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