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 "ci/ciReplay.hpp"
  29 #include "classfile/systemDictionary.hpp"
  30 #include "code/exceptionHandlerTable.hpp"
  31 #include "code/nmethod.hpp"
  32 #include "compiler/compileLog.hpp"
  33 #include "compiler/disassembler.hpp"
  34 #include "compiler/oopMap.hpp"
  35 #include "opto/addnode.hpp"
  36 #include "opto/block.hpp"
  37 #include "opto/c2compiler.hpp"
  38 #include "opto/callGenerator.hpp"
  39 #include "opto/callnode.hpp"
  40 #include "opto/cfgnode.hpp"
  41 #include "opto/chaitin.hpp"
  42 #include "opto/compile.hpp"
  43 #include "opto/connode.hpp"
  44 #include "opto/divnode.hpp"
  45 #include "opto/escape.hpp"
  46 #include "opto/idealGraphPrinter.hpp"
  47 #include "opto/loopnode.hpp"
  48 #include "opto/machnode.hpp"
  49 #include "opto/macro.hpp"
  50 #include "opto/matcher.hpp"
  51 #include "opto/mathexactnode.hpp"
  52 #include "opto/memnode.hpp"
  53 #include "opto/mulnode.hpp"
  54 #include "opto/node.hpp"
  55 #include "opto/opcodes.hpp"
  56 #include "opto/output.hpp"
  57 #include "opto/parse.hpp"
  58 #include "opto/phaseX.hpp"
  59 #include "opto/rootnode.hpp"
  60 #include "opto/runtime.hpp"
  61 #include "opto/stringopts.hpp"
  62 #include "opto/type.hpp"
  63 #include "opto/vectornode.hpp"
  64 #include "runtime/arguments.hpp"
  65 #include "runtime/signature.hpp"
  66 #include "runtime/stubRoutines.hpp"
  67 #include "runtime/timer.hpp"
  68 #include "trace/tracing.hpp"
  69 #include "utilities/copy.hpp"
  70 #ifdef TARGET_ARCH_MODEL_x86_32
  71 # include "adfiles/ad_x86_32.hpp"
  72 #endif
  73 #ifdef TARGET_ARCH_MODEL_x86_64
  74 # include "adfiles/ad_x86_64.hpp"
  75 #endif
  76 #ifdef TARGET_ARCH_MODEL_sparc
  77 # include "adfiles/ad_sparc.hpp"
  78 #endif
  79 #ifdef TARGET_ARCH_MODEL_zero
  80 # include "adfiles/ad_zero.hpp"
  81 #endif
  82 #ifdef TARGET_ARCH_MODEL_arm
  83 # include "adfiles/ad_arm.hpp"
  84 #endif
  85 #ifdef TARGET_ARCH_MODEL_ppc
  86 # include "adfiles/ad_ppc.hpp"
  87 #endif
  88 
  89 
  90 // -------------------- Compile::mach_constant_base_node -----------------------
  91 // Constant table base node singleton.
  92 MachConstantBaseNode* Compile::mach_constant_base_node() {
  93   if (_mach_constant_base_node == NULL) {
  94     _mach_constant_base_node = new (C) MachConstantBaseNode();
  95     _mach_constant_base_node->add_req(C->root());
  96   }
  97   return _mach_constant_base_node;
  98 }
  99 
 100 
 101 /// Support for intrinsics.
 102 
 103 // Return the index at which m must be inserted (or already exists).
 104 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
 105 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
 106 #ifdef ASSERT
 107   for (int i = 1; i < _intrinsics->length(); i++) {
 108     CallGenerator* cg1 = _intrinsics->at(i-1);
 109     CallGenerator* cg2 = _intrinsics->at(i);
 110     assert(cg1->method() != cg2->method()
 111            ? cg1->method()     < cg2->method()
 112            : cg1->is_virtual() < cg2->is_virtual(),
 113            "compiler intrinsics list must stay sorted");
 114   }
 115 #endif
 116   // Binary search sorted list, in decreasing intervals [lo, hi].
 117   int lo = 0, hi = _intrinsics->length()-1;
 118   while (lo <= hi) {
 119     int mid = (uint)(hi + lo) / 2;
 120     ciMethod* mid_m = _intrinsics->at(mid)->method();
 121     if (m < mid_m) {
 122       hi = mid-1;
 123     } else if (m > mid_m) {
 124       lo = mid+1;
 125     } else {
 126       // look at minor sort key
 127       bool mid_virt = _intrinsics->at(mid)->is_virtual();
 128       if (is_virtual < mid_virt) {
 129         hi = mid-1;
 130       } else if (is_virtual > mid_virt) {
 131         lo = mid+1;
 132       } else {
 133         return mid;  // exact match
 134       }
 135     }
 136   }
 137   return lo;  // inexact match
 138 }
 139 
 140 void Compile::register_intrinsic(CallGenerator* cg) {
 141   if (_intrinsics == NULL) {
 142     _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
 143   }
 144   // This code is stolen from ciObjectFactory::insert.
 145   // Really, GrowableArray should have methods for
 146   // insert_at, remove_at, and binary_search.
 147   int len = _intrinsics->length();
 148   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
 149   if (index == len) {
 150     _intrinsics->append(cg);
 151   } else {
 152 #ifdef ASSERT
 153     CallGenerator* oldcg = _intrinsics->at(index);
 154     assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
 155 #endif
 156     _intrinsics->append(_intrinsics->at(len-1));
 157     int pos;
 158     for (pos = len-2; pos >= index; pos--) {
 159       _intrinsics->at_put(pos+1,_intrinsics->at(pos));
 160     }
 161     _intrinsics->at_put(index, cg);
 162   }
 163   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 164 }
 165 
 166 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 167   assert(m->is_loaded(), "don't try this on unloaded methods");
 168   if (_intrinsics != NULL) {
 169     int index = intrinsic_insertion_index(m, is_virtual);
 170     if (index < _intrinsics->length()
 171         && _intrinsics->at(index)->method() == m
 172         && _intrinsics->at(index)->is_virtual() == is_virtual) {
 173       return _intrinsics->at(index);
 174     }
 175   }
 176   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 177   if (m->intrinsic_id() != vmIntrinsics::_none &&
 178       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 179     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 180     if (cg != NULL) {
 181       // Save it for next time:
 182       register_intrinsic(cg);
 183       return cg;
 184     } else {
 185       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 186     }
 187   }
 188   return NULL;
 189 }
 190 
 191 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
 192 // in library_call.cpp.
 193 
 194 
 195 #ifndef PRODUCT
 196 // statistics gathering...
 197 
 198 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
 199 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
 200 
 201 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 202   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 203   int oflags = _intrinsic_hist_flags[id];
 204   assert(flags != 0, "what happened?");
 205   if (is_virtual) {
 206     flags |= _intrinsic_virtual;
 207   }
 208   bool changed = (flags != oflags);
 209   if ((flags & _intrinsic_worked) != 0) {
 210     juint count = (_intrinsic_hist_count[id] += 1);
 211     if (count == 1) {
 212       changed = true;           // first time
 213     }
 214     // increment the overall count also:
 215     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
 216   }
 217   if (changed) {
 218     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 219       // Something changed about the intrinsic's virtuality.
 220       if ((flags & _intrinsic_virtual) != 0) {
 221         // This is the first use of this intrinsic as a virtual call.
 222         if (oflags != 0) {
 223           // We already saw it as a non-virtual, so note both cases.
 224           flags |= _intrinsic_both;
 225         }
 226       } else if ((oflags & _intrinsic_both) == 0) {
 227         // This is the first use of this intrinsic as a non-virtual
 228         flags |= _intrinsic_both;
 229       }
 230     }
 231     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
 232   }
 233   // update the overall flags also:
 234   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
 235   return changed;
 236 }
 237 
 238 static char* format_flags(int flags, char* buf) {
 239   buf[0] = 0;
 240   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 241   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 242   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 243   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 244   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 245   if (buf[0] == 0)  strcat(buf, ",");
 246   assert(buf[0] == ',', "must be");
 247   return &buf[1];
 248 }
 249 
 250 void Compile::print_intrinsic_statistics() {
 251   char flagsbuf[100];
 252   ttyLocker ttyl;
 253   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
 254   tty->print_cr("Compiler intrinsic usage:");
 255   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
 256   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 257   #define PRINT_STAT_LINE(name, c, f) \
 258     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 259   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
 260     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
 261     int   flags = _intrinsic_hist_flags[id];
 262     juint count = _intrinsic_hist_count[id];
 263     if ((flags | count) != 0) {
 264       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 265     }
 266   }
 267   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
 268   if (xtty != NULL)  xtty->tail("statistics");
 269 }
 270 
 271 void Compile::print_statistics() {
 272   { ttyLocker ttyl;
 273     if (xtty != NULL)  xtty->head("statistics type='opto'");
 274     Parse::print_statistics();
 275     PhaseCCP::print_statistics();
 276     PhaseRegAlloc::print_statistics();
 277     Scheduling::print_statistics();
 278     PhasePeephole::print_statistics();
 279     PhaseIdealLoop::print_statistics();
 280     if (xtty != NULL)  xtty->tail("statistics");
 281   }
 282   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
 283     // put this under its own <statistics> element.
 284     print_intrinsic_statistics();
 285   }
 286 }
 287 #endif //PRODUCT
 288 
 289 // Support for bundling info
 290 Bundle* Compile::node_bundling(const Node *n) {
 291   assert(valid_bundle_info(n), "oob");
 292   return &_node_bundling_base[n->_idx];
 293 }
 294 
 295 bool Compile::valid_bundle_info(const Node *n) {
 296   return (_node_bundling_limit > n->_idx);
 297 }
 298 
 299 
 300 void Compile::gvn_replace_by(Node* n, Node* nn) {
 301   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 302     Node* use = n->last_out(i);
 303     bool is_in_table = initial_gvn()->hash_delete(use);
 304     uint uses_found = 0;
 305     for (uint j = 0; j < use->len(); j++) {
 306       if (use->in(j) == n) {
 307         if (j < use->req())
 308           use->set_req(j, nn);
 309         else
 310           use->set_prec(j, nn);
 311         uses_found++;
 312       }
 313     }
 314     if (is_in_table) {
 315       // reinsert into table
 316       initial_gvn()->hash_find_insert(use);
 317     }
 318     record_for_igvn(use);
 319     i -= uses_found;    // we deleted 1 or more copies of this edge
 320   }
 321 }
 322 
 323 
 324 static inline bool not_a_node(const Node* n) {
 325   if (n == NULL)                   return true;
 326   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
 327   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
 328   return false;
 329 }
 330 
 331 // Identify all nodes that are reachable from below, useful.
 332 // Use breadth-first pass that records state in a Unique_Node_List,
 333 // recursive traversal is slower.
 334 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 335   int estimated_worklist_size = unique();
 336   useful.map( estimated_worklist_size, NULL );  // preallocate space
 337 
 338   // Initialize worklist
 339   if (root() != NULL)     { useful.push(root()); }
 340   // If 'top' is cached, declare it useful to preserve cached node
 341   if( cached_top_node() ) { useful.push(cached_top_node()); }
 342 
 343   // Push all useful nodes onto the list, breadthfirst
 344   for( uint next = 0; next < useful.size(); ++next ) {
 345     assert( next < unique(), "Unique useful nodes < total nodes");
 346     Node *n  = useful.at(next);
 347     uint max = n->len();
 348     for( uint i = 0; i < max; ++i ) {
 349       Node *m = n->in(i);
 350       if (not_a_node(m))  continue;
 351       useful.push(m);
 352     }
 353   }
 354 }
 355 
 356 // Update dead_node_list with any missing dead nodes using useful
 357 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 358 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 359   uint max_idx = unique();
 360   VectorSet& useful_node_set = useful.member_set();
 361 
 362   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 363     // If node with index node_idx is not in useful set,
 364     // mark it as dead in dead node list.
 365     if (! useful_node_set.test(node_idx) ) {
 366       record_dead_node(node_idx);
 367     }
 368   }
 369 }
 370 
 371 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 372   int shift = 0;
 373   for (int i = 0; i < inlines->length(); i++) {
 374     CallGenerator* cg = inlines->at(i);
 375     CallNode* call = cg->call_node();
 376     if (shift > 0) {
 377       inlines->at_put(i-shift, cg);
 378     }
 379     if (!useful.member(call)) {
 380       shift++;
 381     }
 382   }
 383   inlines->trunc_to(inlines->length()-shift);
 384 }
 385 
 386 // Disconnect all useless nodes by disconnecting those at the boundary.
 387 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
 388   uint next = 0;
 389   while (next < useful.size()) {
 390     Node *n = useful.at(next++);
 391     // Use raw traversal of out edges since this code removes out edges
 392     int max = n->outcnt();
 393     for (int j = 0; j < max; ++j) {
 394       Node* child = n->raw_out(j);
 395       if (! useful.member(child)) {
 396         assert(!child->is_top() || child != top(),
 397                "If top is cached in Compile object it is in useful list");
 398         // Only need to remove this out-edge to the useless node
 399         n->raw_del_out(j);
 400         --j;
 401         --max;
 402       }
 403     }
 404     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 405       record_for_igvn(n->unique_out());
 406     }
 407   }
 408   // Remove useless macro and predicate opaq nodes
 409   for (int i = C->macro_count()-1; i >= 0; i--) {
 410     Node* n = C->macro_node(i);
 411     if (!useful.member(n)) {
 412       remove_macro_node(n);
 413     }
 414   }
 415   // Remove useless expensive node
 416   for (int i = C->expensive_count()-1; i >= 0; i--) {
 417     Node* n = C->expensive_node(i);
 418     if (!useful.member(n)) {
 419       remove_expensive_node(n);
 420     }
 421   }
 422   // clean up the late inline lists
 423   remove_useless_late_inlines(&_string_late_inlines, useful);
 424   remove_useless_late_inlines(&_boxing_late_inlines, useful);
 425   remove_useless_late_inlines(&_late_inlines, useful);
 426   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 427 }
 428 
 429 //------------------------------frame_size_in_words-----------------------------
 430 // frame_slots in units of words
 431 int Compile::frame_size_in_words() const {
 432   // shift is 0 in LP32 and 1 in LP64
 433   const int shift = (LogBytesPerWord - LogBytesPerInt);
 434   int words = _frame_slots >> shift;
 435   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
 436   return words;
 437 }
 438 
 439 // ============================================================================
 440 //------------------------------CompileWrapper---------------------------------
 441 class CompileWrapper : public StackObj {
 442   Compile *const _compile;
 443  public:
 444   CompileWrapper(Compile* compile);
 445 
 446   ~CompileWrapper();
 447 };
 448 
 449 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 450   // the Compile* pointer is stored in the current ciEnv:
 451   ciEnv* env = compile->env();
 452   assert(env == ciEnv::current(), "must already be a ciEnv active");
 453   assert(env->compiler_data() == NULL, "compile already active?");
 454   env->set_compiler_data(compile);
 455   assert(compile == Compile::current(), "sanity");
 456 
 457   compile->set_type_dict(NULL);
 458   compile->set_type_hwm(NULL);
 459   compile->set_type_last_size(0);
 460   compile->set_last_tf(NULL, NULL);
 461   compile->set_indexSet_arena(NULL);
 462   compile->set_indexSet_free_block_list(NULL);
 463   compile->init_type_arena();
 464   Type::Initialize(compile);
 465   _compile->set_scratch_buffer_blob(NULL);
 466   _compile->begin_method();
 467 }
 468 CompileWrapper::~CompileWrapper() {
 469   _compile->end_method();
 470   if (_compile->scratch_buffer_blob() != NULL)
 471     BufferBlob::free(_compile->scratch_buffer_blob());
 472   _compile->env()->set_compiler_data(NULL);
 473 }
 474 
 475 
 476 //----------------------------print_compile_messages---------------------------
 477 void Compile::print_compile_messages() {
 478 #ifndef PRODUCT
 479   // Check if recompiling
 480   if (_subsume_loads == false && PrintOpto) {
 481     // Recompiling without allowing machine instructions to subsume loads
 482     tty->print_cr("*********************************************************");
 483     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 484     tty->print_cr("*********************************************************");
 485   }
 486   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
 487     // Recompiling without escape analysis
 488     tty->print_cr("*********************************************************");
 489     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 490     tty->print_cr("*********************************************************");
 491   }
 492   if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
 493     // Recompiling without boxing elimination
 494     tty->print_cr("*********************************************************");
 495     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 496     tty->print_cr("*********************************************************");
 497   }
 498   if (env()->break_at_compile()) {
 499     // Open the debugger when compiling this method.
 500     tty->print("### Breaking when compiling: ");
 501     method()->print_short_name();
 502     tty->cr();
 503     BREAKPOINT;
 504   }
 505 
 506   if( PrintOpto ) {
 507     if (is_osr_compilation()) {
 508       tty->print("[OSR]%3d", _compile_id);
 509     } else {
 510       tty->print("%3d", _compile_id);
 511     }
 512   }
 513 #endif
 514 }
 515 
 516 
 517 //-----------------------init_scratch_buffer_blob------------------------------
 518 // Construct a temporary BufferBlob and cache it for this compile.
 519 void Compile::init_scratch_buffer_blob(int const_size) {
 520   // If there is already a scratch buffer blob allocated and the
 521   // constant section is big enough, use it.  Otherwise free the
 522   // current and allocate a new one.
 523   BufferBlob* blob = scratch_buffer_blob();
 524   if ((blob != NULL) && (const_size <= _scratch_const_size)) {
 525     // Use the current blob.
 526   } else {
 527     if (blob != NULL) {
 528       BufferBlob::free(blob);
 529     }
 530 
 531     ResourceMark rm;
 532     _scratch_const_size = const_size;
 533     int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
 534     blob = BufferBlob::create("Compile::scratch_buffer", size);
 535     // Record the buffer blob for next time.
 536     set_scratch_buffer_blob(blob);
 537     // Have we run out of code space?
 538     if (scratch_buffer_blob() == NULL) {
 539       // Let CompilerBroker disable further compilations.
 540       record_failure("Not enough space for scratch buffer in CodeCache");
 541       return;
 542     }
 543   }
 544 
 545   // Initialize the relocation buffers
 546   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
 547   set_scratch_locs_memory(locs_buf);
 548 }
 549 
 550 
 551 //-----------------------scratch_emit_size-------------------------------------
 552 // Helper function that computes size by emitting code
 553 uint Compile::scratch_emit_size(const Node* n) {
 554   // Start scratch_emit_size section.
 555   set_in_scratch_emit_size(true);
 556 
 557   // Emit into a trash buffer and count bytes emitted.
 558   // This is a pretty expensive way to compute a size,
 559   // but it works well enough if seldom used.
 560   // All common fixed-size instructions are given a size
 561   // method by the AD file.
 562   // Note that the scratch buffer blob and locs memory are
 563   // allocated at the beginning of the compile task, and
 564   // may be shared by several calls to scratch_emit_size.
 565   // The allocation of the scratch buffer blob is particularly
 566   // expensive, since it has to grab the code cache lock.
 567   BufferBlob* blob = this->scratch_buffer_blob();
 568   assert(blob != NULL, "Initialize BufferBlob at start");
 569   assert(blob->size() > MAX_inst_size, "sanity");
 570   relocInfo* locs_buf = scratch_locs_memory();
 571   address blob_begin = blob->content_begin();
 572   address blob_end   = (address)locs_buf;
 573   assert(blob->content_contains(blob_end), "sanity");
 574   CodeBuffer buf(blob_begin, blob_end - blob_begin);
 575   buf.initialize_consts_size(_scratch_const_size);
 576   buf.initialize_stubs_size(MAX_stubs_size);
 577   assert(locs_buf != NULL, "sanity");
 578   int lsize = MAX_locs_size / 3;
 579   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
 580   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
 581   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
 582 
 583   // Do the emission.
 584 
 585   Label fakeL; // Fake label for branch instructions.
 586   Label*   saveL = NULL;
 587   uint save_bnum = 0;
 588   bool is_branch = n->is_MachBranch();
 589   if (is_branch) {
 590     MacroAssembler masm(&buf);
 591     masm.bind(fakeL);
 592     n->as_MachBranch()->save_label(&saveL, &save_bnum);
 593     n->as_MachBranch()->label_set(&fakeL, 0);
 594   }
 595   n->emit(buf, this->regalloc());
 596   if (is_branch) // Restore label.
 597     n->as_MachBranch()->label_set(saveL, save_bnum);
 598 
 599   // End scratch_emit_size section.
 600   set_in_scratch_emit_size(false);
 601 
 602   return buf.insts_size();
 603 }
 604 
 605 
 606 // ============================================================================
 607 //------------------------------Compile standard-------------------------------
 608 debug_only( int Compile::_debug_idx = 100000; )
 609 
 610 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 611 // the continuation bci for on stack replacement.
 612 
 613 
 614 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
 615                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
 616                 : Phase(Compiler),
 617                   _env(ci_env),
 618                   _log(ci_env->log()),
 619                   _compile_id(ci_env->compile_id()),
 620                   _save_argument_registers(false),
 621                   _stub_name(NULL),
 622                   _stub_function(NULL),
 623                   _stub_entry_point(NULL),
 624                   _method(target),
 625                   _entry_bci(osr_bci),
 626                   _initial_gvn(NULL),
 627                   _for_igvn(NULL),
 628                   _warm_calls(NULL),
 629                   _subsume_loads(subsume_loads),
 630                   _do_escape_analysis(do_escape_analysis),
 631                   _eliminate_boxing(eliminate_boxing),
 632                   _failure_reason(NULL),
 633                   _code_buffer("Compile::Fill_buffer"),
 634                   _orig_pc_slot(0),
 635                   _orig_pc_slot_offset_in_bytes(0),
 636                   _has_method_handle_invokes(false),
 637                   _mach_constant_base_node(NULL),
 638                   _node_bundling_limit(0),
 639                   _node_bundling_base(NULL),
 640                   _java_calls(0),
 641                   _inner_loops(0),
 642                   _scratch_const_size(-1),
 643                   _in_scratch_emit_size(false),
 644                   _dead_node_list(comp_arena()),
 645                   _dead_node_count(0),
 646 #ifndef PRODUCT
 647                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
 648                   _printer(IdealGraphPrinter::printer()),
 649 #endif
 650                   _congraph(NULL),
 651                   _replay_inline_data(NULL),
 652                   _late_inlines(comp_arena(), 2, 0, NULL),
 653                   _string_late_inlines(comp_arena(), 2, 0, NULL),
 654                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
 655                   _late_inlines_pos(0),
 656                   _number_of_mh_late_inlines(0),
 657                   _inlining_progress(false),
 658                   _inlining_incrementally(false),
 659                   _print_inlining_list(NULL),
 660                   _print_inlining_idx(0),
 661                   _preserve_jvm_state(0) {
 662   C = this;
 663 
 664   CompileWrapper cw(this);
 665 #ifndef PRODUCT
 666   if (TimeCompiler2) {
 667     tty->print(" ");
 668     target->holder()->name()->print();
 669     tty->print(".");
 670     target->print_short_name();
 671     tty->print("  ");
 672   }
 673   TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
 674   TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
 675   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
 676   if (!print_opto_assembly) {
 677     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
 678     if (print_assembly && !Disassembler::can_decode()) {
 679       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
 680       print_opto_assembly = true;
 681     }
 682   }
 683   set_print_assembly(print_opto_assembly);
 684   set_parsed_irreducible_loop(false);
 685 
 686   if (method()->has_option("ReplayInline")) {
 687     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 688   }
 689 #endif
 690   set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
 691   set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
 692 
 693   if (ProfileTraps) {
 694     // Make sure the method being compiled gets its own MDO,
 695     // so we can at least track the decompile_count().
 696     method()->ensure_method_data();
 697   }
 698 
 699   Init(::AliasLevel);
 700 
 701 
 702   print_compile_messages();
 703 
 704   if (UseOldInlining || PrintCompilation NOT_PRODUCT( || PrintOpto) )
 705     _ilt = InlineTree::build_inline_tree_root();
 706   else
 707     _ilt = NULL;
 708 
 709   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 710   assert(num_alias_types() >= AliasIdxRaw, "");
 711 
 712 #define MINIMUM_NODE_HASH  1023
 713   // Node list that Iterative GVN will start with
 714   Unique_Node_List for_igvn(comp_arena());
 715   set_for_igvn(&for_igvn);
 716 
 717   // GVN that will be run immediately on new nodes
 718   uint estimated_size = method()->code_size()*4+64;
 719   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 720   PhaseGVN gvn(node_arena(), estimated_size);
 721   set_initial_gvn(&gvn);
 722 
 723   if (print_inlining() || print_intrinsics()) {
 724     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
 725   }
 726   { // Scope for timing the parser
 727     TracePhase t3("parse", &_t_parser, true);
 728 
 729     // Put top into the hash table ASAP.
 730     initial_gvn()->transform_no_reclaim(top());
 731 
 732     // Set up tf(), start(), and find a CallGenerator.
 733     CallGenerator* cg = NULL;
 734     if (is_osr_compilation()) {
 735       const TypeTuple *domain = StartOSRNode::osr_domain();
 736       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 737       init_tf(TypeFunc::make(domain, range));
 738       StartNode* s = new (this) StartOSRNode(root(), domain);
 739       initial_gvn()->set_type_bottom(s);
 740       init_start(s);
 741       cg = CallGenerator::for_osr(method(), entry_bci());
 742     } else {
 743       // Normal case.
 744       init_tf(TypeFunc::make(method()));
 745       StartNode* s = new (this) StartNode(root(), tf()->domain());
 746       initial_gvn()->set_type_bottom(s);
 747       init_start(s);
 748       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
 749         // With java.lang.ref.reference.get() we must go through the
 750         // intrinsic when G1 is enabled - even when get() is the root
 751         // method of the compile - so that, if necessary, the value in
 752         // the referent field of the reference object gets recorded by
 753         // the pre-barrier code.
 754         // Specifically, if G1 is enabled, the value in the referent
 755         // field is recorded by the G1 SATB pre barrier. This will
 756         // result in the referent being marked live and the reference
 757         // object removed from the list of discovered references during
 758         // reference processing.
 759         cg = find_intrinsic(method(), false);
 760       }
 761       if (cg == NULL) {
 762         float past_uses = method()->interpreter_invocation_count();
 763         float expected_uses = past_uses;
 764         cg = CallGenerator::for_inline(method(), expected_uses);
 765       }
 766     }
 767     if (failing())  return;
 768     if (cg == NULL) {
 769       record_method_not_compilable_all_tiers("cannot parse method");
 770       return;
 771     }
 772     JVMState* jvms = build_start_state(start(), tf());
 773     if ((jvms = cg->generate(jvms, NULL)) == NULL) {
 774       record_method_not_compilable("method parse failed");
 775       return;
 776     }
 777     GraphKit kit(jvms);
 778 
 779     if (!kit.stopped()) {
 780       // Accept return values, and transfer control we know not where.
 781       // This is done by a special, unique ReturnNode bound to root.
 782       return_values(kit.jvms());
 783     }
 784 
 785     if (kit.has_exceptions()) {
 786       // Any exceptions that escape from this call must be rethrown
 787       // to whatever caller is dynamically above us on the stack.
 788       // This is done by a special, unique RethrowNode bound to root.
 789       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 790     }
 791 
 792     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 793 
 794     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 795       inline_string_calls(true);
 796     }
 797 
 798     if (failing())  return;
 799 
 800     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
 801 
 802     // Remove clutter produced by parsing.
 803     if (!failing()) {
 804       ResourceMark rm;
 805       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 806     }
 807   }
 808 
 809   // Note:  Large methods are capped off in do_one_bytecode().
 810   if (failing())  return;
 811 
 812   // After parsing, node notes are no longer automagic.
 813   // They must be propagated by register_new_node_with_optimizer(),
 814   // clone(), or the like.
 815   set_default_node_notes(NULL);
 816 
 817   for (;;) {
 818     int successes = Inline_Warm();
 819     if (failing())  return;
 820     if (successes == 0)  break;
 821   }
 822 
 823   // Drain the list.
 824   Finish_Warm();
 825 #ifndef PRODUCT
 826   if (_printer) {
 827     _printer->print_inlining(this);
 828   }
 829 #endif
 830 
 831   if (failing())  return;
 832   NOT_PRODUCT( verify_graph_edges(); )
 833 
 834   // Now optimize
 835   Optimize();
 836   if (failing())  return;
 837   NOT_PRODUCT( verify_graph_edges(); )
 838 
 839 #ifndef PRODUCT
 840   if (PrintIdeal) {
 841     ttyLocker ttyl;  // keep the following output all in one block
 842     // This output goes directly to the tty, not the compiler log.
 843     // To enable tools to match it up with the compilation activity,
 844     // be sure to tag this tty output with the compile ID.
 845     if (xtty != NULL) {
 846       xtty->head("ideal compile_id='%d'%s", compile_id(),
 847                  is_osr_compilation()    ? " compile_kind='osr'" :
 848                  "");
 849     }
 850     root()->dump(9999);
 851     if (xtty != NULL) {
 852       xtty->tail("ideal");
 853     }
 854   }
 855 #endif
 856 
 857   NOT_PRODUCT( verify_barriers(); )
 858 
 859   // Dump compilation data to replay it.
 860   if (method()->has_option("DumpReplay")) {
 861     env()->dump_replay_data(_compile_id);
 862   }
 863   if (method()->has_option("DumpInline") && (ilt() != NULL)) {
 864     env()->dump_inline_data(_compile_id);
 865   }
 866 
 867   // Now that we know the size of all the monitors we can add a fixed slot
 868   // for the original deopt pc.
 869 
 870   _orig_pc_slot =  fixed_slots();
 871   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 872   set_fixed_slots(next_slot);
 873 
 874   // Now generate code
 875   Code_Gen();
 876   if (failing())  return;
 877 
 878   // Check if we want to skip execution of all compiled code.
 879   {
 880 #ifndef PRODUCT
 881     if (OptoNoExecute) {
 882       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 883       return;
 884     }
 885     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
 886 #endif
 887 
 888     if (is_osr_compilation()) {
 889       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 890       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 891     } else {
 892       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 893       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 894     }
 895 
 896     env()->register_method(_method, _entry_bci,
 897                            &_code_offsets,
 898                            _orig_pc_slot_offset_in_bytes,
 899                            code_buffer(),
 900                            frame_size_in_words(), _oop_map_set,
 901                            &_handler_table, &_inc_table,
 902                            compiler,
 903                            env()->comp_level(),
 904                            has_unsafe_access(),
 905                            SharedRuntime::is_wide_vector(max_vector_size())
 906                            );
 907 
 908     if (log() != NULL) // Print code cache state into compiler log
 909       log()->code_cache_state();
 910   }
 911 }
 912 
 913 //------------------------------Compile----------------------------------------
 914 // Compile a runtime stub
 915 Compile::Compile( ciEnv* ci_env,
 916                   TypeFunc_generator generator,
 917                   address stub_function,
 918                   const char *stub_name,
 919                   int is_fancy_jump,
 920                   bool pass_tls,
 921                   bool save_arg_registers,
 922                   bool return_pc )
 923   : Phase(Compiler),
 924     _env(ci_env),
 925     _log(ci_env->log()),
 926     _compile_id(0),
 927     _save_argument_registers(save_arg_registers),
 928     _method(NULL),
 929     _stub_name(stub_name),
 930     _stub_function(stub_function),
 931     _stub_entry_point(NULL),
 932     _entry_bci(InvocationEntryBci),
 933     _initial_gvn(NULL),
 934     _for_igvn(NULL),
 935     _warm_calls(NULL),
 936     _orig_pc_slot(0),
 937     _orig_pc_slot_offset_in_bytes(0),
 938     _subsume_loads(true),
 939     _do_escape_analysis(false),
 940     _eliminate_boxing(false),
 941     _failure_reason(NULL),
 942     _code_buffer("Compile::Fill_buffer"),
 943     _has_method_handle_invokes(false),
 944     _mach_constant_base_node(NULL),
 945     _node_bundling_limit(0),
 946     _node_bundling_base(NULL),
 947     _java_calls(0),
 948     _inner_loops(0),
 949 #ifndef PRODUCT
 950     _trace_opto_output(TraceOptoOutput),
 951     _printer(NULL),
 952 #endif
 953     _dead_node_list(comp_arena()),
 954     _dead_node_count(0),
 955     _congraph(NULL),
 956     _replay_inline_data(NULL),
 957     _number_of_mh_late_inlines(0),
 958     _inlining_progress(false),
 959     _inlining_incrementally(false),
 960     _print_inlining_list(NULL),
 961     _print_inlining_idx(0),
 962     _preserve_jvm_state(0) {
 963   C = this;
 964 
 965 #ifndef PRODUCT
 966   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
 967   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
 968   set_print_assembly(PrintFrameConverterAssembly);
 969   set_parsed_irreducible_loop(false);
 970 #endif
 971   CompileWrapper cw(this);
 972   Init(/*AliasLevel=*/ 0);
 973   init_tf((*generator)());
 974 
 975   {
 976     // The following is a dummy for the sake of GraphKit::gen_stub
 977     Unique_Node_List for_igvn(comp_arena());
 978     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
 979     PhaseGVN gvn(Thread::current()->resource_area(),255);
 980     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
 981     gvn.transform_no_reclaim(top());
 982 
 983     GraphKit kit;
 984     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
 985   }
 986 
 987   NOT_PRODUCT( verify_graph_edges(); )
 988   Code_Gen();
 989   if (failing())  return;
 990 
 991 
 992   // Entry point will be accessed using compile->stub_entry_point();
 993   if (code_buffer() == NULL) {
 994     Matcher::soft_match_failure();
 995   } else {
 996     if (PrintAssembly && (WizardMode || Verbose))
 997       tty->print_cr("### Stub::%s", stub_name);
 998 
 999     if (!failing()) {
1000       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1001 
1002       // Make the NMethod
1003       // For now we mark the frame as never safe for profile stackwalking
1004       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1005                                                       code_buffer(),
1006                                                       CodeOffsets::frame_never_safe,
1007                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
1008                                                       frame_size_in_words(),
1009                                                       _oop_map_set,
1010                                                       save_arg_registers);
1011       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1012 
1013       _stub_entry_point = rs->entry_point();
1014     }
1015   }
1016 }
1017 
1018 //------------------------------Init-------------------------------------------
1019 // Prepare for a single compilation
1020 void Compile::Init(int aliaslevel) {
1021   _unique  = 0;
1022   _regalloc = NULL;
1023 
1024   _tf      = NULL;  // filled in later
1025   _top     = NULL;  // cached later
1026   _matcher = NULL;  // filled in later
1027   _cfg     = NULL;  // filled in later
1028 
1029   set_24_bit_selection_and_mode(Use24BitFP, false);
1030 
1031   _node_note_array = NULL;
1032   _default_node_notes = NULL;
1033 
1034   _immutable_memory = NULL; // filled in at first inquiry
1035 
1036   // Globally visible Nodes
1037   // First set TOP to NULL to give safe behavior during creation of RootNode
1038   set_cached_top_node(NULL);
1039   set_root(new (this) RootNode());
1040   // Now that you have a Root to point to, create the real TOP
1041   set_cached_top_node( new (this) ConNode(Type::TOP) );
1042   set_recent_alloc(NULL, NULL);
1043 
1044   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1045   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1046   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1047   env()->set_dependencies(new Dependencies(env()));
1048 
1049   _fixed_slots = 0;
1050   set_has_split_ifs(false);
1051   set_has_loops(has_method() && method()->has_loops()); // first approximation
1052   set_has_stringbuilder(false);
1053   set_has_boxed_value(false);
1054   _trap_can_recompile = false;  // no traps emitted yet
1055   _major_progress = true; // start out assuming good things will happen
1056   set_has_unsafe_access(false);
1057   set_max_vector_size(0);
1058   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1059   set_decompile_count(0);
1060 
1061   set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
1062   set_num_loop_opts(LoopOptsCount);
1063   set_do_inlining(Inline);
1064   set_max_inline_size(MaxInlineSize);
1065   set_freq_inline_size(FreqInlineSize);
1066   set_do_scheduling(OptoScheduling);
1067   set_do_count_invocations(false);
1068   set_do_method_data_update(false);
1069 
1070   if (debug_info()->recording_non_safepoints()) {
1071     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1072                         (comp_arena(), 8, 0, NULL));
1073     set_default_node_notes(Node_Notes::make(this));
1074   }
1075 
1076   // // -- Initialize types before each compile --
1077   // // Update cached type information
1078   // if( _method && _method->constants() )
1079   //   Type::update_loaded_types(_method, _method->constants());
1080 
1081   // Init alias_type map.
1082   if (!_do_escape_analysis && aliaslevel == 3)
1083     aliaslevel = 2;  // No unique types without escape analysis
1084   _AliasLevel = aliaslevel;
1085   const int grow_ats = 16;
1086   _max_alias_types = grow_ats;
1087   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1088   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1089   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1090   {
1091     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1092   }
1093   // Initialize the first few types.
1094   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1095   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1096   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1097   _num_alias_types = AliasIdxRaw+1;
1098   // Zero out the alias type cache.
1099   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1100   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1101   probe_alias_cache(NULL)->_index = AliasIdxTop;
1102 
1103   _intrinsics = NULL;
1104   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1105   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1106   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1107   register_library_intrinsics();
1108 }
1109 
1110 //---------------------------init_start----------------------------------------
1111 // Install the StartNode on this compile object.
1112 void Compile::init_start(StartNode* s) {
1113   if (failing())
1114     return; // already failing
1115   assert(s == start(), "");
1116 }
1117 
1118 StartNode* Compile::start() const {
1119   assert(!failing(), "");
1120   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1121     Node* start = root()->fast_out(i);
1122     if( start->is_Start() )
1123       return start->as_Start();
1124   }
1125   ShouldNotReachHere();
1126   return NULL;
1127 }
1128 
1129 //-------------------------------immutable_memory-------------------------------------
1130 // Access immutable memory
1131 Node* Compile::immutable_memory() {
1132   if (_immutable_memory != NULL) {
1133     return _immutable_memory;
1134   }
1135   StartNode* s = start();
1136   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1137     Node *p = s->fast_out(i);
1138     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1139       _immutable_memory = p;
1140       return _immutable_memory;
1141     }
1142   }
1143   ShouldNotReachHere();
1144   return NULL;
1145 }
1146 
1147 //----------------------set_cached_top_node------------------------------------
1148 // Install the cached top node, and make sure Node::is_top works correctly.
1149 void Compile::set_cached_top_node(Node* tn) {
1150   if (tn != NULL)  verify_top(tn);
1151   Node* old_top = _top;
1152   _top = tn;
1153   // Calling Node::setup_is_top allows the nodes the chance to adjust
1154   // their _out arrays.
1155   if (_top != NULL)     _top->setup_is_top();
1156   if (old_top != NULL)  old_top->setup_is_top();
1157   assert(_top == NULL || top()->is_top(), "");
1158 }
1159 
1160 #ifdef ASSERT
1161 uint Compile::count_live_nodes_by_graph_walk() {
1162   Unique_Node_List useful(comp_arena());
1163   // Get useful node list by walking the graph.
1164   identify_useful_nodes(useful);
1165   return useful.size();
1166 }
1167 
1168 void Compile::print_missing_nodes() {
1169 
1170   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1171   if ((_log == NULL) && (! PrintIdealNodeCount)) {
1172     return;
1173   }
1174 
1175   // This is an expensive function. It is executed only when the user
1176   // specifies VerifyIdealNodeCount option or otherwise knows the
1177   // additional work that needs to be done to identify reachable nodes
1178   // by walking the flow graph and find the missing ones using
1179   // _dead_node_list.
1180 
1181   Unique_Node_List useful(comp_arena());
1182   // Get useful node list by walking the graph.
1183   identify_useful_nodes(useful);
1184 
1185   uint l_nodes = C->live_nodes();
1186   uint l_nodes_by_walk = useful.size();
1187 
1188   if (l_nodes != l_nodes_by_walk) {
1189     if (_log != NULL) {
1190       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1191       _log->stamp();
1192       _log->end_head();
1193     }
1194     VectorSet& useful_member_set = useful.member_set();
1195     int last_idx = l_nodes_by_walk;
1196     for (int i = 0; i < last_idx; i++) {
1197       if (useful_member_set.test(i)) {
1198         if (_dead_node_list.test(i)) {
1199           if (_log != NULL) {
1200             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1201           }
1202           if (PrintIdealNodeCount) {
1203             // Print the log message to tty
1204               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1205               useful.at(i)->dump();
1206           }
1207         }
1208       }
1209       else if (! _dead_node_list.test(i)) {
1210         if (_log != NULL) {
1211           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1212         }
1213         if (PrintIdealNodeCount) {
1214           // Print the log message to tty
1215           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1216         }
1217       }
1218     }
1219     if (_log != NULL) {
1220       _log->tail("mismatched_nodes");
1221     }
1222   }
1223 }
1224 #endif
1225 
1226 #ifndef PRODUCT
1227 void Compile::verify_top(Node* tn) const {
1228   if (tn != NULL) {
1229     assert(tn->is_Con(), "top node must be a constant");
1230     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1231     assert(tn->in(0) != NULL, "must have live top node");
1232   }
1233 }
1234 #endif
1235 
1236 
1237 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1238 
1239 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1240   guarantee(arr != NULL, "");
1241   int num_blocks = arr->length();
1242   if (grow_by < num_blocks)  grow_by = num_blocks;
1243   int num_notes = grow_by * _node_notes_block_size;
1244   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1245   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1246   while (num_notes > 0) {
1247     arr->append(notes);
1248     notes     += _node_notes_block_size;
1249     num_notes -= _node_notes_block_size;
1250   }
1251   assert(num_notes == 0, "exact multiple, please");
1252 }
1253 
1254 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1255   if (source == NULL || dest == NULL)  return false;
1256 
1257   if (dest->is_Con())
1258     return false;               // Do not push debug info onto constants.
1259 
1260 #ifdef ASSERT
1261   // Leave a bread crumb trail pointing to the original node:
1262   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1263     dest->set_debug_orig(source);
1264   }
1265 #endif
1266 
1267   if (node_note_array() == NULL)
1268     return false;               // Not collecting any notes now.
1269 
1270   // This is a copy onto a pre-existing node, which may already have notes.
1271   // If both nodes have notes, do not overwrite any pre-existing notes.
1272   Node_Notes* source_notes = node_notes_at(source->_idx);
1273   if (source_notes == NULL || source_notes->is_clear())  return false;
1274   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1275   if (dest_notes == NULL || dest_notes->is_clear()) {
1276     return set_node_notes_at(dest->_idx, source_notes);
1277   }
1278 
1279   Node_Notes merged_notes = (*source_notes);
1280   // The order of operations here ensures that dest notes will win...
1281   merged_notes.update_from(dest_notes);
1282   return set_node_notes_at(dest->_idx, &merged_notes);
1283 }
1284 
1285 
1286 //--------------------------allow_range_check_smearing-------------------------
1287 // Gating condition for coalescing similar range checks.
1288 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1289 // single covering check that is at least as strong as any of them.
1290 // If the optimization succeeds, the simplified (strengthened) range check
1291 // will always succeed.  If it fails, we will deopt, and then give up
1292 // on the optimization.
1293 bool Compile::allow_range_check_smearing() const {
1294   // If this method has already thrown a range-check,
1295   // assume it was because we already tried range smearing
1296   // and it failed.
1297   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1298   return !already_trapped;
1299 }
1300 
1301 
1302 //------------------------------flatten_alias_type-----------------------------
1303 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1304   int offset = tj->offset();
1305   TypePtr::PTR ptr = tj->ptr();
1306 
1307   // Known instance (scalarizable allocation) alias only with itself.
1308   bool is_known_inst = tj->isa_oopptr() != NULL &&
1309                        tj->is_oopptr()->is_known_instance();
1310 
1311   // Process weird unsafe references.
1312   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1313     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1314     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1315     tj = TypeOopPtr::BOTTOM;
1316     ptr = tj->ptr();
1317     offset = tj->offset();
1318   }
1319 
1320   // Array pointers need some flattening
1321   const TypeAryPtr *ta = tj->isa_aryptr();
1322   if (ta && ta->is_stable()) {
1323     // Erase stability property for alias analysis.
1324     tj = ta = ta->cast_to_stable(false);
1325   }
1326   if( ta && is_known_inst ) {
1327     if ( offset != Type::OffsetBot &&
1328          offset > arrayOopDesc::length_offset_in_bytes() ) {
1329       offset = Type::OffsetBot; // Flatten constant access into array body only
1330       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1331     }
1332   } else if( ta && _AliasLevel >= 2 ) {
1333     // For arrays indexed by constant indices, we flatten the alias
1334     // space to include all of the array body.  Only the header, klass
1335     // and array length can be accessed un-aliased.
1336     if( offset != Type::OffsetBot ) {
1337       if( ta->const_oop() ) { // MethodData* or Method*
1338         offset = Type::OffsetBot;   // Flatten constant access into array body
1339         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1340       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1341         // range is OK as-is.
1342         tj = ta = TypeAryPtr::RANGE;
1343       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1344         tj = TypeInstPtr::KLASS; // all klass loads look alike
1345         ta = TypeAryPtr::RANGE; // generic ignored junk
1346         ptr = TypePtr::BotPTR;
1347       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1348         tj = TypeInstPtr::MARK;
1349         ta = TypeAryPtr::RANGE; // generic ignored junk
1350         ptr = TypePtr::BotPTR;
1351       } else {                  // Random constant offset into array body
1352         offset = Type::OffsetBot;   // Flatten constant access into array body
1353         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1354       }
1355     }
1356     // Arrays of fixed size alias with arrays of unknown size.
1357     if (ta->size() != TypeInt::POS) {
1358       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1359       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1360     }
1361     // Arrays of known objects become arrays of unknown objects.
1362     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1363       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1364       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1365     }
1366     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1367       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1368       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1369     }
1370     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1371     // cannot be distinguished by bytecode alone.
1372     if (ta->elem() == TypeInt::BOOL) {
1373       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1374       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1375       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1376     }
1377     // During the 2nd round of IterGVN, NotNull castings are removed.
1378     // Make sure the Bottom and NotNull variants alias the same.
1379     // Also, make sure exact and non-exact variants alias the same.
1380     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1381       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1382     }
1383   }
1384 
1385   // Oop pointers need some flattening
1386   const TypeInstPtr *to = tj->isa_instptr();
1387   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1388     ciInstanceKlass *k = to->klass()->as_instance_klass();
1389     if( ptr == TypePtr::Constant ) {
1390       if (to->klass() != ciEnv::current()->Class_klass() ||
1391           offset < k->size_helper() * wordSize) {
1392         // No constant oop pointers (such as Strings); they alias with
1393         // unknown strings.
1394         assert(!is_known_inst, "not scalarizable allocation");
1395         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1396       }
1397     } else if( is_known_inst ) {
1398       tj = to; // Keep NotNull and klass_is_exact for instance type
1399     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1400       // During the 2nd round of IterGVN, NotNull castings are removed.
1401       // Make sure the Bottom and NotNull variants alias the same.
1402       // Also, make sure exact and non-exact variants alias the same.
1403       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1404     }
1405     if (to->speculative() != NULL) {
1406       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
1407     }
1408     // Canonicalize the holder of this field
1409     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1410       // First handle header references such as a LoadKlassNode, even if the
1411       // object's klass is unloaded at compile time (4965979).
1412       if (!is_known_inst) { // Do it only for non-instance types
1413         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1414       }
1415     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1416       // Static fields are in the space above the normal instance
1417       // fields in the java.lang.Class instance.
1418       if (to->klass() != ciEnv::current()->Class_klass()) {
1419         to = NULL;
1420         tj = TypeOopPtr::BOTTOM;
1421         offset = tj->offset();
1422       }
1423     } else {
1424       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1425       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1426         if( is_known_inst ) {
1427           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1428         } else {
1429           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1430         }
1431       }
1432     }
1433   }
1434 
1435   // Klass pointers to object array klasses need some flattening
1436   const TypeKlassPtr *tk = tj->isa_klassptr();
1437   if( tk ) {
1438     // If we are referencing a field within a Klass, we need
1439     // to assume the worst case of an Object.  Both exact and
1440     // inexact types must flatten to the same alias class so
1441     // use NotNull as the PTR.
1442     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1443 
1444       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1445                                    TypeKlassPtr::OBJECT->klass(),
1446                                    offset);
1447     }
1448 
1449     ciKlass* klass = tk->klass();
1450     if( klass->is_obj_array_klass() ) {
1451       ciKlass* k = TypeAryPtr::OOPS->klass();
1452       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1453         k = TypeInstPtr::BOTTOM->klass();
1454       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1455     }
1456 
1457     // Check for precise loads from the primary supertype array and force them
1458     // to the supertype cache alias index.  Check for generic array loads from
1459     // the primary supertype array and also force them to the supertype cache
1460     // alias index.  Since the same load can reach both, we need to merge
1461     // these 2 disparate memories into the same alias class.  Since the
1462     // primary supertype array is read-only, there's no chance of confusion
1463     // where we bypass an array load and an array store.
1464     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1465     if (offset == Type::OffsetBot ||
1466         (offset >= primary_supers_offset &&
1467          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1468         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1469       offset = in_bytes(Klass::secondary_super_cache_offset());
1470       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1471     }
1472   }
1473 
1474   // Flatten all Raw pointers together.
1475   if (tj->base() == Type::RawPtr)
1476     tj = TypeRawPtr::BOTTOM;
1477 
1478   if (tj->base() == Type::AnyPtr)
1479     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1480 
1481   // Flatten all to bottom for now
1482   switch( _AliasLevel ) {
1483   case 0:
1484     tj = TypePtr::BOTTOM;
1485     break;
1486   case 1:                       // Flatten to: oop, static, field or array
1487     switch (tj->base()) {
1488     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1489     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1490     case Type::AryPtr:   // do not distinguish arrays at all
1491     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1492     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1493     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1494     default: ShouldNotReachHere();
1495     }
1496     break;
1497   case 2:                       // No collapsing at level 2; keep all splits
1498   case 3:                       // No collapsing at level 3; keep all splits
1499     break;
1500   default:
1501     Unimplemented();
1502   }
1503 
1504   offset = tj->offset();
1505   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1506 
1507   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1508           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1509           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1510           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1511           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1512           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1513           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
1514           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1515   assert( tj->ptr() != TypePtr::TopPTR &&
1516           tj->ptr() != TypePtr::AnyNull &&
1517           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1518 //    assert( tj->ptr() != TypePtr::Constant ||
1519 //            tj->base() == Type::RawPtr ||
1520 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1521 
1522   return tj;
1523 }
1524 
1525 void Compile::AliasType::Init(int i, const TypePtr* at) {
1526   _index = i;
1527   _adr_type = at;
1528   _field = NULL;
1529   _element = NULL;
1530   _is_rewritable = true; // default
1531   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1532   if (atoop != NULL && atoop->is_known_instance()) {
1533     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1534     _general_index = Compile::current()->get_alias_index(gt);
1535   } else {
1536     _general_index = 0;
1537   }
1538 }
1539 
1540 //---------------------------------print_on------------------------------------
1541 #ifndef PRODUCT
1542 void Compile::AliasType::print_on(outputStream* st) {
1543   if (index() < 10)
1544         st->print("@ <%d> ", index());
1545   else  st->print("@ <%d>",  index());
1546   st->print(is_rewritable() ? "   " : " RO");
1547   int offset = adr_type()->offset();
1548   if (offset == Type::OffsetBot)
1549         st->print(" +any");
1550   else  st->print(" +%-3d", offset);
1551   st->print(" in ");
1552   adr_type()->dump_on(st);
1553   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1554   if (field() != NULL && tjp) {
1555     if (tjp->klass()  != field()->holder() ||
1556         tjp->offset() != field()->offset_in_bytes()) {
1557       st->print(" != ");
1558       field()->print();
1559       st->print(" ***");
1560     }
1561   }
1562 }
1563 
1564 void print_alias_types() {
1565   Compile* C = Compile::current();
1566   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1567   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1568     C->alias_type(idx)->print_on(tty);
1569     tty->cr();
1570   }
1571 }
1572 #endif
1573 
1574 
1575 //----------------------------probe_alias_cache--------------------------------
1576 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1577   intptr_t key = (intptr_t) adr_type;
1578   key ^= key >> logAliasCacheSize;
1579   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1580 }
1581 
1582 
1583 //-----------------------------grow_alias_types--------------------------------
1584 void Compile::grow_alias_types() {
1585   const int old_ats  = _max_alias_types; // how many before?
1586   const int new_ats  = old_ats;          // how many more?
1587   const int grow_ats = old_ats+new_ats;  // how many now?
1588   _max_alias_types = grow_ats;
1589   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1590   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1591   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1592   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1593 }
1594 
1595 
1596 //--------------------------------find_alias_type------------------------------
1597 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1598   if (_AliasLevel == 0)
1599     return alias_type(AliasIdxBot);
1600 
1601   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1602   if (ace->_adr_type == adr_type) {
1603     return alias_type(ace->_index);
1604   }
1605 
1606   // Handle special cases.
1607   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1608   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1609 
1610   // Do it the slow way.
1611   const TypePtr* flat = flatten_alias_type(adr_type);
1612 
1613 #ifdef ASSERT
1614   assert(flat == flatten_alias_type(flat), "idempotent");
1615   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
1616   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1617     const TypeOopPtr* foop = flat->is_oopptr();
1618     // Scalarizable allocations have exact klass always.
1619     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1620     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1621     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
1622   }
1623   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
1624 #endif
1625 
1626   int idx = AliasIdxTop;
1627   for (int i = 0; i < num_alias_types(); i++) {
1628     if (alias_type(i)->adr_type() == flat) {
1629       idx = i;
1630       break;
1631     }
1632   }
1633 
1634   if (idx == AliasIdxTop) {
1635     if (no_create)  return NULL;
1636     // Grow the array if necessary.
1637     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1638     // Add a new alias type.
1639     idx = _num_alias_types++;
1640     _alias_types[idx]->Init(idx, flat);
1641     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1642     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1643     if (flat->isa_instptr()) {
1644       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1645           && flat->is_instptr()->klass() == env()->Class_klass())
1646         alias_type(idx)->set_rewritable(false);
1647     }
1648     if (flat->isa_aryptr()) {
1649 #ifdef ASSERT
1650       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1651       // (T_BYTE has the weakest alignment and size restrictions...)
1652       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1653 #endif
1654       if (flat->offset() == TypePtr::OffsetBot) {
1655         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1656       }
1657     }
1658     if (flat->isa_klassptr()) {
1659       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1660         alias_type(idx)->set_rewritable(false);
1661       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1662         alias_type(idx)->set_rewritable(false);
1663       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1664         alias_type(idx)->set_rewritable(false);
1665       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1666         alias_type(idx)->set_rewritable(false);
1667     }
1668     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1669     // but the base pointer type is not distinctive enough to identify
1670     // references into JavaThread.)
1671 
1672     // Check for final fields.
1673     const TypeInstPtr* tinst = flat->isa_instptr();
1674     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1675       ciField* field;
1676       if (tinst->const_oop() != NULL &&
1677           tinst->klass() == ciEnv::current()->Class_klass() &&
1678           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1679         // static field
1680         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1681         field = k->get_field_by_offset(tinst->offset(), true);
1682       } else {
1683         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1684         field = k->get_field_by_offset(tinst->offset(), false);
1685       }
1686       assert(field == NULL ||
1687              original_field == NULL ||
1688              (field->holder() == original_field->holder() &&
1689               field->offset() == original_field->offset() &&
1690               field->is_static() == original_field->is_static()), "wrong field?");
1691       // Set field() and is_rewritable() attributes.
1692       if (field != NULL)  alias_type(idx)->set_field(field);
1693     }
1694   }
1695 
1696   // Fill the cache for next time.
1697   ace->_adr_type = adr_type;
1698   ace->_index    = idx;
1699   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1700 
1701   // Might as well try to fill the cache for the flattened version, too.
1702   AliasCacheEntry* face = probe_alias_cache(flat);
1703   if (face->_adr_type == NULL) {
1704     face->_adr_type = flat;
1705     face->_index    = idx;
1706     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1707   }
1708 
1709   return alias_type(idx);
1710 }
1711 
1712 
1713 Compile::AliasType* Compile::alias_type(ciField* field) {
1714   const TypeOopPtr* t;
1715   if (field->is_static())
1716     t = TypeInstPtr::make(field->holder()->java_mirror());
1717   else
1718     t = TypeOopPtr::make_from_klass_raw(field->holder());
1719   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1720   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1721   return atp;
1722 }
1723 
1724 
1725 //------------------------------have_alias_type--------------------------------
1726 bool Compile::have_alias_type(const TypePtr* adr_type) {
1727   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1728   if (ace->_adr_type == adr_type) {
1729     return true;
1730   }
1731 
1732   // Handle special cases.
1733   if (adr_type == NULL)             return true;
1734   if (adr_type == TypePtr::BOTTOM)  return true;
1735 
1736   return find_alias_type(adr_type, true, NULL) != NULL;
1737 }
1738 
1739 //-----------------------------must_alias--------------------------------------
1740 // True if all values of the given address type are in the given alias category.
1741 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1742   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1743   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1744   if (alias_idx == AliasIdxTop)         return false; // the empty category
1745   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1746 
1747   // the only remaining possible overlap is identity
1748   int adr_idx = get_alias_index(adr_type);
1749   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1750   assert(adr_idx == alias_idx ||
1751          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1752           && adr_type                       != TypeOopPtr::BOTTOM),
1753          "should not be testing for overlap with an unsafe pointer");
1754   return adr_idx == alias_idx;
1755 }
1756 
1757 //------------------------------can_alias--------------------------------------
1758 // True if any values of the given address type are in the given alias category.
1759 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1760   if (alias_idx == AliasIdxTop)         return false; // the empty category
1761   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1762   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1763   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1764 
1765   // the only remaining possible overlap is identity
1766   int adr_idx = get_alias_index(adr_type);
1767   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1768   return adr_idx == alias_idx;
1769 }
1770 
1771 
1772 
1773 //---------------------------pop_warm_call-------------------------------------
1774 WarmCallInfo* Compile::pop_warm_call() {
1775   WarmCallInfo* wci = _warm_calls;
1776   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1777   return wci;
1778 }
1779 
1780 //----------------------------Inline_Warm--------------------------------------
1781 int Compile::Inline_Warm() {
1782   // If there is room, try to inline some more warm call sites.
1783   // %%% Do a graph index compaction pass when we think we're out of space?
1784   if (!InlineWarmCalls)  return 0;
1785 
1786   int calls_made_hot = 0;
1787   int room_to_grow   = NodeCountInliningCutoff - unique();
1788   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1789   int amount_grown   = 0;
1790   WarmCallInfo* call;
1791   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1792     int est_size = (int)call->size();
1793     if (est_size > (room_to_grow - amount_grown)) {
1794       // This one won't fit anyway.  Get rid of it.
1795       call->make_cold();
1796       continue;
1797     }
1798     call->make_hot();
1799     calls_made_hot++;
1800     amount_grown   += est_size;
1801     amount_to_grow -= est_size;
1802   }
1803 
1804   if (calls_made_hot > 0)  set_major_progress();
1805   return calls_made_hot;
1806 }
1807 
1808 
1809 //----------------------------Finish_Warm--------------------------------------
1810 void Compile::Finish_Warm() {
1811   if (!InlineWarmCalls)  return;
1812   if (failing())  return;
1813   if (warm_calls() == NULL)  return;
1814 
1815   // Clean up loose ends, if we are out of space for inlining.
1816   WarmCallInfo* call;
1817   while ((call = pop_warm_call()) != NULL) {
1818     call->make_cold();
1819   }
1820 }
1821 
1822 //---------------------cleanup_loop_predicates-----------------------
1823 // Remove the opaque nodes that protect the predicates so that all unused
1824 // checks and uncommon_traps will be eliminated from the ideal graph
1825 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1826   if (predicate_count()==0) return;
1827   for (int i = predicate_count(); i > 0; i--) {
1828     Node * n = predicate_opaque1_node(i-1);
1829     assert(n->Opcode() == Op_Opaque1, "must be");
1830     igvn.replace_node(n, n->in(1));
1831   }
1832   assert(predicate_count()==0, "should be clean!");
1833 }
1834 
1835 // StringOpts and late inlining of string methods
1836 void Compile::inline_string_calls(bool parse_time) {
1837   {
1838     // remove useless nodes to make the usage analysis simpler
1839     ResourceMark rm;
1840     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1841   }
1842 
1843   {
1844     ResourceMark rm;
1845     print_method(PHASE_BEFORE_STRINGOPTS, 3);
1846     PhaseStringOpts pso(initial_gvn(), for_igvn());
1847     print_method(PHASE_AFTER_STRINGOPTS, 3);
1848   }
1849 
1850   // now inline anything that we skipped the first time around
1851   if (!parse_time) {
1852     _late_inlines_pos = _late_inlines.length();
1853   }
1854 
1855   while (_string_late_inlines.length() > 0) {
1856     CallGenerator* cg = _string_late_inlines.pop();
1857     cg->do_late_inline();
1858     if (failing())  return;
1859   }
1860   _string_late_inlines.trunc_to(0);
1861 }
1862 
1863 // Late inlining of boxing methods
1864 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
1865   if (_boxing_late_inlines.length() > 0) {
1866     assert(has_boxed_value(), "inconsistent");
1867 
1868     PhaseGVN* gvn = initial_gvn();
1869     set_inlining_incrementally(true);
1870 
1871     assert( igvn._worklist.size() == 0, "should be done with igvn" );
1872     for_igvn()->clear();
1873     gvn->replace_with(&igvn);
1874 
1875     while (_boxing_late_inlines.length() > 0) {
1876       CallGenerator* cg = _boxing_late_inlines.pop();
1877       cg->do_late_inline();
1878       if (failing())  return;
1879     }
1880     _boxing_late_inlines.trunc_to(0);
1881 
1882     {
1883       ResourceMark rm;
1884       PhaseRemoveUseless pru(gvn, for_igvn());
1885     }
1886 
1887     igvn = PhaseIterGVN(gvn);
1888     igvn.optimize();
1889 
1890     set_inlining_progress(false);
1891     set_inlining_incrementally(false);
1892   }
1893 }
1894 
1895 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
1896   assert(IncrementalInline, "incremental inlining should be on");
1897   PhaseGVN* gvn = initial_gvn();
1898 
1899   set_inlining_progress(false);
1900   for_igvn()->clear();
1901   gvn->replace_with(&igvn);
1902 
1903   int i = 0;
1904 
1905   for (; i <_late_inlines.length() && !inlining_progress(); i++) {
1906     CallGenerator* cg = _late_inlines.at(i);
1907     _late_inlines_pos = i+1;
1908     cg->do_late_inline();
1909     if (failing())  return;
1910   }
1911   int j = 0;
1912   for (; i < _late_inlines.length(); i++, j++) {
1913     _late_inlines.at_put(j, _late_inlines.at(i));
1914   }
1915   _late_inlines.trunc_to(j);
1916 
1917   {
1918     ResourceMark rm;
1919     PhaseRemoveUseless pru(gvn, for_igvn());
1920   }
1921 
1922   igvn = PhaseIterGVN(gvn);
1923 }
1924 
1925 // Perform incremental inlining until bound on number of live nodes is reached
1926 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
1927   PhaseGVN* gvn = initial_gvn();
1928 
1929   set_inlining_incrementally(true);
1930   set_inlining_progress(true);
1931   uint low_live_nodes = 0;
1932 
1933   while(inlining_progress() && _late_inlines.length() > 0) {
1934 
1935     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
1936       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
1937         // PhaseIdealLoop is expensive so we only try it once we are
1938         // out of loop and we only try it again if the previous helped
1939         // got the number of nodes down significantly
1940         PhaseIdealLoop ideal_loop( igvn, false, true );
1941         if (failing())  return;
1942         low_live_nodes = live_nodes();
1943         _major_progress = true;
1944       }
1945 
1946       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
1947         break;
1948       }
1949     }
1950 
1951     inline_incrementally_one(igvn);
1952 
1953     if (failing())  return;
1954 
1955     igvn.optimize();
1956 
1957     if (failing())  return;
1958   }
1959 
1960   assert( igvn._worklist.size() == 0, "should be done with igvn" );
1961 
1962   if (_string_late_inlines.length() > 0) {
1963     assert(has_stringbuilder(), "inconsistent");
1964     for_igvn()->clear();
1965     initial_gvn()->replace_with(&igvn);
1966 
1967     inline_string_calls(false);
1968 
1969     if (failing())  return;
1970 
1971     {
1972       ResourceMark rm;
1973       PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1974     }
1975 
1976     igvn = PhaseIterGVN(gvn);
1977 
1978     igvn.optimize();
1979   }
1980 
1981   set_inlining_incrementally(false);
1982 }
1983 
1984 
1985 //------------------------------Optimize---------------------------------------
1986 // Given a graph, optimize it.
1987 void Compile::Optimize() {
1988   TracePhase t1("optimizer", &_t_optimizer, true);
1989 
1990 #ifndef PRODUCT
1991   if (env()->break_at_compile()) {
1992     BREAKPOINT;
1993   }
1994 
1995 #endif
1996 
1997   ResourceMark rm;
1998   int          loop_opts_cnt;
1999 
2000   NOT_PRODUCT( verify_graph_edges(); )
2001 
2002   print_method(PHASE_AFTER_PARSING);
2003 
2004  {
2005   // Iterative Global Value Numbering, including ideal transforms
2006   // Initialize IterGVN with types and values from parse-time GVN
2007   PhaseIterGVN igvn(initial_gvn());
2008   {
2009     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
2010     igvn.optimize();
2011   }
2012 
2013   print_method(PHASE_ITER_GVN1, 2);
2014 
2015   if (failing())  return;
2016 
2017   {
2018     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
2019     inline_incrementally(igvn);
2020   }
2021 
2022   print_method(PHASE_INCREMENTAL_INLINE, 2);
2023 
2024   if (failing())  return;
2025 
2026   if (eliminate_boxing()) {
2027     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
2028     // Inline valueOf() methods now.
2029     inline_boxing_calls(igvn);
2030 
2031     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2032 
2033     if (failing())  return;
2034   }
2035 
2036   // Remove the speculative part of types and clean up the graph from
2037   // the extra CastPP nodes whose only purpose is to carry them. Do
2038   // that early so that optimizations are not disrupted by the extra
2039   // CastPP nodes.
2040   remove_speculative_types(igvn);
2041 
2042   // No more new expensive nodes will be added to the list from here
2043   // so keep only the actual candidates for optimizations.
2044   cleanup_expensive_nodes(igvn);
2045 
2046   // Perform escape analysis
2047   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2048     if (has_loops()) {
2049       // Cleanup graph (remove dead nodes).
2050       TracePhase t2("idealLoop", &_t_idealLoop, true);
2051       PhaseIdealLoop ideal_loop( igvn, false, true );
2052       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2053       if (failing())  return;
2054     }
2055     ConnectionGraph::do_analysis(this, &igvn);
2056 
2057     if (failing())  return;
2058 
2059     // Optimize out fields loads from scalar replaceable allocations.
2060     igvn.optimize();
2061     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2062 
2063     if (failing())  return;
2064 
2065     if (congraph() != NULL && macro_count() > 0) {
2066       NOT_PRODUCT( TracePhase t2("macroEliminate", &_t_macroEliminate, TimeCompiler); )
2067       PhaseMacroExpand mexp(igvn);
2068       mexp.eliminate_macro_nodes();
2069       igvn.set_delay_transform(false);
2070 
2071       igvn.optimize();
2072       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2073 
2074       if (failing())  return;
2075     }
2076   }
2077 
2078   // Loop transforms on the ideal graph.  Range Check Elimination,
2079   // peeling, unrolling, etc.
2080 
2081   // Set loop opts counter
2082   loop_opts_cnt = num_loop_opts();
2083   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2084     {
2085       TracePhase t2("idealLoop", &_t_idealLoop, true);
2086       PhaseIdealLoop ideal_loop( igvn, true );
2087       loop_opts_cnt--;
2088       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2089       if (failing())  return;
2090     }
2091     // Loop opts pass if partial peeling occurred in previous pass
2092     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
2093       TracePhase t3("idealLoop", &_t_idealLoop, true);
2094       PhaseIdealLoop ideal_loop( igvn, false );
2095       loop_opts_cnt--;
2096       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2097       if (failing())  return;
2098     }
2099     // Loop opts pass for loop-unrolling before CCP
2100     if(major_progress() && (loop_opts_cnt > 0)) {
2101       TracePhase t4("idealLoop", &_t_idealLoop, true);
2102       PhaseIdealLoop ideal_loop( igvn, false );
2103       loop_opts_cnt--;
2104       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2105     }
2106     if (!failing()) {
2107       // Verify that last round of loop opts produced a valid graph
2108       NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
2109       PhaseIdealLoop::verify(igvn);
2110     }
2111   }
2112   if (failing())  return;
2113 
2114   // Conditional Constant Propagation;
2115   PhaseCCP ccp( &igvn );
2116   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2117   {
2118     TracePhase t2("ccp", &_t_ccp, true);
2119     ccp.do_transform();
2120   }
2121   print_method(PHASE_CPP1, 2);
2122 
2123   assert( true, "Break here to ccp.dump_old2new_map()");
2124 
2125   // Iterative Global Value Numbering, including ideal transforms
2126   {
2127     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
2128     igvn = ccp;
2129     igvn.optimize();
2130   }
2131 
2132   print_method(PHASE_ITER_GVN2, 2);
2133 
2134   if (failing())  return;
2135 
2136   // Loop transforms on the ideal graph.  Range Check Elimination,
2137   // peeling, unrolling, etc.
2138   if(loop_opts_cnt > 0) {
2139     debug_only( int cnt = 0; );
2140     while(major_progress() && (loop_opts_cnt > 0)) {
2141       TracePhase t2("idealLoop", &_t_idealLoop, true);
2142       assert( cnt++ < 40, "infinite cycle in loop optimization" );
2143       PhaseIdealLoop ideal_loop( igvn, true);
2144       loop_opts_cnt--;
2145       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2146       if (failing())  return;
2147     }
2148   }
2149 
2150   {
2151     // Verify that all previous optimizations produced a valid graph
2152     // at least to this point, even if no loop optimizations were done.
2153     NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
2154     PhaseIdealLoop::verify(igvn);
2155   }
2156 
2157   {
2158     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
2159     PhaseMacroExpand  mex(igvn);
2160     if (mex.expand_macro_nodes()) {
2161       assert(failing(), "must bail out w/ explicit message");
2162       return;
2163     }
2164   }
2165 
2166  } // (End scope of igvn; run destructor if necessary for asserts.)
2167 
2168   dump_inlining();
2169   // A method with only infinite loops has no edges entering loops from root
2170   {
2171     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
2172     if (final_graph_reshaping()) {
2173       assert(failing(), "must bail out w/ explicit message");
2174       return;
2175     }
2176   }
2177 
2178   print_method(PHASE_OPTIMIZE_FINISHED, 2);
2179 }
2180 
2181 
2182 //------------------------------Code_Gen---------------------------------------
2183 // Given a graph, generate code for it
2184 void Compile::Code_Gen() {
2185   if (failing()) {
2186     return;
2187   }
2188 
2189   // Perform instruction selection.  You might think we could reclaim Matcher
2190   // memory PDQ, but actually the Matcher is used in generating spill code.
2191   // Internals of the Matcher (including some VectorSets) must remain live
2192   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2193   // set a bit in reclaimed memory.
2194 
2195   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2196   // nodes.  Mapping is only valid at the root of each matched subtree.
2197   NOT_PRODUCT( verify_graph_edges(); )
2198 
2199   Matcher matcher;
2200   _matcher = &matcher;
2201   {
2202     TracePhase t2("matcher", &_t_matcher, true);
2203     matcher.match();
2204   }
2205   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2206   // nodes.  Mapping is only valid at the root of each matched subtree.
2207   NOT_PRODUCT( verify_graph_edges(); )
2208 
2209   // If you have too many nodes, or if matching has failed, bail out
2210   check_node_count(0, "out of nodes matching instructions");
2211   if (failing()) {
2212     return;
2213   }
2214 
2215   // Build a proper-looking CFG
2216   PhaseCFG cfg(node_arena(), root(), matcher);
2217   _cfg = &cfg;
2218   {
2219     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
2220     bool success = cfg.do_global_code_motion();
2221     if (!success) {
2222       return;
2223     }
2224 
2225     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2226     NOT_PRODUCT( verify_graph_edges(); )
2227     debug_only( cfg.verify(); )
2228   }
2229 
2230   PhaseChaitin regalloc(unique(), cfg, matcher);
2231   _regalloc = &regalloc;
2232   {
2233     TracePhase t2("regalloc", &_t_registerAllocation, true);
2234     // Perform register allocation.  After Chaitin, use-def chains are
2235     // no longer accurate (at spill code) and so must be ignored.
2236     // Node->LRG->reg mappings are still accurate.
2237     _regalloc->Register_Allocate();
2238 
2239     // Bail out if the allocator builds too many nodes
2240     if (failing()) {
2241       return;
2242     }
2243   }
2244 
2245   // Prior to register allocation we kept empty basic blocks in case the
2246   // the allocator needed a place to spill.  After register allocation we
2247   // are not adding any new instructions.  If any basic block is empty, we
2248   // can now safely remove it.
2249   {
2250     NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
2251     cfg.remove_empty_blocks();
2252     if (do_freq_based_layout()) {
2253       PhaseBlockLayout layout(cfg);
2254     } else {
2255       cfg.set_loop_alignment();
2256     }
2257     cfg.fixup_flow();
2258   }
2259 
2260   // Apply peephole optimizations
2261   if( OptoPeephole ) {
2262     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
2263     PhasePeephole peep( _regalloc, cfg);
2264     peep.do_transform();
2265   }
2266 
2267   // Convert Nodes to instruction bits in a buffer
2268   {
2269     // %%%% workspace merge brought two timers together for one job
2270     TracePhase t2a("output", &_t_output, true);
2271     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
2272     Output();
2273   }
2274 
2275   print_method(PHASE_FINAL_CODE);
2276 
2277   // He's dead, Jim.
2278   _cfg     = (PhaseCFG*)0xdeadbeef;
2279   _regalloc = (PhaseChaitin*)0xdeadbeef;
2280 }
2281 
2282 
2283 //------------------------------dump_asm---------------------------------------
2284 // Dump formatted assembly
2285 #ifndef PRODUCT
2286 void Compile::dump_asm(int *pcs, uint pc_limit) {
2287   bool cut_short = false;
2288   tty->print_cr("#");
2289   tty->print("#  ");  _tf->dump();  tty->cr();
2290   tty->print_cr("#");
2291 
2292   // For all blocks
2293   int pc = 0x0;                 // Program counter
2294   char starts_bundle = ' ';
2295   _regalloc->dump_frame();
2296 
2297   Node *n = NULL;
2298   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2299     if (VMThread::should_terminate()) {
2300       cut_short = true;
2301       break;
2302     }
2303     Block* block = _cfg->get_block(i);
2304     if (block->is_connector() && !Verbose) {
2305       continue;
2306     }
2307     n = block->head();
2308     if (pcs && n->_idx < pc_limit) {
2309       tty->print("%3.3x   ", pcs[n->_idx]);
2310     } else {
2311       tty->print("      ");
2312     }
2313     block->dump_head(_cfg);
2314     if (block->is_connector()) {
2315       tty->print_cr("        # Empty connector block");
2316     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2317       tty->print_cr("        # Block is sole successor of call");
2318     }
2319 
2320     // For all instructions
2321     Node *delay = NULL;
2322     for (uint j = 0; j < block->number_of_nodes(); j++) {
2323       if (VMThread::should_terminate()) {
2324         cut_short = true;
2325         break;
2326       }
2327       n = block->get_node(j);
2328       if (valid_bundle_info(n)) {
2329         Bundle* bundle = node_bundling(n);
2330         if (bundle->used_in_unconditional_delay()) {
2331           delay = n;
2332           continue;
2333         }
2334         if (bundle->starts_bundle()) {
2335           starts_bundle = '+';
2336         }
2337       }
2338 
2339       if (WizardMode) {
2340         n->dump();
2341       }
2342 
2343       if( !n->is_Region() &&    // Dont print in the Assembly
2344           !n->is_Phi() &&       // a few noisely useless nodes
2345           !n->is_Proj() &&
2346           !n->is_MachTemp() &&
2347           !n->is_SafePointScalarObject() &&
2348           !n->is_Catch() &&     // Would be nice to print exception table targets
2349           !n->is_MergeMem() &&  // Not very interesting
2350           !n->is_top() &&       // Debug info table constants
2351           !(n->is_Con() && !n->is_Mach())// Debug info table constants
2352           ) {
2353         if (pcs && n->_idx < pc_limit)
2354           tty->print("%3.3x", pcs[n->_idx]);
2355         else
2356           tty->print("   ");
2357         tty->print(" %c ", starts_bundle);
2358         starts_bundle = ' ';
2359         tty->print("\t");
2360         n->format(_regalloc, tty);
2361         tty->cr();
2362       }
2363 
2364       // If we have an instruction with a delay slot, and have seen a delay,
2365       // then back up and print it
2366       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2367         assert(delay != NULL, "no unconditional delay instruction");
2368         if (WizardMode) delay->dump();
2369 
2370         if (node_bundling(delay)->starts_bundle())
2371           starts_bundle = '+';
2372         if (pcs && n->_idx < pc_limit)
2373           tty->print("%3.3x", pcs[n->_idx]);
2374         else
2375           tty->print("   ");
2376         tty->print(" %c ", starts_bundle);
2377         starts_bundle = ' ';
2378         tty->print("\t");
2379         delay->format(_regalloc, tty);
2380         tty->print_cr("");
2381         delay = NULL;
2382       }
2383 
2384       // Dump the exception table as well
2385       if( n->is_Catch() && (Verbose || WizardMode) ) {
2386         // Print the exception table for this offset
2387         _handler_table.print_subtable_for(pc);
2388       }
2389     }
2390 
2391     if (pcs && n->_idx < pc_limit)
2392       tty->print_cr("%3.3x", pcs[n->_idx]);
2393     else
2394       tty->print_cr("");
2395 
2396     assert(cut_short || delay == NULL, "no unconditional delay branch");
2397 
2398   } // End of per-block dump
2399   tty->print_cr("");
2400 
2401   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
2402 }
2403 #endif
2404 
2405 //------------------------------Final_Reshape_Counts---------------------------
2406 // This class defines counters to help identify when a method
2407 // may/must be executed using hardware with only 24-bit precision.
2408 struct Final_Reshape_Counts : public StackObj {
2409   int  _call_count;             // count non-inlined 'common' calls
2410   int  _float_count;            // count float ops requiring 24-bit precision
2411   int  _double_count;           // count double ops requiring more precision
2412   int  _java_call_count;        // count non-inlined 'java' calls
2413   int  _inner_loop_count;       // count loops which need alignment
2414   VectorSet _visited;           // Visitation flags
2415   Node_List _tests;             // Set of IfNodes & PCTableNodes
2416 
2417   Final_Reshape_Counts() :
2418     _call_count(0), _float_count(0), _double_count(0),
2419     _java_call_count(0), _inner_loop_count(0),
2420     _visited( Thread::current()->resource_area() ) { }
2421 
2422   void inc_call_count  () { _call_count  ++; }
2423   void inc_float_count () { _float_count ++; }
2424   void inc_double_count() { _double_count++; }
2425   void inc_java_call_count() { _java_call_count++; }
2426   void inc_inner_loop_count() { _inner_loop_count++; }
2427 
2428   int  get_call_count  () const { return _call_count  ; }
2429   int  get_float_count () const { return _float_count ; }
2430   int  get_double_count() const { return _double_count; }
2431   int  get_java_call_count() const { return _java_call_count; }
2432   int  get_inner_loop_count() const { return _inner_loop_count; }
2433 };
2434 
2435 #ifdef ASSERT
2436 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2437   ciInstanceKlass *k = tp->klass()->as_instance_klass();
2438   // Make sure the offset goes inside the instance layout.
2439   return k->contains_field_offset(tp->offset());
2440   // Note that OffsetBot and OffsetTop are very negative.
2441 }
2442 #endif
2443 
2444 // Eliminate trivially redundant StoreCMs and accumulate their
2445 // precedence edges.
2446 void Compile::eliminate_redundant_card_marks(Node* n) {
2447   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2448   if (n->in(MemNode::Address)->outcnt() > 1) {
2449     // There are multiple users of the same address so it might be
2450     // possible to eliminate some of the StoreCMs
2451     Node* mem = n->in(MemNode::Memory);
2452     Node* adr = n->in(MemNode::Address);
2453     Node* val = n->in(MemNode::ValueIn);
2454     Node* prev = n;
2455     bool done = false;
2456     // Walk the chain of StoreCMs eliminating ones that match.  As
2457     // long as it's a chain of single users then the optimization is
2458     // safe.  Eliminating partially redundant StoreCMs would require
2459     // cloning copies down the other paths.
2460     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2461       if (adr == mem->in(MemNode::Address) &&
2462           val == mem->in(MemNode::ValueIn)) {
2463         // redundant StoreCM
2464         if (mem->req() > MemNode::OopStore) {
2465           // Hasn't been processed by this code yet.
2466           n->add_prec(mem->in(MemNode::OopStore));
2467         } else {
2468           // Already converted to precedence edge
2469           for (uint i = mem->req(); i < mem->len(); i++) {
2470             // Accumulate any precedence edges
2471             if (mem->in(i) != NULL) {
2472               n->add_prec(mem->in(i));
2473             }
2474           }
2475           // Everything above this point has been processed.
2476           done = true;
2477         }
2478         // Eliminate the previous StoreCM
2479         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2480         assert(mem->outcnt() == 0, "should be dead");
2481         mem->disconnect_inputs(NULL, this);
2482       } else {
2483         prev = mem;
2484       }
2485       mem = prev->in(MemNode::Memory);
2486     }
2487   }
2488 }
2489 
2490 //------------------------------final_graph_reshaping_impl----------------------
2491 // Implement items 1-5 from final_graph_reshaping below.
2492 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2493 
2494   if ( n->outcnt() == 0 ) return; // dead node
2495   uint nop = n->Opcode();
2496 
2497   // Check for 2-input instruction with "last use" on right input.
2498   // Swap to left input.  Implements item (2).
2499   if( n->req() == 3 &&          // two-input instruction
2500       n->in(1)->outcnt() > 1 && // left use is NOT a last use
2501       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2502       n->in(2)->outcnt() == 1 &&// right use IS a last use
2503       !n->in(2)->is_Con() ) {   // right use is not a constant
2504     // Check for commutative opcode
2505     switch( nop ) {
2506     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
2507     case Op_MaxI:  case Op_MinI:
2508     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
2509     case Op_AndL:  case Op_XorL:  case Op_OrL:
2510     case Op_AndI:  case Op_XorI:  case Op_OrI: {
2511       // Move "last use" input to left by swapping inputs
2512       n->swap_edges(1, 2);
2513       break;
2514     }
2515     default:
2516       break;
2517     }
2518   }
2519 
2520 #ifdef ASSERT
2521   if( n->is_Mem() ) {
2522     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2523     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2524             // oop will be recorded in oop map if load crosses safepoint
2525             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2526                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
2527             "raw memory operations should have control edge");
2528   }
2529 #endif
2530   // Count FPU ops and common calls, implements item (3)
2531   switch( nop ) {
2532   // Count all float operations that may use FPU
2533   case Op_AddF:
2534   case Op_SubF:
2535   case Op_MulF:
2536   case Op_DivF:
2537   case Op_NegF:
2538   case Op_ModF:
2539   case Op_ConvI2F:
2540   case Op_ConF:
2541   case Op_CmpF:
2542   case Op_CmpF3:
2543   // case Op_ConvL2F: // longs are split into 32-bit halves
2544     frc.inc_float_count();
2545     break;
2546 
2547   case Op_ConvF2D:
2548   case Op_ConvD2F:
2549     frc.inc_float_count();
2550     frc.inc_double_count();
2551     break;
2552 
2553   // Count all double operations that may use FPU
2554   case Op_AddD:
2555   case Op_SubD:
2556   case Op_MulD:
2557   case Op_DivD:
2558   case Op_NegD:
2559   case Op_ModD:
2560   case Op_ConvI2D:
2561   case Op_ConvD2I:
2562   // case Op_ConvL2D: // handled by leaf call
2563   // case Op_ConvD2L: // handled by leaf call
2564   case Op_ConD:
2565   case Op_CmpD:
2566   case Op_CmpD3:
2567     frc.inc_double_count();
2568     break;
2569   case Op_Opaque1:              // Remove Opaque Nodes before matching
2570   case Op_Opaque2:              // Remove Opaque Nodes before matching
2571     n->subsume_by(n->in(1), this);
2572     break;
2573   case Op_CallStaticJava:
2574   case Op_CallJava:
2575   case Op_CallDynamicJava:
2576     frc.inc_java_call_count(); // Count java call site;
2577   case Op_CallRuntime:
2578   case Op_CallLeaf:
2579   case Op_CallLeafNoFP: {
2580     assert( n->is_Call(), "" );
2581     CallNode *call = n->as_Call();
2582     // Count call sites where the FP mode bit would have to be flipped.
2583     // Do not count uncommon runtime calls:
2584     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2585     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2586     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
2587       frc.inc_call_count();   // Count the call site
2588     } else {                  // See if uncommon argument is shared
2589       Node *n = call->in(TypeFunc::Parms);
2590       int nop = n->Opcode();
2591       // Clone shared simple arguments to uncommon calls, item (1).
2592       if( n->outcnt() > 1 &&
2593           !n->is_Proj() &&
2594           nop != Op_CreateEx &&
2595           nop != Op_CheckCastPP &&
2596           nop != Op_DecodeN &&
2597           nop != Op_DecodeNKlass &&
2598           !n->is_Mem() ) {
2599         Node *x = n->clone();
2600         call->set_req( TypeFunc::Parms, x );
2601       }
2602     }
2603     break;
2604   }
2605 
2606   case Op_StoreD:
2607   case Op_LoadD:
2608   case Op_LoadD_unaligned:
2609     frc.inc_double_count();
2610     goto handle_mem;
2611   case Op_StoreF:
2612   case Op_LoadF:
2613     frc.inc_float_count();
2614     goto handle_mem;
2615 
2616   case Op_StoreCM:
2617     {
2618       // Convert OopStore dependence into precedence edge
2619       Node* prec = n->in(MemNode::OopStore);
2620       n->del_req(MemNode::OopStore);
2621       n->add_prec(prec);
2622       eliminate_redundant_card_marks(n);
2623     }
2624 
2625     // fall through
2626 
2627   case Op_StoreB:
2628   case Op_StoreC:
2629   case Op_StorePConditional:
2630   case Op_StoreI:
2631   case Op_StoreL:
2632   case Op_StoreIConditional:
2633   case Op_StoreLConditional:
2634   case Op_CompareAndSwapI:
2635   case Op_CompareAndSwapL:
2636   case Op_CompareAndSwapP:
2637   case Op_CompareAndSwapN:
2638   case Op_GetAndAddI:
2639   case Op_GetAndAddL:
2640   case Op_GetAndSetI:
2641   case Op_GetAndSetL:
2642   case Op_GetAndSetP:
2643   case Op_GetAndSetN:
2644   case Op_StoreP:
2645   case Op_StoreN:
2646   case Op_StoreNKlass:
2647   case Op_LoadB:
2648   case Op_LoadUB:
2649   case Op_LoadUS:
2650   case Op_LoadI:
2651   case Op_LoadKlass:
2652   case Op_LoadNKlass:
2653   case Op_LoadL:
2654   case Op_LoadL_unaligned:
2655   case Op_LoadPLocked:
2656   case Op_LoadP:
2657   case Op_LoadN:
2658   case Op_LoadRange:
2659   case Op_LoadS: {
2660   handle_mem:
2661 #ifdef ASSERT
2662     if( VerifyOptoOopOffsets ) {
2663       assert( n->is_Mem(), "" );
2664       MemNode *mem  = (MemNode*)n;
2665       // Check to see if address types have grounded out somehow.
2666       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2667       assert( !tp || oop_offset_is_sane(tp), "" );
2668     }
2669 #endif
2670     break;
2671   }
2672 
2673   case Op_AddP: {               // Assert sane base pointers
2674     Node *addp = n->in(AddPNode::Address);
2675     assert( !addp->is_AddP() ||
2676             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2677             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2678             "Base pointers must match" );
2679 #ifdef _LP64
2680     if ((UseCompressedOops || UseCompressedClassPointers) &&
2681         addp->Opcode() == Op_ConP &&
2682         addp == n->in(AddPNode::Base) &&
2683         n->in(AddPNode::Offset)->is_Con()) {
2684       // Use addressing with narrow klass to load with offset on x86.
2685       // On sparc loading 32-bits constant and decoding it have less
2686       // instructions (4) then load 64-bits constant (7).
2687       // Do this transformation here since IGVN will convert ConN back to ConP.
2688       const Type* t = addp->bottom_type();
2689       if (t->isa_oopptr() || t->isa_klassptr()) {
2690         Node* nn = NULL;
2691 
2692         int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
2693 
2694         // Look for existing ConN node of the same exact type.
2695         Node* r  = root();
2696         uint cnt = r->outcnt();
2697         for (uint i = 0; i < cnt; i++) {
2698           Node* m = r->raw_out(i);
2699           if (m!= NULL && m->Opcode() == op &&
2700               m->bottom_type()->make_ptr() == t) {
2701             nn = m;
2702             break;
2703           }
2704         }
2705         if (nn != NULL) {
2706           // Decode a narrow oop to match address
2707           // [R12 + narrow_oop_reg<<3 + offset]
2708           if (t->isa_oopptr()) {
2709             nn = new (this) DecodeNNode(nn, t);
2710           } else {
2711             nn = new (this) DecodeNKlassNode(nn, t);
2712           }
2713           n->set_req(AddPNode::Base, nn);
2714           n->set_req(AddPNode::Address, nn);
2715           if (addp->outcnt() == 0) {
2716             addp->disconnect_inputs(NULL, this);
2717           }
2718         }
2719       }
2720     }
2721 #endif
2722     break;
2723   }
2724 
2725 #ifdef _LP64
2726   case Op_CastPP:
2727     if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
2728       Node* in1 = n->in(1);
2729       const Type* t = n->bottom_type();
2730       Node* new_in1 = in1->clone();
2731       new_in1->as_DecodeN()->set_type(t);
2732 
2733       if (!Matcher::narrow_oop_use_complex_address()) {
2734         //
2735         // x86, ARM and friends can handle 2 adds in addressing mode
2736         // and Matcher can fold a DecodeN node into address by using
2737         // a narrow oop directly and do implicit NULL check in address:
2738         //
2739         // [R12 + narrow_oop_reg<<3 + offset]
2740         // NullCheck narrow_oop_reg
2741         //
2742         // On other platforms (Sparc) we have to keep new DecodeN node and
2743         // use it to do implicit NULL check in address:
2744         //
2745         // decode_not_null narrow_oop_reg, base_reg
2746         // [base_reg + offset]
2747         // NullCheck base_reg
2748         //
2749         // Pin the new DecodeN node to non-null path on these platform (Sparc)
2750         // to keep the information to which NULL check the new DecodeN node
2751         // corresponds to use it as value in implicit_null_check().
2752         //
2753         new_in1->set_req(0, n->in(0));
2754       }
2755 
2756       n->subsume_by(new_in1, this);
2757       if (in1->outcnt() == 0) {
2758         in1->disconnect_inputs(NULL, this);
2759       }
2760     }
2761     break;
2762 
2763   case Op_CmpP:
2764     // Do this transformation here to preserve CmpPNode::sub() and
2765     // other TypePtr related Ideal optimizations (for example, ptr nullness).
2766     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
2767       Node* in1 = n->in(1);
2768       Node* in2 = n->in(2);
2769       if (!in1->is_DecodeNarrowPtr()) {
2770         in2 = in1;
2771         in1 = n->in(2);
2772       }
2773       assert(in1->is_DecodeNarrowPtr(), "sanity");
2774 
2775       Node* new_in2 = NULL;
2776       if (in2->is_DecodeNarrowPtr()) {
2777         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
2778         new_in2 = in2->in(1);
2779       } else if (in2->Opcode() == Op_ConP) {
2780         const Type* t = in2->bottom_type();
2781         if (t == TypePtr::NULL_PTR) {
2782           assert(in1->is_DecodeN(), "compare klass to null?");
2783           // Don't convert CmpP null check into CmpN if compressed
2784           // oops implicit null check is not generated.
2785           // This will allow to generate normal oop implicit null check.
2786           if (Matcher::gen_narrow_oop_implicit_null_checks())
2787             new_in2 = ConNode::make(this, TypeNarrowOop::NULL_PTR);
2788           //
2789           // This transformation together with CastPP transformation above
2790           // will generated code for implicit NULL checks for compressed oops.
2791           //
2792           // The original code after Optimize()
2793           //
2794           //    LoadN memory, narrow_oop_reg
2795           //    decode narrow_oop_reg, base_reg
2796           //    CmpP base_reg, NULL
2797           //    CastPP base_reg // NotNull
2798           //    Load [base_reg + offset], val_reg
2799           //
2800           // after these transformations will be
2801           //
2802           //    LoadN memory, narrow_oop_reg
2803           //    CmpN narrow_oop_reg, NULL
2804           //    decode_not_null narrow_oop_reg, base_reg
2805           //    Load [base_reg + offset], val_reg
2806           //
2807           // and the uncommon path (== NULL) will use narrow_oop_reg directly
2808           // since narrow oops can be used in debug info now (see the code in
2809           // final_graph_reshaping_walk()).
2810           //
2811           // At the end the code will be matched to
2812           // on x86:
2813           //
2814           //    Load_narrow_oop memory, narrow_oop_reg
2815           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
2816           //    NullCheck narrow_oop_reg
2817           //
2818           // and on sparc:
2819           //
2820           //    Load_narrow_oop memory, narrow_oop_reg
2821           //    decode_not_null narrow_oop_reg, base_reg
2822           //    Load [base_reg + offset], val_reg
2823           //    NullCheck base_reg
2824           //
2825         } else if (t->isa_oopptr()) {
2826           new_in2 = ConNode::make(this, t->make_narrowoop());
2827         } else if (t->isa_klassptr()) {
2828           new_in2 = ConNode::make(this, t->make_narrowklass());
2829         }
2830       }
2831       if (new_in2 != NULL) {
2832         Node* cmpN = new (this) CmpNNode(in1->in(1), new_in2);
2833         n->subsume_by(cmpN, this);
2834         if (in1->outcnt() == 0) {
2835           in1->disconnect_inputs(NULL, this);
2836         }
2837         if (in2->outcnt() == 0) {
2838           in2->disconnect_inputs(NULL, this);
2839         }
2840       }
2841     }
2842     break;
2843 
2844   case Op_DecodeN:
2845   case Op_DecodeNKlass:
2846     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
2847     // DecodeN could be pinned when it can't be fold into
2848     // an address expression, see the code for Op_CastPP above.
2849     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
2850     break;
2851 
2852   case Op_EncodeP:
2853   case Op_EncodePKlass: {
2854     Node* in1 = n->in(1);
2855     if (in1->is_DecodeNarrowPtr()) {
2856       n->subsume_by(in1->in(1), this);
2857     } else if (in1->Opcode() == Op_ConP) {
2858       const Type* t = in1->bottom_type();
2859       if (t == TypePtr::NULL_PTR) {
2860         assert(t->isa_oopptr(), "null klass?");
2861         n->subsume_by(ConNode::make(this, TypeNarrowOop::NULL_PTR), this);
2862       } else if (t->isa_oopptr()) {
2863         n->subsume_by(ConNode::make(this, t->make_narrowoop()), this);
2864       } else if (t->isa_klassptr()) {
2865         n->subsume_by(ConNode::make(this, t->make_narrowklass()), this);
2866       }
2867     }
2868     if (in1->outcnt() == 0) {
2869       in1->disconnect_inputs(NULL, this);
2870     }
2871     break;
2872   }
2873 
2874   case Op_Proj: {
2875     if (OptimizeStringConcat) {
2876       ProjNode* p = n->as_Proj();
2877       if (p->_is_io_use) {
2878         // Separate projections were used for the exception path which
2879         // are normally removed by a late inline.  If it wasn't inlined
2880         // then they will hang around and should just be replaced with
2881         // the original one.
2882         Node* proj = NULL;
2883         // Replace with just one
2884         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
2885           Node *use = i.get();
2886           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
2887             proj = use;
2888             break;
2889           }
2890         }
2891         assert(proj != NULL, "must be found");
2892         p->subsume_by(proj, this);
2893       }
2894     }
2895     break;
2896   }
2897 
2898   case Op_Phi:
2899     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
2900       // The EncodeP optimization may create Phi with the same edges
2901       // for all paths. It is not handled well by Register Allocator.
2902       Node* unique_in = n->in(1);
2903       assert(unique_in != NULL, "");
2904       uint cnt = n->req();
2905       for (uint i = 2; i < cnt; i++) {
2906         Node* m = n->in(i);
2907         assert(m != NULL, "");
2908         if (unique_in != m)
2909           unique_in = NULL;
2910       }
2911       if (unique_in != NULL) {
2912         n->subsume_by(unique_in, this);
2913       }
2914     }
2915     break;
2916 
2917 #endif
2918 
2919   case Op_ModI:
2920     if (UseDivMod) {
2921       // Check if a%b and a/b both exist
2922       Node* d = n->find_similar(Op_DivI);
2923       if (d) {
2924         // Replace them with a fused divmod if supported
2925         if (Matcher::has_match_rule(Op_DivModI)) {
2926           DivModINode* divmod = DivModINode::make(this, n);
2927           d->subsume_by(divmod->div_proj(), this);
2928           n->subsume_by(divmod->mod_proj(), this);
2929         } else {
2930           // replace a%b with a-((a/b)*b)
2931           Node* mult = new (this) MulINode(d, d->in(2));
2932           Node* sub  = new (this) SubINode(d->in(1), mult);
2933           n->subsume_by(sub, this);
2934         }
2935       }
2936     }
2937     break;
2938 
2939   case Op_ModL:
2940     if (UseDivMod) {
2941       // Check if a%b and a/b both exist
2942       Node* d = n->find_similar(Op_DivL);
2943       if (d) {
2944         // Replace them with a fused divmod if supported
2945         if (Matcher::has_match_rule(Op_DivModL)) {
2946           DivModLNode* divmod = DivModLNode::make(this, n);
2947           d->subsume_by(divmod->div_proj(), this);
2948           n->subsume_by(divmod->mod_proj(), this);
2949         } else {
2950           // replace a%b with a-((a/b)*b)
2951           Node* mult = new (this) MulLNode(d, d->in(2));
2952           Node* sub  = new (this) SubLNode(d->in(1), mult);
2953           n->subsume_by(sub, this);
2954         }
2955       }
2956     }
2957     break;
2958 
2959   case Op_LoadVector:
2960   case Op_StoreVector:
2961     break;
2962 
2963   case Op_PackB:
2964   case Op_PackS:
2965   case Op_PackI:
2966   case Op_PackF:
2967   case Op_PackL:
2968   case Op_PackD:
2969     if (n->req()-1 > 2) {
2970       // Replace many operand PackNodes with a binary tree for matching
2971       PackNode* p = (PackNode*) n;
2972       Node* btp = p->binary_tree_pack(this, 1, n->req());
2973       n->subsume_by(btp, this);
2974     }
2975     break;
2976   case Op_Loop:
2977   case Op_CountedLoop:
2978     if (n->as_Loop()->is_inner_loop()) {
2979       frc.inc_inner_loop_count();
2980     }
2981     break;
2982   case Op_LShiftI:
2983   case Op_RShiftI:
2984   case Op_URShiftI:
2985   case Op_LShiftL:
2986   case Op_RShiftL:
2987   case Op_URShiftL:
2988     if (Matcher::need_masked_shift_count) {
2989       // The cpu's shift instructions don't restrict the count to the
2990       // lower 5/6 bits. We need to do the masking ourselves.
2991       Node* in2 = n->in(2);
2992       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
2993       const TypeInt* t = in2->find_int_type();
2994       if (t != NULL && t->is_con()) {
2995         juint shift = t->get_con();
2996         if (shift > mask) { // Unsigned cmp
2997           n->set_req(2, ConNode::make(this, TypeInt::make(shift & mask)));
2998         }
2999       } else {
3000         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3001           Node* shift = new (this) AndINode(in2, ConNode::make(this, TypeInt::make(mask)));
3002           n->set_req(2, shift);
3003         }
3004       }
3005       if (in2->outcnt() == 0) { // Remove dead node
3006         in2->disconnect_inputs(NULL, this);
3007       }
3008     }
3009     break;
3010   case Op_MemBarStoreStore:
3011   case Op_MemBarRelease:
3012     // Break the link with AllocateNode: it is no longer useful and
3013     // confuses register allocation.
3014     if (n->req() > MemBarNode::Precedent) {
3015       n->set_req(MemBarNode::Precedent, top());
3016     }
3017     break;
3018     // Must set a control edge on all nodes that produce a FlagsProj
3019     // so they can't escape the block that consumes the flags.
3020     // Must also set the non throwing branch as the control
3021     // for all nodes that depends on the result. Unless the node
3022     // already have a control that isn't the control of the
3023     // flag producer
3024   case Op_FlagsProj:
3025     {
3026       MathExactNode* math = (MathExactNode*)  n->in(0);
3027       Node* ctrl = math->control_node();
3028       Node* non_throwing = math->non_throwing_branch();
3029       math->set_req(0, ctrl);
3030 
3031       Node* result = math->result_node();
3032       if (result != NULL) {
3033         for (DUIterator_Fast jmax, j = result->fast_outs(jmax); j < jmax; j++) {
3034           Node* out = result->fast_out(j);
3035           // Phi nodes shouldn't be moved. They would only match below if they
3036           // had the same control as the MathExactNode. The only time that
3037           // would happen is if the Phi is also an input to the MathExact
3038           //
3039           // Cmp nodes shouldn't have control set at all.
3040           if (out->is_Phi() ||
3041               out->is_Cmp()) {
3042             continue;
3043           }
3044 
3045           if (out->in(0) == NULL) {
3046             out->set_req(0, non_throwing);
3047           } else if (out->in(0) == ctrl) {
3048             out->set_req(0, non_throwing);
3049           }
3050         }
3051       }
3052     }
3053     break;
3054   default:
3055     assert( !n->is_Call(), "" );
3056     assert( !n->is_Mem(), "" );
3057     break;
3058   }
3059 
3060   // Collect CFG split points
3061   if (n->is_MultiBranch())
3062     frc._tests.push(n);
3063 }
3064 
3065 //------------------------------final_graph_reshaping_walk---------------------
3066 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3067 // requires that the walk visits a node's inputs before visiting the node.
3068 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3069   ResourceArea *area = Thread::current()->resource_area();
3070   Unique_Node_List sfpt(area);
3071 
3072   frc._visited.set(root->_idx); // first, mark node as visited
3073   uint cnt = root->req();
3074   Node *n = root;
3075   uint  i = 0;
3076   while (true) {
3077     if (i < cnt) {
3078       // Place all non-visited non-null inputs onto stack
3079       Node* m = n->in(i);
3080       ++i;
3081       if (m != NULL && !frc._visited.test_set(m->_idx)) {
3082         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL)
3083           sfpt.push(m);
3084         cnt = m->req();
3085         nstack.push(n, i); // put on stack parent and next input's index
3086         n = m;
3087         i = 0;
3088       }
3089     } else {
3090       // Now do post-visit work
3091       final_graph_reshaping_impl( n, frc );
3092       if (nstack.is_empty())
3093         break;             // finished
3094       n = nstack.node();   // Get node from stack
3095       cnt = n->req();
3096       i = nstack.index();
3097       nstack.pop();        // Shift to the next node on stack
3098     }
3099   }
3100 
3101   // Skip next transformation if compressed oops are not used.
3102   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3103       (!UseCompressedOops && !UseCompressedClassPointers))
3104     return;
3105 
3106   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3107   // It could be done for an uncommon traps or any safepoints/calls
3108   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3109   while (sfpt.size() > 0) {
3110     n = sfpt.pop();
3111     JVMState *jvms = n->as_SafePoint()->jvms();
3112     assert(jvms != NULL, "sanity");
3113     int start = jvms->debug_start();
3114     int end   = n->req();
3115     bool is_uncommon = (n->is_CallStaticJava() &&
3116                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3117     for (int j = start; j < end; j++) {
3118       Node* in = n->in(j);
3119       if (in->is_DecodeNarrowPtr()) {
3120         bool safe_to_skip = true;
3121         if (!is_uncommon ) {
3122           // Is it safe to skip?
3123           for (uint i = 0; i < in->outcnt(); i++) {
3124             Node* u = in->raw_out(i);
3125             if (!u->is_SafePoint() ||
3126                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
3127               safe_to_skip = false;
3128             }
3129           }
3130         }
3131         if (safe_to_skip) {
3132           n->set_req(j, in->in(1));
3133         }
3134         if (in->outcnt() == 0) {
3135           in->disconnect_inputs(NULL, this);
3136         }
3137       }
3138     }
3139   }
3140 }
3141 
3142 //------------------------------final_graph_reshaping--------------------------
3143 // Final Graph Reshaping.
3144 //
3145 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3146 //     and not commoned up and forced early.  Must come after regular
3147 //     optimizations to avoid GVN undoing the cloning.  Clone constant
3148 //     inputs to Loop Phis; these will be split by the allocator anyways.
3149 //     Remove Opaque nodes.
3150 // (2) Move last-uses by commutative operations to the left input to encourage
3151 //     Intel update-in-place two-address operations and better register usage
3152 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
3153 //     calls canonicalizing them back.
3154 // (3) Count the number of double-precision FP ops, single-precision FP ops
3155 //     and call sites.  On Intel, we can get correct rounding either by
3156 //     forcing singles to memory (requires extra stores and loads after each
3157 //     FP bytecode) or we can set a rounding mode bit (requires setting and
3158 //     clearing the mode bit around call sites).  The mode bit is only used
3159 //     if the relative frequency of single FP ops to calls is low enough.
3160 //     This is a key transform for SPEC mpeg_audio.
3161 // (4) Detect infinite loops; blobs of code reachable from above but not
3162 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
3163 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
3164 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
3165 //     Detection is by looking for IfNodes where only 1 projection is
3166 //     reachable from below or CatchNodes missing some targets.
3167 // (5) Assert for insane oop offsets in debug mode.
3168 
3169 bool Compile::final_graph_reshaping() {
3170   // an infinite loop may have been eliminated by the optimizer,
3171   // in which case the graph will be empty.
3172   if (root()->req() == 1) {
3173     record_method_not_compilable("trivial infinite loop");
3174     return true;
3175   }
3176 
3177   // Expensive nodes have their control input set to prevent the GVN
3178   // from freely commoning them. There's no GVN beyond this point so
3179   // no need to keep the control input. We want the expensive nodes to
3180   // be freely moved to the least frequent code path by gcm.
3181   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3182   for (int i = 0; i < expensive_count(); i++) {
3183     _expensive_nodes->at(i)->set_req(0, NULL);
3184   }
3185 
3186   Final_Reshape_Counts frc;
3187 
3188   // Visit everybody reachable!
3189   // Allocate stack of size C->unique()/2 to avoid frequent realloc
3190   Node_Stack nstack(unique() >> 1);
3191   final_graph_reshaping_walk(nstack, root(), frc);
3192 
3193   // Check for unreachable (from below) code (i.e., infinite loops).
3194   for( uint i = 0; i < frc._tests.size(); i++ ) {
3195     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3196     // Get number of CFG targets.
3197     // Note that PCTables include exception targets after calls.
3198     uint required_outcnt = n->required_outcnt();
3199     if (n->outcnt() != required_outcnt) {
3200       // Check for a few special cases.  Rethrow Nodes never take the
3201       // 'fall-thru' path, so expected kids is 1 less.
3202       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3203         if (n->in(0)->in(0)->is_Call()) {
3204           CallNode *call = n->in(0)->in(0)->as_Call();
3205           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3206             required_outcnt--;      // Rethrow always has 1 less kid
3207           } else if (call->req() > TypeFunc::Parms &&
3208                      call->is_CallDynamicJava()) {
3209             // Check for null receiver. In such case, the optimizer has
3210             // detected that the virtual call will always result in a null
3211             // pointer exception. The fall-through projection of this CatchNode
3212             // will not be populated.
3213             Node *arg0 = call->in(TypeFunc::Parms);
3214             if (arg0->is_Type() &&
3215                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3216               required_outcnt--;
3217             }
3218           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3219                      call->req() > TypeFunc::Parms+1 &&
3220                      call->is_CallStaticJava()) {
3221             // Check for negative array length. In such case, the optimizer has
3222             // detected that the allocation attempt will always result in an
3223             // exception. There is no fall-through projection of this CatchNode .
3224             Node *arg1 = call->in(TypeFunc::Parms+1);
3225             if (arg1->is_Type() &&
3226                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3227               required_outcnt--;
3228             }
3229           }
3230         }
3231       }
3232       // Recheck with a better notion of 'required_outcnt'
3233       if (n->outcnt() != required_outcnt) {
3234         record_method_not_compilable("malformed control flow");
3235         return true;            // Not all targets reachable!
3236       }
3237     }
3238     // Check that I actually visited all kids.  Unreached kids
3239     // must be infinite loops.
3240     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3241       if (!frc._visited.test(n->fast_out(j)->_idx)) {
3242         record_method_not_compilable("infinite loop");
3243         return true;            // Found unvisited kid; must be unreach
3244       }
3245   }
3246 
3247   // If original bytecodes contained a mixture of floats and doubles
3248   // check if the optimizer has made it homogenous, item (3).
3249   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3250       frc.get_float_count() > 32 &&
3251       frc.get_double_count() == 0 &&
3252       (10 * frc.get_call_count() < frc.get_float_count()) ) {
3253     set_24_bit_selection_and_mode( false,  true );
3254   }
3255 
3256   set_java_calls(frc.get_java_call_count());
3257   set_inner_loops(frc.get_inner_loop_count());
3258 
3259   // No infinite loops, no reason to bail out.
3260   return false;
3261 }
3262 
3263 //-----------------------------too_many_traps----------------------------------
3264 // Report if there are too many traps at the current method and bci.
3265 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3266 bool Compile::too_many_traps(ciMethod* method,
3267                              int bci,
3268                              Deoptimization::DeoptReason reason) {
3269   ciMethodData* md = method->method_data();
3270   if (md->is_empty()) {
3271     // Assume the trap has not occurred, or that it occurred only
3272     // because of a transient condition during start-up in the interpreter.
3273     return false;
3274   }
3275   if (md->has_trap_at(bci, reason) != 0) {
3276     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3277     // Also, if there are multiple reasons, or if there is no per-BCI record,
3278     // assume the worst.
3279     if (log())
3280       log()->elem("observe trap='%s' count='%d'",
3281                   Deoptimization::trap_reason_name(reason),
3282                   md->trap_count(reason));
3283     return true;
3284   } else {
3285     // Ignore method/bci and see if there have been too many globally.
3286     return too_many_traps(reason, md);
3287   }
3288 }
3289 
3290 // Less-accurate variant which does not require a method and bci.
3291 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3292                              ciMethodData* logmd) {
3293  if (trap_count(reason) >= (uint)PerMethodTrapLimit) {
3294     // Too many traps globally.
3295     // Note that we use cumulative trap_count, not just md->trap_count.
3296     if (log()) {
3297       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3298       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3299                   Deoptimization::trap_reason_name(reason),
3300                   mcount, trap_count(reason));
3301     }
3302     return true;
3303   } else {
3304     // The coast is clear.
3305     return false;
3306   }
3307 }
3308 
3309 //--------------------------too_many_recompiles--------------------------------
3310 // Report if there are too many recompiles at the current method and bci.
3311 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3312 // Is not eager to return true, since this will cause the compiler to use
3313 // Action_none for a trap point, to avoid too many recompilations.
3314 bool Compile::too_many_recompiles(ciMethod* method,
3315                                   int bci,
3316                                   Deoptimization::DeoptReason reason) {
3317   ciMethodData* md = method->method_data();
3318   if (md->is_empty()) {
3319     // Assume the trap has not occurred, or that it occurred only
3320     // because of a transient condition during start-up in the interpreter.
3321     return false;
3322   }
3323   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3324   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3325   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
3326   Deoptimization::DeoptReason per_bc_reason
3327     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3328   if ((per_bc_reason == Deoptimization::Reason_none
3329        || md->has_trap_at(bci, reason) != 0)
3330       // The trap frequency measure we care about is the recompile count:
3331       && md->trap_recompiled_at(bci)
3332       && md->overflow_recompile_count() >= bc_cutoff) {
3333     // Do not emit a trap here if it has already caused recompilations.
3334     // Also, if there are multiple reasons, or if there is no per-BCI record,
3335     // assume the worst.
3336     if (log())
3337       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3338                   Deoptimization::trap_reason_name(reason),
3339                   md->trap_count(reason),
3340                   md->overflow_recompile_count());
3341     return true;
3342   } else if (trap_count(reason) != 0
3343              && decompile_count() >= m_cutoff) {
3344     // Too many recompiles globally, and we have seen this sort of trap.
3345     // Use cumulative decompile_count, not just md->decompile_count.
3346     if (log())
3347       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3348                   Deoptimization::trap_reason_name(reason),
3349                   md->trap_count(reason), trap_count(reason),
3350                   md->decompile_count(), decompile_count());
3351     return true;
3352   } else {
3353     // The coast is clear.
3354     return false;
3355   }
3356 }
3357 
3358 
3359 #ifndef PRODUCT
3360 //------------------------------verify_graph_edges---------------------------
3361 // Walk the Graph and verify that there is a one-to-one correspondence
3362 // between Use-Def edges and Def-Use edges in the graph.
3363 void Compile::verify_graph_edges(bool no_dead_code) {
3364   if (VerifyGraphEdges) {
3365     ResourceArea *area = Thread::current()->resource_area();
3366     Unique_Node_List visited(area);
3367     // Call recursive graph walk to check edges
3368     _root->verify_edges(visited);
3369     if (no_dead_code) {
3370       // Now make sure that no visited node is used by an unvisited node.
3371       bool dead_nodes = 0;
3372       Unique_Node_List checked(area);
3373       while (visited.size() > 0) {
3374         Node* n = visited.pop();
3375         checked.push(n);
3376         for (uint i = 0; i < n->outcnt(); i++) {
3377           Node* use = n->raw_out(i);
3378           if (checked.member(use))  continue;  // already checked
3379           if (visited.member(use))  continue;  // already in the graph
3380           if (use->is_Con())        continue;  // a dead ConNode is OK
3381           // At this point, we have found a dead node which is DU-reachable.
3382           if (dead_nodes++ == 0)
3383             tty->print_cr("*** Dead nodes reachable via DU edges:");
3384           use->dump(2);
3385           tty->print_cr("---");
3386           checked.push(use);  // No repeats; pretend it is now checked.
3387         }
3388       }
3389       assert(dead_nodes == 0, "using nodes must be reachable from root");
3390     }
3391   }
3392 }
3393 
3394 // Verify GC barriers consistency
3395 // Currently supported:
3396 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
3397 void Compile::verify_barriers() {
3398   if (UseG1GC) {
3399     // Verify G1 pre-barriers
3400     const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
3401 
3402     ResourceArea *area = Thread::current()->resource_area();
3403     Unique_Node_List visited(area);
3404     Node_List worklist(area);
3405     // We're going to walk control flow backwards starting from the Root
3406     worklist.push(_root);
3407     while (worklist.size() > 0) {
3408       Node* x = worklist.pop();
3409       if (x == NULL || x == top()) continue;
3410       if (visited.member(x)) {
3411         continue;
3412       } else {
3413         visited.push(x);
3414       }
3415 
3416       if (x->is_Region()) {
3417         for (uint i = 1; i < x->req(); i++) {
3418           worklist.push(x->in(i));
3419         }
3420       } else {
3421         worklist.push(x->in(0));
3422         // We are looking for the pattern:
3423         //                            /->ThreadLocal
3424         // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
3425         //              \->ConI(0)
3426         // We want to verify that the If and the LoadB have the same control
3427         // See GraphKit::g1_write_barrier_pre()
3428         if (x->is_If()) {
3429           IfNode *iff = x->as_If();
3430           if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
3431             CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
3432             if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
3433                 && cmp->in(1)->is_Load()) {
3434               LoadNode* load = cmp->in(1)->as_Load();
3435               if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
3436                   && load->in(2)->in(3)->is_Con()
3437                   && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
3438 
3439                 Node* if_ctrl = iff->in(0);
3440                 Node* load_ctrl = load->in(0);
3441 
3442                 if (if_ctrl != load_ctrl) {
3443                   // Skip possible CProj->NeverBranch in infinite loops
3444                   if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
3445                       && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
3446                     if_ctrl = if_ctrl->in(0)->in(0);
3447                   }
3448                 }
3449                 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
3450               }
3451             }
3452           }
3453         }
3454       }
3455     }
3456   }
3457 }
3458 
3459 #endif
3460 
3461 // The Compile object keeps track of failure reasons separately from the ciEnv.
3462 // This is required because there is not quite a 1-1 relation between the
3463 // ciEnv and its compilation task and the Compile object.  Note that one
3464 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3465 // to backtrack and retry without subsuming loads.  Other than this backtracking
3466 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3467 // by the logic in C2Compiler.
3468 void Compile::record_failure(const char* reason) {
3469   if (log() != NULL) {
3470     log()->elem("failure reason='%s' phase='compile'", reason);
3471   }
3472   if (_failure_reason == NULL) {
3473     // Record the first failure reason.
3474     _failure_reason = reason;
3475   }
3476 
3477   EventCompilerFailure event;
3478   if (event.should_commit()) {
3479     event.set_compileID(Compile::compile_id());
3480     event.set_failure(reason);
3481     event.commit();
3482   }
3483 
3484   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3485     C->print_method(PHASE_FAILURE);
3486   }
3487   _root = NULL;  // flush the graph, too
3488 }
3489 
3490 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
3491   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false),
3492     _phase_name(name), _dolog(dolog)
3493 {
3494   if (dolog) {
3495     C = Compile::current();
3496     _log = C->log();
3497   } else {
3498     C = NULL;
3499     _log = NULL;
3500   }
3501   if (_log != NULL) {
3502     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3503     _log->stamp();
3504     _log->end_head();
3505   }
3506 }
3507 
3508 Compile::TracePhase::~TracePhase() {
3509 
3510   C = Compile::current();
3511   if (_dolog) {
3512     _log = C->log();
3513   } else {
3514     _log = NULL;
3515   }
3516 
3517 #ifdef ASSERT
3518   if (PrintIdealNodeCount) {
3519     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3520                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3521   }
3522 
3523   if (VerifyIdealNodeCount) {
3524     Compile::current()->print_missing_nodes();
3525   }
3526 #endif
3527 
3528   if (_log != NULL) {
3529     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3530   }
3531 }
3532 
3533 //=============================================================================
3534 // Two Constant's are equal when the type and the value are equal.
3535 bool Compile::Constant::operator==(const Constant& other) {
3536   if (type()          != other.type()         )  return false;
3537   if (can_be_reused() != other.can_be_reused())  return false;
3538   // For floating point values we compare the bit pattern.
3539   switch (type()) {
3540   case T_FLOAT:   return (_v._value.i == other._v._value.i);
3541   case T_LONG:
3542   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
3543   case T_OBJECT:
3544   case T_ADDRESS: return (_v._value.l == other._v._value.l);
3545   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
3546   case T_METADATA: return (_v._metadata == other._v._metadata);
3547   default: ShouldNotReachHere();
3548   }
3549   return false;
3550 }
3551 
3552 static int type_to_size_in_bytes(BasicType t) {
3553   switch (t) {
3554   case T_LONG:    return sizeof(jlong  );
3555   case T_FLOAT:   return sizeof(jfloat );
3556   case T_DOUBLE:  return sizeof(jdouble);
3557   case T_METADATA: return sizeof(Metadata*);
3558     // We use T_VOID as marker for jump-table entries (labels) which
3559     // need an internal word relocation.
3560   case T_VOID:
3561   case T_ADDRESS:
3562   case T_OBJECT:  return sizeof(jobject);
3563   }
3564 
3565   ShouldNotReachHere();
3566   return -1;
3567 }
3568 
3569 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3570   // sort descending
3571   if (a->freq() > b->freq())  return -1;
3572   if (a->freq() < b->freq())  return  1;
3573   return 0;
3574 }
3575 
3576 void Compile::ConstantTable::calculate_offsets_and_size() {
3577   // First, sort the array by frequencies.
3578   _constants.sort(qsort_comparator);
3579 
3580 #ifdef ASSERT
3581   // Make sure all jump-table entries were sorted to the end of the
3582   // array (they have a negative frequency).
3583   bool found_void = false;
3584   for (int i = 0; i < _constants.length(); i++) {
3585     Constant con = _constants.at(i);
3586     if (con.type() == T_VOID)
3587       found_void = true;  // jump-tables
3588     else
3589       assert(!found_void, "wrong sorting");
3590   }
3591 #endif
3592 
3593   int offset = 0;
3594   for (int i = 0; i < _constants.length(); i++) {
3595     Constant* con = _constants.adr_at(i);
3596 
3597     // Align offset for type.
3598     int typesize = type_to_size_in_bytes(con->type());
3599     offset = align_size_up(offset, typesize);
3600     con->set_offset(offset);   // set constant's offset
3601 
3602     if (con->type() == T_VOID) {
3603       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
3604       offset = offset + typesize * n->outcnt();  // expand jump-table
3605     } else {
3606       offset = offset + typesize;
3607     }
3608   }
3609 
3610   // Align size up to the next section start (which is insts; see
3611   // CodeBuffer::align_at_start).
3612   assert(_size == -1, "already set?");
3613   _size = align_size_up(offset, CodeEntryAlignment);
3614 }
3615 
3616 void Compile::ConstantTable::emit(CodeBuffer& cb) {
3617   MacroAssembler _masm(&cb);
3618   for (int i = 0; i < _constants.length(); i++) {
3619     Constant con = _constants.at(i);
3620     address constant_addr;
3621     switch (con.type()) {
3622     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
3623     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
3624     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
3625     case T_OBJECT: {
3626       jobject obj = con.get_jobject();
3627       int oop_index = _masm.oop_recorder()->find_index(obj);
3628       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
3629       break;
3630     }
3631     case T_ADDRESS: {
3632       address addr = (address) con.get_jobject();
3633       constant_addr = _masm.address_constant(addr);
3634       break;
3635     }
3636     // We use T_VOID as marker for jump-table entries (labels) which
3637     // need an internal word relocation.
3638     case T_VOID: {
3639       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
3640       // Fill the jump-table with a dummy word.  The real value is
3641       // filled in later in fill_jump_table.
3642       address dummy = (address) n;
3643       constant_addr = _masm.address_constant(dummy);
3644       // Expand jump-table
3645       for (uint i = 1; i < n->outcnt(); i++) {
3646         address temp_addr = _masm.address_constant(dummy + i);
3647         assert(temp_addr, "consts section too small");
3648       }
3649       break;
3650     }
3651     case T_METADATA: {
3652       Metadata* obj = con.get_metadata();
3653       int metadata_index = _masm.oop_recorder()->find_index(obj);
3654       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
3655       break;
3656     }
3657     default: ShouldNotReachHere();
3658     }
3659     assert(constant_addr, "consts section too small");
3660     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(), err_msg_res("must be: %d == %d", constant_addr - _masm.code()->consts()->start(), con.offset()));
3661   }
3662 }
3663 
3664 int Compile::ConstantTable::find_offset(Constant& con) const {
3665   int idx = _constants.find(con);
3666   assert(idx != -1, "constant must be in constant table");
3667   int offset = _constants.at(idx).offset();
3668   assert(offset != -1, "constant table not emitted yet?");
3669   return offset;
3670 }
3671 
3672 void Compile::ConstantTable::add(Constant& con) {
3673   if (con.can_be_reused()) {
3674     int idx = _constants.find(con);
3675     if (idx != -1 && _constants.at(idx).can_be_reused()) {
3676       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
3677       return;
3678     }
3679   }
3680   (void) _constants.append(con);
3681 }
3682 
3683 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
3684   Block* b = Compile::current()->cfg()->get_block_for_node(n);
3685   Constant con(type, value, b->_freq);
3686   add(con);
3687   return con;
3688 }
3689 
3690 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
3691   Constant con(metadata);
3692   add(con);
3693   return con;
3694 }
3695 
3696 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
3697   jvalue value;
3698   BasicType type = oper->type()->basic_type();
3699   switch (type) {
3700   case T_LONG:    value.j = oper->constantL(); break;
3701   case T_FLOAT:   value.f = oper->constantF(); break;
3702   case T_DOUBLE:  value.d = oper->constantD(); break;
3703   case T_OBJECT:
3704   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
3705   case T_METADATA: return add((Metadata*)oper->constant()); break;
3706   default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
3707   }
3708   return add(n, type, value);
3709 }
3710 
3711 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
3712   jvalue value;
3713   // We can use the node pointer here to identify the right jump-table
3714   // as this method is called from Compile::Fill_buffer right before
3715   // the MachNodes are emitted and the jump-table is filled (means the
3716   // MachNode pointers do not change anymore).
3717   value.l = (jobject) n;
3718   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
3719   add(con);
3720   return con;
3721 }
3722 
3723 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
3724   // If called from Compile::scratch_emit_size do nothing.
3725   if (Compile::current()->in_scratch_emit_size())  return;
3726 
3727   assert(labels.is_nonempty(), "must be");
3728   assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
3729 
3730   // Since MachConstantNode::constant_offset() also contains
3731   // table_base_offset() we need to subtract the table_base_offset()
3732   // to get the plain offset into the constant table.
3733   int offset = n->constant_offset() - table_base_offset();
3734 
3735   MacroAssembler _masm(&cb);
3736   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
3737 
3738   for (uint i = 0; i < n->outcnt(); i++) {
3739     address* constant_addr = &jump_table_base[i];
3740     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)));
3741     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
3742     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
3743   }
3744 }
3745 
3746 void Compile::dump_inlining() {
3747   if (print_inlining() || print_intrinsics()) {
3748     // Print inlining message for candidates that we couldn't inline
3749     // for lack of space or non constant receiver
3750     for (int i = 0; i < _late_inlines.length(); i++) {
3751       CallGenerator* cg = _late_inlines.at(i);
3752       cg->print_inlining_late("live nodes > LiveNodeCountInliningCutoff");
3753     }
3754     Unique_Node_List useful;
3755     useful.push(root());
3756     for (uint next = 0; next < useful.size(); ++next) {
3757       Node* n  = useful.at(next);
3758       if (n->is_Call() && n->as_Call()->generator() != NULL && n->as_Call()->generator()->call_node() == n) {
3759         CallNode* call = n->as_Call();
3760         CallGenerator* cg = call->generator();
3761         cg->print_inlining_late("receiver not constant");
3762       }
3763       uint max = n->len();
3764       for ( uint i = 0; i < max; ++i ) {
3765         Node *m = n->in(i);
3766         if ( m == NULL ) continue;
3767         useful.push(m);
3768       }
3769     }
3770     for (int i = 0; i < _print_inlining_list->length(); i++) {
3771       tty->print(_print_inlining_list->adr_at(i)->ss()->as_string());
3772     }
3773   }
3774 }
3775 
3776 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
3777   if (n1->Opcode() < n2->Opcode())      return -1;
3778   else if (n1->Opcode() > n2->Opcode()) return 1;
3779 
3780   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()));
3781   for (uint i = 1; i < n1->req(); i++) {
3782     if (n1->in(i) < n2->in(i))      return -1;
3783     else if (n1->in(i) > n2->in(i)) return 1;
3784   }
3785 
3786   return 0;
3787 }
3788 
3789 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
3790   Node* n1 = *n1p;
3791   Node* n2 = *n2p;
3792 
3793   return cmp_expensive_nodes(n1, n2);
3794 }
3795 
3796 void Compile::sort_expensive_nodes() {
3797   if (!expensive_nodes_sorted()) {
3798     _expensive_nodes->sort(cmp_expensive_nodes);
3799   }
3800 }
3801 
3802 bool Compile::expensive_nodes_sorted() const {
3803   for (int i = 1; i < _expensive_nodes->length(); i++) {
3804     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
3805       return false;
3806     }
3807   }
3808   return true;
3809 }
3810 
3811 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
3812   if (_expensive_nodes->length() == 0) {
3813     return false;
3814   }
3815 
3816   assert(OptimizeExpensiveOps, "optimization off?");
3817 
3818   // Take this opportunity to remove dead nodes from the list
3819   int j = 0;
3820   for (int i = 0; i < _expensive_nodes->length(); i++) {
3821     Node* n = _expensive_nodes->at(i);
3822     if (!n->is_unreachable(igvn)) {
3823       assert(n->is_expensive(), "should be expensive");
3824       _expensive_nodes->at_put(j, n);
3825       j++;
3826     }
3827   }
3828   _expensive_nodes->trunc_to(j);
3829 
3830   // Then sort the list so that similar nodes are next to each other
3831   // and check for at least two nodes of identical kind with same data
3832   // inputs.
3833   sort_expensive_nodes();
3834 
3835   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
3836     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
3837       return true;
3838     }
3839   }
3840 
3841   return false;
3842 }
3843 
3844 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
3845   if (_expensive_nodes->length() == 0) {
3846     return;
3847   }
3848 
3849   assert(OptimizeExpensiveOps, "optimization off?");
3850 
3851   // Sort to bring similar nodes next to each other and clear the
3852   // control input of nodes for which there's only a single copy.
3853   sort_expensive_nodes();
3854 
3855   int j = 0;
3856   int identical = 0;
3857   int i = 0;
3858   for (; i < _expensive_nodes->length()-1; i++) {
3859     assert(j <= i, "can't write beyond current index");
3860     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
3861       identical++;
3862       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
3863       continue;
3864     }
3865     if (identical > 0) {
3866       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
3867       identical = 0;
3868     } else {
3869       Node* n = _expensive_nodes->at(i);
3870       igvn.hash_delete(n);
3871       n->set_req(0, NULL);
3872       igvn.hash_insert(n);
3873     }
3874   }
3875   if (identical > 0) {
3876     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
3877   } else if (_expensive_nodes->length() >= 1) {
3878     Node* n = _expensive_nodes->at(i);
3879     igvn.hash_delete(n);
3880     n->set_req(0, NULL);
3881     igvn.hash_insert(n);
3882   }
3883   _expensive_nodes->trunc_to(j);
3884 }
3885 
3886 void Compile::add_expensive_node(Node * n) {
3887   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
3888   assert(n->is_expensive(), "expensive nodes with non-null control here only");
3889   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
3890   if (OptimizeExpensiveOps) {
3891     _expensive_nodes->append(n);
3892   } else {
3893     // Clear control input and let IGVN optimize expensive nodes if
3894     // OptimizeExpensiveOps is off.
3895     n->set_req(0, NULL);
3896   }
3897 }
3898 
3899 /**
3900  * Remove the speculative part of types and clean up the graph
3901  */
3902 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
3903   if (UseTypeSpeculation) {
3904     Unique_Node_List worklist;
3905     worklist.push(root());
3906     int modified = 0;
3907     // Go over all type nodes that carry a speculative type, drop the
3908     // speculative part of the type and enqueue the node for an igvn
3909     // which may optimize it out.
3910     for (uint next = 0; next < worklist.size(); ++next) {
3911       Node *n  = worklist.at(next);
3912       if (n->is_Type() && n->as_Type()->type()->isa_oopptr() != NULL &&
3913           n->as_Type()->type()->is_oopptr()->speculative() != NULL) {
3914         TypeNode* tn = n->as_Type();
3915         const TypeOopPtr* t = tn->type()->is_oopptr();
3916         bool in_hash = igvn.hash_delete(n);
3917         assert(in_hash, "node should be in igvn hash table");
3918         tn->set_type(t->remove_speculative());
3919         igvn.hash_insert(n);
3920         igvn._worklist.push(n); // give it a chance to go away
3921         modified++;
3922       }
3923       uint max = n->len();
3924       for( uint i = 0; i < max; ++i ) {
3925         Node *m = n->in(i);
3926         if (not_a_node(m))  continue;
3927         worklist.push(m);
3928       }
3929     }
3930     // Drop the speculative part of all types in the igvn's type table
3931     igvn.remove_speculative_types();
3932     if (modified > 0) {
3933       igvn.optimize();
3934     }
3935   }
3936 }
3937 
3938 // Auxiliary method to support randomized stressing/fuzzing.
3939 //
3940 // This method can be called the arbitrary number of times, with current count
3941 // as the argument. The logic allows selecting a single candidate from the
3942 // running list of candidates as follows:
3943 //    int count = 0;
3944 //    Cand* selected = null;
3945 //    while(cand = cand->next()) {
3946 //      if (randomized_select(++count)) {
3947 //        selected = cand;
3948 //      }
3949 //    }
3950 //
3951 // Including count equalizes the chances any candidate is "selected".
3952 // This is useful when we don't have the complete list of candidates to choose
3953 // from uniformly. In this case, we need to adjust the randomicity of the
3954 // selection, or else we will end up biasing the selection towards the latter
3955 // candidates.
3956 //
3957 // Quick back-envelope calculation shows that for the list of n candidates
3958 // the equal probability for the candidate to persist as "best" can be
3959 // achieved by replacing it with "next" k-th candidate with the probability
3960 // of 1/k. It can be easily shown that by the end of the run, the
3961 // probability for any candidate is converged to 1/n, thus giving the
3962 // uniform distribution among all the candidates.
3963 //
3964 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
3965 #define RANDOMIZED_DOMAIN_POW 29
3966 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
3967 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
3968 bool Compile::randomized_select(int count) {
3969   assert(count > 0, "only positive");
3970   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
3971 }
3972 
3973 // Don't change thread state and acquire any locks.
3974 void Compile::dump_inline_data(outputStream* out) {
3975   InlineTree* inl_tree = ilt();
3976   if (inl_tree != NULL) {
3977     out->print(" inline %d", inl_tree->count());
3978     inl_tree->dump_replay_data(out);
3979   }
3980 }
--- EOF ---