1 /*
   2  * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "asm/macroAssembler.hpp"
  27 #include "asm/macroAssembler.inline.hpp"
  28 #include "classfile/systemDictionary.hpp"
  29 #include "code/exceptionHandlerTable.hpp"
  30 #include "code/nmethod.hpp"
  31 #include "compiler/compileLog.hpp"
  32 #include "compiler/disassembler.hpp"
  33 #include "compiler/oopMap.hpp"
  34 #include "opto/addnode.hpp"
  35 #include "opto/block.hpp"
  36 #include "opto/c2compiler.hpp"
  37 #include "opto/callGenerator.hpp"
  38 #include "opto/callnode.hpp"
  39 #include "opto/cfgnode.hpp"
  40 #include "opto/chaitin.hpp"
  41 #include "opto/compile.hpp"
  42 #include "opto/connode.hpp"
  43 #include "opto/divnode.hpp"
  44 #include "opto/escape.hpp"
  45 #include "opto/idealGraphPrinter.hpp"
  46 #include "opto/loopnode.hpp"
  47 #include "opto/machnode.hpp"
  48 #include "opto/macro.hpp"
  49 #include "opto/matcher.hpp"
  50 #include "opto/mathexactnode.hpp"
  51 #include "opto/memnode.hpp"
  52 #include "opto/mulnode.hpp"
  53 #include "opto/node.hpp"
  54 #include "opto/opcodes.hpp"
  55 #include "opto/output.hpp"
  56 #include "opto/parse.hpp"
  57 #include "opto/phaseX.hpp"
  58 #include "opto/rootnode.hpp"
  59 #include "opto/runtime.hpp"
  60 #include "opto/stringopts.hpp"
  61 #include "opto/type.hpp"
  62 #include "opto/vectornode.hpp"
  63 #include "runtime/arguments.hpp"
  64 #include "runtime/signature.hpp"
  65 #include "runtime/stubRoutines.hpp"
  66 #include "runtime/timer.hpp"
  67 #include "trace/tracing.hpp"
  68 #include "utilities/copy.hpp"
  69 #ifdef TARGET_ARCH_MODEL_x86_32
  70 # include "adfiles/ad_x86_32.hpp"
  71 #endif
  72 #ifdef TARGET_ARCH_MODEL_x86_64
  73 # include "adfiles/ad_x86_64.hpp"
  74 #endif
  75 #ifdef TARGET_ARCH_MODEL_sparc
  76 # include "adfiles/ad_sparc.hpp"
  77 #endif
  78 #ifdef TARGET_ARCH_MODEL_zero
  79 # include "adfiles/ad_zero.hpp"
  80 #endif
  81 #ifdef TARGET_ARCH_MODEL_arm
  82 # include "adfiles/ad_arm.hpp"
  83 #endif
  84 #ifdef TARGET_ARCH_MODEL_ppc
  85 # include "adfiles/ad_ppc.hpp"
  86 #endif
  87 
  88 
  89 // -------------------- Compile::mach_constant_base_node -----------------------
  90 // Constant table base node singleton.
  91 MachConstantBaseNode* Compile::mach_constant_base_node() {
  92   if (_mach_constant_base_node == NULL) {
  93     _mach_constant_base_node = new (C) MachConstantBaseNode();
  94     _mach_constant_base_node->add_req(C->root());
  95   }
  96   return _mach_constant_base_node;
  97 }
  98 
  99 
 100 /// Support for intrinsics.
 101 
 102 // Return the index at which m must be inserted (or already exists).
 103 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
 104 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
 105 #ifdef ASSERT
 106   for (int i = 1; i < _intrinsics->length(); i++) {
 107     CallGenerator* cg1 = _intrinsics->at(i-1);
 108     CallGenerator* cg2 = _intrinsics->at(i);
 109     assert(cg1->method() != cg2->method()
 110            ? cg1->method()     < cg2->method()
 111            : cg1->is_virtual() < cg2->is_virtual(),
 112            "compiler intrinsics list must stay sorted");
 113   }
 114 #endif
 115   // Binary search sorted list, in decreasing intervals [lo, hi].
 116   int lo = 0, hi = _intrinsics->length()-1;
 117   while (lo <= hi) {
 118     int mid = (uint)(hi + lo) / 2;
 119     ciMethod* mid_m = _intrinsics->at(mid)->method();
 120     if (m < mid_m) {
 121       hi = mid-1;
 122     } else if (m > mid_m) {
 123       lo = mid+1;
 124     } else {
 125       // look at minor sort key
 126       bool mid_virt = _intrinsics->at(mid)->is_virtual();
 127       if (is_virtual < mid_virt) {
 128         hi = mid-1;
 129       } else if (is_virtual > mid_virt) {
 130         lo = mid+1;
 131       } else {
 132         return mid;  // exact match
 133       }
 134     }
 135   }
 136   return lo;  // inexact match
 137 }
 138 
 139 void Compile::register_intrinsic(CallGenerator* cg) {
 140   if (_intrinsics == NULL) {
 141     _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
 142   }
 143   // This code is stolen from ciObjectFactory::insert.
 144   // Really, GrowableArray should have methods for
 145   // insert_at, remove_at, and binary_search.
 146   int len = _intrinsics->length();
 147   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
 148   if (index == len) {
 149     _intrinsics->append(cg);
 150   } else {
 151 #ifdef ASSERT
 152     CallGenerator* oldcg = _intrinsics->at(index);
 153     assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
 154 #endif
 155     _intrinsics->append(_intrinsics->at(len-1));
 156     int pos;
 157     for (pos = len-2; pos >= index; pos--) {
 158       _intrinsics->at_put(pos+1,_intrinsics->at(pos));
 159     }
 160     _intrinsics->at_put(index, cg);
 161   }
 162   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 163 }
 164 
 165 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 166   assert(m->is_loaded(), "don't try this on unloaded methods");
 167   if (_intrinsics != NULL) {
 168     int index = intrinsic_insertion_index(m, is_virtual);
 169     if (index < _intrinsics->length()
 170         && _intrinsics->at(index)->method() == m
 171         && _intrinsics->at(index)->is_virtual() == is_virtual) {
 172       return _intrinsics->at(index);
 173     }
 174   }
 175   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 176   if (m->intrinsic_id() != vmIntrinsics::_none &&
 177       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 178     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 179     if (cg != NULL) {
 180       // Save it for next time:
 181       register_intrinsic(cg);
 182       return cg;
 183     } else {
 184       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 185     }
 186   }
 187   return NULL;
 188 }
 189 
 190 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
 191 // in library_call.cpp.
 192 
 193 
 194 #ifndef PRODUCT
 195 // statistics gathering...
 196 
 197 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
 198 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
 199 
 200 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 201   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 202   int oflags = _intrinsic_hist_flags[id];
 203   assert(flags != 0, "what happened?");
 204   if (is_virtual) {
 205     flags |= _intrinsic_virtual;
 206   }
 207   bool changed = (flags != oflags);
 208   if ((flags & _intrinsic_worked) != 0) {
 209     juint count = (_intrinsic_hist_count[id] += 1);
 210     if (count == 1) {
 211       changed = true;           // first time
 212     }
 213     // increment the overall count also:
 214     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
 215   }
 216   if (changed) {
 217     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 218       // Something changed about the intrinsic's virtuality.
 219       if ((flags & _intrinsic_virtual) != 0) {
 220         // This is the first use of this intrinsic as a virtual call.
 221         if (oflags != 0) {
 222           // We already saw it as a non-virtual, so note both cases.
 223           flags |= _intrinsic_both;
 224         }
 225       } else if ((oflags & _intrinsic_both) == 0) {
 226         // This is the first use of this intrinsic as a non-virtual
 227         flags |= _intrinsic_both;
 228       }
 229     }
 230     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
 231   }
 232   // update the overall flags also:
 233   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
 234   return changed;
 235 }
 236 
 237 static char* format_flags(int flags, char* buf) {
 238   buf[0] = 0;
 239   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 240   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 241   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 242   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 243   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 244   if (buf[0] == 0)  strcat(buf, ",");
 245   assert(buf[0] == ',', "must be");
 246   return &buf[1];
 247 }
 248 
 249 void Compile::print_intrinsic_statistics() {
 250   char flagsbuf[100];
 251   ttyLocker ttyl;
 252   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
 253   tty->print_cr("Compiler intrinsic usage:");
 254   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
 255   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 256   #define PRINT_STAT_LINE(name, c, f) \
 257     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 258   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
 259     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
 260     int   flags = _intrinsic_hist_flags[id];
 261     juint count = _intrinsic_hist_count[id];
 262     if ((flags | count) != 0) {
 263       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 264     }
 265   }
 266   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
 267   if (xtty != NULL)  xtty->tail("statistics");
 268 }
 269 
 270 void Compile::print_statistics() {
 271   { ttyLocker ttyl;
 272     if (xtty != NULL)  xtty->head("statistics type='opto'");
 273     Parse::print_statistics();
 274     PhaseCCP::print_statistics();
 275     PhaseRegAlloc::print_statistics();
 276     Scheduling::print_statistics();
 277     PhasePeephole::print_statistics();
 278     PhaseIdealLoop::print_statistics();
 279     if (xtty != NULL)  xtty->tail("statistics");
 280   }
 281   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
 282     // put this under its own <statistics> element.
 283     print_intrinsic_statistics();
 284   }
 285 }
 286 #endif //PRODUCT
 287 
 288 // Support for bundling info
 289 Bundle* Compile::node_bundling(const Node *n) {
 290   assert(valid_bundle_info(n), "oob");
 291   return &_node_bundling_base[n->_idx];
 292 }
 293 
 294 bool Compile::valid_bundle_info(const Node *n) {
 295   return (_node_bundling_limit > n->_idx);
 296 }
 297 
 298 
 299 void Compile::gvn_replace_by(Node* n, Node* nn) {
 300   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 301     Node* use = n->last_out(i);
 302     bool is_in_table = initial_gvn()->hash_delete(use);
 303     uint uses_found = 0;
 304     for (uint j = 0; j < use->len(); j++) {
 305       if (use->in(j) == n) {
 306         if (j < use->req())
 307           use->set_req(j, nn);
 308         else
 309           use->set_prec(j, nn);
 310         uses_found++;
 311       }
 312     }
 313     if (is_in_table) {
 314       // reinsert into table
 315       initial_gvn()->hash_find_insert(use);
 316     }
 317     record_for_igvn(use);
 318     i -= uses_found;    // we deleted 1 or more copies of this edge
 319   }
 320 }
 321 
 322 
 323 static inline bool not_a_node(const Node* n) {
 324   if (n == NULL)                   return true;
 325   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
 326   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
 327   return false;
 328 }
 329 
 330 // Identify all nodes that are reachable from below, useful.
 331 // Use breadth-first pass that records state in a Unique_Node_List,
 332 // recursive traversal is slower.
 333 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 334   int estimated_worklist_size = unique();
 335   useful.map( estimated_worklist_size, NULL );  // preallocate space
 336 
 337   // Initialize worklist
 338   if (root() != NULL)     { useful.push(root()); }
 339   // If 'top' is cached, declare it useful to preserve cached node
 340   if( cached_top_node() ) { useful.push(cached_top_node()); }
 341 
 342   // Push all useful nodes onto the list, breadthfirst
 343   for( uint next = 0; next < useful.size(); ++next ) {
 344     assert( next < unique(), "Unique useful nodes < total nodes");
 345     Node *n  = useful.at(next);
 346     uint max = n->len();
 347     for( uint i = 0; i < max; ++i ) {
 348       Node *m = n->in(i);
 349       if (not_a_node(m))  continue;
 350       useful.push(m);
 351     }
 352   }
 353 }
 354 
 355 // Update dead_node_list with any missing dead nodes using useful
 356 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 357 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 358   uint max_idx = unique();
 359   VectorSet& useful_node_set = useful.member_set();
 360 
 361   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 362     // If node with index node_idx is not in useful set,
 363     // mark it as dead in dead node list.
 364     if (! useful_node_set.test(node_idx) ) {
 365       record_dead_node(node_idx);
 366     }
 367   }
 368 }
 369 
 370 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 371   int shift = 0;
 372   for (int i = 0; i < inlines->length(); i++) {
 373     CallGenerator* cg = inlines->at(i);
 374     CallNode* call = cg->call_node();
 375     if (shift > 0) {
 376       inlines->at_put(i-shift, cg);
 377     }
 378     if (!useful.member(call)) {
 379       shift++;
 380     }
 381   }
 382   inlines->trunc_to(inlines->length()-shift);
 383 }
 384 
 385 // Disconnect all useless nodes by disconnecting those at the boundary.
 386 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
 387   uint next = 0;
 388   while (next < useful.size()) {
 389     Node *n = useful.at(next++);
 390     // Use raw traversal of out edges since this code removes out edges
 391     int max = n->outcnt();
 392     for (int j = 0; j < max; ++j) {
 393       Node* child = n->raw_out(j);
 394       if (! useful.member(child)) {
 395         assert(!child->is_top() || child != top(),
 396                "If top is cached in Compile object it is in useful list");
 397         // Only need to remove this out-edge to the useless node
 398         n->raw_del_out(j);
 399         --j;
 400         --max;
 401       }
 402     }
 403     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 404       record_for_igvn(n->unique_out());
 405     }
 406   }
 407   // Remove useless macro and predicate opaq nodes
 408   for (int i = C->macro_count()-1; i >= 0; i--) {
 409     Node* n = C->macro_node(i);
 410     if (!useful.member(n)) {
 411       remove_macro_node(n);
 412     }
 413   }
 414   // Remove useless expensive node
 415   for (int i = C->expensive_count()-1; i >= 0; i--) {
 416     Node* n = C->expensive_node(i);
 417     if (!useful.member(n)) {
 418       remove_expensive_node(n);
 419     }
 420   }
 421   // clean up the late inline lists
 422   remove_useless_late_inlines(&_string_late_inlines, useful);
 423   remove_useless_late_inlines(&_boxing_late_inlines, useful);
 424   remove_useless_late_inlines(&_late_inlines, useful);
 425   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 426 }
 427 
 428 //------------------------------frame_size_in_words-----------------------------
 429 // frame_slots in units of words
 430 int Compile::frame_size_in_words() const {
 431   // shift is 0 in LP32 and 1 in LP64
 432   const int shift = (LogBytesPerWord - LogBytesPerInt);
 433   int words = _frame_slots >> shift;
 434   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
 435   return words;
 436 }
 437 
 438 // ============================================================================
 439 //------------------------------CompileWrapper---------------------------------
 440 class CompileWrapper : public StackObj {
 441   Compile *const _compile;
 442  public:
 443   CompileWrapper(Compile* compile);
 444 
 445   ~CompileWrapper();
 446 };
 447 
 448 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 449   // the Compile* pointer is stored in the current ciEnv:
 450   ciEnv* env = compile->env();
 451   assert(env == ciEnv::current(), "must already be a ciEnv active");
 452   assert(env->compiler_data() == NULL, "compile already active?");
 453   env->set_compiler_data(compile);
 454   assert(compile == Compile::current(), "sanity");
 455 
 456   compile->set_type_dict(NULL);
 457   compile->set_type_hwm(NULL);
 458   compile->set_type_last_size(0);
 459   compile->set_last_tf(NULL, NULL);
 460   compile->set_indexSet_arena(NULL);
 461   compile->set_indexSet_free_block_list(NULL);
 462   compile->init_type_arena();
 463   Type::Initialize(compile);
 464   _compile->set_scratch_buffer_blob(NULL);
 465   _compile->begin_method();
 466 }
 467 CompileWrapper::~CompileWrapper() {
 468   _compile->end_method();
 469   if (_compile->scratch_buffer_blob() != NULL)
 470     BufferBlob::free(_compile->scratch_buffer_blob());
 471   _compile->env()->set_compiler_data(NULL);
 472 }
 473 
 474 
 475 //----------------------------print_compile_messages---------------------------
 476 void Compile::print_compile_messages() {
 477 #ifndef PRODUCT
 478   // Check if recompiling
 479   if (_subsume_loads == false && PrintOpto) {
 480     // Recompiling without allowing machine instructions to subsume loads
 481     tty->print_cr("*********************************************************");
 482     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 483     tty->print_cr("*********************************************************");
 484   }
 485   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
 486     // Recompiling without escape analysis
 487     tty->print_cr("*********************************************************");
 488     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 489     tty->print_cr("*********************************************************");
 490   }
 491   if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
 492     // Recompiling without boxing elimination
 493     tty->print_cr("*********************************************************");
 494     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 495     tty->print_cr("*********************************************************");
 496   }
 497   if (env()->break_at_compile()) {
 498     // Open the debugger when compiling this method.
 499     tty->print("### Breaking when compiling: ");
 500     method()->print_short_name();
 501     tty->cr();
 502     BREAKPOINT;
 503   }
 504 
 505   if( PrintOpto ) {
 506     if (is_osr_compilation()) {
 507       tty->print("[OSR]%3d", _compile_id);
 508     } else {
 509       tty->print("%3d", _compile_id);
 510     }
 511   }
 512 #endif
 513 }
 514 
 515 
 516 //-----------------------init_scratch_buffer_blob------------------------------
 517 // Construct a temporary BufferBlob and cache it for this compile.
 518 void Compile::init_scratch_buffer_blob(int const_size) {
 519   // If there is already a scratch buffer blob allocated and the
 520   // constant section is big enough, use it.  Otherwise free the
 521   // current and allocate a new one.
 522   BufferBlob* blob = scratch_buffer_blob();
 523   if ((blob != NULL) && (const_size <= _scratch_const_size)) {
 524     // Use the current blob.
 525   } else {
 526     if (blob != NULL) {
 527       BufferBlob::free(blob);
 528     }
 529 
 530     ResourceMark rm;
 531     _scratch_const_size = const_size;
 532     int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
 533     blob = BufferBlob::create("Compile::scratch_buffer", size);
 534     // Record the buffer blob for next time.
 535     set_scratch_buffer_blob(blob);
 536     // Have we run out of code space?
 537     if (scratch_buffer_blob() == NULL) {
 538       // Let CompilerBroker disable further compilations.
 539       record_failure("Not enough space for scratch buffer in CodeCache");
 540       return;
 541     }
 542   }
 543 
 544   // Initialize the relocation buffers
 545   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
 546   set_scratch_locs_memory(locs_buf);
 547 }
 548 
 549 
 550 //-----------------------scratch_emit_size-------------------------------------
 551 // Helper function that computes size by emitting code
 552 uint Compile::scratch_emit_size(const Node* n) {
 553   // Start scratch_emit_size section.
 554   set_in_scratch_emit_size(true);
 555 
 556   // Emit into a trash buffer and count bytes emitted.
 557   // This is a pretty expensive way to compute a size,
 558   // but it works well enough if seldom used.
 559   // All common fixed-size instructions are given a size
 560   // method by the AD file.
 561   // Note that the scratch buffer blob and locs memory are
 562   // allocated at the beginning of the compile task, and
 563   // may be shared by several calls to scratch_emit_size.
 564   // The allocation of the scratch buffer blob is particularly
 565   // expensive, since it has to grab the code cache lock.
 566   BufferBlob* blob = this->scratch_buffer_blob();
 567   assert(blob != NULL, "Initialize BufferBlob at start");
 568   assert(blob->size() > MAX_inst_size, "sanity");
 569   relocInfo* locs_buf = scratch_locs_memory();
 570   address blob_begin = blob->content_begin();
 571   address blob_end   = (address)locs_buf;
 572   assert(blob->content_contains(blob_end), "sanity");
 573   CodeBuffer buf(blob_begin, blob_end - blob_begin);
 574   buf.initialize_consts_size(_scratch_const_size);
 575   buf.initialize_stubs_size(MAX_stubs_size);
 576   assert(locs_buf != NULL, "sanity");
 577   int lsize = MAX_locs_size / 3;
 578   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
 579   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
 580   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
 581 
 582   // Do the emission.
 583 
 584   Label fakeL; // Fake label for branch instructions.
 585   Label*   saveL = NULL;
 586   uint save_bnum = 0;
 587   bool is_branch = n->is_MachBranch();
 588   if (is_branch) {
 589     MacroAssembler masm(&buf);
 590     masm.bind(fakeL);
 591     n->as_MachBranch()->save_label(&saveL, &save_bnum);
 592     n->as_MachBranch()->label_set(&fakeL, 0);
 593   }
 594   n->emit(buf, this->regalloc());
 595   if (is_branch) // Restore label.
 596     n->as_MachBranch()->label_set(saveL, save_bnum);
 597 
 598   // End scratch_emit_size section.
 599   set_in_scratch_emit_size(false);
 600 
 601   return buf.insts_size();
 602 }
 603 
 604 
 605 // ============================================================================
 606 //------------------------------Compile standard-------------------------------
 607 debug_only( int Compile::_debug_idx = 100000; )
 608 
 609 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 610 // the continuation bci for on stack replacement.
 611 
 612 
 613 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
 614                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
 615                 : Phase(Compiler),
 616                   _env(ci_env),
 617                   _log(ci_env->log()),
 618                   _compile_id(ci_env->compile_id()),
 619                   _save_argument_registers(false),
 620                   _stub_name(NULL),
 621                   _stub_function(NULL),
 622                   _stub_entry_point(NULL),
 623                   _method(target),
 624                   _entry_bci(osr_bci),
 625                   _initial_gvn(NULL),
 626                   _for_igvn(NULL),
 627                   _warm_calls(NULL),
 628                   _subsume_loads(subsume_loads),
 629                   _do_escape_analysis(do_escape_analysis),
 630                   _eliminate_boxing(eliminate_boxing),
 631                   _failure_reason(NULL),
 632                   _code_buffer("Compile::Fill_buffer"),
 633                   _orig_pc_slot(0),
 634                   _orig_pc_slot_offset_in_bytes(0),
 635                   _has_method_handle_invokes(false),
 636                   _mach_constant_base_node(NULL),
 637                   _node_bundling_limit(0),
 638                   _node_bundling_base(NULL),
 639                   _java_calls(0),
 640                   _inner_loops(0),
 641                   _scratch_const_size(-1),
 642                   _in_scratch_emit_size(false),
 643                   _dead_node_list(comp_arena()),
 644                   _dead_node_count(0),
 645 #ifndef PRODUCT
 646                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
 647                   _printer(IdealGraphPrinter::printer()),
 648 #endif
 649                   _congraph(NULL),
 650                   _late_inlines(comp_arena(), 2, 0, NULL),
 651                   _string_late_inlines(comp_arena(), 2, 0, NULL),
 652                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
 653                   _late_inlines_pos(0),
 654                   _number_of_mh_late_inlines(0),
 655                   _inlining_progress(false),
 656                   _inlining_incrementally(false),
 657                   _print_inlining_list(NULL),
 658                   _print_inlining_idx(0),
 659                   _preserve_jvm_state(0) {
 660   C = this;
 661 
 662   CompileWrapper cw(this);
 663 #ifndef PRODUCT
 664   if (TimeCompiler2) {
 665     tty->print(" ");
 666     target->holder()->name()->print();
 667     tty->print(".");
 668     target->print_short_name();
 669     tty->print("  ");
 670   }
 671   TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
 672   TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
 673   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
 674   if (!print_opto_assembly) {
 675     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
 676     if (print_assembly && !Disassembler::can_decode()) {
 677       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
 678       print_opto_assembly = true;
 679     }
 680   }
 681   set_print_assembly(print_opto_assembly);
 682   set_parsed_irreducible_loop(false);
 683 #endif
 684   set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
 685   set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
 686 
 687   if (ProfileTraps) {
 688     // Make sure the method being compiled gets its own MDO,
 689     // so we can at least track the decompile_count().
 690     method()->ensure_method_data();
 691   }
 692 
 693   Init(::AliasLevel);
 694 
 695 
 696   print_compile_messages();
 697 
 698   if (UseOldInlining || PrintCompilation NOT_PRODUCT( || PrintOpto) )
 699     _ilt = InlineTree::build_inline_tree_root();
 700   else
 701     _ilt = NULL;
 702 
 703   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 704   assert(num_alias_types() >= AliasIdxRaw, "");
 705 
 706 #define MINIMUM_NODE_HASH  1023
 707   // Node list that Iterative GVN will start with
 708   Unique_Node_List for_igvn(comp_arena());
 709   set_for_igvn(&for_igvn);
 710 
 711   // GVN that will be run immediately on new nodes
 712   uint estimated_size = method()->code_size()*4+64;
 713   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 714   PhaseGVN gvn(node_arena(), estimated_size);
 715   set_initial_gvn(&gvn);
 716 
 717   if (print_inlining() || print_intrinsics()) {
 718     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
 719   }
 720   { // Scope for timing the parser
 721     TracePhase t3("parse", &_t_parser, true);
 722 
 723     // Put top into the hash table ASAP.
 724     initial_gvn()->transform_no_reclaim(top());
 725 
 726     // Set up tf(), start(), and find a CallGenerator.
 727     CallGenerator* cg = NULL;
 728     if (is_osr_compilation()) {
 729       const TypeTuple *domain = StartOSRNode::osr_domain();
 730       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 731       init_tf(TypeFunc::make(domain, range));
 732       StartNode* s = new (this) StartOSRNode(root(), domain);
 733       initial_gvn()->set_type_bottom(s);
 734       init_start(s);
 735       cg = CallGenerator::for_osr(method(), entry_bci());
 736     } else {
 737       // Normal case.
 738       init_tf(TypeFunc::make(method()));
 739       StartNode* s = new (this) StartNode(root(), tf()->domain());
 740       initial_gvn()->set_type_bottom(s);
 741       init_start(s);
 742       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
 743         // With java.lang.ref.reference.get() we must go through the
 744         // intrinsic when G1 is enabled - even when get() is the root
 745         // method of the compile - so that, if necessary, the value in
 746         // the referent field of the reference object gets recorded by
 747         // the pre-barrier code.
 748         // Specifically, if G1 is enabled, the value in the referent
 749         // field is recorded by the G1 SATB pre barrier. This will
 750         // result in the referent being marked live and the reference
 751         // object removed from the list of discovered references during
 752         // reference processing.
 753         cg = find_intrinsic(method(), false);
 754       }
 755       if (cg == NULL) {
 756         float past_uses = method()->interpreter_invocation_count();
 757         float expected_uses = past_uses;
 758         cg = CallGenerator::for_inline(method(), expected_uses);
 759       }
 760     }
 761     if (failing())  return;
 762     if (cg == NULL) {
 763       record_method_not_compilable_all_tiers("cannot parse method");
 764       return;
 765     }
 766     JVMState* jvms = build_start_state(start(), tf());
 767     if ((jvms = cg->generate(jvms, NULL)) == NULL) {
 768       record_method_not_compilable("method parse failed");
 769       return;
 770     }
 771     GraphKit kit(jvms);
 772 
 773     if (!kit.stopped()) {
 774       // Accept return values, and transfer control we know not where.
 775       // This is done by a special, unique ReturnNode bound to root.
 776       return_values(kit.jvms());
 777     }
 778 
 779     if (kit.has_exceptions()) {
 780       // Any exceptions that escape from this call must be rethrown
 781       // to whatever caller is dynamically above us on the stack.
 782       // This is done by a special, unique RethrowNode bound to root.
 783       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 784     }
 785 
 786     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 787 
 788     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 789       inline_string_calls(true);
 790     }
 791 
 792     if (failing())  return;
 793 
 794     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
 795 
 796     // Remove clutter produced by parsing.
 797     if (!failing()) {
 798       ResourceMark rm;
 799       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 800     }
 801   }
 802 
 803   // Note:  Large methods are capped off in do_one_bytecode().
 804   if (failing())  return;
 805 
 806   // After parsing, node notes are no longer automagic.
 807   // They must be propagated by register_new_node_with_optimizer(),
 808   // clone(), or the like.
 809   set_default_node_notes(NULL);
 810 
 811   for (;;) {
 812     int successes = Inline_Warm();
 813     if (failing())  return;
 814     if (successes == 0)  break;
 815   }
 816 
 817   // Drain the list.
 818   Finish_Warm();
 819 #ifndef PRODUCT
 820   if (_printer) {
 821     _printer->print_inlining(this);
 822   }
 823 #endif
 824 
 825   if (failing())  return;
 826   NOT_PRODUCT( verify_graph_edges(); )
 827 
 828   // Now optimize
 829   Optimize();
 830   if (failing())  return;
 831   NOT_PRODUCT( verify_graph_edges(); )
 832 
 833 #ifndef PRODUCT
 834   if (PrintIdeal) {
 835     ttyLocker ttyl;  // keep the following output all in one block
 836     // This output goes directly to the tty, not the compiler log.
 837     // To enable tools to match it up with the compilation activity,
 838     // be sure to tag this tty output with the compile ID.
 839     if (xtty != NULL) {
 840       xtty->head("ideal compile_id='%d'%s", compile_id(),
 841                  is_osr_compilation()    ? " compile_kind='osr'" :
 842                  "");
 843     }
 844     root()->dump(9999);
 845     if (xtty != NULL) {
 846       xtty->tail("ideal");
 847     }
 848   }
 849 #endif
 850 
 851   NOT_PRODUCT( verify_barriers(); )
 852   // Now that we know the size of all the monitors we can add a fixed slot
 853   // for the original deopt pc.
 854 
 855   _orig_pc_slot =  fixed_slots();
 856   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 857   set_fixed_slots(next_slot);
 858 
 859   // Now generate code
 860   Code_Gen();
 861   if (failing())  return;
 862 
 863   // Check if we want to skip execution of all compiled code.
 864   {
 865 #ifndef PRODUCT
 866     if (OptoNoExecute) {
 867       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 868       return;
 869     }
 870     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
 871 #endif
 872 
 873     if (is_osr_compilation()) {
 874       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 875       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 876     } else {
 877       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 878       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 879     }
 880 
 881     env()->register_method(_method, _entry_bci,
 882                            &_code_offsets,
 883                            _orig_pc_slot_offset_in_bytes,
 884                            code_buffer(),
 885                            frame_size_in_words(), _oop_map_set,
 886                            &_handler_table, &_inc_table,
 887                            compiler,
 888                            env()->comp_level(),
 889                            has_unsafe_access(),
 890                            SharedRuntime::is_wide_vector(max_vector_size())
 891                            );
 892 
 893     if (log() != NULL) // Print code cache state into compiler log
 894       log()->code_cache_state();
 895   }
 896 }
 897 
 898 //------------------------------Compile----------------------------------------
 899 // Compile a runtime stub
 900 Compile::Compile( ciEnv* ci_env,
 901                   TypeFunc_generator generator,
 902                   address stub_function,
 903                   const char *stub_name,
 904                   int is_fancy_jump,
 905                   bool pass_tls,
 906                   bool save_arg_registers,
 907                   bool return_pc )
 908   : Phase(Compiler),
 909     _env(ci_env),
 910     _log(ci_env->log()),
 911     _compile_id(0),
 912     _save_argument_registers(save_arg_registers),
 913     _method(NULL),
 914     _stub_name(stub_name),
 915     _stub_function(stub_function),
 916     _stub_entry_point(NULL),
 917     _entry_bci(InvocationEntryBci),
 918     _initial_gvn(NULL),
 919     _for_igvn(NULL),
 920     _warm_calls(NULL),
 921     _orig_pc_slot(0),
 922     _orig_pc_slot_offset_in_bytes(0),
 923     _subsume_loads(true),
 924     _do_escape_analysis(false),
 925     _eliminate_boxing(false),
 926     _failure_reason(NULL),
 927     _code_buffer("Compile::Fill_buffer"),
 928     _has_method_handle_invokes(false),
 929     _mach_constant_base_node(NULL),
 930     _node_bundling_limit(0),
 931     _node_bundling_base(NULL),
 932     _java_calls(0),
 933     _inner_loops(0),
 934 #ifndef PRODUCT
 935     _trace_opto_output(TraceOptoOutput),
 936     _printer(NULL),
 937 #endif
 938     _dead_node_list(comp_arena()),
 939     _dead_node_count(0),
 940     _congraph(NULL),
 941     _number_of_mh_late_inlines(0),
 942     _inlining_progress(false),
 943     _inlining_incrementally(false),
 944     _print_inlining_list(NULL),
 945     _print_inlining_idx(0),
 946     _preserve_jvm_state(0) {
 947   C = this;
 948 
 949 #ifndef PRODUCT
 950   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
 951   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
 952   set_print_assembly(PrintFrameConverterAssembly);
 953   set_parsed_irreducible_loop(false);
 954 #endif
 955   CompileWrapper cw(this);
 956   Init(/*AliasLevel=*/ 0);
 957   init_tf((*generator)());
 958 
 959   {
 960     // The following is a dummy for the sake of GraphKit::gen_stub
 961     Unique_Node_List for_igvn(comp_arena());
 962     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
 963     PhaseGVN gvn(Thread::current()->resource_area(),255);
 964     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
 965     gvn.transform_no_reclaim(top());
 966 
 967     GraphKit kit;
 968     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
 969   }
 970 
 971   NOT_PRODUCT( verify_graph_edges(); )
 972   Code_Gen();
 973   if (failing())  return;
 974 
 975 
 976   // Entry point will be accessed using compile->stub_entry_point();
 977   if (code_buffer() == NULL) {
 978     Matcher::soft_match_failure();
 979   } else {
 980     if (PrintAssembly && (WizardMode || Verbose))
 981       tty->print_cr("### Stub::%s", stub_name);
 982 
 983     if (!failing()) {
 984       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
 985 
 986       // Make the NMethod
 987       // For now we mark the frame as never safe for profile stackwalking
 988       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
 989                                                       code_buffer(),
 990                                                       CodeOffsets::frame_never_safe,
 991                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
 992                                                       frame_size_in_words(),
 993                                                       _oop_map_set,
 994                                                       save_arg_registers);
 995       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
 996 
 997       _stub_entry_point = rs->entry_point();
 998     }
 999   }
1000 }
1001 
1002 //------------------------------Init-------------------------------------------
1003 // Prepare for a single compilation
1004 void Compile::Init(int aliaslevel) {
1005   _unique  = 0;
1006   _regalloc = NULL;
1007 
1008   _tf      = NULL;  // filled in later
1009   _top     = NULL;  // cached later
1010   _matcher = NULL;  // filled in later
1011   _cfg     = NULL;  // filled in later
1012 
1013   set_24_bit_selection_and_mode(Use24BitFP, false);
1014 
1015   _node_note_array = NULL;
1016   _default_node_notes = NULL;
1017 
1018   _immutable_memory = NULL; // filled in at first inquiry
1019 
1020   // Globally visible Nodes
1021   // First set TOP to NULL to give safe behavior during creation of RootNode
1022   set_cached_top_node(NULL);
1023   set_root(new (this) RootNode());
1024   // Now that you have a Root to point to, create the real TOP
1025   set_cached_top_node( new (this) ConNode(Type::TOP) );
1026   set_recent_alloc(NULL, NULL);
1027 
1028   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1029   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1030   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1031   env()->set_dependencies(new Dependencies(env()));
1032 
1033   _fixed_slots = 0;
1034   set_has_split_ifs(false);
1035   set_has_loops(has_method() && method()->has_loops()); // first approximation
1036   set_has_stringbuilder(false);
1037   set_has_boxed_value(false);
1038   _trap_can_recompile = false;  // no traps emitted yet
1039   _major_progress = true; // start out assuming good things will happen
1040   set_has_unsafe_access(false);
1041   set_max_vector_size(0);
1042   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1043   set_decompile_count(0);
1044 
1045   set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
1046   set_num_loop_opts(LoopOptsCount);
1047   set_do_inlining(Inline);
1048   set_max_inline_size(MaxInlineSize);
1049   set_freq_inline_size(FreqInlineSize);
1050   set_do_scheduling(OptoScheduling);
1051   set_do_count_invocations(false);
1052   set_do_method_data_update(false);
1053 
1054   if (debug_info()->recording_non_safepoints()) {
1055     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1056                         (comp_arena(), 8, 0, NULL));
1057     set_default_node_notes(Node_Notes::make(this));
1058   }
1059 
1060   // // -- Initialize types before each compile --
1061   // // Update cached type information
1062   // if( _method && _method->constants() )
1063   //   Type::update_loaded_types(_method, _method->constants());
1064 
1065   // Init alias_type map.
1066   if (!_do_escape_analysis && aliaslevel == 3)
1067     aliaslevel = 2;  // No unique types without escape analysis
1068   _AliasLevel = aliaslevel;
1069   const int grow_ats = 16;
1070   _max_alias_types = grow_ats;
1071   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1072   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1073   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1074   {
1075     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1076   }
1077   // Initialize the first few types.
1078   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1079   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1080   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1081   _num_alias_types = AliasIdxRaw+1;
1082   // Zero out the alias type cache.
1083   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1084   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1085   probe_alias_cache(NULL)->_index = AliasIdxTop;
1086 
1087   _intrinsics = NULL;
1088   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1089   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1090   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1091   register_library_intrinsics();
1092 }
1093 
1094 //---------------------------init_start----------------------------------------
1095 // Install the StartNode on this compile object.
1096 void Compile::init_start(StartNode* s) {
1097   if (failing())
1098     return; // already failing
1099   assert(s == start(), "");
1100 }
1101 
1102 StartNode* Compile::start() const {
1103   assert(!failing(), "");
1104   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1105     Node* start = root()->fast_out(i);
1106     if( start->is_Start() )
1107       return start->as_Start();
1108   }
1109   ShouldNotReachHere();
1110   return NULL;
1111 }
1112 
1113 //-------------------------------immutable_memory-------------------------------------
1114 // Access immutable memory
1115 Node* Compile::immutable_memory() {
1116   if (_immutable_memory != NULL) {
1117     return _immutable_memory;
1118   }
1119   StartNode* s = start();
1120   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1121     Node *p = s->fast_out(i);
1122     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1123       _immutable_memory = p;
1124       return _immutable_memory;
1125     }
1126   }
1127   ShouldNotReachHere();
1128   return NULL;
1129 }
1130 
1131 //----------------------set_cached_top_node------------------------------------
1132 // Install the cached top node, and make sure Node::is_top works correctly.
1133 void Compile::set_cached_top_node(Node* tn) {
1134   if (tn != NULL)  verify_top(tn);
1135   Node* old_top = _top;
1136   _top = tn;
1137   // Calling Node::setup_is_top allows the nodes the chance to adjust
1138   // their _out arrays.
1139   if (_top != NULL)     _top->setup_is_top();
1140   if (old_top != NULL)  old_top->setup_is_top();
1141   assert(_top == NULL || top()->is_top(), "");
1142 }
1143 
1144 #ifdef ASSERT
1145 uint Compile::count_live_nodes_by_graph_walk() {
1146   Unique_Node_List useful(comp_arena());
1147   // Get useful node list by walking the graph.
1148   identify_useful_nodes(useful);
1149   return useful.size();
1150 }
1151 
1152 void Compile::print_missing_nodes() {
1153 
1154   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1155   if ((_log == NULL) && (! PrintIdealNodeCount)) {
1156     return;
1157   }
1158 
1159   // This is an expensive function. It is executed only when the user
1160   // specifies VerifyIdealNodeCount option or otherwise knows the
1161   // additional work that needs to be done to identify reachable nodes
1162   // by walking the flow graph and find the missing ones using
1163   // _dead_node_list.
1164 
1165   Unique_Node_List useful(comp_arena());
1166   // Get useful node list by walking the graph.
1167   identify_useful_nodes(useful);
1168 
1169   uint l_nodes = C->live_nodes();
1170   uint l_nodes_by_walk = useful.size();
1171 
1172   if (l_nodes != l_nodes_by_walk) {
1173     if (_log != NULL) {
1174       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1175       _log->stamp();
1176       _log->end_head();
1177     }
1178     VectorSet& useful_member_set = useful.member_set();
1179     int last_idx = l_nodes_by_walk;
1180     for (int i = 0; i < last_idx; i++) {
1181       if (useful_member_set.test(i)) {
1182         if (_dead_node_list.test(i)) {
1183           if (_log != NULL) {
1184             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1185           }
1186           if (PrintIdealNodeCount) {
1187             // Print the log message to tty
1188               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1189               useful.at(i)->dump();
1190           }
1191         }
1192       }
1193       else if (! _dead_node_list.test(i)) {
1194         if (_log != NULL) {
1195           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1196         }
1197         if (PrintIdealNodeCount) {
1198           // Print the log message to tty
1199           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1200         }
1201       }
1202     }
1203     if (_log != NULL) {
1204       _log->tail("mismatched_nodes");
1205     }
1206   }
1207 }
1208 #endif
1209 
1210 #ifndef PRODUCT
1211 void Compile::verify_top(Node* tn) const {
1212   if (tn != NULL) {
1213     assert(tn->is_Con(), "top node must be a constant");
1214     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1215     assert(tn->in(0) != NULL, "must have live top node");
1216   }
1217 }
1218 #endif
1219 
1220 
1221 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1222 
1223 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1224   guarantee(arr != NULL, "");
1225   int num_blocks = arr->length();
1226   if (grow_by < num_blocks)  grow_by = num_blocks;
1227   int num_notes = grow_by * _node_notes_block_size;
1228   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1229   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1230   while (num_notes > 0) {
1231     arr->append(notes);
1232     notes     += _node_notes_block_size;
1233     num_notes -= _node_notes_block_size;
1234   }
1235   assert(num_notes == 0, "exact multiple, please");
1236 }
1237 
1238 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1239   if (source == NULL || dest == NULL)  return false;
1240 
1241   if (dest->is_Con())
1242     return false;               // Do not push debug info onto constants.
1243 
1244 #ifdef ASSERT
1245   // Leave a bread crumb trail pointing to the original node:
1246   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1247     dest->set_debug_orig(source);
1248   }
1249 #endif
1250 
1251   if (node_note_array() == NULL)
1252     return false;               // Not collecting any notes now.
1253 
1254   // This is a copy onto a pre-existing node, which may already have notes.
1255   // If both nodes have notes, do not overwrite any pre-existing notes.
1256   Node_Notes* source_notes = node_notes_at(source->_idx);
1257   if (source_notes == NULL || source_notes->is_clear())  return false;
1258   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1259   if (dest_notes == NULL || dest_notes->is_clear()) {
1260     return set_node_notes_at(dest->_idx, source_notes);
1261   }
1262 
1263   Node_Notes merged_notes = (*source_notes);
1264   // The order of operations here ensures that dest notes will win...
1265   merged_notes.update_from(dest_notes);
1266   return set_node_notes_at(dest->_idx, &merged_notes);
1267 }
1268 
1269 
1270 //--------------------------allow_range_check_smearing-------------------------
1271 // Gating condition for coalescing similar range checks.
1272 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1273 // single covering check that is at least as strong as any of them.
1274 // If the optimization succeeds, the simplified (strengthened) range check
1275 // will always succeed.  If it fails, we will deopt, and then give up
1276 // on the optimization.
1277 bool Compile::allow_range_check_smearing() const {
1278   // If this method has already thrown a range-check,
1279   // assume it was because we already tried range smearing
1280   // and it failed.
1281   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1282   return !already_trapped;
1283 }
1284 
1285 
1286 //------------------------------flatten_alias_type-----------------------------
1287 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1288   int offset = tj->offset();
1289   TypePtr::PTR ptr = tj->ptr();
1290 
1291   // Known instance (scalarizable allocation) alias only with itself.
1292   bool is_known_inst = tj->isa_oopptr() != NULL &&
1293                        tj->is_oopptr()->is_known_instance();
1294 
1295   // Process weird unsafe references.
1296   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1297     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1298     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1299     tj = TypeOopPtr::BOTTOM;
1300     ptr = tj->ptr();
1301     offset = tj->offset();
1302   }
1303 
1304   // Array pointers need some flattening
1305   const TypeAryPtr *ta = tj->isa_aryptr();
1306   if (ta && ta->is_stable()) {
1307     // Erase stability property for alias analysis.
1308     tj = ta = ta->cast_to_stable(false);
1309   }
1310   if( ta && is_known_inst ) {
1311     if ( offset != Type::OffsetBot &&
1312          offset > arrayOopDesc::length_offset_in_bytes() ) {
1313       offset = Type::OffsetBot; // Flatten constant access into array body only
1314       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1315     }
1316   } else if( ta && _AliasLevel >= 2 ) {
1317     // For arrays indexed by constant indices, we flatten the alias
1318     // space to include all of the array body.  Only the header, klass
1319     // and array length can be accessed un-aliased.
1320     if( offset != Type::OffsetBot ) {
1321       if( ta->const_oop() ) { // MethodData* or Method*
1322         offset = Type::OffsetBot;   // Flatten constant access into array body
1323         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1324       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1325         // range is OK as-is.
1326         tj = ta = TypeAryPtr::RANGE;
1327       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1328         tj = TypeInstPtr::KLASS; // all klass loads look alike
1329         ta = TypeAryPtr::RANGE; // generic ignored junk
1330         ptr = TypePtr::BotPTR;
1331       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1332         tj = TypeInstPtr::MARK;
1333         ta = TypeAryPtr::RANGE; // generic ignored junk
1334         ptr = TypePtr::BotPTR;
1335       } else {                  // Random constant offset into array body
1336         offset = Type::OffsetBot;   // Flatten constant access into array body
1337         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1338       }
1339     }
1340     // Arrays of fixed size alias with arrays of unknown size.
1341     if (ta->size() != TypeInt::POS) {
1342       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1343       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1344     }
1345     // Arrays of known objects become arrays of unknown objects.
1346     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1347       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1348       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1349     }
1350     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1351       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1352       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1353     }
1354     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1355     // cannot be distinguished by bytecode alone.
1356     if (ta->elem() == TypeInt::BOOL) {
1357       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1358       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1359       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1360     }
1361     // During the 2nd round of IterGVN, NotNull castings are removed.
1362     // Make sure the Bottom and NotNull variants alias the same.
1363     // Also, make sure exact and non-exact variants alias the same.
1364     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1365       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1366     }
1367   }
1368 
1369   // Oop pointers need some flattening
1370   const TypeInstPtr *to = tj->isa_instptr();
1371   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1372     ciInstanceKlass *k = to->klass()->as_instance_klass();
1373     if( ptr == TypePtr::Constant ) {
1374       if (to->klass() != ciEnv::current()->Class_klass() ||
1375           offset < k->size_helper() * wordSize) {
1376         // No constant oop pointers (such as Strings); they alias with
1377         // unknown strings.
1378         assert(!is_known_inst, "not scalarizable allocation");
1379         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1380       }
1381     } else if( is_known_inst ) {
1382       tj = to; // Keep NotNull and klass_is_exact for instance type
1383     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1384       // During the 2nd round of IterGVN, NotNull castings are removed.
1385       // Make sure the Bottom and NotNull variants alias the same.
1386       // Also, make sure exact and non-exact variants alias the same.
1387       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1388     }
1389     if (to->speculative() != NULL) {
1390       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
1391     }
1392     // Canonicalize the holder of this field
1393     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1394       // First handle header references such as a LoadKlassNode, even if the
1395       // object's klass is unloaded at compile time (4965979).
1396       if (!is_known_inst) { // Do it only for non-instance types
1397         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1398       }
1399     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1400       // Static fields are in the space above the normal instance
1401       // fields in the java.lang.Class instance.
1402       if (to->klass() != ciEnv::current()->Class_klass()) {
1403         to = NULL;
1404         tj = TypeOopPtr::BOTTOM;
1405         offset = tj->offset();
1406       }
1407     } else {
1408       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1409       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1410         if( is_known_inst ) {
1411           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1412         } else {
1413           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1414         }
1415       }
1416     }
1417   }
1418 
1419   // Klass pointers to object array klasses need some flattening
1420   const TypeKlassPtr *tk = tj->isa_klassptr();
1421   if( tk ) {
1422     // If we are referencing a field within a Klass, we need
1423     // to assume the worst case of an Object.  Both exact and
1424     // inexact types must flatten to the same alias class so
1425     // use NotNull as the PTR.
1426     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1427 
1428       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1429                                    TypeKlassPtr::OBJECT->klass(),
1430                                    offset);
1431     }
1432 
1433     ciKlass* klass = tk->klass();
1434     if( klass->is_obj_array_klass() ) {
1435       ciKlass* k = TypeAryPtr::OOPS->klass();
1436       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1437         k = TypeInstPtr::BOTTOM->klass();
1438       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1439     }
1440 
1441     // Check for precise loads from the primary supertype array and force them
1442     // to the supertype cache alias index.  Check for generic array loads from
1443     // the primary supertype array and also force them to the supertype cache
1444     // alias index.  Since the same load can reach both, we need to merge
1445     // these 2 disparate memories into the same alias class.  Since the
1446     // primary supertype array is read-only, there's no chance of confusion
1447     // where we bypass an array load and an array store.
1448     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1449     if (offset == Type::OffsetBot ||
1450         (offset >= primary_supers_offset &&
1451          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1452         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1453       offset = in_bytes(Klass::secondary_super_cache_offset());
1454       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1455     }
1456   }
1457 
1458   // Flatten all Raw pointers together.
1459   if (tj->base() == Type::RawPtr)
1460     tj = TypeRawPtr::BOTTOM;
1461 
1462   if (tj->base() == Type::AnyPtr)
1463     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1464 
1465   // Flatten all to bottom for now
1466   switch( _AliasLevel ) {
1467   case 0:
1468     tj = TypePtr::BOTTOM;
1469     break;
1470   case 1:                       // Flatten to: oop, static, field or array
1471     switch (tj->base()) {
1472     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1473     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1474     case Type::AryPtr:   // do not distinguish arrays at all
1475     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1476     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1477     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1478     default: ShouldNotReachHere();
1479     }
1480     break;
1481   case 2:                       // No collapsing at level 2; keep all splits
1482   case 3:                       // No collapsing at level 3; keep all splits
1483     break;
1484   default:
1485     Unimplemented();
1486   }
1487 
1488   offset = tj->offset();
1489   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1490 
1491   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1492           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1493           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1494           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1495           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1496           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1497           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
1498           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1499   assert( tj->ptr() != TypePtr::TopPTR &&
1500           tj->ptr() != TypePtr::AnyNull &&
1501           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1502 //    assert( tj->ptr() != TypePtr::Constant ||
1503 //            tj->base() == Type::RawPtr ||
1504 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1505 
1506   return tj;
1507 }
1508 
1509 void Compile::AliasType::Init(int i, const TypePtr* at) {
1510   _index = i;
1511   _adr_type = at;
1512   _field = NULL;
1513   _element = NULL;
1514   _is_rewritable = true; // default
1515   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1516   if (atoop != NULL && atoop->is_known_instance()) {
1517     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1518     _general_index = Compile::current()->get_alias_index(gt);
1519   } else {
1520     _general_index = 0;
1521   }
1522 }
1523 
1524 //---------------------------------print_on------------------------------------
1525 #ifndef PRODUCT
1526 void Compile::AliasType::print_on(outputStream* st) {
1527   if (index() < 10)
1528         st->print("@ <%d> ", index());
1529   else  st->print("@ <%d>",  index());
1530   st->print(is_rewritable() ? "   " : " RO");
1531   int offset = adr_type()->offset();
1532   if (offset == Type::OffsetBot)
1533         st->print(" +any");
1534   else  st->print(" +%-3d", offset);
1535   st->print(" in ");
1536   adr_type()->dump_on(st);
1537   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1538   if (field() != NULL && tjp) {
1539     if (tjp->klass()  != field()->holder() ||
1540         tjp->offset() != field()->offset_in_bytes()) {
1541       st->print(" != ");
1542       field()->print();
1543       st->print(" ***");
1544     }
1545   }
1546 }
1547 
1548 void print_alias_types() {
1549   Compile* C = Compile::current();
1550   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1551   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1552     C->alias_type(idx)->print_on(tty);
1553     tty->cr();
1554   }
1555 }
1556 #endif
1557 
1558 
1559 //----------------------------probe_alias_cache--------------------------------
1560 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1561   intptr_t key = (intptr_t) adr_type;
1562   key ^= key >> logAliasCacheSize;
1563   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1564 }
1565 
1566 
1567 //-----------------------------grow_alias_types--------------------------------
1568 void Compile::grow_alias_types() {
1569   const int old_ats  = _max_alias_types; // how many before?
1570   const int new_ats  = old_ats;          // how many more?
1571   const int grow_ats = old_ats+new_ats;  // how many now?
1572   _max_alias_types = grow_ats;
1573   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1574   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1575   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1576   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1577 }
1578 
1579 
1580 //--------------------------------find_alias_type------------------------------
1581 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1582   if (_AliasLevel == 0)
1583     return alias_type(AliasIdxBot);
1584 
1585   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1586   if (ace->_adr_type == adr_type) {
1587     return alias_type(ace->_index);
1588   }
1589 
1590   // Handle special cases.
1591   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1592   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1593 
1594   // Do it the slow way.
1595   const TypePtr* flat = flatten_alias_type(adr_type);
1596 
1597 #ifdef ASSERT
1598   assert(flat == flatten_alias_type(flat), "idempotent");
1599   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
1600   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1601     const TypeOopPtr* foop = flat->is_oopptr();
1602     // Scalarizable allocations have exact klass always.
1603     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1604     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1605     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
1606   }
1607   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
1608 #endif
1609 
1610   int idx = AliasIdxTop;
1611   for (int i = 0; i < num_alias_types(); i++) {
1612     if (alias_type(i)->adr_type() == flat) {
1613       idx = i;
1614       break;
1615     }
1616   }
1617 
1618   if (idx == AliasIdxTop) {
1619     if (no_create)  return NULL;
1620     // Grow the array if necessary.
1621     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1622     // Add a new alias type.
1623     idx = _num_alias_types++;
1624     _alias_types[idx]->Init(idx, flat);
1625     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1626     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1627     if (flat->isa_instptr()) {
1628       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1629           && flat->is_instptr()->klass() == env()->Class_klass())
1630         alias_type(idx)->set_rewritable(false);
1631     }
1632     if (flat->isa_aryptr()) {
1633 #ifdef ASSERT
1634       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1635       // (T_BYTE has the weakest alignment and size restrictions...)
1636       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1637 #endif
1638       if (flat->offset() == TypePtr::OffsetBot) {
1639         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1640       }
1641     }
1642     if (flat->isa_klassptr()) {
1643       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1644         alias_type(idx)->set_rewritable(false);
1645       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1646         alias_type(idx)->set_rewritable(false);
1647       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1648         alias_type(idx)->set_rewritable(false);
1649       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1650         alias_type(idx)->set_rewritable(false);
1651     }
1652     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1653     // but the base pointer type is not distinctive enough to identify
1654     // references into JavaThread.)
1655 
1656     // Check for final fields.
1657     const TypeInstPtr* tinst = flat->isa_instptr();
1658     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1659       ciField* field;
1660       if (tinst->const_oop() != NULL &&
1661           tinst->klass() == ciEnv::current()->Class_klass() &&
1662           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1663         // static field
1664         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1665         field = k->get_field_by_offset(tinst->offset(), true);
1666       } else {
1667         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1668         field = k->get_field_by_offset(tinst->offset(), false);
1669       }
1670       assert(field == NULL ||
1671              original_field == NULL ||
1672              (field->holder() == original_field->holder() &&
1673               field->offset() == original_field->offset() &&
1674               field->is_static() == original_field->is_static()), "wrong field?");
1675       // Set field() and is_rewritable() attributes.
1676       if (field != NULL)  alias_type(idx)->set_field(field);
1677     }
1678   }
1679 
1680   // Fill the cache for next time.
1681   ace->_adr_type = adr_type;
1682   ace->_index    = idx;
1683   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1684 
1685   // Might as well try to fill the cache for the flattened version, too.
1686   AliasCacheEntry* face = probe_alias_cache(flat);
1687   if (face->_adr_type == NULL) {
1688     face->_adr_type = flat;
1689     face->_index    = idx;
1690     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1691   }
1692 
1693   return alias_type(idx);
1694 }
1695 
1696 
1697 Compile::AliasType* Compile::alias_type(ciField* field) {
1698   const TypeOopPtr* t;
1699   if (field->is_static())
1700     t = TypeInstPtr::make(field->holder()->java_mirror());
1701   else
1702     t = TypeOopPtr::make_from_klass_raw(field->holder());
1703   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1704   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1705   return atp;
1706 }
1707 
1708 
1709 //------------------------------have_alias_type--------------------------------
1710 bool Compile::have_alias_type(const TypePtr* adr_type) {
1711   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1712   if (ace->_adr_type == adr_type) {
1713     return true;
1714   }
1715 
1716   // Handle special cases.
1717   if (adr_type == NULL)             return true;
1718   if (adr_type == TypePtr::BOTTOM)  return true;
1719 
1720   return find_alias_type(adr_type, true, NULL) != NULL;
1721 }
1722 
1723 //-----------------------------must_alias--------------------------------------
1724 // True if all values of the given address type are in the given alias category.
1725 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1726   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1727   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1728   if (alias_idx == AliasIdxTop)         return false; // the empty category
1729   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1730 
1731   // the only remaining possible overlap is identity
1732   int adr_idx = get_alias_index(adr_type);
1733   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1734   assert(adr_idx == alias_idx ||
1735          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1736           && adr_type                       != TypeOopPtr::BOTTOM),
1737          "should not be testing for overlap with an unsafe pointer");
1738   return adr_idx == alias_idx;
1739 }
1740 
1741 //------------------------------can_alias--------------------------------------
1742 // True if any values of the given address type are in the given alias category.
1743 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1744   if (alias_idx == AliasIdxTop)         return false; // the empty category
1745   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1746   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1747   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1748 
1749   // the only remaining possible overlap is identity
1750   int adr_idx = get_alias_index(adr_type);
1751   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1752   return adr_idx == alias_idx;
1753 }
1754 
1755 
1756 
1757 //---------------------------pop_warm_call-------------------------------------
1758 WarmCallInfo* Compile::pop_warm_call() {
1759   WarmCallInfo* wci = _warm_calls;
1760   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1761   return wci;
1762 }
1763 
1764 //----------------------------Inline_Warm--------------------------------------
1765 int Compile::Inline_Warm() {
1766   // If there is room, try to inline some more warm call sites.
1767   // %%% Do a graph index compaction pass when we think we're out of space?
1768   if (!InlineWarmCalls)  return 0;
1769 
1770   int calls_made_hot = 0;
1771   int room_to_grow   = NodeCountInliningCutoff - unique();
1772   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1773   int amount_grown   = 0;
1774   WarmCallInfo* call;
1775   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1776     int est_size = (int)call->size();
1777     if (est_size > (room_to_grow - amount_grown)) {
1778       // This one won't fit anyway.  Get rid of it.
1779       call->make_cold();
1780       continue;
1781     }
1782     call->make_hot();
1783     calls_made_hot++;
1784     amount_grown   += est_size;
1785     amount_to_grow -= est_size;
1786   }
1787 
1788   if (calls_made_hot > 0)  set_major_progress();
1789   return calls_made_hot;
1790 }
1791 
1792 
1793 //----------------------------Finish_Warm--------------------------------------
1794 void Compile::Finish_Warm() {
1795   if (!InlineWarmCalls)  return;
1796   if (failing())  return;
1797   if (warm_calls() == NULL)  return;
1798 
1799   // Clean up loose ends, if we are out of space for inlining.
1800   WarmCallInfo* call;
1801   while ((call = pop_warm_call()) != NULL) {
1802     call->make_cold();
1803   }
1804 }
1805 
1806 //---------------------cleanup_loop_predicates-----------------------
1807 // Remove the opaque nodes that protect the predicates so that all unused
1808 // checks and uncommon_traps will be eliminated from the ideal graph
1809 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1810   if (predicate_count()==0) return;
1811   for (int i = predicate_count(); i > 0; i--) {
1812     Node * n = predicate_opaque1_node(i-1);
1813     assert(n->Opcode() == Op_Opaque1, "must be");
1814     igvn.replace_node(n, n->in(1));
1815   }
1816   assert(predicate_count()==0, "should be clean!");
1817 }
1818 
1819 // StringOpts and late inlining of string methods
1820 void Compile::inline_string_calls(bool parse_time) {
1821   {
1822     // remove useless nodes to make the usage analysis simpler
1823     ResourceMark rm;
1824     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1825   }
1826 
1827   {
1828     ResourceMark rm;
1829     print_method(PHASE_BEFORE_STRINGOPTS, 3);
1830     PhaseStringOpts pso(initial_gvn(), for_igvn());
1831     print_method(PHASE_AFTER_STRINGOPTS, 3);
1832   }
1833 
1834   // now inline anything that we skipped the first time around
1835   if (!parse_time) {
1836     _late_inlines_pos = _late_inlines.length();
1837   }
1838 
1839   while (_string_late_inlines.length() > 0) {
1840     CallGenerator* cg = _string_late_inlines.pop();
1841     cg->do_late_inline();
1842     if (failing())  return;
1843   }
1844   _string_late_inlines.trunc_to(0);
1845 }
1846 
1847 // Late inlining of boxing methods
1848 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
1849   if (_boxing_late_inlines.length() > 0) {
1850     assert(has_boxed_value(), "inconsistent");
1851 
1852     PhaseGVN* gvn = initial_gvn();
1853     set_inlining_incrementally(true);
1854 
1855     assert( igvn._worklist.size() == 0, "should be done with igvn" );
1856     for_igvn()->clear();
1857     gvn->replace_with(&igvn);
1858 
1859     while (_boxing_late_inlines.length() > 0) {
1860       CallGenerator* cg = _boxing_late_inlines.pop();
1861       cg->do_late_inline();
1862       if (failing())  return;
1863     }
1864     _boxing_late_inlines.trunc_to(0);
1865 
1866     {
1867       ResourceMark rm;
1868       PhaseRemoveUseless pru(gvn, for_igvn());
1869     }
1870 
1871     igvn = PhaseIterGVN(gvn);
1872     igvn.optimize();
1873 
1874     set_inlining_progress(false);
1875     set_inlining_incrementally(false);
1876   }
1877 }
1878 
1879 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
1880   assert(IncrementalInline, "incremental inlining should be on");
1881   PhaseGVN* gvn = initial_gvn();
1882 
1883   set_inlining_progress(false);
1884   for_igvn()->clear();
1885   gvn->replace_with(&igvn);
1886 
1887   int i = 0;
1888 
1889   for (; i <_late_inlines.length() && !inlining_progress(); i++) {
1890     CallGenerator* cg = _late_inlines.at(i);
1891     _late_inlines_pos = i+1;
1892     cg->do_late_inline();
1893     if (failing())  return;
1894   }
1895   int j = 0;
1896   for (; i < _late_inlines.length(); i++, j++) {
1897     _late_inlines.at_put(j, _late_inlines.at(i));
1898   }
1899   _late_inlines.trunc_to(j);
1900 
1901   {
1902     ResourceMark rm;
1903     PhaseRemoveUseless pru(gvn, for_igvn());
1904   }
1905 
1906   igvn = PhaseIterGVN(gvn);
1907 }
1908 
1909 // Perform incremental inlining until bound on number of live nodes is reached
1910 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
1911   PhaseGVN* gvn = initial_gvn();
1912 
1913   set_inlining_incrementally(true);
1914   set_inlining_progress(true);
1915   uint low_live_nodes = 0;
1916 
1917   while(inlining_progress() && _late_inlines.length() > 0) {
1918 
1919     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
1920       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
1921         // PhaseIdealLoop is expensive so we only try it once we are
1922         // out of loop and we only try it again if the previous helped
1923         // got the number of nodes down significantly
1924         PhaseIdealLoop ideal_loop( igvn, false, true );
1925         if (failing())  return;
1926         low_live_nodes = live_nodes();
1927         _major_progress = true;
1928       }
1929 
1930       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
1931         break;
1932       }
1933     }
1934 
1935     inline_incrementally_one(igvn);
1936 
1937     if (failing())  return;
1938 
1939     igvn.optimize();
1940 
1941     if (failing())  return;
1942   }
1943 
1944   assert( igvn._worklist.size() == 0, "should be done with igvn" );
1945 
1946   if (_string_late_inlines.length() > 0) {
1947     assert(has_stringbuilder(), "inconsistent");
1948     for_igvn()->clear();
1949     initial_gvn()->replace_with(&igvn);
1950 
1951     inline_string_calls(false);
1952 
1953     if (failing())  return;
1954 
1955     {
1956       ResourceMark rm;
1957       PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1958     }
1959 
1960     igvn = PhaseIterGVN(gvn);
1961 
1962     igvn.optimize();
1963   }
1964 
1965   set_inlining_incrementally(false);
1966 }
1967 
1968 
1969 //------------------------------Optimize---------------------------------------
1970 // Given a graph, optimize it.
1971 void Compile::Optimize() {
1972   TracePhase t1("optimizer", &_t_optimizer, true);
1973 
1974 #ifndef PRODUCT
1975   if (env()->break_at_compile()) {
1976     BREAKPOINT;
1977   }
1978 
1979 #endif
1980 
1981   ResourceMark rm;
1982   int          loop_opts_cnt;
1983 
1984   NOT_PRODUCT( verify_graph_edges(); )
1985 
1986   print_method(PHASE_AFTER_PARSING);
1987 
1988  {
1989   // Iterative Global Value Numbering, including ideal transforms
1990   // Initialize IterGVN with types and values from parse-time GVN
1991   PhaseIterGVN igvn(initial_gvn());
1992   {
1993     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
1994     igvn.optimize();
1995   }
1996 
1997   print_method(PHASE_ITER_GVN1, 2);
1998 
1999   if (failing())  return;
2000 
2001   {
2002     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
2003     inline_incrementally(igvn);
2004   }
2005 
2006   print_method(PHASE_INCREMENTAL_INLINE, 2);
2007 
2008   if (failing())  return;
2009 
2010   if (eliminate_boxing()) {
2011     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
2012     // Inline valueOf() methods now.
2013     inline_boxing_calls(igvn);
2014 
2015     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2016 
2017     if (failing())  return;
2018   }
2019 
2020   // Remove the speculative part of types and clean up the graph from
2021   // the extra CastPP nodes whose only purpose is to carry them. Do
2022   // that early so that optimizations are not disrupted by the extra
2023   // CastPP nodes.
2024   remove_speculative_types(igvn);
2025 
2026   // No more new expensive nodes will be added to the list from here
2027   // so keep only the actual candidates for optimizations.
2028   cleanup_expensive_nodes(igvn);
2029 
2030   // Perform escape analysis
2031   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2032     if (has_loops()) {
2033       // Cleanup graph (remove dead nodes).
2034       TracePhase t2("idealLoop", &_t_idealLoop, true);
2035       PhaseIdealLoop ideal_loop( igvn, false, true );
2036       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2037       if (failing())  return;
2038     }
2039     ConnectionGraph::do_analysis(this, &igvn);
2040 
2041     if (failing())  return;
2042 
2043     // Optimize out fields loads from scalar replaceable allocations.
2044     igvn.optimize();
2045     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2046 
2047     if (failing())  return;
2048 
2049     if (congraph() != NULL && macro_count() > 0) {
2050       NOT_PRODUCT( TracePhase t2("macroEliminate", &_t_macroEliminate, TimeCompiler); )
2051       PhaseMacroExpand mexp(igvn);
2052       mexp.eliminate_macro_nodes();
2053       igvn.set_delay_transform(false);
2054 
2055       igvn.optimize();
2056       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2057 
2058       if (failing())  return;
2059     }
2060   }
2061 
2062   // Loop transforms on the ideal graph.  Range Check Elimination,
2063   // peeling, unrolling, etc.
2064 
2065   // Set loop opts counter
2066   loop_opts_cnt = num_loop_opts();
2067   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2068     {
2069       TracePhase t2("idealLoop", &_t_idealLoop, true);
2070       PhaseIdealLoop ideal_loop( igvn, true );
2071       loop_opts_cnt--;
2072       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2073       if (failing())  return;
2074     }
2075     // Loop opts pass if partial peeling occurred in previous pass
2076     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
2077       TracePhase t3("idealLoop", &_t_idealLoop, true);
2078       PhaseIdealLoop ideal_loop( igvn, false );
2079       loop_opts_cnt--;
2080       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2081       if (failing())  return;
2082     }
2083     // Loop opts pass for loop-unrolling before CCP
2084     if(major_progress() && (loop_opts_cnt > 0)) {
2085       TracePhase t4("idealLoop", &_t_idealLoop, true);
2086       PhaseIdealLoop ideal_loop( igvn, false );
2087       loop_opts_cnt--;
2088       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2089     }
2090     if (!failing()) {
2091       // Verify that last round of loop opts produced a valid graph
2092       NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
2093       PhaseIdealLoop::verify(igvn);
2094     }
2095   }
2096   if (failing())  return;
2097 
2098   // Conditional Constant Propagation;
2099   PhaseCCP ccp( &igvn );
2100   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2101   {
2102     TracePhase t2("ccp", &_t_ccp, true);
2103     ccp.do_transform();
2104   }
2105   print_method(PHASE_CPP1, 2);
2106 
2107   assert( true, "Break here to ccp.dump_old2new_map()");
2108 
2109   // Iterative Global Value Numbering, including ideal transforms
2110   {
2111     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
2112     igvn = ccp;
2113     igvn.optimize();
2114   }
2115 
2116   print_method(PHASE_ITER_GVN2, 2);
2117 
2118   if (failing())  return;
2119 
2120   // Loop transforms on the ideal graph.  Range Check Elimination,
2121   // peeling, unrolling, etc.
2122   if(loop_opts_cnt > 0) {
2123     debug_only( int cnt = 0; );
2124     while(major_progress() && (loop_opts_cnt > 0)) {
2125       TracePhase t2("idealLoop", &_t_idealLoop, true);
2126       assert( cnt++ < 40, "infinite cycle in loop optimization" );
2127       PhaseIdealLoop ideal_loop( igvn, true);
2128       loop_opts_cnt--;
2129       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2130       if (failing())  return;
2131     }
2132   }
2133 
2134   {
2135     // Verify that all previous optimizations produced a valid graph
2136     // at least to this point, even if no loop optimizations were done.
2137     NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
2138     PhaseIdealLoop::verify(igvn);
2139   }
2140 
2141   {
2142     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
2143     PhaseMacroExpand  mex(igvn);
2144     if (mex.expand_macro_nodes()) {
2145       assert(failing(), "must bail out w/ explicit message");
2146       return;
2147     }
2148   }
2149 
2150  } // (End scope of igvn; run destructor if necessary for asserts.)
2151 
2152   dump_inlining();
2153   // A method with only infinite loops has no edges entering loops from root
2154   {
2155     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
2156     if (final_graph_reshaping()) {
2157       assert(failing(), "must bail out w/ explicit message");
2158       return;
2159     }
2160   }
2161 
2162   print_method(PHASE_OPTIMIZE_FINISHED, 2);
2163 }
2164 
2165 
2166 //------------------------------Code_Gen---------------------------------------
2167 // Given a graph, generate code for it
2168 void Compile::Code_Gen() {
2169   if (failing()) {
2170     return;
2171   }
2172 
2173   // Perform instruction selection.  You might think we could reclaim Matcher
2174   // memory PDQ, but actually the Matcher is used in generating spill code.
2175   // Internals of the Matcher (including some VectorSets) must remain live
2176   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2177   // set a bit in reclaimed memory.
2178 
2179   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2180   // nodes.  Mapping is only valid at the root of each matched subtree.
2181   NOT_PRODUCT( verify_graph_edges(); )
2182 
2183   Matcher matcher;
2184   _matcher = &matcher;
2185   {
2186     TracePhase t2("matcher", &_t_matcher, true);
2187     matcher.match();
2188   }
2189   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2190   // nodes.  Mapping is only valid at the root of each matched subtree.
2191   NOT_PRODUCT( verify_graph_edges(); )
2192 
2193   // If you have too many nodes, or if matching has failed, bail out
2194   check_node_count(0, "out of nodes matching instructions");
2195   if (failing()) {
2196     return;
2197   }
2198 
2199   // Build a proper-looking CFG
2200   PhaseCFG cfg(node_arena(), root(), matcher);
2201   _cfg = &cfg;
2202   {
2203     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
2204     bool success = cfg.do_global_code_motion();
2205     if (!success) {
2206       return;
2207     }
2208 
2209     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2210     NOT_PRODUCT( verify_graph_edges(); )
2211     debug_only( cfg.verify(); )
2212   }
2213 
2214   PhaseChaitin regalloc(unique(), cfg, matcher);
2215   _regalloc = &regalloc;
2216   {
2217     TracePhase t2("regalloc", &_t_registerAllocation, true);
2218     // Perform register allocation.  After Chaitin, use-def chains are
2219     // no longer accurate (at spill code) and so must be ignored.
2220     // Node->LRG->reg mappings are still accurate.
2221     _regalloc->Register_Allocate();
2222 
2223     // Bail out if the allocator builds too many nodes
2224     if (failing()) {
2225       return;
2226     }
2227   }
2228 
2229   // Prior to register allocation we kept empty basic blocks in case the
2230   // the allocator needed a place to spill.  After register allocation we
2231   // are not adding any new instructions.  If any basic block is empty, we
2232   // can now safely remove it.
2233   {
2234     NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
2235     cfg.remove_empty_blocks();
2236     if (do_freq_based_layout()) {
2237       PhaseBlockLayout layout(cfg);
2238     } else {
2239       cfg.set_loop_alignment();
2240     }
2241     cfg.fixup_flow();
2242   }
2243 
2244   // Apply peephole optimizations
2245   if( OptoPeephole ) {
2246     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
2247     PhasePeephole peep( _regalloc, cfg);
2248     peep.do_transform();
2249   }
2250 
2251   // Convert Nodes to instruction bits in a buffer
2252   {
2253     // %%%% workspace merge brought two timers together for one job
2254     TracePhase t2a("output", &_t_output, true);
2255     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
2256     Output();
2257   }
2258 
2259   print_method(PHASE_FINAL_CODE);
2260 
2261   // He's dead, Jim.
2262   _cfg     = (PhaseCFG*)0xdeadbeef;
2263   _regalloc = (PhaseChaitin*)0xdeadbeef;
2264 }
2265 
2266 
2267 //------------------------------dump_asm---------------------------------------
2268 // Dump formatted assembly
2269 #ifndef PRODUCT
2270 void Compile::dump_asm(int *pcs, uint pc_limit) {
2271   bool cut_short = false;
2272   tty->print_cr("#");
2273   tty->print("#  ");  _tf->dump();  tty->cr();
2274   tty->print_cr("#");
2275 
2276   // For all blocks
2277   int pc = 0x0;                 // Program counter
2278   char starts_bundle = ' ';
2279   _regalloc->dump_frame();
2280 
2281   Node *n = NULL;
2282   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2283     if (VMThread::should_terminate()) {
2284       cut_short = true;
2285       break;
2286     }
2287     Block* block = _cfg->get_block(i);
2288     if (block->is_connector() && !Verbose) {
2289       continue;
2290     }
2291     n = block->head();
2292     if (pcs && n->_idx < pc_limit) {
2293       tty->print("%3.3x   ", pcs[n->_idx]);
2294     } else {
2295       tty->print("      ");
2296     }
2297     block->dump_head(_cfg);
2298     if (block->is_connector()) {
2299       tty->print_cr("        # Empty connector block");
2300     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2301       tty->print_cr("        # Block is sole successor of call");
2302     }
2303 
2304     // For all instructions
2305     Node *delay = NULL;
2306     for (uint j = 0; j < block->number_of_nodes(); j++) {
2307       if (VMThread::should_terminate()) {
2308         cut_short = true;
2309         break;
2310       }
2311       n = block->get_node(j);
2312       if (valid_bundle_info(n)) {
2313         Bundle* bundle = node_bundling(n);
2314         if (bundle->used_in_unconditional_delay()) {
2315           delay = n;
2316           continue;
2317         }
2318         if (bundle->starts_bundle()) {
2319           starts_bundle = '+';
2320         }
2321       }
2322 
2323       if (WizardMode) {
2324         n->dump();
2325       }
2326 
2327       if( !n->is_Region() &&    // Dont print in the Assembly
2328           !n->is_Phi() &&       // a few noisely useless nodes
2329           !n->is_Proj() &&
2330           !n->is_MachTemp() &&
2331           !n->is_SafePointScalarObject() &&
2332           !n->is_Catch() &&     // Would be nice to print exception table targets
2333           !n->is_MergeMem() &&  // Not very interesting
2334           !n->is_top() &&       // Debug info table constants
2335           !(n->is_Con() && !n->is_Mach())// Debug info table constants
2336           ) {
2337         if (pcs && n->_idx < pc_limit)
2338           tty->print("%3.3x", pcs[n->_idx]);
2339         else
2340           tty->print("   ");
2341         tty->print(" %c ", starts_bundle);
2342         starts_bundle = ' ';
2343         tty->print("\t");
2344         n->format(_regalloc, tty);
2345         tty->cr();
2346       }
2347 
2348       // If we have an instruction with a delay slot, and have seen a delay,
2349       // then back up and print it
2350       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2351         assert(delay != NULL, "no unconditional delay instruction");
2352         if (WizardMode) delay->dump();
2353 
2354         if (node_bundling(delay)->starts_bundle())
2355           starts_bundle = '+';
2356         if (pcs && n->_idx < pc_limit)
2357           tty->print("%3.3x", pcs[n->_idx]);
2358         else
2359           tty->print("   ");
2360         tty->print(" %c ", starts_bundle);
2361         starts_bundle = ' ';
2362         tty->print("\t");
2363         delay->format(_regalloc, tty);
2364         tty->print_cr("");
2365         delay = NULL;
2366       }
2367 
2368       // Dump the exception table as well
2369       if( n->is_Catch() && (Verbose || WizardMode) ) {
2370         // Print the exception table for this offset
2371         _handler_table.print_subtable_for(pc);
2372       }
2373     }
2374 
2375     if (pcs && n->_idx < pc_limit)
2376       tty->print_cr("%3.3x", pcs[n->_idx]);
2377     else
2378       tty->print_cr("");
2379 
2380     assert(cut_short || delay == NULL, "no unconditional delay branch");
2381 
2382   } // End of per-block dump
2383   tty->print_cr("");
2384 
2385   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
2386 }
2387 #endif
2388 
2389 //------------------------------Final_Reshape_Counts---------------------------
2390 // This class defines counters to help identify when a method
2391 // may/must be executed using hardware with only 24-bit precision.
2392 struct Final_Reshape_Counts : public StackObj {
2393   int  _call_count;             // count non-inlined 'common' calls
2394   int  _float_count;            // count float ops requiring 24-bit precision
2395   int  _double_count;           // count double ops requiring more precision
2396   int  _java_call_count;        // count non-inlined 'java' calls
2397   int  _inner_loop_count;       // count loops which need alignment
2398   VectorSet _visited;           // Visitation flags
2399   Node_List _tests;             // Set of IfNodes & PCTableNodes
2400 
2401   Final_Reshape_Counts() :
2402     _call_count(0), _float_count(0), _double_count(0),
2403     _java_call_count(0), _inner_loop_count(0),
2404     _visited( Thread::current()->resource_area() ) { }
2405 
2406   void inc_call_count  () { _call_count  ++; }
2407   void inc_float_count () { _float_count ++; }
2408   void inc_double_count() { _double_count++; }
2409   void inc_java_call_count() { _java_call_count++; }
2410   void inc_inner_loop_count() { _inner_loop_count++; }
2411 
2412   int  get_call_count  () const { return _call_count  ; }
2413   int  get_float_count () const { return _float_count ; }
2414   int  get_double_count() const { return _double_count; }
2415   int  get_java_call_count() const { return _java_call_count; }
2416   int  get_inner_loop_count() const { return _inner_loop_count; }
2417 };
2418 
2419 #ifdef ASSERT
2420 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2421   ciInstanceKlass *k = tp->klass()->as_instance_klass();
2422   // Make sure the offset goes inside the instance layout.
2423   return k->contains_field_offset(tp->offset());
2424   // Note that OffsetBot and OffsetTop are very negative.
2425 }
2426 #endif
2427 
2428 // Eliminate trivially redundant StoreCMs and accumulate their
2429 // precedence edges.
2430 void Compile::eliminate_redundant_card_marks(Node* n) {
2431   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2432   if (n->in(MemNode::Address)->outcnt() > 1) {
2433     // There are multiple users of the same address so it might be
2434     // possible to eliminate some of the StoreCMs
2435     Node* mem = n->in(MemNode::Memory);
2436     Node* adr = n->in(MemNode::Address);
2437     Node* val = n->in(MemNode::ValueIn);
2438     Node* prev = n;
2439     bool done = false;
2440     // Walk the chain of StoreCMs eliminating ones that match.  As
2441     // long as it's a chain of single users then the optimization is
2442     // safe.  Eliminating partially redundant StoreCMs would require
2443     // cloning copies down the other paths.
2444     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2445       if (adr == mem->in(MemNode::Address) &&
2446           val == mem->in(MemNode::ValueIn)) {
2447         // redundant StoreCM
2448         if (mem->req() > MemNode::OopStore) {
2449           // Hasn't been processed by this code yet.
2450           n->add_prec(mem->in(MemNode::OopStore));
2451         } else {
2452           // Already converted to precedence edge
2453           for (uint i = mem->req(); i < mem->len(); i++) {
2454             // Accumulate any precedence edges
2455             if (mem->in(i) != NULL) {
2456               n->add_prec(mem->in(i));
2457             }
2458           }
2459           // Everything above this point has been processed.
2460           done = true;
2461         }
2462         // Eliminate the previous StoreCM
2463         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2464         assert(mem->outcnt() == 0, "should be dead");
2465         mem->disconnect_inputs(NULL, this);
2466       } else {
2467         prev = mem;
2468       }
2469       mem = prev->in(MemNode::Memory);
2470     }
2471   }
2472 }
2473 
2474 //------------------------------final_graph_reshaping_impl----------------------
2475 // Implement items 1-5 from final_graph_reshaping below.
2476 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2477 
2478   if ( n->outcnt() == 0 ) return; // dead node
2479   uint nop = n->Opcode();
2480 
2481   // Check for 2-input instruction with "last use" on right input.
2482   // Swap to left input.  Implements item (2).
2483   if( n->req() == 3 &&          // two-input instruction
2484       n->in(1)->outcnt() > 1 && // left use is NOT a last use
2485       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2486       n->in(2)->outcnt() == 1 &&// right use IS a last use
2487       !n->in(2)->is_Con() ) {   // right use is not a constant
2488     // Check for commutative opcode
2489     switch( nop ) {
2490     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
2491     case Op_MaxI:  case Op_MinI:
2492     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
2493     case Op_AndL:  case Op_XorL:  case Op_OrL:
2494     case Op_AndI:  case Op_XorI:  case Op_OrI: {
2495       // Move "last use" input to left by swapping inputs
2496       n->swap_edges(1, 2);
2497       break;
2498     }
2499     default:
2500       break;
2501     }
2502   }
2503 
2504 #ifdef ASSERT
2505   if( n->is_Mem() ) {
2506     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2507     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2508             // oop will be recorded in oop map if load crosses safepoint
2509             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2510                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
2511             "raw memory operations should have control edge");
2512   }
2513 #endif
2514   // Count FPU ops and common calls, implements item (3)
2515   switch( nop ) {
2516   // Count all float operations that may use FPU
2517   case Op_AddF:
2518   case Op_SubF:
2519   case Op_MulF:
2520   case Op_DivF:
2521   case Op_NegF:
2522   case Op_ModF:
2523   case Op_ConvI2F:
2524   case Op_ConF:
2525   case Op_CmpF:
2526   case Op_CmpF3:
2527   // case Op_ConvL2F: // longs are split into 32-bit halves
2528     frc.inc_float_count();
2529     break;
2530 
2531   case Op_ConvF2D:
2532   case Op_ConvD2F:
2533     frc.inc_float_count();
2534     frc.inc_double_count();
2535     break;
2536 
2537   // Count all double operations that may use FPU
2538   case Op_AddD:
2539   case Op_SubD:
2540   case Op_MulD:
2541   case Op_DivD:
2542   case Op_NegD:
2543   case Op_ModD:
2544   case Op_ConvI2D:
2545   case Op_ConvD2I:
2546   // case Op_ConvL2D: // handled by leaf call
2547   // case Op_ConvD2L: // handled by leaf call
2548   case Op_ConD:
2549   case Op_CmpD:
2550   case Op_CmpD3:
2551     frc.inc_double_count();
2552     break;
2553   case Op_Opaque1:              // Remove Opaque Nodes before matching
2554   case Op_Opaque2:              // Remove Opaque Nodes before matching
2555     n->subsume_by(n->in(1), this);
2556     break;
2557   case Op_CallStaticJava:
2558   case Op_CallJava:
2559   case Op_CallDynamicJava:
2560     frc.inc_java_call_count(); // Count java call site;
2561   case Op_CallRuntime:
2562   case Op_CallLeaf:
2563   case Op_CallLeafNoFP: {
2564     assert( n->is_Call(), "" );
2565     CallNode *call = n->as_Call();
2566     // Count call sites where the FP mode bit would have to be flipped.
2567     // Do not count uncommon runtime calls:
2568     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2569     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2570     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
2571       frc.inc_call_count();   // Count the call site
2572     } else {                  // See if uncommon argument is shared
2573       Node *n = call->in(TypeFunc::Parms);
2574       int nop = n->Opcode();
2575       // Clone shared simple arguments to uncommon calls, item (1).
2576       if( n->outcnt() > 1 &&
2577           !n->is_Proj() &&
2578           nop != Op_CreateEx &&
2579           nop != Op_CheckCastPP &&
2580           nop != Op_DecodeN &&
2581           nop != Op_DecodeNKlass &&
2582           !n->is_Mem() ) {
2583         Node *x = n->clone();
2584         call->set_req( TypeFunc::Parms, x );
2585       }
2586     }
2587     break;
2588   }
2589 
2590   case Op_StoreD:
2591   case Op_LoadD:
2592   case Op_LoadD_unaligned:
2593     frc.inc_double_count();
2594     goto handle_mem;
2595   case Op_StoreF:
2596   case Op_LoadF:
2597     frc.inc_float_count();
2598     goto handle_mem;
2599 
2600   case Op_StoreCM:
2601     {
2602       // Convert OopStore dependence into precedence edge
2603       Node* prec = n->in(MemNode::OopStore);
2604       n->del_req(MemNode::OopStore);
2605       n->add_prec(prec);
2606       eliminate_redundant_card_marks(n);
2607     }
2608 
2609     // fall through
2610 
2611   case Op_StoreB:
2612   case Op_StoreC:
2613   case Op_StorePConditional:
2614   case Op_StoreI:
2615   case Op_StoreL:
2616   case Op_StoreIConditional:
2617   case Op_StoreLConditional:
2618   case Op_CompareAndSwapI:
2619   case Op_CompareAndSwapL:
2620   case Op_CompareAndSwapP:
2621   case Op_CompareAndSwapN:
2622   case Op_GetAndAddI:
2623   case Op_GetAndAddL:
2624   case Op_GetAndSetI:
2625   case Op_GetAndSetL:
2626   case Op_GetAndSetP:
2627   case Op_GetAndSetN:
2628   case Op_StoreP:
2629   case Op_StoreN:
2630   case Op_StoreNKlass:
2631   case Op_LoadB:
2632   case Op_LoadUB:
2633   case Op_LoadUS:
2634   case Op_LoadI:
2635   case Op_LoadKlass:
2636   case Op_LoadNKlass:
2637   case Op_LoadL:
2638   case Op_LoadL_unaligned:
2639   case Op_LoadPLocked:
2640   case Op_LoadP:
2641   case Op_LoadN:
2642   case Op_LoadRange:
2643   case Op_LoadS: {
2644   handle_mem:
2645 #ifdef ASSERT
2646     if( VerifyOptoOopOffsets ) {
2647       assert( n->is_Mem(), "" );
2648       MemNode *mem  = (MemNode*)n;
2649       // Check to see if address types have grounded out somehow.
2650       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2651       assert( !tp || oop_offset_is_sane(tp), "" );
2652     }
2653 #endif
2654     break;
2655   }
2656 
2657   case Op_AddP: {               // Assert sane base pointers
2658     Node *addp = n->in(AddPNode::Address);
2659     assert( !addp->is_AddP() ||
2660             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2661             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2662             "Base pointers must match" );
2663 #ifdef _LP64
2664     if ((UseCompressedOops || UseCompressedClassPointers) &&
2665         addp->Opcode() == Op_ConP &&
2666         addp == n->in(AddPNode::Base) &&
2667         n->in(AddPNode::Offset)->is_Con()) {
2668       // Use addressing with narrow klass to load with offset on x86.
2669       // On sparc loading 32-bits constant and decoding it have less
2670       // instructions (4) then load 64-bits constant (7).
2671       // Do this transformation here since IGVN will convert ConN back to ConP.
2672       const Type* t = addp->bottom_type();
2673       if (t->isa_oopptr() || t->isa_klassptr()) {
2674         Node* nn = NULL;
2675 
2676         int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
2677 
2678         // Look for existing ConN node of the same exact type.
2679         Node* r  = root();
2680         uint cnt = r->outcnt();
2681         for (uint i = 0; i < cnt; i++) {
2682           Node* m = r->raw_out(i);
2683           if (m!= NULL && m->Opcode() == op &&
2684               m->bottom_type()->make_ptr() == t) {
2685             nn = m;
2686             break;
2687           }
2688         }
2689         if (nn != NULL) {
2690           // Decode a narrow oop to match address
2691           // [R12 + narrow_oop_reg<<3 + offset]
2692           if (t->isa_oopptr()) {
2693             nn = new (this) DecodeNNode(nn, t);
2694           } else {
2695             nn = new (this) DecodeNKlassNode(nn, t);
2696           }
2697           n->set_req(AddPNode::Base, nn);
2698           n->set_req(AddPNode::Address, nn);
2699           if (addp->outcnt() == 0) {
2700             addp->disconnect_inputs(NULL, this);
2701           }
2702         }
2703       }
2704     }
2705 #endif
2706     break;
2707   }
2708 
2709 #ifdef _LP64
2710   case Op_CastPP:
2711     if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
2712       Node* in1 = n->in(1);
2713       const Type* t = n->bottom_type();
2714       Node* new_in1 = in1->clone();
2715       new_in1->as_DecodeN()->set_type(t);
2716 
2717       if (!Matcher::narrow_oop_use_complex_address()) {
2718         //
2719         // x86, ARM and friends can handle 2 adds in addressing mode
2720         // and Matcher can fold a DecodeN node into address by using
2721         // a narrow oop directly and do implicit NULL check in address:
2722         //
2723         // [R12 + narrow_oop_reg<<3 + offset]
2724         // NullCheck narrow_oop_reg
2725         //
2726         // On other platforms (Sparc) we have to keep new DecodeN node and
2727         // use it to do implicit NULL check in address:
2728         //
2729         // decode_not_null narrow_oop_reg, base_reg
2730         // [base_reg + offset]
2731         // NullCheck base_reg
2732         //
2733         // Pin the new DecodeN node to non-null path on these platform (Sparc)
2734         // to keep the information to which NULL check the new DecodeN node
2735         // corresponds to use it as value in implicit_null_check().
2736         //
2737         new_in1->set_req(0, n->in(0));
2738       }
2739 
2740       n->subsume_by(new_in1, this);
2741       if (in1->outcnt() == 0) {
2742         in1->disconnect_inputs(NULL, this);
2743       }
2744     }
2745     break;
2746 
2747   case Op_CmpP:
2748     // Do this transformation here to preserve CmpPNode::sub() and
2749     // other TypePtr related Ideal optimizations (for example, ptr nullness).
2750     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
2751       Node* in1 = n->in(1);
2752       Node* in2 = n->in(2);
2753       if (!in1->is_DecodeNarrowPtr()) {
2754         in2 = in1;
2755         in1 = n->in(2);
2756       }
2757       assert(in1->is_DecodeNarrowPtr(), "sanity");
2758 
2759       Node* new_in2 = NULL;
2760       if (in2->is_DecodeNarrowPtr()) {
2761         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
2762         new_in2 = in2->in(1);
2763       } else if (in2->Opcode() == Op_ConP) {
2764         const Type* t = in2->bottom_type();
2765         if (t == TypePtr::NULL_PTR) {
2766           assert(in1->is_DecodeN(), "compare klass to null?");
2767           // Don't convert CmpP null check into CmpN if compressed
2768           // oops implicit null check is not generated.
2769           // This will allow to generate normal oop implicit null check.
2770           if (Matcher::gen_narrow_oop_implicit_null_checks())
2771             new_in2 = ConNode::make(this, TypeNarrowOop::NULL_PTR);
2772           //
2773           // This transformation together with CastPP transformation above
2774           // will generated code for implicit NULL checks for compressed oops.
2775           //
2776           // The original code after Optimize()
2777           //
2778           //    LoadN memory, narrow_oop_reg
2779           //    decode narrow_oop_reg, base_reg
2780           //    CmpP base_reg, NULL
2781           //    CastPP base_reg // NotNull
2782           //    Load [base_reg + offset], val_reg
2783           //
2784           // after these transformations will be
2785           //
2786           //    LoadN memory, narrow_oop_reg
2787           //    CmpN narrow_oop_reg, NULL
2788           //    decode_not_null narrow_oop_reg, base_reg
2789           //    Load [base_reg + offset], val_reg
2790           //
2791           // and the uncommon path (== NULL) will use narrow_oop_reg directly
2792           // since narrow oops can be used in debug info now (see the code in
2793           // final_graph_reshaping_walk()).
2794           //
2795           // At the end the code will be matched to
2796           // on x86:
2797           //
2798           //    Load_narrow_oop memory, narrow_oop_reg
2799           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
2800           //    NullCheck narrow_oop_reg
2801           //
2802           // and on sparc:
2803           //
2804           //    Load_narrow_oop memory, narrow_oop_reg
2805           //    decode_not_null narrow_oop_reg, base_reg
2806           //    Load [base_reg + offset], val_reg
2807           //    NullCheck base_reg
2808           //
2809         } else if (t->isa_oopptr()) {
2810           new_in2 = ConNode::make(this, t->make_narrowoop());
2811         } else if (t->isa_klassptr()) {
2812           new_in2 = ConNode::make(this, t->make_narrowklass());
2813         }
2814       }
2815       if (new_in2 != NULL) {
2816         Node* cmpN = new (this) CmpNNode(in1->in(1), new_in2);
2817         n->subsume_by(cmpN, this);
2818         if (in1->outcnt() == 0) {
2819           in1->disconnect_inputs(NULL, this);
2820         }
2821         if (in2->outcnt() == 0) {
2822           in2->disconnect_inputs(NULL, this);
2823         }
2824       }
2825     }
2826     break;
2827 
2828   case Op_DecodeN:
2829   case Op_DecodeNKlass:
2830     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
2831     // DecodeN could be pinned when it can't be fold into
2832     // an address expression, see the code for Op_CastPP above.
2833     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
2834     break;
2835 
2836   case Op_EncodeP:
2837   case Op_EncodePKlass: {
2838     Node* in1 = n->in(1);
2839     if (in1->is_DecodeNarrowPtr()) {
2840       n->subsume_by(in1->in(1), this);
2841     } else if (in1->Opcode() == Op_ConP) {
2842       const Type* t = in1->bottom_type();
2843       if (t == TypePtr::NULL_PTR) {
2844         assert(t->isa_oopptr(), "null klass?");
2845         n->subsume_by(ConNode::make(this, TypeNarrowOop::NULL_PTR), this);
2846       } else if (t->isa_oopptr()) {
2847         n->subsume_by(ConNode::make(this, t->make_narrowoop()), this);
2848       } else if (t->isa_klassptr()) {
2849         n->subsume_by(ConNode::make(this, t->make_narrowklass()), this);
2850       }
2851     }
2852     if (in1->outcnt() == 0) {
2853       in1->disconnect_inputs(NULL, this);
2854     }
2855     break;
2856   }
2857 
2858   case Op_Proj: {
2859     if (OptimizeStringConcat) {
2860       ProjNode* p = n->as_Proj();
2861       if (p->_is_io_use) {
2862         // Separate projections were used for the exception path which
2863         // are normally removed by a late inline.  If it wasn't inlined
2864         // then they will hang around and should just be replaced with
2865         // the original one.
2866         Node* proj = NULL;
2867         // Replace with just one
2868         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
2869           Node *use = i.get();
2870           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
2871             proj = use;
2872             break;
2873           }
2874         }
2875         assert(proj != NULL, "must be found");
2876         p->subsume_by(proj, this);
2877       }
2878     }
2879     break;
2880   }
2881 
2882   case Op_Phi:
2883     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
2884       // The EncodeP optimization may create Phi with the same edges
2885       // for all paths. It is not handled well by Register Allocator.
2886       Node* unique_in = n->in(1);
2887       assert(unique_in != NULL, "");
2888       uint cnt = n->req();
2889       for (uint i = 2; i < cnt; i++) {
2890         Node* m = n->in(i);
2891         assert(m != NULL, "");
2892         if (unique_in != m)
2893           unique_in = NULL;
2894       }
2895       if (unique_in != NULL) {
2896         n->subsume_by(unique_in, this);
2897       }
2898     }
2899     break;
2900 
2901 #endif
2902 
2903   case Op_ModI:
2904     if (UseDivMod) {
2905       // Check if a%b and a/b both exist
2906       Node* d = n->find_similar(Op_DivI);
2907       if (d) {
2908         // Replace them with a fused divmod if supported
2909         if (Matcher::has_match_rule(Op_DivModI)) {
2910           DivModINode* divmod = DivModINode::make(this, n);
2911           d->subsume_by(divmod->div_proj(), this);
2912           n->subsume_by(divmod->mod_proj(), this);
2913         } else {
2914           // replace a%b with a-((a/b)*b)
2915           Node* mult = new (this) MulINode(d, d->in(2));
2916           Node* sub  = new (this) SubINode(d->in(1), mult);
2917           n->subsume_by(sub, this);
2918         }
2919       }
2920     }
2921     break;
2922 
2923   case Op_ModL:
2924     if (UseDivMod) {
2925       // Check if a%b and a/b both exist
2926       Node* d = n->find_similar(Op_DivL);
2927       if (d) {
2928         // Replace them with a fused divmod if supported
2929         if (Matcher::has_match_rule(Op_DivModL)) {
2930           DivModLNode* divmod = DivModLNode::make(this, n);
2931           d->subsume_by(divmod->div_proj(), this);
2932           n->subsume_by(divmod->mod_proj(), this);
2933         } else {
2934           // replace a%b with a-((a/b)*b)
2935           Node* mult = new (this) MulLNode(d, d->in(2));
2936           Node* sub  = new (this) SubLNode(d->in(1), mult);
2937           n->subsume_by(sub, this);
2938         }
2939       }
2940     }
2941     break;
2942 
2943   case Op_LoadVector:
2944   case Op_StoreVector:
2945     break;
2946 
2947   case Op_PackB:
2948   case Op_PackS:
2949   case Op_PackI:
2950   case Op_PackF:
2951   case Op_PackL:
2952   case Op_PackD:
2953     if (n->req()-1 > 2) {
2954       // Replace many operand PackNodes with a binary tree for matching
2955       PackNode* p = (PackNode*) n;
2956       Node* btp = p->binary_tree_pack(this, 1, n->req());
2957       n->subsume_by(btp, this);
2958     }
2959     break;
2960   case Op_Loop:
2961   case Op_CountedLoop:
2962     if (n->as_Loop()->is_inner_loop()) {
2963       frc.inc_inner_loop_count();
2964     }
2965     break;
2966   case Op_LShiftI:
2967   case Op_RShiftI:
2968   case Op_URShiftI:
2969   case Op_LShiftL:
2970   case Op_RShiftL:
2971   case Op_URShiftL:
2972     if (Matcher::need_masked_shift_count) {
2973       // The cpu's shift instructions don't restrict the count to the
2974       // lower 5/6 bits. We need to do the masking ourselves.
2975       Node* in2 = n->in(2);
2976       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
2977       const TypeInt* t = in2->find_int_type();
2978       if (t != NULL && t->is_con()) {
2979         juint shift = t->get_con();
2980         if (shift > mask) { // Unsigned cmp
2981           n->set_req(2, ConNode::make(this, TypeInt::make(shift & mask)));
2982         }
2983       } else {
2984         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
2985           Node* shift = new (this) AndINode(in2, ConNode::make(this, TypeInt::make(mask)));
2986           n->set_req(2, shift);
2987         }
2988       }
2989       if (in2->outcnt() == 0) { // Remove dead node
2990         in2->disconnect_inputs(NULL, this);
2991       }
2992     }
2993     break;
2994   case Op_MemBarStoreStore:
2995   case Op_MemBarRelease:
2996     // Break the link with AllocateNode: it is no longer useful and
2997     // confuses register allocation.
2998     if (n->req() > MemBarNode::Precedent) {
2999       n->set_req(MemBarNode::Precedent, top());
3000     }
3001     break;
3002     // Must set a control edge on all nodes that produce a FlagsProj
3003     // so they can't escape the block that consumes the flags.
3004     // Must also set the non throwing branch as the control
3005     // for all nodes that depends on the result. Unless the node
3006     // already have a control that isn't the control of the
3007     // flag producer
3008   case Op_FlagsProj:
3009     {
3010       MathExactNode* math = (MathExactNode*)  n->in(0);
3011       Node* ctrl = math->control_node();
3012       Node* non_throwing = math->non_throwing_branch();
3013       math->set_req(0, ctrl);
3014 
3015       Node* result = math->result_node();
3016       if (result != NULL) {
3017         for (DUIterator_Fast jmax, j = result->fast_outs(jmax); j < jmax; j++) {
3018           Node* out = result->fast_out(j);
3019           // Phi nodes shouldn't be moved. They would only match below if they
3020           // had the same control as the MathExactNode. The only time that
3021           // would happen is if the Phi is also an input to the MathExact
3022           if (!out->is_Phi()) {
3023             if (out->in(0) == NULL) {
3024               out->set_req(0, non_throwing);
3025             } else if (out->in(0) == ctrl) {
3026               out->set_req(0, non_throwing);
3027             }
3028           }
3029         }
3030       }
3031     }
3032     break;
3033   default:
3034     assert( !n->is_Call(), "" );
3035     assert( !n->is_Mem(), "" );
3036     break;
3037   }
3038 
3039   // Collect CFG split points
3040   if (n->is_MultiBranch())
3041     frc._tests.push(n);
3042 }
3043 
3044 //------------------------------final_graph_reshaping_walk---------------------
3045 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3046 // requires that the walk visits a node's inputs before visiting the node.
3047 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3048   ResourceArea *area = Thread::current()->resource_area();
3049   Unique_Node_List sfpt(area);
3050 
3051   frc._visited.set(root->_idx); // first, mark node as visited
3052   uint cnt = root->req();
3053   Node *n = root;
3054   uint  i = 0;
3055   while (true) {
3056     if (i < cnt) {
3057       // Place all non-visited non-null inputs onto stack
3058       Node* m = n->in(i);
3059       ++i;
3060       if (m != NULL && !frc._visited.test_set(m->_idx)) {
3061         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL)
3062           sfpt.push(m);
3063         cnt = m->req();
3064         nstack.push(n, i); // put on stack parent and next input's index
3065         n = m;
3066         i = 0;
3067       }
3068     } else {
3069       // Now do post-visit work
3070       final_graph_reshaping_impl( n, frc );
3071       if (nstack.is_empty())
3072         break;             // finished
3073       n = nstack.node();   // Get node from stack
3074       cnt = n->req();
3075       i = nstack.index();
3076       nstack.pop();        // Shift to the next node on stack
3077     }
3078   }
3079 
3080   // Skip next transformation if compressed oops are not used.
3081   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3082       (!UseCompressedOops && !UseCompressedClassPointers))
3083     return;
3084 
3085   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3086   // It could be done for an uncommon traps or any safepoints/calls
3087   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3088   while (sfpt.size() > 0) {
3089     n = sfpt.pop();
3090     JVMState *jvms = n->as_SafePoint()->jvms();
3091     assert(jvms != NULL, "sanity");
3092     int start = jvms->debug_start();
3093     int end   = n->req();
3094     bool is_uncommon = (n->is_CallStaticJava() &&
3095                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3096     for (int j = start; j < end; j++) {
3097       Node* in = n->in(j);
3098       if (in->is_DecodeNarrowPtr()) {
3099         bool safe_to_skip = true;
3100         if (!is_uncommon ) {
3101           // Is it safe to skip?
3102           for (uint i = 0; i < in->outcnt(); i++) {
3103             Node* u = in->raw_out(i);
3104             if (!u->is_SafePoint() ||
3105                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
3106               safe_to_skip = false;
3107             }
3108           }
3109         }
3110         if (safe_to_skip) {
3111           n->set_req(j, in->in(1));
3112         }
3113         if (in->outcnt() == 0) {
3114           in->disconnect_inputs(NULL, this);
3115         }
3116       }
3117     }
3118   }
3119 }
3120 
3121 //------------------------------final_graph_reshaping--------------------------
3122 // Final Graph Reshaping.
3123 //
3124 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3125 //     and not commoned up and forced early.  Must come after regular
3126 //     optimizations to avoid GVN undoing the cloning.  Clone constant
3127 //     inputs to Loop Phis; these will be split by the allocator anyways.
3128 //     Remove Opaque nodes.
3129 // (2) Move last-uses by commutative operations to the left input to encourage
3130 //     Intel update-in-place two-address operations and better register usage
3131 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
3132 //     calls canonicalizing them back.
3133 // (3) Count the number of double-precision FP ops, single-precision FP ops
3134 //     and call sites.  On Intel, we can get correct rounding either by
3135 //     forcing singles to memory (requires extra stores and loads after each
3136 //     FP bytecode) or we can set a rounding mode bit (requires setting and
3137 //     clearing the mode bit around call sites).  The mode bit is only used
3138 //     if the relative frequency of single FP ops to calls is low enough.
3139 //     This is a key transform for SPEC mpeg_audio.
3140 // (4) Detect infinite loops; blobs of code reachable from above but not
3141 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
3142 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
3143 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
3144 //     Detection is by looking for IfNodes where only 1 projection is
3145 //     reachable from below or CatchNodes missing some targets.
3146 // (5) Assert for insane oop offsets in debug mode.
3147 
3148 bool Compile::final_graph_reshaping() {
3149   // an infinite loop may have been eliminated by the optimizer,
3150   // in which case the graph will be empty.
3151   if (root()->req() == 1) {
3152     record_method_not_compilable("trivial infinite loop");
3153     return true;
3154   }
3155 
3156   // Expensive nodes have their control input set to prevent the GVN
3157   // from freely commoning them. There's no GVN beyond this point so
3158   // no need to keep the control input. We want the expensive nodes to
3159   // be freely moved to the least frequent code path by gcm.
3160   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3161   for (int i = 0; i < expensive_count(); i++) {
3162     _expensive_nodes->at(i)->set_req(0, NULL);
3163   }
3164 
3165   Final_Reshape_Counts frc;
3166 
3167   // Visit everybody reachable!
3168   // Allocate stack of size C->unique()/2 to avoid frequent realloc
3169   Node_Stack nstack(unique() >> 1);
3170   final_graph_reshaping_walk(nstack, root(), frc);
3171 
3172   // Check for unreachable (from below) code (i.e., infinite loops).
3173   for( uint i = 0; i < frc._tests.size(); i++ ) {
3174     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3175     // Get number of CFG targets.
3176     // Note that PCTables include exception targets after calls.
3177     uint required_outcnt = n->required_outcnt();
3178     if (n->outcnt() != required_outcnt) {
3179       // Check for a few special cases.  Rethrow Nodes never take the
3180       // 'fall-thru' path, so expected kids is 1 less.
3181       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3182         if (n->in(0)->in(0)->is_Call()) {
3183           CallNode *call = n->in(0)->in(0)->as_Call();
3184           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3185             required_outcnt--;      // Rethrow always has 1 less kid
3186           } else if (call->req() > TypeFunc::Parms &&
3187                      call->is_CallDynamicJava()) {
3188             // Check for null receiver. In such case, the optimizer has
3189             // detected that the virtual call will always result in a null
3190             // pointer exception. The fall-through projection of this CatchNode
3191             // will not be populated.
3192             Node *arg0 = call->in(TypeFunc::Parms);
3193             if (arg0->is_Type() &&
3194                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3195               required_outcnt--;
3196             }
3197           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3198                      call->req() > TypeFunc::Parms+1 &&
3199                      call->is_CallStaticJava()) {
3200             // Check for negative array length. In such case, the optimizer has
3201             // detected that the allocation attempt will always result in an
3202             // exception. There is no fall-through projection of this CatchNode .
3203             Node *arg1 = call->in(TypeFunc::Parms+1);
3204             if (arg1->is_Type() &&
3205                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3206               required_outcnt--;
3207             }
3208           }
3209         }
3210       }
3211       // Recheck with a better notion of 'required_outcnt'
3212       if (n->outcnt() != required_outcnt) {
3213         record_method_not_compilable("malformed control flow");
3214         return true;            // Not all targets reachable!
3215       }
3216     }
3217     // Check that I actually visited all kids.  Unreached kids
3218     // must be infinite loops.
3219     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3220       if (!frc._visited.test(n->fast_out(j)->_idx)) {
3221         record_method_not_compilable("infinite loop");
3222         return true;            // Found unvisited kid; must be unreach
3223       }
3224   }
3225 
3226   // If original bytecodes contained a mixture of floats and doubles
3227   // check if the optimizer has made it homogenous, item (3).
3228   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3229       frc.get_float_count() > 32 &&
3230       frc.get_double_count() == 0 &&
3231       (10 * frc.get_call_count() < frc.get_float_count()) ) {
3232     set_24_bit_selection_and_mode( false,  true );
3233   }
3234 
3235   set_java_calls(frc.get_java_call_count());
3236   set_inner_loops(frc.get_inner_loop_count());
3237 
3238   // No infinite loops, no reason to bail out.
3239   return false;
3240 }
3241 
3242 //-----------------------------too_many_traps----------------------------------
3243 // Report if there are too many traps at the current method and bci.
3244 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3245 bool Compile::too_many_traps(ciMethod* method,
3246                              int bci,
3247                              Deoptimization::DeoptReason reason) {
3248   ciMethodData* md = method->method_data();
3249   if (md->is_empty()) {
3250     // Assume the trap has not occurred, or that it occurred only
3251     // because of a transient condition during start-up in the interpreter.
3252     return false;
3253   }
3254   if (md->has_trap_at(bci, reason) != 0) {
3255     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3256     // Also, if there are multiple reasons, or if there is no per-BCI record,
3257     // assume the worst.
3258     if (log())
3259       log()->elem("observe trap='%s' count='%d'",
3260                   Deoptimization::trap_reason_name(reason),
3261                   md->trap_count(reason));
3262     return true;
3263   } else {
3264     // Ignore method/bci and see if there have been too many globally.
3265     return too_many_traps(reason, md);
3266   }
3267 }
3268 
3269 // Less-accurate variant which does not require a method and bci.
3270 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3271                              ciMethodData* logmd) {
3272  if (trap_count(reason) >= (uint)PerMethodTrapLimit) {
3273     // Too many traps globally.
3274     // Note that we use cumulative trap_count, not just md->trap_count.
3275     if (log()) {
3276       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3277       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3278                   Deoptimization::trap_reason_name(reason),
3279                   mcount, trap_count(reason));
3280     }
3281     return true;
3282   } else {
3283     // The coast is clear.
3284     return false;
3285   }
3286 }
3287 
3288 //--------------------------too_many_recompiles--------------------------------
3289 // Report if there are too many recompiles at the current method and bci.
3290 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3291 // Is not eager to return true, since this will cause the compiler to use
3292 // Action_none for a trap point, to avoid too many recompilations.
3293 bool Compile::too_many_recompiles(ciMethod* method,
3294                                   int bci,
3295                                   Deoptimization::DeoptReason reason) {
3296   ciMethodData* md = method->method_data();
3297   if (md->is_empty()) {
3298     // Assume the trap has not occurred, or that it occurred only
3299     // because of a transient condition during start-up in the interpreter.
3300     return false;
3301   }
3302   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3303   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3304   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
3305   Deoptimization::DeoptReason per_bc_reason
3306     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3307   if ((per_bc_reason == Deoptimization::Reason_none
3308        || md->has_trap_at(bci, reason) != 0)
3309       // The trap frequency measure we care about is the recompile count:
3310       && md->trap_recompiled_at(bci)
3311       && md->overflow_recompile_count() >= bc_cutoff) {
3312     // Do not emit a trap here if it has already caused recompilations.
3313     // Also, if there are multiple reasons, or if there is no per-BCI record,
3314     // assume the worst.
3315     if (log())
3316       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3317                   Deoptimization::trap_reason_name(reason),
3318                   md->trap_count(reason),
3319                   md->overflow_recompile_count());
3320     return true;
3321   } else if (trap_count(reason) != 0
3322              && decompile_count() >= m_cutoff) {
3323     // Too many recompiles globally, and we have seen this sort of trap.
3324     // Use cumulative decompile_count, not just md->decompile_count.
3325     if (log())
3326       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3327                   Deoptimization::trap_reason_name(reason),
3328                   md->trap_count(reason), trap_count(reason),
3329                   md->decompile_count(), decompile_count());
3330     return true;
3331   } else {
3332     // The coast is clear.
3333     return false;
3334   }
3335 }
3336 
3337 
3338 #ifndef PRODUCT
3339 //------------------------------verify_graph_edges---------------------------
3340 // Walk the Graph and verify that there is a one-to-one correspondence
3341 // between Use-Def edges and Def-Use edges in the graph.
3342 void Compile::verify_graph_edges(bool no_dead_code) {
3343   if (VerifyGraphEdges) {
3344     ResourceArea *area = Thread::current()->resource_area();
3345     Unique_Node_List visited(area);
3346     // Call recursive graph walk to check edges
3347     _root->verify_edges(visited);
3348     if (no_dead_code) {
3349       // Now make sure that no visited node is used by an unvisited node.
3350       bool dead_nodes = 0;
3351       Unique_Node_List checked(area);
3352       while (visited.size() > 0) {
3353         Node* n = visited.pop();
3354         checked.push(n);
3355         for (uint i = 0; i < n->outcnt(); i++) {
3356           Node* use = n->raw_out(i);
3357           if (checked.member(use))  continue;  // already checked
3358           if (visited.member(use))  continue;  // already in the graph
3359           if (use->is_Con())        continue;  // a dead ConNode is OK
3360           // At this point, we have found a dead node which is DU-reachable.
3361           if (dead_nodes++ == 0)
3362             tty->print_cr("*** Dead nodes reachable via DU edges:");
3363           use->dump(2);
3364           tty->print_cr("---");
3365           checked.push(use);  // No repeats; pretend it is now checked.
3366         }
3367       }
3368       assert(dead_nodes == 0, "using nodes must be reachable from root");
3369     }
3370   }
3371 }
3372 
3373 // Verify GC barriers consistency
3374 // Currently supported:
3375 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
3376 void Compile::verify_barriers() {
3377   if (UseG1GC) {
3378     // Verify G1 pre-barriers
3379     const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
3380 
3381     ResourceArea *area = Thread::current()->resource_area();
3382     Unique_Node_List visited(area);
3383     Node_List worklist(area);
3384     // We're going to walk control flow backwards starting from the Root
3385     worklist.push(_root);
3386     while (worklist.size() > 0) {
3387       Node* x = worklist.pop();
3388       if (x == NULL || x == top()) continue;
3389       if (visited.member(x)) {
3390         continue;
3391       } else {
3392         visited.push(x);
3393       }
3394 
3395       if (x->is_Region()) {
3396         for (uint i = 1; i < x->req(); i++) {
3397           worklist.push(x->in(i));
3398         }
3399       } else {
3400         worklist.push(x->in(0));
3401         // We are looking for the pattern:
3402         //                            /->ThreadLocal
3403         // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
3404         //              \->ConI(0)
3405         // We want to verify that the If and the LoadB have the same control
3406         // See GraphKit::g1_write_barrier_pre()
3407         if (x->is_If()) {
3408           IfNode *iff = x->as_If();
3409           if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
3410             CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
3411             if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
3412                 && cmp->in(1)->is_Load()) {
3413               LoadNode* load = cmp->in(1)->as_Load();
3414               if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
3415                   && load->in(2)->in(3)->is_Con()
3416                   && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
3417 
3418                 Node* if_ctrl = iff->in(0);
3419                 Node* load_ctrl = load->in(0);
3420 
3421                 if (if_ctrl != load_ctrl) {
3422                   // Skip possible CProj->NeverBranch in infinite loops
3423                   if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
3424                       && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
3425                     if_ctrl = if_ctrl->in(0)->in(0);
3426                   }
3427                 }
3428                 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
3429               }
3430             }
3431           }
3432         }
3433       }
3434     }
3435   }
3436 }
3437 
3438 #endif
3439 
3440 // The Compile object keeps track of failure reasons separately from the ciEnv.
3441 // This is required because there is not quite a 1-1 relation between the
3442 // ciEnv and its compilation task and the Compile object.  Note that one
3443 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3444 // to backtrack and retry without subsuming loads.  Other than this backtracking
3445 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3446 // by the logic in C2Compiler.
3447 void Compile::record_failure(const char* reason) {
3448   if (log() != NULL) {
3449     log()->elem("failure reason='%s' phase='compile'", reason);
3450   }
3451   if (_failure_reason == NULL) {
3452     // Record the first failure reason.
3453     _failure_reason = reason;
3454   }
3455 
3456   EventCompilerFailure event;
3457   if (event.should_commit()) {
3458     event.set_compileID(Compile::compile_id());
3459     event.set_failure(reason);
3460     event.commit();
3461   }
3462 
3463   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3464     C->print_method(PHASE_FAILURE);
3465   }
3466   _root = NULL;  // flush the graph, too
3467 }
3468 
3469 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
3470   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false),
3471     _phase_name(name), _dolog(dolog)
3472 {
3473   if (dolog) {
3474     C = Compile::current();
3475     _log = C->log();
3476   } else {
3477     C = NULL;
3478     _log = NULL;
3479   }
3480   if (_log != NULL) {
3481     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3482     _log->stamp();
3483     _log->end_head();
3484   }
3485 }
3486 
3487 Compile::TracePhase::~TracePhase() {
3488 
3489   C = Compile::current();
3490   if (_dolog) {
3491     _log = C->log();
3492   } else {
3493     _log = NULL;
3494   }
3495 
3496 #ifdef ASSERT
3497   if (PrintIdealNodeCount) {
3498     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3499                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3500   }
3501 
3502   if (VerifyIdealNodeCount) {
3503     Compile::current()->print_missing_nodes();
3504   }
3505 #endif
3506 
3507   if (_log != NULL) {
3508     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3509   }
3510 }
3511 
3512 //=============================================================================
3513 // Two Constant's are equal when the type and the value are equal.
3514 bool Compile::Constant::operator==(const Constant& other) {
3515   if (type()          != other.type()         )  return false;
3516   if (can_be_reused() != other.can_be_reused())  return false;
3517   // For floating point values we compare the bit pattern.
3518   switch (type()) {
3519   case T_FLOAT:   return (_v._value.i == other._v._value.i);
3520   case T_LONG:
3521   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
3522   case T_OBJECT:
3523   case T_ADDRESS: return (_v._value.l == other._v._value.l);
3524   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
3525   case T_METADATA: return (_v._metadata == other._v._metadata);
3526   default: ShouldNotReachHere();
3527   }
3528   return false;
3529 }
3530 
3531 static int type_to_size_in_bytes(BasicType t) {
3532   switch (t) {
3533   case T_LONG:    return sizeof(jlong  );
3534   case T_FLOAT:   return sizeof(jfloat );
3535   case T_DOUBLE:  return sizeof(jdouble);
3536   case T_METADATA: return sizeof(Metadata*);
3537     // We use T_VOID as marker for jump-table entries (labels) which
3538     // need an internal word relocation.
3539   case T_VOID:
3540   case T_ADDRESS:
3541   case T_OBJECT:  return sizeof(jobject);
3542   }
3543 
3544   ShouldNotReachHere();
3545   return -1;
3546 }
3547 
3548 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3549   // sort descending
3550   if (a->freq() > b->freq())  return -1;
3551   if (a->freq() < b->freq())  return  1;
3552   return 0;
3553 }
3554 
3555 void Compile::ConstantTable::calculate_offsets_and_size() {
3556   // First, sort the array by frequencies.
3557   _constants.sort(qsort_comparator);
3558 
3559 #ifdef ASSERT
3560   // Make sure all jump-table entries were sorted to the end of the
3561   // array (they have a negative frequency).
3562   bool found_void = false;
3563   for (int i = 0; i < _constants.length(); i++) {
3564     Constant con = _constants.at(i);
3565     if (con.type() == T_VOID)
3566       found_void = true;  // jump-tables
3567     else
3568       assert(!found_void, "wrong sorting");
3569   }
3570 #endif
3571 
3572   int offset = 0;
3573   for (int i = 0; i < _constants.length(); i++) {
3574     Constant* con = _constants.adr_at(i);
3575 
3576     // Align offset for type.
3577     int typesize = type_to_size_in_bytes(con->type());
3578     offset = align_size_up(offset, typesize);
3579     con->set_offset(offset);   // set constant's offset
3580 
3581     if (con->type() == T_VOID) {
3582       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
3583       offset = offset + typesize * n->outcnt();  // expand jump-table
3584     } else {
3585       offset = offset + typesize;
3586     }
3587   }
3588 
3589   // Align size up to the next section start (which is insts; see
3590   // CodeBuffer::align_at_start).
3591   assert(_size == -1, "already set?");
3592   _size = align_size_up(offset, CodeEntryAlignment);
3593 }
3594 
3595 void Compile::ConstantTable::emit(CodeBuffer& cb) {
3596   MacroAssembler _masm(&cb);
3597   for (int i = 0; i < _constants.length(); i++) {
3598     Constant con = _constants.at(i);
3599     address constant_addr;
3600     switch (con.type()) {
3601     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
3602     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
3603     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
3604     case T_OBJECT: {
3605       jobject obj = con.get_jobject();
3606       int oop_index = _masm.oop_recorder()->find_index(obj);
3607       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
3608       break;
3609     }
3610     case T_ADDRESS: {
3611       address addr = (address) con.get_jobject();
3612       constant_addr = _masm.address_constant(addr);
3613       break;
3614     }
3615     // We use T_VOID as marker for jump-table entries (labels) which
3616     // need an internal word relocation.
3617     case T_VOID: {
3618       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
3619       // Fill the jump-table with a dummy word.  The real value is
3620       // filled in later in fill_jump_table.
3621       address dummy = (address) n;
3622       constant_addr = _masm.address_constant(dummy);
3623       // Expand jump-table
3624       for (uint i = 1; i < n->outcnt(); i++) {
3625         address temp_addr = _masm.address_constant(dummy + i);
3626         assert(temp_addr, "consts section too small");
3627       }
3628       break;
3629     }
3630     case T_METADATA: {
3631       Metadata* obj = con.get_metadata();
3632       int metadata_index = _masm.oop_recorder()->find_index(obj);
3633       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
3634       break;
3635     }
3636     default: ShouldNotReachHere();
3637     }
3638     assert(constant_addr, "consts section too small");
3639     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(), err_msg_res("must be: %d == %d", constant_addr - _masm.code()->consts()->start(), con.offset()));
3640   }
3641 }
3642 
3643 int Compile::ConstantTable::find_offset(Constant& con) const {
3644   int idx = _constants.find(con);
3645   assert(idx != -1, "constant must be in constant table");
3646   int offset = _constants.at(idx).offset();
3647   assert(offset != -1, "constant table not emitted yet?");
3648   return offset;
3649 }
3650 
3651 void Compile::ConstantTable::add(Constant& con) {
3652   if (con.can_be_reused()) {
3653     int idx = _constants.find(con);
3654     if (idx != -1 && _constants.at(idx).can_be_reused()) {
3655       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
3656       return;
3657     }
3658   }
3659   (void) _constants.append(con);
3660 }
3661 
3662 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
3663   Block* b = Compile::current()->cfg()->get_block_for_node(n);
3664   Constant con(type, value, b->_freq);
3665   add(con);
3666   return con;
3667 }
3668 
3669 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
3670   Constant con(metadata);
3671   add(con);
3672   return con;
3673 }
3674 
3675 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
3676   jvalue value;
3677   BasicType type = oper->type()->basic_type();
3678   switch (type) {
3679   case T_LONG:    value.j = oper->constantL(); break;
3680   case T_FLOAT:   value.f = oper->constantF(); break;
3681   case T_DOUBLE:  value.d = oper->constantD(); break;
3682   case T_OBJECT:
3683   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
3684   case T_METADATA: return add((Metadata*)oper->constant()); break;
3685   default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
3686   }
3687   return add(n, type, value);
3688 }
3689 
3690 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
3691   jvalue value;
3692   // We can use the node pointer here to identify the right jump-table
3693   // as this method is called from Compile::Fill_buffer right before
3694   // the MachNodes are emitted and the jump-table is filled (means the
3695   // MachNode pointers do not change anymore).
3696   value.l = (jobject) n;
3697   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
3698   add(con);
3699   return con;
3700 }
3701 
3702 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
3703   // If called from Compile::scratch_emit_size do nothing.
3704   if (Compile::current()->in_scratch_emit_size())  return;
3705 
3706   assert(labels.is_nonempty(), "must be");
3707   assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
3708 
3709   // Since MachConstantNode::constant_offset() also contains
3710   // table_base_offset() we need to subtract the table_base_offset()
3711   // to get the plain offset into the constant table.
3712   int offset = n->constant_offset() - table_base_offset();
3713 
3714   MacroAssembler _masm(&cb);
3715   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
3716 
3717   for (uint i = 0; i < n->outcnt(); i++) {
3718     address* constant_addr = &jump_table_base[i];
3719     assert(*constant_addr == (((address) n) + i), err_msg_res("all jump-table entries must contain adjusted node pointer: " INTPTR_FORMAT " == " INTPTR_FORMAT, *constant_addr, (((address) n) + i)));
3720     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
3721     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
3722   }
3723 }
3724 
3725 void Compile::dump_inlining() {
3726   if (print_inlining() || print_intrinsics()) {
3727     // Print inlining message for candidates that we couldn't inline
3728     // for lack of space or non constant receiver
3729     for (int i = 0; i < _late_inlines.length(); i++) {
3730       CallGenerator* cg = _late_inlines.at(i);
3731       cg->print_inlining_late("live nodes > LiveNodeCountInliningCutoff");
3732     }
3733     Unique_Node_List useful;
3734     useful.push(root());
3735     for (uint next = 0; next < useful.size(); ++next) {
3736       Node* n  = useful.at(next);
3737       if (n->is_Call() && n->as_Call()->generator() != NULL && n->as_Call()->generator()->call_node() == n) {
3738         CallNode* call = n->as_Call();
3739         CallGenerator* cg = call->generator();
3740         cg->print_inlining_late("receiver not constant");
3741       }
3742       uint max = n->len();
3743       for ( uint i = 0; i < max; ++i ) {
3744         Node *m = n->in(i);
3745         if ( m == NULL ) continue;
3746         useful.push(m);
3747       }
3748     }
3749     for (int i = 0; i < _print_inlining_list->length(); i++) {
3750       tty->print(_print_inlining_list->adr_at(i)->ss()->as_string());
3751     }
3752   }
3753 }
3754 
3755 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
3756   if (n1->Opcode() < n2->Opcode())      return -1;
3757   else if (n1->Opcode() > n2->Opcode()) return 1;
3758 
3759   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()));
3760   for (uint i = 1; i < n1->req(); i++) {
3761     if (n1->in(i) < n2->in(i))      return -1;
3762     else if (n1->in(i) > n2->in(i)) return 1;
3763   }
3764 
3765   return 0;
3766 }
3767 
3768 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
3769   Node* n1 = *n1p;
3770   Node* n2 = *n2p;
3771 
3772   return cmp_expensive_nodes(n1, n2);
3773 }
3774 
3775 void Compile::sort_expensive_nodes() {
3776   if (!expensive_nodes_sorted()) {
3777     _expensive_nodes->sort(cmp_expensive_nodes);
3778   }
3779 }
3780 
3781 bool Compile::expensive_nodes_sorted() const {
3782   for (int i = 1; i < _expensive_nodes->length(); i++) {
3783     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
3784       return false;
3785     }
3786   }
3787   return true;
3788 }
3789 
3790 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
3791   if (_expensive_nodes->length() == 0) {
3792     return false;
3793   }
3794 
3795   assert(OptimizeExpensiveOps, "optimization off?");
3796 
3797   // Take this opportunity to remove dead nodes from the list
3798   int j = 0;
3799   for (int i = 0; i < _expensive_nodes->length(); i++) {
3800     Node* n = _expensive_nodes->at(i);
3801     if (!n->is_unreachable(igvn)) {
3802       assert(n->is_expensive(), "should be expensive");
3803       _expensive_nodes->at_put(j, n);
3804       j++;
3805     }
3806   }
3807   _expensive_nodes->trunc_to(j);
3808 
3809   // Then sort the list so that similar nodes are next to each other
3810   // and check for at least two nodes of identical kind with same data
3811   // inputs.
3812   sort_expensive_nodes();
3813 
3814   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
3815     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
3816       return true;
3817     }
3818   }
3819 
3820   return false;
3821 }
3822 
3823 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
3824   if (_expensive_nodes->length() == 0) {
3825     return;
3826   }
3827 
3828   assert(OptimizeExpensiveOps, "optimization off?");
3829 
3830   // Sort to bring similar nodes next to each other and clear the
3831   // control input of nodes for which there's only a single copy.
3832   sort_expensive_nodes();
3833 
3834   int j = 0;
3835   int identical = 0;
3836   int i = 0;
3837   for (; i < _expensive_nodes->length()-1; i++) {
3838     assert(j <= i, "can't write beyond current index");
3839     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
3840       identical++;
3841       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
3842       continue;
3843     }
3844     if (identical > 0) {
3845       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
3846       identical = 0;
3847     } else {
3848       Node* n = _expensive_nodes->at(i);
3849       igvn.hash_delete(n);
3850       n->set_req(0, NULL);
3851       igvn.hash_insert(n);
3852     }
3853   }
3854   if (identical > 0) {
3855     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
3856   } else if (_expensive_nodes->length() >= 1) {
3857     Node* n = _expensive_nodes->at(i);
3858     igvn.hash_delete(n);
3859     n->set_req(0, NULL);
3860     igvn.hash_insert(n);
3861   }
3862   _expensive_nodes->trunc_to(j);
3863 }
3864 
3865 void Compile::add_expensive_node(Node * n) {
3866   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
3867   assert(n->is_expensive(), "expensive nodes with non-null control here only");
3868   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
3869   if (OptimizeExpensiveOps) {
3870     _expensive_nodes->append(n);
3871   } else {
3872     // Clear control input and let IGVN optimize expensive nodes if
3873     // OptimizeExpensiveOps is off.
3874     n->set_req(0, NULL);
3875   }
3876 }
3877 
3878 /**
3879  * Remove the speculative part of types and clean up the graph
3880  */
3881 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
3882   if (UseTypeSpeculation) {
3883     Unique_Node_List worklist;
3884     worklist.push(root());
3885     int modified = 0;
3886     // Go over all type nodes that carry a speculative type, drop the
3887     // speculative part of the type and enqueue the node for an igvn
3888     // which may optimize it out.
3889     for (uint next = 0; next < worklist.size(); ++next) {
3890       Node *n  = worklist.at(next);
3891       if (n->is_Type() && n->as_Type()->type()->isa_oopptr() != NULL &&
3892           n->as_Type()->type()->is_oopptr()->speculative() != NULL) {
3893         TypeNode* tn = n->as_Type();
3894         const TypeOopPtr* t = tn->type()->is_oopptr();
3895         bool in_hash = igvn.hash_delete(n);
3896         assert(in_hash, "node should be in igvn hash table");
3897         tn->set_type(t->remove_speculative());
3898         igvn.hash_insert(n);
3899         igvn._worklist.push(n); // give it a chance to go away
3900         modified++;
3901       }
3902       uint max = n->len();
3903       for( uint i = 0; i < max; ++i ) {
3904         Node *m = n->in(i);
3905         if (not_a_node(m))  continue;
3906         worklist.push(m);
3907       }
3908     }
3909     // Drop the speculative part of all types in the igvn's type table
3910     igvn.remove_speculative_types();
3911     if (modified > 0) {
3912       igvn.optimize();
3913     }
3914   }
3915 }
3916 
3917 // Auxiliary method to support randomized stressing/fuzzing.
3918 //
3919 // This method can be called the arbitrary number of times, with current count
3920 // as the argument. The logic allows selecting a single candidate from the
3921 // running list of candidates as follows:
3922 //    int count = 0;
3923 //    Cand* selected = null;
3924 //    while(cand = cand->next()) {
3925 //      if (randomized_select(++count)) {
3926 //        selected = cand;
3927 //      }
3928 //    }
3929 //
3930 // Including count equalizes the chances any candidate is "selected".
3931 // This is useful when we don't have the complete list of candidates to choose
3932 // from uniformly. In this case, we need to adjust the randomicity of the
3933 // selection, or else we will end up biasing the selection towards the latter
3934 // candidates.
3935 //
3936 // Quick back-envelope calculation shows that for the list of n candidates
3937 // the equal probability for the candidate to persist as "best" can be
3938 // achieved by replacing it with "next" k-th candidate with the probability
3939 // of 1/k. It can be easily shown that by the end of the run, the
3940 // probability for any candidate is converged to 1/n, thus giving the
3941 // uniform distribution among all the candidates.
3942 //
3943 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
3944 #define RANDOMIZED_DOMAIN_POW 29
3945 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
3946 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
3947 bool Compile::randomized_select(int count) {
3948   assert(count > 0, "only positive");
3949   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
3950 }