1 /*
   2  * Copyright (c) 1997, 2013, 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 "classfile/systemDictionary.hpp"
  29 #include "code/exceptionHandlerTable.hpp"
  30 #include "code/nmethod.hpp"
  31 #include "compiler/compileLog.hpp"
  32 #include "compiler/disassembler.hpp"
  33 #include "compiler/oopMap.hpp"
  34 #include "opto/addnode.hpp"
  35 #include "opto/block.hpp"
  36 #include "opto/c2compiler.hpp"
  37 #include "opto/callGenerator.hpp"
  38 #include "opto/callnode.hpp"
  39 #include "opto/cfgnode.hpp"
  40 #include "opto/chaitin.hpp"
  41 #include "opto/compile.hpp"
  42 #include "opto/connode.hpp"
  43 #include "opto/divnode.hpp"
  44 #include "opto/escape.hpp"
  45 #include "opto/idealGraphPrinter.hpp"
  46 #include "opto/loopnode.hpp"
  47 #include "opto/machnode.hpp"
  48 #include "opto/macro.hpp"
  49 #include "opto/matcher.hpp"
  50 #include "opto/memnode.hpp"
  51 #include "opto/mulnode.hpp"
  52 #include "opto/node.hpp"
  53 #include "opto/opcodes.hpp"
  54 #include "opto/output.hpp"
  55 #include "opto/parse.hpp"
  56 #include "opto/phaseX.hpp"
  57 #include "opto/rootnode.hpp"
  58 #include "opto/runtime.hpp"
  59 #include "opto/stringopts.hpp"
  60 #include "opto/type.hpp"
  61 #include "opto/vectornode.hpp"
  62 #include "runtime/arguments.hpp"
  63 #include "runtime/signature.hpp"
  64 #include "runtime/stubRoutines.hpp"
  65 #include "runtime/timer.hpp"
  66 #include "trace/tracing.hpp"
  67 #include "utilities/copy.hpp"
  68 #ifdef TARGET_ARCH_MODEL_x86_32
  69 # include "adfiles/ad_x86_32.hpp"
  70 #endif
  71 #ifdef TARGET_ARCH_MODEL_x86_64
  72 # include "adfiles/ad_x86_64.hpp"
  73 #endif
  74 #ifdef TARGET_ARCH_MODEL_sparc
  75 # include "adfiles/ad_sparc.hpp"
  76 #endif
  77 #ifdef TARGET_ARCH_MODEL_zero
  78 # include "adfiles/ad_zero.hpp"
  79 #endif
  80 #ifdef TARGET_ARCH_MODEL_arm
  81 # include "adfiles/ad_arm.hpp"
  82 #endif
  83 #ifdef TARGET_ARCH_MODEL_ppc
  84 # include "adfiles/ad_ppc.hpp"
  85 #endif
  86 
  87 
  88 // -------------------- Compile::mach_constant_base_node -----------------------
  89 // Constant table base node singleton.
  90 MachConstantBaseNode* Compile::mach_constant_base_node() {
  91   if (_mach_constant_base_node == NULL) {
  92     _mach_constant_base_node = new (C) MachConstantBaseNode();
  93     _mach_constant_base_node->add_req(C->root());
  94   }
  95   return _mach_constant_base_node;
  96 }
  97 
  98 
  99 /// Support for intrinsics.
 100 
 101 // Return the index at which m must be inserted (or already exists).
 102 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
 103 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
 104 #ifdef ASSERT
 105   for (int i = 1; i < _intrinsics->length(); i++) {
 106     CallGenerator* cg1 = _intrinsics->at(i-1);
 107     CallGenerator* cg2 = _intrinsics->at(i);
 108     assert(cg1->method() != cg2->method()
 109            ? cg1->method()     < cg2->method()
 110            : cg1->is_virtual() < cg2->is_virtual(),
 111            "compiler intrinsics list must stay sorted");
 112   }
 113 #endif
 114   // Binary search sorted list, in decreasing intervals [lo, hi].
 115   int lo = 0, hi = _intrinsics->length()-1;
 116   while (lo <= hi) {
 117     int mid = (uint)(hi + lo) / 2;
 118     ciMethod* mid_m = _intrinsics->at(mid)->method();
 119     if (m < mid_m) {
 120       hi = mid-1;
 121     } else if (m > mid_m) {
 122       lo = mid+1;
 123     } else {
 124       // look at minor sort key
 125       bool mid_virt = _intrinsics->at(mid)->is_virtual();
 126       if (is_virtual < mid_virt) {
 127         hi = mid-1;
 128       } else if (is_virtual > mid_virt) {
 129         lo = mid+1;
 130       } else {
 131         return mid;  // exact match
 132       }
 133     }
 134   }
 135   return lo;  // inexact match
 136 }
 137 
 138 void Compile::register_intrinsic(CallGenerator* cg) {
 139   if (_intrinsics == NULL) {
 140     _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
 141   }
 142   // This code is stolen from ciObjectFactory::insert.
 143   // Really, GrowableArray should have methods for
 144   // insert_at, remove_at, and binary_search.
 145   int len = _intrinsics->length();
 146   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
 147   if (index == len) {
 148     _intrinsics->append(cg);
 149   } else {
 150 #ifdef ASSERT
 151     CallGenerator* oldcg = _intrinsics->at(index);
 152     assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
 153 #endif
 154     _intrinsics->append(_intrinsics->at(len-1));
 155     int pos;
 156     for (pos = len-2; pos >= index; pos--) {
 157       _intrinsics->at_put(pos+1,_intrinsics->at(pos));
 158     }
 159     _intrinsics->at_put(index, cg);
 160   }
 161   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 162 }
 163 
 164 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 165   assert(m->is_loaded(), "don't try this on unloaded methods");
 166   if (_intrinsics != NULL) {
 167     int index = intrinsic_insertion_index(m, is_virtual);
 168     if (index < _intrinsics->length()
 169         && _intrinsics->at(index)->method() == m
 170         && _intrinsics->at(index)->is_virtual() == is_virtual) {
 171       return _intrinsics->at(index);
 172     }
 173   }
 174   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 175   if (m->intrinsic_id() != vmIntrinsics::_none &&
 176       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 177     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 178     if (cg != NULL) {
 179       // Save it for next time:
 180       register_intrinsic(cg);
 181       return cg;
 182     } else {
 183       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 184     }
 185   }
 186   return NULL;
 187 }
 188 
 189 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
 190 // in library_call.cpp.
 191 
 192 
 193 #ifndef PRODUCT
 194 // statistics gathering...
 195 
 196 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
 197 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
 198 
 199 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 200   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 201   int oflags = _intrinsic_hist_flags[id];
 202   assert(flags != 0, "what happened?");
 203   if (is_virtual) {
 204     flags |= _intrinsic_virtual;
 205   }
 206   bool changed = (flags != oflags);
 207   if ((flags & _intrinsic_worked) != 0) {
 208     juint count = (_intrinsic_hist_count[id] += 1);
 209     if (count == 1) {
 210       changed = true;           // first time
 211     }
 212     // increment the overall count also:
 213     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
 214   }
 215   if (changed) {
 216     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 217       // Something changed about the intrinsic's virtuality.
 218       if ((flags & _intrinsic_virtual) != 0) {
 219         // This is the first use of this intrinsic as a virtual call.
 220         if (oflags != 0) {
 221           // We already saw it as a non-virtual, so note both cases.
 222           flags |= _intrinsic_both;
 223         }
 224       } else if ((oflags & _intrinsic_both) == 0) {
 225         // This is the first use of this intrinsic as a non-virtual
 226         flags |= _intrinsic_both;
 227       }
 228     }
 229     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
 230   }
 231   // update the overall flags also:
 232   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
 233   return changed;
 234 }
 235 
 236 static char* format_flags(int flags, char* buf) {
 237   buf[0] = 0;
 238   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 239   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 240   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 241   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 242   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 243   if (buf[0] == 0)  strcat(buf, ",");
 244   assert(buf[0] == ',', "must be");
 245   return &buf[1];
 246 }
 247 
 248 void Compile::print_intrinsic_statistics() {
 249   char flagsbuf[100];
 250   ttyLocker ttyl;
 251   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
 252   tty->print_cr("Compiler intrinsic usage:");
 253   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
 254   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 255   #define PRINT_STAT_LINE(name, c, f) \
 256     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 257   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
 258     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
 259     int   flags = _intrinsic_hist_flags[id];
 260     juint count = _intrinsic_hist_count[id];
 261     if ((flags | count) != 0) {
 262       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 263     }
 264   }
 265   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
 266   if (xtty != NULL)  xtty->tail("statistics");
 267 }
 268 
 269 void Compile::print_statistics() {
 270   { ttyLocker ttyl;
 271     if (xtty != NULL)  xtty->head("statistics type='opto'");
 272     Parse::print_statistics();
 273     PhaseCCP::print_statistics();
 274     PhaseRegAlloc::print_statistics();
 275     Scheduling::print_statistics();
 276     PhasePeephole::print_statistics();
 277     PhaseIdealLoop::print_statistics();
 278     if (xtty != NULL)  xtty->tail("statistics");
 279   }
 280   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
 281     // put this under its own <statistics> element.
 282     print_intrinsic_statistics();
 283   }
 284 }
 285 #endif //PRODUCT
 286 
 287 // Support for bundling info
 288 Bundle* Compile::node_bundling(const Node *n) {
 289   assert(valid_bundle_info(n), "oob");
 290   return &_node_bundling_base[n->_idx];
 291 }
 292 
 293 bool Compile::valid_bundle_info(const Node *n) {
 294   return (_node_bundling_limit > n->_idx);
 295 }
 296 
 297 
 298 void Compile::gvn_replace_by(Node* n, Node* nn) {
 299   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 300     Node* use = n->last_out(i);
 301     bool is_in_table = initial_gvn()->hash_delete(use);
 302     uint uses_found = 0;
 303     for (uint j = 0; j < use->len(); j++) {
 304       if (use->in(j) == n) {
 305         if (j < use->req())
 306           use->set_req(j, nn);
 307         else
 308           use->set_prec(j, nn);
 309         uses_found++;
 310       }
 311     }
 312     if (is_in_table) {
 313       // reinsert into table
 314       initial_gvn()->hash_find_insert(use);
 315     }
 316     record_for_igvn(use);
 317     i -= uses_found;    // we deleted 1 or more copies of this edge
 318   }
 319 }
 320 
 321 
 322 static inline bool not_a_node(const Node* n) {
 323   if (n == NULL)                   return true;
 324   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
 325   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
 326   return false;
 327 }
 328 
 329 // Identify all nodes that are reachable from below, useful.
 330 // Use breadth-first pass that records state in a Unique_Node_List,
 331 // recursive traversal is slower.
 332 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 333   int estimated_worklist_size = unique();
 334   useful.map( estimated_worklist_size, NULL );  // preallocate space
 335 
 336   // Initialize worklist
 337   if (root() != NULL)     { useful.push(root()); }
 338   // If 'top' is cached, declare it useful to preserve cached node
 339   if( cached_top_node() ) { useful.push(cached_top_node()); }
 340 
 341   // Push all useful nodes onto the list, breadthfirst
 342   for( uint next = 0; next < useful.size(); ++next ) {
 343     assert( next < unique(), "Unique useful nodes < total nodes");
 344     Node *n  = useful.at(next);
 345     uint max = n->len();
 346     for( uint i = 0; i < max; ++i ) {
 347       Node *m = n->in(i);
 348       if (not_a_node(m))  continue;
 349       useful.push(m);
 350     }
 351   }
 352 }
 353 
 354 // Update dead_node_list with any missing dead nodes using useful
 355 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 356 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 357   uint max_idx = unique();
 358   VectorSet& useful_node_set = useful.member_set();
 359 
 360   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 361     // If node with index node_idx is not in useful set,
 362     // mark it as dead in dead node list.
 363     if (! useful_node_set.test(node_idx) ) {
 364       record_dead_node(node_idx);
 365     }
 366   }
 367 }
 368 
 369 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 370   int shift = 0;
 371   for (int i = 0; i < inlines->length(); i++) {
 372     CallGenerator* cg = inlines->at(i);
 373     CallNode* call = cg->call_node();
 374     if (shift > 0) {
 375       inlines->at_put(i-shift, cg);
 376     }
 377     if (!useful.member(call)) {
 378       shift++;
 379     }
 380   }
 381   inlines->trunc_to(inlines->length()-shift);
 382 }
 383 
 384 // Disconnect all useless nodes by disconnecting those at the boundary.
 385 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
 386   uint next = 0;
 387   while (next < useful.size()) {
 388     Node *n = useful.at(next++);
 389     // Use raw traversal of out edges since this code removes out edges
 390     int max = n->outcnt();
 391     for (int j = 0; j < max; ++j) {
 392       Node* child = n->raw_out(j);
 393       if (! useful.member(child)) {
 394         assert(!child->is_top() || child != top(),
 395                "If top is cached in Compile object it is in useful list");
 396         // Only need to remove this out-edge to the useless node
 397         n->raw_del_out(j);
 398         --j;
 399         --max;
 400       }
 401     }
 402     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 403       record_for_igvn(n->unique_out());
 404     }
 405   }
 406   // Remove useless macro and predicate opaq nodes
 407   for (int i = C->macro_count()-1; i >= 0; i--) {
 408     Node* n = C->macro_node(i);
 409     if (!useful.member(n)) {
 410       remove_macro_node(n);
 411     }
 412   }
 413   // Remove useless expensive node
 414   for (int i = C->expensive_count()-1; i >= 0; i--) {
 415     Node* n = C->expensive_node(i);
 416     if (!useful.member(n)) {
 417       remove_expensive_node(n);
 418     }
 419   }
 420   // clean up the late inline lists
 421   remove_useless_late_inlines(&_string_late_inlines, useful);
 422   remove_useless_late_inlines(&_boxing_late_inlines, useful);
 423   remove_useless_late_inlines(&_late_inlines, useful);
 424   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 425 }
 426 
 427 //------------------------------frame_size_in_words-----------------------------
 428 // frame_slots in units of words
 429 int Compile::frame_size_in_words() const {
 430   // shift is 0 in LP32 and 1 in LP64
 431   const int shift = (LogBytesPerWord - LogBytesPerInt);
 432   int words = _frame_slots >> shift;
 433   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
 434   return words;
 435 }
 436 
 437 // ============================================================================
 438 //------------------------------CompileWrapper---------------------------------
 439 class CompileWrapper : public StackObj {
 440   Compile *const _compile;
 441  public:
 442   CompileWrapper(Compile* compile);
 443 
 444   ~CompileWrapper();
 445 };
 446 
 447 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 448   // the Compile* pointer is stored in the current ciEnv:
 449   ciEnv* env = compile->env();
 450   assert(env == ciEnv::current(), "must already be a ciEnv active");
 451   assert(env->compiler_data() == NULL, "compile already active?");
 452   env->set_compiler_data(compile);
 453   assert(compile == Compile::current(), "sanity");
 454 
 455   compile->set_type_dict(NULL);
 456   compile->set_type_hwm(NULL);
 457   compile->set_type_last_size(0);
 458   compile->set_last_tf(NULL, NULL);
 459   compile->set_indexSet_arena(NULL);
 460   compile->set_indexSet_free_block_list(NULL);
 461   compile->init_type_arena();
 462   Type::Initialize(compile);
 463   _compile->set_scratch_buffer_blob(NULL);
 464   _compile->begin_method();
 465 }
 466 CompileWrapper::~CompileWrapper() {
 467   _compile->end_method();
 468   if (_compile->scratch_buffer_blob() != NULL)
 469     BufferBlob::free(_compile->scratch_buffer_blob());
 470   _compile->env()->set_compiler_data(NULL);
 471 }
 472 
 473 
 474 //----------------------------print_compile_messages---------------------------
 475 void Compile::print_compile_messages() {
 476 #ifndef PRODUCT
 477   // Check if recompiling
 478   if (_subsume_loads == false && PrintOpto) {
 479     // Recompiling without allowing machine instructions to subsume loads
 480     tty->print_cr("*********************************************************");
 481     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 482     tty->print_cr("*********************************************************");
 483   }
 484   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
 485     // Recompiling without escape analysis
 486     tty->print_cr("*********************************************************");
 487     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 488     tty->print_cr("*********************************************************");
 489   }
 490   if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
 491     // Recompiling without boxing elimination
 492     tty->print_cr("*********************************************************");
 493     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 494     tty->print_cr("*********************************************************");
 495   }
 496   if (env()->break_at_compile()) {
 497     // Open the debugger when compiling this method.
 498     tty->print("### Breaking when compiling: ");
 499     method()->print_short_name();
 500     tty->cr();
 501     BREAKPOINT;
 502   }
 503 
 504   if( PrintOpto ) {
 505     if (is_osr_compilation()) {
 506       tty->print("[OSR]%3d", _compile_id);
 507     } else {
 508       tty->print("%3d", _compile_id);
 509     }
 510   }
 511 #endif
 512 }
 513 
 514 
 515 //-----------------------init_scratch_buffer_blob------------------------------
 516 // Construct a temporary BufferBlob and cache it for this compile.
 517 void Compile::init_scratch_buffer_blob(int const_size) {
 518   // If there is already a scratch buffer blob allocated and the
 519   // constant section is big enough, use it.  Otherwise free the
 520   // current and allocate a new one.
 521   BufferBlob* blob = scratch_buffer_blob();
 522   if ((blob != NULL) && (const_size <= _scratch_const_size)) {
 523     // Use the current blob.
 524   } else {
 525     if (blob != NULL) {
 526       BufferBlob::free(blob);
 527     }
 528 
 529     ResourceMark rm;
 530     _scratch_const_size = const_size;
 531     int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
 532     blob = BufferBlob::create("Compile::scratch_buffer", size);
 533     // Record the buffer blob for next time.
 534     set_scratch_buffer_blob(blob);
 535     // Have we run out of code space?
 536     if (scratch_buffer_blob() == NULL) {
 537       // Let CompilerBroker disable further compilations.
 538       record_failure("Not enough space for scratch buffer in CodeCache");
 539       return;
 540     }
 541   }
 542 
 543   // Initialize the relocation buffers
 544   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
 545   set_scratch_locs_memory(locs_buf);
 546 }
 547 
 548 
 549 //-----------------------scratch_emit_size-------------------------------------
 550 // Helper function that computes size by emitting code
 551 uint Compile::scratch_emit_size(const Node* n) {
 552   // Start scratch_emit_size section.
 553   set_in_scratch_emit_size(true);
 554 
 555   // Emit into a trash buffer and count bytes emitted.
 556   // This is a pretty expensive way to compute a size,
 557   // but it works well enough if seldom used.
 558   // All common fixed-size instructions are given a size
 559   // method by the AD file.
 560   // Note that the scratch buffer blob and locs memory are
 561   // allocated at the beginning of the compile task, and
 562   // may be shared by several calls to scratch_emit_size.
 563   // The allocation of the scratch buffer blob is particularly
 564   // expensive, since it has to grab the code cache lock.
 565   BufferBlob* blob = this->scratch_buffer_blob();
 566   assert(blob != NULL, "Initialize BufferBlob at start");
 567   assert(blob->size() > MAX_inst_size, "sanity");
 568   relocInfo* locs_buf = scratch_locs_memory();
 569   address blob_begin = blob->content_begin();
 570   address blob_end   = (address)locs_buf;
 571   assert(blob->content_contains(blob_end), "sanity");
 572   CodeBuffer buf(blob_begin, blob_end - blob_begin);
 573   buf.initialize_consts_size(_scratch_const_size);
 574   buf.initialize_stubs_size(MAX_stubs_size);
 575   assert(locs_buf != NULL, "sanity");
 576   int lsize = MAX_locs_size / 3;
 577   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
 578   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
 579   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
 580 
 581   // Do the emission.
 582 
 583   Label fakeL; // Fake label for branch instructions.
 584   Label*   saveL = NULL;
 585   uint save_bnum = 0;
 586   bool is_branch = n->is_MachBranch();
 587   if (is_branch) {
 588     MacroAssembler masm(&buf);
 589     masm.bind(fakeL);
 590     n->as_MachBranch()->save_label(&saveL, &save_bnum);
 591     n->as_MachBranch()->label_set(&fakeL, 0);
 592   }
 593   n->emit(buf, this->regalloc());
 594   if (is_branch) // Restore label.
 595     n->as_MachBranch()->label_set(saveL, save_bnum);
 596 
 597   // End scratch_emit_size section.
 598   set_in_scratch_emit_size(false);
 599 
 600   return buf.insts_size();
 601 }
 602 
 603 
 604 // ============================================================================
 605 //------------------------------Compile standard-------------------------------
 606 debug_only( int Compile::_debug_idx = 100000; )
 607 
 608 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 609 // the continuation bci for on stack replacement.
 610 
 611 
 612 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
 613                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
 614                 : Phase(Compiler),
 615                   _env(ci_env),
 616                   _log(ci_env->log()),
 617                   _compile_id(ci_env->compile_id()),
 618                   _save_argument_registers(false),
 619                   _stub_name(NULL),
 620                   _stub_function(NULL),
 621                   _stub_entry_point(NULL),
 622                   _method(target),
 623                   _entry_bci(osr_bci),
 624                   _initial_gvn(NULL),
 625                   _for_igvn(NULL),
 626                   _warm_calls(NULL),
 627                   _subsume_loads(subsume_loads),
 628                   _do_escape_analysis(do_escape_analysis),
 629                   _eliminate_boxing(eliminate_boxing),
 630                   _failure_reason(NULL),
 631                   _code_buffer("Compile::Fill_buffer"),
 632                   _orig_pc_slot(0),
 633                   _orig_pc_slot_offset_in_bytes(0),
 634                   _has_method_handle_invokes(false),
 635                   _mach_constant_base_node(NULL),
 636                   _node_bundling_limit(0),
 637                   _node_bundling_base(NULL),
 638                   _java_calls(0),
 639                   _inner_loops(0),
 640                   _scratch_const_size(-1),
 641                   _in_scratch_emit_size(false),
 642                   _dead_node_list(comp_arena()),
 643                   _dead_node_count(0),
 644 #ifndef PRODUCT
 645                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
 646                   _printer(IdealGraphPrinter::printer()),
 647 #endif
 648                   _congraph(NULL),
 649                   _late_inlines(comp_arena(), 2, 0, NULL),
 650                   _string_late_inlines(comp_arena(), 2, 0, NULL),
 651                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
 652                   _late_inlines_pos(0),
 653                   _number_of_mh_late_inlines(0),
 654                   _inlining_progress(false),
 655                   _inlining_incrementally(false),
 656                   _print_inlining_list(NULL),
 657                   _print_inlining_idx(0) {
 658   C = this;
 659 
 660   CompileWrapper cw(this);
 661 #ifndef PRODUCT
 662   if (TimeCompiler2) {
 663     tty->print(" ");
 664     target->holder()->name()->print();
 665     tty->print(".");
 666     target->print_short_name();
 667     tty->print("  ");
 668   }
 669   TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
 670   TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
 671   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
 672   if (!print_opto_assembly) {
 673     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
 674     if (print_assembly && !Disassembler::can_decode()) {
 675       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
 676       print_opto_assembly = true;
 677     }
 678   }
 679   set_print_assembly(print_opto_assembly);
 680   set_parsed_irreducible_loop(false);
 681 #endif
 682   set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
 683   set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
 684 
 685   if (ProfileTraps) {
 686     // Make sure the method being compiled gets its own MDO,
 687     // so we can at least track the decompile_count().
 688     method()->ensure_method_data();
 689   }
 690 
 691   Init(::AliasLevel);
 692 
 693 
 694   print_compile_messages();
 695 
 696   if (UseOldInlining || PrintCompilation NOT_PRODUCT( || PrintOpto) )
 697     _ilt = InlineTree::build_inline_tree_root();
 698   else
 699     _ilt = NULL;
 700 
 701   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 702   assert(num_alias_types() >= AliasIdxRaw, "");
 703 
 704 #define MINIMUM_NODE_HASH  1023
 705   // Node list that Iterative GVN will start with
 706   Unique_Node_List for_igvn(comp_arena());
 707   set_for_igvn(&for_igvn);
 708 
 709   // GVN that will be run immediately on new nodes
 710   uint estimated_size = method()->code_size()*4+64;
 711   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 712   PhaseGVN gvn(node_arena(), estimated_size);
 713   set_initial_gvn(&gvn);
 714 
 715   if (print_inlining() || print_intrinsics()) {
 716     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
 717   }
 718   { // Scope for timing the parser
 719     TracePhase t3("parse", &_t_parser, true);
 720 
 721     // Put top into the hash table ASAP.
 722     initial_gvn()->transform_no_reclaim(top());
 723 
 724     // Set up tf(), start(), and find a CallGenerator.
 725     CallGenerator* cg = NULL;
 726     if (is_osr_compilation()) {
 727       const TypeTuple *domain = StartOSRNode::osr_domain();
 728       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 729       init_tf(TypeFunc::make(domain, range));
 730       StartNode* s = new (this) StartOSRNode(root(), domain);
 731       initial_gvn()->set_type_bottom(s);
 732       init_start(s);
 733       cg = CallGenerator::for_osr(method(), entry_bci());
 734     } else {
 735       // Normal case.
 736       init_tf(TypeFunc::make(method()));
 737       StartNode* s = new (this) StartNode(root(), tf()->domain());
 738       initial_gvn()->set_type_bottom(s);
 739       init_start(s);
 740       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
 741         // With java.lang.ref.reference.get() we must go through the
 742         // intrinsic when G1 is enabled - even when get() is the root
 743         // method of the compile - so that, if necessary, the value in
 744         // the referent field of the reference object gets recorded by
 745         // the pre-barrier code.
 746         // Specifically, if G1 is enabled, the value in the referent
 747         // field is recorded by the G1 SATB pre barrier. This will
 748         // result in the referent being marked live and the reference
 749         // object removed from the list of discovered references during
 750         // reference processing.
 751         cg = find_intrinsic(method(), false);
 752       }
 753       if (cg == NULL) {
 754         float past_uses = method()->interpreter_invocation_count();
 755         float expected_uses = past_uses;
 756         cg = CallGenerator::for_inline(method(), expected_uses);
 757       }
 758     }
 759     if (failing())  return;
 760     if (cg == NULL) {
 761       record_method_not_compilable_all_tiers("cannot parse method");
 762       return;
 763     }
 764     JVMState* jvms = build_start_state(start(), tf());
 765     if ((jvms = cg->generate(jvms)) == NULL) {
 766       record_method_not_compilable("method parse failed");
 767       return;
 768     }
 769     GraphKit kit(jvms);
 770 
 771     if (!kit.stopped()) {
 772       // Accept return values, and transfer control we know not where.
 773       // This is done by a special, unique ReturnNode bound to root.
 774       return_values(kit.jvms());
 775     }
 776 
 777     if (kit.has_exceptions()) {
 778       // Any exceptions that escape from this call must be rethrown
 779       // to whatever caller is dynamically above us on the stack.
 780       // This is done by a special, unique RethrowNode bound to root.
 781       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 782     }
 783 
 784     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 785 
 786     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 787       inline_string_calls(true);
 788     }
 789 
 790     if (failing())  return;
 791 
 792     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
 793 
 794     // Remove clutter produced by parsing.
 795     if (!failing()) {
 796       ResourceMark rm;
 797       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 798     }
 799   }
 800 
 801   // Note:  Large methods are capped off in do_one_bytecode().
 802   if (failing())  return;
 803 
 804   // After parsing, node notes are no longer automagic.
 805   // They must be propagated by register_new_node_with_optimizer(),
 806   // clone(), or the like.
 807   set_default_node_notes(NULL);
 808 
 809   for (;;) {
 810     int successes = Inline_Warm();
 811     if (failing())  return;
 812     if (successes == 0)  break;
 813   }
 814 
 815   // Drain the list.
 816   Finish_Warm();
 817 #ifndef PRODUCT
 818   if (_printer) {
 819     _printer->print_inlining(this);
 820   }
 821 #endif
 822 
 823   if (failing())  return;
 824   NOT_PRODUCT( verify_graph_edges(); )
 825 
 826   // Now optimize
 827   Optimize();
 828   if (failing())  return;
 829   NOT_PRODUCT( verify_graph_edges(); )
 830 
 831 #ifndef PRODUCT
 832   if (PrintIdeal) {
 833     ttyLocker ttyl;  // keep the following output all in one block
 834     // This output goes directly to the tty, not the compiler log.
 835     // To enable tools to match it up with the compilation activity,
 836     // be sure to tag this tty output with the compile ID.
 837     if (xtty != NULL) {
 838       xtty->head("ideal compile_id='%d'%s", compile_id(),
 839                  is_osr_compilation()    ? " compile_kind='osr'" :
 840                  "");
 841     }
 842     root()->dump(9999);
 843     if (xtty != NULL) {
 844       xtty->tail("ideal");
 845     }
 846   }
 847 #endif
 848 
 849   // Now that we know the size of all the monitors we can add a fixed slot
 850   // for the original deopt pc.
 851 
 852   _orig_pc_slot =  fixed_slots();
 853   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 854   set_fixed_slots(next_slot);
 855 
 856   // Now generate code
 857   Code_Gen();
 858   if (failing())  return;
 859 
 860   // Check if we want to skip execution of all compiled code.
 861   {
 862 #ifndef PRODUCT
 863     if (OptoNoExecute) {
 864       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 865       return;
 866     }
 867     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
 868 #endif
 869 
 870     if (is_osr_compilation()) {
 871       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 872       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 873     } else {
 874       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 875       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 876     }
 877 
 878     env()->register_method(_method, _entry_bci,
 879                            &_code_offsets,
 880                            _orig_pc_slot_offset_in_bytes,
 881                            code_buffer(),
 882                            frame_size_in_words(), _oop_map_set,
 883                            &_handler_table, &_inc_table,
 884                            compiler,
 885                            env()->comp_level(),
 886                            has_unsafe_access(),
 887                            SharedRuntime::is_wide_vector(max_vector_size())
 888                            );
 889 
 890     if (log() != NULL) // Print code cache state into compiler log
 891       log()->code_cache_state();
 892   }
 893 }
 894 
 895 //------------------------------Compile----------------------------------------
 896 // Compile a runtime stub
 897 Compile::Compile( ciEnv* ci_env,
 898                   TypeFunc_generator generator,
 899                   address stub_function,
 900                   const char *stub_name,
 901                   int is_fancy_jump,
 902                   bool pass_tls,
 903                   bool save_arg_registers,
 904                   bool return_pc )
 905   : Phase(Compiler),
 906     _env(ci_env),
 907     _log(ci_env->log()),
 908     _compile_id(0),
 909     _save_argument_registers(save_arg_registers),
 910     _method(NULL),
 911     _stub_name(stub_name),
 912     _stub_function(stub_function),
 913     _stub_entry_point(NULL),
 914     _entry_bci(InvocationEntryBci),
 915     _initial_gvn(NULL),
 916     _for_igvn(NULL),
 917     _warm_calls(NULL),
 918     _orig_pc_slot(0),
 919     _orig_pc_slot_offset_in_bytes(0),
 920     _subsume_loads(true),
 921     _do_escape_analysis(false),
 922     _eliminate_boxing(false),
 923     _failure_reason(NULL),
 924     _code_buffer("Compile::Fill_buffer"),
 925     _has_method_handle_invokes(false),
 926     _mach_constant_base_node(NULL),
 927     _node_bundling_limit(0),
 928     _node_bundling_base(NULL),
 929     _java_calls(0),
 930     _inner_loops(0),
 931 #ifndef PRODUCT
 932     _trace_opto_output(TraceOptoOutput),
 933     _printer(NULL),
 934 #endif
 935     _dead_node_list(comp_arena()),
 936     _dead_node_count(0),
 937     _congraph(NULL),
 938     _number_of_mh_late_inlines(0),
 939     _inlining_progress(false),
 940     _inlining_incrementally(false),
 941     _print_inlining_list(NULL),
 942     _print_inlining_idx(0) {
 943   C = this;
 944 
 945 #ifndef PRODUCT
 946   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
 947   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
 948   set_print_assembly(PrintFrameConverterAssembly);
 949   set_parsed_irreducible_loop(false);
 950 #endif
 951   CompileWrapper cw(this);
 952   Init(/*AliasLevel=*/ 0);
 953   init_tf((*generator)());
 954 
 955   {
 956     // The following is a dummy for the sake of GraphKit::gen_stub
 957     Unique_Node_List for_igvn(comp_arena());
 958     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
 959     PhaseGVN gvn(Thread::current()->resource_area(),255);
 960     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
 961     gvn.transform_no_reclaim(top());
 962 
 963     GraphKit kit;
 964     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
 965   }
 966 
 967   NOT_PRODUCT( verify_graph_edges(); )
 968   Code_Gen();
 969   if (failing())  return;
 970 
 971 
 972   // Entry point will be accessed using compile->stub_entry_point();
 973   if (code_buffer() == NULL) {
 974     Matcher::soft_match_failure();
 975   } else {
 976     if (PrintAssembly && (WizardMode || Verbose))
 977       tty->print_cr("### Stub::%s", stub_name);
 978 
 979     if (!failing()) {
 980       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
 981 
 982       // Make the NMethod
 983       // For now we mark the frame as never safe for profile stackwalking
 984       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
 985                                                       code_buffer(),
 986                                                       CodeOffsets::frame_never_safe,
 987                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
 988                                                       frame_size_in_words(),
 989                                                       _oop_map_set,
 990                                                       save_arg_registers);
 991       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
 992 
 993       _stub_entry_point = rs->entry_point();
 994     }
 995   }
 996 }
 997 
 998 //------------------------------Init-------------------------------------------
 999 // Prepare for a single compilation
1000 void Compile::Init(int aliaslevel) {
1001   _unique  = 0;
1002   _regalloc = NULL;
1003 
1004   _tf      = NULL;  // filled in later
1005   _top     = NULL;  // cached later
1006   _matcher = NULL;  // filled in later
1007   _cfg     = NULL;  // filled in later
1008 
1009   set_24_bit_selection_and_mode(Use24BitFP, false);
1010 
1011   _node_note_array = NULL;
1012   _default_node_notes = NULL;
1013 
1014   _immutable_memory = NULL; // filled in at first inquiry
1015 
1016   // Globally visible Nodes
1017   // First set TOP to NULL to give safe behavior during creation of RootNode
1018   set_cached_top_node(NULL);
1019   set_root(new (this) RootNode());
1020   // Now that you have a Root to point to, create the real TOP
1021   set_cached_top_node( new (this) ConNode(Type::TOP) );
1022   set_recent_alloc(NULL, NULL);
1023 
1024   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1025   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1026   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1027   env()->set_dependencies(new Dependencies(env()));
1028 
1029   _fixed_slots = 0;
1030   set_has_split_ifs(false);
1031   set_has_loops(has_method() && method()->has_loops()); // first approximation
1032   set_has_stringbuilder(false);
1033   set_has_boxed_value(false);
1034   _trap_can_recompile = false;  // no traps emitted yet
1035   _major_progress = true; // start out assuming good things will happen
1036   set_has_unsafe_access(false);
1037   set_max_vector_size(0);
1038   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1039   set_decompile_count(0);
1040 
1041   set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
1042   set_num_loop_opts(LoopOptsCount);
1043   set_do_inlining(Inline);
1044   set_max_inline_size(MaxInlineSize);
1045   set_freq_inline_size(FreqInlineSize);
1046   set_do_scheduling(OptoScheduling);
1047   set_do_count_invocations(false);
1048   set_do_method_data_update(false);
1049 
1050   if (debug_info()->recording_non_safepoints()) {
1051     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1052                         (comp_arena(), 8, 0, NULL));
1053     set_default_node_notes(Node_Notes::make(this));
1054   }
1055 
1056   // // -- Initialize types before each compile --
1057   // // Update cached type information
1058   // if( _method && _method->constants() )
1059   //   Type::update_loaded_types(_method, _method->constants());
1060 
1061   // Init alias_type map.
1062   if (!_do_escape_analysis && aliaslevel == 3)
1063     aliaslevel = 2;  // No unique types without escape analysis
1064   _AliasLevel = aliaslevel;
1065   const int grow_ats = 16;
1066   _max_alias_types = grow_ats;
1067   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1068   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1069   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1070   {
1071     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1072   }
1073   // Initialize the first few types.
1074   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1075   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1076   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1077   _num_alias_types = AliasIdxRaw+1;
1078   // Zero out the alias type cache.
1079   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1080   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1081   probe_alias_cache(NULL)->_index = AliasIdxTop;
1082 
1083   _intrinsics = NULL;
1084   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1085   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1086   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1087   register_library_intrinsics();
1088 }
1089 
1090 //---------------------------init_start----------------------------------------
1091 // Install the StartNode on this compile object.
1092 void Compile::init_start(StartNode* s) {
1093   if (failing())
1094     return; // already failing
1095   assert(s == start(), "");
1096 }
1097 
1098 StartNode* Compile::start() const {
1099   assert(!failing(), "");
1100   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1101     Node* start = root()->fast_out(i);
1102     if( start->is_Start() )
1103       return start->as_Start();
1104   }
1105   ShouldNotReachHere();
1106   return NULL;
1107 }
1108 
1109 //-------------------------------immutable_memory-------------------------------------
1110 // Access immutable memory
1111 Node* Compile::immutable_memory() {
1112   if (_immutable_memory != NULL) {
1113     return _immutable_memory;
1114   }
1115   StartNode* s = start();
1116   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1117     Node *p = s->fast_out(i);
1118     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1119       _immutable_memory = p;
1120       return _immutable_memory;
1121     }
1122   }
1123   ShouldNotReachHere();
1124   return NULL;
1125 }
1126 
1127 //----------------------set_cached_top_node------------------------------------
1128 // Install the cached top node, and make sure Node::is_top works correctly.
1129 void Compile::set_cached_top_node(Node* tn) {
1130   if (tn != NULL)  verify_top(tn);
1131   Node* old_top = _top;
1132   _top = tn;
1133   // Calling Node::setup_is_top allows the nodes the chance to adjust
1134   // their _out arrays.
1135   if (_top != NULL)     _top->setup_is_top();
1136   if (old_top != NULL)  old_top->setup_is_top();
1137   assert(_top == NULL || top()->is_top(), "");
1138 }
1139 
1140 #ifdef ASSERT
1141 uint Compile::count_live_nodes_by_graph_walk() {
1142   Unique_Node_List useful(comp_arena());
1143   // Get useful node list by walking the graph.
1144   identify_useful_nodes(useful);
1145   return useful.size();
1146 }
1147 
1148 void Compile::print_missing_nodes() {
1149 
1150   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1151   if ((_log == NULL) && (! PrintIdealNodeCount)) {
1152     return;
1153   }
1154 
1155   // This is an expensive function. It is executed only when the user
1156   // specifies VerifyIdealNodeCount option or otherwise knows the
1157   // additional work that needs to be done to identify reachable nodes
1158   // by walking the flow graph and find the missing ones using
1159   // _dead_node_list.
1160 
1161   Unique_Node_List useful(comp_arena());
1162   // Get useful node list by walking the graph.
1163   identify_useful_nodes(useful);
1164 
1165   uint l_nodes = C->live_nodes();
1166   uint l_nodes_by_walk = useful.size();
1167 
1168   if (l_nodes != l_nodes_by_walk) {
1169     if (_log != NULL) {
1170       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1171       _log->stamp();
1172       _log->end_head();
1173     }
1174     VectorSet& useful_member_set = useful.member_set();
1175     int last_idx = l_nodes_by_walk;
1176     for (int i = 0; i < last_idx; i++) {
1177       if (useful_member_set.test(i)) {
1178         if (_dead_node_list.test(i)) {
1179           if (_log != NULL) {
1180             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1181           }
1182           if (PrintIdealNodeCount) {
1183             // Print the log message to tty
1184               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1185               useful.at(i)->dump();
1186           }
1187         }
1188       }
1189       else if (! _dead_node_list.test(i)) {
1190         if (_log != NULL) {
1191           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1192         }
1193         if (PrintIdealNodeCount) {
1194           // Print the log message to tty
1195           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1196         }
1197       }
1198     }
1199     if (_log != NULL) {
1200       _log->tail("mismatched_nodes");
1201     }
1202   }
1203 }
1204 #endif
1205 
1206 #ifndef PRODUCT
1207 void Compile::verify_top(Node* tn) const {
1208   if (tn != NULL) {
1209     assert(tn->is_Con(), "top node must be a constant");
1210     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1211     assert(tn->in(0) != NULL, "must have live top node");
1212   }
1213 }
1214 #endif
1215 
1216 
1217 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1218 
1219 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1220   guarantee(arr != NULL, "");
1221   int num_blocks = arr->length();
1222   if (grow_by < num_blocks)  grow_by = num_blocks;
1223   int num_notes = grow_by * _node_notes_block_size;
1224   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1225   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1226   while (num_notes > 0) {
1227     arr->append(notes);
1228     notes     += _node_notes_block_size;
1229     num_notes -= _node_notes_block_size;
1230   }
1231   assert(num_notes == 0, "exact multiple, please");
1232 }
1233 
1234 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1235   if (source == NULL || dest == NULL)  return false;
1236 
1237   if (dest->is_Con())
1238     return false;               // Do not push debug info onto constants.
1239 
1240 #ifdef ASSERT
1241   // Leave a bread crumb trail pointing to the original node:
1242   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1243     dest->set_debug_orig(source);
1244   }
1245 #endif
1246 
1247   if (node_note_array() == NULL)
1248     return false;               // Not collecting any notes now.
1249 
1250   // This is a copy onto a pre-existing node, which may already have notes.
1251   // If both nodes have notes, do not overwrite any pre-existing notes.
1252   Node_Notes* source_notes = node_notes_at(source->_idx);
1253   if (source_notes == NULL || source_notes->is_clear())  return false;
1254   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1255   if (dest_notes == NULL || dest_notes->is_clear()) {
1256     return set_node_notes_at(dest->_idx, source_notes);
1257   }
1258 
1259   Node_Notes merged_notes = (*source_notes);
1260   // The order of operations here ensures that dest notes will win...
1261   merged_notes.update_from(dest_notes);
1262   return set_node_notes_at(dest->_idx, &merged_notes);
1263 }
1264 
1265 
1266 //--------------------------allow_range_check_smearing-------------------------
1267 // Gating condition for coalescing similar range checks.
1268 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1269 // single covering check that is at least as strong as any of them.
1270 // If the optimization succeeds, the simplified (strengthened) range check
1271 // will always succeed.  If it fails, we will deopt, and then give up
1272 // on the optimization.
1273 bool Compile::allow_range_check_smearing() const {
1274   // If this method has already thrown a range-check,
1275   // assume it was because we already tried range smearing
1276   // and it failed.
1277   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1278   return !already_trapped;
1279 }
1280 
1281 
1282 //------------------------------flatten_alias_type-----------------------------
1283 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1284   int offset = tj->offset();
1285   TypePtr::PTR ptr = tj->ptr();
1286 
1287   // Known instance (scalarizable allocation) alias only with itself.
1288   bool is_known_inst = tj->isa_oopptr() != NULL &&
1289                        tj->is_oopptr()->is_known_instance();
1290 
1291   // Process weird unsafe references.
1292   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1293     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1294     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1295     tj = TypeOopPtr::BOTTOM;
1296     ptr = tj->ptr();
1297     offset = tj->offset();
1298   }
1299 
1300   // Array pointers need some flattening
1301   const TypeAryPtr *ta = tj->isa_aryptr();
1302   if (ta && ta->is_stable()) {
1303     // Erase stability property for alias analysis.
1304     tj = ta = ta->cast_to_stable(false);
1305   }
1306   if( ta && is_known_inst ) {
1307     if ( offset != Type::OffsetBot &&
1308          offset > arrayOopDesc::length_offset_in_bytes() ) {
1309       offset = Type::OffsetBot; // Flatten constant access into array body only
1310       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1311     }
1312   } else if( ta && _AliasLevel >= 2 ) {
1313     // For arrays indexed by constant indices, we flatten the alias
1314     // space to include all of the array body.  Only the header, klass
1315     // and array length can be accessed un-aliased.
1316     if( offset != Type::OffsetBot ) {
1317       if( ta->const_oop() ) { // MethodData* or Method*
1318         offset = Type::OffsetBot;   // Flatten constant access into array body
1319         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1320       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1321         // range is OK as-is.
1322         tj = ta = TypeAryPtr::RANGE;
1323       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1324         tj = TypeInstPtr::KLASS; // all klass loads look alike
1325         ta = TypeAryPtr::RANGE; // generic ignored junk
1326         ptr = TypePtr::BotPTR;
1327       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1328         tj = TypeInstPtr::MARK;
1329         ta = TypeAryPtr::RANGE; // generic ignored junk
1330         ptr = TypePtr::BotPTR;
1331       } else {                  // Random constant offset into array body
1332         offset = Type::OffsetBot;   // Flatten constant access into array body
1333         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1334       }
1335     }
1336     // Arrays of fixed size alias with arrays of unknown size.
1337     if (ta->size() != TypeInt::POS) {
1338       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1339       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1340     }
1341     // Arrays of known objects become arrays of unknown objects.
1342     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1343       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1344       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1345     }
1346     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1347       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1348       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1349     }
1350     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1351     // cannot be distinguished by bytecode alone.
1352     if (ta->elem() == TypeInt::BOOL) {
1353       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1354       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1355       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1356     }
1357     // During the 2nd round of IterGVN, NotNull castings are removed.
1358     // Make sure the Bottom and NotNull variants alias the same.
1359     // Also, make sure exact and non-exact variants alias the same.
1360     if( ptr == TypePtr::NotNull || ta->klass_is_exact() ) {
1361       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1362     }
1363   }
1364 
1365   // Oop pointers need some flattening
1366   const TypeInstPtr *to = tj->isa_instptr();
1367   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1368     ciInstanceKlass *k = to->klass()->as_instance_klass();
1369     if( ptr == TypePtr::Constant ) {
1370       if (to->klass() != ciEnv::current()->Class_klass() ||
1371           offset < k->size_helper() * wordSize) {
1372         // No constant oop pointers (such as Strings); they alias with
1373         // unknown strings.
1374         assert(!is_known_inst, "not scalarizable allocation");
1375         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1376       }
1377     } else if( is_known_inst ) {
1378       tj = to; // Keep NotNull and klass_is_exact for instance type
1379     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1380       // During the 2nd round of IterGVN, NotNull castings are removed.
1381       // Make sure the Bottom and NotNull variants alias the same.
1382       // Also, make sure exact and non-exact variants alias the same.
1383       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1384     }
1385     // Canonicalize the holder of this field
1386     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1387       // First handle header references such as a LoadKlassNode, even if the
1388       // object's klass is unloaded at compile time (4965979).
1389       if (!is_known_inst) { // Do it only for non-instance types
1390         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1391       }
1392     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1393       // Static fields are in the space above the normal instance
1394       // fields in the java.lang.Class instance.
1395       if (to->klass() != ciEnv::current()->Class_klass()) {
1396         to = NULL;
1397         tj = TypeOopPtr::BOTTOM;
1398         offset = tj->offset();
1399       }
1400     } else {
1401       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1402       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1403         if( is_known_inst ) {
1404           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1405         } else {
1406           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1407         }
1408       }
1409     }
1410   }
1411 
1412   // Klass pointers to object array klasses need some flattening
1413   const TypeKlassPtr *tk = tj->isa_klassptr();
1414   if( tk ) {
1415     // If we are referencing a field within a Klass, we need
1416     // to assume the worst case of an Object.  Both exact and
1417     // inexact types must flatten to the same alias class so
1418     // use NotNull as the PTR.
1419     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1420 
1421       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1422                                    TypeKlassPtr::OBJECT->klass(),
1423                                    offset);
1424     }
1425 
1426     ciKlass* klass = tk->klass();
1427     if( klass->is_obj_array_klass() ) {
1428       ciKlass* k = TypeAryPtr::OOPS->klass();
1429       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1430         k = TypeInstPtr::BOTTOM->klass();
1431       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1432     }
1433 
1434     // Check for precise loads from the primary supertype array and force them
1435     // to the supertype cache alias index.  Check for generic array loads from
1436     // the primary supertype array and also force them to the supertype cache
1437     // alias index.  Since the same load can reach both, we need to merge
1438     // these 2 disparate memories into the same alias class.  Since the
1439     // primary supertype array is read-only, there's no chance of confusion
1440     // where we bypass an array load and an array store.
1441     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1442     if (offset == Type::OffsetBot ||
1443         (offset >= primary_supers_offset &&
1444          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1445         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1446       offset = in_bytes(Klass::secondary_super_cache_offset());
1447       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1448     }
1449   }
1450 
1451   // Flatten all Raw pointers together.
1452   if (tj->base() == Type::RawPtr)
1453     tj = TypeRawPtr::BOTTOM;
1454 
1455   if (tj->base() == Type::AnyPtr)
1456     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1457 
1458   // Flatten all to bottom for now
1459   switch( _AliasLevel ) {
1460   case 0:
1461     tj = TypePtr::BOTTOM;
1462     break;
1463   case 1:                       // Flatten to: oop, static, field or array
1464     switch (tj->base()) {
1465     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1466     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1467     case Type::AryPtr:   // do not distinguish arrays at all
1468     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1469     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1470     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1471     default: ShouldNotReachHere();
1472     }
1473     break;
1474   case 2:                       // No collapsing at level 2; keep all splits
1475   case 3:                       // No collapsing at level 3; keep all splits
1476     break;
1477   default:
1478     Unimplemented();
1479   }
1480 
1481   offset = tj->offset();
1482   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1483 
1484   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1485           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1486           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1487           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1488           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1489           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1490           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
1491           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1492   assert( tj->ptr() != TypePtr::TopPTR &&
1493           tj->ptr() != TypePtr::AnyNull &&
1494           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1495 //    assert( tj->ptr() != TypePtr::Constant ||
1496 //            tj->base() == Type::RawPtr ||
1497 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1498 
1499   return tj;
1500 }
1501 
1502 void Compile::AliasType::Init(int i, const TypePtr* at) {
1503   _index = i;
1504   _adr_type = at;
1505   _field = NULL;
1506   _element = NULL;
1507   _is_rewritable = true; // default
1508   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1509   if (atoop != NULL && atoop->is_known_instance()) {
1510     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1511     _general_index = Compile::current()->get_alias_index(gt);
1512   } else {
1513     _general_index = 0;
1514   }
1515 }
1516 
1517 //---------------------------------print_on------------------------------------
1518 #ifndef PRODUCT
1519 void Compile::AliasType::print_on(outputStream* st) {
1520   if (index() < 10)
1521         st->print("@ <%d> ", index());
1522   else  st->print("@ <%d>",  index());
1523   st->print(is_rewritable() ? "   " : " RO");
1524   int offset = adr_type()->offset();
1525   if (offset == Type::OffsetBot)
1526         st->print(" +any");
1527   else  st->print(" +%-3d", offset);
1528   st->print(" in ");
1529   adr_type()->dump_on(st);
1530   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1531   if (field() != NULL && tjp) {
1532     if (tjp->klass()  != field()->holder() ||
1533         tjp->offset() != field()->offset_in_bytes()) {
1534       st->print(" != ");
1535       field()->print();
1536       st->print(" ***");
1537     }
1538   }
1539 }
1540 
1541 void print_alias_types() {
1542   Compile* C = Compile::current();
1543   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1544   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1545     C->alias_type(idx)->print_on(tty);
1546     tty->cr();
1547   }
1548 }
1549 #endif
1550 
1551 
1552 //----------------------------probe_alias_cache--------------------------------
1553 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1554   intptr_t key = (intptr_t) adr_type;
1555   key ^= key >> logAliasCacheSize;
1556   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1557 }
1558 
1559 
1560 //-----------------------------grow_alias_types--------------------------------
1561 void Compile::grow_alias_types() {
1562   const int old_ats  = _max_alias_types; // how many before?
1563   const int new_ats  = old_ats;          // how many more?
1564   const int grow_ats = old_ats+new_ats;  // how many now?
1565   _max_alias_types = grow_ats;
1566   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1567   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1568   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1569   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1570 }
1571 
1572 
1573 //--------------------------------find_alias_type------------------------------
1574 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1575   if (_AliasLevel == 0)
1576     return alias_type(AliasIdxBot);
1577 
1578   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1579   if (ace->_adr_type == adr_type) {
1580     return alias_type(ace->_index);
1581   }
1582 
1583   // Handle special cases.
1584   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1585   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1586 
1587   // Do it the slow way.
1588   const TypePtr* flat = flatten_alias_type(adr_type);
1589 
1590 #ifdef ASSERT
1591   assert(flat == flatten_alias_type(flat), "idempotent");
1592   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
1593   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1594     const TypeOopPtr* foop = flat->is_oopptr();
1595     // Scalarizable allocations have exact klass always.
1596     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1597     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1598     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
1599   }
1600   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
1601 #endif
1602 
1603   int idx = AliasIdxTop;
1604   for (int i = 0; i < num_alias_types(); i++) {
1605     if (alias_type(i)->adr_type() == flat) {
1606       idx = i;
1607       break;
1608     }
1609   }
1610 
1611   if (idx == AliasIdxTop) {
1612     if (no_create)  return NULL;
1613     // Grow the array if necessary.
1614     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1615     // Add a new alias type.
1616     idx = _num_alias_types++;
1617     _alias_types[idx]->Init(idx, flat);
1618     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1619     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1620     if (flat->isa_instptr()) {
1621       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1622           && flat->is_instptr()->klass() == env()->Class_klass())
1623         alias_type(idx)->set_rewritable(false);
1624     }
1625     if (flat->isa_aryptr()) {
1626 #ifdef ASSERT
1627       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1628       // (T_BYTE has the weakest alignment and size restrictions...)
1629       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1630 #endif
1631       if (flat->offset() == TypePtr::OffsetBot) {
1632         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1633       }
1634     }
1635     if (flat->isa_klassptr()) {
1636       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1637         alias_type(idx)->set_rewritable(false);
1638       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1639         alias_type(idx)->set_rewritable(false);
1640       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1641         alias_type(idx)->set_rewritable(false);
1642       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1643         alias_type(idx)->set_rewritable(false);
1644     }
1645     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1646     // but the base pointer type is not distinctive enough to identify
1647     // references into JavaThread.)
1648 
1649     // Check for final fields.
1650     const TypeInstPtr* tinst = flat->isa_instptr();
1651     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1652       ciField* field;
1653       if (tinst->const_oop() != NULL &&
1654           tinst->klass() == ciEnv::current()->Class_klass() &&
1655           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1656         // static field
1657         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1658         field = k->get_field_by_offset(tinst->offset(), true);
1659       } else {
1660         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1661         field = k->get_field_by_offset(tinst->offset(), false);
1662       }
1663       assert(field == NULL ||
1664              original_field == NULL ||
1665              (field->holder() == original_field->holder() &&
1666               field->offset() == original_field->offset() &&
1667               field->is_static() == original_field->is_static()), "wrong field?");
1668       // Set field() and is_rewritable() attributes.
1669       if (field != NULL)  alias_type(idx)->set_field(field);
1670     }
1671   }
1672 
1673   // Fill the cache for next time.
1674   ace->_adr_type = adr_type;
1675   ace->_index    = idx;
1676   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1677 
1678   // Might as well try to fill the cache for the flattened version, too.
1679   AliasCacheEntry* face = probe_alias_cache(flat);
1680   if (face->_adr_type == NULL) {
1681     face->_adr_type = flat;
1682     face->_index    = idx;
1683     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1684   }
1685 
1686   return alias_type(idx);
1687 }
1688 
1689 
1690 Compile::AliasType* Compile::alias_type(ciField* field) {
1691   const TypeOopPtr* t;
1692   if (field->is_static())
1693     t = TypeInstPtr::make(field->holder()->java_mirror());
1694   else
1695     t = TypeOopPtr::make_from_klass_raw(field->holder());
1696   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1697   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1698   return atp;
1699 }
1700 
1701 
1702 //------------------------------have_alias_type--------------------------------
1703 bool Compile::have_alias_type(const TypePtr* adr_type) {
1704   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1705   if (ace->_adr_type == adr_type) {
1706     return true;
1707   }
1708 
1709   // Handle special cases.
1710   if (adr_type == NULL)             return true;
1711   if (adr_type == TypePtr::BOTTOM)  return true;
1712 
1713   return find_alias_type(adr_type, true, NULL) != NULL;
1714 }
1715 
1716 //-----------------------------must_alias--------------------------------------
1717 // True if all values of the given address type are in the given alias category.
1718 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1719   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1720   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1721   if (alias_idx == AliasIdxTop)         return false; // the empty category
1722   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1723 
1724   // the only remaining possible overlap is identity
1725   int adr_idx = get_alias_index(adr_type);
1726   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1727   assert(adr_idx == alias_idx ||
1728          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1729           && adr_type                       != TypeOopPtr::BOTTOM),
1730          "should not be testing for overlap with an unsafe pointer");
1731   return adr_idx == alias_idx;
1732 }
1733 
1734 //------------------------------can_alias--------------------------------------
1735 // True if any values of the given address type are in the given alias category.
1736 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1737   if (alias_idx == AliasIdxTop)         return false; // the empty category
1738   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1739   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1740   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1741 
1742   // the only remaining possible overlap is identity
1743   int adr_idx = get_alias_index(adr_type);
1744   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1745   return adr_idx == alias_idx;
1746 }
1747 
1748 
1749 
1750 //---------------------------pop_warm_call-------------------------------------
1751 WarmCallInfo* Compile::pop_warm_call() {
1752   WarmCallInfo* wci = _warm_calls;
1753   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1754   return wci;
1755 }
1756 
1757 //----------------------------Inline_Warm--------------------------------------
1758 int Compile::Inline_Warm() {
1759   // If there is room, try to inline some more warm call sites.
1760   // %%% Do a graph index compaction pass when we think we're out of space?
1761   if (!InlineWarmCalls)  return 0;
1762 
1763   int calls_made_hot = 0;
1764   int room_to_grow   = NodeCountInliningCutoff - unique();
1765   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1766   int amount_grown   = 0;
1767   WarmCallInfo* call;
1768   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1769     int est_size = (int)call->size();
1770     if (est_size > (room_to_grow - amount_grown)) {
1771       // This one won't fit anyway.  Get rid of it.
1772       call->make_cold();
1773       continue;
1774     }
1775     call->make_hot();
1776     calls_made_hot++;
1777     amount_grown   += est_size;
1778     amount_to_grow -= est_size;
1779   }
1780 
1781   if (calls_made_hot > 0)  set_major_progress();
1782   return calls_made_hot;
1783 }
1784 
1785 
1786 //----------------------------Finish_Warm--------------------------------------
1787 void Compile::Finish_Warm() {
1788   if (!InlineWarmCalls)  return;
1789   if (failing())  return;
1790   if (warm_calls() == NULL)  return;
1791 
1792   // Clean up loose ends, if we are out of space for inlining.
1793   WarmCallInfo* call;
1794   while ((call = pop_warm_call()) != NULL) {
1795     call->make_cold();
1796   }
1797 }
1798 
1799 //---------------------cleanup_loop_predicates-----------------------
1800 // Remove the opaque nodes that protect the predicates so that all unused
1801 // checks and uncommon_traps will be eliminated from the ideal graph
1802 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1803   if (predicate_count()==0) return;
1804   for (int i = predicate_count(); i > 0; i--) {
1805     Node * n = predicate_opaque1_node(i-1);
1806     assert(n->Opcode() == Op_Opaque1, "must be");
1807     igvn.replace_node(n, n->in(1));
1808   }
1809   assert(predicate_count()==0, "should be clean!");
1810 }
1811 
1812 // StringOpts and late inlining of string methods
1813 void Compile::inline_string_calls(bool parse_time) {
1814   {
1815     // remove useless nodes to make the usage analysis simpler
1816     ResourceMark rm;
1817     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1818   }
1819 
1820   {
1821     ResourceMark rm;
1822     print_method(PHASE_BEFORE_STRINGOPTS, 3);
1823     PhaseStringOpts pso(initial_gvn(), for_igvn());
1824     print_method(PHASE_AFTER_STRINGOPTS, 3);
1825   }
1826 
1827   // now inline anything that we skipped the first time around
1828   if (!parse_time) {
1829     _late_inlines_pos = _late_inlines.length();
1830   }
1831 
1832   while (_string_late_inlines.length() > 0) {
1833     CallGenerator* cg = _string_late_inlines.pop();
1834     cg->do_late_inline();
1835     if (failing())  return;
1836   }
1837   _string_late_inlines.trunc_to(0);
1838 }
1839 
1840 // Late inlining of boxing methods
1841 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
1842   if (_boxing_late_inlines.length() > 0) {
1843     assert(has_boxed_value(), "inconsistent");
1844 
1845     PhaseGVN* gvn = initial_gvn();
1846     set_inlining_incrementally(true);
1847 
1848     assert( igvn._worklist.size() == 0, "should be done with igvn" );
1849     for_igvn()->clear();
1850     gvn->replace_with(&igvn);
1851 
1852     while (_boxing_late_inlines.length() > 0) {
1853       CallGenerator* cg = _boxing_late_inlines.pop();
1854       cg->do_late_inline();
1855       if (failing())  return;
1856     }
1857     _boxing_late_inlines.trunc_to(0);
1858 
1859     {
1860       ResourceMark rm;
1861       PhaseRemoveUseless pru(gvn, for_igvn());
1862     }
1863 
1864     igvn = PhaseIterGVN(gvn);
1865     igvn.optimize();
1866 
1867     set_inlining_progress(false);
1868     set_inlining_incrementally(false);
1869   }
1870 }
1871 
1872 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
1873   assert(IncrementalInline, "incremental inlining should be on");
1874   PhaseGVN* gvn = initial_gvn();
1875 
1876   set_inlining_progress(false);
1877   for_igvn()->clear();
1878   gvn->replace_with(&igvn);
1879 
1880   int i = 0;
1881 
1882   for (; i <_late_inlines.length() && !inlining_progress(); i++) {
1883     CallGenerator* cg = _late_inlines.at(i);
1884     _late_inlines_pos = i+1;
1885     cg->do_late_inline();
1886     if (failing())  return;
1887   }
1888   int j = 0;
1889   for (; i < _late_inlines.length(); i++, j++) {
1890     _late_inlines.at_put(j, _late_inlines.at(i));
1891   }
1892   _late_inlines.trunc_to(j);
1893 
1894   {
1895     ResourceMark rm;
1896     PhaseRemoveUseless pru(gvn, for_igvn());
1897   }
1898 
1899   igvn = PhaseIterGVN(gvn);
1900 }
1901 
1902 // Perform incremental inlining until bound on number of live nodes is reached
1903 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
1904   PhaseGVN* gvn = initial_gvn();
1905 
1906   set_inlining_incrementally(true);
1907   set_inlining_progress(true);
1908   uint low_live_nodes = 0;
1909 
1910   while(inlining_progress() && _late_inlines.length() > 0) {
1911 
1912     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
1913       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
1914         // PhaseIdealLoop is expensive so we only try it once we are
1915         // out of loop and we only try it again if the previous helped
1916         // got the number of nodes down significantly
1917         PhaseIdealLoop ideal_loop( igvn, false, true );
1918         if (failing())  return;
1919         low_live_nodes = live_nodes();
1920         _major_progress = true;
1921       }
1922 
1923       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
1924         break;
1925       }
1926     }
1927 
1928     inline_incrementally_one(igvn);
1929 
1930     if (failing())  return;
1931 
1932     igvn.optimize();
1933 
1934     if (failing())  return;
1935   }
1936 
1937   assert( igvn._worklist.size() == 0, "should be done with igvn" );
1938 
1939   if (_string_late_inlines.length() > 0) {
1940     assert(has_stringbuilder(), "inconsistent");
1941     for_igvn()->clear();
1942     initial_gvn()->replace_with(&igvn);
1943 
1944     inline_string_calls(false);
1945 
1946     if (failing())  return;
1947 
1948     {
1949       ResourceMark rm;
1950       PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1951     }
1952 
1953     igvn = PhaseIterGVN(gvn);
1954 
1955     igvn.optimize();
1956   }
1957 
1958   set_inlining_incrementally(false);
1959 }
1960 
1961 
1962 //------------------------------Optimize---------------------------------------
1963 // Given a graph, optimize it.
1964 void Compile::Optimize() {
1965   TracePhase t1("optimizer", &_t_optimizer, true);
1966 
1967 #ifndef PRODUCT
1968   if (env()->break_at_compile()) {
1969     BREAKPOINT;
1970   }
1971 
1972 #endif
1973 
1974   ResourceMark rm;
1975   int          loop_opts_cnt;
1976 
1977   NOT_PRODUCT( verify_graph_edges(); )
1978 
1979   print_method(PHASE_AFTER_PARSING);
1980 
1981  {
1982   // Iterative Global Value Numbering, including ideal transforms
1983   // Initialize IterGVN with types and values from parse-time GVN
1984   PhaseIterGVN igvn(initial_gvn());
1985   {
1986     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
1987     igvn.optimize();
1988   }
1989 
1990   print_method(PHASE_ITER_GVN1, 2);
1991 
1992   if (failing())  return;
1993 
1994   {
1995     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
1996     inline_incrementally(igvn);
1997   }
1998 
1999   print_method(PHASE_INCREMENTAL_INLINE, 2);
2000 
2001   if (failing())  return;
2002 
2003   if (eliminate_boxing()) {
2004     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
2005     // Inline valueOf() methods now.
2006     inline_boxing_calls(igvn);
2007 
2008     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2009 
2010     if (failing())  return;
2011   }
2012 
2013   // No more new expensive nodes will be added to the list from here
2014   // so keep only the actual candidates for optimizations.
2015   cleanup_expensive_nodes(igvn);
2016 
2017   // Perform escape analysis
2018   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2019     if (has_loops()) {
2020       // Cleanup graph (remove dead nodes).
2021       TracePhase t2("idealLoop", &_t_idealLoop, true);
2022       PhaseIdealLoop ideal_loop( igvn, false, true );
2023       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2024       if (failing())  return;
2025     }
2026     ConnectionGraph::do_analysis(this, &igvn);
2027 
2028     if (failing())  return;
2029 
2030     // Optimize out fields loads from scalar replaceable allocations.
2031     igvn.optimize();
2032     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2033 
2034     if (failing())  return;
2035 
2036     if (congraph() != NULL && macro_count() > 0) {
2037       NOT_PRODUCT( TracePhase t2("macroEliminate", &_t_macroEliminate, TimeCompiler); )
2038       PhaseMacroExpand mexp(igvn);
2039       mexp.eliminate_macro_nodes();
2040       igvn.set_delay_transform(false);
2041 
2042       igvn.optimize();
2043       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2044 
2045       if (failing())  return;
2046     }
2047   }
2048 
2049   // Loop transforms on the ideal graph.  Range Check Elimination,
2050   // peeling, unrolling, etc.
2051 
2052   // Set loop opts counter
2053   loop_opts_cnt = num_loop_opts();
2054   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2055     {
2056       TracePhase t2("idealLoop", &_t_idealLoop, true);
2057       PhaseIdealLoop ideal_loop( igvn, true );
2058       loop_opts_cnt--;
2059       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2060       if (failing())  return;
2061     }
2062     // Loop opts pass if partial peeling occurred in previous pass
2063     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
2064       TracePhase t3("idealLoop", &_t_idealLoop, true);
2065       PhaseIdealLoop ideal_loop( igvn, false );
2066       loop_opts_cnt--;
2067       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2068       if (failing())  return;
2069     }
2070     // Loop opts pass for loop-unrolling before CCP
2071     if(major_progress() && (loop_opts_cnt > 0)) {
2072       TracePhase t4("idealLoop", &_t_idealLoop, true);
2073       PhaseIdealLoop ideal_loop( igvn, false );
2074       loop_opts_cnt--;
2075       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2076     }
2077     if (!failing()) {
2078       // Verify that last round of loop opts produced a valid graph
2079       NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
2080       PhaseIdealLoop::verify(igvn);
2081     }
2082   }
2083   if (failing())  return;
2084 
2085   // Conditional Constant Propagation;
2086   PhaseCCP ccp( &igvn );
2087   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2088   {
2089     TracePhase t2("ccp", &_t_ccp, true);
2090     ccp.do_transform();
2091   }
2092   print_method(PHASE_CPP1, 2);
2093 
2094   assert( true, "Break here to ccp.dump_old2new_map()");
2095 
2096   // Iterative Global Value Numbering, including ideal transforms
2097   {
2098     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
2099     igvn = ccp;
2100     igvn.optimize();
2101   }
2102 
2103   print_method(PHASE_ITER_GVN2, 2);
2104 
2105   if (failing())  return;
2106 
2107   // Loop transforms on the ideal graph.  Range Check Elimination,
2108   // peeling, unrolling, etc.
2109   if(loop_opts_cnt > 0) {
2110     debug_only( int cnt = 0; );
2111     while(major_progress() && (loop_opts_cnt > 0)) {
2112       TracePhase t2("idealLoop", &_t_idealLoop, true);
2113       assert( cnt++ < 40, "infinite cycle in loop optimization" );
2114       PhaseIdealLoop ideal_loop( igvn, true);
2115       loop_opts_cnt--;
2116       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2117       if (failing())  return;
2118     }
2119   }
2120 
2121   {
2122     // Verify that all previous optimizations produced a valid graph
2123     // at least to this point, even if no loop optimizations were done.
2124     NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
2125     PhaseIdealLoop::verify(igvn);
2126   }
2127 
2128   {
2129     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
2130     PhaseMacroExpand  mex(igvn);
2131     if (mex.expand_macro_nodes()) {
2132       assert(failing(), "must bail out w/ explicit message");
2133       return;
2134     }
2135   }
2136 
2137  } // (End scope of igvn; run destructor if necessary for asserts.)
2138 
2139   dump_inlining();
2140   // A method with only infinite loops has no edges entering loops from root
2141   {
2142     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
2143     if (final_graph_reshaping()) {
2144       assert(failing(), "must bail out w/ explicit message");
2145       return;
2146     }
2147   }
2148 
2149   print_method(PHASE_OPTIMIZE_FINISHED, 2);
2150 }
2151 
2152 
2153 //------------------------------Code_Gen---------------------------------------
2154 // Given a graph, generate code for it
2155 void Compile::Code_Gen() {
2156   if (failing()) {
2157     return;
2158   }
2159 
2160   // Perform instruction selection.  You might think we could reclaim Matcher
2161   // memory PDQ, but actually the Matcher is used in generating spill code.
2162   // Internals of the Matcher (including some VectorSets) must remain live
2163   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2164   // set a bit in reclaimed memory.
2165 
2166   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2167   // nodes.  Mapping is only valid at the root of each matched subtree.
2168   NOT_PRODUCT( verify_graph_edges(); )
2169 
2170   Matcher matcher;
2171   _matcher = &matcher;
2172   {
2173     TracePhase t2("matcher", &_t_matcher, true);
2174     matcher.match();
2175   }
2176   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2177   // nodes.  Mapping is only valid at the root of each matched subtree.
2178   NOT_PRODUCT( verify_graph_edges(); )
2179 
2180   // If you have too many nodes, or if matching has failed, bail out
2181   check_node_count(0, "out of nodes matching instructions");
2182   if (failing()) {
2183     return;
2184   }
2185 
2186   // Build a proper-looking CFG
2187   PhaseCFG cfg(node_arena(), root(), matcher);
2188   _cfg = &cfg;
2189   {
2190     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
2191     bool success = cfg.do_global_code_motion();
2192     if (!success) {
2193       return;
2194     }
2195 
2196     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2197     NOT_PRODUCT( verify_graph_edges(); )
2198     debug_only( cfg.verify(); )
2199   }
2200 
2201   PhaseChaitin regalloc(unique(), cfg, matcher);
2202   _regalloc = &regalloc;
2203   {
2204     TracePhase t2("regalloc", &_t_registerAllocation, true);
2205     // Perform register allocation.  After Chaitin, use-def chains are
2206     // no longer accurate (at spill code) and so must be ignored.
2207     // Node->LRG->reg mappings are still accurate.
2208     _regalloc->Register_Allocate();
2209 
2210     // Bail out if the allocator builds too many nodes
2211     if (failing()) {
2212       return;
2213     }
2214   }
2215 
2216   // Prior to register allocation we kept empty basic blocks in case the
2217   // the allocator needed a place to spill.  After register allocation we
2218   // are not adding any new instructions.  If any basic block is empty, we
2219   // can now safely remove it.
2220   {
2221     NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
2222     cfg.remove_empty_blocks();
2223     if (do_freq_based_layout()) {
2224       PhaseBlockLayout layout(cfg);
2225     } else {
2226       cfg.set_loop_alignment();
2227     }
2228     cfg.fixup_flow();
2229   }
2230 
2231   // Apply peephole optimizations
2232   if( OptoPeephole ) {
2233     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
2234     PhasePeephole peep( _regalloc, cfg);
2235     peep.do_transform();
2236   }
2237 
2238   // Convert Nodes to instruction bits in a buffer
2239   {
2240     // %%%% workspace merge brought two timers together for one job
2241     TracePhase t2a("output", &_t_output, true);
2242     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
2243     Output();
2244   }
2245 
2246   print_method(PHASE_FINAL_CODE);
2247 
2248   // He's dead, Jim.
2249   _cfg     = (PhaseCFG*)0xdeadbeef;
2250   _regalloc = (PhaseChaitin*)0xdeadbeef;
2251 }
2252 
2253 
2254 //------------------------------dump_asm---------------------------------------
2255 // Dump formatted assembly
2256 #ifndef PRODUCT
2257 void Compile::dump_asm(int *pcs, uint pc_limit) {
2258   bool cut_short = false;
2259   tty->print_cr("#");
2260   tty->print("#  ");  _tf->dump();  tty->cr();
2261   tty->print_cr("#");
2262 
2263   // For all blocks
2264   int pc = 0x0;                 // Program counter
2265   char starts_bundle = ' ';
2266   _regalloc->dump_frame();
2267 
2268   Node *n = NULL;
2269   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2270     if (VMThread::should_terminate()) {
2271       cut_short = true;
2272       break;
2273     }
2274     Block* block = _cfg->get_block(i);
2275     if (block->is_connector() && !Verbose) {
2276       continue;
2277     }
2278     n = block->head();
2279     if (pcs && n->_idx < pc_limit) {
2280       tty->print("%3.3x   ", pcs[n->_idx]);
2281     } else {
2282       tty->print("      ");
2283     }
2284     block->dump_head(_cfg);
2285     if (block->is_connector()) {
2286       tty->print_cr("        # Empty connector block");
2287     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2288       tty->print_cr("        # Block is sole successor of call");
2289     }
2290 
2291     // For all instructions
2292     Node *delay = NULL;
2293     for (uint j = 0; j < block->number_of_nodes(); j++) {
2294       if (VMThread::should_terminate()) {
2295         cut_short = true;
2296         break;
2297       }
2298       n = block->get_node(j);
2299       if (valid_bundle_info(n)) {
2300         Bundle* bundle = node_bundling(n);
2301         if (bundle->used_in_unconditional_delay()) {
2302           delay = n;
2303           continue;
2304         }
2305         if (bundle->starts_bundle()) {
2306           starts_bundle = '+';
2307         }
2308       }
2309 
2310       if (WizardMode) {
2311         n->dump();
2312       }
2313 
2314       if( !n->is_Region() &&    // Dont print in the Assembly
2315           !n->is_Phi() &&       // a few noisely useless nodes
2316           !n->is_Proj() &&
2317           !n->is_MachTemp() &&
2318           !n->is_SafePointScalarObject() &&
2319           !n->is_Catch() &&     // Would be nice to print exception table targets
2320           !n->is_MergeMem() &&  // Not very interesting
2321           !n->is_top() &&       // Debug info table constants
2322           !(n->is_Con() && !n->is_Mach())// Debug info table constants
2323           ) {
2324         if (pcs && n->_idx < pc_limit)
2325           tty->print("%3.3x", pcs[n->_idx]);
2326         else
2327           tty->print("   ");
2328         tty->print(" %c ", starts_bundle);
2329         starts_bundle = ' ';
2330         tty->print("\t");
2331         n->format(_regalloc, tty);
2332         tty->cr();
2333       }
2334 
2335       // If we have an instruction with a delay slot, and have seen a delay,
2336       // then back up and print it
2337       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2338         assert(delay != NULL, "no unconditional delay instruction");
2339         if (WizardMode) delay->dump();
2340 
2341         if (node_bundling(delay)->starts_bundle())
2342           starts_bundle = '+';
2343         if (pcs && n->_idx < pc_limit)
2344           tty->print("%3.3x", pcs[n->_idx]);
2345         else
2346           tty->print("   ");
2347         tty->print(" %c ", starts_bundle);
2348         starts_bundle = ' ';
2349         tty->print("\t");
2350         delay->format(_regalloc, tty);
2351         tty->print_cr("");
2352         delay = NULL;
2353       }
2354 
2355       // Dump the exception table as well
2356       if( n->is_Catch() && (Verbose || WizardMode) ) {
2357         // Print the exception table for this offset
2358         _handler_table.print_subtable_for(pc);
2359       }
2360     }
2361 
2362     if (pcs && n->_idx < pc_limit)
2363       tty->print_cr("%3.3x", pcs[n->_idx]);
2364     else
2365       tty->print_cr("");
2366 
2367     assert(cut_short || delay == NULL, "no unconditional delay branch");
2368 
2369   } // End of per-block dump
2370   tty->print_cr("");
2371 
2372   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
2373 }
2374 #endif
2375 
2376 //------------------------------Final_Reshape_Counts---------------------------
2377 // This class defines counters to help identify when a method
2378 // may/must be executed using hardware with only 24-bit precision.
2379 struct Final_Reshape_Counts : public StackObj {
2380   int  _call_count;             // count non-inlined 'common' calls
2381   int  _float_count;            // count float ops requiring 24-bit precision
2382   int  _double_count;           // count double ops requiring more precision
2383   int  _java_call_count;        // count non-inlined 'java' calls
2384   int  _inner_loop_count;       // count loops which need alignment
2385   VectorSet _visited;           // Visitation flags
2386   Node_List _tests;             // Set of IfNodes & PCTableNodes
2387 
2388   Final_Reshape_Counts() :
2389     _call_count(0), _float_count(0), _double_count(0),
2390     _java_call_count(0), _inner_loop_count(0),
2391     _visited( Thread::current()->resource_area() ) { }
2392 
2393   void inc_call_count  () { _call_count  ++; }
2394   void inc_float_count () { _float_count ++; }
2395   void inc_double_count() { _double_count++; }
2396   void inc_java_call_count() { _java_call_count++; }
2397   void inc_inner_loop_count() { _inner_loop_count++; }
2398 
2399   int  get_call_count  () const { return _call_count  ; }
2400   int  get_float_count () const { return _float_count ; }
2401   int  get_double_count() const { return _double_count; }
2402   int  get_java_call_count() const { return _java_call_count; }
2403   int  get_inner_loop_count() const { return _inner_loop_count; }
2404 };
2405 
2406 #ifdef ASSERT
2407 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2408   ciInstanceKlass *k = tp->klass()->as_instance_klass();
2409   // Make sure the offset goes inside the instance layout.
2410   return k->contains_field_offset(tp->offset());
2411   // Note that OffsetBot and OffsetTop are very negative.
2412 }
2413 #endif
2414 
2415 // Eliminate trivially redundant StoreCMs and accumulate their
2416 // precedence edges.
2417 void Compile::eliminate_redundant_card_marks(Node* n) {
2418   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2419   if (n->in(MemNode::Address)->outcnt() > 1) {
2420     // There are multiple users of the same address so it might be
2421     // possible to eliminate some of the StoreCMs
2422     Node* mem = n->in(MemNode::Memory);
2423     Node* adr = n->in(MemNode::Address);
2424     Node* val = n->in(MemNode::ValueIn);
2425     Node* prev = n;
2426     bool done = false;
2427     // Walk the chain of StoreCMs eliminating ones that match.  As
2428     // long as it's a chain of single users then the optimization is
2429     // safe.  Eliminating partially redundant StoreCMs would require
2430     // cloning copies down the other paths.
2431     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2432       if (adr == mem->in(MemNode::Address) &&
2433           val == mem->in(MemNode::ValueIn)) {
2434         // redundant StoreCM
2435         if (mem->req() > MemNode::OopStore) {
2436           // Hasn't been processed by this code yet.
2437           n->add_prec(mem->in(MemNode::OopStore));
2438         } else {
2439           // Already converted to precedence edge
2440           for (uint i = mem->req(); i < mem->len(); i++) {
2441             // Accumulate any precedence edges
2442             if (mem->in(i) != NULL) {
2443               n->add_prec(mem->in(i));
2444             }
2445           }
2446           // Everything above this point has been processed.
2447           done = true;
2448         }
2449         // Eliminate the previous StoreCM
2450         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2451         assert(mem->outcnt() == 0, "should be dead");
2452         mem->disconnect_inputs(NULL, this);
2453       } else {
2454         prev = mem;
2455       }
2456       mem = prev->in(MemNode::Memory);
2457     }
2458   }
2459 }
2460 
2461 //------------------------------final_graph_reshaping_impl----------------------
2462 // Implement items 1-5 from final_graph_reshaping below.
2463 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2464 
2465   if ( n->outcnt() == 0 ) return; // dead node
2466   uint nop = n->Opcode();
2467 
2468   // Check for 2-input instruction with "last use" on right input.
2469   // Swap to left input.  Implements item (2).
2470   if( n->req() == 3 &&          // two-input instruction
2471       n->in(1)->outcnt() > 1 && // left use is NOT a last use
2472       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2473       n->in(2)->outcnt() == 1 &&// right use IS a last use
2474       !n->in(2)->is_Con() ) {   // right use is not a constant
2475     // Check for commutative opcode
2476     switch( nop ) {
2477     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
2478     case Op_MaxI:  case Op_MinI:
2479     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
2480     case Op_AndL:  case Op_XorL:  case Op_OrL:
2481     case Op_AndI:  case Op_XorI:  case Op_OrI: {
2482       // Move "last use" input to left by swapping inputs
2483       n->swap_edges(1, 2);
2484       break;
2485     }
2486     default:
2487       break;
2488     }
2489   }
2490 
2491 #ifdef ASSERT
2492   if( n->is_Mem() ) {
2493     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2494     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2495             // oop will be recorded in oop map if load crosses safepoint
2496             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2497                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
2498             "raw memory operations should have control edge");
2499   }
2500 #endif
2501   // Count FPU ops and common calls, implements item (3)
2502   switch( nop ) {
2503   // Count all float operations that may use FPU
2504   case Op_AddF:
2505   case Op_SubF:
2506   case Op_MulF:
2507   case Op_DivF:
2508   case Op_NegF:
2509   case Op_ModF:
2510   case Op_ConvI2F:
2511   case Op_ConF:
2512   case Op_CmpF:
2513   case Op_CmpF3:
2514   // case Op_ConvL2F: // longs are split into 32-bit halves
2515     frc.inc_float_count();
2516     break;
2517 
2518   case Op_ConvF2D:
2519   case Op_ConvD2F:
2520     frc.inc_float_count();
2521     frc.inc_double_count();
2522     break;
2523 
2524   // Count all double operations that may use FPU
2525   case Op_AddD:
2526   case Op_SubD:
2527   case Op_MulD:
2528   case Op_DivD:
2529   case Op_NegD:
2530   case Op_ModD:
2531   case Op_ConvI2D:
2532   case Op_ConvD2I:
2533   // case Op_ConvL2D: // handled by leaf call
2534   // case Op_ConvD2L: // handled by leaf call
2535   case Op_ConD:
2536   case Op_CmpD:
2537   case Op_CmpD3:
2538     frc.inc_double_count();
2539     break;
2540   case Op_Opaque1:              // Remove Opaque Nodes before matching
2541   case Op_Opaque2:              // Remove Opaque Nodes before matching
2542     n->subsume_by(n->in(1), this);
2543     break;
2544   case Op_CallStaticJava:
2545   case Op_CallJava:
2546   case Op_CallDynamicJava:
2547     frc.inc_java_call_count(); // Count java call site;
2548   case Op_CallRuntime:
2549   case Op_CallLeaf:
2550   case Op_CallLeafNoFP: {
2551     assert( n->is_Call(), "" );
2552     CallNode *call = n->as_Call();
2553     // Count call sites where the FP mode bit would have to be flipped.
2554     // Do not count uncommon runtime calls:
2555     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2556     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2557     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
2558       frc.inc_call_count();   // Count the call site
2559     } else {                  // See if uncommon argument is shared
2560       Node *n = call->in(TypeFunc::Parms);
2561       int nop = n->Opcode();
2562       // Clone shared simple arguments to uncommon calls, item (1).
2563       if( n->outcnt() > 1 &&
2564           !n->is_Proj() &&
2565           nop != Op_CreateEx &&
2566           nop != Op_CheckCastPP &&
2567           nop != Op_DecodeN &&
2568           nop != Op_DecodeNKlass &&
2569           !n->is_Mem() ) {
2570         Node *x = n->clone();
2571         call->set_req( TypeFunc::Parms, x );
2572       }
2573     }
2574     break;
2575   }
2576 
2577   case Op_StoreD:
2578   case Op_LoadD:
2579   case Op_LoadD_unaligned:
2580     frc.inc_double_count();
2581     goto handle_mem;
2582   case Op_StoreF:
2583   case Op_LoadF:
2584     frc.inc_float_count();
2585     goto handle_mem;
2586 
2587   case Op_StoreCM:
2588     {
2589       // Convert OopStore dependence into precedence edge
2590       Node* prec = n->in(MemNode::OopStore);
2591       n->del_req(MemNode::OopStore);
2592       n->add_prec(prec);
2593       eliminate_redundant_card_marks(n);
2594     }
2595 
2596     // fall through
2597 
2598   case Op_StoreB:
2599   case Op_StoreC:
2600   case Op_StorePConditional:
2601   case Op_StoreI:
2602   case Op_StoreL:
2603   case Op_StoreIConditional:
2604   case Op_StoreLConditional:
2605   case Op_CompareAndSwapI:
2606   case Op_CompareAndSwapL:
2607   case Op_CompareAndSwapP:
2608   case Op_CompareAndSwapN:
2609   case Op_GetAndAddI:
2610   case Op_GetAndAddL:
2611   case Op_GetAndSetI:
2612   case Op_GetAndSetL:
2613   case Op_GetAndSetP:
2614   case Op_GetAndSetN:
2615   case Op_StoreP:
2616   case Op_StoreN:
2617   case Op_StoreNKlass:
2618   case Op_LoadB:
2619   case Op_LoadUB:
2620   case Op_LoadUS:
2621   case Op_LoadI:
2622   case Op_LoadKlass:
2623   case Op_LoadNKlass:
2624   case Op_LoadL:
2625   case Op_LoadL_unaligned:
2626   case Op_LoadPLocked:
2627   case Op_LoadP:
2628   case Op_LoadN:
2629   case Op_LoadRange:
2630   case Op_LoadS: {
2631   handle_mem:
2632 #ifdef ASSERT
2633     if( VerifyOptoOopOffsets ) {
2634       assert( n->is_Mem(), "" );
2635       MemNode *mem  = (MemNode*)n;
2636       // Check to see if address types have grounded out somehow.
2637       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2638       assert( !tp || oop_offset_is_sane(tp), "" );
2639     }
2640 #endif
2641     break;
2642   }
2643 
2644   case Op_AddP: {               // Assert sane base pointers
2645     Node *addp = n->in(AddPNode::Address);
2646     assert( !addp->is_AddP() ||
2647             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2648             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2649             "Base pointers must match" );
2650 #ifdef _LP64
2651     if ((UseCompressedOops || UseCompressedKlassPointers) &&
2652         addp->Opcode() == Op_ConP &&
2653         addp == n->in(AddPNode::Base) &&
2654         n->in(AddPNode::Offset)->is_Con()) {
2655       // Use addressing with narrow klass to load with offset on x86.
2656       // On sparc loading 32-bits constant and decoding it have less
2657       // instructions (4) then load 64-bits constant (7).
2658       // Do this transformation here since IGVN will convert ConN back to ConP.
2659       const Type* t = addp->bottom_type();
2660       if (t->isa_oopptr() || t->isa_klassptr()) {
2661         Node* nn = NULL;
2662 
2663         int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
2664 
2665         // Look for existing ConN node of the same exact type.
2666         Node* r  = root();
2667         uint cnt = r->outcnt();
2668         for (uint i = 0; i < cnt; i++) {
2669           Node* m = r->raw_out(i);
2670           if (m!= NULL && m->Opcode() == op &&
2671               m->bottom_type()->make_ptr() == t) {
2672             nn = m;
2673             break;
2674           }
2675         }
2676         if (nn != NULL) {
2677           // Decode a narrow oop to match address
2678           // [R12 + narrow_oop_reg<<3 + offset]
2679           if (t->isa_oopptr()) {
2680             nn = new (this) DecodeNNode(nn, t);
2681           } else {
2682             nn = new (this) DecodeNKlassNode(nn, t);
2683           }
2684           n->set_req(AddPNode::Base, nn);
2685           n->set_req(AddPNode::Address, nn);
2686           if (addp->outcnt() == 0) {
2687             addp->disconnect_inputs(NULL, this);
2688           }
2689         }
2690       }
2691     }
2692 #endif
2693     break;
2694   }
2695 
2696 #ifdef _LP64
2697   case Op_CastPP:
2698     if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
2699       Node* in1 = n->in(1);
2700       const Type* t = n->bottom_type();
2701       Node* new_in1 = in1->clone();
2702       new_in1->as_DecodeN()->set_type(t);
2703 
2704       if (!Matcher::narrow_oop_use_complex_address()) {
2705         //
2706         // x86, ARM and friends can handle 2 adds in addressing mode
2707         // and Matcher can fold a DecodeN node into address by using
2708         // a narrow oop directly and do implicit NULL check in address:
2709         //
2710         // [R12 + narrow_oop_reg<<3 + offset]
2711         // NullCheck narrow_oop_reg
2712         //
2713         // On other platforms (Sparc) we have to keep new DecodeN node and
2714         // use it to do implicit NULL check in address:
2715         //
2716         // decode_not_null narrow_oop_reg, base_reg
2717         // [base_reg + offset]
2718         // NullCheck base_reg
2719         //
2720         // Pin the new DecodeN node to non-null path on these platform (Sparc)
2721         // to keep the information to which NULL check the new DecodeN node
2722         // corresponds to use it as value in implicit_null_check().
2723         //
2724         new_in1->set_req(0, n->in(0));
2725       }
2726 
2727       n->subsume_by(new_in1, this);
2728       if (in1->outcnt() == 0) {
2729         in1->disconnect_inputs(NULL, this);
2730       }
2731     }
2732     break;
2733 
2734   case Op_CmpP:
2735     // Do this transformation here to preserve CmpPNode::sub() and
2736     // other TypePtr related Ideal optimizations (for example, ptr nullness).
2737     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
2738       Node* in1 = n->in(1);
2739       Node* in2 = n->in(2);
2740       if (!in1->is_DecodeNarrowPtr()) {
2741         in2 = in1;
2742         in1 = n->in(2);
2743       }
2744       assert(in1->is_DecodeNarrowPtr(), "sanity");
2745 
2746       Node* new_in2 = NULL;
2747       if (in2->is_DecodeNarrowPtr()) {
2748         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
2749         new_in2 = in2->in(1);
2750       } else if (in2->Opcode() == Op_ConP) {
2751         const Type* t = in2->bottom_type();
2752         if (t == TypePtr::NULL_PTR) {
2753           assert(in1->is_DecodeN(), "compare klass to null?");
2754           // Don't convert CmpP null check into CmpN if compressed
2755           // oops implicit null check is not generated.
2756           // This will allow to generate normal oop implicit null check.
2757           if (Matcher::gen_narrow_oop_implicit_null_checks())
2758             new_in2 = ConNode::make(this, TypeNarrowOop::NULL_PTR);
2759           //
2760           // This transformation together with CastPP transformation above
2761           // will generated code for implicit NULL checks for compressed oops.
2762           //
2763           // The original code after Optimize()
2764           //
2765           //    LoadN memory, narrow_oop_reg
2766           //    decode narrow_oop_reg, base_reg
2767           //    CmpP base_reg, NULL
2768           //    CastPP base_reg // NotNull
2769           //    Load [base_reg + offset], val_reg
2770           //
2771           // after these transformations will be
2772           //
2773           //    LoadN memory, narrow_oop_reg
2774           //    CmpN narrow_oop_reg, NULL
2775           //    decode_not_null narrow_oop_reg, base_reg
2776           //    Load [base_reg + offset], val_reg
2777           //
2778           // and the uncommon path (== NULL) will use narrow_oop_reg directly
2779           // since narrow oops can be used in debug info now (see the code in
2780           // final_graph_reshaping_walk()).
2781           //
2782           // At the end the code will be matched to
2783           // on x86:
2784           //
2785           //    Load_narrow_oop memory, narrow_oop_reg
2786           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
2787           //    NullCheck narrow_oop_reg
2788           //
2789           // and on sparc:
2790           //
2791           //    Load_narrow_oop memory, narrow_oop_reg
2792           //    decode_not_null narrow_oop_reg, base_reg
2793           //    Load [base_reg + offset], val_reg
2794           //    NullCheck base_reg
2795           //
2796         } else if (t->isa_oopptr()) {
2797           new_in2 = ConNode::make(this, t->make_narrowoop());
2798         } else if (t->isa_klassptr()) {
2799           new_in2 = ConNode::make(this, t->make_narrowklass());
2800         }
2801       }
2802       if (new_in2 != NULL) {
2803         Node* cmpN = new (this) CmpNNode(in1->in(1), new_in2);
2804         n->subsume_by(cmpN, this);
2805         if (in1->outcnt() == 0) {
2806           in1->disconnect_inputs(NULL, this);
2807         }
2808         if (in2->outcnt() == 0) {
2809           in2->disconnect_inputs(NULL, this);
2810         }
2811       }
2812     }
2813     break;
2814 
2815   case Op_DecodeN:
2816   case Op_DecodeNKlass:
2817     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
2818     // DecodeN could be pinned when it can't be fold into
2819     // an address expression, see the code for Op_CastPP above.
2820     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
2821     break;
2822 
2823   case Op_EncodeP:
2824   case Op_EncodePKlass: {
2825     Node* in1 = n->in(1);
2826     if (in1->is_DecodeNarrowPtr()) {
2827       n->subsume_by(in1->in(1), this);
2828     } else if (in1->Opcode() == Op_ConP) {
2829       const Type* t = in1->bottom_type();
2830       if (t == TypePtr::NULL_PTR) {
2831         assert(t->isa_oopptr(), "null klass?");
2832         n->subsume_by(ConNode::make(this, TypeNarrowOop::NULL_PTR), this);
2833       } else if (t->isa_oopptr()) {
2834         n->subsume_by(ConNode::make(this, t->make_narrowoop()), this);
2835       } else if (t->isa_klassptr()) {
2836         n->subsume_by(ConNode::make(this, t->make_narrowklass()), this);
2837       }
2838     }
2839     if (in1->outcnt() == 0) {
2840       in1->disconnect_inputs(NULL, this);
2841     }
2842     break;
2843   }
2844 
2845   case Op_Proj: {
2846     if (OptimizeStringConcat) {
2847       ProjNode* p = n->as_Proj();
2848       if (p->_is_io_use) {
2849         // Separate projections were used for the exception path which
2850         // are normally removed by a late inline.  If it wasn't inlined
2851         // then they will hang around and should just be replaced with
2852         // the original one.
2853         Node* proj = NULL;
2854         // Replace with just one
2855         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
2856           Node *use = i.get();
2857           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
2858             proj = use;
2859             break;
2860           }
2861         }
2862         assert(proj != NULL, "must be found");
2863         p->subsume_by(proj, this);
2864       }
2865     }
2866     break;
2867   }
2868 
2869   case Op_Phi:
2870     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
2871       // The EncodeP optimization may create Phi with the same edges
2872       // for all paths. It is not handled well by Register Allocator.
2873       Node* unique_in = n->in(1);
2874       assert(unique_in != NULL, "");
2875       uint cnt = n->req();
2876       for (uint i = 2; i < cnt; i++) {
2877         Node* m = n->in(i);
2878         assert(m != NULL, "");
2879         if (unique_in != m)
2880           unique_in = NULL;
2881       }
2882       if (unique_in != NULL) {
2883         n->subsume_by(unique_in, this);
2884       }
2885     }
2886     break;
2887 
2888 #endif
2889 
2890   case Op_ModI:
2891     if (UseDivMod) {
2892       // Check if a%b and a/b both exist
2893       Node* d = n->find_similar(Op_DivI);
2894       if (d) {
2895         // Replace them with a fused divmod if supported
2896         if (Matcher::has_match_rule(Op_DivModI)) {
2897           DivModINode* divmod = DivModINode::make(this, n);
2898           d->subsume_by(divmod->div_proj(), this);
2899           n->subsume_by(divmod->mod_proj(), this);
2900         } else {
2901           // replace a%b with a-((a/b)*b)
2902           Node* mult = new (this) MulINode(d, d->in(2));
2903           Node* sub  = new (this) SubINode(d->in(1), mult);
2904           n->subsume_by(sub, this);
2905         }
2906       }
2907     }
2908     break;
2909 
2910   case Op_ModL:
2911     if (UseDivMod) {
2912       // Check if a%b and a/b both exist
2913       Node* d = n->find_similar(Op_DivL);
2914       if (d) {
2915         // Replace them with a fused divmod if supported
2916         if (Matcher::has_match_rule(Op_DivModL)) {
2917           DivModLNode* divmod = DivModLNode::make(this, n);
2918           d->subsume_by(divmod->div_proj(), this);
2919           n->subsume_by(divmod->mod_proj(), this);
2920         } else {
2921           // replace a%b with a-((a/b)*b)
2922           Node* mult = new (this) MulLNode(d, d->in(2));
2923           Node* sub  = new (this) SubLNode(d->in(1), mult);
2924           n->subsume_by(sub, this);
2925         }
2926       }
2927     }
2928     break;
2929 
2930   case Op_LoadVector:
2931   case Op_StoreVector:
2932     break;
2933 
2934   case Op_PackB:
2935   case Op_PackS:
2936   case Op_PackI:
2937   case Op_PackF:
2938   case Op_PackL:
2939   case Op_PackD:
2940     if (n->req()-1 > 2) {
2941       // Replace many operand PackNodes with a binary tree for matching
2942       PackNode* p = (PackNode*) n;
2943       Node* btp = p->binary_tree_pack(this, 1, n->req());
2944       n->subsume_by(btp, this);
2945     }
2946     break;
2947   case Op_Loop:
2948   case Op_CountedLoop:
2949     if (n->as_Loop()->is_inner_loop()) {
2950       frc.inc_inner_loop_count();
2951     }
2952     break;
2953   case Op_LShiftI:
2954   case Op_RShiftI:
2955   case Op_URShiftI:
2956   case Op_LShiftL:
2957   case Op_RShiftL:
2958   case Op_URShiftL:
2959     if (Matcher::need_masked_shift_count) {
2960       // The cpu's shift instructions don't restrict the count to the
2961       // lower 5/6 bits. We need to do the masking ourselves.
2962       Node* in2 = n->in(2);
2963       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
2964       const TypeInt* t = in2->find_int_type();
2965       if (t != NULL && t->is_con()) {
2966         juint shift = t->get_con();
2967         if (shift > mask) { // Unsigned cmp
2968           n->set_req(2, ConNode::make(this, TypeInt::make(shift & mask)));
2969         }
2970       } else {
2971         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
2972           Node* shift = new (this) AndINode(in2, ConNode::make(this, TypeInt::make(mask)));
2973           n->set_req(2, shift);
2974         }
2975       }
2976       if (in2->outcnt() == 0) { // Remove dead node
2977         in2->disconnect_inputs(NULL, this);
2978       }
2979     }
2980     break;
2981   case Op_MemBarStoreStore:
2982   case Op_MemBarRelease:
2983     // Break the link with AllocateNode: it is no longer useful and
2984     // confuses register allocation.
2985     if (n->req() > MemBarNode::Precedent) {
2986       n->set_req(MemBarNode::Precedent, top());
2987     }
2988     break;
2989   default:
2990     assert( !n->is_Call(), "" );
2991     assert( !n->is_Mem(), "" );
2992     break;
2993   }
2994 
2995   // Collect CFG split points
2996   if (n->is_MultiBranch())
2997     frc._tests.push(n);
2998 }
2999 
3000 //------------------------------final_graph_reshaping_walk---------------------
3001 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3002 // requires that the walk visits a node's inputs before visiting the node.
3003 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3004   ResourceArea *area = Thread::current()->resource_area();
3005   Unique_Node_List sfpt(area);
3006 
3007   frc._visited.set(root->_idx); // first, mark node as visited
3008   uint cnt = root->req();
3009   Node *n = root;
3010   uint  i = 0;
3011   while (true) {
3012     if (i < cnt) {
3013       // Place all non-visited non-null inputs onto stack
3014       Node* m = n->in(i);
3015       ++i;
3016       if (m != NULL && !frc._visited.test_set(m->_idx)) {
3017         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL)
3018           sfpt.push(m);
3019         cnt = m->req();
3020         nstack.push(n, i); // put on stack parent and next input's index
3021         n = m;
3022         i = 0;
3023       }
3024     } else {
3025       // Now do post-visit work
3026       final_graph_reshaping_impl( n, frc );
3027       if (nstack.is_empty())
3028         break;             // finished
3029       n = nstack.node();   // Get node from stack
3030       cnt = n->req();
3031       i = nstack.index();
3032       nstack.pop();        // Shift to the next node on stack
3033     }
3034   }
3035 
3036   // Skip next transformation if compressed oops are not used.
3037   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3038       (!UseCompressedOops && !UseCompressedKlassPointers))
3039     return;
3040 
3041   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3042   // It could be done for an uncommon traps or any safepoints/calls
3043   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3044   while (sfpt.size() > 0) {
3045     n = sfpt.pop();
3046     JVMState *jvms = n->as_SafePoint()->jvms();
3047     assert(jvms != NULL, "sanity");
3048     int start = jvms->debug_start();
3049     int end   = n->req();
3050     bool is_uncommon = (n->is_CallStaticJava() &&
3051                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3052     for (int j = start; j < end; j++) {
3053       Node* in = n->in(j);
3054       if (in->is_DecodeNarrowPtr()) {
3055         bool safe_to_skip = true;
3056         if (!is_uncommon ) {
3057           // Is it safe to skip?
3058           for (uint i = 0; i < in->outcnt(); i++) {
3059             Node* u = in->raw_out(i);
3060             if (!u->is_SafePoint() ||
3061                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
3062               safe_to_skip = false;
3063             }
3064           }
3065         }
3066         if (safe_to_skip) {
3067           n->set_req(j, in->in(1));
3068         }
3069         if (in->outcnt() == 0) {
3070           in->disconnect_inputs(NULL, this);
3071         }
3072       }
3073     }
3074   }
3075 }
3076 
3077 //------------------------------final_graph_reshaping--------------------------
3078 // Final Graph Reshaping.
3079 //
3080 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3081 //     and not commoned up and forced early.  Must come after regular
3082 //     optimizations to avoid GVN undoing the cloning.  Clone constant
3083 //     inputs to Loop Phis; these will be split by the allocator anyways.
3084 //     Remove Opaque nodes.
3085 // (2) Move last-uses by commutative operations to the left input to encourage
3086 //     Intel update-in-place two-address operations and better register usage
3087 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
3088 //     calls canonicalizing them back.
3089 // (3) Count the number of double-precision FP ops, single-precision FP ops
3090 //     and call sites.  On Intel, we can get correct rounding either by
3091 //     forcing singles to memory (requires extra stores and loads after each
3092 //     FP bytecode) or we can set a rounding mode bit (requires setting and
3093 //     clearing the mode bit around call sites).  The mode bit is only used
3094 //     if the relative frequency of single FP ops to calls is low enough.
3095 //     This is a key transform for SPEC mpeg_audio.
3096 // (4) Detect infinite loops; blobs of code reachable from above but not
3097 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
3098 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
3099 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
3100 //     Detection is by looking for IfNodes where only 1 projection is
3101 //     reachable from below or CatchNodes missing some targets.
3102 // (5) Assert for insane oop offsets in debug mode.
3103 
3104 bool Compile::final_graph_reshaping() {
3105   // an infinite loop may have been eliminated by the optimizer,
3106   // in which case the graph will be empty.
3107   if (root()->req() == 1) {
3108     record_method_not_compilable("trivial infinite loop");
3109     return true;
3110   }
3111 
3112   // Expensive nodes have their control input set to prevent the GVN
3113   // from freely commoning them. There's no GVN beyond this point so
3114   // no need to keep the control input. We want the expensive nodes to
3115   // be freely moved to the least frequent code path by gcm.
3116   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3117   for (int i = 0; i < expensive_count(); i++) {
3118     _expensive_nodes->at(i)->set_req(0, NULL);
3119   }
3120 
3121   Final_Reshape_Counts frc;
3122 
3123   // Visit everybody reachable!
3124   // Allocate stack of size C->unique()/2 to avoid frequent realloc
3125   Node_Stack nstack(unique() >> 1);
3126   final_graph_reshaping_walk(nstack, root(), frc);
3127 
3128   // Check for unreachable (from below) code (i.e., infinite loops).
3129   for( uint i = 0; i < frc._tests.size(); i++ ) {
3130     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3131     // Get number of CFG targets.
3132     // Note that PCTables include exception targets after calls.
3133     uint required_outcnt = n->required_outcnt();
3134     if (n->outcnt() != required_outcnt) {
3135       // Check for a few special cases.  Rethrow Nodes never take the
3136       // 'fall-thru' path, so expected kids is 1 less.
3137       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3138         if (n->in(0)->in(0)->is_Call()) {
3139           CallNode *call = n->in(0)->in(0)->as_Call();
3140           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3141             required_outcnt--;      // Rethrow always has 1 less kid
3142           } else if (call->req() > TypeFunc::Parms &&
3143                      call->is_CallDynamicJava()) {
3144             // Check for null receiver. In such case, the optimizer has
3145             // detected that the virtual call will always result in a null
3146             // pointer exception. The fall-through projection of this CatchNode
3147             // will not be populated.
3148             Node *arg0 = call->in(TypeFunc::Parms);
3149             if (arg0->is_Type() &&
3150                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3151               required_outcnt--;
3152             }
3153           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3154                      call->req() > TypeFunc::Parms+1 &&
3155                      call->is_CallStaticJava()) {
3156             // Check for negative array length. In such case, the optimizer has
3157             // detected that the allocation attempt will always result in an
3158             // exception. There is no fall-through projection of this CatchNode .
3159             Node *arg1 = call->in(TypeFunc::Parms+1);
3160             if (arg1->is_Type() &&
3161                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3162               required_outcnt--;
3163             }
3164           }
3165         }
3166       }
3167       // Recheck with a better notion of 'required_outcnt'
3168       if (n->outcnt() != required_outcnt) {
3169         record_method_not_compilable("malformed control flow");
3170         return true;            // Not all targets reachable!
3171       }
3172     }
3173     // Check that I actually visited all kids.  Unreached kids
3174     // must be infinite loops.
3175     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3176       if (!frc._visited.test(n->fast_out(j)->_idx)) {
3177         record_method_not_compilable("infinite loop");
3178         return true;            // Found unvisited kid; must be unreach
3179       }
3180   }
3181 
3182   // If original bytecodes contained a mixture of floats and doubles
3183   // check if the optimizer has made it homogenous, item (3).
3184   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3185       frc.get_float_count() > 32 &&
3186       frc.get_double_count() == 0 &&
3187       (10 * frc.get_call_count() < frc.get_float_count()) ) {
3188     set_24_bit_selection_and_mode( false,  true );
3189   }
3190 
3191   set_java_calls(frc.get_java_call_count());
3192   set_inner_loops(frc.get_inner_loop_count());
3193 
3194   // No infinite loops, no reason to bail out.
3195   return false;
3196 }
3197 
3198 //-----------------------------too_many_traps----------------------------------
3199 // Report if there are too many traps at the current method and bci.
3200 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3201 bool Compile::too_many_traps(ciMethod* method,
3202                              int bci,
3203                              Deoptimization::DeoptReason reason) {
3204   ciMethodData* md = method->method_data();
3205   if (md->is_empty()) {
3206     // Assume the trap has not occurred, or that it occurred only
3207     // because of a transient condition during start-up in the interpreter.
3208     return false;
3209   }
3210   if (md->has_trap_at(bci, reason) != 0) {
3211     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3212     // Also, if there are multiple reasons, or if there is no per-BCI record,
3213     // assume the worst.
3214     if (log())
3215       log()->elem("observe trap='%s' count='%d'",
3216                   Deoptimization::trap_reason_name(reason),
3217                   md->trap_count(reason));
3218     return true;
3219   } else {
3220     // Ignore method/bci and see if there have been too many globally.
3221     return too_many_traps(reason, md);
3222   }
3223 }
3224 
3225 // Less-accurate variant which does not require a method and bci.
3226 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3227                              ciMethodData* logmd) {
3228  if (trap_count(reason) >= (uint)PerMethodTrapLimit) {
3229     // Too many traps globally.
3230     // Note that we use cumulative trap_count, not just md->trap_count.
3231     if (log()) {
3232       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3233       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3234                   Deoptimization::trap_reason_name(reason),
3235                   mcount, trap_count(reason));
3236     }
3237     return true;
3238   } else {
3239     // The coast is clear.
3240     return false;
3241   }
3242 }
3243 
3244 //--------------------------too_many_recompiles--------------------------------
3245 // Report if there are too many recompiles at the current method and bci.
3246 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3247 // Is not eager to return true, since this will cause the compiler to use
3248 // Action_none for a trap point, to avoid too many recompilations.
3249 bool Compile::too_many_recompiles(ciMethod* method,
3250                                   int bci,
3251                                   Deoptimization::DeoptReason reason) {
3252   ciMethodData* md = method->method_data();
3253   if (md->is_empty()) {
3254     // Assume the trap has not occurred, or that it occurred only
3255     // because of a transient condition during start-up in the interpreter.
3256     return false;
3257   }
3258   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3259   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3260   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
3261   Deoptimization::DeoptReason per_bc_reason
3262     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3263   if ((per_bc_reason == Deoptimization::Reason_none
3264        || md->has_trap_at(bci, reason) != 0)
3265       // The trap frequency measure we care about is the recompile count:
3266       && md->trap_recompiled_at(bci)
3267       && md->overflow_recompile_count() >= bc_cutoff) {
3268     // Do not emit a trap here if it has already caused recompilations.
3269     // Also, if there are multiple reasons, or if there is no per-BCI record,
3270     // assume the worst.
3271     if (log())
3272       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3273                   Deoptimization::trap_reason_name(reason),
3274                   md->trap_count(reason),
3275                   md->overflow_recompile_count());
3276     return true;
3277   } else if (trap_count(reason) != 0
3278              && decompile_count() >= m_cutoff) {
3279     // Too many recompiles globally, and we have seen this sort of trap.
3280     // Use cumulative decompile_count, not just md->decompile_count.
3281     if (log())
3282       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3283                   Deoptimization::trap_reason_name(reason),
3284                   md->trap_count(reason), trap_count(reason),
3285                   md->decompile_count(), decompile_count());
3286     return true;
3287   } else {
3288     // The coast is clear.
3289     return false;
3290   }
3291 }
3292 
3293 
3294 #ifndef PRODUCT
3295 //------------------------------verify_graph_edges---------------------------
3296 // Walk the Graph and verify that there is a one-to-one correspondence
3297 // between Use-Def edges and Def-Use edges in the graph.
3298 void Compile::verify_graph_edges(bool no_dead_code) {
3299   if (VerifyGraphEdges) {
3300     ResourceArea *area = Thread::current()->resource_area();
3301     Unique_Node_List visited(area);
3302     // Call recursive graph walk to check edges
3303     _root->verify_edges(visited);
3304     if (no_dead_code) {
3305       // Now make sure that no visited node is used by an unvisited node.
3306       bool dead_nodes = 0;
3307       Unique_Node_List checked(area);
3308       while (visited.size() > 0) {
3309         Node* n = visited.pop();
3310         checked.push(n);
3311         for (uint i = 0; i < n->outcnt(); i++) {
3312           Node* use = n->raw_out(i);
3313           if (checked.member(use))  continue;  // already checked
3314           if (visited.member(use))  continue;  // already in the graph
3315           if (use->is_Con())        continue;  // a dead ConNode is OK
3316           // At this point, we have found a dead node which is DU-reachable.
3317           if (dead_nodes++ == 0)
3318             tty->print_cr("*** Dead nodes reachable via DU edges:");
3319           use->dump(2);
3320           tty->print_cr("---");
3321           checked.push(use);  // No repeats; pretend it is now checked.
3322         }
3323       }
3324       assert(dead_nodes == 0, "using nodes must be reachable from root");
3325     }
3326   }
3327 }
3328 #endif
3329 
3330 // The Compile object keeps track of failure reasons separately from the ciEnv.
3331 // This is required because there is not quite a 1-1 relation between the
3332 // ciEnv and its compilation task and the Compile object.  Note that one
3333 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3334 // to backtrack and retry without subsuming loads.  Other than this backtracking
3335 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3336 // by the logic in C2Compiler.
3337 void Compile::record_failure(const char* reason) {
3338   if (log() != NULL) {
3339     log()->elem("failure reason='%s' phase='compile'", reason);
3340   }
3341   if (_failure_reason == NULL) {
3342     // Record the first failure reason.
3343     _failure_reason = reason;
3344   }
3345 
3346   EventCompilerFailure event;
3347   if (event.should_commit()) {
3348     event.set_compileID(Compile::compile_id());
3349     event.set_failure(reason);
3350     event.commit();
3351   }
3352 
3353   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3354     C->print_method(PHASE_FAILURE);
3355   }
3356   _root = NULL;  // flush the graph, too
3357 }
3358 
3359 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
3360   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false),
3361     _phase_name(name), _dolog(dolog)
3362 {
3363   if (dolog) {
3364     C = Compile::current();
3365     _log = C->log();
3366   } else {
3367     C = NULL;
3368     _log = NULL;
3369   }
3370   if (_log != NULL) {
3371     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3372     _log->stamp();
3373     _log->end_head();
3374   }
3375 }
3376 
3377 Compile::TracePhase::~TracePhase() {
3378 
3379   C = Compile::current();
3380   if (_dolog) {
3381     _log = C->log();
3382   } else {
3383     _log = NULL;
3384   }
3385 
3386 #ifdef ASSERT
3387   if (PrintIdealNodeCount) {
3388     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3389                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3390   }
3391 
3392   if (VerifyIdealNodeCount) {
3393     Compile::current()->print_missing_nodes();
3394   }
3395 #endif
3396 
3397   if (_log != NULL) {
3398     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3399   }
3400 }
3401 
3402 //=============================================================================
3403 // Two Constant's are equal when the type and the value are equal.
3404 bool Compile::Constant::operator==(const Constant& other) {
3405   if (type()          != other.type()         )  return false;
3406   if (can_be_reused() != other.can_be_reused())  return false;
3407   // For floating point values we compare the bit pattern.
3408   switch (type()) {
3409   case T_FLOAT:   return (_v._value.i == other._v._value.i);
3410   case T_LONG:
3411   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
3412   case T_OBJECT:
3413   case T_ADDRESS: return (_v._value.l == other._v._value.l);
3414   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
3415   case T_METADATA: return (_v._metadata == other._v._metadata);
3416   default: ShouldNotReachHere();
3417   }
3418   return false;
3419 }
3420 
3421 static int type_to_size_in_bytes(BasicType t) {
3422   switch (t) {
3423   case T_LONG:    return sizeof(jlong  );
3424   case T_FLOAT:   return sizeof(jfloat );
3425   case T_DOUBLE:  return sizeof(jdouble);
3426   case T_METADATA: return sizeof(Metadata*);
3427     // We use T_VOID as marker for jump-table entries (labels) which
3428     // need an internal word relocation.
3429   case T_VOID:
3430   case T_ADDRESS:
3431   case T_OBJECT:  return sizeof(jobject);
3432   }
3433 
3434   ShouldNotReachHere();
3435   return -1;
3436 }
3437 
3438 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3439   // sort descending
3440   if (a->freq() > b->freq())  return -1;
3441   if (a->freq() < b->freq())  return  1;
3442   return 0;
3443 }
3444 
3445 void Compile::ConstantTable::calculate_offsets_and_size() {
3446   // First, sort the array by frequencies.
3447   _constants.sort(qsort_comparator);
3448 
3449 #ifdef ASSERT
3450   // Make sure all jump-table entries were sorted to the end of the
3451   // array (they have a negative frequency).
3452   bool found_void = false;
3453   for (int i = 0; i < _constants.length(); i++) {
3454     Constant con = _constants.at(i);
3455     if (con.type() == T_VOID)
3456       found_void = true;  // jump-tables
3457     else
3458       assert(!found_void, "wrong sorting");
3459   }
3460 #endif
3461 
3462   int offset = 0;
3463   for (int i = 0; i < _constants.length(); i++) {
3464     Constant* con = _constants.adr_at(i);
3465 
3466     // Align offset for type.
3467     int typesize = type_to_size_in_bytes(con->type());
3468     offset = align_size_up(offset, typesize);
3469     con->set_offset(offset);   // set constant's offset
3470 
3471     if (con->type() == T_VOID) {
3472       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
3473       offset = offset + typesize * n->outcnt();  // expand jump-table
3474     } else {
3475       offset = offset + typesize;
3476     }
3477   }
3478 
3479   // Align size up to the next section start (which is insts; see
3480   // CodeBuffer::align_at_start).
3481   assert(_size == -1, "already set?");
3482   _size = align_size_up(offset, CodeEntryAlignment);
3483 }
3484 
3485 void Compile::ConstantTable::emit(CodeBuffer& cb) {
3486   MacroAssembler _masm(&cb);
3487   for (int i = 0; i < _constants.length(); i++) {
3488     Constant con = _constants.at(i);
3489     address constant_addr;
3490     switch (con.type()) {
3491     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
3492     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
3493     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
3494     case T_OBJECT: {
3495       jobject obj = con.get_jobject();
3496       int oop_index = _masm.oop_recorder()->find_index(obj);
3497       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
3498       break;
3499     }
3500     case T_ADDRESS: {
3501       address addr = (address) con.get_jobject();
3502       constant_addr = _masm.address_constant(addr);
3503       break;
3504     }
3505     // We use T_VOID as marker for jump-table entries (labels) which
3506     // need an internal word relocation.
3507     case T_VOID: {
3508       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
3509       // Fill the jump-table with a dummy word.  The real value is
3510       // filled in later in fill_jump_table.
3511       address dummy = (address) n;
3512       constant_addr = _masm.address_constant(dummy);
3513       // Expand jump-table
3514       for (uint i = 1; i < n->outcnt(); i++) {
3515         address temp_addr = _masm.address_constant(dummy + i);
3516         assert(temp_addr, "consts section too small");
3517       }
3518       break;
3519     }
3520     case T_METADATA: {
3521       Metadata* obj = con.get_metadata();
3522       int metadata_index = _masm.oop_recorder()->find_index(obj);
3523       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
3524       break;
3525     }
3526     default: ShouldNotReachHere();
3527     }
3528     assert(constant_addr, "consts section too small");
3529     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(), err_msg_res("must be: %d == %d", constant_addr - _masm.code()->consts()->start(), con.offset()));
3530   }
3531 }
3532 
3533 int Compile::ConstantTable::find_offset(Constant& con) const {
3534   int idx = _constants.find(con);
3535   assert(idx != -1, "constant must be in constant table");
3536   int offset = _constants.at(idx).offset();
3537   assert(offset != -1, "constant table not emitted yet?");
3538   return offset;
3539 }
3540 
3541 void Compile::ConstantTable::add(Constant& con) {
3542   if (con.can_be_reused()) {
3543     int idx = _constants.find(con);
3544     if (idx != -1 && _constants.at(idx).can_be_reused()) {
3545       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
3546       return;
3547     }
3548   }
3549   (void) _constants.append(con);
3550 }
3551 
3552 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
3553   Block* b = Compile::current()->cfg()->get_block_for_node(n);
3554   Constant con(type, value, b->_freq);
3555   add(con);
3556   return con;
3557 }
3558 
3559 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
3560   Constant con(metadata);
3561   add(con);
3562   return con;
3563 }
3564 
3565 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
3566   jvalue value;
3567   BasicType type = oper->type()->basic_type();
3568   switch (type) {
3569   case T_LONG:    value.j = oper->constantL(); break;
3570   case T_FLOAT:   value.f = oper->constantF(); break;
3571   case T_DOUBLE:  value.d = oper->constantD(); break;
3572   case T_OBJECT:
3573   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
3574   case T_METADATA: return add((Metadata*)oper->constant()); break;
3575   default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
3576   }
3577   return add(n, type, value);
3578 }
3579 
3580 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
3581   jvalue value;
3582   // We can use the node pointer here to identify the right jump-table
3583   // as this method is called from Compile::Fill_buffer right before
3584   // the MachNodes are emitted and the jump-table is filled (means the
3585   // MachNode pointers do not change anymore).
3586   value.l = (jobject) n;
3587   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
3588   add(con);
3589   return con;
3590 }
3591 
3592 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
3593   // If called from Compile::scratch_emit_size do nothing.
3594   if (Compile::current()->in_scratch_emit_size())  return;
3595 
3596   assert(labels.is_nonempty(), "must be");
3597   assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
3598 
3599   // Since MachConstantNode::constant_offset() also contains
3600   // table_base_offset() we need to subtract the table_base_offset()
3601   // to get the plain offset into the constant table.
3602   int offset = n->constant_offset() - table_base_offset();
3603 
3604   MacroAssembler _masm(&cb);
3605   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
3606 
3607   for (uint i = 0; i < n->outcnt(); i++) {
3608     address* constant_addr = &jump_table_base[i];
3609     assert(*constant_addr == (((address) n) + i), err_msg_res("all jump-table entries must contain adjusted node pointer: " INTPTR_FORMAT " == " INTPTR_FORMAT, *constant_addr, (((address) n) + i)));
3610     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
3611     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
3612   }
3613 }
3614 
3615 void Compile::dump_inlining() {
3616   if (print_inlining() || print_intrinsics()) {
3617     // Print inlining message for candidates that we couldn't inline
3618     // for lack of space or non constant receiver
3619     for (int i = 0; i < _late_inlines.length(); i++) {
3620       CallGenerator* cg = _late_inlines.at(i);
3621       cg->print_inlining_late("live nodes > LiveNodeCountInliningCutoff");
3622     }
3623     Unique_Node_List useful;
3624     useful.push(root());
3625     for (uint next = 0; next < useful.size(); ++next) {
3626       Node* n  = useful.at(next);
3627       if (n->is_Call() && n->as_Call()->generator() != NULL && n->as_Call()->generator()->call_node() == n) {
3628         CallNode* call = n->as_Call();
3629         CallGenerator* cg = call->generator();
3630         cg->print_inlining_late("receiver not constant");
3631       }
3632       uint max = n->len();
3633       for ( uint i = 0; i < max; ++i ) {
3634         Node *m = n->in(i);
3635         if ( m == NULL ) continue;
3636         useful.push(m);
3637       }
3638     }
3639     for (int i = 0; i < _print_inlining_list->length(); i++) {
3640       tty->print(_print_inlining_list->adr_at(i)->ss()->as_string());
3641     }
3642   }
3643 }
3644 
3645 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
3646   if (n1->Opcode() < n2->Opcode())      return -1;
3647   else if (n1->Opcode() > n2->Opcode()) return 1;
3648 
3649   assert(n1->req() == n2->req(), err_msg_res("can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req()));
3650   for (uint i = 1; i < n1->req(); i++) {
3651     if (n1->in(i) < n2->in(i))      return -1;
3652     else if (n1->in(i) > n2->in(i)) return 1;
3653   }
3654 
3655   return 0;
3656 }
3657 
3658 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
3659   Node* n1 = *n1p;
3660   Node* n2 = *n2p;
3661 
3662   return cmp_expensive_nodes(n1, n2);
3663 }
3664 
3665 void Compile::sort_expensive_nodes() {
3666   if (!expensive_nodes_sorted()) {
3667     _expensive_nodes->sort(cmp_expensive_nodes);
3668   }
3669 }
3670 
3671 bool Compile::expensive_nodes_sorted() const {
3672   for (int i = 1; i < _expensive_nodes->length(); i++) {
3673     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
3674       return false;
3675     }
3676   }
3677   return true;
3678 }
3679 
3680 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
3681   if (_expensive_nodes->length() == 0) {
3682     return false;
3683   }
3684 
3685   assert(OptimizeExpensiveOps, "optimization off?");
3686 
3687   // Take this opportunity to remove dead nodes from the list
3688   int j = 0;
3689   for (int i = 0; i < _expensive_nodes->length(); i++) {
3690     Node* n = _expensive_nodes->at(i);
3691     if (!n->is_unreachable(igvn)) {
3692       assert(n->is_expensive(), "should be expensive");
3693       _expensive_nodes->at_put(j, n);
3694       j++;
3695     }
3696   }
3697   _expensive_nodes->trunc_to(j);
3698 
3699   // Then sort the list so that similar nodes are next to each other
3700   // and check for at least two nodes of identical kind with same data
3701   // inputs.
3702   sort_expensive_nodes();
3703 
3704   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
3705     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
3706       return true;
3707     }
3708   }
3709 
3710   return false;
3711 }
3712 
3713 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
3714   if (_expensive_nodes->length() == 0) {
3715     return;
3716   }
3717 
3718   assert(OptimizeExpensiveOps, "optimization off?");
3719 
3720   // Sort to bring similar nodes next to each other and clear the
3721   // control input of nodes for which there's only a single copy.
3722   sort_expensive_nodes();
3723 
3724   int j = 0;
3725   int identical = 0;
3726   int i = 0;
3727   for (; i < _expensive_nodes->length()-1; i++) {
3728     assert(j <= i, "can't write beyond current index");
3729     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
3730       identical++;
3731       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
3732       continue;
3733     }
3734     if (identical > 0) {
3735       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
3736       identical = 0;
3737     } else {
3738       Node* n = _expensive_nodes->at(i);
3739       igvn.hash_delete(n);
3740       n->set_req(0, NULL);
3741       igvn.hash_insert(n);
3742     }
3743   }
3744   if (identical > 0) {
3745     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
3746   } else if (_expensive_nodes->length() >= 1) {
3747     Node* n = _expensive_nodes->at(i);
3748     igvn.hash_delete(n);
3749     n->set_req(0, NULL);
3750     igvn.hash_insert(n);
3751   }
3752   _expensive_nodes->trunc_to(j);
3753 }
3754 
3755 void Compile::add_expensive_node(Node * n) {
3756   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
3757   assert(n->is_expensive(), "expensive nodes with non-null control here only");
3758   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
3759   if (OptimizeExpensiveOps) {
3760     _expensive_nodes->append(n);
3761   } else {
3762     // Clear control input and let IGVN optimize expensive nodes if
3763     // OptimizeExpensiveOps is off.
3764     n->set_req(0, NULL);
3765   }
3766 }
3767 
3768 // Auxiliary method to support randomized stressing/fuzzing.
3769 //
3770 // This method can be called the arbitrary number of times, with current count
3771 // as the argument. The logic allows selecting a single candidate from the
3772 // running list of candidates as follows:
3773 //    int count = 0;
3774 //    Cand* selected = null;
3775 //    while(cand = cand->next()) {
3776 //      if (randomized_select(++count)) {
3777 //        selected = cand;
3778 //      }
3779 //    }
3780 //
3781 // Including count equalizes the chances any candidate is "selected".
3782 // This is useful when we don't have the complete list of candidates to choose
3783 // from uniformly. In this case, we need to adjust the randomicity of the
3784 // selection, or else we will end up biasing the selection towards the latter
3785 // candidates.
3786 //
3787 // Quick back-envelope calculation shows that for the list of n candidates
3788 // the equal probability for the candidate to persist as "best" can be
3789 // achieved by replacing it with "next" k-th candidate with the probability
3790 // of 1/k. It can be easily shown that by the end of the run, the
3791 // probability for any candidate is converged to 1/n, thus giving the
3792 // uniform distribution among all the candidates.
3793 //
3794 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
3795 #define RANDOMIZED_DOMAIN_POW 29
3796 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
3797 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
3798 bool Compile::randomized_select(int count) {
3799   assert(count > 0, "only positive");
3800   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
3801 }