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