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                   _preserve_jvm_state(0) {
 659   C = this;
 660 
 661   CompileWrapper cw(this);
 662 #ifndef PRODUCT
 663   if (TimeCompiler2) {
 664     tty->print(" ");
 665     target->holder()->name()->print();
 666     tty->print(".");
 667     target->print_short_name();
 668     tty->print("  ");
 669   }
 670   TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
 671   TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
 672   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
 673   if (!print_opto_assembly) {
 674     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
 675     if (print_assembly && !Disassembler::can_decode()) {
 676       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
 677       print_opto_assembly = true;
 678     }
 679   }
 680   set_print_assembly(print_opto_assembly);
 681   set_parsed_irreducible_loop(false);
 682 #endif
 683   set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
 684   set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
 685 
 686   if (ProfileTraps) {
 687     // Make sure the method being compiled gets its own MDO,
 688     // so we can at least track the decompile_count().
 689     method()->ensure_method_data();
 690   }
 691 
 692   Init(::AliasLevel);
 693 
 694 
 695   print_compile_messages();
 696 
 697   if (UseOldInlining || PrintCompilation NOT_PRODUCT( || PrintOpto) )
 698     _ilt = InlineTree::build_inline_tree_root();
 699   else
 700     _ilt = NULL;
 701 
 702   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 703   assert(num_alias_types() >= AliasIdxRaw, "");
 704 
 705 #define MINIMUM_NODE_HASH  1023
 706   // Node list that Iterative GVN will start with
 707   Unique_Node_List for_igvn(comp_arena());
 708   set_for_igvn(&for_igvn);
 709 
 710   // GVN that will be run immediately on new nodes
 711   uint estimated_size = method()->code_size()*4+64;
 712   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 713   PhaseGVN gvn(node_arena(), estimated_size);
 714   set_initial_gvn(&gvn);
 715 
 716   if (print_inlining() || print_intrinsics()) {
 717     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
 718   }
 719   { // Scope for timing the parser
 720     TracePhase t3("parse", &_t_parser, true);
 721 
 722     // Put top into the hash table ASAP.
 723     initial_gvn()->transform_no_reclaim(top());
 724 
 725     // Set up tf(), start(), and find a CallGenerator.
 726     CallGenerator* cg = NULL;
 727     if (is_osr_compilation()) {
 728       const TypeTuple *domain = StartOSRNode::osr_domain();
 729       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 730       init_tf(TypeFunc::make(domain, range));
 731       StartNode* s = new (this) StartOSRNode(root(), domain);
 732       initial_gvn()->set_type_bottom(s);
 733       init_start(s);
 734       cg = CallGenerator::for_osr(method(), entry_bci());
 735     } else {
 736       // Normal case.
 737       init_tf(TypeFunc::make(method()));
 738       StartNode* s = new (this) StartNode(root(), tf()->domain());
 739       initial_gvn()->set_type_bottom(s);
 740       init_start(s);
 741       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
 742         // With java.lang.ref.reference.get() we must go through the
 743         // intrinsic when G1 is enabled - even when get() is the root
 744         // method of the compile - so that, if necessary, the value in
 745         // the referent field of the reference object gets recorded by
 746         // the pre-barrier code.
 747         // Specifically, if G1 is enabled, the value in the referent
 748         // field is recorded by the G1 SATB pre barrier. This will
 749         // result in the referent being marked live and the reference
 750         // object removed from the list of discovered references during
 751         // reference processing.
 752         cg = find_intrinsic(method(), false);
 753       }
 754       if (cg == NULL) {
 755         float past_uses = method()->interpreter_invocation_count();
 756         float expected_uses = past_uses;
 757         cg = CallGenerator::for_inline(method(), expected_uses);
 758       }
 759     }
 760     if (failing())  return;
 761     if (cg == NULL) {
 762       record_method_not_compilable_all_tiers("cannot parse method");
 763       return;
 764     }
 765     JVMState* jvms = build_start_state(start(), tf());
 766     if ((jvms = cg->generate(jvms, NULL)) == NULL) {
 767       record_method_not_compilable("method parse failed");
 768       return;
 769     }
 770     GraphKit kit(jvms);
 771 
 772     if (!kit.stopped()) {
 773       // Accept return values, and transfer control we know not where.
 774       // This is done by a special, unique ReturnNode bound to root.
 775       return_values(kit.jvms());
 776     }
 777 
 778     if (kit.has_exceptions()) {
 779       // Any exceptions that escape from this call must be rethrown
 780       // to whatever caller is dynamically above us on the stack.
 781       // This is done by a special, unique RethrowNode bound to root.
 782       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 783     }
 784 
 785     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 786 
 787     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 788       inline_string_calls(true);
 789     }
 790 
 791     if (failing())  return;
 792 
 793     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
 794 
 795     // Remove clutter produced by parsing.
 796     if (!failing()) {
 797       ResourceMark rm;
 798       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 799     }
 800   }
 801 
 802   // Note:  Large methods are capped off in do_one_bytecode().
 803   if (failing())  return;
 804 
 805   // After parsing, node notes are no longer automagic.
 806   // They must be propagated by register_new_node_with_optimizer(),
 807   // clone(), or the like.
 808   set_default_node_notes(NULL);
 809 
 810   for (;;) {
 811     int successes = Inline_Warm();
 812     if (failing())  return;
 813     if (successes == 0)  break;
 814   }
 815 
 816   // Drain the list.
 817   Finish_Warm();
 818 #ifndef PRODUCT
 819   if (_printer) {
 820     _printer->print_inlining(this);
 821   }
 822 #endif
 823 
 824   if (failing())  return;
 825   NOT_PRODUCT( verify_graph_edges(); )
 826 
 827   // Now optimize
 828   Optimize();
 829   if (failing())  return;
 830   NOT_PRODUCT( verify_graph_edges(); )
 831 
 832 #ifndef PRODUCT
 833   if (PrintIdeal) {
 834     ttyLocker ttyl;  // keep the following output all in one block
 835     // This output goes directly to the tty, not the compiler log.
 836     // To enable tools to match it up with the compilation activity,
 837     // be sure to tag this tty output with the compile ID.
 838     if (xtty != NULL) {
 839       xtty->head("ideal compile_id='%d'%s", compile_id(),
 840                  is_osr_compilation()    ? " compile_kind='osr'" :
 841                  "");
 842     }
 843     root()->dump(9999);
 844     if (xtty != NULL) {
 845       xtty->tail("ideal");
 846     }
 847   }
 848 #endif
 849 
 850   // Now that we know the size of all the monitors we can add a fixed slot
 851   // for the original deopt pc.
 852 
 853   _orig_pc_slot =  fixed_slots();
 854   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 855   set_fixed_slots(next_slot);
 856 
 857   // Now generate code
 858   Code_Gen();
 859   if (failing())  return;
 860 
 861   // Check if we want to skip execution of all compiled code.
 862   {
 863 #ifndef PRODUCT
 864     if (OptoNoExecute) {
 865       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 866       return;
 867     }
 868     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
 869 #endif
 870 
 871     if (is_osr_compilation()) {
 872       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 873       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 874     } else {
 875       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 876       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 877     }
 878 
 879     env()->register_method(_method, _entry_bci,
 880                            &_code_offsets,
 881                            _orig_pc_slot_offset_in_bytes,
 882                            code_buffer(),
 883                            frame_size_in_words(), _oop_map_set,
 884                            &_handler_table, &_inc_table,
 885                            compiler,
 886                            env()->comp_level(),
 887                            has_unsafe_access(),
 888                            SharedRuntime::is_wide_vector(max_vector_size())
 889                            );
 890 
 891     if (log() != NULL) // Print code cache state into compiler log
 892       log()->code_cache_state();
 893   }
 894 }
 895 
 896 //------------------------------Compile----------------------------------------
 897 // Compile a runtime stub
 898 Compile::Compile( ciEnv* ci_env,
 899                   TypeFunc_generator generator,
 900                   address stub_function,
 901                   const char *stub_name,
 902                   int is_fancy_jump,
 903                   bool pass_tls,
 904                   bool save_arg_registers,
 905                   bool return_pc )
 906   : Phase(Compiler),
 907     _env(ci_env),
 908     _log(ci_env->log()),
 909     _compile_id(0),
 910     _save_argument_registers(save_arg_registers),
 911     _method(NULL),
 912     _stub_name(stub_name),
 913     _stub_function(stub_function),
 914     _stub_entry_point(NULL),
 915     _entry_bci(InvocationEntryBci),
 916     _initial_gvn(NULL),
 917     _for_igvn(NULL),
 918     _warm_calls(NULL),
 919     _orig_pc_slot(0),
 920     _orig_pc_slot_offset_in_bytes(0),
 921     _subsume_loads(true),
 922     _do_escape_analysis(false),
 923     _eliminate_boxing(false),
 924     _failure_reason(NULL),
 925     _code_buffer("Compile::Fill_buffer"),
 926     _has_method_handle_invokes(false),
 927     _mach_constant_base_node(NULL),
 928     _node_bundling_limit(0),
 929     _node_bundling_base(NULL),
 930     _java_calls(0),
 931     _inner_loops(0),
 932 #ifndef PRODUCT
 933     _trace_opto_output(TraceOptoOutput),
 934     _printer(NULL),
 935 #endif
 936     _dead_node_list(comp_arena()),
 937     _dead_node_count(0),
 938     _congraph(NULL),
 939     _number_of_mh_late_inlines(0),
 940     _inlining_progress(false),
 941     _inlining_incrementally(false),
 942     _print_inlining_list(NULL),
 943     _print_inlining_idx(0),
 944     _preserve_jvm_state(0) {
 945   C = this;
 946 
 947 #ifndef PRODUCT
 948   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
 949   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
 950   set_print_assembly(PrintFrameConverterAssembly);
 951   set_parsed_irreducible_loop(false);
 952 #endif
 953   CompileWrapper cw(this);
 954   Init(/*AliasLevel=*/ 0);
 955   init_tf((*generator)());
 956 
 957   {
 958     // The following is a dummy for the sake of GraphKit::gen_stub
 959     Unique_Node_List for_igvn(comp_arena());
 960     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
 961     PhaseGVN gvn(Thread::current()->resource_area(),255);
 962     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
 963     gvn.transform_no_reclaim(top());
 964 
 965     GraphKit kit;
 966     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
 967   }
 968 
 969   NOT_PRODUCT( verify_graph_edges(); )
 970   Code_Gen();
 971   if (failing())  return;
 972 
 973 
 974   // Entry point will be accessed using compile->stub_entry_point();
 975   if (code_buffer() == NULL) {
 976     Matcher::soft_match_failure();
 977   } else {
 978     if (PrintAssembly && (WizardMode || Verbose))
 979       tty->print_cr("### Stub::%s", stub_name);
 980 
 981     if (!failing()) {
 982       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
 983 
 984       // Make the NMethod
 985       // For now we mark the frame as never safe for profile stackwalking
 986       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
 987                                                       code_buffer(),
 988                                                       CodeOffsets::frame_never_safe,
 989                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
 990                                                       frame_size_in_words(),
 991                                                       _oop_map_set,
 992                                                       save_arg_registers);
 993       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
 994 
 995       _stub_entry_point = rs->entry_point();
 996     }
 997   }
 998 }
 999 
1000 //------------------------------Init-------------------------------------------
1001 // Prepare for a single compilation
1002 void Compile::Init(int aliaslevel) {
1003   _unique  = 0;
1004   _regalloc = NULL;
1005 
1006   _tf      = NULL;  // filled in later
1007   _top     = NULL;  // cached later
1008   _matcher = NULL;  // filled in later
1009   _cfg     = NULL;  // filled in later
1010 
1011   set_24_bit_selection_and_mode(Use24BitFP, false);
1012 
1013   _node_note_array = NULL;
1014   _default_node_notes = NULL;
1015 
1016   _immutable_memory = NULL; // filled in at first inquiry
1017 
1018   // Globally visible Nodes
1019   // First set TOP to NULL to give safe behavior during creation of RootNode
1020   set_cached_top_node(NULL);
1021   set_root(new (this) RootNode());
1022   // Now that you have a Root to point to, create the real TOP
1023   set_cached_top_node( new (this) ConNode(Type::TOP) );
1024   set_recent_alloc(NULL, NULL);
1025 
1026   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1027   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1028   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1029   env()->set_dependencies(new Dependencies(env()));
1030 
1031   _fixed_slots = 0;
1032   set_has_split_ifs(false);
1033   set_has_loops(has_method() && method()->has_loops()); // first approximation
1034   set_has_stringbuilder(false);
1035   set_has_boxed_value(false);
1036   _trap_can_recompile = false;  // no traps emitted yet
1037   _major_progress = true; // start out assuming good things will happen
1038   set_has_unsafe_access(false);
1039   set_max_vector_size(0);
1040   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1041   set_decompile_count(0);
1042 
1043   set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
1044   set_num_loop_opts(LoopOptsCount);
1045   set_do_inlining(Inline);
1046   set_max_inline_size(MaxInlineSize);
1047   set_freq_inline_size(FreqInlineSize);
1048   set_do_scheduling(OptoScheduling);
1049   set_do_count_invocations(false);
1050   set_do_method_data_update(false);
1051 
1052   if (debug_info()->recording_non_safepoints()) {
1053     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1054                         (comp_arena(), 8, 0, NULL));
1055     set_default_node_notes(Node_Notes::make(this));
1056   }
1057 
1058   // // -- Initialize types before each compile --
1059   // // Update cached type information
1060   // if( _method && _method->constants() )
1061   //   Type::update_loaded_types(_method, _method->constants());
1062 
1063   // Init alias_type map.
1064   if (!_do_escape_analysis && aliaslevel == 3)
1065     aliaslevel = 2;  // No unique types without escape analysis
1066   _AliasLevel = aliaslevel;
1067   const int grow_ats = 16;
1068   _max_alias_types = grow_ats;
1069   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1070   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1071   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1072   {
1073     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1074   }
1075   // Initialize the first few types.
1076   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1077   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1078   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1079   _num_alias_types = AliasIdxRaw+1;
1080   // Zero out the alias type cache.
1081   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1082   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1083   probe_alias_cache(NULL)->_index = AliasIdxTop;
1084 
1085   _intrinsics = NULL;
1086   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1087   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1088   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1089   register_library_intrinsics();
1090 }
1091 
1092 //---------------------------init_start----------------------------------------
1093 // Install the StartNode on this compile object.
1094 void Compile::init_start(StartNode* s) {
1095   if (failing())
1096     return; // already failing
1097   assert(s == start(), "");
1098 }
1099 
1100 StartNode* Compile::start() const {
1101   assert(!failing(), "");
1102   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1103     Node* start = root()->fast_out(i);
1104     if( start->is_Start() )
1105       return start->as_Start();
1106   }
1107   ShouldNotReachHere();
1108   return NULL;
1109 }
1110 
1111 //-------------------------------immutable_memory-------------------------------------
1112 // Access immutable memory
1113 Node* Compile::immutable_memory() {
1114   if (_immutable_memory != NULL) {
1115     return _immutable_memory;
1116   }
1117   StartNode* s = start();
1118   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1119     Node *p = s->fast_out(i);
1120     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1121       _immutable_memory = p;
1122       return _immutable_memory;
1123     }
1124   }
1125   ShouldNotReachHere();
1126   return NULL;
1127 }
1128 
1129 //----------------------set_cached_top_node------------------------------------
1130 // Install the cached top node, and make sure Node::is_top works correctly.
1131 void Compile::set_cached_top_node(Node* tn) {
1132   if (tn != NULL)  verify_top(tn);
1133   Node* old_top = _top;
1134   _top = tn;
1135   // Calling Node::setup_is_top allows the nodes the chance to adjust
1136   // their _out arrays.
1137   if (_top != NULL)     _top->setup_is_top();
1138   if (old_top != NULL)  old_top->setup_is_top();
1139   assert(_top == NULL || top()->is_top(), "");
1140 }
1141 
1142 #ifdef ASSERT
1143 uint Compile::count_live_nodes_by_graph_walk() {
1144   Unique_Node_List useful(comp_arena());
1145   // Get useful node list by walking the graph.
1146   identify_useful_nodes(useful);
1147   return useful.size();
1148 }
1149 
1150 void Compile::print_missing_nodes() {
1151 
1152   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1153   if ((_log == NULL) && (! PrintIdealNodeCount)) {
1154     return;
1155   }
1156 
1157   // This is an expensive function. It is executed only when the user
1158   // specifies VerifyIdealNodeCount option or otherwise knows the
1159   // additional work that needs to be done to identify reachable nodes
1160   // by walking the flow graph and find the missing ones using
1161   // _dead_node_list.
1162 
1163   Unique_Node_List useful(comp_arena());
1164   // Get useful node list by walking the graph.
1165   identify_useful_nodes(useful);
1166 
1167   uint l_nodes = C->live_nodes();
1168   uint l_nodes_by_walk = useful.size();
1169 
1170   if (l_nodes != l_nodes_by_walk) {
1171     if (_log != NULL) {
1172       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1173       _log->stamp();
1174       _log->end_head();
1175     }
1176     VectorSet& useful_member_set = useful.member_set();
1177     int last_idx = l_nodes_by_walk;
1178     for (int i = 0; i < last_idx; i++) {
1179       if (useful_member_set.test(i)) {
1180         if (_dead_node_list.test(i)) {
1181           if (_log != NULL) {
1182             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1183           }
1184           if (PrintIdealNodeCount) {
1185             // Print the log message to tty
1186               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1187               useful.at(i)->dump();
1188           }
1189         }
1190       }
1191       else if (! _dead_node_list.test(i)) {
1192         if (_log != NULL) {
1193           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1194         }
1195         if (PrintIdealNodeCount) {
1196           // Print the log message to tty
1197           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1198         }
1199       }
1200     }
1201     if (_log != NULL) {
1202       _log->tail("mismatched_nodes");
1203     }
1204   }
1205 }
1206 #endif
1207 
1208 #ifndef PRODUCT
1209 void Compile::verify_top(Node* tn) const {
1210   if (tn != NULL) {
1211     assert(tn->is_Con(), "top node must be a constant");
1212     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1213     assert(tn->in(0) != NULL, "must have live top node");
1214   }
1215 }
1216 #endif
1217 
1218 
1219 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1220 
1221 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1222   guarantee(arr != NULL, "");
1223   int num_blocks = arr->length();
1224   if (grow_by < num_blocks)  grow_by = num_blocks;
1225   int num_notes = grow_by * _node_notes_block_size;
1226   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1227   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1228   while (num_notes > 0) {
1229     arr->append(notes);
1230     notes     += _node_notes_block_size;
1231     num_notes -= _node_notes_block_size;
1232   }
1233   assert(num_notes == 0, "exact multiple, please");
1234 }
1235 
1236 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1237   if (source == NULL || dest == NULL)  return false;
1238 
1239   if (dest->is_Con())
1240     return false;               // Do not push debug info onto constants.
1241 
1242 #ifdef ASSERT
1243   // Leave a bread crumb trail pointing to the original node:
1244   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1245     dest->set_debug_orig(source);
1246   }
1247 #endif
1248 
1249   if (node_note_array() == NULL)
1250     return false;               // Not collecting any notes now.
1251 
1252   // This is a copy onto a pre-existing node, which may already have notes.
1253   // If both nodes have notes, do not overwrite any pre-existing notes.
1254   Node_Notes* source_notes = node_notes_at(source->_idx);
1255   if (source_notes == NULL || source_notes->is_clear())  return false;
1256   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1257   if (dest_notes == NULL || dest_notes->is_clear()) {
1258     return set_node_notes_at(dest->_idx, source_notes);
1259   }
1260 
1261   Node_Notes merged_notes = (*source_notes);
1262   // The order of operations here ensures that dest notes will win...
1263   merged_notes.update_from(dest_notes);
1264   return set_node_notes_at(dest->_idx, &merged_notes);
1265 }
1266 
1267 
1268 //--------------------------allow_range_check_smearing-------------------------
1269 // Gating condition for coalescing similar range checks.
1270 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1271 // single covering check that is at least as strong as any of them.
1272 // If the optimization succeeds, the simplified (strengthened) range check
1273 // will always succeed.  If it fails, we will deopt, and then give up
1274 // on the optimization.
1275 bool Compile::allow_range_check_smearing() const {
1276   // If this method has already thrown a range-check,
1277   // assume it was because we already tried range smearing
1278   // and it failed.
1279   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1280   return !already_trapped;
1281 }
1282 
1283 
1284 //------------------------------flatten_alias_type-----------------------------
1285 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1286   int offset = tj->offset();
1287   TypePtr::PTR ptr = tj->ptr();
1288 
1289   // Known instance (scalarizable allocation) alias only with itself.
1290   bool is_known_inst = tj->isa_oopptr() != NULL &&
1291                        tj->is_oopptr()->is_known_instance();
1292 
1293   // Process weird unsafe references.
1294   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1295     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1296     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1297     tj = TypeOopPtr::BOTTOM;
1298     ptr = tj->ptr();
1299     offset = tj->offset();
1300   }
1301 
1302   // Array pointers need some flattening
1303   const TypeAryPtr *ta = tj->isa_aryptr();
1304   if (ta && ta->is_stable()) {
1305     // Erase stability property for alias analysis.
1306     tj = ta = ta->cast_to_stable(false);
1307   }
1308   if( ta && is_known_inst ) {
1309     if ( offset != Type::OffsetBot &&
1310          offset > arrayOopDesc::length_offset_in_bytes() ) {
1311       offset = Type::OffsetBot; // Flatten constant access into array body only
1312       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1313     }
1314   } else if( ta && _AliasLevel >= 2 ) {
1315     // For arrays indexed by constant indices, we flatten the alias
1316     // space to include all of the array body.  Only the header, klass
1317     // and array length can be accessed un-aliased.
1318     if( offset != Type::OffsetBot ) {
1319       if( ta->const_oop() ) { // MethodData* or Method*
1320         offset = Type::OffsetBot;   // Flatten constant access into array body
1321         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1322       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1323         // range is OK as-is.
1324         tj = ta = TypeAryPtr::RANGE;
1325       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1326         tj = TypeInstPtr::KLASS; // all klass loads look alike
1327         ta = TypeAryPtr::RANGE; // generic ignored junk
1328         ptr = TypePtr::BotPTR;
1329       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1330         tj = TypeInstPtr::MARK;
1331         ta = TypeAryPtr::RANGE; // generic ignored junk
1332         ptr = TypePtr::BotPTR;
1333       } else {                  // Random constant offset into array body
1334         offset = Type::OffsetBot;   // Flatten constant access into array body
1335         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1336       }
1337     }
1338     // Arrays of fixed size alias with arrays of unknown size.
1339     if (ta->size() != TypeInt::POS) {
1340       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1341       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1342     }
1343     // Arrays of known objects become arrays of unknown objects.
1344     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1345       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1346       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1347     }
1348     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1349       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1350       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1351     }
1352     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1353     // cannot be distinguished by bytecode alone.
1354     if (ta->elem() == TypeInt::BOOL) {
1355       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1356       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1357       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1358     }
1359     // During the 2nd round of IterGVN, NotNull castings are removed.
1360     // Make sure the Bottom and NotNull variants alias the same.
1361     // Also, make sure exact and non-exact variants alias the same.
1362     if( ptr == TypePtr::NotNull || ta->klass_is_exact() ) {
1363       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1364     }
1365   }
1366 
1367   // Oop pointers need some flattening
1368   const TypeInstPtr *to = tj->isa_instptr();
1369   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1370     ciInstanceKlass *k = to->klass()->as_instance_klass();
1371     if( ptr == TypePtr::Constant ) {
1372       if (to->klass() != ciEnv::current()->Class_klass() ||
1373           offset < k->size_helper() * wordSize) {
1374         // No constant oop pointers (such as Strings); they alias with
1375         // unknown strings.
1376         assert(!is_known_inst, "not scalarizable allocation");
1377         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1378       }
1379     } else if( is_known_inst ) {
1380       tj = to; // Keep NotNull and klass_is_exact for instance type
1381     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1382       // During the 2nd round of IterGVN, NotNull castings are removed.
1383       // Make sure the Bottom and NotNull variants alias the same.
1384       // Also, make sure exact and non-exact variants alias the same.
1385       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1386     }
1387     // Canonicalize the holder of this field
1388     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1389       // First handle header references such as a LoadKlassNode, even if the
1390       // object's klass is unloaded at compile time (4965979).
1391       if (!is_known_inst) { // Do it only for non-instance types
1392         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1393       }
1394     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1395       // Static fields are in the space above the normal instance
1396       // fields in the java.lang.Class instance.
1397       if (to->klass() != ciEnv::current()->Class_klass()) {
1398         to = NULL;
1399         tj = TypeOopPtr::BOTTOM;
1400         offset = tj->offset();
1401       }
1402     } else {
1403       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1404       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1405         if( is_known_inst ) {
1406           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1407         } else {
1408           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1409         }
1410       }
1411     }
1412   }
1413 
1414   // Klass pointers to object array klasses need some flattening
1415   const TypeKlassPtr *tk = tj->isa_klassptr();
1416   if( tk ) {
1417     // If we are referencing a field within a Klass, we need
1418     // to assume the worst case of an Object.  Both exact and
1419     // inexact types must flatten to the same alias class so
1420     // use NotNull as the PTR.
1421     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1422 
1423       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1424                                    TypeKlassPtr::OBJECT->klass(),
1425                                    offset);
1426     }
1427 
1428     ciKlass* klass = tk->klass();
1429     if( klass->is_obj_array_klass() ) {
1430       ciKlass* k = TypeAryPtr::OOPS->klass();
1431       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1432         k = TypeInstPtr::BOTTOM->klass();
1433       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1434     }
1435 
1436     // Check for precise loads from the primary supertype array and force them
1437     // to the supertype cache alias index.  Check for generic array loads from
1438     // the primary supertype array and also force them to the supertype cache
1439     // alias index.  Since the same load can reach both, we need to merge
1440     // these 2 disparate memories into the same alias class.  Since the
1441     // primary supertype array is read-only, there's no chance of confusion
1442     // where we bypass an array load and an array store.
1443     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1444     if (offset == Type::OffsetBot ||
1445         (offset >= primary_supers_offset &&
1446          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1447         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1448       offset = in_bytes(Klass::secondary_super_cache_offset());
1449       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1450     }
1451   }
1452 
1453   // Flatten all Raw pointers together.
1454   if (tj->base() == Type::RawPtr)
1455     tj = TypeRawPtr::BOTTOM;
1456 
1457   if (tj->base() == Type::AnyPtr)
1458     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1459 
1460   // Flatten all to bottom for now
1461   switch( _AliasLevel ) {
1462   case 0:
1463     tj = TypePtr::BOTTOM;
1464     break;
1465   case 1:                       // Flatten to: oop, static, field or array
1466     switch (tj->base()) {
1467     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1468     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1469     case Type::AryPtr:   // do not distinguish arrays at all
1470     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1471     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1472     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1473     default: ShouldNotReachHere();
1474     }
1475     break;
1476   case 2:                       // No collapsing at level 2; keep all splits
1477   case 3:                       // No collapsing at level 3; keep all splits
1478     break;
1479   default:
1480     Unimplemented();
1481   }
1482 
1483   offset = tj->offset();
1484   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1485 
1486   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1487           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1488           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1489           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1490           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1491           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1492           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
1493           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1494   assert( tj->ptr() != TypePtr::TopPTR &&
1495           tj->ptr() != TypePtr::AnyNull &&
1496           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1497 //    assert( tj->ptr() != TypePtr::Constant ||
1498 //            tj->base() == Type::RawPtr ||
1499 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1500 
1501   return tj;
1502 }
1503 
1504 void Compile::AliasType::Init(int i, const TypePtr* at) {
1505   _index = i;
1506   _adr_type = at;
1507   _field = NULL;
1508   _element = NULL;
1509   _is_rewritable = true; // default
1510   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1511   if (atoop != NULL && atoop->is_known_instance()) {
1512     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1513     _general_index = Compile::current()->get_alias_index(gt);
1514   } else {
1515     _general_index = 0;
1516   }
1517 }
1518 
1519 //---------------------------------print_on------------------------------------
1520 #ifndef PRODUCT
1521 void Compile::AliasType::print_on(outputStream* st) {
1522   if (index() < 10)
1523         st->print("@ <%d> ", index());
1524   else  st->print("@ <%d>",  index());
1525   st->print(is_rewritable() ? "   " : " RO");
1526   int offset = adr_type()->offset();
1527   if (offset == Type::OffsetBot)
1528         st->print(" +any");
1529   else  st->print(" +%-3d", offset);
1530   st->print(" in ");
1531   adr_type()->dump_on(st);
1532   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1533   if (field() != NULL && tjp) {
1534     if (tjp->klass()  != field()->holder() ||
1535         tjp->offset() != field()->offset_in_bytes()) {
1536       st->print(" != ");
1537       field()->print();
1538       st->print(" ***");
1539     }
1540   }
1541 }
1542 
1543 void print_alias_types() {
1544   Compile* C = Compile::current();
1545   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1546   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1547     C->alias_type(idx)->print_on(tty);
1548     tty->cr();
1549   }
1550 }
1551 #endif
1552 
1553 
1554 //----------------------------probe_alias_cache--------------------------------
1555 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1556   intptr_t key = (intptr_t) adr_type;
1557   key ^= key >> logAliasCacheSize;
1558   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1559 }
1560 
1561 
1562 //-----------------------------grow_alias_types--------------------------------
1563 void Compile::grow_alias_types() {
1564   const int old_ats  = _max_alias_types; // how many before?
1565   const int new_ats  = old_ats;          // how many more?
1566   const int grow_ats = old_ats+new_ats;  // how many now?
1567   _max_alias_types = grow_ats;
1568   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1569   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1570   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1571   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1572 }
1573 
1574 
1575 //--------------------------------find_alias_type------------------------------
1576 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1577   if (_AliasLevel == 0)
1578     return alias_type(AliasIdxBot);
1579 
1580   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1581   if (ace->_adr_type == adr_type) {
1582     return alias_type(ace->_index);
1583   }
1584 
1585   // Handle special cases.
1586   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1587   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1588 
1589   // Do it the slow way.
1590   const TypePtr* flat = flatten_alias_type(adr_type);
1591 
1592 #ifdef ASSERT
1593   assert(flat == flatten_alias_type(flat), "idempotent");
1594   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
1595   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1596     const TypeOopPtr* foop = flat->is_oopptr();
1597     // Scalarizable allocations have exact klass always.
1598     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1599     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1600     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
1601   }
1602   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
1603 #endif
1604 
1605   int idx = AliasIdxTop;
1606   for (int i = 0; i < num_alias_types(); i++) {
1607     if (alias_type(i)->adr_type() == flat) {
1608       idx = i;
1609       break;
1610     }
1611   }
1612 
1613   if (idx == AliasIdxTop) {
1614     if (no_create)  return NULL;
1615     // Grow the array if necessary.
1616     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1617     // Add a new alias type.
1618     idx = _num_alias_types++;
1619     _alias_types[idx]->Init(idx, flat);
1620     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1621     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1622     if (flat->isa_instptr()) {
1623       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1624           && flat->is_instptr()->klass() == env()->Class_klass())
1625         alias_type(idx)->set_rewritable(false);
1626     }
1627     if (flat->isa_aryptr()) {
1628 #ifdef ASSERT
1629       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1630       // (T_BYTE has the weakest alignment and size restrictions...)
1631       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1632 #endif
1633       if (flat->offset() == TypePtr::OffsetBot) {
1634         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1635       }
1636     }
1637     if (flat->isa_klassptr()) {
1638       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1639         alias_type(idx)->set_rewritable(false);
1640       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1641         alias_type(idx)->set_rewritable(false);
1642       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1643         alias_type(idx)->set_rewritable(false);
1644       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1645         alias_type(idx)->set_rewritable(false);
1646     }
1647     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1648     // but the base pointer type is not distinctive enough to identify
1649     // references into JavaThread.)
1650 
1651     // Check for final fields.
1652     const TypeInstPtr* tinst = flat->isa_instptr();
1653     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1654       ciField* field;
1655       if (tinst->const_oop() != NULL &&
1656           tinst->klass() == ciEnv::current()->Class_klass() &&
1657           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1658         // static field
1659         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1660         field = k->get_field_by_offset(tinst->offset(), true);
1661       } else {
1662         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1663         field = k->get_field_by_offset(tinst->offset(), false);
1664       }
1665       assert(field == NULL ||
1666              original_field == NULL ||
1667              (field->holder() == original_field->holder() &&
1668               field->offset() == original_field->offset() &&
1669               field->is_static() == original_field->is_static()), "wrong field?");
1670       // Set field() and is_rewritable() attributes.
1671       if (field != NULL)  alias_type(idx)->set_field(field);
1672     }
1673   }
1674 
1675   // Fill the cache for next time.
1676   ace->_adr_type = adr_type;
1677   ace->_index    = idx;
1678   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1679 
1680   // Might as well try to fill the cache for the flattened version, too.
1681   AliasCacheEntry* face = probe_alias_cache(flat);
1682   if (face->_adr_type == NULL) {
1683     face->_adr_type = flat;
1684     face->_index    = idx;
1685     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1686   }
1687 
1688   return alias_type(idx);
1689 }
1690 
1691 
1692 Compile::AliasType* Compile::alias_type(ciField* field) {
1693   const TypeOopPtr* t;
1694   if (field->is_static())
1695     t = TypeInstPtr::make(field->holder()->java_mirror());
1696   else
1697     t = TypeOopPtr::make_from_klass_raw(field->holder());
1698   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1699   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1700   return atp;
1701 }
1702 
1703 
1704 //------------------------------have_alias_type--------------------------------
1705 bool Compile::have_alias_type(const TypePtr* adr_type) {
1706   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1707   if (ace->_adr_type == adr_type) {
1708     return true;
1709   }
1710 
1711   // Handle special cases.
1712   if (adr_type == NULL)             return true;
1713   if (adr_type == TypePtr::BOTTOM)  return true;
1714 
1715   return find_alias_type(adr_type, true, NULL) != NULL;
1716 }
1717 
1718 //-----------------------------must_alias--------------------------------------
1719 // True if all values of the given address type are in the given alias category.
1720 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1721   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1722   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1723   if (alias_idx == AliasIdxTop)         return false; // the empty category
1724   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1725 
1726   // the only remaining possible overlap is identity
1727   int adr_idx = get_alias_index(adr_type);
1728   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1729   assert(adr_idx == alias_idx ||
1730          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1731           && adr_type                       != TypeOopPtr::BOTTOM),
1732          "should not be testing for overlap with an unsafe pointer");
1733   return adr_idx == alias_idx;
1734 }
1735 
1736 //------------------------------can_alias--------------------------------------
1737 // True if any values of the given address type are in the given alias category.
1738 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1739   if (alias_idx == AliasIdxTop)         return false; // the empty category
1740   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1741   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1742   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1743 
1744   // the only remaining possible overlap is identity
1745   int adr_idx = get_alias_index(adr_type);
1746   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1747   return adr_idx == alias_idx;
1748 }
1749 
1750 
1751 
1752 //---------------------------pop_warm_call-------------------------------------
1753 WarmCallInfo* Compile::pop_warm_call() {
1754   WarmCallInfo* wci = _warm_calls;
1755   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1756   return wci;
1757 }
1758 
1759 //----------------------------Inline_Warm--------------------------------------
1760 int Compile::Inline_Warm() {
1761   // If there is room, try to inline some more warm call sites.
1762   // %%% Do a graph index compaction pass when we think we're out of space?
1763   if (!InlineWarmCalls)  return 0;
1764 
1765   int calls_made_hot = 0;
1766   int room_to_grow   = NodeCountInliningCutoff - unique();
1767   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1768   int amount_grown   = 0;
1769   WarmCallInfo* call;
1770   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1771     int est_size = (int)call->size();
1772     if (est_size > (room_to_grow - amount_grown)) {
1773       // This one won't fit anyway.  Get rid of it.
1774       call->make_cold();
1775       continue;
1776     }
1777     call->make_hot();
1778     calls_made_hot++;
1779     amount_grown   += est_size;
1780     amount_to_grow -= est_size;
1781   }
1782 
1783   if (calls_made_hot > 0)  set_major_progress();
1784   return calls_made_hot;
1785 }
1786 
1787 
1788 //----------------------------Finish_Warm--------------------------------------
1789 void Compile::Finish_Warm() {
1790   if (!InlineWarmCalls)  return;
1791   if (failing())  return;
1792   if (warm_calls() == NULL)  return;
1793 
1794   // Clean up loose ends, if we are out of space for inlining.
1795   WarmCallInfo* call;
1796   while ((call = pop_warm_call()) != NULL) {
1797     call->make_cold();
1798   }
1799 }
1800 
1801 //---------------------cleanup_loop_predicates-----------------------
1802 // Remove the opaque nodes that protect the predicates so that all unused
1803 // checks and uncommon_traps will be eliminated from the ideal graph
1804 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1805   if (predicate_count()==0) return;
1806   for (int i = predicate_count(); i > 0; i--) {
1807     Node * n = predicate_opaque1_node(i-1);
1808     assert(n->Opcode() == Op_Opaque1, "must be");
1809     igvn.replace_node(n, n->in(1));
1810   }
1811   assert(predicate_count()==0, "should be clean!");
1812 }
1813 
1814 // StringOpts and late inlining of string methods
1815 void Compile::inline_string_calls(bool parse_time) {
1816   {
1817     // remove useless nodes to make the usage analysis simpler
1818     ResourceMark rm;
1819     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1820   }
1821 
1822   {
1823     ResourceMark rm;
1824     print_method(PHASE_BEFORE_STRINGOPTS, 3);
1825     PhaseStringOpts pso(initial_gvn(), for_igvn());
1826     print_method(PHASE_AFTER_STRINGOPTS, 3);
1827   }
1828 
1829   // now inline anything that we skipped the first time around
1830   if (!parse_time) {
1831     _late_inlines_pos = _late_inlines.length();
1832   }
1833 
1834   while (_string_late_inlines.length() > 0) {
1835     CallGenerator* cg = _string_late_inlines.pop();
1836     cg->do_late_inline();
1837     if (failing())  return;
1838   }
1839   _string_late_inlines.trunc_to(0);
1840 }
1841 
1842 // Late inlining of boxing methods
1843 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
1844   if (_boxing_late_inlines.length() > 0) {
1845     assert(has_boxed_value(), "inconsistent");
1846 
1847     PhaseGVN* gvn = initial_gvn();
1848     set_inlining_incrementally(true);
1849 
1850     assert( igvn._worklist.size() == 0, "should be done with igvn" );
1851     for_igvn()->clear();
1852     gvn->replace_with(&igvn);
1853 
1854     while (_boxing_late_inlines.length() > 0) {
1855       CallGenerator* cg = _boxing_late_inlines.pop();
1856       cg->do_late_inline();
1857       if (failing())  return;
1858     }
1859     _boxing_late_inlines.trunc_to(0);
1860 
1861     {
1862       ResourceMark rm;
1863       PhaseRemoveUseless pru(gvn, for_igvn());
1864     }
1865 
1866     igvn = PhaseIterGVN(gvn);
1867     igvn.optimize();
1868 
1869     set_inlining_progress(false);
1870     set_inlining_incrementally(false);
1871   }
1872 }
1873 
1874 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
1875   assert(IncrementalInline, "incremental inlining should be on");
1876   PhaseGVN* gvn = initial_gvn();
1877 
1878   set_inlining_progress(false);
1879   for_igvn()->clear();
1880   gvn->replace_with(&igvn);
1881 
1882   int i = 0;
1883 
1884   for (; i <_late_inlines.length() && !inlining_progress(); i++) {
1885     CallGenerator* cg = _late_inlines.at(i);
1886     _late_inlines_pos = i+1;
1887     cg->do_late_inline();
1888     if (failing())  return;
1889   }
1890   int j = 0;
1891   for (; i < _late_inlines.length(); i++, j++) {
1892     _late_inlines.at_put(j, _late_inlines.at(i));
1893   }
1894   _late_inlines.trunc_to(j);
1895 
1896   {
1897     ResourceMark rm;
1898     PhaseRemoveUseless pru(gvn, for_igvn());
1899   }
1900 
1901   igvn = PhaseIterGVN(gvn);
1902 }
1903 
1904 // Perform incremental inlining until bound on number of live nodes is reached
1905 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
1906   PhaseGVN* gvn = initial_gvn();
1907 
1908   set_inlining_incrementally(true);
1909   set_inlining_progress(true);
1910   uint low_live_nodes = 0;
1911 
1912   while(inlining_progress() && _late_inlines.length() > 0) {
1913 
1914     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
1915       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
1916         // PhaseIdealLoop is expensive so we only try it once we are
1917         // out of loop and we only try it again if the previous helped
1918         // got the number of nodes down significantly
1919         PhaseIdealLoop ideal_loop( igvn, false, true );
1920         if (failing())  return;
1921         low_live_nodes = live_nodes();
1922         _major_progress = true;
1923       }
1924 
1925       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
1926         break;
1927       }
1928     }
1929 
1930     inline_incrementally_one(igvn);
1931 
1932     if (failing())  return;
1933 
1934     igvn.optimize();
1935 
1936     if (failing())  return;
1937   }
1938 
1939   assert( igvn._worklist.size() == 0, "should be done with igvn" );
1940 
1941   if (_string_late_inlines.length() > 0) {
1942     assert(has_stringbuilder(), "inconsistent");
1943     for_igvn()->clear();
1944     initial_gvn()->replace_with(&igvn);
1945 
1946     inline_string_calls(false);
1947 
1948     if (failing())  return;
1949 
1950     {
1951       ResourceMark rm;
1952       PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1953     }
1954 
1955     igvn = PhaseIterGVN(gvn);
1956 
1957     igvn.optimize();
1958   }
1959 
1960   set_inlining_incrementally(false);
1961 }
1962 
1963 
1964 //------------------------------Optimize---------------------------------------
1965 // Given a graph, optimize it.
1966 void Compile::Optimize() {
1967   TracePhase t1("optimizer", &_t_optimizer, true);
1968 
1969 #ifndef PRODUCT
1970   if (env()->break_at_compile()) {
1971     BREAKPOINT;
1972   }
1973 
1974 #endif
1975 
1976   ResourceMark rm;
1977   int          loop_opts_cnt;
1978 
1979   NOT_PRODUCT( verify_graph_edges(); )
1980 
1981   print_method(PHASE_AFTER_PARSING);
1982 
1983  {
1984   // Iterative Global Value Numbering, including ideal transforms
1985   // Initialize IterGVN with types and values from parse-time GVN
1986   PhaseIterGVN igvn(initial_gvn());
1987   {
1988     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
1989     igvn.optimize();
1990   }
1991 
1992   print_method(PHASE_ITER_GVN1, 2);
1993 
1994   if (failing())  return;
1995 
1996   {
1997     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
1998     inline_incrementally(igvn);
1999   }
2000 
2001   print_method(PHASE_INCREMENTAL_INLINE, 2);
2002 
2003   if (failing())  return;
2004 
2005   if (eliminate_boxing()) {
2006     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
2007     // Inline valueOf() methods now.
2008     inline_boxing_calls(igvn);
2009 
2010     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2011 
2012     if (failing())  return;
2013   }
2014 
2015   // No more new expensive nodes will be added to the list from here
2016   // so keep only the actual candidates for optimizations.
2017   cleanup_expensive_nodes(igvn);
2018 
2019   // Perform escape analysis
2020   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2021     if (has_loops()) {
2022       // Cleanup graph (remove dead nodes).
2023       TracePhase t2("idealLoop", &_t_idealLoop, true);
2024       PhaseIdealLoop ideal_loop( igvn, false, true );
2025       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2026       if (failing())  return;
2027     }
2028     ConnectionGraph::do_analysis(this, &igvn);
2029 
2030     if (failing())  return;
2031 
2032     // Optimize out fields loads from scalar replaceable allocations.
2033     igvn.optimize();
2034     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2035 
2036     if (failing())  return;
2037 
2038     if (congraph() != NULL && macro_count() > 0) {
2039       NOT_PRODUCT( TracePhase t2("macroEliminate", &_t_macroEliminate, TimeCompiler); )
2040       PhaseMacroExpand mexp(igvn);
2041       mexp.eliminate_macro_nodes();
2042       igvn.set_delay_transform(false);
2043 
2044       igvn.optimize();
2045       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2046 
2047       if (failing())  return;
2048     }
2049   }
2050 
2051   // Loop transforms on the ideal graph.  Range Check Elimination,
2052   // peeling, unrolling, etc.
2053 
2054   // Set loop opts counter
2055   loop_opts_cnt = num_loop_opts();
2056   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2057     {
2058       TracePhase t2("idealLoop", &_t_idealLoop, true);
2059       PhaseIdealLoop ideal_loop( igvn, true );
2060       loop_opts_cnt--;
2061       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2062       if (failing())  return;
2063     }
2064     // Loop opts pass if partial peeling occurred in previous pass
2065     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
2066       TracePhase t3("idealLoop", &_t_idealLoop, true);
2067       PhaseIdealLoop ideal_loop( igvn, false );
2068       loop_opts_cnt--;
2069       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2070       if (failing())  return;
2071     }
2072     // Loop opts pass for loop-unrolling before CCP
2073     if(major_progress() && (loop_opts_cnt > 0)) {
2074       TracePhase t4("idealLoop", &_t_idealLoop, true);
2075       PhaseIdealLoop ideal_loop( igvn, false );
2076       loop_opts_cnt--;
2077       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2078     }
2079     if (!failing()) {
2080       // Verify that last round of loop opts produced a valid graph
2081       NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
2082       PhaseIdealLoop::verify(igvn);
2083     }
2084   }
2085   if (failing())  return;
2086 
2087   // Conditional Constant Propagation;
2088   PhaseCCP ccp( &igvn );
2089   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2090   {
2091     TracePhase t2("ccp", &_t_ccp, true);
2092     ccp.do_transform();
2093   }
2094   print_method(PHASE_CPP1, 2);
2095 
2096   assert( true, "Break here to ccp.dump_old2new_map()");
2097 
2098   // Iterative Global Value Numbering, including ideal transforms
2099   {
2100     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
2101     igvn = ccp;
2102     igvn.optimize();
2103   }
2104 
2105   print_method(PHASE_ITER_GVN2, 2);
2106 
2107   if (failing())  return;
2108 
2109   // Loop transforms on the ideal graph.  Range Check Elimination,
2110   // peeling, unrolling, etc.
2111   if(loop_opts_cnt > 0) {
2112     debug_only( int cnt = 0; );
2113     while(major_progress() && (loop_opts_cnt > 0)) {
2114       TracePhase t2("idealLoop", &_t_idealLoop, true);
2115       assert( cnt++ < 40, "infinite cycle in loop optimization" );
2116       PhaseIdealLoop ideal_loop( igvn, true);
2117       loop_opts_cnt--;
2118       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2119       if (failing())  return;
2120     }
2121   }
2122 
2123   {
2124     // Verify that all previous optimizations produced a valid graph
2125     // at least to this point, even if no loop optimizations were done.
2126     NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
2127     PhaseIdealLoop::verify(igvn);
2128   }
2129 
2130   {
2131     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
2132     PhaseMacroExpand  mex(igvn);
2133     if (mex.expand_macro_nodes()) {
2134       assert(failing(), "must bail out w/ explicit message");
2135       return;
2136     }
2137   }
2138 
2139  } // (End scope of igvn; run destructor if necessary for asserts.)
2140 
2141   dump_inlining();
2142   // A method with only infinite loops has no edges entering loops from root
2143   {
2144     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
2145     if (final_graph_reshaping()) {
2146       assert(failing(), "must bail out w/ explicit message");
2147       return;
2148     }
2149   }
2150 
2151   print_method(PHASE_OPTIMIZE_FINISHED, 2);
2152 }
2153 
2154 
2155 //------------------------------Code_Gen---------------------------------------
2156 // Given a graph, generate code for it
2157 void Compile::Code_Gen() {
2158   if (failing()) {
2159     return;
2160   }
2161 
2162   // Perform instruction selection.  You might think we could reclaim Matcher
2163   // memory PDQ, but actually the Matcher is used in generating spill code.
2164   // Internals of the Matcher (including some VectorSets) must remain live
2165   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2166   // set a bit in reclaimed memory.
2167 
2168   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2169   // nodes.  Mapping is only valid at the root of each matched subtree.
2170   NOT_PRODUCT( verify_graph_edges(); )
2171 
2172   Matcher matcher;
2173   _matcher = &matcher;
2174   {
2175     TracePhase t2("matcher", &_t_matcher, true);
2176     matcher.match();
2177   }
2178   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2179   // nodes.  Mapping is only valid at the root of each matched subtree.
2180   NOT_PRODUCT( verify_graph_edges(); )
2181 
2182   // If you have too many nodes, or if matching has failed, bail out
2183   check_node_count(0, "out of nodes matching instructions");
2184   if (failing()) {
2185     return;
2186   }
2187 
2188   // Build a proper-looking CFG
2189   PhaseCFG cfg(node_arena(), root(), matcher);
2190   _cfg = &cfg;
2191   {
2192     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
2193     bool success = cfg.do_global_code_motion();
2194     if (!success) {
2195       return;
2196     }
2197 
2198     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2199     NOT_PRODUCT( verify_graph_edges(); )
2200     debug_only( cfg.verify(); )
2201   }
2202 
2203   PhaseChaitin regalloc(unique(), cfg, matcher);
2204   _regalloc = &regalloc;
2205   {
2206     TracePhase t2("regalloc", &_t_registerAllocation, true);
2207     // Perform register allocation.  After Chaitin, use-def chains are
2208     // no longer accurate (at spill code) and so must be ignored.
2209     // Node->LRG->reg mappings are still accurate.
2210     _regalloc->Register_Allocate();
2211 
2212     // Bail out if the allocator builds too many nodes
2213     if (failing()) {
2214       return;
2215     }
2216   }
2217 
2218   // Prior to register allocation we kept empty basic blocks in case the
2219   // the allocator needed a place to spill.  After register allocation we
2220   // are not adding any new instructions.  If any basic block is empty, we
2221   // can now safely remove it.
2222   {
2223     NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
2224     cfg.remove_empty_blocks();
2225     if (do_freq_based_layout()) {
2226       PhaseBlockLayout layout(cfg);
2227     } else {
2228       cfg.set_loop_alignment();
2229     }
2230     cfg.fixup_flow();
2231   }
2232 
2233   // Apply peephole optimizations
2234   if( OptoPeephole ) {
2235     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
2236     PhasePeephole peep( _regalloc, cfg);
2237     peep.do_transform();
2238   }
2239 
2240   // Convert Nodes to instruction bits in a buffer
2241   {
2242     // %%%% workspace merge brought two timers together for one job
2243     TracePhase t2a("output", &_t_output, true);
2244     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
2245     Output();
2246   }
2247 
2248   print_method(PHASE_FINAL_CODE);
2249 
2250   // He's dead, Jim.
2251   _cfg     = (PhaseCFG*)0xdeadbeef;
2252   _regalloc = (PhaseChaitin*)0xdeadbeef;
2253 }
2254 
2255 
2256 //------------------------------dump_asm---------------------------------------
2257 // Dump formatted assembly
2258 #ifndef PRODUCT
2259 void Compile::dump_asm(int *pcs, uint pc_limit) {
2260   bool cut_short = false;
2261   tty->print_cr("#");
2262   tty->print("#  ");  _tf->dump();  tty->cr();
2263   tty->print_cr("#");
2264 
2265   // For all blocks
2266   int pc = 0x0;                 // Program counter
2267   char starts_bundle = ' ';
2268   _regalloc->dump_frame();
2269 
2270   Node *n = NULL;
2271   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2272     if (VMThread::should_terminate()) {
2273       cut_short = true;
2274       break;
2275     }
2276     Block* block = _cfg->get_block(i);
2277     if (block->is_connector() && !Verbose) {
2278       continue;
2279     }
2280     n = block->head();
2281     if (pcs && n->_idx < pc_limit) {
2282       tty->print("%3.3x   ", pcs[n->_idx]);
2283     } else {
2284       tty->print("      ");
2285     }
2286     block->dump_head(_cfg);
2287     if (block->is_connector()) {
2288       tty->print_cr("        # Empty connector block");
2289     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2290       tty->print_cr("        # Block is sole successor of call");
2291     }
2292 
2293     // For all instructions
2294     Node *delay = NULL;
2295     for (uint j = 0; j < block->number_of_nodes(); j++) {
2296       if (VMThread::should_terminate()) {
2297         cut_short = true;
2298         break;
2299       }
2300       n = block->get_node(j);
2301       if (valid_bundle_info(n)) {
2302         Bundle* bundle = node_bundling(n);
2303         if (bundle->used_in_unconditional_delay()) {
2304           delay = n;
2305           continue;
2306         }
2307         if (bundle->starts_bundle()) {
2308           starts_bundle = '+';
2309         }
2310       }
2311 
2312       if (WizardMode) {
2313         n->dump();
2314       }
2315 
2316       if( !n->is_Region() &&    // Dont print in the Assembly
2317           !n->is_Phi() &&       // a few noisely useless nodes
2318           !n->is_Proj() &&
2319           !n->is_MachTemp() &&
2320           !n->is_SafePointScalarObject() &&
2321           !n->is_Catch() &&     // Would be nice to print exception table targets
2322           !n->is_MergeMem() &&  // Not very interesting
2323           !n->is_top() &&       // Debug info table constants
2324           !(n->is_Con() && !n->is_Mach())// Debug info table constants
2325           ) {
2326         if (pcs && n->_idx < pc_limit)
2327           tty->print("%3.3x", pcs[n->_idx]);
2328         else
2329           tty->print("   ");
2330         tty->print(" %c ", starts_bundle);
2331         starts_bundle = ' ';
2332         tty->print("\t");
2333         n->format(_regalloc, tty);
2334         tty->cr();
2335       }
2336 
2337       // If we have an instruction with a delay slot, and have seen a delay,
2338       // then back up and print it
2339       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2340         assert(delay != NULL, "no unconditional delay instruction");
2341         if (WizardMode) delay->dump();
2342 
2343         if (node_bundling(delay)->starts_bundle())
2344           starts_bundle = '+';
2345         if (pcs && n->_idx < pc_limit)
2346           tty->print("%3.3x", pcs[n->_idx]);
2347         else
2348           tty->print("   ");
2349         tty->print(" %c ", starts_bundle);
2350         starts_bundle = ' ';
2351         tty->print("\t");
2352         delay->format(_regalloc, tty);
2353         tty->print_cr("");
2354         delay = NULL;
2355       }
2356 
2357       // Dump the exception table as well
2358       if( n->is_Catch() && (Verbose || WizardMode) ) {
2359         // Print the exception table for this offset
2360         _handler_table.print_subtable_for(pc);
2361       }
2362     }
2363 
2364     if (pcs && n->_idx < pc_limit)
2365       tty->print_cr("%3.3x", pcs[n->_idx]);
2366     else
2367       tty->print_cr("");
2368 
2369     assert(cut_short || delay == NULL, "no unconditional delay branch");
2370 
2371   } // End of per-block dump
2372   tty->print_cr("");
2373 
2374   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
2375 }
2376 #endif
2377 
2378 //------------------------------Final_Reshape_Counts---------------------------
2379 // This class defines counters to help identify when a method
2380 // may/must be executed using hardware with only 24-bit precision.
2381 struct Final_Reshape_Counts : public StackObj {
2382   int  _call_count;             // count non-inlined 'common' calls
2383   int  _float_count;            // count float ops requiring 24-bit precision
2384   int  _double_count;           // count double ops requiring more precision
2385   int  _java_call_count;        // count non-inlined 'java' calls
2386   int  _inner_loop_count;       // count loops which need alignment
2387   VectorSet _visited;           // Visitation flags
2388   Node_List _tests;             // Set of IfNodes & PCTableNodes
2389 
2390   Final_Reshape_Counts() :
2391     _call_count(0), _float_count(0), _double_count(0),
2392     _java_call_count(0), _inner_loop_count(0),
2393     _visited( Thread::current()->resource_area() ) { }
2394 
2395   void inc_call_count  () { _call_count  ++; }
2396   void inc_float_count () { _float_count ++; }
2397   void inc_double_count() { _double_count++; }
2398   void inc_java_call_count() { _java_call_count++; }
2399   void inc_inner_loop_count() { _inner_loop_count++; }
2400 
2401   int  get_call_count  () const { return _call_count  ; }
2402   int  get_float_count () const { return _float_count ; }
2403   int  get_double_count() const { return _double_count; }
2404   int  get_java_call_count() const { return _java_call_count; }
2405   int  get_inner_loop_count() const { return _inner_loop_count; }
2406 };
2407 
2408 #ifdef ASSERT
2409 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2410   ciInstanceKlass *k = tp->klass()->as_instance_klass();
2411   // Make sure the offset goes inside the instance layout.
2412   return k->contains_field_offset(tp->offset());
2413   // Note that OffsetBot and OffsetTop are very negative.
2414 }
2415 #endif
2416 
2417 // Eliminate trivially redundant StoreCMs and accumulate their
2418 // precedence edges.
2419 void Compile::eliminate_redundant_card_marks(Node* n) {
2420   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2421   if (n->in(MemNode::Address)->outcnt() > 1) {
2422     // There are multiple users of the same address so it might be
2423     // possible to eliminate some of the StoreCMs
2424     Node* mem = n->in(MemNode::Memory);
2425     Node* adr = n->in(MemNode::Address);
2426     Node* val = n->in(MemNode::ValueIn);
2427     Node* prev = n;
2428     bool done = false;
2429     // Walk the chain of StoreCMs eliminating ones that match.  As
2430     // long as it's a chain of single users then the optimization is
2431     // safe.  Eliminating partially redundant StoreCMs would require
2432     // cloning copies down the other paths.
2433     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2434       if (adr == mem->in(MemNode::Address) &&
2435           val == mem->in(MemNode::ValueIn)) {
2436         // redundant StoreCM
2437         if (mem->req() > MemNode::OopStore) {
2438           // Hasn't been processed by this code yet.
2439           n->add_prec(mem->in(MemNode::OopStore));
2440         } else {
2441           // Already converted to precedence edge
2442           for (uint i = mem->req(); i < mem->len(); i++) {
2443             // Accumulate any precedence edges
2444             if (mem->in(i) != NULL) {
2445               n->add_prec(mem->in(i));
2446             }
2447           }
2448           // Everything above this point has been processed.
2449           done = true;
2450         }
2451         // Eliminate the previous StoreCM
2452         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2453         assert(mem->outcnt() == 0, "should be dead");
2454         mem->disconnect_inputs(NULL, this);
2455       } else {
2456         prev = mem;
2457       }
2458       mem = prev->in(MemNode::Memory);
2459     }
2460   }
2461 }
2462 
2463 //------------------------------final_graph_reshaping_impl----------------------
2464 // Implement items 1-5 from final_graph_reshaping below.
2465 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2466 
2467   if ( n->outcnt() == 0 ) return; // dead node
2468   uint nop = n->Opcode();
2469 
2470   // Check for 2-input instruction with "last use" on right input.
2471   // Swap to left input.  Implements item (2).
2472   if( n->req() == 3 &&          // two-input instruction
2473       n->in(1)->outcnt() > 1 && // left use is NOT a last use
2474       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2475       n->in(2)->outcnt() == 1 &&// right use IS a last use
2476       !n->in(2)->is_Con() ) {   // right use is not a constant
2477     // Check for commutative opcode
2478     switch( nop ) {
2479     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
2480     case Op_MaxI:  case Op_MinI:
2481     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
2482     case Op_AndL:  case Op_XorL:  case Op_OrL:
2483     case Op_AndI:  case Op_XorI:  case Op_OrI: {
2484       // Move "last use" input to left by swapping inputs
2485       n->swap_edges(1, 2);
2486       break;
2487     }
2488     default:
2489       break;
2490     }
2491   }
2492 
2493 #ifdef ASSERT
2494   if( n->is_Mem() ) {
2495     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2496     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2497             // oop will be recorded in oop map if load crosses safepoint
2498             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2499                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
2500             "raw memory operations should have control edge");
2501   }
2502 #endif
2503   // Count FPU ops and common calls, implements item (3)
2504   switch( nop ) {
2505   // Count all float operations that may use FPU
2506   case Op_AddF:
2507   case Op_SubF:
2508   case Op_MulF:
2509   case Op_DivF:
2510   case Op_NegF:
2511   case Op_ModF:
2512   case Op_ConvI2F:
2513   case Op_ConF:
2514   case Op_CmpF:
2515   case Op_CmpF3:
2516   // case Op_ConvL2F: // longs are split into 32-bit halves
2517     frc.inc_float_count();
2518     break;
2519 
2520   case Op_ConvF2D:
2521   case Op_ConvD2F:
2522     frc.inc_float_count();
2523     frc.inc_double_count();
2524     break;
2525 
2526   // Count all double operations that may use FPU
2527   case Op_AddD:
2528   case Op_SubD:
2529   case Op_MulD:
2530   case Op_DivD:
2531   case Op_NegD:
2532   case Op_ModD:
2533   case Op_ConvI2D:
2534   case Op_ConvD2I:
2535   // case Op_ConvL2D: // handled by leaf call
2536   // case Op_ConvD2L: // handled by leaf call
2537   case Op_ConD:
2538   case Op_CmpD:
2539   case Op_CmpD3:
2540     frc.inc_double_count();
2541     break;
2542   case Op_Opaque1:              // Remove Opaque Nodes before matching
2543   case Op_Opaque2:              // Remove Opaque Nodes before matching
2544     n->subsume_by(n->in(1), this);
2545     break;
2546   case Op_CallStaticJava:
2547   case Op_CallJava:
2548   case Op_CallDynamicJava:
2549     frc.inc_java_call_count(); // Count java call site;
2550   case Op_CallRuntime:
2551   case Op_CallLeaf:
2552   case Op_CallLeafNoFP: {
2553     assert( n->is_Call(), "" );
2554     CallNode *call = n->as_Call();
2555     // Count call sites where the FP mode bit would have to be flipped.
2556     // Do not count uncommon runtime calls:
2557     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2558     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2559     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
2560       frc.inc_call_count();   // Count the call site
2561     } else {                  // See if uncommon argument is shared
2562       Node *n = call->in(TypeFunc::Parms);
2563       int nop = n->Opcode();
2564       // Clone shared simple arguments to uncommon calls, item (1).
2565       if( n->outcnt() > 1 &&
2566           !n->is_Proj() &&
2567           nop != Op_CreateEx &&
2568           nop != Op_CheckCastPP &&
2569           nop != Op_DecodeN &&
2570           nop != Op_DecodeNKlass &&
2571           !n->is_Mem() ) {
2572         Node *x = n->clone();
2573         call->set_req( TypeFunc::Parms, x );
2574       }
2575     }
2576     break;
2577   }
2578 
2579   case Op_StoreD:
2580   case Op_LoadD:
2581   case Op_LoadD_unaligned:
2582     frc.inc_double_count();
2583     goto handle_mem;
2584   case Op_StoreF:
2585   case Op_LoadF:
2586     frc.inc_float_count();
2587     goto handle_mem;
2588 
2589   case Op_StoreCM:
2590     {
2591       // Convert OopStore dependence into precedence edge
2592       Node* prec = n->in(MemNode::OopStore);
2593       n->del_req(MemNode::OopStore);
2594       n->add_prec(prec);
2595       eliminate_redundant_card_marks(n);
2596     }
2597 
2598     // fall through
2599 
2600   case Op_StoreB:
2601   case Op_StoreC:
2602   case Op_StorePConditional:
2603   case Op_StoreI:
2604   case Op_StoreL:
2605   case Op_StoreIConditional:
2606   case Op_StoreLConditional:
2607   case Op_CompareAndSwapI:
2608   case Op_CompareAndSwapL:
2609   case Op_CompareAndSwapP:
2610   case Op_CompareAndSwapN:
2611   case Op_GetAndAddI:
2612   case Op_GetAndAddL:
2613   case Op_GetAndSetI:
2614   case Op_GetAndSetL:
2615   case Op_GetAndSetP:
2616   case Op_GetAndSetN:
2617   case Op_StoreP:
2618   case Op_StoreN:
2619   case Op_StoreNKlass:
2620   case Op_LoadB:
2621   case Op_LoadUB:
2622   case Op_LoadUS:
2623   case Op_LoadI:
2624   case Op_LoadKlass:
2625   case Op_LoadNKlass:
2626   case Op_LoadL:
2627   case Op_LoadL_unaligned:
2628   case Op_LoadPLocked:
2629   case Op_LoadP:
2630   case Op_LoadN:
2631   case Op_LoadRange:
2632   case Op_LoadS: {
2633   handle_mem:
2634 #ifdef ASSERT
2635     if( VerifyOptoOopOffsets ) {
2636       assert( n->is_Mem(), "" );
2637       MemNode *mem  = (MemNode*)n;
2638       // Check to see if address types have grounded out somehow.
2639       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2640       assert( !tp || oop_offset_is_sane(tp), "" );
2641     }
2642 #endif
2643     break;
2644   }
2645 
2646   case Op_AddP: {               // Assert sane base pointers
2647     Node *addp = n->in(AddPNode::Address);
2648     assert( !addp->is_AddP() ||
2649             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2650             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2651             "Base pointers must match" );
2652 #ifdef _LP64
2653     if ((UseCompressedOops || UseCompressedClassPointers) &&
2654         addp->Opcode() == Op_ConP &&
2655         addp == n->in(AddPNode::Base) &&
2656         n->in(AddPNode::Offset)->is_Con()) {
2657       // Use addressing with narrow klass to load with offset on x86.
2658       // On sparc loading 32-bits constant and decoding it have less
2659       // instructions (4) then load 64-bits constant (7).
2660       // Do this transformation here since IGVN will convert ConN back to ConP.
2661       const Type* t = addp->bottom_type();
2662       if (t->isa_oopptr() || t->isa_klassptr()) {
2663         Node* nn = NULL;
2664 
2665         int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
2666 
2667         // Look for existing ConN node of the same exact type.
2668         Node* r  = root();
2669         uint cnt = r->outcnt();
2670         for (uint i = 0; i < cnt; i++) {
2671           Node* m = r->raw_out(i);
2672           if (m!= NULL && m->Opcode() == op &&
2673               m->bottom_type()->make_ptr() == t) {
2674             nn = m;
2675             break;
2676           }
2677         }
2678         if (nn != NULL) {
2679           // Decode a narrow oop to match address
2680           // [R12 + narrow_oop_reg<<3 + offset]
2681           if (t->isa_oopptr()) {
2682             nn = new (this) DecodeNNode(nn, t);
2683           } else {
2684             nn = new (this) DecodeNKlassNode(nn, t);
2685           }
2686           n->set_req(AddPNode::Base, nn);
2687           n->set_req(AddPNode::Address, nn);
2688           if (addp->outcnt() == 0) {
2689             addp->disconnect_inputs(NULL, this);
2690           }
2691         }
2692       }
2693     }
2694 #endif
2695     break;
2696   }
2697 
2698 #ifdef _LP64
2699   case Op_CastPP:
2700     if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
2701       Node* in1 = n->in(1);
2702       const Type* t = n->bottom_type();
2703       Node* new_in1 = in1->clone();
2704       new_in1->as_DecodeN()->set_type(t);
2705 
2706       if (!Matcher::narrow_oop_use_complex_address()) {
2707         //
2708         // x86, ARM and friends can handle 2 adds in addressing mode
2709         // and Matcher can fold a DecodeN node into address by using
2710         // a narrow oop directly and do implicit NULL check in address:
2711         //
2712         // [R12 + narrow_oop_reg<<3 + offset]
2713         // NullCheck narrow_oop_reg
2714         //
2715         // On other platforms (Sparc) we have to keep new DecodeN node and
2716         // use it to do implicit NULL check in address:
2717         //
2718         // decode_not_null narrow_oop_reg, base_reg
2719         // [base_reg + offset]
2720         // NullCheck base_reg
2721         //
2722         // Pin the new DecodeN node to non-null path on these platform (Sparc)
2723         // to keep the information to which NULL check the new DecodeN node
2724         // corresponds to use it as value in implicit_null_check().
2725         //
2726         new_in1->set_req(0, n->in(0));
2727       }
2728 
2729       n->subsume_by(new_in1, this);
2730       if (in1->outcnt() == 0) {
2731         in1->disconnect_inputs(NULL, this);
2732       }
2733     }
2734     break;
2735 
2736   case Op_CmpP:
2737     // Do this transformation here to preserve CmpPNode::sub() and
2738     // other TypePtr related Ideal optimizations (for example, ptr nullness).
2739     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
2740       Node* in1 = n->in(1);
2741       Node* in2 = n->in(2);
2742       if (!in1->is_DecodeNarrowPtr()) {
2743         in2 = in1;
2744         in1 = n->in(2);
2745       }
2746       assert(in1->is_DecodeNarrowPtr(), "sanity");
2747 
2748       Node* new_in2 = NULL;
2749       if (in2->is_DecodeNarrowPtr()) {
2750         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
2751         new_in2 = in2->in(1);
2752       } else if (in2->Opcode() == Op_ConP) {
2753         const Type* t = in2->bottom_type();
2754         if (t == TypePtr::NULL_PTR) {
2755           assert(in1->is_DecodeN(), "compare klass to null?");
2756           // Don't convert CmpP null check into CmpN if compressed
2757           // oops implicit null check is not generated.
2758           // This will allow to generate normal oop implicit null check.
2759           if (Matcher::gen_narrow_oop_implicit_null_checks())
2760             new_in2 = ConNode::make(this, TypeNarrowOop::NULL_PTR);
2761           //
2762           // This transformation together with CastPP transformation above
2763           // will generated code for implicit NULL checks for compressed oops.
2764           //
2765           // The original code after Optimize()
2766           //
2767           //    LoadN memory, narrow_oop_reg
2768           //    decode narrow_oop_reg, base_reg
2769           //    CmpP base_reg, NULL
2770           //    CastPP base_reg // NotNull
2771           //    Load [base_reg + offset], val_reg
2772           //
2773           // after these transformations will be
2774           //
2775           //    LoadN memory, narrow_oop_reg
2776           //    CmpN narrow_oop_reg, NULL
2777           //    decode_not_null narrow_oop_reg, base_reg
2778           //    Load [base_reg + offset], val_reg
2779           //
2780           // and the uncommon path (== NULL) will use narrow_oop_reg directly
2781           // since narrow oops can be used in debug info now (see the code in
2782           // final_graph_reshaping_walk()).
2783           //
2784           // At the end the code will be matched to
2785           // on x86:
2786           //
2787           //    Load_narrow_oop memory, narrow_oop_reg
2788           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
2789           //    NullCheck narrow_oop_reg
2790           //
2791           // and on sparc:
2792           //
2793           //    Load_narrow_oop memory, narrow_oop_reg
2794           //    decode_not_null narrow_oop_reg, base_reg
2795           //    Load [base_reg + offset], val_reg
2796           //    NullCheck base_reg
2797           //
2798         } else if (t->isa_oopptr()) {
2799           new_in2 = ConNode::make(this, t->make_narrowoop());
2800         } else if (t->isa_klassptr()) {
2801           new_in2 = ConNode::make(this, t->make_narrowklass());
2802         }
2803       }
2804       if (new_in2 != NULL) {
2805         Node* cmpN = new (this) CmpNNode(in1->in(1), new_in2);
2806         n->subsume_by(cmpN, this);
2807         if (in1->outcnt() == 0) {
2808           in1->disconnect_inputs(NULL, this);
2809         }
2810         if (in2->outcnt() == 0) {
2811           in2->disconnect_inputs(NULL, this);
2812         }
2813       }
2814     }
2815     break;
2816 
2817   case Op_DecodeN:
2818   case Op_DecodeNKlass:
2819     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
2820     // DecodeN could be pinned when it can't be fold into
2821     // an address expression, see the code for Op_CastPP above.
2822     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
2823     break;
2824 
2825   case Op_EncodeP:
2826   case Op_EncodePKlass: {
2827     Node* in1 = n->in(1);
2828     if (in1->is_DecodeNarrowPtr()) {
2829       n->subsume_by(in1->in(1), this);
2830     } else if (in1->Opcode() == Op_ConP) {
2831       const Type* t = in1->bottom_type();
2832       if (t == TypePtr::NULL_PTR) {
2833         assert(t->isa_oopptr(), "null klass?");
2834         n->subsume_by(ConNode::make(this, TypeNarrowOop::NULL_PTR), this);
2835       } else if (t->isa_oopptr()) {
2836         n->subsume_by(ConNode::make(this, t->make_narrowoop()), this);
2837       } else if (t->isa_klassptr()) {
2838         n->subsume_by(ConNode::make(this, t->make_narrowklass()), this);
2839       }
2840     }
2841     if (in1->outcnt() == 0) {
2842       in1->disconnect_inputs(NULL, this);
2843     }
2844     break;
2845   }
2846 
2847   case Op_Proj: {
2848     if (OptimizeStringConcat) {
2849       ProjNode* p = n->as_Proj();
2850       if (p->_is_io_use) {
2851         // Separate projections were used for the exception path which
2852         // are normally removed by a late inline.  If it wasn't inlined
2853         // then they will hang around and should just be replaced with
2854         // the original one.
2855         Node* proj = NULL;
2856         // Replace with just one
2857         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
2858           Node *use = i.get();
2859           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
2860             proj = use;
2861             break;
2862           }
2863         }
2864         assert(proj != NULL, "must be found");
2865         p->subsume_by(proj, this);
2866       }
2867     }
2868     break;
2869   }
2870 
2871   case Op_Phi:
2872     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
2873       // The EncodeP optimization may create Phi with the same edges
2874       // for all paths. It is not handled well by Register Allocator.
2875       Node* unique_in = n->in(1);
2876       assert(unique_in != NULL, "");
2877       uint cnt = n->req();
2878       for (uint i = 2; i < cnt; i++) {
2879         Node* m = n->in(i);
2880         assert(m != NULL, "");
2881         if (unique_in != m)
2882           unique_in = NULL;
2883       }
2884       if (unique_in != NULL) {
2885         n->subsume_by(unique_in, this);
2886       }
2887     }
2888     break;
2889 
2890 #endif
2891 
2892   case Op_ModI:
2893     if (UseDivMod) {
2894       // Check if a%b and a/b both exist
2895       Node* d = n->find_similar(Op_DivI);
2896       if (d) {
2897         // Replace them with a fused divmod if supported
2898         if (Matcher::has_match_rule(Op_DivModI)) {
2899           DivModINode* divmod = DivModINode::make(this, n);
2900           d->subsume_by(divmod->div_proj(), this);
2901           n->subsume_by(divmod->mod_proj(), this);
2902         } else {
2903           // replace a%b with a-((a/b)*b)
2904           Node* mult = new (this) MulINode(d, d->in(2));
2905           Node* sub  = new (this) SubINode(d->in(1), mult);
2906           n->subsume_by(sub, this);
2907         }
2908       }
2909     }
2910     break;
2911 
2912   case Op_ModL:
2913     if (UseDivMod) {
2914       // Check if a%b and a/b both exist
2915       Node* d = n->find_similar(Op_DivL);
2916       if (d) {
2917         // Replace them with a fused divmod if supported
2918         if (Matcher::has_match_rule(Op_DivModL)) {
2919           DivModLNode* divmod = DivModLNode::make(this, n);
2920           d->subsume_by(divmod->div_proj(), this);
2921           n->subsume_by(divmod->mod_proj(), this);
2922         } else {
2923           // replace a%b with a-((a/b)*b)
2924           Node* mult = new (this) MulLNode(d, d->in(2));
2925           Node* sub  = new (this) SubLNode(d->in(1), mult);
2926           n->subsume_by(sub, this);
2927         }
2928       }
2929     }
2930     break;
2931 
2932   case Op_LoadVector:
2933   case Op_StoreVector:
2934     break;
2935 
2936   case Op_PackB:
2937   case Op_PackS:
2938   case Op_PackI:
2939   case Op_PackF:
2940   case Op_PackL:
2941   case Op_PackD:
2942     if (n->req()-1 > 2) {
2943       // Replace many operand PackNodes with a binary tree for matching
2944       PackNode* p = (PackNode*) n;
2945       Node* btp = p->binary_tree_pack(this, 1, n->req());
2946       n->subsume_by(btp, this);
2947     }
2948     break;
2949   case Op_Loop:
2950   case Op_CountedLoop:
2951     if (n->as_Loop()->is_inner_loop()) {
2952       frc.inc_inner_loop_count();
2953     }
2954     break;
2955   case Op_LShiftI:
2956   case Op_RShiftI:
2957   case Op_URShiftI:
2958   case Op_LShiftL:
2959   case Op_RShiftL:
2960   case Op_URShiftL:
2961     if (Matcher::need_masked_shift_count) {
2962       // The cpu's shift instructions don't restrict the count to the
2963       // lower 5/6 bits. We need to do the masking ourselves.
2964       Node* in2 = n->in(2);
2965       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
2966       const TypeInt* t = in2->find_int_type();
2967       if (t != NULL && t->is_con()) {
2968         juint shift = t->get_con();
2969         if (shift > mask) { // Unsigned cmp
2970           n->set_req(2, ConNode::make(this, TypeInt::make(shift & mask)));
2971         }
2972       } else {
2973         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
2974           Node* shift = new (this) AndINode(in2, ConNode::make(this, TypeInt::make(mask)));
2975           n->set_req(2, shift);
2976         }
2977       }
2978       if (in2->outcnt() == 0) { // Remove dead node
2979         in2->disconnect_inputs(NULL, this);
2980       }
2981     }
2982     break;
2983   case Op_MemBarStoreStore:
2984   case Op_MemBarRelease:
2985     // Break the link with AllocateNode: it is no longer useful and
2986     // confuses register allocation.
2987     if (n->req() > MemBarNode::Precedent) {
2988       n->set_req(MemBarNode::Precedent, top());
2989     }
2990     break;
2991   default:
2992     assert( !n->is_Call(), "" );
2993     assert( !n->is_Mem(), "" );
2994     break;
2995   }
2996 
2997   // Collect CFG split points
2998   if (n->is_MultiBranch())
2999     frc._tests.push(n);
3000 }
3001 
3002 //------------------------------final_graph_reshaping_walk---------------------
3003 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3004 // requires that the walk visits a node's inputs before visiting the node.
3005 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3006   ResourceArea *area = Thread::current()->resource_area();
3007   Unique_Node_List sfpt(area);
3008 
3009   frc._visited.set(root->_idx); // first, mark node as visited
3010   uint cnt = root->req();
3011   Node *n = root;
3012   uint  i = 0;
3013   while (true) {
3014     if (i < cnt) {
3015       // Place all non-visited non-null inputs onto stack
3016       Node* m = n->in(i);
3017       ++i;
3018       if (m != NULL && !frc._visited.test_set(m->_idx)) {
3019         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL)
3020           sfpt.push(m);
3021         cnt = m->req();
3022         nstack.push(n, i); // put on stack parent and next input's index
3023         n = m;
3024         i = 0;
3025       }
3026     } else {
3027       // Now do post-visit work
3028       final_graph_reshaping_impl( n, frc );
3029       if (nstack.is_empty())
3030         break;             // finished
3031       n = nstack.node();   // Get node from stack
3032       cnt = n->req();
3033       i = nstack.index();
3034       nstack.pop();        // Shift to the next node on stack
3035     }
3036   }
3037 
3038   // Skip next transformation if compressed oops are not used.
3039   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3040       (!UseCompressedOops && !UseCompressedClassPointers))
3041     return;
3042 
3043   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3044   // It could be done for an uncommon traps or any safepoints/calls
3045   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3046   while (sfpt.size() > 0) {
3047     n = sfpt.pop();
3048     JVMState *jvms = n->as_SafePoint()->jvms();
3049     assert(jvms != NULL, "sanity");
3050     int start = jvms->debug_start();
3051     int end   = n->req();
3052     bool is_uncommon = (n->is_CallStaticJava() &&
3053                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3054     for (int j = start; j < end; j++) {
3055       Node* in = n->in(j);
3056       if (in->is_DecodeNarrowPtr()) {
3057         bool safe_to_skip = true;
3058         if (!is_uncommon ) {
3059           // Is it safe to skip?
3060           for (uint i = 0; i < in->outcnt(); i++) {
3061             Node* u = in->raw_out(i);
3062             if (!u->is_SafePoint() ||
3063                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
3064               safe_to_skip = false;
3065             }
3066           }
3067         }
3068         if (safe_to_skip) {
3069           n->set_req(j, in->in(1));
3070         }
3071         if (in->outcnt() == 0) {
3072           in->disconnect_inputs(NULL, this);
3073         }
3074       }
3075     }
3076   }
3077 }
3078 
3079 //------------------------------final_graph_reshaping--------------------------
3080 // Final Graph Reshaping.
3081 //
3082 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3083 //     and not commoned up and forced early.  Must come after regular
3084 //     optimizations to avoid GVN undoing the cloning.  Clone constant
3085 //     inputs to Loop Phis; these will be split by the allocator anyways.
3086 //     Remove Opaque nodes.
3087 // (2) Move last-uses by commutative operations to the left input to encourage
3088 //     Intel update-in-place two-address operations and better register usage
3089 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
3090 //     calls canonicalizing them back.
3091 // (3) Count the number of double-precision FP ops, single-precision FP ops
3092 //     and call sites.  On Intel, we can get correct rounding either by
3093 //     forcing singles to memory (requires extra stores and loads after each
3094 //     FP bytecode) or we can set a rounding mode bit (requires setting and
3095 //     clearing the mode bit around call sites).  The mode bit is only used
3096 //     if the relative frequency of single FP ops to calls is low enough.
3097 //     This is a key transform for SPEC mpeg_audio.
3098 // (4) Detect infinite loops; blobs of code reachable from above but not
3099 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
3100 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
3101 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
3102 //     Detection is by looking for IfNodes where only 1 projection is
3103 //     reachable from below or CatchNodes missing some targets.
3104 // (5) Assert for insane oop offsets in debug mode.
3105 
3106 bool Compile::final_graph_reshaping() {
3107   // an infinite loop may have been eliminated by the optimizer,
3108   // in which case the graph will be empty.
3109   if (root()->req() == 1) {
3110     record_method_not_compilable("trivial infinite loop");
3111     return true;
3112   }
3113 
3114   // Expensive nodes have their control input set to prevent the GVN
3115   // from freely commoning them. There's no GVN beyond this point so
3116   // no need to keep the control input. We want the expensive nodes to
3117   // be freely moved to the least frequent code path by gcm.
3118   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3119   for (int i = 0; i < expensive_count(); i++) {
3120     _expensive_nodes->at(i)->set_req(0, NULL);
3121   }
3122 
3123   Final_Reshape_Counts frc;
3124 
3125   // Visit everybody reachable!
3126   // Allocate stack of size C->unique()/2 to avoid frequent realloc
3127   Node_Stack nstack(unique() >> 1);
3128   final_graph_reshaping_walk(nstack, root(), frc);
3129 
3130   // Check for unreachable (from below) code (i.e., infinite loops).
3131   for( uint i = 0; i < frc._tests.size(); i++ ) {
3132     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3133     // Get number of CFG targets.
3134     // Note that PCTables include exception targets after calls.
3135     uint required_outcnt = n->required_outcnt();
3136     if (n->outcnt() != required_outcnt) {
3137       // Check for a few special cases.  Rethrow Nodes never take the
3138       // 'fall-thru' path, so expected kids is 1 less.
3139       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3140         if (n->in(0)->in(0)->is_Call()) {
3141           CallNode *call = n->in(0)->in(0)->as_Call();
3142           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3143             required_outcnt--;      // Rethrow always has 1 less kid
3144           } else if (call->req() > TypeFunc::Parms &&
3145                      call->is_CallDynamicJava()) {
3146             // Check for null receiver. In such case, the optimizer has
3147             // detected that the virtual call will always result in a null
3148             // pointer exception. The fall-through projection of this CatchNode
3149             // will not be populated.
3150             Node *arg0 = call->in(TypeFunc::Parms);
3151             if (arg0->is_Type() &&
3152                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3153               required_outcnt--;
3154             }
3155           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3156                      call->req() > TypeFunc::Parms+1 &&
3157                      call->is_CallStaticJava()) {
3158             // Check for negative array length. In such case, the optimizer has
3159             // detected that the allocation attempt will always result in an
3160             // exception. There is no fall-through projection of this CatchNode .
3161             Node *arg1 = call->in(TypeFunc::Parms+1);
3162             if (arg1->is_Type() &&
3163                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3164               required_outcnt--;
3165             }
3166           }
3167         }
3168       }
3169       // Recheck with a better notion of 'required_outcnt'
3170       if (n->outcnt() != required_outcnt) {
3171         record_method_not_compilable("malformed control flow");
3172         return true;            // Not all targets reachable!
3173       }
3174     }
3175     // Check that I actually visited all kids.  Unreached kids
3176     // must be infinite loops.
3177     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3178       if (!frc._visited.test(n->fast_out(j)->_idx)) {
3179         record_method_not_compilable("infinite loop");
3180         return true;            // Found unvisited kid; must be unreach
3181       }
3182   }
3183 
3184   // If original bytecodes contained a mixture of floats and doubles
3185   // check if the optimizer has made it homogenous, item (3).
3186   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3187       frc.get_float_count() > 32 &&
3188       frc.get_double_count() == 0 &&
3189       (10 * frc.get_call_count() < frc.get_float_count()) ) {
3190     set_24_bit_selection_and_mode( false,  true );
3191   }
3192 
3193   set_java_calls(frc.get_java_call_count());
3194   set_inner_loops(frc.get_inner_loop_count());
3195 
3196   // No infinite loops, no reason to bail out.
3197   return false;
3198 }
3199 
3200 //-----------------------------too_many_traps----------------------------------
3201 // Report if there are too many traps at the current method and bci.
3202 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3203 bool Compile::too_many_traps(ciMethod* method,
3204                              int bci,
3205                              Deoptimization::DeoptReason reason) {
3206   ciMethodData* md = method->method_data();
3207   if (md->is_empty()) {
3208     // Assume the trap has not occurred, or that it occurred only
3209     // because of a transient condition during start-up in the interpreter.
3210     return false;
3211   }
3212   if (md->has_trap_at(bci, reason) != 0) {
3213     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3214     // Also, if there are multiple reasons, or if there is no per-BCI record,
3215     // assume the worst.
3216     if (log())
3217       log()->elem("observe trap='%s' count='%d'",
3218                   Deoptimization::trap_reason_name(reason),
3219                   md->trap_count(reason));
3220     return true;
3221   } else {
3222     // Ignore method/bci and see if there have been too many globally.
3223     return too_many_traps(reason, md);
3224   }
3225 }
3226 
3227 // Less-accurate variant which does not require a method and bci.
3228 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3229                              ciMethodData* logmd) {
3230  if (trap_count(reason) >= (uint)PerMethodTrapLimit) {
3231     // Too many traps globally.
3232     // Note that we use cumulative trap_count, not just md->trap_count.
3233     if (log()) {
3234       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3235       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3236                   Deoptimization::trap_reason_name(reason),
3237                   mcount, trap_count(reason));
3238     }
3239     return true;
3240   } else {
3241     // The coast is clear.
3242     return false;
3243   }
3244 }
3245 
3246 //--------------------------too_many_recompiles--------------------------------
3247 // Report if there are too many recompiles at the current method and bci.
3248 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3249 // Is not eager to return true, since this will cause the compiler to use
3250 // Action_none for a trap point, to avoid too many recompilations.
3251 bool Compile::too_many_recompiles(ciMethod* method,
3252                                   int bci,
3253                                   Deoptimization::DeoptReason reason) {
3254   ciMethodData* md = method->method_data();
3255   if (md->is_empty()) {
3256     // Assume the trap has not occurred, or that it occurred only
3257     // because of a transient condition during start-up in the interpreter.
3258     return false;
3259   }
3260   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3261   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3262   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
3263   Deoptimization::DeoptReason per_bc_reason
3264     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3265   if ((per_bc_reason == Deoptimization::Reason_none
3266        || md->has_trap_at(bci, reason) != 0)
3267       // The trap frequency measure we care about is the recompile count:
3268       && md->trap_recompiled_at(bci)
3269       && md->overflow_recompile_count() >= bc_cutoff) {
3270     // Do not emit a trap here if it has already caused recompilations.
3271     // Also, if there are multiple reasons, or if there is no per-BCI record,
3272     // assume the worst.
3273     if (log())
3274       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3275                   Deoptimization::trap_reason_name(reason),
3276                   md->trap_count(reason),
3277                   md->overflow_recompile_count());
3278     return true;
3279   } else if (trap_count(reason) != 0
3280              && decompile_count() >= m_cutoff) {
3281     // Too many recompiles globally, and we have seen this sort of trap.
3282     // Use cumulative decompile_count, not just md->decompile_count.
3283     if (log())
3284       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3285                   Deoptimization::trap_reason_name(reason),
3286                   md->trap_count(reason), trap_count(reason),
3287                   md->decompile_count(), decompile_count());
3288     return true;
3289   } else {
3290     // The coast is clear.
3291     return false;
3292   }
3293 }
3294 
3295 
3296 #ifndef PRODUCT
3297 //------------------------------verify_graph_edges---------------------------
3298 // Walk the Graph and verify that there is a one-to-one correspondence
3299 // between Use-Def edges and Def-Use edges in the graph.
3300 void Compile::verify_graph_edges(bool no_dead_code) {
3301   if (VerifyGraphEdges) {
3302     ResourceArea *area = Thread::current()->resource_area();
3303     Unique_Node_List visited(area);
3304     // Call recursive graph walk to check edges
3305     _root->verify_edges(visited);
3306     if (no_dead_code) {
3307       // Now make sure that no visited node is used by an unvisited node.
3308       bool dead_nodes = 0;
3309       Unique_Node_List checked(area);
3310       while (visited.size() > 0) {
3311         Node* n = visited.pop();
3312         checked.push(n);
3313         for (uint i = 0; i < n->outcnt(); i++) {
3314           Node* use = n->raw_out(i);
3315           if (checked.member(use))  continue;  // already checked
3316           if (visited.member(use))  continue;  // already in the graph
3317           if (use->is_Con())        continue;  // a dead ConNode is OK
3318           // At this point, we have found a dead node which is DU-reachable.
3319           if (dead_nodes++ == 0)
3320             tty->print_cr("*** Dead nodes reachable via DU edges:");
3321           use->dump(2);
3322           tty->print_cr("---");
3323           checked.push(use);  // No repeats; pretend it is now checked.
3324         }
3325       }
3326       assert(dead_nodes == 0, "using nodes must be reachable from root");
3327     }
3328   }
3329 }
3330 #endif
3331 
3332 // The Compile object keeps track of failure reasons separately from the ciEnv.
3333 // This is required because there is not quite a 1-1 relation between the
3334 // ciEnv and its compilation task and the Compile object.  Note that one
3335 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3336 // to backtrack and retry without subsuming loads.  Other than this backtracking
3337 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3338 // by the logic in C2Compiler.
3339 void Compile::record_failure(const char* reason) {
3340   if (log() != NULL) {
3341     log()->elem("failure reason='%s' phase='compile'", reason);
3342   }
3343   if (_failure_reason == NULL) {
3344     // Record the first failure reason.
3345     _failure_reason = reason;
3346   }
3347 
3348   EventCompilerFailure event;
3349   if (event.should_commit()) {
3350     event.set_compileID(Compile::compile_id());
3351     event.set_failure(reason);
3352     event.commit();
3353   }
3354 
3355   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3356     C->print_method(PHASE_FAILURE);
3357   }
3358   _root = NULL;  // flush the graph, too
3359 }
3360 
3361 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
3362   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false),
3363     _phase_name(name), _dolog(dolog)
3364 {
3365   if (dolog) {
3366     C = Compile::current();
3367     _log = C->log();
3368   } else {
3369     C = NULL;
3370     _log = NULL;
3371   }
3372   if (_log != NULL) {
3373     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3374     _log->stamp();
3375     _log->end_head();
3376   }
3377 }
3378 
3379 Compile::TracePhase::~TracePhase() {
3380 
3381   C = Compile::current();
3382   if (_dolog) {
3383     _log = C->log();
3384   } else {
3385     _log = NULL;
3386   }
3387 
3388 #ifdef ASSERT
3389   if (PrintIdealNodeCount) {
3390     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3391                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3392   }
3393 
3394   if (VerifyIdealNodeCount) {
3395     Compile::current()->print_missing_nodes();
3396   }
3397 #endif
3398 
3399   if (_log != NULL) {
3400     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3401   }
3402 }
3403 
3404 //=============================================================================
3405 // Two Constant's are equal when the type and the value are equal.
3406 bool Compile::Constant::operator==(const Constant& other) {
3407   if (type()          != other.type()         )  return false;
3408   if (can_be_reused() != other.can_be_reused())  return false;
3409   // For floating point values we compare the bit pattern.
3410   switch (type()) {
3411   case T_FLOAT:   return (_v._value.i == other._v._value.i);
3412   case T_LONG:
3413   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
3414   case T_OBJECT:
3415   case T_ADDRESS: return (_v._value.l == other._v._value.l);
3416   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
3417   case T_METADATA: return (_v._metadata == other._v._metadata);
3418   default: ShouldNotReachHere();
3419   }
3420   return false;
3421 }
3422 
3423 static int type_to_size_in_bytes(BasicType t) {
3424   switch (t) {
3425   case T_LONG:    return sizeof(jlong  );
3426   case T_FLOAT:   return sizeof(jfloat );
3427   case T_DOUBLE:  return sizeof(jdouble);
3428   case T_METADATA: return sizeof(Metadata*);
3429     // We use T_VOID as marker for jump-table entries (labels) which
3430     // need an internal word relocation.
3431   case T_VOID:
3432   case T_ADDRESS:
3433   case T_OBJECT:  return sizeof(jobject);
3434   }
3435 
3436   ShouldNotReachHere();
3437   return -1;
3438 }
3439 
3440 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3441   // sort descending
3442   if (a->freq() > b->freq())  return -1;
3443   if (a->freq() < b->freq())  return  1;
3444   return 0;
3445 }
3446 
3447 void Compile::ConstantTable::calculate_offsets_and_size() {
3448   // First, sort the array by frequencies.
3449   _constants.sort(qsort_comparator);
3450 
3451 #ifdef ASSERT
3452   // Make sure all jump-table entries were sorted to the end of the
3453   // array (they have a negative frequency).
3454   bool found_void = false;
3455   for (int i = 0; i < _constants.length(); i++) {
3456     Constant con = _constants.at(i);
3457     if (con.type() == T_VOID)
3458       found_void = true;  // jump-tables
3459     else
3460       assert(!found_void, "wrong sorting");
3461   }
3462 #endif
3463 
3464   int offset = 0;
3465   for (int i = 0; i < _constants.length(); i++) {
3466     Constant* con = _constants.adr_at(i);
3467 
3468     // Align offset for type.
3469     int typesize = type_to_size_in_bytes(con->type());
3470     offset = align_size_up(offset, typesize);
3471     con->set_offset(offset);   // set constant's offset
3472 
3473     if (con->type() == T_VOID) {
3474       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
3475       offset = offset + typesize * n->outcnt();  // expand jump-table
3476     } else {
3477       offset = offset + typesize;
3478     }
3479   }
3480 
3481   // Align size up to the next section start (which is insts; see
3482   // CodeBuffer::align_at_start).
3483   assert(_size == -1, "already set?");
3484   _size = align_size_up(offset, CodeEntryAlignment);
3485 }
3486 
3487 void Compile::ConstantTable::emit(CodeBuffer& cb) {
3488   MacroAssembler _masm(&cb);
3489   for (int i = 0; i < _constants.length(); i++) {
3490     Constant con = _constants.at(i);
3491     address constant_addr;
3492     switch (con.type()) {
3493     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
3494     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
3495     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
3496     case T_OBJECT: {
3497       jobject obj = con.get_jobject();
3498       int oop_index = _masm.oop_recorder()->find_index(obj);
3499       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
3500       break;
3501     }
3502     case T_ADDRESS: {
3503       address addr = (address) con.get_jobject();
3504       constant_addr = _masm.address_constant(addr);
3505       break;
3506     }
3507     // We use T_VOID as marker for jump-table entries (labels) which
3508     // need an internal word relocation.
3509     case T_VOID: {
3510       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
3511       // Fill the jump-table with a dummy word.  The real value is
3512       // filled in later in fill_jump_table.
3513       address dummy = (address) n;
3514       constant_addr = _masm.address_constant(dummy);
3515       // Expand jump-table
3516       for (uint i = 1; i < n->outcnt(); i++) {
3517         address temp_addr = _masm.address_constant(dummy + i);
3518         assert(temp_addr, "consts section too small");
3519       }
3520       break;
3521     }
3522     case T_METADATA: {
3523       Metadata* obj = con.get_metadata();
3524       int metadata_index = _masm.oop_recorder()->find_index(obj);
3525       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
3526       break;
3527     }
3528     default: ShouldNotReachHere();
3529     }
3530     assert(constant_addr, "consts section too small");
3531     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(), err_msg_res("must be: %d == %d", constant_addr - _masm.code()->consts()->start(), con.offset()));
3532   }
3533 }
3534 
3535 int Compile::ConstantTable::find_offset(Constant& con) const {
3536   int idx = _constants.find(con);
3537   assert(idx != -1, "constant must be in constant table");
3538   int offset = _constants.at(idx).offset();
3539   assert(offset != -1, "constant table not emitted yet?");
3540   return offset;
3541 }
3542 
3543 void Compile::ConstantTable::add(Constant& con) {
3544   if (con.can_be_reused()) {
3545     int idx = _constants.find(con);
3546     if (idx != -1 && _constants.at(idx).can_be_reused()) {
3547       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
3548       return;
3549     }
3550   }
3551   (void) _constants.append(con);
3552 }
3553 
3554 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
3555   Block* b = Compile::current()->cfg()->get_block_for_node(n);
3556   Constant con(type, value, b->_freq);
3557   add(con);
3558   return con;
3559 }
3560 
3561 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
3562   Constant con(metadata);
3563   add(con);
3564   return con;
3565 }
3566 
3567 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
3568   jvalue value;
3569   BasicType type = oper->type()->basic_type();
3570   switch (type) {
3571   case T_LONG:    value.j = oper->constantL(); break;
3572   case T_FLOAT:   value.f = oper->constantF(); break;
3573   case T_DOUBLE:  value.d = oper->constantD(); break;
3574   case T_OBJECT:
3575   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
3576   case T_METADATA: return add((Metadata*)oper->constant()); break;
3577   default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
3578   }
3579   return add(n, type, value);
3580 }
3581 
3582 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
3583   jvalue value;
3584   // We can use the node pointer here to identify the right jump-table
3585   // as this method is called from Compile::Fill_buffer right before
3586   // the MachNodes are emitted and the jump-table is filled (means the
3587   // MachNode pointers do not change anymore).
3588   value.l = (jobject) n;
3589   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
3590   add(con);
3591   return con;
3592 }
3593 
3594 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
3595   // If called from Compile::scratch_emit_size do nothing.
3596   if (Compile::current()->in_scratch_emit_size())  return;
3597 
3598   assert(labels.is_nonempty(), "must be");
3599   assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
3600 
3601   // Since MachConstantNode::constant_offset() also contains
3602   // table_base_offset() we need to subtract the table_base_offset()
3603   // to get the plain offset into the constant table.
3604   int offset = n->constant_offset() - table_base_offset();
3605 
3606   MacroAssembler _masm(&cb);
3607   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
3608 
3609   for (uint i = 0; i < n->outcnt(); i++) {
3610     address* constant_addr = &jump_table_base[i];
3611     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)));
3612     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
3613     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
3614   }
3615 }
3616 
3617 void Compile::dump_inlining() {
3618   if (print_inlining() || print_intrinsics()) {
3619     // Print inlining message for candidates that we couldn't inline
3620     // for lack of space or non constant receiver
3621     for (int i = 0; i < _late_inlines.length(); i++) {
3622       CallGenerator* cg = _late_inlines.at(i);
3623       cg->print_inlining_late("live nodes > LiveNodeCountInliningCutoff");
3624     }
3625     Unique_Node_List useful;
3626     useful.push(root());
3627     for (uint next = 0; next < useful.size(); ++next) {
3628       Node* n  = useful.at(next);
3629       if (n->is_Call() && n->as_Call()->generator() != NULL && n->as_Call()->generator()->call_node() == n) {
3630         CallNode* call = n->as_Call();
3631         CallGenerator* cg = call->generator();
3632         cg->print_inlining_late("receiver not constant");
3633       }
3634       uint max = n->len();
3635       for ( uint i = 0; i < max; ++i ) {
3636         Node *m = n->in(i);
3637         if ( m == NULL ) continue;
3638         useful.push(m);
3639       }
3640     }
3641     for (int i = 0; i < _print_inlining_list->length(); i++) {
3642       tty->print(_print_inlining_list->adr_at(i)->ss()->as_string());
3643     }
3644   }
3645 }
3646 
3647 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
3648   if (n1->Opcode() < n2->Opcode())      return -1;
3649   else if (n1->Opcode() > n2->Opcode()) return 1;
3650 
3651   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()));
3652   for (uint i = 1; i < n1->req(); i++) {
3653     if (n1->in(i) < n2->in(i))      return -1;
3654     else if (n1->in(i) > n2->in(i)) return 1;
3655   }
3656 
3657   return 0;
3658 }
3659 
3660 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
3661   Node* n1 = *n1p;
3662   Node* n2 = *n2p;
3663 
3664   return cmp_expensive_nodes(n1, n2);
3665 }
3666 
3667 void Compile::sort_expensive_nodes() {
3668   if (!expensive_nodes_sorted()) {
3669     _expensive_nodes->sort(cmp_expensive_nodes);
3670   }
3671 }
3672 
3673 bool Compile::expensive_nodes_sorted() const {
3674   for (int i = 1; i < _expensive_nodes->length(); i++) {
3675     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
3676       return false;
3677     }
3678   }
3679   return true;
3680 }
3681 
3682 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
3683   if (_expensive_nodes->length() == 0) {
3684     return false;
3685   }
3686 
3687   assert(OptimizeExpensiveOps, "optimization off?");
3688 
3689   // Take this opportunity to remove dead nodes from the list
3690   int j = 0;
3691   for (int i = 0; i < _expensive_nodes->length(); i++) {
3692     Node* n = _expensive_nodes->at(i);
3693     if (!n->is_unreachable(igvn)) {
3694       assert(n->is_expensive(), "should be expensive");
3695       _expensive_nodes->at_put(j, n);
3696       j++;
3697     }
3698   }
3699   _expensive_nodes->trunc_to(j);
3700 
3701   // Then sort the list so that similar nodes are next to each other
3702   // and check for at least two nodes of identical kind with same data
3703   // inputs.
3704   sort_expensive_nodes();
3705 
3706   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
3707     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
3708       return true;
3709     }
3710   }
3711 
3712   return false;
3713 }
3714 
3715 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
3716   if (_expensive_nodes->length() == 0) {
3717     return;
3718   }
3719 
3720   assert(OptimizeExpensiveOps, "optimization off?");
3721 
3722   // Sort to bring similar nodes next to each other and clear the
3723   // control input of nodes for which there's only a single copy.
3724   sort_expensive_nodes();
3725 
3726   int j = 0;
3727   int identical = 0;
3728   int i = 0;
3729   for (; i < _expensive_nodes->length()-1; i++) {
3730     assert(j <= i, "can't write beyond current index");
3731     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
3732       identical++;
3733       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
3734       continue;
3735     }
3736     if (identical > 0) {
3737       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
3738       identical = 0;
3739     } else {
3740       Node* n = _expensive_nodes->at(i);
3741       igvn.hash_delete(n);
3742       n->set_req(0, NULL);
3743       igvn.hash_insert(n);
3744     }
3745   }
3746   if (identical > 0) {
3747     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
3748   } else if (_expensive_nodes->length() >= 1) {
3749     Node* n = _expensive_nodes->at(i);
3750     igvn.hash_delete(n);
3751     n->set_req(0, NULL);
3752     igvn.hash_insert(n);
3753   }
3754   _expensive_nodes->trunc_to(j);
3755 }
3756 
3757 void Compile::add_expensive_node(Node * n) {
3758   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
3759   assert(n->is_expensive(), "expensive nodes with non-null control here only");
3760   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
3761   if (OptimizeExpensiveOps) {
3762     _expensive_nodes->append(n);
3763   } else {
3764     // Clear control input and let IGVN optimize expensive nodes if
3765     // OptimizeExpensiveOps is off.
3766     n->set_req(0, NULL);
3767   }
3768 }
3769 
3770 // Auxiliary method to support randomized stressing/fuzzing.
3771 //
3772 // This method can be called the arbitrary number of times, with current count
3773 // as the argument. The logic allows selecting a single candidate from the
3774 // running list of candidates as follows:
3775 //    int count = 0;
3776 //    Cand* selected = null;
3777 //    while(cand = cand->next()) {
3778 //      if (randomized_select(++count)) {
3779 //        selected = cand;
3780 //      }
3781 //    }
3782 //
3783 // Including count equalizes the chances any candidate is "selected".
3784 // This is useful when we don't have the complete list of candidates to choose
3785 // from uniformly. In this case, we need to adjust the randomicity of the
3786 // selection, or else we will end up biasing the selection towards the latter
3787 // candidates.
3788 //
3789 // Quick back-envelope calculation shows that for the list of n candidates
3790 // the equal probability for the candidate to persist as "best" can be
3791 // achieved by replacing it with "next" k-th candidate with the probability
3792 // of 1/k. It can be easily shown that by the end of the run, the
3793 // probability for any candidate is converged to 1/n, thus giving the
3794 // uniform distribution among all the candidates.
3795 //
3796 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
3797 #define RANDOMIZED_DOMAIN_POW 29
3798 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
3799 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
3800 bool Compile::randomized_select(int count) {
3801   assert(count > 0, "only positive");
3802   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
3803 }