1 /*
   2  * Copyright (c) 1997, 2014, 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 "ci/ciReplay.hpp"
  29 #include "classfile/systemDictionary.hpp"
  30 #include "code/exceptionHandlerTable.hpp"
  31 #include "code/nmethod.hpp"
  32 #include "compiler/compileBroker.hpp"
  33 #include "compiler/compileLog.hpp"
  34 #include "compiler/disassembler.hpp"
  35 #include "compiler/oopMap.hpp"
  36 #include "opto/addnode.hpp"
  37 #include "opto/block.hpp"
  38 #include "opto/c2compiler.hpp"
  39 #include "opto/callGenerator.hpp"
  40 #include "opto/callnode.hpp"
  41 #include "opto/cfgnode.hpp"
  42 #include "opto/chaitin.hpp"
  43 #include "opto/compile.hpp"
  44 #include "opto/connode.hpp"
  45 #include "opto/divnode.hpp"
  46 #include "opto/escape.hpp"
  47 #include "opto/idealGraphPrinter.hpp"
  48 #include "opto/loopnode.hpp"
  49 #include "opto/machnode.hpp"
  50 #include "opto/macro.hpp"
  51 #include "opto/matcher.hpp"
  52 #include "opto/mathexactnode.hpp"
  53 #include "opto/memnode.hpp"
  54 #include "opto/mulnode.hpp"
  55 #include "opto/narrowptrnode.hpp"
  56 #include "opto/node.hpp"
  57 #include "opto/opcodes.hpp"
  58 #include "opto/output.hpp"
  59 #include "opto/parse.hpp"
  60 #include "opto/phaseX.hpp"
  61 #include "opto/rootnode.hpp"
  62 #include "opto/runtime.hpp"
  63 #include "opto/stringopts.hpp"
  64 #include "opto/type.hpp"
  65 #include "opto/vectornode.hpp"
  66 #include "runtime/arguments.hpp"
  67 #include "runtime/signature.hpp"
  68 #include "runtime/stubRoutines.hpp"
  69 #include "runtime/timer.hpp"
  70 #include "trace/tracing.hpp"
  71 #include "utilities/copy.hpp"
  72 
  73 
  74 // -------------------- Compile::mach_constant_base_node -----------------------
  75 // Constant table base node singleton.
  76 MachConstantBaseNode* Compile::mach_constant_base_node() {
  77   if (_mach_constant_base_node == NULL) {
  78     _mach_constant_base_node = new MachConstantBaseNode();
  79     _mach_constant_base_node->add_req(C->root());
  80   }
  81   return _mach_constant_base_node;
  82 }
  83 
  84 
  85 /// Support for intrinsics.
  86 
  87 // Return the index at which m must be inserted (or already exists).
  88 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
  89 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
  90 #ifdef ASSERT
  91   for (int i = 1; i < _intrinsics->length(); i++) {
  92     CallGenerator* cg1 = _intrinsics->at(i-1);
  93     CallGenerator* cg2 = _intrinsics->at(i);
  94     assert(cg1->method() != cg2->method()
  95            ? cg1->method()     < cg2->method()
  96            : cg1->is_virtual() < cg2->is_virtual(),
  97            "compiler intrinsics list must stay sorted");
  98   }
  99 #endif
 100   // Binary search sorted list, in decreasing intervals [lo, hi].
 101   int lo = 0, hi = _intrinsics->length()-1;
 102   while (lo <= hi) {
 103     int mid = (uint)(hi + lo) / 2;
 104     ciMethod* mid_m = _intrinsics->at(mid)->method();
 105     if (m < mid_m) {
 106       hi = mid-1;
 107     } else if (m > mid_m) {
 108       lo = mid+1;
 109     } else {
 110       // look at minor sort key
 111       bool mid_virt = _intrinsics->at(mid)->is_virtual();
 112       if (is_virtual < mid_virt) {
 113         hi = mid-1;
 114       } else if (is_virtual > mid_virt) {
 115         lo = mid+1;
 116       } else {
 117         return mid;  // exact match
 118       }
 119     }
 120   }
 121   return lo;  // inexact match
 122 }
 123 
 124 void Compile::register_intrinsic(CallGenerator* cg) {
 125   if (_intrinsics == NULL) {
 126     _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
 127   }
 128   // This code is stolen from ciObjectFactory::insert.
 129   // Really, GrowableArray should have methods for
 130   // insert_at, remove_at, and binary_search.
 131   int len = _intrinsics->length();
 132   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
 133   if (index == len) {
 134     _intrinsics->append(cg);
 135   } else {
 136 #ifdef ASSERT
 137     CallGenerator* oldcg = _intrinsics->at(index);
 138     assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
 139 #endif
 140     _intrinsics->append(_intrinsics->at(len-1));
 141     int pos;
 142     for (pos = len-2; pos >= index; pos--) {
 143       _intrinsics->at_put(pos+1,_intrinsics->at(pos));
 144     }
 145     _intrinsics->at_put(index, cg);
 146   }
 147   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 148 }
 149 
 150 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 151   assert(m->is_loaded(), "don't try this on unloaded methods");
 152   if (_intrinsics != NULL) {
 153     int index = intrinsic_insertion_index(m, is_virtual);
 154     if (index < _intrinsics->length()
 155         && _intrinsics->at(index)->method() == m
 156         && _intrinsics->at(index)->is_virtual() == is_virtual) {
 157       return _intrinsics->at(index);
 158     }
 159   }
 160   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 161   if (m->intrinsic_id() != vmIntrinsics::_none &&
 162       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 163     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 164     if (cg != NULL) {
 165       // Save it for next time:
 166       register_intrinsic(cg);
 167       return cg;
 168     } else {
 169       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 170     }
 171   }
 172   return NULL;
 173 }
 174 
 175 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
 176 // in library_call.cpp.
 177 
 178 
 179 #ifndef PRODUCT
 180 // statistics gathering...
 181 
 182 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
 183 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
 184 
 185 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 186   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 187   int oflags = _intrinsic_hist_flags[id];
 188   assert(flags != 0, "what happened?");
 189   if (is_virtual) {
 190     flags |= _intrinsic_virtual;
 191   }
 192   bool changed = (flags != oflags);
 193   if ((flags & _intrinsic_worked) != 0) {
 194     juint count = (_intrinsic_hist_count[id] += 1);
 195     if (count == 1) {
 196       changed = true;           // first time
 197     }
 198     // increment the overall count also:
 199     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
 200   }
 201   if (changed) {
 202     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 203       // Something changed about the intrinsic's virtuality.
 204       if ((flags & _intrinsic_virtual) != 0) {
 205         // This is the first use of this intrinsic as a virtual call.
 206         if (oflags != 0) {
 207           // We already saw it as a non-virtual, so note both cases.
 208           flags |= _intrinsic_both;
 209         }
 210       } else if ((oflags & _intrinsic_both) == 0) {
 211         // This is the first use of this intrinsic as a non-virtual
 212         flags |= _intrinsic_both;
 213       }
 214     }
 215     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
 216   }
 217   // update the overall flags also:
 218   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
 219   return changed;
 220 }
 221 
 222 static char* format_flags(int flags, char* buf) {
 223   buf[0] = 0;
 224   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 225   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 226   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 227   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 228   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 229   if (buf[0] == 0)  strcat(buf, ",");
 230   assert(buf[0] == ',', "must be");
 231   return &buf[1];
 232 }
 233 
 234 void Compile::print_intrinsic_statistics() {
 235   char flagsbuf[100];
 236   ttyLocker ttyl;
 237   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
 238   tty->print_cr("Compiler intrinsic usage:");
 239   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
 240   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 241   #define PRINT_STAT_LINE(name, c, f) \
 242     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 243   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
 244     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
 245     int   flags = _intrinsic_hist_flags[id];
 246     juint count = _intrinsic_hist_count[id];
 247     if ((flags | count) != 0) {
 248       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 249     }
 250   }
 251   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
 252   if (xtty != NULL)  xtty->tail("statistics");
 253 }
 254 
 255 void Compile::print_statistics() {
 256   { ttyLocker ttyl;
 257     if (xtty != NULL)  xtty->head("statistics type='opto'");
 258     Parse::print_statistics();
 259     PhaseCCP::print_statistics();
 260     PhaseRegAlloc::print_statistics();
 261     Scheduling::print_statistics();
 262     PhasePeephole::print_statistics();
 263     PhaseIdealLoop::print_statistics();
 264     if (xtty != NULL)  xtty->tail("statistics");
 265   }
 266   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
 267     // put this under its own <statistics> element.
 268     print_intrinsic_statistics();
 269   }
 270 }
 271 #endif //PRODUCT
 272 
 273 // Support for bundling info
 274 Bundle* Compile::node_bundling(const Node *n) {
 275   assert(valid_bundle_info(n), "oob");
 276   return &_node_bundling_base[n->_idx];
 277 }
 278 
 279 bool Compile::valid_bundle_info(const Node *n) {
 280   return (_node_bundling_limit > n->_idx);
 281 }
 282 
 283 
 284 void Compile::gvn_replace_by(Node* n, Node* nn) {
 285   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 286     Node* use = n->last_out(i);
 287     bool is_in_table = initial_gvn()->hash_delete(use);
 288     uint uses_found = 0;
 289     for (uint j = 0; j < use->len(); j++) {
 290       if (use->in(j) == n) {
 291         if (j < use->req())
 292           use->set_req(j, nn);
 293         else
 294           use->set_prec(j, nn);
 295         uses_found++;
 296       }
 297     }
 298     if (is_in_table) {
 299       // reinsert into table
 300       initial_gvn()->hash_find_insert(use);
 301     }
 302     record_for_igvn(use);
 303     i -= uses_found;    // we deleted 1 or more copies of this edge
 304   }
 305 }
 306 
 307 
 308 static inline bool not_a_node(const Node* n) {
 309   if (n == NULL)                   return true;
 310   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
 311   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
 312   return false;
 313 }
 314 
 315 // Identify all nodes that are reachable from below, useful.
 316 // Use breadth-first pass that records state in a Unique_Node_List,
 317 // recursive traversal is slower.
 318 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 319   int estimated_worklist_size = unique();
 320   useful.map( estimated_worklist_size, NULL );  // preallocate space
 321 
 322   // Initialize worklist
 323   if (root() != NULL)     { useful.push(root()); }
 324   // If 'top' is cached, declare it useful to preserve cached node
 325   if( cached_top_node() ) { useful.push(cached_top_node()); }
 326 
 327   // Push all useful nodes onto the list, breadthfirst
 328   for( uint next = 0; next < useful.size(); ++next ) {
 329     assert( next < unique(), "Unique useful nodes < total nodes");
 330     Node *n  = useful.at(next);
 331     uint max = n->len();
 332     for( uint i = 0; i < max; ++i ) {
 333       Node *m = n->in(i);
 334       if (not_a_node(m))  continue;
 335       useful.push(m);
 336     }
 337   }
 338 }
 339 
 340 // Update dead_node_list with any missing dead nodes using useful
 341 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 342 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 343   uint max_idx = unique();
 344   VectorSet& useful_node_set = useful.member_set();
 345 
 346   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 347     // If node with index node_idx is not in useful set,
 348     // mark it as dead in dead node list.
 349     if (! useful_node_set.test(node_idx) ) {
 350       record_dead_node(node_idx);
 351     }
 352   }
 353 }
 354 
 355 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 356   int shift = 0;
 357   for (int i = 0; i < inlines->length(); i++) {
 358     CallGenerator* cg = inlines->at(i);
 359     CallNode* call = cg->call_node();
 360     if (shift > 0) {
 361       inlines->at_put(i-shift, cg);
 362     }
 363     if (!useful.member(call)) {
 364       shift++;
 365     }
 366   }
 367   inlines->trunc_to(inlines->length()-shift);
 368 }
 369 
 370 // Disconnect all useless nodes by disconnecting those at the boundary.
 371 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
 372   uint next = 0;
 373   while (next < useful.size()) {
 374     Node *n = useful.at(next++);
 375     if (n->is_SafePoint()) {
 376       // We're done with a parsing phase. Replaced nodes are not valid
 377       // beyond that point.
 378       n->as_SafePoint()->delete_replaced_nodes();
 379     }
 380     // Use raw traversal of out edges since this code removes out edges
 381     int max = n->outcnt();
 382     for (int j = 0; j < max; ++j) {
 383       Node* child = n->raw_out(j);
 384       if (! useful.member(child)) {
 385         assert(!child->is_top() || child != top(),
 386                "If top is cached in Compile object it is in useful list");
 387         // Only need to remove this out-edge to the useless node
 388         n->raw_del_out(j);
 389         --j;
 390         --max;
 391       }
 392     }
 393     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 394       record_for_igvn(n->unique_out());
 395     }
 396   }
 397   // Remove useless macro and predicate opaq nodes
 398   for (int i = C->macro_count()-1; i >= 0; i--) {
 399     Node* n = C->macro_node(i);
 400     if (!useful.member(n)) {
 401       remove_macro_node(n);
 402     }
 403   }
 404   // Remove useless expensive node
 405   for (int i = C->expensive_count()-1; i >= 0; i--) {
 406     Node* n = C->expensive_node(i);
 407     if (!useful.member(n)) {
 408       remove_expensive_node(n);
 409     }
 410   }
 411   // clean up the late inline lists
 412   remove_useless_late_inlines(&_string_late_inlines, useful);
 413   remove_useless_late_inlines(&_boxing_late_inlines, useful);
 414   remove_useless_late_inlines(&_late_inlines, useful);
 415   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 416 }
 417 
 418 //------------------------------frame_size_in_words-----------------------------
 419 // frame_slots in units of words
 420 int Compile::frame_size_in_words() const {
 421   // shift is 0 in LP32 and 1 in LP64
 422   const int shift = (LogBytesPerWord - LogBytesPerInt);
 423   int words = _frame_slots >> shift;
 424   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
 425   return words;
 426 }
 427 
 428 // To bang the stack of this compiled method we use the stack size
 429 // that the interpreter would need in case of a deoptimization. This
 430 // removes the need to bang the stack in the deoptimization blob which
 431 // in turn simplifies stack overflow handling.
 432 int Compile::bang_size_in_bytes() const {
 433   return MAX2(frame_size_in_bytes() + os::extra_bang_size_in_bytes(), _interpreter_frame_size);
 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       CompileBroker::handle_full_code_cache(CodeBlobType::NonMethod);
 539       return;
 540     }
 541   }
 542 
 543   // Initialize the relocation buffers
 544   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
 545   set_scratch_locs_memory(locs_buf);
 546 }
 547 
 548 
 549 //-----------------------scratch_emit_size-------------------------------------
 550 // Helper function that computes size by emitting code
 551 uint Compile::scratch_emit_size(const Node* n) {
 552   // Start scratch_emit_size section.
 553   set_in_scratch_emit_size(true);
 554 
 555   // Emit into a trash buffer and count bytes emitted.
 556   // This is a pretty expensive way to compute a size,
 557   // but it works well enough if seldom used.
 558   // All common fixed-size instructions are given a size
 559   // method by the AD file.
 560   // Note that the scratch buffer blob and locs memory are
 561   // allocated at the beginning of the compile task, and
 562   // may be shared by several calls to scratch_emit_size.
 563   // The allocation of the scratch buffer blob is particularly
 564   // expensive, since it has to grab the code cache lock.
 565   BufferBlob* blob = this->scratch_buffer_blob();
 566   assert(blob != NULL, "Initialize BufferBlob at start");
 567   assert(blob->size() > MAX_inst_size, "sanity");
 568   relocInfo* locs_buf = scratch_locs_memory();
 569   address blob_begin = blob->content_begin();
 570   address blob_end   = (address)locs_buf;
 571   assert(blob->content_contains(blob_end), "sanity");
 572   CodeBuffer buf(blob_begin, blob_end - blob_begin);
 573   buf.initialize_consts_size(_scratch_const_size);
 574   buf.initialize_stubs_size(MAX_stubs_size);
 575   assert(locs_buf != NULL, "sanity");
 576   int lsize = MAX_locs_size / 3;
 577   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
 578   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
 579   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
 580 
 581   // Do the emission.
 582 
 583   Label fakeL; // Fake label for branch instructions.
 584   Label*   saveL = NULL;
 585   uint save_bnum = 0;
 586   bool is_branch = n->is_MachBranch();
 587   if (is_branch) {
 588     MacroAssembler masm(&buf);
 589     masm.bind(fakeL);
 590     n->as_MachBranch()->save_label(&saveL, &save_bnum);
 591     n->as_MachBranch()->label_set(&fakeL, 0);
 592   }
 593   n->emit(buf, this->regalloc());
 594   if (is_branch) // Restore label.
 595     n->as_MachBranch()->label_set(saveL, save_bnum);
 596 
 597   // End scratch_emit_size section.
 598   set_in_scratch_emit_size(false);
 599 
 600   return buf.insts_size();
 601 }
 602 
 603 
 604 // ============================================================================
 605 //------------------------------Compile standard-------------------------------
 606 debug_only( int Compile::_debug_idx = 100000; )
 607 
 608 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 609 // the continuation bci for on stack replacement.
 610 
 611 
 612 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
 613                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
 614                 : Phase(Compiler),
 615                   _env(ci_env),
 616                   _log(ci_env->log()),
 617                   _compile_id(ci_env->compile_id()),
 618                   _save_argument_registers(false),
 619                   _stub_name(NULL),
 620                   _stub_function(NULL),
 621                   _stub_entry_point(NULL),
 622                   _method(target),
 623                   _entry_bci(osr_bci),
 624                   _initial_gvn(NULL),
 625                   _for_igvn(NULL),
 626                   _warm_calls(NULL),
 627                   _subsume_loads(subsume_loads),
 628                   _do_escape_analysis(do_escape_analysis),
 629                   _eliminate_boxing(eliminate_boxing),
 630                   _failure_reason(NULL),
 631                   _code_buffer("Compile::Fill_buffer"),
 632                   _orig_pc_slot(0),
 633                   _orig_pc_slot_offset_in_bytes(0),
 634                   _has_method_handle_invokes(false),
 635                   _mach_constant_base_node(NULL),
 636                   _node_bundling_limit(0),
 637                   _node_bundling_base(NULL),
 638                   _java_calls(0),
 639                   _inner_loops(0),
 640                   _scratch_const_size(-1),
 641                   _in_scratch_emit_size(false),
 642                   _dead_node_list(comp_arena()),
 643                   _dead_node_count(0),
 644 #ifndef PRODUCT
 645                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
 646                   _in_dump_cnt(0),
 647                   _printer(IdealGraphPrinter::printer()),
 648 #endif
 649                   _congraph(NULL),
 650                   _comp_arena(mtCompiler),
 651                   _node_arena(mtCompiler),
 652                   _old_arena(mtCompiler),
 653                   _Compile_types(mtCompiler),
 654                   _replay_inline_data(NULL),
 655                   _late_inlines(comp_arena(), 2, 0, NULL),
 656                   _string_late_inlines(comp_arena(), 2, 0, NULL),
 657                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
 658                   _late_inlines_pos(0),
 659                   _number_of_mh_late_inlines(0),
 660                   _inlining_progress(false),
 661                   _inlining_incrementally(false),
 662                   _print_inlining_list(NULL),
 663                   _print_inlining_stream(NULL),
 664                   _print_inlining_idx(0),
 665                   _print_inlining_output(NULL),
 666                   _interpreter_frame_size(0) {
 667   C = this;
 668 
 669   CompileWrapper cw(this);
 670 
 671   if (CITimeVerbose) {
 672     tty->print(" ");
 673     target->holder()->name()->print();
 674     tty->print(".");
 675     target->print_short_name();
 676     tty->print("  ");
 677   }
 678   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 679   TraceTime t2(NULL, &_t_methodCompilation, CITime, false);
 680 
 681 #ifndef PRODUCT
 682   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
 683   if (!print_opto_assembly) {
 684     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
 685     if (print_assembly && !Disassembler::can_decode()) {
 686       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
 687       print_opto_assembly = true;
 688     }
 689   }
 690   set_print_assembly(print_opto_assembly);
 691   set_parsed_irreducible_loop(false);
 692 
 693   if (method()->has_option("ReplayInline")) {
 694     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 695   }
 696 #endif
 697   set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
 698   set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
 699   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 700 
 701   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
 702     // Make sure the method being compiled gets its own MDO,
 703     // so we can at least track the decompile_count().
 704     // Need MDO to record RTM code generation state.
 705     method()->ensure_method_data();
 706   }
 707 
 708   Init(::AliasLevel);
 709 
 710 
 711   print_compile_messages();
 712 
 713   _ilt = InlineTree::build_inline_tree_root();
 714 
 715   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 716   assert(num_alias_types() >= AliasIdxRaw, "");
 717 
 718 #define MINIMUM_NODE_HASH  1023
 719   // Node list that Iterative GVN will start with
 720   Unique_Node_List for_igvn(comp_arena());
 721   set_for_igvn(&for_igvn);
 722 
 723   // GVN that will be run immediately on new nodes
 724   uint estimated_size = method()->code_size()*4+64;
 725   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 726   PhaseGVN gvn(node_arena(), estimated_size);
 727   set_initial_gvn(&gvn);
 728 
 729   print_inlining_init();
 730   { // Scope for timing the parser
 731     TracePhase tp("parse", &timers[_t_parser]);
 732 
 733     // Put top into the hash table ASAP.
 734     initial_gvn()->transform_no_reclaim(top());
 735 
 736     // Set up tf(), start(), and find a CallGenerator.
 737     CallGenerator* cg = NULL;
 738     if (is_osr_compilation()) {
 739       const TypeTuple *domain = StartOSRNode::osr_domain();
 740       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 741       init_tf(TypeFunc::make(domain, range));
 742       StartNode* s = new StartOSRNode(root(), domain);
 743       initial_gvn()->set_type_bottom(s);
 744       init_start(s);
 745       cg = CallGenerator::for_osr(method(), entry_bci());
 746     } else {
 747       // Normal case.
 748       init_tf(TypeFunc::make(method()));
 749       StartNode* s = new StartNode(root(), tf()->domain());
 750       initial_gvn()->set_type_bottom(s);
 751       init_start(s);
 752       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
 753         // With java.lang.ref.reference.get() we must go through the
 754         // intrinsic when G1 is enabled - even when get() is the root
 755         // method of the compile - so that, if necessary, the value in
 756         // the referent field of the reference object gets recorded by
 757         // the pre-barrier code.
 758         // Specifically, if G1 is enabled, the value in the referent
 759         // field is recorded by the G1 SATB pre barrier. This will
 760         // result in the referent being marked live and the reference
 761         // object removed from the list of discovered references during
 762         // reference processing.
 763         cg = find_intrinsic(method(), false);
 764       }
 765       if (cg == NULL) {
 766         float past_uses = method()->interpreter_invocation_count();
 767         float expected_uses = past_uses;
 768         cg = CallGenerator::for_inline(method(), expected_uses);
 769       }
 770     }
 771     if (failing())  return;
 772     if (cg == NULL) {
 773       record_method_not_compilable_all_tiers("cannot parse method");
 774       return;
 775     }
 776     JVMState* jvms = build_start_state(start(), tf());
 777     if ((jvms = cg->generate(jvms)) == NULL) {
 778       record_method_not_compilable("method parse failed");
 779       return;
 780     }
 781     GraphKit kit(jvms);
 782 
 783     if (!kit.stopped()) {
 784       // Accept return values, and transfer control we know not where.
 785       // This is done by a special, unique ReturnNode bound to root.
 786       return_values(kit.jvms());
 787     }
 788 
 789     if (kit.has_exceptions()) {
 790       // Any exceptions that escape from this call must be rethrown
 791       // to whatever caller is dynamically above us on the stack.
 792       // This is done by a special, unique RethrowNode bound to root.
 793       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 794     }
 795 
 796     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 797 
 798     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 799       inline_string_calls(true);
 800     }
 801 
 802     if (failing())  return;
 803 
 804     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
 805 
 806     // Remove clutter produced by parsing.
 807     if (!failing()) {
 808       ResourceMark rm;
 809       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 810     }
 811   }
 812 
 813   // Note:  Large methods are capped off in do_one_bytecode().
 814   if (failing())  return;
 815 
 816   // After parsing, node notes are no longer automagic.
 817   // They must be propagated by register_new_node_with_optimizer(),
 818   // clone(), or the like.
 819   set_default_node_notes(NULL);
 820 
 821   for (;;) {
 822     int successes = Inline_Warm();
 823     if (failing())  return;
 824     if (successes == 0)  break;
 825   }
 826 
 827   // Drain the list.
 828   Finish_Warm();
 829 #ifndef PRODUCT
 830   if (_printer) {
 831     _printer->print_inlining(this);
 832   }
 833 #endif
 834 
 835   if (failing())  return;
 836   NOT_PRODUCT( verify_graph_edges(); )
 837 
 838   // Now optimize
 839   Optimize();
 840   if (failing())  return;
 841   NOT_PRODUCT( verify_graph_edges(); )
 842 
 843 #ifndef PRODUCT
 844   if (PrintIdeal) {
 845     ttyLocker ttyl;  // keep the following output all in one block
 846     // This output goes directly to the tty, not the compiler log.
 847     // To enable tools to match it up with the compilation activity,
 848     // be sure to tag this tty output with the compile ID.
 849     if (xtty != NULL) {
 850       xtty->head("ideal compile_id='%d'%s", compile_id(),
 851                  is_osr_compilation()    ? " compile_kind='osr'" :
 852                  "");
 853     }
 854     root()->dump(9999);
 855     if (xtty != NULL) {
 856       xtty->tail("ideal");
 857     }
 858   }
 859 #endif
 860 
 861   NOT_PRODUCT( verify_barriers(); )
 862 
 863   // Dump compilation data to replay it.
 864   if (method()->has_option("DumpReplay")) {
 865     env()->dump_replay_data(_compile_id);
 866   }
 867   if (method()->has_option("DumpInline") && (ilt() != NULL)) {
 868     env()->dump_inline_data(_compile_id);
 869   }
 870 
 871   // Now that we know the size of all the monitors we can add a fixed slot
 872   // for the original deopt pc.
 873 
 874   _orig_pc_slot =  fixed_slots();
 875   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 876   set_fixed_slots(next_slot);
 877 
 878   // Compute when to use implicit null checks. Used by matching trap based
 879   // nodes and NullCheck optimization.
 880   set_allowed_deopt_reasons();
 881 
 882   // Now generate code
 883   Code_Gen();
 884   if (failing())  return;
 885 
 886   // Check if we want to skip execution of all compiled code.
 887   {
 888 #ifndef PRODUCT
 889     if (OptoNoExecute) {
 890       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 891       return;
 892     }
 893 #endif
 894     TracePhase tp("install_code", &timers[_t_registerMethod]);
 895 
 896     if (is_osr_compilation()) {
 897       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 898       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 899     } else {
 900       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 901       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 902     }
 903 
 904     env()->register_method(_method, _entry_bci,
 905                            &_code_offsets,
 906                            _orig_pc_slot_offset_in_bytes,
 907                            code_buffer(),
 908                            frame_size_in_words(), _oop_map_set,
 909                            &_handler_table, &_inc_table,
 910                            compiler,
 911                            env()->comp_level(),
 912                            has_unsafe_access(),
 913                            SharedRuntime::is_wide_vector(max_vector_size()),
 914                            rtm_state()
 915                            );
 916 
 917     if (log() != NULL) // Print code cache state into compiler log
 918       log()->code_cache_state();
 919   }
 920 }
 921 
 922 //------------------------------Compile----------------------------------------
 923 // Compile a runtime stub
 924 Compile::Compile( ciEnv* ci_env,
 925                   TypeFunc_generator generator,
 926                   address stub_function,
 927                   const char *stub_name,
 928                   int is_fancy_jump,
 929                   bool pass_tls,
 930                   bool save_arg_registers,
 931                   bool return_pc )
 932   : Phase(Compiler),
 933     _env(ci_env),
 934     _log(ci_env->log()),
 935     _compile_id(0),
 936     _save_argument_registers(save_arg_registers),
 937     _method(NULL),
 938     _stub_name(stub_name),
 939     _stub_function(stub_function),
 940     _stub_entry_point(NULL),
 941     _entry_bci(InvocationEntryBci),
 942     _initial_gvn(NULL),
 943     _for_igvn(NULL),
 944     _warm_calls(NULL),
 945     _orig_pc_slot(0),
 946     _orig_pc_slot_offset_in_bytes(0),
 947     _subsume_loads(true),
 948     _do_escape_analysis(false),
 949     _eliminate_boxing(false),
 950     _failure_reason(NULL),
 951     _code_buffer("Compile::Fill_buffer"),
 952     _has_method_handle_invokes(false),
 953     _mach_constant_base_node(NULL),
 954     _node_bundling_limit(0),
 955     _node_bundling_base(NULL),
 956     _java_calls(0),
 957     _inner_loops(0),
 958 #ifndef PRODUCT
 959     _trace_opto_output(TraceOptoOutput),
 960     _in_dump_cnt(0),
 961     _printer(NULL),
 962 #endif
 963     _comp_arena(mtCompiler),
 964     _node_arena(mtCompiler),
 965     _old_arena(mtCompiler),
 966     _Compile_types(mtCompiler),
 967     _dead_node_list(comp_arena()),
 968     _dead_node_count(0),
 969     _congraph(NULL),
 970     _replay_inline_data(NULL),
 971     _number_of_mh_late_inlines(0),
 972     _inlining_progress(false),
 973     _inlining_incrementally(false),
 974     _print_inlining_list(NULL),
 975     _print_inlining_stream(NULL),
 976     _print_inlining_idx(0),
 977     _print_inlining_output(NULL),
 978     _allowed_reasons(0),
 979     _interpreter_frame_size(0) {
 980   C = this;
 981 
 982   TraceTime t1(NULL, &_t_totalCompilation, CITime, false);
 983   TraceTime t2(NULL, &_t_stubCompilation, CITime, false);
 984 
 985 #ifndef PRODUCT
 986   set_print_assembly(PrintFrameConverterAssembly);
 987   set_parsed_irreducible_loop(false);
 988 #endif
 989   set_has_irreducible_loop(false); // no loops
 990 
 991   CompileWrapper cw(this);
 992   Init(/*AliasLevel=*/ 0);
 993   init_tf((*generator)());
 994 
 995   {
 996     // The following is a dummy for the sake of GraphKit::gen_stub
 997     Unique_Node_List for_igvn(comp_arena());
 998     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
 999     PhaseGVN gvn(Thread::current()->resource_area(),255);
1000     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1001     gvn.transform_no_reclaim(top());
1002 
1003     GraphKit kit;
1004     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1005   }
1006 
1007   NOT_PRODUCT( verify_graph_edges(); )
1008   Code_Gen();
1009   if (failing())  return;
1010 
1011 
1012   // Entry point will be accessed using compile->stub_entry_point();
1013   if (code_buffer() == NULL) {
1014     Matcher::soft_match_failure();
1015   } else {
1016     if (PrintAssembly && (WizardMode || Verbose))
1017       tty->print_cr("### Stub::%s", stub_name);
1018 
1019     if (!failing()) {
1020       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1021 
1022       // Make the NMethod
1023       // For now we mark the frame as never safe for profile stackwalking
1024       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1025                                                       code_buffer(),
1026                                                       CodeOffsets::frame_never_safe,
1027                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
1028                                                       frame_size_in_words(),
1029                                                       _oop_map_set,
1030                                                       save_arg_registers);
1031       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1032 
1033       _stub_entry_point = rs->entry_point();
1034     }
1035   }
1036 }
1037 
1038 //------------------------------Init-------------------------------------------
1039 // Prepare for a single compilation
1040 void Compile::Init(int aliaslevel) {
1041   _unique  = 0;
1042   _regalloc = NULL;
1043 
1044   _tf      = NULL;  // filled in later
1045   _top     = NULL;  // cached later
1046   _matcher = NULL;  // filled in later
1047   _cfg     = NULL;  // filled in later
1048 
1049   set_24_bit_selection_and_mode(Use24BitFP, false);
1050 
1051   _node_note_array = NULL;
1052   _default_node_notes = NULL;
1053   DEBUG_ONLY( _modified_nodes = NULL; ) // Used in Optimize()
1054 
1055   _immutable_memory = NULL; // filled in at first inquiry
1056 
1057   // Globally visible Nodes
1058   // First set TOP to NULL to give safe behavior during creation of RootNode
1059   set_cached_top_node(NULL);
1060   set_root(new RootNode());
1061   // Now that you have a Root to point to, create the real TOP
1062   set_cached_top_node( new ConNode(Type::TOP) );
1063   set_recent_alloc(NULL, NULL);
1064 
1065   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1066   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1067   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1068   env()->set_dependencies(new Dependencies(env()));
1069 
1070   _fixed_slots = 0;
1071   set_has_split_ifs(false);
1072   set_has_loops(has_method() && method()->has_loops()); // first approximation
1073   set_has_stringbuilder(false);
1074   set_has_boxed_value(false);
1075   _trap_can_recompile = false;  // no traps emitted yet
1076   _major_progress = true; // start out assuming good things will happen
1077   set_has_unsafe_access(false);
1078   set_max_vector_size(0);
1079   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1080   set_decompile_count(0);
1081 
1082   set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
1083   set_num_loop_opts(LoopOptsCount);
1084   set_do_inlining(Inline);
1085   set_max_inline_size(MaxInlineSize);
1086   set_freq_inline_size(FreqInlineSize);
1087   set_do_scheduling(OptoScheduling);
1088   set_do_count_invocations(false);
1089   set_do_method_data_update(false);
1090   set_age_code(has_method() && method()->profile_aging());
1091   set_rtm_state(NoRTM); // No RTM lock eliding by default
1092 #if INCLUDE_RTM_OPT
1093   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1094     int rtm_state = method()->method_data()->rtm_state();
1095     if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
1096       // Don't generate RTM lock eliding code.
1097       set_rtm_state(NoRTM);
1098     } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1099       // Generate RTM lock eliding code without abort ratio calculation code.
1100       set_rtm_state(UseRTM);
1101     } else if (UseRTMDeopt) {
1102       // Generate RTM lock eliding code and include abort ratio calculation
1103       // code if UseRTMDeopt is on.
1104       set_rtm_state(ProfileRTM);
1105     }
1106   }
1107 #endif
1108   if (debug_info()->recording_non_safepoints()) {
1109     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1110                         (comp_arena(), 8, 0, NULL));
1111     set_default_node_notes(Node_Notes::make(this));
1112   }
1113 
1114   // // -- Initialize types before each compile --
1115   // // Update cached type information
1116   // if( _method && _method->constants() )
1117   //   Type::update_loaded_types(_method, _method->constants());
1118 
1119   // Init alias_type map.
1120   if (!_do_escape_analysis && aliaslevel == 3)
1121     aliaslevel = 2;  // No unique types without escape analysis
1122   _AliasLevel = aliaslevel;
1123   const int grow_ats = 16;
1124   _max_alias_types = grow_ats;
1125   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1126   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1127   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1128   {
1129     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1130   }
1131   // Initialize the first few types.
1132   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1133   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1134   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1135   _num_alias_types = AliasIdxRaw+1;
1136   // Zero out the alias type cache.
1137   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1138   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1139   probe_alias_cache(NULL)->_index = AliasIdxTop;
1140 
1141   _intrinsics = NULL;
1142   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1143   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1144   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1145   register_library_intrinsics();
1146 }
1147 
1148 //---------------------------init_start----------------------------------------
1149 // Install the StartNode on this compile object.
1150 void Compile::init_start(StartNode* s) {
1151   if (failing())
1152     return; // already failing
1153   assert(s == start(), "");
1154 }
1155 
1156 StartNode* Compile::start() const {
1157   assert(!failing(), "");
1158   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1159     Node* start = root()->fast_out(i);
1160     if( start->is_Start() )
1161       return start->as_Start();
1162   }
1163   fatal("Did not find Start node!");
1164   return NULL;
1165 }
1166 
1167 //-------------------------------immutable_memory-------------------------------------
1168 // Access immutable memory
1169 Node* Compile::immutable_memory() {
1170   if (_immutable_memory != NULL) {
1171     return _immutable_memory;
1172   }
1173   StartNode* s = start();
1174   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1175     Node *p = s->fast_out(i);
1176     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1177       _immutable_memory = p;
1178       return _immutable_memory;
1179     }
1180   }
1181   ShouldNotReachHere();
1182   return NULL;
1183 }
1184 
1185 //----------------------set_cached_top_node------------------------------------
1186 // Install the cached top node, and make sure Node::is_top works correctly.
1187 void Compile::set_cached_top_node(Node* tn) {
1188   if (tn != NULL)  verify_top(tn);
1189   Node* old_top = _top;
1190   _top = tn;
1191   // Calling Node::setup_is_top allows the nodes the chance to adjust
1192   // their _out arrays.
1193   if (_top != NULL)     _top->setup_is_top();
1194   if (old_top != NULL)  old_top->setup_is_top();
1195   assert(_top == NULL || top()->is_top(), "");
1196 }
1197 
1198 #ifdef ASSERT
1199 uint Compile::count_live_nodes_by_graph_walk() {
1200   Unique_Node_List useful(comp_arena());
1201   // Get useful node list by walking the graph.
1202   identify_useful_nodes(useful);
1203   return useful.size();
1204 }
1205 
1206 void Compile::print_missing_nodes() {
1207 
1208   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1209   if ((_log == NULL) && (! PrintIdealNodeCount)) {
1210     return;
1211   }
1212 
1213   // This is an expensive function. It is executed only when the user
1214   // specifies VerifyIdealNodeCount option or otherwise knows the
1215   // additional work that needs to be done to identify reachable nodes
1216   // by walking the flow graph and find the missing ones using
1217   // _dead_node_list.
1218 
1219   Unique_Node_List useful(comp_arena());
1220   // Get useful node list by walking the graph.
1221   identify_useful_nodes(useful);
1222 
1223   uint l_nodes = C->live_nodes();
1224   uint l_nodes_by_walk = useful.size();
1225 
1226   if (l_nodes != l_nodes_by_walk) {
1227     if (_log != NULL) {
1228       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1229       _log->stamp();
1230       _log->end_head();
1231     }
1232     VectorSet& useful_member_set = useful.member_set();
1233     int last_idx = l_nodes_by_walk;
1234     for (int i = 0; i < last_idx; i++) {
1235       if (useful_member_set.test(i)) {
1236         if (_dead_node_list.test(i)) {
1237           if (_log != NULL) {
1238             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1239           }
1240           if (PrintIdealNodeCount) {
1241             // Print the log message to tty
1242               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1243               useful.at(i)->dump();
1244           }
1245         }
1246       }
1247       else if (! _dead_node_list.test(i)) {
1248         if (_log != NULL) {
1249           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1250         }
1251         if (PrintIdealNodeCount) {
1252           // Print the log message to tty
1253           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1254         }
1255       }
1256     }
1257     if (_log != NULL) {
1258       _log->tail("mismatched_nodes");
1259     }
1260   }
1261 }
1262 void Compile::record_modified_node(Node* n) {
1263   if (_modified_nodes != NULL && !_inlining_incrementally &&
1264       n->outcnt() != 0 && !n->is_Con()) {
1265     _modified_nodes->push(n);
1266   }
1267 }
1268 
1269 void Compile::remove_modified_node(Node* n) {
1270   if (_modified_nodes != NULL) {
1271     _modified_nodes->remove(n);
1272   }
1273 }
1274 #endif
1275 
1276 #ifndef PRODUCT
1277 void Compile::verify_top(Node* tn) const {
1278   if (tn != NULL) {
1279     assert(tn->is_Con(), "top node must be a constant");
1280     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1281     assert(tn->in(0) != NULL, "must have live top node");
1282   }
1283 }
1284 #endif
1285 
1286 
1287 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1288 
1289 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1290   guarantee(arr != NULL, "");
1291   int num_blocks = arr->length();
1292   if (grow_by < num_blocks)  grow_by = num_blocks;
1293   int num_notes = grow_by * _node_notes_block_size;
1294   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1295   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1296   while (num_notes > 0) {
1297     arr->append(notes);
1298     notes     += _node_notes_block_size;
1299     num_notes -= _node_notes_block_size;
1300   }
1301   assert(num_notes == 0, "exact multiple, please");
1302 }
1303 
1304 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1305   if (source == NULL || dest == NULL)  return false;
1306 
1307   if (dest->is_Con())
1308     return false;               // Do not push debug info onto constants.
1309 
1310 #ifdef ASSERT
1311   // Leave a bread crumb trail pointing to the original node:
1312   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1313     dest->set_debug_orig(source);
1314   }
1315 #endif
1316 
1317   if (node_note_array() == NULL)
1318     return false;               // Not collecting any notes now.
1319 
1320   // This is a copy onto a pre-existing node, which may already have notes.
1321   // If both nodes have notes, do not overwrite any pre-existing notes.
1322   Node_Notes* source_notes = node_notes_at(source->_idx);
1323   if (source_notes == NULL || source_notes->is_clear())  return false;
1324   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1325   if (dest_notes == NULL || dest_notes->is_clear()) {
1326     return set_node_notes_at(dest->_idx, source_notes);
1327   }
1328 
1329   Node_Notes merged_notes = (*source_notes);
1330   // The order of operations here ensures that dest notes will win...
1331   merged_notes.update_from(dest_notes);
1332   return set_node_notes_at(dest->_idx, &merged_notes);
1333 }
1334 
1335 
1336 //--------------------------allow_range_check_smearing-------------------------
1337 // Gating condition for coalescing similar range checks.
1338 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1339 // single covering check that is at least as strong as any of them.
1340 // If the optimization succeeds, the simplified (strengthened) range check
1341 // will always succeed.  If it fails, we will deopt, and then give up
1342 // on the optimization.
1343 bool Compile::allow_range_check_smearing() const {
1344   // If this method has already thrown a range-check,
1345   // assume it was because we already tried range smearing
1346   // and it failed.
1347   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1348   return !already_trapped;
1349 }
1350 
1351 
1352 //------------------------------flatten_alias_type-----------------------------
1353 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1354   int offset = tj->offset();
1355   TypePtr::PTR ptr = tj->ptr();
1356 
1357   // Known instance (scalarizable allocation) alias only with itself.
1358   bool is_known_inst = tj->isa_oopptr() != NULL &&
1359                        tj->is_oopptr()->is_known_instance();
1360 
1361   // Process weird unsafe references.
1362   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1363     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1364     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1365     tj = TypeOopPtr::BOTTOM;
1366     ptr = tj->ptr();
1367     offset = tj->offset();
1368   }
1369 
1370   // Array pointers need some flattening
1371   const TypeAryPtr *ta = tj->isa_aryptr();
1372   if (ta && ta->is_stable()) {
1373     // Erase stability property for alias analysis.
1374     tj = ta = ta->cast_to_stable(false);
1375   }
1376   if( ta && is_known_inst ) {
1377     if ( offset != Type::OffsetBot &&
1378          offset > arrayOopDesc::length_offset_in_bytes() ) {
1379       offset = Type::OffsetBot; // Flatten constant access into array body only
1380       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1381     }
1382   } else if( ta && _AliasLevel >= 2 ) {
1383     // For arrays indexed by constant indices, we flatten the alias
1384     // space to include all of the array body.  Only the header, klass
1385     // and array length can be accessed un-aliased.
1386     if( offset != Type::OffsetBot ) {
1387       if( ta->const_oop() ) { // MethodData* or Method*
1388         offset = Type::OffsetBot;   // Flatten constant access into array body
1389         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1390       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1391         // range is OK as-is.
1392         tj = ta = TypeAryPtr::RANGE;
1393       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1394         tj = TypeInstPtr::KLASS; // all klass loads look alike
1395         ta = TypeAryPtr::RANGE; // generic ignored junk
1396         ptr = TypePtr::BotPTR;
1397       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1398         tj = TypeInstPtr::MARK;
1399         ta = TypeAryPtr::RANGE; // generic ignored junk
1400         ptr = TypePtr::BotPTR;
1401       } else {                  // Random constant offset into array body
1402         offset = Type::OffsetBot;   // Flatten constant access into array body
1403         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1404       }
1405     }
1406     // Arrays of fixed size alias with arrays of unknown size.
1407     if (ta->size() != TypeInt::POS) {
1408       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1409       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1410     }
1411     // Arrays of known objects become arrays of unknown objects.
1412     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1413       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1414       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1415     }
1416     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1417       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1418       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1419     }
1420     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1421     // cannot be distinguished by bytecode alone.
1422     if (ta->elem() == TypeInt::BOOL) {
1423       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1424       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1425       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1426     }
1427     // During the 2nd round of IterGVN, NotNull castings are removed.
1428     // Make sure the Bottom and NotNull variants alias the same.
1429     // Also, make sure exact and non-exact variants alias the same.
1430     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1431       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1432     }
1433   }
1434 
1435   // Oop pointers need some flattening
1436   const TypeInstPtr *to = tj->isa_instptr();
1437   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1438     ciInstanceKlass *k = to->klass()->as_instance_klass();
1439     if( ptr == TypePtr::Constant ) {
1440       if (to->klass() != ciEnv::current()->Class_klass() ||
1441           offset < k->size_helper() * wordSize) {
1442         // No constant oop pointers (such as Strings); they alias with
1443         // unknown strings.
1444         assert(!is_known_inst, "not scalarizable allocation");
1445         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1446       }
1447     } else if( is_known_inst ) {
1448       tj = to; // Keep NotNull and klass_is_exact for instance type
1449     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1450       // During the 2nd round of IterGVN, NotNull castings are removed.
1451       // Make sure the Bottom and NotNull variants alias the same.
1452       // Also, make sure exact and non-exact variants alias the same.
1453       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1454     }
1455     if (to->speculative() != NULL) {
1456       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
1457     }
1458     // Canonicalize the holder of this field
1459     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1460       // First handle header references such as a LoadKlassNode, even if the
1461       // object's klass is unloaded at compile time (4965979).
1462       if (!is_known_inst) { // Do it only for non-instance types
1463         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1464       }
1465     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1466       // Static fields are in the space above the normal instance
1467       // fields in the java.lang.Class instance.
1468       if (to->klass() != ciEnv::current()->Class_klass()) {
1469         to = NULL;
1470         tj = TypeOopPtr::BOTTOM;
1471         offset = tj->offset();
1472       }
1473     } else {
1474       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1475       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1476         if( is_known_inst ) {
1477           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1478         } else {
1479           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1480         }
1481       }
1482     }
1483   }
1484 
1485   // Klass pointers to object array klasses need some flattening
1486   const TypeKlassPtr *tk = tj->isa_klassptr();
1487   if( tk ) {
1488     // If we are referencing a field within a Klass, we need
1489     // to assume the worst case of an Object.  Both exact and
1490     // inexact types must flatten to the same alias class so
1491     // use NotNull as the PTR.
1492     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1493 
1494       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1495                                    TypeKlassPtr::OBJECT->klass(),
1496                                    offset);
1497     }
1498 
1499     ciKlass* klass = tk->klass();
1500     if( klass->is_obj_array_klass() ) {
1501       ciKlass* k = TypeAryPtr::OOPS->klass();
1502       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1503         k = TypeInstPtr::BOTTOM->klass();
1504       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1505     }
1506 
1507     // Check for precise loads from the primary supertype array and force them
1508     // to the supertype cache alias index.  Check for generic array loads from
1509     // the primary supertype array and also force them to the supertype cache
1510     // alias index.  Since the same load can reach both, we need to merge
1511     // these 2 disparate memories into the same alias class.  Since the
1512     // primary supertype array is read-only, there's no chance of confusion
1513     // where we bypass an array load and an array store.
1514     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1515     if (offset == Type::OffsetBot ||
1516         (offset >= primary_supers_offset &&
1517          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1518         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1519       offset = in_bytes(Klass::secondary_super_cache_offset());
1520       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1521     }
1522   }
1523 
1524   // Flatten all Raw pointers together.
1525   if (tj->base() == Type::RawPtr)
1526     tj = TypeRawPtr::BOTTOM;
1527 
1528   if (tj->base() == Type::AnyPtr)
1529     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1530 
1531   // Flatten all to bottom for now
1532   switch( _AliasLevel ) {
1533   case 0:
1534     tj = TypePtr::BOTTOM;
1535     break;
1536   case 1:                       // Flatten to: oop, static, field or array
1537     switch (tj->base()) {
1538     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1539     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1540     case Type::AryPtr:   // do not distinguish arrays at all
1541     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1542     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1543     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1544     default: ShouldNotReachHere();
1545     }
1546     break;
1547   case 2:                       // No collapsing at level 2; keep all splits
1548   case 3:                       // No collapsing at level 3; keep all splits
1549     break;
1550   default:
1551     Unimplemented();
1552   }
1553 
1554   offset = tj->offset();
1555   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1556 
1557   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1558           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1559           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1560           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1561           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1562           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1563           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
1564           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1565   assert( tj->ptr() != TypePtr::TopPTR &&
1566           tj->ptr() != TypePtr::AnyNull &&
1567           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1568 //    assert( tj->ptr() != TypePtr::Constant ||
1569 //            tj->base() == Type::RawPtr ||
1570 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1571 
1572   return tj;
1573 }
1574 
1575 void Compile::AliasType::Init(int i, const TypePtr* at) {
1576   _index = i;
1577   _adr_type = at;
1578   _field = NULL;
1579   _element = NULL;
1580   _is_rewritable = true; // default
1581   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1582   if (atoop != NULL && atoop->is_known_instance()) {
1583     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1584     _general_index = Compile::current()->get_alias_index(gt);
1585   } else {
1586     _general_index = 0;
1587   }
1588 }
1589 
1590 //---------------------------------print_on------------------------------------
1591 #ifndef PRODUCT
1592 void Compile::AliasType::print_on(outputStream* st) {
1593   if (index() < 10)
1594         st->print("@ <%d> ", index());
1595   else  st->print("@ <%d>",  index());
1596   st->print(is_rewritable() ? "   " : " RO");
1597   int offset = adr_type()->offset();
1598   if (offset == Type::OffsetBot)
1599         st->print(" +any");
1600   else  st->print(" +%-3d", offset);
1601   st->print(" in ");
1602   adr_type()->dump_on(st);
1603   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1604   if (field() != NULL && tjp) {
1605     if (tjp->klass()  != field()->holder() ||
1606         tjp->offset() != field()->offset_in_bytes()) {
1607       st->print(" != ");
1608       field()->print();
1609       st->print(" ***");
1610     }
1611   }
1612 }
1613 
1614 void print_alias_types() {
1615   Compile* C = Compile::current();
1616   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1617   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1618     C->alias_type(idx)->print_on(tty);
1619     tty->cr();
1620   }
1621 }
1622 #endif
1623 
1624 
1625 //----------------------------probe_alias_cache--------------------------------
1626 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1627   intptr_t key = (intptr_t) adr_type;
1628   key ^= key >> logAliasCacheSize;
1629   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1630 }
1631 
1632 
1633 //-----------------------------grow_alias_types--------------------------------
1634 void Compile::grow_alias_types() {
1635   const int old_ats  = _max_alias_types; // how many before?
1636   const int new_ats  = old_ats;          // how many more?
1637   const int grow_ats = old_ats+new_ats;  // how many now?
1638   _max_alias_types = grow_ats;
1639   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1640   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1641   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1642   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1643 }
1644 
1645 
1646 //--------------------------------find_alias_type------------------------------
1647 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1648   if (_AliasLevel == 0)
1649     return alias_type(AliasIdxBot);
1650 
1651   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1652   if (ace->_adr_type == adr_type) {
1653     return alias_type(ace->_index);
1654   }
1655 
1656   // Handle special cases.
1657   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1658   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1659 
1660   // Do it the slow way.
1661   const TypePtr* flat = flatten_alias_type(adr_type);
1662 
1663 #ifdef ASSERT
1664   assert(flat == flatten_alias_type(flat), "idempotent");
1665   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
1666   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1667     const TypeOopPtr* foop = flat->is_oopptr();
1668     // Scalarizable allocations have exact klass always.
1669     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1670     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1671     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
1672   }
1673   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
1674 #endif
1675 
1676   int idx = AliasIdxTop;
1677   for (int i = 0; i < num_alias_types(); i++) {
1678     if (alias_type(i)->adr_type() == flat) {
1679       idx = i;
1680       break;
1681     }
1682   }
1683 
1684   if (idx == AliasIdxTop) {
1685     if (no_create)  return NULL;
1686     // Grow the array if necessary.
1687     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1688     // Add a new alias type.
1689     idx = _num_alias_types++;
1690     _alias_types[idx]->Init(idx, flat);
1691     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1692     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1693     if (flat->isa_instptr()) {
1694       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1695           && flat->is_instptr()->klass() == env()->Class_klass())
1696         alias_type(idx)->set_rewritable(false);
1697     }
1698     if (flat->isa_aryptr()) {
1699 #ifdef ASSERT
1700       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1701       // (T_BYTE has the weakest alignment and size restrictions...)
1702       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1703 #endif
1704       if (flat->offset() == TypePtr::OffsetBot) {
1705         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1706       }
1707     }
1708     if (flat->isa_klassptr()) {
1709       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1710         alias_type(idx)->set_rewritable(false);
1711       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1712         alias_type(idx)->set_rewritable(false);
1713       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1714         alias_type(idx)->set_rewritable(false);
1715       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1716         alias_type(idx)->set_rewritable(false);
1717     }
1718     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1719     // but the base pointer type is not distinctive enough to identify
1720     // references into JavaThread.)
1721 
1722     // Check for final fields.
1723     const TypeInstPtr* tinst = flat->isa_instptr();
1724     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1725       ciField* field;
1726       if (tinst->const_oop() != NULL &&
1727           tinst->klass() == ciEnv::current()->Class_klass() &&
1728           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1729         // static field
1730         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1731         field = k->get_field_by_offset(tinst->offset(), true);
1732       } else {
1733         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1734         field = k->get_field_by_offset(tinst->offset(), false);
1735       }
1736       assert(field == NULL ||
1737              original_field == NULL ||
1738              (field->holder() == original_field->holder() &&
1739               field->offset() == original_field->offset() &&
1740               field->is_static() == original_field->is_static()), "wrong field?");
1741       // Set field() and is_rewritable() attributes.
1742       if (field != NULL)  alias_type(idx)->set_field(field);
1743     }
1744   }
1745 
1746   // Fill the cache for next time.
1747   ace->_adr_type = adr_type;
1748   ace->_index    = idx;
1749   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1750 
1751   // Might as well try to fill the cache for the flattened version, too.
1752   AliasCacheEntry* face = probe_alias_cache(flat);
1753   if (face->_adr_type == NULL) {
1754     face->_adr_type = flat;
1755     face->_index    = idx;
1756     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1757   }
1758 
1759   return alias_type(idx);
1760 }
1761 
1762 
1763 Compile::AliasType* Compile::alias_type(ciField* field) {
1764   const TypeOopPtr* t;
1765   if (field->is_static())
1766     t = TypeInstPtr::make(field->holder()->java_mirror());
1767   else
1768     t = TypeOopPtr::make_from_klass_raw(field->holder());
1769   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1770   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1771   return atp;
1772 }
1773 
1774 
1775 //------------------------------have_alias_type--------------------------------
1776 bool Compile::have_alias_type(const TypePtr* adr_type) {
1777   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1778   if (ace->_adr_type == adr_type) {
1779     return true;
1780   }
1781 
1782   // Handle special cases.
1783   if (adr_type == NULL)             return true;
1784   if (adr_type == TypePtr::BOTTOM)  return true;
1785 
1786   return find_alias_type(adr_type, true, NULL) != NULL;
1787 }
1788 
1789 //-----------------------------must_alias--------------------------------------
1790 // True if all values of the given address type are in the given alias category.
1791 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1792   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1793   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1794   if (alias_idx == AliasIdxTop)         return false; // the empty category
1795   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1796 
1797   // the only remaining possible overlap is identity
1798   int adr_idx = get_alias_index(adr_type);
1799   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1800   assert(adr_idx == alias_idx ||
1801          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1802           && adr_type                       != TypeOopPtr::BOTTOM),
1803          "should not be testing for overlap with an unsafe pointer");
1804   return adr_idx == alias_idx;
1805 }
1806 
1807 //------------------------------can_alias--------------------------------------
1808 // True if any values of the given address type are in the given alias category.
1809 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1810   if (alias_idx == AliasIdxTop)         return false; // the empty category
1811   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1812   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1813   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1814 
1815   // the only remaining possible overlap is identity
1816   int adr_idx = get_alias_index(adr_type);
1817   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1818   return adr_idx == alias_idx;
1819 }
1820 
1821 
1822 
1823 //---------------------------pop_warm_call-------------------------------------
1824 WarmCallInfo* Compile::pop_warm_call() {
1825   WarmCallInfo* wci = _warm_calls;
1826   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1827   return wci;
1828 }
1829 
1830 //----------------------------Inline_Warm--------------------------------------
1831 int Compile::Inline_Warm() {
1832   // If there is room, try to inline some more warm call sites.
1833   // %%% Do a graph index compaction pass when we think we're out of space?
1834   if (!InlineWarmCalls)  return 0;
1835 
1836   int calls_made_hot = 0;
1837   int room_to_grow   = NodeCountInliningCutoff - unique();
1838   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1839   int amount_grown   = 0;
1840   WarmCallInfo* call;
1841   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1842     int est_size = (int)call->size();
1843     if (est_size > (room_to_grow - amount_grown)) {
1844       // This one won't fit anyway.  Get rid of it.
1845       call->make_cold();
1846       continue;
1847     }
1848     call->make_hot();
1849     calls_made_hot++;
1850     amount_grown   += est_size;
1851     amount_to_grow -= est_size;
1852   }
1853 
1854   if (calls_made_hot > 0)  set_major_progress();
1855   return calls_made_hot;
1856 }
1857 
1858 
1859 //----------------------------Finish_Warm--------------------------------------
1860 void Compile::Finish_Warm() {
1861   if (!InlineWarmCalls)  return;
1862   if (failing())  return;
1863   if (warm_calls() == NULL)  return;
1864 
1865   // Clean up loose ends, if we are out of space for inlining.
1866   WarmCallInfo* call;
1867   while ((call = pop_warm_call()) != NULL) {
1868     call->make_cold();
1869   }
1870 }
1871 
1872 //---------------------cleanup_loop_predicates-----------------------
1873 // Remove the opaque nodes that protect the predicates so that all unused
1874 // checks and uncommon_traps will be eliminated from the ideal graph
1875 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1876   if (predicate_count()==0) return;
1877   for (int i = predicate_count(); i > 0; i--) {
1878     Node * n = predicate_opaque1_node(i-1);
1879     assert(n->Opcode() == Op_Opaque1, "must be");
1880     igvn.replace_node(n, n->in(1));
1881   }
1882   assert(predicate_count()==0, "should be clean!");
1883 }
1884 
1885 // StringOpts and late inlining of string methods
1886 void Compile::inline_string_calls(bool parse_time) {
1887   {
1888     // remove useless nodes to make the usage analysis simpler
1889     ResourceMark rm;
1890     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1891   }
1892 
1893   {
1894     ResourceMark rm;
1895     print_method(PHASE_BEFORE_STRINGOPTS, 3);
1896     PhaseStringOpts pso(initial_gvn(), for_igvn());
1897     print_method(PHASE_AFTER_STRINGOPTS, 3);
1898   }
1899 
1900   // now inline anything that we skipped the first time around
1901   if (!parse_time) {
1902     _late_inlines_pos = _late_inlines.length();
1903   }
1904 
1905   while (_string_late_inlines.length() > 0) {
1906     CallGenerator* cg = _string_late_inlines.pop();
1907     cg->do_late_inline();
1908     if (failing())  return;
1909   }
1910   _string_late_inlines.trunc_to(0);
1911 }
1912 
1913 // Late inlining of boxing methods
1914 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
1915   if (_boxing_late_inlines.length() > 0) {
1916     assert(has_boxed_value(), "inconsistent");
1917 
1918     PhaseGVN* gvn = initial_gvn();
1919     set_inlining_incrementally(true);
1920 
1921     assert( igvn._worklist.size() == 0, "should be done with igvn" );
1922     for_igvn()->clear();
1923     gvn->replace_with(&igvn);
1924 
1925     _late_inlines_pos = _late_inlines.length();
1926 
1927     while (_boxing_late_inlines.length() > 0) {
1928       CallGenerator* cg = _boxing_late_inlines.pop();
1929       cg->do_late_inline();
1930       if (failing())  return;
1931     }
1932     _boxing_late_inlines.trunc_to(0);
1933 
1934     {
1935       ResourceMark rm;
1936       PhaseRemoveUseless pru(gvn, for_igvn());
1937     }
1938 
1939     igvn = PhaseIterGVN(gvn);
1940     igvn.optimize();
1941 
1942     set_inlining_progress(false);
1943     set_inlining_incrementally(false);
1944   }
1945 }
1946 
1947 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
1948   assert(IncrementalInline, "incremental inlining should be on");
1949   PhaseGVN* gvn = initial_gvn();
1950 
1951   set_inlining_progress(false);
1952   for_igvn()->clear();
1953   gvn->replace_with(&igvn);
1954 
1955   {
1956     TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
1957     int i = 0;
1958     for (; i <_late_inlines.length() && !inlining_progress(); i++) {
1959       CallGenerator* cg = _late_inlines.at(i);
1960       _late_inlines_pos = i+1;
1961       cg->do_late_inline();
1962       if (failing())  return;
1963     }
1964     int j = 0;
1965     for (; i < _late_inlines.length(); i++, j++) {
1966       _late_inlines.at_put(j, _late_inlines.at(i));
1967     }
1968     _late_inlines.trunc_to(j);
1969   }
1970 
1971   {
1972     TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
1973     ResourceMark rm;
1974     PhaseRemoveUseless pru(gvn, for_igvn());
1975   }
1976 
1977   {
1978     TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
1979     igvn = PhaseIterGVN(gvn);
1980   }
1981 }
1982 
1983 // Perform incremental inlining until bound on number of live nodes is reached
1984 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
1985   TracePhase tp("incrementalInline", &timers[_t_incrInline]);
1986 
1987   PhaseGVN* gvn = initial_gvn();
1988 
1989   set_inlining_incrementally(true);
1990   set_inlining_progress(true);
1991   uint low_live_nodes = 0;
1992 
1993   while(inlining_progress() && _late_inlines.length() > 0) {
1994 
1995     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
1996       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
1997         TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
1998         // PhaseIdealLoop is expensive so we only try it once we are
1999         // out of live nodes and we only try it again if the previous
2000         // helped got the number of nodes down significantly
2001         PhaseIdealLoop ideal_loop( igvn, false, true );
2002         if (failing())  return;
2003         low_live_nodes = live_nodes();
2004         _major_progress = true;
2005       }
2006 
2007       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2008         break;
2009       }
2010     }
2011 
2012     inline_incrementally_one(igvn);
2013 
2014     if (failing())  return;
2015 
2016     {
2017       TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2018       igvn.optimize();
2019     }
2020 
2021     if (failing())  return;
2022   }
2023 
2024   assert( igvn._worklist.size() == 0, "should be done with igvn" );
2025 
2026   if (_string_late_inlines.length() > 0) {
2027     assert(has_stringbuilder(), "inconsistent");
2028     for_igvn()->clear();
2029     initial_gvn()->replace_with(&igvn);
2030 
2031     inline_string_calls(false);
2032 
2033     if (failing())  return;
2034 
2035     {
2036       TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2037       ResourceMark rm;
2038       PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2039     }
2040 
2041     {
2042       TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2043       igvn = PhaseIterGVN(gvn);
2044       igvn.optimize();
2045     }
2046   }
2047 
2048   set_inlining_incrementally(false);
2049 }
2050 
2051 
2052 //------------------------------Optimize---------------------------------------
2053 // Given a graph, optimize it.
2054 void Compile::Optimize() {
2055   TracePhase tp("optimizer", &timers[_t_optimizer]);
2056 
2057 #ifndef PRODUCT
2058   if (env()->break_at_compile()) {
2059     BREAKPOINT;
2060   }
2061 
2062 #endif
2063 
2064   ResourceMark rm;
2065   int          loop_opts_cnt;
2066 
2067   print_inlining_reinit();
2068 
2069   NOT_PRODUCT( verify_graph_edges(); )
2070 
2071   print_method(PHASE_AFTER_PARSING);
2072 
2073  {
2074   // Iterative Global Value Numbering, including ideal transforms
2075   // Initialize IterGVN with types and values from parse-time GVN
2076   PhaseIterGVN igvn(initial_gvn());
2077 #ifdef ASSERT
2078   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2079 #endif
2080   {
2081     TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2082     igvn.optimize();
2083   }
2084 
2085   print_method(PHASE_ITER_GVN1, 2);
2086 
2087   if (failing())  return;
2088 
2089   inline_incrementally(igvn);
2090 
2091   print_method(PHASE_INCREMENTAL_INLINE, 2);
2092 
2093   if (failing())  return;
2094 
2095   if (eliminate_boxing()) {
2096     // Inline valueOf() methods now.
2097     inline_boxing_calls(igvn);
2098 
2099     if (AlwaysIncrementalInline) {
2100       inline_incrementally(igvn);
2101     }
2102 
2103     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2104 
2105     if (failing())  return;
2106   }
2107 
2108   // Remove the speculative part of types and clean up the graph from
2109   // the extra CastPP nodes whose only purpose is to carry them. Do
2110   // that early so that optimizations are not disrupted by the extra
2111   // CastPP nodes.
2112   remove_speculative_types(igvn);
2113 
2114   // No more new expensive nodes will be added to the list from here
2115   // so keep only the actual candidates for optimizations.
2116   cleanup_expensive_nodes(igvn);
2117 
2118   // Perform escape analysis
2119   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2120     if (has_loops()) {
2121       // Cleanup graph (remove dead nodes).
2122       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2123       PhaseIdealLoop ideal_loop( igvn, false, true );
2124       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2125       if (failing())  return;
2126     }
2127     ConnectionGraph::do_analysis(this, &igvn);
2128 
2129     if (failing())  return;
2130 
2131     // Optimize out fields loads from scalar replaceable allocations.
2132     igvn.optimize();
2133     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2134 
2135     if (failing())  return;
2136 
2137     if (congraph() != NULL && macro_count() > 0) {
2138       TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2139       PhaseMacroExpand mexp(igvn);
2140       mexp.eliminate_macro_nodes();
2141       igvn.set_delay_transform(false);
2142 
2143       igvn.optimize();
2144       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2145 
2146       if (failing())  return;
2147     }
2148   }
2149 
2150   // Loop transforms on the ideal graph.  Range Check Elimination,
2151   // peeling, unrolling, etc.
2152 
2153   // Set loop opts counter
2154   loop_opts_cnt = num_loop_opts();
2155   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2156     {
2157       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2158       PhaseIdealLoop ideal_loop( igvn, true );
2159       loop_opts_cnt--;
2160       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2161       if (failing())  return;
2162     }
2163     // Loop opts pass if partial peeling occurred in previous pass
2164     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
2165       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2166       PhaseIdealLoop ideal_loop( igvn, false );
2167       loop_opts_cnt--;
2168       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2169       if (failing())  return;
2170     }
2171     // Loop opts pass for loop-unrolling before CCP
2172     if(major_progress() && (loop_opts_cnt > 0)) {
2173       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2174       PhaseIdealLoop ideal_loop( igvn, false );
2175       loop_opts_cnt--;
2176       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2177     }
2178     if (!failing()) {
2179       // Verify that last round of loop opts produced a valid graph
2180       TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2181       PhaseIdealLoop::verify(igvn);
2182     }
2183   }
2184   if (failing())  return;
2185 
2186   // Conditional Constant Propagation;
2187   PhaseCCP ccp( &igvn );
2188   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2189   {
2190     TracePhase tp("ccp", &timers[_t_ccp]);
2191     ccp.do_transform();
2192   }
2193   print_method(PHASE_CPP1, 2);
2194 
2195   assert( true, "Break here to ccp.dump_old2new_map()");
2196 
2197   // Iterative Global Value Numbering, including ideal transforms
2198   {
2199     TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2200     igvn = ccp;
2201     igvn.optimize();
2202   }
2203 
2204   print_method(PHASE_ITER_GVN2, 2);
2205 
2206   if (failing())  return;
2207 
2208   // Loop transforms on the ideal graph.  Range Check Elimination,
2209   // peeling, unrolling, etc.
2210   if(loop_opts_cnt > 0) {
2211     debug_only( int cnt = 0; );
2212     while(major_progress() && (loop_opts_cnt > 0)) {
2213       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2214       assert( cnt++ < 40, "infinite cycle in loop optimization" );
2215       PhaseIdealLoop ideal_loop( igvn, true);
2216       loop_opts_cnt--;
2217       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2218       if (failing())  return;
2219     }
2220   }
2221 
2222   {
2223     // Verify that all previous optimizations produced a valid graph
2224     // at least to this point, even if no loop optimizations were done.
2225     TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2226     PhaseIdealLoop::verify(igvn);
2227   }
2228 
2229   {
2230     TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2231     PhaseMacroExpand  mex(igvn);
2232     if (mex.expand_macro_nodes()) {
2233       assert(failing(), "must bail out w/ explicit message");
2234       return;
2235     }
2236   }
2237 
2238   DEBUG_ONLY( _modified_nodes = NULL; )
2239  } // (End scope of igvn; run destructor if necessary for asserts.)
2240 
2241   process_print_inlining();
2242   // A method with only infinite loops has no edges entering loops from root
2243   {
2244     TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2245     if (final_graph_reshaping()) {
2246       assert(failing(), "must bail out w/ explicit message");
2247       return;
2248     }
2249   }
2250 
2251   print_method(PHASE_OPTIMIZE_FINISHED, 2);
2252 }
2253 
2254 
2255 //------------------------------Code_Gen---------------------------------------
2256 // Given a graph, generate code for it
2257 void Compile::Code_Gen() {
2258   if (failing()) {
2259     return;
2260   }
2261 
2262   // Perform instruction selection.  You might think we could reclaim Matcher
2263   // memory PDQ, but actually the Matcher is used in generating spill code.
2264   // Internals of the Matcher (including some VectorSets) must remain live
2265   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2266   // set a bit in reclaimed memory.
2267 
2268   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2269   // nodes.  Mapping is only valid at the root of each matched subtree.
2270   NOT_PRODUCT( verify_graph_edges(); )
2271 
2272   Matcher matcher;
2273   _matcher = &matcher;
2274   {
2275     TracePhase tp("matcher", &timers[_t_matcher]);
2276     matcher.match();
2277   }
2278   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2279   // nodes.  Mapping is only valid at the root of each matched subtree.
2280   NOT_PRODUCT( verify_graph_edges(); )
2281 
2282   // If you have too many nodes, or if matching has failed, bail out
2283   check_node_count(0, "out of nodes matching instructions");
2284   if (failing()) {
2285     return;
2286   }
2287 
2288   // Build a proper-looking CFG
2289   PhaseCFG cfg(node_arena(), root(), matcher);
2290   _cfg = &cfg;
2291   {
2292     TracePhase tp("scheduler", &timers[_t_scheduler]);
2293     bool success = cfg.do_global_code_motion();
2294     if (!success) {
2295       return;
2296     }
2297 
2298     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2299     NOT_PRODUCT( verify_graph_edges(); )
2300     debug_only( cfg.verify(); )
2301   }
2302 
2303   PhaseChaitin regalloc(unique(), cfg, matcher);
2304   _regalloc = &regalloc;
2305   {
2306     TracePhase tp("regalloc", &timers[_t_registerAllocation]);
2307     // Perform register allocation.  After Chaitin, use-def chains are
2308     // no longer accurate (at spill code) and so must be ignored.
2309     // Node->LRG->reg mappings are still accurate.
2310     _regalloc->Register_Allocate();
2311 
2312     // Bail out if the allocator builds too many nodes
2313     if (failing()) {
2314       return;
2315     }
2316   }
2317 
2318   // Prior to register allocation we kept empty basic blocks in case the
2319   // the allocator needed a place to spill.  After register allocation we
2320   // are not adding any new instructions.  If any basic block is empty, we
2321   // can now safely remove it.
2322   {
2323     TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
2324     cfg.remove_empty_blocks();
2325     if (do_freq_based_layout()) {
2326       PhaseBlockLayout layout(cfg);
2327     } else {
2328       cfg.set_loop_alignment();
2329     }
2330     cfg.fixup_flow();
2331   }
2332 
2333   // Apply peephole optimizations
2334   if( OptoPeephole ) {
2335     TracePhase tp("peephole", &timers[_t_peephole]);
2336     PhasePeephole peep( _regalloc, cfg);
2337     peep.do_transform();
2338   }
2339 
2340   // Do late expand if CPU requires this.
2341   if (Matcher::require_postalloc_expand) {
2342     TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
2343     cfg.postalloc_expand(_regalloc);
2344   }
2345 
2346   // Convert Nodes to instruction bits in a buffer
2347   {
2348     TraceTime tp("output", &timers[_t_output], CITime);
2349     Output();
2350   }
2351 
2352   print_method(PHASE_FINAL_CODE);
2353 
2354   // He's dead, Jim.
2355   _cfg     = (PhaseCFG*)0xdeadbeef;
2356   _regalloc = (PhaseChaitin*)0xdeadbeef;
2357 }
2358 
2359 
2360 //------------------------------dump_asm---------------------------------------
2361 // Dump formatted assembly
2362 #ifndef PRODUCT
2363 void Compile::dump_asm(int *pcs, uint pc_limit) {
2364   bool cut_short = false;
2365   tty->print_cr("#");
2366   tty->print("#  ");  _tf->dump();  tty->cr();
2367   tty->print_cr("#");
2368 
2369   // For all blocks
2370   int pc = 0x0;                 // Program counter
2371   char starts_bundle = ' ';
2372   _regalloc->dump_frame();
2373 
2374   Node *n = NULL;
2375   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2376     if (VMThread::should_terminate()) {
2377       cut_short = true;
2378       break;
2379     }
2380     Block* block = _cfg->get_block(i);
2381     if (block->is_connector() && !Verbose) {
2382       continue;
2383     }
2384     n = block->head();
2385     if (pcs && n->_idx < pc_limit) {
2386       tty->print("%3.3x   ", pcs[n->_idx]);
2387     } else {
2388       tty->print("      ");
2389     }
2390     block->dump_head(_cfg);
2391     if (block->is_connector()) {
2392       tty->print_cr("        # Empty connector block");
2393     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2394       tty->print_cr("        # Block is sole successor of call");
2395     }
2396 
2397     // For all instructions
2398     Node *delay = NULL;
2399     for (uint j = 0; j < block->number_of_nodes(); j++) {
2400       if (VMThread::should_terminate()) {
2401         cut_short = true;
2402         break;
2403       }
2404       n = block->get_node(j);
2405       if (valid_bundle_info(n)) {
2406         Bundle* bundle = node_bundling(n);
2407         if (bundle->used_in_unconditional_delay()) {
2408           delay = n;
2409           continue;
2410         }
2411         if (bundle->starts_bundle()) {
2412           starts_bundle = '+';
2413         }
2414       }
2415 
2416       if (WizardMode) {
2417         n->dump();
2418       }
2419 
2420       if( !n->is_Region() &&    // Dont print in the Assembly
2421           !n->is_Phi() &&       // a few noisely useless nodes
2422           !n->is_Proj() &&
2423           !n->is_MachTemp() &&
2424           !n->is_SafePointScalarObject() &&
2425           !n->is_Catch() &&     // Would be nice to print exception table targets
2426           !n->is_MergeMem() &&  // Not very interesting
2427           !n->is_top() &&       // Debug info table constants
2428           !(n->is_Con() && !n->is_Mach())// Debug info table constants
2429           ) {
2430         if (pcs && n->_idx < pc_limit)
2431           tty->print("%3.3x", pcs[n->_idx]);
2432         else
2433           tty->print("   ");
2434         tty->print(" %c ", starts_bundle);
2435         starts_bundle = ' ';
2436         tty->print("\t");
2437         n->format(_regalloc, tty);
2438         tty->cr();
2439       }
2440 
2441       // If we have an instruction with a delay slot, and have seen a delay,
2442       // then back up and print it
2443       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2444         assert(delay != NULL, "no unconditional delay instruction");
2445         if (WizardMode) delay->dump();
2446 
2447         if (node_bundling(delay)->starts_bundle())
2448           starts_bundle = '+';
2449         if (pcs && n->_idx < pc_limit)
2450           tty->print("%3.3x", pcs[n->_idx]);
2451         else
2452           tty->print("   ");
2453         tty->print(" %c ", starts_bundle);
2454         starts_bundle = ' ';
2455         tty->print("\t");
2456         delay->format(_regalloc, tty);
2457         tty->cr();
2458         delay = NULL;
2459       }
2460 
2461       // Dump the exception table as well
2462       if( n->is_Catch() && (Verbose || WizardMode) ) {
2463         // Print the exception table for this offset
2464         _handler_table.print_subtable_for(pc);
2465       }
2466     }
2467 
2468     if (pcs && n->_idx < pc_limit)
2469       tty->print_cr("%3.3x", pcs[n->_idx]);
2470     else
2471       tty->cr();
2472 
2473     assert(cut_short || delay == NULL, "no unconditional delay branch");
2474 
2475   } // End of per-block dump
2476   tty->cr();
2477 
2478   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
2479 }
2480 #endif
2481 
2482 //------------------------------Final_Reshape_Counts---------------------------
2483 // This class defines counters to help identify when a method
2484 // may/must be executed using hardware with only 24-bit precision.
2485 struct Final_Reshape_Counts : public StackObj {
2486   int  _call_count;             // count non-inlined 'common' calls
2487   int  _float_count;            // count float ops requiring 24-bit precision
2488   int  _double_count;           // count double ops requiring more precision
2489   int  _java_call_count;        // count non-inlined 'java' calls
2490   int  _inner_loop_count;       // count loops which need alignment
2491   VectorSet _visited;           // Visitation flags
2492   Node_List _tests;             // Set of IfNodes & PCTableNodes
2493 
2494   Final_Reshape_Counts() :
2495     _call_count(0), _float_count(0), _double_count(0),
2496     _java_call_count(0), _inner_loop_count(0),
2497     _visited( Thread::current()->resource_area() ) { }
2498 
2499   void inc_call_count  () { _call_count  ++; }
2500   void inc_float_count () { _float_count ++; }
2501   void inc_double_count() { _double_count++; }
2502   void inc_java_call_count() { _java_call_count++; }
2503   void inc_inner_loop_count() { _inner_loop_count++; }
2504 
2505   int  get_call_count  () const { return _call_count  ; }
2506   int  get_float_count () const { return _float_count ; }
2507   int  get_double_count() const { return _double_count; }
2508   int  get_java_call_count() const { return _java_call_count; }
2509   int  get_inner_loop_count() const { return _inner_loop_count; }
2510 };
2511 
2512 #ifdef ASSERT
2513 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2514   ciInstanceKlass *k = tp->klass()->as_instance_klass();
2515   // Make sure the offset goes inside the instance layout.
2516   return k->contains_field_offset(tp->offset());
2517   // Note that OffsetBot and OffsetTop are very negative.
2518 }
2519 #endif
2520 
2521 // Eliminate trivially redundant StoreCMs and accumulate their
2522 // precedence edges.
2523 void Compile::eliminate_redundant_card_marks(Node* n) {
2524   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2525   if (n->in(MemNode::Address)->outcnt() > 1) {
2526     // There are multiple users of the same address so it might be
2527     // possible to eliminate some of the StoreCMs
2528     Node* mem = n->in(MemNode::Memory);
2529     Node* adr = n->in(MemNode::Address);
2530     Node* val = n->in(MemNode::ValueIn);
2531     Node* prev = n;
2532     bool done = false;
2533     // Walk the chain of StoreCMs eliminating ones that match.  As
2534     // long as it's a chain of single users then the optimization is
2535     // safe.  Eliminating partially redundant StoreCMs would require
2536     // cloning copies down the other paths.
2537     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2538       if (adr == mem->in(MemNode::Address) &&
2539           val == mem->in(MemNode::ValueIn)) {
2540         // redundant StoreCM
2541         if (mem->req() > MemNode::OopStore) {
2542           // Hasn't been processed by this code yet.
2543           n->add_prec(mem->in(MemNode::OopStore));
2544         } else {
2545           // Already converted to precedence edge
2546           for (uint i = mem->req(); i < mem->len(); i++) {
2547             // Accumulate any precedence edges
2548             if (mem->in(i) != NULL) {
2549               n->add_prec(mem->in(i));
2550             }
2551           }
2552           // Everything above this point has been processed.
2553           done = true;
2554         }
2555         // Eliminate the previous StoreCM
2556         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2557         assert(mem->outcnt() == 0, "should be dead");
2558         mem->disconnect_inputs(NULL, this);
2559       } else {
2560         prev = mem;
2561       }
2562       mem = prev->in(MemNode::Memory);
2563     }
2564   }
2565 }
2566 
2567 //------------------------------final_graph_reshaping_impl----------------------
2568 // Implement items 1-5 from final_graph_reshaping below.
2569 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2570 
2571   if ( n->outcnt() == 0 ) return; // dead node
2572   uint nop = n->Opcode();
2573 
2574   // Check for 2-input instruction with "last use" on right input.
2575   // Swap to left input.  Implements item (2).
2576   if( n->req() == 3 &&          // two-input instruction
2577       n->in(1)->outcnt() > 1 && // left use is NOT a last use
2578       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2579       n->in(2)->outcnt() == 1 &&// right use IS a last use
2580       !n->in(2)->is_Con() ) {   // right use is not a constant
2581     // Check for commutative opcode
2582     switch( nop ) {
2583     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
2584     case Op_MaxI:  case Op_MinI:
2585     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
2586     case Op_AndL:  case Op_XorL:  case Op_OrL:
2587     case Op_AndI:  case Op_XorI:  case Op_OrI: {
2588       // Move "last use" input to left by swapping inputs
2589       n->swap_edges(1, 2);
2590       break;
2591     }
2592     default:
2593       break;
2594     }
2595   }
2596 
2597 #ifdef ASSERT
2598   if( n->is_Mem() ) {
2599     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2600     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2601             // oop will be recorded in oop map if load crosses safepoint
2602             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2603                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
2604             "raw memory operations should have control edge");
2605   }
2606 #endif
2607   // Count FPU ops and common calls, implements item (3)
2608   switch( nop ) {
2609   // Count all float operations that may use FPU
2610   case Op_AddF:
2611   case Op_SubF:
2612   case Op_MulF:
2613   case Op_DivF:
2614   case Op_NegF:
2615   case Op_ModF:
2616   case Op_ConvI2F:
2617   case Op_ConF:
2618   case Op_CmpF:
2619   case Op_CmpF3:
2620   // case Op_ConvL2F: // longs are split into 32-bit halves
2621     frc.inc_float_count();
2622     break;
2623 
2624   case Op_ConvF2D:
2625   case Op_ConvD2F:
2626     frc.inc_float_count();
2627     frc.inc_double_count();
2628     break;
2629 
2630   // Count all double operations that may use FPU
2631   case Op_AddD:
2632   case Op_SubD:
2633   case Op_MulD:
2634   case Op_DivD:
2635   case Op_NegD:
2636   case Op_ModD:
2637   case Op_ConvI2D:
2638   case Op_ConvD2I:
2639   // case Op_ConvL2D: // handled by leaf call
2640   // case Op_ConvD2L: // handled by leaf call
2641   case Op_ConD:
2642   case Op_CmpD:
2643   case Op_CmpD3:
2644     frc.inc_double_count();
2645     break;
2646   case Op_Opaque1:              // Remove Opaque Nodes before matching
2647   case Op_Opaque2:              // Remove Opaque Nodes before matching
2648   case Op_Opaque3:
2649     n->subsume_by(n->in(1), this);
2650     break;
2651   case Op_CallStaticJava:
2652   case Op_CallJava:
2653   case Op_CallDynamicJava:
2654     frc.inc_java_call_count(); // Count java call site;
2655   case Op_CallRuntime:
2656   case Op_CallLeaf:
2657   case Op_CallLeafNoFP: {
2658     assert( n->is_Call(), "" );
2659     CallNode *call = n->as_Call();
2660     // Count call sites where the FP mode bit would have to be flipped.
2661     // Do not count uncommon runtime calls:
2662     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2663     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2664     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
2665       frc.inc_call_count();   // Count the call site
2666     } else {                  // See if uncommon argument is shared
2667       Node *n = call->in(TypeFunc::Parms);
2668       int nop = n->Opcode();
2669       // Clone shared simple arguments to uncommon calls, item (1).
2670       if( n->outcnt() > 1 &&
2671           !n->is_Proj() &&
2672           nop != Op_CreateEx &&
2673           nop != Op_CheckCastPP &&
2674           nop != Op_DecodeN &&
2675           nop != Op_DecodeNKlass &&
2676           !n->is_Mem() ) {
2677         Node *x = n->clone();
2678         call->set_req( TypeFunc::Parms, x );
2679       }
2680     }
2681     break;
2682   }
2683 
2684   case Op_StoreD:
2685   case Op_LoadD:
2686   case Op_LoadD_unaligned:
2687     frc.inc_double_count();
2688     goto handle_mem;
2689   case Op_StoreF:
2690   case Op_LoadF:
2691     frc.inc_float_count();
2692     goto handle_mem;
2693 
2694   case Op_StoreCM:
2695     {
2696       // Convert OopStore dependence into precedence edge
2697       Node* prec = n->in(MemNode::OopStore);
2698       n->del_req(MemNode::OopStore);
2699       n->add_prec(prec);
2700       eliminate_redundant_card_marks(n);
2701     }
2702 
2703     // fall through
2704 
2705   case Op_StoreB:
2706   case Op_StoreC:
2707   case Op_StorePConditional:
2708   case Op_StoreI:
2709   case Op_StoreL:
2710   case Op_StoreIConditional:
2711   case Op_StoreLConditional:
2712   case Op_CompareAndSwapI:
2713   case Op_CompareAndSwapL:
2714   case Op_CompareAndSwapP:
2715   case Op_CompareAndSwapN:
2716   case Op_GetAndAddI:
2717   case Op_GetAndAddL:
2718   case Op_GetAndSetI:
2719   case Op_GetAndSetL:
2720   case Op_GetAndSetP:
2721   case Op_GetAndSetN:
2722   case Op_StoreP:
2723   case Op_StoreN:
2724   case Op_StoreNKlass:
2725   case Op_LoadB:
2726   case Op_LoadUB:
2727   case Op_LoadUS:
2728   case Op_LoadI:
2729   case Op_LoadKlass:
2730   case Op_LoadNKlass:
2731   case Op_LoadL:
2732   case Op_LoadL_unaligned:
2733   case Op_LoadPLocked:
2734   case Op_LoadP:
2735   case Op_LoadN:
2736   case Op_LoadRange:
2737   case Op_LoadS: {
2738   handle_mem:
2739 #ifdef ASSERT
2740     if( VerifyOptoOopOffsets ) {
2741       assert( n->is_Mem(), "" );
2742       MemNode *mem  = (MemNode*)n;
2743       // Check to see if address types have grounded out somehow.
2744       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2745       assert( !tp || oop_offset_is_sane(tp), "" );
2746     }
2747 #endif
2748     break;
2749   }
2750 
2751   case Op_AddP: {               // Assert sane base pointers
2752     Node *addp = n->in(AddPNode::Address);
2753     assert( !addp->is_AddP() ||
2754             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2755             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2756             "Base pointers must match" );
2757 #ifdef _LP64
2758     if ((UseCompressedOops || UseCompressedClassPointers) &&
2759         addp->Opcode() == Op_ConP &&
2760         addp == n->in(AddPNode::Base) &&
2761         n->in(AddPNode::Offset)->is_Con()) {
2762       // Use addressing with narrow klass to load with offset on x86.
2763       // On sparc loading 32-bits constant and decoding it have less
2764       // instructions (4) then load 64-bits constant (7).
2765       // Do this transformation here since IGVN will convert ConN back to ConP.
2766       const Type* t = addp->bottom_type();
2767       if (t->isa_oopptr() || t->isa_klassptr()) {
2768         Node* nn = NULL;
2769 
2770         int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
2771 
2772         // Look for existing ConN node of the same exact type.
2773         Node* r  = root();
2774         uint cnt = r->outcnt();
2775         for (uint i = 0; i < cnt; i++) {
2776           Node* m = r->raw_out(i);
2777           if (m!= NULL && m->Opcode() == op &&
2778               m->bottom_type()->make_ptr() == t) {
2779             nn = m;
2780             break;
2781           }
2782         }
2783         if (nn != NULL) {
2784           // Decode a narrow oop to match address
2785           // [R12 + narrow_oop_reg<<3 + offset]
2786           if (t->isa_oopptr()) {
2787             nn = new DecodeNNode(nn, t);
2788           } else {
2789             nn = new DecodeNKlassNode(nn, t);
2790           }
2791           n->set_req(AddPNode::Base, nn);
2792           n->set_req(AddPNode::Address, nn);
2793           if (addp->outcnt() == 0) {
2794             addp->disconnect_inputs(NULL, this);
2795           }
2796         }
2797       }
2798     }
2799 #endif
2800     break;
2801   }
2802 
2803 #ifdef _LP64
2804   case Op_CastPP:
2805     if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
2806       Node* in1 = n->in(1);
2807       const Type* t = n->bottom_type();
2808       Node* new_in1 = in1->clone();
2809       new_in1->as_DecodeN()->set_type(t);
2810 
2811       if (!Matcher::narrow_oop_use_complex_address()) {
2812         //
2813         // x86, ARM and friends can handle 2 adds in addressing mode
2814         // and Matcher can fold a DecodeN node into address by using
2815         // a narrow oop directly and do implicit NULL check in address:
2816         //
2817         // [R12 + narrow_oop_reg<<3 + offset]
2818         // NullCheck narrow_oop_reg
2819         //
2820         // On other platforms (Sparc) we have to keep new DecodeN node and
2821         // use it to do implicit NULL check in address:
2822         //
2823         // decode_not_null narrow_oop_reg, base_reg
2824         // [base_reg + offset]
2825         // NullCheck base_reg
2826         //
2827         // Pin the new DecodeN node to non-null path on these platform (Sparc)
2828         // to keep the information to which NULL check the new DecodeN node
2829         // corresponds to use it as value in implicit_null_check().
2830         //
2831         new_in1->set_req(0, n->in(0));
2832       }
2833 
2834       n->subsume_by(new_in1, this);
2835       if (in1->outcnt() == 0) {
2836         in1->disconnect_inputs(NULL, this);
2837       }
2838     }
2839     break;
2840 
2841   case Op_CmpP:
2842     // Do this transformation here to preserve CmpPNode::sub() and
2843     // other TypePtr related Ideal optimizations (for example, ptr nullness).
2844     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
2845       Node* in1 = n->in(1);
2846       Node* in2 = n->in(2);
2847       if (!in1->is_DecodeNarrowPtr()) {
2848         in2 = in1;
2849         in1 = n->in(2);
2850       }
2851       assert(in1->is_DecodeNarrowPtr(), "sanity");
2852 
2853       Node* new_in2 = NULL;
2854       if (in2->is_DecodeNarrowPtr()) {
2855         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
2856         new_in2 = in2->in(1);
2857       } else if (in2->Opcode() == Op_ConP) {
2858         const Type* t = in2->bottom_type();
2859         if (t == TypePtr::NULL_PTR) {
2860           assert(in1->is_DecodeN(), "compare klass to null?");
2861           // Don't convert CmpP null check into CmpN if compressed
2862           // oops implicit null check is not generated.
2863           // This will allow to generate normal oop implicit null check.
2864           if (Matcher::gen_narrow_oop_implicit_null_checks())
2865             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
2866           //
2867           // This transformation together with CastPP transformation above
2868           // will generated code for implicit NULL checks for compressed oops.
2869           //
2870           // The original code after Optimize()
2871           //
2872           //    LoadN memory, narrow_oop_reg
2873           //    decode narrow_oop_reg, base_reg
2874           //    CmpP base_reg, NULL
2875           //    CastPP base_reg // NotNull
2876           //    Load [base_reg + offset], val_reg
2877           //
2878           // after these transformations will be
2879           //
2880           //    LoadN memory, narrow_oop_reg
2881           //    CmpN narrow_oop_reg, NULL
2882           //    decode_not_null narrow_oop_reg, base_reg
2883           //    Load [base_reg + offset], val_reg
2884           //
2885           // and the uncommon path (== NULL) will use narrow_oop_reg directly
2886           // since narrow oops can be used in debug info now (see the code in
2887           // final_graph_reshaping_walk()).
2888           //
2889           // At the end the code will be matched to
2890           // on x86:
2891           //
2892           //    Load_narrow_oop memory, narrow_oop_reg
2893           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
2894           //    NullCheck narrow_oop_reg
2895           //
2896           // and on sparc:
2897           //
2898           //    Load_narrow_oop memory, narrow_oop_reg
2899           //    decode_not_null narrow_oop_reg, base_reg
2900           //    Load [base_reg + offset], val_reg
2901           //    NullCheck base_reg
2902           //
2903         } else if (t->isa_oopptr()) {
2904           new_in2 = ConNode::make(t->make_narrowoop());
2905         } else if (t->isa_klassptr()) {
2906           new_in2 = ConNode::make(t->make_narrowklass());
2907         }
2908       }
2909       if (new_in2 != NULL) {
2910         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
2911         n->subsume_by(cmpN, this);
2912         if (in1->outcnt() == 0) {
2913           in1->disconnect_inputs(NULL, this);
2914         }
2915         if (in2->outcnt() == 0) {
2916           in2->disconnect_inputs(NULL, this);
2917         }
2918       }
2919     }
2920     break;
2921 
2922   case Op_DecodeN:
2923   case Op_DecodeNKlass:
2924     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
2925     // DecodeN could be pinned when it can't be fold into
2926     // an address expression, see the code for Op_CastPP above.
2927     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
2928     break;
2929 
2930   case Op_EncodeP:
2931   case Op_EncodePKlass: {
2932     Node* in1 = n->in(1);
2933     if (in1->is_DecodeNarrowPtr()) {
2934       n->subsume_by(in1->in(1), this);
2935     } else if (in1->Opcode() == Op_ConP) {
2936       const Type* t = in1->bottom_type();
2937       if (t == TypePtr::NULL_PTR) {
2938         assert(t->isa_oopptr(), "null klass?");
2939         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
2940       } else if (t->isa_oopptr()) {
2941         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
2942       } else if (t->isa_klassptr()) {
2943         n->subsume_by(ConNode::make(t->make_narrowklass()), this);
2944       }
2945     }
2946     if (in1->outcnt() == 0) {
2947       in1->disconnect_inputs(NULL, this);
2948     }
2949     break;
2950   }
2951 
2952   case Op_Proj: {
2953     if (OptimizeStringConcat) {
2954       ProjNode* p = n->as_Proj();
2955       if (p->_is_io_use) {
2956         // Separate projections were used for the exception path which
2957         // are normally removed by a late inline.  If it wasn't inlined
2958         // then they will hang around and should just be replaced with
2959         // the original one.
2960         Node* proj = NULL;
2961         // Replace with just one
2962         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
2963           Node *use = i.get();
2964           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
2965             proj = use;
2966             break;
2967           }
2968         }
2969         assert(proj != NULL, "must be found");
2970         p->subsume_by(proj, this);
2971       }
2972     }
2973     break;
2974   }
2975 
2976   case Op_Phi:
2977     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
2978       // The EncodeP optimization may create Phi with the same edges
2979       // for all paths. It is not handled well by Register Allocator.
2980       Node* unique_in = n->in(1);
2981       assert(unique_in != NULL, "");
2982       uint cnt = n->req();
2983       for (uint i = 2; i < cnt; i++) {
2984         Node* m = n->in(i);
2985         assert(m != NULL, "");
2986         if (unique_in != m)
2987           unique_in = NULL;
2988       }
2989       if (unique_in != NULL) {
2990         n->subsume_by(unique_in, this);
2991       }
2992     }
2993     break;
2994 
2995 #endif
2996 
2997   case Op_ModI:
2998     if (UseDivMod) {
2999       // Check if a%b and a/b both exist
3000       Node* d = n->find_similar(Op_DivI);
3001       if (d) {
3002         // Replace them with a fused divmod if supported
3003         if (Matcher::has_match_rule(Op_DivModI)) {
3004           DivModINode* divmod = DivModINode::make(n);
3005           d->subsume_by(divmod->div_proj(), this);
3006           n->subsume_by(divmod->mod_proj(), this);
3007         } else {
3008           // replace a%b with a-((a/b)*b)
3009           Node* mult = new MulINode(d, d->in(2));
3010           Node* sub  = new SubINode(d->in(1), mult);
3011           n->subsume_by(sub, this);
3012         }
3013       }
3014     }
3015     break;
3016 
3017   case Op_ModL:
3018     if (UseDivMod) {
3019       // Check if a%b and a/b both exist
3020       Node* d = n->find_similar(Op_DivL);
3021       if (d) {
3022         // Replace them with a fused divmod if supported
3023         if (Matcher::has_match_rule(Op_DivModL)) {
3024           DivModLNode* divmod = DivModLNode::make(n);
3025           d->subsume_by(divmod->div_proj(), this);
3026           n->subsume_by(divmod->mod_proj(), this);
3027         } else {
3028           // replace a%b with a-((a/b)*b)
3029           Node* mult = new MulLNode(d, d->in(2));
3030           Node* sub  = new SubLNode(d->in(1), mult);
3031           n->subsume_by(sub, this);
3032         }
3033       }
3034     }
3035     break;
3036 
3037   case Op_LoadVector:
3038   case Op_StoreVector:
3039     break;
3040 
3041   case Op_PackB:
3042   case Op_PackS:
3043   case Op_PackI:
3044   case Op_PackF:
3045   case Op_PackL:
3046   case Op_PackD:
3047     if (n->req()-1 > 2) {
3048       // Replace many operand PackNodes with a binary tree for matching
3049       PackNode* p = (PackNode*) n;
3050       Node* btp = p->binary_tree_pack(1, n->req());
3051       n->subsume_by(btp, this);
3052     }
3053     break;
3054   case Op_Loop:
3055   case Op_CountedLoop:
3056     if (n->as_Loop()->is_inner_loop()) {
3057       frc.inc_inner_loop_count();
3058     }
3059     break;
3060   case Op_LShiftI:
3061   case Op_RShiftI:
3062   case Op_URShiftI:
3063   case Op_LShiftL:
3064   case Op_RShiftL:
3065   case Op_URShiftL:
3066     if (Matcher::need_masked_shift_count) {
3067       // The cpu's shift instructions don't restrict the count to the
3068       // lower 5/6 bits. We need to do the masking ourselves.
3069       Node* in2 = n->in(2);
3070       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3071       const TypeInt* t = in2->find_int_type();
3072       if (t != NULL && t->is_con()) {
3073         juint shift = t->get_con();
3074         if (shift > mask) { // Unsigned cmp
3075           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3076         }
3077       } else {
3078         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3079           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3080           n->set_req(2, shift);
3081         }
3082       }
3083       if (in2->outcnt() == 0) { // Remove dead node
3084         in2->disconnect_inputs(NULL, this);
3085       }
3086     }
3087     break;
3088   case Op_MemBarStoreStore:
3089   case Op_MemBarRelease:
3090     // Break the link with AllocateNode: it is no longer useful and
3091     // confuses register allocation.
3092     if (n->req() > MemBarNode::Precedent) {
3093       n->set_req(MemBarNode::Precedent, top());
3094     }
3095     break;
3096   default:
3097     assert( !n->is_Call(), "" );
3098     assert( !n->is_Mem(), "" );
3099     break;
3100   }
3101 
3102   // Collect CFG split points
3103   if (n->is_MultiBranch())
3104     frc._tests.push(n);
3105 }
3106 
3107 //------------------------------final_graph_reshaping_walk---------------------
3108 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3109 // requires that the walk visits a node's inputs before visiting the node.
3110 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3111   ResourceArea *area = Thread::current()->resource_area();
3112   Unique_Node_List sfpt(area);
3113 
3114   frc._visited.set(root->_idx); // first, mark node as visited
3115   uint cnt = root->req();
3116   Node *n = root;
3117   uint  i = 0;
3118   while (true) {
3119     if (i < cnt) {
3120       // Place all non-visited non-null inputs onto stack
3121       Node* m = n->in(i);
3122       ++i;
3123       if (m != NULL && !frc._visited.test_set(m->_idx)) {
3124         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
3125           // compute worst case interpreter size in case of a deoptimization
3126           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3127 
3128           sfpt.push(m);
3129         }
3130         cnt = m->req();
3131         nstack.push(n, i); // put on stack parent and next input's index
3132         n = m;
3133         i = 0;
3134       }
3135     } else {
3136       // Now do post-visit work
3137       final_graph_reshaping_impl( n, frc );
3138       if (nstack.is_empty())
3139         break;             // finished
3140       n = nstack.node();   // Get node from stack
3141       cnt = n->req();
3142       i = nstack.index();
3143       nstack.pop();        // Shift to the next node on stack
3144     }
3145   }
3146 
3147   // Skip next transformation if compressed oops are not used.
3148   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3149       (!UseCompressedOops && !UseCompressedClassPointers))
3150     return;
3151 
3152   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3153   // It could be done for an uncommon traps or any safepoints/calls
3154   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3155   while (sfpt.size() > 0) {
3156     n = sfpt.pop();
3157     JVMState *jvms = n->as_SafePoint()->jvms();
3158     assert(jvms != NULL, "sanity");
3159     int start = jvms->debug_start();
3160     int end   = n->req();
3161     bool is_uncommon = (n->is_CallStaticJava() &&
3162                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3163     for (int j = start; j < end; j++) {
3164       Node* in = n->in(j);
3165       if (in->is_DecodeNarrowPtr()) {
3166         bool safe_to_skip = true;
3167         if (!is_uncommon ) {
3168           // Is it safe to skip?
3169           for (uint i = 0; i < in->outcnt(); i++) {
3170             Node* u = in->raw_out(i);
3171             if (!u->is_SafePoint() ||
3172                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
3173               safe_to_skip = false;
3174             }
3175           }
3176         }
3177         if (safe_to_skip) {
3178           n->set_req(j, in->in(1));
3179         }
3180         if (in->outcnt() == 0) {
3181           in->disconnect_inputs(NULL, this);
3182         }
3183       }
3184     }
3185   }
3186 }
3187 
3188 //------------------------------final_graph_reshaping--------------------------
3189 // Final Graph Reshaping.
3190 //
3191 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3192 //     and not commoned up and forced early.  Must come after regular
3193 //     optimizations to avoid GVN undoing the cloning.  Clone constant
3194 //     inputs to Loop Phis; these will be split by the allocator anyways.
3195 //     Remove Opaque nodes.
3196 // (2) Move last-uses by commutative operations to the left input to encourage
3197 //     Intel update-in-place two-address operations and better register usage
3198 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
3199 //     calls canonicalizing them back.
3200 // (3) Count the number of double-precision FP ops, single-precision FP ops
3201 //     and call sites.  On Intel, we can get correct rounding either by
3202 //     forcing singles to memory (requires extra stores and loads after each
3203 //     FP bytecode) or we can set a rounding mode bit (requires setting and
3204 //     clearing the mode bit around call sites).  The mode bit is only used
3205 //     if the relative frequency of single FP ops to calls is low enough.
3206 //     This is a key transform for SPEC mpeg_audio.
3207 // (4) Detect infinite loops; blobs of code reachable from above but not
3208 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
3209 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
3210 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
3211 //     Detection is by looking for IfNodes where only 1 projection is
3212 //     reachable from below or CatchNodes missing some targets.
3213 // (5) Assert for insane oop offsets in debug mode.
3214 
3215 bool Compile::final_graph_reshaping() {
3216   // an infinite loop may have been eliminated by the optimizer,
3217   // in which case the graph will be empty.
3218   if (root()->req() == 1) {
3219     record_method_not_compilable("trivial infinite loop");
3220     return true;
3221   }
3222 
3223   // Expensive nodes have their control input set to prevent the GVN
3224   // from freely commoning them. There's no GVN beyond this point so
3225   // no need to keep the control input. We want the expensive nodes to
3226   // be freely moved to the least frequent code path by gcm.
3227   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3228   for (int i = 0; i < expensive_count(); i++) {
3229     _expensive_nodes->at(i)->set_req(0, NULL);
3230   }
3231 
3232   Final_Reshape_Counts frc;
3233 
3234   // Visit everybody reachable!
3235   // Allocate stack of size C->unique()/2 to avoid frequent realloc
3236   Node_Stack nstack(unique() >> 1);
3237   final_graph_reshaping_walk(nstack, root(), frc);
3238 
3239   // Check for unreachable (from below) code (i.e., infinite loops).
3240   for( uint i = 0; i < frc._tests.size(); i++ ) {
3241     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3242     // Get number of CFG targets.
3243     // Note that PCTables include exception targets after calls.
3244     uint required_outcnt = n->required_outcnt();
3245     if (n->outcnt() != required_outcnt) {
3246       // Check for a few special cases.  Rethrow Nodes never take the
3247       // 'fall-thru' path, so expected kids is 1 less.
3248       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3249         if (n->in(0)->in(0)->is_Call()) {
3250           CallNode *call = n->in(0)->in(0)->as_Call();
3251           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3252             required_outcnt--;      // Rethrow always has 1 less kid
3253           } else if (call->req() > TypeFunc::Parms &&
3254                      call->is_CallDynamicJava()) {
3255             // Check for null receiver. In such case, the optimizer has
3256             // detected that the virtual call will always result in a null
3257             // pointer exception. The fall-through projection of this CatchNode
3258             // will not be populated.
3259             Node *arg0 = call->in(TypeFunc::Parms);
3260             if (arg0->is_Type() &&
3261                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3262               required_outcnt--;
3263             }
3264           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3265                      call->req() > TypeFunc::Parms+1 &&
3266                      call->is_CallStaticJava()) {
3267             // Check for negative array length. In such case, the optimizer has
3268             // detected that the allocation attempt will always result in an
3269             // exception. There is no fall-through projection of this CatchNode .
3270             Node *arg1 = call->in(TypeFunc::Parms+1);
3271             if (arg1->is_Type() &&
3272                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3273               required_outcnt--;
3274             }
3275           }
3276         }
3277       }
3278       // Recheck with a better notion of 'required_outcnt'
3279       if (n->outcnt() != required_outcnt) {
3280         record_method_not_compilable("malformed control flow");
3281         return true;            // Not all targets reachable!
3282       }
3283     }
3284     // Check that I actually visited all kids.  Unreached kids
3285     // must be infinite loops.
3286     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3287       if (!frc._visited.test(n->fast_out(j)->_idx)) {
3288         record_method_not_compilable("infinite loop");
3289         return true;            // Found unvisited kid; must be unreach
3290       }
3291   }
3292 
3293   // If original bytecodes contained a mixture of floats and doubles
3294   // check if the optimizer has made it homogenous, item (3).
3295   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3296       frc.get_float_count() > 32 &&
3297       frc.get_double_count() == 0 &&
3298       (10 * frc.get_call_count() < frc.get_float_count()) ) {
3299     set_24_bit_selection_and_mode( false,  true );
3300   }
3301 
3302   set_java_calls(frc.get_java_call_count());
3303   set_inner_loops(frc.get_inner_loop_count());
3304 
3305   // No infinite loops, no reason to bail out.
3306   return false;
3307 }
3308 
3309 //-----------------------------too_many_traps----------------------------------
3310 // Report if there are too many traps at the current method and bci.
3311 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3312 bool Compile::too_many_traps(ciMethod* method,
3313                              int bci,
3314                              Deoptimization::DeoptReason reason) {
3315   ciMethodData* md = method->method_data();
3316   if (md->is_empty()) {
3317     // Assume the trap has not occurred, or that it occurred only
3318     // because of a transient condition during start-up in the interpreter.
3319     return false;
3320   }
3321   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3322   if (md->has_trap_at(bci, m, reason) != 0) {
3323     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3324     // Also, if there are multiple reasons, or if there is no per-BCI record,
3325     // assume the worst.
3326     if (log())
3327       log()->elem("observe trap='%s' count='%d'",
3328                   Deoptimization::trap_reason_name(reason),
3329                   md->trap_count(reason));
3330     return true;
3331   } else {
3332     // Ignore method/bci and see if there have been too many globally.
3333     return too_many_traps(reason, md);
3334   }
3335 }
3336 
3337 // Less-accurate variant which does not require a method and bci.
3338 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3339                              ciMethodData* logmd) {
3340   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
3341     // Too many traps globally.
3342     // Note that we use cumulative trap_count, not just md->trap_count.
3343     if (log()) {
3344       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3345       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3346                   Deoptimization::trap_reason_name(reason),
3347                   mcount, trap_count(reason));
3348     }
3349     return true;
3350   } else {
3351     // The coast is clear.
3352     return false;
3353   }
3354 }
3355 
3356 //--------------------------too_many_recompiles--------------------------------
3357 // Report if there are too many recompiles at the current method and bci.
3358 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3359 // Is not eager to return true, since this will cause the compiler to use
3360 // Action_none for a trap point, to avoid too many recompilations.
3361 bool Compile::too_many_recompiles(ciMethod* method,
3362                                   int bci,
3363                                   Deoptimization::DeoptReason reason) {
3364   ciMethodData* md = method->method_data();
3365   if (md->is_empty()) {
3366     // Assume the trap has not occurred, or that it occurred only
3367     // because of a transient condition during start-up in the interpreter.
3368     return false;
3369   }
3370   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3371   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3372   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
3373   Deoptimization::DeoptReason per_bc_reason
3374     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3375   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3376   if ((per_bc_reason == Deoptimization::Reason_none
3377        || md->has_trap_at(bci, m, reason) != 0)
3378       // The trap frequency measure we care about is the recompile count:
3379       && md->trap_recompiled_at(bci, m)
3380       && md->overflow_recompile_count() >= bc_cutoff) {
3381     // Do not emit a trap here if it has already caused recompilations.
3382     // Also, if there are multiple reasons, or if there is no per-BCI record,
3383     // assume the worst.
3384     if (log())
3385       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3386                   Deoptimization::trap_reason_name(reason),
3387                   md->trap_count(reason),
3388                   md->overflow_recompile_count());
3389     return true;
3390   } else if (trap_count(reason) != 0
3391              && decompile_count() >= m_cutoff) {
3392     // Too many recompiles globally, and we have seen this sort of trap.
3393     // Use cumulative decompile_count, not just md->decompile_count.
3394     if (log())
3395       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3396                   Deoptimization::trap_reason_name(reason),
3397                   md->trap_count(reason), trap_count(reason),
3398                   md->decompile_count(), decompile_count());
3399     return true;
3400   } else {
3401     // The coast is clear.
3402     return false;
3403   }
3404 }
3405 
3406 // Compute when not to trap. Used by matching trap based nodes and
3407 // NullCheck optimization.
3408 void Compile::set_allowed_deopt_reasons() {
3409   _allowed_reasons = 0;
3410   if (is_method_compilation()) {
3411     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
3412       assert(rs < BitsPerInt, "recode bit map");
3413       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
3414         _allowed_reasons |= nth_bit(rs);
3415       }
3416     }
3417   }
3418 }
3419 
3420 #ifndef PRODUCT
3421 //------------------------------verify_graph_edges---------------------------
3422 // Walk the Graph and verify that there is a one-to-one correspondence
3423 // between Use-Def edges and Def-Use edges in the graph.
3424 void Compile::verify_graph_edges(bool no_dead_code) {
3425   if (VerifyGraphEdges) {
3426     ResourceArea *area = Thread::current()->resource_area();
3427     Unique_Node_List visited(area);
3428     // Call recursive graph walk to check edges
3429     _root->verify_edges(visited);
3430     if (no_dead_code) {
3431       // Now make sure that no visited node is used by an unvisited node.
3432       bool dead_nodes = false;
3433       Unique_Node_List checked(area);
3434       while (visited.size() > 0) {
3435         Node* n = visited.pop();
3436         checked.push(n);
3437         for (uint i = 0; i < n->outcnt(); i++) {
3438           Node* use = n->raw_out(i);
3439           if (checked.member(use))  continue;  // already checked
3440           if (visited.member(use))  continue;  // already in the graph
3441           if (use->is_Con())        continue;  // a dead ConNode is OK
3442           // At this point, we have found a dead node which is DU-reachable.
3443           if (!dead_nodes) {
3444             tty->print_cr("*** Dead nodes reachable via DU edges:");
3445             dead_nodes = true;
3446           }
3447           use->dump(2);
3448           tty->print_cr("---");
3449           checked.push(use);  // No repeats; pretend it is now checked.
3450         }
3451       }
3452       assert(!dead_nodes, "using nodes must be reachable from root");
3453     }
3454   }
3455 }
3456 
3457 // Verify GC barriers consistency
3458 // Currently supported:
3459 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
3460 void Compile::verify_barriers() {
3461   if (UseG1GC) {
3462     // Verify G1 pre-barriers
3463     const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
3464 
3465     ResourceArea *area = Thread::current()->resource_area();
3466     Unique_Node_List visited(area);
3467     Node_List worklist(area);
3468     // We're going to walk control flow backwards starting from the Root
3469     worklist.push(_root);
3470     while (worklist.size() > 0) {
3471       Node* x = worklist.pop();
3472       if (x == NULL || x == top()) continue;
3473       if (visited.member(x)) {
3474         continue;
3475       } else {
3476         visited.push(x);
3477       }
3478 
3479       if (x->is_Region()) {
3480         for (uint i = 1; i < x->req(); i++) {
3481           worklist.push(x->in(i));
3482         }
3483       } else {
3484         worklist.push(x->in(0));
3485         // We are looking for the pattern:
3486         //                            /->ThreadLocal
3487         // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
3488         //              \->ConI(0)
3489         // We want to verify that the If and the LoadB have the same control
3490         // See GraphKit::g1_write_barrier_pre()
3491         if (x->is_If()) {
3492           IfNode *iff = x->as_If();
3493           if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
3494             CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
3495             if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
3496                 && cmp->in(1)->is_Load()) {
3497               LoadNode* load = cmp->in(1)->as_Load();
3498               if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
3499                   && load->in(2)->in(3)->is_Con()
3500                   && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
3501 
3502                 Node* if_ctrl = iff->in(0);
3503                 Node* load_ctrl = load->in(0);
3504 
3505                 if (if_ctrl != load_ctrl) {
3506                   // Skip possible CProj->NeverBranch in infinite loops
3507                   if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
3508                       && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
3509                     if_ctrl = if_ctrl->in(0)->in(0);
3510                   }
3511                 }
3512                 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
3513               }
3514             }
3515           }
3516         }
3517       }
3518     }
3519   }
3520 }
3521 
3522 #endif
3523 
3524 // The Compile object keeps track of failure reasons separately from the ciEnv.
3525 // This is required because there is not quite a 1-1 relation between the
3526 // ciEnv and its compilation task and the Compile object.  Note that one
3527 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3528 // to backtrack and retry without subsuming loads.  Other than this backtracking
3529 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3530 // by the logic in C2Compiler.
3531 void Compile::record_failure(const char* reason) {
3532   if (log() != NULL) {
3533     log()->elem("failure reason='%s' phase='compile'", reason);
3534   }
3535   if (_failure_reason == NULL) {
3536     // Record the first failure reason.
3537     _failure_reason = reason;
3538   }
3539 
3540   EventCompilerFailure event;
3541   if (event.should_commit()) {
3542     event.set_compileID(Compile::compile_id());
3543     event.set_failure(reason);
3544     event.commit();
3545   }
3546 
3547   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3548     C->print_method(PHASE_FAILURE);
3549   }
3550   _root = NULL;  // flush the graph, too
3551 }
3552 
3553 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
3554   : TraceTime(name, accumulator, CITime, CITimeVerbose),
3555     _phase_name(name), _dolog(CITimeVerbose)
3556 {
3557   if (_dolog) {
3558     C = Compile::current();
3559     _log = C->log();
3560   } else {
3561     C = NULL;
3562     _log = NULL;
3563   }
3564   if (_log != NULL) {
3565     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3566     _log->stamp();
3567     _log->end_head();
3568   }
3569 }
3570 
3571 Compile::TracePhase::~TracePhase() {
3572 
3573   C = Compile::current();
3574   if (_dolog) {
3575     _log = C->log();
3576   } else {
3577     _log = NULL;
3578   }
3579 
3580 #ifdef ASSERT
3581   if (PrintIdealNodeCount) {
3582     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3583                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3584   }
3585 
3586   if (VerifyIdealNodeCount) {
3587     Compile::current()->print_missing_nodes();
3588   }
3589 #endif
3590 
3591   if (_log != NULL) {
3592     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3593   }
3594 }
3595 
3596 //=============================================================================
3597 // Two Constant's are equal when the type and the value are equal.
3598 bool Compile::Constant::operator==(const Constant& other) {
3599   if (type()          != other.type()         )  return false;
3600   if (can_be_reused() != other.can_be_reused())  return false;
3601   // For floating point values we compare the bit pattern.
3602   switch (type()) {
3603   case T_FLOAT:   return (_v._value.i == other._v._value.i);
3604   case T_LONG:
3605   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
3606   case T_OBJECT:
3607   case T_ADDRESS: return (_v._value.l == other._v._value.l);
3608   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
3609   case T_METADATA: return (_v._metadata == other._v._metadata);
3610   default: ShouldNotReachHere();
3611   }
3612   return false;
3613 }
3614 
3615 static int type_to_size_in_bytes(BasicType t) {
3616   switch (t) {
3617   case T_LONG:    return sizeof(jlong  );
3618   case T_FLOAT:   return sizeof(jfloat );
3619   case T_DOUBLE:  return sizeof(jdouble);
3620   case T_METADATA: return sizeof(Metadata*);
3621     // We use T_VOID as marker for jump-table entries (labels) which
3622     // need an internal word relocation.
3623   case T_VOID:
3624   case T_ADDRESS:
3625   case T_OBJECT:  return sizeof(jobject);
3626   }
3627 
3628   ShouldNotReachHere();
3629   return -1;
3630 }
3631 
3632 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3633   // sort descending
3634   if (a->freq() > b->freq())  return -1;
3635   if (a->freq() < b->freq())  return  1;
3636   return 0;
3637 }
3638 
3639 void Compile::ConstantTable::calculate_offsets_and_size() {
3640   // First, sort the array by frequencies.
3641   _constants.sort(qsort_comparator);
3642 
3643 #ifdef ASSERT
3644   // Make sure all jump-table entries were sorted to the end of the
3645   // array (they have a negative frequency).
3646   bool found_void = false;
3647   for (int i = 0; i < _constants.length(); i++) {
3648     Constant con = _constants.at(i);
3649     if (con.type() == T_VOID)
3650       found_void = true;  // jump-tables
3651     else
3652       assert(!found_void, "wrong sorting");
3653   }
3654 #endif
3655 
3656   int offset = 0;
3657   for (int i = 0; i < _constants.length(); i++) {
3658     Constant* con = _constants.adr_at(i);
3659 
3660     // Align offset for type.
3661     int typesize = type_to_size_in_bytes(con->type());
3662     offset = align_size_up(offset, typesize);
3663     con->set_offset(offset);   // set constant's offset
3664 
3665     if (con->type() == T_VOID) {
3666       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
3667       offset = offset + typesize * n->outcnt();  // expand jump-table
3668     } else {
3669       offset = offset + typesize;
3670     }
3671   }
3672 
3673   // Align size up to the next section start (which is insts; see
3674   // CodeBuffer::align_at_start).
3675   assert(_size == -1, "already set?");
3676   _size = align_size_up(offset, CodeEntryAlignment);
3677 }
3678 
3679 void Compile::ConstantTable::emit(CodeBuffer& cb) {
3680   MacroAssembler _masm(&cb);
3681   for (int i = 0; i < _constants.length(); i++) {
3682     Constant con = _constants.at(i);
3683     address constant_addr;
3684     switch (con.type()) {
3685     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
3686     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
3687     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
3688     case T_OBJECT: {
3689       jobject obj = con.get_jobject();
3690       int oop_index = _masm.oop_recorder()->find_index(obj);
3691       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
3692       break;
3693     }
3694     case T_ADDRESS: {
3695       address addr = (address) con.get_jobject();
3696       constant_addr = _masm.address_constant(addr);
3697       break;
3698     }
3699     // We use T_VOID as marker for jump-table entries (labels) which
3700     // need an internal word relocation.
3701     case T_VOID: {
3702       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
3703       // Fill the jump-table with a dummy word.  The real value is
3704       // filled in later in fill_jump_table.
3705       address dummy = (address) n;
3706       constant_addr = _masm.address_constant(dummy);
3707       // Expand jump-table
3708       for (uint i = 1; i < n->outcnt(); i++) {
3709         address temp_addr = _masm.address_constant(dummy + i);
3710         assert(temp_addr, "consts section too small");
3711       }
3712       break;
3713     }
3714     case T_METADATA: {
3715       Metadata* obj = con.get_metadata();
3716       int metadata_index = _masm.oop_recorder()->find_index(obj);
3717       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
3718       break;
3719     }
3720     default: ShouldNotReachHere();
3721     }
3722     assert(constant_addr, "consts section too small");
3723     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
3724             err_msg_res("must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset())));
3725   }
3726 }
3727 
3728 int Compile::ConstantTable::find_offset(Constant& con) const {
3729   int idx = _constants.find(con);
3730   assert(idx != -1, "constant must be in constant table");
3731   int offset = _constants.at(idx).offset();
3732   assert(offset != -1, "constant table not emitted yet?");
3733   return offset;
3734 }
3735 
3736 void Compile::ConstantTable::add(Constant& con) {
3737   if (con.can_be_reused()) {
3738     int idx = _constants.find(con);
3739     if (idx != -1 && _constants.at(idx).can_be_reused()) {
3740       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
3741       return;
3742     }
3743   }
3744   (void) _constants.append(con);
3745 }
3746 
3747 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
3748   Block* b = Compile::current()->cfg()->get_block_for_node(n);
3749   Constant con(type, value, b->_freq);
3750   add(con);
3751   return con;
3752 }
3753 
3754 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
3755   Constant con(metadata);
3756   add(con);
3757   return con;
3758 }
3759 
3760 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
3761   jvalue value;
3762   BasicType type = oper->type()->basic_type();
3763   switch (type) {
3764   case T_LONG:    value.j = oper->constantL(); break;
3765   case T_FLOAT:   value.f = oper->constantF(); break;
3766   case T_DOUBLE:  value.d = oper->constantD(); break;
3767   case T_OBJECT:
3768   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
3769   case T_METADATA: return add((Metadata*)oper->constant()); break;
3770   default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
3771   }
3772   return add(n, type, value);
3773 }
3774 
3775 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
3776   jvalue value;
3777   // We can use the node pointer here to identify the right jump-table
3778   // as this method is called from Compile::Fill_buffer right before
3779   // the MachNodes are emitted and the jump-table is filled (means the
3780   // MachNode pointers do not change anymore).
3781   value.l = (jobject) n;
3782   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
3783   add(con);
3784   return con;
3785 }
3786 
3787 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
3788   // If called from Compile::scratch_emit_size do nothing.
3789   if (Compile::current()->in_scratch_emit_size())  return;
3790 
3791   assert(labels.is_nonempty(), "must be");
3792   assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
3793 
3794   // Since MachConstantNode::constant_offset() also contains
3795   // table_base_offset() we need to subtract the table_base_offset()
3796   // to get the plain offset into the constant table.
3797   int offset = n->constant_offset() - table_base_offset();
3798 
3799   MacroAssembler _masm(&cb);
3800   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
3801 
3802   for (uint i = 0; i < n->outcnt(); i++) {
3803     address* constant_addr = &jump_table_base[i];
3804     assert(*constant_addr == (((address) n) + i), err_msg_res("all jump-table entries must contain adjusted node pointer: " INTPTR_FORMAT " == " INTPTR_FORMAT, p2i(*constant_addr), p2i(((address) n) + i)));
3805     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
3806     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
3807   }
3808 }
3809 
3810 //----------------------------static_subtype_check-----------------------------
3811 // Shortcut important common cases when superklass is exact:
3812 // (0) superklass is java.lang.Object (can occur in reflective code)
3813 // (1) subklass is already limited to a subtype of superklass => always ok
3814 // (2) subklass does not overlap with superklass => always fail
3815 // (3) superklass has NO subtypes and we can check with a simple compare.
3816 int Compile::static_subtype_check(ciKlass* superk, ciKlass* subk) {
3817   if (StressReflectiveCode) {
3818     return SSC_full_test;       // Let caller generate the general case.
3819   }
3820 
3821   if (superk == env()->Object_klass()) {
3822     return SSC_always_true;     // (0) this test cannot fail
3823   }
3824 
3825   ciType* superelem = superk;
3826   if (superelem->is_array_klass())
3827     superelem = superelem->as_array_klass()->base_element_type();
3828 
3829   if (!subk->is_interface()) {  // cannot trust static interface types yet
3830     if (subk->is_subtype_of(superk)) {
3831       return SSC_always_true;   // (1) false path dead; no dynamic test needed
3832     }
3833     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
3834         !superk->is_subtype_of(subk)) {
3835       return SSC_always_false;
3836     }
3837   }
3838 
3839   // If casting to an instance klass, it must have no subtypes
3840   if (superk->is_interface()) {
3841     // Cannot trust interfaces yet.
3842     // %%% S.B. superk->nof_implementors() == 1
3843   } else if (superelem->is_instance_klass()) {
3844     ciInstanceKlass* ik = superelem->as_instance_klass();
3845     if (!ik->has_subklass() && !ik->is_interface()) {
3846       if (!ik->is_final()) {
3847         // Add a dependency if there is a chance of a later subclass.
3848         dependencies()->assert_leaf_type(ik);
3849       }
3850       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
3851     }
3852   } else {
3853     // A primitive array type has no subtypes.
3854     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
3855   }
3856 
3857   return SSC_full_test;
3858 }
3859 
3860 // The message about the current inlining is accumulated in
3861 // _print_inlining_stream and transfered into the _print_inlining_list
3862 // once we know whether inlining succeeds or not. For regular
3863 // inlining, messages are appended to the buffer pointed by
3864 // _print_inlining_idx in the _print_inlining_list. For late inlining,
3865 // a new buffer is added after _print_inlining_idx in the list. This
3866 // way we can update the inlining message for late inlining call site
3867 // when the inlining is attempted again.
3868 void Compile::print_inlining_init() {
3869   if (print_inlining() || print_intrinsics()) {
3870     _print_inlining_stream = new stringStream();
3871     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
3872   }
3873 }
3874 
3875 void Compile::print_inlining_reinit() {
3876   if (print_inlining() || print_intrinsics()) {
3877     // Re allocate buffer when we change ResourceMark
3878     _print_inlining_stream = new stringStream();
3879   }
3880 }
3881 
3882 void Compile::print_inlining_reset() {
3883   _print_inlining_stream->reset();
3884 }
3885 
3886 void Compile::print_inlining_commit() {
3887   assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
3888   // Transfer the message from _print_inlining_stream to the current
3889   // _print_inlining_list buffer and clear _print_inlining_stream.
3890   _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->as_string(), _print_inlining_stream->size());
3891   print_inlining_reset();
3892 }
3893 
3894 void Compile::print_inlining_push() {
3895   // Add new buffer to the _print_inlining_list at current position
3896   _print_inlining_idx++;
3897   _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
3898 }
3899 
3900 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
3901   return _print_inlining_list->at(_print_inlining_idx);
3902 }
3903 
3904 void Compile::print_inlining_update(CallGenerator* cg) {
3905   if (print_inlining() || print_intrinsics()) {
3906     if (!cg->is_late_inline()) {
3907       if (print_inlining_current().cg() != NULL) {
3908         print_inlining_push();
3909       }
3910       print_inlining_commit();
3911     } else {
3912       if (print_inlining_current().cg() != cg &&
3913           (print_inlining_current().cg() != NULL ||
3914            print_inlining_current().ss()->size() != 0)) {
3915         print_inlining_push();
3916       }
3917       print_inlining_commit();
3918       print_inlining_current().set_cg(cg);
3919     }
3920   }
3921 }
3922 
3923 void Compile::print_inlining_move_to(CallGenerator* cg) {
3924   // We resume inlining at a late inlining call site. Locate the
3925   // corresponding inlining buffer so that we can update it.
3926   if (print_inlining()) {
3927     for (int i = 0; i < _print_inlining_list->length(); i++) {
3928       if (_print_inlining_list->adr_at(i)->cg() == cg) {
3929         _print_inlining_idx = i;
3930         return;
3931       }
3932     }
3933     ShouldNotReachHere();
3934   }
3935 }
3936 
3937 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
3938   if (print_inlining()) {
3939     assert(_print_inlining_stream->size() > 0, "missing inlining msg");
3940     assert(print_inlining_current().cg() == cg, "wrong entry");
3941     // replace message with new message
3942     _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
3943     print_inlining_commit();
3944     print_inlining_current().set_cg(cg);
3945   }
3946 }
3947 
3948 void Compile::print_inlining_assert_ready() {
3949   assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
3950 }
3951 
3952 void Compile::process_print_inlining() {
3953   bool do_print_inlining = print_inlining() || print_intrinsics();
3954   if (do_print_inlining || log() != NULL) {
3955     // Print inlining message for candidates that we couldn't inline
3956     // for lack of space
3957     for (int i = 0; i < _late_inlines.length(); i++) {
3958       CallGenerator* cg = _late_inlines.at(i);
3959       if (!cg->is_mh_late_inline()) {
3960         const char* msg = "live nodes > LiveNodeCountInliningCutoff";
3961         if (do_print_inlining) {
3962           cg->print_inlining_late(msg);
3963         }
3964         log_late_inline_failure(cg, msg);
3965       }
3966     }
3967   }
3968   if (do_print_inlining) {
3969     ResourceMark rm;
3970     stringStream ss;
3971     for (int i = 0; i < _print_inlining_list->length(); i++) {
3972       ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
3973     }
3974     size_t end = ss.size();
3975     _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
3976     strncpy(_print_inlining_output, ss.base(), end+1);
3977     _print_inlining_output[end] = 0;
3978   }
3979 }
3980 
3981 void Compile::dump_print_inlining() {
3982   if (_print_inlining_output != NULL) {
3983     tty->print_raw(_print_inlining_output);
3984   }
3985 }
3986 
3987 void Compile::log_late_inline(CallGenerator* cg) {
3988   if (log() != NULL) {
3989     log()->head("late_inline method='%d'  inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
3990                 cg->unique_id());
3991     JVMState* p = cg->call_node()->jvms();
3992     while (p != NULL) {
3993       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
3994       p = p->caller();
3995     }
3996     log()->tail("late_inline");
3997   }
3998 }
3999 
4000 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4001   log_late_inline(cg);
4002   if (log() != NULL) {
4003     log()->inline_fail(msg);
4004   }
4005 }
4006 
4007 void Compile::log_inline_id(CallGenerator* cg) {
4008   if (log() != NULL) {
4009     // The LogCompilation tool needs a unique way to identify late
4010     // inline call sites. This id must be unique for this call site in
4011     // this compilation. Try to have it unique across compilations as
4012     // well because it can be convenient when grepping through the log
4013     // file.
4014     // Distinguish OSR compilations from others in case CICountOSR is
4015     // on.
4016     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4017     cg->set_unique_id(id);
4018     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4019   }
4020 }
4021 
4022 void Compile::log_inline_failure(const char* msg) {
4023   if (C->log() != NULL) {
4024     C->log()->inline_fail(msg);
4025   }
4026 }
4027 
4028 
4029 // Dump inlining replay data to the stream.
4030 // Don't change thread state and acquire any locks.
4031 void Compile::dump_inline_data(outputStream* out) {
4032   InlineTree* inl_tree = ilt();
4033   if (inl_tree != NULL) {
4034     out->print(" inline %d", inl_tree->count());
4035     inl_tree->dump_replay_data(out);
4036   }
4037 }
4038 
4039 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4040   if (n1->Opcode() < n2->Opcode())      return -1;
4041   else if (n1->Opcode() > n2->Opcode()) return 1;
4042 
4043   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()));
4044   for (uint i = 1; i < n1->req(); i++) {
4045     if (n1->in(i) < n2->in(i))      return -1;
4046     else if (n1->in(i) > n2->in(i)) return 1;
4047   }
4048 
4049   return 0;
4050 }
4051 
4052 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4053   Node* n1 = *n1p;
4054   Node* n2 = *n2p;
4055 
4056   return cmp_expensive_nodes(n1, n2);
4057 }
4058 
4059 void Compile::sort_expensive_nodes() {
4060   if (!expensive_nodes_sorted()) {
4061     _expensive_nodes->sort(cmp_expensive_nodes);
4062   }
4063 }
4064 
4065 bool Compile::expensive_nodes_sorted() const {
4066   for (int i = 1; i < _expensive_nodes->length(); i++) {
4067     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
4068       return false;
4069     }
4070   }
4071   return true;
4072 }
4073 
4074 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4075   if (_expensive_nodes->length() == 0) {
4076     return false;
4077   }
4078 
4079   assert(OptimizeExpensiveOps, "optimization off?");
4080 
4081   // Take this opportunity to remove dead nodes from the list
4082   int j = 0;
4083   for (int i = 0; i < _expensive_nodes->length(); i++) {
4084     Node* n = _expensive_nodes->at(i);
4085     if (!n->is_unreachable(igvn)) {
4086       assert(n->is_expensive(), "should be expensive");
4087       _expensive_nodes->at_put(j, n);
4088       j++;
4089     }
4090   }
4091   _expensive_nodes->trunc_to(j);
4092 
4093   // Then sort the list so that similar nodes are next to each other
4094   // and check for at least two nodes of identical kind with same data
4095   // inputs.
4096   sort_expensive_nodes();
4097 
4098   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
4099     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
4100       return true;
4101     }
4102   }
4103 
4104   return false;
4105 }
4106 
4107 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4108   if (_expensive_nodes->length() == 0) {
4109     return;
4110   }
4111 
4112   assert(OptimizeExpensiveOps, "optimization off?");
4113 
4114   // Sort to bring similar nodes next to each other and clear the
4115   // control input of nodes for which there's only a single copy.
4116   sort_expensive_nodes();
4117 
4118   int j = 0;
4119   int identical = 0;
4120   int i = 0;
4121   bool modified = false;
4122   for (; i < _expensive_nodes->length()-1; i++) {
4123     assert(j <= i, "can't write beyond current index");
4124     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
4125       identical++;
4126       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4127       continue;
4128     }
4129     if (identical > 0) {
4130       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4131       identical = 0;
4132     } else {
4133       Node* n = _expensive_nodes->at(i);
4134       igvn.replace_input_of(n, 0, NULL);
4135       igvn.hash_insert(n);
4136       modified = true;
4137     }
4138   }
4139   if (identical > 0) {
4140     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4141   } else if (_expensive_nodes->length() >= 1) {
4142     Node* n = _expensive_nodes->at(i);
4143     igvn.replace_input_of(n, 0, NULL);
4144     igvn.hash_insert(n);
4145     modified = true;
4146   }
4147   _expensive_nodes->trunc_to(j);
4148   if (modified) {
4149     igvn.optimize();
4150   }
4151 }
4152 
4153 void Compile::add_expensive_node(Node * n) {
4154   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
4155   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4156   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4157   if (OptimizeExpensiveOps) {
4158     _expensive_nodes->append(n);
4159   } else {
4160     // Clear control input and let IGVN optimize expensive nodes if
4161     // OptimizeExpensiveOps is off.
4162     n->set_req(0, NULL);
4163   }
4164 }
4165 
4166 /**
4167  * Remove the speculative part of types and clean up the graph
4168  */
4169 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4170   if (UseTypeSpeculation) {
4171     Unique_Node_List worklist;
4172     worklist.push(root());
4173     int modified = 0;
4174     // Go over all type nodes that carry a speculative type, drop the
4175     // speculative part of the type and enqueue the node for an igvn
4176     // which may optimize it out.
4177     for (uint next = 0; next < worklist.size(); ++next) {
4178       Node *n  = worklist.at(next);
4179       if (n->is_Type()) {
4180         TypeNode* tn = n->as_Type();
4181         const Type* t = tn->type();
4182         const Type* t_no_spec = t->remove_speculative();
4183         if (t_no_spec != t) {
4184           bool in_hash = igvn.hash_delete(n);
4185           assert(in_hash, "node should be in igvn hash table");
4186           tn->set_type(t_no_spec);
4187           igvn.hash_insert(n);
4188           igvn._worklist.push(n); // give it a chance to go away
4189           modified++;
4190         }
4191       }
4192       uint max = n->len();
4193       for( uint i = 0; i < max; ++i ) {
4194         Node *m = n->in(i);
4195         if (not_a_node(m))  continue;
4196         worklist.push(m);
4197       }
4198     }
4199     // Drop the speculative part of all types in the igvn's type table
4200     igvn.remove_speculative_types();
4201     if (modified > 0) {
4202       igvn.optimize();
4203     }
4204 #ifdef ASSERT
4205     // Verify that after the IGVN is over no speculative type has resurfaced
4206     worklist.clear();
4207     worklist.push(root());
4208     for (uint next = 0; next < worklist.size(); ++next) {
4209       Node *n  = worklist.at(next);
4210       const Type* t = igvn.type_or_null(n);
4211       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
4212       if (n->is_Type()) {
4213         t = n->as_Type()->type();
4214         assert(t == t->remove_speculative(), "no more speculative types");
4215       }
4216       uint max = n->len();
4217       for( uint i = 0; i < max; ++i ) {
4218         Node *m = n->in(i);
4219         if (not_a_node(m))  continue;
4220         worklist.push(m);
4221       }
4222     }
4223     igvn.check_no_speculative_types();
4224 #endif
4225   }
4226 }
4227 
4228 // Auxiliary method to support randomized stressing/fuzzing.
4229 //
4230 // This method can be called the arbitrary number of times, with current count
4231 // as the argument. The logic allows selecting a single candidate from the
4232 // running list of candidates as follows:
4233 //    int count = 0;
4234 //    Cand* selected = null;
4235 //    while(cand = cand->next()) {
4236 //      if (randomized_select(++count)) {
4237 //        selected = cand;
4238 //      }
4239 //    }
4240 //
4241 // Including count equalizes the chances any candidate is "selected".
4242 // This is useful when we don't have the complete list of candidates to choose
4243 // from uniformly. In this case, we need to adjust the randomicity of the
4244 // selection, or else we will end up biasing the selection towards the latter
4245 // candidates.
4246 //
4247 // Quick back-envelope calculation shows that for the list of n candidates
4248 // the equal probability for the candidate to persist as "best" can be
4249 // achieved by replacing it with "next" k-th candidate with the probability
4250 // of 1/k. It can be easily shown that by the end of the run, the
4251 // probability for any candidate is converged to 1/n, thus giving the
4252 // uniform distribution among all the candidates.
4253 //
4254 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4255 #define RANDOMIZED_DOMAIN_POW 29
4256 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4257 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
4258 bool Compile::randomized_select(int count) {
4259   assert(count > 0, "only positive");
4260   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4261 }