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