF:
2708   case Op_SubF:
2709   case Op_MulF:
2710   case Op_DivF:
2711   case Op_NegF:
2712   case Op_ModF:
2713   case Op_ConvI2F:
2714   case Op_ConF:
2715   case Op_CmpF:
2716   case Op_CmpF3:
2717   // case Op_ConvL2F: // longs are split into 32-bit halves
2718     frc.inc_float_count();
2719     break;
2720 
2721   case Op_ConvF2D:
2722   case Op_ConvD2F:
2723     frc.inc_float_count();
2724     frc.inc_double_count();
2725     break;
2726 
2727   // Count all double operations that may use FPU
2728   case Op_AddD:
2729   case Op_SubD:
2730   case Op_MulD:
2731   case Op_DivD:
2732   case Op_NegD:
2733   case Op_ModD:
2734   case Op_ConvI2D:
2735   case Op_ConvD2I:
2736   // case Op_ConvL2D: // handled by leaf call
2737   // case Op_ConvD2L: // handled by leaf call
2738   case Op_ConD:
2739   case Op_CmpD:
2740   case Op_CmpD3:
2741     frc.inc_double_count();
2742     break;
2743   case Op_Opaque1:              // Remove Opaque Nodes before matching
2744   case Op_Opaque2:              // Remove Opaque Nodes before matching
2745   case Op_Opaque3:
2746     n->subsume_by(n->in(1), this);
2747     break;
2748   case Op_CallStaticJava:
2749   case Op_CallJava:
2750   case Op_CallDynamicJava:
2751     frc.inc_java_call_count(); // Count java call site;
2752   case Op_CallRuntime:
2753   case Op_CallLeaf:
2754   case Op_CallLeafNoFP: {
2755     assert (n->is_Call(), "");
2756     CallNode *call = n->as_Call();
2757     // Count call sites where the FP mode bit would have to be flipped.
2758     // Do not count uncommon runtime calls:
2759     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2760     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2761     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
2762       frc.inc_call_count();   // Count the call site
2763     } else {                  // See if uncommon argument is shared
2764       Node *n = call->in(TypeFunc::Parms);
2765       int nop = n->Opcode();
2766       // Clone shared simple arguments to uncommon calls, item (1).
2767       if (n->outcnt() > 1 &&
2768           !n->is_Proj() &&
2769           nop != Op_CreateEx &&
2770           nop != Op_CheckCastPP &&
2771           nop != Op_DecodeN &&
2772           nop != Op_DecodeNKlass &&
2773           !n->is_Mem() &&
2774           !n->is_Phi()) {
2775         Node *x = n->clone();
2776         call->set_req(TypeFunc::Parms, x);
2777       }
2778     }
2779     break;
2780   }
2781 
2782   case Op_StoreD:
2783   case Op_LoadD:
2784   case Op_LoadD_unaligned:
2785     frc.inc_double_count();
2786     goto handle_mem;
2787   case Op_StoreF:
2788   case Op_LoadF:
2789     frc.inc_float_count();
2790     goto handle_mem;
2791 
2792   case Op_StoreCM:
2793     {
2794       // Convert OopStore dependence into precedence edge
2795       Node* prec = n->in(MemNode::OopStore);
2796       n->del_req(MemNode::OopStore);
2797       n->add_prec(prec);
2798       eliminate_redundant_card_marks(n);
2799     }
2800 
2801     // fall through
2802 
2803   case Op_StoreB:
2804   case Op_StoreC:
2805   case Op_StorePConditional:
2806   case Op_StoreI:
2807   case Op_StoreL:
2808   case Op_StoreIConditional:
2809   case Op_StoreLConditional:
2810   case Op_CompareAndSwapB:
2811   case Op_CompareAndSwapS:
2812   case Op_CompareAndSwapI:
2813   case Op_CompareAndSwapL:
2814   case Op_CompareAndSwapP:
2815   case Op_CompareAndSwapN:
2816   case Op_WeakCompareAndSwapB:
2817   case Op_WeakCompareAndSwapS:
2818   case Op_WeakCompareAndSwapI:
2819   case Op_WeakCompareAndSwapL:
2820   case Op_WeakCompareAndSwapP:
2821   case Op_WeakCompareAndSwapN:
2822   case Op_CompareAndExchangeB:
2823   case Op_CompareAndExchangeS:
2824   case Op_CompareAndExchangeI:
2825   case Op_CompareAndExchangeL:
2826   case Op_CompareAndExchangeP:
2827   case Op_CompareAndExchangeN:
2828   case Op_GetAndAddS:
2829   case Op_GetAndAddB:
2830   case Op_GetAndAddI:
2831   case Op_GetAndAddL:
2832   case Op_GetAndSetS:
2833   case Op_GetAndSetB:
2834   case Op_GetAndSetI:
2835   case Op_GetAndSetL:
2836   case Op_GetAndSetP:
2837   case Op_GetAndSetN:
2838   case Op_StoreP:
2839   case Op_StoreN:
2840   case Op_StoreNKlass:
2841   case Op_LoadB:
2842   case Op_LoadUB:
2843   case Op_LoadUS:
2844   case Op_LoadI:
2845   case Op_LoadKlass:
2846   case Op_LoadNKlass:
2847   case Op_LoadL:
2848   case Op_LoadL_unaligned:
2849   case Op_LoadPLocked:
2850   case Op_LoadP:
2851   case Op_LoadN:
2852   case Op_LoadRange:
2853   case Op_LoadS: {
2854   handle_mem:
2855 #ifdef ASSERT
2856     if( VerifyOptoOopOffsets ) {
2857       assert( n->is_Mem(), "" );
2858       MemNode *mem  = (MemNode*)n;
2859       // Check to see if address types have grounded out somehow.
2860       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2861       assert( !tp || oop_offset_is_sane(tp), "" );
2862     }
2863 #endif
2864     break;
2865   }
2866 
2867   case Op_AddP: {               // Assert sane base pointers
2868     Node *addp = n->in(AddPNode::Address);
2869     assert( !addp->is_AddP() ||
2870             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2871             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2872             "Base pointers must match (addp %u)", addp->_idx );
2873 #ifdef _LP64
2874     if ((UseCompressedOops || UseCompressedClassPointers) &&
2875         addp->Opcode() == Op_ConP &&
2876         addp == n->in(AddPNode::Base) &&
2877         n->in(AddPNode::Offset)->is_Con()) {
2878       // If the transformation of ConP to ConN+DecodeN is beneficial depends
2879       // on the platform and on the compressed oops mode.
2880       // Use addressing with narrow klass to load with offset on x86.
2881       // Some platforms can use the constant pool to load ConP.
2882       // Do this transformation here since IGVN will convert ConN back to ConP.
2883       const Type* t = addp->bottom_type();
2884       bool is_oop   = t->isa_oopptr() != NULL;
2885       bool is_klass = t->isa_klassptr() != NULL;
2886 
2887       if ((is_oop   && Matcher::const_oop_prefer_decode()  ) ||
2888           (is_klass && Matcher::const_klass_prefer_decode())) {
2889         Node* nn = NULL;
2890 
2891         int op = is_oop ? Op_ConN : Op_ConNKlass;
2892 
2893         // Look for existing ConN node of the same exact type.
2894         Node* r  = root();
2895         uint cnt = r->outcnt();
2896         for (uint i = 0; i < cnt; i++) {
2897           Node* m = r->raw_out(i);
2898           if (m!= NULL && m->Opcode() == op &&
2899               m->bottom_type()->make_ptr() == t) {
2900             nn = m;
2901             break;
2902           }
2903         }
2904         if (nn != NULL) {
2905           // Decode a narrow oop to match address
2906           // [R12 + narrow_oop_reg<<3 + offset]
2907           if (is_oop) {
2908             nn = new DecodeNNode(nn, t);
2909           } else {
2910             nn = new DecodeNKlassNode(nn, t);
2911           }
2912           // Check for succeeding AddP which uses the same Base.
2913           // Otherwise we will run into the assertion above when visiting that guy.
2914           for (uint i = 0; i < n->outcnt(); ++i) {
2915             Node *out_i = n->raw_out(i);
2916             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
2917               out_i->set_req(AddPNode::Base, nn);
2918 #ifdef ASSERT
2919               for (uint j = 0; j < out_i->outcnt(); ++j) {
2920                 Node *out_j = out_i->raw_out(j);
2921                 assert(out_j == NULL || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
2922                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
2923               }
2924 #endif
2925             }
2926           }
2927           n->set_req(AddPNode::Base, nn);
2928           n->set_req(AddPNode::Address, nn);
2929           if (addp->outcnt() == 0) {
2930             addp->disconnect_inputs(NULL, this);
2931           }
2932         }
2933       }
2934     }
2935 #endif
2936     // platform dependent reshaping of the address expression
2937     reshape_address(n->as_AddP());
2938     break;
2939   }
2940 
2941   case Op_CastPP: {
2942     // Remove CastPP nodes to gain more freedom during scheduling but
2943     // keep the dependency they encode as control or precedence edges
2944     // (if control is set already) on memory operations. Some CastPP
2945     // nodes don't have a control (don't carry a dependency): skip
2946     // those.
2947     if (n->in(0) != NULL) {
2948       ResourceMark rm;
2949       Unique_Node_List wq;
2950       wq.push(n);
2951       for (uint next = 0; next < wq.size(); ++next) {
2952         Node *m = wq.at(next);
2953         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
2954           Node* use = m->fast_out(i);
2955           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
2956             use->ensure_control_or_add_prec(n->in(0));
2957           } else {
2958             switch(use->Opcode()) {
2959             case Op_AddP:
2960             case Op_DecodeN:
2961             case Op_DecodeNKlass:
2962             case Op_CheckCastPP:
2963             case Op_CastPP:
2964               wq.push(use);
2965               break;
2966             }
2967           }
2968         }
2969       }
2970     }
2971     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
2972     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
2973       Node* in1 = n->in(1);
2974       const Type* t = n->bottom_type();
2975       Node* new_in1 = in1->clone();
2976       new_in1->as_DecodeN()->set_type(t);
2977 
2978       if (!Matcher::narrow_oop_use_complex_address()) {
2979         //
2980         // x86, ARM and friends can handle 2 adds in addressing mode
2981         // and Matcher can fold a DecodeN node into address by using
2982         // a narrow oop directly and do implicit NULL check in address:
2983         //
2984         // [R12 + narrow_oop_reg<<3 + offset]
2985         // NullCheck narrow_oop_reg
2986         //
2987         // On other platforms (Sparc) we have to keep new DecodeN node and
2988         // use it to do implicit NULL check in address:
2989         //
2990         // decode_not_null narrow_oop_reg, base_reg
2991         // [base_reg + offset]
2992         // NullCheck base_reg
2993         //
2994         // Pin the new DecodeN node to non-null path on these platform (Sparc)
2995         // to keep the information to which NULL check the new DecodeN node
2996         // corresponds to use it as value in implicit_null_check().
2997         //
2998         new_in1->set_req(0, n->in(0));
2999       }
3000 
3001       n->subsume_by(new_in1, this);
3002       if (in1->outcnt() == 0) {
3003         in1->disconnect_inputs(NULL, this);
3004       }
3005     } else {
3006       n->subsume_by(n->in(1), this);
3007       if (n->outcnt() == 0) {
3008         n->disconnect_inputs(NULL, this);
3009       }
3010     }
3011     break;
3012   }
3013 #ifdef _LP64
3014   case Op_CmpP:
3015     // Do this transformation here to preserve CmpPNode::sub() and
3016     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3017     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3018       Node* in1 = n->in(1);
3019       Node* in2 = n->in(2);
3020       if (!in1->is_DecodeNarrowPtr()) {
3021         in2 = in1;
3022         in1 = n->in(2);
3023       }
3024       assert(in1->is_DecodeNarrowPtr(), "sanity");
3025 
3026       Node* new_in2 = NULL;
3027       if (in2->is_DecodeNarrowPtr()) {
3028         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3029         new_in2 = in2->in(1);
3030       } else if (in2->Opcode() == Op_ConP) {
3031         const Type* t = in2->bottom_type();
3032         if (t == TypePtr::NULL_PTR) {
3033           assert(in1->is_DecodeN(), "compare klass to null?");
3034           // Don't convert CmpP null check into CmpN if compressed
3035           // oops implicit null check is not generated.
3036           // This will allow to generate normal oop implicit null check.
3037           if (Matcher::gen_narrow_oop_implicit_null_checks())
3038             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3039           //
3040           // This transformation together with CastPP transformation above
3041           // will generated code for implicit NULL checks for compressed oops.
3042           //
3043           // The original code after Optimize()
3044           //
3045           //    LoadN memory, narrow_oop_reg
3046           //    decode narrow_oop_reg, base_reg
3047           //    CmpP base_reg, NULL
3048           //    CastPP base_reg // NotNull
3049           //    Load [base_reg + offset], val_reg
3050           //
3051           // after these transformations will be
3052           //
3053           //    LoadN memory, narrow_oop_reg
3054           //    CmpN narrow_oop_reg, NULL
3055           //    decode_not_null narrow_oop_reg, base_reg
3056           //    Load [base_reg + offset], val_reg
3057           //
3058           // and the uncommon path (== NULL) will use narrow_oop_reg directly
3059           // since narrow oops can be used in debug info now (see the code in
3060           // final_graph_reshaping_walk()).
3061           //
3062           // At the end the code will be matched to
3063           // on x86:
3064           //
3065           //    Load_narrow_oop memory, narrow_oop_reg
3066           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3067           //    NullCheck narrow_oop_reg
3068           //
3069           // and on sparc:
3070           //
3071           //    Load_narrow_oop memory, narrow_oop_reg
3072           //    decode_not_null narrow_oop_reg, base_reg
3073           //    Load [base_reg + offset], val_reg
3074           //    NullCheck base_reg
3075           //
3076         } else if (t->isa_oopptr()) {
3077           new_in2 = ConNode::make(t->make_narrowoop());
3078         } else if (t->isa_klassptr()) {
3079           new_in2 = ConNode::make(t->make_narrowklass());
3080         }
3081       }
3082       if (new_in2 != NULL) {
3083         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3084         n->subsume_by(cmpN, this);
3085         if (in1->outcnt() == 0) {
3086           in1->disconnect_inputs(NULL, this);
3087         }
3088         if (in2->outcnt() == 0) {
3089           in2->disconnect_inputs(NULL, this);
3090         }
3091       }
3092     }
3093     break;
3094 
3095   case Op_DecodeN:
3096   case Op_DecodeNKlass:
3097     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3098     // DecodeN could be pinned when it can't be fold into
3099     // an address expression, see the code for Op_CastPP above.
3100     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3101     break;
3102 
3103   case Op_EncodeP:
3104   case Op_EncodePKlass: {
3105     Node* in1 = n->in(1);
3106     if (in1->is_DecodeNarrowPtr()) {
3107       n->subsume_by(in1->in(1), this);
3108     } else if (in1->Opcode() == Op_ConP) {
3109       const Type* t = in1->bottom_type();
3110       if (t == TypePtr::NULL_PTR) {
3111         assert(t->isa_oopptr(), "null klass?");
3112         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3113       } else if (t->isa_oopptr()) {
3114         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3115       } else if (t->isa_klassptr()) {
3116         n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3117       }
3118     }
3119     if (in1->outcnt() == 0) {
3120       in1->disconnect_inputs(NULL, this);
3121     }
3122     break;
3123   }
3124 
3125   case Op_Proj: {
3126     if (OptimizeStringConcat) {
3127       ProjNode* p = n->as_Proj();
3128       if (p->_is_io_use) {
3129         // Separate projections were used for the exception path which
3130         // are normally removed by a late inline.  If it wasn't inlined
3131         // then they will hang around and should just be replaced with
3132         // the original one.
3133         Node* proj = NULL;
3134         // Replace with just one
3135         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
3136           Node *use = i.get();
3137           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
3138             proj = use;
3139             break;
3140           }
3141         }
3142         assert(proj != NULL, "must be found");
3143         p->subsume_by(proj, this);
3144       }
3145     }
3146     break;
3147   }
3148 
3149   case Op_Phi:
3150     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3151       // The EncodeP optimization may create Phi with the same edges
3152       // for all paths. It is not handled well by Register Allocator.
3153       Node* unique_in = n->in(1);
3154       assert(unique_in != NULL, "");
3155       uint cnt = n->req();
3156       for (uint i = 2; i < cnt; i++) {
3157         Node* m = n->in(i);
3158         assert(m != NULL, "");
3159         if (unique_in != m)
3160           unique_in = NULL;
3161       }
3162       if (unique_in != NULL) {
3163         n->subsume_by(unique_in, this);
3164       }
3165     }
3166     break;
3167 
3168 #endif
3169 
3170 #ifdef ASSERT
3171   case Op_CastII:
3172     // Verify that all range check dependent CastII nodes were removed.
3173     if (n->isa_CastII()->has_range_check()) {
3174       n->dump(3);
3175       assert(false, "Range check dependent CastII node was not removed");
3176     }
3177     break;
3178 #endif
3179 
3180   case Op_ModI:
3181     if (UseDivMod) {
3182       // Check if a%b and a/b both exist
3183       Node* d = n->find_similar(Op_DivI);
3184       if (d) {
3185         // Replace them with a fused divmod if supported
3186         if (Matcher::has_match_rule(Op_DivModI)) {
3187           DivModINode* divmod = DivModINode::make(n);
3188           d->subsume_by(divmod->div_proj(), this);
3189           n->subsume_by(divmod->mod_proj(), this);
3190         } else {
3191           // replace a%b with a-((a/b)*b)
3192           Node* mult = new MulINode(d, d->in(2));
3193           Node* sub  = new SubINode(d->in(1), mult);
3194           n->subsume_by(sub, this);
3195         }
3196       }
3197     }
3198     break;
3199 
3200   case Op_ModL:
3201     if (UseDivMod) {
3202       // Check if a%b and a/b both exist
3203       Node* d = n->find_similar(Op_DivL);
3204       if (d) {
3205         // Replace them with a fused divmod if supported
3206         if (Matcher::has_match_rule(Op_DivModL)) {
3207           DivModLNode* divmod = DivModLNode::make(n);
3208           d->subsume_by(divmod->div_proj(), this);
3209           n->subsume_by(divmod->mod_proj(), this);
3210         } else {
3211           // replace a%b with a-((a/b)*b)
3212           Node* mult = new MulLNode(d, d->in(2));
3213           Node* sub  = new SubLNode(d->in(1), mult);
3214           n->subsume_by(sub, this);
3215         }
3216       }
3217     }
3218     break;
3219 
3220   case Op_LoadVector:
3221   case Op_StoreVector:
3222     break;
3223 
3224   case Op_AddReductionVI:
3225   case Op_AddReductionVL:
3226   case Op_AddReductionVF:
3227   case Op_AddReductionVD:
3228   case Op_MulReductionVI:
3229   case Op_MulReductionVL:
3230   case Op_MulReductionVF:
3231   case Op_MulReductionVD:
3232     break;
3233 
3234   case Op_PackB:
3235   case Op_PackS:
3236   case Op_PackI:
3237   case Op_PackF:
3238   case Op_PackL:
3239   case Op_PackD:
3240     if (n->req()-1 > 2) {
3241       // Replace many operand PackNodes with a binary tree for matching
3242       PackNode* p = (PackNode*) n;
3243       Node* btp = p->binary_tree_pack(1, n->req());
3244       n->subsume_by(btp, this);
3245     }
3246     break;
3247   case Op_Loop:
3248   case Op_CountedLoop:
3249   case Op_OuterStripMinedLoop:
3250     if (n->as_Loop()->is_inner_loop()) {
3251       frc.inc_inner_loop_count();
3252     }
3253     n->as_Loop()->verify_strip_mined(0);
3254     break;
3255   case Op_LShiftI:
3256   case Op_RShiftI:
3257   case Op_URShiftI:
3258   case Op_LShiftL:
3259   case Op_RShiftL:
3260   case Op_URShiftL:
3261     if (Matcher::need_masked_shift_count) {
3262       // The cpu's shift instructions don't restrict the count to the
3263       // lower 5/6 bits. We need to do the masking ourselves.
3264       Node* in2 = n->in(2);
3265       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3266       const TypeInt* t = in2->find_int_type();
3267       if (t != NULL && t->is_con()) {
3268         juint shift = t->get_con();
3269         if (shift > mask) { // Unsigned cmp
3270           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3271         }
3272       } else {
3273         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3274           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3275           n->set_req(2, shift);
3276         }
3277       }
3278       if (in2->outcnt() == 0) { // Remove dead node
3279         in2->disconnect_inputs(NULL, this);
3280       }
3281     }
3282     break;
3283   case Op_MemBarStoreStore:
3284   case Op_MemBarRelease:
3285     // Break the link with AllocateNode: it is no longer useful and
3286     // confuses register allocation.
3287     if (n->req() > MemBarNode::Precedent) {
3288       n->set_req(MemBarNode::Precedent, top());
3289     }
3290     break;
3291   case Op_RangeCheck: {
3292     RangeCheckNode* rc = n->as_RangeCheck();
3293     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3294     n->subsume_by(iff, this);
3295     frc._tests.push(iff);
3296     break;
3297   }
3298   case Op_ConvI2L: {
3299     if (!Matcher::convi2l_type_required) {
3300       // Code generation on some platforms doesn't need accurate
3301       // ConvI2L types. Widening the type can help remove redundant
3302       // address computations.
3303       n->as_Type()->set_type(TypeLong::INT);
3304       ResourceMark rm;
3305       Node_List wq;
3306       wq.push(n);
3307       for (uint next = 0; next < wq.size(); next++) {
3308         Node *m = wq.at(next);
3309 
3310         for(;;) {
3311           // Loop over all nodes with identical inputs edges as m
3312           Node* k = m->find_similar(m->Opcode());
3313           if (k == NULL) {
3314             break;
3315           }
3316           // Push their uses so we get a chance to remove node made
3317           // redundant
3318           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3319             Node* u = k->fast_out(i);
3320             assert(!wq.contains(u), "shouldn't process one node several times");
3321             if (u->Opcode() == Op_LShiftL ||
3322                 u->Opcode() == Op_AddL ||
3323                 u->Opcode() == Op_SubL ||
3324                 u->Opcode() == Op_AddP) {
3325               wq.push(u);
3326             }
3327           }
3328           // Replace all nodes with identical edges as m with m
3329           k->subsume_by(m, this);
3330         }
3331       }
3332     }
3333     break;
3334   }
3335   default:
3336     assert( !n->is_Call(), "" );
3337     assert( !n->is_Mem(), "" );
3338     assert( nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3339     break;
3340   }
3341 
3342   // Collect CFG split points
3343   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
3344     frc._tests.push(n);
3345   }
3346 }
3347 
3348 //------------------------------final_graph_reshaping_walk---------------------
3349 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3350 // requires that the walk visits a node's inputs before visiting the node.
3351 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3352   ResourceArea *area = Thread::current()->resource_area();
3353   Unique_Node_List sfpt(area);
3354 
3355   frc._visited.set(root->_idx); // first, mark node as visited
3356   uint cnt = root->req();
3357   Node *n = root;
3358   uint  i = 0;
3359   while (true) {
3360     if (i < cnt) {
3361       // Place all non-visited non-null inputs onto stack
3362       Node* m = n->in(i);
3363       ++i;
3364       if (m != NULL && !frc._visited.test_set(m->_idx)) {
3365         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
3366           // compute worst case interpreter size in case of a deoptimization
3367           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3368 
3369           sfpt.push(m);
3370         }
3371         cnt = m->req();
3372         nstack.push(n, i); // put on stack parent and next input's index
3373         n = m;
3374         i = 0;
3375       }
3376     } else {
3377       // Now do post-visit work
3378       final_graph_reshaping_impl( n, frc );
3379       if (nstack.is_empty())
3380         break;             // finished
3381       n = nstack.node();   // Get node from stack
3382       cnt = n->req();
3383       i = nstack.index();
3384       nstack.pop();        // Shift to the next node on stack
3385     }
3386   }
3387 
3388   // Skip next transformation if compressed oops are not used.
3389   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3390       (!UseCompressedOops && !UseCompressedClassPointers))
3391     return;
3392 
3393   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3394   // It could be done for an uncommon traps or any safepoints/calls
3395   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3396   while (sfpt.size() > 0) {
3397     n = sfpt.pop();
3398     JVMState *jvms = n->as_SafePoint()->jvms();
3399     assert(jvms != NULL, "sanity");
3400     int start = jvms->debug_start();
3401     int end   = n->req();
3402     bool is_uncommon = (n->is_CallStaticJava() &&
3403                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3404     for (int j = start; j < end; j++) {
3405       Node* in = n->in(j);
3406       if (in->is_DecodeNarrowPtr()) {
3407         bool safe_to_skip = true;
3408         if (!is_uncommon ) {
3409           // Is it safe to skip?
3410           for (uint i = 0; i < in->outcnt(); i++) {
3411             Node* u = in->raw_out(i);
3412             if (!u->is_SafePoint() ||
3413                 (u->is_Call() && u->as_Call()->has_non_debug_use(n))) {
3414               safe_to_skip = false;
3415             }
3416           }
3417         }
3418         if (safe_to_skip) {
3419           n->set_req(j, in->in(1));
3420         }
3421         if (in->outcnt() == 0) {
3422           in->disconnect_inputs(NULL, this);
3423         }
3424       }
3425     }
3426   }
3427 }
3428 
3429 //------------------------------final_graph_reshaping--------------------------
3430 // Final Graph Reshaping.
3431 //
3432 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3433 //     and not commoned up and forced early.  Must come after regular
3434 //     optimizations to avoid GVN undoing the cloning.  Clone constant
3435 //     inputs to Loop Phis; these will be split by the allocator anyways.
3436 //     Remove Opaque nodes.
3437 // (2) Move last-uses by commutative operations to the left input to encourage
3438 //     Intel update-in-place two-address operations and better register usage
3439 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
3440 //     calls canonicalizing them back.
3441 // (3) Count the number of double-precision FP ops, single-precision FP ops
3442 //     and call sites.  On Intel, we can get correct rounding either by
3443 //     forcing singles to memory (requires extra stores and loads after each
3444 //     FP bytecode) or we can set a rounding mode bit (requires setting and
3445 //     clearing the mode bit around call sites).  The mode bit is only used
3446 //     if the relative frequency of single FP ops to calls is low enough.
3447 //     This is a key transform for SPEC mpeg_audio.
3448 // (4) Detect infinite loops; blobs of code reachable from above but not
3449 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
3450 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
3451 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
3452 //     Detection is by looking for IfNodes where only 1 projection is
3453 //     reachable from below or CatchNodes missing some targets.
3454 // (5) Assert for insane oop offsets in debug mode.
3455 
3456 bool Compile::final_graph_reshaping() {
3457   // an infinite loop may have been eliminated by the optimizer,
3458   // in which case the graph will be empty.
3459   if (root()->req() == 1) {
3460     record_method_not_compilable("trivial infinite loop");
3461     return true;
3462   }
3463 
3464   // Expensive nodes have their control input set to prevent the GVN
3465   // from freely commoning them. There's no GVN beyond this point so
3466   // no need to keep the control input. We want the expensive nodes to
3467   // be freely moved to the least frequent code path by gcm.
3468   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3469   for (int i = 0; i < expensive_count(); i++) {
3470     _expensive_nodes->at(i)->set_req(0, NULL);
3471   }
3472 
3473   Final_Reshape_Counts frc;
3474 
3475   // Visit everybody reachable!
3476   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
3477   Node_Stack nstack(live_nodes() >> 1);
3478   final_graph_reshaping_walk(nstack, root(), frc);
3479 
3480   // Check for unreachable (from below) code (i.e., infinite loops).
3481   for( uint i = 0; i < frc._tests.size(); i++ ) {
3482     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3483     // Get number of CFG targets.
3484     // Note that PCTables include exception targets after calls.
3485     uint required_outcnt = n->required_outcnt();
3486     if (n->outcnt() != required_outcnt) {
3487       // Check for a few special cases.  Rethrow Nodes never take the
3488       // 'fall-thru' path, so expected kids is 1 less.
3489       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3490         if (n->in(0)->in(0)->is_Call()) {
3491           CallNode *call = n->in(0)->in(0)->as_Call();
3492           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3493             required_outcnt--;      // Rethrow always has 1 less kid
3494           } else if (call->req() > TypeFunc::Parms &&
3495                      call->is_CallDynamicJava()) {
3496             // Check for null receiver. In such case, the optimizer has
3497             // detected that the virtual call will always result in a null
3498             // pointer exception. The fall-through projection of this CatchNode
3499             // will not be populated.
3500             Node *arg0 = call->in(TypeFunc::Parms);
3501             if (arg0->is_Type() &&
3502                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3503               required_outcnt--;
3504             }
3505           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3506                      call->req() > TypeFunc::Parms+1 &&
3507                      call->is_CallStaticJava()) {
3508             // Check for negative array length. In such case, the optimizer has
3509             // detected that the allocation attempt will always result in an
3510             // exception. There is no fall-through projection of this CatchNode .
3511             Node *arg1 = call->in(TypeFunc::Parms+1);
3512             if (arg1->is_Type() &&
3513                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3514               required_outcnt--;
3515             }
3516           }
3517         }
3518       }
3519       // Recheck with a better notion of 'required_outcnt'
3520       if (n->outcnt() != required_outcnt) {
3521         record_method_not_compilable("malformed control flow");
3522         return true;            // Not all targets reachable!
3523       }
3524     }
3525     // Check that I actually visited all kids.  Unreached kids
3526     // must be infinite loops.
3527     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3528       if (!frc._visited.test(n->fast_out(j)->_idx)) {
3529         record_method_not_compilable("infinite loop");
3530         return true;            // Found unvisited kid; must be unreach
3531       }
3532 
3533     // Here so verification code in final_graph_reshaping_walk()
3534     // always see an OuterStripMinedLoopEnd
3535     if (n->is_OuterStripMinedLoopEnd()) {
3536       IfNode* init_iff = n->as_If();
3537       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
3538       n->subsume_by(iff, this);
3539     }
3540   }
3541 
3542   // If original bytecodes contained a mixture of floats and doubles
3543   // check if the optimizer has made it homogenous, item (3).
3544   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3545       frc.get_float_count() > 32 &&
3546       frc.get_double_count() == 0 &&
3547       (10 * frc.get_call_count() < frc.get_float_count()) ) {
3548     set_24_bit_selection_and_mode( false,  true );
3549   }
3550 
3551   set_java_calls(frc.get_java_call_count());
3552   set_inner_loops(frc.get_inner_loop_count());
3553 
3554   // No infinite loops, no reason to bail out.
3555   return false;
3556 }
3557 
3558 //-----------------------------too_many_traps----------------------------------
3559 // Report if there are too many traps at the current method and bci.
3560 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3561 bool Compile::too_many_traps(ciMethod* method,
3562                              int bci,
3563                              Deoptimization::DeoptReason reason) {
3564   ciMethodData* md = method->method_data();
3565   if (md->is_empty()) {
3566     // Assume the trap has not occurred, or that it occurred only
3567     // because of a transient condition during start-up in the interpreter.
3568     return false;
3569   }
3570   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3571   if (md->has_trap_at(bci, m, reason) != 0) {
3572     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3573     // Also, if there are multiple reasons, or if there is no per-BCI record,
3574     // assume the worst.
3575     if (log())
3576       log()->elem("observe trap='%s' count='%d'",
3577                   Deoptimization::trap_reason_name(reason),
3578                   md->trap_count(reason));
3579     return true;
3580   } else {
3581     // Ignore method/bci and see if there have been too many globally.
3582     return too_many_traps(reason, md);
3583   }
3584 }
3585 
3586 // Less-accurate variant which does not require a method and bci.
3587 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3588                              ciMethodData* logmd) {
3589   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
3590     // Too many traps globally.
3591     // Note that we use cumulative trap_count, not just md->trap_count.
3592     if (log()) {
3593       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3594       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3595                   Deoptimization::trap_reason_name(reason),
3596                   mcount, trap_count(reason));
3597     }
3598     return true;
3599   } else {
3600     // The coast is clear.
3601     return false;
3602   }
3603 }
3604 
3605 //--------------------------too_many_recompiles--------------------------------
3606 // Report if there are too many recompiles at the current method and bci.
3607 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3608 // Is not eager to return true, since this will cause the compiler to use
3609 // Action_none for a trap point, to avoid too many recompilations.
3610 bool Compile::too_many_recompiles(ciMethod* method,
3611                                   int bci,
3612                                   Deoptimization::DeoptReason reason) {
3613   ciMethodData* md = method->method_data();
3614   if (md->is_empty()) {
3615     // Assume the trap has not occurred, or that it occurred only
3616     // because of a transient condition during start-up in the interpreter.
3617     return false;
3618   }
3619   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3620   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3621   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
3622   Deoptimization::DeoptReason per_bc_reason
3623     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3624   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3625   if ((per_bc_reason == Deoptimization::Reason_none
3626        || md->has_trap_at(bci, m, reason) != 0)
3627       // The trap frequency measure we care about is the recompile count:
3628       && md->trap_recompiled_at(bci, m)
3629       && md->overflow_recompile_count() >= bc_cutoff) {
3630     // Do not emit a trap here if it has already caused recompilations.
3631     // Also, if there are multiple reasons, or if there is no per-BCI record,
3632     // assume the worst.
3633     if (log())
3634       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3635                   Deoptimization::trap_reason_name(reason),
3636                   md->trap_count(reason),
3637                   md->overflow_recompile_count());
3638     return true;
3639   } else if (trap_count(reason) != 0
3640              && decompile_count() >= m_cutoff) {
3641     // Too many recompiles globally, and we have seen this sort of trap.
3642     // Use cumulative decompile_count, not just md->decompile_count.
3643     if (log())
3644       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3645                   Deoptimization::trap_reason_name(reason),
3646                   md->trap_count(reason), trap_count(reason),
3647                   md->decompile_count(), decompile_count());
3648     return true;
3649   } else {
3650     // The coast is clear.
3651     return false;
3652   }
3653 }
3654 
3655 // Compute when not to trap. Used by matching trap based nodes and
3656 // NullCheck optimization.
3657 void Compile::set_allowed_deopt_reasons() {
3658   _allowed_reasons = 0;
3659   if (is_method_compilation()) {
3660     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
3661       assert(rs < BitsPerInt, "recode bit map");
3662       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
3663         _allowed_reasons |= nth_bit(rs);
3664       }
3665     }
3666   }
3667 }
3668 
3669 #ifndef PRODUCT
3670 //------------------------------verify_graph_edges---------------------------
3671 // Walk the Graph and verify that there is a one-to-one correspondence
3672 // between Use-Def edges and Def-Use edges in the graph.
3673 void Compile::verify_graph_edges(bool no_dead_code) {
3674   if (VerifyGraphEdges) {
3675     ResourceArea *area = Thread::current()->resource_area();
3676     Unique_Node_List visited(area);
3677     // Call recursive graph walk to check edges
3678     _root->verify_edges(visited);
3679     if (no_dead_code) {
3680       // Now make sure that no visited node is used by an unvisited node.
3681       bool dead_nodes = false;
3682       Unique_Node_List checked(area);
3683       while (visited.size() > 0) {
3684         Node* n = visited.pop();
3685         checked.push(n);
3686         for (uint i = 0; i < n->outcnt(); i++) {
3687           Node* use = n->raw_out(i);
3688           if (checked.member(use))  continue;  // already checked
3689           if (visited.member(use))  continue;  // already in the graph
3690           if (use->is_Con())        continue;  // a dead ConNode is OK
3691           // At this point, we have found a dead node which is DU-reachable.
3692           if (!dead_nodes) {
3693             tty->print_cr("*** Dead nodes reachable via DU edges:");
3694             dead_nodes = true;
3695           }
3696           use->dump(2);
3697           tty->print_cr("---");
3698           checked.push(use);  // No repeats; pretend it is now checked.
3699         }
3700       }
3701       assert(!dead_nodes, "using nodes must be reachable from root");
3702     }
3703   }
3704 }
3705 
3706 // Verify GC barriers consistency
3707 // Currently supported:
3708 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
3709 void Compile::verify_barriers() {
3710   if (UseG1GC) {
3711     // Verify G1 pre-barriers
3712     const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + SATBMarkQueue::byte_offset_of_active());
3713 
3714     ResourceArea *area = Thread::current()->resource_area();
3715     Unique_Node_List visited(area);
3716     Node_List worklist(area);
3717     // We're going to walk control flow backwards starting from the Root
3718     worklist.push(_root);
3719     while (worklist.size() > 0) {
3720       Node* x = worklist.pop();
3721       if (x == NULL || x == top()) continue;
3722       if (visited.member(x)) {
3723         continue;
3724       } else {
3725         visited.push(x);
3726       }
3727 
3728       if (x->is_Region()) {
3729         for (uint i = 1; i < x->req(); i++) {
3730           worklist.push(x->in(i));
3731         }
3732       } else {
3733         worklist.push(x->in(0));
3734         // We are looking for the pattern:
3735         //                            /->ThreadLocal
3736         // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
3737         //              \->ConI(0)
3738         // We want to verify that the If and the LoadB have the same control
3739         // See GraphKit::g1_write_barrier_pre()
3740         if (x->is_If()) {
3741           IfNode *iff = x->as_If();
3742           if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
3743             CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
3744             if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
3745                 && cmp->in(1)->is_Load()) {
3746               LoadNode* load = cmp->in(1)->as_Load();
3747               if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
3748                   && load->in(2)->in(3)->is_Con()
3749                   && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
3750 
3751                 Node* if_ctrl = iff->in(0);
3752                 Node* load_ctrl = load->in(0);
3753 
3754                 if (if_ctrl != load_ctrl) {
3755                   // Skip possible CProj->NeverBranch in infinite loops
3756                   if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
3757                       && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
3758                     if_ctrl = if_ctrl->in(0)->in(0);
3759                   }
3760                 }
3761                 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
3762               }
3763             }
3764           }
3765         }
3766       }
3767     }
3768   }
3769 }
3770 
3771 #endif
3772 
3773 // The Compile object keeps track of failure reasons separately from the ciEnv.
3774 // This is required because there is not quite a 1-1 relation between the
3775 // ciEnv and its compilation task and the Compile object.  Note that one
3776 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3777 // to backtrack and retry without subsuming loads.  Other than this backtracking
3778 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3779 // by the logic in C2Compiler.
3780 void Compile::record_failure(const char* reason) {
3781   if (log() != NULL) {
3782     log()->elem("failure reason='%s' phase='compile'", reason);
3783   }
3784   if (_failure_reason == NULL) {
3785     // Record the first failure reason.
3786     _failure_reason = reason;
3787   }
3788 
3789   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3790     C->print_method(PHASE_FAILURE);
3791   }
3792   _root = NULL;  // flush the graph, too
3793 }
3794 
3795 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
3796   : TraceTime(name, accumulator, CITime, CITimeVerbose),
3797     _phase_name(name), _dolog(CITimeVerbose)
3798 {
3799   if (_dolog) {
3800     C = Compile::current();
3801     _log = C->log();
3802   } else {
3803     C = NULL;
3804     _log = NULL;
3805   }
3806   if (_log != NULL) {
3807     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3808     _log->stamp();
3809     _log->end_head();
3810   }
3811 }
3812 
3813 Compile::TracePhase::~TracePhase() {
3814 
3815   C = Compile::current();
3816   if (_dolog) {
3817     _log = C->log();
3818   } else {
3819     _log = NULL;
3820   }
3821 
3822 #ifdef ASSERT
3823   if (PrintIdealNodeCount) {
3824     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3825                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3826   }
3827 
3828   if (VerifyIdealNodeCount) {
3829     Compile::current()->print_missing_nodes();
3830   }
3831 #endif
3832 
3833   if (_log != NULL) {
3834     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3835   }
3836 }
3837 
3838 //=============================================================================
3839 // Two Constant's are equal when the type and the value are equal.
3840 bool Compile::Constant::operator==(const Constant& other) {
3841   if (type()          != other.type()         )  return false;
3842   if (can_be_reused() != other.can_be_reused())  return false;
3843   // For floating point values we compare the bit pattern.
3844   switch (type()) {
3845   case T_INT:
3846   case T_FLOAT:   return (_v._value.i == other._v._value.i);
3847   case T_LONG:
3848   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
3849   case T_OBJECT:
3850   case T_ADDRESS: return (_v._value.l == other._v._value.l);
3851   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
3852   case T_METADATA: return (_v._metadata == other._v._metadata);
3853   default: ShouldNotReachHere(); return false;
3854   }
3855 }
3856 
3857 static int type_to_size_in_bytes(BasicType t) {
3858   switch (t) {
3859   case T_INT:     return sizeof(jint   );
3860   case T_LONG:    return sizeof(jlong  );
3861   case T_FLOAT:   return sizeof(jfloat );
3862   case T_DOUBLE:  return sizeof(jdouble);
3863   case T_METADATA: return sizeof(Metadata*);
3864     // We use T_VOID as marker for jump-table entries (labels) which
3865     // need an internal word relocation.
3866   case T_VOID:
3867   case T_ADDRESS:
3868   case T_OBJECT:  return sizeof(jobject);
3869   default:
3870     ShouldNotReachHere();
3871     return -1;
3872   }
3873 }
3874 
3875 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3876   // sort descending
3877   if (a->freq() > b->freq())  return -1;
3878   if (a->freq() < b->freq())  return  1;
3879   return 0;
3880 }
3881 
3882 void Compile::ConstantTable::calculate_offsets_and_size() {
3883   // First, sort the array by frequencies.
3884   _constants.sort(qsort_comparator);
3885 
3886 #ifdef ASSERT
3887   // Make sure all jump-table entries were sorted to the end of the
3888   // array (they have a negative frequency).
3889   bool found_void = false;
3890   for (int i = 0; i < _constants.length(); i++) {
3891     Constant con = _constants.at(i);
3892     if (con.type() == T_VOID)
3893       found_void = true;  // jump-tables
3894     else
3895       assert(!found_void, "wrong sorting");
3896   }
3897 #endif
3898 
3899   int offset = 0;
3900   for (int i = 0; i < _constants.length(); i++) {
3901     Constant* con = _constants.adr_at(i);
3902 
3903     // Align offset for type.
3904     int typesize = type_to_size_in_bytes(con->type());
3905     offset = align_up(offset, typesize);
3906     con->set_offset(offset);   // set constant's offset
3907 
3908     if (con->type() == T_VOID) {
3909       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
3910       offset = offset + typesize * n->outcnt();  // expand jump-table
3911     } else {
3912       offset = offset + typesize;
3913     }
3914   }
3915 
3916   // Align size up to the next section start (which is insts; see
3917   // CodeBuffer::align_at_start).
3918   assert(_size == -1, "already set?");
3919   _size = align_up(offset, (int)CodeEntryAlignment);
3920 }
3921 
3922 void Compile::ConstantTable::emit(CodeBuffer& cb) {
3923   MacroAssembler _masm(&cb);
3924   for (int i = 0; i < _constants.length(); i++) {
3925     Constant con = _constants.at(i);
3926     address constant_addr = NULL;
3927     switch (con.type()) {
3928     case T_INT:    constant_addr = _masm.int_constant(   con.get_jint()   ); break;
3929     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
3930     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
3931     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
3932     case T_OBJECT: {
3933       jobject obj = con.get_jobject();
3934       int oop_index = _masm.oop_recorder()->find_index(obj);
3935       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
3936       break;
3937     }
3938     case T_ADDRESS: {
3939       address addr = (address) con.get_jobject();
3940       constant_addr = _masm.address_constant(addr);
3941       break;
3942     }
3943     // We use T_VOID as marker for jump-table entries (labels) which
3944     // need an internal word relocation.
3945     case T_VOID: {
3946       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
3947       // Fill the jump-table with a dummy word.  The real value is
3948       // filled in later in fill_jump_table.
3949       address dummy = (address) n;
3950       constant_addr = _masm.address_constant(dummy);
3951       // Expand jump-table
3952       for (uint i = 1; i < n->outcnt(); i++) {
3953         address temp_addr = _masm.address_constant(dummy + i);
3954         assert(temp_addr, "consts section too small");
3955       }
3956       break;
3957     }
3958     case T_METADATA: {
3959       Metadata* obj = con.get_metadata();
3960       int metadata_index = _masm.oop_recorder()->find_index(obj);
3961       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
3962       break;
3963     }
3964     default: ShouldNotReachHere();
3965     }
3966     assert(constant_addr, "consts section too small");
3967     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
3968             "must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset()));
3969   }
3970 }
3971 
3972 int Compile::ConstantTable::find_offset(Constant& con) const {
3973   int idx = _constants.find(con);
3974   assert(idx != -1, "constant must be in constant table");
3975   int offset = _constants.at(idx).offset();
3976   assert(offset != -1, "constant table not emitted yet?");
3977   return offset;
3978 }
3979 
3980 void Compile::ConstantTable::add(Constant& con) {
3981   if (con.can_be_reused()) {
3982     int idx = _constants.find(con);
3983     if (idx != -1 && _constants.at(idx).can_be_reused()) {
3984       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
3985       return;
3986     }
3987   }
3988   (void) _constants.append(con);
3989 }
3990 
3991 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
3992   Block* b = Compile::current()->cfg()->get_block_for_node(n);
3993   Constant con(type, value, b->_freq);
3994   add(con);
3995   return con;
3996 }
3997 
3998 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
3999   Constant con(metadata);
4000   add(con);
4001   return con;
4002 }
4003 
4004 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
4005   jvalue value;
4006   BasicType type = oper->type()->basic_type();
4007   switch (type) {
4008   case T_LONG:    value.j = oper->constantL(); break;
4009   case T_FLOAT:   value.f = oper->constantF(); break;
4010   case T_DOUBLE:  value.d = oper->constantD(); break;
4011   case T_OBJECT:
4012   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
4013   case T_METADATA: return add((Metadata*)oper->constant()); break;
4014   default: guarantee(false, "unhandled type: %s", type2name(type));
4015   }
4016   return add(n, type, value);
4017 }
4018 
4019 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
4020   jvalue value;
4021   // We can use the node pointer here to identify the right jump-table
4022   // as this method is called from Compile::Fill_buffer right before
4023   // the MachNodes are emitted and the jump-table is filled (means the
4024   // MachNode pointers do not change anymore).
4025   value.l = (jobject) n;
4026   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
4027   add(con);
4028   return con;
4029 }
4030 
4031 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
4032   // If called from Compile::scratch_emit_size do nothing.
4033   if (Compile::current()->in_scratch_emit_size())  return;
4034 
4035   assert(labels.is_nonempty(), "must be");
4036   assert((uint) labels.length() == n->outcnt(), "must be equal: %d == %d", labels.length(), n->outcnt());
4037 
4038   // Since MachConstantNode::constant_offset() also contains
4039   // table_base_offset() we need to subtract the table_base_offset()
4040   // to get the plain offset into the constant table.
4041   int offset = n->constant_offset() - table_base_offset();
4042 
4043   MacroAssembler _masm(&cb);
4044   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
4045 
4046   for (uint i = 0; i < n->outcnt(); i++) {
4047     address* constant_addr = &jump_table_base[i];
4048     assert(*constant_addr == (((address) n) + i), "all jump-table entries must contain adjusted node pointer: " INTPTR_FORMAT " == " INTPTR_FORMAT, p2i(*constant_addr), p2i(((address) n) + i));
4049     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
4050     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
4051   }
4052 }
4053 
4054 //----------------------------static_subtype_check-----------------------------
4055 // Shortcut important common cases when superklass is exact:
4056 // (0) superklass is java.lang.Object (can occur in reflective code)
4057 // (1) subklass is already limited to a subtype of superklass => always ok
4058 // (2) subklass does not overlap with superklass => always fail
4059 // (3) superklass has NO subtypes and we can check with a simple compare.
4060 int Compile::static_subtype_check(ciKlass* superk, ciKlass* subk) {
4061   if (StressReflectiveCode) {
4062     return SSC_full_test;       // Let caller generate the general case.
4063   }
4064 
4065   if (superk == env()->Object_klass()) {
4066     return SSC_always_true;     // (0) this test cannot fail
4067   }
4068 
4069   ciType* superelem = superk;
4070   if (superelem->is_array_klass())
4071     superelem = superelem->as_array_klass()->base_element_type();
4072 
4073   if (!subk->is_interface()) {  // cannot trust static interface types yet
4074     if (subk->is_subtype_of(superk)) {
4075       return SSC_always_true;   // (1) false path dead; no dynamic test needed
4076     }
4077     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
4078         !superk->is_subtype_of(subk)) {
4079       return SSC_always_false;
4080     }
4081   }
4082 
4083   // If casting to an instance klass, it must have no subtypes
4084   if (superk->is_interface()) {
4085     // Cannot trust interfaces yet.
4086     // %%% S.B. superk->nof_implementors() == 1
4087   } else if (superelem->is_instance_klass()) {
4088     ciInstanceKlass* ik = superelem->as_instance_klass();
4089     if (!ik->has_subklass() && !ik->is_interface()) {
4090       if (!ik->is_final()) {
4091         // Add a dependency if there is a chance of a later subclass.
4092         dependencies()->assert_leaf_type(ik);
4093       }
4094       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4095     }
4096   } else {
4097     // A primitive array type has no subtypes.
4098     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4099   }
4100 
4101   return SSC_full_test;
4102 }
4103 
4104 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4105 #ifdef _LP64
4106   // The scaled index operand to AddP must be a clean 64-bit value.
4107   // Java allows a 32-bit int to be incremented to a negative
4108   // value, which appears in a 64-bit register as a large
4109   // positive number.  Using that large positive number as an
4110   // operand in pointer arithmetic has bad consequences.
4111   // On the other hand, 32-bit overflow is rare, and the possibility
4112   // can often be excluded, if we annotate the ConvI2L node with
4113   // a type assertion that its value is known to be a small positive
4114   // number.  (The prior range check has ensured this.)
4115   // This assertion is used by ConvI2LNode::Ideal.
4116   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4117   if (sizetype != NULL) index_max = sizetype->_hi - 1;
4118   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4119   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4120 #endif
4121   return idx;
4122 }
4123 
4124 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4125 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl) {
4126   if (ctrl != NULL) {
4127     // Express control dependency by a CastII node with a narrow type.
4128     value = new CastIINode(value, itype, false, true /* range check dependency */);
4129     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4130     // node from floating above the range check during loop optimizations. Otherwise, the
4131     // ConvI2L node may be eliminated independently of the range check, causing the data path
4132     // to become TOP while the control path is still there (although it's unreachable).
4133     value->set_req(0, ctrl);
4134     // Save CastII node to remove it after loop optimizations.
4135     phase->C->add_range_check_cast(value);
4136     value = phase->transform(value);
4137   }
4138   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4139   return phase->transform(new ConvI2LNode(value, ltype));
4140 }
4141 
4142 // The message about the current inlining is accumulated in
4143 // _print_inlining_stream and transfered into the _print_inlining_list
4144 // once we know whether inlining succeeds or not. For regular
4145 // inlining, messages are appended to the buffer pointed by
4146 // _print_inlining_idx in the _print_inlining_list. For late inlining,
4147 // a new buffer is added after _print_inlining_idx in the list. This
4148 // way we can update the inlining message for late inlining call site
4149 // when the inlining is attempted again.
4150 void Compile::print_inlining_init() {
4151   if (print_inlining() || print_intrinsics()) {
4152     _print_inlining_stream = new stringStream();
4153     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
4154   }
4155 }
4156 
4157 void Compile::print_inlining_reinit() {
4158   if (print_inlining() || print_intrinsics()) {
4159     // Re allocate buffer when we change ResourceMark
4160     _print_inlining_stream = new stringStream();
4161   }
4162 }
4163 
4164 void Compile::print_inlining_reset() {
4165   _print_inlining_stream->reset();
4166 }
4167 
4168 void Compile::print_inlining_commit() {
4169   assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
4170   // Transfer the message from _print_inlining_stream to the current
4171   // _print_inlining_list buffer and clear _print_inlining_stream.
4172   _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->as_string(), _print_inlining_stream->size());
4173   print_inlining_reset();
4174 }
4175 
4176 void Compile::print_inlining_push() {
4177   // Add new buffer to the _print_inlining_list at current position
4178   _print_inlining_idx++;
4179   _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
4180 }
4181 
4182 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
4183   return _print_inlining_list->at(_print_inlining_idx);
4184 }
4185 
4186 void Compile::print_inlining_update(CallGenerator* cg) {
4187   if (print_inlining() || print_intrinsics()) {
4188     if (!cg->is_late_inline()) {
4189       if (print_inlining_current().cg() != NULL) {
4190         print_inlining_push();
4191       }
4192       print_inlining_commit();
4193     } else {
4194       if (print_inlining_current().cg() != cg &&
4195           (print_inlining_current().cg() != NULL ||
4196            print_inlining_current().ss()->size() != 0)) {
4197         print_inlining_push();
4198       }
4199       print_inlining_commit();
4200       print_inlining_current().set_cg(cg);
4201     }
4202   }
4203 }
4204 
4205 void Compile::print_inlining_move_to(CallGenerator* cg) {
4206   // We resume inlining at a late inlining call site. Locate the
4207   // corresponding inlining buffer so that we can update it.
4208   if (print_inlining()) {
4209     for (int i = 0; i < _print_inlining_list->length(); i++) {
4210       if (_print_inlining_list->adr_at(i)->cg() == cg) {
4211         _print_inlining_idx = i;
4212         return;
4213       }
4214     }
4215     ShouldNotReachHere();
4216   }
4217 }
4218 
4219 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
4220   if (print_inlining()) {
4221     assert(_print_inlining_stream->size() > 0, "missing inlining msg");
4222     assert(print_inlining_current().cg() == cg, "wrong entry");
4223     // replace message with new message
4224     _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
4225     print_inlining_commit();
4226     print_inlining_current().set_cg(cg);
4227   }
4228 }
4229 
4230 void Compile::print_inlining_assert_ready() {
4231   assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
4232 }
4233 
4234 void Compile::process_print_inlining() {
4235   bool do_print_inlining = print_inlining() || print_intrinsics();
4236   if (do_print_inlining || log() != NULL) {
4237     // Print inlining message for candidates that we couldn't inline
4238     // for lack of space
4239     for (int i = 0; i < _late_inlines.length(); i++) {
4240       CallGenerator* cg = _late_inlines.at(i);
4241       if (!cg->is_mh_late_inline()) {
4242         const char* msg = "live nodes > LiveNodeCountInliningCutoff";
4243         if (do_print_inlining) {
4244           cg->print_inlining_late(msg);
4245         }
4246         log_late_inline_failure(cg, msg);
4247       }
4248     }
4249   }
4250   if (do_print_inlining) {
4251     ResourceMark rm;
4252     stringStream ss;
4253     for (int i = 0; i < _print_inlining_list->length(); i++) {
4254       ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
4255     }
4256     size_t end = ss.size();
4257     _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
4258     strncpy(_print_inlining_output, ss.base(), end+1);
4259     _print_inlining_output[end] = 0;
4260   }
4261 }
4262 
4263 void Compile::dump_print_inlining() {
4264   if (_print_inlining_output != NULL) {
4265     tty->print_raw(_print_inlining_output);
4266   }
4267 }
4268 
4269 void Compile::log_late_inline(CallGenerator* cg) {
4270   if (log() != NULL) {
4271     log()->head("late_inline method='%d'  inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4272                 cg->unique_id());
4273     JVMState* p = cg->call_node()->jvms();
4274     while (p != NULL) {
4275       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4276       p = p->caller();
4277     }
4278     log()->tail("late_inline");
4279   }
4280 }
4281 
4282 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4283   log_late_inline(cg);
4284   if (log() != NULL) {
4285     log()->inline_fail(msg);
4286   }
4287 }
4288 
4289 void Compile::log_inline_id(CallGenerator* cg) {
4290   if (log() != NULL) {
4291     // The LogCompilation tool needs a unique way to identify late
4292     // inline call sites. This id must be unique for this call site in
4293     // this compilation. Try to have it unique across compilations as
4294     // well because it can be convenient when grepping through the log
4295     // file.
4296     // Distinguish OSR compilations from others in case CICountOSR is
4297     // on.
4298     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4299     cg->set_unique_id(id);
4300     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4301   }
4302 }
4303 
4304 void Compile::log_inline_failure(const char* msg) {
4305   if (C->log() != NULL) {
4306     C->log()->inline_fail(msg);
4307   }
4308 }
4309 
4310 
4311 // Dump inlining replay data to the stream.
4312 // Don't change thread state and acquire any locks.
4313 void Compile::dump_inline_data(outputStream* out) {
4314   InlineTree* inl_tree = ilt();
4315   if (inl_tree != NULL) {
4316     out->print(" inline %d", inl_tree->count());
4317     inl_tree->dump_replay_data(out);
4318   }
4319 }
4320 
4321 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4322   if (n1->Opcode() < n2->Opcode())      return -1;
4323   else if (n1->Opcode() > n2->Opcode()) return 1;
4324 
4325   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4326   for (uint i = 1; i < n1->req(); i++) {
4327     if (n1->in(i) < n2->in(i))      return -1;
4328     else if (n1->in(i) > n2->in(i)) return 1;
4329   }
4330 
4331   return 0;
4332 }
4333 
4334 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4335   Node* n1 = *n1p;
4336   Node* n2 = *n2p;
4337 
4338   return cmp_expensive_nodes(n1, n2);
4339 }
4340 
4341 void Compile::sort_expensive_nodes() {
4342   if (!expensive_nodes_sorted()) {
4343     _expensive_nodes->sort(cmp_expensive_nodes);
4344   }
4345 }
4346 
4347 bool Compile::expensive_nodes_sorted() const {
4348   for (int i = 1; i < _expensive_nodes->length(); i++) {
4349     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
4350       return false;
4351     }
4352   }
4353   return true;
4354 }
4355 
4356 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4357   if (_expensive_nodes->length() == 0) {
4358     return false;
4359   }
4360 
4361   assert(OptimizeExpensiveOps, "optimization off?");
4362 
4363   // Take this opportunity to remove dead nodes from the list
4364   int j = 0;
4365   for (int i = 0; i < _expensive_nodes->length(); i++) {
4366     Node* n = _expensive_nodes->at(i);
4367     if (!n->is_unreachable(igvn)) {
4368       assert(n->is_expensive(), "should be expensive");
4369       _expensive_nodes->at_put(j, n);
4370       j++;
4371     }
4372   }
4373   _expensive_nodes->trunc_to(j);
4374 
4375   // Then sort the list so that similar nodes are next to each other
4376   // and check for at least two nodes of identical kind with same data
4377   // inputs.
4378   sort_expensive_nodes();
4379 
4380   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
4381     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
4382       return true;
4383     }
4384   }
4385 
4386   return false;
4387 }
4388 
4389 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4390   if (_expensive_nodes->length() == 0) {
4391     return;
4392   }
4393 
4394   assert(OptimizeExpensiveOps, "optimization off?");
4395 
4396   // Sort to bring similar nodes next to each other and clear the
4397   // control input of nodes for which there's only a single copy.
4398   sort_expensive_nodes();
4399 
4400   int j = 0;
4401   int identical = 0;
4402   int i = 0;
4403   bool modified = false;
4404   for (; i < _expensive_nodes->length()-1; i++) {
4405     assert(j <= i, "can't write beyond current index");
4406     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
4407       identical++;
4408       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4409       continue;
4410     }
4411     if (identical > 0) {
4412       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4413       identical = 0;
4414     } else {
4415       Node* n = _expensive_nodes->at(i);
4416       igvn.replace_input_of(n, 0, NULL);
4417       igvn.hash_insert(n);
4418       modified = true;
4419     }
4420   }
4421   if (identical > 0) {
4422     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4423   } else if (_expensive_nodes->length() >= 1) {
4424     Node* n = _expensive_nodes->at(i);
4425     igvn.replace_input_of(n, 0, NULL);
4426     igvn.hash_insert(n);
4427     modified = true;
4428   }
4429   _expensive_nodes->trunc_to(j);
4430   if (modified) {
4431     igvn.optimize();
4432   }
4433 }
4434 
4435 void Compile::add_expensive_node(Node * n) {
4436   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
4437   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4438   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4439   if (OptimizeExpensiveOps) {
4440     _expensive_nodes->append(n);
4441   } else {
4442     // Clear control input and let IGVN optimize expensive nodes if
4443     // OptimizeExpensiveOps is off.
4444     n->set_req(0, NULL);
4445   }
4446 }
4447 
4448 /**
4449  * Remove the speculative part of types and clean up the graph
4450  */
4451 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4452   if (UseTypeSpeculation) {
4453     Unique_Node_List worklist;
4454     worklist.push(root());
4455     int modified = 0;
4456     // Go over all type nodes that carry a speculative type, drop the
4457     // speculative part of the type and enqueue the node for an igvn
4458     // which may optimize it out.
4459     for (uint next = 0; next < worklist.size(); ++next) {
4460       Node *n  = worklist.at(next);
4461       if (n->is_Type()) {
4462         TypeNode* tn = n->as_Type();
4463         const Type* t = tn->type();
4464         const Type* t_no_spec = t->remove_speculative();
4465         if (t_no_spec != t) {
4466           bool in_hash = igvn.hash_delete(n);
4467           assert(in_hash, "node should be in igvn hash table");
4468           tn->set_type(t_no_spec);
4469           igvn.hash_insert(n);
4470           igvn._worklist.push(n); // give it a chance to go away
4471           modified++;
4472         }
4473       }
4474       uint max = n->len();
4475       for( uint i = 0; i < max; ++i ) {
4476         Node *m = n->in(i);
4477         if (not_a_node(m))  continue;
4478         worklist.push(m);
4479       }
4480     }
4481     // Drop the speculative part of all types in the igvn's type table
4482     igvn.remove_speculative_types();
4483     if (modified > 0) {
4484       igvn.optimize();
4485     }
4486 #ifdef ASSERT
4487     // Verify that after the IGVN is over no speculative type has resurfaced
4488     worklist.clear();
4489     worklist.push(root());
4490     for (uint next = 0; next < worklist.size(); ++next) {
4491       Node *n  = worklist.at(next);
4492       const Type* t = igvn.type_or_null(n);
4493       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
4494       if (n->is_Type()) {
4495         t = n->as_Type()->type();
4496         assert(t == t->remove_speculative(), "no more speculative types");
4497       }
4498       uint max = n->len();
4499       for( uint i = 0; i < max; ++i ) {
4500         Node *m = n->in(i);
4501         if (not_a_node(m))  continue;
4502         worklist.push(m);
4503       }
4504     }
4505     igvn.check_no_speculative_types();
4506 #endif
4507   }
4508 }
4509 























































4510 // Auxiliary method to support randomized stressing/fuzzing.
4511 //
4512 // This method can be called the arbitrary number of times, with current count
4513 // as the argument. The logic allows selecting a single candidate from the
4514 // running list of candidates as follows:
4515 //    int count = 0;
4516 //    Cand* selected = null;
4517 //    while(cand = cand->next()) {
4518 //      if (randomized_select(++count)) {
4519 //        selected = cand;
4520 //      }
4521 //    }
4522 //
4523 // Including count equalizes the chances any candidate is "selected".
4524 // This is useful when we don't have the complete list of candidates to choose
4525 // from uniformly. In this case, we need to adjust the randomicity of the
4526 // selection, or else we will end up biasing the selection towards the latter
4527 // candidates.
4528 //
4529 // Quick back-envelope calculation shows that for the list of n candidates
4530 // the equal probability for the candidate to persist as "best" can be
4531 // achieved by replacing it with "next" k-th candidate with the probability
4532 // of 1/k. It can be easily shown that by the end of the run, the
4533 // probability for any candidate is converged to 1/n, thus giving the
4534 // uniform distribution among all the candidates.
4535 //
4536 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4537 #define RANDOMIZED_DOMAIN_POW 29
4538 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4539 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
4540 bool Compile::randomized_select(int count) {
4541   assert(count > 0, "only positive");
4542   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4543 }
4544 
4545 CloneMap&     Compile::clone_map()                 { return _clone_map; }
4546 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
4547 
4548 void NodeCloneInfo::dump() const {
4549   tty->print(" {%d:%d} ", idx(), gen());
4550 }
4551 
4552 void CloneMap::clone(Node* old, Node* nnn, int gen) {
4553   uint64_t val = value(old->_idx);
4554   NodeCloneInfo cio(val);
4555   assert(val != 0, "old node should be in the map");
4556   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
4557   insert(nnn->_idx, cin.get());
4558 #ifndef PRODUCT
4559   if (is_debug()) {
4560     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
4561   }
4562 #endif
4563 }
4564 
4565 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
4566   NodeCloneInfo cio(value(old->_idx));
4567   if (cio.get() == 0) {
4568     cio.set(old->_idx, 0);
4569     insert(old->_idx, cio.get());
4570 #ifndef PRODUCT
4571     if (is_debug()) {
4572       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
4573     }
4574 #endif
4575   }
4576   clone(old, nnn, gen);
4577 }
4578 
4579 int CloneMap::max_gen() const {
4580   int g = 0;
4581   DictI di(_dict);
4582   for(; di.test(); ++di) {
4583     int t = gen(di._key);
4584     if (g < t) {
4585       g = t;
4586 #ifndef PRODUCT
4587       if (is_debug()) {
4588         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
4589       }
4590 #endif
4591     }
4592   }
4593   return g;
4594 }
4595 
4596 void CloneMap::dump(node_idx_t key) const {
4597   uint64_t val = value(key);
4598   if (val != 0) {
4599     NodeCloneInfo ni(val);
4600     ni.dump();
4601   }
4602 }
--- EOF ---