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