1 /*
   2  * Copyright (c) 1997, 2011, 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/assembler.hpp"
  27 #include "classfile/systemDictionary.hpp"
  28 #include "code/exceptionHandlerTable.hpp"
  29 #include "code/nmethod.hpp"
  30 #include "compiler/compileLog.hpp"
  31 #include "compiler/oopMap.hpp"
  32 #include "opto/addnode.hpp"
  33 #include "opto/block.hpp"
  34 #include "opto/c2compiler.hpp"
  35 #include "opto/callGenerator.hpp"
  36 #include "opto/callnode.hpp"
  37 #include "opto/cfgnode.hpp"
  38 #include "opto/chaitin.hpp"
  39 #include "opto/compile.hpp"
  40 #include "opto/connode.hpp"
  41 #include "opto/divnode.hpp"
  42 #include "opto/escape.hpp"
  43 #include "opto/idealGraphPrinter.hpp"
  44 #include "opto/loopnode.hpp"
  45 #include "opto/machnode.hpp"
  46 #include "opto/macro.hpp"
  47 #include "opto/matcher.hpp"
  48 #include "opto/memnode.hpp"
  49 #include "opto/mulnode.hpp"
  50 #include "opto/node.hpp"
  51 #include "opto/opcodes.hpp"
  52 #include "opto/output.hpp"
  53 #include "opto/parse.hpp"
  54 #include "opto/phaseX.hpp"
  55 #include "opto/rootnode.hpp"
  56 #include "opto/runtime.hpp"
  57 #include "opto/stringopts.hpp"
  58 #include "opto/type.hpp"
  59 #include "opto/vectornode.hpp"
  60 #include "runtime/arguments.hpp"
  61 #include "runtime/signature.hpp"
  62 #include "runtime/stubRoutines.hpp"
  63 #include "runtime/timer.hpp"
  64 #include "utilities/copy.hpp"
  65 #ifdef TARGET_ARCH_MODEL_x86_32
  66 # include "adfiles/ad_x86_32.hpp"
  67 #endif
  68 #ifdef TARGET_ARCH_MODEL_x86_64
  69 # include "adfiles/ad_x86_64.hpp"
  70 #endif
  71 #ifdef TARGET_ARCH_MODEL_sparc
  72 # include "adfiles/ad_sparc.hpp"
  73 #endif
  74 #ifdef TARGET_ARCH_MODEL_zero
  75 # include "adfiles/ad_zero.hpp"
  76 #endif
  77 #ifdef TARGET_ARCH_MODEL_arm
  78 # include "adfiles/ad_arm.hpp"
  79 #endif
  80 #ifdef TARGET_ARCH_MODEL_ppc
  81 # include "adfiles/ad_ppc.hpp"
  82 #endif
  83 
  84 
  85 // -------------------- Compile::mach_constant_base_node -----------------------
  86 // Constant table base node singleton.
  87 MachConstantBaseNode* Compile::mach_constant_base_node() {
  88   if (_mach_constant_base_node == NULL) {
  89     _mach_constant_base_node = new (C) MachConstantBaseNode();
  90     _mach_constant_base_node->add_req(C->root());
  91   }
  92   return _mach_constant_base_node;
  93 }
  94 
  95 
  96 /// Support for intrinsics.
  97 
  98 // Return the index at which m must be inserted (or already exists).
  99 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
 100 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
 101 #ifdef ASSERT
 102   for (int i = 1; i < _intrinsics->length(); i++) {
 103     CallGenerator* cg1 = _intrinsics->at(i-1);
 104     CallGenerator* cg2 = _intrinsics->at(i);
 105     assert(cg1->method() != cg2->method()
 106            ? cg1->method()     < cg2->method()
 107            : cg1->is_virtual() < cg2->is_virtual(),
 108            "compiler intrinsics list must stay sorted");
 109   }
 110 #endif
 111   // Binary search sorted list, in decreasing intervals [lo, hi].
 112   int lo = 0, hi = _intrinsics->length()-1;
 113   while (lo <= hi) {
 114     int mid = (uint)(hi + lo) / 2;
 115     ciMethod* mid_m = _intrinsics->at(mid)->method();
 116     if (m < mid_m) {
 117       hi = mid-1;
 118     } else if (m > mid_m) {
 119       lo = mid+1;
 120     } else {
 121       // look at minor sort key
 122       bool mid_virt = _intrinsics->at(mid)->is_virtual();
 123       if (is_virtual < mid_virt) {
 124         hi = mid-1;
 125       } else if (is_virtual > mid_virt) {
 126         lo = mid+1;
 127       } else {
 128         return mid;  // exact match
 129       }
 130     }
 131   }
 132   return lo;  // inexact match
 133 }
 134 
 135 void Compile::register_intrinsic(CallGenerator* cg) {
 136   if (_intrinsics == NULL) {
 137     _intrinsics = new GrowableArray<CallGenerator*>(60);
 138   }
 139   // This code is stolen from ciObjectFactory::insert.
 140   // Really, GrowableArray should have methods for
 141   // insert_at, remove_at, and binary_search.
 142   int len = _intrinsics->length();
 143   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
 144   if (index == len) {
 145     _intrinsics->append(cg);
 146   } else {
 147 #ifdef ASSERT
 148     CallGenerator* oldcg = _intrinsics->at(index);
 149     assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
 150 #endif
 151     _intrinsics->append(_intrinsics->at(len-1));
 152     int pos;
 153     for (pos = len-2; pos >= index; pos--) {
 154       _intrinsics->at_put(pos+1,_intrinsics->at(pos));
 155     }
 156     _intrinsics->at_put(index, cg);
 157   }
 158   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 159 }
 160 
 161 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 162   assert(m->is_loaded(), "don't try this on unloaded methods");
 163   if (_intrinsics != NULL) {
 164     int index = intrinsic_insertion_index(m, is_virtual);
 165     if (index < _intrinsics->length()
 166         && _intrinsics->at(index)->method() == m
 167         && _intrinsics->at(index)->is_virtual() == is_virtual) {
 168       return _intrinsics->at(index);
 169     }
 170   }
 171   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 172   if (m->intrinsic_id() != vmIntrinsics::_none &&
 173       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 174     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 175     if (cg != NULL) {
 176       // Save it for next time:
 177       register_intrinsic(cg);
 178       return cg;
 179     } else {
 180       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 181     }
 182   }
 183   return NULL;
 184 }
 185 
 186 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
 187 // in library_call.cpp.
 188 
 189 
 190 #ifndef PRODUCT
 191 // statistics gathering...
 192 
 193 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
 194 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
 195 
 196 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 197   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 198   int oflags = _intrinsic_hist_flags[id];
 199   assert(flags != 0, "what happened?");
 200   if (is_virtual) {
 201     flags |= _intrinsic_virtual;
 202   }
 203   bool changed = (flags != oflags);
 204   if ((flags & _intrinsic_worked) != 0) {
 205     juint count = (_intrinsic_hist_count[id] += 1);
 206     if (count == 1) {
 207       changed = true;           // first time
 208     }
 209     // increment the overall count also:
 210     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
 211   }
 212   if (changed) {
 213     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 214       // Something changed about the intrinsic's virtuality.
 215       if ((flags & _intrinsic_virtual) != 0) {
 216         // This is the first use of this intrinsic as a virtual call.
 217         if (oflags != 0) {
 218           // We already saw it as a non-virtual, so note both cases.
 219           flags |= _intrinsic_both;
 220         }
 221       } else if ((oflags & _intrinsic_both) == 0) {
 222         // This is the first use of this intrinsic as a non-virtual
 223         flags |= _intrinsic_both;
 224       }
 225     }
 226     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
 227   }
 228   // update the overall flags also:
 229   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
 230   return changed;
 231 }
 232 
 233 static char* format_flags(int flags, char* buf) {
 234   buf[0] = 0;
 235   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 236   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 237   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 238   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 239   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 240   if (buf[0] == 0)  strcat(buf, ",");
 241   assert(buf[0] == ',', "must be");
 242   return &buf[1];
 243 }
 244 
 245 void Compile::print_intrinsic_statistics() {
 246   char flagsbuf[100];
 247   ttyLocker ttyl;
 248   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
 249   tty->print_cr("Compiler intrinsic usage:");
 250   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
 251   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 252   #define PRINT_STAT_LINE(name, c, f) \
 253     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 254   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
 255     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
 256     int   flags = _intrinsic_hist_flags[id];
 257     juint count = _intrinsic_hist_count[id];
 258     if ((flags | count) != 0) {
 259       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 260     }
 261   }
 262   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
 263   if (xtty != NULL)  xtty->tail("statistics");
 264 }
 265 
 266 void Compile::print_statistics() {
 267   { ttyLocker ttyl;
 268     if (xtty != NULL)  xtty->head("statistics type='opto'");
 269     Parse::print_statistics();
 270     PhaseCCP::print_statistics();
 271     PhaseRegAlloc::print_statistics();
 272     Scheduling::print_statistics();
 273     PhasePeephole::print_statistics();
 274     PhaseIdealLoop::print_statistics();
 275     if (xtty != NULL)  xtty->tail("statistics");
 276   }
 277   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
 278     // put this under its own <statistics> element.
 279     print_intrinsic_statistics();
 280   }
 281 }
 282 #endif //PRODUCT
 283 
 284 // Support for bundling info
 285 Bundle* Compile::node_bundling(const Node *n) {
 286   assert(valid_bundle_info(n), "oob");
 287   return &_node_bundling_base[n->_idx];
 288 }
 289 
 290 bool Compile::valid_bundle_info(const Node *n) {
 291   return (_node_bundling_limit > n->_idx);
 292 }
 293 
 294 
 295 void Compile::gvn_replace_by(Node* n, Node* nn) {
 296   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 297     Node* use = n->last_out(i);
 298     bool is_in_table = initial_gvn()->hash_delete(use);
 299     uint uses_found = 0;
 300     for (uint j = 0; j < use->len(); j++) {
 301       if (use->in(j) == n) {
 302         if (j < use->req())
 303           use->set_req(j, nn);
 304         else
 305           use->set_prec(j, nn);
 306         uses_found++;
 307       }
 308     }
 309     if (is_in_table) {
 310       // reinsert into table
 311       initial_gvn()->hash_find_insert(use);
 312     }
 313     record_for_igvn(use);
 314     i -= uses_found;    // we deleted 1 or more copies of this edge
 315   }
 316 }
 317 
 318 
 319 
 320 
 321 // Identify all nodes that are reachable from below, useful.
 322 // Use breadth-first pass that records state in a Unique_Node_List,
 323 // recursive traversal is slower.
 324 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 325   int estimated_worklist_size = unique();
 326   useful.map( estimated_worklist_size, NULL );  // preallocate space
 327 
 328   // Initialize worklist
 329   if (root() != NULL)     { useful.push(root()); }
 330   // If 'top' is cached, declare it useful to preserve cached node
 331   if( cached_top_node() ) { useful.push(cached_top_node()); }
 332 
 333   // Push all useful nodes onto the list, breadthfirst
 334   for( uint next = 0; next < useful.size(); ++next ) {
 335     assert( next < unique(), "Unique useful nodes < total nodes");
 336     Node *n  = useful.at(next);
 337     uint max = n->len();
 338     for( uint i = 0; i < max; ++i ) {
 339       Node *m = n->in(i);
 340       if( m == NULL ) continue;
 341       useful.push(m);
 342     }
 343   }
 344 }
 345 
 346 // Disconnect all useless nodes by disconnecting those at the boundary.
 347 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
 348   uint next = 0;
 349   while( next < useful.size() ) {
 350     Node *n = useful.at(next++);
 351     // Use raw traversal of out edges since this code removes out edges
 352     int max = n->outcnt();
 353     for (int j = 0; j < max; ++j ) {
 354       Node* child = n->raw_out(j);
 355       if( ! useful.member(child) ) {
 356         assert( !child->is_top() || child != top(),
 357                 "If top is cached in Compile object it is in useful list");
 358         // Only need to remove this out-edge to the useless node
 359         n->raw_del_out(j);
 360         --j;
 361         --max;
 362       }
 363     }
 364     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 365       record_for_igvn( n->unique_out() );
 366     }
 367   }
 368   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 369 }
 370 
 371 //------------------------------frame_size_in_words-----------------------------
 372 // frame_slots in units of words
 373 int Compile::frame_size_in_words() const {
 374   // shift is 0 in LP32 and 1 in LP64
 375   const int shift = (LogBytesPerWord - LogBytesPerInt);
 376   int words = _frame_slots >> shift;
 377   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
 378   return words;
 379 }
 380 
 381 // ============================================================================
 382 //------------------------------CompileWrapper---------------------------------
 383 class CompileWrapper : public StackObj {
 384   Compile *const _compile;
 385  public:
 386   CompileWrapper(Compile* compile);
 387 
 388   ~CompileWrapper();
 389 };
 390 
 391 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 392   // the Compile* pointer is stored in the current ciEnv:
 393   ciEnv* env = compile->env();
 394   assert(env == ciEnv::current(), "must already be a ciEnv active");
 395   assert(env->compiler_data() == NULL, "compile already active?");
 396   env->set_compiler_data(compile);
 397   assert(compile == Compile::current(), "sanity");
 398 
 399   compile->set_type_dict(NULL);
 400   compile->set_type_hwm(NULL);
 401   compile->set_type_last_size(0);
 402   compile->set_last_tf(NULL, NULL);
 403   compile->set_indexSet_arena(NULL);
 404   compile->set_indexSet_free_block_list(NULL);
 405   compile->init_type_arena();
 406   Type::Initialize(compile);
 407   _compile->set_scratch_buffer_blob(NULL);
 408   _compile->begin_method();
 409 }
 410 CompileWrapper::~CompileWrapper() {
 411   _compile->end_method();
 412   if (_compile->scratch_buffer_blob() != NULL)
 413     BufferBlob::free(_compile->scratch_buffer_blob());
 414   _compile->env()->set_compiler_data(NULL);
 415 }
 416 
 417 
 418 //----------------------------print_compile_messages---------------------------
 419 void Compile::print_compile_messages() {
 420 #ifndef PRODUCT
 421   // Check if recompiling
 422   if (_subsume_loads == false && PrintOpto) {
 423     // Recompiling without allowing machine instructions to subsume loads
 424     tty->print_cr("*********************************************************");
 425     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 426     tty->print_cr("*********************************************************");
 427   }
 428   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
 429     // Recompiling without escape analysis
 430     tty->print_cr("*********************************************************");
 431     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 432     tty->print_cr("*********************************************************");
 433   }
 434   if (env()->break_at_compile()) {
 435     // Open the debugger when compiling this method.
 436     tty->print("### Breaking when compiling: ");
 437     method()->print_short_name();
 438     tty->cr();
 439     BREAKPOINT;
 440   }
 441 
 442   if( PrintOpto ) {
 443     if (is_osr_compilation()) {
 444       tty->print("[OSR]%3d", _compile_id);
 445     } else {
 446       tty->print("%3d", _compile_id);
 447     }
 448   }
 449 #endif
 450 }
 451 
 452 
 453 //-----------------------init_scratch_buffer_blob------------------------------
 454 // Construct a temporary BufferBlob and cache it for this compile.
 455 void Compile::init_scratch_buffer_blob(int const_size) {
 456   // If there is already a scratch buffer blob allocated and the
 457   // constant section is big enough, use it.  Otherwise free the
 458   // current and allocate a new one.
 459   BufferBlob* blob = scratch_buffer_blob();
 460   if ((blob != NULL) && (const_size <= _scratch_const_size)) {
 461     // Use the current blob.
 462   } else {
 463     if (blob != NULL) {
 464       BufferBlob::free(blob);
 465     }
 466 
 467     ResourceMark rm;
 468     _scratch_const_size = const_size;
 469     int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
 470     blob = BufferBlob::create("Compile::scratch_buffer", size);
 471     // Record the buffer blob for next time.
 472     set_scratch_buffer_blob(blob);
 473     // Have we run out of code space?
 474     if (scratch_buffer_blob() == NULL) {
 475       // Let CompilerBroker disable further compilations.
 476       record_failure("Not enough space for scratch buffer in CodeCache");
 477       return;
 478     }
 479   }
 480 
 481   // Initialize the relocation buffers
 482   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
 483   set_scratch_locs_memory(locs_buf);
 484 }
 485 
 486 
 487 //-----------------------scratch_emit_size-------------------------------------
 488 // Helper function that computes size by emitting code
 489 uint Compile::scratch_emit_size(const Node* n) {
 490   // Start scratch_emit_size section.
 491   set_in_scratch_emit_size(true);
 492 
 493   // Emit into a trash buffer and count bytes emitted.
 494   // This is a pretty expensive way to compute a size,
 495   // but it works well enough if seldom used.
 496   // All common fixed-size instructions are given a size
 497   // method by the AD file.
 498   // Note that the scratch buffer blob and locs memory are
 499   // allocated at the beginning of the compile task, and
 500   // may be shared by several calls to scratch_emit_size.
 501   // The allocation of the scratch buffer blob is particularly
 502   // expensive, since it has to grab the code cache lock.
 503   BufferBlob* blob = this->scratch_buffer_blob();
 504   assert(blob != NULL, "Initialize BufferBlob at start");
 505   assert(blob->size() > MAX_inst_size, "sanity");
 506   relocInfo* locs_buf = scratch_locs_memory();
 507   address blob_begin = blob->content_begin();
 508   address blob_end   = (address)locs_buf;
 509   assert(blob->content_contains(blob_end), "sanity");
 510   CodeBuffer buf(blob_begin, blob_end - blob_begin);
 511   buf.initialize_consts_size(_scratch_const_size);
 512   buf.initialize_stubs_size(MAX_stubs_size);
 513   assert(locs_buf != NULL, "sanity");
 514   int lsize = MAX_locs_size / 3;
 515   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
 516   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
 517   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
 518 
 519   // Do the emission.
 520   n->emit(buf, this->regalloc());
 521 
 522   // End scratch_emit_size section.
 523   set_in_scratch_emit_size(false);
 524 
 525   return buf.insts_size();
 526 }
 527 
 528 
 529 // ============================================================================
 530 //------------------------------Compile standard-------------------------------
 531 debug_only( int Compile::_debug_idx = 100000; )
 532 
 533 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 534 // the continuation bci for on stack replacement.
 535 
 536 
 537 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci, bool subsume_loads, bool do_escape_analysis )
 538                 : Phase(Compiler),
 539                   _env(ci_env),
 540                   _log(ci_env->log()),
 541                   _compile_id(ci_env->compile_id()),
 542                   _save_argument_registers(false),
 543                   _stub_name(NULL),
 544                   _stub_function(NULL),
 545                   _stub_entry_point(NULL),
 546                   _method(target),
 547                   _entry_bci(osr_bci),
 548                   _initial_gvn(NULL),
 549                   _for_igvn(NULL),
 550                   _warm_calls(NULL),
 551                   _subsume_loads(subsume_loads),
 552                   _do_escape_analysis(do_escape_analysis),
 553                   _failure_reason(NULL),
 554                   _code_buffer("Compile::Fill_buffer"),
 555                   _orig_pc_slot(0),
 556                   _orig_pc_slot_offset_in_bytes(0),
 557                   _has_method_handle_invokes(false),
 558                   _mach_constant_base_node(NULL),
 559                   _node_bundling_limit(0),
 560                   _node_bundling_base(NULL),
 561                   _java_calls(0),
 562                   _inner_loops(0),
 563                   _scratch_const_size(-1),
 564                   _in_scratch_emit_size(false),
 565 #ifndef PRODUCT
 566                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
 567                   _printer(IdealGraphPrinter::printer()),
 568 #endif
 569                   _congraph(NULL) {
 570   C = this;
 571 
 572   CompileWrapper cw(this);
 573 #ifndef PRODUCT
 574   if (TimeCompiler2) {
 575     tty->print(" ");
 576     target->holder()->name()->print();
 577     tty->print(".");
 578     target->print_short_name();
 579     tty->print("  ");
 580   }
 581   TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
 582   TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
 583   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
 584   if (!print_opto_assembly) {
 585     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
 586     if (print_assembly && !Disassembler::can_decode()) {
 587       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
 588       print_opto_assembly = true;
 589     }
 590   }
 591   set_print_assembly(print_opto_assembly);
 592   set_parsed_irreducible_loop(false);
 593 #endif
 594 
 595   if (ProfileTraps) {
 596     // Make sure the method being compiled gets its own MDO,
 597     // so we can at least track the decompile_count().
 598     method()->ensure_method_data();
 599   }
 600 
 601   Init(::AliasLevel);
 602 
 603 
 604   print_compile_messages();
 605 
 606   if (UseOldInlining || PrintCompilation NOT_PRODUCT( || PrintOpto) )
 607     _ilt = InlineTree::build_inline_tree_root();
 608   else
 609     _ilt = NULL;
 610 
 611   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 612   assert(num_alias_types() >= AliasIdxRaw, "");
 613 
 614 #define MINIMUM_NODE_HASH  1023
 615   // Node list that Iterative GVN will start with
 616   Unique_Node_List for_igvn(comp_arena());
 617   set_for_igvn(&for_igvn);
 618 
 619   // GVN that will be run immediately on new nodes
 620   uint estimated_size = method()->code_size()*4+64;
 621   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 622   PhaseGVN gvn(node_arena(), estimated_size);
 623   set_initial_gvn(&gvn);
 624 
 625   { // Scope for timing the parser
 626     TracePhase t3("parse", &_t_parser, true);
 627 
 628     // Put top into the hash table ASAP.
 629     initial_gvn()->transform_no_reclaim(top());
 630 
 631     // Set up tf(), start(), and find a CallGenerator.
 632     CallGenerator* cg = NULL;
 633     if (is_osr_compilation()) {
 634       const TypeTuple *domain = StartOSRNode::osr_domain();
 635       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 636       init_tf(TypeFunc::make(domain, range));
 637       StartNode* s = new (this, 2) StartOSRNode(root(), domain);
 638       initial_gvn()->set_type_bottom(s);
 639       init_start(s);
 640       cg = CallGenerator::for_osr(method(), entry_bci());
 641     } else {
 642       // Normal case.
 643       init_tf(TypeFunc::make(method()));
 644       StartNode* s = new (this, 2) StartNode(root(), tf()->domain());
 645       initial_gvn()->set_type_bottom(s);
 646       init_start(s);
 647       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
 648         // With java.lang.ref.reference.get() we must go through the
 649         // intrinsic when G1 is enabled - even when get() is the root
 650         // method of the compile - so that, if necessary, the value in
 651         // the referent field of the reference object gets recorded by
 652         // the pre-barrier code.
 653         // Specifically, if G1 is enabled, the value in the referent
 654         // field is recorded by the G1 SATB pre barrier. This will
 655         // result in the referent being marked live and the reference
 656         // object removed from the list of discovered references during
 657         // reference processing.
 658         cg = find_intrinsic(method(), false);
 659       }
 660       if (cg == NULL) {
 661         float past_uses = method()->interpreter_invocation_count();
 662         float expected_uses = past_uses;
 663         cg = CallGenerator::for_inline(method(), expected_uses);
 664       }
 665     }
 666     if (failing())  return;
 667     if (cg == NULL) {
 668       record_method_not_compilable_all_tiers("cannot parse method");
 669       return;
 670     }
 671     JVMState* jvms = build_start_state(start(), tf());
 672     if ((jvms = cg->generate(jvms)) == NULL) {
 673       record_method_not_compilable("method parse failed");
 674       return;
 675     }
 676     GraphKit kit(jvms);
 677 
 678     if (!kit.stopped()) {
 679       // Accept return values, and transfer control we know not where.
 680       // This is done by a special, unique ReturnNode bound to root.
 681       return_values(kit.jvms());
 682     }
 683 
 684     if (kit.has_exceptions()) {
 685       // Any exceptions that escape from this call must be rethrown
 686       // to whatever caller is dynamically above us on the stack.
 687       // This is done by a special, unique RethrowNode bound to root.
 688       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 689     }
 690 
 691     if (!failing() && has_stringbuilder()) {
 692       {
 693         // remove useless nodes to make the usage analysis simpler
 694         ResourceMark rm;
 695         PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 696       }
 697 
 698       {
 699         ResourceMark rm;
 700         print_method("Before StringOpts", 3);
 701         PhaseStringOpts pso(initial_gvn(), &for_igvn);
 702         print_method("After StringOpts", 3);
 703       }
 704 
 705       // now inline anything that we skipped the first time around
 706       while (_late_inlines.length() > 0) {
 707         CallGenerator* cg = _late_inlines.pop();
 708         cg->do_late_inline();
 709       }
 710     }
 711     assert(_late_inlines.length() == 0, "should have been processed");
 712 
 713     print_method("Before RemoveUseless", 3);
 714 
 715     // Remove clutter produced by parsing.
 716     if (!failing()) {
 717       ResourceMark rm;
 718       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 719     }
 720   }
 721 
 722   // Note:  Large methods are capped off in do_one_bytecode().
 723   if (failing())  return;
 724 
 725   // After parsing, node notes are no longer automagic.
 726   // They must be propagated by register_new_node_with_optimizer(),
 727   // clone(), or the like.
 728   set_default_node_notes(NULL);
 729 
 730   for (;;) {
 731     int successes = Inline_Warm();
 732     if (failing())  return;
 733     if (successes == 0)  break;
 734   }
 735 
 736   // Drain the list.
 737   Finish_Warm();
 738 #ifndef PRODUCT
 739   if (_printer) {
 740     _printer->print_inlining(this);
 741   }
 742 #endif
 743 
 744   if (failing())  return;
 745   NOT_PRODUCT( verify_graph_edges(); )
 746 
 747   // Now optimize
 748   Optimize();
 749   if (failing())  return;
 750   NOT_PRODUCT( verify_graph_edges(); )
 751 
 752 #ifndef PRODUCT
 753   if (PrintIdeal) {
 754     ttyLocker ttyl;  // keep the following output all in one block
 755     // This output goes directly to the tty, not the compiler log.
 756     // To enable tools to match it up with the compilation activity,
 757     // be sure to tag this tty output with the compile ID.
 758     if (xtty != NULL) {
 759       xtty->head("ideal compile_id='%d'%s", compile_id(),
 760                  is_osr_compilation()    ? " compile_kind='osr'" :
 761                  "");
 762     }
 763     root()->dump(9999);
 764     if (xtty != NULL) {
 765       xtty->tail("ideal");
 766     }
 767   }
 768 #endif
 769 
 770   // Now that we know the size of all the monitors we can add a fixed slot
 771   // for the original deopt pc.
 772 
 773   _orig_pc_slot =  fixed_slots();
 774   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 775   set_fixed_slots(next_slot);
 776 
 777   // Now generate code
 778   Code_Gen();
 779   if (failing())  return;
 780 
 781   // Check if we want to skip execution of all compiled code.
 782   {
 783 #ifndef PRODUCT
 784     if (OptoNoExecute) {
 785       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 786       return;
 787     }
 788     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
 789 #endif
 790 
 791     if (is_osr_compilation()) {
 792       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 793       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 794     } else {
 795       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 796       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 797     }
 798 
 799     env()->register_method(_method, _entry_bci,
 800                            &_code_offsets,
 801                            _orig_pc_slot_offset_in_bytes,
 802                            code_buffer(),
 803                            frame_size_in_words(), _oop_map_set,
 804                            &_handler_table, &_inc_table,
 805                            compiler,
 806                            env()->comp_level(),
 807                            true, /*has_debug_info*/
 808                            has_unsafe_access()
 809                            );
 810   }
 811 }
 812 
 813 //------------------------------Compile----------------------------------------
 814 // Compile a runtime stub
 815 Compile::Compile( ciEnv* ci_env,
 816                   TypeFunc_generator generator,
 817                   address stub_function,
 818                   const char *stub_name,
 819                   int is_fancy_jump,
 820                   bool pass_tls,
 821                   bool save_arg_registers,
 822                   bool return_pc )
 823   : Phase(Compiler),
 824     _env(ci_env),
 825     _log(ci_env->log()),
 826     _compile_id(-1),
 827     _save_argument_registers(save_arg_registers),
 828     _method(NULL),
 829     _stub_name(stub_name),
 830     _stub_function(stub_function),
 831     _stub_entry_point(NULL),
 832     _entry_bci(InvocationEntryBci),
 833     _initial_gvn(NULL),
 834     _for_igvn(NULL),
 835     _warm_calls(NULL),
 836     _orig_pc_slot(0),
 837     _orig_pc_slot_offset_in_bytes(0),
 838     _subsume_loads(true),
 839     _do_escape_analysis(false),
 840     _failure_reason(NULL),
 841     _code_buffer("Compile::Fill_buffer"),
 842     _has_method_handle_invokes(false),
 843     _mach_constant_base_node(NULL),
 844     _node_bundling_limit(0),
 845     _node_bundling_base(NULL),
 846     _java_calls(0),
 847     _inner_loops(0),
 848 #ifndef PRODUCT
 849     _trace_opto_output(TraceOptoOutput),
 850     _printer(NULL),
 851 #endif
 852     _congraph(NULL) {
 853   C = this;
 854 
 855 #ifndef PRODUCT
 856   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
 857   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
 858   set_print_assembly(PrintFrameConverterAssembly);
 859   set_parsed_irreducible_loop(false);
 860 #endif
 861   CompileWrapper cw(this);
 862   Init(/*AliasLevel=*/ 0);
 863   init_tf((*generator)());
 864 
 865   {
 866     // The following is a dummy for the sake of GraphKit::gen_stub
 867     Unique_Node_List for_igvn(comp_arena());
 868     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
 869     PhaseGVN gvn(Thread::current()->resource_area(),255);
 870     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
 871     gvn.transform_no_reclaim(top());
 872 
 873     GraphKit kit;
 874     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
 875   }
 876 
 877   NOT_PRODUCT( verify_graph_edges(); )
 878   Code_Gen();
 879   if (failing())  return;
 880 
 881 
 882   // Entry point will be accessed using compile->stub_entry_point();
 883   if (code_buffer() == NULL) {
 884     Matcher::soft_match_failure();
 885   } else {
 886     if (PrintAssembly && (WizardMode || Verbose))
 887       tty->print_cr("### Stub::%s", stub_name);
 888 
 889     if (!failing()) {
 890       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
 891 
 892       // Make the NMethod
 893       // For now we mark the frame as never safe for profile stackwalking
 894       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
 895                                                       code_buffer(),
 896                                                       CodeOffsets::frame_never_safe,
 897                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
 898                                                       frame_size_in_words(),
 899                                                       _oop_map_set,
 900                                                       save_arg_registers);
 901       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
 902 
 903       _stub_entry_point = rs->entry_point();
 904     }
 905   }
 906 }
 907 
 908 #ifndef PRODUCT
 909 void print_opto_verbose_signature( const TypeFunc *j_sig, const char *stub_name ) {
 910   if(PrintOpto && Verbose) {
 911     tty->print("%s   ", stub_name); j_sig->print_flattened(); tty->cr();
 912   }
 913 }
 914 #endif
 915 
 916 void Compile::print_codes() {
 917 }
 918 
 919 //------------------------------Init-------------------------------------------
 920 // Prepare for a single compilation
 921 void Compile::Init(int aliaslevel) {
 922   _unique  = 0;
 923   _regalloc = NULL;
 924 
 925   _tf      = NULL;  // filled in later
 926   _top     = NULL;  // cached later
 927   _matcher = NULL;  // filled in later
 928   _cfg     = NULL;  // filled in later
 929 
 930   set_24_bit_selection_and_mode(Use24BitFP, false);
 931 
 932   _node_note_array = NULL;
 933   _default_node_notes = NULL;
 934 
 935   _immutable_memory = NULL; // filled in at first inquiry
 936 
 937   // Globally visible Nodes
 938   // First set TOP to NULL to give safe behavior during creation of RootNode
 939   set_cached_top_node(NULL);
 940   set_root(new (this, 3) RootNode());
 941   // Now that you have a Root to point to, create the real TOP
 942   set_cached_top_node( new (this, 1) ConNode(Type::TOP) );
 943   set_recent_alloc(NULL, NULL);
 944 
 945   // Create Debug Information Recorder to record scopes, oopmaps, etc.
 946   env()->set_oop_recorder(new OopRecorder(comp_arena()));
 947   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
 948   env()->set_dependencies(new Dependencies(env()));
 949 
 950   _fixed_slots = 0;
 951   set_has_split_ifs(false);
 952   set_has_loops(has_method() && method()->has_loops()); // first approximation
 953   set_has_stringbuilder(false);
 954   _trap_can_recompile = false;  // no traps emitted yet
 955   _major_progress = true; // start out assuming good things will happen
 956   set_has_unsafe_access(false);
 957   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
 958   set_decompile_count(0);
 959 
 960   set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
 961   set_num_loop_opts(LoopOptsCount);
 962   set_do_inlining(Inline);
 963   set_max_inline_size(MaxInlineSize);
 964   set_freq_inline_size(FreqInlineSize);
 965   set_do_scheduling(OptoScheduling);
 966   set_do_count_invocations(false);
 967   set_do_method_data_update(false);
 968 
 969   if (debug_info()->recording_non_safepoints()) {
 970     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
 971                         (comp_arena(), 8, 0, NULL));
 972     set_default_node_notes(Node_Notes::make(this));
 973   }
 974 
 975   // // -- Initialize types before each compile --
 976   // // Update cached type information
 977   // if( _method && _method->constants() )
 978   //   Type::update_loaded_types(_method, _method->constants());
 979 
 980   // Init alias_type map.
 981   if (!_do_escape_analysis && aliaslevel == 3)
 982     aliaslevel = 2;  // No unique types without escape analysis
 983   _AliasLevel = aliaslevel;
 984   const int grow_ats = 16;
 985   _max_alias_types = grow_ats;
 986   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
 987   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
 988   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
 989   {
 990     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
 991   }
 992   // Initialize the first few types.
 993   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
 994   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
 995   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
 996   _num_alias_types = AliasIdxRaw+1;
 997   // Zero out the alias type cache.
 998   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
 999   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1000   probe_alias_cache(NULL)->_index = AliasIdxTop;
1001 
1002   _intrinsics = NULL;
1003   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1004   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1005   register_library_intrinsics();
1006 }
1007 
1008 //---------------------------init_start----------------------------------------
1009 // Install the StartNode on this compile object.
1010 void Compile::init_start(StartNode* s) {
1011   if (failing())
1012     return; // already failing
1013   assert(s == start(), "");
1014 }
1015 
1016 StartNode* Compile::start() const {
1017   assert(!failing(), "");
1018   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1019     Node* start = root()->fast_out(i);
1020     if( start->is_Start() )
1021       return start->as_Start();
1022   }
1023   ShouldNotReachHere();
1024   return NULL;
1025 }
1026 
1027 //-------------------------------immutable_memory-------------------------------------
1028 // Access immutable memory
1029 Node* Compile::immutable_memory() {
1030   if (_immutable_memory != NULL) {
1031     return _immutable_memory;
1032   }
1033   StartNode* s = start();
1034   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1035     Node *p = s->fast_out(i);
1036     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1037       _immutable_memory = p;
1038       return _immutable_memory;
1039     }
1040   }
1041   ShouldNotReachHere();
1042   return NULL;
1043 }
1044 
1045 //----------------------set_cached_top_node------------------------------------
1046 // Install the cached top node, and make sure Node::is_top works correctly.
1047 void Compile::set_cached_top_node(Node* tn) {
1048   if (tn != NULL)  verify_top(tn);
1049   Node* old_top = _top;
1050   _top = tn;
1051   // Calling Node::setup_is_top allows the nodes the chance to adjust
1052   // their _out arrays.
1053   if (_top != NULL)     _top->setup_is_top();
1054   if (old_top != NULL)  old_top->setup_is_top();
1055   assert(_top == NULL || top()->is_top(), "");
1056 }
1057 
1058 #ifndef PRODUCT
1059 void Compile::verify_top(Node* tn) const {
1060   if (tn != NULL) {
1061     assert(tn->is_Con(), "top node must be a constant");
1062     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1063     assert(tn->in(0) != NULL, "must have live top node");
1064   }
1065 }
1066 #endif
1067 
1068 
1069 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1070 
1071 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1072   guarantee(arr != NULL, "");
1073   int num_blocks = arr->length();
1074   if (grow_by < num_blocks)  grow_by = num_blocks;
1075   int num_notes = grow_by * _node_notes_block_size;
1076   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1077   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1078   while (num_notes > 0) {
1079     arr->append(notes);
1080     notes     += _node_notes_block_size;
1081     num_notes -= _node_notes_block_size;
1082   }
1083   assert(num_notes == 0, "exact multiple, please");
1084 }
1085 
1086 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1087   if (source == NULL || dest == NULL)  return false;
1088 
1089   if (dest->is_Con())
1090     return false;               // Do not push debug info onto constants.
1091 
1092 #ifdef ASSERT
1093   // Leave a bread crumb trail pointing to the original node:
1094   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1095     dest->set_debug_orig(source);
1096   }
1097 #endif
1098 
1099   if (node_note_array() == NULL)
1100     return false;               // Not collecting any notes now.
1101 
1102   // This is a copy onto a pre-existing node, which may already have notes.
1103   // If both nodes have notes, do not overwrite any pre-existing notes.
1104   Node_Notes* source_notes = node_notes_at(source->_idx);
1105   if (source_notes == NULL || source_notes->is_clear())  return false;
1106   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1107   if (dest_notes == NULL || dest_notes->is_clear()) {
1108     return set_node_notes_at(dest->_idx, source_notes);
1109   }
1110 
1111   Node_Notes merged_notes = (*source_notes);
1112   // The order of operations here ensures that dest notes will win...
1113   merged_notes.update_from(dest_notes);
1114   return set_node_notes_at(dest->_idx, &merged_notes);
1115 }
1116 
1117 
1118 //--------------------------allow_range_check_smearing-------------------------
1119 // Gating condition for coalescing similar range checks.
1120 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1121 // single covering check that is at least as strong as any of them.
1122 // If the optimization succeeds, the simplified (strengthened) range check
1123 // will always succeed.  If it fails, we will deopt, and then give up
1124 // on the optimization.
1125 bool Compile::allow_range_check_smearing() const {
1126   // If this method has already thrown a range-check,
1127   // assume it was because we already tried range smearing
1128   // and it failed.
1129   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1130   return !already_trapped;
1131 }
1132 
1133 
1134 //------------------------------flatten_alias_type-----------------------------
1135 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1136   int offset = tj->offset();
1137   TypePtr::PTR ptr = tj->ptr();
1138 
1139   // Known instance (scalarizable allocation) alias only with itself.
1140   bool is_known_inst = tj->isa_oopptr() != NULL &&
1141                        tj->is_oopptr()->is_known_instance();
1142 
1143   // Process weird unsafe references.
1144   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1145     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1146     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1147     tj = TypeOopPtr::BOTTOM;
1148     ptr = tj->ptr();
1149     offset = tj->offset();
1150   }
1151 
1152   // Array pointers need some flattening
1153   const TypeAryPtr *ta = tj->isa_aryptr();
1154   if( ta && is_known_inst ) {
1155     if ( offset != Type::OffsetBot &&
1156          offset > arrayOopDesc::length_offset_in_bytes() ) {
1157       offset = Type::OffsetBot; // Flatten constant access into array body only
1158       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1159     }
1160   } else if( ta && _AliasLevel >= 2 ) {
1161     // For arrays indexed by constant indices, we flatten the alias
1162     // space to include all of the array body.  Only the header, klass
1163     // and array length can be accessed un-aliased.
1164     if( offset != Type::OffsetBot ) {
1165       if( ta->const_oop() ) { // methodDataOop or methodOop
1166         offset = Type::OffsetBot;   // Flatten constant access into array body
1167         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1168       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1169         // range is OK as-is.
1170         tj = ta = TypeAryPtr::RANGE;
1171       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1172         tj = TypeInstPtr::KLASS; // all klass loads look alike
1173         ta = TypeAryPtr::RANGE; // generic ignored junk
1174         ptr = TypePtr::BotPTR;
1175       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1176         tj = TypeInstPtr::MARK;
1177         ta = TypeAryPtr::RANGE; // generic ignored junk
1178         ptr = TypePtr::BotPTR;
1179       } else {                  // Random constant offset into array body
1180         offset = Type::OffsetBot;   // Flatten constant access into array body
1181         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1182       }
1183     }
1184     // Arrays of fixed size alias with arrays of unknown size.
1185     if (ta->size() != TypeInt::POS) {
1186       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1187       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1188     }
1189     // Arrays of known objects become arrays of unknown objects.
1190     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1191       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1192       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1193     }
1194     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1195       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1196       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1197     }
1198     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1199     // cannot be distinguished by bytecode alone.
1200     if (ta->elem() == TypeInt::BOOL) {
1201       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1202       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1203       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1204     }
1205     // During the 2nd round of IterGVN, NotNull castings are removed.
1206     // Make sure the Bottom and NotNull variants alias the same.
1207     // Also, make sure exact and non-exact variants alias the same.
1208     if( ptr == TypePtr::NotNull || ta->klass_is_exact() ) {
1209       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1210     }
1211   }
1212 
1213   // Oop pointers need some flattening
1214   const TypeInstPtr *to = tj->isa_instptr();
1215   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1216     ciInstanceKlass *k = to->klass()->as_instance_klass();
1217     if( ptr == TypePtr::Constant ) {
1218       if (to->klass() != ciEnv::current()->Class_klass() ||
1219           offset < k->size_helper() * wordSize) {
1220         // No constant oop pointers (such as Strings); they alias with
1221         // unknown strings.
1222         assert(!is_known_inst, "not scalarizable allocation");
1223         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1224       }
1225     } else if( is_known_inst ) {
1226       tj = to; // Keep NotNull and klass_is_exact for instance type
1227     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1228       // During the 2nd round of IterGVN, NotNull castings are removed.
1229       // Make sure the Bottom and NotNull variants alias the same.
1230       // Also, make sure exact and non-exact variants alias the same.
1231       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1232     }
1233     // Canonicalize the holder of this field
1234     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1235       // First handle header references such as a LoadKlassNode, even if the
1236       // object's klass is unloaded at compile time (4965979).
1237       if (!is_known_inst) { // Do it only for non-instance types
1238         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1239       }
1240     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1241       // Static fields are in the space above the normal instance
1242       // fields in the java.lang.Class instance.
1243       if (to->klass() != ciEnv::current()->Class_klass()) {
1244         to = NULL;
1245         tj = TypeOopPtr::BOTTOM;
1246         offset = tj->offset();
1247       }
1248     } else {
1249       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1250       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1251         if( is_known_inst ) {
1252           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1253         } else {
1254           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1255         }
1256       }
1257     }
1258   }
1259 
1260   // Klass pointers to object array klasses need some flattening
1261   const TypeKlassPtr *tk = tj->isa_klassptr();
1262   if( tk ) {
1263     // If we are referencing a field within a Klass, we need
1264     // to assume the worst case of an Object.  Both exact and
1265     // inexact types must flatten to the same alias class.
1266     // Since the flattened result for a klass is defined to be
1267     // precisely java.lang.Object, use a constant ptr.
1268     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1269 
1270       tj = tk = TypeKlassPtr::make(TypePtr::Constant,
1271                                    TypeKlassPtr::OBJECT->klass(),
1272                                    offset);
1273     }
1274 
1275     ciKlass* klass = tk->klass();
1276     if( klass->is_obj_array_klass() ) {
1277       ciKlass* k = TypeAryPtr::OOPS->klass();
1278       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1279         k = TypeInstPtr::BOTTOM->klass();
1280       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1281     }
1282 
1283     // Check for precise loads from the primary supertype array and force them
1284     // to the supertype cache alias index.  Check for generic array loads from
1285     // the primary supertype array and also force them to the supertype cache
1286     // alias index.  Since the same load can reach both, we need to merge
1287     // these 2 disparate memories into the same alias class.  Since the
1288     // primary supertype array is read-only, there's no chance of confusion
1289     // where we bypass an array load and an array store.
1290     uint off2 = offset - Klass::primary_supers_offset_in_bytes();
1291     if( offset == Type::OffsetBot ||
1292         off2 < Klass::primary_super_limit()*wordSize ) {
1293       offset = sizeof(oopDesc) +Klass::secondary_super_cache_offset_in_bytes();
1294       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1295     }
1296   }
1297 
1298   // Flatten all Raw pointers together.
1299   if (tj->base() == Type::RawPtr)
1300     tj = TypeRawPtr::BOTTOM;
1301 
1302   if (tj->base() == Type::AnyPtr)
1303     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1304 
1305   // Flatten all to bottom for now
1306   switch( _AliasLevel ) {
1307   case 0:
1308     tj = TypePtr::BOTTOM;
1309     break;
1310   case 1:                       // Flatten to: oop, static, field or array
1311     switch (tj->base()) {
1312     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1313     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1314     case Type::AryPtr:   // do not distinguish arrays at all
1315     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1316     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1317     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1318     default: ShouldNotReachHere();
1319     }
1320     break;
1321   case 2:                       // No collapsing at level 2; keep all splits
1322   case 3:                       // No collapsing at level 3; keep all splits
1323     break;
1324   default:
1325     Unimplemented();
1326   }
1327 
1328   offset = tj->offset();
1329   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1330 
1331   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1332           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1333           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1334           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1335           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1336           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1337           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
1338           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1339   assert( tj->ptr() != TypePtr::TopPTR &&
1340           tj->ptr() != TypePtr::AnyNull &&
1341           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1342 //    assert( tj->ptr() != TypePtr::Constant ||
1343 //            tj->base() == Type::RawPtr ||
1344 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1345 
1346   return tj;
1347 }
1348 
1349 void Compile::AliasType::Init(int i, const TypePtr* at) {
1350   _index = i;
1351   _adr_type = at;
1352   _field = NULL;
1353   _is_rewritable = true; // default
1354   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1355   if (atoop != NULL && atoop->is_known_instance()) {
1356     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1357     _general_index = Compile::current()->get_alias_index(gt);
1358   } else {
1359     _general_index = 0;
1360   }
1361 }
1362 
1363 //---------------------------------print_on------------------------------------
1364 #ifndef PRODUCT
1365 void Compile::AliasType::print_on(outputStream* st) {
1366   if (index() < 10)
1367         st->print("@ <%d> ", index());
1368   else  st->print("@ <%d>",  index());
1369   st->print(is_rewritable() ? "   " : " RO");
1370   int offset = adr_type()->offset();
1371   if (offset == Type::OffsetBot)
1372         st->print(" +any");
1373   else  st->print(" +%-3d", offset);
1374   st->print(" in ");
1375   adr_type()->dump_on(st);
1376   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1377   if (field() != NULL && tjp) {
1378     if (tjp->klass()  != field()->holder() ||
1379         tjp->offset() != field()->offset_in_bytes()) {
1380       st->print(" != ");
1381       field()->print();
1382       st->print(" ***");
1383     }
1384   }
1385 }
1386 
1387 void print_alias_types() {
1388   Compile* C = Compile::current();
1389   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1390   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1391     C->alias_type(idx)->print_on(tty);
1392     tty->cr();
1393   }
1394 }
1395 #endif
1396 
1397 
1398 //----------------------------probe_alias_cache--------------------------------
1399 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1400   intptr_t key = (intptr_t) adr_type;
1401   key ^= key >> logAliasCacheSize;
1402   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1403 }
1404 
1405 
1406 //-----------------------------grow_alias_types--------------------------------
1407 void Compile::grow_alias_types() {
1408   const int old_ats  = _max_alias_types; // how many before?
1409   const int new_ats  = old_ats;          // how many more?
1410   const int grow_ats = old_ats+new_ats;  // how many now?
1411   _max_alias_types = grow_ats;
1412   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1413   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1414   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1415   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1416 }
1417 
1418 
1419 //--------------------------------find_alias_type------------------------------
1420 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1421   if (_AliasLevel == 0)
1422     return alias_type(AliasIdxBot);
1423 
1424   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1425   if (ace->_adr_type == adr_type) {
1426     return alias_type(ace->_index);
1427   }
1428 
1429   // Handle special cases.
1430   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1431   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1432 
1433   // Do it the slow way.
1434   const TypePtr* flat = flatten_alias_type(adr_type);
1435 
1436 #ifdef ASSERT
1437   assert(flat == flatten_alias_type(flat), "idempotent");
1438   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
1439   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1440     const TypeOopPtr* foop = flat->is_oopptr();
1441     // Scalarizable allocations have exact klass always.
1442     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1443     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1444     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
1445   }
1446   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
1447 #endif
1448 
1449   int idx = AliasIdxTop;
1450   for (int i = 0; i < num_alias_types(); i++) {
1451     if (alias_type(i)->adr_type() == flat) {
1452       idx = i;
1453       break;
1454     }
1455   }
1456 
1457   if (idx == AliasIdxTop) {
1458     if (no_create)  return NULL;
1459     // Grow the array if necessary.
1460     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1461     // Add a new alias type.
1462     idx = _num_alias_types++;
1463     _alias_types[idx]->Init(idx, flat);
1464     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1465     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1466     if (flat->isa_instptr()) {
1467       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1468           && flat->is_instptr()->klass() == env()->Class_klass())
1469         alias_type(idx)->set_rewritable(false);
1470     }
1471     if (flat->isa_klassptr()) {
1472       if (flat->offset() == Klass::super_check_offset_offset_in_bytes() + (int)sizeof(oopDesc))
1473         alias_type(idx)->set_rewritable(false);
1474       if (flat->offset() == Klass::modifier_flags_offset_in_bytes() + (int)sizeof(oopDesc))
1475         alias_type(idx)->set_rewritable(false);
1476       if (flat->offset() == Klass::access_flags_offset_in_bytes() + (int)sizeof(oopDesc))
1477         alias_type(idx)->set_rewritable(false);
1478       if (flat->offset() == Klass::java_mirror_offset_in_bytes() + (int)sizeof(oopDesc))
1479         alias_type(idx)->set_rewritable(false);
1480     }
1481     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1482     // but the base pointer type is not distinctive enough to identify
1483     // references into JavaThread.)
1484 
1485     // Check for final fields.
1486     const TypeInstPtr* tinst = flat->isa_instptr();
1487     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1488       ciField* field;
1489       if (tinst->const_oop() != NULL &&
1490           tinst->klass() == ciEnv::current()->Class_klass() &&
1491           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1492         // static field
1493         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1494         field = k->get_field_by_offset(tinst->offset(), true);
1495       } else {
1496         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1497         field = k->get_field_by_offset(tinst->offset(), false);
1498       }
1499       assert(field == NULL ||
1500              original_field == NULL ||
1501              (field->holder() == original_field->holder() &&
1502               field->offset() == original_field->offset() &&
1503               field->is_static() == original_field->is_static()), "wrong field?");
1504       // Set field() and is_rewritable() attributes.
1505       if (field != NULL)  alias_type(idx)->set_field(field);
1506     }
1507   }
1508 
1509   // Fill the cache for next time.
1510   ace->_adr_type = adr_type;
1511   ace->_index    = idx;
1512   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1513 
1514   // Might as well try to fill the cache for the flattened version, too.
1515   AliasCacheEntry* face = probe_alias_cache(flat);
1516   if (face->_adr_type == NULL) {
1517     face->_adr_type = flat;
1518     face->_index    = idx;
1519     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1520   }
1521 
1522   return alias_type(idx);
1523 }
1524 
1525 
1526 Compile::AliasType* Compile::alias_type(ciField* field) {
1527   const TypeOopPtr* t;
1528   if (field->is_static())
1529     t = TypeInstPtr::make(field->holder()->java_mirror());
1530   else
1531     t = TypeOopPtr::make_from_klass_raw(field->holder());
1532   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1533   assert(field->is_final() == !atp->is_rewritable(), "must get the rewritable bits correct");
1534   return atp;
1535 }
1536 
1537 
1538 //------------------------------have_alias_type--------------------------------
1539 bool Compile::have_alias_type(const TypePtr* adr_type) {
1540   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1541   if (ace->_adr_type == adr_type) {
1542     return true;
1543   }
1544 
1545   // Handle special cases.
1546   if (adr_type == NULL)             return true;
1547   if (adr_type == TypePtr::BOTTOM)  return true;
1548 
1549   return find_alias_type(adr_type, true, NULL) != NULL;
1550 }
1551 
1552 //-----------------------------must_alias--------------------------------------
1553 // True if all values of the given address type are in the given alias category.
1554 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1555   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1556   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1557   if (alias_idx == AliasIdxTop)         return false; // the empty category
1558   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1559 
1560   // the only remaining possible overlap is identity
1561   int adr_idx = get_alias_index(adr_type);
1562   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1563   assert(adr_idx == alias_idx ||
1564          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1565           && adr_type                       != TypeOopPtr::BOTTOM),
1566          "should not be testing for overlap with an unsafe pointer");
1567   return adr_idx == alias_idx;
1568 }
1569 
1570 //------------------------------can_alias--------------------------------------
1571 // True if any values of the given address type are in the given alias category.
1572 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1573   if (alias_idx == AliasIdxTop)         return false; // the empty category
1574   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1575   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1576   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1577 
1578   // the only remaining possible overlap is identity
1579   int adr_idx = get_alias_index(adr_type);
1580   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1581   return adr_idx == alias_idx;
1582 }
1583 
1584 
1585 
1586 //---------------------------pop_warm_call-------------------------------------
1587 WarmCallInfo* Compile::pop_warm_call() {
1588   WarmCallInfo* wci = _warm_calls;
1589   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1590   return wci;
1591 }
1592 
1593 //----------------------------Inline_Warm--------------------------------------
1594 int Compile::Inline_Warm() {
1595   // If there is room, try to inline some more warm call sites.
1596   // %%% Do a graph index compaction pass when we think we're out of space?
1597   if (!InlineWarmCalls)  return 0;
1598 
1599   int calls_made_hot = 0;
1600   int room_to_grow   = NodeCountInliningCutoff - unique();
1601   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1602   int amount_grown   = 0;
1603   WarmCallInfo* call;
1604   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1605     int est_size = (int)call->size();
1606     if (est_size > (room_to_grow - amount_grown)) {
1607       // This one won't fit anyway.  Get rid of it.
1608       call->make_cold();
1609       continue;
1610     }
1611     call->make_hot();
1612     calls_made_hot++;
1613     amount_grown   += est_size;
1614     amount_to_grow -= est_size;
1615   }
1616 
1617   if (calls_made_hot > 0)  set_major_progress();
1618   return calls_made_hot;
1619 }
1620 
1621 
1622 //----------------------------Finish_Warm--------------------------------------
1623 void Compile::Finish_Warm() {
1624   if (!InlineWarmCalls)  return;
1625   if (failing())  return;
1626   if (warm_calls() == NULL)  return;
1627 
1628   // Clean up loose ends, if we are out of space for inlining.
1629   WarmCallInfo* call;
1630   while ((call = pop_warm_call()) != NULL) {
1631     call->make_cold();
1632   }
1633 }
1634 
1635 //---------------------cleanup_loop_predicates-----------------------
1636 // Remove the opaque nodes that protect the predicates so that all unused
1637 // checks and uncommon_traps will be eliminated from the ideal graph
1638 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1639   if (predicate_count()==0) return;
1640   for (int i = predicate_count(); i > 0; i--) {
1641     Node * n = predicate_opaque1_node(i-1);
1642     assert(n->Opcode() == Op_Opaque1, "must be");
1643     igvn.replace_node(n, n->in(1));
1644   }
1645   assert(predicate_count()==0, "should be clean!");
1646 }
1647 
1648 //------------------------------Optimize---------------------------------------
1649 // Given a graph, optimize it.
1650 void Compile::Optimize() {
1651   TracePhase t1("optimizer", &_t_optimizer, true);
1652 
1653 #ifndef PRODUCT
1654   if (env()->break_at_compile()) {
1655     BREAKPOINT;
1656   }
1657 
1658 #endif
1659 
1660   ResourceMark rm;
1661   int          loop_opts_cnt;
1662 
1663   NOT_PRODUCT( verify_graph_edges(); )
1664 
1665   print_method("After Parsing");
1666 
1667  {
1668   // Iterative Global Value Numbering, including ideal transforms
1669   // Initialize IterGVN with types and values from parse-time GVN
1670   PhaseIterGVN igvn(initial_gvn());
1671   {
1672     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
1673     igvn.optimize();
1674   }
1675 
1676   print_method("Iter GVN 1", 2);
1677 
1678   if (failing())  return;
1679 
1680   // Perform escape analysis
1681   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
1682     TracePhase t2("escapeAnalysis", &_t_escapeAnalysis, true);
1683     ConnectionGraph::do_analysis(this, &igvn);
1684 
1685     if (failing())  return;
1686 
1687     igvn.optimize();
1688     print_method("Iter GVN 3", 2);
1689 
1690     if (failing())  return;
1691 
1692   }
1693 
1694   // Loop transforms on the ideal graph.  Range Check Elimination,
1695   // peeling, unrolling, etc.
1696 
1697   // Set loop opts counter
1698   loop_opts_cnt = num_loop_opts();
1699   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
1700     {
1701       TracePhase t2("idealLoop", &_t_idealLoop, true);
1702       PhaseIdealLoop ideal_loop( igvn, true );
1703       loop_opts_cnt--;
1704       if (major_progress()) print_method("PhaseIdealLoop 1", 2);
1705       if (failing())  return;
1706     }
1707     // Loop opts pass if partial peeling occurred in previous pass
1708     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
1709       TracePhase t3("idealLoop", &_t_idealLoop, true);
1710       PhaseIdealLoop ideal_loop( igvn, false );
1711       loop_opts_cnt--;
1712       if (major_progress()) print_method("PhaseIdealLoop 2", 2);
1713       if (failing())  return;
1714     }
1715     // Loop opts pass for loop-unrolling before CCP
1716     if(major_progress() && (loop_opts_cnt > 0)) {
1717       TracePhase t4("idealLoop", &_t_idealLoop, true);
1718       PhaseIdealLoop ideal_loop( igvn, false );
1719       loop_opts_cnt--;
1720       if (major_progress()) print_method("PhaseIdealLoop 3", 2);
1721     }
1722     if (!failing()) {
1723       // Verify that last round of loop opts produced a valid graph
1724       NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
1725       PhaseIdealLoop::verify(igvn);
1726     }
1727   }
1728   if (failing())  return;
1729 
1730   // Conditional Constant Propagation;
1731   PhaseCCP ccp( &igvn );
1732   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
1733   {
1734     TracePhase t2("ccp", &_t_ccp, true);
1735     ccp.do_transform();
1736   }
1737   print_method("PhaseCPP 1", 2);
1738 
1739   assert( true, "Break here to ccp.dump_old2new_map()");
1740 
1741   // Iterative Global Value Numbering, including ideal transforms
1742   {
1743     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
1744     igvn = ccp;
1745     igvn.optimize();
1746   }
1747 
1748   print_method("Iter GVN 2", 2);
1749 
1750   if (failing())  return;
1751 
1752   // Loop transforms on the ideal graph.  Range Check Elimination,
1753   // peeling, unrolling, etc.
1754   if(loop_opts_cnt > 0) {
1755     debug_only( int cnt = 0; );
1756     while(major_progress() && (loop_opts_cnt > 0)) {
1757       TracePhase t2("idealLoop", &_t_idealLoop, true);
1758       assert( cnt++ < 40, "infinite cycle in loop optimization" );
1759       PhaseIdealLoop ideal_loop( igvn, true);
1760       loop_opts_cnt--;
1761       if (major_progress()) print_method("PhaseIdealLoop iterations", 2);
1762       if (failing())  return;
1763     }
1764   }
1765 
1766   {
1767     // Verify that all previous optimizations produced a valid graph
1768     // at least to this point, even if no loop optimizations were done.
1769     NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
1770     PhaseIdealLoop::verify(igvn);
1771   }
1772 
1773   {
1774     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
1775     PhaseMacroExpand  mex(igvn);
1776     if (mex.expand_macro_nodes()) {
1777       assert(failing(), "must bail out w/ explicit message");
1778       return;
1779     }
1780   }
1781 
1782  } // (End scope of igvn; run destructor if necessary for asserts.)
1783 
1784   // A method with only infinite loops has no edges entering loops from root
1785   {
1786     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
1787     if (final_graph_reshaping()) {
1788       assert(failing(), "must bail out w/ explicit message");
1789       return;
1790     }
1791   }
1792 
1793   print_method("Optimize finished", 2);
1794 }
1795 
1796 
1797 //------------------------------Code_Gen---------------------------------------
1798 // Given a graph, generate code for it
1799 void Compile::Code_Gen() {
1800   if (failing())  return;
1801 
1802   // Perform instruction selection.  You might think we could reclaim Matcher
1803   // memory PDQ, but actually the Matcher is used in generating spill code.
1804   // Internals of the Matcher (including some VectorSets) must remain live
1805   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
1806   // set a bit in reclaimed memory.
1807 
1808   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
1809   // nodes.  Mapping is only valid at the root of each matched subtree.
1810   NOT_PRODUCT( verify_graph_edges(); )
1811 
1812   Node_List proj_list;
1813   Matcher m(proj_list);
1814   _matcher = &m;
1815   {
1816     TracePhase t2("matcher", &_t_matcher, true);
1817     m.match();
1818   }
1819   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
1820   // nodes.  Mapping is only valid at the root of each matched subtree.
1821   NOT_PRODUCT( verify_graph_edges(); )
1822 
1823   // If you have too many nodes, or if matching has failed, bail out
1824   check_node_count(0, "out of nodes matching instructions");
1825   if (failing())  return;
1826 
1827   // Build a proper-looking CFG
1828   PhaseCFG cfg(node_arena(), root(), m);
1829   _cfg = &cfg;
1830   {
1831     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
1832     cfg.Dominators();
1833     if (failing())  return;
1834 
1835     NOT_PRODUCT( verify_graph_edges(); )
1836 
1837     cfg.Estimate_Block_Frequency();
1838     cfg.GlobalCodeMotion(m,unique(),proj_list);
1839 
1840     print_method("Global code motion", 2);
1841 
1842     if (failing())  return;
1843     NOT_PRODUCT( verify_graph_edges(); )
1844 
1845     debug_only( cfg.verify(); )
1846   }
1847   NOT_PRODUCT( verify_graph_edges(); )
1848 
1849   PhaseChaitin regalloc(unique(),cfg,m);
1850   _regalloc = &regalloc;
1851   {
1852     TracePhase t2("regalloc", &_t_registerAllocation, true);
1853     // Perform any platform dependent preallocation actions.  This is used,
1854     // for example, to avoid taking an implicit null pointer exception
1855     // using the frame pointer on win95.
1856     _regalloc->pd_preallocate_hook();
1857 
1858     // Perform register allocation.  After Chaitin, use-def chains are
1859     // no longer accurate (at spill code) and so must be ignored.
1860     // Node->LRG->reg mappings are still accurate.
1861     _regalloc->Register_Allocate();
1862 
1863     // Bail out if the allocator builds too many nodes
1864     if (failing())  return;
1865   }
1866 
1867   // Prior to register allocation we kept empty basic blocks in case the
1868   // the allocator needed a place to spill.  After register allocation we
1869   // are not adding any new instructions.  If any basic block is empty, we
1870   // can now safely remove it.
1871   {
1872     NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
1873     cfg.remove_empty();
1874     if (do_freq_based_layout()) {
1875       PhaseBlockLayout layout(cfg);
1876     } else {
1877       cfg.set_loop_alignment();
1878     }
1879     cfg.fixup_flow();
1880   }
1881 
1882   // Perform any platform dependent postallocation verifications.
1883   debug_only( _regalloc->pd_postallocate_verify_hook(); )
1884 
1885   // Apply peephole optimizations
1886   if( OptoPeephole ) {
1887     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
1888     PhasePeephole peep( _regalloc, cfg);
1889     peep.do_transform();
1890   }
1891 
1892   // Convert Nodes to instruction bits in a buffer
1893   {
1894     // %%%% workspace merge brought two timers together for one job
1895     TracePhase t2a("output", &_t_output, true);
1896     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
1897     Output();
1898   }
1899 
1900   print_method("Final Code");
1901 
1902   // He's dead, Jim.
1903   _cfg     = (PhaseCFG*)0xdeadbeef;
1904   _regalloc = (PhaseChaitin*)0xdeadbeef;
1905 }
1906 
1907 
1908 //------------------------------dump_asm---------------------------------------
1909 // Dump formatted assembly
1910 #ifndef PRODUCT
1911 void Compile::dump_asm(int *pcs, uint pc_limit) {
1912   bool cut_short = false;
1913   tty->print_cr("#");
1914   tty->print("#  ");  _tf->dump();  tty->cr();
1915   tty->print_cr("#");
1916 
1917   // For all blocks
1918   int pc = 0x0;                 // Program counter
1919   char starts_bundle = ' ';
1920   _regalloc->dump_frame();
1921 
1922   Node *n = NULL;
1923   for( uint i=0; i<_cfg->_num_blocks; i++ ) {
1924     if (VMThread::should_terminate()) { cut_short = true; break; }
1925     Block *b = _cfg->_blocks[i];
1926     if (b->is_connector() && !Verbose) continue;
1927     n = b->_nodes[0];
1928     if (pcs && n->_idx < pc_limit)
1929       tty->print("%3.3x   ", pcs[n->_idx]);
1930     else
1931       tty->print("      ");
1932     b->dump_head( &_cfg->_bbs );
1933     if (b->is_connector()) {
1934       tty->print_cr("        # Empty connector block");
1935     } else if (b->num_preds() == 2 && b->pred(1)->is_CatchProj() && b->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
1936       tty->print_cr("        # Block is sole successor of call");
1937     }
1938 
1939     // For all instructions
1940     Node *delay = NULL;
1941     for( uint j = 0; j<b->_nodes.size(); j++ ) {
1942       if (VMThread::should_terminate()) { cut_short = true; break; }
1943       n = b->_nodes[j];
1944       if (valid_bundle_info(n)) {
1945         Bundle *bundle = node_bundling(n);
1946         if (bundle->used_in_unconditional_delay()) {
1947           delay = n;
1948           continue;
1949         }
1950         if (bundle->starts_bundle())
1951           starts_bundle = '+';
1952       }
1953 
1954       if (WizardMode) n->dump();
1955 
1956       if( !n->is_Region() &&    // Dont print in the Assembly
1957           !n->is_Phi() &&       // a few noisely useless nodes
1958           !n->is_Proj() &&
1959           !n->is_MachTemp() &&
1960           !n->is_SafePointScalarObject() &&
1961           !n->is_Catch() &&     // Would be nice to print exception table targets
1962           !n->is_MergeMem() &&  // Not very interesting
1963           !n->is_top() &&       // Debug info table constants
1964           !(n->is_Con() && !n->is_Mach())// Debug info table constants
1965           ) {
1966         if (pcs && n->_idx < pc_limit)
1967           tty->print("%3.3x", pcs[n->_idx]);
1968         else
1969           tty->print("   ");
1970         tty->print(" %c ", starts_bundle);
1971         starts_bundle = ' ';
1972         tty->print("\t");
1973         n->format(_regalloc, tty);
1974         tty->cr();
1975       }
1976 
1977       // If we have an instruction with a delay slot, and have seen a delay,
1978       // then back up and print it
1979       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
1980         assert(delay != NULL, "no unconditional delay instruction");
1981         if (WizardMode) delay->dump();
1982 
1983         if (node_bundling(delay)->starts_bundle())
1984           starts_bundle = '+';
1985         if (pcs && n->_idx < pc_limit)
1986           tty->print("%3.3x", pcs[n->_idx]);
1987         else
1988           tty->print("   ");
1989         tty->print(" %c ", starts_bundle);
1990         starts_bundle = ' ';
1991         tty->print("\t");
1992         delay->format(_regalloc, tty);
1993         tty->print_cr("");
1994         delay = NULL;
1995       }
1996 
1997       // Dump the exception table as well
1998       if( n->is_Catch() && (Verbose || WizardMode) ) {
1999         // Print the exception table for this offset
2000         _handler_table.print_subtable_for(pc);
2001       }
2002     }
2003 
2004     if (pcs && n->_idx < pc_limit)
2005       tty->print_cr("%3.3x", pcs[n->_idx]);
2006     else
2007       tty->print_cr("");
2008 
2009     assert(cut_short || delay == NULL, "no unconditional delay branch");
2010 
2011   } // End of per-block dump
2012   tty->print_cr("");
2013 
2014   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
2015 }
2016 #endif
2017 
2018 //------------------------------Final_Reshape_Counts---------------------------
2019 // This class defines counters to help identify when a method
2020 // may/must be executed using hardware with only 24-bit precision.
2021 struct Final_Reshape_Counts : public StackObj {
2022   int  _call_count;             // count non-inlined 'common' calls
2023   int  _float_count;            // count float ops requiring 24-bit precision
2024   int  _double_count;           // count double ops requiring more precision
2025   int  _java_call_count;        // count non-inlined 'java' calls
2026   int  _inner_loop_count;       // count loops which need alignment
2027   VectorSet _visited;           // Visitation flags
2028   Node_List _tests;             // Set of IfNodes & PCTableNodes
2029 
2030   Final_Reshape_Counts() :
2031     _call_count(0), _float_count(0), _double_count(0),
2032     _java_call_count(0), _inner_loop_count(0),
2033     _visited( Thread::current()->resource_area() ) { }
2034 
2035   void inc_call_count  () { _call_count  ++; }
2036   void inc_float_count () { _float_count ++; }
2037   void inc_double_count() { _double_count++; }
2038   void inc_java_call_count() { _java_call_count++; }
2039   void inc_inner_loop_count() { _inner_loop_count++; }
2040 
2041   int  get_call_count  () const { return _call_count  ; }
2042   int  get_float_count () const { return _float_count ; }
2043   int  get_double_count() const { return _double_count; }
2044   int  get_java_call_count() const { return _java_call_count; }
2045   int  get_inner_loop_count() const { return _inner_loop_count; }
2046 };
2047 
2048 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2049   ciInstanceKlass *k = tp->klass()->as_instance_klass();
2050   // Make sure the offset goes inside the instance layout.
2051   return k->contains_field_offset(tp->offset());
2052   // Note that OffsetBot and OffsetTop are very negative.
2053 }
2054 
2055 // Eliminate trivially redundant StoreCMs and accumulate their
2056 // precedence edges.
2057 static void eliminate_redundant_card_marks(Node* n) {
2058   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2059   if (n->in(MemNode::Address)->outcnt() > 1) {
2060     // There are multiple users of the same address so it might be
2061     // possible to eliminate some of the StoreCMs
2062     Node* mem = n->in(MemNode::Memory);
2063     Node* adr = n->in(MemNode::Address);
2064     Node* val = n->in(MemNode::ValueIn);
2065     Node* prev = n;
2066     bool done = false;
2067     // Walk the chain of StoreCMs eliminating ones that match.  As
2068     // long as it's a chain of single users then the optimization is
2069     // safe.  Eliminating partially redundant StoreCMs would require
2070     // cloning copies down the other paths.
2071     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2072       if (adr == mem->in(MemNode::Address) &&
2073           val == mem->in(MemNode::ValueIn)) {
2074         // redundant StoreCM
2075         if (mem->req() > MemNode::OopStore) {
2076           // Hasn't been processed by this code yet.
2077           n->add_prec(mem->in(MemNode::OopStore));
2078         } else {
2079           // Already converted to precedence edge
2080           for (uint i = mem->req(); i < mem->len(); i++) {
2081             // Accumulate any precedence edges
2082             if (mem->in(i) != NULL) {
2083               n->add_prec(mem->in(i));
2084             }
2085           }
2086           // Everything above this point has been processed.
2087           done = true;
2088         }
2089         // Eliminate the previous StoreCM
2090         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2091         assert(mem->outcnt() == 0, "should be dead");
2092         mem->disconnect_inputs(NULL);
2093       } else {
2094         prev = mem;
2095       }
2096       mem = prev->in(MemNode::Memory);
2097     }
2098   }
2099 }
2100 
2101 //------------------------------final_graph_reshaping_impl----------------------
2102 // Implement items 1-5 from final_graph_reshaping below.
2103 static void final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc ) {
2104 
2105   if ( n->outcnt() == 0 ) return; // dead node
2106   uint nop = n->Opcode();
2107 
2108   // Check for 2-input instruction with "last use" on right input.
2109   // Swap to left input.  Implements item (2).
2110   if( n->req() == 3 &&          // two-input instruction
2111       n->in(1)->outcnt() > 1 && // left use is NOT a last use
2112       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2113       n->in(2)->outcnt() == 1 &&// right use IS a last use
2114       !n->in(2)->is_Con() ) {   // right use is not a constant
2115     // Check for commutative opcode
2116     switch( nop ) {
2117     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
2118     case Op_MaxI:  case Op_MinI:
2119     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
2120     case Op_AndL:  case Op_XorL:  case Op_OrL:
2121     case Op_AndI:  case Op_XorI:  case Op_OrI: {
2122       // Move "last use" input to left by swapping inputs
2123       n->swap_edges(1, 2);
2124       break;
2125     }
2126     default:
2127       break;
2128     }
2129   }
2130 
2131 #ifdef ASSERT
2132   if( n->is_Mem() ) {
2133     Compile* C = Compile::current();
2134     int alias_idx = C->get_alias_index(n->as_Mem()->adr_type());
2135     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2136             // oop will be recorded in oop map if load crosses safepoint
2137             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2138                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
2139             "raw memory operations should have control edge");
2140   }
2141 #endif
2142   // Count FPU ops and common calls, implements item (3)
2143   switch( nop ) {
2144   // Count all float operations that may use FPU
2145   case Op_AddF:
2146   case Op_SubF:
2147   case Op_MulF:
2148   case Op_DivF:
2149   case Op_NegF:
2150   case Op_ModF:
2151   case Op_ConvI2F:
2152   case Op_ConF:
2153   case Op_CmpF:
2154   case Op_CmpF3:
2155   // case Op_ConvL2F: // longs are split into 32-bit halves
2156     frc.inc_float_count();
2157     break;
2158 
2159   case Op_ConvF2D:
2160   case Op_ConvD2F:
2161     frc.inc_float_count();
2162     frc.inc_double_count();
2163     break;
2164 
2165   // Count all double operations that may use FPU
2166   case Op_AddD:
2167   case Op_SubD:
2168   case Op_MulD:
2169   case Op_DivD:
2170   case Op_NegD:
2171   case Op_ModD:
2172   case Op_ConvI2D:
2173   case Op_ConvD2I:
2174   // case Op_ConvL2D: // handled by leaf call
2175   // case Op_ConvD2L: // handled by leaf call
2176   case Op_ConD:
2177   case Op_CmpD:
2178   case Op_CmpD3:
2179     frc.inc_double_count();
2180     break;
2181   case Op_Opaque1:              // Remove Opaque Nodes before matching
2182   case Op_Opaque2:              // Remove Opaque Nodes before matching
2183     n->subsume_by(n->in(1));
2184     break;
2185   case Op_CallStaticJava:
2186   case Op_CallJava:
2187   case Op_CallDynamicJava:
2188     frc.inc_java_call_count(); // Count java call site;
2189   case Op_CallRuntime:
2190   case Op_CallLeaf:
2191   case Op_CallLeafNoFP: {
2192     assert( n->is_Call(), "" );
2193     CallNode *call = n->as_Call();
2194     // Count call sites where the FP mode bit would have to be flipped.
2195     // Do not count uncommon runtime calls:
2196     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2197     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2198     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
2199       frc.inc_call_count();   // Count the call site
2200     } else {                  // See if uncommon argument is shared
2201       Node *n = call->in(TypeFunc::Parms);
2202       int nop = n->Opcode();
2203       // Clone shared simple arguments to uncommon calls, item (1).
2204       if( n->outcnt() > 1 &&
2205           !n->is_Proj() &&
2206           nop != Op_CreateEx &&
2207           nop != Op_CheckCastPP &&
2208           nop != Op_DecodeN &&
2209           !n->is_Mem() ) {
2210         Node *x = n->clone();
2211         call->set_req( TypeFunc::Parms, x );
2212       }
2213     }
2214     break;
2215   }
2216 
2217   case Op_StoreD:
2218   case Op_LoadD:
2219   case Op_LoadD_unaligned:
2220     frc.inc_double_count();
2221     goto handle_mem;
2222   case Op_StoreF:
2223   case Op_LoadF:
2224     frc.inc_float_count();
2225     goto handle_mem;
2226 
2227   case Op_StoreCM:
2228     {
2229       // Convert OopStore dependence into precedence edge
2230       Node* prec = n->in(MemNode::OopStore);
2231       n->del_req(MemNode::OopStore);
2232       n->add_prec(prec);
2233       eliminate_redundant_card_marks(n);
2234     }
2235 
2236     // fall through
2237 
2238   case Op_StoreB:
2239   case Op_StoreC:
2240   case Op_StorePConditional:
2241   case Op_StoreI:
2242   case Op_StoreL:
2243   case Op_StoreIConditional:
2244   case Op_StoreLConditional:
2245   case Op_CompareAndSwapI:
2246   case Op_CompareAndSwapL:
2247   case Op_CompareAndSwapP:
2248   case Op_CompareAndSwapN:
2249   case Op_StoreP:
2250   case Op_StoreN:
2251   case Op_LoadB:
2252   case Op_LoadUB:
2253   case Op_LoadUS:
2254   case Op_LoadI:
2255   case Op_LoadUI2L:
2256   case Op_LoadKlass:
2257   case Op_LoadNKlass:
2258   case Op_LoadL:
2259   case Op_LoadL_unaligned:
2260   case Op_LoadPLocked:
2261   case Op_LoadLLocked:
2262   case Op_LoadP:
2263   case Op_LoadN:
2264   case Op_LoadRange:
2265   case Op_LoadS: {
2266   handle_mem:
2267 #ifdef ASSERT
2268     if( VerifyOptoOopOffsets ) {
2269       assert( n->is_Mem(), "" );
2270       MemNode *mem  = (MemNode*)n;
2271       // Check to see if address types have grounded out somehow.
2272       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2273       assert( !tp || oop_offset_is_sane(tp), "" );
2274     }
2275 #endif
2276     break;
2277   }
2278 
2279   case Op_AddP: {               // Assert sane base pointers
2280     Node *addp = n->in(AddPNode::Address);
2281     assert( !addp->is_AddP() ||
2282             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2283             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2284             "Base pointers must match" );
2285 #ifdef _LP64
2286     if (UseCompressedOops &&
2287         addp->Opcode() == Op_ConP &&
2288         addp == n->in(AddPNode::Base) &&
2289         n->in(AddPNode::Offset)->is_Con()) {
2290       // Use addressing with narrow klass to load with offset on x86.
2291       // On sparc loading 32-bits constant and decoding it have less
2292       // instructions (4) then load 64-bits constant (7).
2293       // Do this transformation here since IGVN will convert ConN back to ConP.
2294       const Type* t = addp->bottom_type();
2295       if (t->isa_oopptr()) {
2296         Node* nn = NULL;
2297 
2298         // Look for existing ConN node of the same exact type.
2299         Compile* C = Compile::current();
2300         Node* r  = C->root();
2301         uint cnt = r->outcnt();
2302         for (uint i = 0; i < cnt; i++) {
2303           Node* m = r->raw_out(i);
2304           if (m!= NULL && m->Opcode() == Op_ConN &&
2305               m->bottom_type()->make_ptr() == t) {
2306             nn = m;
2307             break;
2308           }
2309         }
2310         if (nn != NULL) {
2311           // Decode a narrow oop to match address
2312           // [R12 + narrow_oop_reg<<3 + offset]
2313           nn = new (C,  2) DecodeNNode(nn, t);
2314           n->set_req(AddPNode::Base, nn);
2315           n->set_req(AddPNode::Address, nn);
2316           if (addp->outcnt() == 0) {
2317             addp->disconnect_inputs(NULL);
2318           }
2319         }
2320       }
2321     }
2322 #endif
2323     break;
2324   }
2325 
2326 #ifdef _LP64
2327   case Op_CastPP:
2328     if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
2329       Compile* C = Compile::current();
2330       Node* in1 = n->in(1);
2331       const Type* t = n->bottom_type();
2332       Node* new_in1 = in1->clone();
2333       new_in1->as_DecodeN()->set_type(t);
2334 
2335       if (!Matcher::narrow_oop_use_complex_address()) {
2336         //
2337         // x86, ARM and friends can handle 2 adds in addressing mode
2338         // and Matcher can fold a DecodeN node into address by using
2339         // a narrow oop directly and do implicit NULL check in address:
2340         //
2341         // [R12 + narrow_oop_reg<<3 + offset]
2342         // NullCheck narrow_oop_reg
2343         //
2344         // On other platforms (Sparc) we have to keep new DecodeN node and
2345         // use it to do implicit NULL check in address:
2346         //
2347         // decode_not_null narrow_oop_reg, base_reg
2348         // [base_reg + offset]
2349         // NullCheck base_reg
2350         //
2351         // Pin the new DecodeN node to non-null path on these platform (Sparc)
2352         // to keep the information to which NULL check the new DecodeN node
2353         // corresponds to use it as value in implicit_null_check().
2354         //
2355         new_in1->set_req(0, n->in(0));
2356       }
2357 
2358       n->subsume_by(new_in1);
2359       if (in1->outcnt() == 0) {
2360         in1->disconnect_inputs(NULL);
2361       }
2362     }
2363     break;
2364 
2365   case Op_CmpP:
2366     // Do this transformation here to preserve CmpPNode::sub() and
2367     // other TypePtr related Ideal optimizations (for example, ptr nullness).
2368     if (n->in(1)->is_DecodeN() || n->in(2)->is_DecodeN()) {
2369       Node* in1 = n->in(1);
2370       Node* in2 = n->in(2);
2371       if (!in1->is_DecodeN()) {
2372         in2 = in1;
2373         in1 = n->in(2);
2374       }
2375       assert(in1->is_DecodeN(), "sanity");
2376 
2377       Compile* C = Compile::current();
2378       Node* new_in2 = NULL;
2379       if (in2->is_DecodeN()) {
2380         new_in2 = in2->in(1);
2381       } else if (in2->Opcode() == Op_ConP) {
2382         const Type* t = in2->bottom_type();
2383         if (t == TypePtr::NULL_PTR) {
2384           // Don't convert CmpP null check into CmpN if compressed
2385           // oops implicit null check is not generated.
2386           // This will allow to generate normal oop implicit null check.
2387           if (Matcher::gen_narrow_oop_implicit_null_checks())
2388             new_in2 = ConNode::make(C, TypeNarrowOop::NULL_PTR);
2389           //
2390           // This transformation together with CastPP transformation above
2391           // will generated code for implicit NULL checks for compressed oops.
2392           //
2393           // The original code after Optimize()
2394           //
2395           //    LoadN memory, narrow_oop_reg
2396           //    decode narrow_oop_reg, base_reg
2397           //    CmpP base_reg, NULL
2398           //    CastPP base_reg // NotNull
2399           //    Load [base_reg + offset], val_reg
2400           //
2401           // after these transformations will be
2402           //
2403           //    LoadN memory, narrow_oop_reg
2404           //    CmpN narrow_oop_reg, NULL
2405           //    decode_not_null narrow_oop_reg, base_reg
2406           //    Load [base_reg + offset], val_reg
2407           //
2408           // and the uncommon path (== NULL) will use narrow_oop_reg directly
2409           // since narrow oops can be used in debug info now (see the code in
2410           // final_graph_reshaping_walk()).
2411           //
2412           // At the end the code will be matched to
2413           // on x86:
2414           //
2415           //    Load_narrow_oop memory, narrow_oop_reg
2416           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
2417           //    NullCheck narrow_oop_reg
2418           //
2419           // and on sparc:
2420           //
2421           //    Load_narrow_oop memory, narrow_oop_reg
2422           //    decode_not_null narrow_oop_reg, base_reg
2423           //    Load [base_reg + offset], val_reg
2424           //    NullCheck base_reg
2425           //
2426         } else if (t->isa_oopptr()) {
2427           new_in2 = ConNode::make(C, t->make_narrowoop());
2428         }
2429       }
2430       if (new_in2 != NULL) {
2431         Node* cmpN = new (C, 3) CmpNNode(in1->in(1), new_in2);
2432         n->subsume_by( cmpN );
2433         if (in1->outcnt() == 0) {
2434           in1->disconnect_inputs(NULL);
2435         }
2436         if (in2->outcnt() == 0) {
2437           in2->disconnect_inputs(NULL);
2438         }
2439       }
2440     }
2441     break;
2442 
2443   case Op_DecodeN:
2444     assert(!n->in(1)->is_EncodeP(), "should be optimized out");
2445     // DecodeN could be pinned when it can't be fold into
2446     // an address expression, see the code for Op_CastPP above.
2447     assert(n->in(0) == NULL || !Matcher::narrow_oop_use_complex_address(), "no control");
2448     break;
2449 
2450   case Op_EncodeP: {
2451     Node* in1 = n->in(1);
2452     if (in1->is_DecodeN()) {
2453       n->subsume_by(in1->in(1));
2454     } else if (in1->Opcode() == Op_ConP) {
2455       Compile* C = Compile::current();
2456       const Type* t = in1->bottom_type();
2457       if (t == TypePtr::NULL_PTR) {
2458         n->subsume_by(ConNode::make(C, TypeNarrowOop::NULL_PTR));
2459       } else if (t->isa_oopptr()) {
2460         n->subsume_by(ConNode::make(C, t->make_narrowoop()));
2461       }
2462     }
2463     if (in1->outcnt() == 0) {
2464       in1->disconnect_inputs(NULL);
2465     }
2466     break;
2467   }
2468 
2469   case Op_Proj: {
2470     if (OptimizeStringConcat) {
2471       ProjNode* p = n->as_Proj();
2472       if (p->_is_io_use) {
2473         // Separate projections were used for the exception path which
2474         // are normally removed by a late inline.  If it wasn't inlined
2475         // then they will hang around and should just be replaced with
2476         // the original one.
2477         Node* proj = NULL;
2478         // Replace with just one
2479         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
2480           Node *use = i.get();
2481           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
2482             proj = use;
2483             break;
2484           }
2485         }
2486         assert(p != NULL, "must be found");
2487         p->subsume_by(proj);
2488       }
2489     }
2490     break;
2491   }
2492 
2493   case Op_Phi:
2494     if (n->as_Phi()->bottom_type()->isa_narrowoop()) {
2495       // The EncodeP optimization may create Phi with the same edges
2496       // for all paths. It is not handled well by Register Allocator.
2497       Node* unique_in = n->in(1);
2498       assert(unique_in != NULL, "");
2499       uint cnt = n->req();
2500       for (uint i = 2; i < cnt; i++) {
2501         Node* m = n->in(i);
2502         assert(m != NULL, "");
2503         if (unique_in != m)
2504           unique_in = NULL;
2505       }
2506       if (unique_in != NULL) {
2507         n->subsume_by(unique_in);
2508       }
2509     }
2510     break;
2511 
2512 #endif
2513 
2514   case Op_ModI:
2515     if (UseDivMod) {
2516       // Check if a%b and a/b both exist
2517       Node* d = n->find_similar(Op_DivI);
2518       if (d) {
2519         // Replace them with a fused divmod if supported
2520         Compile* C = Compile::current();
2521         if (Matcher::has_match_rule(Op_DivModI)) {
2522           DivModINode* divmod = DivModINode::make(C, n);
2523           d->subsume_by(divmod->div_proj());
2524           n->subsume_by(divmod->mod_proj());
2525         } else {
2526           // replace a%b with a-((a/b)*b)
2527           Node* mult = new (C, 3) MulINode(d, d->in(2));
2528           Node* sub  = new (C, 3) SubINode(d->in(1), mult);
2529           n->subsume_by( sub );
2530         }
2531       }
2532     }
2533     break;
2534 
2535   case Op_ModL:
2536     if (UseDivMod) {
2537       // Check if a%b and a/b both exist
2538       Node* d = n->find_similar(Op_DivL);
2539       if (d) {
2540         // Replace them with a fused divmod if supported
2541         Compile* C = Compile::current();
2542         if (Matcher::has_match_rule(Op_DivModL)) {
2543           DivModLNode* divmod = DivModLNode::make(C, n);
2544           d->subsume_by(divmod->div_proj());
2545           n->subsume_by(divmod->mod_proj());
2546         } else {
2547           // replace a%b with a-((a/b)*b)
2548           Node* mult = new (C, 3) MulLNode(d, d->in(2));
2549           Node* sub  = new (C, 3) SubLNode(d->in(1), mult);
2550           n->subsume_by( sub );
2551         }
2552       }
2553     }
2554     break;
2555 
2556   case Op_Load16B:
2557   case Op_Load8B:
2558   case Op_Load4B:
2559   case Op_Load8S:
2560   case Op_Load4S:
2561   case Op_Load2S:
2562   case Op_Load8C:
2563   case Op_Load4C:
2564   case Op_Load2C:
2565   case Op_Load4I:
2566   case Op_Load2I:
2567   case Op_Load2L:
2568   case Op_Load4F:
2569   case Op_Load2F:
2570   case Op_Load2D:
2571   case Op_Store16B:
2572   case Op_Store8B:
2573   case Op_Store4B:
2574   case Op_Store8C:
2575   case Op_Store4C:
2576   case Op_Store2C:
2577   case Op_Store4I:
2578   case Op_Store2I:
2579   case Op_Store2L:
2580   case Op_Store4F:
2581   case Op_Store2F:
2582   case Op_Store2D:
2583     break;
2584 
2585   case Op_PackB:
2586   case Op_PackS:
2587   case Op_PackC:
2588   case Op_PackI:
2589   case Op_PackF:
2590   case Op_PackL:
2591   case Op_PackD:
2592     if (n->req()-1 > 2) {
2593       // Replace many operand PackNodes with a binary tree for matching
2594       PackNode* p = (PackNode*) n;
2595       Node* btp = p->binaryTreePack(Compile::current(), 1, n->req());
2596       n->subsume_by(btp);
2597     }
2598     break;
2599   case Op_Loop:
2600   case Op_CountedLoop:
2601     if (n->as_Loop()->is_inner_loop()) {
2602       frc.inc_inner_loop_count();
2603     }
2604     break;
2605   case Op_LShiftI:
2606   case Op_RShiftI:
2607   case Op_URShiftI:
2608   case Op_LShiftL:
2609   case Op_RShiftL:
2610   case Op_URShiftL:
2611     if (Matcher::need_masked_shift_count) {
2612       // The cpu's shift instructions don't restrict the count to the
2613       // lower 5/6 bits. We need to do the masking ourselves.
2614       Node* in2 = n->in(2);
2615       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
2616       const TypeInt* t = in2->find_int_type();
2617       if (t != NULL && t->is_con()) {
2618         juint shift = t->get_con();
2619         if (shift > mask) { // Unsigned cmp
2620           Compile* C = Compile::current();
2621           n->set_req(2, ConNode::make(C, TypeInt::make(shift & mask)));
2622         }
2623       } else {
2624         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
2625           Compile* C = Compile::current();
2626           Node* shift = new (C, 3) AndINode(in2, ConNode::make(C, TypeInt::make(mask)));
2627           n->set_req(2, shift);
2628         }
2629       }
2630       if (in2->outcnt() == 0) { // Remove dead node
2631         in2->disconnect_inputs(NULL);
2632       }
2633     }
2634     break;
2635   default:
2636     assert( !n->is_Call(), "" );
2637     assert( !n->is_Mem(), "" );
2638     break;
2639   }
2640 
2641   // Collect CFG split points
2642   if (n->is_MultiBranch())
2643     frc._tests.push(n);
2644 }
2645 
2646 //------------------------------final_graph_reshaping_walk---------------------
2647 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
2648 // requires that the walk visits a node's inputs before visiting the node.
2649 static void final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
2650   ResourceArea *area = Thread::current()->resource_area();
2651   Unique_Node_List sfpt(area);
2652 
2653   frc._visited.set(root->_idx); // first, mark node as visited
2654   uint cnt = root->req();
2655   Node *n = root;
2656   uint  i = 0;
2657   while (true) {
2658     if (i < cnt) {
2659       // Place all non-visited non-null inputs onto stack
2660       Node* m = n->in(i);
2661       ++i;
2662       if (m != NULL && !frc._visited.test_set(m->_idx)) {
2663         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL)
2664           sfpt.push(m);
2665         cnt = m->req();
2666         nstack.push(n, i); // put on stack parent and next input's index
2667         n = m;
2668         i = 0;
2669       }
2670     } else {
2671       // Now do post-visit work
2672       final_graph_reshaping_impl( n, frc );
2673       if (nstack.is_empty())
2674         break;             // finished
2675       n = nstack.node();   // Get node from stack
2676       cnt = n->req();
2677       i = nstack.index();
2678       nstack.pop();        // Shift to the next node on stack
2679     }
2680   }
2681 
2682   // Skip next transformation if compressed oops are not used.
2683   if (!UseCompressedOops || !Matcher::gen_narrow_oop_implicit_null_checks())
2684     return;
2685 
2686   // Go over safepoints nodes to skip DecodeN nodes for debug edges.
2687   // It could be done for an uncommon traps or any safepoints/calls
2688   // if the DecodeN node is referenced only in a debug info.
2689   while (sfpt.size() > 0) {
2690     n = sfpt.pop();
2691     JVMState *jvms = n->as_SafePoint()->jvms();
2692     assert(jvms != NULL, "sanity");
2693     int start = jvms->debug_start();
2694     int end   = n->req();
2695     bool is_uncommon = (n->is_CallStaticJava() &&
2696                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
2697     for (int j = start; j < end; j++) {
2698       Node* in = n->in(j);
2699       if (in->is_DecodeN()) {
2700         bool safe_to_skip = true;
2701         if (!is_uncommon ) {
2702           // Is it safe to skip?
2703           for (uint i = 0; i < in->outcnt(); i++) {
2704             Node* u = in->raw_out(i);
2705             if (!u->is_SafePoint() ||
2706                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
2707               safe_to_skip = false;
2708             }
2709           }
2710         }
2711         if (safe_to_skip) {
2712           n->set_req(j, in->in(1));
2713         }
2714         if (in->outcnt() == 0) {
2715           in->disconnect_inputs(NULL);
2716         }
2717       }
2718     }
2719   }
2720 }
2721 
2722 //------------------------------final_graph_reshaping--------------------------
2723 // Final Graph Reshaping.
2724 //
2725 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
2726 //     and not commoned up and forced early.  Must come after regular
2727 //     optimizations to avoid GVN undoing the cloning.  Clone constant
2728 //     inputs to Loop Phis; these will be split by the allocator anyways.
2729 //     Remove Opaque nodes.
2730 // (2) Move last-uses by commutative operations to the left input to encourage
2731 //     Intel update-in-place two-address operations and better register usage
2732 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
2733 //     calls canonicalizing them back.
2734 // (3) Count the number of double-precision FP ops, single-precision FP ops
2735 //     and call sites.  On Intel, we can get correct rounding either by
2736 //     forcing singles to memory (requires extra stores and loads after each
2737 //     FP bytecode) or we can set a rounding mode bit (requires setting and
2738 //     clearing the mode bit around call sites).  The mode bit is only used
2739 //     if the relative frequency of single FP ops to calls is low enough.
2740 //     This is a key transform for SPEC mpeg_audio.
2741 // (4) Detect infinite loops; blobs of code reachable from above but not
2742 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
2743 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
2744 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
2745 //     Detection is by looking for IfNodes where only 1 projection is
2746 //     reachable from below or CatchNodes missing some targets.
2747 // (5) Assert for insane oop offsets in debug mode.
2748 
2749 bool Compile::final_graph_reshaping() {
2750   // an infinite loop may have been eliminated by the optimizer,
2751   // in which case the graph will be empty.
2752   if (root()->req() == 1) {
2753     record_method_not_compilable("trivial infinite loop");
2754     return true;
2755   }
2756 
2757   Final_Reshape_Counts frc;
2758 
2759   // Visit everybody reachable!
2760   // Allocate stack of size C->unique()/2 to avoid frequent realloc
2761   Node_Stack nstack(unique() >> 1);
2762   final_graph_reshaping_walk(nstack, root(), frc);
2763 
2764   // Check for unreachable (from below) code (i.e., infinite loops).
2765   for( uint i = 0; i < frc._tests.size(); i++ ) {
2766     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
2767     // Get number of CFG targets.
2768     // Note that PCTables include exception targets after calls.
2769     uint required_outcnt = n->required_outcnt();
2770     if (n->outcnt() != required_outcnt) {
2771       // Check for a few special cases.  Rethrow Nodes never take the
2772       // 'fall-thru' path, so expected kids is 1 less.
2773       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
2774         if (n->in(0)->in(0)->is_Call()) {
2775           CallNode *call = n->in(0)->in(0)->as_Call();
2776           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
2777             required_outcnt--;      // Rethrow always has 1 less kid
2778           } else if (call->req() > TypeFunc::Parms &&
2779                      call->is_CallDynamicJava()) {
2780             // Check for null receiver. In such case, the optimizer has
2781             // detected that the virtual call will always result in a null
2782             // pointer exception. The fall-through projection of this CatchNode
2783             // will not be populated.
2784             Node *arg0 = call->in(TypeFunc::Parms);
2785             if (arg0->is_Type() &&
2786                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
2787               required_outcnt--;
2788             }
2789           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
2790                      call->req() > TypeFunc::Parms+1 &&
2791                      call->is_CallStaticJava()) {
2792             // Check for negative array length. In such case, the optimizer has
2793             // detected that the allocation attempt will always result in an
2794             // exception. There is no fall-through projection of this CatchNode .
2795             Node *arg1 = call->in(TypeFunc::Parms+1);
2796             if (arg1->is_Type() &&
2797                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
2798               required_outcnt--;
2799             }
2800           }
2801         }
2802       }
2803       // Recheck with a better notion of 'required_outcnt'
2804       if (n->outcnt() != required_outcnt) {
2805         record_method_not_compilable("malformed control flow");
2806         return true;            // Not all targets reachable!
2807       }
2808     }
2809     // Check that I actually visited all kids.  Unreached kids
2810     // must be infinite loops.
2811     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
2812       if (!frc._visited.test(n->fast_out(j)->_idx)) {
2813         record_method_not_compilable("infinite loop");
2814         return true;            // Found unvisited kid; must be unreach
2815       }
2816   }
2817 
2818   // If original bytecodes contained a mixture of floats and doubles
2819   // check if the optimizer has made it homogenous, item (3).
2820   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
2821       frc.get_float_count() > 32 &&
2822       frc.get_double_count() == 0 &&
2823       (10 * frc.get_call_count() < frc.get_float_count()) ) {
2824     set_24_bit_selection_and_mode( false,  true );
2825   }
2826 
2827   set_java_calls(frc.get_java_call_count());
2828   set_inner_loops(frc.get_inner_loop_count());
2829 
2830   // No infinite loops, no reason to bail out.
2831   return false;
2832 }
2833 
2834 //-----------------------------too_many_traps----------------------------------
2835 // Report if there are too many traps at the current method and bci.
2836 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
2837 bool Compile::too_many_traps(ciMethod* method,
2838                              int bci,
2839                              Deoptimization::DeoptReason reason) {
2840   ciMethodData* md = method->method_data();
2841   if (md->is_empty()) {
2842     // Assume the trap has not occurred, or that it occurred only
2843     // because of a transient condition during start-up in the interpreter.
2844     return false;
2845   }
2846   if (md->has_trap_at(bci, reason) != 0) {
2847     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
2848     // Also, if there are multiple reasons, or if there is no per-BCI record,
2849     // assume the worst.
2850     if (log())
2851       log()->elem("observe trap='%s' count='%d'",
2852                   Deoptimization::trap_reason_name(reason),
2853                   md->trap_count(reason));
2854     return true;
2855   } else {
2856     // Ignore method/bci and see if there have been too many globally.
2857     return too_many_traps(reason, md);
2858   }
2859 }
2860 
2861 // Less-accurate variant which does not require a method and bci.
2862 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
2863                              ciMethodData* logmd) {
2864  if (trap_count(reason) >= (uint)PerMethodTrapLimit) {
2865     // Too many traps globally.
2866     // Note that we use cumulative trap_count, not just md->trap_count.
2867     if (log()) {
2868       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
2869       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
2870                   Deoptimization::trap_reason_name(reason),
2871                   mcount, trap_count(reason));
2872     }
2873     return true;
2874   } else {
2875     // The coast is clear.
2876     return false;
2877   }
2878 }
2879 
2880 //--------------------------too_many_recompiles--------------------------------
2881 // Report if there are too many recompiles at the current method and bci.
2882 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
2883 // Is not eager to return true, since this will cause the compiler to use
2884 // Action_none for a trap point, to avoid too many recompilations.
2885 bool Compile::too_many_recompiles(ciMethod* method,
2886                                   int bci,
2887                                   Deoptimization::DeoptReason reason) {
2888   ciMethodData* md = method->method_data();
2889   if (md->is_empty()) {
2890     // Assume the trap has not occurred, or that it occurred only
2891     // because of a transient condition during start-up in the interpreter.
2892     return false;
2893   }
2894   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
2895   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
2896   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
2897   Deoptimization::DeoptReason per_bc_reason
2898     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
2899   if ((per_bc_reason == Deoptimization::Reason_none
2900        || md->has_trap_at(bci, reason) != 0)
2901       // The trap frequency measure we care about is the recompile count:
2902       && md->trap_recompiled_at(bci)
2903       && md->overflow_recompile_count() >= bc_cutoff) {
2904     // Do not emit a trap here if it has already caused recompilations.
2905     // Also, if there are multiple reasons, or if there is no per-BCI record,
2906     // assume the worst.
2907     if (log())
2908       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
2909                   Deoptimization::trap_reason_name(reason),
2910                   md->trap_count(reason),
2911                   md->overflow_recompile_count());
2912     return true;
2913   } else if (trap_count(reason) != 0
2914              && decompile_count() >= m_cutoff) {
2915     // Too many recompiles globally, and we have seen this sort of trap.
2916     // Use cumulative decompile_count, not just md->decompile_count.
2917     if (log())
2918       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
2919                   Deoptimization::trap_reason_name(reason),
2920                   md->trap_count(reason), trap_count(reason),
2921                   md->decompile_count(), decompile_count());
2922     return true;
2923   } else {
2924     // The coast is clear.
2925     return false;
2926   }
2927 }
2928 
2929 
2930 #ifndef PRODUCT
2931 //------------------------------verify_graph_edges---------------------------
2932 // Walk the Graph and verify that there is a one-to-one correspondence
2933 // between Use-Def edges and Def-Use edges in the graph.
2934 void Compile::verify_graph_edges(bool no_dead_code) {
2935   if (VerifyGraphEdges) {
2936     ResourceArea *area = Thread::current()->resource_area();
2937     Unique_Node_List visited(area);
2938     // Call recursive graph walk to check edges
2939     _root->verify_edges(visited);
2940     if (no_dead_code) {
2941       // Now make sure that no visited node is used by an unvisited node.
2942       bool dead_nodes = 0;
2943       Unique_Node_List checked(area);
2944       while (visited.size() > 0) {
2945         Node* n = visited.pop();
2946         checked.push(n);
2947         for (uint i = 0; i < n->outcnt(); i++) {
2948           Node* use = n->raw_out(i);
2949           if (checked.member(use))  continue;  // already checked
2950           if (visited.member(use))  continue;  // already in the graph
2951           if (use->is_Con())        continue;  // a dead ConNode is OK
2952           // At this point, we have found a dead node which is DU-reachable.
2953           if (dead_nodes++ == 0)
2954             tty->print_cr("*** Dead nodes reachable via DU edges:");
2955           use->dump(2);
2956           tty->print_cr("---");
2957           checked.push(use);  // No repeats; pretend it is now checked.
2958         }
2959       }
2960       assert(dead_nodes == 0, "using nodes must be reachable from root");
2961     }
2962   }
2963 }
2964 #endif
2965 
2966 // The Compile object keeps track of failure reasons separately from the ciEnv.
2967 // This is required because there is not quite a 1-1 relation between the
2968 // ciEnv and its compilation task and the Compile object.  Note that one
2969 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
2970 // to backtrack and retry without subsuming loads.  Other than this backtracking
2971 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
2972 // by the logic in C2Compiler.
2973 void Compile::record_failure(const char* reason) {
2974   if (log() != NULL) {
2975     log()->elem("failure reason='%s' phase='compile'", reason);
2976   }
2977   if (_failure_reason == NULL) {
2978     // Record the first failure reason.
2979     _failure_reason = reason;
2980   }
2981   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
2982     C->print_method(_failure_reason);
2983   }
2984   _root = NULL;  // flush the graph, too
2985 }
2986 
2987 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
2988   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false)
2989 {
2990   if (dolog) {
2991     C = Compile::current();
2992     _log = C->log();
2993   } else {
2994     C = NULL;
2995     _log = NULL;
2996   }
2997   if (_log != NULL) {
2998     _log->begin_head("phase name='%s' nodes='%d'", name, C->unique());
2999     _log->stamp();
3000     _log->end_head();
3001   }
3002 }
3003 
3004 Compile::TracePhase::~TracePhase() {
3005   if (_log != NULL) {
3006     _log->done("phase nodes='%d'", C->unique());
3007   }
3008 }
3009 
3010 //=============================================================================
3011 // Two Constant's are equal when the type and the value are equal.
3012 bool Compile::Constant::operator==(const Constant& other) {
3013   if (type()          != other.type()         )  return false;
3014   if (can_be_reused() != other.can_be_reused())  return false;
3015   // For floating point values we compare the bit pattern.
3016   switch (type()) {
3017   case T_FLOAT:   return (_value.i == other._value.i);
3018   case T_LONG:
3019   case T_DOUBLE:  return (_value.j == other._value.j);
3020   case T_OBJECT:
3021   case T_ADDRESS: return (_value.l == other._value.l);
3022   case T_VOID:    return (_value.l == other._value.l);  // jump-table entries
3023   default: ShouldNotReachHere();
3024   }
3025   return false;
3026 }
3027 
3028 // Emit constants grouped in the following order:
3029 static BasicType type_order[] = {
3030   T_FLOAT,    // 32-bit
3031   T_OBJECT,   // 32 or 64-bit
3032   T_ADDRESS,  // 32 or 64-bit
3033   T_DOUBLE,   // 64-bit
3034   T_LONG,     // 64-bit
3035   T_VOID,     // 32 or 64-bit (jump-tables are at the end of the constant table for code emission reasons)
3036   T_ILLEGAL
3037 };
3038 
3039 static int type_to_size_in_bytes(BasicType t) {
3040   switch (t) {
3041   case T_LONG:    return sizeof(jlong  );
3042   case T_FLOAT:   return sizeof(jfloat );
3043   case T_DOUBLE:  return sizeof(jdouble);
3044     // We use T_VOID as marker for jump-table entries (labels) which
3045     // need an interal word relocation.
3046   case T_VOID:
3047   case T_ADDRESS:
3048   case T_OBJECT:  return sizeof(jobject);
3049   }
3050 
3051   ShouldNotReachHere();
3052   return -1;
3053 }
3054 
3055 void Compile::ConstantTable::calculate_offsets_and_size() {
3056   int size = 0;
3057   for (int t = 0; type_order[t] != T_ILLEGAL; t++) {
3058     BasicType type = type_order[t];
3059 
3060     for (int i = 0; i < _constants.length(); i++) {
3061       Constant con = _constants.at(i);
3062       if (con.type() != type)  continue;  // Skip other types.
3063 
3064       // Align size for type.
3065       int typesize = type_to_size_in_bytes(con.type());
3066       size = align_size_up(size, typesize);
3067 
3068       // Set offset.
3069       con.set_offset(size);
3070       _constants.at_put(i, con);
3071 
3072       // Add type size.
3073       size = size + typesize;
3074     }
3075   }
3076 
3077   // Align size up to the next section start (which is insts; see
3078   // CodeBuffer::align_at_start).
3079   assert(_size == -1, "already set?");
3080   _size = align_size_up(size, CodeEntryAlignment);
3081 
3082   if (Matcher::constant_table_absolute_addressing) {
3083     set_table_base_offset(0);  // No table base offset required
3084   } else {
3085     if (UseRDPCForConstantTableBase) {
3086       // table base offset is set in MachConstantBaseNode::emit
3087     } else {
3088       // When RDPC is not used, the table base is set into the middle of
3089       // the constant table.
3090       int half_size = _size / 2;
3091       assert(half_size * 2 == _size, "sanity");
3092       set_table_base_offset(-half_size);
3093     }
3094   }
3095 }
3096 
3097 void Compile::ConstantTable::emit(CodeBuffer& cb) {
3098   MacroAssembler _masm(&cb);
3099   for (int t = 0; type_order[t] != T_ILLEGAL; t++) {
3100     BasicType type = type_order[t];
3101 
3102     for (int i = 0; i < _constants.length(); i++) {
3103       Constant con = _constants.at(i);
3104       if (con.type() != type)  continue;  // Skip other types.
3105 
3106       address constant_addr;
3107       switch (con.type()) {
3108       case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
3109       case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
3110       case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
3111       case T_OBJECT: {
3112         jobject obj = con.get_jobject();
3113         int oop_index = _masm.oop_recorder()->find_index(obj);
3114         constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
3115         break;
3116       }
3117       case T_ADDRESS: {
3118         address addr = (address) con.get_jobject();
3119         constant_addr = _masm.address_constant(addr);
3120         break;
3121       }
3122       // We use T_VOID as marker for jump-table entries (labels) which
3123       // need an interal word relocation.
3124       case T_VOID: {
3125         // Write a dummy word.  The real value is filled in later
3126         // in fill_jump_table_in_constant_table.
3127         address addr = (address) con.get_jobject();
3128         constant_addr = _masm.address_constant(addr);
3129         break;
3130       }
3131       default: ShouldNotReachHere();
3132       }
3133       assert(constant_addr != NULL, "consts section too small");
3134       assert((constant_addr - _masm.code()->consts()->start()) == con.offset(), err_msg("must be: %d == %d", constant_addr - _masm.code()->consts()->start(), con.offset()));
3135     }
3136   }
3137 }
3138 
3139 int Compile::ConstantTable::find_offset(Constant& con) const {
3140   int idx = _constants.find(con);
3141   assert(idx != -1, "constant must be in constant table");
3142   int offset = _constants.at(idx).offset();
3143   assert(offset != -1, "constant table not emitted yet?");
3144   return offset;
3145 }
3146 
3147 void Compile::ConstantTable::add(Constant& con) {
3148   if (con.can_be_reused()) {
3149     int idx = _constants.find(con);
3150     if (idx != -1 && _constants.at(idx).can_be_reused()) {
3151       return;
3152     }
3153   }
3154   (void) _constants.append(con);
3155 }
3156 
3157 Compile::Constant Compile::ConstantTable::add(BasicType type, jvalue value) {
3158   Constant con(type, value);
3159   add(con);
3160   return con;
3161 }
3162 
3163 Compile::Constant Compile::ConstantTable::add(MachOper* oper) {
3164   jvalue value;
3165   BasicType type = oper->type()->basic_type();
3166   switch (type) {
3167   case T_LONG:    value.j = oper->constantL(); break;
3168   case T_FLOAT:   value.f = oper->constantF(); break;
3169   case T_DOUBLE:  value.d = oper->constantD(); break;
3170   case T_OBJECT:
3171   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
3172   default: ShouldNotReachHere();
3173   }
3174   return add(type, value);
3175 }
3176 
3177 Compile::Constant Compile::ConstantTable::allocate_jump_table(MachConstantNode* n) {
3178   jvalue value;
3179   // We can use the node pointer here to identify the right jump-table
3180   // as this method is called from Compile::Fill_buffer right before
3181   // the MachNodes are emitted and the jump-table is filled (means the
3182   // MachNode pointers do not change anymore).
3183   value.l = (jobject) n;
3184   Constant con(T_VOID, value, false);  // Labels of a jump-table cannot be reused.
3185   for (uint i = 0; i < n->outcnt(); i++) {
3186     add(con);
3187   }
3188   return con;
3189 }
3190 
3191 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
3192   // If called from Compile::scratch_emit_size do nothing.
3193   if (Compile::current()->in_scratch_emit_size())  return;
3194 
3195   assert(labels.is_nonempty(), "must be");
3196   assert((uint) labels.length() == n->outcnt(), err_msg("must be equal: %d == %d", labels.length(), n->outcnt()));
3197 
3198   // Since MachConstantNode::constant_offset() also contains
3199   // table_base_offset() we need to subtract the table_base_offset()
3200   // to get the plain offset into the constant table.
3201   int offset = n->constant_offset() - table_base_offset();
3202 
3203   MacroAssembler _masm(&cb);
3204   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
3205 
3206   for (int i = 0; i < labels.length(); i++) {
3207     address* constant_addr = &jump_table_base[i];
3208     assert(*constant_addr == (address) n, "all jump-table entries must contain node pointer");
3209     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
3210     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
3211   }
3212 }